Vapor cycle system with de-superheater

Abstract

A vapor cycle system comprises a compressor for compressing a coolant to form a superheated vapor, a de-superheater for cooling the superheated vapor to form a reduced temperature vapor by exchanging heat with a cooling fluid flow, a condenser for condensing the reduced temperature vapor to form a condensed liquid by exchanging heat with the cooling fluid flow, and an evaporator for evaporating the condensed liquid. The de-superheater is located downstream of the condenser in the cooling fluid flow, and a temperature of the cooling fluid flow is higher at the de-superheater than at the condenser.

1 . A vapor cycle system comprising:
 a compressor for compressing a refrigerant to form a superheated vapor;   a de-superheater for cooling the superheated vapor to form a reduced temperature vapor by exchanging heat with a cooling fluid flow;   a condenser for condensing the reduced temperature vapor to form a condensed liquid by exchanging heat with the cooling fluid flow; and   an evaporator for evaporating the condensed liquid;   wherein the de-superheater is located downstream of the condenser in the cooling fluid flow, such that a temperature of the cooling fluid flow is higher at the de-superheater than at the condenser.   
     
     
         2 . The system of  claim 1 , wherein the cooling fluid flow comprises an air flow. 
     
     
         3 . The system of  claim 2 , further comprising an air cycle system for generating the air flow from at least one source selected from the group consisting of a ram air supply, a bleed air supply, or a third-stream air supply from an aircraft engine. 
     
     
         4 . The system of  claim 2 , wherein the de-superheater comprises an air-vapor heat exchanger to cool the superheated vapor by heat exchange with the air flow. 
     
     
         5 . The system of  claim 2 , further comprising a heat load located between the condenser and the de-superheater in the cooling air flow; wherein the heat load comprises a heat exchanger to cool a fluid by heat exchange with the air flow. 
     
     
         6 . The system of  claim 1 , wherein the cooling fluid flow comprises a fuel flow. 
     
     
         7 . The system of  claim 6 , wherein the de-superheater comprises a fuel-vapor heat exchanger to cool the superheated vapor by direct heat exchange with the fuel flow. 
     
     
         8 . The system of  claim 1 , further comprising a cooling loop for exchanging heat between a heat load and the evaporator. 
     
     
         9 . The system of  claim 8 , wherein the cooling loop comprises a heat exchanger located upstream of the condenser in the cooling fluid flow, such that the temperature of the cooling fluid flow is lower at the heat exchanger than at the condenser. 
     
     
         10 . The system of  claim 9 , wherein the heat load comprises at least one selected from the group consisting of a passenger cabin, a cargo bay, a galley, an avionics system, a radar system and power electronics for actuating a flight control surface. 
     
     
         11 . A thermal management system for an aircraft, the system comprising:
 a cooling loop, wherein the cooling loop circulates coolant inside the aircraft; and   a vapor cycle unit, wherein the vapor cycle unit operates on a fluid to cool the coolant, the vapor cycle unit comprising:
 a compressor, configured to compress the fluid to a superheated vapor phase; 
 a de-superheater, configured to cool the fluid from the superheated vapor phase to a cooled vapor phase by exchanging heat with a cooling flow; 
 a condenser, configured to condense the fluid from the cooled vapor phase to a condensed liquid phase by exchanging heat with the cooling flow; 
 an expansion device, configured to expand the fluid from the condensed liquid phase to an expanded phase; and 
 an evaporator, configured to cool the coolant by evaporation of the fluid from the expanded phase to the vapor phase; 
   wherein the de-superheater is located downstream of the condenser in the cooling flow, such that the cooling flow is hotter at the de-superheater than at the condenser.   
     
     
         12 . The system of  claim 11 , wherein the cooling flow comprises a fuel flow for the aircraft, and wherein the de-superheater comprises a vapor-fuel heat exchanger for cooling the superheated vapor phase by direct heat exchange with the fuel flow. 
     
     
         13 . The system of  claim 11 , wherein the cooling flow comprises a cooling air flow. 
     
     
         14 . The system of  claim 13 , further comprising a fuel cooler located downstream of the condenser and upstream of the de-superheater in the cooling air flow, such that the cooling flow is hotter at the de-superheater than at the fuel cooler. 
     
     
         15 . The system of  claim 13 , wherein the cooling loop comprises a heat exchanger located upstream of the condenser in the cooling air flow, such that the cooling air flow is colder at the heat exchanger than at the condenser. 
     
     
         16 . A method for cooling an aircraft system, the method comprising:
 circulating a coolant through the aircraft system;   cooling the coolant by exchanging heat with an evaporating fluid;   compressing the evaporating fluid to form a superheated vapor;   de-superheating the superheated vapor by exchanging heat with a cooling flow at a de-superheat temperature; and   condensing the superheated vapor by exchanging heat with the cooling flow at a condensation temperature, wherein the condensation temperature is lower than the de-superheat temperature.   
     
     
         17 . The method of  claim 16 , further comprising generating the cooling flow as a fuel flow for the aircraft by pumping fuel from a fuel tank. 
     
     
         18 . The method of  claim 16 , further comprising generating the cooling flow as a stream of cooling air by expansion of a compressed air source. 
     
     
         19 . The method of  claim 16 , further comprising cooling the coolant by exchanging heat with the cooling flow at a temperature lower than the condensation temperature. 
     
     
         20 . The method of  claim 16 , further comprising cooling a fuel flow for the aircraft by exchanging heat with the cooling flow at a temperature higher than the condensation temperature and lower than the de-superheat temperature.