Power station boiler smoke waste heat deep recycling and emission reducing system

Abstract

The invention discloses a power station boiler smoke waste heat deep recycling and emission reducing system. A first low-temperature heat exchanger is arranged between an air pre-heater and a dust remover, a second low-temperature heat exchanger is arranged between a pressurizing fan and a desulfurizing tower, an air heat exchanger is arranged between a secondary fan and the air pre-heater, a heat exchanging medium output end of the air heat exchanger is connected with a heat exchanging medium input end of the second low-temperature heat exchanger through a first water pump, a heat exchanging medium output end of the second low-temperature heat exchanger is connected with a heat exchanging medium input end of the first low-temperature heat exchanger, and a heat exchanging medium output end of the first low-temperature heat exchanger is connected with a heat exchanging medium input end of the air heat exchanger. According to the power station boiler smoke waste heat deep recycling and emission reducing system, the defect existing in waste heat recycle of traditional low-temperature economizers is overcome, smoke temperatures can be deeply reduced, smoke temperature distribution is optimized, and the purposes of deeply recycling smoke waste heat and reducing dust discharge concentration are achieved.

Description

technical field [0001] The invention relates to a system for deep recycling and emission reduction of boiler flue gas waste heat in a power plant. Background technique [0002] The main heat loss in a thermal power plant is caused by the heat loss of the steam turbine and the exhaust heat loss of the boiler flue gas. Among them, the exhaust heat loss of boiler flue gas is the largest item among various heat losses of boilers. The exhaust gas temperature of power plant boilers is usually 120-150°C, and the corresponding heat loss is equivalent to 5%-12% of the heat of fuel. Usually, a low-temperature economizer is used in the tail flue of the boiler to recover the waste heat of the flue gas, but it cannot deeply reduce the temperature of the flue gas, the efficiency of waste heat utilization is low, and the effect of energy saving and emission reduction is poor. The Chinese patent No. 201320157980.7 discloses a boiler flue gas waste heat recovery and utilization system with ...

AI Technical Summary

Problems solved by technology

Although this patented technical solution can deeply recover the waste heat of the flue gas, there is only a high-temperature heat exchanger before the dust collector, and the heat recovered from the remaining heat is limited, and the temperature of the flue gas after passing through the high-temperature heat exchanger is higher than the acid dew point, making The dust removal effect is not good, which affects the emission reduction effect of the system

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