| The use of traditional bulk coal heating in rural areas of China has caused serious air pollution,and clean heating schemes such as "coal-to-gas" and "coal-toelectricity" cannot be applied to all regions due to factors such as energy endowment and geographical location.China has sufficient methanol reserves,and heating with methanol as fuel can be used as a supplement to the existing clean heating scheme s.However,the methanol heating scheme is still in its infancy,the design theory and method of methanol burner are not perfect,and the applicable areas of methanol heating need to be further clarified.In this paper,a high-efficiency and lowemission domestic methanol heating stove is developed.The technical economy of methanol heating is analyzed from the aspects of energy consumption,emission,and economy.The application scenarios suitable for methanol heating are proposed.A numerical model of a partial premixed methanol burner is established by using Fluent.The structure is optimized for the problems of uneven flow distribution and poor airflow organization in the combustion chamber.The effects of the swirl sheet,the depth of the fire holes,the inlet area of the fire pipes and the area of the fire holes on the flow field of the burner are studied.The results show that: the structure without swirl sheet can be more conducive to the optimization of flow distribution;when the depth of the fire hole is 1.5 mm,a better airflow structure can be obtained under the condition of low processing difficulty;the optimal inlet area of the fire exhaust is obtained,which significantly improved the uniformity of the mixed gas flow of each fire pipe;the area of the fire holes with large flow differences is adjusted to improve the uniformity of the mixed gas flow of each fire hole.The whole experimental platform of methanol heating stove is built,and the influences of excess air coefficient α on pollutant emission and exhaust gas temperature under different burner loads are studied.The effect of exhaust gas temperature on thermal efficiency is theoretically analyzed.The results show that:in the actual operating condition range,the CO emissions increase with the decrease of α,NO emission first decreases and then increases with the decrease of α,and the exhaust gas temperature decreases with the decrease of α;it is concluded that α=1.3is the optimal excess air coefficient,at this time higher thermal efficiency can be obtained with lower emissions;the exhaust gas temperature can be further reduced to recover more waste heat.When the exhaust gas temperature drops to 70～50°C,the thermal efficiency will increase to 97～105%.The heat load model of typical houses in rural areas of China and the evaluation index model of different heating schemes in terms of energy consumption,economy and emission are established.The differences in standard coal consumption,initial investment,operating costs,pollutant emissions between methanol heating stove and common heating schemes such as bulk coal heating stove,natural gas wallhung boilers,electric wall-hung boilers,and air source heat pump were compared.It is suggested that methanol heating should be promoted in areas with abundant coal resources,sufficient methanol production and low population density,and in rural areas with insufficient power grid capacity and lack of gas sources to replace the "coal-to-electricity" and "coal-to-gas" schemes. |
