太阳能空气源热泵复合系统实验研究

本文基于太阳能集热器的运行不稳定性和空气源热泵冬夏季极限天气性能衰减,建立了一种太阳能一空气源复合热泵系统,并对其运行模式和技术特点进行了分析.实验测试了夏季名义工况和最大负荷工况下复合系统制冷兼制热水性能系数;冬季室外换热器需要和不需要周期除霜工况下复合系统的制热性能系数;冬季周期除霜工况下热泵的除霜时间和除霜效果.结果表明:该复合系统在夏季(名义和最大负荷工况)和冬季(除霜、不除霜工况)的COP比常规空气源热泵系统高;冬季除霜条件下利用蓄热热水热量反向除霜时间明显小于常规除霜模式的除霜时间且效果良好.     

空气源热泵除霜动态特性实验台研制

针对空气源热泵冬季运行时室外侧蒸发器结霜问题,为了研究空气源热泵的除霜机理、规律和除霜能耗,研制了空气源热泵除霜动态特性实验台.介绍了该实验台的设计方案、主要构成和数据采集系统,并对数据采集系统实时采集出的热泵四个主要部件的压力和温度等热工数据进行分析,综合得出:该实验台操作简单、数据采集自动化程度高且可靠,完全可以模拟实际工况,可为空气源热泵除霜动态特性研究提供十分便捷的平台.     

太阳能辅助加热土壤源热泵系统理论分析

土壤源热泵在冬季运行一段时间之后,存在工作温度降低的工况。为提高土壤源热泵的性能,在负荷匹配的情况下增加其经济性,本文提出了一种太阳能辅助加热方法。通过冬季供暖工况的理论分析得到供热系数与埋管进出口温度、空调供热负荷的关系。得出在增设太阳能辅助系统之后热泵供热系数能有较大提高的结论。     

太阳能辅助加热土壤源热泵系统理论分析

土壤源热泵在冬季运行一段时间之后，存在工作温度降低的工况。为提高土壤源热泵的性能，在负荷匹配的情况下增加其经济性，本文提出了一种太阳能辅助加热方法。通过冬季供暖工况的理论分析得到供热系数与埋管进出口温度、空调供热负荷的关系。得出在增设太阳能辅助系统之后热泵供热系数能有较大提高的结论。     

一种新型阳台壁挂太阳能—空气源复合热泵系统

介绍了一种新型阳台壁挂式太阳能一空气源复合热泵系统,说明了系统在冬季、夏季和过渡季节的运行方式、控制模式及技术特点.系统结构简单,安装上与现有空气源热泵协调一致,易实现高层建筑热水系统和建筑一体化.系统充分利用了低品位的太阳能,实现太阳能热效应和空气源热泵的优势互补,既可有效提高空气源热泵冬夏季运行的可靠性,又可提高夏季阴雨天气、过渡季节及冬季太阳能热水器运行的稳定性,对于节约能源和环境保护具有重要意义.     

双级耦合热泵供暖化霜

在江浙等湿热地区应用双级耦合热泵即空气源热泵代替水环热泵系统中的锅炉，空气源热泵制取低温热水作为水环热泵的热源，空气源热泵制冷循环除霜会使其供热量减少.在水环热泵空调系统中有串联在水环路上的蓄热水箱来改善系统的运行特性.通过计算，选择了合适的空气源热泵、水环热泵和蓄热水箱，通过实验研究了蓄热水箱对化霜的影响.由于蓄热水箱的存在，中间环路的热惯性较大，空气源热泵机组结、化霜对系统的影响与室温的稳定性几乎无关.空气源热泵机组可以应用于该系统，本实验系统的各项技术指标均能满足实际工程要求，为推广应用提供了必要的数据.     

土壤源热泵空调系统的性能模拟分析

以上海某小型办公楼为例,用DEST模拟出了该建筑全年累计冷热负荷和逐时冷热负荷的需求,采用集中参数的方法建立能耗模拟模型,分别模拟出空气源热泵和土壤源热泵空调系统的能效。反映出一定条件下热泵空调系统能效随系统负荷变化等条件改变的变化趋势,得出土壤源热泵空调系统较空气源热泵系统具有系统性能系数（COP）高、运行稳定、受外部气候条件干扰小的结论。     

横式水箱空气源热泵热水器性能实验研究

搭建了横式水箱空气源热泵热水器的性能测试台,实验考察了水箱内水温、系统运行功率、蒸发压力、冷凝压力、过热度及热泵性能系数对R134a充灌量的变化规律.在此基础上以性能系数最大为优化目标,对系统制冷剂充灌量进行了优化研究.     

空气源分体式热管-热泵供暖系统在煤矿井口防冻中的特性研究

为提高空气源热泵的性能,同时更好地满足煤矿井口防冻特殊工艺要求,将空气源热泵与热管技术相耦合,使用小压比热泵机组搭建了空气源分体式热管-热泵供暖系统实验平台。该耦合系统中蒸发器和冷凝器两端均采用相变传热的方式,并对其进行不同运行工况下的性能特性研究,结果表明:该耦合供暖系统即使在0 ℃左右的室外条件下,耦合机组的系统制热性能仍可达到4.5以上,远远优于传统空气源热泵机组。     

太阳能-空气源热泵的直接采暖系统

为了提高太阳能集热器运行稳定性及空气源热泵适应冬季低温环境的能力,构造一种太阳能-空气源热泵串联连接的直接采暖系统。实验测试冬季工况下,热泵压缩机的供热特性和实验房间的温度变化。结果表明:系统经过180 min的预热时间,地板表面温度达到26.2℃,室内环境温度达到22.1℃;稳定供热过程中,室内温度波动范围为0.2℃,完全满足室内冬季供暖需求;系统停机3 h,地板温度下降3.1℃,室内环境温度下降1.2℃,仍能满足人体热舒适性需求,验证了该供暖系统运行的可行性及稳定性。     

湖库塘开式水源热泵系统年能耗分析方法研究

提出一种简单可行的湖库塘开式水源热泵系统全年能耗分析方法,然后以小型办公建筑为实例,进行具体的全年能耗分析,最后与空气源热泵的能耗相对比。分析结果表明：湖库塘水源热泵系统的季节性能比均高于空气源热泵机组;室外循环水泵能耗对湖库塘开式水源热泵系统有较大的影响,应该在实际工程应用中采取措施降低循环水泵能耗。     

一种新型阳台壁挂太阳能—空气源复合热泵系统

介绍了一种新型阳台壁挂式太阳能—空气源复合热泵系统,说明了系统在冬季、夏季和过渡季节的运行方式、控制模式及技术特点。系统结构简单,安装上与现有空气源热泵协调一致,易实现高层建筑热水系统和建筑一体化。系统充分利用了低品位的太阳能,实现太阳能热效应和空气源热泵的优势互补,既可有效提高空气源热泵冬夏季运行的可靠性,又可提高夏季阴雨天气、过渡季节及冬季太阳能热水器运行的稳定性,对于节约能源和环境保护具有重要意义。     

Energy efficiency performance of multi-energy district heating and hot water supply system

A district heating and hot water supply system is presented which synthetically utilizes geothermal energy, solar thermal energy and natural gas thermal energy. The multi-energy utilization system has been set at the new campus of Tianjin Polytechnic University (TPU). A couple of deep geothermal wells which are 2 300 m in depth were dug. Deep geothermal energy cascade utilization is achieved by two stages of plate heat exchangers (PHE) and two stages of water source heat pumps (WSHP). Shallow geothermal energy is used in assistant heating by two ground coupled heat pumps (GCHPs) with 580 vertical ground wells which are 120 m in depth. Solar thermal energy collected by vacuum tube arrays (VTAs) and geothermal energy are complementarily utilized to make domestic hot water. Superfluous solar energy can be stored in shallow soil for the GCHP utilization. The system can use fossil fuel thermal energy by two natural gas boilers (NGB) to assist in heating and making hot water. The heating energy efficiency was measured in the winter of 2010-2011. The coefficients of performance (COP) under different heating conditions are discussed. The performance of hot water production is tested in a local typical winter day and the solar thermal energy utilization factor is presented. The rusults show that the average system COP is 5.75 or 4.96 under different working conditions, and the typical solar energy utilization factor is 0.324.     

建筑物冷热电联产联动控制策略

建筑物冷热电联产系统是通过建筑物中制冷、制热、低品位热能回收利用和热量储存等多个不同的能量转换和能量运行系统进行联动控制,以实现能源高效率利用.分别给出了夏季和冬季运行联动控制方案,以及吸收式冷温水机的冷却水回收利用控制策略.工程案例表明,某大楼中央空调系统改造并运行1年,采用板式换热器、水源热泵机组与智能控制器相结合,有效地利用具有低位热能的冷却水,实现冷却水输出总量减排30%~50%,系统节能40%~50%.     

Performance analysis of air-water dual source heat pump water heater with heat recovery

A new air-water dual source heat pump water heater with heat recovery is proposed.The heat pump system can heat water by using a single air source,a single water source,or air-water dual sources.The water is first pre-heated by waste hot water,then heated by the heat pump.Waste heat is recovered by first preheating the cold water and as water source of the heat pump.According to the correlated formulas of the coefficient of performance of air-source heat pump and water-source heat pump,and the gain coefficient of heat recovery-preheater,the formulas for the coefficient of performance of heat pump in six operating modes are obtained by using the dimensionless correspondence analysis method.The system characteristics of heat absorption and release associated with the heat recovery-preheater are analyzed at different working conditions.The developed approaches can provide reference for the optimization of the operating modes and parameters.The results of analysis and experiments show that the coefficient of performance of the device can reach 4-5.5 in winter,twice as much as air source heat pump water heater.The utilization of waste heat in the proposed system is higher than that in the system which only uses waste water to preheating or as heat source.Thus,the effect of energy saving of the new system is obvious.On the other hand,the dimensionless correspondence analysis method is introduced to performance analysis of the heat pump,which also has theoretical significance and practical value.     

水源热泵集中冷热水系统能耗及其效益分析

对水源热泵的能耗进行了分析,表明水源热泵机组的性能系数与水源温度直接相关,并对水源热泵空调系统集中冷热水供水系统夏季空调工况与冬季热泵工况的社会经济效益进行了计算与分析,结果表明,利用水源热泵建立集中冷热水供水系统的社会经济效益显著,具有节能与环保意义.     

Case study of underground pipe ground coupled heat pump system

Aiming to give some advices on the ground coupled heat pump system design in Sichuan Province, China, a typical ground source heat pump (GSHP) system in Sichuan Province was tested in a whole operational year, and the parameters of temperature and flow rate in different parts of system were measured during this period. The seasonal energy efficiency ratio was calculated and the performance of heat pump system in summer was compared with that in winter. The result shows that the coefficient of performance of the system reaches 3.63 in summer and 3.49 in winter, respectively. The heat balance in underground rock mass is acquired basically throughout the year, and the heat accumulation in the earth tends to be zero.     

Research trend of cascade heat pumps

Most commercial and industrial facilities require very low temperatures for refrigeration and high temperatures for space heating and hot water purposes. Single stage heat pumps have not been able to meet these temperature demands and have been characterized by low capacities and coefficient of performance(COP). Cascade heat pump has been developed to overcome the weaknesses of single stage heat pumps. This study reviews recent works done by researchers on cascade heat pumps for refrigeration, heating and hot water generation. Selection of suitable refrigerants to meet the pressure and temperature demands of each stage of the cascade heat pump has been discussed. Optimization of design parameters such as intermediate temperature(low stage condensing and high stage evaporating temperatures), and temperature difference in the cascade heat exchanger for optimum performance of the cascade heat pump has been reviewed. It was found that optimising each design parameter of the cascade heat pump is necessary for maximum system performance and this may improve the exergetic efficiency, especially of cascade refrigeration systems, by about 30.88%. Cascade heat pumps have wider range of application especially for artificial snow production, in the supermarkets,for natural gas liquefaction, in drying clothes and food and as heat recovery system. The performance of cascade heat pumps can be improved by 19% when coupled with other renewable energy sources for various real time applications. Also, there is the need for much research on refrigerant charge amount of cascade heat pumps, refrigerant-refrigerant heat exchangers to be used as cascade heat exchanger, cascade heat pumps for simultaneous cooling, heating and hot water generation and on the use of variable speed compressors and their control strategies in matching system capacity especially at part load conditions.     

福州住宅应用土壤源热泵的全年能耗与可行性分析

以福州地区典型的单户住宅为实例,在全年逐时建筑负荷计算的基础上,进行空气源热泵和地源热泵的全年能耗分析,并在此基础上进行两者的经济性比较。结果表明,从全年能耗比较,土壤源热泵比空气源热泵节能15%,其中夏季节能13%;冬季节能20%。尽管土壤源热泵机组的季节性能比SE-ER高于空气源热泵,但由于福州冬季室外气温较温和,夏季地温偏高,土壤源热泵的节能效果不及夏热冬冷地区明显,并且初投资回收期较长,经济可行性较差。     

重庆村镇空气源热泵供暖系统夜间性能实测分析

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。