Integrated receiver and suction line heat exchanger for refrigerant systems

Abstract

A refrigeration system may be provided with a space-saving suction-line heat exchanger. The heat exchanger may be incorporated into a receiver. As heated liquid refrigerant enters and flows through the receiver, it may transfer heat into the heat exchanger. The heat exchanger may be connected to a suction line of the system so that refrigerant vapor and an oil-refrigerant mixture may be heated as it passes from an evaporator and into an inlet of a compressor.

1 . A distributed cooling system for an aircraft, comprising:
 an evaporator;   a compressor;   a condenser; and   a receiver interposed between the condenser and the evaporator for receiving liquid refrigerant from the condenser, the receiver comprising an integral heat exchanger; and   the heat exchanger interposed between the evaporator and the compressor and configured to transfer heat from the liquid refrigerant in the receiver to a suction-line mixture emerging from the evaporator.   
     
     
         2 . The cooling system of  claim 1 , further comprising a head pressure control valve interposed between the compressor and an inlet of the receiver. 
     
     
         3 . The cooling system of  claim 1 , further comprising a bypass line through which liquid refrigerant can flow into the receiver without passing through the condenser. 
     
     
         4 . The cooling system of  claim 1 :
 wherein the receiver comprises an enclosure;   wherein the heat exchanger comprises:
 a serpentine tube; and 
 one or more baffles in contact with the serpentine tube; and 
 wherein the baffles are in contact with an interior of the enclosure. 
   
     
     
         5 . The cooling system of  claim 4 :
 wherein the baffles have outer peripheries; and   wherein a portion of the outer peripheries are spaced away from the interior of the enclosure so that flow passages for liquid refrigerant are interposed between the enclosure and non-contact portions of the outer peripheries of the baffles.   
     
     
         6 . A receiver for a refrigeration system comprising:
 an enclosure with an inlet for liquid refrigerant at a first end and an outlet for the liquid refrigerant at a second end; and   a heat exchanger with an inlet and an outlet for refrigerant vapor; wherein the heat exchanger is surrounded by the enclosure.   
     
     
         7 . The receiver of  claim 6  wherein the heat exchanger comprises:
 a tube for passage of refrigerant vapor; and 
 one or more baffles in contact with the tube for defining a flow path for the liquid refrigerant through the receiver. 
 
     
     
         8 . The receiver of  claim 7  wherein the tube is a serpentine tube. 
     
     
         9 . The receiver of  claim 7  wherein the baffles have a outer periphery, a first portion of which conforms in shape to a shape of an interior of the enclosure and a second portion of which does not conform to the shape of the interior of the enclosure so that a flow passage for the liquid refrigerant is present in a space between the second portion of the outer periphery and the interior of the enclosure. 
     
     
         10 . The receiver of  claim 9  wherein the first portion of the outer periphery of the baffle is in contact with the interior of the enclosure so that flow of the liquid refrigerant is directed to the flow passage. 
     
     
         11 . The receiver of  claim 9 , wherein the baffle is provided with one or more holes though which the tube passes. 
     
     
         12 . The receiver of  claim 11  wherein the tube is in contact with the baffle at the hole so that flow of the liquid refrigerant is directed to the flow passage. 
     
     
         13 . The receiver of  claim 12  further comprising:
 at least two of the baffles; and 
 wherein a first one of the flow passages formed by the a first one of the baffles is at a first side of the enclosure; and 
 wherein a second one of the flow passages formed by a second one of the baffles is at a second side of the enclosure so that the liquid refrigerant is constrained to flow from the first side of the enclosure to the second side of the enclosure to effectively transfer heat to the tube. 
 
     
     
         14 . A method for performing suction line heating in a refrigeration system comprising:
 passing a vapor and liquid mixture emerging from an evaporator through a heat exchanger incorporated in a receiver;   passing heated liquid refrigerant into the receiver and into contact with the heat exchanger;   transferring heat from the liquid refrigerant to the vapor; and   passing the heated vapor and liquid mixture to an inlet of a compressor.   
     
     
         15 . The method of  claim 14  wherein the step of transferring heat increases viscosity of an oil-refrigerant mixture entering the compressor. 
     
     
         16 . The method of  claim 14 , wherein the step of passing heated liquid refrigerant into the receiver comprises passing liquid refrigerant from a condenser of the refrigeration system into the receiver. 
     
     
         17 . The method of  claim 14 , wherein the step of passing heated liquid refrigerant into the receiver comprises passing liquid refrigerant from a bypass line connected to an outlet of the compressor into the receiver. 
     
     
         18 . The method of  claim 14 , wherein the step of passing heated liquid refrigerant into the receiver comprises the step of flowing the liquid refrigerant over one or more baffles. 
     
     
         19 . The method of  claim 18 :
 wherein the liquid refrigerant flows laterally across a first one of the baffles to a first side of the receiver;   wherein the liquid refrigerant flows laterally across a second one of the baffles to a second side of the receiver.   
     
     
         20 . The method of  claim 19 , wherein the liquid refrigerant flows past a tube through which the vapor and liquid mixture passes so that heat is transferred from the liquid refrigerant into the tube.