Supercooling apparatus

Abstract

A subcooling unit ( 200 ) includes a refrigerant passage ( 205 ) connected to liquid side communication pipes ( 21, 22 ) of a refrigerating apparatus ( 10 ). When a subcooling compressor ( 221 ) is operated, subcooling refrigerant circulates in the subcooling refrigerant circuit ( 220 ) to perform a refrigeration cycle, thereby cooling refrigerant of the refrigerating apparatus ( 10 ) which flows in the refrigerant passage ( 205 ). A controller ( 240 ) of the subcooling unit ( 200 ) receives the detection value of a suction pressure sensor ( 234 ) and a refrigerant temperature sensor ( 236 ). The controller ( 240 ) utilizes input signals from the sensors ( 234, 236 ) to control driving operation of the subcooling compressor ( 221 ) on the basis of information obtained within the subcooling unit ( 200 ). Thus, the operation of the subcooling compressor ( 221 ) can be controlled without sending and receiving a singal to and from the refrigerating apparatus ( 10 ) to which the subcooling unit ( 200 ) is incorporated.

1 . A subcooling apparatus which is incorporated to a refrigerating apparatus ( 10 ) that performs a refrigeration cycle by circulating heat source side refrigerant between a heat source unit ( 11 ) and a utility unit ( 12 ,  13 ,  14 ) connected to each other by means of communication pipes and which cools the heat source side refrigerant in the refrigerating apparatus ( 10 ) sent from the heat source unit ( 11 ) to the utility unit ( 12 ,  13 ,  14 ), the subcooling apparatus, comprising: 
 a refrigerant passage ( 205 ) connected to liquid side communication pipes ( 21 ,  22 ) of the refrigerating apparatus ( 10 );    a cooling fluid circuit ( 220 ) in which cooling fluid flows;    a subcooling heat exchanger ( 210 ) for cooling the heat source side refrigerant in the refrigerant passage ( 205 ) by heat exchange with the cooling fluid; and    control means ( 240 ) for controlling a flowing state of the cooling fluid in the cooling fluid circuit ( 220 ) according to a flowing state of the heat source side refrigerant in the refrigerant passage ( 205 ).    
   
   
       2 . The subcooling apparatus of  claim 1 , 
 wherein the cooling fluid circuit is composed of a subcooling refrigerant circuit ( 220 ), and    the subcooling refrigerant circuit ( 220 ) includes a subcooling compressor ( 221 ) and performs a refrigeration cycle by circulating subcooling refrigerant as the cooling fluid.    
   
   
       3 . The subcooling apparatus of  claim 2 , 
 wherein the control means ( 240 ) controls a circulation state of the subcooling refrigerant in the subcooling refrigerant circuit ( 220 ) by controlling operation of the subcooling compressor ( 221 ).    
   
   
       4 . The subcooling apparatus of  claim 3 , 
 wherein the control means ( 240 ) detects a direction in which the heat source side refrigerant flows in the refrigerant passage ( 205 ) and a state in which the heat source side refrigerant flows or does not flow in refrigerant passage ( 205 ) in operation of the subcooling compressor ( 221 ) as the flowing state of the heat source side refrigerant, and the control means ( 240 ) allows the subcooling compressor ( 221 ) to continue operating in a state that the heat source side refrigerant flows from the heat source unit ( 11 ) towards the utility unit ( 12 ,  13 ,  14 ) in the refrigerant passage ( 205 ) or stops the operation of the subcooling compressor ( 221 ) in a state that the heat source side refrigerant flows from the utility unit ( 12 ,  13 ,  14 ) towards the heat source unit ( 11 ) in the refrigerant passage ( 205 ) or in a state that the heat source side refrigerant does not flow in the refrigerant passage ( 205 ).    
   
   
       5 . The subcooling apparatus of  claim 4   wherein the control means ( 240 ) activates the subcooling compressor ( 221 ) after a predetermined time period elapses from a time point when the subcooling compressor ( 221 ) is stopped.    
   
   
       6 . The subcooling apparatus of any one of claims  3 ,  4 , and  5 , further comprising: 
 refrigerant temperature detection means ( 236 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the utility unit ( 12 ,  13 ,  14 ) than the subcooling heat exchanger ( 210 ),    wherein the control means ( 240 ) judges the flowing state of the heat source side refrigerant on the basis of variation in detection value of the refrigerant temperature detection means ( 236 ) from a time point when the subcooling compressor ( 221 ) is activated.    
   
   
       7 . The subcooling apparatus of any one of claims  3 ,  4 , and  5 , further comprising: 
 refrigerant temperature detection means ( 236 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the utility unit ( 12 ,  13 ,  14 ) than the subcooling heat exchanger ( 210 ); and    evaporation temperature detection means ( 234 ) for detecting evaporation temperature of the subcooling refrigerant in the subcooling heat exchanger ( 210 ),    wherein the control means ( 240 ) judges the flowing state of the heat source side refrigerant on the basis of a detection value of the refrigerant temperature detection means ( 236 ) and a detection value of the evaporation temperature detection means ( 234 ).    
   
   
       8 . The subcooling apparatus of any one of claims  3 ,  4 , and  5 , further comprising: 
 first refrigerant temperature detection means ( 237 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the utility unit ( 12 ,  13 ,  14 ) than the subcooling heat exchanger ( 210 ); and    second refrigerant temperature detection means ( 238 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the heat source unit ( 11 ) than the subcooling heat exchanger ( 210 ),    wherein the control means ( 240 ) judges the flowing state of the heat source side refrigerant on the basis of a detection value of the first refrigerant temperature detection means ( 237 ) and a detection value of the second refrigerant temperature detection means ( 238 ).    
   
   
       9 . The subcooling apparatus of any one of claims  1 ,  2 , and  3 , 
 wherein a flow meter ( 251 ) is provided at the refrigerant passage ( 205 ) for detecting a flow rate of the heat source side refrigerant, and    the control means ( 240 ) uses a detection value of the flow meter ( 251 ) as a flowing state indication vale that indicates the flowing state of the heat source side refrigerant, and the control means ( 240 ) determines, on the basis of the flowing state indication value, whether the flow of the cooling fluid should be continued or stopped in a state that the cooling fluid flows in the cooling fluid circuit ( 220 ).    
   
   
       10 . The subcooling apparatus of any one of claims  1 ,  2 , and  3 , further comprising: 
 first refrigerant temperature detection means ( 237 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the utility unit ( 12 ,  13 ,  14 ) than the subcooling heat exchanger ( 210 ); and    second refrigerant temperature detection means ( 238 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the heat source unit ( 11 ) than the subcooling heat exchanger ( 210 ),    wherein the control means ( 240 ) uses a difference between a detection value of the first refrigerant temperature detection means ( 237 ) and a detection value of the second refrigerant temperature detection means ( 238 ) as a flowing state indication value that indicates the flowing state of the heat source side refrigerant, and the control means ( 240 ) determines, on the basis of the flowing state indication value, whether the flow of the cooling fluid should be continued or stopped in a state that the cooling fluid flows in the cooling fluid circuit ( 220 ).    
   
   
       11 . The subcooling apparatus of any one of claims  1 ,  2 , and  3 , further comprising: 
 refrigerant temperature detection means ( 236 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the utility unit ( 12 ,  13 ,  14 ) than the subcooling heat exchanger ( 210 ),    wherein the control means ( 240 ) uses variation in detection value of the refrigerant temperature detection means ( 236 ) as a flowing state indication value that indicates the flowing state of the heat source side refrigerant, and the control means ( 240 ) determines, on the basis of the flowing state indication value, whether the flow of the cooling fluid should be continued or stopped in a state that the cooling fluid flows in the cooling fluid circuit ( 220 ).    
   
   
       12 . The subcooling apparatus of any one of claims  1 ,  2 , and  3 , 
 wherein the cooling fluid circuit ( 220 ) includes inlet side fluid temperature detection means ( 252 ) for detecting temperature of the cooling fluid at an inlet of the subcooling heat exchanger ( 210 ) and outlet side fluid temperature detection means ( 253 ) for detecting temperature of the cooling fluid at an outlet of the subcooling heat exchanger ( 210 ), and    the control means ( 240 ) uses a difference between a detection value of the inlet side fluid temperature detection means ( 252 ) and a detection value of the outlet side fluid temperature detection means ( 253 ) as a flowing state indication value that indicates the flowing state of the heat source side refrigerant, and the control means ( 240 ) determines, on the basis of the flowing state indication value, whether the flow of the cooling fluid should be continued or stopped in a state that the cooling fluid flows in the cooling fluid circuit ( 220 ).    
   
   
       13 . The subcooling apparatus of  claim 2  or  3 , 
 wherein the subcooling refrigerant circuit ( 220 ) includes evaporation pressure detection means ( 234 ) for detecting evaporation pressure of the subcooling refrigerant in the subcooling heat exchanger ( 210 ), and    the control means ( 240 ) uses a detection value of the evaporation pressure detection means ( 234 ) as a flowing state indication value that indicates the flowing state of the heat source side refrigerant, and the control means ( 240 ) determines, on the basis of the flowing state indication value, whether circulation of the subcooling fluid should be continued or stopped in a state that the subcooling fluid circulates in the cooling fluid circuit ( 220 ).    
   
   
       14 . The subcooling apparatus of  claim 2  or  3 , further comprising: 
 refrigerant temperature detection means ( 236 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the utility unit ( 12 ,  13 ,  14 ) than the subcooling heat exchanger ( 210 ); and    evaporation temperature detection means ( 234 ) for detecting evaporation temperature of the subcooling refrigerant in the subcooling heat exchanger ( 210 ),    wherein the control means ( 240 ) uses a difference between a detection value of the refrigerant temperature detection means ( 236 ) and a detection value of the evaporation temperature detection means ( 234 ) as a flowing state indication value that indicates the flowing state of the heat source side refrigerant, and the control means ( 240 ) determines, on the basis of the flowing state indication value, whether circulation of the subcooling refrigerant should be continued or stopped in a state that the subcooling refrigerant circulates in the subcooling refrigerant circuit ( 220 ).    
   
   
       15 . The subcooling apparatus of any one of claims  1 ,  2  and  3 , further comprising: 
 refrigerant temperature detection means ( 236 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the utility unit ( 12 ,  13 ,  14 ) than the subcooling heat exchanger ( 210 ),    wherein the control means ( 240 ) uses a detection value of the refrigerant temperature detection means ( 236 ) as a flowing state indication value that indicates the flowing state of the heat source side refrigerant, and the control means ( 240 ) determines, on the basis of the flowing state indication value, whether the flow of the cooling fluid should be started or kept stopping in a state that the cooling fluid stops flowing in the cooling fluid circuit ( 220 ).    
   
   
       16 . The subcooling apparatus of any one of claims  1 ,  2  and  3 , further comprising: 
 refrigerant temperature detection means ( 236 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the utility unit ( 12 ,  13 ,  14 ) than the subcooling heat exchanger ( 210 ),    wherein the control means ( 240 ) uses variation in detection value of the refrigerant temperature detection means ( 236 ) as a flowing state indication value that indicates the flowing state of the heat source side refrigerant, and the control means ( 240 ) determines, on the basis of the flowing state indication value, whether the flow of the cooling fluid should be started or kept stopping in a state that the cooling fluid stops flowing in the cooling fluid circuit ( 220 ).    
   
   
       17 . The subcooling apparatus of  claim 2  and  3 , further comprising: 
 outside air temperature detection means ( 231 ) for detecting temperature of outside air; and    refrigerant temperature detection means ( 236 ) for detecting temperature of the heat source side refrigerant at a part of the refrigerant passage ( 205 ) nearer the utility unit ( 12 ,  13 ,  14 ) than the subcooling heat exchanger ( 210 ),    wherein the control means ( 240 ) uses a difference between a detection value of the refrigerant temperature detection means ( 236 ) and a detection value of the outside air temperature detection means ( 231 ) as a flowing state indication value that indicates the flowing state of the heat source side refrigerant, and the control means ( 240 ) determines, on the basis of the flowing state indication value, whether the flow of the subcooling refrigerant should be started or kept stopping in a state that the subcooling refrigerant stops flowing in the subcooling refrigerant circuit ( 220 ).    
   
   
       18 . A subcooling apparatus which is incorporated to a refrigerating apparatus ( 10 ) that performs a refrigeration cycle by circulating heat source side refrigerant between a heat source unit ( 11 ) and a utility unit ( 12 ,  13 ,  14 ) connected to each other by means of communication pipes and which cools the heat source side refrigerant in the refrigerating apparatus ( 10 ) sent from the heat source unit ( 11 ) to the utility unit ( 12 ,  13 ,  14 ), 
 wherein the heat source unit ( 11 ) of the refrigerating apparatus ( 10 ) performs heat exchange between the heat source side refrigerant and outdoor air,    the subcooling apparatus comprising:    a refrigerant passage ( 205 ) connected to liquid side communication pipes ( 21 ,  22 ) of the refrigerating apparatus ( 10 );    a cooling fluid circuit ( 220 ) in which cooling fluid flows;    a subcooling heat exchanger ( 210 ) for cooling the heat source side refrigerant in the refrigerant passage ( 205 ) by heat exchange with the cooling fluid;    outside air temperature detection means ( 231 ) for detecting temperature of outside air; and    control means ( 240 ) for controlling a flowing state of the cooling fluid in the cooling fluid circuit ( 220 ) according to a detection value of the outside air temperature detection means ( 231 ).    
   
   
       19 . The subcooling apparatus of  claim 18 , 
 wherein the cooling fluid circuit is composed of a subcooling refrigerant circuit ( 220 ), and    the subcooling refrigerant circuit ( 220 ) includes a subcooling compressor ( 221 ) and performs a refrigeration cycle by circulating the subcooling refrigerant as the cooling fluid.    
   
   
       20 . The subcooling apparatus of  claim 18  or  19 , 
 wherein the control means ( 240 ) determines, on the basis of a detection value of the outside air temperature detection means ( 231 ), whether the flow of the cooling fluid should be continued or stopped in a state that the cooling fluid flows in the cooling fluid circuit ( 220 ).    
   
   
       21 . The subcooling apparatus of  claim 18  or  19 , 
 wherein the control means ( 240 ) determines, on the basis of a detection value of the outside air temperature detection means ( 231 ), whether the flow of the cooling fluid should be started or kept stopping in a state that the cooling fluid does not flow in the cooling fluid circuit ( 220 ).    
   
   
       22 . The subcooling apparatus of  claim 2  or  19 , further comprising: 
 heat radiation heat exchanger ( 222 ) connected to the subcooling refrigerant circuit ( 220 ) for performing heat exchange between the subcooling refrigerant and outside air; and    outdoor fan ( 230 ) for supplying outdoor air to the heat radiation heat exchanger ( 222 ),    wherein the subcooling refrigerant circuit ( 220 ) is capable of performing natural circulation operation that allows the subcooling refrigerant to naturally circulate by operating the outdoor fan ( 230 ) in non-operation of the subcooling compressor ( 221 ), and    the control means ( 240 ) allows the subcooling refrigerant circuit ( 220 ) to perform the natural circulation operation by activating the outdoor fan ( 230 ) in order to start circulation of the subcooling refrigerant, and the control means ( 240 ) determines whether the subcooling compressor ( 221 ) should be activated or kept stopping according to the flowing state of the heat source side refrigerant in the refrigerant passage ( 205 ) in natural circulation operation.