Pressure relief in high pressure refrigeration system
AssigneeCarrier Corporation
InventorsZvonko Asprovski, Suresh Duraisamy
Life of this patent
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Abstract
A CO2 vapor compression system is provided with at least one pressure relief device which is designed to open when the pressure in the low pressure side exceeds the predetermined level because of exposure to high temperatures during non-operational periods. A pressure relief device is provided near the compressor suction inlet to relieve one section of the circuit and another is provided upstream of an unloading valve to relieve pressure in another section thereof.
Claims15
A vapor compression system comprising:
- a refrigerant circuit having in serial flow relationship at least one compressor for compressing CO2 vapor as a refrigerant, a heat rejecting heat exchanger, an expansion device, and a heat absorbing heat exchanger;
- a compressor unloading circuit fluidly interconnecting an intermediate stage of said at least one compressor to a low pressure point between said heat absorbing heat exchanger and a suction inlet of said at least one compressor, said low pressure point being downstream of the heat absorbing heat exchanger and upstream of the suction inlet of said at least one compressor, said compressor unloading circuit including an unloading valve;
- and
- at least one pressure relief device disposed between said unloading valve and said intermediate stage for relieving pressure in said compressor unloading circuit during periods in which the system is not operating but is exposed to relatively high temperature conditions.
A method of preventing the occurrence of undesirable high pressures in a CO2 vapor compression system when exposed to high temperature ambient conditions during shut down, wherein said vapor compression system includes at least one compressor and a compressor unloading circuit fluidly interconnecting an intermediate stage of said at least one compressor to a low pressure point between a heat absorbing heat exchanger and a suction inlet of said at least one compressor, said low pressure point being downstream of the heat absorbing heat exchanger and upstream of the suction inlet of said at least one compressor, said compressor unloading circuit including an unloading valve, the method comprising:
- providing at least one pressure relief device disposed between said unloading valve and said intermediate stage, said at least one pressure relief device being adapted to open when the pressure in said compressor unloading circuit upstream of said unloading valve reaches a predetermined level.
Dependencies are inferred from the claim text.