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山积图在汽车总装配工时分析中的应用

汽车行业的快速发展和激烈竞争要求企业以最低的成本生产出高品质的产品,因此如何充分利用各种资源提高总装车间各线体的生产效率成为各企业关注的重点问题。主要介绍如何运用山积图发掘线体不合理的工位,对员工作业进行优化,减少作业浪费,提高工时平衡率。     

Statistical analysis of solar measurements in Algeria using beta distributions

A method of smoothing solar data by beta probability distributions is implemented in this paper. In the first step, this method has been used to process daily sunshine duration data recorded at thirty-three meteorological stations in Algeria for eleven year periods or more. In the second step, it has been applied to hourly global solar irradiation flux measured in Algiers during the 1987/89 period. For each location and each month of the year, beta probability density functions fitting the monthly frequency distributions of the daily sunshine duration measurements are obtained. Both the parameters characterising the resulting beta distributions are then mapped, enabling us to build the frequency distributions of sunshine duration for every site in Algeria. In the case of solar radiation for Algiers, the recorded data have been processed following two different ways. The first one consists in sorting the hourly global solar irradiation data into eight typical classes of the daily clearness index. The second one is based on the repartition of these data per month. The results of the first classification show that for each class of daily clearness index, the hourly data under consideration are modelled by only one beta distribution. When using the second classification, linear combinations of two beta distributions are found to fit the monthly frequency distributions of the hourly solar radiation data.     

山东雷电监测定位系统数据分析与应用

本文给出了山东雷电定位网的布网形状、覆盖区域、探测效率及定位精度，并介绍了雷电定位网在电网调度中的实时应用，主要为：雷击故障点的确定及自动报警、雷电活动趋势的预报及电网走廊雷电活动特性的实时分析。另外还对山东雷电监测定位网１９９３年到１９９６年期间探测到的１３７６６５次闪电数据进行了统计分析，得到了山东雷暴月、雷暴天、雷暴小时数以及雷电强度分布、回击数分布、密度分布等。     

Estimation of monthly global solar radiation from sunshine duration measurement in Elazi

In this study, the relation between a and b terms and / was investigated to estimate the global solar radiation in Elazi by using different regression analyses. Equations which contain the whole year and two different periods, winter and summer, were developed. Eqs. (5)–(7) which represent second, third and fourth degree equations respectively, gave the best results in all of the equations having an error less than 1%. Contrary to expectations, the equations developed for summer and winter periods had higher errors than the others.     

Potential of renewable surplus electricity for power-to-gas and geo-methanation in Switzerland

Energy systems are increasingly exposed to variable surplus electricity from renewable sources, particularly photovoltaics. This study estimates the potential to use surplus electricity for power-to-gas with geo-methanation for Switzerland by integrated energy system and power-to-gas modelling. Various CO₂ point sources are assessed concerning exploitable emissions for power-to-gas, which were found to be abundantly available such that 60 TWh surplus electricity could be converted to methane, which is the equivalent of the current annual Swiss natural gas demand. However, the maximum available surplus electricity is only 19 TWh even in a scenario with high photovoltaic expansion. Moreover, making this surplus electricity available for power-to-gas requires an ideal load shifting capacity of up to 10 times the currently installed pumped-hydro capacity. Considering also geological and economic boundary conditions for geo-methanation at run-of-river and municipal waste incinerator sites with nearby CO₂ sources reduces the exploitable surplus electricity from 19 to 2 TWh.     

Underground hydrogen storage in Australia: A review on the feasibility of geological sites

Hydrogen has attracted attention worldwide with its favourable inherent properties to contribute towards a carbon-free green energy future. Australia aims to make hydrogen as its next major export component to economize the growing global demand for hydrogen. Cost-effective and safe large-scale hydrogen storage in subsurface geology can assist Australia in meeting the projected domestic and export targets. This article discusses the available subsurface storage options in detail by first presenting the projected demand for hydrogen storage. Australia has many subsurface formations, such as depleted gas fields, salt caverns, aquifers, coal seams and abandoned underground mines, which can contribute to underground hydrogen storage. The article presents basin-wide geological information on the storage structures, the technical challenges, and the factors to consider during site selection. With the experience and knowledge Australia has in utilizing depleted reservoirs for gas storage and carbon capture and sequestration, Australia can benefit from the depleted gas reservoirs in developing hydrogen energy infrastructure. The lack of experience and knowledge associated with other geostructures favours the utilization of underground gas storage sites for the storage of hydrogen during the initial stages of the shift towards hydrogen energy. The article also provides future directions to address the identified important knowledge gaps to utilize the subsurface geology for hydrogen storage successfully.