Combined air cycle heat pump and refrigeration system

A combined air cycle heat pump and refrigeration system comprising:

• a source of refrigerant air;
• a regenerative heat exchanger having low pressure fluid passage means and high pressure fluid passage means in heat exchange relation;
• means for passing said refrigerant air through the low pressure fluid passage means of said regenerative heat exchanger;
• a compressor;
• a turbine for providing torque to said compressor;
• motor means for providing additional torque to said compressor;
• means for passing said refrigerant air from the low pressure fluid passage means of said regenerative heat exchanger to said compressor, said compressor raising said refrigerant air in pressure and temperature;
• additional heat exchange means receiving said compressed refrigerant air whereby some of the heat in said compressed refrigerant air is rejected to a fluid passed through said additional heat exchange means and in heat exchange relationship with said compressed refrigerant air;
• means passing said compressed refrigerant air from said additional heat exchange means to the high pressure fluid passage means of said regenerative heat exchanger where additional heat from said compressed refrigerant air is rejected to the refrigerant air passed through the said low pressure fluid passage means of said regenerative heat exchanger;
• and means for expanding the refrigerant air passed through the high pressure fluid passage means of said regenerative heat exchanger in said turbine.

A method for selectively heating and cooling a load utilizing an air cycle comprising the steps of:

• providing a first source of air from said load and returning said load air to said load;
• providing a second source of ambient air and returning said ambient air to ambient;
• selecting one of said first or second air sources as refrigerant air, said first air source being selected when it is desired to cool said load and said second air source being selected when it is desired to heat said load;
• compressing said refrigerant air to increase the pressure and temperature thereof;
• expanding said compressed refrigerant air in a turbine and discharging said refrigerant air therefrom;
• connecting through heat transfer surfaces within a regenerative heat exchanger the source of refrigerant air with the compressed refrigerant air upstream of said turbine whereby said compressed refrigerant air rejects some of its heat to said refrigerant air from said source, thereby reducing the temperature of the compressed refrigerant air expanded in said turbine so as to maximize the reduction in temperature of air discharged from said turbine;
• and connecting through heat transfer surfaces within an additional heat exchanger located upstream of said regenerative heat exchanger and compressed refrigerant air with the other of said first or second air sources whereby said compressed refrigerant air rejects heat to said other air source.

In an air cycle refrigeration machine using ambient air as the refrigerant air and operating as a heat pump to supply heat to a load;

• a turbine driven compressor receiving said refrigerant ambient air and increasing the temperature and pressure thereof;
• a first heat exchanger downstream from said compressor;
• means for circulating a fluid from said load through said first heat exchanger and returning said fluid to said load;
• means connecting said compressed refrigerant air from said compressor through heat transfer surfaces in said first heat exchanger with said fluid whereby said compressed refrigerant air rejects heat to said fluid, said heated fluid being used to provide heat to said load;
• a regenerative heat exchanger downstream from said first heat exchanger and connecting through heat transfer surfaces within said regenerative heat exchanger the ambient air used as the refrigerant air with the pressurized refrigerant air from said first heat exchanger whereby said pressurized refrigerant air rejects some of its heat to said ambient air and reduces the temperature of said pressurized refrigerant air to as close to ambient as possible;
• and means for conducting said pressurized refrigerant air from said regenerative heat exchanger to said turbine for expansion therein, said turbine cooling said refrigerant air and discharging said cooled refrigerant air to ambient at a temperature as far below ambient as possible.

In an air cycle refrigeration machine using a source of air from a load as the refrigerant and operating as a refrigeration machine to cool said load;

• a turbine driven compressor receiving said refrigerant air from said load and increasing the pressure and temperature thereof;
• a first heat exchanger downstream from said compressor;
• means for providing a source of ambient air to said first heat exchanger and discharging said ambient air to ambient;
• means connecting said compressed refrigerant air from said compressor through heat transfer surfaces within said heat exchanger with said ambient air whereby said compressed refrigerant air rejects heat to said ambient air;
• a regenerative heat exchanger downstream from said first heat exchanger and connecting through heat transfer surfaces within said regenerative heat exchanger the source of refrigerant air from said load with the pressurized refrigerant air from said first heat exchanger whereby said pressurized refrigerant air rejects some of its heat to said refrigerant air from said load and reduces the temperature of said pressurized refrigerant air to as close to the refrigerant air temperature from said load as possible;
• and means for conducting said pressurized refrigerant air from said regenerative heat exchanger to said turbine for expansion therein, the turbine discharge air being conducted to said load to cool said load, said turbine discharge air being as far below load temperature as possible.