Research On Energy-saving Renovation Of Existing Farm Houses In Taizhou Based On Solar Chimney Design

In rural areas,most residential buildings did not consider the energy consumption of buildings at the beginning of construction,and energy-saving renovation of them can help alleviate the current energy pressure.Using solar energy as the driving force of thermal pressure,the solar chimney has the advantages of strengthening indoor natural ventilation and saving energy consumption.Therefore,this thesis takes the existing rural houses in Taizhou as the research object,and uses solar chimneys to carry out energy-saving renovation research and focuses on the following key issues.Question one,what is the current situation of existing rural houses in Taizhou;secondly,what are the factors affecting the ventilation performance of solar chimneys;third,how to optimize the ventilation performance of solar chimney;fourth,how to apply solar chimneys to energy-saving renovation and practice of existing rural houses in Taizhou area.First,through field research and measurement methods to study question one.In this study,six villages in Taizhou were investigated on the spot,and questionnaires were distributed to three villages and three typical houses were selected for field measurement.(1)Through the analysis of SPSS software,the reliability coefficients of the three villages were 0.755,0.711 and 0.750 respectively.The KMO values of the validity were 0.820,0.806 and 0.755,respectively.The reliability and validity of the questionnaire were good.The results of the questionnaire show that 78.1%,68.1%and 61.9%of the respondents are not satisfied with the current indoor thermal comfort,67.6%of the respondents have the intention to install solar chimneys in buildings after understanding the principles and functions of solar chimneys,and the remaining reasons for the installation are mainly considered to affect the building structure,lighting and aesthetics.(2)The measured results show that the average radiation intensity of sunshine time on the test day is 330W/m~2.During the test period,the average indoor temperature of the three buildings is about 35°C,the average relative humidity is about 60%,and the indoor air is basically in a calm state.The results show that the existing rural houses in Taizhou area have the use of solar chimneys to strengthen nature.Secondly,the second question is studied through the method of literature research.Through literature research,the ventilation principle of solar chimney is summarized.The main influencing factors of its ventilation performance can be divided into climate,shape structure and material.The climate is mainly affected by solar radiation,ambient temperature and external wind environment.The shape structure is mainly affected by its own height,depth,width and the position and size of the chimney inlet and outlet.The material is mainly affected by the transparent wall,the heat collecting wall and the heat insulation wall.Thirdly,the problem three is studied by software simulation.Combined with typical residential buildings in Taizhou,three forms of solar chimneys are designed,which are combined with window wall,stairs and windows.Under steady-state conditions,the influence of the shape structure of the three combined solar chimneys on their ventilation performance is simulated and analyzed.It is found that the ventilation performance of the three solar chimneys increases with the increase of height.For the solar chimney combined with the window wall,when the air inlet of the second-layer chimney is set in the lower position,it is more conducive to hot-press ventilation than in the middle and upper positions;when the depth is set to 0.8m and the height of the first and second air inlets is set to 0.25m-0.3m,the ventilation performance is the best.The solar chimney combined with stairs,when the depth reaches more than 1.2 m,the chimney can produce hot pressing effect on the second floor inlet,then with the increase of depth,its ventilation performance is gradually enhanced,when the depth reaches the maximum 2.2 m,its ventilation performance is the best;the solar chimney combined with the window has the best ventilation performance when the depth is 0.6m,and then the increase of ventilation rate decreases with the increase of depth.Finally,the above research conclusions are applied to the energy-saving transformation and practice of existing rural houses in Taizhou area.Fluent and Energy Plus software were used to simulate and analyze the indoor ventilation and air conditioning energy consumption after the installation of solar chimneys.The results show that under the typical climatic conditions of Taizhou,the solar chimney combined with the stairs has better indoor ventilation performance.In the air conditioning refrigeration season(April-October),the energy saving rate of air conditioning energy consumption after adding a solar chimney combined with the window wall reaches 21.1%.