The Optimization Research Of Coal-fired Power Plant Flue Gas Waste Heat Recovery System

High temperature of power plant boiler flue gases not only affect the heateconomy of the whole plant, but also air preheater and safe operation of the bag-typedust collector. With the electricity reform and the country’s increasing emphasis onenergy conservation, flue gas waste heat recycling is paid more and more attention byrelated researchers and plant management. And this increase flue gas waste heatrecovery and utilization projects in active or new large power plant. Thus recover fluegas waste heat effectively. Flue gas heat recovery projects bring economic benefits,and also maintain such problems like low temperature of waste heat, low-temperaturecorrosion, wear and dust and so on. These need enough attention in the process oftransformation in the project.This paper studies the working principle of flue gas waste heat recovery system,and reducing the exhaust temperature in practical application in the low pressureeconomizer system is focused. Equipped with the flue gas cooler in a power station, asan example, using the test results of the thermodynamic cycle performance, wasterecycled heat, the water consumption of FGD system of the unit after the power stationequipped with the flue gas cooler during my joint training. The thermal systemembeded flue gas cooler was analyzed according to the principle of the local economy.Thermal efficiency and coal consumption rate of the whole plant is calculated andcompared. And also, influence of designed parameters and operation parameters onheat exchange coefficient is analyzed and optimized. Differences between the flue gascooler and the traditional of low-level economizer is compared. The advantages of theflue gas cooler are highlighted.In addition, the selection software is compiled according to the equivalententhalpy drop method. And also it solves selection problem of adding the low-leveleconomizer in different capacity and operating conditions of the unit. The workloadreduces. This provides a reference to optimize the selection of flue gas heat recoveryunit.