分布式冷热电联产系统的能量梯级利用率新准则

分布式冷热电联产系统评价准则对系统集成开拓与设计优化至关重要,传统的热效率、火用效率等难以全面科学地评估多供能系统性能特性,也不适于作为联产系统设计优化的目标函数。文章概述了目前常用的评价准则及其存在问题,基于热力学基本方程和联产系统的本质特征,提出了能量梯级利用率的评价准则。新准则从发电、制冷及供热等过程耗用能量的品位和生产产品的品质等来全面权衡不同能量转换利用过程的本质差异,并借助权重系数来综合量化描述。还结合实际的联产系统算例,对新准则和原有的评价准则进行比较分析。研究表明,该准则应用简便、合理、准确,为冷热电联产系统集成开拓与设计优化提供了一个更好的新准则。     

燃气轮机总能系统及其能的梯级利用原理

吴仲华先生从科学原理出发,阐述热力系统中能的梯级利用与品位概念,倡导总能系统,提出了著名的:温度对口、梯级利用"原理.这里,介绍他的部分论述和我们对它的理解,侧重概述作者等在其基础上的相关拓展,包括联合循环的梯级利用原理、热(或和冷)功联产的梯级利用原理、以及中低温热能的梯级利用原理等.还通过许多典型实例研究,剖析系统集成的能量梯级利用机制和特性规律.能量梯级利用原理是热力系统及其转换利用过程的核心科学问题,不仅为热力循环系统集成开拓提供理论依据,而且为相关的系统设计优化等指明有效途径与方法.     

化工动力多联产系统及其集成优化机理

系统集成优化理论是发展多联产系统的最重要核心科学问题,本集体依托国家重大科研项目开展相关研究,得出部分阶段成果：概述化工动力多联产系统的基本概念、本质特征与特点,阐述研究提出的多联产系统集成原则思路与体现这些原则的优化整合手段,以及从系统集成构成层面把多联产系统分为5类基本类型（简单并联型、综合并联型、简单串联型、综合串联型和串并联综合型等）,列举实例及分析其主要特征等。     

IGCC多联产总能系统

从能源与环境领域渗透交叉层面、化学Yong梯级利用结合的角度综述IGCC多联产总能系统的研究动态；阐述了多联产系统概念与过程机理。分析了系统集成的关键技术及其应用与发展前景。     

化工动力多联产系统评价准则问题研究综述

多联产系统评价准则对系统集成开拓与设计优化至关重要。传统的热力学性能指标难以全面科学地评估多能源输入、多功能的联产系统性能特性,也不适合作为系统设计优化的目标函数。文章概述了系统热效率、效率及折合性能指标等目前常用的评价准则及其存在问题;概述了采用相对节能率时的通常做法和存在问题以及对它的改进;概述了经济效率和经济系数以及能量综合梯级利用率等新评价准则的研究进展;还介绍了联产系统全工况评价准则的探讨研究等。     

内燃机分布式冷热电联供技术应用及发展趋势

分布式冷热电联产技术符合"温度对口,梯级利用"的科学用能原则,是实现节能减排的重要途径。以内燃机为动力装置的冷热电联产系统在国内外已有一定的应用,但在单元技术和系统集成技术上仍处于较低水平,系统节能率较低。新一代内燃机分布式冷热电联产技术通过吸收式除湿技术、升温型热泵技术等对内燃机缸套水低温余热进行更为有效的利用,使系统节能率上升至25%以上。本文介绍了内燃机分布式冷热电联产技术的研究现状和应用现状,对新一代内燃机分布式冷热电联产技术应用的发展趋势进行了系统分析。     

日本分布式热电联产系统的应用现状及未来展望

从应用布局和技术分布角度阐述了日本分布式热电联产系统的应用现状。医院是民用分布式热电联产系统的主要应用领域,而石化、制药行业则占据工业用热电联产的主导地位。就技术角度而言,燃气内燃机装机数量较大,燃气轮机贡献了主要容量,燃料电池则是未来重点发展方向。此外,从能源梯级利用的深度和广度两个层面,探讨了今后分布式热电联产系统集成的可能方案。     

先进分布式供能系统的关键技术与核心科学问题

分布式供能系统为直接面向用户的可持续发展能源动力系统,对开拓能源利用新模式、推动可再生能源发展应用、优化能源结构以及系统节能等将发挥重要作用。文章基于作者团队有关的研究成果和国内外相关的研究情况,综述分布式供能系统:概述了新系统概念、技术特点与梯级利用节能理念及国内外研究发展简况;全面归纳新系统集成的主要关键技术(系统集成技术和主要过程部件关键技术);凝练归纳新系统开拓集成的主要核心科学问题(系统设计优化和评估基础问题,多能源互补的多功能梯级综合利用机理,不同循环的耦合机理以及变工况主动调控机制和优化基础等)。     

双机联调抽汽-高背压联合供热■分析与优化

为了实现热电联产机组运行优化,采用自主研发的热力系统集成优化(TPIS)软件搭建热力系统仿真模型,建立了热电联产机组■分析模型,研究了供热■效率、当量电耗■效率以及电厂总■效率随主蒸汽质量流量的变化特性;通过■分析得到了抽汽供热、抽汽-高背压联合供热、抽汽梯级利用-高背压联合供热的最优运行工况。结果表明:双机联调抽汽梯级利用-高背压联合供热方式最佳运行区间大于其他2种供热方式,双机联调抽汽-高背压联合供热方式的供热能力最大,研究结果为热电联产电厂能耗评价与运行优化提供了借鉴。     

水煤气变换反应对多联产系统能源转换效率与温室气体排放的影响

建立并完善了煤基合成气液体燃料/电力多联产仿真和优化模型.应用该模型能准确地预测出系统在不同压力下蒸汽发生潜力和相应的蒸汽循环发电能力.研究了水煤气变换反应器对系统能源转换效率与温室气体排放的影响,其结果对于未来多联产系统设计优化及控制温室气体排放方面研究具有参考价值.图3表3参14     

Integrated energy systems based on cascade utilization of energy

Focusing on the traditional principle of physical energy utilization, new integration concepts for combined cooling, heating and power (CCHP) system were identified, and corresponding systems were investigated. Furthermore, the principle of cascade utilization of both chemical and physical energy in energy systems with the integration of chemical processes and thermal cycles was introduced, along with a general equation describing the interrelationship among energy levels of substance, Gibbs free energy of chemical reaction and physical energy. On the basis of this principle, a polygeneration system for power and liquid fuel (methanol) production has been presented and investigated. This system innovatively integrates a fresh gas preparation subsystem without composition adjustment process (NA) and a methanol synthesis subsystem with partial-recycle scheme (PR). Meanwhile, a multi-functional energy system (MES) that consumes coal and natural gas as fuels simultaneously, and co-generates methanol and power, has been presented. In the MES, coal and natural gas are utilized synthetically based on the method of dual-fuel reforming, which integrates methane/steam reforming and coal combustion. Compared with conventional energy systems that do not consider cascade utilization of chemical energy, both of these systems provide superior performance, whose energy saving ratio can be as high as 10%–15%. With special attention paid to chemical energy utilization, the integration features of these two systems have been revealed, and the important role that the principle of cascade utilization of both chemical and physical energy plays in system integration has been identified.     

System study on natural gas-based polygeneration system of DME and electricity

An innovative system for the polygeneration of dimethyl ether (DME) and electricity was proposed in this paper. The system uses natural gas as the raw material. Polygeneration is sequential, with one-step and once-through DME synthesis. Syngas is made to react to synthesize DME first, and then the residual syngas is sent to the power generation unit as fuel. The exergy analysis from the view of cascade utilization was executed for individual generation and for polygeneration. The analysis results showed that both chemical energy and thermal energy in polygeneration were effectively utilized, and both chemical exergy destruction and thermal exergy destruction in polygeneration were decreased. The cause of the decrease in exergy destruction was revealed. The analysis showed that hydrogen-rich (natural gas-based) polygeneration was as desirable as carbon-rich (coal-based) polygeneration. The energy saving ratio of polygeneration was about 10.2%, which demonstrated that high efficiency natural gas-based polygeneration is attainable, and the cascade utilizations of both chemical energy and thermal energy are key contributors to the improvement of performance. Copyright © 2007 John Wiley & Sons, Ltd.     

Emergy evaluation of polygeneration systems

To expand the application range of the emergy evaluation method, an emergy evaluation index, which can reflect the particular feature of polygeneration systems, has been elaborated on the basis of energy and emergy conservation, guided by the fundamental principle of emergy analysis. With this index, the cost structure, emission effect and energy saved were all considered on the same level of importance. To exemplify, some power polygeneration systems (methanol-power generation, hydrogen-power generation) are considered using coal as the basic fuel. The results showed that emergy evaluation indices are practical for comprehensively evaluating polygeneration systems and their sustainability, which is influenced by such factors as the joining mode of polygeneration and the technologies used. The sustainability of polygeneration systems, which work on an appropriate ratio of fuel-to-electric power basis, is higher than that of singular production systems. Translated from Chinese Journal of Power Engineering, 2006, 26(2): 278–282 [译自: 动力工程]     

多联产系统的能值评估

为了扩展能值分析方法的应用范围,根据能值分析的基本思想,并以能量守恒和能值守恒为依据,提出了能反映多联产系统特点的能值评价指标,该能值评价指标将多联产系统的成本结构、排放影响和节约的资源置于同样重要位置考虑.以煤基燃料-电力多联产系统（甲醇-电力,氢-电力）为案例进行了能值分析.结果表明：该能值评价指标能全面度量多联产系统及其可持续性;多联产系统的连接模式、技术配置等因素均影响着多联产系统的可持续性;合适的燃料-电力比例的多联产系统的可持续性与单产系统相比有明显改善.图4表3参11     

层次分析法在多联产系统综合性能评价中的应用

按照系统工程方法进行多联产系统的优化设计，应用层次分析法建立了多联产系统综合评价模型，对多种甲醇．电多联产系统方案进行了单项效益和综合效益的计算、分析和评价，进一步证明了多联产方案比单产方案在节能、经济、环境保护方面有较大优势，并指出：在年产甲醇20万t，发电容量300MW的规模下，富CO气体一次通过并联多联产系统（E1）和富CO气体一次通过串联多联产系统（F1）综合效益较高，可以根据实际情况来选取，为系统进一步优化指明了方向。图1表8参10     

二甲醚多联产系统的能量分析

多联产系统是未来源环境可持续发展的重要方向。二甲醚性能优秀,应用广泛。本文提出了以煤气化为核心一步法制取二甲醚的多联产系统流程,利用热力学方法分析了其热效率,比较了联产和分产的能耗,显示出多联产系统的节能优势。分析了水煤气变换和脱碳单元对多联产系统效率的影响,在复杂流程的基础上构建简单流程进行对比,其节约煤耗更加可观,体现了多联产系统整体优化的思路。     

Proposal of a natural gas-based polygeneration system for power and methanol production

A new kind of natural gas-based polygeneration system for methanol and power production is proposed in this paper. With the sequential connection between chemical production and power generation, the new system adopts innovative integration of partial-reforming and partial-recycle scheme in methanol synthesis subsystem. To reveal the characteristics of the new system, exegetic comparisons between the new system and a reference polygeneration system with full-reforming and once through methanol synthesis scheme have been carried out. Results indicate that the new system can save energy about 6 percentages versus single product systems. By the aid of graphical exergy analysis methodology, the specific information on internal phenomena of key processes was illustrated. The analysis shows that it is the synergetic combination of partial-reforming and partial-recycle schemes that makes the significant contribution to the performance improvement, and plays the most important role in system integration.     

多联产配置是推进我国IGCC系统发展的重要途径

分析了IGCC电站在我国及世界的发展形势,并从经济和技术角度分析了影响其发展的主要因素,重点对多联产系统相对IGCC电站具有更好的经济性和操作灵活性进行分析。提出通过多联产系统来推进IGCC这种清洁煤发电技术发展的观点。