Integrated environmental control systems and methods for controlling environmental temperature of an enclosed space

Abstract

Environmental control systems and methods to control environmental temperature of an enclosed space by integrating a passive heat exchange subsystem (e.g., a loop heat pipe (LHP) heat exchange subsystem) having a closed loop heat exchange fluid circuit in heat-exchange relationship with the enclosed space for providing environmental temperature control therewithin, a RAM-air subsystem having a RAM-air circuit for circulating RAM cooling air, and a vapor compression cycle machine (VCM) subsystem having a VCM fluid circuit having a compressor, an evaporator, a condenser and an expansion valve.

What is claimed is: 
     
         1 . An environmental control system for controlling environmental temperature of an enclosed space comprising:
 a passive phase change heat exchange subsystem having a closed loop heat exchange fluid circuit in heat-exchange relationship with the enclosed space for providing environmental temperature control therewithin;   a second RAM-air subsystem having an air circuit for circulation of cooling air; and   a third vapor closed loop compression cycle machine (VCM) subsystem having a VCM fluid circuit comprising a compressor, an evaporator, a condenser and an expansion valve, wherein   the evaporator of the VCM subsystem is in operative heat-exchange relationship with the heat exchange fluid circuit of the passive heat exchange subsystem, and wherein   the condenser of the VCM subsystem is in operative heat-exchange relationship with the air circuit of the RAM-air subsystem.   
     
     
         2 . The environmental control system of  claim 1 , wherein the passive heat exchange subsystem comprises a primary condenser in operative heat-exchange relationship with the VCM evaporator of the VCM subsystem. 
     
     
         3 . The environmental control system of  claim 2 , wherein the passive heat exchange subsystem comprises a secondary skin heat exchange (SHX) condenser, and a control valve for directing the working fluid to either the primary condenser or the secondary SHX condenser. 
     
     
         4 . The environmental control system of  claim 2 , wherein the air circuit of the RAM-air subsystem includes an air duct having an inlet and an inlet control door for controlling air flow into the duct, and a cooling fan for drawing air into the inlet and through the duct. 
     
     
         5 . The environmental control system of  claim 4 , wherein the RAM-air subsystem comprises an embedded skin heat exchange (SHX) in operative heat-exchange relationship with the air flow in the duct. 
     
     
         6 . The environmental control system of  claim 5 , wherein
 the passive heat exchange subsystem comprises a primary condenser in operative heat-exchange relationship with the VCM evaporator of the VCM subsystem, and a skin heat exchange (SHX) condenser, and wherein   the system further comprises a control valve for directing the working fluid to either the primary condenser of the passive heat exchange subsystem, the secondary SHX condenser of the passive heat exchange subsystem or the embedded skin heat exchanger SHX of the RAM-air subsystem.   
     
     
         7 . The environmental control system of  claim 1 , wherein the VCM subsystem further includes a VCM skin heat exchange (SHX) condenser downstream of the VCM condenser. 
     
     
         8 . The environmental control system of  claim 7 , wherein the VCM SHX condenser is in operative heat exchange relationship with an on-board fluid. 
     
     
         9 . The environmental control system of  claim 8 , wherein the on-board fluid is on-board fuel or cabin air. 
     
     
         10 . The environmental control system of  claim 7 , wherein the VCM subsystem includes a bypass valve to direct the VCM fluid circuit to or bypass the VCM fluid circuit around the VCM condenser SHX. 
     
     
         11 . An aircraft which comprises an environmental control system according to any one of  claims 1 - 10 . 
     
     
         12 . A method for controlling environmental temperature of an enclosed space comprising:
 (a) controlling the environmental temperature within the enclosed space by circulating a working heat exchange fluid within a passive heat exchange subsystem having a closed loop heat exchange fluid circuit in heat-exchange relationship with the enclosed space; and   (b) integrating heat-exchange of the working fluid of the passive heat exchange subsystem with (1) an air circuit of a RAM-air subsystem and (2) a vapor compression machine (VCM) fluid circuit of a VCM subsystem by:
 (i) establishing a heat-exchange relationship between the working heat exchange fluid circuit of the passive heat exchange subsystem and an evaporator of the VCM subsystem; and 
 (ii) establishing a heat-exchange relationship between the air circuit of the RAM-air subsystem and a condenser of the VCM subsystem. 
   
     
     
         13 . The method of  claim 12 , wherein step (b)(i) comprises providing the passive heat exchange subsystem with a primary condenser and establishing a heat-exchange relationship between the primary condenser and the VCM evaporator of the VCM subsystem. 
     
     
         14 . The method of  claim 13 , which further comprises providing the passive heat exchange subsystem with a secondary skin heat exchange (SHX) condenser, and controllably directing the working heat exchange fluid to either the primary condenser or the secondary SHX condenser. 
     
     
         15 . The method of  claim 14 , which further comprises providing the air circuit with an air duct having an inlet and an inlet control door for controlling air flow into the duct, and a cooling fan for drawing air into the inlet and through the duct. 
     
     
         16 . The method of  claim 15 , which further comprises providing the Ram-air subsystem with an embedded skin heat exchanger (SHX) device and establishing an operative heat-exchange relationship between the embedded SHX device and air flow in the duct. 
     
     
         17 . The method of  claim 16 , which further comprises controllably directing the working heat exchange fluid in the passive heat exchange subsystem to either the primary condenser of the passive heat exchange subsystem, the secondary SHX condenser of the passive heat exchange subsystem or the embedded SHX device of the RAM-air subsystem. 
     
     
         18 . The method of  claim 12 , which further comprises providing the VCM subsystem with a VCM skin heat exchanger (SHX) condenser downstream of a VCM condenser. 
     
     
         19 . The method of  claim 18 , which further comprises establishing a heat-exchange relationship between the VCM SHX condenser and an on-board fluid. 
     
     
         20 . The method of  claim 19 , wherein the on-board fluid is on-board fuel or cabin air. 
     
     
         21 . The method of  claim 18 , which further comprises allowing the VCM fluid circuit to bypass the VCM SHX condenser in response to a predetermined environmental condition. 
     
     
         22 . The method of  claim 18 , which further comprises utilizing heat released from the VCM condenser SHX as ice and rain protection of an external surface which contains the SHX. 
     
     
         23 . The method of  claim 17 , which further comprises utilizing heat released from the secondary SHX condenser of the passive heat exchange subsystem as ice and rain protection of an external surface which contains the SHX.