History of Internal Combustion Engine

The internal combustion engine is famous for its high thermal efficiency, compact structure, high mobility and easy operation and maintenance. For more than one hundred years, the tremendous vitality of the internal combustion engine has endured. At present, the number of internal combustion engines in the world greatly exceeds that of any other heat engine and occupies a rather important position in the national economy. The modern internal combustion engine has become the largest amount of today, the most widely used, no one with the most important thermal energy machinery.

Of course, the internal combustion engine also exists a lot of shortcomings, mainly: high fuel requirements, can not be directly combusted with poor-quality fuels and solid fuels; due to the intermittent gas exchange and the difficulties in manufacturing, the increase in the power of a single machine is limited, the maximum power of the modern combustion engine is generally less than 40,000 kilowatts, while the power of a single steam engine can be as high as hundreds of thousands of kilowatts; the combustion engine can not be reversed; the noise and harmful components of exhaust gas in the internal combustion engine on the environment. The noise of the internal combustion engine and the pollution of the environment by the harmful components of the exhaust gas are especially prominent. It can be said that the history of the development of the internal combustion engine over the past hundred years is the history of human beings who have constantly innovated and challenged to overcome these shortcomings.

The development of the internal combustion engine has a history of about one and a half centuries. Like other sciences, every progress of the internal combustion engine is a generalization and summary of the practical experience of human production. The invention of the internal combustion engine began with the study and improvement of the piston steam engine. In the history of its development should be particularly mentioned is the German Otto and Diesel, it is they summarized the previous countless practical experience on the basis of the internal combustion engine work cycle put forward a more perfect Otto cycle and Diesel cycle, only to get them so far in the decades of countless people's practical and creative activities have been scientifically summed up, and there is a qualitative leap, they will be before the crude, purely empirical, They will predecessor rough, purely empirical, fragmented experience, to inherit, develop, summarize, improve, and find out the regularity of the modern gasoline and diesel engine thermal cycle laid the thermodynamic foundation for the development of internal combustion engines made a great contribution to the development.

Reciprocating piston internal combustion engine

There are many kinds of reciprocating piston internal combustion engines, and the main classification methods are as follows: according to the different fuels, they are divided into gasoline engines, diesel engines, kerosene engines, gas engines (including all kinds of gaseous combustion engines), etc.; according to the number of strokes of each working cycle, they are divided into four-stroke and two-stroke; according to the different ways of ignition, they are divided into ignition and compression ignition; according to the different cooling methods, they are divided into ignition and compression ignition. According to the different ways of cooling, it is divided into water-cooled and air-cooled; according to the different forms of cylinder arrangement, it is divided into in-line, V-type, opposed, star, etc.; according to the different number of cylinders, it is divided into single-cylinder combustion engine and multi-cylinder combustion engine, etc.; according to the different uses of the internal combustion engine, it is divided into automotive, agricultural, locomotive, marine and stationary, etc. This paper will mainly focus on gas engine, gas engine and gas engine, and will also focus on the different types of internal combustion engine. This article will focus on the gas engine, gasoline engine, diesel engine such a development pulse to introduce to you.

The earliest internal combustion engine--gas engine

The earliest internal combustion engine is the gas engine which is fueled by gas. 1860, the French inventor Lenoir made the first practical internal combustion engine (a single-cylinder, two-stroke, uncompressed and electrically ignited gas engine, with an output of 0.74-1.47KW, rotating speed of 0.5kW and a speed of 0.5kW). -1.47KW, speed of 100r/min, thermal efficiency of 4%). The French engineer De Rosa realized that to improve the thermal efficiency of the internal combustion engine as much as possible, it is necessary to make the cooling area per unit cylinder volume as small as possible, the rate of the piston during expansion as fast as possible, and the range of expansion (stroke) as long as possible. On this basis, he proposed in 1862 the famous four-stroke cycle of isovolumetric combustion: intake, compression, combustion and expansion, exhaust.

In 1876, Otto, a German, made the first four-stroke reciprocating piston internal combustion engine (single-cylinder, horizontal, gas-fueled, power of about 2.21KW, 180r/min). In this engine, Otto increased the flywheel to make smooth running, lengthened the intake tract, and improved the cylinder head to make the mixture fully formed. This was a very successful engine, with a thermal efficiency equivalent to twice that of the steam engine of the time. Otto integrated three key technical ideas: internal combustion, compressed gas, and four-stroke into one, giving this internal combustion engine a series of advantages such as high efficiency, small size, light weight, and high power. At the Paris Universal Exhibition in 1878, it was hailed as "the greatest achievement in the power engine since Watt". The four-stroke cycle of equal-capacity combustion was realized by Otto and is also known as the Otto cycle.

Though the gas engine was superior to the steam engine, it could not meet the requirements of high-speed, lightweight and other features of the transportation industry in the case of socialized mass production. Because it is fueled by gas, need a huge gas furnace and pipeline system. And the calorific value of gas is low (about 1.75×107～2.09×107J/m3), so the speed of the gas engine is slow and the specific power is small. In the second half of the 19th century, with the rise of the petroleum industry, the use of petroleum products to replace gas as fuel has become an inevitable trend.

The emergence of the gasoline engine

1883, Daimler and Maybach made the first four-stroke reciprocating gasoline engine, this engine is installed on the Maybach designed carburetor, but also with incandescent tubes to solve the ignition problem. Whereas the speed of internal combustion engines had previously been no more than 200 r/min, Daimler's gasoline engine jumped to 800-1000 r/min. It was characterized by high power, light weight, small size, high speed and high efficiency, and was particularly suitable for transportation. At the same time, Benz developed the ignition and water-cooled cooler that are still in use today.

By the end of the nineteenth century, the main centralized piston internal combustion engines had largely entered the practical stage and were soon showing great vitality. The internal combustion engine has been continuously improved and innovated in a wide range of applications, and has so far reached a high level of technology. In such a long history of development, there are two important stages of development is epoch-making: one is the rise of the 50's supercharging technology in the engine on the wide range of applications; and then is the 70's in the development of electronic technology and computers in the application of the engine development, the two development trends are still in the ascendant

First of all, let's take a look at the gasoline engine in the development of this century. Driven by the automobile and aircraft industries, gasoline engines have made great progress. According to improve the power of gasoline engines, thermal efficiency, specific power and reduce fuel consumption and other major performance indicators of the process, the development of gasoline engines can be divided into four stages.

The first stage is the first two decades of this century, in order to adapt to the requirements of transportation, to improve the power and specific power. The main technical measures taken to increase speed, increase the number of cylinders and improve the corresponding auxiliary devices. During this period, the rotational speed was increased from 500-800r/min in the last century to 1000-1500r/min, and the specific power was increased from 3.68W/Kg to 441.3-735.5W/Kg, which is of great significance for improving the flight performance of airplanes and the loading capacity of automobiles. great significance.

The second stage of the time in the 20's, mainly to solve the problem of gasoline engine burst combustion. At that time, the compression ratio of gasoline engines reached 4, gasoline engine burst. General Motors research laboratory of the United States Miguel and Bowie through the addition of a small amount of tetraethylaluminum in gasoline, interference with oxygen and gasoline molecules of the normal process of chemosynthesis, to solve the problem of vibration, so that the compression ratio from 4 to 8, greatly improving the power of gasoline engines and thermal efficiency. At that time, another serious impact on the power and thermal efficiency of gasoline engines is the shape and structure of the combustion chamber, the British Ricardo and his collaborators through a variety of combustion chambers and combustion principles of research, improved combustion chambers, so that the power of the gasoline engine increased by 20%.

The third stage was from the late 1920s to the early 1940s, and was mainly concerned with equipping gasoline engines with superchargers. Exhaust gas turbocharging can be increased to 1.4-1.6 atmospheric pressure, his application for the improvement of gasoline engine power and thermal efficiency opened up a new way. But its real widespread use was popularized only in the late 1950s.

The fourth stage from the 50's to the present, gasoline engine technology before the principle of major changes in the development of the nearly extreme. It became more and more compact and higher speed. The current state of the technology: in-cylinder injection; multi-valve technology; intake air flow, thin stratified combustion; electronic control of ignition timing, gasoline injection and air-fuel ratio with the conditions of precise control of the overall electronic engine management; exhaust gas in the cycle and three-way catalytic and other exhaust purification technology. It is concentrated in the successful development and production in recent years, the cylinder direct injection stratified gasoline engine (GDI).

But with the application of electronic technology in the engine since the 70s, the improvement of internal combustion engine technology provides the conditions for the internal combustion engine basically meets the current requirements of the world's emission, energy saving, reliability and comfort. Internal combustion engine electronic control now includes electronically controlled fuel injection, electronically controlled ignition, idle control, emission control, air intake control, boost control, warning tips, self-diagnosis, failure protection and many other aspects.

The same internal combustion engine electronic control technology development can be roughly divided into four stages:

1, internal combustion engine parts or local system of individual control, such as electronic fuel pump, electronic ignition device.

2, the internal combustion engine single system or several related systems of independent control, such as fuel supply system control, optimal air-fuel ratio control.

3, the whole internal combustion engine unified intelligent control, such as the internal combustion engine electronic control system.

4, the device and the centralized electronic control of internal combustion engine power, such as automobiles, ships, generating sets of centralized electronic control system.

Electronic control systems are generally composed of sensors, actuators and controllers. This constitutes a variety of different functions, different purposes of the control system. Its main goal is to maintain the best value of the engine operating parameters, in order to find the best balance of engine power, fuel consumption and emissions performance, and monitor the operating conditions. Such as Caterpillar's 3406PEPC system is a 3406 diesel engine with variable program engine control system, with electronic speed control function, the use of electronic control of the air-fuel ratio, can be sprayed with the advance angle is always maintained at the optimal value. The United States Stanaclyne company will produce the DB-type distribution pump into an electronically controlled injection pump, known as the PFP system, the use of stepper motors as an executive element to control the amount of fuel injection and injection timing

Diesel - another star of the internal combustion engine family

Diesel engines are almost the same time as the development of gasoline engines, they have many advantages. developed at the same time, they have many points in common. So the development of the diesel engine also has many similarities with the gasoline engine, it can be said that in the entire history of the development of the internal combustion engine, they are driving each other.

Dr. Diesel of Germany in 1892 to obtain compression ignition compressor technology patents, in 1897 made the first compression ignition "Diesel" internal combustion engine, that is, diesel engine.

The high compression ratio of the diesel engine brings many advantages:

1, not only can eliminate the carburetor and ignition device, improve the thermal efficiency, and can be used much cheaper than gasoline diesel fuel.

2, diesel engine because of its compression ratio, maximum power point, low fuel consumption per unit of power. In the modern excellent engine, diesel fuel consumption is about 70% of the gasoline engine. Especially like cars, usually under part-load conditions, its fuel consumption is about 60% of the gasoline engine. The diesel engine is currently the most thermally efficient internal combustion engine.

3, diesel engine because of high compression ratio, the engine is strong, so durable, long life.

At the same time, high compression ratio also brings disadvantages:

1, the structure of the diesel engine is bulky. Usually the unit power of diesel fuel is about 1.5-3 times the mass of gasoline engines. Diesel engine compression ratio is high, the outbreak of pressure is also high, up to about 1.5 times the gasoline engine (without pressurization). In order to withstand the high temperature and high pressure, it requires a strong structure. So the diesel engine was initially used only as a stationary engine.

2, in the same displacement, the diesel engine power output is about 1/3 of the gasoline engine, because the diesel engine to inject fuel directly into the cylinder, can not make full use of air, the corresponding power output is low. Assuming that the gasoline engine air utilization rate of 100%, then only 80% to 90% of the diesel engine. Another reason for the small power output of diesel engines is the compression ratio, the engine friction losses than gasoline engines. This friction loss is directly proportional to the speed, can not be expected to increase speed to improve power. The highest speed of gasoline engines can run more than 10,000 times per minute (such as racing engines), while the maximum speed of diesel engines is only 5,000r/min.

In recent years, the thermal efficiency of diesel engines increased by nearly 80%, than the power to increase dozens of times, the air utilization rate of 90%. The technical level of today's diesel engine performance: excellent combustion system; the use of 4-valve technology; ultra-high-pressure injection; supercharging and supercharged intercooling; controlled exhaust gas recirculation and oxidation of catalytic converters; reduce the noise of the double-spring injector; full electronic engine management, etc., concentrated in the use of electronically controlled ****-rail type fuel injection system as a feature of the new generation of diesel engines. At present, Japan's Nippondeno (ECDU2), Germany Bosch (ZECCEL) and the U.S. Caterpilla (HELII) is the research and production of *** rail-type electronically controlled fuel injection system of the main companies.

The application of supercharging technology in diesel engines is a little later than in gasoline engines. As early as in the 20's was proposed to compress air to improve the intake density of the idea, until 1926 the Swiss A.J. Burjuhi only the first design of a supercharged engine with exhaust gas turbocharger. Due to the technical level and process, material limitations, it is difficult to manufacture a good performance turbocharger, coupled with the impact of the Second World War, supercharging technology to be able to quickly popularize, until the end of the war, the research and application of supercharging technology has only been paid attention to. 1950 supercharging technology began to be used in diesel engines and as a product to provide the market.

In the 1950s, the degree of supercharging is about 50%, the average effective pressure of the four-stroke machine is about 0.7-0.8MPa, no intercooling, in a lower level of technology development stage. During the following 20 years, pressurization technology has been rapidly developed and widely adopted.

In the 1970s, the degree of supercharging up to 200% or more, formally provided as a commodity diesel engine average effective pressure, four-stroke machine has reached more than 2.0MPa, two-stroke machine has more than 1.3MPa, the widespread use of intercooling, so that the high increase in the sub (> 2.0MPa) four-stroke machine is practical. Single-stage boost ratio close to 5, and the development of two-stage supercharging and ultra-high boost system, relative to the early 1950s just adopted the level of engine technology of supercharging technology, 30 years has been an amazing development.

Entering the 80s, this development momentum is still maintained. Optimized design of the intake and exhaust systems to improve the filling efficiency and make full use of the exhaust gas energy, the emergence of resonance intake system and MPC supercharging system. Variable cross-section turbocharger, so that the single-stage turbocharging ratio can reach 5 or even higher. With the ultra-high supercharging system, the pressure ratio can reach more than 10, while the compression ratio of the engine can be reduced to less than 6, and the power output of the engine can be increased by 2-3 times. Further development to the composite two-stage turbocharging system with power turbine. It can be seen that the effect of high and ultra-high supercharging is considerable, raising engine performance to a whole new level.

The rotary internal combustion engine

In the history of the steam engine there was an evolution from the reciprocating piston steam engine to the steam turbine. This is a great inspiration for the development of the internal combustion engine. Reciprocating internal combustion engine movement through the crankshaft linkage mechanism or cam mechanism, pendulum mechanism, rocker mechanism, etc., converted to the power output shaft rotation, which not only makes the mechanism complex, but also due to the friction loss of the rotating mechanism, but also reduces the mechanical efficiency. In addition, due to the reciprocating motion of the piston group caused by the reciprocating inertia force of the crank linkage mechanism, this inertia force is proportional to the square of the rotational speed. With the increase of rotational speed, the inertia load on the bearings increases significantly and produces strong vibration due to the imbalance of inertia force. In addition, the reciprocating internal combustion engine has a complex valve control mechanism. So people envisioned: since most of the form of motion of the tool machine is the rotation of the shaft, can follow the path from the reciprocating piston steam engine to the steam turbine, so that the heat energy is directly converted into shaft rotation? So people began to explore in this field.

Gas turbine

In 1873 Brayton (GeorgeBrayton) made a fixed-pressure combustion engine. The machine can provide the gas fully expanded to atmospheric pressure issued by the power. the early 20th century, France's Amanca (BeneArmangaud) and other successful application of the principle of the Brayton cycle made of gas turbines. However, because of the limitations of the conditions at that time, the thermal efficiency was very low and failed to develop.

To the 30's, because of the aerodynamics and high temperature alloy materials and cooling system progress, for the gas turbine into practical conditions. Although the gas turbine is an internal combustion engine, but it is not like reciprocating internal combustion engine must be in a closed space and limited time combustion restrictions, so it will not occur like gasoline engines like the fear of bursting, but also very little like diesel engines by the friction loss of the limitations; and fuel combustion of the gas produced by the impeller directly drive the rotation, so it is a simple structure (compared with the piston type internal combustion engine, its components are only for it 1 /6 or so), light weight, small size, operating costs, and easy to use a variety of fuels, but also less likely to fail. Although the gas turbine still exists in some shortcomings: short life, the need for high-grade heat-resistant steel and high cost and emissions (mainly NOx) is more serious, resulting in so far the application of gas turbines are still limited to aircraft, ships, power plants and locomotives, but due to the advantages of the Bratton cycle and the gas turbine on the fuel less restrictive and the other advantages mentioned above, so that it is still for the present and the future of the people are committed to researching the power of one of the technology. technology. If the breakthrough turbine inlet temperature, greatly improve the thermal efficiency, and to overcome other shortcomings, the gas turbine is expected to replace the steam and diesel engines.

Rotary piston engine

Has been committed to the construction of rotary engines, the goal is to avoid the inherent complexity of reciprocating engines. More than 2,000 rotary engine proposals were made before 1910, and in the early 1900s many more different proposals were put forward, but most could not be realized because of the complexity of the structure or the inability to solve the cylinder sealing problem. Until 1954, the German Wankel (FelixWankel) after a long period of research, breakthroughs in the cylinder seal this key technology, only to make the long and short amplitude circular external rotary wheel line cylinder triangle rotary piston engine for the first time running successfully. Rotor every turn can realize the intake, compression, combustion expansion and exhaust process, according to Otto cycle operation. 1962 triangular rotor engine as a marine power, to the 80's Japan Toyo Kogyo used it for automobile engines.

The rotor engine has a series of advantages:

1, it eliminates the crank linkage mechanism, valve mechanism, etc., to achieve high speed.

2, light weight (1/2 to 1/3 less mass than reciprocating internal combustion engines), simple structure and operation (40% fewer parts than reciprocating, 50% less volume).

3. There are also improvements in exhaust pollution, such as less NOx production.

But rotor engines also have serious shortcomings:

1.. The structure has poor sealing performance and has so far been used only as a gasoline engine with a low compression ratio.

2. Difficulty in organizing an economical combustion process due to the low torque brought about by high speed.

3, short life, low reliability and processing of long and short axis rotary wheel line of the special machine tool construction complex.

The development trend of the internal combustion engine

The invention of the internal combustion engine has been more than 100 years of history. If the invention of the steam engine is considered the first power revolution, then the introduction of the internal combustion engine deserves to be the second power revolution. Because it is not only a big leap in the history of power, but also its wide range of applications, the number of any other power machinery is unparalleled today. With the development of science and technology, the internal combustion engine in the economy, power, reliability and many other aspects of the amazing progress, for mankind has made great contributions. It took a century for the steam engine to be completed, another century for it to flourish, and about a century for it to decline. The invention of the internal combustion engine also took a century, and since then, mankind has moved forward another century, and it can be said that the internal combustion engine is now in its prime. Today, at the turn of the century, we are concerned about the future of the internal combustion engine, people are waiting for the same time, but also hope that the internal combustion engine in the new century to create another brilliant performance. Here I will show you the development trend of the internal combustion engine in the new century.

Booster technology for internal combustion engines

From the development pattern of important parameters of internal combustion engines (pressure, temperature and speed), it can be found that these three parameters increased rapidly with the passage of time before 1900. After 1900, especially after 1950, the temperature, speed to improve the slow, while the average effective pressure with the increase of the years is still straight up. It has been proved that increasing the average effective pressure can greatly improve the efficiency and reduce the quality. And improve the average effective pressure of the technology is to improve the degree of pressurization. Such as diesel pressurization can significantly reduce the size of the diesel intake pipe, and so that the cylinder has a large enough inflatable efficiency used to improve the power of the diesel engine, so that it can be in a wide range of speeds both to improve the power and have a large torque. A supercharged intercooled diesel engine can make the power increased exponentially, while the cost of only 15% to 30%, that is, the cost per horsepower can be reduced by an average of 40%. So supercharging, high boost, ultra-high boost is one of the important development direction of the current internal combustion engine. But this is only one aspect of the problem, another aspect of the engine strengthening and ultra-strengthening will give parts and components to bring excessive mechanical load and thermal load, especially the thermal load problem has become a further strengthening of the engine limitations; and then a single-stage high-efficiency, high-pressure pressure than the pressurization of the pressurization technology has also limited the further development of the technology, so it is not the higher the higher the better the degree of pressurization.

Electronic control technology of internal combustion engine

Electronic control technology of internal combustion engine was produced in the late 1960s, through the development of the 1970s, the 1980s tend to mature. With the further development of electronic technology, the internal combustion engine electronic control technology will assume a more important task, its control surface will be wider, the control accuracy will be higher, the level of intelligence will be higher. Such as combustion chamber volume and shape change control, compression ratio change control, working condition of mechanical wear detection control and other difficult internal combustion engine control will become a reality and widely used. Internal combustion engine electronic control is from a separate control to integrated, centralized control direction, is from the control of low efficiency and low precision to the control of high efficiency and high precision development. As mankind enters the electronic age, the internal combustion engine of the 21st century will also step into the "electronic age of the internal combustion engine", and its development will be compatible with the high-speed development of electronic technology. Electronic control technology of internal combustion engine is the main technical support for internal combustion engine to adapt to the social development demand, and it is also the important influence factor for internal combustion engine to keep the splendor of the 21st century.

Internal combustion engine material technology

The traditional materials used in internal combustion engine are steel, cast iron and non-ferrous metals and their alloys. In the process of internal combustion engine development, people constantly put forward higher requirements for its economy, power, emissions, etc., thus the requirements for internal combustion engine materials are correspondingly increased. According to the future development goal of the internal combustion engine, the requirements for internal combustion engine materials mainly focus on adiabatic properties, heat resistance, wear resistance, friction reduction, corrosion resistance, and thermal expansion of small, lightweight and other aspects. To promote the development of internal combustion engine materials, in addition to changing the chemical composition and content of the material to achieve the required physical and mechanical properties of parts and components of the conventional method, can also be used to strengthen the surface of the process to make the material to achieve the desired requirements, but the development of internal combustion engine materials more need to adapt to the development of different working conditions of the new material. Compared with the traditional materials for internal combustion engines, ceramic materials have unparalleled thermal insulation and heat resistance, ceramic materials and engineering plastics (such as fiber-reinforced plastics) has a superior friction reduction than the traditional materials, wear resistance and corrosion resistance, its specific gravity is not comparable to aluminum alloys and much lighter than steel and cast iron. Therefore, ceramic materials (high-performance ceramics) by virtue of its excellent overall performance, can be used in many internal combustion engine parts, such as fuel injection parts, combustion chambers, piston tops, etc., if the brittleness, cost and other aspects of the weaknesses can be overcome, in the new century will be widely used. Engineering plastics can also be used for many internal combustion engine parts, such as internal combustion engines on a variety of cover, piston skirt, timing gears, push rods, etc., with the improvement of technology and price reduction, the future application of engineering plastics in the internal combustion engine will increase day by day. Comprehensive internal combustion engine of various materials, in order to maximize the strengths and avoid the weaknesses in the new material on the basis of the development of a metal, plastic or ceramic as the substrate for a variety of composite materials, and began to gradually promote the use of internal combustion engines.

Looking ahead to the new century, in the next period of time, steel, cast iron and non-ferrous metals and their alloys, will still be the main materials for internal combustion engines. A variety of surface strengthening process will be more advanced and widely used. To metal, plastic, ceramic as a substrate for a variety of composite materials will be 10 years later into the amazing high-speed promotion period, the use of new materials in the internal combustion engine will also be accelerated at the same time.

Internal combustion engine manufacturing technology

The level of development of the internal combustion engine depends on the level of development of its parts and components, and the level of development of the internal combustion engine parts and components, by the production of manufacturing technology and other factors to determine. That is to say, the level of manufacturing technology of internal combustion engine parts and components, the performance of the host, life and reliability have a decisive impact. Similarly, the relationship between manufacturing technology and equipment is inextricably linked, whenever a new generation of equipment or process materials developed successfully, will bring breakthroughs to the innovation of manufacturing technology. Into the new century, the development of science and technology will be exceptionally rapid, the development cycle of new equipment will be shorter and shorter, so the new century, the internal combustion engine manufacturing technology is bound to form a rapid development of the situation.

As a result of the improvement of casting technology level, gas impulse molding, static pressure molding, resin self-hardening sand molding core, disappearance mold casting, so that the internal combustion engine casting of the main parts, such as body, cylinder head can be made into the shape of complex curved surfaces and box-type structure of the thin-walled castings. This not only to a large extent to improve the rigidity of the body, reduce the noise radiation, and make the internal combustion engine to achieve lightweight. As like spraying, remelting, sintering, surfacing, electrochemical processing, laser processing and other local surface strengthening technology advances, so that the material function to get the perfect play; due to the level of equipment to improve the processing and manufacturing technology to high-precision, high-efficiency, automation direction, driven by the internal combustion engine parts and components production to a high degree of centralization development. On the other hand, the promotion of flexible manufacturing technology, so that the internal combustion engine product renewal with greater flexibility and adaptability. Multi-species small batch production of flexible manufacturing system has caused a wide range of manufacturers of internal combustion engines recognized, but also in line with the development of production technology and changes in the market situation. The application of electronic technology and computer in design, manufacturing, testing, inspection and process control has promoted the technical progress of the industry and improved the quality of internal combustion engine products. The development of new materials has also promoted the change of the production process of internal combustion engine parts, especially the use of engineering plastics, ceramic materials and composite materials in the internal combustion engine, which strongly promotes the development of the internal combustion engine manufacturing technology. With the development of internal combustion engine electronic control technology, the three major components of the electronic control system (sensors, actuators, control units) will become an important branch of the internal combustion engine parts and components industry, and at the same time to the traditional internal combustion engine manufacturing industry puts forward new issues.

From this, we can infer: in the 21st century, the internal combustion engine manufacturing technology will be to the high precision, diversified aspects of rapid development. The speed and direction of its development is not only related to the quality of the internal combustion engine, but also has a direct impact on the future of the internal combustion engine. In terms of its product technology progress, automobile internal combustion engine development is the fastest, followed by locomotives, ships, generator sets, construction machinery, agricultural machinery, and so on.

Alternative fuels for internal combustion engines

As a result of the world oil crisis and engine exhaust pollution of the environment is becoming increasingly serious, the research of internal combustion engine technology to energy efficient and the development and utilization of clean alternative fuels. Based on the gasoline and diesel engines for transformation or redesign, the development of natural gas, liquefied petroleum gas and hydrogen as fuel gas engine for the current and future period of time for the internal combustion engine technology is one of the focuses. Among them, the power recovery technology of gas engine and the combustion control of hydrogen engine is one of the most important.

Summary

Internal combustion engine in the application of continuous development, a variety of internal combustion engines compete with each other, mutual penetration, mutual synthesis, from which evolved a variety of new hybrid engine. Such as the invention and development of gas turbines on the one hand, the formation of competition for diesel engines, on the other hand, also supplemented the diesel engine, so that the diesel exhaust gas turbocharging has been perfected, in turn, enhance the competitiveness of the diesel engine. Gas turbine is also a competitor of steam turbine, but people put gas turbine and steam turbine which are two kinds of heat engines working according to different heat cycle together, constituting a new kind of high-efficiency cycle: gas - steam turbine combined cycle. The second law of thermodynamics tells us that in order to improve the thermal efficiency, the heating temperature of the heat engine should be increased as much as possible and the heat exhaust temperature should be lowered. The heat exhaust temperature of the steam engine is low (about 300K), but due to the characteristics of the water vapor itself and the limitation of the equipment conditions, its heating temperature cannot be too high, and it is currently stabilized at below 800-900K. With the development of metallurgy and cooling technology, the heating temperature of the gas turbine has been on the rise, and now it has reached about 1300-1500K; however, its heat discharge temperature can not be too low, generally 700-800K, or even higher. So the actual thermal efficiency of these two kinds of heat engines at present has not exceeded 40%. Gas - steam combined cycle, the exhaust of the gas turbine will be sent to the waste heat boiler to produce steam for steam turbine utilization. The combined cycle has the dual advantage of a high heating temperature for the gas turbine and a low exhaust temperature for the steam turbine. At present, the highest thermal efficiency of this combined cycle unit has reached more than 47%. If it is used as a thermoelectric and supply unit, its fuel utilization rate can reach about 80%.

Hybrid power is getting wider and wider significance, such as electric motor plus gasoline engine or diesel engine to apply the advantages of each and shield the disadvantages of each. Nissan Motor Industries, Inc. is a high-performance generator and electric motor into the diesel engine flywheel position, the successful development of a veritable hybrid engine, that is, the successful development of the two principles of simultaneous action of the prime mover (HIMR engine). The hybrid engine is one of the hotspots of future power technology, and it is highly expected to become a machine that does not jeopardize the convenience that mankind has gained, but also maintains a beautiful environment.

The history of the development of the internal combustion engine shows that the essential superiority of the new technology, is rich in vitality of the new thing, there must be a broad development prospects. The first practical internal combustion engine thermal efficiency of only 4%, while the thermal efficiency of the steam engine at that time has reached 8% to 10%; but the internal combustion engine "internal combustion" the essential superiority of the decision that it quickly exceeded the steam engine.

Summary of the above, the 21st century internal combustion engine will face challenges from all aspects, it will not return towards energy saving, fuel diversification, improve power, extend the life of the reliability, reduce emissions and noise, reduce the quality, reduce the size, reduce costs, simplify the maintenance of the direction of rapid development. In the 21st century, natural gas, alcohols, vegetable oils and hydrogen and other alternative fuels will add new vitality to the internal combustion engine, while the internal combustion engine electronic control technology to improve the quality of the internal combustion engine industry at the same time to extend the "life". The technological revolution of new materials and new techniques has given a new impetus to the development of the internal combustion engine in the 21st century, and the internal combustion engine in the 21st century will continue to make up for its own defects while benefiting mankind and make new contributions to mankind with as perfect an image as possible

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