Study On The Heat Transferper Formance Of The Steel Structure Used Wood-plastic Self Thermal Insulation Wallboards

This research is based on the sub-project "Steel structure used wood-plastic self thermal insulation wallboards" (2006BAJ02B01-04) of the Key Technology R&D Program in National 11th Five Year Plan "Research on environment-friendly building materials and products ", the research of four types insulation walls are presented in this paper.Four types wood-plastic self thermal insulation wallboards are designed based on the requirements in the project assignment including energy-saving rate of 65 % and more than 80% voidage. Their theoretical averaged thermal resistances with various size and insulation material are calculated by means of MATLAB program. There are errors between the theoretical averaged thermal resistance and its measured data. however, it indicates approximately the trend of the averaged thermal resistance whensize is changed.Mathematical model of heat transfer is set to solve the problem of wood-plastic s self thermal insulation wallboards. The discrete mathematical model is obtained by finite element method. The steady numerical simulation of the wall with different size and insulation material are completed by means of ANSYS. The main influences on heat transfer of wall and the revised coefficients are obtained by analyzing temperature fields and thermal flux fields of different walls. The simulated averaged thermal resistances different wall sizes are also obtained since the distribution of temperature and thermal flux are known. Structure size at the maximum averaged thermal resistance is obtained by analyzing and comparing the results.The averaged thermal resistance of full-filled type is tested to testify the correctness of numerical simulation. A nondimensional correlation of natural convection heat transfer with different construction size and thermal boundary condition is obtained on the basis of inducing and calculating the experimental data.Heat insulation, damp proof and sound insulation of block are checked in the designing of self thermal insulation wallboards. The results indicate properties of wall such satisfy the acceptance criterions.wallboard requires both practicability and economy, therefore, wood-plastic self thermal insulation wallboard and ordinary 240 mm solid and hollow brick wall are discussed on economy. Effect of energy reduction is very remarkable.The conclusions and calculation results provide guidance and foundation for the further design of self thermal insulation wallboards.