Some aspects of biodiesel oxidative stability

Biodiesel, an “alternative” diesel fuel derived from vegetable oils, animals fats or used frying oils, largely consists of the mono-alkyl esters of the fatty acids comprising these feedstocks. One of the major technical issue facing biodiesel is its susceptibility to oxidation upon exposure to oxygen in ambient air. This susceptibility is due to its content of unsaturated fatty acid chains, especially those with bis-allylic methylene moieties. Oxidation of fatty acid chains is a complex process that proceeds by a variety of mechanisms. Besides the presence of air, various other factors influence the oxidation process of biodiesel including presence of light, elevated temperature, extraneous materials such as metals which may be even present in the container material, peroxides, and antioxidants, as well as the size of the surface area between biodiesel and air. Approaches to improving biodiesel oxidative stability include the deliberate addition of antioxidants or modification of the fatty ester profile. This article discusses some factors influencing biodiesel oxidative stability and their interaction. Resulting approaches to improving this property of biodiesel are related to these factors and the corresponding mechanisms.     

The effectiveness of storage and relocation options in renewable energy systems

Across the world, energy planners and transmission system operators are faced with decisions on how to deal with challenges associated with high penetration levels of intermittent energy resources and combined heat and power (CHP). At the same time, distributed plant operators are eager to reduce uncertainties related to fuel and electricity price fluctuations. These interests meet-up for options in distributed supply that introduces the principle of storage and relocation, typically by integrating heat pumps (HP) or electric boilers (EBs) into the operational strategies of existing CHP plants. This paper introduces the principle of storage and relocation by energy system design, and proposes for the storage and relocation potential of a technology option to be found by comparing options by their storage and relocation coefficient R_c, defined as the statistical correlation between net electricity exchange between plant and grid, and the electricity demand minus intermittent renewable electricity production. Detailed operational analyses made for various CHP options within the West Danish energy system, point to the concepts of CHP-HP and CHP-HP cold storage for effectively increasing energy system flexibility. For CHP-HP cold storage, R_c increases from 0.518 to 0.547, while the plant's fuel efficiency increases from 92.0% to 97.2%. These findings are discussed within frameworks of renewable energy systems, suggesting principles for 1st, 2nd, and 3rd generation system designs.     

基于直接采样相移法的蓄电池内阻测量

现代通信系统中,蓄电池是直流供电系统的最后一道安全保障屏障。蓄电池的好坏及供电质量,直接影响到整个通信系统的安全可靠运行。蓄电池内阻检测,是评价蓄电池质量的重要参数。本文详细介绍交流法测量蓄电池内阻的基本原理,依据该方法存在的缺陷,提出直接采样相移法测量蓄电池内阻的新方法,并用硬件电路实现该功能。     

蓄冷蓄热技术

简要介绍了蓄冷蓄热技术的应用与发展现状，归纳了蓄冷蓄热空调系统的原理和技术特点，提出了中央空调系统（包括采暖）采用蓄冷蓄热技术的诸多优势、宏观（社会）效益和微观（用户）效益以及对电网“移峰填谷”的重要作用；并例举出常州市金禧园生活小区蓄能中央空调系统运行情况的工程实例。     

MP310卡在温度信息采集与存储系统中的应用

本文详述了使用MP310卡实现温度信息采集与存储系统的开发方法,并简要介绍了VC通信控件及其使用方法,给出了调试程序。     

深圳抽水蓄能电站厂房洞室群优选渗控方案分析

利用求解有自由面渗流场改进的节点虚流量全域迭代法，结合精确的排水孔模拟技术，对深圳抽水蓄能电站运行期地下引水管线区及厂房洞室群围岩区三维渗流场进行了有限元仿真分析，着重研究了优选方案中高压岔管开裂时引水支管区域防渗排水系统的渗流特性．研究表明，该区域设置封闭性防渗帷幕加排水孔幕组合防渗体系，能有效控制高压引水管开裂时的高压渗水，改善该区岩体渗透比降分布，保证了下游厂房运行期的安全．     

Wood preparation, storage, and drying

The research cooperation in this activity has shown a fundamentally different attitude between the participating scientists in the scientific line of procedure considered.

One group proceeds pragmatically. The group has the opinion that drying progress in big chip stacks is determined by so many intercorrelated factors that it is practically impossible to work out mathematical models of the drying progress. Therefore, the group conducts full scale field trials.

Contrary to this attitude a more scientific line of procedure is maintained by other scientists. This line of procedure tries to establish the natural laws which determine drying of comminuted wood fuels. This is done by mathematical modelling and controlled laboratory experiments.

Both types of experiment are described in this paper.     

拆除爆破技术在西龙池抽水蓄能电站危岩处理中的应用

在西龙池抽水蓄能电站危岩处理过程中，借鉴了拆除爆破施工的一般经验，结合危岩处理的具体情况，将拆除爆破技术应用于柱状危岩的开挖处理中，实现了快速、安全、经济处理危岩的目的，爆破效果十分理想。     

沙河电站东副坝混凝土面板抬动原因分析及处理

沙河抽水蓄能电站东副坝在施工过程中由于面板受反向渗水顶托而抬动并产生裂缝。在对其事故原因进行认真分析的基础上，采用对面板空腔进行回填灌浆、对裂缝进行化学灌浆处理后，电站运行期间测得坝体渗水量为0．04L/s，面板防渗效果很好，事故处理效果显著，为类似工程设计和施工提供了宝贵的资料。     

安全环保达标投产争创国优——宝泉抽水蓄能电站工程建设目标纪实

在宝泉抽水蓄能电站建设过程中,宝泉公司提出了"安全环保、达标投产、争创国优"的工程建设目标,并在组织措施、制度建设等方面扎扎实实地开展了工作,取得了连续安全生产2000d、电站环境保护工作初见成效、已完单元工程质量合格率100%、土建单元工程优良率90%、安装工程单元优良率100%的优异成绩,工程造价控制工作、移民工作和档案工作也均成效显著,争创国优目标正稳步推进。