WO2021250789A1

WO2021250789A1 - Refrigeration cycle device

Info

Publication number: WO2021250789A1
Application number: PCT/JP2020/022734
Authority: WO
Inventors: 端之松下; 康敬落合; 尚弘市川; 勝也谷口
Original assignee: 三菱電機株式会社; 三菱電機ビルテクノサービス株式会社
Priority date: 2020-06-09
Filing date: 2020-06-09
Publication date: 2021-12-16
Also published as: CN115698606B; JP7367216B2; CN115698606A; EP4163574A1; US20230221050A1; JPWO2021250789A1; EP4163574A4

Abstract

A refrigeration cycle device (1) is provided with a refrigeration circuit (100), a water circuit (200), and a control device (300). The refrigeration circuit (100) includes a compressor (101), a four-way valve (104), a heat exchanger (105), a fan (106), a diaphragm mechanism (108), a water heat exchanger (109), and an accumulator (110). The refrigeration cycle device (1) determines whether there is a problem of grime being attached to an internal plate of the water heat exchanger (109) on the basis of the water temperature on the outlet side of the water heat exchanger (109) and the value of a low-pressure pressure sensor (111) or a high-pressure pressure sensor (103).

Description

Refrigeration cycle device

This disclosure relates to a refrigeration cycle device.

Conventionally, a refrigerating cycle device including a first refrigerant circuit constituting a heat source machine and a second refrigerant circuit connected to a load device using the heat of the heat source machine is known. Some refrigeration cycle devices of this type are provided with a plate heat exchanger between the first refrigerant circuit and the second refrigerant circuit.

Patent Document 1 describes that the plate heat exchanger is clogged by the calcium ions and the like contained in the water in the heat medium circuit solidifying inside the plate heat exchanger. The cooling device described in Patent Document 1 is a plate heat exchanger by determining whether or not the temperature difference between the temperature on the upstream side and the temperature on the downstream side of the plate heat exchanger exceeds the threshold value. Detects the presence or absence of clogging.

Japanese Unexamined Patent Publication No. 2003-50067

Clogged plate heat exchangers occur when dirt such as calcium ions gradually accumulates on the plate. Therefore, if an abnormality in the plate heat exchanger can be detected at a stage prior to the occurrence of clogging, the occurrence of clogging can be prevented by appropriate subsequent measures.

It is an object of the present disclosure to provide a refrigeration cycle apparatus capable of detecting the occurrence of an abnormality in a plate heat exchanger at an early stage.

The refrigeration cycle apparatus of the present disclosure includes a heat source side first refrigerant circuit that circulates the first refrigerant, and the heat source side first refrigerant circuit exchanges heat between the first compressor, the outside air, and the first refrigerant. It has one heat exchanger, a first throttle mechanism, and further includes a load-side refrigerant circuit that circulates a second refrigerant. The load-side refrigerant circuit has a pump and a load device that utilizes heat. A first plate type heat exchanger that exchanges heat between the first refrigerant and the second refrigerant, and a temperature sensor that detects the temperature of the second refrigerant on the outlet side of the first plate type heat exchanger are further provided, and the heat source side. The first refrigerant circuit circulates the first refrigerant between at least the first compressor, the first heat exchanger, the first throttle mechanism and the first plate heat exchanger, and the load side refrigerant circuit is at least the pump. The second refrigerant is circulated in one direction between the load device and the first plate heat exchanger, and the temperature detected by the temperature sensor and the saturation temperature of the first refrigerant are used in the first plate heat exchanger. Further, a control device for diagnosing the flow path of the second refrigerant of the above is provided.

According to the present disclosure, it is possible to provide a refrigeration cycle device capable of more accurately diagnosing an abnormality in a plate heat exchanger.

It is a figure which shows the structure of the refrigerating cycle apparatus which concerns on Embodiment 1. FIG. It is a flowchart which shows the dirt diagnosis processing at the time of a cooling operation. It is a ph diagram which shows the difference of the state with and without the refrigerant leakage. It is a flowchart which shows the dirt diagnosis processing at the time of a heating operation. It is a flowchart for determining whether a blockage occurs in a water heat exchanger or a strainer. It is a graph which shows the situation which dirt progresses. It is a flowchart for recording the progress of dirt inside a water heat exchanger. It is a figure which shows the structure of the refrigerating cycle apparatus which concerns on Embodiment 2. It is a flowchart which shows the content of control of the refrigeration cycle apparatus which concerns on Embodiment 2. It is a figure which shows the structure of the refrigerating cycle apparatus which concerns on Embodiment 3. It is a figure which shows the water heat exchanger part of the refrigeration cycle apparatus which concerns on Embodiment 4. FIG.

Hereinafter, the present embodiment will be described in detail with reference to the drawings. Hereinafter, a plurality of embodiments will be described, but it is planned from the beginning of the application to appropriately combine the configurations described in the respective embodiments. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated.

Embodiment 1.
FIG. 1 is a diagram showing a configuration of a refrigeration cycle device 1 according to a first embodiment. The circuit configuration and operation of the refrigeration cycle apparatus 1 will be described with reference to FIG. The refrigeration cycle device 1 includes a refrigerant circuit 100, a water circuit 200, and a control device 300. The control device 300 wirelessly communicates with the remote control device 400 (hereinafter, abbreviated as a remote controller) operated by the user.
<Structure of Refrigerant Circuit 100>
The refrigerant circuit 100 constitutes, for example, a heat source machine installed outdoors. The refrigerant circuit 100 includes a compressor 101, a four-way valve 104, a heat exchanger 105, a fan 106, a throttle mechanism 108, a water heat exchanger 109, an accumulator 110, and a refrigerant pipe 10 connecting them. include. Refrigerants such as chlorofluorocarbons circulate in the refrigerant circuit 100. The refrigerant pipe 10 is provided with a discharge temperature sensor 102, a high pressure pressure sensor 103, a refrigerant temperature sensor 107, and a low pressure pressure sensor 111.

The compressor 101 circulates the refrigerant in the refrigerant circuit 100 by increasing the pressure of the refrigerant. The compressor 101 changes the operating capacity according to the situation by controlling a motor (not shown) inside the compressor 101 by an inverter. The compressor 101 controls the frequency of the compressor 101 so as to reach the target outlet water temperature set by the control board 301 of the control device 300 or the remote controller 400 during the cooling operation and the heating operation. Two or more compressors 101 may be connected in parallel or in series with the refrigerant pipe 10.

The four-way valve 104 switches the direction in which the refrigerant flows. The four-way valve 104 switches the flow path of the refrigerant as shown by the solid line in FIG. 1 during the cooling operation. The four-way valve 104 switches the flow path of the refrigerant as shown by the broken line in FIG. 1 during the heating operation. During the heating operation, the refrigerant circuit 100 acts as a heat source. On the other hand, during the cooling operation, the refrigerant circuit 100 acts as a cold heat source.

The heat exchanger 105 is, for example, a fin tube type heat exchanger composed of a large number of fins and a heat transfer tube. The heat exchanger 105 exchanges heat between the refrigerant circulating in the refrigerant pipe 10 and the outdoor air. The heat exchanger 105 functions as a condenser during the cooling operation. On the other hand, the heat exchanger 105 functions as an evaporator during the heating operation.

The fan 106 is, for example, a propeller fan driven by a motor. The fan 106 has a function of sucking outdoor air for heat exchange by the heat exchanger 105 and discharging the heat exchanged air by the heat exchanger 105 to the outside.

The throttle mechanism 108 adjusts the flow rate of the refrigerant flowing through the refrigerant pipe 10. The throttle mechanism 108 is, for example, an electronic expansion valve or a capillary. The electronic expansion valve has a function of efficiently controlling the flow rate of the refrigerant by adjusting the throttle opening.

The water heat exchanger 109 is a plate heat exchanger. In the plate heat exchanger, wavy plates are arranged in layers. The plates are brazed to a closed structure. The water heat exchanger 109 alternately flows the refrigerant of the refrigerant circuit 100 and the refrigerant (water) of the water circuit 200 through the gaps between the stacked plates. That is, inside the water heat exchanger 109, a first flow path through which the refrigerant of the refrigerant circuit 100 flows and a second flow path through which the refrigerant of the water circuit 200 flows are formed. In the first flow path and the second flow path, the heat of the refrigerant of the refrigerant circuit 100 and the heat of the refrigerant of the water circuit 200 are exchanged. The water heat exchanger 109 functions as an evaporator during the cooling operation and as a condenser during the heating operation.

The accumulator 110 separates the liquid refrigerant and the gas refrigerant and stores an excess liquid refrigerant. The accumulator 110 is provided to prevent failure of the compressor 101 due to suction of the refrigerant liquid into the compressor 101 (liquid back).

The discharge temperature sensor 102 is provided on the discharge side of the compressor 101. The discharge temperature sensor 102 detects the temperature of the high-temperature refrigerant discharged by the compressor 101. The high pressure pressure sensor 103 is provided on the discharge side of the compressor 101. The high pressure saturation temperature CT can be calculated from the detection value of the high pressure pressure sensor 103.

The refrigerant temperature sensor 107 is provided between the heat exchanger 105 and the throttle mechanism 108. The refrigerant temperature sensor 107 detects the temperature of the refrigerant on the outlet side of the heat exchanger 105, which exchanges heat between air and the refrigerant during cooling operation. If necessary, the refrigerant circuit 100 may be provided with a temperature sensor that detects the temperature on the inlet side of the water heat exchanger 109 and a temperature sensor that detects the temperature of the refrigerant on the outlet side of the water heat exchanger 109.

The low pressure pressure sensor 111 is provided on the suction portion side of the compressor 101. The low pressure saturation temperature ET can be calculated from the detection value of the low pressure pressure sensor 111.

The refrigerant circuit 100 circulates the refrigerant in a circulation path including the compressor 101, the heat exchanger 105, the throttle mechanism 108, and the water heat exchanger 109. The circulation direction of the refrigerant differs between cooling and heating. The refrigerant circuit 100 is equipped with a microcomputer that operates in response to a command from the control device 300.

<Structure of water circuit 200>
The water circuit 200 constitutes, for example, an air conditioner installed indoors. The water circuit 200 includes a pump 201, a load device 202, a strainer 209, and a water pipe 20 connecting them. Water as a refrigerant flows through the water pipe 20. Water may be mixed with additives that lower the freezing point. The refrigerant pipe 10 is provided with a temperature sensor 203, a temperature sensor 204, a flow meter 205, and a differential pressure meter 206. The water heat exchanger 109 described as the configuration on the refrigerant circuit 100 side may have a configuration on the water circuit 200 side instead of the configuration on the refrigerant circuit 100 side.

The water circuit 200 drives the pump 201 under inverter control so as to reach the target value of the preset flow meter 205 or differential pressure gauge 206. The type of control of the pump 201 is set according to the type of the air conditioner and the installation status of the air conditioner.

The load device 202 is an air conditioner such as an air handling unit and a fan coil unit. The load device 202 has a heat exchanger that exchanges heat between the air in the room and the water circulating in the water pipe 20. FIG. 1 shows a configuration in which one load device 202 is provided in the water circuit 200. This configuration is an example, and a plurality of load devices 202 may be provided in the water circuit 200.

The temperature sensor 203 is provided on the inlet side of the water heat exchanger 109. The temperature sensor 203 detects the temperature Twin of the water flowing into the water heat exchanger 109. The temperature sensor 204 is provided on the outlet side of the water heat exchanger 109. The temperature sensor 204 detects the temperature Twout of water after heat exchange with the refrigerant of the refrigerant circuit 100 inside the water heat exchanger 109. That is, Twout is the temperature on the outlet side of the second flow path through which water flows in the water heat exchanger 109. The flow meter 205 is provided on the discharge side of the pump 201. The flow meter 205 detects the flow rate Gw of water circulating in the water circuit 200. The differential pressure gauge 206 measures the water pressure difference ΔPw between the inlet and the outlet of the water heat exchanger 109. The strainer 209 removes foreign matter mixed in the water circulating in the water pipe 20. The flow path in the strainer 209 may be clogged by foreign matter.

The water circuit 200 circulates the refrigerant in one direction from the left to the right in FIG. 1 in a circulation path including the pump 201, the load device 202, and the water heat exchanger 109. The water circuit 200 is equipped with a microcomputer that operates in response to a command from the control device 300.

<Configuration of control device 300>
The control device 300 includes a control board 301. A processor 302, a memory 303, a display unit 304, and a communication unit 305 are mounted on the control board 301. The processor 302 executes the operating system and application programs stored in the memory 303. When executing the application program, various data stored in the memory 303 are referred to. The processor 302 receives a command transmitted from the remote controller 400 and controls the refrigerant circuit 100 and the water circuit 200. The processor 302 collects the detection values of various sensors provided in the refrigerant circuit 100 and the water circuit 200, and the operation data of the load device (air conditioner) 202.

The memory 303 includes, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), and a flash memory. The operating system and application programs are stored in the flash memory. Further, the flash memory stores the detection values of various sensors provided in the refrigerant circuit 100 and the water circuit 200, and the operation data of the load device 202 measured from the equipment.

The communication unit 305 communicates with the remote controller 400 and also communicates with the refrigerant circuit 100 and the water circuit 200. The communication unit 305 receives the command information transmitted from the remote controller 400. The communication unit 305 receives the detection values of various sensors and the operation data of the load device 202 measured from the equipment from the refrigerant circuit 100 and the water circuit 200. Information indicating the occurrence of an abnormality is displayed on the display unit 304.

The remote controller 400 remotely controls the control device 300 by communicating with the control device 300. The remote controller 400 includes a display unit 401 and an operation unit 402. By operating the operation unit 402, the user can switch ON / OFF of the indoor unit and adjust the set temperature. The remote controller 400 transmits various commands corresponding to the operation of the operation unit 402 to the control device. For example, an operation command (command of cooling or heating) is transmitted from the remote controller 400 to the control device 300. Alternatively, the remote controller 400 transmits the outlet water temperature of the water heat exchanger 109 to the control device 300. In addition to various setting information, information for notifying the occurrence of an abnormality is displayed on the display unit 401.

<Operation of refrigerant circuit 100>
First, the operation of the refrigerant circuit 100 during the cooling operation will be described. During the cooling operation, the four-way valve 104 switches the flow path of the refrigerant as shown by the solid line in FIG. The high-temperature, high-pressure gas refrigerant discharged from the compressor 101 flows to the heat exchanger 105. At this time, the heat exchanger 105 functions as a condenser. The refrigerant in the refrigerant pipe 10 exchanges heat with air by the fan 106, so that the refrigerant changes from a gas refrigerant to a liquid refrigerant.

The liquid refrigerant heading from the heat exchanger 105 to the throttle mechanism 108 is depressurized by the throttle mechanism 108. As a result, the liquid refrigerant changes to a low pressure two-phase refrigerant. The low pressure two-phase refrigerant moves from the throttle mechanism 108 to the water heat exchanger 109. At this time, the water heat exchanger 109 functions as an evaporator. The refrigerant flowing into the water heat exchanger 109 changes to a gas refrigerant by exchanging heat with water inside the water heat exchanger 109. The gas refrigerant passes through the accumulator 110 and is sucked into the compressor 101.

Next, the operation of the refrigerant circuit 100 during the heating operation will be described. During the heating operation, the four-way valve 104 switches the flow path of the refrigerant as shown by the broken line in FIG. The high-temperature, high-pressure gas refrigerant discharged from the compressor 101 flows to the water heat exchanger 109. At this time, the water heat exchanger 109 functions as a condenser. Since the refrigerant in the refrigerant pipe 10 exchanges heat with the water in the water pipe 20, the refrigerant changes from a gas refrigerant to a liquid refrigerant.

The liquid refrigerant heading from the water heat exchanger 109 to the throttle mechanism 108 is depressurized by the throttle mechanism 108. As a result, the liquid refrigerant changes to a low pressure two-phase refrigerant. The low pressure two-phase refrigerant moves from the throttle mechanism 108 to the heat exchanger 105. At this time, the heat exchanger 105 functions as an evaporator. The refrigerant flowing into the heat exchanger 105 is heat exchanged with air by the fan 106. After that, the refrigerant flowing into the accumulator 110 is separated into a liquid refrigerant and a gas refrigerant, and the gas refrigerant is sucked into the compressor 101.

The refrigerant circuit 100 can perform cooling operation and heating operation by providing the four-way valve 104. However, as the present embodiment, the refrigeration cycle device may be constructed by a refrigerant circuit not provided with the four-way valve 104. That is, as the present embodiment, a cooling-only model or a heating-only model may be adopted.

<Cause of freezing of refrigerant in water heat exchanger 109>
Freezing of the water flowing through the water heat exchanger 109 adversely affects the plate of the water heat exchanger 109. If freezing and thawing occur repeatedly, the plate may burst (so-called freeze puncture), leading to damage to the water heat exchanger 109. At that time, if water infiltrates into the refrigerant circuit 100, the degree of failure increases, and as a result, a lot of time is required for maintenance and inspection work. Therefore, it is important to clarify the cause of freezing and then take measures to prevent freezing.

The cause of water freezing is the dirt generated in the water pipe 20. The dirt generated in the water pipe 20 gradually adheres to the plate surface of the water heat exchanger 109. Dirt adhering to the plate surface is called scale or sludge. Repeated adhesion of dirt to the plate surface increases the flow path resistance of the water flow path formed by the gap between the plates. Inside the water heat exchanger 109, a portion where water is locally stagnant is generated, the flow of water is impaired, and eventually the water flow path is blocked. The so-called water heat exchanger 109 is clogged. If dirt adheres to the plate surface, the heat transfer performance of the water heat exchanger 109 deteriorates. During the cooling operation, it is necessary to further lower the refrigerant temperature of the refrigerant circuit 100 in order to compensate for the deterioration of the heat transfer performance. When the refrigerant temperature is below the freezing point of water, freezing is likely to occur in the portion where water is locally stagnant inside the water heat exchanger 109.

Therefore, in order to prevent freezing, it is important to prevent the occurrence of clogging in the water heat exchanger 109. For this purpose, it is desirable to be able to grasp whether or not the inside of the water heat exchanger 109 is contaminated to the extent that it adversely affects the inside. Therefore, in the refrigerating cycle apparatus according to the present embodiment, it is possible to diagnose the dirt inside the water heat exchanger 109. Hereinafter, the dirt diagnosis according to the present embodiment will be described separately for the cooling operation and the heating operation.

<Dirt diagnosis method during cooling operation>
During the cooling operation, the four-way valve 104 switches the flow path of the refrigerant as shown by the solid line in FIG. At this time, the water heat exchanger 109 functions as an evaporator. The refrigerant in the refrigerant pipe 10 flows from the left to the right in FIG. The control device 300 calculates the low pressure saturation temperature ET from the pressure value Ps detected by the low pressure pressure sensor 111. The control device 300 calculates "Twout-ET" from the low-pressure saturation temperature ET and the water temperature Twout detected by the temperature sensor 204.

If dirt adheres to the plate surface of the water heat exchanger 109, heat transfer failure will occur, and the low pressure saturation temperature ET will decrease. Therefore, the difference temperature "Twout-ET" between the water temperature Twout and the low pressure saturation temperature ET increases. Therefore, when "Twout-ET> threshold value" is satisfied, it can be diagnosed that dirt affecting the water flow inside the water heat exchanger 109 is attached to the plate. In this case, the threshold value is set to an appropriate value for stain diagnosis. By setting the threshold value to an appropriate value, it is possible to detect an abnormality in the water heat exchanger 109 at an early stage before the water heat exchanger 109 is clogged.

During work such as periodic inspections, the operator may change the set water temperature of the water heat exchanger 109 depending on the inspection status. However, the difference temperature "Twout-ET" is hardly affected by the set value of the outlet water temperature of the water heat exchanger 109. Therefore, even when the operator changes the setting of the target outlet water temperature of the water heat exchanger 109 on the control board 301 of the remote controller 400 or the control device 300, the dirt inside the water heat exchanger 109 can be diagnosed.

If the surface of the plate of the water heat exchanger 109 becomes dirty, the water flow path inside the water heat exchanger 109 may be blocked and clogging may occur. The control device 300 may determine whether or not the inside of the water heat exchanger 109 is clogged together with the dirt diagnosis by comparing the detected value of the flow meter 205 or the differential pressure gauge 206 with the reference value.

The control device 300 may estimate the water flow rate during the cooling operation based on a predetermined calculation formula, and determine whether or not the inside of the water heat exchanger 109 is clogged based on the estimation result. An example of the equation related to the estimation of the water flow rate during the cooling operation is shown below. The control device 300 may estimate the water flow rate using the equations (1) and (2).

Here, Qr indicates the amount of heat on the refrigerant side [kW], Gr indicates the amount of circulation of the refrigerant [kg / s], h2 indicates the water heat exchanger outlet specific enthalpy [kJ / kg], and h1 indicates the water heat exchanger inlet. Specific enthalpy [kJ / kg], Gw indicates water flow rate [m3 / h], ρw indicates water density [kg / m3], Cp indicates water specific heat [kJ / kg · K], and Twin indicates water specific heat [kJ / kg · K]. The water heat exchanger inlet water temperature [° C.] is indicated, and Twout indicates the water heat exchanger outlet water temperature [° C.].

<Dirty diagnosis method during heating operation>
During the heating operation, the four-way valve 104 switches the flow path of the refrigerant in the direction indicated by the broken line in FIG. At this time, the water heat exchanger 109 functions as a condenser. The refrigerant in the refrigerant pipe 10 flows from right to left in FIG. The control device 300 calculates the high pressure saturation temperature CT from the pressure value Pd detected by the high pressure pressure sensor 103. The control device 300 calculates "CT-Twout" from the high-pressure saturation temperature CT and the water temperature Twout detected by the temperature sensor 204.

If the surface of the plate of the water heat exchanger 109 becomes dirty, heat transfer failure will occur, and the high-pressure saturation temperature CT will rise. Therefore, the difference temperature "CT-Twout" between the water temperature Twout and the high-pressure saturation temperature CT increases. Therefore, when "CT-Twout> threshold value" is satisfied, it can be diagnosed that dirt affecting the water flow inside the water heat exchanger 109 is attached to the plate. In this case, the threshold value is set to an appropriate value for stain diagnosis. By setting the threshold value to an appropriate value, it is possible to detect an abnormality in the water heat exchanger 109 at an early stage before the water heat exchanger 109 is clogged.

Similar to the cooling operation, the difference temperature "CT-Twout" shows the same value regardless of the set value of the outlet water temperature of the water heat exchanger 109. Therefore, even when the operator changes the setting of the target outlet water temperature of the water heat exchanger 109 on the control board 301 of the remote controller 400 or the control device 300, the dirt inside the water heat exchanger 109 can be diagnosed. The control device 300 may determine whether or not the inside of the water heat exchanger 109 is clogged together with the dirt diagnosis by comparing the detected value of the flow meter 205 or the differential pressure gauge 206 with the reference value.

<Dirt diagnosis flow during cooling operation>
FIG. 2 is a flowchart showing a stain diagnosis process during cooling operation. This flowchart shows the process executed by the control device 300. The control program required for this process is stored in the memory 303 of the control device 300.

Of the steps in the flowchart of FIG. 2, steps S2 to S6 are processes related to the determination of refrigerant leakage. That is, the control device 300 also determines the presence or absence of refrigerant leakage in the refrigerant circuit 100 in the dirt diagnosis process of the water heat exchanger 109. Here, before explaining each step of the flowchart, the reason why the control device 300 determines the presence or absence of refrigerant leakage together with the dirt diagnosis of the water heat exchanger 109 will be described. Refer to FIG. 3 for the explanation.

FIG. 3 is a ph diagram showing the difference between the state with and without the refrigerant leakage. With reference to FIG. 3, SC indicates the degree of supercooling, TdSH indicates the degree of discharge superheat, ET indicates the low pressure saturation temperature, and CT indicates the high pressure saturation temperature. Whereas the ph diagram "1 → 2 → 3 → 4 → 1" when the refrigerant is not leaking, the ph diagram when the refrigerant is leaking is "1'→ 2'→ 3'". → 4'→ 1'". Therefore, when the refrigerant is leaking, the low-pressure saturation temperature ET and the high-pressure saturation temperature CT decrease, while the TdSH increases.

As already explained, the low pressure saturation temperature ET is a value used when diagnosing dirt on the water heat exchanger 109 during cooling operation. The high-pressure saturation temperature CT is a value used when diagnosing dirt on the water heat exchanger 109 during heating operation. Therefore, the refrigerant leakage affects the dirt diagnosis of the water heat exchanger 109. Therefore, in the present embodiment, when the water heat exchanger 109 is diagnosed as dirty, the presence or absence of refrigerant leakage is also determined. That is, in the present embodiment, the dirt diagnosis of the water heat exchanger 109 is performed by combining the determination of the presence or absence of the refrigerant leakage. This prevents an error in the dirt diagnosis of the water heat exchanger 109 due to the influence of the refrigerant leak.

Returning to FIG. 2, the dirt diagnosis process during cooling operation will be explained. First, the control device 300 collects operation data from the refrigerant circuit 100 and the water circuit 200 (step S1). Next, the control device 300 calculates SC and TdsH in order to determine the refrigerant leakage based on the operation data collected in step S1 (step S2). The calculation procedure is as follows. First, the control device 300 extracts the pressure Pd obtained from the high-pressure pressure sensor 103, the Trout obtained from the refrigerant temperature sensor 107, and the discharge temperature Td obtained from the discharge temperature sensor 102. The high pressure saturation temperature CT is obtained by converting the pressure Pd into the saturation temperature. Further, using the following

formulas

3 and 4, the supercooling degree SC on the outlet side of the heat exchanger 105 and the discharge superheating degree TdSH of the refrigerant circuit 100 are calculated.

Next, the control device 300 determines whether or not SC <A (step S3). A indicates a threshold value set for detecting a refrigerant leak. Next, the control device 300 determines whether or not TdsH> B (step S4). B also indicates a threshold value set for detecting a refrigerant leak. The threshold values A and B appropriately adopt optimum values according to the type of the air conditioner. When the supercooling degree SC is smaller than the threshold value A and the discharge heating degree TdSH is larger than the threshold value B, the control device 300 determines that there is a refrigerant leak (step S5). In this case, the control device 300 notifies the refrigerant leak (step S6).

Specifically, the control device 300 outputs a signal notifying the refrigerant leak from the communication unit 305 to the remote controller 400. As a result, a message indicating the occurrence of refrigerant leakage is displayed on the display unit of the remote controller 400. Further, the control device 300 outputs a signal indicating the occurrence of refrigerant leakage to the display unit 304 of the control board 301. A message indicating the occurrence of refrigerant leakage is displayed on the display unit 304.

After step S6, the control device 300 finishes the process of this flowchart. That is, when the refrigerant circuit 100 has a refrigerant leak, the control device 300 does not diagnose the water heat exchanger 109 for contamination. As described above, the control device 300 determines the refrigerant leak before diagnosing the contamination of the water heat exchanger 109, whereby in addition to the determination of the refrigerant leak, the contamination diagnosis that may result in an inaccurate diagnosis result. Is prevented from doing.

If NO is determined in step S3 or step S4, the control device 300 converts the detected value of the low pressure pressure sensor 111 into the low pressure saturation temperature ET (step S7). Next, the control device 300 determines whether or not Twoout-ET> C (step S8). Here, Twout indicates the temperature of water after heat exchange with the refrigerant of the refrigerant circuit 100 inside the water heat exchanger 109. In other words, Twout indicates the temperature on the outlet side of the second flow path through which water flows in the water heat exchanger 109.

Further, C indicates a threshold value set for diagnosing dirt in the water heat exchanger 109. By adjusting this value, it is possible to make a diagnosis according to the degree of dirt. The threshold value C varies depending on the specifications of the water heat exchanger. Further, the abnormality level may be diagnosed by setting a threshold value step by step. When Twout-ET> C, the control device 300 diagnoses that there is an abnormality due to dirt (step S9). In other words, when Twoout-ET> C, the control device 300 diagnoses that the water heat exchanger 109 has an electric heating defect. This electric heating failure occurs because the flow path resistance increases due to the adhesion of dirt to the flow path in the water heat exchanger 109. Therefore, it can be said that the diagnosis in step S9 is a diagnosis of poor electric heating or a diagnosis of flow path resistance (difficulty of water flow).

The control device 300 determines whether or not ET <D before notifying the abnormality of the water heat exchanger 109 (step S10). Here, D indicates a threshold value for knowing the possibility of freezing of water in the second flow path of the water heat exchanger 109 from the low pressure saturation temperature ET. For example, the threshold value D indicates the freezing determination temperature of water. The freezing determination temperature is the temperature at which water freezes. The freezing determination temperature may be about 1 degree or 2 degrees higher than the temperature at which water freezes. If ET <D, the water may freeze in the water heat exchanger 109. Therefore, when the control device 300 determines that ET <D, the control device 300 raises the set temperature (target outlet water temperature) on the outlet side of the water heat exchanger 109 (step S11). This prevents the water from freezing in the water heat exchanger 109. As a result, the water heat exchanger 109 is prevented from being damaged due to freezing of water.

When NO is determined in step S10, the control device 300 prohibits the set temperature from dropping (step S12). In step S12, for example, when the user operates the remote controller 400 to give a command to lower the set temperature, the control device 300 does not accept the command. As a result, the current set temperature is maintained. As a result, it is possible to prevent the water from freezing due to the water temperature being lower than the present.

As described above, when Twout-ET> C, the control device 300 determines the possibility of freezing of water and determines the possibility of freezing of water, instead of proceeding to the step of notifying the abnormality of the contamination of the water heat exchanger 109. Perform processing to prevent freezing. Therefore, it is possible to prevent the water from freezing, as compared with the case where the abnormality of the contamination of the water heat exchanger 109 is only notified. The control device 300 may notify the possibility of freezing of water.

After step S11 or S12, the control device 300 notifies the dirt abnormality (step S13). Specifically, the control device 300 outputs a signal notifying that the water heat exchanger 109 is dirty from the communication unit 305 to the remote controller 400. As a result, a message indicating the occurrence of a dirt abnormality is displayed on the display unit of the remote controller 400. Further, the control device 300 outputs a signal indicating that the water heat exchanger 109 is dirty to the display unit 304 of the control board 301. A message indicating the occurrence of a dirt abnormality is displayed on the display unit 304. After step S13, the control device 300 ends the processing of this flowchart.

In the flowchart of FIG. 2, the presence or absence of refrigerant leakage may be determined after the dirt diagnosis of the water heat exchanger 109. Further, in the flowchart of FIG. 2, the processes of steps S10 to S12 may be executed after the notification of the dirt abnormality in step S13. Further, when the control device 300 determines in step S8 that the water heat exchanger 109 is dirty, the control device 300 controls the compressor 101 according to the set value of the remote controller 400.

<Dirt diagnosis flow during heating operation>
FIG. 4 is a diagram showing a flowchart of dirt diagnosis during heating operation. This flowchart shows the process executed by the control device 300. The control program required for this process is stored in the memory 303 of the control device 300. An example of the diagnostic flow during the heating operation will be described with reference to FIG.

The control device 300 collects operation data from the refrigerant circuit 100 and the water circuit 200 (step S100). The control device 300 determines whether or not there is a refrigerant leak in the refrigerant circuit 100 before diagnosing the contamination of the water heat exchanger 109. The reason is as already explained. That is, when the refrigerant leaks in the refrigerant circuit 100, the high-pressure saturation temperature CT decreases. Since the high-pressure saturation temperature CT is a parameter used when diagnosing dirt on the water heat exchanger 109 during heating operation, if a refrigerant leak occurs, an error will occur in the dirt diagnosis on the water heat exchanger 109.

Therefore, the control device 300 first determines whether or not there is a refrigerant leak. First, the control device 300 calculates the discharge superheat degree TdSH (step S101). The discharge superheat degree TdSH is calculated using the equation (4) already shown. That is, the discharge superheat degree TdSH is calculated by subtracting the high pressure saturation temperature CT from the discharge temperature Td. Here, the discharge temperature Td is obtained from the detection value of the discharge temperature sensor 102. Further, the high pressure saturation temperature CT is obtained by converting the pressure Pd obtained from the high pressure pressure sensor 103 into the saturation temperature.

In particular, during heating operation, excess refrigerant tends to stay in the accumulator 110. Therefore, the control device 300 determines the presence or absence of the refrigerant leak by using the discharge superheat degree TdSH in which the difference between the time when the refrigerant is not leaking and the time when the refrigerant is leaking is clear.

Next, the control device 300 determines whether or not TdsH> E (step S102). E indicates a threshold value set for detecting a refrigerant leak. The threshold value E varies depending on the type of air conditioner. When the discharge heating degree TdSH is larger than the threshold value E, the control device 300 determines that there is a refrigerant leak (step S103). In this case, the control device 300 notifies the refrigerant leak (step S104). The process of step S104 is the same as that of step S6 already described. As a result, a message indicating the occurrence of refrigerant leakage is displayed on the display unit of the remote controller 400 and the display unit 304 of the control board 301.

After step S104, the control device 300 ends the processing of this flowchart. That is, when the refrigerant circuit 100 has a refrigerant leak, the control device 300 does not diagnose the water heat exchanger 109 for contamination. In this way, the control unit determines the refrigerant leakage before diagnosing the contamination of the water heat exchanger 109, so that in addition to the determination of the refrigerant leakage, the contamination diagnosis that may result in an inaccurate diagnosis result is performed. It prevents you from doing so.

If NO is determined in step S102, the control device 300 converts the detected value of the high pressure pressure sensor 103 into the high pressure saturation temperature CT (step S105). Next, the control device 300 determines whether or not CT-Twout> F (step S106). Here, Twout indicates the temperature of water after heat exchange with the refrigerant of the refrigerant circuit 100 inside the water heat exchanger 109. In other words, Twout indicates the temperature on the outlet side of the second flow path through which water flows in the water heat exchanger 109.

Further, F indicates a threshold value set for diagnosing dirt in the water heat exchanger 109. By adjusting this value, it is possible to make a diagnosis according to the degree of dirt. The threshold value F varies depending on the specifications of the water heat exchanger. Further, the abnormality level may be diagnosed by setting a threshold value step by step. When CT-Twout> F, the control device 300 diagnoses that there is an abnormality due to dirt (step S107). In other words, when CT-Twout> F, the control device 300 diagnoses that the water heat exchanger 109 has an electric heating defect. This electric heating failure occurs because the flow path resistance increases due to the adhesion of dirt to the flow path in the water heat exchanger 109. Therefore, it can be said that the diagnosis in step S107 is a diagnosis of poor electric heating or a diagnosis of flow path resistance (difficulty of water flow).

After step S106, the control device 300 notifies the dirt abnormality (step S108). The process of step S108 is the same as that of step S13 already described. As a result, a message indicating the occurrence of a dirt abnormality is displayed on the display unit of the remote controller 400 and the display unit 304 of the control board 301. After step S108, the control device 300 ends the processing of this flowchart.

In the flowchart of FIG. 4, the presence or absence of refrigerant leakage may be determined after the dirt diagnosis of the water heat exchanger 109. Further, when the control device 300 determines in step S107 that the water heat exchanger 109 is dirty, the control device 300 controls the compressor 101 according to the set value of the remote controller 400.

<Identification of jammed area>
FIG. 5 is a flowchart for determining whether the clogging has occurred in the water heat exchanger 109 or the strainer 209. This flowchart shows the process executed by the control device 300. The control program required for this process is stored in the memory 303 of the control device 300.

With reference to FIG. 5, the control device 300 determines whether or not Gw <G (step S200). Here, Gw indicates the flow rate of water circulating in the water circuit 200. Gw is specified from the measured value of the flow meter 205. Further, G indicates a threshold value set for determining the degree of water flow rate. By determining whether or not water Gw <G, it is possible to determine whether or not the flow of water in the water circuit 200 is lower than the reference value. Further, by adjusting the threshold value G, it can be determined whether or not the water circuit 200 is clogged.

As shown in the parentheses of step S200, the control device 300 may determine ΔPw> H instead of determining Gw <G. Here, ΔPw indicates the differential pressure between the inlet and the outlet of the water heat exchanger 109 on the water circuit 200 side. This differential pressure is specified from the detected value of the differential pressure gauge 206. Further, H indicates a threshold value set for determining the degree of differential pressure.

If NO is determined in step S200, the control device 300 ends the process. If YES is determined in step S200, the control device 300 determines whether or not the water heat exchanger 109 is diagnosed as having an abnormality in contamination (step S201). The control device 300 makes a determination in step S201 by referring to the determination result of step S9 in FIG. 2 during the cooling operation and the determination result in step S107 in FIG. 4 during the heating operation.

When the control device 300 determines in step S201 that the water heat exchanger 109 is dirty, it determines that the cause of the decrease in the amount of water in step S200 is the water heat exchanger 109. That is, the control device 300 determines that the water heat exchanger 109 is clogged (step S202). When the control device 300 determines in step S201 that there is no contamination abnormality in the water heat exchanger 109, it determines that the cause of the decrease in the amount of water in step S200 is the strainer 209. That is, the control device 300 determines that the strainer 209 is clogged (step S204).

When the control device 300 determines in step S202 that the water heat exchanger 109 is clogged, the control device 300 notifies that the water heat exchanger 109 is clogged (step S203). When the control device 300 determines in step S204 that the strainer 209 is clogged, the control device 300 notifies that the strainer 209 is clogged (step S205). Specifically, the control device 300 outputs a signal notifying the clogging in the water heat exchanger 109 or the clogging in the strainer 209 from the communication unit 305 to the remote controller 400. As a result, a message indicating clogging in the water heat exchanger 109 or the strainer 209 is displayed on the display unit of the remote controller 400 and the display unit 304 of the control device 300. The control device 300 ends the processing of this flowchart after step S203 and step S205.

As described above, the control device 300 has a function of not only diagnosing the dirt of the water heat exchanger 109 but also identifying the location of the clogging and notifying the location of the clogging. In other words, the control device 300 can identify the blockage of the water channel in a wide range including the water heat exchanger 109 and the strainer 209, and further, whether the blockage occurs in the water heat exchanger 109 or occurs in the strainer 209. You can identify if it is.

<Graphing the progress of dirt>
FIG. 6 is a graph showing a situation in which dirt progresses. FIG. 6 is a graph during cooling operation. The control device 300 calculates the dirt state of the water heat exchanger 109 at a preset timing, and stores the calculation result in the memory 303. The control device 300 displays the graph shown in FIG. 6 in response to the operation of the remote controller 400 or the direct operation of the control board 301. This graph is displayed on the display unit 304 of the control board 301. Further, this graph is displayed on the display unit 401 of the remote controller 400.

With reference to FIG. 6, in the graph, the vertical axis indicates “Twout-ET” and the horizontal axis indicates time. In the graph, the limit of "Twout-ET" determined to be a stain abnormality is indicated by the display of "abnormality". 30A, 30B, 30C, 30D, and 30D indicate the values of "Twout-ET" calculated at different timings. By looking at this graph, it can be easily understood that “Twout-ET” approaches the threshold value and the degree of contamination increases with the passage of time. Further, by looking at this graph, it can be understood that the water heat exchanger 109 is in a state of being diagnosed as having an abnormality in dirt at the stage of 30D, and the degree of dirt is still progressing. Therefore, by displaying such a graph on the control device 300, the convenience of the user or the operator of the periodic inspection is improved.

The graph in FIG. 6 is for cooling operation. The control device 300 may also display a graph corresponding to the heating operation. In this case, "CT-Twout" is displayed on the vertical axis.

FIG. 7 is a flowchart for recording the progress of dirt inside the water heat exchanger. This flowchart shows the process executed by the control device 300. The control program required for this process is stored in the memory 303 of the control device 300. By this process, for example, the graph shown in FIG. 6 is presented to the user.

First, the control device 300 determines whether or not it is the set calculation timing (step S300). The calculation timing can be set arbitrarily. For example, the calculation timing may be freely set by using the remote controller 400 or the control board 301. Next, the control board 301 collects operation data from the refrigerant circuit 100 and the water circuit 200 (step S301). Next, the control device 300 calculates Twoout-ET from the collected operation data (step S302). Since the procedure for calculating Twoout-ET has already been described, the description will not be repeated here.

Next, the control device 300 stores the calculation result in the memory 303 together with the calculation date and time (step S303). Next, the control device 300 determines whether or not there is an instruction to display the graph (step S304). In the present embodiment, an instruction to display a graph can be input by operating the remote controller 400 or the control board 301. The control device 300 determines whether or not there is an instruction by those operations. When the control device 300 determines that there is an instruction to display a graph, the control device 300 reads out the memory 303 and displays it as a graph (step S305). After that, the control device 300 finishes the processing of this flowchart.

Assuming periodic inspections, it is advisable to have the control device 300 calculate the differential temperature "Twout-ET" on a regular basis. Thereby, for example, the worker of the periodic inspection can grasp the progress of the contamination of the water heat exchanger 109. For example, the operator can understand that the water heat exchanger 109 is approaching an abnormal state by looking at the calculation result 30C in FIG. Therefore, the operator can perform planned maintenance and inspection such as inspecting the water pipe 20 at the next periodic inspection and cleaning the inside of the water heat exchanger 109. As a result, it is possible to prevent defects from occurring in the refrigeration cycle device. A plurality of threshold values for determining an abnormality in the water heat exchanger 109 may be set stepwise.

For example, set a first threshold value and a second threshold value having a larger value than the first threshold value. The control device 300 shall stepwise determine whether or not the dirt on the water heat exchanger 109 exceeds the first threshold value and whether or not the dirt on the water heat exchanger 109 exceeds the second threshold value. do.

Embodiment 2.
FIG. 8 is a diagram showing the configuration of the refrigeration cycle device 2 according to the second embodiment. The refrigerating cycle device 2 according to the second embodiment differs from the refrigerating cycle device 1 according to the second embodiment in the number of refrigerant circuits connected to one water circuit 200. In the refrigeration cycle device 1 according to the first embodiment, one refrigerant circuit 100 is connected to one water circuit 200. On the other hand, in the refrigerating cycle device 2 according to the second embodiment, a plurality of refrigerant circuits A100a and a refrigerant circuit B100b are connected to one water circuit 200.

The refrigerant circuit A100a includes a compressor 101a, a four-way valve 104a, a heat exchanger 105a, a fan 106a, a throttle mechanism 108a, a water heat exchanger 109a, an accumulator 110a, and a refrigerant pipe 10a connecting them. include. The refrigerant circuit B100b includes a compressor 101b, a four-way valve 104b, a heat exchanger 105b, a fan 106b, a throttle mechanism 108b, a water heat exchanger 109b, an accumulator 110b, and a refrigerant pipe 10b connecting them. include. Each of these configurations has the same function as the corresponding configuration described as the first embodiment.

The water circuit 200 according to the second embodiment is connected in series with two water heat exchangers A109a and a water heat exchanger B109b. A differential pressure gauge 206 for detecting the differential pressure between the inlet side of the water heat exchanger A109a and the outlet side of the water heat exchanger B109b is provided in the water circuit 200. The refrigerant circuit A100a and the refrigerant circuit B100b control the frequencies of the

compressors

101a and 101b so that the water temperature at the outlet of the water heat exchanger B109b becomes a target set value. The refrigeration cycle device 2 according to the second embodiment can execute each process described as the first embodiment. As a result, the control device 300 can diagnose the dirt abnormality of the water heat exchanger A109a and the water heat exchanger B109b.

FIG. 9 is a flowchart showing the content of control of the refrigeration cycle device 2 according to the second embodiment. This flowchart shows a process executed by the control device 300 of FIG. The control program required for this process is stored in the memory 303 of the control device 300 of FIG.

The control device 300 diagnoses whether or not the water heat exchanger A109a has a dirt abnormality (step S400). When the water heat exchanger A109a has no dirt abnormality, the control device 300 diagnoses whether or not the water heat exchanger B109b has a dirt abnormality (step S401). If there is no dirt abnormality in the water heat exchanger B109b, the control device 300 ends the process of this flowchart. If the water heat exchanger B109b is dirty, the control device 300 stops the refrigerant circuit B100b (step S403). As a result, it is possible to prevent the abnormal contamination of the water heat exchanger B109b from adversely affecting the refrigeration cycle device 2. Further, the control device 300 notifies the water heat exchanger B109b of a dirt abnormality (step S404).

After step S404, the control device 300 adjusts the compressor 101a of the refrigerant circuit A100a (step S405). This adjustment is for adjusting the temperature on the outlet side of the water heat exchanger B109b (detected by the temperature sensor 204) to the target outlet temperature only by the refrigerant circuit A100a. Next, the control device 300 determines whether or not the temperature on the outlet side of the water heat exchanger B109b has reached the target outlet temperature (step S406). The control device 300 continues the adjustment of the compressor 101a in step S405 until it can be determined as YES in step S406. When the control device 300 determines YES in step S406, the control device 300 ends the processing of this flowchart.

When the control device 300 diagnoses that the water heat exchanger A109a has a dirt abnormality in step S400, it diagnoses whether or not the water heat exchanger B109b has a dirt abnormality (step S402). If the water heat exchanger B109b is not dirty, the control device 300 stops the refrigerant circuit A100a (step S407). As a result, it is possible to prevent the abnormal contamination of the water heat exchanger A109a from adversely affecting the refrigeration cycle device 2. Further, the control device 300 notifies the water heat exchanger A109a of a dirt abnormality (step S408).

After step S408, the control device 300 adjusts the compressor 101b of the refrigerant circuit B100b (step S409). This adjustment is for adjusting the temperature on the outlet side of the water heat exchanger B109b (detected by the temperature sensor 204) to the target outlet temperature only by the refrigerant circuit B100b. Next, the control device 300 determines whether or not the temperature on the outlet side of the water heat exchanger B109b has reached the target outlet temperature (step S410). The control device 300 continues the adjustment of the compressor 101b in step S409 until it can be determined as YES in step S410. When the control device 300 determines YES in step S410, the control device 300 ends the processing of this flowchart.

When the control device 300 determines YES in step S402, that is, when both the water heat exchanger A109a and the water heat exchanger B109b are diagnosed as having an abnormality in contamination, the refrigerant circuit A100a and the refrigerant circuit B100b are stopped (step S411). Further, the control device 300 notifies the water heat exchanger A109a and the water heat exchanger B109b of a dirt abnormality (step S412), and ends the process of this flowchart.

The diagnostic method of steps S400 to S402 and the notification method of steps S404, S408, and S412 are the same as those of the first embodiment described with reference to FIGS. 2 and 4. In this flowchart, when both the water heat exchanger A109a and the water heat exchanger B109b are diagnosed as having an abnormality in contamination, the refrigerant circuit A100a and the refrigerant circuit B100b are stopped. However, instead of such a process, various processes for avoiding an immediate stop of the refrigeration cycle device 2 may be applied. For example, it is conceivable to continue the operation in the refrigerant circuit having the lower degree of contamination abnormality.

As the second embodiment, FIG. 8 has described an example in which two refrigerant circuits A100a and two refrigerant circuits B100b are provided for one water circuit 200. However, more refrigerant circuits may be provided for one water circuit 200. The refrigerant flowing through the refrigerant circuit A100a and the refrigerant flowing through the refrigerant circuit B100b may be the same type of refrigerant or different types of refrigerant.

Embodiment 3.
FIG. 10 is a diagram showing the configuration of the refrigeration cycle device 3 according to the third embodiment. In the refrigeration cycle device 2 according to the third embodiment, the refrigerant circuit group is connected in parallel to one water circuit 200. As shown in FIG. 10, in the refrigerating cycle device 2 according to the third embodiment, the refrigerant circuit 100a and the refrigerant circuit 100b are connected in series, and these two refrigerant circuits form the first group of refrigerant circuits. On the other hand, the refrigerant circuit 100c and the refrigerant circuit 100d are connected in series, and these two refrigerant circuits form the second group of refrigerant circuits. In the water circuit 200, the refrigerant circuit of the first group and the refrigerant circuit of the second group are connected in parallel. Each of the refrigerant circuits 100a to 100d includes a water heat exchanger (plate heat exchanger).

The refrigeration cycle apparatus 3 according to the third embodiment similarly executes the processes according to the first embodiment and the second embodiment. For example, the dirt diagnosis of the water heat exchanger is executed for each water heat exchanger, and the determination of the refrigerant leakage of the refrigerant circuit is executed for each refrigerant circuit.

Embodiment 4.
FIG. 11 is a diagram showing a water heat exchanger portion of the refrigeration cycle device according to the fourth embodiment. The fourth embodiment shows an example in which the saturation temperature is directly detected by the temperature sensor. As shown in FIG. 11, in the fourth embodiment, the saturation temperature sensor 210 for detecting the saturation temperature is provided inside the water heat exchanger 109. In the first embodiment, the high pressure saturation temperature CT and the low pressure saturation temperature ET are calculated from the pressures of the pressure sensors (high pressure pressure sensor 103, low pressure pressure sensor 111) provided in the refrigerant circuit 100. However, the saturation temperature sensor 210 for detecting the saturation temperature may be provided at an appropriate position in the water heat exchanger 109, and the control device 300 may specify the saturation temperature by the detection value of the saturation temperature sensor 210. This makes it possible to simplify the control of the control device 300. The method of specifying the saturation temperature using the saturation temperature sensor 210 may be applied to any of the first to third embodiments.

As described above, according to the refrigeration cycle apparatus according to each embodiment, it is possible to diagnose the dirt inside the plate type water heat exchanger 109. In other words, this dirt diagnosis is a diagnosis of an electric heat defect of the water heat exchanger 109 or a diagnosis of the state of the flow path in the water heat exchanger 109. By such a diagnosis, a defect of the water heat exchanger 109 can be found. In particular, since the clogging between the plates is caused by the accumulation of dirt, according to the refrigeration cycle apparatus according to each embodiment, the water heat exchanger 109 is defective at an early stage leading to the clogging of the water heat exchanger 109. Can be detected.

According to the refrigeration cycle apparatus according to each embodiment, it is possible to diagnose the dirty state inside the plate heat exchanger regardless of the set water temperature on the outlet side. Therefore, it is possible to avoid a malfunction (for example, freezing) of the water heat exchanger 109 at an early stage.

The refrigeration cycle device according to the first to fourth embodiments can also be applied to a hot water supply device. Further, in the first to fourth embodiments, water has been described as an example as a heat medium for exchanging heat with the refrigerant circuit as a heat source. However, the heat medium may be a medium other than water as long as it is a medium that carries heat. For example, brine or the like may be used instead of water.

The control device 300 may control the air conditioning system including the refrigerant circuit 100 and the water circuit 200 via a network such as the Internet. The control device 300 may control one air conditioning system including the refrigerant circuit 100 and the water circuit 200, or may control a plurality of such air conditioning systems.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present disclosure is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope of the claims.

1,2,3 refrigeration cycle device, 100,100a-100d refrigerant circuit, 101 compressor, 102 discharge temperature sensor, 103 high pressure pressure sensor, 104 four-way valve, 105 heat exchanger, 106 fan, 107 refrigerant temperature sensor, 108 throttle Mechanism, 109 water heat exchanger, 110 accumulator, 111 low pressure pressure sensor, 200 water circuit, 201 pump, 202 load device, 203,204 temperature sensor, 205 flow meter, 206 differential pressure sensor, 209 strainer, 210 saturation temperature sensor, 300 Control device, 400 remote control.

Claims

It ’s a refrigeration cycle device.
The first refrigerant circuit on the heat source side that circulates the first refrigerant is provided, and the first refrigerant circuit on the heat source side is
With the first compressor,
A first heat exchanger that exchanges heat between the outside air and the first refrigerant,
It has a first aperture mechanism and
A load-side refrigerant circuit for circulating the second refrigerant is further provided, and the load-side refrigerant circuit is provided.
With a pump,
It has a load device that utilizes heat,
A first plate heat exchanger that exchanges heat between the first refrigerant and the second refrigerant,
Further provided with a temperature sensor for detecting the temperature of the second refrigerant on the outlet side of the first plate heat exchanger.
The first refrigerant circuit on the heat source side circulates the first refrigerant between at least the first compressor, the first heat exchanger, the first throttle mechanism, and the first plate heat exchanger.
The load-side refrigerant circuit circulates the second refrigerant in one direction at least between the pump, the load device, and the first plate heat exchanger.
A refrigeration cycle apparatus further comprising a control device for diagnosing the flow path of the second refrigerant in the first plate heat exchanger using the temperature detected by the temperature sensor and the saturation temperature of the first refrigerant.
The control device adjusts the temperature of the second refrigerant on the outlet side of the first plate heat exchanger to a set target temperature by controlling the frequency of the first compressor, according to claim 1. The refrigeration cycle device described.
The control device diagnoses the flow path of the second refrigerant in the first plate heat exchanger based on the temperature difference between the temperature detected by the temperature sensor and the saturation temperature of the first refrigerant. The refrigerating cycle apparatus according to claim 1 or 2.
The refrigerating cycle device according to any one of claims 1 to 3, wherein the control device determines the presence or absence of leakage of the first refrigerant.
The refrigerating cycle device according to claim 4, wherein the control device determines the presence or absence of leakage of the first refrigerant when diagnosing the flow path of the second refrigerant in the first plate heat exchanger.
In the control device, when the first plate heat exchanger functions as an evaporator of the first refrigerant, the degree of supercooling on the outlet side of the first heat exchanger and the degree of supercooling on the outlet side of the first refrigerant circuit and the first refrigerant circuit on the heat source side. The refrigerating cycle apparatus according to claim 4 or 5, wherein the presence or absence of leakage of the first refrigerant is determined based on the discharge superheat degree.
In the control device, when the first plate heat exchanger functions as a condenser of the first refrigerant, the presence or absence of leakage of the first refrigerant is based on the degree of superheat discharge of the first refrigerant circuit on the heat source side. The refrigerating cycle apparatus according to any one of claims 4 to 6, wherein the refrigerating cycle apparatus is determined.
The refrigerating cycle device according to any one of claims 1 to 7, wherein the control device outputs a diagnosis result of the flow path of the second refrigerant in the first plate heat exchanger to a display unit. ..
The load-side refrigerant circuit is
With a strainer,
Further equipped with a differential pressure gauge or a flow meter,
The control device is
It is diagnosed that there is an abnormality in the flow path of the second refrigerant in the first plate heat exchanger, and the flow of the second refrigerant is higher than the reference value based on the measurement result of the differential pressure gauge or the flow meter. When it is determined that the amount has decreased, it is determined that the flow path of the second refrigerant in the first plate heat exchanger is clogged.
It is diagnosed that there is no abnormality in the flow path of the second refrigerant in the first plate heat exchanger, and the flow of the second refrigerant is based on the reference value based on the measurement result of the differential pressure gauge or the flow meter. The refrigerating cycle apparatus according to any one of claims 1 to 8, wherein it is determined that the strainer is clogged when it is determined that the amount is reduced.
The control device diagnoses that there is an abnormality in the flow path of the second refrigerant in the first plate heat exchanger when the first plate heat exchanger is functioning as an evaporator of the first refrigerant. If so, it is determined whether or not the temperature detected by the temperature sensor has reached the freezing determination temperature.
The one according to any one of claims 1 to 9, wherein the control device does not accept an operation of lowering the temperature of the second refrigerant when the temperature detected by the temperature sensor does not reach the freezing determination temperature. Refrigeration cycle equipment.
The control device diagnoses that there is an abnormality in the flow path of the second refrigerant in the first plate heat exchanger when the first plate heat exchanger is functioning as an evaporator of the first refrigerant. If so, it is determined whether or not the temperature detected by the temperature sensor has reached the freezing determination temperature.
The refrigerating cycle apparatus according to any one of claims 1 to 10, wherein the control device raises the temperature of the second refrigerant when the temperature detected by the temperature sensor reaches the freezing determination temperature. ..
A second heat exchanger that exchanges heat between the second compressor, the outside air and the third refrigerant, and a second refrigerant circuit on the heat source side having a second throttle mechanism.
Further, a second plate heat exchanger for heat exchange between the first refrigerant, the third refrigerant, and the second refrigerant is provided.
The second refrigerant circuit on the heat source side circulates the third refrigerant between at least the second compressor, the second heat exchanger, the second throttle mechanism, and the second plate heat exchanger.
The load-side refrigerant circuit circulates the second refrigerant in one direction at least between the pump, the load device, the first plate heat exchanger, and the second plate heat exchanger.
The refrigeration according to any one of claims 1 to 11, wherein the first plate heat exchanger and the second plate heat exchanger are connected in series to the load-side refrigerant circuit. Cycle device.
The control device is
When it is diagnosed that there is an abnormality in the flow path of the second refrigerant in the first plate heat exchanger and that there is no abnormality in the flow path of the second refrigerant in the second plate heat exchanger. To,
By stopping the operation of the first compressor and controlling the second compressor, the second plate flowing on the downstream side of the first plate heat exchanger and the second plate heat exchanger. The refrigeration cycle apparatus according to claim 12, wherein the temperature of the refrigerant is adjusted to a set target temperature.
A pressure sensor provided in the suction portion or the discharge portion of the first compressor is further provided.
The refrigeration cycle device according to any one of claims 1 to 13, wherein the control device specifies the saturation temperature based on a detection value of the pressure sensor.
It is further equipped with a saturation temperature sensor which is installed inside the first plate heat exchanger and detects the saturation temperature of the first refrigerant.
The refrigeration cycle device according to any one of claims 1 to 13, wherein the control device specifies the saturation temperature based on a detection value of the saturation temperature sensor.
The load-side refrigerant circuit further comprises a flow meter.
One of claims 1 to 15, wherein the control device determines whether or not the flow path of the second refrigerant in the first plate heat exchanger is clogged based on the measurement result of the flow meter. Refrigeration cycle device according to the section.
The load-side refrigerant circuit further comprises a differential pressure gauge.
One of claims 1 to 15, wherein the control device determines whether or not the flow path of the second refrigerant in the first plate heat exchanger is clogged based on the measurement result of the differential pressure gauge. Refrigeration cycle device according to the section.
The control device estimates the flow rate of the second refrigerant based on a predetermined calculation formula, and based on the estimation result, determines whether or not the flow path of the second refrigerant in the first plate heat exchanger is clogged. The refrigerating cycle apparatus according to any one of claims 1 to 15, which is determined.