Research On The Optimization Design Of The Thermal Performance Of Straight Hole Fire Kang Based On Simulation Technology

Fire Kang,as an important place for farmers and herdsmen in the north,is generally composed of stoves,Kang bodies and chimneys.It represents the regional and national characteristics of the NorthernChina region.Fire Kang is one of the main facilities of indoor heating in winter for farmers and herdsmen in NorthernChina,which is still widely used.The main advantages are easy to build,convenient to pick up materials,low cost.However,with the development of modern new energy,Fire Kang is gradually replaced by bed,as a Fire Kang with a history of more than 2000 years,its status is gradually declining.At present,the construction of Fire Kang is still based on folk experience,lacking of systematic theoretical research and technical charter.It is common that the range of high temperature flue gas flow field is small,the effective flue is short,the heat transfer resistance is large,the indoor heat transfer area is small,and the contact Kang board area is small.Kang surface temperature is very uneven,smoke outlet temperature is high and so on,which leads to its low thermal efficiency,poor thermal comfort,fast cooling,high fuel consumption and so on.Domestic scholars have carried out many experiments and studies on the thermal performance evaluation index of Fire Kang,but using fluid mechanics VENT simulation technology and ANSYS simulation technology to affect the thermal comfort of Fire Kang flue.Few studies have been carried out on thermal efficiency.Under the guidance of fluid mechanics and building thermal engineering knowledge,the flue gas flow field distribution,inlet and exit temperature and vortex condition of Fire Kang are simulated and analyzed by VENT simulation technology and ANSYS simulation technology,and then the flue is optimized.It can be seen from the comparative analysis that compared with the present Fire Kang,the improved Fire Kang can make the smoke channel Kang hole in a wider range,the Kang panel contact with the high temperature flue gas and then absorb,store,release the flue gas heat,and at the same time reduce the smoke outlet temperature.It greatly improves the thermal efficiency and thermal comfort of the Fire Kang,and also provides a new technical method for the optimal design of the Fire Kang.The thermal performance of the improved Fire Kang has been improved in many aspects:(1)The area of the flow field where the flue gas velocity is above 0.4 m/s increases,the area of the flue gas flow field expands,and the temperature uniformity of the Kang surface increases.The thermal comfort increased.(2)The distribution range of high temperature flue gas at 270 ℃-350 ℃ accounted for the increase of Kang panel area,the heat absorption and heat storage of Kang panel increased;The distribution range of low temperature flue gas at 204 ℃ accounts for the area of Kang panel,and the temperature uniformity of Kang panel is improved.(3)The smoke exhaust temperature of improved Fire Kang is reduced by 15 ℃-20 ℃,and the high temperature smoke is discharged out of the chimney after full heat transfer in the flue.The heat of flue gas is fully utilized.The heat storage of the Fire Kang increases,and the thermal efficiency of the Fire Kang increases obviously.(4)The flue gas flow in the improved Fire Kang is more uniform,the temperature in the Kang head area is decreased,the temperature in the Kang tip area is increased,and the average temperature is increased by about 20 ℃.It not only increases the heat transfer area between high temperature flue gas and Kang body,but also prolongs the flow path and time of flue gas in Kang body,and the heating capacity of Fire Kang is greatly improved.