Subcooling 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 a 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 an outside air temperature sensor ( 231 ) or a refrigerant temperature sensor ( 236 ). The controller ( 240 ) controls the operation of the subcooling compressor ( 221 ) with the use of only information obtainable within the subcooling unit ( 200 ).

1 . A subcooling apparatus which is incorporated to a refrigerating apparatus ( 10 ) that performs a vapor compression refrigeration cycle by circulating 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 refrigerant of 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 of the refrigerating apparatus ( 10 );   a cooling fluid circuit ( 220 ) including a subcooling heat exchanger ( 210 ) that cools the refrigerant of the refrigerant passage ( 205 ) by heat exchange with cooling fluid; and   control means ( 240 ) for adjusting cooling temperature of the refrigerant of the refrigerant passage ( 205 ) in the subcooling heat exchanger ( 210 ) on the basis of an ambient condition of the subcooling heat exchanger ( 210 ).   
   
   
       2 . The subcooling apparatus of  claim 1 , wherein the control means ( 240 ) includes a control section ( 242 ) for adjusting a flow rate of the cooling fluid flowing in the subcooling heat exchanger ( 210 ) on the basis of a target cooling temperature of the refrigerant of the refrigerant passage ( 205 ) in the subcooling heat exchanger ( 210 ) which is set in advance according to the ambient condition of the subcooling heat exchanger ( 210 ). 
   
   
       3 . The subcooling apparatus of  claim 2 ,
 wherein the cooling fluid circuit serves as a subcooling refrigerant circuit ( 220 ) which includes a capacity variable subcooling compressor ( 221 ) and a heat source side heat exchanger ( 222 ) and which performs the vapor compression refrigeration cycle by circulating subcooling refrigerant as the cooling fluid, and   the control section ( 242 ) of the control means ( 240 ) adjusts a flow rate of the subcooling refrigerant flowing in the subcooling heat exchanger ( 210 ) by controlling operation frequency of the subcooling compressor ( 221 ) on the basis of the target cooling temperature.   
   
   
       4 . The subcooling apparatus of  claim 2 ,
 wherein the cooling fluid circuit serves as a subcooling refrigerant circuit ( 220 ) which includes a capacity variable subcooling compressor ( 221 ) and a heat source side heat exchanger ( 222 ) and which performs the vapor compression refrigeration cycle by circulating subcooling refrigerant as the cooling fluid, and   the control section ( 242 ) of the control means ( 240 ) adjusts a flow rate of the subcooling refrigerant flowing in the subcooling heat exchanger ( 210 ) by controlling operation frequency of a fan ( 230 ) of the heat source side heat exchanger ( 222 ) on the basis of the target cooling temperature.   
   
   
       5 . The subcooling apparatus of  claim 3 ,
 wherein the control section ( 242 ) of the control means ( 240 ) controls the operation frequency of the subcooling compressor ( 221 ) on the basis of difference between the target cooling temperature and temperature of the refrigerant of the refrigerant passage ( 205 ) which is cooled in the subcooling heat exchanger ( 210 ).   
   
   
       6 . The subcooling apparatus of  claim 3 ,
 wherein the control section ( 242 ) of the control means ( 240 ) controls the operation frequency of the subcooling compressor ( 221 ) on the basis of difference between the target cooling temperature and set temperature set from saturation temperature corresponding to low pressure of the subcooling refrigerant of the subcooling refrigerant circuit ( 220 ).   
   
   
       7 . The subcooling apparatus of  claim 3 ,
 wherein the control section ( 242 ) of the control means ( 240 ) controls the operation frequency of the subcooling compressor ( 221 ) on the basis of difference between the target cooling temperature and set temperature set from suction temperature of the subcooling compressor ( 221 ).   
   
   
       8 . The subcooling apparatus of  claim 4 ,
 wherein the control section ( 242 ) of the control means ( 240 ) controls the operation frequency of the fan ( 230 ) on the basis of difference between the target cooling temperature and temperature of the refrigerant of the refrigerant passage ( 205 ) which is cooled in the subcooling heat exchanger ( 210 ).   
   
   
       9 . The subcooling apparatus of  claim 4 ,
 wherein the control section ( 242 ) of the control means ( 240 ) controls the operation frequency of the fan ( 230 ) on the basis of difference between the target cooling temperature and set temperature set from saturation temperature corresponding to low pressure of the subcooling refrigerant in the subcooling refrigerant circuit ( 220 ).   
   
   
       10 . The subcooling apparatus of  claim 4 ,
 wherein the control section ( 242 ) of the control means ( 240 ) controls the operation frequency of the fan ( 230 ) on the basis of difference between the target cooling temperature and set temperature set from suction temperature of the subcooling compressor ( 221 ).   
   
   
       11 . The subcooling apparatus of  claim 1 ,
 wherein the ambient condition of the subcooling heat exchanger ( 210 ) is outside air temperature.   
   
   
       12 . The subcooling apparatus of  claim 1 ,
 wherein the ambient condition of the subcooling heat exchanger ( 210 ) is a flow rate of the refrigerant of the refrigerant passage ( 205 ).   
   
   
       13 . The subcooling apparatus of  claim 1 ,
 wherein the ambient condition of the subcooling heat exchanger ( 210 ) is temperature of the refrigerant of the refrigerant passage ( 205 ) before cooled in the subcooling heat exchanger ( 210 ) or temperature of the refrigerant of the refrigerant passage ( 205 ) after cooled in the subcooling heat exchanger ( 210 ).   
   
   
       14 . The subcooling apparatus of  claim 1 ,
 wherein the cooling fluid circuit is a subcooling refrigerant circuit ( 220 ) that performs a vapor compression refrigeration cycle by circulating subcooling refrigerant as the cooling fluid, and   the ambient condition of the subcooling heat exchanger ( 210 ) is low pressure or high pressure of the subcooling refrigerant in the subcooling refrigerant circuit ( 220 ).   
   
   
       15 . The subcooling apparatus of  claim 1 ,
 wherein the cooling fluid circuit is a subcooling refrigerant circuit ( 220 ) that performs a vapor compression refrigeration cycle by circulating subcooling refrigerant as the cooling fluid, and   the ambient condition of the subcooling heat exchanger ( 210 ) is temperature of the subcooling refrigerant after cooled, in the subcooling heat exchange ( 210 ), the refrigerant of the refrigerant passage ( 205 ).