热电联产与合理用能

热电联产对于提高一次能源利用率是一个有效途径。作者分析比较了各种热电联产方式的节效果；指出了热电联产建设中应考虑的问题。     

热电联产分布式能源与能源节约

经过几十年的发展,我国热电联产已具有相当规模。为适应电力工业的发展,热电联产应不断进行技术改造,保持节约能源的优势。文中提出增强经济效益措施和向科技、管理、环保要效益,走可持续发展的健康之路。我国能源的状况决定必须大抓节能。     

加速发展热电联产

热电联产是一项重要的节能措施 ,本文论述了热电联产的合理规模和选择并介绍了热电联产的多种方式。     

热电联产系统供热比计算办法的探讨

通过对供热比分析计算来进行合理的热电分摊,克服传统的计算缺点;通过对热量法进行修正,将冷源损失合理地分配给供热、发电,以期正确确定供热、供电价格,调动热电双方的积极性。     

热电联产的节能探析

就国家计委等四部委发下的（1998）220号文《关于发展热电联产的若干规定》进行商榷,并就热电联产的节能界定指标提出看法。     

热电联产中能级比加权热电分摊法

通过对现有热电分摊方法的分析,引入能级的概念,建立了能级比另权热电分摊法数学模型。该方法物理意义明确,计算简便、克服了热量法和实际焓降法的缺点。     

热电联产中供热煤耗计算方法的探讨

<正> 一、急需制定合理的热价体系热电联产是一种既有明显经济效益,又有广泛社会效益的优越能量生产方式。近年来,热电联产供热亏损的普遍性挫伤了热电厂供热的积极性,妨碍着热化事业的进一步发展。1985年在国家豁免供热税收的情况下,全同供热亏损2.38亿元,亏损面积达93％,仅北京热电总厂就亏损7347万元。造成供热亏损的主要原因在于热价制定的不合理,使供热价格低于供热成本,没能真正体现供热热能的价值。此外,由于近年来燃料价格的不断上涨,而供热热价却没能进行相应的、合理的调整。致使供热亏损现象日趋严重。不合理的热价体系已严重影响着热化事业的发展。因此,制定一个合理的热价体系是一项十分重要而又紧迫的任     

江西省工业锅炉热电联产现状及前景

1 现状 热电联产是一种节能效果显著的成熟技术,是国家“八五”期间重点推广的节能项目。根据国家和我省现有的热电联产技术规范,凡出力在10t/h及以上的工业锅炉,具备条件的,应大力发展热电联产。据初步统计,我省现已实现热电联产的企业约30余家,分布在轻工、纺织、化工等行业,装机容量约9万kW,年节标煤约6.5万t,年发电量约3.6亿kW.h。直接经济效益9000多万元。     

Ensuring emergency power for critical municipal services with natural gas-fired combined heat and power (CHP) systems: A cost–benefit analysis of a preemptive strategy

Electric power failures in the aftermath of disasters cripple the delivery of critical emergency services. While emergency generators are available in some facilities, these systems are designed for short-term use and support limited functions. The substantial investment required to ensure emergency power for all critical services is difficult to justify because of the uncertainty associated with the likelihood and magnitude of future disasters. Investment evaluations change when a new source of emergency power is considered. This study evaluates the costs and benefits of a program to preemptively install new building-sited electric combined heat and power (CHP) generation technologies to ensure reliable long-term power for critical municipal services in hurricane-prone regions of the US. Three municipalities are selected for this analysis: Houston, Texas; Miami, Florida; and Charleston, South Carolina. Analysis indicates that costs of such a program can, in some cases, provide net energy bill savings regardless of the occurrence of a disaster.     

Exergetic comparison of efficiency indicators for combined heat and power (CHP)

Legislative regulations in favor of combined heat and power (CHP) production have been implemented in many countries. Although these regulations put different emphasis on power production vs. process heat production, they are based on energy quantities and not on exergy. In order to analyze and compare the exergetic consequences of the various legislations, a relative avoided irreversibility (RAI) is defined. This can be regarded as the exergy loss that is avoided when reference plants with separate production are replaced by an actual CHP plant. Some series of industrial and district heating CHP plants, under varying operational conditions, are used as test cases. It is seen that some, but not all, CHP cases are exergetically beneficial to separate generation. Comparison with the RAI allows a quantitative assessment of the various performance indicators. It is seen that exergetic improvements were only captured to a limited degree by the various energy-based efficiency indicators. Some legislatively defined indicators even appear to discourage thermodynamic improvements.     

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.     

国外热电联产发展政策、经验及我国发展分布式小型热电联产的前景

热电联产被公认为2l世纪的清洁能源,工业性的应用已经较为广泛,商业设施和区域供热方面的应用也有很大发展。生产技术上的特殊性造成其发展依然面临着很多困难,需要政策扶持。然而全社会对环保、对能源安全的共识又为其提供了良好的发展机遇。根据联合国亚太经济与社会委员会的相关报告,热电联产事业面临的障碍可以归纳为：1)技术障碍;2)经济激励措施的缺失;3)政策框架尚不完善;4)电力工业的短视;5)对环境保护缺乏重视。另外还有技术和管理人才的缺乏等。这些障碍在中国都不同程度地存在,发展热电联产要从以上各方面共同推进。而西方国家在发展热电联产的过程中,在国家能源结构和供求情况、全球环境政策、电力和燃料市场自由化等国内和国际因素的影响下,能源政策随之变化,热电联产事业也历经起伏。由于他们起步较早,技术和政策方面的基础较强,电力市场化改革也在进行中,它们的经验,会对中国的热电联产事业发展有所启迪。下面我们介绍一些具有代表性的国家发展热电的努力。在文章的最后,我们还将重点讨论热电技术中极有前途的小型分散式热电联产技术。     

Evaluation of combined heat and power (CHP) systems performance with dual power generation units for different building configurations

This paper evaluates the economic, energetic, and environmental feasibility of using two power generation units (PGUs) to operate a combined heat and power (CHP) system. Several benchmark buildings developed by the Department of Energy simulated using the weather data for Chicago, IL, are used to analyze the proposed configuration. This location has been selected because it usually provides favorable CHP system conditions in terms of cost and emission reduction. For the proposed configuration, one PGU is operated at base load to satisfy part of the electricity building requirements, whereas the other is used to satisfy the remaining electricity requirement operating following the electric load. The dual‐PGU CHP configuration (D‐CHP) is modeled for four different scenarios to determine the optimum operating range for the selected benchmark buildings. The dual‐PGU scenario is compared with the reference building using conventional technology to determine the benefits of this proposed system in terms of operational cost, primary energy reduction, and carbon dioxide emissions. The D‐CHP system results are also compared with a CHP system operating following the electric load (FEL) and base‐loaded CHP system. For three of the selected buildings, the proposed D‐CHP system provides comparable or greater savings in operating cost, primary energy consumption, and carbon dioxide emissions than the optimized conditions for base loading and FEL. In addition, the effect of operating the D‐CHP system only during certain months of the year on the overall operational cost is also evaluated. Results indicate that not operating the D‐CHP system for the months where the thermal load is too low is beneficial for the overall system performance. Copyright © 2012 John Wiley & Sons, Ltd.     

A novel hybrid heat pipe solar collector/CHP system—Part 1: System design and construction

The process of selecting and designing the major components for a hybrid solar collector/CHP system is described. Particular attention was given to the design of the solar collector and a number of options, including thin membrane heat pipe solar collectors (both ‘normal’ and ‘artery’ types) and hybrid heat pipe solar collectors (both wicked and wickless types), were considered. Performance comparisons were made using theoretical and experimental data and a hybrid solar collector was selected as the best option for the system. Micro impulse-reaction turbine using n-pentane as its working fluid was selected for the system although further work is being carried out on a compressed-gas driven turbo alternator. A prototype hybrid solar collector/CHP system has been constructed and the results of its theoretical and experimental testing are presented in Part II of this paper.     

Combined heat and power systems with dual power generation units and thermal storage

The objective of this paper is to study the performance of a combined heat and power (CHP) system that uses two power generation units (PGU). In addition, the effect of thermal energy storage is evaluated for the proposed dual‐PGU CHP configuration (D‐CHP). Two scenarios are evaluated in this paper. In the first scenario, one PGU operates at base‐loading condition, while the second PGU operates following the electric load. In the second scenario, one PGU operates at base‐loading condition, while the second PGU operates following the thermal load. The D‐CHP system is modeled for the same building in four different locations to account for variation of the electric and thermal loads due to weather data. The D‐CHP system results are compared with the reference building by using conventional technology to determine the benefits of this proposed system in terms of operational cost and carbon dioxide emissions. The D‐CHP system results, with and without thermal storage, are also compared with that of single‐PGU CHP systems operating following the electric load (FEL), following the thermal load (FTL), and base‐loaded (BL). Results indicate that the D‐CHP system operating either FEL or FTL in general provides better results than a single‐PGU CHP system operating FEL, FTL, or BL. The addition of thermal storage enhances the potential benefits from D‐CHP system operation in terms of operational cost savings and emissions savings. Copyright © 2013 John Wiley & Sons, Ltd.     

Assessment of combined heat and power (CHP) integrated with wood-based ethanol production

A techno-economic assessment is made of wood-based production of ethanol, where the by-products are used for internal energy needs as well as for generation of electricity, district heat and pelletised fuel in different proportions for external use. Resulting ethanol production costs do not differ much between the options but a process where electricity generation is maximised by use of the solid residues as fuel for a combined cycle is found to give 20% more reduction of green-house gas emissions per liter of ethanol produced than the other options. Maximising electricity generation at the expense of district heat generation also allows more freedom when suitable sites for ethanol plants are looked for. Use of gasified biofuel for a combined cycle power plant is a demonstrated technology, however, the low ash and alkali content of the hydrolysis residue may allow direct combustion in the gas turbine topping cycle. This would reduce the necessary investment considerably. The potential advantages of using a combined cycle for maximising the electric power output from an energy combinate, producing ethanol and electricity from biomass, justifies further exploration of the possibilities for using hydrolysis residue directly as gas turbine fuel.     

Performance improvement of a 70 kWe natural gas combined heat and power (CHP) system

Combined heat and power is the simultaneous production of electricity and heat. CHP plants produce energy in an efficient way. A natural gas CHP system based on an internal combustion engine (ICE) is described, which has been set up at the Building Energy Research Center in Beijing, China. The system is composed of an ICE, a flue gas heat exchanger, a jacket water heat exchanger and other assistant facilities. The ICE generates power on-site, and the exhaust of the ICE is recovered by the flue gas heat exchanger, and the heat of the engine jacket is recovered by the jacket water heat exchanger to district heating system. In order to improve the performance of the system, an absorption heat pump (AHP) is adopted. The exhaust of the ICE drives the AHP to recover the sensible and latent heat step by step, and the temperature of the exhaust could be lowered to below 30 °C. In this paper, the performance of the new system were tested and compared with conventional cogeneration systems. The results show that the new CHP system could increase the heat utilization efficiency 10% compared to conventional systems in winter. All the results could be valuable references for the improvement of the CHP system.     

Analyzing a self-managed CHP system for greenhouse cultivation as a profitable way to reduce CO2-emissions

To counter global warming, a transition to a low-carbon economy is needed. The greenhouse sector can contribute by installing Combined Heat and Power (CHP) systems, known for their excellent energy efficiency. Due to the recent European liberalization of the energy market, glass horticulturists have the opportunity to sell excess electricity to the market and by tailored policy and support measures, regional governments can fill the lack of technical and economic knowledge, causing initial resistance. This research investigates the economic and environmental opportunities using two detailed cases applying a self managed cogeneration system. The Net Present Value is calculated to investigate the economic feasibility. The Primary Energy Saving, the CO₂ Emission Reduction indicator and an Emission Balance are applied to quantify the environmental impact. The results demonstrate that a self-managed CHP system is economic viable and that CO₂ emissions are reduced.