Cooling system applied to urea dewaxing process

Abstract

The invention provides a cooling system applied to a urea dewaxing process and relates to the technical field of lithium bromide absorption refrigeration. A lithium bromide absorption refrigerator unit is connected with a driving heat source control unit and a master control system unit, and a double-tube reactor is connected with a chilled water system of the lithium bromide absorption refrigerator unit; the master control system unit comprises a control execution unit used for detecting temperature of each point of the lithium bromide absorption refrigerator unit, internal pressure, regeneration liquid level and flow data of the chilled water system and a cooling water system in real time; a liquid in the double-tube reactor and fresh chilled water fed into a shell pass of the reactor bya chilled water pump exchange heat for cooling. With the adoption of design of large temperature difference and small flow of the lithium bromide absorption refrigerator unit with large temperature difference, equipment investment can be reduced, and running cost of power equipment can be reduced substantially; the master control system adopts an adaptive PID temperature control algorithm and a safe interlocking control mode, and drastic temperature fluctuation of a urea dewaxing cooling system due to unstable water flow can be reduced or eliminated.

Description

technical field [0001] The invention relates to the technical field of lithium bromide absorption refrigeration, in particular to a cooling system applied in a urea dewaxing process. Background technique [0002] The urea dewaxing device is independently researched and designed by my country, and produces -35# military tank diesel oil and 300# liquid paraffin. A large amount of heat is generated in the urea dewaxing process. The traditional cooling process is to use groundwater for cooling, due to the seasonal instability of groundwater temperature. Urea dewaxing is the separation of certain hydrocarbons in different hydrocarbon mixtures based on molecular size and shape. That is, according to the method that n-alkanes and urea molecules can form complexes, n-alkanes are recovered and separated from petroleum fractions. Its chemical reaction equation can be regarded as: [0003] m CO(NH2)2+ CnH2n+2→CnH2n+2 [CO(NH2)2 ]+△H [0004] In the formula: m—the molar ratio of ure...

AI Technical Summary

Problems solved by technology

There are the following disadvantages: (1) It causes a lot of groundwater waste and ecological damage, and consumes a lot of energy for transportation (water pumps)

(2) After running for a period of time, the complex will adhere to the tube wall of the casing scraper crystallizer, resulting in poor heat transfer effect. At this time, warm washing is required---that is, first cut off one group of raw materials, and use hot Water replaces raw material flushing casing

(3) In summer, due to the high groundwater temperature, the production requirements cannot be met, which seriously affects the product quality

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