Investigation of the impact of changes in demand forecasting method on the financial performance of an electricity supply undertaking

Peak demand forecasts obtained from six different univariate forecasting methods, under a range of conditions, were used to drive a capacity acquisition model of a large electrical supply system; and the resulting physical and financial performance of the model was observed for each set of forecasts. The results obtained are discussed in the context of their implications for the choice of load forecasting method used in capacity acquisition planning by a power supply undertaking.     

探讨电石法PVC烟气治理方法

分析了电石法PVC生产链中电石炉烟气及电厂烟气二氧化硫的排放情况,指出利用电石炉烟气中的CO合成氨、再将合成氨用于燃煤电厂烟气的"氨法"脱硫是具有较大应用潜力的循环经济产业链。     

Heat Transfer Analysis for Gas-to-Liquids Transportation Through Trans Alaska Pipeline

Gas-to-liquids (GTL) technology involves the conversion of natural gas to liquid hydrocarbons. In this article, theoretical studies have been presented to determine the feasibility of transporting GTL products through the Trans-Alaska Pipeline System (TAPS). To successfully transport GTL through TAPS, heat loss along the route must be carefully determined. This study presents heat transfer and fluid dynamic calculations to evaluate this feasibility. Because of heat loss, the fluid temperature decreases in the direction of flow and this affects the fluid properties, which in turn influence convection coefficient and pumping power requirements. The temperature and heat loss distribution along the pipeline at different locations have been calculated. Fairly good agreement with measured oil temperatures is observed. The powers required to pump crude oil and GTL individually, against various losses have been calculated. Two GTL transportation modes have been considered; one as a pure stream of GTL and the second as a commingled mixture with crude oil. These results show that the pumping power and heat loss for GTL are less than that of the crude oil for the same volumetric flow rate. Therefore, GTL can be transported through TAPS using existing equipment at pump stations.     

延长测井电缆使用寿命的方法探讨

由于对测井电缆机械性能缺乏了解,使用不规范,使测井电缆使用寿命降低.通过对测井电缆结构、制造工艺进行分析,进一步掌握其性能,提出通过正确安装、使用前需进行稳定化处理、在使用中注意控制起下速度、日常清洁润滑、定期对电缆进行维护保养等方法维持铠装层正常状态,减少层间摩擦力,不扭曲,缆芯通断良好等方法,从而延长电缆的使用寿命.     

主跨348m+348m三塔单索面PC梁斜拉桥

宜昌市夷陵长江大桥采用三塔斜拉桥，总体布置为(128．08 348 348 120．35)m。介绍了该桥的合理性及结构特点。     

电力负荷削峰减载系统在珠钢电炉的应用

借助现场采集装置,在计算机上获取每一分钟的冶炼工艺电能需求量,显示当前15分钟时段已发生的电耗量,调整用户设定,实现需量自动刷新、报警和专家分析推荐后续用量;实现平稳用电并减少对电网冲击,同时降低电能最大需用量以减少成本。     

操纵员心理评价方法研究

文章对核电厂操纵员心理定性化评价以及定量化评价方法进行分析和探讨。对轮廓图匹配法和模糊综合评价法的适用范围、应用效果进行了比较分析。该研究的结果可为操纵员评价提供有益参考。     

基于多随机变量风险约束的水电站长期优化调度

针对市场环境下水电站如何综合考虑电价和来水等不确定性因素下的优化调度是当前研究的热点和难点,建立了考虑电价和来水等不确定性因素的风险约束水电站长期优化调度模型。根据此模型发电商可方便地在预期的目标收益和风险之间进行权衡,达到以较小的风险获得较大的收益的目的。以二滩电厂实算为例,表明了该模型的有效性。     

嵌入式Web服务器在中小水电信息采集系统中的应用

中小水电站大多数建在偏远山区，并网管理难度非常大，解决中小水电站的信息传输是主要的技术难点之一。随着计算机技术的发展，嵌入式Web服务器技术在远程监控和实时通信系统中的应用越来越广泛。将Web技术引入中小水电站信息采集系统中，可以实现对中小水电站基于浏览器方式的远程监控。文中结合中小水电站通信结构，介绍了嵌入式Web服务器技术在中小水电站信息采集系统中的应用。     

Effects of low radiation on the power quality of a distributed PV-grid connected system

We have previously investigated effects of radiation levels on power quality of a number PV-grid interactive systems in Thailand, in terms of harmonics and voltage variation at the point of common coupling (PCC). In this paper, we focus on the nature of components of complex power (actual, reactive and apparent power) of inverter output of a PV-grid interactive system due to low radiation, below 400 W/m². The system being investigated has an array of 4.2 kWp and representative of roof top units. It is observed that a PV array supplies increasing real power, in magnitude and as percentage of complex power, at high values of radiation. At low radiation level when the array does not provide enough output power, reactive power is drawn from distribution transformer and fed into an inverter and loads. Based on results from the test site and long term radiation data of Bangkok, we then estimate energy available from low radiation from a hypothetical PV-grid interactive unit in Bangkok of a similar size. It can be seen that for a tropical climate like Thailand a significant amount of energy, 20–30% of radiation energy, is in the form of reactive power. Methods must be devised to capture this low radiation energy and converted into real power form.