Cascade recovery and utilization method of flue gas waste heat of domestic waste incineration boiler

Abstract

The invention discloses a method for cascaded recovery and utilization of flue gas waste heat of domestic waste incineration boilers, which solves the problem of how to deeply recycle the waste heat of flue gas in existing domestic waste incineration power plants. The flue gas-water heat exchanger and the gas-water direct contact heat exchanger are used to reduce the temperature of the high-temperature and high-humidity flue gas discharged from the flue gas purification system of the domestic waste incineration boiler through two steps of heat exchange, so that the temperature of the flue gas is reduced from 140°C-150°C is reduced to 20°C-30°C; the external circulation water heat exchange closed-loop system is composed of heat users, heat pump or cooling tower system, water-water heat exchanger and flue gas-water heat exchanger, which consists of water-water The heat exchanger and the deep wet-cooling heat exchanger form an internal circulating water heat exchange closed-loop system. After the internal circulating water in the internal circulating water heat exchange closed-loop system absorbs the heat of the flue gas in the air-water direct contact heat exchanger, it is combined with the heat from the heat pump. The cooling water is heat exchanged, and the cooling water is initially heated to make it meet the requirements, which improves the heat utilization of the secondary energy.

Description

technical field [0001] The invention relates to a method for recovering and utilizing waste heat of flue gas produced by garbage incineration, in particular to a method for recovering and utilizing stepwise depth of waste heat of flue gas produced by a domestic waste incineration boiler. Background technique [0002] The flue gas discharged from the boiler that incinerates domestic waste needs to be treated by a series of flue gas purification systems. The flue gas after treatment has the characteristics of high temperature and high humidity, and the volume fraction of water vapor in the exhaust flue gas can reach 15%-40%. , the final exhaust gas temperature is also as high as 140°C-150°C; at present, waste incineration plants directly process the flue gas generated by incinerating garbage and then discharge it into the atmosphere. There is a serious problem of energy waste; in addition, due to the difference in the quality of incinerated waste, the flue gas discharged from ...

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Problems solved by technology

[0003] The present invention provides a cascade recycling method for flue gas waste heat of domestic waste incineration boilers, which solves the technical problem of how to deeply recycle the flue gas waste heat of existing domestic waste incineration power plants

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