Flashgas Removal From a Receiver in a Refrigeration Circuit

Abstract

Refrigeration circuit ( 2 ) for circulating a refrigerant in a predetermined flow direction, comprising in flow direction a heat rejecting heat exchanger ( 4 ), an intermediate throttle valve ( 6 ), a receiver ( 8 ), an evaporator throttle valve ( 10 ), an evaporator ( 14 ) a compressor ( 20 ), and a flash gas tapping line ( 26 ) connected to the receiver ( 8 ), wherein the flash gas tapping line ( 26 ) being further connected to the compressor ( 20 ).

1 . Refrigeration circuit ( 2 ) for circulating a refrigerant in a predetermined flow direction, comprising in flow direction a heat rejecting heat exchanger ( 4 ), an intermediate throttle valve ( 6 ), a receiver ( 8 ), an evaporator throttle valve ( 10 ), an evaporator ( 14 ) a compressor ( 20 ), and a flash gas tapping line ( 26 ) connected to the receiver ( 8 ), the flash gas tapping line ( 26 ) being further connected to the compressor ( 20 ). 
   
   
       2 . Refrigeration circuit ( 2 ) according to  claim 1  wherein the compressor ( 20 ) is of the type allowing for output adjustment, and further comprising a control ( 28 ) adjusting the capacity of the compressor ( 20 ) in accordance with the amount of flash gas. 
   
   
       3 . Refrigeration circuit ( 2 ) according to  claim 1 , further comprising a receiver pressure sensor ( 30 ). 
   
   
       4 . Refrigeration circuit ( 2 ) according to  claim 1 , wherein the flash gas tapping line ( 26 ) is in heat exchange relationship with the pressure line ( 24 ) connecting the compressor ( 20 ) to the heat rejecting heat exchanger ( 4 ). 
   
   
       5 . Refrigeration circuit ( 2 ) according to  claim 1 , wherein the heat rejecting heat exchanger is a gascooler ( 4 ). 
   
   
       6 . Refrigeration circuit ( 2 ) according to  claim 1 , wherein the compressor ( 20 ) is one of a plurality of compressors ( 20 ,  22 ) in a compressor unit ( 18 ). 
   
   
       7 . Refrigeration circuit ( 2 ) according to  claim 1 , wherein the flash gas tapping line ( 26 ) comprises a flash gas valve ( 36 ). 
   
   
       8 . Refrigeration circuit ( 2 ) according to  claim 1 , further comprising a suction gas valve ( 38 ) in a suction line ( 40 ) to the compressor ( 20 ). 
   
   
       9 . Refrigeration circuit ( 2 ) according to  claim 1 , further comprising a flash gas branch line ( 44 ) branching from the flash gas tapping line ( 26 ), comprising a flash gas discharge valve ( 46 ) and connecting to the suction line. 
   
   
       10 . Refrigeration apparatus comprising a refrigeration circuit ( 2 ) in accordance with  claim 1 . 
   
   
       11 . Method for operating a refrigeration circuit for circulating a refrigerant in a predetermined flow direction, comprising in flow direction a heat rejecting heat exchanger ( 4 ), an intermediate throttle valve ( 6 ), a receiver ( 8 ), an evaporator throttle valve ( 10 ), an evaporator ( 14 ) and a compressor ( 20 ), the method comprising the following steps:
 (a) tapping flash gas from the receiver ( 8 ); and (b) supplying the tapped flash gas to the compressor ( 20 ).   
   
   
       12 . Method according to  claim 11 , further including the step
 (c) adjusting the output of the compressor ( 20 ) in accordance with the amount of flash gas.   
   
   
       13 . Method according to  claim 11 , further including the step of measuring the receiver pressure. 
   
   
       14 . Method according to  claim 11 , further including the step of superheating the flash gas in advance of step (b). 
   
   
       15 . Method according to  claim 11 , further comprising in advance of performing steps (a) and (b) a step
 (d) deciding on the basis of operational conditions of the refrigeration circuit ( 2 ) as to whether to perform steps (a) and (b).   
   
   
       16 . Method in accordance with  claim 15 , comprising a step of supplying suction gas instead of supplying tap gas to the compressor ( 20 ).