Design And Experimental Study Of Adsorption Refrigeration System Using Activated Carbon-Methanol Of Powered By Solar Energy And Biomass Energy

This study was supported by the National 863 High Technology Research and Development Projects "Research on clean and efficient pretreatment technology of biomass" (NO.2012AA051502), Henan province science and technology plan of innovative talents "Research on high efficient combustion of biomass fuel for clean technology" (NO. 2014HNSKJCXJCRC015) and the Zhengzhou City Scientific Research and Innovation Program "Research on transformation and utilization technology of biomass energy"(NO. 131PCXTD588)ofChina.Energy is an important material foundation for the current national accounts and social economic sustainable development. With the continued rapid growth of social and economic development and energy demand, fossil energy supply and environmental pollution is worsening, development and use of alternatives to fossil fuels, such as solar energy and biomass renewable energy strategy was referred to a higher position for improving the living environment and ecological problems in the suburban fruit and vegetable cultivation park and lack of electricity in remote mountains areas and energy resources. Because CFC, HCFC refrigerants gradually deactivated, adsorption refrigeration can be effectively used as a low-grade environment-friendly energy cooling methods, in line with the current trend of energy resources and environmental development, has become a hot topic at home and abroad.In this study, based on China’s rural industrial structure adjustment and industrial model of development situation of farmers in the present, according to theoretical analysis and experimental study, we propose a lettuce and other fruits and vegetables as vacuum cooling and cold storage cold source, suitable for solar energy, biomass energy and other low-grade energy-driven adsorption cooling system design. Research on the use of solar energy and biomass joint drive to corn straw gasification remaining charcoal activated carbon preparation for activated carbon- methanol working pair of adsorption refrigeration system, for the cultivation of fruits and vegetables and other agricultural parks farmers achieve self preservation small storage cold storage to provide effective technical support in order to ease the pressure on local fruits and vegetables and other agricultural products sales concentrated market to solve local due to poor sales, logistics lag and other issues.In this paper, adsorption refrigeration system using activated carbon (straw carbon material preparation)-methanol of powered by solar energy and biomass energy was made detailed experimental and theoretical studies, including the following:1. With the changes in the characteristics, the analysis based on heat change characteristics and their impact on the performance of the adsorption unit based refrigeration system cooling capacity and heat load requirements, make a joint cooling system design. With local biomass resources and climatic conditions are different, made suitable for combined cooling system running three control modes. 2. Based on The mechanism of enhanced heat transfer and mass transfer analysis, designed a shell and tube type adsorbent bed as a small test for laboratory, a round holes thorns diaphragm tube with the dispersed adsorbent rectangular branch pipe.(1) Heat and mass transfer diffusion properties beneficial aspects of the adsorbent bed to improve the adsorbent bed discussed adsorbent liquidity squeeze diaphragm when bending normal stress and shear stress, between change of the diffusion flux and mass transfer coefficient.(2) In order to study solar energy, biomass energy utilization efficiency, analysis bed thermal conductivity, thermal conductivity were making the bed housing materials Test. The results show that the average value of the thermal conductivity of a heat insulating layer when the insulating layer is not provided, and were 16.283 W/m·℃,13.839PF/w·℃, comparison error is 15.01%.3. Biomass boilers and solar absorption refrigeration system combined with the actual match drive and operation were analyzed. We studied biomass energy and solar energy suitability (coupling process) problems by system simulation and experimental testing. The results show that biomass boilers and solar collectors in parallel conditions, backwater flow distribution ratio ranges from 0.5 to 0.6, respectively, split ratio of different systems for different modes of operation, proposed storage tank export (import refrigeration unit) varies depending on the water temperature values; biomass energy and solar energy to match or not have a greater impact on the capacity of the system, reflecting the cooling capacity of the system and the end of the heat load has to change same characteristics.4. Preparation of phosphate granular activated carbon tests corn stalks. The results showed that the activation temperature, activation time greater impact on yield and carbon adsorption capacity. The optimum conditions for the preparation of activated carbon:Mass fraction of 55% phosphoric acid, solid-liquid ratio of 1:3, the activation temperature of 450 ℃, activation time 3h. Preparation of activated carbon adsorption of methylene blue excellent value was 15.416ml/0.1g.5. Build a simulation test bed adsorption properties, the use of granular activated carbon prepared by gravimetric method to test for methanol adsorption, desorption capacity.(1) The adsorbent bed with new structure reached 0.203 g/g adsorption, the adsorption time compared to non-structural improvements bed ahead four minutes to complete the equilibrium adsorption capacity of 80.56%;(2) Comparison test bed dressed in the different size of the same size of activated carbon adsorption at the same temperature, the adsorption performance was significantly better than the same size of the dress, and to achieve the same amount of 0.201 g/g adsorption, the adsorption ahead 15 minutes to complete the equilibrium sorption 75.69% volume.(3) Inside the refrigeration cycle time, the oil bath temperature under different temperature and pressure within the adsorbent bed with the increase of the heating time is gradually increased. Corresponding to the initial oil bath temperature, bed memory in three temperature peaks and three pressure inflection point:41.3℃,54.5℃ and 68℃, 0.04MP, -0.052 MP and -0.064 MP. The results showed that COP, the cooling capacity with the desorption temperature were increased, when the amount of adsorption cycle was 0.248, COP was 0.086.(4) According to adsorption heat equation and test results solved the same amount of methanol in the heat of adsorption on activated carbon with an average of 1867.23 kJ/kg.6. In order to verify the feasibility of the design issues in the application of vacuum cooling, the southern fruit and vegetable cultivation park from Pingdingshan planting lettuce as the research object, using MATLAB software, lettuce vacuum heat and mass transfer during storage modeling analyzed and validated the model with experimental methods.(1) The simulation results showed that the pre-cooling process vacuum chamber pressure, dry air pressure and wet air density were decreasing trend, and the lower the vacuum pressure, lettuce cooling rate and the greater the rate of water loss.(2) The results showed that pre-wet treatment pre-cooling process compared to a sample material without pre-cooling time of a control sample of wet treatment is reduced by about 10 minutes; the amount of water added to the test sample by mass 4.21%～5.98%, respectively, the mass of the sample the total mass loss of 1.99%-2.87%; water trap when the wall temperature is -5 ℃,2019g lettuce in a vacuum cooling process, the water is about the best trapping 90.716g, the required cooling capacity is 210.13W. The results showed that the amount allocated in line with the cold design.