Modeling method for coupling numerical value of cracking reaction in furnace tube and combustion of industrial dichloroethane cracking furnace chamber

Abstract

The invention provides a modeling method for a coupling numerical value of cracking reaction in a furnace tube and combustion of an industrial dichloroethane cracking furnace chamber. According to the method, the dichloroethane cracking furnace is divided into a furnace chamber model and a furnace tube model during modeling, and grids are divided on the furnace chamber and the furnace tube. The furnace chamber takes an outer tube wall temperature given by the furnace tube model as a boundary condition, important furnace chamber parameter distribution of the furnace chamber flue gas temperature, the speed, the component concentration and the like is calculated by a combustion model, a flowing model and a heat transmission model; the furnace tube takes a furnace tube heat flux calculated by the furnace chamber as a boundary condition, and process temperature, pressure and concentration distribution in a tube length direction is calculated through a cracking reaction model in the tube and taking mass conservation, momentum conservation, energy conservation relations in the tube, so that analyses of important economic targets of the dichloroethane cracking conversion rate, the selectivity, the unit consumption and the like under current operation conditions are facilitated, and guidance of filed process optimization is facilitated. The modeling method is applicable to various high-temperature cracking furnaces and has a wide adaptability.

Description

technical field [0001] The invention relates to a process device modeling method, in particular to a coupled numerical modeling method for furnace combustion and cracking reaction in a furnace tube of an industrial dichloroethane cracking furnace. Background technique [0002] Ethylene dichloride cracking furnace is the core unit and large energy consumer of vinyl chloride production plant. The benefit of the entire vinyl chloride plant is closely related to the design and operation level of the cracking furnace. The key to improving the economic efficiency of vinyl chloride production plant lies in high-level design and how to optimize it. Operating conditions of the cracking furnace. At present, most of the ethylene dichloride cracking technologies and devices in my country are imported from abroad. The introduction of advanced and mature vinyl chloride devices provides a higher starting point for the development of my country's vinyl chloride industry. However, my countr...

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Problems solved by technology

However, my country's ethylene dichloride cracking operation level generally lags behind the world's advanced level. The conversion rate of ethylene dichloride cracking is low, the selectivity is low, and the unit consumption is high.

However, the licensors’ secrecy of the key technology makes it difficult for my country to grasp the mechanism of dichloroethane cracking process deeply enough, and it is difficult to achieve a substantial breakthrough in the technical level.

Domestic understanding of material fluid flow, heat transfer, mass transfer, and chemical reactions inside the cracking furnace is not clear enough, and lacks sufficient theoretical support, so that the transformation of cracking furnaces and the design of domestic cracking furnaces mainly imitate foreign technologies without theoretical basis , often makes the transformation and design improper, or when the cracking raw material and operating conditions change, the operating parameters can only be determined by experience, so there is a certain blindness in the design and operation, and the potential of the device has not been fully utilized.

Therefore, if we blindly introduce complete sets of foreign technologies and imitate them, but do not pay attention to digesting, absorbing and re-innovating the fundamental and basic technologies, then my country's vinyl chloride cracking production technology will always lag behind the world's leading level and lack international competitiveness.

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