Efficiency of an internal combustion engine - let's understand the efficiency by comparison

The efficiency of a diesel engine is the ratio of the power supplied to the crankshaft to the power received by the piston due to the pressure of the gases produced when the fuel used is ignited.

That is, this quantity is the energy that is converted from thermal or thermal energy into a mechanical quantity.

Gasoline engines have forced ignition of the air-fuel mixture with a spark plug.

More about losses

Looking ahead, we can confidently say that the efficiency of a gasoline engine ranges from 20 to 25%. And there are many reasons for this. If we take the incoming fuel and convert it into percentages, then we seem to get “100% of the energy” that is transferred to the engine, and then there are losses:

1) Fuel efficiency . Not all the fuel is burned, a small part of it goes with the exhaust gases, at this level we already lose up to 25% efficiency. Of course, now fuel systems are improving, an injector has appeared, but it is far from ideal.

2) The second is thermal losses and . The engine warms itself and many other elements, such as radiators, its body, and the liquid that circulates in it. Also, some of the heat leaves with exhaust gases. All this results in up to 35% loss of efficiency.

3) The third is mechanical losses . ON all kinds of pistons, connecting rods, rings - all places where there is friction. This can also include losses from the load of the generator, for example, the more electricity the generator generates, the more it slows down the rotation of the crankshaft. Of course, lubricants have also made progress, but again, no one has yet been able to completely overcome friction - losses are still 20%.

Thus, the bottom line is that the efficiency is about 20%! Of course, among the gasoline options, there are standout options in which this figure is increased to 25%, but there are not many of them.

That is, if your car consumes fuel 10 liters per 100 km, then only 2 liters of them will go directly to work, and the rest are losses!

Of course, you can increase the power, for example, by boring the head, watch a short video.

If you remember the formula, it turns out:

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On methods for increasing efficiency in technical creativity

The relatively modest successes of state research institutes (it is no coincidence that basic information about heavy fuel engines was obtained on the basis of test data on foreign technology or from foreign literature) forced the search for new forms of organizing creative activity. One of these forms of organization was the creation of design bureaus under the auspices of the OGPU. It is quite well known for its OKB-1 aircraft at plant No. 39. OKB-2 at plant No. 24 designed a series of FED engines (Felix Edmundovich Dzerzhinsky), in particular, it created a 24-cylinder X-shaped diesel engine with mixed valve-slotted gas distribution FED-8. The FED-8 engine was conceived as an aviation engine. The development of a diesel engine for the needs of ground transport was undertaken by the ATTB OGPU. The Podolsk plant became the production base of the newly created design bureau. The work of the design bureau was supervised by the head of the OGPU ECU Mironov and the head of the OGPU Technical Department Goryakov.

The designers of ATTB were undoubtedly aware of the latest German pre-chamber transport diesel engines (six-cylinder Daimler-Benz, as well as four- and six-cylinder Deutz), but they approached the development of the engine creatively. The design of the Deitz diesel engine was critically reviewed and the engineers chose a three-cylinder in-line engine, which was a completely independent design, and only the injector was completely copied from the Deitz.

The three-cylinder engine was relatively easy to manufacture. At the same time, both two-stroke and four-stroke three-cylinder engines were unbalanced due to the presence of moments of inertia of the pistons and connecting rods, which forced them to further complicate their design by introducing a stilling shaft to compensate for 1st order moments. The two-stroke engine was considered to be the smoothest three-cylinder in-line engine.

By the time the work of the ATTB OGPU was organized, a fundamental decision had been made to organize the production of Caterpillar tractors in our country. Initially, the “Thirty” tractor was considered, but later the choice was made on the “Sixty”. was one of the world leaders in the production of tractors, and the “Sixty” was considered one of the most advanced models of crawler tractors of the late 1920s. At the same time, this tractor was designed as a national economic tractor, and not a special military high-speed one, so it had relatively low speeds. One of the possibilities for increasing travel speeds was to change the gear ratios in the transmission. However, as the tractor speed increased, the traction force inevitably decreased.

Changing the towing speed due to a change in traction force could be realized by upgrading the gearbox or introducing an additional device - a multiplier or range-multiplier. Probably, for the first time such a possibility of increasing the speed of an artillery tractor was considered at a meeting of Comet in 1922 when discussing an order to Obukhovsky) for Holt 75NR tractors. However, at that time, the plant successfully solved the problem of speed (increasing the maximum speed from about 3.5 to almost 5 versts per hour) by improving the quality and precision of manufacturing components and increasing engine power from the actual 60 to 75 declared horsepower.

When modernizing the Kommunar tractors, this principle was implemented in the development of the “high-speed” (relatively speaking, of course) modification 9EU and the more “traction” modification 9A. Subsequently, innovations were introduced comprehensively in the most advanced model 3-90, equipped with a powerful engine, which made it possible to obtain a tractor with satisfactory traction and speed characteristics.

Another peculiar disadvantage of the Sixty tractor was the use of expensive light fuel. The creation of a powerful diesel engine was intended to solve both problems at once.

Another important aspect in the development of new types of weapons (and the tractor was considered primarily as a high-speed military one) is the significant material burden on the national economy, so the mobilization readiness of the state became an important factor - to transfer the economy to a military footing with minimal costs. Creating an army tractor on the basis of the mass-produced Sixty tractor was seen as extremely tempting.

The ATTB team had to solve a complex of these extremely difficult problems in the shortest possible time.

Less than a year after the resolution of the PB Central Committee was issued, Mironov and Goryakov reported on the work done to develop the Party’s decision and on the successes of the design team they supervised:

“The Caterpillar tractor is armored and armed with a DT machine gun.

Armor thickness: forehead, front 6 mm, top 4 mm Motor protection 3 mm Number of cartridges 1260 pcs.

The tractor is equipped with an oil-fueled, two-stroke, non-compressor diesel engine of its own design, instead of an American gasoline engine, which results in greater savings both in value and in consumption (212-222 grams per hour instead of 330-360 grams of gasoline).

The tractor is equipped with an additional gearbox/multiplier, which makes it possible to increase its speed to 13.3 km/h instead of 5.9 km/h for the American model. The tractor caterpillar is lightweight and made of high quality steel. A version of the caterpillar on rubberized tiles has been designed.

Thus, the tractor can be mobilized into an armored and armed tractor with increased travel speeds.”

During factory tests, completed by the winter of 1931-1932, the lightweight track was abandoned, giving preference to the original track, borrowed from the Sixty tractor.

The tractor was presented for state testing at the end of February 1932 under the brand KPD (“Caterpillar Podolsk Diesel”). Along with the KPD, “Sixty” (“Caterpillar-60”) and a number of other tractors were tested.

The tests were designed to identify the type of tractor suitable for transporting artillery systems and other military cargo. Tractors were evaluated for ease of maintenance, efficiency, structural strength and a number of other parameters, in particular, they were determined

“convenience of handling and ease of both workshop and especially field repair - a change in the most vital and suffering parts.”

The commission inspected the tractors on February 24, 1932. Then they were run-in, dynamometer-tested, and in the period from March 1 to March 16, runs of up to 300 km along the highway and 50 km along dirt roads and virgin snow in the near Moscow region took place in the area of ​​the village of Chernoy and along the Khoroshevskoe highway (now it is already within the city limits).

Tractors were put out for testing with trains consisting of a 203-mm M-6 howitzer, a 152-mm mortar with a limber, a 76-mm anti-aircraft gun, and a pair of P-26 wagons.

The daily mileage was 8 hours, and if necessary, the tractor remained overnight on the road. During intensive testing on March 5, the track spurs on the KPD tractor were bent, and on March 8 the multiplier was broken. All repairs to the KPD, like other machines, were carried out in the field.

When moving at low speeds, all trains moved without difficulty. As the towing speed increased to 8-10 km/h, wobbling (skidding) of the train was observed. As the speed increased to 16 km/h, the wobble of the trailers became very strong,

“threatening with the possibility of rolling into a ditch or hitting the oncoming crew with the rear hitch.”

During the next high-speed race, the KPD tractor slid off the road downhill and had to be retrieved with the help of Kommunar.

Based on the test results, the military stated:

“The Caterpillar-60 tractor is durable and simple, easy to use. The motor operates exceptionally reliably in various conditions, regardless of the duration of continuous operation.”

Among the shortcomings of the Sixty tractor were the following: speed not exceeding 5.9 km/h, a bulky roof, the presence of non-replaceable spurs that caused severe shaking when driving at maximum speed on hard ground, as well as a defective pump.

The KPD tractor had the same track disadvantages as the base model, and therefore the military noted that it could operate reliably in the same conditions as the Sixty. The exhaust gases greatly unmasked the tractor, which was noted as a serious drawback. Starting the engine with compressed air also turned out to be unreliable.

In general, the presented design confirmed the obvious advantages of diesel engines and the fundamental possibility of creating a relatively high-speed tractor based on the Sixty, but the identified defects prevented the adoption of the efficiency into service. The experience of developing and testing the KPD tractor was taken into account when creating new machine designs.

Illustrative and documentary materials from the RGVA were used.

Engine thermal efficiency. Not so scary physics.

Typically, if someone hears the slogan “engine thermal efficiency,” they immediately change the topic. You can talk about engines about their power, about their fuel consumption or - earning the respect of your interlocutors as an expert - about performance systems such as Diesel, Otto, Wankel and Atkinson. But thermal efficiency sounds like physics homework, that is, it causes disgust and negative reactions. Meanwhile, all this merges into one...

Engine efficiency - denoted by the Latin symbol η (eta) - is a parameter that characterizes a given engine and means how much supplied heat is converted into useful work. In the case of an internal combustion engine, this is the conversion of thermal energy resulting from the combustion of fuel into mechanical energy released by the engine as a result of the rotation of the crankshaft.

The values ​​of this efficiency vary for different types of engines and, for example, for spark-ignition engines it is about 0.30–0.36, and for diesel engines it is about 0.40–0.45. This means nothing more than that when filling a tank with 50 liters of fuel, only 15-18 liters of gasoline and 20-22.5 liters of diesel fuel are used to drive the vehicle components. The rest is irretrievably lost.

Advantages of diesel engines

The efficiency of a diesel engine can be increased by creating air resistance due to the absence of a throttle valve, but this leads to increased fuel consumption.

Diesel engines develop the greatest torque at low crankshaft speeds.

Outdated designs of diesel engines differ from their gasoline counterparts in certain disadvantages:

• greater weight and price with equal power;
• increased noise created during fuel combustion in the cylinders;
• lower crankshaft speeds, increased inertial loads.

Power losses - where and why

• fuel efficiency - the fuel does not burn completely, a small part of it simply flies out into the exhaust pipe. At this stage, 25% is lost;
• thermal - the engine heats not only itself, but also its other elements. To obtain heat, energy is required, this is loss. Another 35% is spent on them;
• mechanical - friction occurs during the movement of mechanisms. Of course, lubricants weaken its effect, but it has not yet been possible to completely defeat it. That's another 20%.

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At the output we find that the engine efficiency is only 20-25%. In fact, if a car consumes 10 liters of gasoline per 100 km, then only 2 liters will be spent on work, the rest is losses.

What is useful energy spent on?

The first point here is the losses that occur directly during fuel combustion, because all the fuel in the engine never burns, part of it flies into the exhaust pipe. This part, on average, is about 25%.

The next place (more precisely, phenomenon) where energy disappears is the heat released during combustion. Perhaps some of you still remember from the times spent in school that energy is required to produce heat, and accordingly, the heat generated is a loss of energy. It is worth noting here that when an internal combustion engine operates, heat is generated in excess, which requires the implementation of a serious cooling system.

Further, in addition to the heat generated from combustion, heat is also released during the operation of the engine itself, because all its parts rub, thereby losing part of their energy.

To sum it up, we get another 35-40% of energy loss for heat generation.

Well, the third group of losses are losses for servicing additional equipment. Cooling system pump, generator, air conditioner, etc. - they all also consume energy for their operation. This energy is taken from the operation of the engine - in the amount of about 10%.

To summarize, we find that when burning fuel, in reality, a car spends only a quarter, and sometimes even a fifth, of the energy that its engine produces on “useful” work. The numbers are average, but the range is generally clear.

Which engine has the highest efficiency?

Now I want to talk about gasoline and diesel options, and find out which of them is the most efficient.

To put it in simple language and without getting into the weeds of technical terms, if you compare the two efficiencies of gasoline and diesel units, the more efficient of them is, of course, diesel and here’s why:

1) A gasoline engine converts only 25% of energy into mechanical energy, but a diesel engine converts about 40%.

2) If you equip a diesel type with turbocharging, you can achieve an efficiency of 50-53%, and this is very significant.

So why is it so effective? It's simple - despite the similar type of work (both are internal combustion units), diesel does its job much more efficiently. It has greater compression, and the fuel ignites using a different principle. It heats up less, which means there is a saving on cooling, it has fewer valves (saving on friction), and it also does not have the usual ignition coils and spark plugs, which means it does not require additional energy costs from the generator. It operates at lower speeds, there is no need to frantically spin the crankshaft - all this makes the diesel version a champion in terms of efficiency.

Comparison of efficiency of heat engines - gasoline and diesel

If we compare the useful power, we immediately note that the gasoline one is not as efficient. Its value is only 25-30%, while for diesel it is -40%.

Despite the similarity of the units, they have different types of mixture formation.

• In a gasoline engine, the pistons operate at higher temperatures, which requires good cooling. Therefore, thermal energy that could be transformed into mechanical energy is wasted, thereby reducing efficiency.
• In a diesel engine, the working mixture ignites during compression, so the pressure in the cylinders is much higher.
  In addition, the motor is much smaller and more environmentally friendly. At low speeds and large displacement, efficiency levels can increase to 50%.

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Formula for working in physics

For mechanical work, the formula is simple: A = F x S. If deciphered, it is equal to the applied force along the path along which this force acted. For example, we lift a load weighing 15 kg to a height of 2 meters. The mechanical work to overcome the force of gravity will be equal to F x S = mxgx S. That is, 15 x 9.8 x 2 = 294 J. If we are talking about the amount of heat, then A in this case is equal to the change in the amount of heat. For example, water was heated on the stove. Its internal energy has changed, it has increased by an amount equal to the product of the mass of water and the specific heat capacity by the number of degrees by which it has heated up.

Asynchronous motor and stirling

Today, asynchronous machines are presented on the market, most of which are electric. An asynchronous mechanism converts electrical energy into mechanical energy.

Their main advantages:

• ease of manufacture and relatively low cost;
• high reliability;
• operating costs are low.

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The efficiency formula is calculated as follows: η = P2 / P1 = (P1 - (Pob - Ps - Pmx - Pd)) / P1, where Rob = Pob1 + Rob2 - the total losses in the windings of an asynchronous motor. For most modern mechanisms of this type, the coefficient reaches 80 - 90%.

Another internal combustion engine that can be powered by any heat source is the Stirling engine.

It should be noted that such mechanisms are used on spacecraft and modern submarines.

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It operates at any temperature, does not require additional systems to start, and their efficiency is 50-70 higher than that of conventional engines.

Fuel efficiency

Calculating the efficiency of a diesel engine allows you to determine the feasibility of its use.

Diesel is considered one of the variants of the internal combustion engine, which is characterized by ignition of the working mixture after compression.

In order to reveal the essence of the functioning of a gasoline engine, and the efficiency of a diesel engine, mathematical calculations are carried out.

Electric motor efficiency and power

Efficiency and power are what you should first pay attention to when choosing an AIR asynchronous electric motor. The essence of the operation of any electric engine is that electrical energy, with accompanying losses, is converted into mechanical energy. The lower the losses during this process, the higher its efficiency and the more efficient the electric motor. But, despite the importance of efficiency, do not forget about the power of the motor. After all, even with extremely high efficiency and the power it produces, it may not be enough to solve the problems you need. Therefore, when purchasing, it is very important to know not only what the efficiency of the electric motor is, but also what useful power it can produce on its shaft. Both of these values ​​must be specified by the manufacturer. Sometimes it happens that you don’t have access to the motor’s passport (for example, if you buy it secondhand, which is highly not recommended) and you have to independently calculate such important parameters. First, it’s worth defining what the coefficient of performance, or simply efficiency, is. And so, this is the ratio of useful work to energy expended.

Determination of electric motor efficiency

It turns out that in order to determine this parameter it is necessary to compare the energy it produces with the energy it needs to function. The efficiency is calculated using the expression:

η=P2/P1 where η is efficiency

P2 – useful mechanical power of the electric motor, W P1 – electrical power consumed by the motor, W;

Efficiency is a value ranging from 0 to 1; the closer its value is to unity, the better. Accordingly, if the efficiency has a value of 0.95, this shows that 95 percent of electrical energy will be converted into mechanical energy and only 5 percent will be losses. It is worth noting that efficiency is not a constant value, it can vary depending on the load, and it reaches its maximum at loads around 80 percent of the rated power, that is, that stated by the motor manufacturer. Modern asynchronous electric motors have a nominal efficiency (declared by the manufacturer) of 0.75 - 0.95. Losses during engine operation are mainly caused by heating of the motor (part of the consumed energy is released in the form of thermal energy), reactive currents, bearing friction and other negative factors. Motor power refers to the mechanical power that it produces on its shaft. In general, power is a parameter that shows how much work a mechanism does in a certain unit of time.

The efficiency of an electric motor is a very important parameter that determines, first of all, the efficiency of using the energy resources of an enterprise . As you know, the efficiency of an electric motor decreases significantly after its repair; we wrote about this in this article. As the efficiency decreases, electricity losses will correspondingly increase. Recently, energy-efficient electric motors from different manufacturers have been gaining popularity; in Russia, motors produced by Vladimir Electric Motor Plant OJSC are popular. Any asynchronous electric motors are presented in the product catalog. You can find additional useful information in the catalog of articles.

Why is diesel efficiency higher?

The efficiency indicator for different engines can vary greatly and depends on a number of factors. Gasoline engines have relatively low efficiency due to the large number of mechanical and thermal losses that occur during the operation of a power unit of this type.

The second factor is friction that occurs during the interaction of mating parts. Most of the useful energy consumption is driven by the movement of the engine pistons, as well as the rotation of parts inside the motor, which are structurally fixed to bearings. About 60% of the combustion energy of gasoline is spent only to ensure the operation of these units.

Additional losses are caused by the operation of other mechanisms, systems and attachments. The percentage of resistance losses at the moment of admission of the next charge of fuel and air, and then the release of exhaust gases from the internal combustion engine cylinder, is also taken into account.

If we compare a diesel unit and a gasoline engine, a diesel engine has a noticeably higher efficiency compared to a gasoline unit. Gasoline power units have an efficiency of about 25-30% of the total amount of energy received.

In other words, out of 10 liters of gasoline spent on engine operation, only 3 liters are used to perform useful work. The rest of the energy from fuel combustion was lost.

As for the efficiency of an atmospheric diesel unit, this figure is about 40%. Installing a turbocharger allows you to increase the mark to an impressive 50%. The use of modern fuel injection systems on diesel internal combustion engines in combination with a turbine made it possible to achieve an efficiency of about 55%.

This difference in the performance of structurally similar gasoline and diesel internal combustion engines is directly related to the type of fuel, the principle of formation of the working fuel-air mixture and the subsequent implementation of charge ignition. Gasoline units are more efficient than diesel units, but large losses are associated with the consumption of useful energy for heat. It turns out that the energy of gasoline is less efficiently converted into full-fledged mechanical work, and a large portion is simply dissipated by the cooling system into the atmosphere.

We also recommend reading the article on how to increase the power of a diesel engine using chip tuning. From this article you will learn about what engine ECU firmware is and what results are achieved by changing the standard parameters of the controller.

Maximum efficiency value of an ideal engine

How to find the efficiency of an engine whose value would be ideal and equal to 100%. Is this possible? The answer to this question was given back in 1824 by engineer S. Carnot. In his developments, he came up with an ideal machine, where the formula for the efficiency of a heat engine looks like this: η = (T1 - T2)/ T1.

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As a result, it was found that a 100% coefficient can be achieved only if the cooler temperature is equal to absolute zero, and this is impossible, since it cannot be lower than the air temperature.

Power and torque

When the displacement figures are the same, the power of a naturally aspirated petrol engine is higher, but is only achieved at higher speeds. The unit needs to be “twisted” more strongly, while losses increase, and fuel consumption increases accordingly. In addition, it is worth mentioning torque, under the influence of which the force that is transmitted from the engine to the wheels increases and contributes to the movement of the car. Gasoline engines reach their maximum torque level only at high speeds.

An atmospheric diesel engine with the same parameters reaches peak torque only at low speeds. This contributes to less fuel consumption required to perform work, resulting in higher efficiency and more economical fuel consumption.

Compared to gasoline, diesel fuel generates more heat, since the combustion temperature of diesel fuel is much higher, which contributes to higher detonation resistance. It turns out that a diesel engine has much more useful work done on a specific amount of fuel.

Energy value of diesel fuel and gasoline

Diesel oil contains more heavy hydrocarbons than gasoline. The lower efficiency of such an engine compared to a diesel unit is due to the energy component of gasoline and the method of its combustion. When equal amounts of gasoline and diesel fuel are burned, a greater amount of heat is characteristic of gasoline. Heat in a diesel unit is more fully converted into mechanical energy. Accordingly, when burning an equal amount of fuel in a certain amount of time, it is the diesel engine that will do more work.

In addition, it is necessary to take into account the characteristics of injection and conditions conducive to high-quality combustion of the mixture. In a diesel unit, fuel enters separately from the air and is injected directly into the cylinder at the end of compression, bypassing the intake manifold. The result of this process is a temperature higher than that of a gasoline engine and maximum combustion of the fuel-air mixture.

This is interesting

Science has proven that the efficiency of any mechanism is always less than one. This is due to the second law of thermodynamics.

For comparison, the efficiencies of various devices:

• hydroelectric power stations 93-95%;
• NPP – no more than 35%;
• thermal power plants – 25-40%;
• gasoline engine - about 20%;
• diesel engine - about 40%;
• electric kettle – more than 95%;
• electric vehicle – 88-95%.

Science and engineering do not stand still. Ways are constantly being invented to reduce heat loss, reduce friction between parts of the unit, and increase the energy efficiency of equipment.

Summary

In the production of modern internal combustion engines, manufacturing plants invest heavily in the pursuit of increasing the efficiency of their products by at least a few percent. To this end, engineers are improving and complicating motor designs and using new materials to manufacture individual elements.

Sometimes it happens that the financial costs of developers are inappropriate, in comparison with the obtained result of 2 - 3%. Therefore, it may be more profitable to subject standard engines to various boosts, fine-tuning, and modifications using tuning improvements in small repair shops. As a result, the power and other traction characteristics of power units increase.

Coefficient of performance (COP) is a widely used characteristic of the efficiency of some system or device. In our case, this system is the internal combustion engine. It would seem, what kind of efficiency can we talk about in the world of modern engines? Isn’t it equal to 100 percent? But it turns out that just as there is no ideal black or white in our world, there is no car in which all the energy received from burning fuel is completely converted into mechanical energy, and the latter, in turn, into useful energy that presses the driver of the car into his seat.

Literature

• [1] Kotelnikov V., Medved A. Aviation diesel engines, or the thorny path A.D. Charomsky // Engine.-2002, No. 2(20).
• [2] Zubov E. Legendary V-2: three pages of fate // Engine. 1999, No. 4(4).
• [3] Ways to resolve the issue of domestic tractor construction // Bulletin of the Scientific Automotive Institute. - 1922, No. 4.
• [4] Bukharin N.A. Modern tractors. Design and operation. -M-L., 1931.

source: Alexander Kirindas, Mikhail Pavlov “MECHANICAL TRACTION. DIESEL Efficiency" // "Equipment and weapons" January 2012

About diesel fuel efficiency

FROM a higher efficiency value, fuel efficiency follows. So, for example, a 1.6-liter engine can consume only 3–5 liters in the city, in contrast to the gasoline type, where the consumption is 7–12 liters. A diesel engine has much more torque, the engine itself is often more compact and lighter, and, recently, also more environmentally friendly. All these positive aspects are achieved thanks to a higher compression ratio; there is a direct relationship between efficiency and compression, see the small plate.

However, despite all the advantages, it also has many disadvantages.

As it becomes clear, the efficiency of an internal combustion engine is far from ideal, so the future clearly belongs to electric options - all that remains is to find efficient batteries that are not afraid of frost and hold a charge for a long time.

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I’ll finish here, read our AUTOBLOG.

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Surely, many car enthusiasts have wondered how the power of an internal combustion engine corresponds to its utility. It is assumed that the higher the efficiency of a power system, the more efficient it is. Speaking in absolute terms, today the highest coefficient is for electric motors; in some models it reaches about 95 percent. As for internal combustion engines, for most of them, regardless of the type of fuel, this figure is very far from ideal figures.

Internal combustion engine efficiency

Of course, modern engines are much more efficient than those that were developed and released ten years ago, this is due to objective reasons for the development of technology. At the beginning of the 2000s, a one and a half liter engine produced an average of about seventy horsepower, and this was normal. Today, the number of heads in a herd of the same volume can reach more than 150. Every little step in terms of increasing the engine power factor is given to manufacturers through painstaking work and trial, error and success.

Definition option

In the technical documentation you can find information about the power of the internal combustion engine. After filling it with fuel and operating at maximum speed for several minutes, the remaining fuel is drained. By subtracting the final result from the initial volume and armed with density, you can calculate the mass of the fuel mixture.

Currently, the electric power unit has maximum efficiency. Its efficiency can reach 95%, which is an excellent result. If the first engines with an engine capacity of 1.6 liters developed no more than 70 horsepower, today this figure reaches 150 horsepower.

Efficiency is the ratio of the power supplied to the engine crankshaft to the value obtained from the combustion of the gas mixture by the piston. Depending on what fuel is used to run a car engine, efficiency can range from 20 to 85 percent. Of course, manufacturers of fuel systems are looking for ways to improve them, allowing them to significantly increase the final value of the internal combustion engine.

To reduce mechanical losses from the generator load and friction, lubricants are currently used in industry. But, despite such achievements, no one has yet managed to completely cope with the force of friction.

Even after improvements to the gasoline engine, it was possible to achieve a change in its efficiency up to 20 percent; only in some cases it is possible to increase the efficiency to 25%.

A higher efficiency rating indicates fuel efficiency. For example, with a diesel engine capacity of 1.6 liters in the urban cycle, fuel consumption is no more than 5 liters. For a gasoline analogue, this value reaches 12 liters. The diesel unit itself is much lighter and more compact, and is also considered a more environmentally friendly option than a gasoline engine.

These positive technical characteristics guarantee diesel engines a longer operational life.

Thermal Cycle Analysis

The thermal cycle includes four thermodynamic basic processes. First, the state of the working fluid is transformed, and then it returns to its original state: compression, heat generation, expansion and heat removal.

Each of these processes is carried out according to the following scheme, which determines the conditions for the implementation of the cycle:

• Isothermal - work is performed at a constant temperature.
• Isobaric - the operating cycle is implemented at constant pressure.
• Isometric - the thermal process occurs at a constant volume
• Adiabatic - the cycle is carried out at constant entropy.

In order for the process to be as close to reversible as possible, there are two ways to move the piston: isothermal - this means that heat gradually enters or leaves the reservoir at a temperature infinitely different from the temperature of the gas in the piston, and adiabatic, in which no heat exchange occurs at all, the gas acts like a spring.

Thus, when heat is added and the gas expands, the temperature of the gas must remain the same as that of the heat source, with the gas expanding isothermally. Likewise, it will later be compressed in the cycle isothermally, releasing heat.

To find out efficiency, you need to follow the engine through its entire cycle, find out how long it runs, how much heat is taken from the fuel, and how much energy is lost in preparation for the next cycle.

The thermal cycle characteristics associated with a heat engine are typically described using two state diagrams : a PV diagram showing the pressure-volume relationship and a TS diagram showing the temperature-entropy pair.

For a constant mass of gas, the operation of a heat engine is a repeating cycle, and its PV diagram will look like a closed figure.

ESTEC Basic Components

Gasoline engine Gazelle Next 2.7 l. timing device, technical specifications Evotech 2.7

The main design features of the ESTEC are the Atkinson cycle, a geometric compression ratio of 13.5:1 and a liquid-cooled EGR system (the regular 1NR-FE has an 11.5:1 compression ratio and internal exhaust gas recirculation). The electrically driven VVT-iE continuously variable phase control system is a key element in the implementation of the Atkinson cycle. It allows you to quickly and accurately adjust the lift of the intake valves and avoid difficulties arising from the difference in temperature and oil pressure during a cold start and on a warm engine.

The exhaust gas recirculation system uses an efficient cooler and a fast-acting valve. In addition, the inlet pipe, cooler and valve are directly connected to each other to reduce the formation of condensation from the cooler.

The optimized shape of the intake ports ensures rapid filling of the cylinders, and the created swirl contributes to improved combustion of the mixture. To meet both performance and fuel consumption requirements, the exhaust manifold is designed in a 4-2-1 design. This allows you to reduce the amount of residual gases in the engine cylinders.

Restoring Performance

Increasing the compression ratio to 13.5:1 reduced torque from 104 Nm to 96 Nm. To make up for this loss, Toyota has used a reshaped exhaust manifold that reduces residual gases and cylinder temperatures; a new water jacket that maintains optimal cylinder surface temperature; optimization of injection time. The combination of these measures (of which the modified exhaust manifold plays a major role) has increased torque to 105 Nm.

At light loads, excessive torque fluctuations occur due to the operation of the cooled EGR. To eliminate this drawback, an exhaust valve control system (Exhaust VVT) and internal exhaust gas recirculation are used. At medium and high loads, the Exhaust VVT is suspended and the EGR valve pitch is increased.

Cooling is an effective measure against torque reduction in engines with high compression ratios. However, at the same time this leads to increased fuel consumption due to increased friction and cooling losses. In conventional engines, the top of the cylinder heats up more than the bottom. Due to uneven heating, friction in the cylinder increases. In ESTEC, a new water jacket with a special gasket equalizes the temperature in different parts of the cylinder surface, reducing friction losses and the possibility of detonation.

Atkinson cycle

Atkinson cycle

In an Atkinson cycle engine, during the intake stroke the intake valve closes not near BDC, but much later. This provides a number of benefits.

Firstly, pumping losses are reduced, because part of the mixture, when the piston has passed BDC and began to move upward, is pushed back into the intake manifold (and then used in another cylinder), which reduces the vacuum in it. The combustible mixture pushed out of the cylinder also takes away some of the heat from its walls.

Since the duration of the compression stroke in relation to the power stroke decreases, the engine operates according to the so-called cycle with an increased expansion ratio, in which the energy of the exhaust gases is used for a longer time, i.e., with a decrease in exhaust losses. Thus, we get better environmental performance, efficiency and greater efficiency, but less power.

Types of power systems

The carburetor option involves mixing air and gasoline in the inlet pipe of the carburetor. Recently, the production of such engine options has been significantly reduced due to the insignificant efficiency of such engines and their inconsistency with modern environmental standards.

In injection engine versions, fuel is supplied using one injector (nozzle) into the central pipeline.

In the case of distributor injection, fuel enters the engine through several injectors. In this case, the maximum power increases, which significantly increases the efficiency of the diesel engine.

At the same time, gasoline consumption and toxicity of processed gases are reduced due to a fixed fuel dosage by electronic control systems of the automobile engine.

When discussing the efficiency of a modern diesel engine, you need to know about the injection system of the gasoline mixture into the storage chamber. If fuel is supplied in portions, this guarantees that the engine runs on lean mixtures, which helps reduce fuel consumption and reduce the emission of harmful gases into the atmosphere.

Next, I present to your attention the WOT efficiency calculator

so that you can have an idea of ​​which category you belong to:

W.G.R.

WN8

WN6

EFF

xTE

Let's start in order:

WGR is the official rating from Wargaming, a four-digit rating.

Probably the most difficult in terms of pumping up statistics. Here the greatest influence on the efficiency result is exerted by:

Average damage per battle

Average damage due to radio exposure

Average damage due to holding on gusle (it doesn't matter if you deal damage or allies)

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wn8 - WN8 rating is more advanced player statistics (reference statistics), in its original form it is four-digit.

The greatest influence on the result is exerted by:

Total player damage dealt

Total number of destroyed

It should be noted here that these statistics are highly dependent on the machine you are playing on, since reference statistics use reference readings for calculations. Roughly speaking, the standard damage of the ISU-152 will be 700. So, if you are playing on this tank destroyer, then you must knock out this same 700 damage from a shot, targeting the enemy’s weak spots or punching into the side and stern. In other words, the closer your damage is to the standard, the higher your statistics. (Note: the number 700 was taken out of thin air...)

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wn6 - four-digit efficiency, taken from behind the scenes and developed by American players. Here you will have to work hard to increase this efficiency. The wn6 formula is very large and complex, but we agreed that I will not burden you with formulas, so I will convey the main points. The main thing to remember here is:

base defense points do not greatly affect efficiency;

The first exposure of the enemy also has virtually no effect on efficiency;

Capturing a base is not taken into account at all;

Destroying low-level tanks has less impact on the rating, so choose a tank a couple of levels higher than you and bite;

It turns out that WN6 completely depends on your contribution to the battle

And special attention is paid to the total damage dealt to the player and the total number of tanks destroyed (this takes into account the strength of the enemy you destroyed)

To increase this rating, I would advise you to deal more damage and “take out” more enemy equipment. But not all tanks in the game can do this. For example, self-propelled guns, tank destroyers (top-end and pre-top, as well as French drum tanks). They have the highest damage per minute. The minimum damage per battle for you should be numbers above 1500-2000.

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EFF is the good old Efficiency Rating, also known as ER.

For those who are new to the tank, here the greatest influence on the result is exerted by:

Average damage per battle;

Average number of frags (killed opponents) per battle;

Average number of base defense points per battle;

Those. in other words, to increase this efficiency you need to destroy, kill, and also have time to defend your own base! Go for it

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xTE is a rating that evaluates your ability to play on a specific tank compared to all other players on that particular tank.

Here, just like in RE, the main thing will be:

Average damage per battle;

Average number of frags per battle;

WOT efficiency

What is efficiency

Literally, the abbreviation efficiency stands for coefficient of efficiency. In other words, this indicator indicates how useful a player can be to his team, as well as how good his skills are in battle.

Efficiency is calculated based on statistical data. When calculating efficiency, it takes into account the number of victories and defeats, the capture of an enemy base and the shooting down of an allied base, the detection and destruction of opponents. In addition, the level of efficiency is influenced by the player’s technique. On high-level vehicles it is easier to increase this indicator.

Why is efficiency needed?

Also, beginners think about why World of Tanks efficiency is needed. Everything is very simple. There are two explanations

The main thing is that since efficiency reflects skills and abilities in battle, they definitely pay attention to it when joining a clan. It's difficult to get into a good clan if this indicator is low

In addition, efficiency gives many players an additional incentive. After all, you want to be the best among others. As a result, the player strives to improve his statistics and efficiency. Increasing this indicator will please the vanity of any gamer.

How to find out your efficiency?

In the game, efficiency can be viewed as a personal rating. But experienced players claim that the calculation of the efficiency factor inside the game is carried out according to an unfair algorithm, as a result of which laurels do not always go to the winners. This means that a player can perform well in battle, but at the same time increase his efficiency very slightly.

To find out how useful a player really is to his team and what skills he has, efficiency is looked at on special online resources. To check your personal indicator, just enter your nickname and click the “Determine” or “Download data” button. The most popular sites where you can view efficiency in World of Tanks are:

• wot-news.com;
• wot-game.com;
• wot-noobs.ru.

"Olenemeter" comes to the rescue

Directly in the game, the players’ efficiency is determined by the “Olenometer”. This is a special mod that is installed into the game. It got its name because it helps determine the opponent’s experience and detect “deer,” that is, inexperienced players.

The mod highlights all players in a certain color depending on their statistics and skills. Red players don't know how to play at all, orange ones are a little better than the first ones. Gamers with the color yellow are considered average, and gamers with the color green are considered good. High-class craftsmen are highlighted in blue, and unique players are highlighted in purple.

But the “Olenometer” is often mistaken, so when you see an enemy team in which the majority of players are highlighted in red, you should not relax, since in this case the risk of defeat is very high. By the way, if you miss good online games, then be sure to come here, on this site you will find a lot of interesting virtual entertainment. Sometimes it’s worth taking a break from the “tanks”.

How to increase efficiency in World of Tanks?

Once the answer to the question “What is efficiency in the World of Tanks?” has been found, many players are thinking about how to increase this important indicator. The strategy here is very simple: you need to gain capture points, break the enemy's capture, destroy enemies and help your team and allies in every possible way, but at the same time remain alive until the end of the battle. In addition, to improve efficiency, you should choose a technique of at least level 8, or better yet, even higher.