Simulative And Experimental Study On The Second Class LiBr-H₂O Absorption Heat Pump

The second class Absorption Heat Pump is also named Absorption Heat Transformer (AHT), which is a heating device that can use steam, water, oil, gas and waste heat of heat source as compensation source. The AHT can achieve thermal energy promotion through thermal energy driving the refrigerant cycle and convert the low grade heat to high grade heat. Absorption Heat Transformer has remarkable energy-saving effect in the use of low potential energy and waste heat. Absorption Heat Transformer works with three heat sources. The temperature parameters have great effects on the operation of the whole system. In this paper, the effects on lithium bromide absorption heat transformer system along with the temperature parameters and refrigerant circulation flow were mainly studied.According to the basic principle of the absorption heat pump, a thermodynamic analysis of the absorption heat pump using lithium bromide-water as the working fluid was established. A power of23.4KW lithium bromide absorption heat pump type was designed. The heat source inlet temperature is75℃, the low temperature heat source inlet temperature is15℃, and the output energy as heat medium water inlet temperature is also75℃. The process simulation of the lithium bromide absorption heat transformer pump system was established using the simulation software Aspen Plus. The results were discussed such as the lithium bromide absorption heat transformer pump system with the different temperature of the driving heat source, different cooling water temperature, and different heat medium water temperatures. Under design conditions, the coefficient of performance (COP) of the absorption heat transformer pump is0.473. The COP of the lithium bromide absorption heat transformer system slightly decreases with increasing working medium flow rate, and the influence is small. COP increased with the increasing of driving heat source temperature, gradually decreased with increasing inlet cooling water temperature, and the performance of the AHT is decline. At the same time, the COP decreased with the increasing of heat medium absorber inlet water temperature.According to the lithium bromide absorption heat transformer pump unit experiment table, an experimental study on the drying process waste heat waste and hot water drive the absorption heat transformer pump at different temperature and different refrigerant flow was conducted. The absorption performance changing tendency and unit type heat pump system of each equipment heat load on different conditions of the absorption heat transformer was obtained, by comparing the experimental results with the simulation results. The coefficient of performance (COP) of the lithium bromide absorption heat transformer system increases with the increasing of driving heat source temperature, gradually decreased with increasing inlet cooling water temperature, and decreased with the increasing of heat medium absorber inlet water temperature, gradually improved with the increasing of driving heat water flow generator, and condenser cooling water flow rate. The heat load of the heat exchanger was increased along with the increasing of the driving heat source temperature, decreased with increasing the temperature of the cooling water and hot water temperature.