内燃机原理中英文课件Word格式.docx

1、internal combustion engine: burning fuel inside the engine, and heating working fluids to work. Including: reciprocating engine and others. The reciprocating engine mainly including: compression-ignition engine such as diesel engine and spark-ignition engine such as gasoline engine. Both of them are

2、 the main content of the course.历史发展：historical perspective1860年 莱诺依尔 大气压力式的内燃机（没有压缩行程）Nicolaus atmospheric engine （without compression cycle）1876年 奥托 4冲程点燃式内燃机Otto four-stroke spark-ignition engine1890年 本茨 2冲程点燃式内燃机Benze two-stroke spark-ignition engine 1892年 狄塞尔 4冲程压燃式内燃机Diesel four-stroke compres

3、sion-ignition engine1902年 雷诺 机械增压Renault mechanically supercharging1915年 波希 涡轮增压器 bocy turbocharger内燃机相对其它动力的优点：Advantage of the internal combustion compares with other power.a. 结构简单； b. 效率较高； c. 重量体积比小；a. simple structure b. higher efficiency c.less specific weight and specific volumed. 成本低，使用方便，技术

4、成熟。d. low cost, operating convenient, mature technology内燃机分类：classification of internal combustion engine 图1-01figure1-01典型内燃机结构：structure of typical engine:点燃式发动机：spark-ignition engine 图1-02、图1-03、图1-04、图1-05 figure1-02 figure1-03 figure1-04 figure1-05压燃式发动机：compression-ignition engine图1-06、图1-07 f

5、igure 1-06 figure 1-07内燃机学 第2章内燃机工作指标 Cheap 2 Engine Operating Parameters内燃机工作指标包括：engine operating parameters including:动力性（功率、转速、扭距）、运转性（冷启动、排气品质）、耐久可靠性（大修时间）、经济性（燃料和润滑油消耗率）。 Power performance （power、speed、torque）、operation performance （cold start、 quality of exhaust）、durable reliability（interval

6、between Overhaul）、economy（specific fuel consumption and lube oil consumption rate）21 示功图 指示性能指标2.1 indicator diagram indicator performance parameters示功图indicator diagram 4冲程内燃机p-示功图图2-01figure2-01 p-diagram for four-storks engine4冲程内燃机p-V示功图图2-02figure 2-02 p-V diagram for four-storks enginep-和p-V有一

7、一对应关系，可以相互转换。方法：用途：p-is one to one correspondence with p-V，Conversing Each Other. method : use:指示性能指标：以工质对活塞做功为基础的指标，反映燃烧过程的特征。indicator performance parameters: the parameters that basic on working fluids pushing the piston to work reflect the characteristic of combustion process 1指示功和平均指示压力 indicat

8、ed work and mean indicated pressure指示功Wi：气缸内完成一个工作循环得到的有用功indicated work Wi: obtained available work per cycle in the cylinder.发动机的p-V图图2-03figure 2-03 p-V diagram of engien 平均指示压力pmi：单位气缸容积一个工作循环所做的指示功；或一个假想的作用在活塞上的不变的压力，使活塞在一个冲程的位移中做的循环指示功。Mean indicated pressure pmi: obtained indicated work with

9、unit cylinder volume per cycle; or obtained cycle indicated work at a piston stroke with an imaginary invariable pressure to the piston application2指示功率 indicated power 指示功率Pi：单位时间做的指示功Wi indicated power Pi: indicated work Wi in unit time3指示热效率和指示燃油消耗率indicated thermal efficiency and indicated speci

10、fic fuel consumption指示热效率it：发动机指示功与消耗燃料热量的比值indicated thermal efficiencyit: rate of indicated work of engine to the heating of consumption fuel 指示燃油消耗率bi：单位指示功的耗油量 indicated specific fuel consumption bi: Fuel Consumption for unit indicated work.22 有效性能指标effective performance parameters有效性能指标：指示性能指标扣

11、除摩擦及附件消耗。反映的是发动机的真正做功能力。effective performance parameters: indicated performance parameters without friction and consumption of accessory. A measure of an engines ability to work veritably1. 机械效率和有效功率 mechanical efficiency and brake（useful） power有效功率：Pe =Pi-Pm brake（useful） power: Pe =Pi-Pm机械效率：m= Pe

12、/ Pi mechanical efficiency: m= Pe/ Pi内燃机有效功率： brake（useful） power of engine:推导：Derivation2. 平均有效压力和升功率 mean effective pressure and power per liter平均有效压力pme：单位气缸容积一个工作循环所做的有效功, 或一个假象的作用在活塞上的不变的压力，使活塞在一个冲程的位移中做的功为循环有效功。Mean indicated pressure pme : obtained effective work with unit cylinder volume per

13、 cycle; or obtained cycle effective work at a piston stroke with an imaginary invariable pressure to the piston升功率 power per liter3、充量系数和过量空气系数 Charging Coefficient and excess air coefficient冲量系数：实际循环进气量与进气管状态下充满气缸的空气量比值。Charging Coefficient: rate of real cycle intake mass to air capacity full of cy

14、linder in the air inlet pipe states过量空气系数a：燃烧单位燃料的实际供给空气量与理论空气量之比。excess air coefficienta: rate of practical to theoretical air mass provided for burning unit fuel柴油机：a=1.2 2.2 汽油机a=0.85 1.1 diesel engine : a=1.2 2.2 gasoline engine: a=0.85 1.1空燃比：空气与燃料的比值。Air/fuel ratio: rate of air to fuel. 4有效热效率

15、和有效燃油消耗率 effective thermal efficiency and brake specific fuel consumption有效热效率：et=We / Q1 effective thermal efficiency : et=We / Q1有效燃油消耗率：单位有效功的耗油量。brake specific fuel consumption: Fuel Consumption for unit brake work23 机械损失与机械效率mechanical loss and mechanical efficiency平均机械损失压力：pm =pi-pe mean mecha

16、nical loss pressure: pm =pi-pe机械损失的主要组成：mechanical loss mainly including:1活塞和活塞环的摩擦损失：45-65% friction loss of piston and piston ring: 45-65%2轴承与气门机构的摩擦损失：2-3% friction loss of bearing and valve train: 2-3%3附件的功率消耗：10-20%。只包括必不可少的附件：油水泵等，不包括：水箱风扇，空气压缩机、空调等。power consumption of accessory: 10-20% only

17、including accessory that is indispensable: pumps for oil or water etc not including: fan for water tank、air compressor4驱动扫气泵和增压器的损失：10-20% loss of driving scavenging pump and supercharger机械损失的测定 mensuration for mechanical loss1示功图法 indicator diagram test method上止点位置不容易精确得到（0.5）。the location of TDC（t

18、op dead center） is not easy to find accurately2倒拖法 motoring test method需要电力测功机。误差有：气缸不能燃烧带来的压力、温度变化，影响到摩擦功。Electrical Dynamometer is needed. The error including: pressure and temperature variety due to not burning in the cylinder, influencing friction work.3灭缸法 extinguish spark of the cylinder test

19、method.必须是多缸机。分别对某一气缸停机，减少制动力矩直到转速恢复，得到此时的功率，则摩擦功率为：P-P。叠加各缸，得到整机的摩擦功。It must be multi-cylinder engine. Stop the engine for each cylinder to reduce the Brake Torque until the speed retrieve, then the power obtained is friction power. Superposition the each cylinders can get the friction work for the

20、 whole engine.4油耗线法Fuel Consumption Curve test Method多用于柴油机或喷射式汽油机。在固定转速下进行负荷特性试验，得燃油消耗量与平均有效压力的关系曲线：Generallyused in diesel engine or injection gasoline engine. Get relation curve of fuel consumption and mean effective pressure from the load characteristic experiments at fixed speeds图2-04figure 2-0

21、4Pme为0时所消耗的油量B为克服摩擦功所用。延长油耗曲线，得到摩擦功。Pme is the fuel consumption B for overcoming friction work at point 0. Get the friction work by prolonging curve of fuel consumption. 24 提高内燃机动力性与经济性的途径the path for improving Power performance and economy of engine1采用增压技术：use supercharging technology 2合理组织燃烧过程，提高指

22、示效率：organize reasonably burning process to improve indicated efficiency3改善换气过程，提高气缸冲量系数：Ameliorate exchange process to improve Charging Coefficient4提高发动机转速： improve the speed of engine5提高机械效率： Improve the mechanical efficiency of the engine.第3章内燃机的工作循环 Cheap 3 Engine Operating Cycles31 内燃机的理论循环 Theo

23、retical cycle of engine内燃机的实际热力循环：燃料的热能转变为机械能的过程The actual thermodynamic cycle of engine :the process that thermal energy of fuel changes into the mechanical energy内燃机的理论循环：将实际循环简化，忽略次要因素，得到便于进行定量分析的假想简化循环theoretical cycle of engine: obtain imaginary predigestion cycle ignoring secondary factor that

24、 is easy to do quantitative analysis with actual predigestion cycle 理论循环的简化假设：the simplifying assumptions of the theoretical cycle1空气为工质，为理想气体。其物理化学性能不变，比热为定值；The working fluids are air which can be treated as ideal gas. Physical and chemical performances keep constant, so does the specific heat.2.工

25、质的总质量不变，忽略了流动损失；The mass of the working fluids is constant ignoring flow loss3工作过程绝热；Operating cycle is adiabatic4用假想的加热放热代替实际的燃烧与排气过程，排气过程视为等容放热过程。Replace actual combustion and exhaust processes with imaginary heating and exothermic. Treat exhaust process as constant-volume exothermic process.研究理论循

26、环的目的：the objective of studying on theoretical cycle.1阐明热力循环参数间的关系；elucidate the relation among the thermodynamic cycle parameters.2确定循环热效率的极限；determine the limit of thermal efficiency of cycle3分析比较不同循环方式的经济性和动力性。analyze and compare economy and dynamic performance among different circulating mode根据不同

27、的燃烧方式，典型的内燃机理论循环有3种：等容加热、等压加热、混合加热。there are three typical engine theoretical cycle according as different combustion mode: constant-volume combustion 、constant-pressure combustion、limited-pressure combustion.典型的理论示功图图3-01Typical pressure-volume theoretica diagram figure 3-01压缩比：Va/Vc，压力升高比pz/pc : V

28、a/Vc , pressure elevation ratio: pz/pc各种理论循环的特点：the characteristics of various theoretical cycle等容加热：加热在等容条件下很快完成，点燃式发动机；constant-volume combustion: heated rapidly in constant-volume condition such as SI engines等压加热：加热在等压条件下缓慢完成，燃气轮机、早期压燃式发动机；constant-pressure combustion: heated slowly in constant-p

29、ressure condition such as gas turbine、former CI engine.混合加热：先在等容条件下很快加热，然后在等压条件下缓慢完成的压燃式发动机。limited-pressure combustion: first heated rapidly in constant-volume condition then slowly in constant-pressure condition as CI engine 初始状态及加热量一致，当压缩比相同时，等容加热效率最高；当循环最高压力相同时，等压加热效率最高。when the Initial State and calefaction heat quantity are consistent, the constant-volume combustion efficiency is the highest with the same compression ratio, while with th