Downward full waste boiler entrained-flow bed gasification device for superheated steam and coal chemical industry system

Abstract

The embodiment of the invention provides a downstream full waste heat boiler entrained-flow bed gasification device for superheated steam and a coal chemical industry system, and relates to the field of coal chemical industry. According to the downstream full waste heat boiler entrained-flow bed gasification devicefor superheated steam, a radiation waste boiler and a convection waste boiler are connected by arranging an ash falling waste boiler, so that synthesis gas is turned back upwards, ash entrained by the synthesis gas flows into a chilling chamber by virtue of gravity, the height of the whole equipment is reduced, and sensible heat recovery of the synthesis gas is realized. The overall height of the frame is relatively low, the device has the remarkable advantages of safe and reliable process operation, high online operation rate, convenience in operation and maintenance, low operation economic cost, low comprehensive energy consumption and the like, and the economic value is greatly improved. The problems of transportation overrun and inconvenience in operation and maintenance of a large gasification furnace with a full waste heat boiler are solved, the recovery rate of sensible heat in recovered synthesis gas is high, and the quality of steam generated by heat recovery is high.

Description

technical field [0001] The invention relates to the field of coal chemical industry, in particular to a down-flow superheated steam entrained-bed gasification device with all waste boilers and a coal chemical industry system. Background technique [0002] At present, the entrained bed gasifiers that produce high-pressure steam by-product mainly include the following types: [0003] (1) Upward flow of waste boiler entrained bed gasifier technology with high-pressure superheated steam as a by-product. The gasifier produces syngas upward and slag downward. The molten slag enters the quenching chamber through the slag mouth (throat pipe) downwards, falls into the water bath for quenching and cooling, and then is discharged. The synthesis gas exits the exit of the gasifier, using a large amount of quenching gas (the synthesis gas produced by the gasifier is dedusted , cooling, and pressurized gas), reduce the temperature of the synthetic gas and the molten ash entrained by the s...

AI Technical Summary

Problems solved by technology

There are main problems: ①The amount of syngas quenching gas is large, which is about 1 / 3 of the gas production of the gasifier. Under the normal design of the gasifier and auxiliary systems, it must be increased by 30%, and the production capacity per unit volume is low; at the same time The generated synthesis gas needs to be cooled, pressurized and then returned to the convection waste pot, which consumes a lot of energy; ② The downward flow of slag depends only on gravity, and the flow rate is low. The mixing effect is poor, which affects the carbon conversion rate. The slag opening is small and the slag opening is easy to block. Therefore, under a certain size of the slag opening and a certain load, the adaptability of the coal is strictly required. The operating window of the coal must be greater than 120°C to ensure that the slag Smooth slag discharge at the mouth

There is a main problem: the diameter of the second passage of the radiation waste boiler is about 1.4 times the diameter of the first passage of the radiation waste boiler, and the transportation of the gasifier (including the radiation waste boiler) is easy to exceed the limit, so it is restrictive for the large-scale gasification furnace with radiation waste boiler Very strong; if an ultra-high pressure waste boiler gasifier with radiation is used, the synthesis gas can be compressed, but the molten ash cannot be compressed, and the anti-risk ability of slagging and coking in the radiant waste boiler is greatly increased, especially for the load of the gasifier and the coal consumption. Strict requirements, requiring extremely small fluctuation range of coal quality parameters

There are main problems: high-temperature syngas has low recovery rate of sensible heat, and the high-pressure saturated steam produced needs to be further overheated; at the same time, the consumption of quenching water is large, the energy consumption is high, and the quenching chamber discharges a large amount of black water to flash evaporation, and the flash evaporation system The installation is relatively large, the construction cost of the flash device is high, and the energy consumption is high

Secondly, ash and slag are easily bonded to the horizontal wall of the water wall at the exit of the slag mouth section and the hanging water wall, which affects the heat transfer efficiency and blocks the high-temperature syngas and slag channels in severe cases

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