JPS598650B2 - Method for obtaining kinetic energy by burning fuel and reciprocating internal combustion engine for carrying out the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method in which the chemical energy of a fuel is converted into kinetic energy by time-controlled combustion and expansion of hot combustion gases after self-ignition of the fuel, Furthermore, the present invention relates to a reciprocating engine for carrying out this method.

In a normal thermodynamic cycle, as occurs, for example, in a steam engine or a piston engine, the work efficiency ranges between 10% and up to 40%.

This low efficiency can be mainly attributed to heat losses during the expansion of the highly pressurized gaseous medium and during the compression of the combustion air in the cylinder (particularly in the case of internal combustion engines).

Due to the nature of the piston and cylinder materials and the customary lubricating oils, the temperature of the cylinder wall or the smooth surface of the push to be lubricated should not exceed 220°C to 250°C.

Since the average temperature in the cylinder chamber is quite high due to the high combustion temperature of more than 2000° C., a large part of the heat transferred from the hot exhaust gases to the cylinder wall is dissipated by water or air cooling.

This necessary cooling of the cylinder walls leads in several ways to overall heat losses.

Due to the large temperature difference between the cylinder interior and the cooled cylinder wall, a large amount of thermal energy is given to the cylinder wall during the expansion and discharge of the hot exhaust gases, especially in the combustion of the mixture. and released by the coolant.

In the case of an Otto engine or a diesel engine, this amount of heat can be as much as 30 inches of the thermal energy of the supplied fuel.

The cooling of the walls of the cylinder or combustion chamber also has the disadvantage that combustion in the vicinity of the cooled walls proceeds at a lower temperature than in the center.

That prevents complete combustion, resulting in power loss and high unburned components in the exhaust gas.

In internal combustion engines of this type, a further factor that has a negative influence on the energy balance is that combustion and expansion take place in one and the same chamber.

The hot walls and possibly the part of the hot exhaust gas that is not released imparts heat to the medium to be compressed, thereby increasing the temperature of the gas during compression in addition to the temperature increase associated with compression due to pressure. Therefore, in order to achieve the final pressure that is to be obtained or adhered to, a greater mechanical work has to be applied than is required, for example, in the case of almost isothermal compression.

Even if sufficient removal of the heat generated by compression can be achieved by very strong cooling of the cylinder walls, the heat losses during expansion are thereby again increased and the combustion process is further exacerbated.

A further loss factor in the Otto and diesel systems is the gap between the cylinder head and the piston head at top dead center for the accommodation of the compressed and possibly partially combusted fuel gas.

Since the combustion time per work stroke depends on the rotational speed, it is very short and often insufficient for complete combustion, especially in rapidly rotating engines; The excess air can also be compensated for in the case of Otto engines by reducing abnormal ignitions by suppressing or increasing pre-ignitions, but this also causes a reduction in efficiency, however.

It is an object of the present invention to provide a method for obtaining kinetic energy by fuel combustion, which makes it possible to form a thermodynamic cycle with essentially lower heat losses, and to provide a method with high thermal and work efficiency for carrying out the method. The object of the present invention is to provide a reciprocating internal combustion engine having the following characteristics.

The problem is that the combustion air is compressed almost isothermally and then heated in such a way that the chemical energy of the fuel is converted into kinetic energy by time-controlled combustion and expansion of hot combustion gases after self-ignition of the fuel. heated by exhaust gas; a part of the compressed and heated combustion air is branched off for at least preheating and vaporization of fuel preheating, vaporization and compression; the remaining part of the combustion air and The fuel gas formed is led separately into a combustion chamber nozzle in a proportion approximately sufficient for combustion, in which it is mixed and combusted by self-ignition with a slight excess of air without pressure increase; uncooled expansion; The problem is solved by a method of obtaining kinetic energy through fuel combustion, characterized in that the energy of the combustion gases is transferred to the piston; and the exhaust gases are discharged from the cylinder chamber.

In order to prevent overheating in the combustion chamber, according to a preferred embodiment of the inventive method, hot steam can be added to the combustion air or the gas-air mixture.

In order to further improve the energy balance, it is preferred to generate this hot steam with hot exhaust gas in a heat exchanger.

The combustion air can be compressed isothermally to the respective desired pressure and then heated as strongly as technically possible by hot exhaust gases.

A reciprocating internal combustion engine for carrying out the method of the invention includes: an air compressor for approximately isothermal compression of combustion air; a heat exchanger heated by exhaust gas for heating the compressed combustion air; a branching valve device for branching a part of the heated air; a mechanism for at least vaporizing and compressing fuel mixed with the branched air;
A fuel conduit and an air conduit provided separately from each other; a cylinder head insulated from the rest of the cylinder; a reservoir for adjusting the supply of fuel gas and air to the combustion chamber, provided in the fuel gas conduit and air conduit; a regulating valve arrangement; and an exhaust valve for discharging expanded combustion gases from the combustion chamber to a heat exchanger during the return stroke of the piston, the piston being at top dead center in the cylinder head portion of the combustion chamber. The compressed fuel gas and air injected when reaching or in the vicinity thereof are combusted and expanded by self-ignition in the combustion chamber without pressure rise, and the output is varied by the control valve device. It is continuously controlled from idle to maximum output depending on the supply amount.

Compressors for compressing combustion air are: Preferably, it can be a cooled multi-stage piston compressor, the intake valve of which is regulated by a pressure regulator connected to a high-pressure line and with intercoolers between the individual compression stages.

Although it is also possible to drive the piston compressor, which is equipped as a special component, by an external motive force, for example an electric motor, according to a preferred embodiment of the invention, the piston compressor is connected directly to the crankshaft of the internal combustion engine. By coupling a single compressor to a pressure reservoir, it is possible to supply combustion air to multiple cylinders of an internal combustion engine.

Adjustment of the air-fuel ratio and thus maintenance of an optimal combustion process is achieved by continuously measuring the proportion of unburned hydrocarbons and carbon monoxide and/or the carbon dioxide content and nitrogen oxide content in the exhaust gas. This is done by means of exhaust gas measuring sensors and thermostats in the exhaust gas line or cylinder head.

The exhaust gas measuring sensor and the thermostat mutually influence the regulating device.

The regulating device operates the valves accordingly, thereby adapting the air-fuel ratio to the current operating conditions.

In order to improve the combustion process, in particular to reduce the flame temperature in the combustion chamber, an evaporator is provided in the heat exchanger, around which the hot exhaust gases flow.

The high-pressure outlet is connected by a special conduit directly to the combustion chamber or to the high-pressure air conduit.

The device for the purification of fuel can be configured as a vaporizer, inserted into the flow path of a liquid fuel, for example gasoline or diesel fuel, which is connected to an injection conduit and a pressure pump to purify the liquid fuel. .

In order to operate a reciprocating internal combustion engine with fuels of varying concentrations that cannot be vaporized without residue, two carburetors that can be connected alternately in parallel are provided, one of which is connected to the engine. Preferably, it can be removed, cleaned and even replaced at any time without interruption of operation.

In the present invention, the essential contribution to improving the efficiency of a reciprocating internal combustion engine is provided by the cylinder head.

That is, if necessary, a recess is formed in one or more extensions of the cylinder head so that the upper part of the piston does not come into contact with the wall of the recess. The recess can be entered in the piston stroke region so as to form a narrow annular gap with the surface, in which combustion takes place under approximately equal pressure.

The advantage of such a cylinder head is that it insulates the cylinder head from the cooled parts of the cylinder block and thereby transfers the heat to the walls of the recess in the cylinder head, i.e. the uncooled combustion chamber parts, without impairing the life of the engine. The reason is that it can be fastened to the wall that partitions the area.

In that case, the space between the recess front wall and the piston front wall when the piston is at top dead center, apart from the essential space required for the accommodation of the highly compressed fuel mixture in a normal reciprocating internal combustion engine, is They are arranged so that they no longer constitute any free space between them.

In order to reduce the thermal load on the cylinder head material and especially on the piston front wall, the inner wall of the recess can be thinly coated with a highly refractory material, while the inner diameter of the coated recess is reduced due to the formation of an annular gap. is made slightly larger than the piston diameter.

The heat release from the combustion chamber in the engine block is further reduced by the fact that the piston is conventionally designed as a hollow piston and that its inner wall is provided with insulation.

No compression work is performed in the cylinder, and fuel gas is supplied to the cylinder at the beginning of each work stroke to accompany combustion, so that the work stroke length coincides with the next piston stroke, ie, the return stroke length.

This results in the further advantage that an exhaust valve arranged, for example, in the cylinder head can be open throughout the exhaust or return stroke, thereby ensuring a uniform expulsion of the combustion gases during the return stroke of the piston.

Fuel gas and combustion air from the vaporizer are fed through flow channels to the cylinder head of the nozzle where they are heated to their autoignition point.

Since the combustion process must first begin at or near top dead center of the binuton, specially designed and timed valves are provided.

This valve ensures that both gases are first collected in the combustion chamber nozzle and swirled there as strongly as possible.

The combustion in the nozzle is . Since this takes place without a pressure increase, there is no risk of flame backflow even if incomplete fuel vaporization occurs and air is still present in the fuel gas line.

For timed mixing of both gases: - The valve can be configured, for example, as a slide valve, as is used in a similar manner in high-pressure steam engines.

However, it is particularly advantageous if the lower inclined surface of the plunger, which is guided perpendicularly into the corresponding cylinder head recess, rests on the inclined surface of the cylinder head recess, which is configured as a valve seat.

Optionally, a flow channel for fuel gas and combustion air is connected to each of these cylinder head ramps.

At its lower end, the plunger has a protruding plate that divides the upper part of the combustion chamber nozzle into two chambers, the side walls of the protruding plate are
It can be shaped to form a swirling flow depending on the time.

With its twisted elongated sides, the protruding plate is guided between the walls of the combustion chamber nozzle and prevents premature mixing of the two gases when the valve is opened.

It is self-evident that it is also possible to provide valves for the supply of fuel gas and combustion air, which gives rise to the advantage of specific quantitative adjustment.

The present invention will be explained in more detail below along with the embodiments shown in the drawings.

The internal combustion engine shown in FIG. 1 consists of two special structural groups: a multistage piston compressor 1 and an internal combustion engine section 2 with optional auxiliary organs.

The pistons of both structural groups are connected to a single crankshaft 3 by a connecting rod in the usual manner.

The wall 4 of the piston compressor 1 is penetrated by flow channels 5 for the coolant.

An intercooler 8 is connected between the outlet 6 of the low pressure stage and the inlet 7 of the high pressure stage.
It consists of 0.

A pressure regulator 12 is connected to the high pressure conduit 11,
This acts in the usual manner on the valve 13 in the suction conduit 14 of the low pressure stage.

In the high-pressure conduit 11 , highly isothermally compressed combustion air flows in the direction of the arrow 15 towards the heat exchanger 16 .

The heat exchanger 16 is connected to an exhaust port 17 through which hot exhaust gas exits and is discharged through the heat exchanger 16 through a conduit 18.

In order to achieve as strong a heat transfer as possible, the high-pressure conduit 11 in the heat exchanger 16 is designed as a helical tube.

For heating the combustion air, a steam generator 20 is also installed in the heat exchanger, in which water or moist steam is heated and optionally heated to reduce the flame temperature in the combustion chamber. It is compressed according to

The exhaust conduit 18 is provided with an exhaust gas measuring sensor 21 and a thermostat 22, the measured values of which are fed to a regulating device 23.

This regulating device acts on a three-pronged valve 24 in which a portion of the heated, highly compressed combustion air is branched off and directed through a conduit 25 to a carburetor 26 .

In the vaporizer 26, the liquid fuel supplied by the conduit 27 and the pump 28 is vaporized. The fuel gas formed is delivered through conduit 29.

The main part of the combustion air enters via the three-pronged valve 24 through a conduit 31 which passes through at least a portion of the cylinder head 30 .

The fuel gas conduit 29 and the combustion air conduit 31 are connected to the inclined surfaces 32 and 33 of the valve seat (FIG. 4).

The end face of a cylindrical rod-shaped valve 34 is notched along this inclined surface 32, 33, and the rod-shaped valve 34 is guided into a recess 35 (FIG. 4) in the cylinder head.

The lower sloped surface of rod valve 34 opens and closes both conduits 29 and 31 simultaneously.

The valve 34 terminates in a lower projecting plate 36 which extends the upper part of the combustion chamber into a combustion air chamber 38 along the length of the chamber.
and a chamber 39 for fuel gas, and the intensive mixing and ignition of both gases is achieved by the protruding plate 3 in the combustion chamber nozzle 37.
6. Make it happen below.

Cylinder head 30 as shown in FIGS.
K has a cylindrical recess 40 extending therethrough, into which an upper portion 41 of a piston 42 can protrude.

This recess 40 forms a unique combustion chamber and expansion chamber.

Its diameter is only slightly larger than the diameter of the upper part 41 of the piston, so that the piston moves without contacting the wall of this recess under the formation of the annular gap R.

Guidance of the piston is provided by a regular piston ring 43 at the bottom of the piston 42, which is guided along the inner wall of the normal cylinder liner.

For control of the temperature of the cylinder wall, which is limited by the lubricant used, the cylinder 45 has cooling fins 46 for air cooling.

It is obvious, however, that the cylinder wall 45 can also be cooled by a liquid coolant, for example water.

In order to maintain the recess 40 of the cylinder head at a high temperature,
In order to prevent significant heat transfer from the cylinder head 30 to the cooled cylinder block, a highly insulating encapsulant 47 is present at the connection location.

The inner walls of the four parts 40 of the cylinder head and at least the upper front wall of the piston 42 are coated with a thin coating 50 of highly refractory material in order to keep the thermal influences of the cylinder head material within limits.

The side walls of the piston upper part 41 can then also be coated with this refractory material.

In order to prevent significant heat radiation by the piston wall in the interior of the hollow piston 42, this interior is provided with a thermal insulation 52, at least in the region of the upper part of the piston.

The front wall of the recess 40 of the cylinder head 30 is connected with an exhaust conduit 17 leading to the heat exchanger 16, which is closed and opened by a conventional exhaust valve 53 that operates in accordance with the timing. .

The method of operating the reciprocating internal combustion engine of the present invention is as follows.

In the cooled multistage piston compressor 1, the air supplied by the suction conduit 14 is compressed, since the heat of compression generated in this case is substantially removed by cooling the piston wall and by the intercooler 8. , compression proceeds approximately isothermally.

If necessary, the air compressed to a technically possible pressure is heated as fully as possible by hot exhaust gas in the heat exchanger 16 and then flows into the three-way valve 24 .

The air branched by the valve vaporizes the liquid fuel supplied through the conduit 27 in the vaporizer 26, and the high-temperature, high-pressure fuel gas is transferred to the combustion chamber nozzle 37 through the conduit 29 as the rod valve 34 rises. (FIG. 4).

The main part of the combustion air passes through the valve 2 during the rise of the rod valve 34.
4 through a pressure conduit 31 into a chamber 38 above the nozzle 31 separated by a projecting plate 36 .

Based on the configuration in which the side wall of the protruding plate 36 is twisted, when the rod-shaped valve 34 is opened, a swirl is imparted that causes both gases to undergo a strong eddying motion at the nozzle 37.

Combustion takes place without a pressure increase in that the hot fuel gas molecules and oxygen molecules, the temperature of which is above the autoignition point, impinge on the hot walls of the nozzle or cylinder head and piston head.

The combustion time under constant supply of fuel gas and combustion air to the nozzle 37 corresponds to a certain crankshaft, a certain rotation angle, or a certain piston stroke.

If the walls of the cylinder head recesses scavenged by the combustion gases are protected to the extent economically possible against heat losses, their surfaces have a temperature of approximately 1000° C. at maximum power.

During the expansion of the combustion gases and the associated temperature drop, the minimal excess air allows the gases the possibility and sufficient time to still burn the last unburned mixture-gas residues.

The entire part of the combustion chamber surrounded by the hot walls is filled with enclosing material 47.
Since the wall is substantially delimited by the wall, the disadvantage in the prior art that the complete combustion of the fuel gas present in the region of the cooled wall is prevented by supercooling does not occur.

By plasma spraying, a high temperature resistant insulating layer with a thickness of 3 to 4/10 am can be formed on the walls of the cylinder head recess and the upper part of the piston.

The insulating layer stores this energy in the highest temperature region until it is mostly returned to the gas whose temperature has been reduced by expansion.

This amount of heat, which must not be given up by the engine coolant, is effectively retained, so that it does not have to be provided additionally by the fuel.

When using high-energy fuels, if too high a flame temperature occurs in the combustion chamber, then the combustion air is transferred to the evaporator 20.
It is preferable to replace the high-pressure steam generated in the combustion chamber or to lead this steam to the combustion chamber or to the carburetor by means of the combustion air conduit 31 or special conduits.

In FIG. 2, a device with two identical units 60, 61 for vaporizing fuel is schematically illustrated.

From the conduit 25 through which part of the combustion air passes, the conduit 62.6
3 to vaporizer units 60, 61, respectively, and regulating valves 64, 65 are installed in these conduits.

Outflow conduits 68, 67 with corresponding control valves 68, 69
is led into conduit 29.

Fuel supply is provided by a three-pronged valve 70 via conduit 27 and pump 28.
Selective K is performed for each unit 60 to 61 through the process.

With this configuration of the carburetor units, each of the carburetor units can be stopped and cleaned or replaced by actuation of the corresponding control valve, without having to interrupt the operation of the internal combustion engine, and can also be completely cleaned or replaced without having to interrupt the operation of the internal combustion engine. fuel can also be inserted.

Solid fuels such as coal, wood, etc. and viscous unrefined fuels such as tar, petroleum spirit, waste oil, etc. can also be used by the vaporizer for driving the internal combustion engine. //For the required tx connection - both vaporization units} In place of the 60 and 61, more units can be provided and connected in parallel depending on the occasion.

In special cases, the connection between the two units 60 and 61 can be formed by a valve 70 in order to enable or even better the combustion of the fresh material filled in the antechamber or in the adjacent unit.

The embodiment of the engine shown in FIG. 3 corresponds in essential parts to that according to FIG. 1, so that there is no need to go into their common features any further.

The embodiment according to FIG. 3 is described for combustion of gaseous fuel.

The fuel gas is supplied to a small multi-stage piston compressor 7 which can optionally be driven by the crankshaft 3
5 in a substantially isothermal manner.

For this purpose, an intercooler 76 is connected between the low pressure stage 77 and the high pressure stage 78.

Both compressors 1 and 75 compress the medium in each case to the same pressure, for example 40 to 50 k9A.

Combustion air and combustion gases are heated through conduits 11 and 82 respectively in two heating helical tubes 79 and 80 around which the hot exhaust gases flow, the regulating device 81 ensuring that the combustion occurs under equal pressure during self-ignition. The amounts of both are adjusted so that the desired air-fuel mixture is generated in the combustion chamber nozzle 37.

The combustion process continues without pressure increase until the intake valve 34 is closed.

The piston 42 then advances through one stroke in the working cylinder, approximately corresponding to the volume of the diesel engine at full load, which volume, after ignition and combustion of the injected diesel oil, carries the combusted gases. It is meant to accommodate.

The optionally required power of the engine is increased in such a way that one or more intake valves only allow "filling", as is the case, for example, in piston-type steam engines.

The compressor or compressors supply only the amount of gas required in the various operating conditions.

After closing the rod valve 34, a pure expansion of the fuel gas takes place without substantial after-combustion.

Due to the arrangement of a special cooled compressor 75 for the fuel gas and the heating of the fuel gas by the exhaust gas in the heat exchanger 16, the respective gases are combusted under high pressure and without danger and with maximum efficiency. be able to.

The timed supply and formation of the air-fuel mixture to the nozzle 37 takes place, as in the embodiment according to FIG. 1, by the valve mechanism illustrated in FIG.

FIG. 5 shows that the depth of the recess 40 in the cylinder head 30 should correspond as closely as possible to the piston stroke.

This ensures that only a very small amount of heat is transferred to the engine coolant, since the specific combustion chamber part is located only in the insulated cylinder head.

When the engine is cold and the air and fuel gases are not yet heated, ignition is effected by an arc originating from the spark plug in the region of the gas or air supply to the working cylinder.

The external igniter is activated until operating temperature is reached for self-ignition.

The internal combustion engine according to the invention can rotate in both directions of rotation.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of an embodiment of a reciprocating internal combustion engine according to the present invention, FIG. 2 is a schematic diagram of a vaporization mechanism for fuel that cannot avoid forming residues, and FIG. 3 is a reciprocating internal combustion engine according to the present invention. FIG. 4 is a partial sectional view showing details of the valve and combustion chamber nozzle provided in the internal combustion engine of FIGS. 1 and 3, and FIG. 5 is a reciprocating engine according to the present invention. 1 is a schematic front view of a dynamic internal combustion engine. 1... Air compressor, 16... Heat exchanger, 2
4... Valve, 26... Fuel vaporization and/or compression mechanism,
29... Fuel gas channel, 30... Cylinder head, 31... Air channel, 34... Channel 2
Valve acting on 9, 31, 37... cylinder head 3
Combustion chamber at 0, 53...exhaust valve.

Claims (1)

[Scope of Claims] 1. A method in which the chemical energy of a fuel is converted into kinetic energy by time-controlled combustion and expansion of hot combustion gases after self-ignition of the fuel, in which the combustion air is compressed approximately isothermally. and then heated by hot exhaust gases; two parts of the compressed and heated combustion air are branched for preheating, vaporization and compression of the fuel, at least for preheating and vaporization; the remainder of the combustion air; and the fuel gas formed, in approximately sufficient proportions for combustion, are conducted separately into a combustion chamber nozzle, where they are mixed and combusted by self-ignition with a slight excess of air without pressure increase; A method for obtaining kinetic energy by fuel combustion, characterized in that the energy of the cooled expanded combustion gases is transferred to the piston; and the exhaust gases are discharged from the cylinder chamber. 2 Air compressor for almost isothermal compression of combustion air; heat exchanger heated by exhaust gas for heating of compressed combustion air; branch for branching off a part of the compressed and heated air A valve device; a mechanism for at least vaporization of the branched fuel mixed with the air; a fuel conduit and an air conduit provided separately from each other; a cylinder insulated from other parts of the cylinder; head; a regulating valve device arranged in said fuel gas conduit and air conduit for regulating the supply of fuel gas and air to the combustion chamber; and a control valve device arranged in said fuel gas conduit and air conduit for regulating the supply of fuel gas and air to the combustion chamber; An exhaust valve is provided for discharge to an exchanger, in the cylinder head portion of the combustion chamber, the compressed fuel gas and air injected when the piston reaches or near top dead center is maintained without pressure increase. A reciprocating motion characterized in that the fuel is combusted and expanded by self-ignition in the combustion chamber, and the output is continuously controlled from idle to maximum output according to the amount of fuel supplied that is varied by the control valve device. Internal combustion engine. 3 Air compressor for nearly isothermal compression of combustion air; heat exchanger heated by exhaust gas for heating of compressed combustion air; branch valve for branching off a part of the compressed and heated air device; a mechanism for at least vaporization of the branched fuel mixed with the air; a fuel conduit and an air conduit provided separately from each other; a cylinder head insulated from other parts of the cylinder; a regulator for regulating the supply of fuel gas and air to the combustion chamber; a regulating valve device arranged in the fuel gas conduit and the air conduit; and a heat exchanger for transferring the expanded combustion gas from the combustion chamber during the return stroke of the piston; 16, in the cylinder head part of the combustion chamber,
When the piston reaches or near top dead center, the injected compressed fuel gas and air are combusted and expanded by self-ignition in the combustion chamber without pressure rise, and the output is:
A control valve device that adjusts the supply of fuel gas and air to the combustion chamber of a reciprocating internal combustion engine that is continuously controlled from idle to maximum output according to the fuel supply amount changed by the control valve device, The plunger has a plunger guided in a hole provided in a wall forming a recess of the cylinder head, and the plunger has a lower inclined surface corresponding to the inclined surface in the closed state of the control valve device. The combustion air conduit is supported by an inclined valve seat and includes a protruding plate that divides a nozzle formed in the upper part of the combustion chamber into a combustion air passage and a fuel gas passage, and the combustion air conduit is connected to the combustion air passage. A reciprocating internal combustion engine, characterized in that the fuel gas conduit is connected to one of the valve seat surfaces and the fuel gas conduit is connected to the other valve seat surface, respectively.