热电联产的节能效益分析——以乌鲁木齐市沙依巴克区热网工程为例

乌鲁木齐市的能源结构目前以煤为主,人均耗煤约3.96 t,位居中国城市人均耗煤量第一位,是中国人均耗煤量的近4倍。乌鲁木齐市冬季大气污染是典型的＂煤烟型＂污染。以乌鲁木齐市沙依巴克区热网工程为例,叙述了乌鲁木齐实行热电联产节能的情况,提出了发展热电联产是改善乌鲁木齐市大气环境、实现资源节约型、环境友好型社会的有效途径。     

国外热电冷三朕产的现状和前景_热电联产工程系列报告之四

本文在前面三个系列报告［１～３］的基础上．着重讨论热电联产工程及技术的新发展──热电冷三联产．对热电冷三联产的基本概念和应用实例进行了介绍。对国内有关工作作了评述和展望。     

区域供热技术在希腊国内供热中的有效应用

希腊的区域供热始于1994年,采用热电联产技术向用户供热。预计目前在建项目完成以后,总装机容量将超过300MW,其中约85％为现有燃煤机组,其余16％主要是烧柴油和液化石油气的调峰机组。目前用户数量已超过25000户,供热建筑超过6000幢。由于区域供热价格具有竞争力,且初始投资成本低,所以时希腊而言尤其具有吸引力。随着希腊能源市场自由化以及输气管线的完善,区域供热技术将在能源和环保领域产生更大的效益。     

Thermoeconomic operation optimization of the Hellenic Aspropyrgos Refinery combined-cycle cogeneration system

Hellenic Aspropyrgos Refinery (HAR) is a state-owned petroleum refinery with a capacity of 130,000 barrels per day. The electric and part of the thermal loads of HAR are covered by a combined-cycle cogeneration plant of 54 MW_e capacity, which is interconnected with the utility grid. The plant consists of two gas-turbine generators, two exhaust-gas boilers, four fuel-oil boilers and one steam-turbine generator. Steam is produced at four levels; high, medium, low and very low pressure. Low-sulphur fuel oil is burned in the boilers, while the gas turbines can operate in any one or in a combination of (a) diesel oil, (b) process-generated fuel gas. (c) a mixture of propane and propylene (LPG). Connection to the utility network allows for importing additional electricity, if there is need, or for exporting excess electricity. Due to the variety of sources which can be used to cover the loads, the interdependency between sources and the variation of technical and economic conditions with time, questions such as the following arise. Given the technical (e.g. needs in electricity and heat), environmental and economic conditions at any instant of time, what source and at what load should be used? Which is the quantity of electricity bought from or sold to the utility grid? In order to answer these questions, an optimization procedure has been developed which is supported by a thermoeconomic analysis of the system and modelling of the performance of the main components. The minimization of the operation expenses has been selected as the objective function. A computer program has been developed for the numerical solution of the optimization problem. In the present work, the optimization procedure and the computer program are described, numerical results are presented which show the importance of applying such a procedure to real-world complex systems, a sensitivity analysis with respect to important parameters is performed and conclusions are drawn regarding the usefulness and further improvements of the program.     

热电联产机组热电解耦改造方案的调峰特性及能耗分析

以某电厂330 MW抽汽凝汽式汽轮发电机组为研究对象,计算分析了低压缸切缸、高低压旁路改造、增设储热罐、电锅炉及吸收式热泵5种改造方案对供热机组安全运行可行域及热电解耦能力的影响规律,并采用EBSILON建立案例机组的热力学模型,模拟了各改造方案的能耗状况。结果表明：5种改造方案均可使热电联产机组的安全运行可行域增大,其中两级旁路改造方案的机组最大供热能力增幅最大;除低压缸切缸改造外,其余4种方案的热电解耦能力均有不同程度的提高,其中电锅炉改造方案在电热负荷较低时的热电解耦能力最强;在相同条件下,各改造方案的机组标准煤耗量由高到低分别为电锅炉、两级旁路、低压缸切缸、储热罐和吸收式热泵。     

EXERGETIC EVALUATION OF GAS TURBINE COGENERATION SYSTEMS FOR DISTRICT HEATING AND COOLING

A cogeneration system (CGS) generating both power and heat for district heating and cooling is required to be able to cope efficiently with its heat demand change. In this paper, two types of gas turbine CGSs were investigated: (1) a CGS using a dual fluid cycle; and (2) a CGS using a combined cycle. Exergy flows at various points of each CGS have been evaluated when its heat demand is changed. The following have been shown through simulation studies: (a) the higher the heat supply ratio, the higher the exergetic efficiency of the dual fluid cycle CGS; (b) the lower the heat supply ratio, the higher the exergetic efficiency of the combined cycle CGS; and (c) the highest exergetic efficiency of the dual fluid cycle CGS at the maximum heat supply operation is higher than that of the combined cycle CGS; and the exergetic efficiency of the combined cycle CGS at the minimum heat supply operation is higher than that of the dual fluid cycle CGS. A simple criterion has also been derived for determining which type of CGS has higher average exergetic efficiency for a specific district when its heat demand characteristics are known. © 1997 by John Wiley & Sons, Ltd.     

Optimization of energy plants including water/lithium bromide absorption chillers

In this paper a methodology for the optimal integration of water/lithium bromide absorption chillers in combined heat and power plants is proposed. This method is based on the economic optimization of an energy plant that interacts with a refrigeration cycle, by using a successive linear programming technique (SLP). The aim of this paper is to study the viability of the integration of already technologically available absorption chillers in CHP plants. The results of this alternative are compared with the results obtained using the conventional way of producing chilled water, that is, using mechanical vapour compression chillers in order to select the best refrigeration cycle alternative for a given refrigeration demand. This approach is implemented in the computer program XV, and tested using the data obtained in the water/LiBr absorption chiller of Bayer in Tarragona (Catalonia, Spain). The results clearly show that absorption chillers are not only a good option when low‐cost process heat is available, but also when a cogeneration system is present. In this latter case, the absorption chiller acts as a bottoming cycle by using steam generated in the heat recovery boiler. In this way, the cogeneration size can be increased producing higher benefits than those obtained with the use of compression chillers. Copyright © 2000 John Wiley & Sons, Ltd.     

HEAT TRANSFER OPTIMIZATION OF A DISTRICT HEATING SYSTEM USING SEARCH METHODS

This study investigates the parameters that allow for the effective use of district heating. A basic objective of this study was to find a method for optimizing the location for the installation of satellite boilers based on eliminating high energy losses in the piping. This was achieved employing the Jacksonville Naval Air Station (NAS) as a study model and using a search method utilizing a standard computer spreadsheet program. Use of a computer spreadsheet to perform search methods allows all probable locations for satellite boilers to be analysed in order to find the optimum location or combination of locations to maximize savings. The annual cost of energy lost in the piping eliminated by using satellite boilers was compared to the additional annualized capital investment of satellite boiler installation. The study found that satellite boilers could save energy and costs if located where the demand was high and if separated by long distances from the district heating plant. © 1997 by John Wiley & Sons, Ltd.     

光照资源富集区太阳能集中供热系统容量配置及热网管径协同设计优化研究

针对常规太阳能供热系统优化设计中太阳集热供热站设计与供热管网设计相互分离,供热管网热传输过程中热损失难以精准计算的问题,建立太阳能集中供热系统容量配置及热网管径协同优化模型,以系统全生命周期成本最小为优化目标,采用遗传算法求解,并通过具体算例与常规优化方法以及工程设计方法的计算结果进行对比分析。结果表明,利用协同优化模型进行太阳能集中供热系统设计,能够有效避免设计系统太阳能保证率偏小以及供热管网比摩阻不满足规范要求的现象。针对具体算例,当太阳能保证率由50%增至100%时,系统最优最低供水温度从60℃降至45℃;随着太阳能保证率的升高,系统单位太阳集热器面积所匹配的储热水箱体积增大,而系统供热管网管径保持不变。     

发展背压机供热替代分散锅炉

针对北方采暖地区中小规模城市集中供热普及率相对较低,分散供热锅炉数量大,采暖运行能耗较高、污染物排放大的情况,为推动地区建设背压机供热替代分散锅炉,研究通过建立背压机煤耗特性变工况计算模型,并结合实际调研,找出了现阶段实施背压机供热存在的问题,并提出了建设背压机供热替代分散锅炉的建议。     

Optimal lay-out and operation of combined heat & power (CHP) distributed generation systems

The paper presents an optimization model of a distributed cogeneration system with a district heating network, applied to a real city centre situation. The distributed urban cogeneration system includes both a set of micro-gas turbines, located inside some public buildings, and a centralized cogeneration system based on a Internal Combustion Engine. The objective function adopted for the optimization is the Total Annual Cost for owning, maintaining and operating the whole system. To face the problem a Mixed Integer Linear Program (MILP) is defined and solved by a commercial software. Starting from the thermal and electrical demand of the buildings, the MILP model allows to define the possible installation of the centralized cogeneration ICE (Internal Combustion Engine) and the number of microturbines in the different buildings, the optimal lay-out of the district heating network and the optimal operation strategy for the whole system as well. In particular the energy performance and global CO₂ emissions are evaluated.     

英国和欧洲的热电联产_热电联产工程系列报告之二

通过对英国在热电联产工程方面的现状、水平、效益、经营方式及发展前景等进行全面、系统、概括的介绍、旨在引起广大热能动力工作者及相关机构和部门的兴趣和重视,并系统考虑抓紧进行自己的工作。