秸秆直燃发电系统的生命周期评价

以装机容量25 MW的生物质秸秆直燃发电系统为评价对象,进行生命周期评价.结果表明,秸秆直燃发电1万kWh,可吸收CO2 2502.87 kg,向环境排放SO237.39 kg,NOx90.37 kg,与燃煤发电相比,虽然氮氧化物的排放量有所增加,但减少了温室气体及硫氧化物的排放,污染物的排放主要发生在秸秆燃烧阶段.每发电1万kWh消耗能量15 340.2 MJ,秸秆预处理阶段是能量消耗的主要阶段,须要输入能量13 830.5MJ.秸秆直燃发电过程对环境影响的总负荷为35.18人当量.在此过程中,烟尘居环境影响总负荷的首位.     

燃生物质颗粒工业锅炉系统的生命周期评价

为了研究生物质工业锅炉系统对环境影响和能源消耗情况,本文采用了生命周期(LCA)的研究方法,从该系统的原料生产制作,到系统建立运行进行全面分析。结果表明:处理每1 t生物质颗粒,对环境的总影响负荷为16 434.47毫人当量,资源耗竭系数为2.547毫人当量,燃生物质工业锅炉系统对环境影响主要为全球变暖为95.36%,各个过程中锅炉系统运行影响为98.55%,秸秆种植从环境中吸收CO22 136.24 kg,因此,燃生物质工业锅炉系统在减少温室气体排放上能起积极作用,与燃煤锅炉相比生物质锅炉是一种环境友好并且减少化石燃料消耗的项目。     

生物质气化合成-尾气发酵制备混合醇系统■及环境影响分析

以林业废弃木屑为原料，构建经气化、合成气催化合成、尾气发酵制乙醇的混合醇制备新工艺模型，对系统物质和能量流动、系统/子系统■效率及损失来源进行分析。通过收集林业、收储运、制备和产品运输等不同阶段的资源能量消耗和排放清单，对包括全球变暖潜值、臭氧层耗竭潜值等9种环境影响类型开展分析。结果表明：尾气发酵子系统，可利用微生物菌株代谢尾气中CO和CO₂来制备乙醇，结合催化合成高级醇的高产率，使得耦合系统混合醇质量收率和■效率分别达0.328 kg/kg木屑和43.8%。混合醇生命周期内，人体非致癌损害和陆地生态毒性是受影响较大的环境类型，分别来源于制备和收储运阶段。     

秸秆直燃发电的生命周期评价

应用生命周期评价(LCA)方法,以秸秆直燃发电项目为研究对象,对秸秆的种植、运输、粉碎干燥和燃烧发电等4个过程进行了清单分析,并分别计算出4个过程的能耗及其对环境的影响.结果表明,每燃烧100kg秸秆发电,对环境的总影响负荷水稻秸为247.36毫人当量,小麦秸为268.74毫人当量,玉米秸为267.33毫人当量.秸秆直燃发电对环境影响主要为烟尘和灰尘,对局部地区的影响占据首位.以水稻秸秆为例,100kg水稻秸秆在直燃发电过程中整个系统共从环境吸收CO2167.60kg,向环境释放CO2164.24kg,由此看到,秸秆直燃发电项目在减少温室气体排放上能起积极作用.     

基于生物质气化耦合发电的气化特性实践研究

在10 MW级生物质气化耦合燃煤发电工程项目上,考察了当量比、添加蒸汽、掺混秸秆对稻壳气化特性的影响。在当前的实验条件下,随着当量比在0. 14～0. 20的范围内增加时,CO、H_2和CH_4的体积分数均随之减少,燃气热值和气化效率也随当量比的增大而降低;添加适量蒸汽可以促进CO、H_2和CH_4及燃气热值的提高,气化效率则随蒸汽量的增加而升高;当秸秆掺混比例逐渐增加时,CO、H_2和CH_4的体积分数和燃气热值出现了不同程度的下降,气化效率也不断降低。     

生物质快速热裂解系统生命周期评估

以流化床快速热裂解制取生物油系统为研究对象,确立系统边界,对其进行全生命周期评估,讨论整个系统在全生命周期中的能耗、全球变暖潜值、酸化潜能及其他环境影响潜值。计算得到系统制取生物油在生命周期中的净能量值为0.68 MJ/MJ,全球变暖潜值为0.0565 CO2-Equiv.kg/MJ,与其他液体燃料相比更具环境友好性;对环境影响潜值进行标准化和加权结果计算,全面显示系统不同部分对环境的影响。     

10 MW生物质气化耦合燃煤机组发电装置性能试验研究

某电厂生物质气化耦合燃煤机组发电项目于2018年9月8日完成72 h满负荷试运,项目主体是循环流化床气化耦合系统及附属设备,为评价该耦合系统的综合性能,进行了额定负荷下的产气率、气化效率、热效率及对燃煤机组煤耗影响等性能试验。试验结果表明:额定负荷下,生物质气化耦合系统以50%稻壳+50%秸秆作为原料时,燃料量为8. 61 t/h,产气率为2. 09 m~3/kg,气化效率为70. 53%,热效率为87. 65%;以100%稻壳作为原料时,燃料量为8. 57 t/h,产气率为2. 15 m~3/kg,气化效率为70. 04%,热效率为88. 12%;气化耦合系统在75%～110%负荷范围内可稳定运行;气化耦合系统额定负荷、燃煤机组维持600 MW负荷的情况下,投运气化耦合系统后,减少标煤量3 291 kg/h;气化耦合系统额定负荷、燃煤机组维持500 MW负荷的情况下,投运气化耦合系统后,减少标煤量3 122 kg/h。     

不同生物质原料的气化合成制航煤的环境影响评价

采用生命周期评价方法对玉米秸秆、稻壳和杨木3种生物质的气化合成航空煤油工艺路线进行环境影响评价。选取全球变暖、酸化、富营养化、光化学污染、人体毒性和固体废弃物6种环境影响类型，对3种工艺路线的全生命周期进行环境影响潜值计算。计算结果表明：系统全生命周期中生产阶段排放最多的是CO2，占比为69.13%～74.36%；运输阶段环境影响最小，在各环境影响潜值中占比不足7%；玉米秸秆是3种生物质中环境影响最小的原料，减少费托合成反应器的耗电量可降低玉米秸秆工艺的环境影响。     

基于生命周期法的电站锅炉静电除尘器环境影响评价

静电除尘器在我国电厂烟尘减排中广泛应用,运用生命周期法(exergy life cycle assessment,ELCA),以某电厂600 MW锅炉的静电除尘器为研究对象,对钢铁生产和运输及静电除尘器运行3个过程进行清单分析,计算不同过程能源消耗及环境影响。结果表明:每年烟气直接排入大气造成的环境影响潜值为2 575 894.44人当量,但静电除尘器可以将其环境影响潜值降低到4 052.95人当量。因此,静电除尘器可以有效改善环境影响。     

混合动力汽车的全生命周期评价

运用生命周期评价方法,以一款非插电式混合动力汽车为研究对象,从制造、使用、报废3个阶段进行了全生命周期评价,得到加权平均后的资源耗竭系数为1.0169mPR90,总环境影响负荷为28.005人当量,与传统的燃油汽车比较,可节省资源28.9%、减少污染35.16%。敏感性分析结果表明：再生材料的使用对降低混合动力汽车制造过程资源消耗与环境影响有积极作用。     

基于电锅炉的火电机组灵活性改造技术研究

为有效解决东北电力产能过剩,促进风电、核电等清洁能源消纳问题,提升燃煤供热机组的灵活性,针对东北地区某热电厂,通过对热电解耦时间、电锅炉型式以及不同电锅炉容量配置对机组实际发电负荷的影响等灵活性改造关键技术进行研究,确定了最佳电锅炉容量,提出了电锅炉装设方案,并对改造前后机组的调峰能力和性能指标进行对比分析。研究表明:随着电锅炉容量增长,抵减电锅炉用电后机组实际发电负荷率显著降低,提升火电机组灵活性改造后,电厂调峰能力显著提升,考虑以全厂172 MW发电负荷运行,电厂调峰能力在采暖初末期增加了368 MW,采暖中期增加了528 MW;全厂供热标煤耗由39.7 kg/GJ降低至34.3 kg/GJ,降低了5.4 kg/GJ;经济效益显著,扣除电锅炉用电成本后1个采暖季的调峰辅助服务补贴收益为1.47亿元;同时,电锅炉投运后可实现电厂的上网电量接近零,为清洁能源就地消纳做出贡献。     

抽凝机组耦合热电转换辅助调峰系统参数设计

  目的  为适应新能源电力并网需求,原有抽凝热电联产机组深度调峰供热改造已为重要途径之一。现有包括电热泵和电锅炉在内的热电转换装置为辅助火电机组调峰提供了潜在途径。  方法  以350 MW抽凝机组为例,建立了以热电转换装置辅助调峰参数优化模型,重点分析了热电转换设备参数对深度调峰性能的影响;其次,分别对比了电热泵和蓄热电锅炉两种典型热电转换系统在不同装置容量、不同放热速率下的调峰深度;最后,介绍了300 MW燃煤机组的煤耗率与污染物排放水平,指出本系统的节能效益,并给出热电转换装置的最优参数。  结果  结果显示:当电热泵的热功率为100 MW、放热速率与热功率相匹配也为100 MW时,机组的调峰深度达到最大值,为73 MW左右;当蓄热式电锅炉的电功率为45 MW、放热速率为100 MW时,机组的调峰深度达到最大值,为70.05 MW。蓄热式电锅炉的储热量在24 h中内略有增加,净储热量的数值为967.5 kWh。  结论  功率和放热速率是衡量热电转换装置辅助机组调峰能力的重要参数,且二者之间要有一定程度上的匹配性,针对不同情景灵活匹配热电转换装置的类型与参数可大幅提升机组的调峰深度。     

A scenario for geothermal electric power development in Imperial Valley

The growth of geothermal electric power operations in Imperial Valley, California is projected over the next 40 yr. With commercial power forecast to become available in the 1980s, the scenario considers three subsequent growth rates of 40, 100 and 250 megawatts (MW) per year. These growth rates, along with estimates of the total resource size, result in a maximum level of electric power production ranging from 1000 to 8000 MW to be attained in the 2010 to 2020 time period. Power plant siting constraints are developed and used to make siting patterns for the 400 through the 8000 MW level of power production. Two geothermal technologies are included in the scenario: flashed steam systems which can produce their own cooling water from the geothermal steam condensate and which emit noncondensable gases to the atmosphere; and high pressure, confined flow systems which inject all the geothermal fluid back into the ground. An analysis of the scenario is made with regard to well drilling and power-plant construction rates, land use, cooling water requirements, and hydrogen sulfide emissions.     

Indonesian geothermal development in the national energy scenario. Development program to the year 2000

The electric power sector in Indonesia will be expanded with an additional generating capacity of about 5256 MW at the end of the Fourth Five-Year Development Plan 1984/85 — 1988/89 from the existing 3912 MW. At present a 30 MW geothermal condensing plant and two non-condensing of 2 MW and 0.25 MW have been operating successfully since 1983. Geothermal energy will be developed primarily for electric power and a total of 220 MW and 660 MW will be added during the 4th (1984 — 89) and 5th (1989 — 94) Five Year Plans, reaching a total capacity of nearly 1000 MW. The government will accelerate geothermal exploration of 18 areas in Sumatera, 29 in Java, 16 in Sulawesi and 14 areas in Bali, the Lesser Sunda islands and Moluccas.     

能量系统的_经济学分析通用模型及其在电厂中的应用

在电厂的运行中,一些主要参数经常偏离设计值,如何研究这些偏离对整个机组经济性的影响,是进行电厂经济分析的一项基础性工作。本文根据热经济学最前沿的理论,西班牙学者Valero提出的“符号(火用)经济学”,建立了能量系统的朋经济学分析模型,并将其运用于国产200MW机组,取得了满意效果。     

Power system optimization

Long-term gas purchase contracts usually determine delivery and payment for gas on the regular hourly basis, independently of demand side consumption. In order to use fuel gas in an economically viable way, optimization of gas distribution for covering consumption must be introduced. In this paper, a mathematical model of the electric utility system which is used for optimization of gas distribution over electric generators is presented. The utility system comprises installed capacity of 1500 MW of thermal power plants, 400 MW of combined heat and power plants, 330 MW of a nuclear power plant and 1600 MW of hydro power plants. Based on known demand curve the optimization model selects plants according to the prescribed criteria. Firstly it engages run-of-river hydro plants, then the public cogeneration plants, the nuclear plant and thermal power plants. Storage hydro plants are used for covering peak load consumption. In case of shortage of installed capacity, the cross-border purchase is allowed. Usage of dual fuel equipment (gas–oil), which is available in some thermal plants, is also controlled by the optimization procedure. It is shown that by using such a model it is possible to properly plan the amount of fuel gas which will be contracted. The contracted amount can easily be distributed over generators efficiently and without losses (no breaks in delivery). The model helps in optimizing of fuel gas–oil ratio for plants with combined burners and enables planning of power plants overhauls over a year in a viable and efficient way.     

Availability growth models and verification of power equipment

The general availability growth models for large scale complicated repairable system such as electric generating units, power station auxiliaries, and transmission and distribution installations are presented. The calculation formulas for the maintenance coefficient, mathematical expressions for general availability growth models, ways for estimating, and fitting on checking the parameters of the model are introduced. Availability growth models for electric generating units, power station auxiliaries, and transmission and distribution installations are given together with verification examples for availability growth models of 320–1000 MW nuclear power units and 1000 MW thermal power units, 200–1000 MW power station auxiliaries, and 220–500 kV transmission and distribution installations. The verification results for operation availability data show that the maintenance coefficients for electric generating units, power station auxiliaries, transmission and distribution installations conform to the power function, and general availability growth models conform to rules of availability growth tendency of power equipment.     

Wind power generation with a parawing on ships,a proposal

It is proposed that electric power can be generated from wind by pulling a ship. A parafoil pulls and tows a ship. Electrical power is generated by hydraulic turbines installed on the ship below the water line. The electric power generated is expended onboard to electrolyze water to produce hydrogen or methanol or to convert carbon dioxide into storable forms of liquid. This paper describes the principle of designing such a system, shows the general features of such a system, and describes in detail two example designs which produce 6 MW and 0.8 GW. It is shown that a fleet of such ships operating in two different regions of the sea can produce much more energy than the world needs.     

Autonomous frequency regulation by controllable loads to increase acceptable wind power generation

Output power fluctuation of high penetration of wind power causes demand and supply imbalance in electric power systems and results in frequency deviation if the fluctuation is not fully compensated by other regulable power plants. In Japan, some electric utilities have started to accept only the wind farms which disconnect and give up generating power during light‐load periods with less adjustable reserve. Otherwise, wind farms are required to employ battery energy storage systems (BESSs) to charge the generated power during the light‐load periods. Instead of these uneconomical solutions, this paper proposes autonomous frequency regulation by controllable loads such as electric water heaters (EWHs). In the paper, the acceptable increase of wind power generation by the proposed load control has been evaluated quantitatively in the power system of the Hokkaido Island in Japan. The result indicates that the acceptable increase of wind power generation goes from 250 to 675 MW by applying the proposed autonomous frequency regulation on all EWHs, and the total cost to implement the autonomous frequency regulation on the EWHs is around 1/26 compared with a solution using BESSs. Copyright © 2009 John Wiley & Sons, Ltd.     

Wind electric power in the world and perspectives of its development in India

The global market for wind power is expanding faster than any other source of renewable energy. From just 4,800 MW in 1995 raise to fifteen-fold to reach 73,904 MW at the end of 2006. Top five wind electric power generating countries at the end of 2006 were Germany, Spain, United States of America (USA), India and Denmark. Since 1980s, when the first commercial wind turbine was deployed, their capacity, efficiency and visual design have all improved a lot. A modern wind turbine annually produces 180 times more electricity at less than half the cost per unit (kWh) than its equivalent twenty years ago. The largest turbines being manufactured now are of rated power of 5 MW capacity and a rotor diameter of 126 m. Modern turbines are modular and quick to install, whilst wind farms vary in size from a few MW to several hundred MW. Keeping these factors in view, an attempt has been made in this paper to present current advances in wind turbine generator technology. Wind energy scenario in the world in general and in India in particular have been presented. Further the cost components of wind turbine electric generation system have been included.