对实验台架往复活塞式柴油机循环过程分析

该实验用往复活塞式内燃机的实际循环是复杂且不可逆的,本文为了简化分析过程,忽略次要因素,应用"空气标准假设"将实际问题抽象概括成内可逆理想循环。通过简化整个循环理想化为以空气为工质的混合加热内可逆理想循环。最终利用Matlab软件代入实测数据对循环各冲程相关参数求解,得出具体参数。所得数据可以用来在线监测内燃机工作状况,对内燃机的维修及优化具有指导意义。     

基于负荷分析的分布式能源站发电技术的选择

通过对某大型工业园的冷、热、电负荷的分析,选择在分布式能源站中采用天然气燃气内燃机,为了更好地实现能源的梯级利用,在后置循环中选择采用蒸汽轮机循环,形成了燃气内燃机一蒸汽轮机联合循环的运行方案,介绍了燃气内燃机一蒸汽轮机联合循环的特点,并简述了天然气燃气内燃机一蒸汽轮机联合循环在冷热电三联供分布式能源系统项目中应用推广前景。     

循环流化床垃圾锅炉的燃烧控制与调整

介绍了循环流化床垃圾焚烧锅炉结构、燃烧及传热特性,并对运行中锅炉热工参数的控制及调整进行了说明.     

试谈柴油锤的热效率η_i、平均指示压力P_i和最大爆炸压力P_z对沉桩效果的影响

众所周知,对于内燃机,Pi和η_i是衡量内燃机工作性能的重要参数,习惯上把P_i称作平均指示压力。因P_i×V_n=W_i,所以P的实际物理意义是表示单位气缸工作容积中的指示功。P_i是从实际的物理循环角度来标志发动机气缸工作容积利用率高低的一个参数。P_i值愈高,同样大小的工作容积将发出更大的指示功,气缸工作容积的利用程度越高。η_i的提高不仅可改善动力性能,也同样改善了经济性能,它表示燃料能量的利用率。但内燃机对最高指示压力Pz是限制的。因     

循环流化床锅炉的工况分析及燃烧调整

介绍了循环流化床锅炉的概念，并对循环流化床锅炉进行了工况分析及燃烧调整，指出运行中应根据实际情况调节锅炉的运行参数，以保证其安全、稳定、经济运行。     

电动汽车火灾原因调查研究

比较了电动汽车与传统内燃机车辆在火灾的形成机理、蔓延燃烧方式、危险性方面的区别。通过对电动汽车的火灾危险性分析,提出电动汽车火灾原因调查方法和区别于传统内燃机车辆调查应该注意的问题。     

沼气内燃机在污水处理厂中的应用

燃气内燃机在完全满足人们对环保严格要求的同时,利用四冲程、高压点火、涡轮增压、中冷器、稀释燃烧等技术,通过沼气在气缸内燃烧做功,将沼气的化学能转换成机械能。与此同时,利用热回收技术可将燃气内燃机中润滑油、中冷器、缸套水和尾气排放中的热量充分回收利用而组成热动机组。一般从内燃机热回收系统中吸收的热量以90℃的热水形式供给热交换中心使用。内燃机正常回水温度为70℃。在污水处理厂中可利用这一热量给消化池进行加热。燃气内燃机机械效率通常达40%,热效率可达50%,总效率高达90%。通常在Ｏ2为5%的情况下燃烧后排放的ＮＯ…     

循环流化床锅炉燃烧控制系统浅析

本文介绍大容量和高参数循环流化床锅炉的结构以及燃烧原理,并提出一些控制策略和控制方法。     

浅谈发动机高温成因及故障处理

<正>0概述内燃机,是一种动力机械,它是通过使燃料在机器内部燃烧,并将其放出的热能直接转换为动力的热力发动机。活塞式内燃机以往复活塞式最为普遍。活塞式内燃机将燃料和空气混合,在其汽缸内燃烧,释放出的热能使汽缸内产生高温高压的燃气。燃气膨胀推动活塞作功,通过曲柄连杆机构将机械功输出,再通过各种专用机械装置驱动从动机械工作。常见的有柴油机和汽油机,发动机在做功的过程中会产生高温高压燃烧,一部分热能通过机械转换为动力,还有一小部分热能     

基于问题的学习方式在研究生课程教学中的探索

基于问题的学习(Problem-based Learning,PBL)方式作为一种高效的学习方式近年来得到了普遍的研究和实践。本文就其在研究生课程"内燃机流动、燃烧与排放控制"中实践PBL方式对若干问题进行了探讨。     

天然气气源变化对燃气内燃机性能影响及对策

分析燃气内燃机用天然气互换性判定指数,应选取华白数、甲烷值。针对多气源并存的局面,从国家及行业标准、燃气内燃机生产厂家、用户端等角度出发,提出稳定燃气内燃机性能的对策。     

燃气内燃机发电机组在LNG接收站的应用

介绍了燃气内燃机发电机组的优点,结合工程实例,对燃气内燃机发电机组在 LNG接收站中应用的技术与经济性进行了探讨。     

内燃叉车高原环境适应性问题分析

从内燃叉车的高原环境适应性技术要求出发,研究了典型高原环境条件对内燃叉车各系统性能的影响,提出了提高内燃叉车各系统高原环境适应性的措施,强调了高原环境适应性研究在内燃叉车发展中的作用和地位.     

内燃机产业园区的绿色设计

提出了内燃机产业园区绿色设计的概念,创新了内燃机产业园区的设计,对园区生产的内燃机产品、园区的选址、绿化、工艺、设备选型、建筑及公用动力设施等诸多方面的绿色设计进行了阐述,旨在倡导设计建设资源节约型、环境友好的生态产业园区.     

Performance and emissions characteristics of a diesel engine with internal jet piston using biodiesel

The paper reports an attempt to test the feasibility of Jatropha methyl ester as a fuel in the engine fuel of a compression ignition engine (C.I.) with turbulence inducements in the combustion chamber. The inefficient mixing of biodiesel oils with air contributes to incomplete combustion. These problems can be eliminated by enhancing in‐cylinder turbulence by providing two holes on the piston crown (internal jet piston) and esterification of the vegetable oil into biodiesel. The performance characteristics revealed that the brake thermal efficiency of the Jatropha methyl ester with an internal jet piston was higher than with a base engine piston. The internal jet piston operation with Jatropha methyl ester exhibited desirable characteristics for other emissions such as lower carbon monoxide (CO), hydrocarbons (HCs) and smoke. The oxides of nitrogen (NOx) emissions were higher for the internal jet piston with increasing load, compared to the base engine piston.     

Performance,emission and combustion characteristics of a single cylinder spark ignition engine using ethanol–petrol-blended fuels

The performance, exhaust emission and combustion analyses of a single cylinder spark ignition engine fuelled with extended range of ethanol–petrol blends were carried out successfully at full load conditions. Ethanol produced from raffia trunks was blended with petrol at different proportions by volume. In order to establish a baseline for comparison, the engine was first run on neat petrol. The engine performance parameters (engine torque, brake power, brake specific fuel consumption, brake mean effective pressure and brake thermal efficiency), exhaust emission parameters (CO, HC, CO₂ and O₂ emissions) and combustion parameters were determined for each blend of fuel at different engine speeds. The test results interestingly revealed that the addition of ethanol to petrol causes an improvement in combustion characteristics and significant reduction in exhaust emissions which in turn improved engine performance. In all, ethanol and its blends with petrol exhibited performance characteristics trends similar to that of petrol thus confirming them as suitable alternative fuels for spark ignition engines.     

Performance and emission characteristics of homogeneous charge compression ignition engine – a review

Homogeneous charge compression ignition (HCCI) engine uses a relatively new mode of combustion technology. In principle, there is no spark plug or injector to assist the combustion process, and the combustion starts at multiple spots once the mixture has reached its auto-ignition temperature. The challenges over the operation of HCCI-mode engines are the difficulties of controlling the auto-ignition of the mixture, operating range, homogeneous charge preparation, cold start, controlling knock and emissions of unburned hydrocarbon (UHC) and carbon monoxide (CO), which needed to be overcome to achieve successful operation of HCCI-mode engine. This paper reviews the working principle of HCCI-mode engine and analyse the knocking in the HCCI combustion. And it also reviews the impact of homogeneous charge on HCCI combustion parameters, such as heat-release rate and maximum pressure. Furthermore, it reviews the performance and emission characteristics of HCCI engine. For each of these parameters, the theories are discussed about successful operation of HCCI engine with comparative evaluation of performance and emission reported in the literature.     

Application of fuzzy logic in internal combustion engines to predict the engine performance

This paper describes an application of fuzzy logic principle for predicting the internal combustion engine performance, emission and combustion characteristics using fish oil biodiesel. Experimental investigations on a single cylinder, constant speed, direct injection diesel engine were carried out under variable load conditions. The performance, emission and combustion characteristics such as brake thermal efficiency, hydrocarbon, exhaust gas temperature, oxides of nitrogen (NO_x), carbon monoxide, smoke, carbon dioxide, ignition delay, combustion delay and maximum rate of pressure rise were considered. Engine performance was measured using an exhaust gas analyser, smoke metre, piezoelectric pressure transducer and crank angle encoder for different fuel blends and engine load conditions. The obtained data were recorded for each experiment and associated data used to develop a multiple inputs and multiple outputs fuzzy logic model. The developed model produced idealised results with the correlation coefficients of 0.988–0.999 and root mean square error, and was found to be useful for predicting the engine performance characteristics with limited number of available data.     

Modeling and economic analysis of gas engine heat pumps for residential and commercial buildings in various climate regions of Iran

There is an increasing trend in using heat pumps in air conditioning (heating/cooling) systems of residential and commercial buildings. The required power to drive the compressor of vapor compression heat pump cycles may be provided by either an electrical motor or an internal combustion engine. In this paper thermal modeling and economic analysis of gas engine heat pumps (GEHPs) are presented based on energy and mass balance equations as well as the gas engine operating parameters (such as thermal efficiency, fuel consumption and fuel mass flow rate) and heat pump operating parameters (such as evaporator and condenser capacity and compressor input power). Based on the modeling results and with estimating GEHP fuel consumption, the economic analysis of using gas engine heat pumps (in comparison with the electrical heat pumps) at various climate regions of Iran, for both residential and commercial (office) buildings, and for both cooling and heating modes, was performed. Appropriate cost functions for predicting GEHP capital investment were proposed. Three approaches including equivalent uniform annual cost (EUAC), the annual cost of energy consumption, and payback period were applied in the economic analysis.