Study On Heat Elimination On Wall Surface Of Industrial Furnace And Control Of Its Thermal Pollution

This thesis performs a research on heat elimination on wall surface and thermal pollution in workshop. First, the author conducts an investigation on kinds of industrial furnaces, their design specification and indices of furnace wall and production site in in ShanHai region, and performs a thermal test on typical furnace, the results show that:the appearances of industrial furnace walls are very complicated and their heat elimination areas are quite large, even up to 8000m, and there are various accessory equipment around. After long-term use of furnaces, the walls begin to crack and age, The traditional method of reducing heat elimination from furnace wall has little effect on reducing heat release from furnace wall. Therefore, it is one of the important topics of reducing thermal pollution in workshop to do researches on heat elimination from furnace wall and recycling of heat.FLUENT is used to do research on heat elimination from thermal surface in different directions. The hot wall surface was placed in the closed physical system of owning entrance and exit passage, The numerical values imitate the situation of thermal pollution at 150℃and seven conditions at angle for under 0,30,60,90,130,150,180 degree, the results are: The variation trend of exhausting temperature,velocity accord with heat elimination. angle of hot wall surface and heat elimination present inclined "m" relationship when it's between 0～180 degree. If turn the wall surface adown (the wall surface was placed horizontally), the heat elimination effect would become worse and system exhaust least heat; then leaning the wall surface, the effect of heat elimination will become better than 0 degree, the heat elimination ability will better when put the hot wall surface upward than downward and will achieve largest when the wall surface was placed vertically. Numerical value imitation and actual test comparison between on-site temperature parameters is performed on influence of heat elimination in rolled steel workshop on temperature distribution in the workshop. The mathematic model constructed matches the actual situation quite well. Calculation and analysis is conducted on the 3 basic situations of supposed furnace wall damages. Compared to the original model data, after furnace wall is damaged, the temperature in the damaged area of the workshop will increase about 2℃. Heat area expands at the same time, which aggravates thermal pollution in the workshop.Methods of reducing heat release from wall of traditional industrial furnaces are analyzed. The deadly defects are:when heat release from furnace wall increases due to external factors, its insulation effect will immediate become invalid. Through analysis and research on mechanism of heat release, the author it is the first one to raise:Air guide sleeve can be used to collect and recycle heat to solve the problem of heat elimination from furnace wall. Through setting up experimental devices and using orthogonal regression design, the relational expression (regression equation) between air recycling temperature and wall temperature, width of runner and lift height of diversion baffle, which provides essential data for design of air guide sleeve to recycle heat elimination from furnace wall, and make the engineering application value of air guide sleeve in recycling of heat elimination from furnace wall.Last,1# furnace of a heat rolling factory in a certain steel company in Shanghai is taken as an example research target to do a research on application of recycling technology of furnace heat elimination of air guide sleeve; engineering design and theoretical calculation are performed. The results show that after recycling technology of air guide sleeve to eliminate heat from furnace wall, the energy saving ratio of furnace becomes 1.76%. So 895130.6Nm3 of natural gas consumption can be saved every year, and thermal pollution from 1049.2 tons of coal equivalent can be reduced. Furthermore, the cost to improve furnace and the expense to run it is very low; it takes only 1 year to obtain investment return, while the economic profitability is remarkable.