The Flue Gas Acid Dew-point Meter Research And Design Based On Jet Impact Heat Transfer Technology

Energy problem has always been one of the basic issues of China’s economic and social health sustainable development, with the sustained and rapid development of our country’s economy, the increasingly prominent contradiction between energy supply and demand, improve the efficiency of the use of fossil fuels is one of the feasible way to solve the contradiction between supply and demand of energy. China’s coal-fired power plants provide most of the country’s electricity, but consume a large amount of coal.Power plant boiler is the most basic equipment in the coal-fired power plant energy transfer and conversion systems, the operation of the power plant boiler performance will directly influence the overall efficiency of coal-fired power plants, which can have an important impact on the national strategy of energy conservation and emissions reduction.When water vapor and SO3 of boiler flue gas enter in the low temperature heating surface,SO3 and water vapor form into sulfuric acid vapor, when the rear wall temperature is lower than the flue gas acid dew point temperature, is likely to happen condensation,causing low temperature corrosion of metal wall. It has a direct impact on the project cost,equipment service life and increasing the difficulty of the shutdown maintenance.Improving the exhaust temperature is a measure to solve this problem, but constantly improving the exhaust temperature will reduce the efficiency of the boiler. For the flue gas acid dew point installed in the tail device, therefore, accurate measurement and forecasting of corrosive environment, for operation in the process of timely control the influence of acid corrosion, guarantee the safe stable operation of the equipment, it is of great significance.Jet impact technology for acid dew-point meter heat exchange technology is a very effective method of strengthening heat transfer. This is because the fluid directly impact need cooling or heating surfaces, the process is short and the boundary layer is very thin,so the heat transfer coefficient is several times higher than usual tube heat ex-changer and an order of magnitude. Based on the advantages and disadvantages of the acid dew point meter at home and abroad summarized, combined with the characteristics of flue gas being easy to low temperature corrosion in the power plant, impact jet technology and current measurement method of growth rate to zero adopted, wetting Angle smaller probe, corrosion resistance of quartz glass material, metal platinum as the electrode material, match with K type thermocouple are identified by, the design and processing of the structure of a new set of acid dew-point meter system, set up a acid dew-point meter measuring system under the condition of laboratory, the process of experiments in the laboratory, according to the existing problems, the acid dew-point meter probe structure is transformed and the system is optimized, aimed at improving the probe temperature resistance, preventing deformation causing of heat bilges cold shrink or due to uneven heating, hair blowout, improve the bad situation in practical application. The experimental results from power plant application show that the designed acid dew-point meter can measure the acid dew point, which has a guiding significance in the boiler efficiency under the premise of preventing corrosion at low temperature and setting reasonable exhaust temperature.