The rapid development of the economy and increasing desire for comfort level and enhancement of building services, result in unprecedented demand for building energy and lead to environmental pollution. Worldwide,the percentage of the total energy consumption of buildings is higher in each country and heating ventilation and air conditioning (HVAC) accounts for 50%~60% of building energy consumption. Hence, it is critical to improve the efficiency of HVAC system. Absorption refrigeration air conditioning system can realize utilizing low-grade thermal energy (e.g. wasted steam and water) with water as refrigerant, avoiding ozone depletion and global warming. The combination of environmental protection and energy efficiency makes absorption refrigeration widely used in heating ventilation and air conditioning fields, especially for large buildings. However, the absorption refrigerating machines always have disadvantages of complicated structure, low efficiency and large volume, which hinder their further development. The absorber is the most significant component in absorption refrigerating system,accounting for more than a quarter of the total mass. Traditional falling film absorption seriously restricts the heat and mass transfer performance which will determines the volume, cost and efficiency of absorption refrigerating system directly. Therefore, how to reinforce the heat and mass transfer efficiency in absorption process becomes the research hotspot of absorption refrigerating system. In this paper, a LiBr absorption refrigeration system with mechanical vibration along with the whole refrigeration is proposed and set up. The heat transfer rates and mass transfer rates before and after introducing vibration are compared. Using variable - separation method and controlling a single parameter, the reinforcement efficiencies of heat and mass transfer during absorption are studied experimentally based on coupled solution film thickness,vibration frequency and vibration amplitude. The influence of mutual restriction relationship between frequency and amplitude on refrigeration efficiency is analyzed. In the condition of vibration, comparison experiments with and without surfactant addition are conducted, and the coupling properties of reinforcement efficiencies under combined effect of active reinforcement and passive reinforcement are discussed. The energy expend ratio of refrigeration system with mechanical vibration is analyzed. Additionally,the energy saving potential of the absorption refrigeration system with mechanical vibration is analyzed. The results show that, mechanical vibration under different vibration conditions has a strengthening effect on the refrigeration capacity,heat and mass transfer. There are better performance when the frequency and amplitude are 25 Hz and 0.2 mm, respectively. On the contrary,the active reinforcement of mechanical vibration and passive reinforcement of surfactant addition can couple with each other or be cancelled out according different vibration conditions. The EER of the absorption refrigeration system with mechanical vibration can improve 14.5%comparison with traditional absorption refrigeration system and about 58.7 kW?h energy per unit area is saved, therefore the energy saving effect is obvious.%实测机械振动强化吸收式制冷系统在不同振动工况下对机组制冷量和传热传质的强化效果,以及机械振动与添加表面活性剂耦合的强化效果,分析了使用机械振动强化吸收式空调系统的节能潜力.结果显示:不同振动工况下的机械振动对机组制冷量和传热传质均有强化作用,其中振动工况:频率为25 Hz、振幅为0.2 mm的强化效果最佳.不同的是,在机械振动耦合表面活性剂时的强化效果,根据不同的振动工况有耦合加强作用,也有相互抵消效果.在本文的实验工况下机械振动强化与无振动相比系统EER提高了14.5%,与普通吸收式空调机组相比单位面积可省58.7 kW?h 的电,节能效果明显.
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