柴油发动机电控电喷控制油门的现状与发展方向

1、柴油发动机电控电喷控制油门的现状与发展方向 目前，国际上的一些知名柴油发动机生产厂家，例如：美国CATERPILIER公司的3126系列发动机；德国的MAN发动机等等，现在已采用了ECU电子控制技术来控制发动机的喷油量和转速，他的优点是：燃油量可根据负载的大小自动调节，发动机的转速升降加速度得到最佳匹配控制、转速的控制取消了传统的软轴而使得机械结构简化；缺点是：价格昂贵，特别是对于工程机械来说，由于他们的ECU软件保密，控制方式和参数无法修改来适应工程机械的特殊需要，因此，在我国国内仅有小批量使用。 在我国国内，目前发动机生产厂家，无论是国内的合资企业产品，如：康明斯发动机，斯太尔发动机，道义

2、兹发动机等等，还是国产老品牌的发动机，如：上海柴油机厂的发动机等等。由于受国外产品技术封锁，关键技术尚未得到充分利用，特别是一些高科技的控制技术，包括硬件、软件等，当然也包括发动机的ECU电子控制技术，受制于国外，加上我国国内的一些技术人员由于受到“国外的产品好”的思想束缚，只把别人的东西拿来用，使得高科技技术基本上处于技术空白。 笔者认为：如果我们一下子将所有的技术问题都解决掉，有一些不现实，但可以通过其他方式来解决上述问题中的一部分，譬如讲：第一步先将柴油发动机电动控制油门，取代ECU电子控制技术来控制发动机。第二步，在发动机厂家的配合下，逐步完成对发动机喷油量的自动控制。 由于ECU电子

3、控制技术是将发动机的喷油量按功率扭矩的最佳匹配曲线来控制，目前以我们的现有技术，尚无法做到。但我们可以另辟蹊径，在喷油泵不作改动的基础上，我们可以做成柴油发动机电动控制油门，可以使得发动机的转速与负载功率达到最佳匹配。例如：工程机械中的发动机，拖动电控液压泵站，泵的排量受电流大小控制（非电控液压泵站，由于系统中的溢流阀的保护作用，在设备不工作时，发动机的负载最大，效率最低，发热量最大）。可以说在同等载荷情况下，泵的排量相当于负载功率，其负载扭矩在发动机转速以及泵的排量增大时随之增大，根据扭矩TFLmaL，当加速度增大时，扭矩必然随之增大，那么，就需要将发动机油门与液压泵的排量两者之间有机的结合

4、起来同时控制，还要符合并简化操作人操作习惯。 这样，既可以解决发动机转速与负载的匹配问题，又可以取消软轴使机械结构简单，同时价格低了许多，还能通过PLC等控制器根据发动机状态对负载进行调控，还可以根据实际需要修改控制方式和参数以及群控多台发动机；缺点是：由于对发动机的喷油系统无法控制（受发动机制造的约束）仍然不能达到喷油量的最佳控制。据此，我们国内以现在的能力，该做什么？怎么做呢？一 现状调查：根据调查了解：1 我国的一些工程机械厂家为解决发动机油门的远程控制问题，曾使用直流伺服电机控制油门，但都是使用按键控制，问题是首先是油门不能连续随机进行变化，并且操作不准确，最重要的是不能与负载匹配调节

5、。2 汽车（大客车）生产厂，除了使用进口发动机上面带有ECU外，国产或合资企业的发动机均为软轴控制。3 柴油发电机组生产厂，除了使用进口发动机带有ECU，但不能实现横频率控制，国产或合资企业的发动机均为拉线控制。二 行业的需要：1 在工程机械行业：由于工程机械的恶劣环境以及反复大负荷工作情况，使得工程作业部分一般为液压驱动作业，即：我们前面所讲的“发动机拖动电控液压泵站，负载由电控的各种阀门或手动阀门来控制，驱动马达或液压缸作旋转或直线运动执行机构”。驱动马达或液压缸的运动速度，受两个方面的控制，一个是阀门开口大小来决定运动速度，该控制范围小，这主要是作为位置控制，控制精度为主要指标；二是泵的

6、排量大小（受电流控制）决定各个驱动马达或液压缸的运动速度，是主要决定整个系统的速度。因此，工程机械行业需要把执行机构的作业与发动机的转速结合起来，发动机的转速提高时，执行机构的执行力度加大或速度加快，反之则线性减小。一般在操作时，操作者往往希望通过操纵一只手柄（或摇杆、脚踏板）便将上述过程通过自动控制系统自动实现。这就需要将一只手柄（或摇杆、脚踏板）的控制信号，既能控制发动机，又能控制电控泵和控制阀，其控制需要具有随动性，并且加速度受到限制。由于该种设备的工作变化频繁、范围小，因此对于电动油门的要求较严，既要精度高，又要使用寿命长（运动周期长）。2 移动发电机组行业：对于恒转速的要求较高，即：

7、要求发电机的输出电能频率控制在4851Hz,因此要求“移动发电机组”启动后，其自动加速到指定转速，并在恒转速的允许范围内，自动调节油门，当负载的变化引起发动机转速波动时，电动油门控制器通过检测发动机转速，在允许范围内通过PID算法自动调整发动机转速，实现发电机频率恒定。 该种设备的工作变化相对而言不太频繁，但控制精度较高，因此可以不需要考虑长运动周期，但要检测发动机转速，而且控制算法相对复杂一些。3 豪华客车生产行业：客车的工作环境非常恶劣，主要是工作时间长，反复变化多，对使用寿命要求高，质量可靠性要求高，而且对成本要求也比较高。曾经有业内专业人士问过笔者：“发动机电动油门是一个很好的东西，为

8、什么这么多年来没有人来推广呢？”实际上，这是由于客车的工作特性与电动机的材料特性不相适应而造成的。譬如：一般的直流电机的碳刷连续使用寿命一般不超过三千小时；其机械结构（包括步进电机，无刷电机）的使用寿命不超过10万个周期。对于一台平均每天工作10小时的大客车来说，其油门的变化率应为40左右，即每天工作约8小时，改变次数约400个周期。如果将碳刷的使用寿命按反复工作的寿命为连续工作寿命的50左右计算，那么碳刷的寿命应为1500小时，这样一年多的时间碳刷就会磨损。最要命的是机械传动部分的运动周期在一年内就会达到10万次，所以一般的电动机的使用寿命，不能满足大客车的工作特点。所以，我们需要找到一种直

9、流电动机，既能保证质量的可靠性，还能保证使用寿命，同时响应与执行速度要高，而且价格不宜过高。同时，对于发动机转速的控制，可以通过CAN总线方式，可以减少电线使用量，脚踏油门改换成电控脚踏控制器可以使工作量大为减少。三 我们该做什么？ 这是每一个有责任心的业界人士要思考的问题。我们的技术要发展，如果完全依靠外国人，那么我们就准备付出大量的资金，也许它的价值只有1千元，但我们也许却要付出1万元，而且技术永远在他人手里。 这就需要国内的有识之士共同努力，第一步先在电控油门上想办法，第二步改进柴油发动机喷油系统，使之达到最佳功率匹配，以节约燃油。发电机组额定功率 发电机组额定功率的定义随运行方式（备载

10、、常载和连续基本功率）的改变而变化，并随温升和绝缘等的不同而变化。备载、常载和连续基本功率 备载适用于大部分紧急/备用状态，备载额定功率不允许过载。故在设计时，过载能力需考虑更多的设备成本，更多的运行成本和较大的维护工作。备载功率。市电断电时提供备用电源，市电供电可靠，80%负载运行，每年运 行时间200h。某些制造厂商用于高峰期功率补偿几乎无过载能力。常载功率。用于无市电供电场合，可连续使用，70%负载运行，每12h允许10% 过载1h，每年运行时间，负载100%时不允许超过500h。连续基本功率。用于长期与市电母排并联或制造厂商和发电厂基本负载要 求，100%基本额定功率可连续运行（即70

11、%负载运行），无过载能力。发电机组温升、绝缘等级和额定带载能力 发电机组额定功率随发电机温升和绝缘等级不同，其额定带载能力也将变化。H级155oC，备载。155oC指在环境温度40oC基础上，允许温升130oC，即最大绕组温度为170oC。F级105oC，备载。105oC指在环境温度40oC基础上，允许温升105oC。B级80oC，备载。80oC指在环境温度40oC基础上，允许温升80oC。较高环境温度下，发电机额定功率衰减，传统绝缘等级为H。温升定义为绕组温度高于环境温度极值。康明斯电力系统柴油发电机组绝缘等级为H级，备载温升为125oC，常载为105oC。机房冷却/通风系统 机房冷却/通风

12、系统考虑不佳将影响发电机组额定功率，冷却系统可限制发动机功率输出，把可变为有效功率输出的热量通过冷却液释放出去。通风系统可增加燃烧空气的温度，减少冷却系统的冷却效果。发电机组冷却系统 发电机组为机电设备，将化学能（燃料）转换为电能。机房通风应进出平衡，否则温度将越来越高，压力将越来越大。散热水箱式冷却系统设计时应考虑：最高冷却温度、预期运行温度、功率衰减、冷却液膨胀体积。为保证正常起动和带载的最低冷却液温度、监视/安全停机、发动机制造商数据正确、散热水箱/冷却风扇数据正确、运行参数、对环境散热、机体加热器、冷却液流速等。机组散热量的计算 假定柴油产生140 000Btu/Gal热量，转换效率为

13、35%。燃油消耗快速估算方法：发动机燃油消耗使用额定功率（kW）0.07（U.S.gal）（kW）0.0185（L）（1）式中，使用额定功率（kW）先转换为Btu.min-1=(kW)(57)Btu.min-1通常发动机散热通过液体空气热交换冷却系统，大约为燃油消耗产生热量的25%（如需要，请经过精确计算确认）。液体空气热交换（散热水箱）为最普通散热器。其他散热量快速计算法：排气系统30%、幅射散热10%、功率输出35%。通风系统空气计算 通风系统提供发动机燃烧空气，带走机房热量，提供发电机冷却空气，冷却发动机（通过散热水箱）。空气流过系统时，产生较大的温升。发电机组冷却系统的设计要求实际测算

14、，制造厂商的数据仅供参考。不佳的设计难以使发电机组在高温环境下进行满负载运行。Q=MCP（2）式中Q排放热量m流体质量CP在恒定的温度T和压力下允许机房的温度变化空气需求量（cfm）=（58）（散热量）/（温升）（3）空气需求量（cfm）=(58)(B.min-1)/（Fo）（4）式（3）和式（4）要注意单位统一。快速估算。有效排风口通风面积约等于散热水箱面积；有效进风口面积约等 于1.5倍的散热水箱面积。排风回流循环系统。在低温环境下，冷空气进入机房前，允许排风回流，使机组讯速升温。一般设计为常闭（防止外面冷空气回流过机组），由发电机组交流（AC）输出或直流（DC）供给电源。通风系统小结。机

15、房通风系统直接影响发电机组额定功率输出和长期安全、可靠运行。足够的进排风面积，避免进排风短路，理顺空气流向，排风回流地方，直进直出设计机房其他热源（即无隔热的排烟管、锅炉）。注意不同的发动机需求不同，2冲程需要更多的空气。机房隔震和消噪 发电机组摆动需要彻底隔震、防止过早损坏。电缆要软联接。噪声源主要有：进气系统、废气涡轮增压器、燃烧噪声、冷却风扇和次震动。噪声产生 噪声大小和传播远近取决于周围的噪声水平，大多数人难以分辨声3dB（A）差别的2个噪声源，然而6dB（A）差别则为2倍的噪声强度，高频噪声容易听见，精确测试要求环境噪声小于发电机组至少10dB（A）。若系统噪声太大，可能会超出当地法

16、规所允许的范围。机房机组距离的影响。近区域：距离大于2倍的噪声场，噪声级变化较大；自由区域：预计噪声级距离2倍减少6dB（A）；反射区域：自由区域，临近反射区域。消噪措施The diesel engine electronically controlled fuel injection throttle Status and Development DirectionAt present, some well-known diesel engine manufacturers in the international arena, such as: U.S. CATERPILIER compa

17、nys 3126 series engine; German MAN engines and so on, has now adopted the ECU electronic control technology to control the fuel injection quantity and speed of the engine, the advantages : the amount of fuel can be adjusted automatically according to the size of the load and engine speed lift accele

18、ration to get the best match control, speed control to cancel the traditional flexible shaft and the mechanical structure simplifies; the disadvantages are: expensive, especially for construction machinery to said, due to their ECU software security, control methods and parameters can not be modifie

19、d to accommodate the special needs of the construction machinery, therefore, only small quantities in our country.In our country, the current engine manufacturers, both domestic and joint venture products, such as: Cummins Engine, Steyr engine, moral hereby engine, one domestic brand engines, such a

20、s: Shanghai Diesel Engine Factory Engine . Due to the blockade of the foreign products, technologies, key technologies have not yet been fully utilized, especially some high-tech control technology, including hardware, software, etc., including of course the engine ECU electronic control technology,

21、 subject to foreign, coupled with the countrys domestic technology due to foreign products ideological restraints, only the things of others make use of high-tech technology is basically in the technology gaps.I think: If we suddenly get rid of to all the technical problems, there are some unrealist

22、ic, but can be other ways to solve the above problems, for example, stresses: the first step in the first diesel engine electric control throttle to replace the ECU electronic control technology to control the engine. The second step, the engine manufacturers with the gradual completion of the autom

23、atic control of engine fuel injection quantity.Since the ECU electronic control technology is the engine fuel injection quantity control, our existing technology is not yet possible to achieve the best match of the power torque curve. But we can look for other ways based on the injection pump withou

24、t changes, we can made the diesel engine electric control throttle makes the engine speed and load power to achieve the best match.For example: construction machinery, engines, drag electronically controlled hydraulic pump station, pump displacement by the current size of the control (non-electronic

25、ally controlled hydraulic pump station, due to the protective effect of the relief valve in the system, the device does not work, the engine the maximum load, the least efficient heat maximum). It can be said in the same load case, the pump displacement is equivalent to the load power, the load torq

26、ue increases in engine speed and pump displacement increases, according to the torque T = the FL = m a L, When the acceleration increases, the torque inevitably increases, then the engine throttle and hydraulic pump displacement between the organic combination of simultaneous control, but also to co

27、mply with and simplify the operating habits of the operator.Both engine speed and load matching problem can be solved, they can cancel the flexible shaft mechanical structure, while the price is low, but also through the PLC and other controllers based on the condition of the engine load regulation

28、can also be modified according to actual needs control mode and parameters, as well as group control more than one engine; The disadvantage is that: (engine manufacturing constraints) still can not achieve optimal control of the fuel injection quantity can not control the engines fuel injection syst

29、em.Accordingly, our domestic ability to now do? What to do?A. Survey:According to the survey to know:A. To solve the problem of remote control of engine throttle, some of our construction machinery manufacturers have used the DC servo motor to control throttle, but they are key control, the problem

30、is first and foremost the throttle can not be continuous random changes, and the operation is not accurate, the most important can not match the load regulation.Two. Motor vehicles (buses) production plant, in addition to the top of the imported engines with ECU, the engine of domestic or joint vent

31、ures are flexible shaft control.3. Diesel generator set production plant, in addition to the use of imported engine with the ECU, but not the horizontal frequency control, the engine of domestic or joint ventures are PULL control.Two. The needs of the industry:A. In the construction machinery indust

32、ry:Due to the harsh environment of construction machinery and repeated heavy load, the project was operating some of the general operations, namely: in front of us said engine drag electronically controlled hydraulic pump station, load by electronically controlled valves or hydraulic drive manual va

33、lves to control the drive motor or hydraulic cylinder for rotary or linear motion of the implementing agencies .The velocity of the drive motor or hydraulic cylinder, controlled by two aspects of a valve opening size to determine the velocity, the control range, which is mainly as a position control

34、, the control precision as the main indicators; the exhaust of the pump volume size (by the current control) to determine the velocity of each drive motor or hydraulic cylinder, is a major determinant of the speed of the entire system.Therefore, the construction machinery industry needs to combine t

35、he executive body of the job and the engine speed, the engine speed increases, the enforcement of the implementing agencies to increase speed, and vice versa decreases linearly.General operation, the operator often by manipulating a lever (or joystick, pedals) put the above process by the automatic

36、control system automatically.This need to be a lever (or joystick, pedals) and the control signal, both to control the engine, but also to control the electronically controlled pump and control valve, control needs to have with mobility, and the acceleration is restricted.Due to frequent changes in

37、the kinds of equipment, the scope, the requirements for electric throttle is more stringent, both to high precision, but also long life (movement cycle).Two. Mobile generator sets industry:Higher, namely: requirements for constant speed requirements of the generator output power frequency control in

38、 the 48 51Hz, thus requiring the start of the mobile generator sets, automatic acceleration to the specified speed and constant speed within the allowable range, the automatic the throttle, when the load changes caused by fluctuations in engine speed, the electric throttle controller by detecting th

39、e engine speed within the allowable range by the PID algorithm automatically adjusts the engine speed, generator frequency constant.Changes in the work of the equipment is relatively less frequent, but the control precision is high, so no need to consider the long movement cycles, but to detect the

40、engine speed control algorithm is relatively complex.3. The luxury bus manufacturing industry:Bus work environment is very harsh, long working hours, and repeated changes, life requirements, quality, reliability requirements, and cost requirements.There have been professionals in the industry asked

41、the author: The electric engine throttle is a good thing, why do so many years to promote it?In fact, this is caused by the bus operating characteristics are incompatible with the material properties of the motor. Such as: continuous service life of the carbon brushes of the DC motor is generally no

42、t more than 3000 hours; its mechanical structure (including the life of the stepper motor, brushless motor), not more than 100,000 cycles. Bus for an average 10 hours a day, the rate of change of the throttle for about 40%, for about eight hours a day, change the number of about 400 cycles. If the c

43、arbon brush service life of the life of the repeated work for about 50% of the working life, then the life of carbon brushes should be 1500 hours, so more than a year the carbon brushes will wear. The most terrible is that the mechanical transmission part of the movement cycle will reach 100,000 wit

44、hin a year, so the general life of the motor can not meet the work characteristics of the bus.Therefore, we need to find a DC motor, can guarantee the quality and reliability, but also to ensure that the service life, while responding to the higher execution speed and the price should not be too hig

45、h.The same time, the engine speed control, the way through the CAN bus can reduce the amount of wire to use, the foot throttle a switch from the electronic control foot controller can be greatly reduced workload.Three. What do we do?It is each responsible people in the industry to think about. To de

46、velop our technology, if you rely entirely on foreigners, then we prepared to pay a lot of money, maybe its worth only $ 1,000, but we may have to pay 10,000 yuan, but the technology is always in the hands of others.Which require domestic insight joint efforts, the first step to think of ways on the

47、 electronic throttle control, the second step to improve diesel engine fuel injection system, so as to achieve optimum power match, in order to save fuel.Genset Power ratingThe definition of the generator set rated power with the operating mode (standby, often set out and the change of continuous po

48、wer), and with different temperature rise and insulation, and other changes.Prepared to set out, often contained and continuous basic powerPrepare the set for most of the emergency / standby, prepared to set out the rated power is not allowed to overload. Therefore, at design time, the overload shou

49、ld be considered more equipment costs, additional operating costs and maintenance.Prepared to set out the power. Mains failure to provide backup power, reliable electricity supply, 80% load running annual running time of 200h. Some manufacturers for the peak of the power compensation almost no overl

50、oad.Often contained power. For no electricity supply situations, continuous use, 70% load operation, and on and on every 12h to allow 10 percent the past contained 1h, annual run-time load 100% does not allow more than 500h.Continuous power. For long-term electricity busbar parallel or manufacturers

51、 and power plants are base load requirements, 100% rated power continuous operation (70% load operation), no overload.Generator set temperature, insulation class and rated load capacityGenerator set rated power with the generator temperature rise and insulation class is different, its rated load cap

52、acity will also change.Class H-155oC to list. 155oC the allowable temperature rise on the the 40oC basis of the ambient temperature, 130oC, the maximum winding temperature of 170oC.Class F-105oC to list. 105oC refers to the ambient temperature of 40oC on the basis of the allowable temperature rise 1

53、05oC.Class B-80oC to list. 80oC refers to 40oC on the basis of the ambient temperature, allowing the temperature rise of 80oC.Higher ambient temperatures, the generator rated power attenuation of traditional insulation class H-.The temperature rise is defined as the winding temperature higher than t

54、he ambient temperature extremes.Cummins Power Generation diesel generator sets insulation class H, prepared contained a heating rate of 125oC, often set out to 105oC.Computer room cooling / ventilation systemComputer room cooling / ventilation system to consider the poor will affect the rated power

55、of generator sets, cooling system to limit the engine power output becomes effective power output of the heat release through the coolant. The ventilation system can increase the combustion temperature of the air, reducing the cooling effect of the cooling system.The cooling system of generator sets

56、Generating units for mechanical and electrical equipment, chemical energy (fuel) is converted to electricity. Engine room ventilation should be out of balance, otherwise the temperature will be higher and higher, the pressure will be more and more. Radiator cooling system design should be considered

57、: the maximum cooling temperature, the expected operating temperature, power attenuation, coolant volume expansion. Minimum coolant temperature monitor / safety shutdown, the engine manufacturer to ensure the normal start-up and load data, Radiator / cooling fan data is correct, the operating parame

58、ters on the thermal environment, body heater, coolant flow rate.The calculation of the unit heat dissipationAssumes that diesel to 140 000Btu/Gal heat, the conversion efficiency of 35%. The fuel consumption of fast estimation methods:Engine fuel consumption = rated power (kW) 0.07 (USgal) = (kW) 0.0185 (L) (1), use the rated power (kW) is first converted toBtu.min-1 = (kW) (57) Btu.min-1Usually the engine cooling