溴化锂吸收式制冷循环的计算机模拟及优化研究

以溴化锂吸收式制冷双效系统为研究对象,开发了辅助设计计算程序,并对串联双效系统进行了优化分析,通过实例计算分析,得到了以最大热力系数和最大性能面积比为优化目标的优化结果。以最大性能面积比为优化目标既兼顾了系统的制造成本又兼顾了系统的运行成本。     

光伏光热与空气源热泵联合供暖系统设计与优化配置研究

针对国家碳减排战略布局及北方居民对清洁采暖的经济性需求,设计了一种光伏、光热、储热一体化供暖系统,并对系统关键组件及设备进行优化配置研究。首先,以光伏、集热器、空气源热泵为主要能量来源,形成多能互补的系统拓扑结构;其次,综合考虑当地收入水平,以系统生命周期碳排放及生命周期费用最小为优化目标,以光伏容量、集热器面积、水箱体积、热泵功率为优化变量,运用Hooke-Jeeves优化算法对系统进行优化;最后,以张家口某地300 m²建筑为例进行系统优化设计。结果表明与电锅炉供暖系统、空气源热泵系统和未优化系统相比,经优化后系统的生命周期费用、碳排放均有显著改善。研究方案具有良好的经济及碳减排性能,可为北方地区清洁供暖提供相应参考。     

基于遗传算法的含电力电子变压器交直流混合配电网优化配置

构建了含电力电子变压器(PET)的交直流混合配电网优化模型,基于该模型,以接入PET和分布式电源的IEEE33节点系统为例,采用遗传算法以系统网损最小为优化目标,以PET的端口量为优化变量进行优化配置,分析了优化结果 PET端口功率流动情况、分布式电源的总利用率、配电网总有功损耗及系统最末端的电压水平。算例结果表明,PET具有改善交直流配电网的潮流分布的功能。     

太阳能电动汽车储能系统的优化配置

在太阳能电动汽车(SEEV)系统中,储能系统的优化配置是一个重要且具挑战性任务.太阳能电动汽车储能系统的优化配置可以看成一个具有约束的优化问题:以储能系统的成本最小为优化目标,以表达系统可靠性指标的负载失电率为约束.决策变量不仅包含传统方法中的蓄电池充电电流而且还包含储能飞轮的质量.优化算法是采用基于遗传算法和神经网络的组合优化方法,即把机会约束遗传算法中比较耗时的个体检验部分交给神经网络处理.研究结果表明,基于遗传算法和神经网络的组合优化算法在被应用于太阳能电动汽车储能系统的优化配置时,算法收敛良好,计算时间少且可行.     

基于标准化矩阵模型的综合能源系统优化方法

针对集成能源系统的优化问题,提出一种标准化的集成能源系统矩阵建模方法并建立了综合能量系统的线性规划模型。在此基础上,实现了综合能源系统的结构优化、设计优化和运行优化。以综合能源效率为目标函数,建立了系统结构优化的数学模型,对区域综合能源系统进行优化结构规划。在满足区域用户总冷、热、电需求的基础上,提出了对同一类型的能量转换设备选择两种或两种以上设备并联运行的建议,进一步提高系统的综合能效和可靠性。针对区域综合能源系统运行优化,以运维成本为目标函数,对区域综合能源系统进行优化运行规划,优化各设备单元的小时运行策略。     

基于双层优化模型的风-光-储互补发电系统优化配置

提出一种基于双层优化模型的风-光-储互补发电系统优化配置方法,外层优化以互补发电系统年净收益最大化为目标、通过量子粒子群算法优化风-光-储容量配置;内层优化以互补发电系统日出力波动率和日出力峰谷差最小化为目标、通过8760 h生产模拟优化储能充放电功率。实际算例仿真计算结果表明,所提算法能有效解决风-光-储互补发电系统在规划阶段的优化配置问题。     

变工况污水源热泵系统性能优化研究

在污水源热泵系统仿真模型的基础上,权衡了各阶段不同工况性能系数对全年总能耗的影响,提出了污水源热泵系统全年性能优化理念,定义了全年性能系数ACOP,并以此作为优化目标函数,以机组蒸发器、冷凝器和污水-中介水换热器的换热面积作为优化变量,研究系统通过机组压缩机启停控制方式下系统的面积优化匹配,并分别与系统初始设计参数、以供热性能系数HSPF、制冷性能系数SEER和EER为优化目标的优化计算结果进行对照,结果表明,采用ACOP作为优化目标具有更加客观的节能效果。     

基于改进粒子群算法的中深层地源热泵供暖系统运行优化

构建变工况运行且包含蓄热装置的中深层地源热泵供暖系统,基于改进粒子群算法,分别以运行费用、系统COP和地热能利用系数为目标函数对系统运行进行优化,并对优化结果进行比较和分析。结果表明：对应目标函数优化后的运行费用、系统COP和地热能利用系数分别为279.27元、6.4420和0.8527。以系统COP为目标函数的优化效果与运行费用相反,而与地热能利用系数相近。     

冷热电联供系统多时间尺度滚动优化运行方法研究

为解决源-荷供需能量不匹配的问题,提出了针对冷热电联供(CCHP)系统的多时间尺度滚动优化运行方法。该策略按照“日前-日内”2个阶段逐级制定机组出力计划,分别构建了以日前运行成本最低为目标的日前优化模型以及以滚动时域内购电成本和储能出力变化惩罚成本最低为目标的日内滚动优化模型,由此得到冷热电联供系统平滑出力计划。在日前优化中考虑多种储能模式对CCHP系统运行经济性的影响;日内滚动优化阶段确定了最佳滚动时长为4 h。结果表明：多元储能模式能够提高CCHP系统的运行经济性;多时间尺度滚动优化不仅可以提高和保证CCHP系统运行的经济性,而且能够有效降低源-荷的波动性对实际系统运行的影响。     

楼宇型分布式能源系统设备容量和运行策略优化研究

设备容量优化和运行策略优化是分布式能源系统设计,运行的关键问题。为实现分布式能源系统的经济效益,能效水平和环境效益最大化,针对楼宇型分布式能源系统建立了相对普适化的物理模型和数学模型,以粒子群优化算法和线性规划相结合,采用两阶段优化方法计算系统的最优容量配置,并给出运行策略。以某写字楼的分布式能源系统为例,得到最优的系统设备容量和全年逐时运行策略,并采用遍历法验证计算结果的准确性。优化的分布式能源系统与传统供能系统相比,费用年值降低7.79%,年总能耗降低24.18%,污染物排放量减少了62.77 %。     

风光互补发电技术在油田边远单井上应用的可行性分析

介绍风光互补供电系统的基本原理及特点,根据用电负荷情况设计成独立的供电系统,并通过工程实例介绍了风光互补的设计步骤,将采用风光互补发电与传统供配电方式进行了比较。     

Optimal design and techno-economic analysis of a hybrid solar–wind power generation system

Solar energy and wind energy are the two most viable renewable energy resources in the world. Good compensation characters are usually found between solar energy and wind energy. This paper recommend an optimal design model for designing hybrid solar–wind systems employing battery banks for calculating the system optimum configurations and ensuring that the annualized cost of the systems is minimized while satisfying the custom required loss of power supply probability (LPSP). The five decision variables included in the optimization process are the PV module number, PV module slope angle, wind turbine number, wind turbine installation height and battery capacity. The proposed method has been applied to design a hybrid system to supply power for a telecommunication relay station along south-east coast of China. The research and project monitoring results of the hybrid project were reported, good complementary characteristics between the solar and wind energy were found, and the hybrid system turned out to be able to perform very well as expected throughout the year with the battery over-discharge situations seldom occurred.     

适用于海岛的独立供电电源规划设计

针对我国浙江省舟山嵊泗列岛中的第二大岛嵊山岛负荷特点,规划设计了独立的可再生能源多能互补供电系统,包括风能、太阳能、波浪能,以及储能蓄电池等。采用回归分析方法对海岛用电负荷进行预测,在此基础上搭建海岛多能互补的混合发电系统的基本框架和模型,通过按机组类型优化的电源规划模型寻找出合适的计算方法进行供电电源优化,基于线性规划的原则得出各可再生能源电源在供电系统中的容量分配比例,即优化的供电电源规划设计方案,具有经济、环保、可靠的特点。     

Multi-objective optimization of the hybrid wind/solar/fuel cell distributed generation system using Hammersley Sequence Sampling

As the development of China's economy, environmental problems in China become more and more serious. Solar energy and wind energy are considered as ones of the best choices to solve the environmental problems in China and the hybrid wind/solar distributed generation (DG) system has received increasing attention recently. However, the instability and intermittency of the wind and solar energy throw a huge challenge on designing of the hybrid system. In order to ensure the continuous and stable power supply, optimal unit sizing of the hybrid wind/solar DG system should be taken into consideration in the design of the hybrid system. This paper establishes a multi-objective optimization framework based on cost, electricity efficiency and energy supply reliability models of the hybrid DG system, which is composed of wind, solar and fuel cell generation systems. Detailed models of each unit for the hybrid wind/solar/fuel cell system were established. Advanced ε-constraints method based on Hammersley Sequence Sampling was employed in the multi-objective optimization of the hybrid DG system. The approximate Pareto surface of the multi-objective optimization problems with a range of possible design solutions and a logical procedure for searching the global optimum solution for decision makers were presented. In this way, this work provided an efficient method for decision makers in the design of the hybrid wind/solar/fuel cell system.     

Weather data and probability analysis of hybrid photovoltaic–wind power generation systems in Hong Kong

This paper describes a simulation model for analyzing the probability of power supply failure in hybrid photovoltaic–wind power generation systems incorporating a storage battery bank, and also analyzes the reliability of the systems. An analysis of the complementary characteristics of solar irradiance and wind power for Hong Kong is presented. The analysis of local weather data patterns shows that solar power and wind power can compensate well for one another, and can provide a good utilization factor for renewable energy applications. For the loss of power supply probability (LPSP) analysis, the calculation objective functions and restraints are set up for the design of hybrid systems and to assess their reliability. To demonstrate the use of the model and LPSP functions, a case study of hybrid solar–wind power supply for a telecommunication system is presented. For a hybrid system on the islands surrounding Hong Kong, a battery bank with an energy storage capacity of 3 days is suitable for ensuring the desired LPSP of 1%, and a LPSP of 0% can be achieved with a battery bank of 5 days storage capacity.     

风光互补发电系统电能质量特性分析

为了解风光互补发电系统电能质量特性,构建了风光互补发电系统出力和控制仿真模型,提取仿真运行中的电压、电流数据,并在孤岛和并网运行方式下分析了电网电能质量的变化特性,进而提出了一套面向风光互补发电系统的电能质量分析指标体系,可为风光互补发电系统运行优化及电能质量治理提供合理建议。     

风光互补发电系统简介

利用西部地区风、光资源,设计一风力发电机组和太阳能光伏电池为一体的风光互补发电系统。通过一个实例,说明了供电系统的可行性,解决了当地日常用电问题。     

Research on non-grid-connected wind power/water-electrolytic hydrogen production system

Hydrogen has been recognized as the most promising future energy carrier. At present, industrial hydrogen production processes are not independent of traditional energy resources, which could easily cause secondary pollution. China has abundant wind energy resources. The total installed capacity of wind power doubled every year in the last five years, and reached 26 000 MW by the end of 2009, but over 9880 MW wind turbines were not integrated into grid because of the peak shaving restraint. In this paper, wind power is directly used in water-electrolytic process by some technical improvements, to design non-grid-connected wind power/water-electrolytic hydrogen production system. The system all works properly, based on not only the wind/grid complementary power supply but also the independent supply of simulation wind power. The large-scale fluctuation of current density has little impact on current efficiency and gas quality, and only affects gas output. The new system can break through the bottlenecks of wind power utilization, and explore a diversified development way of large-scale wind power, which will contribute to the development of green economy and low carbon economy in China.     

A framework for the design & operation of a large-scale wind-powered hydrogen electrolyzer hub

Due to the threat of climate change, renewable feedstocks & alternative energy carriers are becoming more necessary than ever. One key vector is hydrogen, which can fulfil these roles and is a renewable resource when split from water using renewable electricity. Electrolyzers are often not designed for variable operation, such as power from sources like wind or solar. This work develops a framework to optimize the design and operation of a large-scale electrolyzer hub under variable power supply. The framework is a two-part optimization, where designs of repeated, modular units are optimized, then the entire system is optimized based on those modular units. The framework is tested using a case study of an electrolyzer hub powered by a Dutch wind farm to minimize the levelized cost of hydrogen. To understand how the optimal design changes, three power profiles are examined, including a steady power supply, a representative wind farm power supply, and the same wind farm power supply compressed in time. The work finds the compressed power profile uses PEM technology which can ramp up and down more quickly. The framework determines for this case study, pressurized alkaline electrolyzers with large stacks are the cheapest modular unit, and while a steady power profile resulted in the cheapest hydrogen, costing 4.73 €/kg, the typical wind power profile only raised the levelized cost by 2%–4.82 €/kg. This framework is useful for designing large-scale electrolysis plants and understanding the impact of specific design choices on the performance of a plant.     

Impact of hydrogen energy storage on California electric power system: Towards 100% renewable electricity

Decarbonization of the power sector is a key step towards greenhouse gas emissions reduction. Due to the intermittent nature of major renewable sources like wind and solar, storage technologies will be critical in the future power grid to accommodate fluctuating generation. The storage systems will need to decouple supply and demand by shifting electrical energy on many different time scales (hourly, daily, and seasonally). Power-to-Gas can contribute on all of these time scales by producing hydrogen via electrolysis during times of excess electrical generation, and generating power with high-efficiency systems like fuel cells when wind and solar are not sufficiently available. Despite lower immediate round-trip efficiency compared to most battery storage systems, the combination of devices used in Power-to-Gas allows independent scaling of power and energy capacities to enable massive and long duration storage. This study develops and applies a model to simulate the power system balance at very high penetration of renewables. Novelty of the study is the assessment of hydrogen as the primary storage means for balancing energy supply and demand on a large scale: the California power system is analyzed to estimate the needs for electrolyzer and fuel cell systems in 100% renewable scenarios driven by large additions of wind and solar capacities. Results show that the transition requires a massive increase in both generation and storage installations, e.g., a combination of 94 GW of solar PV, 40 GW of wind, and 77 GW of electrolysis systems. A mix of generation technologies appears to reduce the total required capacities with respect to wind-dominated or solar-dominated cases. Hydrogen storage capacity needs are also evaluated and possible alternatives are discussed, including a comparison with battery storage systems.