New method for applying lithium bromide refrigerating device in nitrogenous fertilizer production

Abstract

The invention relates to a new method for applying a lithium bromide refrigerating device in nitrogenous fertilizer production. MDEA solutions which are 85 DEG C-95 DEG C in temperature and are generated in the decarburization working procedure serve as a driving heat source of the lithium bromide refrigerating device, and the steps include (1) the MDEA solutions 85 DEG C-95 DEG C in temperature are pressurized through a pressurizing pump to enter a lithium bromide unit, after the temperature is lowered by 70 DEG C-75 DEG C, the MDEA solutions return to a decarburization system, MDEA solutions 85 DEG C-95 DEG C in temperature are generated again, and a circulation process is completed; (2) the temperature of circulating cooling water conveyed to the lithium bromide refrigerating device ranges from 20 DEG C to 35 DEG C; (3) refrigeration water 8 DEG C-18 DEG C in temperature is output by the lithium bromide refrigerating device and conveyed to various cold utilization points needed by compression and synthesis in nitrogenous fertilizer production, the refrigeration water is pumped into the lithium bromide refrigerating device through a circulation pump for refrigeration after heat exchange is carried out, and a circulation process is completed. By means of the new method, the heat energy of the MDEA heat solutions is used, it is guaranteed that the operational state in the decarburization working procedure is unchanged, and the production cost of enterprises is greatly reduced.

Description

technical field [0001] The invention relates to an application method of a lithium bromide device in nitrogen fertilizer production. Background technique [0002] Waste heat is the energy that is not fully utilized in the system under certain production process conditions, that is, redundant and waste energy. It includes waste heat of high-temperature exhaust gas, waste heat of cooling medium, waste heat of waste steam and waste water, waste heat of high-temperature products and slag, waste heat of chemical reaction, waste heat of combustible waste liquid and waste, and waste pressure of high-pressure fluid, etc. [0003] The synthetic ammonia and urea synthesis processes are exothermic reactions, which will produce a large amount of waste (waste) heat. At present, waste heat boilers and heat exchangers have been used in the industry to utilize some high-temperature waste heat sources. And some low-temperature heat sources are not effectively utilized due to their low grade...

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Problems solved by technology

[0006] Using low-grade heat sources such as low-pressure steam, steam condensate, and high-temperature hot water for lithium bromide refrigeration has been widely used in the nitrogen fertilizer industry. However, when producing low-grade heat sources such as medium-low pressure steam, steam condensate, and high-temperature hot In the case that all of them can be recovered in the production system, the low-temperature cold water produced by synthetic ammonia and urea can only be provided by ammonia compression refrigerators or ice machines, which will also cause the above-mentioned problems of large power consumption and high production costs

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