Performance of an innovative 120 kWe natural gas cogeneration system

The paper deals with an innovative (120 kWe, 195 kWt) natural gas (NG) combined heat and power (CHP) system, at present under development, which has been set up at the FIAT Centre of Research (CRF), Turin, Italy. The main characteristics of the CHP system are: the use of an automotive derived internal combustion engine, a high part load electrical efficiency due to a variable speed operation strategy and an advanced exhaust gas after-treatment to meet the most stringent pollutant emission regulations.     

Exergetic analysis of an innovative small scale combined cycle cogeneration system

The purpose of this paper has been to carry out an exergetic analysis of an innovative natural gas (NG) combined cycle cogeneration system (150-kW_e, 192-kW_t). The combined cycle is composed of a reciprocating Internal Combustion Engine (ICE), which is used as the topping cycle, and a water Rankine cycle (RC), which operates on the exhaust gases from the ICE, as the bottoming cycle.     

凹口型三角风扇皮带的节能效果

发动机的风扇皮带拖动风扇、水泵和发电机,要消耗总功率的10%。普通三角皮带的效率仅75～85%。文章详细分析了皮带传动的能量损失,推导出有关公式。通过试验,发现采用凹口型三角皮带能提高效率6～8%,并延长使用寿命。     

Micro gas turbine thermodynamic and economic analysis up to 500 kWe size

In this paper a thermoeconomic analysis and optimization of micro gas turbines (MGT) up to 500 kWe is presented. This analysis is strongly related to the need of minimizing specific capital cost, still high for MGT large market penetration, and optimizing MGT size to match market needs.     

Design and performance evaluation of an innovative small scale combined cycle cogeneration system

This paper deals with an innovative natural gas (NG) combined cycle cogeneration system (150-kW_e, 192 kW_t). The system is made up of a combination of two interconnected combined heat and power (CHP) systems: a reciprocating internal combustion engine cogenerator (ICE CHP) as the topping cycle and a Rankine cycle cogenerator (RC CHP) which operates as the bottoming cycle on the exhaust gases from the ICE. The expander technology chosen for the Rankine cycle prime mover is a reciprocating single expansion steam engine with three cylinders in a radial architecture. The ICE is an automotive derived internal combustion engine with a high part-load electrical efficiency, due to a variable speed operation strategy and reduced emissions.     

Thermal economic analysis of hybrid open-cathode hydrogen fuel cell and heat pump cogeneration

Proton exchange membrane fuel cell (PEMFC) receives increasing attention as an alternative in small-scale residential distributed generation (DG) application, especially for remote cold region where the utility electricity is not accessible. The open-cathode PEMFC is featured with the integrated fabrication of air supply and coolant flow cathode. Although simple, the waste heat of the exhaust air is difficult to reuse by heat exchangers, because of the low exhaust temperature. To this end, this paper investigates a hybrid structure consisting of open-cathode PEMFC and heat pump. It is revealed in this paper that the oxygen excess ratio of open-cathode PEMFC is usually as big as 100, which makes it doable and safe to directly exporting the exhaust air into the indoor environment. The temperature of the mixed air is thereby lifted. The thermal load of the heat pump is consequently alleviated and the power consumption is reduced. A comprehensive quantitative model is developed by considering the fuel cell electrochemical characteristic, cathode thermodynamics and heat pump coefficient. A case study is carried out by comparing the coefficient of performance (COP) of the system with and without the cogeneration design, showing a 7.6% improvement of the proposed hybrid structure. The results of the paper depict a promising prospect in accelerating the commercialization of open-cathode PEMFC in the field of domestic cogeneration filed.     

内燃机燃烧技术的研究现状及发展

介绍了内燃机燃烧技术的研究现状和发展趋势,各种燃烧技术的工作原理以及对内燃机排放性、动力性等的影响,并对比了各种燃烧技术的优缺点,为燃烧技术的发展提供参考。     

试论九十年代我国内燃机产品发展和系列化问题

本文概述了我国内燃机行业的现状和存在问题,阐明了编制九十年代我国内燃机产品发展纲要和系列型谱的指导思想、技术要求以及制订内燃机系列型谱所遵循的基本原则。最后提出实现纲要和系列型谱应采取的措施并给出系列型谱框图。     

Optimal planning and economic evaluation of cogeneration system

Cogeneration plants, which simultaneously produce electricity and heat energy, have been introduced increasingly for commercial and domestic applications in Korea because of their energy efficiency. The optimal plant configuration of a specific commercial building can be determined by selecting the sizes and the number of cogeneration systems and the auxiliary equipment based on the annual demands of electricity, heating and cooling. In this study, a mixed-integer, linear programming, utilizing the branch and bound algorithm was used to obtain the optimal solution. Both the optimal configuration system equipment and the optimal operational mode were determined based on the annual cost method for the installation of a cogeneration system to a hospital and a group of apartments in Seoul, Korea. In addition, the economic evaluation for the optimal cogeneration system depending on the fuel tariff system was calculated. A short payback period and higher internal rate of return on the initial investment were found to be essential for the adoption of cogeneration plants to hospitals and apartments.     

一种基于DSP的内燃机状态检测与故障诊断系统

本文简述了国内外机械状态检测与故障诊断技术的研究现状，列举了几种不同的检测方法，并分析其实时可实现性；讨论了一种智能内燃机状态检测与故障诊断系统，为其工业应用提供更清晰的分析资料。     

Fuel cell micro-CHP techno-economics: Part 2 – Model application to consider the economic and environmental impact of stack degradation

This article presents a literature review regarding the mechanisms of fuel cell degradation, accompanied by the reported range of observed degradation rates in experimental, demonstration and early commercial systems. It then synthesises and exploits this information to investigate the influence of degradation on the economic and environmental credentials of fuel cell micro-combined heat and power (micro-CHP) for the UK residential sector. The investigation applies a techno-economic model developed in the companion article designed to demarcate the key characteristics of commercially successful systems. Two distinct modes of degradation are examined; one proportional to power density in the stack, and the other proportional to thermal-cycling rate of the stack. It is found that limiting the power-density related degradation rate is very important from economic and environmental viewpoints, but thermal-cycling related degradation is less important when thermal energy storage is available because cycling can be avoided. Furthermore it is noted that techno-economic studies that ignore degradation can overestimate the marginal value of a micro-CHP system with respect to the conventional alternative by up to 45% and the CO₂ emissions reduction potential by up to 57%, for performance degradation rates of 2% per MW_eh output. This conclusion is noteworthy because most techno-economic analyses of fuel cells ignore degradation, potentially providing misleading results. Finally it is concluded that existing commercial degradation targets, such as the SECA targets, are appropriate for achieving marketable systems.     

内燃机理想油耗率特性系数及求解

提出了内燃机外特性理想油耗率特性曲线。根据实际内燃机油耗率曲线与理想油耗率曲线的逼近程度,引入并导出一个新的评价指标－理想油耗率特性系数Ｋａ及其计算公式,用以评价外特性油耗率曲线的变化平坦程度,为正确评价内燃机工作转速范围内的燃油经济性好坏提供了理论依据。     

电子节气门驱动电路设计及系统响应分析

本文研究了电子节气门的结构功能特点,设计了基于L9929的电子节气门伺服电机的驱动电路。用C语言编写了基于PID算法的驱动程序,并开发了基于LabVIEW的实验软件平台,完成了对电子节气门的实时控制。     

《内燃机工程》引文分析及其评价

本文以《内燃机工程》刊载论文所附的引文为统计对象,分析了我国内燃机学科领域科学文献的引证状况,反映出作者的参考习惯;从文献老化、语种与类型分布等方面揭示了该学科文献流的某些内在规律并予以评价。对文献半衰期和核心期刊等作了探讨。     

铝基双金属-钢卷带材料在内燃机、发动机滑动轴承行业的应用研究

介绍"双金属-钢"铝基卷带材料目前发展趋势和应用过程,叙述卷带复合工艺制造、生产和应用,具体阐述了卷带落料工艺特点、生产方式,卷带应用的工艺研究和设备配置,铝基卷带材料在滑动轴承生产制造过程中具有很多优势和发展前景。     

A study on the effect of qualitative control coupling variable engine speed on the hydrogen-fueled Wankel rotary engine at wide-open throttle

Hydrogen-fueled Wankel rotary engine, with few available research currently, has excellent power and emission characteristics, however, with lower efficiency. With increasing attention to low-carbon emission, it is of great significance to explore methods to improve the efficiency of hydrogen-fueled Wankel rotary engines. This work aims to study the effect of qualitative control coupling variable engine speeds at the wide-open throttle on the power control. The comparative effect of qualitative control coupling engine speeds from 1000 r/min to 1500 r/min under the wide-open throttle and quantitative control at 1500 r/min on the combustion and emission characteristic of hydrogen-fueled Wankel rotary engine is investigated. The results show that compared with quantitative control, qualitative control coupling variable engine speed can achieve excellent performance. The brake thermal efficiency can be maximally increased by 43.5%, an absolute increase of 6.22%, as well the volumetric efficiency with a maximal 105% improvement. The thermal load and risk of knock can be greatly reduced. Moreover, NO emission also can be reduced by more than an order of magnitude or even by zero. Although there is an increase in cyclic variation, the value is no more than 4%. In addition, qualitative control coupling variable engine speed allows flexible matching of appropriate engine speed and excess air ratio based on the actual requirements of efficiency, stability, durability and emission.     

煤泥作为低品质燃料的燃烧应用及其经济性评价

煤泥等低热值燃料的综合利用是我国洁净煤技术的一个重要组成部分,应用前景十分广阔,潜力巨大。本文总结了我们几年来对煤泥制浆喷燃的研究成果,并提出了新的经济性评价指标,试验结果表明,该指标是正确的、合理的．     

Numerical energetic and exergetic analysis of CI diesel engine performance for different fuels of hydrogen,dimethyl ether,and diesel under various engine speeds

The current study addresses engine specification and second thermodynamic law analysis of the CI diesel engine fueled with hydrogen, DME, and diesel at six engine speeds. The 3-D simulation was first carried out and then the results were exploited to calculate availability through a developed in-house code. Availability analysis was performed separately for chemical and thermo-mechanical availability to highlight each fuel'0s capacity in chemical and mechanical efficiency delivery. The results indicate that hydrogen fuel prevails in chemical and thermo-mechanical availability, indicated power, and mean effective in-cylinder pressure under all crank angle and engine speeds. Temperature distribution has more extensive and intensified region developed across the cylinder, although hydrogen demonstrated the lowest ISFC (indicated specific fuel consumption) value. With regard to engine speed, 2000 rpm shows overall better IP (indicated power), IMEP (indicated mean effective pressure), chemical and thermo-mechanical availability, irrespective of fuel type. The mean irreversibility rate for PMC (pre-mixed combustion) and MCC (mixing controlled combustion) combustion phase shows a different trend. Furthermore, hydrogen fueled engine demonstrates the highest temperature distribution of 2736 K and the wall heat flux to the amount of 29160 W. The variance of chemical availability for Hydrogen from 1500 to 4000 rpm decreases by crank-angle evolution from 43.3% to 10.1% corresponding to 10–40°CA after top dead center.