Design And Economic Analysis Of Biomass Burner For Absorption Refrigeration System

With the improvement of people’s living standards,farmers planting fruits and vegetables crops have not only been used for their own enjoyment,but also considered for sale to obtain certain economic income.At the same time,with the expansion of crop planting area,more and more waste crop straws are produced.Direct combustion not only wastes,but also pollutes the atmospheric environment.In rural areas,it has become an important task to find a green and environmental protection refrigeration system to solve the growing problem of fresh-keeping of fruits and vegetables in rural areas,and to solve the problem of agricultural waste straw in rural areas.In this paper,based on the research of absorption refrigeration technology,a kind of crop straw pellet fuel burner is designed for heat supply of absorption refrigeration system.Finally,the optimal structure and operating parameters of the burner are obtained through experiments,and the economic benefits of the burner are analyzed.The main contents and results of this paper are as follows:(1)This paper studies the efficiency of absorption refrigeration,calculates the theoretical heat required to maintain a temperature of about5 ℃ in a 30m3 cold storage,analyzes the composition and combustion performance of biomass pellet fuel,calculates the theoretical fuel consumption and theoretical air volume required for complete combustion,in which rice husk particle fuel consumption is the largest,and peanut shell particle fuel requires the largest theoretical air volume.According to the relationship between air volume and ventilation rate,the theoretical ventilation rate is calculated,and the ventilation rate of rice husk granular fuel is the largest.Rice Husk Pellet Fuel,which has the largest combustion consumption in rural biomass,is selected as the calculation object of burner design in this paper.(2)Design the structure and size of each module of burner,including feeding device,feeding system,ignition system,air distribution system,combustion chamber,slag discharge device,etc.,select the models of feeding motor,feeding motor,slag discharging motor and blower motor,design the electrical control system of burner and write control program.(3)The design of the burner for sample preparation,and validation test,optimize and improve the burner structure and the working parameters of each part of the device.The optimized parameters of each part are as follows: when the screw speed of feeding is 15r/min,the feeding time is 1min,the interval is 9min,and the initial 30 s feeding is 0.3kg,the ignition time of the burner is the shortest;when the rotation number of slag discharge device is 30r/min,the starting time is 30 min,and the interval is 12 min,the best slag discharging effect is obtained.The results show that the fuel has the best combustion effect by turning the slag discharge spiral,the chance of contacting with air is increased,and the combustion effect is the best;the cross-sectional area of air inlet is 0.12 m × 0.2m,and the number of holes in the furnace inner wall is 18 × 6,the ventilation rate is the best,the combustion is the most sufficient and the operation is the most stable.(4)The absorption refrigeration driven by biomass pellet combustion can consume 23460 kg biomass pellet fuel in rural areas every year,which can save6232 kwh of electricity,equivalent to about 2517 kg standard coal,reduce carbon dioxide emission by about 6695 kg and sulfur dioxide emission by about 22 kg.The burner studied in this paper has the advantages of uniform combustion,good slag removal effect,sufficient combustion,low power consumption and environmental protection.It is suitable for the absorption refrigeration system built for the preservation of fruits and vegetables in rural areas to provide a continuous and stable heat source.