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《可再生能源》2016,(5)
运行模式对地埋管换热器的热交换性能具有显著影响。文章借助桂林理工大学建立的地源热泵实验平台,对桂林地区地源热泵制冷工况下3种运行模式进行试验,研究地源热泵的运行状况及管壁温度变化特性,分析运行模式对地埋管热交换性能的影响规律。研究结果表明:3种运行工况下,地源热泵机组的性能系数COP分别为4.30,4.03,3.48,竖埋管单位管长换热量为14.4~32.8 W/m,水平埋管单位管长换热量为14.8~17.9W/m;地埋管的管壁温度随着地源热泵的运行发生变化,其恢复程度与停机时间的长短有关;间歇运行模式有利于土壤温度场的恢复,提高地埋管换热器的热交换性能;停运比Ps-o由0变化到1时,热泵机组性能系数COP增加了15.8%。 相似文献
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对实际运行的地源热泵系统夏季制冷间歇运行特性进行实验研究,分析比较不同间歇运行方案下得到的热泵机组性能和地埋管换热性能。研究结果表明:相比于负荷侧流量,地源侧流量对机组性能和地埋管换热性能的影响较大;在流量设定的条件下,采用开机运行2 h停机2 h运行方案机组的性能最好,机组最大性能系数(COP)值可达到4.17,比运行4 h停机2 h机组的COP值高出7.5%;在停机2 h的情况下,机组开机2、3或4 h,地埋管的换热能力均可得到恢复,停机前后埋管的平均换热量基本保持平衡。 相似文献
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在北方地区,由于建筑物的冬季热负荷大于夏季冷负荷,单独采用地源热泵对建筑物供暖、制冷,长期运行会造成土壤的温度逐年下降,最终导致地源热泵机组COP越来越低,严重时会影响机组的正常运行。夏季采用太阳能对土壤补热,解决地源热泵机组单独运行时冷热不平衡问题,有效提高机组热效率,达到综合节能的目的。通过对太阳能-地源热泵复合空调系统进行分析研究,利用TRNSYS软件进行分析模拟,从而得出太阳能-地源热泵空调系统的最佳匹配方案。 相似文献
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建立地埋管传热模型和系统能耗模型,对非平衡冷热负荷条件下地源热泵系统运行特性进行模拟计算。当建筑空调冷负荷大于热负荷,且供冷时间较长时,地源热泵系统从冬季初始运行,到达夏季时段,地温比夏季初始运行低,更加有利于夏季地源热泵系统节能。地源热泵系统运行7a后,采取夏季和冬季初始运行两种方案的地埋管钻孔壁年平均温度与土壤初始温度相比,分别上升3.10和5.12℃,导致机组耗功率逐年增加,应考虑采用复合式地源热泵系统间歇运行或增设地埋管设置分区运行策略,平衡土壤传热量。 相似文献
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针对太阳能-土壤源热泵复合系统在水箱直接供暖模式下运行,存在热泵机组频繁启停以及供暖负荷分配不合理的问题,提出一种基于BP神经网络的动态供暖策略。以沈阳某建筑为对象,设计太阳能-土壤源热泵复合系统,通过TRNSYS和Matlab软件进行仿真。通过与常规水箱直接供暖策略对比,该策略能在典型供暖日中将机组的启停次数从9次减少为2次,机组COP 从3.90提高至4.02。在供暖负荷较大的供暖季中期,平均每天提高机组COP 2.37%。 相似文献
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针对严寒地区的气候条件,选取哈尔滨地区某居民住宅小区作为研究对象,利用TRNSYS软件对太阳能-土壤源热泵联合供暖系统(SGCHP)进行计算分析。结果表明:太阳能-土壤源热泵联合供暖系统中太阳能集热器对热泵机组的进水温度和COP以及节电量等方面有改善作用;对太阳能-土壤源热泵联合供暖系统中太阳能集热器面积与地埋管管长的最佳配比的优化结果表明,1 m~2太阳能集热器可保证17~27 m长的地埋管取热平衡。并继续模拟了沈阳地区,并以哈尔滨地区为基准,给出严寒地区该参数的推荐值。 相似文献
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以南方岩溶地区地下水丰富为前提,利用多含水层渗流提高地埋管的换热能力。该文利用有限元软件建立三维单U型换热孔数值模型,利用相关指标分析有无含水层时地源热泵系统的换热效果研究。结果表明:蓄能岩土体内有无含水层多种情况时,U型管出水口平均温度呈现N1>A1>A2>AF1>AF2;AF2、AF1、A2和A1情况下的平均延米换热量分别比N1高49.87%、44.06%、39.51%、31.93%;AF2、AF1、A2和A1情况下的平均COP分别比N1高4.35%、3.93%、3.52%、2.67%。在地下水丰富区域应合理布置换热孔,提升热泵系统运行效率,对实际工程项目可提供一定的指导。 相似文献
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分析介绍了引入“负荷聚合”方法的改进型圆柱热源(热汇)理论模型,并运用圆柱源理论对太阳能一土壤源联合运行热泵系统全天运行模拟,指出联合运行模式较单独土壤源运行模式节能10%~12%,为圆柱源理论模型应用和太阳能-土壤源热泵运行模式的选择提供参考。 相似文献
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Energy analysis of a solar-ground source heat pump system with vertical closed-loop for heating applications 总被引:1,自引:0,他引:1
A heat pump system is the ideal way to extend the heat supply of existing oil or gas fired heating system. Consumption costs are lowered through the use of free energy from the environment, and the dependence on fossils fuels simultaneously reduces. In order to investigate the performance of the solar-ground source heat pump system in the province of Erzurum having cold climate, an experimental set-up was constructed. The experimental apparatus consisted of solar collectors, a ground heat exchanger (GHE), a liquid-to-liquid vapor compression heat pump, water circulating pumps and other measurement equipments. In this study, the performance of the system was experimentally investigated. The experimental results were obtained from October to May of 2008-2009. The experimentally obtained results are used to calculate the heat pump coefficient of performance (COP) and the system performance (COPS). The coefficient of performance of the heat pump and system were found to be in the range of 3.0-3.4 and 2.7-3.0, respectively. This study also shows that this system could be used for residential heating in the province of Erzurum being a cold climate region of Turkey. 相似文献
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Solar-earth source heat pump (SESHP) is a new type of energy saving air conditioner. In this paper, numerical simulation of the performance of a solar-earth source heat pump system (SESHPS) operated at alternate or combined mode is carried out respectively. The results indicate that a resuming-rate of 30–60% of the earth temperature near buried coil can be preferable when SESHPS is operated alternately at a period of 24 h, and the proportion of the operation time of solar-assisted heat pump (SAHP ) should be confined to 42–58%. When SESHPS is operated at combined modes 2, the energy-saving rate with and without heat storage water tank is 14.5% and 10.4%, respectively, compared with ground source heat pump (GSHP). As for the overall effect, the combined operation mode with water tank in which the heated water flows through the solar collector first and then through the buried coil is preferable. The results are significant for the engineering design, operation and management of SESHPS. 相似文献