氨水吸收压缩太阳能制冷技术在公共建筑的应用分析

本文提出了公共建筑的氨水吸收压缩式太阳能空调制冷方案，对比分析了吸收制冷、机械压缩制冷、吸收压缩并联制冷、吸收压缩串联制冷四种模式的运行参数、系统特点、性能指标及适用条件。结论表明，吸收压缩串联制冷可有效避免系统对太阳能热源温度的依赖，不存在“临界热源温度”限制，可显著降低公共建筑的制冷运行费用，其运行费用较吸收制冷、机械压缩制冷、吸收压缩并联制冷分别降低了4.6%、33.8%、19.2%。氨水吸收压缩太阳能制冷技术具有环保、节能、适用性强等特点，其在以公共建筑太阳能制冷为代表的余热制冷领域具有广阔的应用前景。     

Recent advances in intra-hour solar forecasting: A review of ground-based sky image methods

As the penetration of solar energy generation into power systems keeps rising, intra-hour solar forecasting (IHSF) is becoming increasingly important for the secure and economical operation of a power system. One major difficulty in providing very accurate IHSF emanates from rapid cloud changes in the sky. The ground-based sky image (GSI) provides the intuitive information of intra-hour cloud changes and has thus been widely utilized in studies on IHSF. This paper presents a systematic review of the state-of-the-art of ground-based sky image-based intra-hour solar forecasting (GSI-IHSF). To our knowledge, we first propose a generic framework of GSI-IHSF consisting of four modules, i.e., sky image acquisition, sky image preprocessing, cloud forecasting, and solar forecasting. Then, as for each module, this paper introduces its core function, shows the major challenges, briefly reviews several extensively used techniques, summarizing research trends. Finally, this paper offers a prospect of GSI-IHSF research, discusses recent advances that demonstrate the potential for a great improvement in forecast accuracy, pointing out some new requirements and challenges that should be further investigated in the future.     

混合型组织的可持续成长：多重紧张的战略响应

本文从混合型组织的“多重紧张识别-多重紧张影响效应-多重紧张的战略响应”这一逻辑链条出发，建构混合型组织紧张表现形式的钻石模型，识别出以使命紧张和制度紧张为表现形式的本源性紧张和以战略紧张、治理紧张、运营紧张和身份紧张为表现形式的引致性紧张。在此基础上，提出紧张度对混合型组织可持续成长影响效应的倒U型关系，认为恶性紧张容易引发单向性使命漂移、内外部合法性冲突、组织治理失灵、扩展性受限等组织脆弱性问题，良性紧张则可以激发组织创新性、促进制度逻辑重构并促进组织身份制度化，有利于组织的可持续成长。针对混合型组织出现的多重紧张，本文结合紧张度和混合元素性质认知两个维度，拓展性地提出针对“紧张”的适度竞争、适当激发、分离战略、整合战略和弹性战略五种响应战略，并基于紧张形式与组织类别建立针对恶性紧张的响应战略适配矩阵。     

Access to transportation,residential segregation,and economic opportunity

The Housing Choice Voucher Program assists low-income families to afford decent housing and provide them with better economic opportunities. There is growing evidence that public transportation plays an important role in shaping the residential location choices of low-income households. However, transportation has not been a major focus of the research related to housing voucher programs. We develop a general equilibrium model of a city with multiple districts, decentralized employment, multiple commuting modes, and locally financed education. We compare housing vouchers with transportation vouchers with respect to poverty deconcentration, educational quality in each district, unskilled employment in the suburbs, and welfare.     

基于MATLAB改进的相变蓄热集热器在太阳能制冷系统中的性能分析

为提高太阳能制冷系统的性能参数,建立了集热蓄热一体化集热器模型,以进行应用计算。基于TRNSYS与MATLAB软件联合模拟运行的无辅助热源的太阳能吸收式制冷系统,分别对采用传统集热器的系统和采用改进后的相变蓄热集热器的系统的各部分参数的变化进行分析,对集热器的效率、系统制冷量和性能系数进行了对比。模拟结果表明,在太阳能吸收式制冷系统中,采用改进后的相变蓄热集热器,与传统的集热器相比,其集热效率提高约7.62%,系统制冷量增加约9.99%,系统的COP增加约23.60%。本模型能较好地应用于太阳能吸收式制冷系统的模拟。     

一种新的光伏发电预测模型的设计

为了对光伏发电的输出功率进行预测,本文分析光伏发电的影响因素,提出了一种基于太阳辐射功率曲线匹配的预测模型。该模型将历史数据按时段进行分解,查找与当前时段太阳辐射功率曲线最为匹配的数据,以此构建并训练BP神经网络,来预测未来3个小时内的太阳辐射功率,能够较好的实现预测目标。实验结果表明,该模型有较高的精度,可对电网调度起到重要的指导作用。     

基于PLC的槽式抛物面太阳能集热器单轴跟踪系统设计

主要对基于PLC的单轴槽式抛物面太阳能集热器跟踪系统设计方案进行了研究,根据宁夏特殊的气候环境采用南北水平单轴跟踪系统设计,大大降低成本耗材,用S7-300软件编程复杂的数学公式作为控制中心。选用角度位移,光强和太阳传感器,用以应变阴天晴天两种状况的使用,极大的提高了集热器的使用效率更好的做的实时掌握跟踪情况。     

太阳能热动力发电系统中高温热管式吸热/蓄热器技术研究

介绍了近年来热管式吸热/蓄热器的研制情况,分析了热管式吸热/蓄热器的结构原理,认为热管式吸热器不仅能改善温度均匀性,而且能有效利用相变材料,这使得吸热器的热性能和质量得到明显改善,可成为新一代太阳能热动力系统重点研制的对象,并指明了研制热管式吸热/蓄热器需解决的几个关键问题。     

A copula-based time series model for global horizontal irradiation

The increasing importance of solar power for electricity generation leads to increasing demand for probabilistic forecasting of local and aggregated photovoltaic (PV) yields. Based on publicly available irradiation data, this paper uses an indirect modeling approach for hourly medium to long-term local PV yields. We suggest a time series model for global horizontal irradiation that allows for multivariate probabilistic forecasts for arbitrary time horizons. It features several important stylized facts. Sharp time-dependent lower and upper bounds of global horizontal irradiations are estimated. The parameters of the beta distributed marginals of the transformed data are allowed to be time-dependent. A copula-based time series model is introduced for the hourly and daily dependence structure based on simple vine copulas with so-called tail dependence. Evaluation methods based on scoring rules are used to compare the model’s power for multivariate probabilistic forecasting with other models used in the literature showing that our model outperforms other models in many respects.