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重庆村镇空气源热泵供暖系统夜间性能实测分析.doc

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重庆村镇空气源热泵供暖系统夜间性能实测分析   摘要:针对重庆山地村镇迫切的供暖需求,选取该地区典型村镇搭建了空气源热泵供暖系统实验平台,分析了空气源热泵系统性能影响因素,并从供回水温度、系统耗电量、供热量、性能系数COP等角度对运行过程中的阶段特性(启动、稳定运行及全阶段)进行阐述,发现系统在3个阶段特点差异很大:启动阶段初始温度对COP影响较为明显,除霜时系统性能下降25%;稳定阶段特性与初始温度无关,室外条件较好时,降低设定温度,COP提高明显;总体来看,启动阶段COP最高,全阶段次之,稳定阶段COP最低。   关键词:村镇;空气源热泵;供暖;建筑节能   中图分类号:TU831.1;TU832.1;TU833.3 文献标志码:A 文章编号:1674-4764(2015)06-0087-11   Abstract:According to the urgent requirements for the winter heating in a rural residential in Chongqing, it has set up air-source heat pump heating system experiment platform. From the perspective of supply and return water temperature, power consumption, heat supply and coefficient of performance (COP), it has analyzed the system performance factors and phase characteristics (including starting, stable operation and whole stage) during operation, and the system has been very different characteristics in this three stages. Primarily, the initial temperature of the starting phase has obviously influenced COP of the system and when defrosting, it has a 25% drop in performance of the system. For stable operation of the stage, the performance and the initial temperature are not related. Reducing the set temperature, the COP has increased significantly, when there has been a good outdoor condition. Overall, COP in starting stage is the highest, then the whole stage, and COP of stable operation is lowest.   Key words:rural; air source heat pumps; heating; building energy conservation   从“十二五”开始,中国的能源政策从提高能效逐步转向总量控制。从碳排放总量和能源供应量的约束角度,中国建筑能耗总量应该在2.93×108 kJ以内[1]。生理学家发现,当冬季温度较低时,死亡人数与气温之间存在明显负相关性[2]。在南方地区,由于冬季室外空气温度、地下温度都高于北方地区,所以非常适合作为各类分散式热泵的供暖热源[3-4]。到目前为止,热泵技术已成为应用于供暖领域最成功的技术之一[5]。空气源热泵由于不受水源和建筑地理条件的限制,冬夏共用,设备利用率高等特点[6],发展越来越成熟。   根据逆卡诺循环制热系数定义,当蒸发温度不变时,制热系数随冷凝温度升高而降低,当冷凝温度不变时,制热系数随蒸发温度升高而升高。对于空气源热泵热水系统,环境温度(空气温度)和蒸发温度具有正相关性,热水温度和冷凝温度具有正相关性,而针对夏热冬冷地区的热泵空调器在冬季结霜工况测试中,大约有1/3的供热期受热泵结霜的影响不能正常制热[7],山地城市中海拔会影响干球温度,随着海拔的升高使得热泵性能变差[8]。此外,研究发现,对于冷凝盘管来说,当盘管做成“L”型时可获得更佳的换热效果[9],而垂直单回路的结构会导致水箱内出现了明显的分层[10];实验中发现,当沉浸式冷凝器的盘
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