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External combustion engine

The theory of the external combustion engine

History engines I in. BC.e.

Clean engines for land and sea transport has low noise, low toxicity and the ability to exhaust the various fuels.Comparable to the engine size and weight. All of these options provide an opportunity to challenge the internal combustion engine.The source of thermal energy you can use any heat source: solar energy, biofuels, nuclear energy, electricity and so on.

The challenge underlying the solution is to create a heat engine with expanded functionality.Namely, first, creating the possibility of operating the engine in the heat pump, which will in return the braking energy and store it in a heat accumulator for later use. Secondly, creating the possibility of starting the engine without a forced way, which will abandon the starter device and devices turn off the engine with the clutch mechanism of the executive, as well as from the engine to operate in Idle Mode.Third, creating the possibility of rotation of the motor shaft in any direction, which will abandon the device changes direction of rotation.Together, the rejection of part of the transmission equipment will improve efficiency and reduce material devices serviced engine.

Structurally, the engine has four extensive and four compression cylinder.The cylinders are alternately and in parallel around the axis of the working shaft engine. The mechanism of conversion of reciprocating motion is made in the form of oblique washers, as the drive axial-piston pump.Combustion occurs in the heat exchange chamber. To heat to the working body through the heat transfer tubes.When compressing the working medium is carried out the withdrawal of heat through heat transfer tubing and cooling the working medium in the cooler (radiators).Number of gas (they can be air), a prisoner in a working volume of the engine, continuously and irremovable. Working the body is under great pressure, the order of 40-200 atm.

Appearance engine modifications:

The engine is roughly the same size and weight as an ordinary gasoline engine.

By the features of the proposed engine are:

High KP e. Ability to obtain a high-KP village and, consequently, a large economy is an important feature of the engine. This is due to the full use of differential temperature and pressure in the cycle.But to realize these opportunities need to overcome significant design and technological difficulties, and difficulties in the selection of materials for the manufacture of engine parts.

Various heat sources. The external supply of heat used in the engine, allow the use of different heat sources, without any significant change the engine design.Almost all fossil fuels from solid to gas can be directly used in the engine. To do this, equip the engine combustion chamber with a regenerative heat exchanger for preheating the air charge heat of exhaust gases.
In cities with heavy traffic for use in vehicles has great prospects for the engine to heat the battery.
The advantage of the engine is also in that it can be used in a variety of fuels, but also provides an opportunity to apply various types of heat sources. This means that the engine does not depend on the availability of the atmosphere.It could equally well work in a confined space, as on submarines, and on satellites.

The impact on the environment (toxicity, noise, vibration). Obviously, the toxicity of engine (in the conventional sense), it is possible to speak only when using the heat of combustion of fuel.
Sources of toxic substances are the products of combustion and evaporation of it from the feed system.The engine works on the closed-loop, so it is not the crankcase and the combustion products resulting from the crankcase does not release toxic substances.
Evaporation into the atmosphere in the engine is much less than that of gasoline internal combustion engines, as well as the fuel system of closed type.Virtually the only source of toxic substances — products of combustion out of the atmosphere from the combustion chamber.
The main toxic substances contained in products of combustion of such fuels are carbon monoxide CO, unburned hydrocarbons C x H y, NO x, nitrogen oxides, aldehydes, soot, sulfur oxides (using sulfur fuels), lead (for leaded petrol).
Estimate the toxicity of the engine on the allocation of carbon monoxide, hydrocarbons, nitrogen oxides, as well as opacity. the allocation of available or imposed statutory limitations.Toxic products of incomplete combustion (CO and C x H y) are the result of lack of oxygen during the combustion (at small general or local rates of excess air).
Soot in the exhaust gases is shown in those cases when the thermal decomposition of hydrocarbons (cracking) at high temperatures and lack of oxygen.Cameras combustion engine similar to the combustion chamber of gas turbine and steam engines. The process of burning them is stationary. In such circumstances, can provide enough high quality of mixture.The air entering the combustion chamber, is heated in a special heater exhaust gases. Obviously, the selection of toxic substances in exhaust gases into the engine depends on the coefficient of excess air during combustion and the temperature of inlet air into the combustion chamber.
With the increase of the coefficient of excess air during combustion decreases the concentration of CO, C x H y and NO x.Consideration of the mass of the toxic components released during the combustion of unit quantity of fuel, leads to the same conclusion. It is important to note a very small concentration of CO, C x H in. The concentration of NO x decreases with increasing excess air ratio due to the significant impact of reducing the temperature compared with the impact of increasing the number of free oxygen in the combustion products.Because the coefficient of excess air increases the efficiency of the engine a few drops, then the rational value of the coefficient of excess air during combustion is about 1,5-1,8.
With the increase of air temperature entering the combustion chamber, at a constant ratio of excess air content of products of incomplete combustion (CO and C x H y) is decreasing and the concentration of NO x increases.Efficiency of the engine also increases with increasing air temperature at the inlet to the combustion chamber.Reducing the concentration of CO and C x H a due to improved conditions of combustion in a hot air.Increased concentrations of NO x caused by the increase in the maximum temperature of combustion at a constant ratio of excess air. Inlet air temperature in the combustion chamber in the engine reaches 600-800 В° C.
It should be noted that the engine exhaust gases have no smell and does not contain carbon black.
The above material shows that the greatest impact on emissions of nitrogen oxides have a motor. The allocation might be reduced by exposure to conditions in the combustion chamber (the maximum decrease in temperature and oxygen concentration).To lower the temperature in the combustion zone by selecting the appropriate parameters of the combustion chamber or use exhaust gas recirculation (as in internal combustion engines).
Increasing the number of perepuskaemyh exhaust more than 33% of the number of incoming fresh air is not feasible, as this significantly increases the concentration of CO and NO x concentration decreases less significantly.
To assess the level of toxicity in the table below shows the engine unit of toxic substances in the engine, the diesel engine, gas turbine and the gasoline engine.

Engine type

Toxic constituents in mg / (bhp c)

NO x

CO

C x H in

Engine DVPT 0,1-0,2 0,05-0,2 0,0015-0,009
Gas turbines (with regenerator) 0,7-2,0 2,0-3,6 0,0120-0,072
Diesel 0,4-2,0 0.2-5,0 0,6-12
Petrol engines 0,6-2,0 40-100 15-120

From the table it follows that even without the adoption of special measures, the toxicity of engine exhaust gas is significantly lower toxicity of other types of heat engines.

Low noise and vibration. The main sources of noise in internal combustion engines are turbo, the combustion process, the processes of intake and exhaust timing mechanism, crank, connecting rods and the support mechanisms (due to the presence of gaps in the toothing, occasionally overlapping gaps in the joints and movable etc.).Noise generation mechanisms in the auxiliary engines of the internal and external combustion can take the same, other sources of noise in the engine are not available, so the noise from the engine is running, much less than the internal combustion engine.External combustion in the engine occurs continuously and does not have an explosive character, which, when burned, and release almost no noise is generated.
In addition, the pressure in the cylinders of the engine varies smoothly on almost sinusoidal law.The noise level of the engine at an average of 20-30 dB lower than the diesel engine is the same power.

Consumption of lubricating oil. In internal combustion engines hit the oil in the cylinder, on the one hand, leads to the burning of oil, on the other hand, due to its aging contact with hot gases and engine parts.
The proposed engine oil practically can not get into the working cavity and, moreover, did not come with any hot gases or the hot parts, so not happening either burnout or osmoleniya oil.As a result, the engine is no longer necessary to periodically adding oil.In principle, the engine can develop throughout motoresursa initially filled with oil (if time does not change its properties under the influence of the environment), which is cleared only on the abrasive particles.For the heavy-and medium-power is an important economic advantage (cost of lubricating oil is 10 times higher than the cost of fuel).For low-power engines that significantly reduces labor services.
Release of oil in the engine working conditions is extremely undesirable and extremely damaging phenomenon, as well as changing the properties of gas and, consequently, the effective efficiency of the engine.Therefore, in the engine are not lubricate the piston rings, and lubricant is required only to lubricate the drive mechanism and support units.As the piston seals in the engine used continuous ring of fluoroplastic or composite materials based on the latter.

Reliable and fast start-up of the engine at low temperatures. The proposed engine with high pressure of gas in the inner cavities and sufficiently high temperature heater tubes, easy starts at any temperature environment. His start-up depends entirely on the reliability, which may ignite the fuel in the chamber combustion.Spark plugs, which merged with the nozzle in a single whole, virtually guarantees the start-up of the engine under all environmental parameters.

Tolerance to dust the surrounding area. Because the proposed engine — external combustion engine, the dust in the air charge entering the combustion chamber from the surrounding space, did not reach the crankcase and cylinders (in the engine crankcase ventilation is not required).As a result, the engine no additional abrasion of moving parts of drive mechanism. In addition, because of the low-speed air charge and exhaust gas in the regenerative heat exchanger of a combustion chamber (heater air charge) and its raspylivayuschem device, corrosion of these components is negligible.

Dealing with short-term overloads. Motoresurs engine speed is determined by the onset of creep limit of the material details of the heater operating at high temperature. With increasing pressure of gas in the inner cavities of the engine speed limit creep increases.Nevertheless, short-term overload associated with increased pressure of gas in the inner cavities, slightly reduce the longevity of the engine, as well as details of the heater temperature stays constant.
In general, any engine can be guaranteed to withstand a short-term 50-80% integrated overload without significant reduction in durability.

Heat in the cooling medium. Due to the availability of the engine closed-loop system circulating the working medium heat almost exclusively through the cooler, the heat should be possible at lower temperatures. Therefore the quantity of heat spent in the cooling water in the engine at approximately 2 times higher than in internal combustion engines, where the same effective performance. Therefore, the size of the radiator cooling system of engines in vehicles produced more than internal combustion engines of the same destination .
In the ship’s engines, this feature is not a serious shortcoming.

BASIC PARAMETERS Engines of 1500 cm 3

NAME OF INDICATOR Ed. amend. INDICATOR
Number of cylinders

sh t

8

Power

l. c.

124

Number of turns

of b / min

3000

Efficiency

%

52

The coefficient of the progress of the piston

2.6

The average gas pressure in the cycle

by HS / cm 2

32.0

Displacement Cylinder

with 3 m

1500

The diameter of the engine

with m

21.5

The length of the engine

with m

64.5

The content of CO

g / km

0,05-0,2

Contents of C x H in

g / cm

0,0015-0,009

The contents of NO x

g / km

0,1-0,2

Weight of engine

Ms.

95

Operating body

Helium

Type

Slant Pack

Location of cylinders

Drum

Source of heat

The heat battery and mnogotoplivnaya the combustion chamber

Assignment Engine

The car and ship

 

Appearance PILOT MODEL ENGINE

BASIC PARAMETERS OF SETTLEMENT PILOT MODEL ENGINE
 

NAME OF INDICATOR Ed. amend. INDICATOR
Number of cylinders
pc.
2
Power
kW / hp.
3.5/4.7
Number of turns
rpm
1000
Efficiency
%
61
The coefficient of the progress of the piston
4
The maximum gas pressure in the cycle
atm.
226
Displacement Cylinder
cm 3
100
The diameter of the engine
mm
89
The length of the engine
mm
453
The content of CO
g / km
0.05-0.2
Contents of C x H in
g / cm
0.0015-0.009
The contents of NO x
g / km
0.1-0.2
Weight of engine
kg
7
Operating body
Carbon dioxide
Source of heat
The heat battery and mnogotoplivnaya the combustion chamber

«The engine with the external leads heat.The patent number 2105156 dated June 23, 1995. RF.

«The engine with the external leads heat.Patent number 2149275, dated 31 May 1999. RF.