Combustion utilization method of low calorific value gas and combustion and hot air supply system

Abstract

The invention discloses a low heating value combustion gas combustion utilization method and a combustion and hot air supply system; low heating value combustion gas and combustion air are preheated by an intermediate preheater (2), and enter a main combustor (1) for combustion; burned inertia flue gas enters the intermediate preheater through a hot air inlet (R) for heat release, thus heating up the intermediate preheater; the inertia flue gas after heat release enters a reactor (5) through an air inlet (J) for heat supply, and exhaust air is formed and discharged from an air-discharge port (P); at least partial exhaust air from the air-discharge port is returned to a hot air inlet, thus reducing the temperature of the gas entering the intermediate preheater for heat release; at least partial exhaust air from the air-discharge port is returned to the air inlet so as to reduce the temperature of the gas entering the reactor for heat supply. The system can fully burn and utilize the low heating value combustion gas, can use equipment parts with low cost, and equipment running state in the system is more excellent, thus realizing combustion smoke evacuation, heat release, and exhaust air returning heating value cycle utilization.

Description

technical field [0001] The invention belongs to the field of coal and petrochemical engineering, and in particular relates to the combustion utilization and combustion system of low calorific value gas in this field. Background technique [0002] In coal and petrochemical engineering, fuels with lower calorific value often exist, such as methane-containing gas with a lower calorific value than blast furnace gas, and its typical calorific value is about 1.1-1.9MJ / kg. This type of low calorific value fuel has poor ignition characteristics, is generally not easy to ignite, and it is even more difficult to form a stable combustion, and most of them are released or burned through a torch. In this way, its heating potential has not been fully utilized, and it has also caused environmental pollution and energy waste. [0003] To this end, researchers have conducted various studies to utilize low calorific value gases, typically designing corresponding new burners for low calorific...

AI Technical Summary

Problems solved by technology

However, the preheater used in it has an internal combustion chamber, an air chamber, etc., and has a complex structure, and needs to exchange heat through a heat-conducting partition, resulting in a large size of the preheater and high cost and cost.

The system uses fuel with high calorific value to preheat fuel with low calorific value, which will increase the amount of smoke exhaust and the heat loss of exhaust smoke

[0005] In addition, in the subsequent utilization of gas combustion, the exhaust gas temperature generated by the preheating combustion process of fuel and combustion-supporting air is relatively high, which is not conducive to the use of common metal partition wall heat exchangers. If a regenerative heat exchanger is used, it will May cause air leakage, etc.

There is also the use of introducing cold air before the hot air inlet of the metal partition wall heat exchanger to mix high-temperature flue gas, but this will cause the oxygen content of the incoming mixed gas to exceed the requirements of the inert atmosphere reactor as a follow-up equipment

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