JP2009079842A - Refrigerating cycle device and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely determine availability of a refrigerant quantity of an air conditioner in response to a difference in an apparatus system constitution of the air conditioner, the pipe length, a pipe diameter and a height difference when installing an apparatus, the connecting number of indoor units and indoor unit capacity, with excellent accuracy even under any environmental condition and an installation condition. <P>SOLUTION: This refrigerating cycle device has an operation control means for operating by switching an ordinary operation mode of controlling the respective apparatuses of the refrigerating cycle device in response to an operation load of using side heat exchangers 7a and 7b and a refrigerant quantity determining operation mode of controlling an orifice means so that an overheating degree of a refrigerant becomes a positive value in an outlet of a heat exchanger being an evaporator among the using side heat exchangers 7a and 7b or a heat source side heat exchanger 3, and also determines the availability of the refrigerant quantity filled in a refrigerant circuit by comparing with a reference value of an operation state quantity in a proper refrigerant quantity prestored in a storage means, by detecting the operation state quantity varying in response to the refrigerant quantity in the refrigerant quantity determining operation mode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus having a function of determining whether or not the amount of refrigerant charged in a refrigerant circuit is appropriate from an operating state quantity detected from the apparatus during operation with the appropriate refrigerant quantity and a current operating state quantity. And its control method.

  2. Description of the Related Art Conventionally, a separate type refrigeration cycle apparatus is known in which a refrigerant circuit is configured by connecting a heat source unit and a utilization unit via a connection pipe. In such a case, refrigerant leakage may occur due to insufficient tightening of piping connection points or damage to the piping. Such refrigerant leakage may cause a decrease in cooling or heating capacity of the refrigeration cycle apparatus and damage to constituent devices. Also, if the refrigeration cycle device is filled with an excessive amount of refrigerant when the equipment is installed, the pressure inside the refrigeration cycle equipment will increase when the equipment is in operation, and it will be forced to stop due to equipment safety problems, and operation will fail. I ca n’t do it. On the other hand, when the amount of refrigerant charged is insufficient, desired cooling capacity and heating capacity cannot be obtained. For this reason, it is desirable to have a function of determining the suitability of the amount of refrigerant charged in the refrigeration cycle apparatus.

  Therefore, a method for determining the suitability of the refrigerant amount by using the refrigerant superheat degree at the outlet of the outdoor heat exchanger during the heating operation or the refrigerant superheat degree at the outlet of the indoor heat exchanger during the cooling operation (for example, see Patent Document 1). Also, a method of estimating the refrigerant amount from the degree of supercooling at the outlet of the outdoor heat exchanger during the cooling operation, comparing with the reference value, and determining the suitability of the refrigerant amount (see, for example, Patent Document 2 and Patent Document 3), etc. Has been proposed.

Japanese Patent Laid-Open No. 02-208469 (FIGS. 3 and 5) Japanese Patent Laying-Open No. 2006-313057 (FIGS. 1 and 9 to 11) Japanese Patent No. 3852472 (FIGS. 1 and 8)

  By the way, when the refrigerant is charged after the installation of the equipment, the refrigerant is charged up to the specified refrigerant amount calculated from the pipe length, the capacity of the component equipment, etc. at the site. Due to a mistake, a variation may occur between the initial refrigerant amount actually charged locally and the specified refrigerant amount. In this state, when the above-described conventional method for determining the appropriateness of the refrigerant amount is applied, the specified refrigerant amount is filled even though there is a variation between the initial refrigerant amount and the specified refrigerant amount. The values of the corresponding superheat degree, supercooling degree, etc. (hereinafter, these may be collectively referred to as “operating state quantity”) are used as a reference value as they are, and compared with the current value of the operating state quantity, As a result, determination of suitability is performed, and as a result, there is a problem in that accuracy of judgment of suitability of the refrigerant amount is lowered.

  In addition, in a refrigeration cycle apparatus that has a throttling means on the heat source unit side for determining whether or not the refrigerant amount is appropriate in the cooling operation, the liquid piping of the connecting pipe is filled with the gas-liquid two-phase refrigerant during the cooling operation. During the heating operation, the refrigerant is filled with the liquid refrigerant, and thus the heating operation requires a larger amount of refrigerant. Therefore, in the case where the prescribed enclosed refrigerant amount is determined based on the heating operation, there is a problem that the detection accuracy is lowered when the suitability of the refrigerant amount is determined under the cooling operation state as described above. .

  Moreover, in a model in which a conventional refrigeration cycle apparatus has a container for storing surplus refrigerant such as an accumulator or a receiver as a constituent element, the amount of surplus refrigerant in the container is determined by an ultrasonic sensor or the like in order to detect refrigerant leakage. There is a problem that it is necessary to detect the amount directly by a detector and estimate the amount of refrigerant, which is costly.

Further, in the one that uses a supercooling degree of the refrigerant as the operation state quantity for detecting the amount of refrigerant, when a refrigerant with a change in physical properties in the supercritical region, such as CO ₂ refrigerant supercooling There is a problem that it cannot be applied to a refrigeration cycle apparatus in which the degree cannot be obtained.

  Further, in the conventional refrigeration cycle apparatus, even if the refrigerant amount approaches the appropriate refrigerant amount at the time of additional charging of the refrigerant, control is not performed to reduce the charging speed of the refrigerant, and therefore, from the refrigerant cylinder filled with the additional charging refrigerant. There is a problem that the refrigerant flows excessively into the refrigeration cycle apparatus and is filled with the refrigerant in an overcharged manner.

  The present invention was made in order to solve the above-mentioned problems, accurately under any environmental conditions and installation conditions, the difference in the equipment system configuration of the refrigeration cycle apparatus, the pipe length at the time of equipment installation, It is an object of the present invention to accurately determine the suitability of the refrigerant amount of a refrigeration cycle apparatus according to the pipe diameter, height difference, number of indoor unit connections, and indoor unit capacity.

  The refrigeration cycle apparatus according to the present invention has the following configuration. That is, a compressor, a heat source side heat exchanger, an expansion means, and at least one usage side heat exchanger are connected by a liquid refrigerant connection pipe and a gas refrigerant connection pipe to constitute a refrigerant circuit, Normal operation mode for controlling each device of the refrigeration cycle apparatus according to the operation load of the use side heat exchanger, and heat exchange that is an evaporator of the use side heat exchanger or the heat source side heat exchanger Operation control means for switching and operating the refrigerant amount determination operation mode for controlling the throttling means so that the degree of superheat of the refrigerant at the outlet of the condenser becomes a positive value, and in the refrigerant amount determination operation mode, the refrigerant amount The amount of refrigerant charged in the refrigerant circuit is detected by detecting the amount of operating state that varies depending on the amount of refrigerant and comparing it with the reference value of the amount of operating state stored in advance in the storage means. Judgment of suitability Those having means for.

  According to the refrigeration cycle apparatus of the present invention, the reference value of the operation state quantity of the refrigeration cycle with the appropriate refrigerant amount of the refrigeration cycle apparatus is stored in advance, and the current operation state quantity of the refrigeration cycle is stored in the refrigerant amount determination operation mode. By comparing the reference value with the reference value, it is determined whether or not the refrigerant amount is appropriate, so that it is possible to accurately determine the appropriateness of the refrigerant amount of the refrigeration cycle apparatus accurately under any environmental conditions and installation conditions, A highly reliable refrigeration cycle apparatus can be obtained.

Embodiment 1 FIG.
The present invention will be described below with reference to illustrated embodiments.
FIG. 1 is a refrigerant circuit diagram schematically showing a refrigeration cycle apparatus according to Embodiment 1 of the present invention.

  The refrigeration cycle apparatus of the present embodiment is an apparatus used for indoor air conditioning by performing vapor compression refrigeration cycle operation, and a plurality of heat sources (one in this embodiment) connected mainly in parallel. The unit 301 is composed of a plurality of (two in this embodiment) usage units 302a and 302b connected in parallel via a liquid connection pipe 6 and a gas connection pipe 9 serving as a refrigerant communication pipe. Examples of the refrigerant used in the refrigeration cycle apparatus include HFC refrigerants such as R410A, R407C, and R404A, HCFC refrigerants such as R22 and R134a, or natural refrigerants such as hydrocarbon and helium.

<Usage unit>
The use units 302a and 302b are installed by being embedded or suspended in an indoor ceiling, or wall-mounted on an indoor wall surface, and are connected to the heat source unit 301 via the liquid connection pipe 6 and the gas connection pipe 9 as described above. It is connected and constitutes a part of the refrigerant circuit.

  Next, the detailed configuration of the usage units 302a and 302b will be described. However, since the usage units 302a and 302b have the same configuration, only the usage unit 302a will be described here, and the usage unit 302b will be described. A suffix “b” is attached to each symbol, and description of each part is omitted.

  The usage unit 302a constitutes an indoor refrigerant circuit that is a part of the refrigerant circuit, and includes an indoor fan 8a and an indoor heat exchanger 7a that is a usage-side heat exchanger.

  Here, the indoor heat exchanger 7a 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. In the heating operation, it functions as a refrigerant condenser and heats indoor air.

  The indoor blower 8a is composed of a fan capable of changing the flow rate of air supplied to the indoor heat exchanger 7a, such as a centrifugal fan or a multi-blade fan driven by a DC fan motor (not shown). It has a function of sucking indoor air into the utilization unit 302a and supplying the air, which has been heat-exchanged with the refrigerant by the indoor heat exchanger 7a, into the room as supply air.

  Various sensors are installed in the use unit 302a. That is, on the liquid side of the indoor heat exchanger 7a, the temperature of the refrigerant in the liquid state or the gas-liquid two-phase state (the supercooled liquid temperature Tco during the heating operation or the refrigerant temperature corresponding to the evaporation temperature Te during the cooling operation). A liquid temperature sensor 205a for detection is provided. The indoor heat exchanger 7a is provided with a gas side temperature sensor 207a for detecting the temperature of the refrigerant in the gas-liquid two-phase state (condensation temperature Tc during heating operation or refrigerant temperature corresponding to the evaporation temperature Te during cooling operation). It has been. Further, an indoor temperature sensor 206a for detecting the temperature of the indoor air flowing into the unit is provided on the indoor air inlet side of the utilization unit 302a. Here, all of the liquid side temperature sensor 205a, the gas side temperature sensor 207a, and the room temperature sensor 206a are composed of thermistors. The operation of the indoor fan 8a is controlled by operation control means.

<Heat source unit>
The heat source unit 301 is installed outdoors and is connected to the utilization units 302a and 302b via the liquid connection pipe 6 and the gas connection pipe 9 and constitutes a part of the refrigerant circuit.

  Next, a detailed configuration of the heat source unit 301 will be described. The heat source unit 301 includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3 as a heat source side heat exchanger, an outdoor blower 4, and a throttle means 5a.

  The throttle means 5a is connected to the liquid side of the heat source unit 301 in order to adjust the flow rate of the refrigerant flowing in the refrigerant circuit.

  The compressor 1 is a compressor whose operating capacity can be varied. Here, a positive displacement compressor driven by a motor (not shown) controlled by an inverter is used. In addition, although the compressor 1 is only one here, it is not limited to this, According to the number of use units etc., two or more compressors may be connected in parallel. Needless to say.

  The four-way valve 2 is a valve for switching the flow direction of the refrigerant. During the cooling operation, the outdoor heat exchanger 3 is used as a refrigerant condenser to be compressed in the compressor 1 and the indoor heat exchangers 7a and 7b are used. In order to function as an evaporator of the refrigerant condensed in the outdoor heat exchanger 3, the discharge side of the compressor 1 and the gas side of the outdoor heat exchanger 3 are connected, and the suction side of the compressor 1 and the gas connection pipe The refrigerant flow path is switched so as to connect to the 9 side (see the broken line of the four-way valve 2 in FIG. 1). In the heating operation, the four-way valve 2 uses the indoor heat exchangers 7a and 7b as the refrigerant condenser compressed in the compressor 1, and the outdoor heat exchanger 3 as the refrigerant condensed in the indoor heat exchangers 7a and 7b. In order to function as an evaporator, the discharge side of the compressor 1 and the gas connection pipe 9 side are connected, and the suction side of the compressor 1 and the gas side of the outdoor heat exchanger 3 are connected (see FIG. 1 (see the solid line of the four-way valve 2), and has a function of switching the refrigerant flow path.

  The outdoor heat exchanger 3 is a cross-fin type fin-and-tube heat composed of a heat transfer tube having a gas side connected to the four-way valve 2 and a liquid side connected to the liquid connection pipe 6 and a large number of fins. It consists of an exchanger and functions as a refrigerant condenser during cooling operation and functions as a refrigerant evaporator during heating operation.

  The outdoor blower 4 is composed of a fan capable of varying the flow rate of air supplied to the outdoor heat exchanger 3, for example, a propeller fan driven by a DC fan motor (not shown). It has a function of sucking outdoor air and discharging the air heat-exchanged with the refrigerant by the outdoor heat exchanger 3 to the outside.

  Various sensors are installed in the heat source unit 301. In other words, the compressor 1 is provided with a discharge temperature sensor 201 for detecting the discharge temperature Td, and the outdoor heat exchanger 3 has a gas-liquid two-phase refrigerant temperature (condensation temperature Tc during cooling operation). Alternatively, a gas side temperature sensor 202 that detects a refrigerant temperature corresponding to the evaporation temperature Te during heating operation) is provided. Further, a liquid side temperature sensor 204 for detecting the temperature of the refrigerant in the liquid state or the gas-liquid two-phase state is provided on the liquid side of the outdoor heat exchanger 3. Further, an outdoor temperature sensor 203 for detecting the temperature of the outdoor air flowing into the unit, that is, the outdoor air temperature Ta is provided on the outdoor air inlet side of the heat source unit 301. The compressor 1, the four-way valve 2, the outdoor fan 4, and the throttle means 5a are controlled by operation control means.

  In the operation control means, various amounts detected by various temperature sensors are input to the measurement unit 101, processed by the calculation unit 102, and the calculation result is sent to the control unit 103. The control unit 103 drives and controls the compressor 1, the four-way valve 2, the outdoor fan 4, the throttle unit 5 a, and the indoor fan 8 based on the calculation result of the calculation unit 102 so as to be within a desired control target range. It has become. Further, the calculation result of the operation state quantity obtained by the calculation unit 102 is stored in the storage unit 104. In addition, the storage unit 104 stores a reference operation state quantity that is collected in advance with an appropriate refrigerant amount, and the stored reference value is compared with the current operation state quantity value of the refrigeration cycle by the comparison unit 105. Then, the comparison result is sent to the determination unit 106 to determine the suitability of the refrigerant amount of the refrigeration cycle apparatus, and the determination result is notified by the notification unit 106 to an LED, a remote monitor, or the like.

  As described above, the heat source unit 301 and the utilization units 302a and 302b are connected via the liquid connection pipe 6 and the gas connection pipe 9 to constitute the refrigerant circuit of the refrigeration cycle apparatus.

Next, operation | movement of the refrigerating-cycle apparatus of this embodiment is demonstrated.
The operation mode of the refrigeration cycle apparatus of the present embodiment includes a normal operation mode for controlling each device of the heat source unit 301 and the usage units 302a and 302b in accordance with the operation load of the usage units 302a and 302b, and installation of the refrigeration cycle apparatus. The automatic refrigerant charging operation mode that is performed when the refrigerant is charged later, and the indoor heat exchangers 7a and 7b that function as condensers while heating the usage units 302a and 302b after the automatic refrigerant charging operation is ended and the normal operation is started. There is a refrigerant quantity detection mode in which the state quantity of the refrigerant at the outlet of the refrigerant is detected to determine whether the refrigerant quantity charged in the refrigerant circuit is appropriate. Note that the normal operation mode generally includes a cooling operation and a heating operation.

  Next, the operation in each operation mode of the refrigeration cycle apparatus will be described.

<Normal operation mode>
First, the cooling operation in the normal operation mode will be described with reference to FIG.

  During the cooling operation, the four-way valve 2 is in the state indicated by the broken line in FIG. 1, that is, the discharge side of the compressor 1 is connected to the gas side of the outdoor heat exchanger 3, and the suction side of the compressor 1 is the indoor heat exchanger 7a. , 7b is connected to the gas side. The opening of the throttle means 5a is adjusted so that the degree of superheat of the refrigerant on the suction side of the compressor 1 becomes a predetermined value. In the present embodiment, the degree of superheating of the refrigerant in the suction of the compressor 1 is first obtained by subtracting the refrigerant evaporation temperature Te detected by the gas side temperature sensors 207a and 207b from the compressor suction temperature Ts. Here, the compressor suction temperature Ts is obtained by converting the refrigerant evaporation temperature detected by the gas side temperature sensors 207a and 207b into a low pressure saturation pressure Ps, and the refrigerant condensation temperature detected by the gas side temperature sensor 202 being a high pressure. From the refrigerant discharge temperature Td detected by the discharge temperature sensor 201 of the compressor 1, the compression process of the compressor 1 is assumed to be a polytropic change of the polytropic index n, and is calculated from the following equation (1). Can be calculated.

  Here, Ts and Td are the temperature [K], Ps and Pd are the pressure [MPa], and n is the polytropic index [−]. The polytropic index may be a constant value (for example, n = 1.2), but by defining it as a function of Ps and Pd, the compressor intake temperature Ts can be estimated more accurately.

  As shown in the refrigerant circuit diagram of FIG. 2, the suction pressure sensor 10 and the suction temperature sensor 208 are provided on the suction side of the compressor 1, and the evaporation temperature is determined from the suction pressure Ps of the compressor 1 detected by the suction pressure sensor 10. The degree of superheat of the refrigerant may be detected by converting to a saturation temperature value corresponding to Te and subtracting the saturation temperature value of the refrigerant from the refrigerant temperature value detected by the suction temperature sensor 208.

  Here, the high pressure and the low pressure are calculated by converting from the condensation temperature and the evaporation temperature of the refrigerant. However, a pressure sensor is directly added to the suction side and the discharge side of the compressor 1 to obtain the pressure. Needless to say.

  When the compressor 1, the outdoor fan 4, and the indoor fans 8a and 8b are started in the state of this refrigerant circuit, the low-pressure gas refrigerant is sucked into the compressor 1 and compressed to become a high-pressure gas refrigerant. Thereafter, the high-pressure gas refrigerant is sent to the outdoor heat exchanger 3 via the four-way valve 2, exchanges heat with the outdoor air supplied by the outdoor blower 4, and is condensed to become a high-pressure liquid refrigerant.

  The high-pressure liquid refrigerant is decompressed by the throttling means 5a to become a low-temperature and low-pressure gas-liquid two-phase refrigerant, sent to the utilization units 302a and 302b via the liquid connection pipe 6, and the indoor heat exchanger 7a, In 7b, heat is exchanged with room air to evaporate into a low-pressure gas refrigerant. Here, since the throttle means 5a controls the flow rate of the refrigerant flowing through the indoor heat exchangers 7a and 7b so that the degree of superheat in the suction of the compressor 1 becomes a predetermined value, the indoor heat exchangers 7a and 7b The low-pressure gas refrigerant evaporated in is in a state having a predetermined degree of superheat. Thus, the refrigerant | coolant of the flow volume according to the driving | running load requested | required in each air-conditioning space in which utilization unit 302a, 302b was installed flows into each indoor heat exchanger 7a, 7b.

  This low-pressure gas refrigerant is sent to the heat source unit 301 via the gas connection pipe 9 and is again sucked into the compressor 1 via the four-way valve 2.

  Next, the heating operation in the normal operation mode will be described.

  During heating operation, the four-way valve 2 is in the state indicated by the solid line in FIG. 1, that is, the discharge side of the compressor 1 is connected to the gas side of the indoor heat exchangers 7a and 7b, and the suction side of the compressor 1 is the outdoor heat exchange. It is connected to the gas side of the vessel 3. The opening of the throttle means 5a is adjusted so that the degree of superheat of the refrigerant in the suction of the compressor 1 becomes a predetermined value. In the present embodiment, the degree of superheat of the refrigerant in the suction of the compressor 1 is first obtained by subtracting the refrigerant evaporation temperature Te detected by the gas side temperature sensor 202 from the compressor suction temperature Ts. Here, the compressor suction temperature Ts is obtained by converting the refrigerant evaporation temperature detected by the gas side temperature sensor 202 into a low pressure saturation pressure Ps, and increasing the refrigerant condensation temperature detected by the gas side temperature sensors 207a and 207b. From the refrigerant discharge temperature Td detected by the discharge temperature sensor 201 of the compressor 1 and the compression process of the compressor is assumed to be a change in the polytropy of the polytropic index n, and the above equation (1) is used. Can be calculated.

  As in the cooling operation, as shown in FIG. 2, a suction pressure sensor 10 and a suction temperature sensor 208 are provided on the suction side of the compressor 1, and evaporate from the suction pressure Ps of the compressor 1 detected by the suction pressure sensor 10. The degree of superheat of the refrigerant may be detected by converting to a saturation temperature value corresponding to the temperature Te and subtracting the saturation temperature value of the refrigerant from the refrigerant temperature value detected by the suction temperature sensor 208.

  It should be noted that the high pressure and the low pressure are calculated in the same manner as in the cooling operation, here again converted from the condensing temperature and the evaporating temperature of the refrigerant, but pressure sensors are directly provided on the suction side and the discharge side of the compressor 1. Needless to say, it may be added.

  When the compressor 1, the outdoor blower 4 and the indoor blowers 8a and 8b are started in the state of the refrigerant circuit, the low-pressure gas refrigerant is sucked into the compressor 1 and compressed to become a high-pressure gas refrigerant. The gas is sent to the utilization units 302a and 302b via the gas connection pipe 9.

  The high-pressure gas refrigerant sent to the utilization units 302a and 302b is condensed by exchanging heat with indoor air in the indoor heat exchangers 7a and 7b, and then the liquid connection pipe 6 The refrigerant is reduced in pressure by the throttle means 5a and becomes a low-pressure gas-liquid two-phase refrigerant. Here, since the throttle means 5a controls the flow rate of the refrigerant flowing in the indoor heat exchangers 7a and 7b so that the degree of superheat in the suction of the compressor 1 becomes a predetermined value, the indoor heat exchangers 7a and 7b The high-pressure liquid refrigerant condensed in step 1 has a predetermined degree of supercooling. Thus, the refrigerant | coolant of the flow volume according to the driving | running load requested | required in each air-conditioning space in which each utilization unit 302a, 302b is flowing is flowing in each indoor heat exchanger 7a, 7b.

  The low-pressure gas-liquid two-phase refrigerant flows into the outdoor heat exchanger 3 of the heat source unit 1. The low-pressure gas-liquid two-phase refrigerant flowing into the outdoor heat exchanger 3 is condensed by exchanging heat with the outdoor air supplied by the outdoor blower 4 and becomes a low-pressure gas refrigerant. Then, it is sucked into the compressor 1 again.

  Thus, the normal operation process including the cooling operation and the heating operation is performed by the control unit 103 that functions as a normal operation control unit that performs the normal operation including the cooling operation and the heating operation.

<Automatic refrigerant charging operation mode>
Next, the operation in the automatic refrigerant charging operation mode will be described with reference to FIGS. FIG. 3 is a flowchart showing an operation of determining whether or not the refrigerant amount is appropriate in the refrigerant automatic charging operation mode. Here, a heat source unit 301 preliminarily filled with a predetermined amount of refrigerant and use units 302a and 302b are installed and connected via the liquid connection pipe 6 and the gas connection pipe 9 to configure a refrigerant circuit. After that, the case where additional refrigerant is filled in the refrigerant circuit according to the length of the liquid connection pipe 6 and the gas connection pipe 9 will be described as an example.

  A transition to the refrigerant automatic charging operation mode is made by an operator who issues a command to start the automatic refrigerant charging operation directly to the control unit 103 or remotely through a remote controller (not shown) or the like. Thereby, the operation of the refrigerant automatic charging operation mode in step S11 shown in FIG.

  When an instruction to start the automatic refrigerant charging operation is given, the refrigerant circuit is switched so that the four-way valve 2 of the heat source unit 301 is in the state shown by the solid line in FIG. 1, and the indoor fans 8a, 8b of the utilization units 302a, 302b. And the throttle means 5a are opened, and the compressor 1 and the outdoor blower 4 are further activated to forcibly perform heating operation (hereinafter referred to as “usage unit”) for all the use units 302a and 302b. All operations are called).

  Then, in the refrigerant circuit, the high-pressure gas refrigerant compressed and discharged in the compressor 1 is supplied to the flow path from the compressor 1 to the indoor heat exchangers 7a and 7b. This high-pressure gas refrigerant passes through the gas connection pipe 9 and passes through the indoor heat exchangers 7a and 7b functioning as condensers, and the high-pressure gas refrigerant undergoes a phase change from a gas state to a liquid state by heat exchange with indoor air. It becomes a refrigerant and flows as a high-pressure liquid refrigerant in a flow path including the liquid connection pipe 6 from the indoor heat exchangers 7a and 7b to the throttle means 5a. This high-pressure liquid refrigerant undergoes a phase change from a gas-liquid two-phase state to a gas state by heat exchange with the outdoor air while passing through the outdoor heat exchanger 3 functioning as an evaporator from the throttle means 5a, and the outdoor heat The low-pressure gas refrigerant flows through the flow path from the exchanger 3 to the compressor 1.

  Next, in step S12, the refrigeration cycle such as the environmental conditions such as the outside air temperature and the indoor air temperature, the temperature sensors of the heat source unit 301 and the utilization units 302a and 302b, the operating frequency of the compressor 1, and the opening degree of the throttle means 5a. The operating state of the device is measured.

  Next, the following device control is performed to shift to an operation for stabilizing the state of the refrigerant circulating in the refrigerant circuit. Specifically, the rotation speed of the motor of the compressor 1 is controlled to be constant at a predetermined value (constant compressor rotation speed control), and the superheat degree SH of the outdoor heat exchanger 3 functioning as an evaporator is predetermined. The throttle means 5a is controlled so as to be constant in value (hereinafter referred to as “outdoor heat exchange superheat degree constant control”). Here, the constant rotation speed control is performed in order to stabilize the flow rate of the refrigerant sucked and discharged by the compressor 1. The superheat control is performed in order to keep the amount of refrigerant in the outdoor heat exchanger 3 constant.

  As a result, the state of the refrigerant circulating in the refrigerant circuit is stabilized, and the refrigerant amount in the equipment and piping other than the indoor heat exchangers 7a and 7b becomes substantially constant. Therefore, it is possible to create a state in which only the amount of liquid refrigerant that accumulates in the indoor heat exchangers 7a and 7b changes when the refrigerant circuit starts to be filled by the subsequent additional charging of the refrigerant.

  When the throttle means 5a is on the heat source unit 1 side, the gas-liquid two-phase refrigerant flows through the liquid connection pipe 6 during cooling, and the liquid refrigerant flows during heating. For this reason, the amount of refrigerant present in the liquid connection pipe 6 increases in heating. On the other hand, in the gas connection pipe 9, since the gas refrigerant flows during cooling and heating, the refrigerant density is small, and the difference in the amount of refrigerant existing between the cooling and heating operations is small.

  FIG. 4 is a graph showing the relationship between the length of the connection pipe (liquid connection pipe and gas connection pipe) and the necessary refrigerant amount during cooling and heating operations. As is clear from FIG. 4, the required refrigerant amount with respect to the length of the liquid connection pipe 6 and the gas connection pipe 9 is larger in the heating operation than in the cooling operation. This means that the proper amount of refrigerant should be determined during heating. In other words, the appropriate amount of refrigerant should be determined based on the heating operation. When determining the amount of refrigerant from the operating state of the refrigeration cycle, operation of all units used, constant compressor rotation control, and outdoor heat exchange superheat degree It is desirable to perform constant control by heating operation.

  In addition, when the refrigerant | coolant is not beforehand filled into the heat-source unit 1, it is necessary to fill with a refrigerant | coolant until it becomes the refrigerant | coolant amount of the grade which can perform a refrigerating cycle driving | operation before the process of said step S11.

  Next, a detailed control method of the automatic refrigerant charging operation will be described.

<Constant piping refrigerant density control>
The liquid connection pipe 6 and the gas connection pipe 9 are refrigerant pipes that are constructed on site when the refrigeration cycle apparatus is installed, and the installation conditions such as the installation location and the combination of the heat source unit 301 and the utilization units 302a and 302b. Those having various lengths and tube diameters are used. For this reason, for example, when a new refrigeration cycle apparatus is newly installed, it is necessary to accurately grasp information such as the length and pipe diameter of the liquid connection pipe 6 and the gas connection pipe 9 in order to calculate the appropriate refrigerant charging amount. However, the information management and the calculation of the refrigerant amount are complicated. In addition, when the usage units 302a and 302b and the heat source unit 301 are updated using existing piping, information such as the length and diameter of the liquid connection piping 6 and the gas connection piping 9 may be lost. is there.

  Therefore, even when the length and the pipe diameter of the liquid connection pipe 6 and the gas connection pipe 9 are unknown, it is necessary to be able to enclose a certain amount of refrigerant according to the connection pipe length and pipe diameter. This can be achieved by controlling the refrigerant density of the connecting pipe 6 and the gas connecting pipe 9 at a constant level.

  FIG. 5 shows the condensation temperature at which the refrigerant density of the liquid connection pipe and the gas connection pipe becomes constant when the pipe diameter of the liquid connection pipe is fixed and the gas pipe diameter of the gas connection pipe is changed, and the liquid temperature at the outlet of the condenser. It is a graph which shows the relationship. As apparent from FIG. 5, when the condensing temperature and the liquid temperature are equal (dashed line in the figure), the degree of supercooling becomes zero and cannot be secured. The larger the pipe diameter of the gas connection pipe 9 relative to the pipe diameter of the liquid connection pipe 6, the smaller the slope of the straight line having the same density. This is because, for example, when the liquid pipe temperature rises and the refrigerant density of the liquid connection pipe 6 decreases, the density of the gas connection pipe 9 needs to be increased, so the condensation temperature must be increased and the pressure increased. However, the larger the pipe diameter of the gas connection pipe 9 is relative to the pipe diameter of the liquid connection pipe 6, the smaller the increase in the condensation temperature may be.

  As described above, it is possible to determine the excess or deficiency of the refrigerant from the state of the refrigeration cycle even when the length and the diameter of the connection pipe such as the existing pipe are unknown. In this case, it is indispensable to improve the accuracy of determining the amount of refrigerant that the refrigeration cycle is the same regardless of the length and diameter of the connecting pipe, and it is necessary to eliminate the influence of the increase or decrease in the amount of refrigerant due to the connecting pipe. There is. For this purpose, the condensation temperature may be controlled to a target value according to the liquid pipe temperature at the outlet of the condenser as shown in FIG. 5 by combining the liquid connection pipe 6 and the gas connection pipe 9. Here, as a method of bringing the condensation temperature closer to the desired condensation temperature, the number of revolutions of the compressor 1 is controlled, and when it is smaller than the target value, the number of revolutions is increased to increase the condensation temperature. If it is high, it can be controlled by reducing the number of revolutions and lowering the condensation temperature.

  The target value of the condensation temperature relative to the liquid pipe temperature is determined by inputting the pipe diameter of the liquid connection pipe 6 and the pipe diameter of the gas connection pipe 9 at the time of construction, and determining the slope and intercept of the relationship between the condensation temperature and the liquid pipe temperature. However, since the control target value may be determined, the combination of the standard liquid connection pipe 6 and the gas connection pipe 9 defined for each capacity of the heat source unit 301 based on the capacity information of the heat source unit 301 is complicated. Thus, setting the condensation temperature target value in accordance with the liquid pipe temperature makes the operation simpler and eliminates the need for complicated operations for the operator, improving operability.

  In addition, although it is set as the structure which controls the rotation speed of a compressor here by setting the condensation temperature determined according to the liquid pipe temperature of a condenser exit to a target value, the gas connection piping 9 according to the liquid pipe temperature of a condenser outlet The high pressure of the refrigerant inside may be directly controlled. As a method for detecting the high pressure, for example, a pressure sensor (not shown) may be added to the discharge side of the compressor 1 to detect the high pressure of the refrigerant.

<Heat source unit refrigerant density constant control>
Assuming that the refrigerant existing in the liquid connection pipe 6 and the gas connection pipe 9 is filled in accordance with the length and diameter of the pipe, the internal volume of the heat source unit 301 is set to VOC and the utilization unit 302a as shown in FIG. When the total internal volume of 302b is VIC, the following equation (2) is established during the heating operation.

[Equation 2]
ρe × VOC + ρc × VIC = M (Constant) ………………………………………………………………………………………… (2)

Here, ρe represents the evaporation side average refrigerant density [kg / m ³ ], ρc represents the condensation side average refrigerant density [kg / m ³ ], and M represents the total refrigerant amount [kg] on the condensation side and the evaporation side. In the equation (2), M is a value determined by the internal volume of the heat source unit 301 and the total internal volume of the utilization units 302a and 302b, but is a constant value if the appropriate refrigerant amount is determined. VOC varies depending on the capacity of the heat source unit 301. However, if the value of ρe is controlled to be constant and the amount of refrigerant existing in the heat source unit 301 is kept constant, the VIC determined by the number and volume of connected utilization units is unknown. Even if it exists, it will suffice if the refrigerant is charged with ρc as an appropriate refrigerant amount as a target value.

  Next, a method of controlling ρe to be constant, that is, the amount of refrigerant present in the heat source unit 301 to be constant will be described. The heat source unit 301 is an evaporator, and the amount of refrigerant present in the evaporator can be adjusted by changing the opening degree of the throttle means 5a. FIG. 7 shows the degree of superheat of the outlet of the outdoor heat exchanger 3, that is, the suction of the compressor 1, when the outside air temperature is taken on the horizontal axis and the refrigerant density in the heat source unit 301 is constant (the amount of refrigerant present is constant). It is. As is clear from FIG. 7, in order to make the refrigerant density of the heat source unit 301 constant, it is understood that the degree of superheat should be controlled according to the outside air temperature. In addition, the higher the outside air temperature is, the higher the degree of superheat needs to be controlled. This is because the higher the outside air temperature, the higher the evaporation temperature, and the average density of the gas-liquid two-phase part of the refrigerant increases. This is because it needs to be constant.

  Therefore, in order to control the refrigerant density of the heat source unit 301 to be constant, the target value of the suction superheat degree of the compressor shown in FIG. 7 is set according to the temperature measured by the outdoor temperature sensor 203, and the suction superheat degree is set. What is necessary is just to control by the aperture means 5a. As a method of bringing the superheat degree of the suction of the compressor 1 close to a desired superheat degree, the opening degree of the throttle means 5a is controlled, and when the superheat degree is smaller than the target value, the opening degree is increased, If it is larger, it can be controlled by reducing the opening.

  Here, since the superheat degree of the suction of the compressor 1 can be calculated by the condensation temperature, the evaporation temperature, and the discharge temperature by the method described above, if the suction superheat degree is controlled according to the outdoor temperature sensor 203, However, the suction superheat degree may be obtained as a value obtained by subtracting the value of the liquid side temperature sensor 204 from the value of the gas side temperature sensor 202 of the outdoor heat exchanger 3. By doing so, since the refrigerant is gasified at the intermediate position of the outdoor heat exchanger 3, the average density of the heat source unit 301 is reduced, and the refrigerant is easily stored in the use units 302a and 302b. Since the degree of supercooling in the indoor heat exchangers 7a and 7b having a large correlation is easily secured, there is an effect that the amount of refrigerant can be easily detected at an early stage.

<Judgment of suitability of refrigerant amount>
FIG. 8 is an overview diagram when the refrigerant is charged. As shown in FIG. 8, a service port (not shown) in which the refrigerant cylinder 31 is installed in one of the flow paths from the throttle means 5 a of the heat source unit 301 to the suction of the compressor 1 via the charge hose 33. The refrigerant is filled in the refrigerant circuit by opening the valve 32. When the refrigerant is additionally charged, the amount of refrigerant in the refrigerant circuit gradually increases, so the amount of refrigerant in the indoor heat exchangers 7a and 7b increases, and the degree of supercooling SC at the outlets of the indoor heat exchangers 7a and 7b increases. A tendency to become larger appears.

  FIG. 9 is a diagram illustrating changes in the refrigerant temperature in the condenser. As shown in FIG. 9, the gas refrigerant temperature Tci at the condenser inlet is cooled by the condenser suction air temperature Tao, condensed by the change in latent heat at the condensation temperature Tc, and further cooled and liquid refrigerant temperature Tco at the condenser outlet. It becomes. Here, the degree of supercooling SC is a value obtained by subtracting the condenser outlet refrigerant temperature Tco from the condensation temperature Tc.

  From this temperature change, it can be seen that there is a correlation between the amount of refrigerant at the outlets of the indoor heat exchangers 7a and 7b, that is, the average refrigerant density of the condenser and the degree of supercooling SC representing the amount occupied by the liquid phase.

  FIG. 10 shows the relationship between the refrigerant supercooling degree SC and the average refrigerant density in the condenser, that is, the indoor and outdoor air conditions, and the refrigerant quantity is increased by 10% with respect to the refrigerant quantity and the refrigerant quantity. It is a graph which shows the relationship between supercooling degree SC at the time of heating, and the average refrigerant density (rho) c of a condenser. As shown in FIG. 10, the coefficient of determination R2 representing the correlation between the degree of supercooling SC and the average refrigerant density ρc of the condenser is 0.65, which indicates that the correlation is high.

  Therefore, the value of the degree of supercooling SC at the outlets of the indoor exchangers 7a and 7b corresponding to the average refrigerant density ρc of the condenser when the refrigeration cycle apparatus is operated in the above-described refrigerant automatic charging operation mode with the specified refrigerant amount (hereinafter referred to as “refrigeration cycle device”). If this is referred to as the “reference value of the degree of supercooling SC” in the storage unit 104 in advance, the specified value of the degree of supercooling SC during the automatic refrigerant charging operation and the degree of supercooling SC detected when the refrigerant is charged. By comparing the current value with the current value, it is possible to determine whether or not the amount of refrigerant charged in the refrigerant circuit by additional charging of the refrigerant is appropriate.

  As in the present embodiment, when there are a plurality of usage units, the average value of the degree of supercooling SC of each usage unit may be used.

  Step S13 in FIG. 3 is a process for determining the suitability of the amount of refrigerant charged in the refrigerant circuit by additional charging of the refrigerant, using the correlation as described above.

  That is, when the amount of refrigerant to be additionally charged is small and the refrigerant amount in the refrigerant circuit does not reach the specified refrigerant amount, the refrigerant amount in the indoor heat exchangers 7a and 7b is small. Here, the state in which the amount of refrigerant in the indoor heat exchangers 7a and 7b is small means that the current value of the degree of supercooling SC at the outlets of the indoor heat exchangers 7a and 7b is smaller than the specified value of the degree of supercooling SC. means. For this reason, in step S13, when the value of the degree of supercooling SC at the outlets of the indoor heat exchangers 7a and 7b is smaller than the specified value and the additional charging of the refrigerant has not been completed, the process proceeds to step S15, and the abnormal Display is performed, and the process returns to step S11.

  Then, the process of step S13 is repeated until the current value of the degree of supercooling SC reaches a specified value. When the current value of the degree of supercooling SC reaches the specified value, the additional charging of the refrigerant is completed and the automatic refrigerant charging operation mode is terminated. Note that there may be a case where the specified refrigerant amount calculated from the pipe length, the capacity of the constituent devices, and the like at the site does not match the initial refrigerant amount after completion of additional charging of the refrigerant. Therefore, in the present embodiment, the value of the degree of supercooling SC when the additional charging of the refrigerant is completed in step S14 is stored as the operation state quantity with the initial enclosed refrigerant quantity, and the supercooling in the refrigerant quantity judgment operation mode described later is performed. This is the reference value for the operating state quantity of degree SC.

  As described above, when determining the suitability of the amount of refrigerant charged in the refrigerant circuit in the automatic refrigerant charging operation, the reference value of the operation state amount at the specified refrigerant amount or the initial enclosed refrigerant amount is the storage unit 104 in FIG. And the stored reference value is compared with the current operating state quantity by the comparison unit 105, and the suitability of the refrigerant amount is determined by the determination unit 106. Based on the determination result, the notification unit 107 A process of notifying the excess or deficiency of the amount by an LED or the like is performed. FIG. 11 shows an example of the notification, in which the level of the current driving state quantity with respect to the reference value of the driving state quantity is displayed by color coding or the like.

  That is, as shown in FIG. 11, the determination method in the determination unit 106 is that the amount of refrigerant is excessive when the operation state amount representing the current refrigerant amount is greater than a certain value with respect to the reference operation state amount. If it is determined (displayed) and is smaller than a certain value with respect to the operation state amount of the reference value, it is determined (displayed) that the refrigerant amount is insufficient. Since it can output, not only the suitability of the refrigerant amount but also the excess or deficiency can be determined. Also, if the determination level is set in multiple stages according to the degree of deviation from the reference value, it is easier for the operator to recognize the current refrigerant charge state by switching the display method of the notification unit 107, Since the opening degree of the valve 32 of the refrigerant cylinder 31 shown in FIG. 8 can be adjusted according to the state, the operability is improved.

  Further, in the present embodiment, the supercooling degree SC is described as an example of the operating state amount representing the refrigerant amount, but is not limited to this, and the temperature efficiency SC / dTc representing the heat exchange efficiency of the liquid phase portion of the condenser. Where dTc is a value obtained by subtracting the condenser intake air temperature Tao from the condensation temperature Tc. Generally, the refrigerant density increases as the refrigerant mass velocity decreases, so the temperature efficiency increases as the refrigerant mass velocity decreases. Therefore, the higher the density of the refrigerant, the higher the temperature efficiency. Therefore, the temperature efficiency SC / dTc of the liquid phase part may be adopted as the refrigerant quantity, that is, the operation state quantity representing the refrigerant density.

  FIG. 12 shows the average refrigerant concentration and the temperature efficiency SC / dTc of the liquid phase when the indoor and outdoor air conditions are changed to increase the refrigerant amount by 10% with respect to the appropriate refrigerant amount. It is a graph which shows the relationship with refrigerant density (rho) c. As shown in FIG. 12, the coefficient of determination R2 representing the correlation between the temperature efficiency SC / dTc of the liquid phase part and the average refrigerant density ρc of the condenser is 0.87, which is higher than when the supercooling degree SC is employed. Since the correlation is high, determination with higher detection accuracy is possible.

  In the present embodiment, the valve 32 of the refrigerant cylinder 31 and the heat source unit 301 are connected via the charge hose 33 when the refrigerant is additionally charged as shown in FIG. 8, but the charge hose 33 is shown in FIG. The throttle means 34 is connected in the middle of the flow path from the heat source unit 301 to the heat source unit 301, and in the process of additional refrigerant charging, the reference value of the operating state quantity at the current refrigerant amount and the operating state quantity at the specified refrigerant amount And the opening degree of the throttle means 34 is controlled via the control unit 103 in accordance with the degree of deviation from the reference value in the determination unit 106, with respect to the reference value of the operating state amount at the specified refrigerant amount. When the operating state amount of the current refrigerant amount is small, the opening of the throttle means 34 is opened, and when the current refrigerant amount approaches the specified refrigerant amount, the opening degree of the throttle means 34 is reduced. Refrigerant charging speed Since Dekiru small, the operation state of the refrigeration cycle tends to stabilize, it becomes possible more accurately fill the proper refrigerant quantity, the operator, the operability is improved because the need to adjust the opening degree of the valve 32 is eliminated.

  Further, in the process of additional charging of the refrigerant, when the operation state quantity at the current refrigerant amount and the reference value of the operation state quantity at the specified refrigerant amount come close to each other, the rotational speed of the compressor 1 is reduced or stopped. Since the low-pressure side pressure of the refrigeration cycle apparatus increases, the differential pressure between the internal pressure in the refrigerant cylinder and the refrigerant suction pressure of the refrigeration cycle apparatus decreases, and the refrigerant charging speed into the refrigeration cycle apparatus decreases. By controlling in this way, it is possible to prevent an excessive amount of refrigerant from flowing into the refrigeration cycle apparatus, and more accurate filling and determination of the appropriate refrigerant amount are possible.

  Further, as shown in the refrigerant circuit diagram of FIG. 14, by providing a bypass circuit 12 from the high pressure side of the discharge of the compressor 1 to the low pressure side of the suction of the compressor 1 and providing a throttle means 5c in the flow path, In the process of additional charging of the refrigerant, when the operation state quantity at the current refrigerant amount and the reference value of the operation state quantity at the specified refrigerant amount are close to each other, the opening degree of the throttle means 5c is increased to thereby increase the refrigeration cycle apparatus. Therefore, the pressure difference between the internal pressure in the refrigerant cylinder and the refrigerant suction pressure of the refrigeration cycle apparatus is reduced, and the refrigerant charging speed into the refrigeration cycle apparatus is reduced. By controlling in this way, it is possible to prevent an excessive amount of refrigerant from flowing into the refrigeration cycle apparatus, so that more accurate filling and determination of the appropriate refrigerant amount can be performed.

<Refrigerant amount judgment operation mode>
Next, the operation in the refrigerant quantity determination operation mode will be described with reference to FIG. FIG. 15 is a flowchart showing the operation in the refrigerant quantity determination operation mode. In this example, the case where it is detected periodically whether the refrigerant leaks from the refrigerant circuit due to an unforeseen cause at regular intervals (for example, when it is not necessary to perform air conditioning during holidays or late at night) is taken as an example. I will give you a description.

  First, when the operation in the normal operation mode such as the cooling operation and the heating operation described above has passed for a certain time (for example, half a year to one year), the operation mode is automatically or manually switched from the normal operation mode to the refrigerant amount determination operation mode. Similarly to the automatic refrigerant charging operation mode performed at the time of initial installation, the refrigerant quantity determination operation for heating operation is started in the usage unit total number operation (step S21).

  Next, in step S22, environmental conditions such as indoor / outdoor air temperatures and the operating states of the refrigeration cycle of the heat source unit 301 and the utilization units 302a and 302b are measured. Next, in step S23, the reference value of the operating state quantity stored as the initial amount of refrigerant charged at the time of installation is compared with the current operating state quantity. If the degree of deviation from the reference value is large, the refrigerant leaks and the refrigerant quantity Is determined to be insufficient, a refrigerant leak or a refrigerant shortage abnormality is notified in step S25, and the process returns to step S21. If it is determined in step S23 that the deviation from the reference value is small, since there is no refrigerant leakage and it is normal, it is notified in step S24 that it is normal, and the operation is terminated.

  As described above, the refrigeration cycle apparatus according to the present embodiment also includes a refrigerant amount determination function for determining the suitability of the refrigerant amount charged in the refrigerant circuit after the refrigerant is charged.

  In addition, in the refrigerant automatic charging operation mode and the refrigerant amount determination operation mode, the outdoor fan 4 of the heat source unit 301 and the blower amounts of the indoor fans 8a and 8b of the utilization units 302a and 302b are the refrigerant charging operation mode and the refrigerant amount determination operation mode. It is preferable to always set and fix the same air flow rate. In this case, the refrigeration cycle is stabilized, and it is possible to determine the suitability of the refrigerant amount more accurately.

  In addition, a local controller is connected to the refrigeration cycle apparatus as a management apparatus that manages each component device and obtains operation data by communicating with the outside such as a telephone line, a LAN line, and wireless communication. A refrigerant quantity determination system is configured by connecting via a network to a remote server of the information management center that receives the operation data of the cycle device, and connecting a storage device such as a disk device that stores the operation state quantity to the remote server. May be. For example, the local controller is used as a measurement unit that acquires the operation state quantity of the refrigeration cycle device and a calculation unit that calculates the operation state quantity, the storage device is used as the storage unit, and the remote server is functioned as a comparison unit, a determination unit, and a notification unit. Such a configuration is conceivable. In this case, it is not necessary for the refrigeration cycle apparatus to have a current operation state quantity, a reference value for the operation state quantity, and a function for comparing operations. In addition, by configuring a system that can be remotely monitored in this way, it is not necessary for the operator to visit the site to check the suitability of the refrigerant amount during regular maintenance, thereby improving the reliability and operability of the equipment. .

The above is a description of the refrigerant that is in a two-phase state during the condensation process. If the refrigerant in the refrigeration cycle is a high-pressure refrigerant such as CO ₂ and changes its state at a pressure above the supercritical point, FIG. As shown, since there is no saturation temperature, the average refrigerant density ρc of the gas cooler is expressed as a function of the high pressure side pressure Pd and the refrigerant temperature Tco at the gas cooler outlet (ie, ρc = f (Pd, Tco)). In the same way, when the refrigerant leaks, ρc becomes small, so that it is possible to determine the refrigerant leak even for a refrigerant whose condensation pressure exceeds the critical pressure.

  Note that the method of estimating the average density ρc of the refrigerant in the gas cooler is not limited to the above method, and the average refrigerant density of the gas cooler may be estimated as a function of the gas cooler inlet temperature Tci and the gas cooler intake air temperature Tao. Thus, the estimation accuracy of the density of the refrigerant is improved by increasing the parameters.

  While the present embodiment has been described with reference to the drawings, the specific configuration is not limited to this and can be changed without departing from the scope of the invention. For example, in the above-described embodiment, an example in which the present invention is applied to a refrigeration cycle apparatus capable of switching between cooling and heating has been described as an example, but the present invention is not limited to this, and a refrigeration cycle apparatus dedicated to heating, a refrigeration cycle apparatus dedicated to cooling, The present invention may be applied to a refrigeration cycle apparatus capable of simultaneous cooling and heating. Further, the present invention may be applied to a small refrigeration cycle apparatus such as a room air conditioner or a refrigerator for home use, or a large refrigeration cycle apparatus such as a refrigerator or a heat pump chiller for cooling in a refrigerated warehouse.

  In addition, refrigeration using an injection-type compressor that bypasses the liquid refrigerant having a low enthalpy after passing through the condenser to the compressor in order to suppress an increase in compressor discharge temperature due to a high compression ratio operation from the use environment conditions during normal operation. The present invention can also be applied to a cycle device.

  In the above-described embodiment, the example in which the present invention is applied to the refrigeration cycle apparatus including one heat source unit has been described as an example. However, the present invention is not limited thereto, and the refrigeration apparatus includes a plurality of heat source units. The present invention may be applied to a cycle device.

  Further, in the above-described embodiment, the example in which the present invention is applied to the refrigeration cycle apparatus that performs the heating operation has been described as an example, but the use side heat exchanger serves as an evaporator, and the heat source side heat exchanger serves as a condenser. The refrigerant amount may be determined by applying the present invention in the cooling operation. In this case, since the inside of the liquid connection pipe 6 becomes a two-phase refrigerant as compared with the heating operation, if the refrigerant density error is large and the pipe length is long, the detection accuracy is slightly lowered, but the refrigerant circuit is filled. Appropriateness of the refrigerant amount can be determined.

Embodiment 2. FIG.
FIG. 17 is a refrigerant circuit diagram schematically showing a refrigeration cycle apparatus according to Embodiment 2 of the present invention. In the figure, the same parts as those in Embodiment 1 are given the same reference numerals.

  As shown in FIG. 17, the refrigeration cycle apparatus of the present embodiment is provided with a receiver 20 for accumulating an excess refrigerant amount, which is the difference between the required refrigerant amounts for cooling and heating, after the throttling means 5a, and the receiver 20 and the liquid connection piping. The expansion means 5b is newly added between the six flow paths, and it is suitable for a refrigeration cycle apparatus that has a long connection pipe length in the field and generates a large amount of surplus refrigerant due to the difference between cooling and heating. is there. Other configurations are the same as those of the first embodiment.

  In the refrigeration cycle apparatus of the present embodiment, since there is a portion in which the liquid refrigerant is stored in the refrigeration cycle, the opening of the throttle means 5a is opened during the above-described refrigerant automatic charging operation mode and refrigerant amount determination operation mode. Then, the opening of the throttle means 5b is throttled, the operation of controlling the degree of superheat of the suction portion of the compressor 1 is performed, and the operation of storing the excess refrigerant in the receiver 20 in the indoor heat exchangers 7a and 7b is performed. By controlling in this way, the refrigeration cycle becomes the same refrigerant circuit as that of the first embodiment. As a result, when the amount of refrigerant is smaller than the specified amount of refrigerant, the degree of supercooling of the condenser or the temperature efficiency of the condenser liquid phase is reduced, so the average refrigerant density of the condenser is calculated from the operating state quantity of the refrigeration cycle. Can be estimated. Therefore, when the refrigerant of the refrigeration cycle apparatus is additionally charged, even if the receiver 20 is a model, the accuracy can be obtained regardless of installation conditions and environmental conditions without using a specific detection device that detects the liquid level. It is possible to determine whether the refrigerant amount is appropriate. Further, during normal operation, by periodically performing the operation in the refrigerant amount determination operation mode, refrigerant leakage can be detected at an early stage, and failure of the device can be prevented.

Embodiment 3 FIG.
FIG. 18 is a refrigerant circuit diagram schematically showing a refrigeration cycle apparatus according to Embodiment 3 of the present invention. In the figure, the same parts as those in Embodiment 1 are given the same reference numerals.

  As shown in FIG. 18, the refrigeration cycle apparatus according to the present embodiment is provided with an accumulator 11 at the suction portion of the compressor 1, and is configured to accumulate in the accumulator 11 an excess refrigerant amount that is the difference between the required refrigerant amounts for cooling and heating. Therefore, it is suitable for a refrigeration cycle apparatus of a type that has a long connecting pipe length in the field and generates a large amount of surplus refrigerant due to the difference between cooling and heating. Other configurations are the same as those of the first embodiment.

  When the accumulator 11 is present, it is necessary to perform an operation in which the liquid refrigerant is not accumulated in the accumulator 11, so that the outdoor heat exchanger 3 has a sufficient degree of superheat in the automatic refrigerant charging operation mode and the refrigerant amount determination operation mode. The operation of restricting the expansion means 5a so as to be secured is performed, and the operation of storing the excess refrigerant in the accumulator 11 in the indoor heat exchangers 7a and 7b is performed. By controlling in this way, the refrigeration cycle becomes the same refrigerant circuit as that of the first embodiment. As a result, when the amount of refrigerant is smaller than the specified amount of refrigerant, the degree of supercooling of the condenser or the temperature efficiency of the condenser liquid phase is reduced, so the average refrigerant density of the condenser is calculated from the operating state quantity of the refrigeration cycle. Can be estimated. Therefore, when the refrigerant of the refrigeration cycle apparatus is additionally charged, even if the accumulator 11 is a model, the accuracy can be improved under any installation condition or environmental condition without using a specific detection device that detects the liquid level. It is possible to determine whether the refrigerant amount is appropriate. Further, during normal operation, by periodically performing the operation in the refrigerant amount determination operation mode, refrigerant leakage can be detected at an early stage, and failure of the device can be prevented.

Embodiment 4 FIG.
FIG. 19 is a refrigerant circuit diagram schematically showing a refrigeration cycle apparatus according to Embodiment 4 of the present invention. In the figure, the same parts as those in Embodiment 1 are given the same reference numerals.

  As shown in FIG. 19, the refrigeration cycle apparatus of the present embodiment is provided with a pressure sensor 400 that detects high pressure at the discharge portion of the compressor 1, and the usage unit 302 a is an indoor refrigerant circuit that is part of the refrigerant circuit. A plate-type heat exchanger 401 that is a use-side heat exchanger, and a fluid inlet temperature sensor 402 that detects the temperature before and after heat exchange of the fluid that exchanges heat with the refrigerant flowing in the plate-type heat exchanger; And a fluid outlet temperature sensor 403. Other configurations are the same as those of the first embodiment.

  Here, the fluid that exchanges heat with the refrigerant flowing in the plate heat exchanger 401 is a heat absorption target of the condensation heat of the refrigerant, and this may be water, refrigerant, brine, or the like. A compressor or a pump may be used. Further, the plate heat exchanger 401 is not limited to this form, and may be a double pipe heat exchanger, a microchannel, or the like as long as heat can be exchanged between the refrigerant and the fluid.

  Even in this refrigerant circuit configuration, the throttle means 5a is operated so that the degree of superheat can be sufficiently secured in the outdoor heat exchanger 3 during the above-described refrigerant automatic charging operation mode and refrigerant quantity determination operation mode, and the refrigerant is platen. The operation of storing in the heat exchanger 401 is performed. By controlling in this way, the refrigeration cycle becomes the same refrigerant circuit as that in the first embodiment. As a result, when the amount of refrigerant is small relative to the specified amount of refrigerant, the degree of supercooling at the outlet of the plate heat exchanger or the temperature efficiency of the condenser liquid phase decreases, so the average refrigerant density of the condenser is reduced to that of the refrigeration cycle. It can be estimated from the amount of driving state. Therefore, the suitability of the refrigerant amount can be accurately determined regardless of the installation conditions and environmental conditions regardless of the refrigerant circuit configuration of the refrigeration cycle apparatus. Further, during normal operation, by periodically performing the operation in the refrigerant amount determination operation mode, refrigerant leakage can be detected at an early stage, and failure of the device can be prevented. Here, the temperature difference dTc between the refrigerant and the fluid in calculating the temperature efficiency is the average temperature of the refrigerant (fluid inlet temperature Twi + fluid outlet) from the refrigerant condensation temperature Tc converted from the pressure sensor 400 as shown in FIG. It can be calculated by subtracting the temperature Two) / 2. In FIG. 19, the relationship between the flow of the refrigerant and the fluid is shown as a parallel flow, but it may be a counter flow.

Embodiment 5 FIG.
FIG. 20 is a refrigerant circuit diagram schematically showing a refrigeration cycle apparatus according to Embodiment 5 of the present invention. In the figure, the same parts as those in Embodiment 4 are given the same reference numerals.

  As shown in FIG. 20, the refrigeration cycle apparatus of the present embodiment excludes the liquid temperature sensor 205a shown in the fourth embodiment. Other configurations are the same as those in the fourth embodiment.

  As shown in FIG. 21, when the fluid that exchanges heat with the refrigerant is water, refrigerant, brine, or the like, the heat is compared to the heat exchange mode using fin-and-tube type air as the medium shown in the first embodiment. Since the passage rate is increased by about 20 times or more, in the case of a parallel flow, it may be assumed that the refrigerant temperature Tsc at the outlet of the plate heat exchanger is substantially equal to the fluid outlet temperature Two. Therefore, the subcooling degree or the temperature efficiency of the condenser liquid phase can be calculated by substituting the refrigerant temperature Tsc at the outlet of the plate heat exchanger with the fluid outlet temperature Two. Thus, since the liquid side temperature sensor 205a shown in Embodiment 4 is not necessary, the cost for the liquid side temperature sensor 205a can be reduced, and any installation condition can be achieved regardless of the refrigerant circuit configuration of the refrigeration cycle apparatus. Even under environmental conditions, it is possible to accurately determine the appropriateness of the refrigerant amount at low cost.

Embodiment 6 FIG.
FIG. 22 is a refrigerant circuit diagram schematically showing a refrigeration cycle apparatus according to Embodiment 6 of the present invention. In the figure, the same parts as those in Embodiment 1 described above are denoted by the same reference numerals.

  As shown in FIG. 22, the refrigeration cycle apparatus of the present embodiment is provided with a receiver 20 between the liquid side temperature sensor 204 and the outdoor heat exchanger 3 shown in Embodiment 1, and the receiver 20 and the liquid side temperature sensor. 204, a refrigerant-refrigerant heat exchanger 209 is provided between the high-pressure side refrigerant-refrigerant heat exchanger 209, the refrigerant after passing through the high-pressure side refrigerant-refrigerant heat exchanger is decompressed by the throttle means 5d, and the low-temperature and low-pressure refrigerant flows through the refrigerant-refrigerant heat exchanger. Provided with a bypass circuit that increases the cooling capacity by increasing the degree of supercooling of the refrigerant after passing, the refrigerant-refrigerant heat exchanger inlet temperature sensor 208 and the refrigerant-refrigerant heat exchanger outlet temperature before and after the refrigerant-refrigerant heat exchanger 210 A sensor 209 is provided. Other configurations are the same as those of the first embodiment.

  Even in this refrigerant circuit configuration, the throttle means 5a is throttled so that the degree of superheat can be sufficiently secured by the indoor heat exchangers 207a and 207b in the above-described refrigerant automatic charging operation mode and refrigerant quantity determination operation mode in the cooling operation. So that the degree of superheat calculated by subtracting the temperature detected by the refrigerant-refrigerant heat exchanger inlet temperature sensor 208 from the temperature detected by the refrigerant-refrigerant heat exchanger outlet temperature sensor 209 can be ensured. By performing the operation with the throttle means 5c being throttled, the operation for storing the refrigerant in the outdoor heat exchanger 3 or the receiver 20 is performed. At this time, the subcooling degree of the refrigerant-refrigerant heat exchanger can be calculated by subtracting the liquid side temperature sensor 204 from the condensation temperature detected by the gas side temperature sensor 202, and the temperature efficiency in the refrigerant-refrigerant heat exchanger is The degree of supercooling can be calculated by dividing the condensing temperature by the temperature difference from the refrigerant-refrigerant heat exchanger low pressure inlet temperature sensor 208. When the amount of refrigerant is less than the appropriate amount of refrigerant, the degree of supercooling or temperature efficiency at the high-pressure side outlet of the refrigerant-refrigerant heat exchanger 210 decreases, so the average refrigerant density of the condenser is estimated from the operating state quantity of the refrigeration cycle. be able to. Therefore, the suitability of the refrigerant amount can be accurately determined regardless of the installation conditions and environmental conditions regardless of the refrigerant circuit configuration of the refrigeration cycle apparatus. Further, during normal operation, by periodically performing the operation in the refrigerant amount determination operation mode, refrigerant leakage can be detected at an early stage, and failure of the device can be prevented.

  In the present embodiment, the refrigerant circuit configuration in which the receiver 20 is provided is shown, but the present invention may be applied to a refrigeration cycle apparatus without the receiver 20. Moreover, the refrigerant | coolant-refrigerant heat exchanger 210 shown in FIG. 22 can consider a plate type heat exchanger, a double pipe | tube type heat exchanger, etc.

  If the present invention is used, in the refrigeration cycle apparatus in which the heat source unit and the utilization unit are connected via the connection pipe, the amount of refrigerant charged in the field varies, and the pipe length and pipe diameter of the refrigerant communication pipe Even if there is a change in the reference value of the operating state quantity used for determining the suitability of the specified refrigerant amount due to the combination of the use units having a plurality of capacities, the suitability of the refrigerant amount charged in the apparatus is determined. Judgment can be made with high accuracy.

It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 1 of the present invention. It is another refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 1 of the present invention. It is an operation | movement flowchart at the time of refrigerant | coolant filling of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a graph which shows the relationship between the connection piping length of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention, and the refrigerant | coolant amount required at the time of air_conditioning | cooling and heating operation. It is a graph which shows the relationship between the condenser exit temperature and condensation temperature in which the refrigerant density of the connection piping of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention becomes constant. It is a ph diagram of the refrigerating cycle device concerning Embodiment 1 of the present invention. It is a graph which shows the relationship between external temperature and superheat degree when the refrigerant density of the heat-source unit of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention becomes fixed. It is a general-view figure at the time of refrigerant | coolant filling of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a figure showing the change of the refrigerant | coolant temperature in the condenser of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a graph which shows the relationship between the supercooling degree SC of the refrigerant | coolant of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention, and the average refrigerant density in a condenser. It is a figure which shows the relationship of the alerting | reporting level of the present operation state quantity with respect to the reference value of the operation state quantity of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a graph which shows the relationship between the temperature efficiency SC / dTc of the liquid phase part of the condenser of the refrigerating cycle device concerning Embodiment 1 of the present invention, and the average refrigerant density in a condenser. It is another general-view figure at the time of refrigerant | coolant filling of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. FIG. 5 is still another refrigerant circuit diagram of the refrigeration cycle apparatus according to Embodiment 1 of the present invention. It is an operation | movement flowchart at the time of refrigerant | coolant amount determination of the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. It is a p-h diagram in the case of using a higher pressure refrigerant (CO ₂₎ in a refrigeration cycle apparatus according to a first embodiment of the present invention. It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 2 of the present invention. It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 3 of the present invention. It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 4 of the present invention. It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 5 of the present invention. It is a figure showing the temperature change of the refrigerant | coolant and fluid in the plate type heat exchanger of the refrigerating-cycle apparatus which concerns on Embodiment 4 and 5 of this invention. It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 6 of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Four way valve, 3 Outdoor heat exchanger, 4 Outdoor blower, 5a, 5b, 5c, 5d Restriction means, 6 liquid connection piping, 7a, 7b Indoor heat exchanger, 8a, 8b Indoor blower, 9 Gas connection Piping, 11 Accumulator, 12 Bypass circuit, 20 Receiver, 31 Refrigerant cylinder, 32 Valve, 33 Charge hose, 34 Throttle means, 101 Measuring unit, 102 Calculation unit, 103 Control unit, 104 Storage unit, 105 Comparison unit, 106 Determination unit 107 Notification unit 201 Compressor discharge temperature sensor 202 Gas side temperature sensor 203 Outdoor temperature sensor 204 Liquid side temperature sensor 205a 205b Liquid side temperature sensor 206a 206b Indoor temperature sensor 207a 207b Gas side temperature Sensor, 208 Refrigerant-refrigerant heat exchanger low pressure inlet temperature sensor, 209 Refrigerant- Medium heat exchanger low-pressure outlet temperature sensor, 210 a refrigerant - refrigerant heat exchanger 301 heat source unit, 302a, 302b utilization unit, 400 a pressure sensor, 401 plate heat exchanger, 402 fluid inlet temperature sensor, 403 fluid outlet temperature sensor.

Claims (18)

A compressor, a heat source side heat exchanger, a throttle means, and at least one usage side heat exchanger are connected with a liquid refrigerant connection pipe and a gas refrigerant connection pipe to constitute a refrigerant circuit,
Normal operation mode for controlling each device of the refrigeration cycle apparatus according to the operation load of the use side heat exchanger, and heat exchange that is an evaporator of the use side heat exchanger or the heat source side heat exchanger Operation control means for switching and operating the refrigerant amount determination operation mode for controlling the throttling means so that the degree of superheat of the refrigerant at the outlet of the condenser becomes a positive value, and in the refrigerant amount determination operation mode, the refrigerant amount The amount of refrigerant charged in the refrigerant circuit is detected by detecting the amount of operating state that varies depending on the amount of refrigerant and comparing it with the reference value of the amount of operating state stored in advance in the storage means. A refrigeration cycle apparatus comprising means for determining suitability.   A flow path switching means for the refrigerant flowing out from the compressor, wherein the operation control means causes the flow path switching means to connect the heat source side heat exchanger and the usage side heat exchanger to a condenser or an evaporator. The refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus is switchable.   Either of high pressure detection means for detecting the pressure of the refrigerant at any position in the flow path from the compressor to the throttle means or refrigerant temperature detection means for detecting the pressure of the refrigerant in the condenser by converting it from the condensation temperature. The liquid pipe temperature detecting means for detecting the liquid pipe temperature at the outlet of the use side heat exchanger, and the pressure of the refrigerant of the use side heat exchanger becomes a pressure determined according to the liquid pipe temperature. The refrigeration cycle apparatus according to claim 1, further comprising: means for controlling a rotation speed of the compressor.   The refrigeration according to any one of claims 1 to 3, wherein the liquid pipe temperature at the outlet of the condenser is estimated by a fluid temperature detecting means for detecting a temperature of a fluid to be heat-exchanged in the condenser. Cycle equipment.   5. The refrigeration cycle apparatus according to claim 4, wherein the refrigerant flowing through the condenser and the fluid that exchanges heat with the condenser are in parallel flow.   Either one of low pressure detection means for detecting the pressure of the refrigerant at any position in the flow path from the throttling means to the evaporator or low pressure refrigerant temperature detection means for detecting the evaporation temperature of the refrigerant in the evaporator; Gas pipe temperature detecting means for detecting the gas pipe temperature at the evaporator outlet, and means for controlling the opening area of the throttle means so that the degree of superheat of the refrigerant at the evaporator outlet becomes a predetermined value according to the evaporation temperature And a refrigeration cycle apparatus according to any one of claims 1 to 5.   The means for determining the suitability of the refrigerant quantity compares the operation state quantity calculated in the past with the operation state quantity which is a current calculation value, and judges refrigerant leakage from the change. The refrigeration cycle apparatus according to any one of claims 1 to 6.   After the apparatus is installed, the initial refrigerant is calculated by calculating the operating state quantity and comparing the newly calculated value with a value stored in advance or a value calculated based on a value stored in advance. The refrigeration cycle apparatus according to any one of claims 1 to 7, further comprising means for determining whether the amount is excessive or insufficient.   The throttling means is disposed on both sides of the receiver in the refrigerant circuit, and the means for determining the suitability of the refrigerant amount is based on the opening area of one throttling means located downstream of the refrigerant flow. A special operation mode in which excess refrigerant in the receiver is moved into the condenser so that the outlet refrigerant of the receiver is in a two-phase state with a smaller opening area than the other throttle means located on the upstream side. The refrigeration cycle apparatus according to any one of claims 1 to 8, wherein the refrigeration cycle apparatus is provided.   An accumulator is provided between the condenser and the compressor, and the means for determining the suitability of the refrigerant amount controls the throttling means so that the refrigerant flowing into the accumulator is a gas refrigerant, and the accumulator The refrigeration cycle apparatus according to any one of claims 1 to 8, further comprising a special operation mode in which the excess refrigerant is moved into the condenser.   The refrigeration cycle apparatus according to claim 9 or 10, wherein the means for determining the suitability of the refrigerant amount has a function of entering the special operation mode at regular intervals.   The refrigeration cycle apparatus according to claim 9 or 10, wherein the means for determining the suitability of the refrigerant amount has a function of entering the special operation mode by an operation signal from the outside.   The storage means is a memory in a substrate inside the apparatus, a memory attached to the compressor, or a memory in a device that is installed outside the apparatus and is connected to the apparatus by wire or wirelessly, and is composed of a rewritable memory. The refrigeration cycle apparatus according to any one of claims 1 to 12, characterized in that.   The operating state quantity is a temperature difference between the condensation temperature converted from the pressure of the flow path from the compressor to the throttle means and the temperature of the outlet refrigerant of the condenser detected by the liquid pipe temperature detection means. The refrigeration according to any one of claims 1 to 13, wherein the refrigeration is divided by a temperature difference between the condensing temperature and a temperature of a fluid that absorbs heat of the refrigerant flowing in the condenser. Cycle equipment.   The refrigeration cycle apparatus according to any one of claims 1 to 14, wherein a refrigerant accompanied by a change in physical properties in a supercritical region is used. In a control method for a refrigeration cycle apparatus, in which a compressor, a heat source side heat exchanger, a throttle means, and at least one usage side heat exchanger are connected by a liquid refrigerant connection pipe and a gas refrigerant connection pipe to constitute a refrigerant circuit,
At the time of adjusting the amount of refrigerant, a flow rate adjusting means is provided at the position of the flow path from the refrigerant cylinder filled with the additional charging refrigerant to the refrigerant circuit to the air-conditioning refrigeration cycle apparatus, and the amount of refrigerant is adjusted according to the amount of refrigerant at the time of adjusting the amount of refrigerant. When the operating state quantity is detected and the operating state quantity comes close to the reference value stored in the storage means, the flow rate adjusting means causes the refrigerant filling speed from the refrigerant cylinder to the refrigeration cycle apparatus. A control method for a refrigeration cycle apparatus, wherein the refrigeration cycle apparatus is reduced. In a control method for a refrigeration cycle apparatus, in which a compressor, a heat source side heat exchanger, a throttle means, and at least one usage side heat exchanger are connected by a liquid refrigerant connection pipe and a gas refrigerant connection pipe to constitute a refrigerant circuit,
When the operating state quantity that fluctuates in accordance with the change in the refrigerant quantity when the refrigerant is charged is detected and the operating state quantity comes close to the reference value stored in the storage means, the rotational speed of the compressor is reduced or stopped. A method for controlling a refrigeration cycle apparatus, comprising: reducing a refrigerant charging speed from a refrigerant cylinder filled with a refrigerant for additional charging to the refrigeration cycle apparatus. In a control method for a refrigeration cycle apparatus, in which a compressor, a heat source side heat exchanger, a throttle means, and at least one usage side heat exchanger are connected by a liquid refrigerant connection pipe and a gas refrigerant connection pipe to constitute a refrigerant circuit,
A bypass refrigerant circuit on a high pressure side and a low pressure side of the refrigerant circuit, and a flow rate adjusting means in a flow path of the bypass refrigerant circuit, detecting an operating state amount that varies according to a variation in the refrigerant amount when the refrigerant is charged; When the operating state quantity is close to the reference value stored in the storage means, the opening degree of the flow rate adjusting means is increased so that the refrigerant cylinder filled with the additional charging refrigerant is supplied to the refrigeration cycle apparatus. A control method for a refrigeration cycle apparatus, characterized by reducing a refrigerant charging speed.

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