Application And Research Of The Low-press Economizer In Power Station

The over high exhaust smoke temperature(EST) is a universal problem for power station boilers at present, when the EST exceeds over the design value very much, it not only affects the thermal economic efficiency of power stations, but also affects the safety and reliability of air preheat; it has a great meaning to decrease the EST for saving the energy, promoting safety and reliability of boilers. The EST of the 670t/h boiler of ShengLi power station exceeds 20-30℃above the design value, the boiler efficiency decreases by a large scale, for that, the power station decided to retrofit the boiler to decrease the EST and increase the economy.This paper investigates deeply all kinds of means to decrease the EST and exhaust smoke loss (ESL). At the same time, this paper introduces the application things of the low-press economizer in decreasing the EST and ESL. The low-press economizer not only decreases the EST, but also decreases the carbon-consumption; enhance the operation economy of boiler. It plays an important role in the remaining heat reclaiming in the power plant.This paper mainly introduces the principle of the low-press economizer. The mathematical model of optimum design of the low-press economizer was established, the selection of the aim function, determination of control condition, and multi- optimum scanning was discussed detail under the given the EGT, the optimum arrangement and structure parameters of the low-press economizer are gained; the retrofit income was calculated under different usage lives,coal price,entrain smoke temperature, it explains that the model has a good dynamic and economic stability. It can be apply for all kinds of optimization design work of the economizer.At the same time, the paper gives deep analyst is about the optimization operation of the low-press economizer. There is an water flux which can make the whole heat system reaching the highest economy for the low-press economizer system. Moving from the optimum water flux, the system economy will be decreased. At first, this text establishes the mathematics model of seeking the best flux of the low-press economizer. Then, this text's calculating target is the low-press economizer of WeiHai power station's 140MW unit in ShanDong. Gathering data to this target by engineering test. This text does a series of calculation by utilizing the equivalent enthalpy lower law and finally gets out the calculation conclusion. This text will carry on heating power analysis by using this important computing technology of equivalent enthalpy lower law and obtain the best dividing water flow finally. It can be apply for all kinds of obtain the best dividing water flux of the low-press economize.This paper makes the economical analysis for the low-press economizer. It is the standard coal consumption can lessen about 3.765g/kw*h, the gained that income per year is about 1.79*106 Yuan, the recovery time of the program is about one year and one months, the program has a high ratio value of investment to income. After the investment reclaiming term, the power station will be reclaimed for great economical benefit.