| Trombe wall change south wall from hot and humid part to hot part, which plays an important role in the passive solar house heating in winter. Establish Trombe roof in the reference of Trombe wall to achieve a greater improvement on the indoor thermal environment of solar energy and reduce building energy consumption.Research shows Trombe roof heating process and analysis the thermal characteristics of the heat transfer process. The mathematical model of its heat transfer process are established, the calculation method of hourly solar radiation, the expression of outdoor air temperature wave and the initial and boundary conditions for solving are given, and the numerical solution process is introduced. Through the transient numerical calculation, the roof angle, circulating air volume, ventilation hole center distance, roof materials and thermal insulation layer form five aspects are analyzed the influence on the amount of heat conduction and convection heating quantity, and the results are as follows: the daily average heating amount increase first and decrease then, 45 °reached the maximum heating load when Trombe roof angle changes from 0 ° to 90 °; roof fan air volume is suggested to be taken between 0.086 ~ 0.115 m3 / s; convection heating load during the day increases with the center distance of the vents, otherwise average daily heating load of thermal conductivity decreases with it. But when the center distance increases to 2000 mm, total heating load change is not significant; with the decrease of the roofing material coefficient of thermal conductivity, convective heating quantity increases gradually, such as school and office can choose small coefficient of thermal conductivity of materials, in order to improve the convection heating load during the day; External thermal insulation convection heating is greater than the internal thermal insulation during the day, the amount of without insulation form is minimum. the thermal conductivity of without insulation form is maximum and most volatile at the same time, external thermal insulation form is second, internal insulation form basic no heating load of thermal conductivity changes throughout the day.The mathematic model and the physical model for Trombe roof were Established, and Lhasa meteorological parameters is selected. For flat and pitch roof of typical room, the indoor thermal conditions temperature and temperature fluctuations of four forms roof were calculated. The four forms are without Trombe roof form,Trombe roof without insulation form, Trombe roof with external thermal insulation and Trombe roof with internal thermal insulation. Through the analysis, the following conclusions are as follows:(1) The average basis room temperature of flat roof and pitched roof are 6.69 ℃ and 5.58 ℃ when there is no Trombe roof, both temperatures are lower than the solar house indoor temperature in winter heating requirements.(2) The average indoor temperature of flat roof and pitched roof will increase by about 2.5 ℃ and 3.4 ℃ compared to the basis room temperature when it uses Trombe roof, while it will increase indoor temperature difference between day and night, flat roof diurnal temperature reaches 10 ℃, sloping roof up to 11 ℃.(3) The average indoor temperature of flat roof and pitched roof will increase by about 2.5 ℃ and 3.4 ℃compared to the Trombe roof room when it uses external thermal insulation, and there will be a slight increase in indoor temperature difference between day and night. It can better meet the schools, offices demands during the day.(4) The average indoor temperature of flat roof and pitched roof will increase by about 2.1 ℃ and 3.2 ℃compared to the Trombe roof room when it uses internal thermal insulation,and there will be a slight decrease in indoor temperature difference between day and night. This form will be more suitable for residents in Lhasa building. |
