Biomass Combined Heat and Power Generation for Anticosti Island: A Case Study

Combined heat and power (CHP) plants (co-generation plants) using biomass as fuel, can be an interesting alternative to the predominant electrical heating in Canada. The biomass-fueled boiler provides heat for the steam cycle which in turn generates electricity from the generator connected to the steam turbine. In addition, heat from the process is supplied to a district heating system. The heat can be extracted from the system in a number of ways, by using a back-pressure steam turbine, an extraction steam turbine or by extracting heat directly from the boiler. The objective of the paper is the design, modeling and simulation of such CHP plant. The plant should be sized for providing electric-ity and heat for the Anticosti Island community in Quebec.

Water, Air Emissions, and Cost Impacts of Air-Cooled Microturbines for Combined Cooling, Heating, and Power Systems： A Case Study in the Atlanta Region

The increasing pace of urbanization means that cities and global organizations are looking for ways to increase energy efficiency and reduce emissions. Combined cooling, heating, and power （CCHP） systems have the potential to improve the energy generation efficiency of a city or urban region by providing energy for heating, cooling, and electricity simultaneously. The purpose of this study is to estimate the water consumption for energy generation use, carbon dioxide （CO2） and NOx emissions, and economic impact of implementing CCHP systems for five generic building types within the Atlanta metropolitan region, under various operational scenarios following the building thermal （heating and cooling） demands. Operating the CCHP system to follow the hourly thermal demand reduces CO2 emissions for most building types both with and without net metering. The system can be economically beneficial for all building types depending on the price of natural gas, the implementation of net metering, and the cost structure assumed for the CCHP system. The greatest reduction in water consumption for energy production and NOx emissions occurs when there is net metering and when the system is operated to meet the maximum yearly thermal demand, although this scenario also results in an increase in greenhouse gas emissions and, in some cases, cost. CCHP systems are more economical for medium office, large office, and multifamilv residential buildings.

Optimal Scheduling Method of Cogeneration System with Heat Storage Device Based on Memetic Algorithm

Electric-heat coupling characteristics of a cogeneration system and the operating mode of fixing electricity with heat are the main reasons for wind abandonment during the heating season in the Three North area.To improve the wind-power absorption capacity and operating economy of the system,the structure of the system is improved by adding a heat storage device and an electric boiler.First,aiming at the minimum operating cost of the system,the optimal scheduling model of the cogeneration system,including a heat storage device and electric boiler,is constructed.Second,according to the characteristics of the problem,a cultural gene algorithm program is compiled to simulate the calculation example.Finally,through the system improvement,the comparison between the conditions before and after and the simulation solutions of similar algorithms prove the effectiveness of the proposed scheme.The simulation results show that adding the heat storage device and electric boiler to the scheduling optimization process not only improves the wind power consumption capacity of the cogeneration system but also reduces the operating cost of the system by significantly reducing the coal consumption of the unit and improving the economy of the system operation.The cultural gene algorithm framework has both the global evolution process of the population and the local search for the characteristics of the problem,which has a better optimization effect on the solution.

New generation traction power supply system and its key technologies for electrified railways

Unlike the traditional traction power supply system which enables the electrified railway traction sub- station to be connected to power grid in a way of phase rotation, a new generation traction power supply system without phase splits is proposed in this paper. Three key techniques used in this system have been discussed. First, a combined co-phase traction power supply system is applied at traction substations for compensating negative sequence current and eliminating phase splits at exits of substations; design method and procedure for this system are presented. Second, a new bilateral traction power supply technology is proposed to eliminate the phase split at section post and reduce the influence of equalizing current on the power grid. Meanwhile, power factor should be adjusted to ensure a proper voltage level of the traction network. Third, a seg- mental power supply technology of traction network is used to divide the power supply arms into several segments, and the synchronous measurement and control technology is applied to diagnose faults and their locations quickly and accurately. Thus, the fault impact can be limited to a min- imum degree. In addition, the economy and reliability of the new generation traction power supply system are analyzed.

Diesel generator exhaust heat recovery fully-coupled with intake air heating for off-grid mining operations:An experimental,numerical,and analytical evaluation

The customarily discarded exhaust from the fossil fuel-based power plants of the off-grid mines holds the thermal potential to fulfill the heating requirement of the underground operation.This present research fills in an important research gap by investigating the coupling effect between a diesel exhaust heat recovery and an intake air heating system employed in a remote mine.An integrative approach comprising analytical,numerical,and experimental assessment has been adapted.The novel analytical model developed here establishes the reliability of the proposed mine heating system by providing comparative analysis between a coupled and a decoupled system.The effect of working fluid variation has been examined by the numerical analysis and the possible improvement has been identified.Experimental investigations present a demonstration of the successful lab-scale implementation of the concept and validate the numerical and analytical models developed.Successful deployment of the fully coupled mine heating system proposed here will assist the mining industry on its journey towards energy-efficient,and sustainable mining practices through nearly 70%reduction in fossil fuel consumption for heating intentions.

电力市场环境下生物质气化耦合燃煤机组与风电场联合自调度优化策略

利用生物质气化耦合燃煤发电技术可以提升火电机组的燃料及运行灵活性,从而促进风电的高水平消纳,同时实现生物质能的有效开发利用。该文首先建立反映生物质气化耦合热电联产机组内部能流过程和外部出力特性的运行模型。然后,从能源供应商视角出发,给出耦合机组与风电场联合参与日前、日内和实时平衡市场的多阶段决策框架,提出反映联合体期望收益和条件风险价值的多目标自调度策略。最后,利用基于字典优化框架的增强ε约束法,给出构建帕累托前沿的多目标优化求解流程。以一台350 MW燃煤热电联产机组和一座600 MW风电场构成的联合体为例进行分析。结果可知,增设生物质气化子系统和联合运行能够使其经济效益提升6%左右,同时有利于降低能源供应商的运营风险。

基于压缩空气储能与增强型地热的三联产系统热力学分析

为提升压缩空气储能技术的能量利用率与供能灵活性,基于能量梯级利用原理,提出了一种耦合压缩空气储能与增强型地热技术的冷热电联产系统。通过建立系统的热力学模型,研究了关键运行参数对系统热力学性能的影响规律,并以系统(火用)效率和单位能量成本为目标函数,获得了系统的多目标优化解集。结果表明,膨胀机与换热器是系统高效运行的关键设备,提升这2个设备的运行效率对于系统热力学性能以及输出功量的提升作用显著,采用多目标优化方法得到系统的最优(火用)效率为55.73%,最优单位能量成本为6378.94元/kW,能量效率和相对节能率较设计工况分别提升了6.1%和10.68%。研究结果从热力学和经济学角度为系统的工程应用提供了理论依据。

Biomass gasification technology:The state of the art overview

In the last decades the interest in the biomass gasification process has increased due to the growing attention to the use of sustainable energy. Biomass is a renewable energy source and represents a valid alternative to fossil fuels. Gasification is the thermochemical conversion of an organic material into a valuable gaseous product, called syngas, and a solid product, called char. The biomass gasification represents an efficient process for the production of power and heat and the production of hydrogen and second-generation biofuels.This paper deals with the state of the art biomass gasification technologies, evaluating advantages and disadvantages, the potential use of the syngas and the application of the biomass gasification. Syngas cleaning though fundamental to evaluate any gasification technology is not included in this paper since; in the authors＇ opinion, a dedicated review is necessary.

CO_(2)Plume Geothermal(CPG)Systems for Combined Heat and Power Production:an Evaluation of Various Plant Configurations

CO_(2) Plume Geothermal(CPG)systems are a promising concept for utilising petrothermal resources in the context of a future carbon capture utilisation and sequestration economy.Petrothermal geothermal energy has a tremendous worldwide potential for decarbonising both the power and heating sectors.This paper investigates three potential CPG configurations for combined heating and power generation(CHP).The present work examines scenarios with reservoir depths of 4 km and 5 km,as well as required district heating system(DHS)supply temperatures of 70℃ and 90℃.The results reveal that a two-staged serial CHP concept eventuates in the highest achievable net power output.For a thermosiphon system,the relative net power reduction by the CHP option compared with a sole power generation system is significantly lower than for a pumped system.The net power reduction for pumped systems lies between 62.6%and 22.9%.For a thermosiphon system with a depth of 5 km and a required DHS supply temperature of 70℃,the achievable net power by the most beneficial CHP option is even 9.2%higher than for sole power generation systems.The second law efficiency for the sole power generation concepts are in a range between 33.0%and 43.0%.The second law efficiency can increase up to 63.0%in the case of a CHP application.Thus,the combined heat and power generation can significantly increase the overall second law efficiency of a CPG system.The evaluation of the achievable revenues demonstrates that a CHP application might improve the economic performance of both thermosiphon and pumped CPG systems.However,the minimum heat revenue required for compensating the power reduction increases with higher electricity revenues.In summary,the results of this work provide valuable insights for the potential development of CPG systems for CHP applications and their economic feasibility.

Operation Strategy Analysis and Configuration Optimization of Solar CCHP System

This paper proposed a new type of combined cooling heating and power(CCHP)system,including the parabolic trough solar thermal(PTST)power generation and gas turbine power generation.The thermal energy storage subsystem in the PTST unit provides both thermal energy and electrical energy.Based on the life cycle method,the configuration optimization under eight operation strategies is studied with the economy,energy,and environment indicators.The eight operation strategies include FEL,FEL-EC,FEL-TES,FEL-TES&EC,FTL,FTL-EC,FTL-TES,and FTL-TES&EC.The feasibility of each strategy is verified by taking a residential building cluster as an example.The indicators under the optimal configuration of each strategy are compared with that of the separate production(SP)system.The results showed that the PTST-CCHP system improves the environment and energy performance by changing the ratio of thermal energy and electric energy.The environment and energy indicators of FEL-TES&EC are superior to those of FTL-TES&EC in summer,and the results are just the opposite in winter.The initial annual investment of the PTST-CCHP system is higher than that of the SP system,but its economic performance is better than that of the SP system with the increase of life-cycle.

Schedule for Reducing the Use of Peat and the Possibilities of Replacing It with Forest Chips in Energy Production in Finland

Between 2018 and 2020, an average of 15 TWh of energy peat was consumed in Finland. Energy peat is used in 260 boilers in Finland, which produce district heat and heat and steam for industry, as well as electricity as cogeneration (CHP) in connection with district heating and industrial heat production. Peat accounts for 3% - 5% of the energy sources used in Finland, but its importance has been greater in terms of security of supply. With current use in accordance with the 2018-2020 average, the emissions from peat are almost 6 Mt CO2 per year in Finland, which is 15% of emissions from the energy sector. In this study, the technical limitations related to peat burning, economic limitations related to the availability of biomass, and socio-economic limitations related to the regional economy are reviewed. By 2040, the technical minimum use of peat will fall to 2 TWh. The techno-economical potential may be even lower, but due to socio-economic objectives, peat production will not be completely ceased. The reduction in the minimum share assumes that old peat boilers are replaced with new biomass boilers or are alternatively replaced by other forms of heat production. Based on the biomass reserves, the current use of peat can be completely replaced by forest chips, but regional challenges may occur along the coast and in southern Finland. It is unlikely that the current demand for all peat will be fully replaced by biomass when part of CHP production is replaced by heat production alone and combustion with waste heat sources.

考虑碳捕集技术的虚拟电厂热电联合优化

碳捕集技术作为电力系统低碳转型的关键技术,应用到热电联合系统可降低虚拟电厂的碳排放。为此,提出将碳捕集技术应用至虚拟电厂热电联合优化的技术路线,以促使其低碳经济运行。一方面,依托阶梯碳交易机制、需求响应和电-热之间的互转,以减少虚拟电厂热电联合运行的碳排放;另一方面,以虚拟电厂运行成本最小为目标,综合考虑负荷调节潜力、新能源出力上限等虚拟电厂内部约束,以及电-热-碳互转的物理约束,以提高虚拟电厂运行经济性。基于某园区实况运行数据,围绕是否配置碳捕集技术和需求响应来设计对照场景,验证了所提虚拟电厂热电联合优化模型具有一定的现实可用性和鲁棒性。

石化行业CO_(2)排放核算与减排技术进展

全面细致地进行CO_(2)排放核算是炼化企业挖掘碳减排潜力、升级碳减排技术、实现“双碳”目标的基础依据。综述了国内外石化行业CO_(2)排放的核算方法与减排技术,重点介绍了CO_(2)排放核算模型、核算方法、核算指南与规范,以及基于核算结果的CO_(2)减排技术,分析了国内外大型炼化企业CO_(2)排放核算成果、减排技术效果及发展趋势,以期为炼化企业在转型发展、节能降耗、CO_(2)减排和利用等方面提供借鉴。

计及环境成本的含储能冷热电联供系统多目标优化和运行策略研究

冷热电联供(combined cooling,heating and power,CCHP)系统能够同时满足用户冷热电负荷需求,实现热量梯级利用和能量高效供给。但CCHP系统内部能量耦合程度高,各种能量间相互影响,为CCHP系统的容量配置和能量高效供给带来挑战。为此,建立了含储能和可再生能源的CCHP系统,提出2种余热优先利用运行策略,采用多目标遗传算法对系统设备容量进行优化确定,并对各类运行指标进行分析。结果表明:运行策略二(回收余热优先供热)的“3E”综合指标为0.344高于运行策略一(回收余热优先制冷);运行策略二的年值节约率为4.5%经济性优于运行策略一;运行策略二的各类污染物减排率均高于运行策略一,表现出良好的环境效益。

燃料电池分布式冷热电联供技术的研究及应用

燃料电池分布式多联供技术(冷热电联供)具有高效、超低废气排放量、低噪声等优点,应用前景广阔。综述了燃料电池分布式冷热电联供技术的研究和应用现状,从技术角度将两种处于优势地位的燃料电池(PEMFC和SOFC)在建筑物中的应用进行了对比分析,并指出了燃料电池分布式多联供技术的研究方向。

公用事业的多产品定价与政府规制:由上海观察

上海电力公司热电联供的热力价格调整案例表明,完全分配成本法可能会导致共同成本在热力与电力产品问的不合理分摊。而激励问题的存在将加剧共同成本的不合理分摊状况,最终结果是用户的福利受到损失。同时。政府的规制行为受到特定利益集团间的竞争驱动,并且规制者自身有着特定的利益目标,最终规制政策的出台实质上是利益集团间的博弈均衡。为此,寻求更为合理的多产品价格规制方法,以及如何保证利益集团博弈中的规制均衡成为一种社会合意的结果,成为多产品公用事业政府规制改革中的重要问题。

分布式供能技术的发展现状与展望

在能源结构调整中,分布式供能技术引起了世界能源界的广泛关注,在国家大电站和电网能基本保证供电的情况下,分布式供能和中央电站供能的结合,对于保障国家供应和经济的发展将发挥重要作用。对分布式供能、分布式电力、分布式能源资源的概念进行了详细的说明,指出分布式供能技术就是以一些小型发电设备技术进步为依托,以靠近用户侧建立小型电站为主,并结合热电(冷)联产等应用拓展为前提的整体供能系统。对于该技术发展的经济和社会动力进行了分析说明,对分布式供能技术的特点、应用领域、涉及的主要技术内容和具体特性进行了介绍,最后对其发展前景进行了展望。

热泵供热技术在合成革干法工艺中的应用研究

在分析传统合成革干法工艺干燥技术存在的问题的基础上,提出了一种基于热泵的蒸汽供热技术,并设计了相关的工艺方案和控制系统。此新型干燥方案利用功能园区中热电厂产生的背压蒸汽来代替导热油进行加热,并且结合热泵技术实现了园区热电联产中蒸汽的有效利用,降低了干燥成本,提高了生产安全性。详细阐述了基于热泵的蒸汽供热工艺流程、系统总体控制方案、前馈模糊反馈控制、PID控制等控制算法和基于S7-300 PLC的DCS控制系统。此干燥方案适用于当前国家正大力推广的热电联产合成革工业园区的合成革干法生产线,具有广阔的应用前景。

氢储能接入含风电的热电联产系统日前调度研究

近几十年来,考虑到环境问题和化石燃料的缺乏,可再生能源的整合程度大大提高。由于其不确定性,这种整合在电力系统中出现了新的挑战。氢能储存系统(HES)在电力系统中扮演着重要的角色,它通过使用电力制氢(P2H)技术将额外的风力转化为氢气。此外,热电联供(CHP)机组等新兴技术也能有效提高电力系统的效率。提出了一种基于CHP-HES的电能网络的日前调度方案,并对风电资源进行了高度整合。通过在IEEE 6-总线系统上的实施,研究了所提出的模型的有效性。研究了热负荷增量对发电设备调度、风电调度和系统运行成本的影响。仿真结果证明,采用HES技术后系统的运行成本和风力发电量的缩减都有所降低。

中国热电行业效率评价及时空差异分析

从决策者角度出发,采用MinDS-U-DEA和MinDS-U-M指数模型对我国省际热电行业静态和动态效率进行了测算,基于时间和空间维度分析了我国省际热电行业集群增长模式。结果表明:2004—2017年,我国南北方热电行业综合效率均呈上升趋势;北方热电行业的发展优于南方,南方热电行业增长趋势高于北方;技术进步在南北方热电行业扮演着不同的角色,北方热电行业的改善主要依靠技术效率的提升,呈现“效率驱动”增长模式,南方则主要依靠技术进步,呈现“创新驱动”增长模式;北方和南方的技术追赶能力均很弱。建议在微观方面,鼓励背压抽汽式汽轮机组的应用,加强余热回收利用;提高清洁能源消耗比重。宏观方面,政府应积极引导行业调整布局,加强南北方技术交流,促进热电市场良性竞争。