Viability of solar photovoltaics as an electricity generation source for Jordan

Viability of solar photovoltaics as an electricity generation source for Jordan was assessed utilising a proposed 5 MW grid‐connected solar photovoltaic power plant. Long‐term (1994–2003) monthly average daily global solar radiation and sunshine duration data for 24 locations – distributed all over the country – were studied and analysed to assess the distribution of radiation and sunshine duration over Jordan, and formed an input to the RetScreen Software for evaluation and analysis of the proposed plant's electricity production and economic feasibility. It was found that depending on the geographical location, the global solar radiation on horizontal surface varied between 1.51 and 2.46 MWh/m²/year with an overall mean value of 2.01 MWh/m²/year for Jordan. The sunshine duration was found to vary, according to the location, between 8.47 and 9.68 hours/day, with a mean value of 9.07 hours/day and about 3311 sunshine hours annually for Jordan. The annual electricity production of the proposed plant varied depending on the location between 6.886 and 11.919 GWh/year, with a mean value of 9.46 GWh/year. The specific yield varied between 340.9 and 196.9 kWh/m², while the mean value was 270.59 kWh/m². Analysis of the annual electricity production of the plant, the specific yield, besides the economic indicators, i.e. internal rate of return, simple payback period, years to positive cash flow, net present value, annual life cycle saving, benefit/cost ratio, and cost of energy – for all sites – showed that Tafila and Karak are the most suitable sites for the solar photovoltaic power plant's development and Wadi Yabis is the worst. The results also showed that an average of 7414.9 tons of greenhouse gases can be avoided annually utilising the proposed plant for electricity generation at any part of Jordan.     

System dynamics modelling of hybrid renewable energy systems and combined heating and power generator

The role of energy in the present world is critical in terms of both economical development and environmental impact. Renewable energy sources are considered essential in addressing these challenges. As a result, a growing number of organisations have been adopting hybrid renewable energy system (HRES) to reduce their environmental impact and sometimes take advantage of various incentives. When a HRES is being planned, the ability to model a HRES can provide an organisation with numerous benefits including the capability of optimising sub-systems, predicting performances and carrying out sensitivity analysis. In this paper, we present a comprehensive system dynamics model of HRES and combined heating and power (CHP) generator. Data from a manufacturing company using HRES and CHP generator are used to validate the model and discuss important findings. The results illustrate that the components of a HRES can have conflicting effects on cost and environmental benefits; thus, there is a need for an organisation to make trade-off decisions. The model can be a platform to further simulate and study the composition and operating strategies of organisations that are venturing to adopt new or additional HRESs.     

2015~2020年厦漳泉地区大气氨排放清单及分布特征

收集厦漳泉地区各类大气氨排放源的区县活动水平,基于排放因子法建立了2017年大气氨排放清单（1 km×1 km）,同时对2015~2020年大气氨排放趋势进行了分析.结果表明,厦漳泉2017年大气氨排放量为27.40 kt,其中畜禽养殖、农田生态系统、人体排放、燃料燃烧和废物处理占排放总量的比例分别为42.48%、22.04%、14.71%、7.08%和5.69%.大气氨排放密度顺序为：厦门（1.94 t ·km^-2）>泉州（1.07 t ·km^-2）>漳州（0.95 t ·km^-2）,高值区主要分布于人口集中的沿海城区和畜禽养殖业与种植业发达的内陆乡镇地区,氨排放量月度分布与温度变化规律一致.受不同地市经济结构和发展水平的影响,2015~2020年泉州市氨排放表现为下降,而厦门和漳州两市氨排放变化存在一定的波动,氨排放强度整体呈现随人均GDP上升而下降的趋势.     

Population dynamics of farmland ladybug resources and dominant species in Nyingchi,Tibet, China北大核心CSCD

捕食性瓢虫是重要的天敌昆虫,有利于害虫的生物防治.为查清西藏林芝地区农田瓢虫资源与种群现状,明确优势种类及种群动态和规律,对林芝不同生态区域的青稞、小麦、油菜3种作物农田开展瓢虫资源调查研究,同时选取固定样地定期进行种群动态分析.结果显示:林芝地区农田瓢虫分为2个亚科4个族10个属,共13种,其中11种为捕食性瓢虫.主要优势瓢虫种类为横斑瓢虫、多异瓢虫、二星瓢虫.其中横斑瓢虫在全部调查样地中均有分布,在农田中总体优势度指数、相对多度为最高.3种优势瓢虫在不同作物中种群动态变化规律存在差异,其中横斑瓢虫虫口密度长期高于其余优势瓢虫,且与蚜虫密度曲线有较为明显的重合现象.横斑瓢虫种群密度峰值主要集中在6月中旬至7月上旬,但在不同作物农田中具体峰值时期存在差异.可见,林芝地区农田不同种类瓢虫之间有较大数量差异,在不同生态区域与作物环境下具有不同的种群特征,但是优势瓢虫种类与种群规律较为明确,可用于农田蚜虫生物防治;结果可为保护当地重要昆虫资源及开展生物防治提供基础数据支撑.(图4表6参23)     

OMEGA算法在导弹振动工程中的应用

目的研究位移、速度和加速度谱之间的转换关系,给出三者功率谱密度之间的转换公式,进而用于导弹运输振动环境的设计。同时,研究加速度信号转换为振动位移的方法,并应用于导弹舱内单机设备安全间隙的设计。方法利用OMEGA算法,首先将加速度传感器测得的加速度时域信号转换成加速度频域信号,随后将加速度谱转换成位移谱,并计算位移谱中每个谱线对应的幅值、相位和圆频率,最后将各位移分量简单叠加得到振动位移的时间历程。结果采用该方法计算了高速公路上导弹的运输振动位移功率谱,并得到垂向、横向和纵向的峰-峰位移分别为3.32,0.46,2.14 mm。同时,计算了飞行环境下导弹舱内单机设备的振动位移,与所测得位移在幅值上相当,时域曲线形态一致。结论该方法能够很好地应用于导弹振动工程设计。     

Energy and exergy analysis of a solid-oxide fuel cell power generation system for an aerial vehicle (ISSA- 2015–139)

This paper presents the performance of the solid-oxide fuel cell/gas turbine hybrid power generation system with heat recovery waste unit based on the energy and exergy analyses. The effect of air inlet temperature and air/fuel ratio on exergy destruction and network output is determined. For the numerical calculations, air inlet temperature and air fuel ratio are increased from 273 to 373 K and from 40 to 60, respectively. The results of the numerical calculations bring out that total exergy destruction quantity increases with the increase of air inlet temperature and air/fuel ratio. Furthermore, the maximum system overall first and second law efficiencies are obtained in the cases of air inlet temperature and air/fuel ratio equal to 273 K and 60, respectively, and these values are 62.09% and 54.91%.     

Numerical modeling and optimization of a power augmented S-type vertical axis wind turbine

An axial symmetry augmented vertical axis wind turbine, which is suitable for arbitrary wind directions, is proposed in this paper. In order to improve the power generation ability of the S-type vertical axis wind turbine, a set of so-called “collection-shield boards” are installed symmetrically around the rotating S-type rotor. The flow fields around this type of wind turbine are numerically simulated with the aid of CFD method. The optimized design of geometrical parameters of the rotor and collection-shield boards is conducted by using the orthogonal design method. The obtained results suggest that the power output of the optimized augmented wind turbine can reach nearly three times higher than that of the conventional S-type vertical axis wind turbine.     

我国大型火电机组FGD未来发展方向探讨

针对大型火电机组FGD未来发展方向,对我国近年来火电厂烟气脱硫标准及FGD技术发展进行了回顾、分析,结论是随着国家环保标准的不断提高,必须为大机组FGD设备裕度考虑一定的空间,火电厂FGD将向多元化发展,湿式烟气脱硫(WFGD)将向BOT模式、规范化和大型化发展.     

电力行业实行二氧化硫排污交易浅析

本文介绍了排污权交易在国内外的发展进程及现状。分析了我国电力行业实行二氧化硫排污交易的可行性，同时指出该交易体系目前存在的初始排污权分配、环境公平性、交易市场以及政府职能等问题；建议我国应在借鉴国外成功经验的基础上，结合我国实际情况逐步建立二氧化硫排污权交易的完整的市场体制，并完善相关政策，扩大交易范围。     

森林类型对森林火灾自组织临界性的影响

在真实的森林系统中，由于外界因素的复杂性，森林火灾的自组织临界性要受到影响。森林类型便是影响森林火灾自组织临界性的一个重要因素。本文研究了以密度为控制参数的森林火灾模型以及这个模型在森林密度不同时产生的相变行为，发现对过于稀疏或者过于密集的森林类型，森林火灾的分布会偏离甚至完全背离幂律关系，从而使得自组织临界性不再满足。