Thermally Enhanced Cascade Cooling System

Abstract

A cascade cooling system that uses low-grade thermal and other energy input sources to provide refrigeration and air conditioning in stationary and mobile applications. A two-loop embodiment includes a heat-powered first loop incorporating a vapor-jet compressor and a second loop based on a mechanical compressor powered by an electric motor or other source of rotational torque. The system uses waste heat, solar thermal or a fuel-fired heat source to partially or fully offset mechanical/electrical energy input. The system can also operate entirely on thermal, electrical or mechanical input. The ability to use multiple energy sources in any combination maximizes energy efficiency, performance and reliability. The system is well suited to making beneficial use of waste heat in vehicle applications. In stationary applications, solar thermal and/or waste heat from industrial processes can be used to improve the efficiency of conventional cooling systems.

I claim as my invention: 
     
         1 . A heat-powered cooling system comprising;
 a first cooling circuit including;
 a mechanical refrigerant compressor operably coupled to a vapor expander, said vapor expander receiving a portion of vaporized refrigerant at a first motive pressure from the boiler of a second cooling circuit, 
 a first refrigerant evaporator positioned to cool the air in a compartment by vaporizing a liquid refrigerant, 
 a first refrigerant condenser positioned to transfer heat from the refrigerant of the first cooling circuit to a second cooling circuit, 
   a second cooling circuit including;
 a venturi ejector compressor which accelerates a portion of the said vaporized refrigerant at a first motive pressure through a nozzle and discharges it to a condenser at a lower second pressure such that a vacuum region at a lowest third pressure is created, 
 a second refrigerant evaporator in thermal communication with the said first refrigerant evaporator, which receives liquid refrigerant from a second refrigerant condenser and evaporates it at the said third pressure using heat extracted from the refrigerant of the said first cooling circuit, 
 a second condenser operably positioned to liquify and cool vaporized refrigerant by transferring heat to an exterior heat sink, 
 a liquid refrigerant pump in fluid communication with the second condenser and a refrigerant boiler. 
 a refrigerant boiler which, upon receiving heat energy from an external heat source, boils liquid refrigerant to create the said vapor at a first motive pressure such that, 
   
       thermal energy input into the second cooling circuit cools the condenser of the first cooling circuit and thereby reduces the amount of energy required by the mechanical refrigerant compressor. 
     
     
         2 . The system of  claim 1  which further includes an electric rotating machine operably coupled to the said mechanical refrigerant compressor and vapor expander so that torque energy may be transferred. 
     
     
         3 . The system of  claim 2  in which the electric rotating machine is a motor/generator. 
     
     
         4 . The system of  claim 3  in which the motor/generator uses some or all of the electrical output energy from a generating mode to fulfill the electrical power demand of system controls including, fan, valves, or other system control devices. 
     
     
         5 . The system of  claim 3  in which the motor/generator uses some or all of the electrical output energy from a generating mode to charge an electric energy storage device. 
     
     
         6 . The system of  claim 3  which further includes a plurality of electrically configurable flow control valves operably positioned and configurable so as to bypass the said ejector compressor in the ejector cooling loop and further including such refrigerant flow controls as required to enable the said vapor expander to function as a compressor when powered by the said motor/generator. 
     
     
         7 . The system of  claim 3  which further includes an intelligent control system which adjusts various operational parameters of the systems to identify and optimally use energy input sources according to a predetermined priority or preference. 
     
     
         8 . The system of  claim 7  in which the intelligent control system adjusts various operational parameters of the systems to optimize system efficiency. 
     
     
         9 . The system of  claim 7  in which the intelligent control system further adjusts various operational parameters based partially or entirely on stored historical operational data from previous run cycles. 
     
     
         10 . The system of  claim 7  in which the intelligent control system adjusts the priority of energy input sources or other operational parameters based on information received through sensors or determined by real-time calculations. 
     
     
         11 . The system of  claim 7  in which the intelligent control system adjusts the priority of energy input sources or other operational parameters based on received data which has been transmitted from external sources. 
     
     
         12 . The system of  claim 7  in which the said operational parameters include one or more from a list including flow control position, valve timing, valve opening, condenser temperature, evaporator temperature condensing fan speed, evaporator fan speed, motor input voltage, motor commutation, generator output voltage, generator load, liquid pump speed, compressor capacity, vapor expander capacity, flow of motive vapor to the expander, flow of motive vapor to the ejector compressor, boiler temperature, and cooling capacity.