Comprehensive Benefit Evaluation And Energy-saving Reconstruction On Coal-fired Furnace In The Bulk Curing Barn

Coal-fired furnace has widely used in most bulk curing barn. Because of its low combustion efficiency along with a large amount of pollutants produced during tobacco curing process, it has seriously affected the sustainable development of tobacco production. Tobacco production has become a pillar industry in Pengshui county Chongqing city. But coal-fired furnace in the bulk curing barn has existed so many problems which need to improve and solve, such as high coal consumption, emissions more,labor-intensive.At the beginning of the paper, coal-fired furnace in the bulk curing barn has been energy-saving reconstructed. And then a new coal-fired furnace has been proposed, which has trapezoidal plate grate and automatic feeding device. In order to analyze the effect of coal-fired furnace combustion and demonstrate reconstruction energy-saving scheme, coal-fired furnace combustion test has been launched. Comprehensive comparison tobacco curing effect of reconstructing coal-fired furnace and existing coal-fired furnace,tobacco curing tests have been carried out. In addition, comprehensive benefit of energy-saving reconstruction on coal-fired furnace in the bulk curing barn has been evaluated.The results of the study shows:(1)During the coal-fired furnace combustion test, the combustible component was very high in the exhaust gas, fuel combustion was not sufficient, furnace wall surface dissipated heat severely. After reconstructed furnace, the combustible component decreased significantly, combustion furnace wall surface heat dissipation significantly reduced, burning effect in the furnace had been greatly improved.(2)Compared with the existing coal-fired furnace in the bulk curing barn, a shed tobacco curing with using fully reconstructed coal-fired furnace should consume coal 240 kg and electricity 240kw·h. Per kilogram dry tobacco need coal 0.94 kg. It realizes saving coal 136 kg and electricity 80kw·h, combustion efficiency improved nearly 23.8%, saving-coal rate reached 27.7%, saving-electricity 1/3, the ratio of superior tobacco improved 10.4%. After coal-fired furnace added the automatic feeding device, the times of adding coal is 15,which decreased 41 times than without automatic feeding device. The interval time of automatic feeding device is 11 hours, which increased 8 hours than adding coal by people. It has greatly reduced the labor intensity of tobacco curing.(3)The cost of reconstructing one coal-fired furnace in the bulk curing barn is just ?8000, which is very cheap, and benefit is remarkable. In terms of economic benefit, the investment payback period of this project is just 2 years, economic net present value is ?2487, and EIRR is 44.3%. In terms of environmental benefit, In Pengshui county, every year this project can reduce emissions: CO2:20217.6 tons,SO2:584 tons,NOX:291.2 tons,dust particles:5288 tons. In terms of social benefit, Tobacco farmers,income can increase ?18.48 million in Pengshui county. County specialty tobacco taxes will increase ?3.696 million and the average income of tobacco farmers will increase ?5796. This project is suitable for promoting to the whole county of Pengshui,even the whole city of Chongqing.