化工动力多联产系统设计优化理论与方法

化工动力联产备受关注,文章概述作者团队对多联产系统设计优化理论与方法的研究。从领域交叉层面探讨联产系统集成理论,阐明了能的综合梯级利用和控制CO2一体化原理;基于新原理,诠释了多联产系统类型和集成特征,凝练了系统集成的三个一般性原则思路和体现这些原则的优化整合途径和手段。然后,构建了相关的联产系统设计优化方法：基于相对节能率和基于化学能梯级利用机理的设计方法。实例研究验证了所提出理论与方法的有效性、实用性。     

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     

甲醇/电多联产系统变工况特性的研究

利用Aspen P1us仿真工具和甲醇／电多联产系统的变工况数学模型，对串联或并联、以及有否变换单元的4种多联产系统配置方案进行了模拟计算，详细比较了它们的电负荷调节范围。分析结果表明：4种系统调节能力由强到弱依次为：变换并联系统、变换串联系统、不变换并联系统和不变换串联系统。相关分析方法和结论为多联产系统设计提供了参考。图7参5     

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。     

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。     

并联型IGCC甲醇多联产系统集成与性能指标研究

对不同燃气轮机配置及型式的并联型IGCC甲醇多联产系统进行了探讨,建立了相应的分析评价指标,通过Aspen Plus及Gtpro商用计算软件对多联产系统方案进行了模拟计算,得出各系统方案的性能分析参数,分析了动力与化工集成对系统性能指标的影响,比较了不同配置系统性能的差异.结果表明:IGCC与多联产系统的结合能实现规模效应,有助于IGCC比投资成本的降低和该技术的应用推广;不同形式的甲醇-电力多联产系统中,并联型甲醇-电力多联产系统具有较高的能源利用效率和供电效率,其中F级的系统能源利用效率达到56％,供电效率达到40％.     

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。     

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。     

太阳能联合城市燃气锅炉供暖系统的节能设计优化

研究太阳能联合城市燃气锅炉供暖系统的节能设计优化方案。设计集太阳能集热器、蓄热水箱、换热器、水泵、燃气锅炉等重要设备于一体的联合供暖系统，分析串联供暖与并联供暖组合方式，以及适用于联合供暖组合的太阳能单独供暖、同时供暖、燃气锅炉单独供暖三种供暖模式，采用TRNSYS构建串联供暖系统与并联供暖系统模型，对串联供暖系统与并联供暖系统节能设计进行比选，并从运行经济性角度出发优化联合供暖系统容量匹配节能设计。串联供暖系统节能设计比并联供暖系统节能设计的太阳能保证率高、系统性能好、系统能耗低。     

串联型焦电联产系统的概念性设计与特性规律

根据能量的综合梯级利用原理,设计了串联型炼焦-发电联产系统.新系统缩小了燃料化学能释放侧与热能接受侧的品位差;尽量减少炼焦过程耗气量,把更多富氢的焦炉煤气提供给联合循环,以实现高效洁净发电;还变革传统的焦炉工艺流程,优化和整合燃气轮机和焦炉的排气系统,使得系统总排烟量和损失都降低.研究表明,新系统具有优良的热力特性,系统相对节能率高达23%.     

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.     

High-temperature electrolysis of water vapor—status of development and perspectives for application

Electrolysis of water vapor using solid-oxide electrolyte cells has been demonstrated to be a very efficient method of hydrogen production from water. As a result of an eight-year development program in Germany, the technology of vapor electrolysis cells and their integration into larger molecules has reached an advanced status: Single cells have been operated during long-term tests with current densities of 0.3 A cm^?2 and 100% Faraday efficiency at a voltage of only 1.07 V [corresponding to a specific electrical energy consumption of 2.57 kWh Nm^?3 (H₂)]. With electrolysis tubes of series-connected cells an enrichment of hydrogen in the vapor stream of up to 85% could be demonstrated without major concentration polarization losses. Concepts for integrated modular electrolysis units made up of serial- and parallel-connected tubular cells have been developed and successfully tested. A pre-prototype unit of 3.5 kW hydrogen output power is under development. The high efficiency of this hydrogen production process will allow an extension of the use of electrolytic hydrogen in the near future. The reasons for such a development will be explained and an example for a modified synfuel process will be given.     

Design of a hybrid polygeneration system with solar collectors and a Solid Oxide Fuel Cell: Dynamic simulation and economic assessment

Solid Oxide Fuel Cells (SOFC) are very promising energy conversion devices, producing electricity and heat from a fuel directly via electrochemical reactions. The electrical efficiency of SOFCs is particularly high, so that such systems are very attractive for integration in complex polygeneration systems. In this paper, the integration of SOFC systems with solar thermal collector is investigated seeking to design a novel polygeneration system producing: electricity, space heating and cooling and domestic hot water, for a university building located in Naples (Italy), assumed as case study. The polygeneration system is based on the following main components: concentrating parabolic through solar collectors, a double-stage LiBr-H₂O absorption chiller and an ambient pressure SOFC fuel cell. The system also includes a number of additional components required for the balance of plant, such as: storage tanks, heat exchangers, pumps, controllers, cooling tower, etc. The SOFC operates at full load, producing electric energy that is in part self-consumed for powering building lights and equipments, and in part is used for operating the system itself; the electric energy in excess is eventually released to the grid and sold to the public Company that operates the grid itself. The system was designed and then simulated by means of a zero-dimensional transient simulation model, developed using the TRNSYS software; the investigation of the dynamic behavior of the building is also included. The results of the case study were analyzed for different time bases, from both energetic and economic points of view. Finally, a thermoeconomic optimization is also presented aiming at determining the optimal set of system design parameters. The economic results show that the system under investigation may be profitable, provided that it is properly funded. However, the overall energetic and economic results are more encouraging than those claimed for other similar polygeneration systems in the recent literature.     

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     

300MW燃煤电厂热力系统仿真研究

基于过程系统工程的建模和仿真原则,针对某电厂300MW燃煤机组开发了一套稳态热力学仿真系统,并详细阐述了模型建立的基本思路和方法,通过改变输入参数、负荷和环境条件,仿真电厂在不同工况下的运行特性．结果表明：系统仿真所获得的结果与实际电厂的性能测试数据相比误差不超过2％;通过仿真可获得主要物流、能流的热力学参数（包括质量流量、温度、压力、比焓、比熵等）和主要设备的运行参数（包括汽轮机和泵的等熵效率、加热器端差、热传导系数等）,为燃煤电厂的实际运行优化、炯分析、热经济学分析等提供基础数据．     

Operational optimisation of a complex trigeneration system connected to a district heating and cooling network

The combined production of electricity, heat and cold by polygeneration systems ensures maximum utilization of resources by reducing emissions and energy losses during distribution. Polygeneration systems are highly integrated systems characterized by the simultaneously production of different services (electricity, heating, cooling) by means of several technologies using fossil and renewable fuels that operates together to obtain a higher efficiency than that of an equivalent conventional system. The high number of distribution technologies available to produce electricity, heating and cooling and the different levels of integration make it difficult to select of the optimal configuration. Moreover, the high variability in the energy demand renders difficult the selection of the optimal operational strategy. Optimization methodologies are usually applied for the selection of the optimal configuration and operation of energy supply systems. This paper presents a scenario analysis using optimization models to perform an economic, energetic and environmental assessment of a new polygeneration system in Cerdanyola del Vallès (Spain) in the framework of the Polycity project of the European Concerto Program. This polygeneration system comprise high-efficiency natural gas cogeneration engines with thermal cooling facilities and it will provide electricity, heating and cooling for a new area in growth known as Alba park including a Synchrotron Light Facility and a Science and Technological park through a district heating and cooling network of four tubes. The results of the scenario analysis show that the polygeneration plant is an efficient way to reduce the primary energy consumption and CO₂ emissions (up to 24%).     

Polygeneration and efficient use of natural resources

The consumption of natural resources has been increasing continuously during recent decades, due to the growing demand caused by both the economic and the demographic rise of global population. Environmental overloads that endanger the survival of our civilization and the sustainability of current life support systems are caused by the increased consumption of natural resources—particularly water and energy—which are essential for life and for the socio-economic development of societies. While not yet well utilized, process integration and polygeneration are promising tools which reach the double objective of increasing the efficiency of natural resources, and also minimizing the environmental impact. This paper discusses the concepts of polygeneration and energy integration and various examples of polygeneration systems: (i) sugar and energy production in a sugarcane factory; (ii) district heating and cooling with natural gas cogeneration engines and (iii) combined production of water and energy. It is clearly evident that polygeneration systems which include appropriate process integration significantly increase the efficient use of natural resources.     

颗粒层除尘器过滤和清灰方式的优化

分析了移动床颗粒层除尘器存在颗粒层间隙增大和颗粒错位等影响除尘性能的问题,并优化出能克服这些问题的新型结构和过滤方式的颗粒层除尘器;介绍了新型颗粒层除尘器的结构和特点,特别是组合流化床清灰机构能实现颗粒层的快速清灰;建立了除尘器床层压降的数学模型,通过实验摸索出颗粒层流化清灰规律和除尘器的过滤性能。理论和实践表明,新型颗粒层除尘器的除尘性能优于其它颗粒层除尘器,能实现了除尘和清灰一体化,清灰过程更简便。