Study On The Fourth Step Energy Efficiency Index System For Residential Buildings In Cold And Severe Cold Regions

With the promotion of national energy saving policy,the third step of energy saving have been carried out in 2010.After 8 years,the whole country has reached the target of saving energy in three steps,and some cities in cold regions even arrived at the fourth step energy saving index.In response to the country's new energy saving objective,the author provides theoretical data support for the revision of JGJ26-2010,and mainly carries out research on Heilongjiang Province.First of all,according to the field investigation and literature research,the fourth step energy saving index system of residential buildings in cold and severe cold areas was studied,including the goal of fourth steps of energy saving,the energy saving rate of heating system,the energy efficiency of building,and the energy consumption rate of buildings was in addition to the heat consumption of the buildings in each city.The index complements the heat consumption index of buildings in Heilongjiang which is not stipulated in JGJ26-2010.The energy saving rate and total energy saving rate of buildings in each city were calculated.The conclusions are as follows that the fourth step standard of cold and cold regions can reach 75% of the total energy saving.the energy saving rate of the heating system is 6.7%,the energy saving rate of the building is 25%,in which,the low-rise building has made special consideration.The energy saving rate of buildings is 10%.The overall energy saving rate of Helongjiang can reach 67%.Of which the building energy saving rate is 54.4%,and the energy saving rate of the heating system is 32.2%.Because of the previous energy saving standards,there is no specific research on the sun shading coefficient of the external window,and under the new target needs Low-e glass should be selected for the external window,which restricts the sun shading coefficient and affects the heat of the solar radiation.Therefore,the heat transfer coefficient and shading coefficient of the window are studied in this paper.It is found that the large sun shading coefficient in the northern heating area is beneficial to building energy saving,especially the south window.The thermal performance parameters of Low-e three glass different coating were studied by optics simulation software,and compared with the research data.According to the energy consumption index of the building,the heat transfer coefficient limit of the multi-storey buildings and small high-rise buildings under the fourth step of energy saving of residential buildings is deduced.The relationship between the heat transfer coefficient and the sun shading coefficient of the external window is fitted under certain circumstances,and the heat transfer coefficient of the outside windows of different orientations is limited.According to the established heat transfer coefficient limit of the enclosed structure,a project is simulated by De ST-H.The results of the theoretical energy consumption and dynamic energy consumption in various cities in Heilongjiang are similar.On this basis,the economic analysis of the life cycle of roof,external wall insulation materials and external windows is carried out,and the total cost is reduced under the fourth step energy saving target.As the thickness of the insulation layer of the enclosure has reached the limit,the heat transfer coefficient can not be reduced effectively.It is suggested that the next step of energy conservation is no longer limited to the energy saving of the building enclosure.