共查询到20条相似文献,搜索用时 140 毫秒
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为了提升热泵机组的性能系数COP,合理利用不同温度层次的太阳能集热量,文章基于太阳能—土壤源复合热泵系统的大量实验结果,分析了蒸发器进口温度对热泵系统各项性能的影响,并在此基础上,分析了复合源热泵工况和太阳能热泵工况的运行特点。分析结果表明:随着蒸发器进口温度的升高,热泵机组吸热量逐渐增大,热泵机组输入功率略有增加,导致热泵机组的供热量和COP均逐渐增大;复合源热泵工况下,存在土壤源和太阳能共同供热,以及土壤短期储热与太阳能单独供热同时进行的两种运行情况;为了提升热泵机组的工作性能,在太阳能集热量较低时,优先运行复合源热泵工况;土壤源温度的自然恢复能力较差,需要利用太阳能集热系统对土壤源进行跨季强制蓄热,以提高土壤源温度,缓解土壤源冷堆积现象。 相似文献
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针对寒冷地区的气候特点及建筑负荷特点,提出利用相变蓄热的太阳能热泵系统,介绍该系统的运行原理,建立系统各部分的数学模型,针对哈尔滨地区(45.8°N,126.8°E)的气象条件,编制系统动态运行模拟程序,研究太阳集热器面积及相变蓄热水箱参数对整个系统运行性能的影响。研究结果表明,当设计热负荷为10 k W时,系统所需太阳集热器面积约为60 m2,对应相变蓄热水箱中相变材料最佳质量分数约为70%,相变材料封装尺寸减小有助于提高太阳能集热量,且该效果在供暖初期和末期更为显著。 相似文献
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介绍了一种新型笼屉式相变蓄热水箱,通过实验测试对比分析相变蓄热水箱与普通蓄热水箱对太阳能组合系统的太阳能保证率及系统能效比的影响。实验表明:同等水箱容积,使用相变蓄热水箱时太阳能集热系统的小时集热量为普通蓄热水箱的3.7倍,相变蓄热水箱有利于提高太阳能保证率及系统能效比。在太阳能辐照强度相似的情况下,相变蓄热水箱会使太阳能保证率平均提高72%,使系统能效比平均提高26%。同时相变蓄热水箱可减少夜间水箱上部的热损失,使水箱上部水温降减少50%。 相似文献
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介绍了一种将太阳能相变蓄热技术应用于两级吸收式制冷的新型空调系统,简要分析了该系统的装置结构、工作原理和使用优点。对相变蓄热装置放热过程中放热盘管出水温度随放热时间的变化关系进行了实验测量,并对两级吸收式制冷系统效率进行了分析。通过研究可知,该太阳能空调系统有效解决了以往系统不稳定性和间断性问题;太阳能相变蓄热装置具有体积小、蓄热量大、放热速率大、连续放热温度均匀、便于控制热源加热温度等特点,适合储存太阳能并为吸收式制冷系统提供加热热源。综合考虑系统设备简单,加工要求低的制造特点,所以吸收式制冷以太阳能等低品位热源驱动有着良好的发展前景。 相似文献
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V. R. Tarnawski 《国际能源研究杂志》1989,13(2):137-148
A one-dimensional model of ground heat storage is used to simulate complex heat and moisture processes in the vicinity of double-and single-layer ground heat exchangers. Simulated results indicate that a ground heat pump with the double-layer heat exchanger has certain advantages over the single-layer system in terms of a higher seasonal performance factor, smaller ground area, and reduced ecological risk in the soil subsurface region. Solar energy injection into the ground improves the seasonal performance factor both in the single and in the double layer heat exchanger system. Latent heat released by the freezing of soil moisture is an important component in the total amount of heat extracted from the ground when a phase change takes place. 相似文献
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针对由天气变化导致太阳能利用不稳定和寒冷地区热泵性能低的问题,文章介绍了一种基于相变储能的太阳能空气源热泵系统,该系统能够根据气象情况灵活切换4种供暖模式,大大减少了系统耗电量。文章通过独特设计的储能冷凝器,不仅可以调节太阳能空气源热泵系统能量分配,改善太阳能空气源热泵系统制热量和建筑热负荷之间不平衡的供需关系、提高太阳能利用率,还可以提高空气源热泵低温性能,快速恢复供暖,从而实现提高太阳能空气源热泵系统整体性能的目的。文章以石家庄农村某户为研究对象进行研究,研究结果表明,太阳能空气源热泵系统供暖效果较好,太阳能空气源热泵系统COP最大值为5.19,节能环保效益十分明显。 相似文献
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CHEN Haifei LI Guiqiang LING Yueyue FU Jie WANG Yunjie YANG Jie JIANG Lyulin ALI Badiei ZHANG Yang 《热科学学报(英文版)》2021,30(5):1491-1502
This paper introduces a novel solar-assisted heat pump system with phase change energy storage and describes the methodology used to analyze the performance of the proposed system. A mathematical model was established for the key parts of the system including solar evaporator, condenser, phase change energy storage tank, and compressor. In parallel to the modelling work, an experimental set-up of the proposed solar energy storage heat pump system was developed. The experimental data showed that the designed system is capable of meeting cold day heating demands in rural areas of Yanbian city located in Jilin province of China. In day-time operation, the solar heat pump system stores excess energy in the energy storage tank for heating purposes. A desired indoor temperature was achieved; the average coefficient of performance of solar heat pump was identified as 4.5, and the system showed a stable performance throughout the day. In night-time operation, the energy stored in the storage tank was released through a liquid-solid change of phase in the employed phase-change material. In this way, the provision of continuous heat for ten hours was ensured within the building, and the desired indoor air conditions were achieved. 相似文献
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太阳能和空气源复合热泵在不同模式下具有不同性能,如何在实际应用中以最佳的工作模式运行,对提高系统综合性能至关重要,为此提出2种用于实现系统最优模式切换的判断方法:1)基于最优模式切换的太阳能辐射强度和环境温度的复合环境参数范围表;2)流经2个蒸发器(太阳能集热/蒸发器和风冷蒸发器)的制冷剂质量流量分配比。基于此,在工程方程求解器(EES)中建立太阳能/空气双源辅助热泵热水器的仿真模型。首先,基于上海松江地区的气候条件模拟比较不同模式下的系统性能,再分析和讨论将复合环境参数范围表和质量流量分配比作为系统最优模式切换的判断方法的可行性。结果表明,在相同环境温度下,随着太阳辐射强度的增加,系统最优运行模式将由太阳能-空气模式转变为太阳能模式。此外,将流经2个蒸发器的制冷剂质量流量分配比作为模式切换的准则是可行的,对于本系统其最优运行模式由太阳能-空气模式转变为太阳能模式时的质量流量分配比临界值约为2.02。 相似文献
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In order to produce process heat for drying of agricultural, textile, marine products, heating of buildings and re-generating dehumidify agent, solar energy is one of the promising heat sources for meeting energy demand without putting adverse impact of environment. Hence it plays a key role for sustainable development. Solar energy is intermittent in nature and time dependent energy source. Owing to this nature, PCMs based thermal energy storage system can achieve the more popularity for solar energy based heating systems. The recent researches focused on the phase change materials (PCMs), as latent heat storage is more efficient than sensible heat storage. In this paper an attempt has been made to present holistic view of available solar air heater for different applications and their performance. 相似文献