Refrigeration cycle apparatus

Abstract

A refrigeration cycle apparatus comprises a refrigerant circuit, a water circuit, and a control device. The refrigerant circuit includes a compressor, a four-way valve, a heat exchanger, a fan, a diaphragm mechanism, a water heat exchanger, and an accumulator. Based on a value of a low-pressure sensor or a high-pressure sensor and a water temperature on an outlet side of the water heat exchanger, the refrigeration cycle apparatus determines whether or not there is an abnormality due to dirtiness adhered to a plate inside the water heat exchanger.

1 . A refrigeration cycle apparatus comprising:
 a heat-source-side first refrigerant circuit configured to circulate a first refrigerant, the heat-source-side first refrigerant circuit having
 a first compressor, 
 a first heat exchanger configured to exchange heat between outside air and the first refrigerant, and 
 a first diaphragm mechanism; 
   a load-side refrigerant circuit configured to circulate a second refrigerant, the load-side refrigerant circuit having
 a pump, and 
 a load apparatus configured to use heat; 
   a first plate type heat exchanger configured to exchange heat between the first refrigerant and the second refrigerant; and   a temperature sensor configured to detect a temperature of the second refrigerant on an outlet side of the first plate type heat exchanger, wherein   the heat-source-side first refrigerant circuit circulates the first refrigerant at least among the first compressor, the first heat exchanger, the first diaphragm mechanism, and the first plate type heat exchanger, and   the load-side refrigerant circuit circulates the second refrigerant in one direction at least among the pump, the load apparatus, and the first plate type heat exchanger,   the refrigeration cycle apparatus further comprising a control device configured to diagnose a flow path for the second refrigerant in the first plate type heat exchanger using the temperature detected by the temperature sensor and a saturation temperature of the first refrigerant wherein,   when it is diagnosed that there is an abnormality in the flow path for the second refrigerant in the first plate type heat exchanger while the first plate type heat exchanger functions as an evaporator for the first refrigerant, the control device determines whether or not the temperature detected by the temperature sensor reaches a freezing determination temperature, and   the control device does not accept an operation of decreasing the temperature of the second refrigerant when the temperature detected by the temperature sensor does not reach the freezing determination temperature.   
     
     
         2 . The refrigeration cycle apparatus according to  claim 1 , wherein the control device controls a frequency of the first compressor to adjust, to a set target temperature, the temperature of the second refrigerant on the outlet side of the first plate type heat exchanger. 
     
     
         3 . The refrigeration cycle apparatus according to  claim 1 , wherein the control device diagnoses the flow path for the second refrigerant in the first plate type heat exchanger based on a temperature difference between the temperature detected by the temperature sensor and the saturation temperature of the first refrigerant. 
     
     
         4 . The refrigeration cycle apparatus according to  claims 1 , wherein the control device determines whether or not there is leakage of the first refrigerant. 
     
     
         5 . The refrigeration cycle apparatus according to  claim 4 , wherein when diagnosing the flow path for the second refrigerant in the first plate type heat exchanger, the control device determines whether or not there is the leakage of the first refrigerant. 
     
     
         6 . The refrigeration cycle apparatus according to  claim 4 , wherein when the first plate type heat exchanger functions as an evaporator for the first refrigerant, the control device determines whether or not there is the leakage of the first refrigerant, based on a degree of supercooling on the outlet side of the first heat exchanger and a degree of discharge superheating of the heat-source-side first refrigerant circuit. 
     
     
         7 . The refrigeration cycle apparatus according to  claim 4 , wherein when the first plate type heat exchanger functions as a condenser for the first refrigerant, the control device determines whether or not there is the leakage of the first refrigerant, based on a degree of discharge superheating of the heat-source-side first refrigerant circuit. 
     
     
         8 . The refrigeration cycle apparatus according to  claim 1 , wherein the control device outputs, to a display unit, a diagnosis result for the flow path for the second refrigerant in the first plate type heat exchanger. 
     
     
         9 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the load-side refrigerant circuit further comprises
 a strainer, and 
 a differential manometer or a flowmeter, 
   when it is diagnosed that there is an abnormality in the flow path for the second refrigerant in the first plate type heat exchanger and it is determined that flow of the second refrigerant is lower than a reference value based on a measurement result of the differential manometer or the flowmeter, the control device determines that there is clogging in the flow path for the second refrigerant in the first plate type heat exchanger, and   when it is diagnosed that there is no abnormality in the flow path for the second refrigerant in the first plate type heat exchanger and it is determined that the flow of the second refrigerant is lower than the reference value based on the measurement result of the differential manometer or the flowmeter, the control device determines that there is clogging in the strainer.   
     
     
         10 . (canceled) 
     
     
         11 . The refrigeration cycle apparatus according to  claim 1 , wherein
 when it is diagnosed that there is an abnormality in the flow path for the second refrigerant in the first plate type heat exchanger while the first plate type heat exchanger functions as an evaporator for the first refrigerant, the control device determines whether or not the temperature detected by the temperature sensor reaches a freezing determination temperature, and   the control device increases the temperature of the second refrigerant when the temperature detected by the temperature sensor reaches the freezing determination temperature.   
     
     
         12 . The refrigeration cycle apparatus according to  claim 1 , further comprising:
 a heat-source-side second refrigerant circuit having a second compressor, a second heat exchanger configured to exchange heat between the outside air and a third refrigerant, and a second diaphragm mechanism; and   a second plate type heat exchanger configured to exchange heat between the second refrigerant and each of the first refrigerant and the third refrigerant, wherein   the heat-source-side second refrigerant circuit circulates the third refrigerant at least among the second compressor, the second heat exchanger, the second diaphragm mechanism, and the second plate type heat exchanger,   the load-side refrigerant circuit circulates the second refrigerant in one direction at least among the pump, the load apparatus, the first plate type heat exchanger, and the second plate type heat exchanger, and   the first plate type heat exchanger and the second plate type heat exchanger are connected to the load-side refrigerant circuit in series.   
     
     
         13 . The refrigeration cycle apparatus according to  claim 12 , wherein when it is diagnosed that there is an abnormality in the flow path for the second refrigerant in the first plate type heat exchanger and it is diagnosed that there is no abnormality in the flow path for the second refrigerant in the second plate type heat exchanger, the control device stops an operation of the first compressor and controls the second compressor to adjust, to a set target temperature, the temperature of the second refrigerant flowing on a downstream side with respect to the first plate type heat exchanger and the second plate type heat exchanger. 
     
     
         14 . The refrigeration cycle apparatus according to  claim 1 , further comprising a pressure sensor provided at a suction portion or discharge portion of the first compressor, wherein
 the control device specifies the saturation temperature based on a detection value of the pressure sensor.   
     
     
         15 . The refrigeration cycle apparatus according to  claim 1 , further comprising a saturation temperature sensor configured to detect the saturation temperature of the first refrigerant, the saturation temperature sensor being disposed inside the first plate type heat exchanger, wherein
 the control device specifies the saturation temperature based on a detection value of the saturation temperature sensor.   
     
     
         16 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the load-side refrigerant circuit further comprises a flowmeter, and   the control device determines whether or not there is clogging in the flow path for the second refrigerant in the first plate type heat exchanger based on a measurement result of the flowmeter.   
     
     
         17 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the load-side refrigerant circuit further comprises a differential manometer, and   the control device determines whether or not there is clogging in the flow path for the second refrigerant in the first plate type heat exchanger based on a measurement result of the differential manometer.   
     
     
         18 . The refrigeration cycle apparatus according to  claim 1 , wherein the control device estimates a flow rate of the second refrigerant based on a predetermined calculation formula, and determines whether or not there is clogging in the flow path for the second refrigerant in the first plate type heat exchanger based on an estimation result.