以空气为携热介质的开式太阳能蓄能热泵循环特性研究

以空气为携热介质的开式太阳能吸收式热泵系统为研究对象，在原有开式制冷循环的基础上，根据冬季蓄能热泵运行特点对系统进行改进；并以北京、西安、兰州3个地区为例，结合当地的气象条件，对循环进行计算并分析影响系统工作性能的因素。     

采用氨水溶液的先进蓄能系统工作特性研究(1)——工作原理及过程动态模型

对采用氨水溶液的变质量能量转换及储存系统的工作原理、工作循环和流程进行介绍。由于蓄能系统的能量转换过程是一个与时间有关的动态过程,常规的稳态制冷/热泵循环热力计算方法已不再适用,需给出一种新的动态热力计算方法。通过数值模拟来了解先进蓄能系统的工作特性,为进一步研究、开发该蓄能系统奠定理论基础。     

应用于道路融雪中太阳能集热蓄能和地下换热器影响作用研究

针对新型道路融雪化冰技术的太阳能路面集热和地下蓄能过程进行模型分析,研究逐年长期地能利用和热泵循环过程的基本性能。研究表明:运行5a后,有、无蓄能过程的热泵系统间COP相差达10%。其中,非蓄能条件下,地下均衡温度降低,热泵耗能增加,COP降低;采用集热蓄能,补偿地下热量缺失,可以达到地温恢复或增高,提升运行效能。此外,比较四孔和七孔地下换热器设置规模,两者间的流体最低温度相差2倍以上,孔数规模对地下温度、吸热量和热泵效能影响较大。因此,在地下换热器系统设计中,即要考虑孔数规模的经济性,又要保证热力性能。     

直膨式太阳能热泵采暖蓄能制冷应用研究

以U型管式太阳集热器作为热泵系统的蒸发器,利用太阳能工程及传热学等热力学相关知识,对该直膨式太阳能热泵系统进行能效分析。论证结果表明:太阳集热器的综合效率达到90%以上,系统能效COP约3.53,同时以上海地区单户采暖为例,描述直膨式太阳能热泵采暖蓄能供冷系统的设计过程,该研究能够为太阳能热泵采暖及蓄能供冷的优化设计提供借鉴。     

高温热泵供热系统的最佳供热温差

通过对高温热泵系统高低位热源温度特性和热泵循环特性的分析，构造出一个理想的热泵循环。并以此理想循环为基础，以供热系统总能耗最小为目标函数导出跨临界热泵、多级压缩热泵等新型热泵系统的最佳供热温差，为这些热泵在供热系统中的应用提供参数选择的理论基础。     

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...     

空气源相变蓄能复叠式热泵供暖系统的研究

以空气源相变蓄能复叠式热泵供暖系统为基础,选取晴天、阴雨雪天气2个典型天气工况分别对热泵、储能等各部分模块进行试验数据采集,通过理论计算与实验分析表明,系统在冬季晴天时系统COP要明显高于阴雨雪天气工况,系统在极端天气工况下,随着室外环境温度逐步增大,热泵耗功缓缓下降,而随着环境温度降低,热泵耗功呈上升趋势。研究结果表明,较高的蒸发温度及较低的冷凝温度使热泵循环COP值处于较高水平,因此在不同工况下时,系统仍可高效稳定运行。     

一体化太阳能热泵热水器蓄能特性对比研究

提出一种新型集热/蓄能/蒸发一体化太阳能热泵热水器,搭建实验测试装置,对蓄能材料分别为水、癸酸、石蜡时的太阳能集热/蓄能/蒸发器的蓄能特性和集热总效率进行研究,并在南京地区春季典型工况下,对蓄能材料为癸酸和石蜡的SHPWHICSE系统性能系数进行研究对比。研究结果表明:相变材料比水有更好的集热效果;由于石蜡的比热容大,其集热总效率大于癸酸,采用石蜡的SHPWHICSE系统性能在各种实验条件下均高于采用癸酸的SHPWHICSE系统。     

水源热泵在上海的应用探讨

1水源热泵系统的基本形式 水源热泵是一种利用地球表面、浅层水源（如地下水、河流和湖泊），或者是人工再生水源（工业废水、地热尾水等）的、既可供热又可制冷的高效节能空调系统。水源热泵技术利用热泵机组实现低位热能向高位转移，将水体和地层蓄能分别在冬、夏季作为供暖的热源和空调的冷源，即在冬季，把水体和地层等自然界中的热量“取”出来。     

热泵系统的(火用)分析

用[火用]分析法对热泵供热循环进行了分析，评价了热泵系统的能质利用和损失状况，指出在环境温度、压缩机效率和两器（蒸发器和冷凝器）换热温差一定时，热泵循环存在一个可使循环[火用]效率达到最大的冷凝温度，可在实际中加以利用。     

基于地热能利用的生态建筑能源技术

随着可持续发展思想的日益深入，生态建筑将成为未来建筑业发展的主流形式。能源利用系统设计作为生态建筑研究中的重要内容，是生态建筑从理论走向实践的必经之路。在分析了生态建筑由来及其设计原则的基础上，重点给出了几种基于地热能利用的生态建筑能源技术．内容包括直接利用形式中的覆土建筑、地下通风空调、地下储能及地下水采暖空调技术与间接利用形式中的地源热泵及地热发电技术，并在此基础上提出了两种基于地热能的综合生态能源利用系统。最后对地热能在生态建筑中的利用前景进行了展望。     

等温压缩空气储能系统液气传热特性研究

等温压缩空气储能（I CAES）无需补燃、能源利用率高且碳排放低，在大规模储能领域具有重要应用前景。在建立喷雾的I CAES系统的液气传热模型基础上，通过数值方法分析了喷雾流量对I CAES液气传热特性的影响规律。结果表明：采用喷雾方法能够有效抑制压缩和膨胀过程的温度变化、强化液气传热并实现理想I CAES过程；增大喷雾流量能够降低压缩功耗、提高膨胀做功并降低停机储气过程压损，可提高系统指示效率和储能效率。     

液化空气储能基本循环的热力学分析

  目的  以新能源为主体的新型电力系统对储能的需求不断增加,液化空气储能是一种新兴的长时间、大容量物理储能方法,具有广泛的应用前景。文章旨在探究液化空气储能的热力学原理以及关键参数对储能效率的影响规律。  方法  建立了液化空气储能三种基本循环:分离式循环、冷能回收循环、冷能热能回收循环的热力学模型,分析了冷能回收、热能回收、高压压力、释能压力等关键参数对液化率和循环效率的影响。  结果  结果表明液化率与循环效率正相关。分离式循环的液化率与循环效率极低,冷能回收循环由于利用了液空复温过程中的冷量可以显著提升液化率与循环效率,冷能热能回收循环在此基础上利用了压缩热而进一步提升液化率与循环效率。液化率与循环效率随冷能回收量的增加而升高、随高压压力的升高而升高、随释能压力的升高而下降。  结论  冷能热能回收循环是液化空气储能的优选方案。高效蓄冷将对提升循环效率发挥重要作用。在液空复温过程中利用工业余热、废热有助于进一步提升循环效率。     

带压缩空气储能的冷热电联产系统的

对一种带压缩空气储能的冷热电联产系统进行了热力学(火用)分析,得到了各主要部件和整个系统的(火用)损失及(火用)效率的变化规律.分析结果表明空气透平绝热效率的提高对系统(火用)效率的贡献大于压缩机效率同样提高的功效;在其它参数确定时,存在最佳压比,可使系统的(火用)效率在该条件下达极值;高温换热器是新型冷热电联产系统中产生(火用)损失的主要部件,而循环水量的大小是影响高温换热器(火用)效率的主要因素.     

等温压缩空气储能技术综述

压缩空气储能是解决当前我国遇到的环境问题和能源问题的重要方式之一,其未来的发展方向至关重要。本文综述了不同压缩空气储能系统,通过能量循环效率公式分析了各系统的效率,简要介绍了等温压缩空气实现技术,并结合我国新能源利用率低的现状,提出了一种耦合可再生能源的等温压缩空气储能系统,该系统可作为未来我国压缩空气储能系统可持续的、清洁环保的发展方向。     

Heat Transfer Enhancement for PCM Thermal Energy Storage in Triplex Tube Heat Exchanger

Thermal energy storage is critical for reducing the discrepancy between energy supply and energy demand, as well as for improving the efficiency of solar thermal energy systems. Among the different types of thermal energy storage, phase-change materials (PCM) thermal energy storage has gained significant attention recently because of its high energy density per unit mass/volume at nearly constant temperature. This study experimentally investigates the using of a triplex tube heat exchanger (TTHX) with PCM in the middle tube as the thermal energy storage to power a liquid desiccant air-conditioning system. Four longitudinal fins were welded to each of the inner and middle tubes as a heat transfer enhancement in the TTHX to improve the thermal performance of the thermal energy storage. The average temperature of the PCM during the melting process in the TTHX with and without fins was compared. The PCM temperature gradients in the angular direction were analyzed to study the effect of the natural convection in the melting process of the thermal storage. The energy storage efficiency of the TTHX was determined. Results indicated that there was a considerable enhancement in the melting rate by using fins in the TTHX thermal storage. The PCM melting time is reduced to 86% by increasing of the inlet heat transfer fluid. The average heat storage efficiency calculated from experimental data for all the PCMs is 71.8%, meaning that 28.2% of the heat actually was lost.     

Heat pipe based cold energy storage systems for datacenter energy conservation

In the present paper, design and economics of the novel type of thermal control system for datacenter using heat pipe based cold energy storage has been proposed and discussed. Two types of cold energy storage system namely: ice storage system and cold water storage system are explained and sized for datacenter with heat output capacity of 8800 kW. Basically, the cold energy storage will help to reduce the chiller running time that will save electricity related cost and decrease greenhouse gas emissions resulting from the electricity generation from non-renewable sources. The proposed cold energy storage system can be retrofit or connected in the existing datacenter facilities without major design changes. Out of the two proposed systems, ice based cold energy storage system is mainly recommended for datacenters which are located in very cold locations and therefore can offer long term seasonal storage of cold energy within reasonable cost. One of the potential application domains for ice based cold energy storage system using heat pipes is the emergency backup system for datacenter. Water based cold energy storage system provides more compact size with short term storage (hours to days) and is potential for datacenters located in areas with yearly average temperature below the permissible cooling water temperature (∼25 °C). The aforesaid cold energy storage systems were sized on the basis of metrological conditions in Poughkeepsie, New York. As an outcome of the thermal and cost analysis, water based cold energy storage system with cooling capability to handle 60% of datacenter yearly heat load will provide an optimum system size with minimum payback period of 3.5 years. Water based cold energy storage system using heat pipes can be essentially used as precooler for chiller. Preliminary results obtained from the experimental system to test the capability of heat pipe based cold energy storage system have provided satisfactory outcomes and validated the proposed system concept.     

Experimental Analysis of a Solar Energy Storage Heat Pump System

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.     

Latent heat storage for solar energy systems: Transient simulation of refrigerant storage

This paper presents a brief review of the available latent heat storage systems for solar energy utilization. A new concept of latent heat storage of solar energy via the refrigerant-absorbent mass storage in absorption cycle heat pump systems used for solar space heating/cooling has been proposed and assessed thermodynamically. A computer modelling and numerical simulation study shows that the concept of refrigerant storage is fundamentally sound, technically feasible and yields the following advantages over other storage methods: (i) the storage capacity per unit volume is high as the latent heat of vaporization of the refrigerant is high; (ii) the heat loss from the storage to the surroundings is minimum as the storage temperature is near the ambient; (iii) prolonged energy storage is possible with no degradation in system performance and hence suitable for combined solar heating and airconditioning. The effects of operating parameters on the energy storage concentration and storage efficiency have been studied in detail.