Direct Expansion Evaporator Coil with Ejector Capacity Boost for Low Liquid Temperature and Economized Systems

Abstract

A system and method for increasing the refrigeration capacity of an economized direct expansion refrigeration system employing two-phase refrigerant as the motive flow for an ejector to recirculate liquid refrigerant to the evaporator. After the throttling process at the expansion device, the mixture of liquid and vapor enters the inlet separator. An optional separator sends two phase refrigerant (liquid and vapor) to the ejector to drive recirculation of liquid refrigerant to the evaporator and liquid refrigerant to the evaporator.

1 . An apparatus for improving the performance of a direct expansion refrigeration system, the apparatus comprising:
 an inlet separator adapted to be connected to an expansion device outlet of said direct expansion refrigeration system, said inlet separator having a liquid refrigerant outlet and a two-phase refrigerant outlet,   an evaporator having an evaporator inlet directly connected to said inlet separator liquid outlet,   an ejector having a motive flow inlet directly connected to said inlet separator two-phase refrigerant outlet,   an evaporator outlet refrigerant line connected at a first end to an outlet of said evaporator, said evaporator outlet having an evaporator outlet liquid refrigerant line and an evaporator outlet vapor refrigerant line,   said evaporator outlet liquid refrigerant line connected to a side port of said ejector,   said evaporator outlet vapor refrigerant line connected to a compressor,   said inlet separator configured to simultaneously and continuously deliver two-phase refrigerant to said ejector and refrigerant liquid to said evaporator.   
     
     
         2 . An apparatus according to  claim 1 , wherein said inlet separator is configured to simultaneously and continuously deliver two-phase refrigerant directly to said ejector and refrigerant liquid directly to said evaporator via the evaporator inlet. 
     
     
         3 . An apparatus according to  claim 1 , wherein said inlet separator and said ejector are combined in an integrated refrigerant recycling device. 
     
     
         4 . An apparatus according to  claim 1 , wherein said evaporator inlet is a distributor or liquid header. 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . (canceled) 
     
     
         8 . A direct expansion refrigeration system comprising:
 a refrigerant line connecting the following, in order of refrigerant flow:   an expansion device,   an ejector;   an evaporator, and   a compressor,   said expansion device is configured to deliver two-phase refrigerant to a motive inlet of said ejector, said evaporator is configured to deliver liquid refrigerant to a recirculating liquid inlet of said ejector, and said ejector is configured to deliver two phase refrigerant to said evaporator.   
     
     
         9 . An apparatus for improving the performance of a direct expansion refrigeration system, the apparatus comprising:
 an inlet separator adapted to be connected to an expansion device outlet of said direct expansion refrigeration system, said inlet separator having a liquid refrigerant outlet and a vapor refrigerant outlet,   an evaporator having an evaporator inlet directly connected to said inlet separator vapor outlet,   an ejector having a motive flow inlet directly connected to said inlet separator liquid refrigerant outlet,   an evaporator outlet header having a vapor outlet refrigerant line and a liquid outlet refrigerant line,   said evaporator outlet header outlet liquid refrigerant line connected to a recirculating liquid inlet of said ejector,   said evaporator outlet header vapor outlet refrigerant line connected to a compressor,   said inlet separator configured to simultaneously and continuously deliver vapor refrigerant to said evaporator inlet and liquid refrigerant to said ejector.   
     
     
         10 .- 14 . (canceled) 
     
     
         15 . The apparatus of  claim 1 , wherein said evaporator inlet comprises a distributor. 
     
     
         16 . The apparatus of  claim 9 , wherein said evaporator inlet comprises a distributor.