Study On Energy Conservative Characteristic Of Low-energy Residential Building In Agricultural And Pastoral Areas Of Qinghai Province

With the acceleration of urbanization,the city's energy consumption has increased dramatically,including building energy consumption increased significantly each year.In order to save the energy and reduce the energy consumption of buildings,the concept of building energy efficiency is formally proposed.China's research in low-energy buildings is mostly based on passive heating systems,but few studies on active heating systems or active and passive combined heating systems.Qinghai Province is rich in solar energy resources,and there is a certain amount of passive heating technology research and construction foundation.However,in extreme circumstances,a simple passive heating technology can not meet the needs of indoor thermal comfort.This paper combines active heating technology with passive heating technology to study the indoor thermal environment and energy-saving characteristics of active and passive combined low-energy buildings.The main work contents and results are as follows:(1)Concerning the solar energy resource and architectural features in the agricultural and pastoral areas of Qinghai Province,an active and passive integrated low-energy residential building demonstration project will be constructed.The heating system includes:passive additional sunlight room,passive direct benefit window,and active direct expansion solar-air source.Heat pump with radiant floor heating at the end.Demonstration project were tested in black box mode,passive mode,and active-passive combination mode.And select traditional rural houses with similar structures to conduct black box non-insulated mode tests then analyze and compare the test results under different modes.The results show that the indoor temperature is significantly improved,and the indoor thermal environment can be maintained at 15?-16? when it's basically stable,and indoor and outdoor temperature difference reaches at 20? or more after using active and passive combination heating technology.Compared to passive heating technology,indoor temperature increased 8?-10?,the direct-expansion solar-air source heat pump achieves a time-averaged COP of 2.10,this shows that active and passive combination of heating technology is able to meet the heating and heat comfort needs of agricultural and pastoral areas of Qinghai.(2)Analyze the energy consumption of the active-passive combined heating system during the test and evaluate the economic and energy efficiency of the system.Compared with bulk coal,the active-passive annual energy-saving rate is 30.3%,and the reduction of carbon dioxide emission during the test is 44.213kg,the reduction of sulfur dioxide is 0.358kg,and the emission of dust is reduced.0.179kg.(3)Simulate the thermal environment in the demonstration project by DeST-h software in order to verify the reliability of the software for building simulation.Based on the demonstration project as a basic model,analyze the effect of thermal insulation material and thickness on the outer wall,the depth of sunlight,the heat transfer coefficient of the outer window and the south window wall ratio on the thermal load,then simulate and optimize the demonstration project model.Compared with the basic model,the optimized model obtained in the winter sunlight room temperature increased by 0.9?,the living room temperature increased by 1.09?,and the energy saving rate was 18%.