光伏/光热-地源热泵联合供热系统运行性能研究

为解决太阳电池的发电效率随温度升高而下降以及地源热泵系统供热引起的土壤热失衡问题,以典型居住建筑的光伏/光热-地源热泵（PV/T-GSHP）联合供热系统为研究对象,基于TRNSYS软件,采用土壤温度、地源热泵机组季节能效比、光伏发电效率和太阳能保证率为评价指标,对该联合供热系统进行运行性能分析。研究结果表明：夏热冬冷地区（以长沙为例）太阳能保证率相对较高,PV/T组件面积为满屋顶最大化安装（900 m²）时,第20年末土壤温度相比初始地温仅升高0.8 ℃,热泵机组季节能效比约为5.1,太阳能保证率为97.0%~98.7%;不同气候地区的太阳能保证率与PV/T组件面积和建筑全年累计供热量有关,通过定义单位建筑全年累计供热量PV/T组件面积指标,得到中国不同气候地区的太阳能保证率与该指标的耦合关系,回归方程的决定系数R²为0.983,得出在已知建筑全年累计供热量和太阳保证率设计目标值的条件下所需PV/T组件面积的计算方法。PV/T-GSHP联合供热系统的全年运行能耗显著小于平板太阳能集热器-地源热泵联合系统（最小降幅为沈阳,49.7%）,远小于空气源热泵（最小降幅为石家庄,79.8%）和燃气壁挂炉（最小降幅为沈阳,65.1%）。     

新型土壤源热泵热水复合系统运行特性仿真

为了解决传统土壤源热泵系统在建筑冷负荷较大地区长期运行后地下土壤热堆积、系统能效低等问题,设计了一种土壤源热泵热水复合系统,为建筑物供冷、供热和供生活热水。运用TRNSYS软件建立了土壤源热泵热水复合系统的动态仿真模型,运行仿真结果表明:设计的土壤源热泵热水复合系统能在建筑冷负荷较大的地区利用地下土壤堆积的热量为建筑物供冷、供热和供生活热水,运行稳定,系统平均制冷、制热系数峰值分别为6和4.29。     

新型的太阳能与地源热泵联合供热制冷系统

研究设计了一种新型的太阳能与地源热泵联合供热制冷系统,不仅能够提供冬季热负荷,而且还能够提供夏季冷负荷.经过对新系统的技术经济性分析,证明了该系统是可行的,能够弥补常规太阳能与地源热泵联合运行的缺陷,分析了存在的问题。     

基于圆柱源理论模型的U型埋管换热器的模拟研究

分析了圆柱热源(热汇)理论模型,运用圆柱源理论对太阳能-土壤源联合运行热泵系统进行连续20d运行的状况进行模拟,得出联合运行模式较单独土壤源运行模式节能8%~10%,可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。引入“负荷集合”思想对圆柱热源(热汇)理论模型进行改进,使其适合于对土壤源热泵的全年运行进行模拟,模拟过程更为快捷。     

低品位多热源联供热水系统的节能分析

以太阳能、空气源热泵和废水余热回收联合热水系统为例,介绍系统的构成及运行原理。分析计算全年四季3种热源的供热负荷及其在系统总热负荷构成中的占比,提出全年运行策略。理论分析与工程实际系统分析表明,低品位多热源热水联供系统更具节能潜力与应用推广优势。     

复合地源热泵系统冬季供暖运行实验研究

介绍了地源热泵在冬季运行供暖的实验研究,具体分析了长期连续运行时土壤温度的变化规律,热泵机组系统的COP变化情况,以及太阳能辅助系统与地源热泵系统联合运行时土壤温度的变化规律,热泵机组系统的COP变化情况.试验数据表明了增加太阳能辅助地源热泵系统后,显著地提高了冷凝器出口温度和室内温度,有效地提高了热负荷,增加了供热面积.总结出了本地区地源热泵系统的一般运行规律.     

基于动态热负荷的太阳能——地源热泵运行模式研究

建立了太阳能-地源热泵系统一体化模型,以大连地区气候条件为基础,计算了供暖季某天内房间热负荷的逐时值.在动态热负荷基础上,对联合供暖系统在不同串联运行模式和并联运行模式不同分流比的运行工况进行了模拟计算,将模拟结果与实脸数据对比,两者吻合较好.结果表明:房间热负荷的变化可影响热泵机组COP.联合运行模式在地温的恢复和系...     

西安地区某地源热泵室外换热器运行情况分析

本文旨在研究西安地区某地源热泵的长期运行状况。通过热响应试验、效率测试、热负荷能力测试及对运行参数的监控分析,说明机组能效比达到了设计水平;自投运至今,室外换热器进口水温长期持平,并与地温最高温度差在±13℃之间;室外换热器进口水温随负荷升高降低。研究表明,室外换热器冬季换热能力56 k W/m是可行的;西安适宜采用地源热泵,并且土壤承载负荷高,地温恢复快;该项目作为西安地区最早投入运行的建筑面积6 000 m2以上,设计制冷负荷500 k W以上以浅层土壤源地源热泵项目,可以为地质、气候情况相近地区采用土壤源地源热泵项目提供设计经验。     

太阳能与土壤源耦合供暖系统的实验研究

在分析太阳能、土壤源热泵及联合供热特点的基础上,研究了太阳能热泵独立系统、土壤源耦合热泵系统运行模式的制热性能和节能效果,建立了太阳能蓄能-热泵耦合热泵系统的供暖模式及优化模型.通过采暖季初期的太阳能蓄能、供暖,土壤源热泵独立供暖及太阳能-土壤源耦合热泵供热的实验研究,验证了太阳能-土壤源耦合热泵供暖模式的可行性和经济...     

日间供暖太阳能热泵系统负荷分析及面积优化

以青岛市某公司办公楼太阳能热泵系统为研究对象,通过TRNBuild建立建筑模型,仿真分析同一建筑全天供暖与日间供暖热负荷分布特点,针对建筑日间供暖需求建立太阳能-空气源热泵仿真供热系统,利用TRNSYS软件进行供热季仿真模拟,计算日间供暖集热器最佳设计面积。仿真结果表明：相较于全天供暖,建筑日间供暖热负荷波动更为剧烈,最大峰值约为全天供暖的2倍,针对日间供暖设计的太阳能热泵系统在集热器面积为417 m²时运行经济性最佳,系统COP可达4.1,对应太阳能贡献率为24.7%,供暖季相较于传统空气源热泵可节约电能9 091 kW·h。     

基于相变储能的太阳能空气源热泵系统的研究

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。     

冰源热泵系统在设施水产养殖中的技术经济性研究

针对目前刺参养殖的水温调控系统能耗大及适用性差等问题,提出基于冰源热泵的高效清洁供热及结合跨季节蓄冷实现全年冷热管理的技术思路,采用冰源热泵系统和跨季节蓄冷型冰源热泵系统对养殖水体温度进行调控,建立模型定量对比分析系统的运行能效及技术经济性。结果表明:（1）冰源热泵系统供热和供冷时的性能系数分别为3.33和3.39,全年一次能源利用率为1.05,比燃煤锅炉+冷水机组系统高出34.6%;费用年值最低,投资回收期为3 ~ 5年,具有良好的经济效益和应用前景。（2）跨季节蓄冷型冰源热泵系统全年一次能源利用率为1.46,比冰源热泵系统高39.1%,全年运行费用最低;跨季节蓄冷技术的应用有效提升了系统能效,大幅减少供冷运行费用,具有较大发展潜力。     

Experimental and theoretical investigation of a solar heating system with heat pump

In this study, the performance of a solar heating system with a heat pump was investigated both experimentally and theoretically. The experimental results were obtained from November to April during the heating season. The experimentally obtained results are used to calculate the heat pump coefficient of performance (COP), seasonal heating performance, the fraction of annual load met by free energy, storage and collector efficiencies and total energy consumption of the systems during the heating season. The average seasonal heating performance values are 4.0 and 3.0 for series and parallel heat pump systems, respectively. A mathematical model was also developed for the analysis of the solar heating system. The model consists of dynamic and heat transfer relations concerning the fundamental components in the system such as solar collector, latent heat thermal energy storage tank, compressor, condenser, evaporator and meteorological data. Some model parameters of the system such as COP, theoretical collector numbers (N_c), collector efficiency, heating capacity, compressor power, and temperatures (T₁, T₂, T₃, T_T) in the storage tank were calculated by using the experimental results. It is concluded that the theoretical model agreed well with the experimental results.     

Investigation of thermal performance of a ground coupled heat pump system with a cylindrical energy storage tank

An analytical and computational model for a solar assisted heat pump heating system with an underground seasonal cylindrical storage tank is developed. The heating system consists of flat plate solar collectors, an underground cylindrical storage tank, a heat pump and a house to be heated during winter season. Analytical solution of transient field problem outside the storage tank is obtained by the application of complex finite Fourier transform and finite integral transform techniques. Three expressions for the heat pump, space heat requirement during the winter season and available solar energy are coupled with the solution of the transient temperature field problem. The analytical solution presented can be utilized to determine the annual variation of water temperature in the cylindrical store, transient earth temperature field surrounding the store and annual periodic performance of the heating system. A computer simulation program is developed to evaluate the annual periodic water and earth temperatures and system performance parameters based on the analytical solution. Copyright © 2003 John Wiley & Sons, Ltd.     

Thermal and economical analysis of a central solar heating system with underground seasonal storage in Turkey

Thermal performance and economic feasibility of two types of central solar heating system with seasonal storage under four climatically different Turkey locations are investigated. The effects of storage volume and collector area on the thermal performance and cost are studied for three load sizes. The simulation model of the system consisting of flat plate solar collectors, a heat pump, under ground storage tank and heating load based on a finite element analysis and finite element code ANSYS™ is chosen as a convenient tool. In this study, the lowest solar fraction value for Trabzon (41°N) and the highest solar fraction value for Adana (37°N) are obtained. Based on the economic analysis, the payback period of system is found to be about 25–35 years for Turkey.     

Numerical simulation of solar assisted ground-source heat pump heating system with latent heat energy storage in severely cold area

Solar assisted ground-source heat pump (SAGSHP) heating system with latent heat energy storage tank (LHEST) is investigated. The mathematical model of the system is developed, and the transient numerical simulation is carried out in terms of this model. The operation characteristic of the heating system is analyzed during the heating period in Harbin (N45.75°, E126.77°). From the results of the simulation, the average coefficient of performance (COP) of the heating system is 3.28 in heating period. In the initial and latter heating period, the COP of the heating system is higher, and the highest value is 5.95, because the system can be operated without heat pump. During the middle heating period the COP of the heating system and the operation stability of the system are improved due to solar energy and soil alternately or together as the heat source of heat pump. LHEST is a very important role in operation of the system. The system can be operated more flexibly, effectively, and stably by the charge and discharge heat of LHEST, and the effect becomes especially obvious in the initial and latter heating period.     

太阳能-地源热泵系统双地埋管群利用方式研究

以天津地区一项太阳能地源热泵系统工程实例为研究对象,针对其太阳能储热利用率较低的问题提出了将其两个地埋管群互通互联的解决方案。通过对每个系统进行20年的模拟预测,发现采用了互通互联的两个系统储热利用率较原系统有所增加,系统COP得到了提升。双机组双地埋管群系统运行20年的平均COP可达3.54,单机组双地埋管群系统运行20年的平均COP可达3.36,分别比双机组独立地埋管群系统提高7.9%和2.4%。双地埋管群的改造方案的优越性明显,为太阳能地源热泵系统的应用提供借鉴。