Flue gas treatment system and flue gas reheating method based on fluoroplastic heat exchanger

Abstract

The invention relates to a flue gas treatment system and a flue gas reheating method based on a fluoroplastic heat exchanger. No flue gas treatment system and no flue gas reheating method exist to solve the problems of low-temperature corrosion, air leakage, dust deposition and scaling simultaneously at present. The flue gas treatment system disclosed by the invention is characterized by further comprising a phase-change heat exchanger, a fluoroplastic heat exchanger, a water tank, a water return pipe, a water inlet pipe, a phase-change heat exchanging steam pocket, an ascending pipe, a descending pipe and an ascending heat transfer working medium thermodetector, wherein the phase-change heat exchanging steam pocket is positioned above the phase-change heat exchanger; one end of the water return pipe is fixed on the phase-change heat exchanging steam pocket. The flue gas reheating method disclosed by the invention is characterized in that flue gas flows through the phase-change heat exchanger, condensed working medium in the phase-change heat exchanger is heated, saturated steam is generated, the saturated steam is heat-exchanged with the returned working medium, high-temperature working medium water enters the fluoroplastic heat exchanger through the water inlet pipe, and the working medium water is generated after the treated flue gas is heated. The flue gas treatment system and the flue gas reheating method based on the fluoroplastic heat exchanger have the advantage that the problems of low-temperature corrosion, air leakage, dust deposition, scaling, chimney corrosion and white smoke emission from the chimney can be solved simultaneously.

Description

technical field [0001] The invention relates to a flue gas treatment system and a reheating flue gas method for a thermal power plant, in particular to a flue gas treatment system and a reheating flue gas method based on a fluoroplastic heat exchanger. Background technique [0002] With the proposal of "Emission Standard of Air Pollutants for Thermal Power Plants" (GB 13223-2011), the desulfurization system has become an indispensable auxiliary equipment for thermal power plants. Among them, the limestone wet flue gas desulfurization system (FGD) is famous for its high desulfurization efficiency , good reliability and adaptability to units of different capacities, etc., have been widely used in high-power units in recent years. [0003] When a limestone wet desulfurization system is used, the temperature of the net flue gas after the desulfurization tower is usually 45-60°C. There are usually two methods for this low-temperature flue gas: one is to install a GGH system to in...

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Problems solved by technology

[0004] However, the traditional GGH system has many problems: 1. The reheating section of the traditional GGH system uses a metal heat exchanger. Due to the low operating temperature, there are low-temperature corrosion problems of the heat exchanger, and dust and scaling occur from time to time. The failure rate is high; 2. The traditional GGH system is a rotary heat exchanger. Cold and hot fluids flow through the heat exchanger alternately. The problem of air leakage is serious, which directly affects the efficiency of the boiler.

If the GGH system is not installed, it will cause serious corrosion of the downstream flue and chimney, white smoke from the chimney, etc.

[0005] There is also a relatively good flue gas treatment device now, as disclosed on April 02, 2014, in a Chinese patent with a publication number of CN103697487A, which discloses a flue gas treatment device that combines a wet electrostatic precipitator and a flue gas The heater is integrated in the integrated flue shell, which occupies a smaller area compared with the form of separate arrangement. Since the integrated flue shell does not need to set a two-way transition flue, the flue gas flow is uniform, so there is no need to install a uniform in the flue. Orifice plate, the flue gas resistance is small, but it is difficult for this flue gas treatment device to solve the problems of low-temperature corrosion, air leakage, dust accumulation, scaling, chimney corrosion and white smoke at the same time

[0006] To sum up, there is currently no flue gas treatment system and reheating flue gas method with reasonable structural design that can simultaneously solve low-temperature corrosion problems, air leakage, dust accumulation, scaling problems, chimney corrosion, and white smoke problems

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