Fluid distribution method for rapid-cooling heat exchanger

Abstract

The invention relates to a fluid distribution system for a rapid-cooling heat exchanger. Heat exchange tubes of the rapid-cooling heat exchanger comprise a center heat exchange tube (3) and a periphery heat exchange tube (5), the entrance end of the center heat exchange tube (3) is a short uniform-flow tube (4), the exit end of the center heat exchange tube (3) is an equal-diameter tube, the short uniform-flow tube (4) and the equal-diameter tube are butt-welded, so as to form the whole center heat exchange tube (3), and the periphery heat exchange tube (5) is an equal-diameter tube, the inner diameter of the inner tube of which is invariable in the full-length range. By adopting the method, the flow resistance property of the center heat exchange tube (3) is adjusted to lead the flow resistance of the center heat exchange tube (3) to increase properly, thus reducing the cracking gas flow in the center heat exchange tube (3) and increasing the cracking gas flow in the periphery heat exchange tube (5), so as to lead the fluid to distribute uniformly. The rapid-cooling heat exchanger which is provided with a fluid distribution system can distribute the cracking gas into each heat exchange tube uniformly, thus improving the utilization ratio of the heat exchange tubes and prolonging the running period.

Description

technical field [0001] The invention relates to equipment used in ethylene cracking technology, in particular to a fluid distribution system of a quenching heat exchanger. Background technique [0002] After the pyrolysis raw material is cracked at high temperature in the furnace tube of the cracking furnace, ethylene is generated, and important by-products such as propylene, butadiene, benzene, toluene, and xylene are obtained at the same time. The high-temperature cracked gas at the outlet of the cracking furnace will continue to carry out the cracking reaction (secondary reaction) under the high-temperature condition of the outlet. If the residence time is too long, the secondary reaction will increase. As a result, the yield of olefins in the cracked product will decrease, and methane, hydrogen, Heavy tar increases, and the tendency of coking increases. To keep the yield of ethylene stable and reduce the secondary reaction, the cracked gas must be cooled down as soon as...

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Problems solved by technology

[0005] In order to improve the design of the cracked gas inlet channel of the traditional quenching heat exchanger, improve the flow distribution of the cracked gas, overcome the shortcoming of the cracked gas staying at high temperature for a long time due to the back-mixing of the inlet gas flow, and reduce the uncontrollable adiabatic residence time caused by backflow , foreign developers of quenching heat exchangers have made improvements at the entrance

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