Research On The Residential Indoor Thermal Environment Optimization In Jiarong Tibetan Area Of Northwestern Sichuan

Located in the "Tibetan Yi cultural corridor",the Jiarong Tibetan in northwestern Sichuan has a very high research value because of the distinctive local characteristics and unique residential houses.In recent years,thanks to the implementation of village construction work such as Happy Beautiful New Village,tourism boutique villages and poverty alleviation villages have been completed one after another.Tibetans’ living standards have greatly improved,and improve the indoor environment has become their urgent need.However,the construction methods of traditional houses and heating methods for fuel-wood can no longer fully satisfy residents’ needs for indoor thermal environment demand.Residents spontaneously introduced urban dwellings,resulting in the loss of residential cultural features and increased building energy consumption.Thus,taking Jiarong Tibetan-style dwellings as the research object,using appropriate optimization strategies to improve the indoor thermal environment and provide scientific development proposals for dwellings is the core of this research.Based on the analysis of the influencing factors of indoor thermal environment,a questionnaire survey was firstly conducted on the indoor thermal environment of some residential.Then,a case was selected for on-site testing of indoor and outdoor temperature and humidity and wall radiation temperature.At the same time,EnergyPlus software was used to numerically simulate temperature,humidity,and air flow rates throughout the year.And the indoor thermal environment was evaluated by combining the two indexes of PMV-PPD and APMV.Finally,based on the current status of the indoor thermal environment,the building shape and envelope structure were optimized,and the additional solar room and solar pebble bed low-temperature hot water floor radiation system were used to improve the indoor thermal environment,and discussed optimization effects using EnergyPlus software.In addition,the Ansys software was used to simulate the heating characteristics of the new heating system.According to the research on the current status of indoor thermal environment,the overall indoor thermal environment is poor,the outdoor average temperature is 8.58°C,the indoor average temperature is 13.04°C lower than the thermal-neutral comfort temperatureby 7.22°C,and the indoor average temperatures in winter and summer are 5.34°C and19.76°C,respectively.And room mean radiant temperature is as cold as air temperature.This is mainly because the outdoor climate is cold,the insulation structure of the envelope is poor,the building volume is large,the ratio of window to wall is not reasonable,and the traditional firewood heating is inefficient.The implementation of the optimization strategy can greatly improve the quality of the indoor thermal environment:(1)Additional solar room can increase the temperature of the adjacent room up to 5.96°C and 6.80°C,respectively;(2)When the building is facing north-south and the aspect ratio of the plane is1.2~2.2,the residential building uses an autoclaved aerated concrete block wall or an Eco-stone wall as the thermal insulation exterior wall,combined with PVC double-glazed insulating glass windows and thermal insulation roofs.It can at least increase the indoor average temperature of 4.40 °C and 4.44 °C,respectively,to 17.44 °C and 17.48 °C;(3)In particular,using the new heating system,the temperature in the living room and master bedroom can be increased to 7.55°C and 6.56°C,reaching 20.64°C and 21.01°C,respectively,and the PMV values are-0.34 and-0.30,respectively;(4)In addition,the new heating system can basically meet the needs of heating at night for 10 hours by releasing the heat stored during the day.