Air cycle refrigeration system

An air cycle refrigeration system which comprises:

• an air-to-air heat exchanger including a system air inlet and outlet and a coolant air inlet and outlet, the coolant air outlet of said heat exchanger comprising a discharge plenum;
• first coupling means for coupling the system air inlet of said heat exchanger to a source of high-pressure, high temperature system air;
• second coupling means for coupling the coolant air inlet of said heat exchanger to a source of coolant air;
• a first turbocharger including a first turbine drivingly coupled to a first compressor, the first turbine having an inlet and an outlet, the inlet of the first turbine being connected with the system air outlet of said heat exchanger, the first compressor having an inlet and an outlet, the inlet of the first compressor being connected with the coolant air outlet of said heat exchanger;
• a first ejector pump means having a first inlet connected with the first compressor outlet and a second inlet connected with the coolant air outlet of said heat exchanger, said first ejector pump means further including an outlet, said first ejector pump means being for receiving air from the first compressor outlet into the first inlet in a manner to draw additional inlet air from the coolant air outlet and through the second inlet of said first ejector pump means and exhausting the air,
• the outlet system air from the outlet of the heat exchanger driving the first turbine and being exhausted therefrom at a reduced temperature, the first turbine in turn driving the first compressor which draws air from the plenum of said heat exchanger, the first compressor exhausting high pressure air from the first compressor outlet, the high pressure air from the outlet of the first compressor being directed to said first ejector pump means and operating to draw additional coolant air from the plenum;
• a second turbocharger including a second turbine drivingly coupled to a second compressor, the second turbine having an inlet and an outlet, the inlet of the second turbine being connected with the outlet of the first turbine, the second compressor having an inlet and an outlet, the inlet of the second compressor being connected with the coolant air outlet of said heat exchanger;
• and
• a second ejector pump means having a first inlet connected with the outlet of the second compressor and a second inlet connected with the coolant air outlet of said heat exchanger, said second ejector pump means further including an outlet, said second ejector pump means being for receiving air from the outlet of the second compressor into the first inlet in a manner to draw additional inlet air from the coolant air outlet and through the second inlet of said first ejector pump means and exhausting the air,
• the outlet system air from the outlet of the heat exchanger driving the first turbine and being exhausted therefrom at a reduced temperature, the exhausted air from the first turbine driving the second turbine and being exhausted therefrom at a reduced temperature, the first turbine in turn driving the first compressor and the second turbine in turn driving the second compressor, each compressor drawing air from the plenum of said heat exchanger, each of the first and second compressors exhausting high pressure air from the respective compressor outlet, the high pressure air from the outlet of the first compressor being directed to said first ejector pump means and operating to draw additional coolant air from the plenum, the high pressure air from the outlet of the second compressor being directed to said second ejector pump means and operating to draw additional coolant air from the plenum.