Research On Heat Transfer And Resistance Characteristics Of Corrugated Plate Of Rotary Air Preheaters With Spoiler Holes

By the end of2013, Thermal power accounts for69.14%of China’s total installed capacity, and will still account for more than60percent over the next decade. Rotary air preheaters are very important device in coal fired power plants used to recover residual heat. Heat transfer corrugated plate is the core component of rotary air preheaters. And the heat transfer, resistance and fouling characteristics of rotary air preheaters mainly depend on heat transfer corrugated plate. To explore a method that could enhance the ntegrated characteristics of heat transfer corrugated plate, corrugated plate with spoiler holes is researched in this paper.DU-K(Double Corrugated-Kaier, DU-K) plate which is commonly used in rotary air preheaters is choosen as a substrate. And the temperature fields, velocity fields and pressure fields in the passages of DU-K at different Re are simulated, through the simulation spoiler holes are proposed to enhance heat transfer and heat uniformity of DU-K plate.Through the analysis of heat transfer processes within the test section, the difference of heat transfer area of positioning plate and corrugated plate with air in the passage is considered, mathematical model of single blow technology(STB) is developed to consistent with experimental process which would increase the accuracy of STB. Through the separation of hot and cold air duct imports, the transient convection experimental device are improved. Such transient convection experimental apparatus could saves energy and improves the overall efficiency of test.According to the geometric dimensions of DU-K plate and the surface porosity ration after spoiler holes arranged, the diameter, spacing, position and arrangement of the round holes are reasonable arranged. To systematically explore the foure factors’s influence on the heat transfer and resistance characteristics of corrugated plate of rotary air preheaters with spoiler holes, orthogonal experiments which could increase experiment efficiency considerably are used to determine the experimental plate models. The best combination of the four factors which could enhance heat transfer and reduce flow resistance to the best of DU-K plate is raised through the analysis of the test results, and a validated experiment indicates this kind of DU-K plate with spoiler holes has19.87%increase in heat transfer and24.53%reduction in flow resistance compared with DU-K without round holes.To give an instruction to the actual project, the comprehensive benefits of the best combination DU-K plate with spoiler holes is explored in this paper. A roatry air preheater of600MW coal fired power plant in Zhejiang Province is taken as an example. The best combination DU-K plate with spoiler holes in this paper is taken as the heat transfer corrugated plate. Through a rotary air preheaters’ thermodynamic calculation software, the whole thermodynamic of the roatry air preheater of600MW coal-fired power plant is calculated. Through the calculation, the outlet temperature and flow resistance of the gas with spoiler holes respectively reduct3.23%and19.2%compared with that without spoiler holes under boiler maximum continue rate condition.