JP5213990B2 - Refrigeration air conditioner - Google Patents

Description

  The present invention relates to a refrigeration air conditioner.

  Conventionally, there is a method of calculating the refrigerant density in each refrigeration air conditioner by calculating the refrigerant density of each element from the detection results of the pressure sensor and temperature sensor used for the control of the refrigeration air conditioner and integrating the internal volume of each element. Yes (see, for example, Patent Document 1).

  Some refrigeration and air-conditioning apparatuses include, for example, a receiver on the high-pressure side, an accumulator on the low-pressure side, and the like as an excess liquid refrigerant storage container that stores the excess liquid refrigerant. In such a refrigeration air conditioner, if there is no method for measuring the amount of surplus liquid refrigerant, the amount of surplus liquid refrigerant stored in the surplus liquid refrigerant storage container is not known, so the total amount of refrigerant in the refrigeration air conditioner is accurately determined. Cannot be calculated. For this reason, in a refrigeration air conditioner equipped with a surplus liquid refrigerant storage container, after the state of the refrigeration cycle has changed to a state where there is no surplus liquid refrigerant in the surplus liquid refrigerant storage container, abnormalities, that is, refrigerant shortage and refrigerant leakage occur. It was detected.

  However, in this method, when the operation state is such that the amount of the surplus liquid refrigerant stored in the surplus liquid refrigerant storage container is half the total amount of the refrigerant in the refrigeration air conditioner, the surplus liquid refrigerant storage is performed from the operation state. It takes time to change to a state in which the excess liquid refrigerant does not accumulate in the container. For this reason, it took a long time to detect the refrigerant leakage, and it was a situation in which the refrigerant leakage was detected after many refrigerants leaked to the outside.

  For this reason, in order to detect refrigerant leakage at an early stage, it is necessary to measure the amount of excess liquid refrigerant stored in the excess liquid refrigerant storage container and detect refrigerant leakage from the measured value. It was.

  As a method of measuring the amount of surplus liquid refrigerant, a liquid level detection sensor that detects the liquid level of the surplus liquid refrigerant is used, and the internal volume of the surplus liquid refrigerant storage container is added to the liquid level detected by the liquid level detection sensor. There is a method of measuring the amount of excess liquid refrigerant. As the liquid level detection sensor used at that time, a float type liquid level detection sensor, an ultrasonic type liquid level detection sensor, a temperature type liquid level detection sensor, or the like is used (for example, see Patent Documents 2, 3, and 4). .

Japanese Unexamined Patent Publication No. 2010-236714 (first term, FIG. 1) Japanese Utility Model Publication No.59-004254 (first page, FIG. 1) JP 2001-272266 A (first page, FIG. 1) Japanese Patent No. 3884336 (first page, FIG. 1)

  However, the above liquid level detection sensor has the following problems.

  For example, since the float type liquid level detection sensor has a structure in which a float is placed inside the container, it is necessary to process the container. New containers can be processed, but retrofitting to existing equipment is difficult. As for a new container, the reliability of the container itself is lowered by making a hole, and the processing cost is also generated. Because the pressure inside the refrigeration air conditioner is higher than the atmospheric pressure, and the presence of oil and refrigerant is more severe than usual, the quality level of the float type liquid level detection sensor itself has to be raised, and the cost Become high.

  Further, when replacing the sensor at the time of failure or the like, it is necessary to stop the refrigerating and air-conditioning apparatus and remove the refrigerant filled in the interior, and there is a problem such as poor maintainability.

  In the ultrasonic liquid level detection sensor, it is not necessary to insert a sensor inside as in the float type, and maintenance can be improved because it can be detected from the outside of the container. However, it is impossible to measure when the amount of liquid is small, etc., or because the sensor measurement principle requires that the sensor installation location be directly under the container, the installation itself is difficult when there is no space at the bottom of the container. There were many cases where there were many restrictions on surface detection and measurement was not possible. In addition, since it is necessary to propagate ultrasonic waves inside the metal container, the sensor itself is special and expensive.

  In a temperature-type liquid level detection sensor, an elongated resistance temperature detector is placed in a container so that its longitudinal direction is substantially vertical, and the liquid level position is determined based on the heat dissipation time of the once heated resistance temperature detector. Detected. In this type of temperature-type liquid level detection sensor, the liquid level height position in the container is based on the relationship between the position of the RTD in the entire container height and the liquid level position in the RTD installation range. Is identified. Therefore, when the attachment position of the resistance temperature detector deviates from the intended attachment position, a large error occurs between the detection position of the liquid level by the temperature type liquid level detection sensor and the actual position. Therefore, care must be taken when attaching the temperature type liquid level detection sensor, which takes time and effort, places a heavy burden on the operator, and deteriorates workability.

  In addition, when retrofitting a temperature type liquid level detection sensor to an existing device, if the mounting position is determined in advance, it may have been difficult to mount it at a predetermined location depending on the installation status of the refrigeration air conditioner. .

  The float type, ultrasonic type and temperature type sensors are sensors for detecting the liquid level position. In order to calculate the amount of liquid inside the container from the detected liquid level position, the liquid level position and the liquid level for each container are calculated. It was necessary to understand the relationship with quantity. However, since there are various shapes of containers depending on the model and horsepower, it is difficult to grasp these relationships for each container. In addition, it is complicated to calculate the liquid amount from the liquid surface position in a container whose horizontal cross-sectional area changes depending on the liquid level, which causes an error in the predicted amount of excess liquid refrigerant.

  The present invention has been made in view of the above points, and it is possible to detect refrigerant leakage by obtaining the amount of excess liquid refrigerant in an excess liquid refrigerant storage container using a detection device that has a high degree of installation freedom and can be reduced in cost. An object is to provide a refrigeration air conditioner.

  A refrigerating and air-conditioning apparatus according to the present invention includes a refrigerant circuit having a compressor, a condenser, an expansion valve, an evaporator, and an excess liquid refrigerant storage container, and an excess liquid in an excess liquid refrigerant storage container among the refrigerant circulating in the refrigerant circuit. A refrigerant amount calculation unit that calculates the refrigerant amount excluding the refrigerant amount, and a plurality of temperature sensors that are arranged on the outer surface of the surplus liquid refrigerant storage container and measure the temperature of the outer surface, and temperature measurement values of the plurality of temperature sensors Based on the liquid level detection, the temperature sensor corresponding to the liquid level position of the surplus liquid refrigerant stored in the surplus liquid refrigerant storage container is identified, and the identification information of the identified temperature sensor is output. Control of the operation of the refrigerant circuit, the storage unit storing the correlation between the sensor, the amount of excess liquid refrigerant stored in the excess liquid refrigerant storage container, and the output of the liquid level detection sensor at the amount of excess liquid refrigerant To obtain the actual correlation and store Calculation results of the control unit to be stored, the surplus liquid refrigerant amount calculating unit that calculates the surplus liquid refrigerant amount in the surplus liquid refrigerant storage container based on the output and correlation of the liquid level detection sensor, and the surplus liquid refrigerant amount calculating unit And a determination unit for calculating the total amount of refrigerant in the refrigerant circuit from the calculation result of the refrigerant amount calculation unit and determining the presence or absence of refrigerant leakage.

  According to the present invention, the liquid level detection sensor is composed of a plurality of temperature sensors, and may be installed on the outer surface of the container so as to detect the temperature thereof, so that the degree of freedom of installation is high and the cost can be reduced. It is. Further, since the surplus liquid refrigerant amount is obtained by using the correlation obtained by actual measurement by actually operating the refrigerant circuit, the surplus liquid refrigerant amount can be obtained with high accuracy. The refrigerant leakage can be determined from the calculated surplus liquid refrigerant amount.

It is a refrigerant circuit figure of the refrigerating and air-conditioning apparatus which concerns on one embodiment of this invention. It is a control block diagram of the refrigeration air conditioner of FIG. It is a block diagram which shows the structure of the liquid level detection sensor of FIG. It is a figure which shows the state in which different quantity of excess liquid refrigerant | coolant is stored in ACC of FIG. It is a figure which shows the measured value of the liquid quantity detection sensor with respect to ACC of A and B of FIG. It is a ph diagram at the time of air conditioning operation of the refrigerating and air-conditioning apparatus concerning one embodiment of the present invention. It is a ph diagram at the time of heating operation of the refrigerating and air-conditioning apparatus concerning one embodiment of the present invention. It is a flowchart which shows the flow of the refrigerant | coolant leak detection process in the refrigeration air conditioning apparatus of one embodiment of this invention. It is explanatory drawing of the calculation method of the excess liquid refrigerant | coolant amount. It is a figure which shows the correlation with the sensor number of a liquid level position temperature sensor, and the excess liquid refrigerant | coolant amount. It is a flowchart of the initial learning driving | operation in the refrigerating and air-conditioning apparatus which concerns on one embodiment of this invention. It is a figure which shows an example of the correlation table obtained by the initial learning of FIG.

  Hereinafter, an embodiment of a refrigerating and air-conditioning apparatus according to the present invention will be described based on the drawings.

<Device configuration>
(Configuration of refrigeration air conditioner)
FIG. 1 is a refrigerant circuit diagram of a refrigerating and air-conditioning apparatus 1 according to an embodiment of the present invention. In FIG. 1 and the drawings to be described later, the same reference numerals denote the same or corresponding parts, which are common throughout the entire specification.

  The refrigerating and air-conditioning apparatus 1 is an apparatus used for air conditioning in a room such as a building by performing a vapor compression refrigeration cycle operation. The refrigerating and air-conditioning apparatus 1 mainly includes an outdoor unit 2 as a heat source unit, a plurality of indoor units 4A and 4B (two in the present embodiment) connected in parallel thereto, and a liquid side extension pipe. 6 and a gas-side extension pipe 7 are provided. The refrigerant circuit 10 of the refrigerating and air-conditioning apparatus 1 according to the present embodiment is configured by connecting the outdoor unit 2, the indoor units 4 </ b> A and 4 </ b> B, the liquid side extension pipe 6 and the gas side extension pipe 7. The liquid side extension pipe 6 is a pipe through which the liquid refrigerant passes by connecting the outdoor unit 2 and the indoor units 4A and 4B. The liquid main pipe 6A, the liquid branch pipes 6a and 6b, and the distributor 51a are connected. Configured. The gas-side extension pipe 7 is a pipe through which the gas refrigerant passes through the outdoor unit 2 and the indoor units 4A and 4B. The gas main pipe 7A, the gas branch pipes 7a and 7b, and the distributor 52a are connected to each other. Connected and configured.

(Indoor unit)
The indoor units 4A and 4B are installed by being embedded or suspended in a ceiling of a room such as a building, or by hanging on an indoor mural. The indoor units 4A and 4B are connected to the outdoor unit 2 using a liquid side extension pipe 6 and a gas side extension pipe 7.

  Next, the configuration of the indoor units 4A and 4B will be described. Since the indoor units 4A and 4B have the same configuration, only the configuration of the indoor unit 4A will be described here. The configuration of the indoor unit 4B corresponds to a configuration in which a symbol B is attached instead of a symbol A indicating each part of the indoor unit 4A.

  The indoor unit 4A mainly has an indoor refrigerant circuit 10a (in the indoor unit 4B, the indoor refrigerant circuit 10b) that constitutes a part of the refrigerant circuit 10. This indoor refrigerant circuit 10a mainly has an expansion valve 41A as an expansion mechanism and an indoor heat exchanger 42A as a use side heat exchanger.

  In the present embodiment, the expansion valve 41A is an electric expansion valve connected to the liquid side of the indoor heat exchanger 42A in order to adjust the flow rate of the refrigerant flowing in the indoor refrigerant circuit 10a.

  In the present embodiment, the indoor heat exchanger 42A is a cross-fin type fin-and-tube heat exchanger composed of heat transfer tubes and a large number of fins, and functions as a refrigerant evaporator during cooling operation. It is a heat exchanger that cools the indoor air and functions as a refrigerant condenser during heating operation to heat the indoor air.

  In the present embodiment, the indoor unit 4A sucks indoor air into the unit, exchanges heat with the refrigerant in the indoor heat exchanger 42A, and then supplies the indoor fan as supply air to the room as supply air. 43A. The indoor fan 43A is a fan capable of changing the air volume of air supplied to the indoor heat exchanger 42A. In the present embodiment, the indoor fan 43A is a centrifugal fan or a multiblade fan driven by a DC fan motor.

  Various sensors are provided in the indoor units 4A and 4B. Gas side temperature sensors 33e and 33h that detect the temperature of the refrigerant (that is, the refrigerant temperature corresponding to the condensation temperature Tc during the heating operation or the evaporation temperature Te during the cooling operation) are provided on the gas side of the indoor heat exchangers 42A and 42B. Is provided. Liquid side temperature sensors 33d and 33g for detecting the refrigerant temperature Te are provided on the liquid side of the indoor heat exchangers 42A and 42B. Indoor temperature sensors 33f and 33i for detecting the temperature of indoor air flowing into the units (that is, indoor temperature Tr) are provided on the indoor air inlet side of the indoor units 4A and 4B.

  In the present embodiment, each of the temperature sensors 33d, 33e, 33f, 33g, 33h, and 33i is a thermistor.

  Moreover, indoor unit 4A, 4B has indoor side control part 32a, 32b which controls operation | movement of each part which comprises indoor unit 4A, 4B. And the indoor side control parts 32a and 32b have the microcomputer, memory, etc. which were provided in order to control indoor unit 4A, 4B, and the remote control (individually operates indoor unit 4A, 4B) It is possible to exchange control signals and the like with a unit (not shown), and exchange control signals and the like with the outdoor unit 2 via a transmission line.

(Outdoor unit)
Next, the configuration of the outdoor unit 2 will be described. The outdoor unit 2 mainly has an outdoor refrigerant circuit 10 c that constitutes a part of the refrigerant circuit 10. The outdoor refrigerant circuit 10c mainly includes a compressor 21, a four-way valve 22, an outdoor heat exchanger 23, an accumulator (hereinafter referred to as ACC) 24 that is an excess liquid refrigerant storage container, and a liquid level detection sensor 25. The liquid side closing valve 28 and the gas side closing valve 29 are provided.

  The compressor 21 is a compressor whose operating capacity can be varied. In the present embodiment, the compressor 21 is a product type compressor that is driven by a motor whose number of peripheral fluids is controlled by an inverter.

  In the present embodiment, there is only one compressor 21, but the present invention is not limited to this, and two or more compressors may be connected in parallel according to the number of indoor units connected.

  The four-way valve 22 is a valve for switching the direction of refrigerant flow. During the cooling operation, the four-way valve 22 is switched as indicated by a solid line, and connects the discharge side of the compressor 21 and the gas side of the outdoor heat exchanger 23 and connects the ACC 24 and the gas main pipe 7A side. Thereby, the outdoor heat exchanger 23 functions as a condenser for the refrigerant compressed by the compressor 21, and the indoor heat exchangers 42A and 42B function as an evaporator.

  Further, the four-way valve 22 is switched as shown by the dotted line of the four-way valve 22 during the heating operation, and connects the discharge side of the compressor 21 and the gas main pipe 7A and connects the ACC 24 and the gas side of the outdoor heat exchanger 23. Connecting. Thereby, indoor heat exchanger 42A, 42B functions as a condenser of the refrigerant | coolant compressed by the compressor 21, and the outdoor heat exchanger 23 functions as an evaporator.

  In the present embodiment, the outdoor heat exchanger 23 is a cross fin type fin-and-tube heat exchanger composed of heat transfer tubes and a large number of fins, and functions as a refrigerant condenser during cooling operation. It is a heat exchanger that functions as a refrigerant evaporator during heating operation. The outdoor heat exchanger 23 has a gas side connected to the four-way valve 22 and a liquid side connected to the liquid main pipe 6A.

  In the present embodiment, the outdoor unit 2 has an outdoor fan 27 as a blower fan for sucking outdoor air into the unit and exchanging heat with the refrigerant in the outdoor heat exchanger 23 and then discharging it to the outdoor. doing. The outdoor fan 27 is a fan capable of varying the air volume supplied to the outdoor heat exchanger 23. In the present embodiment, the outdoor fan 27 is a propeller fan or the like driven by a motor including a DC fan motor. .

  The ACC 24 is connected to the suction portion of the compressor 21, and can store excess refrigerant generated in the refrigerant circuit 10 in accordance with fluctuations in the outdoor unit 2, the indoor units 4A and 4B, the operating load of the piping, and the like. Container. The ACC 24 must be a pressure vessel that is formed of a metal such as carbon steel and that is designed and manufactured in consideration of the pressure strength in accordance with regulations.

  In detecting the refrigerant leakage of the refrigerant circuit 10 which is the object of the present embodiment, it is necessary to detect the amount of excess liquid refrigerant stored in the ACC 24. Although it is possible to provide a transparent portion such as a viewing window in a part of the ACC 24, most of the ACC 24 is an opaque container in practical use. It is impossible to measure the amount or to see through the entire interior of the ACC 24 by visual inspection.

  Even if an optically transparent viewing window is attached to a part of the ACC 24, the liquid level in the ACC 24 always fluctuates, so the exact position of the coolant level in the ACC 24 is measured from the viewing window. Or it is difficult to monitor.

  Therefore, in the present embodiment, a liquid level detection sensor that detects the liquid level based on the temperature is attached to the outside of the ACC 24. Details of the liquid level detection sensor will be described later.

  The liquid side shut-off valve 28 and the gas side shut-off valve 29 are valves provided at connection ports with external devices and pipes (specifically, the liquid main pipe 6A and the gas main pipe 7A).

  The outdoor unit 2 is provided with a plurality of pressure sensors and temperature sensors. As the pressure sensors, a suction pressure sensor 34a for detecting the suction pressure Ps of the compressor 21 and a discharge pressure sensor 34b for detecting the discharge pressure Pd of the compressor 21 are installed.

  The temperature sensor is a thermistor, and is provided with an intake temperature sensor 33a, a discharge temperature sensor 33b, a liquid side temperature sensor 33j, and an outdoor temperature sensor 33c. The suction temperature sensor 33 a is provided at a position between the ACC 24 and the compressor 21 and detects the suction temperature Ts of the compressor 21. The discharge temperature sensor 33b detects the discharge temperature Td of the compressor 21. The liquid side temperature sensor 33j is installed on the liquid side of the outdoor heat exchanger 23, and detects the refrigerant temperature on the liquid side of the outdoor heat exchanger 23. The outdoor temperature sensor 33 c is installed on the outdoor air inlet side of the outdoor unit 2 and detects the temperature of the outdoor air flowing into the outdoor unit 2.

  The outdoor unit 2 also has an outdoor control unit 31 that controls the operation of each element constituting the outdoor unit 2. And the outdoor side control part 31 has the microcomputer provided in order to control the outdoor unit 2, memory, an inverter circuit etc. which control a motor. And the outdoor side control part 31 is comprised so that a control signal etc. may be exchanged via the transmission line between indoor side control part 32a, 32b of indoor unit 4A, 4B. The outdoor side control part 31 comprises the control part 3 which performs operation control of the whole refrigerating and air-conditioning apparatus 1 with the indoor side control parts 32a and 32b.

(Extended piping)
The extension pipe is a pipe necessary for connecting the outdoor unit 2 and the indoor units 4A, 4B and circulating the refrigerant in the refrigeration air conditioner 1.

  The extension pipe has a liquid side extension pipe 6 (liquid main pipe 6A, liquid branch pipes 6a, 6b) and a gas side extension pipe 7 (gas main pipe 7A, gas branch pipes 7a, 7b). It is a refrigerant pipe that is installed on site when it is installed at a place such as a building. As the extension pipe, extension pipes each having a pipe diameter determined according to the combination of the outdoor unit 2 and the indoor units 4A and 4B are used.

  In this embodiment, distributors 51a and 52a and extension pipes (liquid side extension pipe 6 and gas side extension pipe 7) are used to connect one outdoor unit 2 and two indoor units 4A and 4B.

  Regarding the liquid side extension pipe 6, the outdoor unit 2 and the distributor 51a are connected by the liquid main pipe 6A, and the distributor 51a and the indoor units 4A and 4B are connected by the liquid branch pipes 6a and 6b. Regarding the gas side extension pipe 7, the indoor units 4A and 4B and the distributor 52a are connected by gas branch pipes 7a and 7b, and the distributor 52a and the outdoor unit 2 are connected by a gas main pipe 7A.

  In the present embodiment, the distributors 51a and 52a use T-shaped tubes, but the present invention is not limited thereto, and headers may be used. When a plurality of indoor units are connected, a plurality of T-shaped tubes may be used for distribution, or a header may be used.

  As described above, the refrigerant circuit 10 is configured by connecting the indoor refrigerant circuits 10a and 10b, the outdoor refrigerant circuit 10c, and the extension pipes (the liquid side extension pipe 6 and the gas side extension pipe 7).

  The refrigerating and air-conditioning apparatus 1 according to the present embodiment is operated by switching the cooling operation and the heating operation by the four-way valve 22 by the control unit 3 including the indoor side control units 32a and 32b and the outdoor side control unit 31. In addition, the devices of the outdoor unit 2 and the indoor units 4A and 4B are controlled in accordance with the operation loads of the indoor units 4A and 4B.

(Control block configuration of refrigeration air conditioner)
FIG. 2 is a control block diagram of the refrigeration air conditioner of FIG. The refrigerating and air-conditioning apparatus 1 includes a refrigerant leakage detection device that detects refrigerant leakage in the refrigerant circuit 10, and FIG. 2 shows a block diagram of a state in which the functional configuration of the refrigerant leakage detection device is developed. .

  The control unit 3 is connected so as to receive detection signals from the pressure sensors 34a and 34b and the temperature sensors 33a to 33j. The control unit 3 also determines various devices (compressor 21, outdoor fan 27, indoor fans 43A, 43B) and valves (four-way valve 22, liquid side closing valve 28, gas side closing valve 29) based on these detection signals and the like. The expansion valves 41A and 41B) are connected to various devices and valves so that they can be controlled. The controller 3 is further connected so as to receive a detection signal from the liquid level detection sensor 25.

  The control unit 3 includes a measurement unit 3a, a refrigerant amount calculation unit 3b, an excess liquid refrigerant amount calculation unit 3c, a determination unit 3d, a storage unit 3e, and a drive unit 3f.

  The measurement unit 3a is a part that measures information from the pressure sensors 34a and 34b and the temperature sensors 33a to 33j, and is a part that constitutes an operation state amount detection unit together with the pressure sensors 34a and 34b and the temperature sensors 33a to 33j.

  The refrigerant amount calculation unit 3b is a part that calculates the refrigerant amount in the refrigerant circuit 10 excluding the ACC surplus liquid refrigerant amount based on the information measured by the measurement unit 3a of the refrigeration air conditioner 1.

  The surplus liquid refrigerant amount calculation unit 3c is a part that calculates the ACC surplus liquid refrigerant amount based on the output of the liquid level detection sensor 25 and a conversion table and a relational expression described later stored in the storage unit 3e.

  The determination part 3d is a part which determines the presence or absence of a refrigerant | coolant leak based on each calculation result of the refrigerant | coolant amount calculation part 3b and the excess liquid refrigerant | coolant amount calculation part 3c. If it is determined that there is refrigerant leakage, the determination unit 3d can also calculate the refrigerant leakage amount by taking the difference between the initial refrigerant amount and the calculated refrigerant amount.

  The storage unit 3e stores values measured by the measurement unit 3a, values calculated by the refrigerant amount calculation unit 3b and the surplus liquid refrigerant amount calculation unit 3c, and stores internal volume data and initial refrigerant amount of each element described later. Or storing information from the outside, or storing a relational expression to be described later that is used when calculating the surplus liquid refrigerant amount.

  The drive unit 3f is a part that controls a compressor motor, a valve, and a fan motor, which are elements driven by the refrigeration air conditioner 1. The input unit 3g is a place for inputting and changing setting values for various controls.

  The output unit 3h is a place where the measurement value measured by the measurement unit 3a, the determination result by the determination unit 3d, and the like are displayed on an LED or a monitor or output to the outside.

  The output unit 3h may be a communication line for communicating with an external device through a telephone line, a LAN line, wireless communication, etc., and the refrigerating and air-conditioning apparatus 1 uses a communication line or the like to transmit refrigerant leakage presence / absence data indicating the result of refrigerant leakage. It is possible to transmit to a management center or the like. As a result, a remote monitoring function can be added that always detects an abnormality at a remote management center and immediately performs maintenance if an abnormality occurs.

  The refrigerant level detection sensor 25, the measurement unit 3a, the refrigerant amount calculation unit 3b, the surplus liquid refrigerant amount calculation unit 3c, the determination unit 3d, the storage unit 3e, and the output unit 3h in FIG. Yes. In the present embodiment, the refrigerant leakage detection device is incorporated in the refrigerating and air-conditioning apparatus 1;

(Liquid level detection sensor)
Here, prior to the description of the configuration of the liquid level detection sensor 25, the liquid level detection principle will be described.
There is a difference in the container surface temperature between the case where the refrigerant inside the container of the ACC 24 is a liquid and the case where it is a gas. Generally, since liquid has a larger heat capacity than gas, the container surface temperature of the part where the liquid is located inside the container is close to the temperature of the liquid refrigerant inside the container, and the gas is located inside the container. The container surface temperature in the part where the container is located is close to the temperature outside the container. Therefore, the liquid level position can be detected by specifying the position where the temperature difference occurs in the container surface temperature.

  By the way, since ACC24 is installed in the exit of an evaporator, if the refrigerant temperature in ACC24 is seen in the whole refrigerant circuit, it will be low temperature. Further, considering that surplus refrigerant is mainly stored in the ACC 24 (this will be described later), the outside temperature of the ACC 24 is low because the outside air temperature is low. Therefore, a temperature difference indicating the liquid level position hardly appears on the outer surface of the container of ACC24. For this reason, in the liquid level detection sensor 25 of this example, for example, a heater as a heating device is installed outside the container of the ACC 24, and the temperature of the outer surface of the ACC 24 is increased by heating the outer surface of the container. A temperature difference is forcibly generated between the liquid refrigerant temperature.

FIG. 3 is a block diagram showing a configuration of the liquid level detection sensor of FIG.
The liquid level detection sensor 25 includes a control unit 25a, a temperature difference generation unit 25b, a measurement unit 25c, a processing unit 25d, a storage unit 25e, and an output unit 25f. The controller 25a is a part that controls the temperature difference generator 25b.

  As described above, the temperature difference generator 25b is composed of a heater and is installed outside the ACC 24. The measurement part 25c is comprised by several temperature sensors 26a-26e, such as a thermistor, for example. The temperature sensors 26a to 26e are installed on the outer surface of the container of the ACC 24 at substantially equal intervals in the vertical direction, and measure the temperature at each installation location. Each of the temperature sensors 26a to 26e is assigned a sensor number as unique identification information in advance, and here, numbers 1 to 5 are assigned in order. The temperature sensors 26a to 26e are installed at positions separated from the temperature difference generation unit 25b to some extent so as not to receive the temperature of the temperature difference generation unit 25b directly.

  The processing unit 25d is a part that specifies a temperature sensor corresponding to the liquid level position in the ACC 24 based on each temperature measurement value measured by the plurality of temperature sensors 26a to 26e of the measurement unit 25c. The storage unit 25e is a part that stores the sensor number of the temperature sensor specified by the processing unit 25d and external data. The output unit 25f is a part that outputs the sensor number of the temperature sensor specified by the processing unit 25d and the signal stored in the storage unit 25e to the outside.

  When the liquid refrigerant temperature in the ACC 24 (hereinafter, internal liquid temperature) is low, the ACC 24 may be surrounded by a heat insulating sheet or the like. In the refrigerating and air-conditioning apparatus having such a configuration, the temperature difference between the internal liquid temperature and the container surface temperature may be given by removing the heat insulating sheet only in the portion where the measuring unit 25c is installed. Further, when there is a sufficient temperature difference between the internal liquid temperature and the container surface temperature, the power supply to the temperature difference generator 25b may be stopped, or the temperature difference generator 25b itself may be omitted.

  In the present embodiment, since the surplus liquid refrigerant storage container is described as an accumulator on the low pressure side, the temperature difference generating unit 25b is a heater (heating device), but the surplus liquid refrigerant storage container is on the high pressure side. In the case of the receiver, the internal liquid temperature is high. Therefore, the temperature difference generating unit 25b is a cooling device such as a fan. Thereby, even if the outside air temperature is a high temperature environment, a temperature difference can be generated. Instead of providing a fan, a receiver may be installed in a place where the wind hits.

  FIG. 4 is a diagram showing a state in which different amounts of excess liquid refrigerant are stored in the ACC of FIG. 4A shows that the entire ACC is in a gas state, that is, a state where excess liquid refrigerant is not stored, and B shows a two-phase state having a gas phase and a liquid phase. . Each line indicated by h1 to h5 in FIG. 4 indicates the installation height position of each of the temperature sensors 26a to 26e in FIG. 5 shows the temperature measurement values of the temperature sensors 26a to 26e in the respective states A and B of FIG. It is the figure plotted according to installation height position h1-h5. FIG. 5 further shows the temperature of the heater constituting the temperature difference generator 25b.

  As can be seen from FIGS. 4 and 5, in state A, any height from h1 to h5 is close to the heater temperature. In state B, the temperature measurement values at the heights of h4 and h5 where gas is present are close to the heater temperature, and at the height of h1 to h3 where the liquid is present, the temperature is higher than the temperatures of h4 and h5. Becomes a low temperature. Therefore, it can be seen that the liquid level is located at a portion where the temperature difference between the temperature measurement values before and after the temperature measurement values of the temperature sensors 26a to 26e is the largest. That is, in this example, it can be seen that the liquid level is located between the temperature sensor 26c and the temperature sensor 26d. Therefore, the processing unit 25d of the liquid level detection sensor 25 sets the sensor number of the lower temperature sensor 26c of the two temperature sensors 26c and 26d that have detected the temperature difference to the temperature corresponding to the liquid level. Output as the sensor number of the sensor (hereinafter, liquid level temperature sensor). Note that the liquid level detection sensor 25 of this example merely specifies the temperature sensor that detects the liquid level, and does not require the height position of the liquid level in the ACC 24.

  In order to convert the output of the liquid level detection sensor 25 (sensor number of the liquid level position temperature sensor) into the amount of liquid refrigerant in the ACC 24, the correlation between the output of the liquid level detection sensor 25 and the amount of liquid refrigerant in the ACC 24. Is obtained in advance, and the amount of liquid refrigerant inside the ACC 24 is obtained based on the correlation and the output of the liquid level detection sensor 25.

  The present invention has one feature in that this correlation is actually obtained by actually operating the refrigeration air conditioner 1 on site. The operation for obtaining the correlation is hereinafter referred to as initial learning operation, and details of the initial learning operation will be described later.

(Liquid level detection sensor correction method)
Next, a sensor correction method will be described.

  The liquid level detection sensor 25 includes a plurality of temperature sensors 26a to 26e. However, since the temperature sensors 26a to 26e have individual differences, the measured values of the temperature sensors 26a to 26e are measured even if the same temperature is measured. May be different. Therefore, in order to measure with high accuracy, it is necessary to eliminate the influence of this sensor individual difference, and therefore sensor correction is performed. As a specific correction method, when the entire ACC 24 is in a gas state, the ACC 24 is heated by the temperature difference generation unit 25b, and in this heating state, the surface temperature of the ACC 24 is measured by the temperature sensors 26a to 26e. Zero point correction is performed using the measured value as a reference value for the zero state of each of the temperature sensors 26a to 26e. That is, it is possible to prevent the occurrence of solid errors as much as possible by setting the measurement value measured in the state where the inside of the ACC 24 is in the gas state and the heat capacity is equal to the reference value in the zero state.

<Operation of Refrigeration Air Conditioner 1>
Next, operation | movement of each component at the time of normal driving | operation of the refrigerating and air-conditioning apparatus 1 of this Embodiment is demonstrated.

  The refrigerating and air-conditioning apparatus 1 according to the present embodiment controls the components of the outdoor unit 2 and the indoor units 4A and 4B according to the operation load of the indoor units 4A and 4B, and performs the cooling and heating operation.

(Cooling operation)
The cooling operation will be described with reference to FIGS. 1 and 6.

  During the cooling operation, the four-way valve 22 is in the state indicated by the solid line in FIG. 1, that is, the discharge side of the compressor 21 is connected to the gas side of the outdoor heat exchanger 23, and the suction side of the compressor 21 is the gas side closing valve. 29 and the gas side extension pipe 7 (gas main pipe 7A, gas branch pipes 7a, 7b) are connected to the gas side of the indoor heat exchangers 42A, 42B. The liquid side closing valve 28 and the gas side closing valve 29 are opened.

  Next, the flow of the refrigerant in the refrigerant circuit 10 in the cooling operation will be described.

  The flow of the refrigerant in the cooling operation is a solid line arrow in FIG. The high-temperature and high-pressure gas refrigerant compressed by the compressor 21 (FIG. 6 (1)) reaches the outdoor heat exchanger 23 through the four-way valve 22 and is condensed and liquefied by the blowing action of the fan 27 (FIG. 6 (2)). The condensation temperature at this time is measured by the liquid side temperature sensor 33j or is obtained by converting the pressure of the discharge pressure sensor 34b to a saturation temperature.

  Thereafter, the pressure drops due to pipe wall friction in the liquid main pipe 6A and the liquid branch pipes 6a and 6b, which are the liquid side extension pipes 6, via the liquid side shut-off valve 28 (FIG. 6 (3)). Then, the pressure is reduced by the expansion valves 41A and 41B to become a low-pressure gas-liquid two-phase refrigerant (FIG. 6 (4)). The gas-liquid two-phase refrigerant is gasified by the air blowing action of the indoor fans 43A and 43B in the indoor heat exchangers 42A and 42B which are evaporators (FIG. 6 (5)).

  The evaporation temperature at this time is measured by the liquid side temperature sensors 33d and 33g, and the superheat degree SH of the refrigerant at the outlets of the indoor heat exchangers 42A and 42B is the refrigerant temperature value detected by the gas side temperature sensors 33e and 33h. Is obtained by subtracting the refrigerant temperature detected by the liquid side temperature sensors 33d and 33g from Each expansion valve 41A, 41B adjusts the opening degree so that the superheat degree SH of the refrigerant at the outlets of the indoor heat exchangers 42A, 42B (that is, the gas side of the indoor heat exchangers 42A, 42B) becomes the superheat degree target value SHm. Has been.

  When the gas refrigerant that has passed through the indoor heat exchangers 42A and 42B (FIG. 6 (5)) reaches the gas main pipe 7A and the gas branch pipes 7a and 7b, which are the gas side extension pipe 7, and passes through the gas side extension pipe 7. The pressure drops due to the tube wall friction of the extension pipe (FIG. 6 (6)), and returns to the compressor 21 through the gas side shut-off valve 29 and the ACC 24.

(Heating operation)
Next, the heating operation will be described with reference to FIGS. 1 and 7.

  During the heating operation, the four-way valve 22 is in the state indicated by the broken line in FIG. 1, that is, the discharge side of the compressor 21 is the gas side closing valve 29 and the gas side extension pipe 7 by the gas main pipe 7A and the gas branch pipes 7a and 7b. The indoor heat exchangers 42 </ b> A and 42 </ b> B are connected to the gas side, and the suction side of the compressor 21 is connected to the gas side of the outdoor heat exchanger 23. Moreover, the liquid side closing valve 28 and the gas side closing valve 29 are open.

  Next, the flow of the refrigerant in the heating operation will be described.

  The flow of the refrigerant under the heating condition is a dotted line arrow in FIG. The high-temperature and high-pressure refrigerant (FIG. 7 (1)) compressed by the compressor 21 passes through the gas main pipe 7A and the gas branch pipes 7a and 7b, which are gas side extension pipes 7, and at this time, the pressure drops due to pipe wall friction. (FIG. 7 (2)), it reaches the indoor heat exchangers 42A and 42B. In the indoor heat exchangers 42A and 42B, it is condensed and liquefied by the blowing action of the indoor fans 43A and 43B (FIG. 7 (3)), and is decompressed by the expansion valves 41A and 41B to become a low-pressure gas-liquid two-phase refrigerant (FIG. 7). (4)).

  At this time, the opening degree of the expansion valves 41A and 41B is adjusted so that the supercooling degree SC of the refrigerant at the outlets of the indoor heat exchangers 42A and 42B becomes the supercooling degree target value SCm. This is a capacity adjustment method for the indoor units 4A and 4B by changing the setting of SCm. When SCm is larger than the current value, the expansion valves 41A and 41B are operated in a direction to throttle in order to increase the SC, so that the refrigerant circulation amount is reduced and the heat exchange capacity in the indoor heat exchangers 42A and 42B is lowered. On the other hand, when SCm is smaller than the present value, the refrigerant circulation amount is increased and the heat exchange capacity in the indoor heat exchangers 42A and 42B is increased because the expansion valve is operated to increase the opening degree. Therefore, when the temperature difference between the room set temperature and the room temperature is small, that is, when the capacity is not so required, SCm is set large. When the temperature difference between the room set temperature and the room temperature is large, that is, a large capacity is required. In this case, SCm is set small.

  In the present embodiment, the supercooling degree SC of the refrigerant at the outlets of the indoor heat exchangers 42A and 42B sets the discharge pressure Pd of the compressor 21 detected by the discharge pressure sensor 34b to a saturation temperature value corresponding to the condensation temperature Tc. It is calculated by subtracting the refrigerant temperature value detected by the liquid side temperature sensors 33d and 33g from this saturation temperature value.

  Although not adopted in the present embodiment, a temperature sensor for detecting the temperature of the refrigerant flowing in each of the indoor heat exchangers 42A and 42B is provided, and the refrigerant corresponding to the condensation temperature Tc detected by this temperature sensor. The subcooling degree SC of the refrigerant at the outlets of the indoor heat exchangers 42A and 42B may be detected by subtracting the temperature value from the refrigerant temperature value detected by the liquid side temperature sensors 33d and 33g.

  The low-pressure gas-liquid two-phase refrigerant decompressed by the expansion valves 41A and 41B is reduced in pressure due to the tube wall friction in the liquid main pipe 6A and the liquid branch pipes 6a and 6b (FIG. 7 (5 )), And reaches the outdoor heat exchanger 23 via the liquid side closing valve 28. In the outdoor heat exchanger 23, evaporative gasification (FIG. 7 (6)) is caused by the blowing action of the outdoor fan 27, and the gas returns to the compressor 21 through the four-way valve 22 and the ACC 24.

(Refrigerant amount)
Next, the refrigerant amount will be described in detail.

  In order for each elemental device of the refrigerant circuit 10 to exhibit predetermined performance, an amount of refrigerant suitable for the internal volume of each elemental device is required. Therefore, if the internal volumes of the indoor units 4A and 4B and the lengths of the extension pipes are different, the refrigerant amount required for the entire refrigerant circuit 10 is also different. From this, the refrigerant filled in the refrigeration air conditioner 1 is filled after the refrigerant circuit 10 is installed at the site where the equipment is installed.

  Further, the amount of refrigerant required in the refrigerant circuit 10 varies depending on the state of the refrigerant circuit 10, and the state of the refrigerant circuit 10 varies depending on the surrounding environment such as the cooling / heating operation state, the outside air temperature, and the room temperature. For this reason, normally, when filling the refrigerant, the refrigerant is filled in accordance with an operation state that requires a large amount of refrigerant.

  In the present embodiment, the refrigerant amount of the refrigerant circuit 10 is required to be larger during the cooling operation than during the heating operation. In this embodiment, since the expansion valves 41A and 41B are provided on the indoor units 4A and 4B side, the refrigerant state of the extension pipe is the liquid phase extension pipe 6 in the liquid phase and gas side extension during the cooling operation. This is because the pipe 7 is in the gas phase while the liquid side extension pipe 6 is in two phases and the gas side extension pipe 7 is in the gas phase during heating operation. In other words, the liquid side extension pipe 6 is in the liquid phase state during the cooling operation, and in the two phase state during the heating operation, and requires a larger amount of refrigerant during the cooling operation because the liquid phase state requires a larger amount of refrigerant. And

  Further, the difference in the internal volume between the condenser and the evaporator and the difference in the condensation density and the evaporation density also greatly affect the required refrigerant amount. Usually, the internal volume of the outdoor heat exchanger 23 is larger than that of the indoor heat exchangers 42A and 42B, and the average density of the condenser is larger than that of the evaporator. Therefore, during the cooling operation, the outdoor heat exchanger 23 side having a large internal volume becomes a condenser having a large average density, and therefore requires a larger amount of refrigerant than during the heating operation.

  From the above, in the present embodiment in which the cooling operation or the heating operation is performed by switching the four-way valve 22, the refrigerant amount required for the cooling operation and the heating operation is different, and the operation state that does not require a large amount of refrigerant, that is, the surplus in the heating operation The liquid refrigerant is stored in an excess liquid refrigerant storage container such as ACC24.

<Refrigerant leak detection method>
Next, the flow of the refrigerant leakage detection method in the refrigeration air conditioner 1 will be described.

  The refrigerant leakage detection is always performed while the refrigeration air conditioner 1 is in operation. In addition, the refrigeration air conditioner is configured to be capable of remote monitoring by transmitting refrigerant leakage presence / absence data indicating the detection result of refrigerant leakage to a management center (not shown) or the like via a communication line.

  In the present embodiment, the refrigerant amount of the refrigeration air conditioner 1 is calculated, and the refrigerant leakage is detected by monitoring the change in the calculated refrigerant amount.

  FIG. 8 is a flowchart showing the flow of the refrigerant leakage detection process in the refrigerating and air-conditioning apparatus according to the embodiment of the present invention. The refrigerant leak detection is performed during normal cooling operation or heating operation instead of performing a specific operation for refrigerant leak detection. That is, the control unit 3 performs the process of the flowchart of FIG. 8 in parallel while performing the normal operation in which the refrigeration and air-conditioning apparatus 1 controls each device according to the operation load, and performs refrigerant leakage detection.

(Operation data acquisition)
First, in the model information acquisition of step S1, the control part 3 acquires the internal volume of each component component required for refrigerant | coolant amount calculation among the refrigerant circuits 10 from the memory | storage part 3e. That is, the internal volume of each piping and each device (compressor 21 and outdoor heat exchanger 23) in the indoor units 4A and 4B, and each piping and each device (indoor heat exchangers 42A and 42B) in the outdoor unit 2. ) And the internal volumes of the liquid side extension pipe 6 and the gas side extension pipe 7 are obtained. These internal volume data are stored in advance in the storage unit 3e of the control unit 3. The input of the internal volume data to the storage unit 3e of the control unit 3 may be input by the installer through the input unit 3g, or the outdoor unit 2 and the indoor units 4A and 4B are installed and communicated. It is good also as a structure which the control part 3 communicates with an external management center etc., and acquires automatically, when setting is performed.

  Next, the control unit 3 collects current operation data (S2). The operation data to be collected is data indicating the operation state quantity. Specifically, in addition to the measurement values obtained by the pressure sensors 34a and 34b and the temperature sensors 33a to 33j, the frequencies of the compressor and the fan which are actuators are also included. Including. Since the refrigerant amount other than the ACC surplus liquid refrigerant amount is calculated using only necessary data used for device operation, the communication load is not increased in calculating the refrigerant amount.

  Next, based on the data collected in S2, it is determined whether the refrigeration cycle is stable (S3). For example, when the rotation speed of the compressor 21 is varied at the time of start-up or the opening degree of the expansion valves 41A and 41B is varied, the refrigerant cycle operation is not stable, so that the refrigerant amount cannot be calculated correctly. . Therefore, after determining whether or not the refrigeration cycle is stable, the refrigerant amount calculation process is started. Here, in addition to the pressure and temperature data acquired in S2, the determination of stability / instability is performed based on operation data such as the frequency of the compressor and fan that are actuators. The stable / unstable determination method is to obtain operation data for an arbitrary time, for example, 10 minutes, calculate the average value thereof, calculate the deviation between this average value and each operation data value, and the deviation is within a certain range. For example, if it is within 15% of the average value, it is determined to be stable, and if it is more than that, it is determined to be unstable.

  If it is determined in S3 that the refrigeration cycle is unstable, the amount of refrigerant cannot be calculated correctly, so the process returns to S2 again to collect data.

  On the other hand, when it is determined in S3 that the refrigeration cycle is stable, the control unit 3 calculates a refrigerant amount in the refrigerant circuit 10 other than the ACC excess liquid refrigerant amount in the refrigerant amount calculation unit 3b (S4, S5). ) And a process (S6-S9) of calculating the ACC surplus refrigerant amount by the surplus liquid refrigerant quantity calculating unit 3c. Hereinafter, each process is demonstrated in order.

(Calculation of refrigerant quantity (excluding ACC excess refrigerant quantity))
First, the density of each element is calculated using the stable data (operation data) obtained in S3 (S4). That is, the density of the single phase portion where the refrigerant is either liquid or gas can be basically calculated from the pressure and temperature. For example, the refrigerant is in a gas state from the compressor 21 to the outdoor heat exchanger 23, and the density of the gas refrigerant in this portion is determined by the discharge pressure detected by the discharge pressure sensor 34b and the discharge temperature detected by the discharge temperature sensor 33b. Can be calculated.

  Further, the density of the portion where the two-phase state exists, such as a heat exchanger, is calculated from the device entrance / exit state quantity by using an approximate expression. Approximate expressions and the like necessary for these calculations are stored in advance in the storage unit 3e, and the refrigerant amount calculation unit 3b includes the operation data obtained in step S3 and the approximate expressions stored in the storage unit 3e in advance. Using the data, the refrigerant density of each component part of the refrigerant circuit 10 other than the ACC is calculated.

  Next, the refrigerant amount calculation unit 3b integrates the internal volume data of each element acquired in S1 and the refrigerant density of each element calculated in S4, so that the refrigerant amount in the refrigeration air conditioner 1 other than the ACC surplus liquid refrigerant is obtained. Is calculated (S5).

(Calculation of ACC surplus liquid refrigerant amount)
Next, a method for calculating the ACC surplus liquid refrigerant amount will be described.

  The liquid level detection sensor 25 generates a temperature difference between the container internal temperature and the container surface temperature at the temperature difference generation unit 25b (S6), and measures the container surface temperature at each of the temperature sensors 26a to 26e of the measurement unit 25c in that state. (S7). And a liquid level temperature sensor is specified based on each temperature measurement value (S8). Since the data necessary for calculating the amount of the ACC surplus liquid refrigerant is data when the refrigeration cycle is stabilized, it is possible to suppress unnecessary measurement as much as possible by heating the container after it is determined to be stable in S3. it can.

  Then, the surplus liquid refrigerant amount calculating unit 3c calculates the ACC surplus liquid refrigerant amount based on the sensor number of the temperature sensor specified by the liquid level detection sensor 25 and the correlation stored in advance in the initial learning (S9).

(Calculation of total refrigerant amount)
Next, the determination unit 3d calculates the total refrigerant amount in the refrigeration air conditioner 1 by adding the refrigerant amount other than the ACC excess liquid refrigerant amount calculated in step S5 and the ACC excess liquid refrigerant amount calculated in step S9. (S10).

(Refrigerant leak judgment)
Next, the determination unit 3d compares the initial refrigerant amount with the calculated total refrigerant amount calculated in step S10 to determine whether there is a refrigerant leak (S11). The initial refrigerant amount used in this determination is the refrigerant amount when the initial refrigerant amount is input to the storage unit 3e by the contractor at the time of installation, and otherwise the refrigerant amount obtained as follows. Good. That is, immediately after the refrigerating and air-conditioning apparatus 1 is installed, the ACC 24 is operated so that the excess liquid refrigerant does not accumulate in the ACC 24, that is, the ACC inlet and outlet are in the superheated gas state. The total amount of refrigerant may be used. Here, the confirmation of the ACC inlet superheated gas state is determined by the ACC inlet and outlet superheat degrees, and if the superheat degree is 0 or more, it indicates that the superheated gas state is present. The ACC inlet / outlet superheat degree can be calculated by subtracting a value obtained by converting the measured value of the suction pressure sensor 34a into a saturated gas from the ACC inlet temperature and outlet temperature.

  In S11, if the calculated total refrigerant quantity is smaller than the initial refrigerant quantity, it is determined that there is a leak, and a leak is issued (S12). If the initial refrigerant amount and the calculated total refrigerant amount are equal, it is determined that the normal refrigerant amount is normal, and no leak is issued. In addition, when it determines with it being normal, you may make it perform normal alerting. In addition, when there is refrigerant leakage, the determination unit 3d can calculate the refrigerant leakage amount by taking the difference between the initial refrigerant amount and the calculated total refrigerant amount.

  As described above, from START to RETURN is repeated and detection is always performed.

<Initial learning>
Next, initial learning for actually operating the refrigerating and air-conditioning apparatus 1 locally to obtain the correlation between the output of the liquid level detection sensor 25 and the ACC surplus refrigerant amount will be described. In the following, first, the principle of initial learning will be described, and then the initial learning operation will be described.

(Principle of initial learning)
In the state A shown in FIG. 4, since the entire ACC 24 is in a gas state, there is no temperature difference between the temperature measurement values of the temperature sensors 26a to 26e of the liquid level detection sensor 25. . In the state B shown in FIG. 4, the sensor number of the temperature sensor 26 c becomes the output of the liquid level detection sensor 25.

FIG. 9 is an explanatory diagram of a method for calculating excess liquid refrigerant in each of the states A and B of FIG.
When the refrigerant amounts in the refrigeration air conditioner 1 other than the excess liquid refrigerant in each of the states A and B shown in FIG. 4 are calculated, in the state A, all the liquid amounts A1 in the refrigerant circuit 10 are calculated. In the state B, B1 that is smaller by the amount of the excess liquid refrigerant stored in the ACC 24 is calculated as the refrigerant amount in the refrigeration air conditioner 1. Therefore, the surplus liquid refrigerant amount B2 can be calculated by taking the difference between A1 and B1.

  Next, when the output of the liquid level detection sensor 25 in each of the states A and B and the calculated surplus liquid refrigerant amount are plotted on the coordinate axis with the horizontal axis representing the sensor number and the vertical axis representing the surplus liquid refrigerant amount, The graph of FIG. 10 can be created. The state A is plotted at 0. Here, an example of two states A and B has been described, but a solid line relational expression as shown in FIG. 10 is created by changing a plurality of excess liquid refrigerants or by narrowing the sensor interval by using more temperature sensors. be able to. Here, the relational expression between the sensor number of the liquid surface position temperature sensor and the surplus liquid refrigerant amount is obtained, but as a conversion table that simply associates the sensor number of the liquid surface position temperature sensor with the surplus liquid refrigerant amount. Also good. These correlations are stored in the storage unit 3e.

(Initial learning driving)
FIG. 11 is a flowchart of the initial learning operation in the refrigerating and air-conditioning apparatus according to one embodiment of the present invention. Hereinafter, the details of the initial learning operation will be described using the flowchart of FIG.

  First, in the model information acquisition in step S101, the control unit 3 acquires the internal volume data of each component necessary for calculating the refrigerant amount of the refrigerant circuit 10 from the storage unit 3e. This process is the same as S1 in FIG.

  Next, heating operation is started and constant supercooling degree control is performed (S102). The constant supercooling degree operation is control for maintaining the supercooling degree (hereinafter referred to as SC) of the indoor units 4A and 4B at a constant value in all the indoor units 4A and 4B. The initial SC in the initial learning is reduced to 5 ° C., for example. Then, operation data is acquired in a state of constant control at SC = 5 (S103). The operation data to be acquired includes the pressure and temperature data, as well as the number of peripheral fluids of the compressor and fan that are actuators.

  By the way, when the value of SC is changed, the excess liquid amount in ACC24 changes. When the SC is high, a large amount of liquid refrigerant is stored in the indoor heat exchangers 42A and 42B, which are condensers, so that the amount of ACC excess liquid refrigerant decreases. Conversely, when the SC is low, the amount of liquid refrigerant stored in the indoor heat exchangers 42A and 42B, which are condensers, decreases, and the amount of ACC excess liquid refrigerant increases. Therefore, in the following process, the SC is increased stepwise up to the maximum SC = 30 here, and the operation data at that time is acquired to determine the ACC surplus liquid refrigerant amount, corresponding to the output of the liquid level detection sensor 25 at that time The correlation is acquired.

  Next, the control unit 3 determines whether the refrigeration cycle is stable (S104). This determination is the same as the determination in S3 of FIG.

  If it is determined in S104 that the refrigeration cycle is unstable, the amount of refrigerant cannot be calculated correctly, so the process returns to S103 again to collect data.

  On the other hand, if it is determined in S104 that the refrigeration cycle is stable, a process of calculating the ACC surplus liquid refrigerant amount (S105 to S107) and a process of detecting the liquid level by the liquid level detection sensor 25 (S108 to S110). Do.

(Calculation of ACC surplus refrigerant amount)
First, the refrigerant quantity calculation unit 3b calculates the refrigerant density of each element (S105). As described above, this is calculated using the measured values of the pressure sensor and the temperature sensor. Moreover, about the refrigerant density of the element in which two-phase refrigerant exists, such as a condenser and an evaporator, the average density of each element is calculated using an approximate expression.

  Next, the refrigerant amount of each element is calculated from the device information acquired in S101, that is, the internal volume data of each element and the refrigerant density of each element calculated in S104 (S106). This process is the same as S4 in FIG. Here, the refrigerant quantity other than the ACC excess liquid refrigerant quantity is calculated.

  Next, the ACC surplus liquid refrigerant amount is calculated using the initial refrigerant amount and the refrigerant amount other than the surplus liquid refrigerant calculated in S106 (S107). That is, the ACC surplus liquid refrigerant amount is calculated by subtracting the calculated value of S106 from the initial refrigerant amount. The initial refrigerant amount used in this calculation uses the refrigerant amount when the initial refrigerant amount is input to the storage unit 3e by the supplier at the time of installation, and otherwise, the refrigerant amount obtained as follows. It is good. That is, immediately after installing the refrigerating and air-conditioning apparatus 1, the operation is performed so that the excess liquid refrigerant does not accumulate in the ACC 24, that is, the evaporator outlet is in a superheated gas state, and The amount of refrigerant may be used.

(Liquid level detection)
The processing in steps S108 to S110 is the same as that in steps S6 to S8 in FIG.

  As described above, when the SC is 5, the ACC surplus liquid refrigerant amount at a certain arbitrary time is calculated in step S107, and the liquid surface position temperature sensor at that arbitrary time is specified in step S110. Then, the ACC surplus liquid refrigerant amount and the sensor number of the liquid surface position temperature sensor are associated with each other and stored in the storage unit 3e (S111).

  Thereafter, the process proceeds to S112, where it is determined whether SC = 30 [K]. If SC ≠ 30, the SC obtained by adding 5 [K] to the current SC is set as the target value for the next SC constant control. Then, the process returns to S103 and the same processing is performed. This is looped until the condition of S112 is satisfied.

  Then, if the condition of S112 is satisfied, it indicates that a plurality of data of the excess liquid refrigerant amount difference has been acquired, so the correlation between the sensor number of the liquid surface position sensor shown in FIG. 10 and the ACC excess liquid refrigerant amount can be acquired. End the initial learning.

  As described above, since the ACC surplus liquid refrigerant amount changes by changing the SC, a plurality of data having different surplus liquid refrigerant amounts can be collected in a short time by intentionally changing the SC.

FIG. 12 is a diagram illustrating an example of a correlation table obtained by the initial learning of FIG.
12 correspond to sensor numbers of the temperature sensors 26a to 26e in order. In the above description, the ACC excess liquid refrigerant amount and the sensor number of the liquid surface position temperature sensor are associated with each other. However, as shown in FIG. 12, the degree of supercooling may also be associated and stored.

  As described above, according to the present embodiment, since the liquid level detection sensor 25 is configured by a plurality of temperature sensors that detect the surface temperature of the ACC 24, the float type, ultrasonic type, and temperature type liquid level detection sensors are used. Compared with the higher degree of freedom of installation, it can be realized at lower cost.

  Further, in the conventional temperature type liquid level detection sensor, when the liquid level detection sensor is mounted in the container, it is necessary to mount the liquid level detection sensor in a predetermined mounting position. And so on. However, in the present embodiment, the correlation between the surplus liquid refrigerant amount in the ACC 24 and the output of the liquid level detection sensor 25 at the surplus liquid refrigerant amount is learned by actual measurement with the liquid level detection sensor 25 installed. I made it. For this reason, the error resulting from the sensor installation is eliminated, the accuracy is improved, and the attachment position can be set to an arbitrary position. As a result, the liquid level detection sensor 25 can be retrofitted to the ACC 24 of the existing refrigeration air conditioner 1.

  In addition, since the liquid level detection sensor 25 is externally attached, it is easy to maintain. In addition, since a plurality of sensors are used, detailed liquid level detection is possible, and as a result, refrigerant leakage detection accuracy is improved.

  As described above, the liquid level detection sensor 25 of the present embodiment has a high degree of freedom in installation and is low in cost, and can be retrofitted to the existing refrigeration air conditioner 1.

  In the present embodiment, since the refrigerant leakage can be detected even if the excess liquid refrigerant amount is stored in the ACC 24 during normal operation, the refrigerant leakage or shortage can be prevented after the entire ACC 24 is in the gas state. Leakage can be detected earlier than the current method of detection.

  In calculating the surplus liquid refrigerant amount in the ACC 24, the sensor number of the liquid surface position temperature sensor is directly converted into the surplus liquid refrigerant amount instead of calculating from the liquid level height in the ACC 24 and the volume of the ACC 24. Therefore, the surplus liquid refrigerant amount can be accurately calculated regardless of the container shape. As a result, refrigerant leakage can be detected with high accuracy.

  Moreover, the liquid level detection sensor 25 of this example does not need to change a structure or a shape with a container shape, and can detect the excess liquid refrigerant | coolant amount in ACC24 of various shapes universally with the same sensor structure.

  In addition, the use of the temperature difference generator 25b makes it easier to detect the boundary between the liquid portion and the gas portion inside the ACC 24, so that the detection accuracy is improved. Further, by using the temperature difference generator 25b, it is possible to correct sensor errors and the like, and the detection accuracy is improved.

  Further, in the present embodiment, the plurality of temperature sensors 26a to 26e and the heater (temperature difference generation unit 25b) are formed as separate bodies, and each is individually attached to the ACC 24. However, the present invention is not limited to this. Absent. For example, a configuration may be adopted in which a plurality of temperature sensors 26a to 26e and heaters arranged at predetermined intervals in advance are unitized, and the back surface can be easily installed at once with a seal or the like. By adopting such a configuration, the intervals between the temperature sensors 26a to 26e are also fixed, so that it is easy to grasp the liquid level, and the operator can easily perform installation work at the site.

  In addition, it is possible to finely measure the change in liquid level by attaching a plurality of temperature sensors 26a to 26e arranged at equal intervals in advance to the container of the ACC 24. The specification can be easily changed.

  Moreover, although the measurement part 25c was made into the some temperature sensor 26a-26e in this Embodiment, it is good also as what the measurement part 25c itself self-heats. Usually, the temperature sensor detects the temperature from a resistance value that changes according to the ambient temperature. Although the temperature sensor element itself self-heats due to the generated electric power, it becomes a cause of error in temperature measurement, and therefore it is generally reduced as much as possible. However, on the other hand, even when the self-heating amount of the temperature sensor is large, the temperature measurement and the difference between the plurality of objects can be determined. This utilizes the characteristic that a self-heated sensor is cooled by a measurement object and the resistance value changes according to the degree of cooling. In the present embodiment, the use of a temperature sensor with a large amount of self-heat generation eliminates the need for adding a temperature difference generating unit such as a heater, so that the configuration can be simplified.

  Moreover, since the liquid level detection sensor 25 of this Embodiment is applicable with respect to both the receiver installed in the high voltage | pressure part, and the accumulator installed in the low voltage | pressure part, either a receiver or an accumulator The present invention can be applied to a wide variety of models, such as a model equipped with the above and a model equipped with both.

  In the present embodiment, the initial learning operation for forcibly changing the SC value as described above is performed in order to shorten the initial learning time. However, the present invention is not limited to this. You may make it acquire the said correlation by implementing normal driving | operation for a fixed number of days after installing the apparatus 1. FIG. This is because the load of the refrigeration air conditioner changes variously from morning to night, and the amount of ACC surplus liquid refrigerant changes variously as in the initial learning operation.

  In the present embodiment, the surplus liquid refrigerant amount is used as the operation state amount associated with the output of the liquid level detection sensor 25 by the initial learning. However, the present invention is not limited to this. For example, parameters that change due to changes in the amount of excess liquid refrigerant in the ACC 24, such as parameters that change due to changes in the degree of supercooling, changes in the degree of supercooling (for example, temperature efficiency), exergy (effective energy), changes in exergy, etc. May be used. Each of these parameters can be calculated from the operation data.

  Specifically, when the degree of supercooling is used, the relationship between the degree of supercooling and the sensor number of the liquid surface position temperature sensor is learned by initial learning, and during normal operation, the liquid level detection sensor 25 causes the current liquid level to be detected. The sensor number of the surface position temperature sensor is specified and the degree of supercooling is calculated from the operation data. The sensor number of the liquid surface temperature sensor corresponding to the calculated degree of supercooling is obtained from the initial learning data. Refrigerant leakage is detected by comparison with the sensor number of the liquid surface position temperature sensor. Here, since the sensor numbers of the temperature sensors 26a to 26e are assigned from the lower installation height, the current sensor number of the liquid surface position temperature sensor is smaller than the sensor number obtained from the initial learning data. Detecting that there is a refrigerant leak. Parameters that change with changes in the degree of supercooling (for example, temperature efficiency) can be used in the same manner.

  Moreover, since the exergy of the refrigerating and air-conditioning apparatus 1 decreases due to a lack of refrigerant, the refrigerant leakage may be detected by the same method as the above-described degree of supercooling using this tendency.

  In addition, a reference condition (for example, the frequency of the compressor is set to a predetermined frequency) is set as an operation condition of the refrigeration air conditioner 1, and the operation of the refrigeration air conditioner 1 is controlled so as to satisfy the reference condition. The sensor number of the liquid surface position temperature sensor in that state and the ACC excess liquid refrigerant amount may be learned in advance. When the refrigerating and air-conditioning apparatus 1 is in a state of satisfying the reference condition naturally or intentionally during normal operation, the liquid level detection sensor 25 identifies the sensor number of the current liquid level position temperature sensor, and the sensor number and initial learning data The ACC surplus liquid refrigerant amount may be obtained from the above, and the refrigerant leakage may be detected by comparing the surplus liquid refrigerant amount with the initial ACC surplus liquid refrigerant amount in a state that satisfies the reference condition. At this time, the reference condition is not limited to one, and a plurality of conditions may be set.

  If these methods are used, it is possible to easily detect refrigerant leakage without calculating the total refrigerant amount in the refrigeration air conditioner 1.

  Moreover, in this Embodiment, it was set as the structure which detects a liquid level using a some temperature sensor, However, It is not restricted to this, The method of detecting the excess liquid refrigerant | coolant in ACC24 using one temperature sensor. It may be used. In this case, during the initial learning, for example, the relationship between the degree of supercooling and the container surface temperature measured by one temperature sensor is learned by changing the degree of supercooling, and then the degree of supercooling is calculated from the operation data during normal operation. The container surface temperature corresponding to the degree of supercooling is obtained from the initial learning data, and the current container surface temperature measured by the temperature sensor is significantly higher than the container surface temperature obtained from the initial learning data. Detect as refrigerant leakage. In other words, if the inside of the container at the location where the temperature sensor is installed at the time of initial learning is liquid, and the amount of liquid is reduced due to refrigerant leakage and the inside of the container at the location where the temperature sensor is installed becomes gas, the temperature measurement value of the temperature sensor Becomes higher. By detecting this, refrigerant leakage can be detected. When the surplus liquid refrigerant storage container is a receiver, conversely, refrigerant leakage can be detected by detecting that the temperature measurement value of the temperature sensor has become low.

  Moreover, although the case where the refrigerating and air-conditioning apparatus 1 detects refrigerant leakage during normal operation is described as an example in the present embodiment, the present invention is not limited to this. For example, when the refrigeration / air-conditioning apparatus 1 performs a special operation such as controlling the degree of supercooling or performing a pump-down operation, or when the compressor 21 is stopped, the same as above. It is possible to detect refrigerant leakage.

  In addition, since the amount of refrigerant leakage can be calculated, the degree of leakage and the maintenance work process can be ascertained in advance before maintenance, thereby improving maintenance work efficiency.

  Further, in the present embodiment, the building multi-air conditioner is described as shown in FIG. 1, but the present invention is not limited to this. For example, there is no four-way valve 22 such as a refrigerator, and excess liquid is provided at the outlet of the outdoor heat exchanger of the high-pressure section. The present invention can also be applied to a refrigeration air conditioner to which a receiver that is a refrigerant storage container is added. That is, it is possible to detect excess liquid refrigerant in the receiver and refrigerant leakage.

  In the present embodiment, the case where the liquid refrigerant is stored in the ACC 24 during the heating operation is described. However, the present invention is not limited to this. Is possible.

  In the above description, the system closed by the refrigerating and air-conditioning apparatus 1 has been described as an example. However, the present invention is not limited to this, and the refrigerating and air-conditioning apparatus 1 and a remote server of the information management center are connected to a network such as a telephone line, a LAN line, or a wireless network. By connecting a storage device such as a disk device that stores the operation state quantity to a remote server, a leak detection system that can constantly monitor a plurality of leak locations may be configured.

  By constructing the above connection configuration and transmitting detection data on the presence or absence of refrigerant leakage to a management center or the like, refrigerant leakage detection can always be performed remotely. Therefore, it is possible to cope with sudden refrigerant leakage immediately before an abnormality such as damage to the equipment or a decrease in capability occurs, and it is possible to suppress the progression of refrigerant leakage as much as possible. Thereby, the reliability of the refrigerating and air-conditioning apparatus 1 can be improved, and deterioration of the environmental state due to refrigerant outflow can be prevented as much as possible.

  Furthermore, since it is possible to prevent the inconvenience of continued operation with a small amount of refrigerant due to refrigerant leakage, it is possible to extend the life of the refrigerating and air-conditioning apparatus 1. When there is refrigerant leakage, the determination unit 3d may calculate the refrigerant leakage amount and notify the outside of the management center or the like from the output unit 3h together with the determination result.

  In the above description, the case where the presence / absence of refrigerant leakage is determined has been described. However, the present invention can also be applied to the determination of whether or not the amount of the refrigerant is excessive when the refrigerant is charged.

  In the above-described embodiment, the refrigeration and air-conditioning apparatus including one outdoor unit and two indoor units is taken as an example. However, the present invention is not limited to this, and the configuration of one outdoor unit and one indoor unit is used. It is good also as a refrigeration air conditioner provided with a plurality of outdoor units and a plurality of indoor units. In either case, the present invention can be applied.

  As mentioned above, although embodiment of this invention was described based on drawing, a specific structure is not restricted to these embodiment, It can change in the range which does not deviate from the summary of invention.

  DESCRIPTION OF SYMBOLS 1 Refrigeration air conditioner, 2 outdoor unit, 3 control part, 3a measurement part, 3b refrigerant | coolant amount calculation part, 3c excess liquid refrigerant | coolant amount calculation part, 3d determination part, 3e memory | storage part, 3f drive part, 3g input part, 3h output part 4A indoor unit, 4B indoor unit, 6 liquid side extension pipe, 6A liquid main pipe, 6a liquid branch pipe, 6b liquid branch pipe, 7 gas side extension pipe, 7A gas main pipe, 7a gas branch pipe, 7b gas branch pipe, 10 Refrigerant circuit, 10a indoor refrigerant circuit, 10b indoor refrigerant circuit, 10c outdoor refrigerant circuit, 21 compressor, 22 four-way valve, 23 outdoor heat exchanger, 24 ACC (excess liquid refrigerant storage container), 25 liquid level detection sensor , 25a control unit, 25b temperature difference generation unit, 25c measurement unit, 25d processing unit, 25e storage unit, 25f output unit, 26a to 26e temperature sensor, 27 outdoor fan, 28 Liquid side closing valve, 29 Gas side closing valve, 31 Outdoor control unit, 32a Indoor side control unit, 32b Indoor side control unit, 33a Suction temperature sensor, 33b Discharge temperature sensor, 33c Outdoor temperature sensor, 33d Liquid side temperature sensor, 33e Gas side temperature sensor, 33f Indoor temperature sensor, 33g Liquid side temperature sensor, 33h Gas side temperature sensor, 33i Indoor temperature sensor, 33j Liquid side temperature sensor, 34a Suction pressure sensor, 34b Discharge pressure sensor, 41A, 41B Expansion valve, 42A, 42B indoor heat exchanger, 43A, 43B indoor fan, 51a distributor, 52a distributor.

Claims (17)

A refrigerant circuit having a compressor, a condenser, an expansion valve, an evaporator, and an excess liquid refrigerant storage container;
Among the refrigerant circulating in the refrigerant circuit, a refrigerant amount calculation unit that calculates the refrigerant amount excluding the excess liquid refrigerant amount in the excess liquid refrigerant storage container;
It has a plurality of temperature sensors arranged on the outer surface of the excess liquid refrigerant storage container to measure the temperature of the outer surface, and based on the temperature measurement values of the plurality of temperature sensors, among the plurality of temperature sensors, A liquid level detection sensor that identifies a temperature sensor corresponding to a liquid level position of the surplus liquid refrigerant stored in the surplus liquid refrigerant storage container, and outputs identification information of the identified temperature sensor;
A storage unit that stores a correlation between an amount of excess liquid refrigerant stored in the excess liquid refrigerant storage container and an output of the liquid level detection sensor at the amount of excess liquid refrigerant;
A control unit that controls the operation of the refrigerant circuit to obtain a measured correlation, and stores the correlation in the storage unit;
An excess liquid refrigerant amount calculating unit that calculates an amount of excess liquid refrigerant in the excess liquid refrigerant storage container based on the output of the liquid level detection sensor and the correlation;
A determination unit that calculates the total refrigerant amount in the refrigerant circuit from the calculation result of the surplus liquid refrigerant amount calculation unit and the calculation result of the refrigerant amount calculation unit, and determines the presence or absence of refrigerant leakage. Refrigeration air conditioner.   The controller performs an initial learning operation in which the refrigerant circuit is heated to perform a constant supercooling degree control as an operation for acquiring the correlation, and the supercooling degree of the constant supercooling degree control is stepwise. The amount of surplus liquid refrigerant is obtained by increasing the operation data at that time, and the amount of surplus liquid refrigerant obtained is associated with the output of the liquid level detection sensor at that time and stored in the storage unit as the correlation. The refrigerating and air-conditioning apparatus according to claim 1.   The refrigerating and air-conditioning apparatus according to claim 1, wherein the determination unit determines refrigerant leakage by comparing the calculated total refrigerant amount with a prestored initial refrigerant amount. A refrigerant circuit having a compressor, a condenser, an expansion valve, an evaporator, and an excess liquid refrigerant storage container;
It has a plurality of temperature sensors arranged on the outer surface of the excess liquid refrigerant storage container to measure the temperature of the outer surface, and based on the temperature measurement values of the plurality of temperature sensors, among the plurality of temperature sensors, A liquid level detection sensor that identifies a temperature sensor corresponding to a liquid level position of the surplus liquid refrigerant stored in the surplus liquid refrigerant storage container, and outputs identification information of the identified temperature sensor;
An operation state amount detection unit for detecting an operation state amount of the refrigerant circuit;
A storage unit that stores a correlation between the operation state amount detected by the operation state amount detection unit and the output of the liquid level detection sensor at the time of the operation state amount;
A control unit that controls the operation of the refrigerant circuit to obtain a measured correlation, and stores the correlation in the storage unit;
The identification information corresponding to the operation state quantity detected by the operation state quantity detection unit is obtained from the correlation, and the first identification information output from the liquid level detection sensor and the second identification information obtained from the correlation. And based on the comparison result, it is determined that the position of the temperature sensor specified by the first identification information is lower than the position of the temperature sensor specified by the second identification information. A refrigerating and air-conditioning apparatus comprising a determination unit for determining.   5. The refrigeration according to claim 4, wherein the operating state quantity is any one of a degree of supercooling, a parameter that varies according to a variation in the degree of supercooling, an exergy of the refrigerant circuit, or a parameter that varies according to the variation of the exergy. Air conditioner. The operation state quantity detection unit detects a degree of supercooling as the operation state quantity,
The controller performs an initial learning operation in which the refrigerant circuit is heated to perform a constant supercooling degree control as an operation for acquiring the correlation, and the supercooling degree of the constant supercooling degree control is stepwise. 5. The degree of supercooling at that time and the output of the liquid level detection sensor at the time of the degree of supercooling are correlated and stored in the storage unit as the correlation. Refrigeration air conditioner. A refrigerant circuit having a compressor, a condenser, an expansion valve, an evaporator, and an excess liquid refrigerant storage container;
It has a plurality of temperature sensors arranged on the outer surface of the excess liquid refrigerant storage container to measure the temperature of the outer surface, and based on the temperature measurement values of the plurality of temperature sensors, among the plurality of temperature sensors, A liquid level detection sensor that identifies a temperature sensor corresponding to a liquid level position of the surplus liquid refrigerant stored in the surplus liquid refrigerant storage container, and outputs identification information of the identified temperature sensor;
A storage unit that stores a correlation between an amount of excess liquid refrigerant stored in the excess liquid refrigerant storage container and an output of the liquid level detection sensor at the amount of excess liquid refrigerant;
A controller that controls the operation of the refrigerant circuit so that the refrigerant circuit is in a state that satisfies a preset reference condition, acquires an actual correlation in that state, and stores the correlation in the storage unit;
An excess liquid refrigerant amount calculating unit that calculates an amount of excess liquid refrigerant in the excess liquid refrigerant storage container based on the output of the liquid level detection sensor and the correlation;
A refrigerating and air-conditioning apparatus comprising: a determination unit that determines whether or not refrigerant leaks based on a calculation result of the surplus liquid refrigerant amount calculation unit when the refrigerant circuit is in a state satisfying the reference condition.   The said determination part determines refrigerant | coolant leakage by comparing with the calculation result of the said excess liquid refrigerant | coolant amount calculation part, and the excess liquid refrigerant | coolant amount in the state which satisfy | filled the said reference conditions of the initial stage memorize | stored beforehand. Refrigeration air conditioner of description.   The external liquid refrigerant storage container is installed outside, for changing the temperature of the outer surface of the excessive liquid refrigerant storage container to generate a temperature difference with the excessive liquid refrigerant temperature inside the excessive liquid refrigerant storage container The refrigerating and air-conditioning apparatus according to any one of claims 1 to 8, further comprising a temperature difference generation unit.   The refrigerating and air-conditioning apparatus according to any one of claims 1 to 9, wherein the surplus liquid refrigerant storage container is an accumulator or a receiver.   The refrigeration according to claim 9, wherein the surplus liquid refrigerant storage container is an accumulator disposed on a low pressure side of the refrigerant circuit, and the temperature difference generating unit is a heating device for heating an outer surface of the accumulator. Air conditioner.   10. The refrigeration according to claim 9, wherein the surplus liquid refrigerant storage container is a receiver disposed on a high pressure side of the refrigerant circuit, and the temperature difference generating unit is a cooling device that cools an outer surface of the receiver. Air conditioner.   The refrigerating and air-conditioning apparatus according to any one of claims 1 to 12, wherein the plurality of temperature sensors are installed at equal intervals.   The refrigerating and air-conditioning apparatus according to any one of claims 1 to 13, wherein the temperature sensor is corrected when the surplus liquid refrigerant storage container is in a gas state.   The refrigerating and air-conditioning apparatus according to any one of claims 1 to 14, further comprising an output unit that outputs a determination result of the determination unit to the outside.   The refrigerating and air-conditioning apparatus according to claim 15, wherein when the determination unit determines that there is refrigerant leakage, the refrigerant leakage amount is calculated and output to the outside from the output unit. A temperature sensor arranged on the outer surface of an excess liquid refrigerant storage container provided in the refrigerant circuit and measuring the temperature of the outer surface;
An operation state amount detection unit for detecting an operation state amount of the refrigerant circuit;
A storage unit for storing a correlation between the operation state amount detected by the operation state amount detection unit and the temperature measurement value of the temperature sensor at the time of the operation state amount;
A control unit that operates the refrigerant circuit to obtain an actual correlation, and stores the correlation in the storage unit;
A temperature measurement value corresponding to the operation state quantity detected by the operation state quantity detection unit is obtained from the correlation, the temperature measurement value is compared with the temperature measurement value measured by the temperature sensor, and based on the comparison result A determination unit that determines that there is refrigerant leakage when it is determined that the refrigerant state inside the surplus liquid refrigerant storage container at the location where the temperature sensor is installed is in a liquid state at the time of the correlation acquisition and is currently in a gas state; A refrigeration air conditioner characterized by comprising.