Performance Study Of Solar LiBr Absorption Chiller And Its Application

As the the world energy crisis more and more serious, a solar lithium bromide (LiBr) absorption refrigeration system has become hotspot in the field of renewable energy utilization owing to its characteristics of saving energy and no pollution. However, there is a long way from large scale application. In this paper, the performance of a solar single-effect lithium bromide absorption refrigeration system is studied.The main studies, by method of numerical simulation, are as follows:Firstly, thermal physical properties mathematical models of of lithium bromide solution, saturated water and water vapor are developed. Mathematical models of the components of the solar LiBr absorption refrigeration system are established, by using lumped parameter method.Secondly, optimization design process of the single-effect LiBr-H2O absorption refrigerating unit is analyzed. The effect of design variables on unit’s area and the COP is gained and heat transfer area of the components and working medium flow are obtained.Thirdly, the performance of a solar single-effect lithium bromide absorption refrigeration system is analyzed. The effect of the inlet temperature of hot water, outlet temperature of cold water, inlet temperature of cooling water and other external conditions on the performance of the chiller is analyzed. Running state of the system under partial load is simulated and the effect of flow rate of hot water, solution, cooling water and cold water on the refrigerating capacity and COP of the unit and heat exchange capability of the components is gained and the range of dangerous condition of the unit is calculated.Finally, The area of collector and tank is optimized and variation of dynamic performance of system on the whole day with solar radiation and the building cooling load is analyzed.