JP7258616B2 - chiller unit - Google Patents

Description

The present invention relates to chiller units.

A chiller unit includes one or more refrigeration cycles and produces cold or hot water by exchanging heat between a refrigerant and water in a water heat exchanger connected to the refrigeration cycles. The generated cold water or hot water is led to the outside and used for indoor air conditioning and hot water supply.

The heat exchanger of the chiller unit is configured to allow heat exchange between the refrigerant circulating in the refrigerating cycle and the water flowing in the water pipe. In a heat exchanger, heat can be exchanged more efficiently with a counter flow in which the direction of flow of the refrigerant and the direction of water are opposite to the parallel flow in which the direction of flow of the refrigerant and the direction of water are the same.

JP 2014-130003

In the refrigeration cycle of a chiller unit, the direction of refrigerant flow is opposite between cooling operation and heating operation. or a countercurrent flow.

Chiller units generally use plate heat exchangers. As a method for determining the inlet and outlet of the heat exchanger, the liquefied refrigerant of the refrigerant flowing through the refrigeration cycle flows in and out of the lower connection port of the heat exchanger, and the gasified refrigerant flows into the upper connection port of the heat exchanger. determined to flow in and out of That is, in cooling operation, since the heat exchanger functions as an evaporator, the liquid refrigerant flows in from the lower side and the gas refrigerant flows out from the upper side. In heating operation, the heat exchanger functions as a condenser, so that the gas refrigerant flows in from the upper side and the liquid refrigerant flows out from the lower side.

Therefore, it is not possible to change the connection ports for the liquid refrigerant and the gas refrigerant in the heat exchanger according to the switching of the operation of the refrigeration cycle. That is, while the flow of the water pipe remains constant, by changing the connection port of the liquid refrigerant and the gas refrigerant according to the switching of the operation of the refrigeration cycle, the flow direction of the refrigerant in the heat exchanger and the flow direction of the water pipe are changed. cannot always be countercurrent.

Therefore, in Patent Document 1, the liquid refrigerant and gas refrigerant connection ports of the refrigeration cycle are kept constant, and the flow direction of the refrigerant in the heat exchanger and the flow direction of the water pipe are changed according to the switching of the operation of the refrigeration cycle. The flow direction of the water pipe is changed so that the water always flows counter-currently. Patent Document 1 discloses that a three-way valve and a branch pipe branching from the three-way valve are installed in the water pipe to change the flow direction of the water pipe in the heat exchanger, and the three-way valve is switched.

However, in a configuration in which a three-way valve and a branch pipe are installed in the water pipe, when water flows in one direction, water flows in the branch pipe branched from the three-way valve and the main pipe, whereas water flows in one direction. When flowing in the opposite direction to , water flows only in the main pipe and not in the branch pipes. Therefore, in either the cooling operation or the heating operation, in the water pipe, a state may occur in which water does not always flow to the branch pipe. As a result, rust occurs in the pipes, and maintenance work such as draining water in the branch pipes is required when switching the operation.

The present invention has been made in view of such circumstances, and when changing the flow direction of water in a water pipe connected to a water heat exchanger, it is possible to switch quickly and prevent problems from occurring. To provide a chiller unit that can be made difficult.

In order to solve the above problems, the chiller unit of the present invention employs the following means.
That is, the chiller unit according to the present invention has a water heat exchanger, a refrigeration cycle system in which a refrigerant circulates, a water pipe connected to the water heat exchanger and through which water flows, and a water pipe installed in the water pipe. , a four-way valve having a first connection port, a second connection port, a third connection port, and a fourth connection port, wherein the water flowing through the water pipe at the first connection port always flows into the four-way valve, The water that has flowed through the water heat exchanger always flows out from the four-way valve at the fourth connection port, and the second connection port and a connection port on one end side of the water heat exchanger are connected by the water pipe. , the third connection port and the connection port on the other end side of the water heat exchanger are connected by the water pipe, the four-way valve allows the first connection port and the second connection port to flow, and , a first mode in which the third connection port and the fourth connection port are allowed to flow, or a first mode in which the first connection port and the third connection port are allowed to flow, and the second connection port and the fourth connection port It has a configuration that can be switched to a second mode in which the connection port can flow.

According to this configuration, when the four-way valve is switched to the first mode, the water flowing through the water pipe flows into the first connection port, and after the water flows from the first connection port to the second connection port, the second Water is supplied to the water heat exchanger from the 2 connection port. In the first mode, the water that has flowed through the water heat exchanger flows in from the third connection port, and after the water flows from the third connection port to the fourth connection port, the water flows out from the fourth connection port. do. Further, when the four-way valve is switched to the second mode, the water flowing through the water pipe flows in at the first connection port, and after the water flows from the first connection port to the third connection port, from the third connection port Water is supplied to the water heat exchanger. In the second mode, the water that has flowed through the water heat exchanger flows in from the second connection port, and after the water flows from the second connection port to the fourth connection port, the water flows out from the fourth connection port. do.

Therefore, by switching the four-way valve, it is possible to change the flow direction of the water pipe connected to the heat exchanger. Therefore, by switching the four-way valve according to the switching between the cooling operation and the heating operation of the refrigerating cycle system, the direction of flow of the refrigerant in the refrigerating cycle system and the direction of flow of the water pipe can always be counterflows. In addition, regardless of switching of the four-way valve, water always flows through the water piping, and there is no system in which water does not flow. Therefore, when changing the flow direction of the water pipe connected to the heat exchanger, it is possible to quickly switch the water flow direction, and it is possible to prevent problems from occurring.

In addition, since the number of four-way valves to be installed is one, which is smaller than the number of installations when three-way valves are installed, the number of parts can be reduced. In addition, when a three-way valve is installed, a plurality of three-way valves need to be operated, whereas only one four-way valve is required to operate.

In the above invention, the four-way valve may be installed inside the unit main body.

According to this configuration, since the four-way valve is installed inside the unit body, simply by connecting the chiller unit to the external water pipe, the flow direction of the refrigerant in the refrigeration cycle system and the flow direction of the water pipe are always adjusted. It is possible to configure a system capable of countercurrent flow.

In the above invention, the four-way valve may be installed outside the unit main body and connected to the water pipe installed inside the unit main body.

According to this configuration, since the four-way valve is installed outside the unit body, by connecting the four-way valve to the water pipe installed inside the unit body, the refrigerant in the refrigeration cycle system flows in the same direction. A system can be configured in which the flow direction of the water pipe can always be counterflow. Since a four-way valve is not installed inside the unit main body, the unit main body can also be applied to a configuration in which the flow direction of the water pipe does not need to be switched.

In the above invention, in the refrigeration cycle system, a temperature detection unit that is installed upstream or downstream of the connection port of the water heat exchanger and detects the temperature of the refrigerant flowing through the refrigeration cycle system; and a control unit that switches the four-way valve based on the temperature detected by the unit.

According to this configuration, in the refrigeration cycle system, the temperature detection unit installed upstream or downstream of the connection port of the water heat exchanger detects the temperature of the refrigerant flowing through the refrigeration cycle system, and the detected temperature , the four-way valve is switched. The temperature of the refrigerant flowing upstream or downstream of the connection port of the water heat exchanger is changed according to the switching between the cooling operation and the heating operation of the refrigeration cycle system. As a result, the four-way valve is automatically switched according to the detected temperature of the refrigerant, so that the direction of flow of the refrigerant in the refrigeration cycle system and the direction of flow of the water pipe can always be counterflows.

In the above invention, the pressure detection unit installed in the refrigeration cycle system to detect the pressure of the refrigerant flowing through the refrigeration cycle system, and the control unit detect the four directions based on the pressure detected by the pressure detection unit. The success or failure of valve switching may be determined.

According to this configuration, the pressure detector installed in the refrigeration cycle system detects the pressure of the refrigerant flowing through the refrigeration cycle system, and based on the detected pressure, it is determined whether the four-way valve has been switched successfully. Therefore, by detecting the temperature of the refrigerant, it can be determined whether the four-way valve is properly switched.

ADVANTAGE OF THE INVENTION According to this invention, when changing the flow direction of the water in the water piping connected to the water heat exchanger, it can switch quickly and can make trouble difficult to occur.

It is a circuit diagram showing a schematic configuration of a chiller unit according to one embodiment of the present invention. FIG. 4 is a schematic diagram showing the configuration of the water piping of the chiller unit according to one embodiment of the present invention, showing a state in which the four-way valve is switched to the first mode; FIG. 4 is a schematic diagram showing the configuration of the water piping of the chiller unit according to one embodiment of the present invention, showing a state in which the four-way valve is switched to the second mode; It is the schematic which shows the modification of a structure of the water piping of the chiller unit which concerns on one Embodiment of this invention.

A chiller unit 1 according to an embodiment of the present invention will be described below. FIG. 1 is a circuit diagram showing a schematic configuration of a chiller unit 1 according to one embodiment of the present invention.
This chiller unit 1 has a configuration in which two refrigerating cycle systems, that is, first and second refrigerating cycle systems R1 and R2, and a water system section 3 are housed inside a housing (not shown). Also, the first refrigerating cycle system R1 and the second refrigerating cycle system R2 are arranged in series in the water pipe 18 . The configuration of the water pipe 18 according to this embodiment is shown in FIGS. 2 and 3, and the configuration of the water pipe 18 is shown in a simplified manner in FIG.

The number of refrigerating cycle systems provided in the chiller unit 1 and the layout relationship of the refrigerating cycle systems with respect to the water pipes 18 are not limited to the examples described in the present embodiment. For example, the number of refrigeration cycle systems may be one or three or more. Moreover, a plurality of refrigerating cycle systems may be arranged in parallel in the water pipe 18, or a series arrangement and a parallel arrangement may be combined.

The first and second refrigeration cycle systems R1 and R2 each include a compressor 5, an oil separator 6, a check valve 7, a four-way valve 8, and a water heat exchanger 9 (first and second water heat exchange 9A, 9B), a receiver 10, an electronic expansion valve 11, an air-cooled heat exchanger 12, and a gas-liquid separator 13. The air-cooled heat exchanger 12 is provided with a cooling fan 12a.

The compressor 5 sucks gas refrigerant, compresses the sucked gas refrigerant, and discharges it. The oil separator 6 separates oil from the compressed refrigerant discharged from the compressor 5 and returns it to the compressor 5 . The check valve 7 prevents backflow of the compressed refrigerant.

The four-way valve 8 is a valve that selects two positions of a heating operation mode in which the compressed refrigerant discharged from the compressor 5 is sent to the water heat exchanger 9 and a cooling operation mode in which the compressed refrigerant is sent to the air-cooled heat exchanger 12 . In FIG. 1, the four-way valve 8 is in the heating operation mode position.

The water heat exchanger 9 is a heat exchanger that functions as a condenser by condensing the compressed refrigerant in the heating operation mode and as an evaporator that vaporizes the condensed refrigerant in the cooling operation mode. The heat of condensation or heat of vaporization heats or cools the water flowing through the water system 3 to generate hot water for heating, hot water or hot water for supplying hot water, or cold water for cooling.

The first refrigeration cycle system R1 has a first water heat exchanger 9A, and the second refrigeration cycle system R2 has a second water heat exchanger 9B.

The receiver 10 is a tank that stores a predetermined amount of condensed liquid refrigerant. The electronic expansion valve 11 lowers the pressure of the condensed refrigerant to promote vaporization. The air-cooled heat exchanger 12 is supplied with outside air by a cooling fan 12a. The air-cooled heat exchanger 12 is a heat exchanger that functions as an evaporator that evaporates the condensed refrigerant in the heating operation mode and functions as a condenser that condenses the compressed refrigerant in the cooling operation mode. The gas-liquid separator 13 separates the refrigerant before being sucked into the compressor 5 into gas and liquid, and causes the compressor 5 to suck only the gas refrigerant.

The water system section 3 includes a water inlet section 15 , a water pump 16 , a water outlet section 17 and a water pipe 18 . A water pump 16 is installed in a water pipe 18 extending from the water inlet portion 15 .

Next, the configuration of the water pipe 18 according to this embodiment will be described with reference to FIGS. 2 and 3. FIG.
The water pipe 18 is composed of, for example, water pipes 18a to 18e. One four-way valve 20 is installed in the water pipe 18 . The four-way valve 20 has a first connection port 21 , a second connection port 22 , a third connection port 23 and a fourth connection port 24 .

The four-way valve 20 has a configuration that can be switched between the first mode and the second mode. In the first mode, as shown in FIG. 2, the first connection port 21 and the second connection port 22 are allowed to flow, and the third connection port 23 and the fourth connection port 24 are allowed to flow. In the second mode, as shown in FIG. 3, the first connection port 21 and the third connection port 23 are allowed to flow, and the second connection port 22 and the fourth connection port 24 are allowed to flow.

The water pipe 18 a is connected to the first connection port 21 of the four-way valve 20 , and the water flowing through the water pipe 18 a sent from the supply source always flows into the four-way valve 20 at the first connection port 21 .

The water pipe 18d is connected to the fourth connection port 24 of the four-way valve 20, and the water flowing through the first and second water heat exchangers 9A and 9B always flows out from the four-way valve 20 at the fourth connection port 24. , is sent to the destination.

One end of the water pipe 18b is connected to the second connection port 22 of the four-way valve 20, and the other end is connected to the one end side connection port of the first water heat exchanger 9A. When the four-way valve 20 is in the first mode in which the first connection port 21 and the second connection port 22 can flow, the water pipe 18b passes water from the second connection port 22 of the four-way valve 20 to the first water heat exchanger 9A. is sent. When the four-way valve 20 is in the second mode in which the second connection port 22 and the fourth connection port 24 can flow, water flows from the first water heat exchanger 9A to the second connection port 22 of the four-way valve 20 in the water pipe 18b. is sent.

One end of the water pipe 18e is connected to the connection port on the other end side of the first water heat exchanger 9A, and the other end is connected to the connection port on the one end side of the second water heat exchanger 9B.

One end of the water pipe 18c is connected to the third connection port 23, and the other end is connected to the other end side connection port of the second water heat exchanger 9B. When the four-way valve 20 is in the first mode in which the third connection port 23 and the fourth connection port 24 can flow, water flows from the second water heat exchanger 9B to the third connection port 23 of the four-way valve 20 in the water pipe 18c. is sent. When the four-way valve 20 is in the second mode in which the first connection port 21 and the third connection port 23 can flow, the water pipe 18c passes water from the third connection port 23 of the four-way valve 20 to the second water heat exchanger 9B. is sent.

When the four-way valve 20 is switched to the first mode, the water flowing through the water pipe 18a flows into the first connection port 21, and after the water flows from the first connection port 21 to the second connection port 22, the second Water is supplied from the connection port 22 to the first water heat exchanger 9A. Further, in the first mode, the water that has flowed through the second water heat exchanger 9B through the first water heat exchanger 9A and the second water heat exchanger 9B in order flows from the third connection port 23, and flows into the third connection. After the water flows from the port 23 to the fourth connection port 24, the water flows out from the fourth connection port 24 through the water pipe 18d.

When the four-way valve 20 is switched to the second mode, the water flowing through the water pipe 18a flows into the first connection port 21, and after the water flows from the first connection port 21 to the third connection port 23, the third Water is supplied from the connection port 23 to the second water heat exchanger 9B. Further, in the second mode, the water that has flowed through the first water heat exchanger 9A through the second water heat exchanger 9B and the first water heat exchanger 9A in order flows from the second connection port 22, and flows into the second connection. After the water flows from the port 22 to the fourth connection port 24, the water flows out from the fourth connection port 24 through the water pipe 18d.

By switching the four-way valve 20, it is possible to change the water flow direction of the water pipe 18 connected to the first and second water heat exchangers 9A, 9B. Therefore, by switching the four-way valve 20 according to the switching between the cooling operation and the heating operation of the first and second refrigerating cycle systems R1 and R2, the flow direction of the refrigerant in the first and second refrigerating cycle systems R1 and R2 and The direction of water flow in the water pipe 18 can always be counterflow. In addition, regardless of switching of the four-way valve 20, water always flows through the water pipe 18, and there is no system in which water does not flow. Therefore, when changing the direction of water flow in the water pipes 18 connected to the first and second water heat exchangers 9A and 9B, the direction of water flow can be quickly switched, and problems are less likely to occur. be able to.

In addition, the number of four-way valves 20 to be installed is one, which is smaller than the number of installations when a three-way valve is installed, so the number of parts can be reduced. In addition, when a three-way valve is installed, a plurality of three-way valves need to be operated, whereas only one four-way valve 20 is required to operate.

The four-way valve 20 is installed inside the unit main body (housing) of the chiller unit 1 . In this case, since the four-way valve 20 is installed inside the unit main body, the water inlet portion 15 and the water outlet portion 17 are connected to external water pipes. As a result, simply by connecting the chiller unit 1 to the external water pipe, the direction of flow of the refrigerant in the first and second refrigeration cycle systems R1 and R2 and the direction of flow of water in the water pipe 18 can always be made to flow in opposite directions. A possible system can be constructed.

In the present embodiment, the four-way valve 20 is not limited to being installed inside the unit main body, and the four-way valve 20 may be installed outside the unit main body (housing) of the chiller unit 1 . In this case, the unit main body includes a water pipe 18b, one end of which is connectable to an external water pipe and the other end of which is connected to the first water heat exchanger 9A, the first water heat exchanger 9A and the second water heat exchanger. A water pipe 18e connecting the exchangers 9B and a water pipe 18c having one end connected to the second water heat exchanger 9B and the other end connectable to an external water pipe are installed. The four-way valve 20 is connected to the water pipes 18b and 18c installed inside these unit bodies, and by installing the water pipes 18a and 18d having the above-described configuration, the chiller unit 1 according to the present embodiment is configured. As a result, it is possible to configure a system in which the direction of flow of refrigerant in the first and second refrigeration cycle systems R1 and R2 and the direction of flow of water in the water pipe 18 are always countercurrent. Since the four-way valve 20 is not installed inside the unit main body, the unit main body can be applied to a configuration in which the direction of water flow in the water pipe 18 does not need to be switched.

The chiller unit 1 according to this embodiment may include a temperature detector 31, a pressure detector 32, and a controller 33, as shown in FIG.

The temperature detection unit 31 is installed upstream and/or downstream of the connection ports of the first and second water heat exchangers 9A and 9B in the first and second refrigeration cycle systems R1 and R2. The temperature of the refrigerant flowing through the second refrigerating cycle systems R1, R2 is detected.

The pressure detection unit 32 is installed on the suction side and the discharge side of the compressor 5 in the first and second refrigeration cycle systems R1 and R2, respectively, and detects the pressure of the refrigerant flowing through the first and second refrigeration cycle systems R1 and R2. To detect.

The controller 33 switches the four-way valve 20 based on the temperature detected by the temperature detector 31 . Based on the temperature of the refrigerant flowing into the first and second water heat exchangers 9A and 9B, or the temperature of the refrigerant flowing out of the first and second water heat exchangers 9A and 9B, , R2 are in cooling operation or heating operation.

During cooling operation, the first and second water heat exchangers 9A and 9B function as evaporators. Therefore, when the detected temperature is lower than a predetermined threshold, it can be determined that the four-way valve 20 is in cooling operation. switch to a mode corresponding to cooling operation. During heating operation, the first and second water heat exchangers 9A and 9B function as condensers. Therefore, when the detected temperature is higher than a predetermined threshold, it can be determined that the heating operation is being performed, and the four-way valve 20 to a mode corresponding to heating operation. As a result, in both the cooling operation and the heating operation, in the first and second water heat exchangers 9A and 9B, the flow direction of the refrigerant in the first and second refrigeration cycle systems R1 and R2 and the flow of water in the water pipe 18 The direction is counter-flow.

Also, the control unit 33 determines whether the switching of the four-way valve 20 has succeeded or failed based on the pressure detected by the pressure detection unit 32 . When the four-way valve 20 is not properly switched, in the first and second water heat exchangers 9A and 9B, the flow direction of the refrigerant in the first and second refrigeration cycle systems R1 and R2 and the flow direction of the water in the water pipe 18 flow in parallel, the heat exchange efficiency in the first and second water heat exchangers 9A and 9B is lowered. Therefore, for example, the pressure detection unit 32 detects the pressure of the refrigerant sucked into the compressor 5 and the pressure of the refrigerant discharged from the compressor 5, and when the pressure difference falls below a predetermined threshold value, the four-way valve 20 is properly operated. It is judged that it is not switched. On the other hand, if the pressure difference exceeds the predetermined threshold value, it is determined that the four-way valve 20 is properly switched.

The control unit 33 includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a computer-readable storage medium, and the like. A series of processes for realizing various functions is stored in a storage medium or the like in the form of a program, for example, and the CPU reads out this program to a RAM or the like, and executes information processing and arithmetic processing. As a result, various functions are realized. The program may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or delivered via wired or wireless communication means. etc. may be applied. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memories, and the like.

According to the present embodiment, in the first and second refrigeration cycle systems R1 and R2, the temperature detector 31 installed upstream or downstream of the connection port of the first and second water heat exchangers 9A and 9B , the temperature of the refrigerant flowing through the first and second refrigeration cycle systems R1 and R2 is detected, and the four-way valve 20 is switched based on the detected temperature. The temperature of the refrigerant flowing upstream or downstream of the connection ports of the first and second water heat exchangers 9A and 9B according to the switching between the cooling operation and the heating operation of the first and second refrigeration cycle systems R1 and R2 is changed. Therefore, by automatically switching the four-way valve 20 according to the detected temperature of the refrigerant, the flow direction of the refrigerant in the first and second refrigeration cycle systems R1 and R2 and the flow direction of the water in the water pipe 18 are changed. Counterflow can always be used.

Moreover, the pressure of the refrigerant flowing through the first and second refrigerating cycle systems R1 and R2 is detected by the pressure detection units 32 installed in the first and second refrigerating cycle systems R1 and R2, and based on the detected pressure, , the success or failure of the switching of the four-way valve 20 is determined. Therefore, when the four-way valve 20 is automatically switched, it can be determined whether the four-way valve 20 is correctly switched.

The chiller unit 1 configured as described above operates as follows. An example in which the four-way valve 20 switches to the first mode shown in FIG. 2 during heating operation and switches to the second mode shown in FIG. 3 during cooling operation will be described below.

First, the operation during heating operation will be described.
During heating operation, the four-way valves 8 of the first and second refrigeration cycle systems R1 and R2 are in the heating operation mode position shown in FIG.

At least one compressor 5 is then activated. The high-temperature and high-pressure compressed refrigerant compressed by the compressor 5 is separated from the oil by the oil separator 6, and passes through the four-way valve 8 to either or all of the first and second water heat exchangers 9A and 9B. flow. At this time, the compressed refrigerant is heat-exchanged with the water flowing through the water pipe 18 of the water system section 3 . Also, the temperature is detected by the temperature detection unit 31, and the four-way valve 20 is switched to the first mode.

That is, the compressed refrigerant compressed by the compressor 5 of the first refrigerating cycle system R1 flows into the first water heat exchanger 9A and is heat-exchanged with the water flowing through the water pipe 18, and the compressor 5 of the second refrigerating cycle system R2 The compressed refrigerant flows into the second water heat exchanger 9B and is heat-exchanged with the water flowing through the water pipe 18 .

That is, in the first refrigerating cycle system R1 and the second refrigerating cycle system R2, heat exchange between the refrigerant and water is performed individually by the first water heat exchanger 9A and the second water heat exchanger 9B, respectively. The water thus heat-exchanged with the high-temperature compressed refrigerant in the first and second water heat exchangers 9A and 9B becomes hot water or hot water, and is supplied from the water outlet 17 to a predetermined heating location or hot water supply location.

By switching the four-way valve 20 to the first mode, the water flowing through the water pipe 18a flows into the first connection port 21, and after the water flows from the first connection port 21 to the second connection port 22, the second connection port Water is supplied from 22 to the first water heat exchanger 9A. Further, in the first mode, water flows in order of the first water heat exchanger 9A and the second water heat exchanger 9B, and the water that has flowed through the second water heat exchanger 9B flows in from the third connection port 23. After the water flows from the third connection port 23 to the fourth connection port 24, the water flows out from the fourth connection port 24 through the water pipe 18d. In the first and second water heat exchangers 9A and 9B, the direction of flow of the refrigerant in the first and second refrigeration cycle systems R1 and R2 and the direction of flow of water in the water pipe 18 are countercurrent.

In addition, the compressed refrigerant that has exchanged heat with water in the first and second water heat exchangers 9A and 9B is condensed and liquefied, passes through the receiver 10 and the electronic expansion valve 11, where the pressure is reduced and the air-cooled heat is It flows through the exchanger 12 and exchanges heat with the air to be vaporized into a gaseous refrigerant.

Next, the operation during cooling operation will be described.
During the cooling operation, the four-way valves 8 of the first and second refrigeration cycle systems R1 and R2 are changed from the direction shown in FIG. 1 to the cooling operation mode position. Therefore, the high-temperature and high-pressure compressed refrigerant compressed by the compressor 5 flows through the four-way valve 8 to the air-cooled heat exchanger 12, where it is supplied with outside air by the cooling fan 12a, exchanges heat with the air, condenses, and liquefies. . The generated condensed refrigerant flows through the receiver 10 to either or all of the first and second water heat exchangers 9A and 9B. At this time, the condensed refrigerant exchanges heat with the water flowing through the water pipe 18 of the water system section 3 and evaporates. Also, the temperature is detected by the temperature detection unit 31, and the four-way valve 20 is switched to the second mode.

Thus, the water heat-exchanged with the low-temperature refrigerant in the first and second water heat exchangers 9A and 9B becomes cold water and is supplied from the water outlet 17 to a predetermined cooling location.

By switching the four-way valve 20 to the second mode, the water flowing through the water pipe 18a flows into the first connection port 21, and after the water flows from the first connection port 21 to the third connection port 23, the third connection port Water is supplied from 23 to the second water heat exchanger 9B. In the second mode, water flows in the order of the second water heat exchanger 9B and the first water heat exchanger 9A, and the water that has flowed through the second water heat exchanger 9B flows in from the second connection port 22. After the water flows from the second connection port 22 to the fourth connection port 24, the water flows out from the fourth connection port 24 through the water pipe 18d. In the first and second water heat exchangers 9A and 9B, the direction of flow of the refrigerant in the first and second refrigeration cycle systems R1 and R2 and the direction of flow of water in the water pipe 18 are countercurrent.

Also, the gaseous refrigerant that has been vaporized by exchanging heat with water in the first and second water heat exchangers 9A and 9B is sucked into the compressor 5 again through the four-way valve 8 and the gas-liquid separator 13 .

Next, a modification of the chiller unit 1 according to one embodiment of the present invention will be described with reference to FIG. The configurations of the first refrigerating cycle system R1 and the second refrigerating cycle system R2 in the chiller unit 1 are the same as those of the embodiment described above. In addition, descriptions of configurations and effects that overlap with those of the above-described embodiment will be omitted.

In the configuration according to the above-described embodiment, the water flowing through the first water heat exchanger 9A and the second water heat exchanger 9B is switched to the first water heat exchanger 9A by switching the four-way valve 20, as shown in FIG. is first, or as shown in FIG. 3, the second water heat exchanger 9B is first, and the order of water flow is changed.

On the other hand, when a plurality of first and second water heat exchangers 9A and 9B are arranged in series, regardless of switching of the four-way valve 20, the first water heat exchanger 9A or the second water heat exchanger A configuration in which device 9B is always first may be required.

In the embodiment described above, only one set of the four-way valve 20 and the water pipes 18a to 18e is installed for the first water heat exchanger 9A and the second water heat exchanger 9B. On the other hand, in the water pipe 18 in this modified example, unlike the above-described embodiment, one set of the four-way valve 20 and the water pipe 18 is provided for each of the first refrigerating cycle system R1 and the second refrigerating cycle system R2. installed one by one.

By switching each four-way valve 20, it is possible to change the flow direction of water in the water pipes 18 connected to the first and second water heat exchangers 9A and 9B. Therefore, by switching the four-way valves 20 according to the switching between the cooling operation and the heating operation of the first and second refrigeration cycle systems R1 and R2, the flow direction of the refrigerant in the first and second refrigeration cycle systems R1 and R2 and the water pipe 18 can always flow in the opposite direction. Further, as shown in FIG. 4, when a plurality of first and second water heat exchangers 9A and 9B are arranged in series, regardless of switching of the four-way valve 20, the first water heat exchanger 9A It can be configured to always be first.

1: Chiller unit 3: Water system unit 5: Compressor 6: Oil separator 7: Check valve 8: Four-way valve 9: Water heat exchanger 9A: First water heat exchanger 9B: Second water heat exchanger 10: Receiver 11: Electronic expansion valve 12: Air-cooled heat exchanger 12a: Cooling fan 13: Gas-liquid separator 15: Water inlet 16: Water pump 17: Water outlet 18, 18a, 18b, 18c, 18d, 18e: Water piping 20: Four-way valve 21: First connection port 22: Second connection port 23: Third connection port 24: Fourth connection port 31: Temperature detection unit 32: Pressure detection unit 33: Control unit R1: First refrigeration cycle system R2 : Second refrigeration cycle system

Claims (3)

A refrigeration cycle system having a water heat exchanger and circulating a refrigerant;
a water pipe connected to the water heat exchanger and through which water flows;
a four-way valve installed in the water pipe and having a first connection port, a second connection port, a third connection port and a fourth connection port;
In the refrigeration cycle system, a temperature detection unit that is installed upstream or downstream of the connection port of the water heat exchanger and detects the temperature of the refrigerant flowing through the refrigeration cycle system;
a pressure detection unit installed in the refrigeration cycle system for detecting the pressure of the refrigerant flowing through the refrigeration cycle system;
a control unit;
with
The water flowing through the water pipe at the first connection port always flows into the four-way valve, and the water flowing through the water heat exchanger at the fourth connection port always flows out from the four-way valve,
The second connection port and the connection port on one end side of the water heat exchanger are connected by the water pipe, and the third connection port and the connection port on the other end side of the water heat exchanger are connected by the water pipe. connected and
The four-way valve is in a first mode in which the first connection port and the second connection port are allowed to flow, and the third connection port and the fourth connection port are allowed to flow, or the first connection port can be switched to a second mode in which the third connection port can be circulated and the second connection port and the fourth connection port can be circulated ,
The control unit switches the four-way valve based on the temperature detected by the temperature detection unit, and determines whether the switching of the four-way valve is successful or failed based on the pressure detected by the pressure detection unit. unit. The chiller unit according to claim 1, wherein the four-way valve is installed inside the unit body. The chiller unit according to claim 1, wherein the four-way valve is installed outside the unit body and connected to the water pipe installed inside the unit body.

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