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US 6,178,761 B2Granted
Air conditioning circuit using a refrigerant fluid in the supercritical state, in particular for a vehicle
AssigneeValeo Climatisation
InventorStefan Karl
Life of this patent
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Abstract
The CO2 refrigerant fluid, compressed by the compressor to a supercritical pressure, is delivered through a three-way valve selectively into a cooler and/or into a bypass branch, so that in the former case, after passing through an expansion device, the fluid is vaporised in an evaporator so as to cool the cabin of the vehicle; while flow of the fluid through the bypass branch avoids the cooler so that the fluid is then cooled in the evaporator, thereby heating the cabin.
Claims34
Air conditioning apparatus for treating the atmosphere in a space in a vehicle, the apparatus comprising
- a fluid flow circuit for flow of a refrigerant fluid therein from upstream to downstream, said fluid flow circuit including:
- a compressor adapted to receive said fluid in a gaseous state and compress said fluid to a supercritical pressure, the compressor having an upstream end and a downstream end;
- a first heat exchanger downstream of the compressor for receiving said fluid compressed by the compressor and cooling said fluid at substantially constant pressure by transfer of heat from said fluid to a first external medium, said first heat exchanger having an inlet and an outlet for said fluid;
- a first expansion device for receiving said fluid from said first heat exchanger and for reducing the pressure in said fluid so as to liquefy at least part of said fluid;
- and
- an evaporator downstream of the first expansion device, for receiving said fluid in the liquid state from the first expansion device and putting said liquid into the gaseous state at substantially constant pressure by taking heat from a second external medium to cool said space, the evaporator having an inlet side and an outlet side;
- means connecting the outlet side of the evaporator with the upstream end of the compressor whereby fluid vaporised in the evaporator is received by the compressor, a first bypass branch having an upstream end and a downstream end, the first bypass branch being connected in parallel with the first heat exchanger,
- fluid flow switching means connected with the inlet of said first heat exchanger and the upstream end of the first bypass branch, for selectively directing said fluid into the first heat exchanger to constitute an air conditioning loop, and into the first bypass branch to constitute a heating loop, whereby in said heating loop the evaporator can transfer heat from said fluid to said second external medium, to heat said spaces
- a second bypass branch connected with said fluid flow switching means, for connection by operation of said fluid flow switching means into the heating loop upstream of the evaporator, and
- a second heat exchanger in said second bypass branch, for transferring heat from said fluid to said second external medium for heating said space.
7 more elements
An apparatus for treating the atmosphere of an enclosed space in a vehicle, the apparatus enabling the flow of a fluid in an upstream to a downstream direction within a fluid flow circuit, the apparatus comprising:
- a compressor for receiving said fluid in a gaseous state and compressing said fluid to a supercritical pressure;
- a first heat exchanger downstream of said compressor, said first heat exchanger receiving said fluid that has been compressed and cooling said fluid at a substantially constant pressure through heat transfer with a first external medium;
- a first expansion device downstream of said first heat exchanger, said first expansion device receiving said fluid from said first heat exchanger and reducing said pressure in said fluid so as place at least a portion of said fluid in a liquid state;
- an evaporator downstream of said first expansion device, said evaporator receiving said fluid in the liquid state from said first expansion device and placing said fluid into the gaseous state at a substantially constant pressure, the downstream of said evaporator connected to the upstream of said compressor to provide said fluid in the gaseous state to said compressor;
- a first bypass branch connected in parallel with said first heat exchanger and between said compressor and said first expansion device;
- a fluid flow switch downstream of said evaporator and upstream of said first heat exchanger and said first bypass branch, said fluid flow switch operative to selectively direct said fluid into said first heat exchanger to form a cooling loop, and into said first bypass branch to form a heating loop, said evaporator transferring heat from a second external medium to said fluid in said cooling loop to cool said atmosphere, said evaporator transferring heat from said fluid to said second medium in said heating loop to heat said atmosphere,
- a second bypass branch controlled by said fluid flow switch, said second bypass branch connected by operation of said switch into said heating loop upstream of said evaporator, and
- a second heat exchanger in said second bypass branch, for transferring heat from said fluid to said second external medium to heat said atmosphere.
5 more elements
An apparatus for treating the atmosphere of an enclosed space in a vehicle, the apparatus enabling the flow of a fluid in an upstream to a downstream direction within a fluid flow circuit, the apparatus comprising:
- a compressor for receiving said fluid in a gaseous state and compressing said fluid to a supercritical pressure;
- a first heat exchanger downstream of said compressor, said first heat exchanger receiving said fluid that has been compressed and cooling said fluid at a substantially constant pressure through heat transfer with a first external medium;
- a first expansion device downstream of said first heat exchanger, said first expansion device receiving said fluid from said first heat exchanger and reducing said pressure in said fluid so as place at least a portion of said fluid in a liquid state;
- an evaporator downstream of said first expansion device, said evaporator receiving said fluid in the liquid state from said first expansion device and placing said fluid into the gaseous state at a substantially constant pressure, the downstream of said evaporator connected to the upstream of said compressor to provide said fluid in the gaseous state to said compressor;
- a first bypass branch connected in parallel with said first heat exchanger and between said compressor and said first expansion device, said first heat exchanger and said first bypass branch meeting at a junction;
- a fluid flow switch downstream of said evaporator and upstream of said first heat exchanger and said first bypass branch, said fluid flow switch operative to selectively direct said fluid into said first heat exchanger to form a cooling loop, and into said first bypass branch to form a heating loop, said evaporator transferring heat from a second external medium to said fluid in said cooling loop to cool said atmosphere, said evaporator transferring heat from said fluid to said second medium in said heating loop to heat said atmosphere;
- a first section and a second section, said first section and said second section common to said cooling loop and said heating loop, said first section connecting said junction and said first expansion device, said second section connecting said evaporator and said compressor, said first circuit section and said second circuit section at least partially in heat transfer relation to thereby forming an internal heat exchanger;
- a second bypass branch controlled by said fluid flow switch, said second bypass branch connected by operation of said switch into said heating loop upstream of said evaporator, said second bypass branch being connected in parallel with said first expansion device,
- a second heat exchanger connected in said second bypass branch, for transferring heat from said fluid to said second external medium to heat said atmosphere;
- a second expansion device connected in said second bypass branch upstream of said second heat exchanger;
- an air stream generator for generating an air stream;
- a path for delivery of said air stream into said enclosed space, wherein said air stream is said second external medium, wherein said evaporator and said second heat exchanger are disposed in series in said path, said air stream first striking said evaporator.
9 more elements
Dependencies are inferred from the claim text.