System for deep cooling and waste heat recovery of smoke gas in boiler

Abstract

The invention relates to a system for deep cooling and waste heat recovery of smoke gas in a boiler with an independent operating system, which comprises a smoke gas deep cooler, an air heater and an independent water circulation system comprising the smoke gas deep cooler and the air heater. The smoke gas of which the dust is removed by an electrostatic dust remover is used for heating the cold water in the smoke gas deep cooler to recover the waste heat of the exhausted smoke, and the hot water at the outlet of the smoke gas deep cooler is transferred to the air heater for preheating the air, thereby increasing the temperature of the combustion-supporting air in the boiler; after the smoke gas passes through the smoke gas deep cooler, the smoke gas is directly introduced into a desulfurizing tower for desulfurization and recovery processing; and finally, the smoke gas is exhausted through a wet chimney. The system of the invention does not need to change the traditional thermodynamic system of the machine unit, and the long-period safe operation of the system can not be influenced in the process of recovering the waste heat of the smoke gas, thereby lowering the temperature of the exhausted smoke, saving the desulfurization water consumption, improving the machine unit efficiency and increasing the machine unit output.

Description

technical field [0001] The invention belongs to the technical field of waste heat recovery and utilization, and in particular relates to a waste heat recovery and utilization system for deep cooling of flue gas of power station boilers and industrial boilers. Background technique [0002] Exhaust heat loss is the largest item among various heat losses of boilers, generally ranging from 5% to 12%, accounting for 80% or more of the total heat loss of boilers. In order to recycle the exhaust heat of boilers, the following two forms are mainly adopted for different units: [0003] 1) For traditional coal-fired units that are not equipped with a desulfurization system, the existing technology usually installs a low-pressure economizer between the air preheater and the electrostatic precipitator of the boiler, and uses the waste heat of the flue gas to heat the condensate in the reheating system. After the water absorbs heat, it returns to the low-pressure heater, and then the lo...

AI Technical Summary

Problems solved by technology

It can be seen that the installation of a gas-gas heat exchanger (GGH) does not bring significant economic benefits, and the waste heat of the flue gas of more than 100 degrees is wasted in vain, and the structure of the gas-gas heat exchanger (GGH) is complex and reliable in operation. Low, long installation cycle, large initial investment in equipment, gas-gas heat exchanger (GGH) can not be widely used

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