The energy consumption of heating and domestic hot water in China is very large.The heat supply system based on air source absorption heat pump (ASAHP)is a promising alternative solution in cold regions.However

the single-stage ASAHP cannot operate normally under very cold weathers. Compression-assisted absorption cycles

including high-pressure boosting and low-pressure boosting in terms of the position of the pressurizer in the cycle

are proposed to improve the performance of ASAHP under low ambient temperatures.Different kinds of compression-assisted ASAHP using NH3-LiNO3 as working fluid have been comparatively simulated and analyzed.The results indicate that both high-pressure and low-pressure boosting can effectively improve the performance of ASAHP in cold conditions.Energy saving rates as high as 20%—45% can be obtained with different outdoor temperatures

driving source temperatures and hot water temperatures.Besides

low-pressure boosting ASAHP can achieve a higher primary energy efficiency than high-pressure boosting cycle in the same condition.Taken energy efficiency as well as difficulty of realization together

it can be concluded that the low-pressure boosting is a better choice for the improvement of ASAHP in cold regions.