Research On The Characteristics Of Heat Transfer Of The Finned Tube Economizer On 600MWe Ultra-supercritical Coal-fired Boilers

Thermal power is still the main power supply of energy structure in our country. With the development of economy, energy supply problem is increasingly prominent; As the electric power industry expands unceasingly, energy consumption is also growing. How to reduce the coal consumption and improve the efficiency of unit is a difficult problem facing the electricity workers. Finned tube economizer as a form of strengthening heat transfer, can effectively reduce the air heater outlet gas temperature, then improve the boiler thermal efficiency and reduce the coal consumption. Finned tube economizer has been widely used in recent years, not only in boiler retrofit applications, but also appeared on the huge new boiler. In 2011 the project of Heze 2 x 600 MWe ultra-supercritical unit is applied by finned tube economizer.This paper treat the finned tube economizer in Heze power plant as the research object. First introduce its design work. There are many types of economizer. Each type has its own application. In order to meet the requirements for different coals, to achieve the target of heat transfer request, the fouling resistance and wear resistance, according to the engineering experience of oneself, rectangular finned tube economizer is designed. Contrast normal economizer, rectangular finned tube economizer have advantages on the structure and performance, such as the fouling resistance and wear resistance, and can also save the cost.In order to get the heat transfer coefficient of the rectangular finned tube economizer, the industrial test is carried on the #1 boiler. The heat transfer coefficient is measured in the test under the working condition of 640 MWe and 500 MWe. By theoretical analysis and calculation, obtained the flue gas side heat transfer corrections of the rectangular finned tube economizer, and compared with 《 Boiler unit thermal calculation standard method》(the former Soviet 1973 edition) and also compared with foreign standards.On the basis of the above work, the rectangular finned tube economizer is simulated. The test condition is simulated. Variable structure is also carried on. The optimization suggestions of the rectangular finned tube economizer is put out.Finally the author summarizes the work that have done and put forwards some suggestions and steps to improve the research.