| Due to its simple structure,low initial investment,and effective improvement of indoor thermal environment,the tromble wall passive house is widely used in most parts of northern China,but its use is limited by solar energy resources.It is difficult to maintain the indoor thermal environment at the design temperature during radiation.Active equipment needs to be set as the auxiliary heat source,and the selection of active equipment is closely related to the calculation of heat load.Because traditional buildings use solar radiation to a small extent,and the average indoor and outdoor temperature difference in winter is much larger than the outdoor temperature fluctuation value,it is undoubtedly a more reasonable method to calculate the heat load of traditional buildings using the steady-state method.Different from traditional buildings,the heat collection and storage wall is affected by the double fluctuations of temperature and solar radiation.The heat transfer to the room has significant fluctuation characteristics,which causes the heat load of the heat collection and storage wall passive house to change from a stable state to a fluctuating state.The traditional steady-state calculation method is no longer applicable.However,the existing dynamic calculation methods are too complicated to meet the requirements of engineering applications,and it is urgent to propose a simplified method for calculating the thermal load of a thermal storage wall passive house suitable for engineering design applications.Based on this,on the basis of considering the heat load of traditional buildings,this article further considers the role of heat collection and heat storage walls to reduce the heat load.It analyzes doors,windows,walls and roofs(hereinafter referred to as "walls"),cold air penetration.And the dynamic heat transfer process of the heat collection and heat storage wall to the room,the mathematical model of heat transfer ofeach part is established,and then a simplified method for calculating the thermal load of the heat collection and heat storage wall passive house is proposed.The main research contents and results are as follows:(1)The composition of the heat load of the heat-collecting and heat-storing wall passive house is analyzed,and the mathematical model of heat transfer is established based on the dynamic heat transfer process of each part.The heat load of the tromble wall passive house includes the heat consumption of doors and windows,the heat dissipation of cold wind penetration,the heat of the wall,and the heat of the heat-collecting wall.Among them,according to the characteristics of light structures such as doors and windows and the fast response of cold wind penetration to outdoor external disturbances,the dynamic heat consumption directly adopts the time-dependent steady-state calculation method.(2)A dynamic simplified calculation method for wall heat consumption is proposed.Firstly,the influencing factors(location,orientation,wall type)of the wall heat consumption are analyzed,and the dynamic heat consumption of the wall under different influencing factors(100 kinds of working conditions)is simulated and calculated through cross-combination tests.The ratio to the heat consumption calculated in steady state is defined as the wall load factor.The wall load coefficients of different locations,different orientations,and different wall types are given,and then a simplified method for calculating the dynamic heat consumption of the wall using the wall load coefficient combined with the steady-state heat consumption is obtained.(3)A dynamic simplified calculation method for the heat gain of the heat storage wall is proposed.First,by analyzing the heat transfer process of the heat-collecting and thermal-storage wall into the room,the heat obtained can be divided into convection heat transfer of ventilation holes and heat-conducting heat transfer of the heat-collecting wall.Secondly,the structural parameters that affect the heat gain of the heat storage wall are analyzed,and the convective and heat transfer heat of the heat storage wall with different structural parameter forms(1280 operating conditions)in a typical area are simulated and analyzed.The ratio of the heat transfer to its maximum value is defined as the heat gain coefficient of the ventilation holes and the heat gain coefficient of the heat collecting wall,respectively.Furthermore,multiple regression methods were usedto construct regression models of convection,heat transfer and heat transfer maximum values and different structural parameter forms.Multivariate regression equation coefficients and heat gain coefficients of ventilation holes and heat-collecting walls are given in typical regions.Then,the heat collection coefficients of heat collection walls are calculated by using the maximum values of convection and heat conduction combined with heat gain coefficients of ventilation holes and heat-collecting walls.Thermal simplified calculation method.(4)The traditional dynamic calculation method is compared with the simplified calculation method proposed in this study,and the rationality of the simplified thermal calculation method for the thermal load of the heat-collecting and thermal storage wall passive house proposed in this study is revealed.The typical tromble wall passive house in Lhasa was selected as the object.Through simulation analysis,it was found that the relative error of the heat load obtained by the simplified calculation method and the traditional dynamic calculation method was 5.1%,which indicates that the heat-collecting and heat-storing wall method proposed in this study The simplified calculation method for the passive house heat load is reasonable and accurate.Through the above research,a dynamic simplified calculation method for the thermal load of the heat-collecting and thermal-storage wall passive house is obtained.The proposed simplified calculation method can provide engineering designers with convenience for the selection of active equipment in the early stage of design,and it also provides relevant specifications for passive houses.Provided some support and reference.And compiled the passive house heat load calculation software to provide designers with simpler means in engineering applications. |
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