A deep heat recovery device and method for boiler flue gas

Abstract

The invention discloses a deep heat recovery device and a deep heat recovery method for boiler smoke, which belong to the technical field of waste heat recovery. The deep heat recovery device disclosed by the invention comprises a boiler, a smoke-backwater heat exchanger, and N stages of heat recovery devices which are serially arranged, wherein N is not less than 1; each stage of the heat recovery device comprises a nozzle, a smoke-air heat exchanger, a smoke water-condensing groove, a smoke water-condensing tube, a heat recovery water collection groove, a heat recovery water drainage tube, and the like; each stage of the heat recovery device increases the equivalent heat capacity of air through the spray humidification for an air side, thus greatly improving the heat-carrying capacity of air, enabling the smoke discharge temperature of the boiler to be lower, and realizing deep heat recovery for the boiler smoke from the air side. According to the deep heat recovery device and the deep heat recovery method disclosed by the invention, heat exchange is carried out by virtue of the inlet air and smoke of the boiler, the water content of air is increased by means of spray humidification for the air side for air inlet, and the equivalent heat capacity of air is increased, thus realizing a higher heat exchange amount, effectively lowering the smoke discharge temperature of the boiler, and adequately recovering the waste heat of smoke; in addition, due to the increase of the humidity of a fuel, a combustion temperature can be lowered, and the formation of NOx can be reduced.

Description

technical field [0001] The invention relates to a deep heat recovery device and method for boiler flue gas, which is particularly suitable for waste heat recovery of flue gas from gas boilers and coal-fired boilers, and belongs to the technical field of waste heat recovery and energy saving. Background technique [0002] Coal and gas are the most important sources of energy in my country. According to statistics, the total number of boilers in my country is nearly 2.2 million, which play an important role in electric power, metallurgy, textile, food and other industries. Heating and heating are closely related to us. Domestic hot water also requires a large amount of heat from the boiler. [0003] Among the various heat losses of boilers, exhaust gas losses account for 60% to 70%. Direct discharge of high-temperature flue gas is not only a huge waste of energy, but also causes environmental pollution. If the heat of the exhaust smoke can be recovered effectively and the the...

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Problems solved by technology

[0008] However, both of the above two technical solutions have their own technical shortcomings

Flue gas waste heat recovery equipment based on absorption cycle has a huge initial investment and poor economy, so it is difficult to promote it on a large scale in actual projects

The main advantage of "a composite equipment for waste heat recovery and dust removal and purification of flue gas" is to solve the corrosive problem in waste heat recovery of flue gas. The temperature is still high, and the heat recovery depth is not enough

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