Method of and apparatus for the generation of cold
AssigneeLinde Aktiengesellschaft
InventorWolfgang Baldus
Life of this patent
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Abstract
Cold is generated, according to the invention, by compressing a refrigerant and expanding the refrigerant isentropically in a nozzle. Advantageously at least a part of the expanded refrigerant is passed in indirect heat exchanging relationship with the portion of the refrigerant prior to expansion. An expansion machine can be used to work-expand a portion of the compressed refrigerant with the expanded gas returned to the compressor. The balance of the compressed stream is expanded in the nozzle.
Claims3
An apparatus for the generation of cold on a very low temperature level, comprising:
- a compressor for compressing a low-boiling gaseous coolant;
- a cooler downstream of said compressor for abstracting compression heat from the compressed gaseous coolant;
- a counterflow heat exchanger downstream and in addition to said cooler for exchanging heat between said compressed gaseous coolant and a cold gaseous low-pressure coolant;
- an expansion nozzle downstream of said heat exchanger for expanding and partially liquefying the compressed gaseous coolant substantially isentropically to produce a cold partially liquefied fluid;
- a cold consumer downstream of said expansion nozzle for transferring heat to said cold partially liquefied fluid;
- means for returning the part of said fluid leaving the cold consumer in the gaseous state to the counterflow heat exchanger as said cold gaseous low-pressure coolant;
- and
- an expansion turbine connected ahead of said nozzle for work-expanding a portion of the compressed gaseous coolant, the balance of the compressed gaseous coolant being substantially isentropically expanded in said nozzle.
In a method for the generation of cold at a very low temperature level in which a low-boiling coolant is liquefied, the method comprising the steps of:
- compressing the low-boiling gaseous coolant quasi-isothermically;
- removing the heat of compression of the compressed gaseous coolant by cooling same;
- cooling further the compressed gaseous coolant by passing it in countercurrent heat exchange with a cold gaseous low-pressure coolant;
- expanding and thereby partially liquefying the compressed coolant cooled by countercurrent heat exchange;
- and
- using the part of the coolant remaining in the gaseous state or the part of the liquiefied coolant re-evaporating during heat exchange with a heat consumer as the cold gaseous low-pressure coolant in the countercurrent heat exchange, the improvement which comprises:
- expanding and partially liquefying said cold compressed coolant in an expansion nozzle substantially isentropically during the expansion and partial liquefaction step, a portion of the compressed coolant being work-expanded in an expansion machine while the balance of the compressed coolant is expanded in said nozzle.
Dependencies are inferred from the claim text.