Improved indoor thermal comfort during defrost with a novel reverse-cycle defrosting method for air source heat pumps
Improved indoor thermal comfort during defrost with a novel reverse-cycle defrosting method for air source heat pumps
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DOI：
10.1016/j.buildenv.2010.04.006
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发表时间：
2010-11
影响因子：
7.4
通讯作者：
Qu Minglu;X. Liang;S. Deng;J. Yiqiang
中科院分区：
文献类型：
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作者：
Qu Minglu;X. Liang;S. Deng;J. Yiqiang
当空气源热泵机组在冬季环境温度较低的情况下用于空间供暖时，其室外盘管表面可能会形成结霜。结霜影响其运行性能和能源效率，因此定期除霜是必要的。目前，应用最广泛的标准除霜方式是逆循环除霜。在标准的逆循环除霜过程中，空气源热泵机组中的室内盘管实际上充当蒸发器，因此，不提供加热，因此加热空间中的室内空气温度可能会下降。此外，在完成除霜后，需要更长的时间才能立即获得空间加热。因此，居住者的热舒适可能会受到不利影响。为了改善逆循环除霜过程中居住者的室内热舒适，本文提出了一种基于热能储存（TES）的逆循环除霜方法，并对其对居住者热舒适的改善进行了实验评价。采用基于TES的新型反循环除霜方法和标准反循环除霜方法进行了对比实验。实验结果和室内热舒适评价指标均表明，与使用标准反循环除霜相比，采用新型反循环除霜方法可以改善室内热舒适，除霜周期更短，除霜时室内送风温度更高。
When an air-source heat pump (ASHP) unit is used for space heating at a low ambient temperature in winter, frost may be formed on its outdoor coil surface. Frosting affects its operational performance and energy efficiency, and therefore periodic defrosting is necessary. Currently, the most widely used standard defrosting method for ASHP units is reverse-cycle defrost. During a standard reverse-cycle defrosting process, the indoor coil in an ASHP unit actually acts as an evaporator, therefore, no heating is provided and hence indoor air temperature in a heated space can drop. Furthermore, a longer period of time is needed before space heating can become available immediately after the completion of defrosting. Consequently, occupants’ thermal comfort may be adversely affected. To improve the indoor thermal comfort for occupants during reverse-cycle defrosting, a novel thermal energy storage (TES) based reverse-cycle defrosting method has been developed and the improvement to occupants’ thermal comfort experimentally evaluated and is reported in this paper. Comparative experiments using both the novel TES based reverse-cycle defrosting method and the standard reverse-cycle defrosting method were carried out. Experimental results and the evaluated indoor thermal comfort indexes clearly suggested that when compared to the use of standard reverse-cycle defrost, the use of the novel reverse-cycle defrosting method can help achieve improved indoor thermal comfort, with a shorter defrosting period and a higher indoor supply air temperature during defrosting.