间接式海水源热泵系统动态运行能耗的模拟分析

由于大气温度同时影响着建筑物空调系统的冷热负荷和海水的温度,而海水温度的变化又会导致海水源热泵系统性能的改变,因此,海水源热泵系统的运行能耗同时受到大气温度和海水温度的影响。文章以青岛市某海水源热泵系统为例,以DeST软件模拟得到的建筑物逐时空调负荷为基础,模拟计算和分析了该系统在海水温度动态变化情况下的运行能耗。     

供热与集热模式下热管式太阳能PV/T热泵系统实验研究

文章搭建了热管式太阳能PV/T热泵系统,设计了供热和集热两种运行模式,并选取了日均太阳辐射强度和室外温度基本接近的两个工作日,对两种运行模式下,该系统的各项性能进行了实验研究。分析结果表明,供热模式下,热管式PV/T热泵系统日均热效率为33.9%,日均电效率为12.2%,比单一光伏发电系统的日均电效率提高了25.7%,日均COPth、日均COPpv/t分别为2.52,3.26;集热模式下,热管式PV/T热泵系统日均热效率为25.3%,日均电效率为12.9%,比单一光伏发电系统的日均电效率提高了14.2%,日均COPth、日均COPpv/t分别为1.82,2.33。因此,供热模式下热管式太阳能PV/T热泵系统的绝大部分性能优于集热模式。     

寒区路基地源热泵型供热装置运行特性及能效优化北大核心CSCD

文章针对寒区路基工程广泛面临的冻害问题,基于地源热泵技术,构建一种主动温控式路基。通过模型试验,对比了热泵在不同运行模式下的换热特性,结果表明:在连续运行模式下,热泵供热温度最高达95.9℃,吸热温度低至-8.5℃,可以有效防治冻胀。热泵定时运行模式的换热效率优于定温模式,定温模式的启停循环次数多、压缩机能耗大;在定时模式下,随着启停比的增大,供热温度逐渐升高,而吸热温度先降低、后升高,启停比为2∶1时,换热效果最优;面向单线铁路路基冻胀抢险时,建议热泵间距取1.5~3.0 m,热泵功率宜取1.0~2.0 kW,根据冻胀程度动态地控制启停比例。     

单双效结合运行的溴化锂第一类吸收式热泵

在传统的单效和双效溴化锂第一类吸收式热泵的基础上,开发单双效结合运行的溴化锂第一类吸收式热泵机组。当用户需求热水温度较低时,机组以双效模式运行;反之,机组则以单效模式运行。克服了溴化锂第一类吸收式热泵供热系统中机组模式单一化、运行效率低的缺点,实现了一台机组两种模式运行的方案,提高了设备和资源的利用率,具有良好的节能效益和经济效益。     

复合热源太阳能热泵供热系统及其性能模拟

提出了一种复合热源太阳能热泵供热系统,通过阀门切换,可根据不同的天气状况改变运行模式,以空气和太阳辐射作为热源制取供暖用水。针对所设计的10kW供热系统,建立了系统的数学模型,对热泵串联集热器(SC+HP)及集热器串联热泵(H+SC)两种运行模式下的循环性能进行了计算机模拟分析,并计算了系统的全年运行状况。从模拟结果可以看出,在模拟进水温度区间内,HP+SC模式下热泵COP较高,最高比SC+HP模式高2.58%;而SC+HP模式集热器热性能较好,总热效率更高,最高比HP+SC模式高2.62%。     

海水热泵系统应用的问题及对策

针对青岛市拟实施建设大型海水热泵站的计划，指出了海水热泵取排水口设置、管道敷设、设备腐蚀及冬季海水温度过低等问题对系统的影响，探讨了解决这些问题的主要措施，提出了适合海水热泵的冷凝器（蒸发器）形式。     

单/双工况运行下地埋管周围土壤温度特性实验研究

以实验研究为基础,分析地埋管周围土壤温度、流体进出口温度及单位管长换热量随热泵运行时间的变化规律,探究雷诺数Re、流体进口温度和热泵运行模式等因素的影响;获得土壤温度及单位管长换热量的时变特性。研究发现:热泵单工况运行条件下,地埋管周围土壤温度及单位管长换热量随热泵运行时间的延长而增加,并最终趋于稳定;适当的增加流体进口速度(Re)可提高单位管长换热量,流体流速的变化对径向距离r80 mm范围内的土壤温度影响较大;间歇运行模式下地埋管附近土壤温升率较低,且单位管长换热量较热泵连续运行模式下有所提高。热泵双工况(连续和间歇运行模式)运行条件下,地埋管周围土壤温度均表现为上下波动的规律,且均随径向距离的增加其波动幅度减小,但连续运行模式下的土壤热波动半径较间歇运行模式下有所增加。     

太阳能-空气源热泵联合干燥系统设计及干燥枸杞的实验研究

为缩短枸杞干燥时间,提高干制枸杞的质量,减少能源消耗,本文提出了一种新型太阳能–空气源热泵联合干燥系统。该系统主要由太阳能集热器和空气源热泵机组等设备组成,可以实现太阳能单独干燥、热泵单独干燥和太阳能–空气源热泵联合干燥三种工作模式。本文根据枸杞的干燥特性,分段设定最佳的干燥温度,进行了热泵单独运行和太阳能–热泵联合运行两种工作模式下干燥枸杞的对比实验。结果表明,干燥50 kg枸杞,太阳能–热泵联合运行比热泵单独运行节省了2.9 kW?h电能,若同时除去系统本身的耗能,节省的电能占热泵单独运行耗电量的29.5%。同时,与太阳能单独干燥相比,太阳能–热泵联合干燥具有较高的除湿能耗比,两者最大差值为0.71 kg/(kW?h)。本文提出的太阳能–热泵联合干燥系统具有提高干燥产品的品质、缩短干燥时间和节约干燥成本等优点,适宜推广。     

地表水源热泵辅助热源节能效果的分析

介绍了地表水水源热泵工程中两种常用的辅助热源形式，指出辅助热源的布置形式影响着系统运行的经济性。推导出了两种形式下热泵系统单位小时运行费用，结合某实例说明采用后置式辅助热源的地表水源热泵系统运行费用小，具有节能的优越性。     

间接膨胀式太阳能多功能热泵单独制热水性能实验研究

简要介绍了间接膨胀式太阳能多功能热泵(IESA-MDHP)系统的功能模式.在冷凝侧采用强制循环和自然循环两种运行模式,对系统在冬季工况下利用中低温水源单独制热水性能进行实验测试.实验结果表明,在两种运行模式下热泵COPhp、系统COPsys及(火用)性能系数COPEX都明显高于空气源热泵热水器系统.实验同时对不同初始水温下IESA-MDHP系统单独制热水性能进行对比,发现初始水温对热泵COPhp、系统COPsys影响不大,而对(火用)性能系数COPEX影响较明显.     

海水制冷热泵装置的节能分析与材料优选

海水具有温度相对稳定、能量蕴含量大等特点,本文对近海地区采用海水作为制冷热泵冷热源的节能特性进行了系统的分析,对耐海水腐蚀金属材料的研究情况进行了介绍,对天津地区适宜用作海水换热器的材料进行了优选,为近海地区高效制冷热泵装置的设计与应用提供了参考。     

Performance of a solar air composite heat source heat pump system

For the shortcoming of air source heat pump in heating condition, a composite heat exchanger was designed which integrates fin tube and tube heat exchanger, and it can achieve synchronous and composite heat exchange in one heat exchanger between working fluids, gaseous and liquid heat source. With the above composite heat exchanger as the core component, the Solar Air Composite Heat Source Heat Pump System (SACHP) was developed which has three working modes, including single solar heat source mode, single air heat source mode and solar air dual heat sources mode. A SACHP experiment table was established and conducted a comprehensive experimental study of three working modes of this system in the standard enthalpy difference laboratory. The results show that when the ambient temperature was −15 °C, compared to the single air heat source mode, the dual heat source mode increased 62% in heat capacity and 59% in COP; when the temperature difference of combined heat transfer was 5 °C, compared to the single air heat source mode, the dual heat source mode increased 51% in heat capacity and 49% in COP. Experimental results demonstrate that the application of the solar air composite heat pump technology can accelerate the application process of the solar heat pump in air conditioners for buildings.     

Experimental investigation of a multi-function heat pump under various operating modes

Heat pumps have been spotlighted as efficient building energy systems because they have great potentials for energy reduction in building air conditioning and reducing CO₂ emission. In this study, a multi-function heat pump which has the functions of heating, cooling, and hot water supply was designed and its performance was investigated according to operating modes. In the cooling-hot water mode, the capacity and COP were enhanced as compared to other modes because the waste heat from the outdoor heat exchanger was utilized as useful heat in the indoor heat exchanger. In the heating and hot water supply mode, the compressor speed should be increased to get appropriate heating and hot water capacities. For all operating modes, the system could be optimized by adjusting the superheat.     

水—水热泵替代工质循环性能及其动态可燃特性研究

水－水热泵在建筑能量系统的环境保护，开发和利用余热资源中起着重要作用，为了研究这种热泵的工质替代问题，就目前具有成功实验结果的水－水热泵的替代工质之一：R32／134a进行热力学及循环性能模拟分析，结果发现R32／134a当浓度为（30／70）时作为常规水－水热泵工质具有较大的优势，针对此替代物在生产使用中的重要环节一贮存和运输中的安全性问题，研究其在贮运过程中由于泄漏引起的动态燃爆特性，得出了具有实际应用价值的规律。     

Vapor compression multifunctional heat pumps in China: A review of configurations and operational modes

With the growing concerns about worldwide energy and environmental sustainability, heat pump water heaters and solar water heaters became popular in China after 2000. The combinations between the heat pump air conditioner, heat pump water heater and solar water heater brought about more energy saving operational modes besides those included in the above three appliances, which promoted the development of multifunctional heat pumps. The combinations also resulted in the higher utilization ratio and lower operational cost of the heat pump, then the payback time can be shortened greatly. The rapid development of multifunctional heat pumps at the beginning of the 21st century in China indicates its promising application prospect.The heat pump air conditioner was the fundamental component of a multifunctional heat pump. Versatile configurations of multifunctional heat pumps were evolved from the integration of the domestic water heat exchanger with the refrigerant loop of the heat pump air conditioner by various approaches. This paper reviewed the development of multifunctional heat pumps in China, mainly focusing on configuration features and operational modes of the heat pump. The configuration of a multifunctional heat pump fundamentally determines the initial cost, operating cost and operating reliability. Therefore, it is reasonable to make a compromise between the simplicity of the configuration and versatile operational modes in the design of the multifunctional heat pump under different application conditions.     

不同加热方式下环路热管蒸发器可视化研究

针对环路热管内部工质相变及流动换热问题,设计了环路热管蒸发器中心通道可视化实验平台,研究了不同加热方式对热管内工质状态和传热特性的影响。结果表明：加热方式直接影响热管10W启动过程,双面加热启动速度最快。相同热载荷时,不同加热方式下环路热管热阻及蒸发器中心通道内液面高度和成核情况存在差异。10W - 40W热载荷时,随着热载荷的增大,三种加热方式的传热热阻均在减小。40W-50W热载荷时,顶部加热方式下的热管性能出现恶化,底部加热传热性能出现停滞,仅双面加热性能稳定并有提高趋势。随着热负荷的增加,蒸发器中心通道内气液界面升高、气泡的产生变得更加剧烈,蒸发器通过吸液芯向储液器的漏热量增加,进而影响环路热管的性能。     

热泵热水器技术及应用

热泵热水器借助外部能量能把不能直接利用的低位热源转换为可以利用的高位热能,从而达到节约部分高位能的目的。阐述了热泵热水器的发展历史与应用现状,分析了空气源热泵的工作原理和节能原理,并将空气源热泵热水机组与电热水器、燃油热水锅炉、燃气热水锅炉等热水供应系统的性能进行了比较。在此基础上,结合企业工程应用实例,指出了推广热泵技术对于节能减排的意义。     

关于中高温热泵试验中的几种特殊现象

在对中高温热泵进行了大量的试验研究之后，发现了四种有别于理论分析结果的试验现象，如冷凝温度下降，COP也下降；压缩机转数降低，COP降低等。针对这些特殊现象，进行了详细的描述、分析和较合理的解释，最终给出了对中高温热泵在设计和实际运行中的一些建议，这将有助于中高温热泵系统的安全高效运行。     

Experimental study on a monovalent inverter-driven water-to-water heat pump with a desuperheater for low energy houses

In this study, a novel monovalent inverter-driven water-to-water heat pump with a desuperheater was developed. In this unique system, domestic hot water is produced at a constant temperature controlled by a variable flow rate and stored in a tank. The heat demand is constantly matched by the system through the use of an inverter-driven compressor, which eliminates the need for a buffer tank. Three heating configurations of the system were examined with respect to variable climate conditions and two space heating target temperatures: space heating (mode 1), domestic hot water production (mode 2) and a combination of both (mode 3). Mappings of the performance variables per frequency were constructed for mode 3. For the other modes, the highest COP was identified for each examined climate condition. The difference between modes 1 and 3 was less than 5% for every variable. The space heating target temperature had a strong influence on both modes, showing an average difference of 29% in the COP between 35 °C and 45 °C. Mode 2 exhibited a considerably reduced COP compared to the other modes, as well as the lowest refrigerant mass flow rate and highest compression ratio among the three modes. From the previous results and the examination of the compressor, the compression ratio presents itself as a key parameter that can help to increase the COP if maintained at low values. The results of this research could be applied to the design of a control methodology for monovalent heat pumps.     

The cost-effectiveness of heat pumps in specific buildings in South Africa

Water heating heat pumps are extremely energy efficient and large savings can be realized when they are compared to direct electrical resistance heaters. In spite of the energy efficiency of heat pumps, a large number of residential buildings in South Africa still use electrical heaters to heat water. The reason for this is that heat pumps are considerably more expensive than electrical heaters. Building owners tend to choose the system with the smallest initial cost and do not compare the two systems on the basis of life-cycle cost. It is also difficult to calculate the life-cycle cost of a heat pump because it depends on many factors like climatological conditions and water temperature. In this paper a methodology is developed to calculate the life-cycle cost of a heat pump hot water installation. The model is used to investigate the effect of daily runtime, electricity tariff, hot water consumption and geographical location on the cost-effectiveness of heat pumps. The cost-effectiveness of heat pumps increases with daily run time, water consumption and electricity tariff. Heat pumps are more cost-effective near the coast than in the interior. If sized correctly, heat pumps are more cost-effective than electrical heaters for all major cities in South Africa. The cost-effectiveness of heat pumps for two specific buildings, one a university student hostel in Potchefstroom and the other a hotel in Durban, is also investigated. For both cases it was found that heat pumps are more cost-effective than direct electrical resistance heaters.