High speed variable delivery helical screw compressor/expander automotive air conditioning and waste heat energy _recovery system
First Claim
1. An improved air conditioning and waste heat energy recovery system for an automotive vehicle, said vehicle including an occupant cab to be air conditioned, an engine driven drive shaft, an engine exhaust gas passage, and a cab conditioned air flow passage leading to said cab, the improvement comprising:
- a helical screw compressor/expander unit, said unit including intermeshed helical screw rotors, one of said rotors being connected to the drive shaft to be driven thereby during compressor operation and for driving said drive shaft during expander operation,inlet and outlet ports for said compressor/expander unit,a capacity control slide valve for said compressor/expander unit operatively controlling inlet flow to said intermeshed helical screw rotors through said inlet port,a volume ratio control slide valve for said compressor/expander unit operatively controlling working fluid discharge flow from said unit at said outlet port,a condenser coil,an evaporator coil mounted within said conditioned air flow passage,a vapor boiler within said exhaust gas passage,conduit means carrying a refrigerant working fluid for fluid connecting said vapor boiler, said compressor/expander unit at said inlet and outlet ports and said evaporator in a closed loop combined refrigeration and vapor power circuit and including a cycle control valve for selectively controlling refrigerant flow to and from said unit, said vapor boiler and said condenser to permit said unit to act selectively as an expander and to and from said unit, said condenser and said evaporator when said unit functions as a compressor, for cooling conditioned air flowing within said conditioned air flow passage leading to said cab,passive heat exchange means between said conditioned air flow and said exhaust gas passages,first bypass means within said exhaust gas passage for selectively bypassing exhaust gas about said vapor boiler and said passive heat exchange means, such that selectively said exhaust gas may vaporize working fluid within said vapor boiler and for driving said helical screw compressor/expanded unit as an expander to positively rotate said drive shaft to thereby recover thermal energy from the exhaust gas, andsecond bypass means within said conditioned air flow passage leading to said cab for selectively causing the air entering said cab when said cab requires air conditioning to bypass said passive heat exchange means or for causing waste heat of the exhaust gas to heat the air entering the cab absent operation of said evaporator coil when said cab requires heat.
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Accused Products
Abstract
A compact, helical screw compressor/expander unit mounted in a vehicle and connected to the vehicle engine driven drive shaft has inlet and outlet ports and a capacity control slide valve and a pressure matching or volume ratio slide valve, respectively, for said ports. A refrigerant loop includes the compressor, a condenser mounted in the path of air flow over the engine and an evaporator mounted in a fresh air/cab return air flow duct for the occupant. Heat pipes thermally connect the cab air flow duct to the engine exhaust system which also bears the vapor boiler. Selectively operated damper valves control the fresh air/cab return air for passage selectively over the evaporator coil and the heat pipes as well as the exhaust gas flow over opposite ends of the heat pipes and the vapor boiler.
38 Citations
23 Claims
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1. An improved air conditioning and waste heat energy recovery system for an automotive vehicle, said vehicle including an occupant cab to be air conditioned, an engine driven drive shaft, an engine exhaust gas passage, and a cab conditioned air flow passage leading to said cab, the improvement comprising:
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a helical screw compressor/expander unit, said unit including intermeshed helical screw rotors, one of said rotors being connected to the drive shaft to be driven thereby during compressor operation and for driving said drive shaft during expander operation, inlet and outlet ports for said compressor/expander unit, a capacity control slide valve for said compressor/expander unit operatively controlling inlet flow to said intermeshed helical screw rotors through said inlet port, a volume ratio control slide valve for said compressor/expander unit operatively controlling working fluid discharge flow from said unit at said outlet port, a condenser coil, an evaporator coil mounted within said conditioned air flow passage, a vapor boiler within said exhaust gas passage, conduit means carrying a refrigerant working fluid for fluid connecting said vapor boiler, said compressor/expander unit at said inlet and outlet ports and said evaporator in a closed loop combined refrigeration and vapor power circuit and including a cycle control valve for selectively controlling refrigerant flow to and from said unit, said vapor boiler and said condenser to permit said unit to act selectively as an expander and to and from said unit, said condenser and said evaporator when said unit functions as a compressor, for cooling conditioned air flowing within said conditioned air flow passage leading to said cab, passive heat exchange means between said conditioned air flow and said exhaust gas passages, first bypass means within said exhaust gas passage for selectively bypassing exhaust gas about said vapor boiler and said passive heat exchange means, such that selectively said exhaust gas may vaporize working fluid within said vapor boiler and for driving said helical screw compressor/expanded unit as an expander to positively rotate said drive shaft to thereby recover thermal energy from the exhaust gas, and second bypass means within said conditioned air flow passage leading to said cab for selectively causing the air entering said cab when said cab requires air conditioning to bypass said passive heat exchange means or for causing waste heat of the exhaust gas to heat the air entering the cab absent operation of said evaporator coil when said cab requires heat. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A high speed, variable delivery, helical screw compressor/expander unit for use in a refrigeration system and for effecting waste heat recovery, said refrigeration system comprising:
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a condenser coil, an evaporator coil, a vapor boiler subjected to waste heat for vaporization of a refrigerant working fluid within said boiler, a prime mover driven helical screw compressor/expander unit including intermeshed helical screw rotors, one of said rotors being connected to said prime mover to be driven thereby during compressor operation and for driving said prime mover during expander operation, inlet and outlet ports for said compressor/expander unit, a capacity control slide valve for said compressor/expander unit operatively controlling working fluid inlet to said unit at said inlet port, a volume ratio control slide valve for said compressor/expander unit operatively controlling unit working fluid discharge at said outlet port, conduit means carrying a refrigerant working fluid and fluid connecting said vapor boiler, said compressor/expander unit at said inlet and outlet ports, said condenser and said evaporator in a closed loop refrigeration and vapor power circuit, said conduit means including a cycle control valve for controlling said unit to permit said unit to act selectively as compressor or expander, for selectively directing working fluid to said vapor boiler or to said evaporator coil, the improvement wherein; said conduit means and said cycle control valve comprise means for delivery of refrigerant working fluid in vapor form from said vapor boiler or from said evaporator coil to operate said unit as an expander or a compressor, respectively, and for driving said helical screw rotor in the same direction regardless of whether said prime mover drives said unit or is driven thereby, means for biasing said capacity control slide valve towards a first fully loaded position, means responsive to system operation for refrigeration loop system operation for shifting said capacity control slide valve in an opposite direction, towards unload position regardless of whether said unit functions as compressor or expander, means for shifting said volume ratio control slide valve in a first direction towards maximum volume ratio for said helical screw compressor/expander unit to maximize efficiency of said unit when acting as a compressor and for selectively shifting said volume ratio control slide valve in the opposite direction towards a minimum volume ratio when said unit functions as an expander to permit maximum expansion of the heated vapor returning from said vapor boiler to said inlet port through said cycle control valve. - View Dependent Claims (23)
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Specification