Performance analysis of absorption heat recovering cycle with high-pressure booster using NH3-LiNO3 as the working pair

Recently, the extensive use of heating, ventilation and air conditioning systems contribute 50% of building consumption, which causes the rapid growth of building consumption. Absorption cycle, which uses low grade energy likes solar heat energy and industrial heat to generate cooling effect, could lower the large amount of high grade electric power for cooling demand in summer. The most common working pair used in absorption chiller, i.e. LiBr-H2O, owes the highest COP but has narrow evaporation temperature range and high crystallization risk, making the limitation for miniaturization and air-cooled design. Although the NH3-H2O can operate in wide range of evaporation temperature, the rectifier is indispensable for increasing the concentration of ammonia gas, that is disadvantageous to performance. The new working pair NH3-LiNO3 has a crystallization temperature which is much higher than that of LiBr-H2O. And the chiller uses it as working medium operates without rectifier. In addition, the high pressure of ammonia gas makes the cycle using it is more suitable to coupled with compressor for performance improvement and operation temperature widening. Therefore, the performance analysis of absorption heat recovering cycle with high-pressure booster using NH3-LiNO3 as the working pair was carried out in this paper, to deeply research the improvement effect of the compressor introduction. As shown in results, with the assist of compressor, the driven temperature of the new cycle can decline to 34℃, and the evaporation temperature decreases to -34℃ as well. Furthermore, the circulating ratio reduced by 52.16%, which means the adaptability for miniaturization and air-cooled design. © 2021, Editorial Board of CIESC Journal. All right reserved.