The Design And Manufacture Of Solar Absorption Refrigerator Having High Heat Driving Force Via Ultrasounic Enhancement

With the continuous increasing energy consumption and the successive warming of the Global climate,solar absorption refrigeration system gets more extensive research, because of its environmental friendly and energy saving. However, though the solar energy absorption refrigeration system has the advantages of environmental protection and energy saving, its COP value is relatively low, compared to the compression refrigeration system. Because when solar energy absorption refrigeration system is drived by low grade solar hot water, the separation capability of refrigerant water within generator is weak. So this paper puts forward a solar absorption refrigeration system which used ultrasound to strengthen the driving force of low grade solar water.This paper firstly investigated the heat and mass transfer strengthening of lithium bromide solution in generator via ultrasound. This experiment includes mass transfer enhancement induced by ultrasound and heat transfer enhancement induced by ultrasound. To mass transfer enhancement, the atomizing effect of ultrasound can reduce the viscosity of solution in gas-liquid interface and the film thickness of mass transfer layer, which accelerates separation and mass transfer process of the refrigerant water in lithium bromide solution. To heat transfer enhancement, the ultrasonic cavitation and acoustic streaming effect can strengthen the convection of the heated tubes in generator and strengthen the boiling heat transfer, which incleases the driving force to separation and mass transfer process of the refrigerant water in lithium bromide solution.Based on the experimental study, this article designed and manufactured a solar single effect lithium bromide absorption chiller. The designed target refrigeration of the chiller was 10 kW and the rated thermal coefficient was 0.64. The design of solar single effect lithium bromide absorption chiller included structural design, piping system design and control system design.In structural design, the parameters of state points of absorption chiller were computed by software of solar Li-Br absorption chiller which is developed our research group. Based on the result of state point parameters, the paper calculates the heat transfer load of internal component of chiller and then designs its structure parameters. The structural design included the design of each component in low pressure chamber, the design of each component in high pressure chamber, the design of cooling tower, and the design of frame. Then the structures of the chiller would be manufactured by structural design.After positions of the pressure chambers and the cooling tower are determined, the piping system would be designed, basing on regulating values and monitoring values of the system. The piping system design of absorption chiller included the design of lithium bromide solution circulation circuit, the design of refrigerant water pipeline, the design of cooling water circuit, the design of heating water circuit and chilled water loop. Then the chiller would be manufactured combined the piping system design. Finally, the solar collectors and the heat storage tank selections would be completed based on the system heat source required.The control system design of absorption chiller included the design of hardware and the corresponding software. The design of hardware system was based on PLC. The software design included the start-up procedure, stop procedure and fault protection procedure.