Study Of Reducing Heat Radiation Loss Of Heat Pipe Network Valves

In recent years, energy saving attracts more and more attention of people. Especially in the field of heat pipe net, energy saving has been the main research direction. The heat radiation loss of heat pipe net valves is discussed in this thesis.Research showed that many valves has no insulation because of maintenance, replacement and costs. And when these valves are working, the heat will be dissipated from these places which have no insulation. Each valve(DN/100) wasted 1.58 GJ heat annually in the condition that none insulation measures were taken. If these heat can be saved, more than 107.95 kg coal can be saved and 248.27 kg CO2 may be reduced. With the energy saving, factories in Chongqing may save energy 1.8 ′ 108 GJ. Also the steam quality will be better while heat radiation loss of heat pipe network valves is reduced. It was found that about 0.02% condensate water will not appear while the 1.58 GJ heat can be saved.In this paper, removable structure of insulation materials was adopted to solve the problem of valves insulation. But the rigid structure is still unfavorable for reducing the heat loss. The rigid structure was used as protective shell, its gravity would make insulation cotton deforming. The deformed cotton would weaken the effect of insulation, and then energy consumption was increased about 50%, steam quality was also decreased. For this reason, flexible structure was suggested to be used.The thermal conductivity of 10 kinds of insulation materials was acquired by test bench with guarded hot plate. And vertical burning method was used to determine the flame retardant of materials. After these experiments, it was found that the insulation effect of Owens cotton and wool board was insignificant when they were used in flexible insulation structure. So, aluminum foil cloth was recommended to be used as outermost layer of insulation structure. And materials with small thermal conductivity, such as wool board can be used as middle layer. At the same time, PE can be supplemented to make the structure be beautiful. Lastly, the innermost layer was suggested to use the silicone coated fabrics, which can be used at high temperature.