Prechamber of a gas internal combustion engine. Prechamber diesel engine

Prechamber

As we have already described above, the prechamber engine has the following operating principle:

The main advantage of an engine with a prechamber is the low shock loads of the parts of the cylinder-piston group during operation of the internal combustion engine. This is ensured precisely due to a smooth increase in pressure, and not in jumps.

In addition, prechamber engines burn fuel efficiently, reduce the amount of emissions of harmful substances, reduce fuel consumption and increase the efficiency of the power unit.

What is and how does the pre-chamber-torch ignition system work?

If there is a pre-chamber in the engine, then it is already clear that there is a main fuel combustion chamber, and there is also an additional one.

The cavities of the prechamber and the main combustion chamber are connected by special nozzles - channels. Through them, flames, vapors and gases of part of the air-fuel mixture that has already burned out enter the main chamber. As a result, the lean mixture in the main chamber ignites.

Thus, the pre-chamber is a sub-injection, which in its operating principle is similar to the principle of two-stage operation of new diesel injection nozzles.

Pros and cons of prechamber units

On the one hand, changing the engine design with the introduction of a prechamber was not widely used due to the significant complication of the engine design.

Although the environmental friendliness of such engines was higher, and fuel consumption was lower, they had a shorter service life than conventional internal combustion engines.

The prechamber is better suited for a diesel engine. It reduces heavy smoke from the exhaust pipe. In addition, prechamber diesel engines are capable of running on low-quality diesel fuel.

The main disadvantage of prechamber engines is the difficulty of starting the engine when cold. If you heat the prechamber, then such an engine starts without problems.

Video

Cylinder heads of prechamber engines.

Prechamber Mercedes OM 601-603.

How to replace prechambers.

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Operating principle of a prechamber diesel engine

As you know, today many manufacturers are looking for options on how to increase the efficiency of internal combustion engines. They found one possible way out of this predicament. The method is to ensure that the engine runs on fuel mixtures containing a lower percentage of fuel. With this approach, it will not only be possible to increase fuel efficiency, but also, moreover, to reduce the emission of harmful waste. But there is a flaw in this method: when the mixture contains a small amount of combustible, it is less flammable. Therefore, the developers came to the conclusion that for stable operation of the engine, an initial source of combustion is needed, from which the fire will spread quickly throughout the entire space of the fuel-air charge.

As a result, there are now two options for obtaining such a source: a spark of increased energy and layer-by-layer distribution of the mixture (by the time the spark is produced, a flammable mixture is formed). The second path includes several options. Today we will take a closer look at the option called prechamber-torch ignition.

The cavity located in the cylinder head of an internal combustion engine is called the prechamber, or prechamber. It, using one or more channels, is connected to the main combustion chamber of the fuel. This type of engine comes in both diesel and gasoline formats. In general, the intermediate chamber can also have another name: a vortex chamber. Based on the name, it becomes clear to us that the fuel in such a chamber is swirled. This effect promotes better mixing of fuel with air. But, when describing the operation of an internal combustion engine with a pre-chamber, it is important to note that initially the fuel, entering the preliminary cavity, collides with its walls and mixes with air, in this this type of engine is inferior to its similarity.

Prechamber of a gas internal combustion engine

The invention relates to engine building, specifically to prechambers of gas internal combustion engines. The prechamber valve assembly is installed in the bore of the prechamber body, in the area washed by the coolant. In the drilling of the prechamber body, in front of the prechamber valve assembly, a throttle is installed, closed on the gas supply side with a filter mesh. The prechamber body is made of a material with high thermal conductivity and strength, for example brass. The prechamber body contains a recess connecting the drilling of the prechamber body, in which the prechamber valve assembly is installed, with the channel of the diesel cylinder cover, designed to drain fuel leaked through the nozzle, and the latter is connected to the prechamber gas supply line. The invention simplifies the design and increases the reliability of the prechamber. 3 salary f-ly, 1 ill.

The invention relates to engine building, specifically to prechambers of gas internal combustion engines.

Pre-chambers of gas internal combustion engines are known, installed in place of injectors in diesel cylinder covers, containing a housing with a working cavity connected to a spray nozzle, a spark plug and a pre-chamber valve assembly connected by a connecting channel to the working cavity. (See, for example, Internal combustion engines “Systems of piston and combined engines.” Third edition, revised and expanded. Under the general editorship of A.S. Orlin, M.G. Kruglov. M.: Mashinostroenie, 1985, fig. 206, p. 228 and fig. 207b, p. 229).

The disadvantage of these designs is the presence of a connecting channel between the prechamber valve assembly and the working cavity, located in the prechamber body near the threaded part of the spark plug, which leads to overheating of the housing at the installation site of the spark plug due to the fact that during each stroke of the power stroke, hot combustion products are exposed to high pressure , developing in the prechamber, penetrate inside the connecting channel. This leads to premature failure of the spark plug.

In addition, the gas supply channel has a small flow area and is often clogged with combustion products, which leads to a decrease in gas supply to the prechamber and loss of its functionality.

Similar prechambers are known, containing prechamber valves installed directly on the prechamber body and penetrating into the working cavity (see the previously mentioned source, Fig. 207a, p. 229). This design is closest to the proposed device and is offered as a prototype. The disadvantage of the device proposed as a prototype is the location of the prechamber valve in an area where there is no liquid cooling of the cylinder cover, which leads to overheating of the prechamber valve and increased wear. At the same time, to reduce the temperature of the body of this prechamber, a network of channels is required in its body, which significantly complicates its design and, if the channels become clogged, leads to failure of the prechamber body.

The present invention is aimed at simplifying the design and increasing the reliability of the prechamber.

This is achieved by the fact that in the prechamber of a gas internal combustion engine, installed in place of a diesel injector, containing a housing with a working cavity connected to the atomizer, a spark plug and a prechamber valve assembly, the latter is installed in the drilling of the prechamber body, in the area washed by the coolant. In the drilling of the prechamber body, in front of the prechamber valve assembly, a throttle is installed, closed on the gas supply side with a filter mesh. The prechamber body is made of a material with high thermal conductivity and strength, for example brass. The prechamber body contains a recess connecting the drilling of the prechamber body, in which the prechamber valve assembly is installed, with the channel of the diesel cylinder cover, designed to drain fuel leaked through the nozzle, and the latter is connected to the prechamber gas supply line.

Based on the foregoing, we believe that what is new in the proposed device is that the prechamber valve assembly is installed in the drilling of the prechamber body, in the area washed by the coolant. In the drilling of the prechamber body, in front of the prechamber valve assembly, a throttle is installed, closed on the gas supply side with a filter mesh. The prechamber body is made of a material with high thermal conductivity and strength, for example brass. The prechamber body contains a recess connecting the drilling of the prechamber body, in which the prechamber valve assembly is installed, with the channel of the diesel cylinder cover, designed to drain fuel leaked through the nozzle, and the latter is connected to the prechamber gas supply line.

The drawing shows a longitudinal section of the proposed design. The pre-chamber of a gas internal combustion engine, installed in place of the nozzle of the cylinder 1 cover of a diesel engine, the latter containing a channel 2 for removing fuel that has leaked through the nozzle and a cooling cavity 3, and the pre-chamber contains a housing 4 with a working cavity 5, a nozzle 6 and a recess 7, a spark plug 8, prechamber valve assembly 9, drilling 10 of the prechamber body 4, throttle 11, filter mesh 12.

The operating principle of the proposed prechamber of a gas internal combustion engine is similar to traditional designs. The difference is that the prechamber valve assembly 9 is installed in the drilling 10 of the prechamber body 4, in the area washed by the liquid of the cooling cavity 3 of the cylinder cover 1, which ensures its satisfactory temperature condition and high performance. The filter mesh 12 has cells smaller than the size of the hole in the throttle 11, which prevents the throttle 11 from clogging during operation. The prechamber body 4, made of a material with high thermal conductivity, allows for intensive heat removal from the installation area of ​​the spark plug 8 and the prechamber valve assembly 9, and also reduces the thermal stress of the atomizer 6. The increased strength of the material of the prechamber body 4 ensures repeated replacement of the spark plug 8 without damaging the threads housing 7 of prechamber 4. Fuel gas from the prechamber gas supply line (not shown) enters channel 2 of the cylinder cover 1, designed to remove fuel leaked through the nozzle in a diesel engine, then the gas enters recess 7 of the prechamber housing 4, passes through the filter mesh 12, throttle 11, drilling 10, then through the prechamber valve assembly 9 and enters the working cavity 5. A collector for collecting leaked fuel through diesel injectors can be used as a prechamber gas supply line.

The economic effect of the implementation of the present invention is to reduce the cost of manufacturing the prechamber, as well as due to an increase in the service life of the prechamber.

Claim

1. A pre-chamber of a gas internal combustion engine, installed in place of the nozzle in the diesel cylinder cover, containing a housing with a working cavity connected to the atomizer, a spark plug and a pre-chamber valve assembly, characterized in that the pre-chamber valve assembly is installed in the drilling of the pre-chamber body, in the area washed with coolant.

2. Prechamber according to claim 1, characterized in that in the drilling of the prechamber body, in front of the prechamber valve assembly, a throttle is installed, closed on the gas supply side with a filter mesh.

3. Prechamber according to claim 1, characterized in that its body is made of a material with high thermal conductivity and strength, for example, brass.

4. The prechamber according to claim 1, characterized in that the prechamber body contains a recess connecting the drilling of the prechamber body, in which the prechamber valve assembly is installed, with the channel of the diesel cylinder cover, designed to drain fuel leaked through the nozzle, and the latter is connected to the prechamber supply line gas.

DRAWINGS

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Why is a prechamber needed in an engine?

Now let's look at the most important question: what is the prechamber for in the engine?

Primarily, such a system was created with the aim of removing, albeit partially, the load on the pistons. This, in turn, had a positive effect on the overall performance of the engine. Moreover, by choosing a prechamber engine, you reduce the amount of toxic waste, since, speaking specifically about our case, the diesel fuel burns completely. We conclude from this that your fuel costs will decrease.

Prechamber-torch ignition system

The main elements that make up a diesel engine with a prechamber are:

Note: we will go through the path along with the fuel in order to fully understand the principle of operation of the prechamber engine.

Now, we hope, it has become clear to you how a pre-chamber diesel engine works and what the pre-chamber structure consists of.

Pros and cons of pre-chamber engines

Mentioning internal combustion engines running on gasoline, we can confidently declare their inefficiency, since the device was imperfect and showed its worst sides in motion. Therefore, none of the manufacturers wanted to rely on such a choice, and as a result, such designs are not currently used. Of course, initially people preferred such analogues because of their efficiency in fuel consumption and, at the same time, a reduction in the toxicity of emitted waste. But users changed their minds after testing the units for durability while driving.

The situation is completely different when it comes to diesel engines, which are our main object of study. The advantages of an engine with a pre-chamber engine are the insignificant smoke of the power plant, regardless of the driving method and, which is also significant, such installations do not require selected fuel.

Let's return to the negative sides, where would we be without them. An unheated engine does not start well. Why is this happening? The bottom line is that for a stable start-up, the pre-chamber must initially be well heated, but due to the fact that electric glow plugs are installed in this system, the air is not fully heated.

In conclusion, it can be noted that the operating principle of such engines has few disadvantages, so you can safely give it preference. Enjoy your travels and don't forget to leave your comments below.

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Prechamber - specifics, features and demand

Creating a comfortable microclimate and purifying indoor air is not always as simple a task as it might seem at first glance. The type and size of the room, the climatic conditions surrounding it, the complexity of the ventilation system used - there may be many conditions to be met.

For a room in an environmentally friendly area, it is enough to install a modern air conditioner. But industrial buildings and supermarkets require a special room for normal air conditioning - an air chamber, a pre-chamber.

Specifics of cleaning large volumes of air

You can easily appreciate the fact how necessary a prechamber is in ventilation by considering what it is in more detail. The prefix “for” is translated “in front”, which allows us to consider the pre-chamber as a preliminary room in which ventilation gas exchange takes place. For places with a heavily polluted atmosphere, it becomes an excellent “filter” separating the internal and external ventilation systems of the room.

Thanks to this separation system, it is possible to reliably cut off most factors that can worsen the condition of the air in the ventilated room. Or vice versa - quickly remove the volatile compounds formed inside it outside.

For these purposes, a separate room is created - a preliminary area or antechamber, in which a working ventilation unit is created. Its technical equipment varies depending on the speed and quality of passing air flows.

In some cases, a special directional fan is sufficient, which separates the incoming and outgoing air into the designated channels. It may be necessary to install air filters for cleaning and provide sound insulation.

Features of “preliminary” air chambers

Modern household climate control systems intended for standard premises, as a rule, do not require the installation of a pre-chamber. The air conditioning system, consisting of an indoor and outdoor unit, is a complex device. It already contains various air-purifying filters and other units, the task of which is to create optimal climatic conditions in the room. But their working capabilities are very limited. Even powerful household air conditioners may not be able to cool large rooms. Their use may not be economically justified.

The idea of ​​installing conventional air conditioners in huge industrial buildings, underground parking lots, and rooms larger than several hundred square meters will be impractical. For them, there are separate powerful installations capable of processing huge cubic capacity of air masses in a minimum time. But such ventilation requires compliance with several conditions for normal operation:

• Good sound insulation. The passage of a large amount of air is accompanied by noticeable noise.
• Balanced supply to operating points. The air intake and transmission speed of powerful air conditioners can create a strong flow that is not suitable for supermarkets.
• Control of air speed in the system. A powerful air flow, designed to remove impurities formed as a result of production, is capable of “capturing” small parts used in the work along with them.
• Maintaining a constant temperature. At high speeds of movement of large volumes of air, their temperature can seriously affect the microclimate of the room.

Prechamber engine and prechamber

The prechamber (prechamber) is a special cavity that is located in the cylinder head of the internal combustion engine. This cavity is structurally connected to the main combustion chamber in the space above the piston through one or more channels. The prechamber (prechamber) engine can be either gasoline or diesel.

An internal combustion engine of this type is a design in which mixture formation and filling of cylinders occurs as follows:

prechamber of an internal combustion engine - RF patent 2270349

The invention relates to engine construction, mainly to internal combustion engines with compression ignition. The prechamber contains a cavity connected to the main combustion chamber by a bypass channel, mounted on the outer part of the cylinder head, has a cavity with a built-in sawing nozzle, and the bypass channel is made in the form of a profiled Laval nozzle, and the inlet section of the bypass channel has a generatrix in the form of a smooth curve, shaped which is determined by the Vitoshinsky relation, and the conjugation of the input and output sections is made along an ellipse arc. The invention ensures the operation of internal combustion engines on lean liquid-fuel-air and gas-air mixtures, saving diesel fuel, low toxicity of exhaust gases, ease of maintenance and low cost. 1 ill.

Drawings for RF patent 2270349

The invention relates to engine construction, mainly to internal combustion engines with compression ignition, and is intended to improve their technical, economic and environmental performance.

Prechambers of internal combustion engines are known, made in the cylinder head, connected to the main combustion chamber by connecting channels (see, for example, US patent No. 4442807 class F 02 B 19/18, 1984, RF patent No. 2099550 F 02 B 19 /18, 1995)

The disadvantages of such prechambers are the high labor intensity of production and maintenance, as well as the impossibility of using them on existing and produced fleets of vehicles, since inevitable changes in the design of the engine will require investment in capital costs for the development of designs for its new parts and assemblies, changes in production technology and additional equipment and technical equipment . The placement of the known pre-chambers in the lower part of the cylinder head significantly complicates their technological maintenance and, if necessary, dismantling, since it will require disassembling the car engine. These disadvantages make it difficult to implement known pre-chambers on the existing fleet and in production cars and to solve in real time the problems of increasing the fuel efficiency of cars and environmental problems in large cities and on highways.

These shortcomings are eliminated in the pre-chambers according to UK patent No. 1261176, Cl. F 02 V 19/12, 1972 and RF No. 2210677, F 02 V 19/18, 2001, mounted on the outer (outer) part of the cylinder head and containing a cavity communicated with the main combustion chamber of the engine using a bypass curved channel. Known prechambers are simple in design, easy and quick to install and extremely cheap to manufacture and operate, and the prechamber according to RF patent No. 2210677 has shown high results in fuel efficiency and environmental friendliness of automobile engines in tests.

However, these prechambers are applicable on engines with forced (spark) ignition and cannot be used on engines with compression ignition of the combustible mixture (diesel internal combustion engines).

Fuel pumps for diesel engines with increased fuel injection pressure of 70-100 MPa (70-100 atm) are known, for example YaMZ TA 423, TA 444, TA 861. Such an increase in fuel injection pressure is necessary for better atomization in the combustion chambers of new engines to burn diesel fuel according to criteria that meet the requirements of environmental standards EURO-1, EURO-2 and EURO-3.

However, such an increase in injection pressure causes an increase in the power of the fuel pump and its drive, which amounts to 10-15% of the internal combustion engine power developed by the car at cruising speed (˜80 km/h). Such a high drive power of the fuel pump causes significant additional fuel consumption, which worsens the fuel efficiency of the internal combustion engine, and the environmental characteristics of the car remain largely dependent on the reliability and efficiency of the injectors and the quality of mixture formation in the internal combustion engine cylinder, which are currently still very low.

The purpose of the present invention is to significantly improve the fuel efficiency and environmental friendliness of an internal combustion engine with compression ignition of a combustible mixture based on a simple and reliable technical solution.

For this purpose, a well-known engine with compression ignition of a combustible mixture (for example, YaMZ-238, KamAZ-740 diesel) according to the invention is equipped with a pre-chamber mounted on the external (outer) part of the cylinder head and containing a cavity connected to the main combustion chamber using a bypass curved a channel made in the form of a profiled Laval nozzle, the outlet section of which goes into the main combustion chamber, and the prechamber cavity contains a spray nozzle for fuel injection.

The installation of a diesel internal combustion engine pre-chamber on the external (outer) part of the cylinder head ensures the simplicity of its design and maintenance, as well as the high availability and efficiency of implementation of the proposed technical solution in real time on existing and new automobile engines. Installing a spray nozzle in the cavity of the pre-chamber eliminates the need to increase the injection pressure of the high-pressure fuel pump (HPF) and leave it at the level of 300-350 atm, because after injection, the pressure in the prechamber cavity, after preliminary combustion of the fuel mixture, can reach more than 1000 atm, which is due to the geometric and structural-strength characteristics of the cylinder head and prechamber. Making the bypass channel in the form of a profiled Laval nozzle will ensure the highest (supersonic) flow rate of the fuel-air mixture into the engine cylinder and its best dispersion and atomization, which will lead to optimal parameters of mixture formation and fuel combustion and, as a result, to a reduction in fuel consumption and exhaust toxicity gases and high efficiency of the car engine.

The compact, easily and quickly installed and dismantled design of the pre-chamber will ensure simplicity of its production, operation and maintenance, low cost and accessibility to the general consumer, solving current environmental problems of motor transport.

The proposed technical solution is not known from available sources of prior art information, from which it does not clearly follow for a specialist engine builder and is industrially easily feasible for the production of prechamber-flare ICE systems, that is, it meets the patentability criteria.

The essence of the invention is illustrated by the drawing (Fig. 1), which has a purely illustrative value and does not limit the scope of rights of the set of essential features of the claim, which shows: a prechamber 1 mounted on the outer part of the head 2 of the cylinder block 3, containing a cavity 4 with an installed spray nozzle 5 , bypass channel 6, made in the form of a profiled Laval nozzle with a contour formed by a smooth curve and consisting of inlet 7 and outlet 8 sections.

Based on the set of design features, the prechamber is a pulsed jet engine operating in a braked (reversed) mode, in which the oxidizer (air) is supplied through the jet nozzle.

The input section 7 of the bypass channel 6 has a generatrix in the form of a smooth curve, the shape of which can be determined, for example, by the known Vitoshinsky relation, and the contour of the output section 8 can be constructed by the known method of characteristics. The conjugation of the generatrices of these sections can be performed along an ellipse arc.

The device operates as follows. During the compression stroke of the internal combustion engine, compressed air at T˜700-900°C from the main combustion chamber through the bypass channel 6 enters the cavity 4 of the prechamber and fills it. At the moment of injection, atomized fuel is injected from the nozzle 5 into the cavity 4, where it ignites and partially burns, the temperature in the prechamber cavity rises to 1500-2000°C, and the pressure rises to a value of more than 1000 atm. Due to the strong pressure difference at the inlet and outlet of bypass channel 6, the hot pre-combustion products flow at supersonic speed into the main combustion chamber, where they are intensively mixed with a compressed air charge and effectively burn out at the highest rate of fuel combustion and maximum completeness of fuel oxidation, providing increased pressure at piston and minimal toxicity of combustion products in the internal combustion engine cylinder.

The limited communication between the cavity of the prechamber 4 and the volume of the internal combustion engine cylinder due to the small cross-section of the bypass channel 6 significantly reduces the possibility of corrosive blocking of the injector nozzle holes 5 due to the formation of starting condensate or their coking due to burning of oil splashes, which increases the reliability of the internal combustion engine fuel equipment.

The use of the present invention ensures reliable start-up of a diesel internal combustion engine, stability and power of its operation on lean fuel-air mixtures while reducing exhaust gases by tens of times and reducing the rate of destruction of the Earth's ozone layer, since diesel internal combustion engines account for more than 50% of vehicles in all countries of the world.

Prechamber-torch ignition system

The presence of a prechamber means that the working combustion chamber in such an engine is divided into component parts: the prechamber and the main chamber. Let's look at the principle of operation of the system using the example of the GAZ Volga carburetor model with a pre-chamber internal combustion engine.

The mixture enters the prechamber through a special channel, which is made in the intake manifold and cylinder head. The mixture is supplied to the prechamber over-enriched, for which purpose there is a separate section in the carburetor. The prechamber also has a separate inlet valve. Next, the mixture is ignited using a spark from a spark plug. At this moment, the intake valve of the main combustion chamber opens, which is driven by the timing camshaft. The fuel-air mixture enters the main chamber. The portion of this mixture is lean.

The pre-chamber is connected to the main chamber by special nozzle channels, through which flames, gases and fuel vapors from the pre-chamber break into the main chamber. Contact with them also causes the lean mixture in the main chamber to ignite. It turns out that the pre-chamber is a kind of mechanical “injection”, vaguely reminiscent of the principle of two-stage operation of modern diesel injection nozzles.

Pre-chamber diesel - Great Encyclopedia of Oil and Gas, article, page 1

Prechamber diesel

Page 1

Pre-chamber diesel engines have separated combustion chambers. The relationship between Vnp - the volume of the pre-chamber and Vc - the volume of the compression space is selected from 0 25 to 0 40 (Fig. The fuel injected into the pre-chamber is partially burned and the resulting energy is used to atomize the unburnt part of the fuel in the volume of the above-piston space. The pre-chamber is connected with one or more holes above the piston space. For the pre-chamber process, a single-hole atomizer is used, which has a small spray cone angle (10 - 15) to avoid sedimentation of fuel particles on the side walls of the pre-chamber. [1]

For pre-chamber diesel engines (see Fig. 34 - the volume of the pre-chamber is 25 - 40% of the total chamber volume. [2]

In pre-chamber diesel engines, the combustion chamber consists of two parts. Its main part, occupying more than 70% of the total volume of the combustion chamber, is located directly above the piston, and its smaller part is located in the prechamber. Pre-chamber diesel engines operate stably without smoking over a wide speed range. [3]

The disadvantage of pre-chamber diesel engines is difficult starting in a cold state, increased fuel consumption and lower efficiency. [4]

In pre-chamber diesel engines, for mixture formation, the vortex movement of gases is used, which is created as a result of preliminary partial combustion of fuel in the pre-chamber. [5]

Some pre-chamber diesel engines use igniters made of smoldering paper soaked in saltpeter. Before starting an unheated diesel engine, rods with a smoldering igniter are screwed into the prechamber. In contact with the injected finely atomized fuel, the igniters ignite it and a flash occurs. [7]

Pre-chamber diesel engines have the worst start-up, as they have the highest air velocities in the bypass channels and the greatest heat losses. Without a glow plug or some other heating device, a pre-chamber diesel engine cannot be started at all. After a long period of parking, sufficient pre-heating of the starting plug is required. Swirl chamber diesel engines with their spacious bypass channel connecting the chamber to the cylinder space, with a good location of the nozzle and at an ambient temperature above 0, are started in most cases without a device for glow ignition. [8]

The combustion process parameters of the pre-chamber diesel engine are as follows: / n0 5; tz0 01407 sec. [9]

The injected fuel pressure in pre-chamber diesel engines is 8 0 - 12 5 MN / m2, fuel consumption is 10 - 20% higher than the consumption in engines with undivided chambers. [10]

To improve the starting qualities of pre-chamber diesel engines, the compression ratios are increased (E 20 - n 21) compared to diesel engines with undivided combustion chambers. In addition, antechambers are usually equipped with glow plugs. [eleven]

In Fig. 11.106 shows a diagram of a pre-chamber diesel engine. The combustion chamber is divided here into two parts: pre-chamber 1 and main chamber 3 above the piston. The volume of the prechamber is 25 - 35% of the total volume of the combustion chamber. Air, compressed by the upward moving piston, fills the main chamber and prechamber. Due to the relatively small volume of the pre-chamber, only part of the fuel injected for one operating cycle burns in it. As a result of fuel combustion, the pressure in the prechamber increases, and the resulting gases, along with unburned fuel, are released into the main combustion chamber. At the same time, due to the high flow rates, the fuel is additionally atomized, mixes well with air and burns in the main combustion chamber 3 above the piston. The resulting gases produce work and are then removed. [13]

A slightly lower average effective pressure is obtained with pre-chamber diesel engines due to increased losses during the operating cycle. [14]

The curves of changes in pe and ge depending on the speed for a number of pre-chamber diesel engines at full load are shown in Fig. [15]

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Pros and cons of pre-chamber engines

The introduction of a prechamber into a gasoline internal combustion engine is not widespread. Certain design difficulties and insufficient efficiency of the system during actual operation led to the abandonment of the prechamber-flare ignition scheme.

As for diesel engines, pre-chamber diesel engines are more common. Prechamber diesel engines have low injection pressure compared to other diesel units. The use of a prechamber in a diesel engine made it possible to reduce the smoke of the power plant at different operating modes of the unit. Another advantage of the pre-chamber on a diesel engine is the lower demands of such engines on the quality of diesel fuel.

The main disadvantage of a pre-chamber diesel engine is the difficulty of starting a cold engine. The fact is that for a reliable start-up, high-quality heating of the prechamber is necessary. The use of electric glow plugs to effectively heat the air in the pre-chamber cavity does not always provide easier engine starting.

Diesel engine exhaust is black. Soot from a diesel exhaust pipe, causes of incomplete combustion of fuel. Determination of main faults.

Features and differences of the boxer engine from other piston internal combustion engines. Advantages of a boxer engine, disadvantages of this design, maintenance nuances.

Why does the fuel-air mixture detonate in the combustion chamber? Reasons causing detonation. Consequences of detonation combustion of fuel in internal combustion engine cylinders.

How to find the engine number on the power unit itself or in other places under the hood of the car. Location of the engine number on popular car models.

Types of internal combustion engines and the principle of operation of a heat engine. Duty cycle and strokes, advantages and disadvantages. Basic and alternative fuels.

Affordable ways to repair a car muffler. How to repair a muffler using cold welding, repairing a muffler without welding, etc.

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Pre-chamber diesels

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