Multi-strand winding pipe type main back heating and heat exchange device for low-temperature liquid nitrogen

Abstract

The invention mainly relates to the technical field of synthesis ammonia and low-temperature liquid nitrogen, and relates to the technology of a multi-strand winding pipe type main back heating and heat exchange device for the low-temperature liquid nitrogen. Through N2-H2 synthesis gas synthesized by H2 at the temperature of 191.5 DEG C below zero and the pressure of 1.8MPa and N2 at the temperature of 193.4 DEG C below zero and the pressure of 5.19MPa and through waste nitrogen N2-Ar-CO-CH4 at the temperature of 191.5 DEG C below zero and the pressure of 0.18MPa, N2 at the temperature of 42 DEG C and the pressure of 5.9MPa is cooled to be N2 at the temperature of 188 DEG C below zero and the pressure of 5.6MPa, and purified gas H2-N2-CO-Ar-CH4 washed by low-temperature methanol is cooled to be purified gas at the temperature of 188.2 DEG C below zero and the pressure of 5.21MPa, namely, the incoming high-pressure N2 and the purified gas washed by the low-temperature methanol are cooled through cooling capacity back heating of the washed N2-H2 synthesis gas, high-pressure H2 and the waste nitrogen, and the temperature condition for washing low-temperature purified gas through the low-temperature liquid nitrogen is provided for a washing tower. Due to a three-section type three-stage low-temperature multi-strand winding pipe type heat exchange structure, the heat exchange efficiency is high, the technical problems of the three-stage multi-strand winding pipe type heat exchange for the low- temperature liquid nitrogen with the temperature ranging from 42 DEG C to 197 DEG C below zero are solved, and the low-temperature back heating and heat exchange efficiency of a low-temperature liquid nitrogen process system is improved.

Description

technical field [0001] The invention is mainly applied to the technical field of low-temperature liquid nitrogen process equipment for synthetic ammonia, and relates to the technology of multi-stream winding tube-type main heat exchange equipment for low-temperature liquid nitrogen. It applies the -191.5°C, 1.8MPaH 2 , -193.4°C, 5.19MPa N flowing out of the top of the washing tower 2 —H 2 -191.5°C, 0.18MPa N of the synthesis gas and the top of the scrubber 2 —A r —CO—CH 4 Contaminated nitrogen, supplemented high-pressure LN 2 Cooling -127.2°C, 5.7MPa N 2 To -188℃, 5.6MPa LN 2 and cooling of H from the cryogenic methanol process 2 —N 2 —CO—A r —CH 4 Purify the gas to -188.2°C and 5.21MPa, that is, apply the washed N 2 —H 2 Syngas, high pressure H 2 And the cooling capacity of polluted nitrogen is reheated, cooled and liquefied to flow high-pressure N 2 , Purified gas washed with low-temperature methanol, providing the washing tower with the temperature conditions...

AI Technical Summary

Problems solved by technology

In addition, because ordinary tube-and-tube heat exchangers use tube-sheet connection parallel tube bundles, the structure is simple, and the self-shrinking ability is poor. Generally, it is a single flow heat exchange, with low heat exchange efficiency, large volume, and small temperature difference. To put the high pressure N 2 Cooling and liquefaction in one process requires multiple tube-and-tube heat exchangers to connect and exchange heat. The number of heat exchangers is too large to manage

In addition, the traditional method of replenishing liquid nitrogen is to directly inject the liquid nitrogen produced by the nitrogen production system into the contaminated nitrogen under the saturated state of 0.18MPa to reduce the entire reflux temperature and accelerate the start of the diffusion refrigeration process, but the vaporized nitrogen is discharged together with the contaminated nitrogen After the system is burned, it is discharged into the atmosphere, resulting in waste of nitrogen

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