集成混合储能及RPC的牵引供电系统优化运行北大核心CSCD

电气化铁路电分相构成了无电区,阻碍各供电区间内能量传递,不利于再生制动能量的回收利用,极大地影响了铁路运营效益。为降低铁路运营成本,在电分相处接入铁路功率调节器(railway power conditioner,RPC),RPC直流环节便于混合储能装置接入。在此基础上,本文提出了一种牵引供电系统优化运行策略,通过控制混合储能充放电,达到削减负荷尖峰,回收制动能量的效果,进而实现牵引负荷的削峰填谷。该模型以牵引供电系统运行总成本最低为目标,以混合储能充放电功率等为决策变量,考虑了系统潮流平衡、混合储能等约束。进一步地,将模型中的非线性函数线性化,得到混合整数线性规划模型,然后利用CPLEX求解得到混合储能充放电策略和牵引供电系统购电方案。最后,基于实测数据,分析了所提模型的降费效果。与既有牵引供电系统对比,接入混合储能和RPC之后牵引供电系统日运营成本降低效果显著,为牵引供电系统优化运行提供了依据。     

相变储能围护结构与太阳能关系

一太阳能利用与相变墙结合太阳能是地球上最主要的天然能源的源泉,也是人类最有希望开发利用的能。但太阳能的特点为人类有效地利用太阳能却带来了困难。由于太阳辐射具有分散性和间歇性的特点,增加了太阳能利用装置的费用,使得太阳能利用在经济上存在的问题,将相变墙如何与太阳能的利用结合起来,形成太阳能-相变墙一体化技术,可有效地解决这些问题,极大地促进节能技术的开展。1利用相变储能材料优越性将相变材料与建筑材料基体复合,可制成相变储能建筑材料。利用相变储能建筑材料构筑建     

徐州居民区相变蓄热供暖的可行性分析

针对徐州当前供暖情况,通过对当地小区采用相变蓄热供暖的分析,提出在徐州地区推广蓄热供暖是缓解电力负荷峰谷差、降低用户采暖费用的理想途径。     

建筑用太阳能光热相变储能瓦片设计

为了解决太阳能不连续、不稳定的问题,在传统的太阳能光热系统中,创新性地加入了相变储能模块,并利用相变温度为58℃的相变材料,持续地向用户提供热水。在此太阳能光热系统中,太阳能光热被转化为显热和潜热并储存起来,这样能够显著提高太阳能的综合利用率。研究结果表明:串联方式下,相变材料的蓄热时间较短,并且当循环水入口流量为0.3 L/min时,相变材料的蓄热时间最短,为134 min;并联方式下,夜间相变储能瓦片的热水生成量较大,并且当循环水出口流量为0.5 L/min时,热水的生成量为9.6 L。     

高电价差地区储能系统应用的探索与实践

高电价差地区峰谷时段用电负荷相差较大,电网调度的难度大,白天用电负荷占比高的用户,用电成本非常高,采用储能系统为用户进行削峰填谷供能,可以大大降低用能成本,平缓负荷波动.文中介绍了一个实际的应用案例,通过分析系统运行数据,证实了储能电站的应用效果.同时提出了建筑间共享储能电站的理念和围绕储能电站开发的综合能源方案,为高...     

相变墙房间传热特性研究

通过建立基于焓法相变墙板的传热模型,研究了其传热特性,分析了影响相变墙板传热性能的因素,选取出了适合于重庆地区的相变墙板,研究了重庆的相变墙房间和普通房间的传热特性,对比分析了夏季和冬季相变墙房间和普通房间的温度情况并经实测验证。结合削峰填谷政策做了经济性分析。结果表明相变墙房间不仅节省能源,能提供舒适的环境。而且投资回收期仅十四个月。     

太阳能化学热泵系统

由太阳能和固相氯化钙二甲醇复合物组成的太阳能化学热泵系统是新能源利用技术发展的一种新型方式,介绍了该太阳能化学热泵系统的工作原理、构成及特点,并从结构的合理性、节能的可观性两方面分析了该系统的新颖之处,以响应国内建设不耗能生态建筑的号召。     

梯次利用电池储能系统参与用户侧削峰填谷的经济性研究

针对梯次利用电池储能系统参与用户侧削峰填谷的经济性问题,采用对比分析方法,基于现阶段新电池和梯次利用电池在技术、经济条件上的差异,建立基于投资回报率、投资回收期的经济性评估模型.结合实际算例,仿真分析梯次利用电池储能系统在不同回收成本下的配置规模及其经济性,并与新电池储能系统的容量配置及经济性进行比较分析.结果表明:当...     

太阳能热泵系统简介

太阳能与热泵相结合的技术是新能源利用技术发展的一个重要方面.文章介绍了太阳能热泵的基本知识,并分析了太阳能和热泵相结合应用的特点,并对其经济性作了初步分析.     

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。     

Heat pump house heating system with phase change heat storage in the place of auxiliary heating

A house heating system consisting of an “energy roof” (unglazed collector), a heat pump, and medium-term phase change heat storage in the place of auxiliary heating was studied using a simple computer model. The least required storage volume is calculated and discussed as a function of the significant parameters. The choice of water for the storage medium is justified by showing the closeness of its phase change temperature to the economic optimum. The system appears technically feasible and permits minimum fossil fuel consumption together with the associated environmental benefits. Its economic position will depend on future price developments.     

太阳能-土壤源热泵相变蓄热供暖系统运行模式

介绍了太阳能-土壤源热泵相变蓄热供暖系统;详细阐述了系统的各个运行模式;确定了模式间的转换条件.选取了供暖期间具有代表性的数据,分析了系统在不同供暖时期、典型天气的运行模式及运行效果.系统采用了太阳能和土壤热能的复合热源,增加了运行的灵活性,提高了运行性能系数.     

A simulation study on a solar heat pump heating system with seasonal latent heat storage

Solar heating systems with seasonal energy storage have attracted an increasing attention over the past decades. However, studies of such systems using a phase change material (PCM) as seasonal storage medium have not been found in the open literature. In this paper a solar heat pump heating system with seasonal latent heat thermal storage (SHPH–SLHTS) is firstly described. This is followed by reporting the development of a simplified mathematical model for a SHPH–SLHTS system. Using the model developed, the operational performances of a SHPH–SLHTS system which provided space heating to a villa building have been investigated by simulation, and simulation results are reported in this paper.     

A new type of phase change heat storage tank in solar energy combination system

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%。     

蓄能互联热泵系统相变装置熔化与凝固过程特性分析

介绍了一种新型的蓄能互联热泵系统。利用数值模拟的方法对填充石蜡C17的球型蓄热单元的熔化与凝固过程进行研究,分析了球壁温度、相变单元尺寸和相变材料初始温度三种影响因素对熔化过程和球壁温度对凝固过程的影响。通过对两个过程对比发现相变单元尺寸对相变过程影响最大,在相同温差条件下完全熔化时间少于完全凝固时间,熔化过程中始终存在的石蜡-壁面与液相石蜡-固相石蜡之间的对流换热过程增加了熔化速率。     

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.     

Performance of a natural circulation solar air heating system with phase change material energy storage

The design, construction and performance evaluation of a passive solar powered air heating system is presented. The system, which has potential applications in crop drying and poultry egg incubation, consists of a single-glazed flat plate solar collector integrated with a phase change material (PCM) heat storage system. The PCM is prepared in modules, with the modules equispaced across the absorber plate. The spaces between the module pairs serve as the air heating channels, the channels being connected to common air inlet and discharge headers. The system was tested experimentally under daytime no-load conditions at Nsukka, Nigeria, over the ambient temperature range of 19–41 °C, and a daily global irradiation range of 4.9–19.9 MJ m⁻². Peak temperature rise of the heated air was about 15 K, while the maximum airflow rate and peak cumulative useful efficiency were about 0.058 kg s⁻¹ and 22%, respectively. These results show that the system can be operated successfully for crop drying applications. With suitable valves to control the working chamber temperature, it can also operate as a poultry egg incubator.     

太阳能单罐相变蓄热系统实验测试和数值模拟研究

太阳能的高效利用是解决能源短缺和环境污染问题的主要手段之一。文章基于太阳能相变蓄热系统,建立带有辅助热源的太阳能单罐相变蓄热系统实验台,并利用该实验台对相变材料(融点为48~50℃的石蜡)进行热能存储实验。实验结果表明:加热12 min后,顶层石蜡温度达到140℃以上,并且融化完全;加载完成后,中层石蜡的最高温度为63℃;静置2 h后,储能罐中的石蜡开始放载,最后均匀混合,顶层、中层和底层石蜡的温度均达到42℃。文章在实验结果的基础上,利用Fluent软件对太阳能单罐相变蓄热系统内相变材料(石蜡和熔融盐)的换热过程进行数值模拟,模拟结果表明,在相同时间内,当采用石蜡作为相变材料时,太阳能单罐相变蓄热系统的换热效率较高。