Permanent gas refrigeration method
First Claim
1. A method of refrigerating a permanent gas by heat exchanging a stream of said gas at a relatively high pressure with a main stream of work-expanded working fluid flowing counter to said high pressure stream, and thereby reducing the temperature of said high pressure stream to its critical temperature or a temperature therebelow, wherein the said main stream is supplemented by at least two work-expanded streams of working fluid introduced into heat exchange the permanent gas stream on the gaseous transitional section of relationship with the permanent gas stream at temperatures of the temperature-enthalpy curve of the permanent gas stream or within 5°
- K. beyond either end of such section, but with no work expanded stream of working fluid other than said main work expanded stream being used to refrigerate the permanent gas stream at its temperature more than 5°
K. below the lower limit of the gaseous transitional section whereby the temperature of the working fluid as it is heated is more closely matched to that of the permanent gas stream as it is cooled along the said gaseous transitional section.
1 Assignment
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Accused Products
Abstract
In cooling a permanent gas stream (e.g. of nitrogen) at elevated pressure to below its critical temperature (e.g. in a process for the liquefaction of the permanent gas), the stream is heat exchanged with a main stream of working fluid (typically also nitrogen) that has been work-expanded in expansion turbine. The refrigeration provided by this stream is supplemented by that provided by at least two supplementary streams of work expanded working fluid. The temperatures at which the supplementary streams are introduced into heat exchange relationship with the permanent gas stream are in a defined range extending from 5° K. above the point at which the rate of change of the heat capacity (at constant pressure) of the gas per standard cubic meter increases by about 1% per Kelvin as the gas is cooled to 5° K. below the point at which the rate of change with temperature of the heat capacity (at constant pressure) of the gas per standard cubic meter is at a maximum.
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Citations
11 Claims
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1. A method of refrigerating a permanent gas by heat exchanging a stream of said gas at a relatively high pressure with a main stream of work-expanded working fluid flowing counter to said high pressure stream, and thereby reducing the temperature of said high pressure stream to its critical temperature or a temperature therebelow, wherein the said main stream is supplemented by at least two work-expanded streams of working fluid introduced into heat exchange the permanent gas stream on the gaseous transitional section of relationship with the permanent gas stream at temperatures of the temperature-enthalpy curve of the permanent gas stream or within 5°
- K. beyond either end of such section, but with no work expanded stream of working fluid other than said main work expanded stream being used to refrigerate the permanent gas stream at its temperature more than 5°
K. below the lower limit of the gaseous transitional section whereby the temperature of the working fluid as it is heated is more closely matched to that of the permanent gas stream as it is cooled along the said gaseous transitional section. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- K. beyond either end of such section, but with no work expanded stream of working fluid other than said main work expanded stream being used to refrigerate the permanent gas stream at its temperature more than 5°
Specification