Optimum Insulation Thicknesses For Large-diameter Preformed Directly Buried Insulation Pipe Fitting With Polyurethane Foamed-plastics

As the improving of People’s economic standard of living, comfortableliving environme nt also need to be raised substantia lly, whic h can drive heatingrapid ly deve lopment. Large-dia meter preformed directly buried insulation p ipewill be more and more important through the scale of the city’s central heatingsystem making larger.The demand for ins ulatio n pipes of large dia metergradually highlight while the research on the area seems to be poor. Theproduction o f large-dia meter insulation p ipes cannot re ly on a re liable basis,which lead to the factories copy foreign standards and ignore their own nationa lcond itions, resulting in an unnecessary waste of cost.Accordingly, in this paper, optimum insulation thicknesses for large-diameter preformed d irectly buried insulation p ipe fitting with polyuretha nefoamed-plastics have been investigated. The virtual source method is se lected asthe optimization algorithm through a variety of buried pipe heat calculationmethod, and then it is inspected the accuracy of the temperature field and heatloss calc ulatio ns. Use the concept of economics calc ulates the thickness of pipeinsulation which satis fies the lowest sum of the investment of insulation pipeand hest loss cost. According to the latest natio nal norms and economicindicators, the paper determine to the va lue of each parameter in optimizationalgorithm. On the bas is of the actual s ituation o f calculating insulation p ipe, thepaper proposes to comb ine with restriction algorithm and optimizatio n algorithmto calculate the thickness of p ipe insulation, and compare the different trend ofinfluenc e factors in the two algorithms.The large-dia meter preformed directly buried ins ulat ion pipe fitting withpolyurethane foa med-plastics widely used in central heating s ystem makes theresearch of this paper very practica lity and instructive ly.