关键词： 机械设备   成本   商业   生产设备   财政管理   本位币   美元   热水系统   生物质能   经济   能源系统   太阳能热动力系统   平板集热器   英热单位   美利坚合众国   北美洲   美国   低温食品  

摘要： 太阳能热系统太阳能热系统能为家庭、农业与工业加工提供热水或热空气,用于谷物干燥、制浆、低温食品加工等。其中家庭应用较多的是烧水和炊事。其它还有制淡水和致冷。平板集热器供热温度能达到93℃,而真空管集热器则可达到约177℃。如用温不高,也可直接利用太阳能浅池。平板和真空管集热器已商品化生产,渗透到美国住宅和商业大楼采暖等市场。在以色列、奥大利亚、日本、美国等有几千只热水系统在运行。实践证明,太阳能热水系统与常规的热水系统一

关键词： 能源   森林   美国   美利坚合众国   北美洲   木材燃料   不发达国家   生物质能  

摘要： 1973年石油危机以来,由于石油供应紧张,国外对森林能源利用的分析研究工作发展很快,受到世界各方专家的重视。现在将一些国家的木材能源的情况简述于下:美国:据美国能源部估计,目前生物质能在全国能源中约占2.5%。主要是燃烧木材,供家庭煮饭和取暖;其次是有机废水厌气消化产生沼气,供发电、动力和加热用,这方面已达到工业化的规模。美国生物质资源潜力很大,每年消耗的生物质只相当于1.8科特~*热量,据能源部估计,还有9科特的生物质未被利用。七十年代之后,美国开始注意生物质能的利用,到目前为止,已有几百个单位参与有关课题的研究,有11个不同的

关键词： 溶解物   生活污水   脱气器   隔膜泵   往复式容积泵   减湿   化工单元操作   双流体   排水管   消气剂  

关键词： 化学制品   碳酸盐硬度   暂时硬度   收集器   混凝土   无机非金属材料   砌砖工   球形   热水器   托架   火炮构件   土木建筑   聚光镜   盘管   链条   围堰   空腔  

关键词： 美元   投资   美国   本位币   财政管理   美利坚合众国   北美洲   能源利用   太阳能利用   太阳电池   太阳光发电系统   生物质能   能源   太阳能热电站   产量   生产量   小型风力机   废物处理装置   沼气池  

摘要： 本文概述了太阳能利用近年来的发展历史和现状,对太阳能利用的前景进行了评论。分析表明,下一个世纪太阳能将成为主要能源之一,当前在我国农村利用太阳能更有实际意义。

关键词： 生物质能   生活用能   习惯   道德修养  

摘要： 我们国家多少年来一直把烧大柴做为生活的主要能源,这是很不科学的,严重地影响了农业生态的良性循环.据有关部门计算,农村生活用能占全国总耗能量的40%以上,而且耗能量中有3/4是生物质能,其中大约80%是消耗在生活用能上.全国农村每年大约要烧掉4亿吨秸秆和柴草.据计算,秸秆燃烧转换率是10%,薪柴也只有15%,这是一个极大的浪费.

关键词： 沼气   能源   资源   制取   作物   甲烷   农村发展   生物质能  

摘要： 农村发展沼气,是一项重要的能源建设、肥源建设、环境保护和卫生建设,是农田基本建设的内容,是实现农业现代化的一项战略性措施。一、我国农村生活燃料严重缺乏在工业发达的国家,农业人口比例很小,农村需原

摘要： The concept of Sustainable Development is an interdisciplinary science. Transcending various academic fields the concept shows paths how the needs of present and future generations can be met through economic development on a finite natural resource base. Global warming and rising sea levels are just two of a series of phenomena that are directly attributable to human-induced increasing greenhouse gas levels in the atmosphere as consequence of the combustion of fossil fuels. Therefore, reducing greenhouse gas emissions through the use of renewable resources such as bioenergy are of vital importance if detrimental environmental effects are to be mitigated. The production of biogas in a decentralized context is receiving much attention in Germany as a means to reduce greenhouse gases and to counteract correlated negative environmental effects, respectively. In addition, socio-economic benefits such as local employment creation have the potential to empower rural communities. Subsidised by the German Renewable Sources Act and its various remuneration schemes, two 500kWel CHP biogas plants are producing through anaerobic digestion of maize silage and manure electricity and heat in the East German village Bollewick, which is the case study. The sustainability of this decentralized system is analyzed by applying a set of indicators. Socio-economic benefits for the population, economic efficiency of the digestion process and impacts of substrate costs on the profitability, greenhouse gas emissions due to land use change and biodiversity loss being some of these indicators. The thesis concludes that none of the sustainability indicators are sufficiently fulfilled in Bollewick. Especially the cultivation of the energy crop maize has despite crop rotations immense negative environmental effects. Therefore, the decentralized biogas production in the rurally coined village Bollewick is not sustainable.

摘要： This project developed a new method to address sustainability aspects relevant to the location of biomass energy plants. The method is based on an integrated geographical information system model to identify optimal sites for biomass energy supply, incorporating spatial biomass availability, and economic, environmental and biomass specific uncertainties in the biomass supply chain. The analysis was carried out in Queensland, Australia as a case study, demonstrating the potential of multiple biomass sources for biomass energy supply.

摘要： A theoretical and experimental study of pyrolysis of charring material applicable to fire safety and biomass utilization is presented in this thesis. This work is divided into three parts. In the first part, thermal decomposition and pressure generation in charring solids undergoing opposed-flow flame spread is numerically studied with a detailed physics- based model. The result indicates that the char density and product yields are functions of depth due to an insulating char layer. The characteristics of various simplifying model assumptions such as global reaction, infinite rate kinetics and no convective gas transport were examined. In the second part, a method of determining the pyrolysis temperature by enforcing mass and energy balance is proposed and validated by comparison with the decomposition kinetics model and the experiments. This pyrolysis temperature has the form of pyrolysis rate weighted average temperature for the entire charring process. Heat flux, sample size, heat of pyrolysis and kinetic parameters are the most important for determining an appropriate pyrolysis temperature. A non-dimensional correlation to determine an appropriate was proposed. Excellent agreement between the pyrolysis front model using the correlation and experimental data of wood cylinder pyrolysis was achieved. Finally, pyrolysis of wood sphere is studied both experimentally and theoretically. Weight loss and temperatures of the sample were measured during the experiments. Center temperature showed two distinct thermal behaviors with endothermic and exothermic reactions. The numerical study revealed the following findings: (i) Contribution of secondary tar decomposition and lignin decomposition to the temperature peak are small. (ii) Exothermic intermediate solid decomposition is responsible for the temperature peak. (iii) The temperature plateau is caused by endothermic cellulose decomposition. Based on the experimental and numerical results, a novel wood pyrolysis model is