Cold box freezing and blocking processing technology for tertiary refrigeration system

Abstract

The invention provides a cold box freezing and blocking processing method for a tertiary refrigeration system. In the cold box freezing and blocking processing method, an auxiliary heat exchanger special for supercooling a light refrigerant and refrigerating the light refrigerant is arranged outside a main heat exchanger used for cooling cracking gas and recovering cold quantity of tail gas. For newly building a device or replacing the conventional device, a tertiary light refrigerant supercooling section can be separated from other material flows, and a heat exchanger is additionally arranged for separate supercooling, and a parallelly connected device is arranged for later use; for reforming an old device, the supercooled light refrigerant can be connected in series with an auxiliary heat exchanger for further supercooling; and other light refrigerant refrigerating channels below -100DEG C can be conditionally selected for later use. Therefore, by starting standby devices or openingbypass, a part most easily frozen and blocked in the tertiary refrigeration system can be timely switched out and cleaned, the freezing and blocking problem is gradually solved, the refrigeration temperatures of the tertiary refrigerant on various parts are restored to be normal finally, and design parameters such as hydrogen purity, ethane loss and the like meet the standard.

Description

technical field [0001] The invention belongs to a cold box freezing blockage treatment technology of a three-way refrigeration system on an ethylene plant, and in particular relates to a backup and blockage removal method for light refrigerant supercooling and refrigerating flow channels in a cryogenic part. Background technique [0002] The cryogenic separation temperature of the ethylene plant ranges from 20 to 30 degrees above zero to 150 to 60 degrees below zero. Therefore, three refrigerants, propylene, ethylene and methane, are usually required to provide cooling capacity, and correspondingly, two or even three refrigerants are required. compressor system. Recently, with the development of technology, some licensors began to mix these three refrigerants together and use one refrigeration compressor instead of the above three to reduce the number of equipment, reduce the layout of the site and save investment. This is the ternary compressor. Cooling System. [0003] I...

AI Technical Summary

Problems solved by technology

[0018] Obviously, these measures are either uneconomical or unrealistic

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