高效制冷机房优化设计及对比分析

为了研究高效制冷机房优化的技术路线，对制冷空调能耗现状以及高效制冷机房的发展进行概述与分析。我国目前制冷机房能效提升具有很大挖掘空间，需要从设计阶段助力实现高效制冷机房优化，提升制冷机房系统综合能效比。对上海地区高效机房实际优化案例进行分析，对高性能COP （制冷性能系数）的冷水机组为主策略下的高效机房优化方案进行能耗模拟，从全年能效和运行成本角度给出分析结果和参考建议。     

空调机组和建筑物节能潜力分析

本文分析了空调的技术节能途径包括空调机组的能效比,以及房间空调器的季节能效比（SEER）和冷水机组的部分负荷值（IPLV）。对于建筑节能,提出了采用新型低能耗的围护结构,合理利用太阳能和地热能等自然能源来减少建筑物能源的消耗,同时从政策节能方面分析了相应的政策法规支持,对减少空调用电负荷有很大的积极作用。     

基于SWMM模型的郑州市运粮河组团区内涝研究

针对以内涝为主要特征的城市洪水问题日趋突出,所造成危害日趋严重的现象,构建了基于地理信息系统（ArcGIS）的城市雨洪模型（SWMM）。以郑州市运粮河组团区为例,模拟分析了不同重现期降雨下规划区域的内涝情况,并选取具有代表性的易涝点进行优化分析。结果表明,该模型的计算结果可以为排水系统设计标准校核及优化设计方案提供一定的技术支持。     

螺杆式冷水机组群控策略

叙述了螺杆式冷水机组在冷冻/冷却水系统定流量情况下,低负荷或高负荷时,能效比均较低的特点,提出了一种在保证机组稳定、可靠运行的基础上,以系统总能效比为目标的螺杆式冷水机组群优化控制策略。     

广域测量系统故障定位新方法

基于全球定位系统（GPS）的相量测量单元（PMU）的出现,使得在电力系统中应用广域电流差动保护成为可能。提出了一种新型的故障定位方法,即采用聚类分析最短距离法,并结合图论工具,对系统进行归类并划分保护区域。计算保护区内的电流之和,并据此判断保护区内是否存在故障。若保护区内存在故障,则通过逐渐减小阀值,将该保护区划分成若干子保护区,并重复以上步骤,最终锁定故障区域。     

基于改进GSA-GWO算法的含分布式电源局部电网孤岛划分策略

为进一步提高局部电网在故障恢复过程中的高效性和可靠性,文章提出了一种基于改进GSA-GWO算法的局部电网故障下孤岛划分策略。首先,采用最优-最劣法对负荷进行评价,得到负荷权重值,从而确定局部电网故障下孤岛划分重要负荷恢复优先级;其次,结合负荷优先级确定负荷等级权重系数值,构建含分布式电源的局部电网孤岛划分目标函数模型;再次,为了获取更佳的目标函数求解结果,引入混沌反向学习和遗传退火算法（Genetic Simulated An-nealing, GSA）对灰狼优化算法（Grey Wolf Optimization, GWO）进行改进,以提高算法的优化性能;最后,以修改后的IEEE 69节点为例进行仿真分析,运用改进的GSA-GWO算法对局部配电网故障模型进行求解,得到更佳的孤岛划分结果。算例分析表明,文章提出的策略可准确实现局部电网故障下孤岛划分最优策略,保证了重要负荷的电力供应,验证了策略的有效性和优越性。     

影响压缩式热泵制冷COP的因素分析

热泵系统可以将低品位能量加以利用,是一种节能环保的能源利用方式,但热泵的制冷经济性受能效比COP的影响很大,所以分析影响COP值的因素对设计高效热泵有一定的参考价值。本文在制冷工况下对影响压缩式热泵COP的温度、流量、负荷等因素进行分析,并通过举例说明,得到各因素对热泵制冷能效比的影响规律。     

上海建成国内第一个省市级能效监控平台

最近,英国碳信托公司宣布投资45．4万英镑（约合73万美元）,资助位于英国威尔士地区的Lomox公司研发一种基于有机发光二极管（OLED）技术的新产品。这种发光材料可以制成覆盖在墙壁上的薄膜,全方位发出类似自然光的柔和光线,避免灯泡带来的阴影和晃眼等问题。据悉,这种材料的能效比现在的标准节能灯还高25倍。     

分布式电源接入交直流混合微电网群优化规划研究

针对区域内负荷、电源优化规划问题,提出分布式电源接入交直流混合微电网群优化配置方法:建立2层交直流混合微电网群优化规划模型,上层模型考虑了节点耦合度和功率平衡度指标,实现了区域节点的集群划分;下层优化配置模型以考虑投资成本、运行维护成本、购售电成本的综合成本最小为目标,运用优化软件分析得到集群划分和优化配置结果.实际工...     

联合模糊聚类和多样本SSO优化SVR的配电通信网络流

针对电力通信网络流量预测问题,提出了一种联合模糊聚类和多样本群居蜘蛛优化（social spider optimization,SSO）SVR的配电网络流量预测方案。针对配电网络流量时序非线性、周期性特点,首先采用自适应模糊聚类方法（adaptive fuzzy C-means clustering）对流量样本数据进行预处理,实现了样本数据聚类自动划分,有效降低了流量数据短相关性对预测精度的影响;然后利用多样本SSO优化算法（multi-sample social spider optimization algorithm）对SVR预测模型参数进行优化,通过引入多样本、网格迭代进化策略,从而得到不同流量数据聚类对应的最佳SVR参数组合;最后,运用多样本SSO优化SVR模型对预测数据进行预测分析。仿真结果表明,同ARIMA、神经网络等配电网路流量预测模型相比,提出的预测方案预测精度提高了18.8%~34.1%。     

CO2双蒸发器压缩/喷射式跨临界制冷循环

为减小CO_2跨临界循环系统节流部分的膨胀功损失,提高系统性能,可在小型制冷系统中采用喷射器代替节流阀,部分回收工质从高压到低压过程的膨胀功。在对系统进行热力学分析的基础上,建立了CO_2跨临界压缩／喷射制冷循环的效率分析模型。计算结果表明：在合理的喷射器出口背压下,CO_2跨临界压缩／喷射制冷循环可以得到较高的循环性能。蒸发温度和气体冷却器出口温度两工况的变化对该系统性能的影响程度相对较大。在较低蒸发温度下,该系统可以明显降低压缩机出口温度,有利于系统稳定运行。     

Should a small combined heat and power plant (CHP) open to its regional power and heat networks? Integrated economic,energy, and emergy evaluation of optimization plans for Jiufa CHP

The development of industrial ecology has led company managers to increasingly consider their company's niche in the regional system, and to develop optimization plans. We used emergy-based, ecological-economic synthesis to evaluate two optimization plans for the Jiufa Combined Heat and Power (CHP) Plant, Shandong China. In addition, we performed economic input–output analysis and energy analysis on the system. The results showed that appropriately incorporating a firm with temporary extra productivity into its regional system will help maximize the total productivity and improve ecological-economic efficiency and benefits to society, even without technical optimization of the firm itself. In addition, developing a closer relationship between a company and its regional system will facilitate the development of new optimization opportunities. Small coal-based CHP plants have lower-energy efficiency, higher environmental loading, and lower sustainability than large fossil fuel and renewable energy-based systems. The emergy exchange ratio (EER) proved to be an important index for evaluating the vitality of highly developed ecological-economic systems.     

Simulation analysis of factors influencing chiller EER

This study constructed a mathematic model of a variable frequency centrifugal chiller using Simulink software. By running the simulation, it was discovered that when the other factors are constant, the EER （Energy Efficiency Ratio） of the chiller increases with decreases in the temperature of the cooling water and increases in the tem- perature of the chilled water. The effect of changes in the cooling water temperature on the EER of the chiller is stronger than that of changes in the chilled water temperature. In addition, as the chiller load decreases, the EER increases until reaching a maximum, after which it decreases. Furthermore, the EER of chillers working under a constant flow rate is slightly higher than that of those working under varying flow rates.     

Simulated and experimental performance of split packaged air conditioner using refrigerant HC-290 as a substitute for HCFC-22

This paper discusses the use of propane (HC-290) as a safe and energy efficient alternative to HCFC-22 in a typical split air conditioner with nominal cooling capacities up to 5.1 kW. Initially split air conditioner performance is simulated for cooling capacity, energy efficiency ratio (EER), and refrigerant charge. Tests were conducted for different test cases in a psychrometric test chamber with HCFC-22 and HC-290. The test conditions considered are as per Indian Standards, IS 1391 (1992) Part I. The various parameters considered were based on simulated performance with the objective to achieve maximum EER for the desired cooling capacity. As the flammability is an issue for HC-290, the reduction of HC-290 charge was another objective. Two different types of condensers, first with smaller size tubing and another parallel flow condenser (PFC) or minichannel condenser were used in order to reduce HC-290 charge. For HC-290, the highest EER achieved was 3.7 for cooling capacity 4.90 kW for a refrigerant charge of 360 g.The important safety aspects of using HC-290 in air conditioner are discussed. The refrigerant charge as per EN 378 for different cooling capacities and room sizes is also considered.     

我国水能资源区划管理体系设计

针对我国水能资源区划管理经验较少的现状,基于水能资源区划管理的必要性与原则,构建了水能资源区划管理体系框架,对水能资源区划的管理机构和队伍建设、管理制度与流程建设、管理关键监管节点等进行了分析。同时提出了水能资源区划管理的规范化建设设想,对加快水能资源区划工作、依法行政和依法管理、促进水能资源的可持续利用均具有重要的现实意义。     

跨临界制冷循环的适用条件及在CO2制冷系统中的应用研究

在热力学第一、第二定律的基础上研究了跨临界制冷循环若干适用条件。详细分析了跨临界制冷循环对环境温度、制冷压力和温度、回热温差的要求，得出了启动危机、最小制冷高低压差等概念，将这些成果用于CO2制冷剂的分析。获得了相应的数据。可供研究CO2跨临界制冷系统应用。     

Ion-exchanged and salt hydrates-encapsulated zeolites for solar refrigeration

Solar refrigeration is the best method of utilization of solar energy due to the in-phase relationship between the availability of the solar radiation and the refrigeration requirements. Zeolites with their water content and ion-exchange capability can be used as the material for solar refrigeration. This study aims at further enhancement in the adsorption refrigeration capacity of zeolite by salt hydrate encapsulation. Ion-exchanged and salt hydrate encapsulated zeolites are prepared and characterized for their application as potential candidates in solar refrigeration. A sorption machine has been constructed with the salt-encapsulated zeolite and the results highlight the enhanced suitability of the salt-encapsulated zeolites for solar refrigeration.     

Experimental Evaluation of One,Two, and Three Stage Evaporative Cooling Systems

The thermal performance of four different arrangements of evaporative air coolers have been evaluated experimentally during the hot summer of Kuwait. The systems include one-stage direct evaporative cooling (DEC), one-stage indirect evaporative cooler (IEC) linked to an external cooling tower, two-stage indirect/direct evaporative coolers (IEC/DEC), and three-stage system of evaporative cooling and mechanical vapor compression (IEC/DEC-MVC). Two variables are used to evaluate the system thermal performance, the thermal effectiveness and the energy efficiency ratio (EER). The data show that the IEC/DEC has the highest EER, followed by the DEC, IEC/DEC-MVC, and IEC. The DEC has the lowest effectiveness, succeeded by the DEC/IEC, IEC, and IEC/DEC-MVC. Coupling MVC with IEC/DEC extends the cooling range and can cool the ambient air dry bulb temperature over a range of 40°C to 15°C at any value of ambient air wet bulb temperature. Two experimental correlations have been developed for each one of the tested systems. The first one relates the effectiveness to water to air mass flow ratio (L/G) or Reynolds number (Re), while the second correlation relates the EER with effectiveness and L/G and/or Re. These relationships are very important in designing and optimizing the studied evaporative cooling units.     

基于分层分区的含DG配网故障恢复策略

为实现计及DG随机性出力的主动配电网分层分区故障恢复,建立了基于DG时段出力模型的主动配电网故障孤岛划分策略,并建立了主动配电网故障两阶段恢复模型,第一阶段综合考虑负荷的波动性和DG出力的随机性,建立考虑负荷恢复价值最优的主动配电网区域恢复方案;第二阶段利用可中断负荷建立配电网开关操作次数最优的全局优化模型,实现主动配电网故障后的故障恢复,既保证重要负荷的优化恢复,又延长了开关寿命,提高了经济性。采用改进的IEEE69节点系统进行仿真验证,验证了文中方案的有效性。