| In recent years,China’s energy consumption has grown rapidly.With the rapid advancement of urbanization,the proportion of energy consumption in the building sector has gradually increased,and the demand for building energy conservation is increasing.Compared with urban areas with dense population,agglomeration of resources,and high level of development of various industries,there are relatively few researches on building energy efficiency in rural areas.In order to improve the situation of harsh environment,scattered resources and slow economic development in rural areas,meet the energy-saving needs of rural areas,and optimize the current situation of heating,the author proposes a prefabricated biomass fire pit heating system and conducts specific research.The research content is as follows:(1)Carry out investigation and research on the current situation of heating in rural areas in western Hunan.By means of questionnaires,on-site inspections and interviews and discussions,based on the investigation of the family members,building conditions,heating methods,thermal comfort and energy consumption status of five villages in rural areas in western Hunan,the current situation of heating in western Hunan is understood in multiple directions.The survey results show that heating thermal comfort in rural areas is poor,heating efficiency is low,and there are potential safety hazards.Therefore,in order to solve the heating problem in rural areas in western Hunan,it is extremely necessary to propose a comfortable,safe,economical and efficient new biomass fire pit heating system,which is of great significance to improve the indoor thermal environment.(2)A prefabricated biomass fire pit heating system is proposed.The system is assembled from three parts: biomass burning furnace,main flue of fire pit and chimney,which respectively complete the process of fuel combustion,heat transfer process of fire pit flue and smoke exhaust process of chimney.According to the characteristics of flue gas flow and heat transfer,the evaluation indexes suitable for the new fire pit are proposed,such as the surface temperature of the fire pit device,the central axis temperature of the upper surface of the fire pit,the flow resistance of the flue gas and the thermal efficiency.(3)Numerical simulation of the prefabricated biomass fire pond heating system.Through the analysis and discussion of CFD simulation results of the prefabricated biomass fire pit heating system,the effects of flue gas input temperat ure,flue gas flow rate,roof thickness,baffle spacing and baffle plate width on the thermal performance of the fire pit are obtained.The simulation results show that when the flue gas input temperature is 200°C,the flue gas flow velocity is 1.5m/s,the top plate thickness is12 cm,the gap between the baffle plates is L1 segment spacing 60 cm,L2 segment spacing is 35 cm,L3 segment is 10 cm,and the breadth plate width is L1 segment 6cm,L2 segment 8cm,L3 segment 10 cm,the maximum temperature difference b etween the upper surface center axis(0.5-5m)is 4.4 °C,which balances the temperature distribution of the upper surface center axis.The circulation resistance is 121 Pa,the heat dissipation of the heating device is 5839 W,and the thermal efficiency of t he main part of the fire pond heating device is maintained at 56.79%.The surface temperature balance of the fire pit heating device has been effectively optimized,and the temperature parameters of the device meet the design requirements,and the excellen t heat dissipation and thermal efficiency are maintained.This study provides a new idea for solving the heating problem in rural areas of Hunan and western Hunan.The new fire pit heating system provides local heating devices with high thermal comfort for residents.It has the advantages of excellent thermal efficiency,low cost,simple operation,firmness and durability.It is of great significance to promote the development of personalized heating devices in rural areas. |
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