Hyperloop environmental control system

Abstract

An environmental control system for conditioning a cabin of a vehicle positioned in an enclosed air-evacuated environment includes a first inlet for receiving a first medium, at least one inlet for receiving a second medium, and a thermodynamic device including a compressor and a plurality of turbines operably coupled by a shaft. The plurality of turbines includes a first turbine and a second turbine arranged in series relative to a flow of the first medium. Energy extracted from the second medium at one of the plurality of turbines is used to drive the compressor. The flow of the first medium and a first flow of the second medium are mixed to form a third medium at a first mixing point located downstream from the thermodynamic device relative to the flow of the first medium.

What is claimed is: 
     
         1 . An environmental control system for conditioning a cabin of a vehicle positioned in an enclosed air-evacuated environment, the environmental control system comprising:
 a first inlet for receiving a first medium;   at least one inlet for receiving a second medium;   a thermodynamic device including a compressor and a plurality of turbines operably coupled by a shaft, the plurality of turbines including a first turbine and a second turbine arranged in series relative to a flow of the first medium, wherein energy extracted from the second medium at one of the plurality of turbines is used to drive the compressor; and   a first mixing point at which the flow of the first medium and a first flow of the second medium are mixed to form a third medium, the first mixing point being arranged downstream from the thermodynamic device relative to the flow of the first medium.   
     
     
         2 . The environmental control system of  claim 1 , wherein the compressor is fluidly coupled to and located upstream from at least one of the first turbine and the second turbine relative to the flow of the first medium. 
     
     
         3 . The environmental control system of  claim 1 , further comprising:
 a bypass conduit arranged in parallel with the first turbine; and   a valve associated with the bypass conduit, the valve being operable to control the flow of the first medium within the bypass conduit.   
     
     
         4 . The environmental control system of  claim 1 , further comprising:
 a bypass conduit fluidly connected to the first inlet, the bypass conduit being arranged in parallel with the compressor; and   a valve associated with the bypass conduit, the valve being operable to control the flow of the first medium within the bypass conduit.   
     
     
         5 . The environmental control system of  claim 4 , further comprising a second mixing point fluidly coupled to the first mixing point and to the bypass conduit, wherein a conditioned medium is output from the second mixing point. 
     
     
         6 . The environmental control system of  claim 5 , further comprising a regeneration heat exchanger fluidly coupled to and located downstream from an outlet of the compressor and an outlet of one of the plurality of turbines. 
     
     
         7 . The environmental control system of  claim 6 , wherein energy extracted from a portion of the conditioned medium at one of the plurality of turbines is used to drive the compressor. 
     
     
         8 . The environmental control system of  claim 7 , wherein a portion of the conditioned medium and a second flow of the second medium is mixed to form a mixed medium at a location upstream from an inlet of the one of the plurality of turbines. 
     
     
         9 . The environmental control system of  claim 8 , wherein an outlet of the one of the plurality of turbines is fluidly coupled to an inlet of the regeneration heat exchanger such that the first medium is cooled by the mixed medium within the regeneration heat exchanger. 
     
     
         10 . The environmental control system of  claim 1 , further comprising at least one vessel of the first medium located on board the vehicle. 
     
     
         11 . The environmental control system of  claim 1 , wherein the vehicle is a train. 
     
     
         12 . A method of operating an environmental control system to condition a cabin of a vehicle positioned in an enclosed, air-evacuated tube, the method comprising:
 compressing a first medium within a compressor of a thermodynamic device to form a compressed first medium;   extracting energy from the compressed first medium at at least one turbine of the thermodynamic device to form an expanded first medium, the extracted energy being used to drive the compressor;   extracting energy from the expanded first medium at the at least one turbine of the thermodynamic device to form a further expanded first medium;   forming a conditioned medium including the further expanded first medium and a first flow of a second medium; and   extracting energy from a mixed medium at the at least one turbine of the thermodynamic device to form an expanded mixed medium.   
     
     
         13 . The method of  claim 12 , further comprising cooling the compressed first medium using the expanded mixed medium. 
     
     
         14 . The method of  claim 12 , wherein forming the conditioned flow further comprises:
 mixing the first flow of the second medium with the further expanded first medium to form a third medium; and   mixing the third medium with a flow of the first medium provided from a bypass conduit to form the conditioned medium, the flow of the first medium provided from the bypass conduit having bypassed the thermodynamic device.   
     
     
         15 . The method of  claim 14 , further comprising:
 providing a first portion of a flow of the conditioned medium to the cabin; and   providing a second portion of the flow of the conditioned medium to a cooling system.   
     
     
         16 . The method of  claim 15 , wherein providing the second portion of the flow of the conditioned medium to the cooling system further comprises removing heat from the cooling system. 
     
     
         17 . The method of  claim 15 , further comprising mixing the second portion of the flow of the conditioned medium with a second flow of the second medium to form the mixed medium. 
     
     
         18 . The method of  claim 12 , further comprising cooling the compressed first medium. 
     
     
         19 . The method of  claim 18 , wherein cooling the compressed first medium further comprises providing the expanded mixed medium and the compressed first medium to a regeneration heat exchanger.