Simulation on performance of air source absorption heat pumps with different compression-assisted approaches

doi:10.3969/j.issn.0438-1157.2013.07.008

Abstract

Abstract: 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.

Key words: air source absorption heat pump, compression-assisted absorption, ammonia-lithium nitrate, cold region, heating

摘要： 我国建筑采暖和生活热水能耗较大,基于空气源吸收式热泵的供热系统是北方寒冷地区具有较大节能潜力的解决方案。由于单效空气源吸收式热泵无法运行在气温较低的环境下,提出采用增压循环来提高空气源吸收式热泵的低温性能,并根据增压方式的不同分为低压增压和高压增压两种形式。以NH₃-LiNO₃作为工质对,对不同形式空气源吸收式热泵进行了对比分析。结果表明:两种增压方式均能有效提高吸收式热泵的低温性能,在不同的室外气温、热源温度和热水温度下,能够实现20%~45%的节能率;此外,低压增压的一次能源效率比高压增压更高。综合节能性和实现难易程度,低压增压是提高空气源吸收式热泵低温性能的较好手段。

关键词: 空气源吸收式热泵, 增压吸收, 氨-硝酸锂, 寒冷地区, 供热

CLC Number:

WU Wei, SHI Wenxing, WANG Baolong, LI Xianting. Simulation on performance of air source absorption heat pumps with different compression-assisted approaches[J]. CIESC Journal, 2013, 64(7): 2360-2368.

吴伟, 石文星, 王宝龙, 李先庭. 不同增压方式对空气源吸收式热泵性能影响的模拟分析[J]. 化工学报, 2013, 64(7): 2360-2368.

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