A circulating fluidized bed boiler capable of suppressing the formation of a combustion high temperature zone and its suppression method

Abstract

A circulating fluidized bed boiler capable of inhibiting formation of a combustion high-temperature region and an inhibiting method are disclosed. The boiler comprises a feeding system. The feeding system comprises a biomass fuel feeding bin. The outlet of the biomass fuel feeding bin is connected to the inlet of a spiral feeding machine. The outlet of the spiral feeding machine is connected to the inlet of a material blanking pipe. The material blanking port of the material blanking pipe penetrates into the center of the bottom of a hearth at the depth direction. The boiler also comprises primary air and secondary air. The primary air is disposed at the bottom of the hearth. The secondary air comprises sealing air and material spreading air which are arranged at the material blanking pipe, and lower secondary air and upper secondary air, wherein the lower secondary air and the upper secondary air are arranged at the side wall of the hearth and far away from the material blanking port of the material blanking pipe. The material blanking pipe penetrates into the center of the bottom of the hearth at the depth direction from the wall of the hearth or penetrates into the center of the bottom of the hearth at the depth direction by passing through an air chamber of the primary air and an air distributing plate. The inhibiting method includes feeding the biomass fuel from the center of the hearth. According to the boiler and the method, formation of the combustion high-temperature region of the biomass fuel in a CFB boiler can be controlled, thus facilitating safe, clean and stable running of the CFB boiler combusting the biomass.

Description

technical field [0001] The invention belongs to the technical field of biomass fuel power generation, and in particular relates to a circulating fluidized bed boiler capable of suppressing the formation of a combustion high-temperature zone and a suppression method. Background technique [0002] At present, my country uses a large amount of fossil fuels such as coal, oil, and natural gas, and some of them rely on imports. Fuel prices have soared, and the advantages of biomass energy as a renewable energy have become more prominent. The biomass fuel direct combustion power generation project not only alleviates the shortage of fossil fuels in my country, but also realizes CO 2 The zero emission is beneficial to the environment. At the same time, it can make a certain contribution to the construction of a low-carbon, intensive and sustainable development society in my country. The application prospect is very broad. CFB boilers have the characteristics of high thermal efficie...

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Problems solved by technology

[0003] However, the ignition temperature of biomass fuel is low. After entering the furnace, it ignites rapidly and releases heat intensively. It is sintered on the pouring material at the upper part of the feeding port and on the water wall, forming white coke, which affects the heat transfer effect of the water wall.

And the temperature of the combustion center is high, and the local temperature can reach up to about 1200°C, resulting in SO 2 and NO X Increased emissions, especially NO X Emissions, except conversion of fuel nitrogen to NO in fuel X , part of the N in the air 2 and O 2 It is also partially converted to NO at high temperature X , resulting in higher desulfurization and denitrification costs

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