JP3994133B1 - Insulated composite engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat efficiency and output by effectively utilizing exhaust loss discarded without being used in a conventional positive displacement engine and cooling loss discarded after cooling a high-temperature engine.
An exhaust energy recovery device 9 recovers exhaust loss and cooling loss discharged from a positive displacement heat insulating engine.
The cooling loss is caused by injecting water or steam or compressed air from the nozzle 5 attached to the side wall of the cylinder 2 of the positive displacement heat insulating engine, cooling the inner wall of the cylinder in the exhaust stroke, and generating superheated steam or expanded air. Effectively used to obtain spraying power.
[Selection] Figure 1

Description

  The present invention relates to a composite engine that improves thermal efficiency and output by effectively using exhaust energy loss.

  The thermal efficiency of conventional engines is approximately 40% for diesel engines and approximately 30% for gasoline engines. Cooling loss and exhaust loss are approximately 30% each, and much energy is discarded without being used.

  The conventional positive displacement engine cools the outside of the cylinder with water or air, thereby suppressing the temperature rise of the engine body and enabling a constant continuous operation.

Also vaporized in the cooling and the inside of absorbing heat in the cylinder tube by injecting water into the cylinder, attempts to achieve an increase in output by the expansion force of the vapor has been made. (For example, refer to Patent Documents 1 and 2.)

A hybrid engine that combines an aircraft diesel engine and an exhaust turbine has been developed. (For example, refer nonpatent literature 1.)
JP-A-60-184923 Japanese Patent Laid-Open No. 3-115743 Internal combustion engine handbook Asakura Shoten P647 Issued in 1969

  As described above, there is energy that has been discarded as cooling loss and exhaust loss in the conventional engine, and if these energy losses are recovered and used as power, thermal efficiency and output are improved.

  Most of the conventional positive displacement engines except the small size have a forced cooling device for cooling the outside of the cylinder with water or air, and require power for forced cooling.

The purpose of the water injection type adiabatic ceramic diesel engine disclosed in Japanese Patent Application Laid-Open No. 60-184923 is to reduce the intake efficiency of fresh air, which is a disadvantage of the heat insulation engine, due to the absorption of the heat of vaporization by the water injection in the expansion stroke following the compression stroke However, it is difficult to increase the output because it is possible to reduce the combustion temperature because the injected water takes part of the heat energy during combustion as the heat of vaporization. It is.
In the six-cycle heat insulation engine disclosed in Japanese Patent Laid-Open No. 3-115743, the six cycles referred to here are suction, compression, expansion, exhaust, expansion, and exhaust stroke, but the water injected in the second expansion stroke is vaporized. It is said that the expansion pressure of the cylinder rises and the expansion work can be performed, but the expansion speed of the steam due to the vaporization of water in the second expansion stroke is different from the combustion speed of the fuel. It is difficult to work (get power) in the second expansion stroke.

  The composite engine developed in the past has good fuel efficiency, but it is said that it has not been put into practical use due to its complicated structure.

  Exhaust gas, which is an exhaust loss generated by combustion of a positive displacement engine, is effectively utilized by turning a turbo and supercharging it, but does not lead to an improvement in thermal efficiency. In addition, although the cooling loss occupies the same amount of energy as the exhaust loss, it has hardly been utilized, and a cooling device and power are required. This is a cooling loss due to the outside-cylinder cooling, and if superheated steam is generated by the heat absorbed by the in-cylinder, the equipment and power for outside-cylinder cooling are not required and superheated steam is used. Thus, the axial flow turbine and the radial turbine can be efficiently rotated, and this power can be utilized. Of course, the turbine may be single-stage or multi-stage.

  To cool the 4-cycle engine in the cylinder, a small hole is made in the cylinder, a nozzle is attached here, water or steam is injected just before the piston reaches bottom dead center in the expansion stroke, and the upper part of the piston becomes hot. The cylinder inner wall and the cylinder head can be cooled. Moreover, not only water or steam but also compressed air can be injected from the nozzle. Since the in-cylinder temperature is automatically controlled so that an appropriate amount of water or steam is injected in the vicinity of the set temperature, the in-cylinder temperature and the exhaust gas temperature are measured. When the temperature is lower than the set temperature, the injection is shut off. In addition, water may be supplied to the water tank, or the exhaust pipe may be cooled to collect water droplets little by little, or both may be equipped, but depending on the region, measures against freezing in winter are required. become.

Since a speed engine such as an exhaust turbine has poor thermal efficiency and response, for example, in the case of power of an automobile with a partial load and a large load fluctuation, the structure becomes complicated for optimal setting corresponding to the operating conditions. Therefore, in a combined engine that combines a positive displacement engine and a speed engine, the power of the exhaust turbine, which is the auxiliary engine, is transmitted to the output shaft of the positive displacement engine, which is the main engine. If the power transmission mechanism adopts a one-way clutch so that it is not transmitted to the output shaft of the exhaust turbine, the structure is simple and the power from the turbine can be taken out efficiently. However, when the turbine and the compressor are directly connected to perform supercharging, the structure is further simplified if the one-way clutch is not necessarily required and is directly connected to the flywheel in order to compensate for insufficient supercharging during acceleration.
A generator can be attached to the output shaft of the exhaust turbine.

As described above, the heat insulating composite engine of the present invention cools the inside of the cylinder by directly injecting water or steam into the cylinder immediately before the end of the expansion stroke, and absorbs the heat in the cylinder to generate superheated steam. Therefore, it becomes a powerful power source to turn the turbine. In conventional engines, the cooling loss cannot be effectively utilized because the cooling is performed outside the cylinder. However, in the in-cylinder cooling type heat insulating composite engine, not only the exhaust loss but also the energy loss including the cooling loss can be effectively utilized. it can.
For this reason, thermal efficiency and output can be improved and fuel consumption can be improved, and not only CO2 but also harmful substances such as NOX and PM can be reduced. Moreover, since superheated steam has a large cleaning ability, it also has an effect of cleaning the cylinder, the exhaust valve, and the exhaust system.

  Hereinafter, the best embodiment of the present invention will be described with reference to FIGS.

  1 and 2, a water or steam injection nozzle 5 and an exhaust energy recovery device 9 are attached to a normal direct injection four-cycle engine having a piston 1, a cylinder 2, an intake valve 6 and an exhaust valve 7. The cylinder 2 and the cylinder head 3 are insulated. FIG. 1 is a cross-sectional structure thereof, and FIG. 2 is a plan cross-sectional structure diagram showing main parts of a four-cylinder four-cycle engine and an exhaust energy recovery device 9. In this figure, the exhaust system is a two-valve system and the turbine is one unit per two cylinders, but it may be one unit per cylinder or one unit per multi-cylinder.

  The exhaust energy recovery device 9 includes a shaft 13, a bearing 14, and a casing 15 that connect the turbine 10, the compressor 11, and the small gear 12, and the turbine driving force is decelerated from the small gear 12 by the gear train 16 to the flywheel 17. Communicated. The turbine is structured to be mounted as close to the exhaust valve 7 as possible in order to efficiently collect the exhaust energy so as not to be cooled as much as possible. The type of turbine may be either a radial turbine or an axial flow turbine.

  In order to effectively use waste heat that has not been converted into motive power out of thermal energy without releasing it outside the cylinder as much as possible, the cylinder 2 and the cylinder head 3 are covered with a heat insulating material 8.

  The water or steam injection nozzle 5 is mounted in the vicinity of three-quarters of the stroke from the top dead center, and injects water or steam immediately after the piston 1 passes the lower end position of the injection nozzle or when the piston 1 is at the bottom dead center. It is like that. An appropriate amount of water or steam is sprayed depending on the temperature outside the cylinder and the exhaust gas temperature.

  In order to generate steam, it is easy to wrap a small diameter pipe around the outer periphery of the exhaust pipe on the turbine outlet side and pass water through this pipe, or cover the exhaust pipe to make a double pipe and pass water through the outer pipe. Can be generated. Temperature control is performed by attaching a thermometer near the outlet of a small diameter pipe or double pipe and controlling the amount of water delivered. Further, cooling the turbine outlet side improves the turbine efficiency and output, and further reduces the pressure and volume of the exhaust gas. Therefore, the muffler (not shown) can be smaller than a normal engine with the same output.

  The fuel injection method may be a normal fuel injection nozzle 4 in the case of a diesel engine, and in the case of a gasoline engine, it may be applied to an intake pipe injection method or a carburetor method in addition to a normal in-cylinder direct injection method.

  FIG. 3 is an operational state diagram in which water or steam injection strokes are added to the suction, compression, expansion, and exhaust strokes and the exhaust stroke of a normal four-cycle engine. Circle 1 is inhaled, Circle 2 is inhaled, Circle 3 is compressed, Circle 4 is fuel injection and expansion starts, Circle 5 is exhausted, Circle 6 is exhaust and water or steam injection and in-cylinder cooling is started, and Circle 7 is exhausted In-cylinder cooling and superheated steam generation, round 8 completes exhaust, and rotates twice in the process from round 1 to round 8, completing four cycles.

FIG. 4 is a diagram showing the operation timings of the intake valve, exhaust valve, fuel injection, water or steam injection for each process of intake, compression, explosion / expansion, and exhaust / cylinder cooling. The exhaust valve is opened near the expansion stroke of about three-quarters, and the exhaust pressure is still high and the exhaust gas is blown vigorously to the turbine. When steam is injected, the injection pressure is small, and when it is injected along the cylinder wall surface, the temperature of the cylinder wall surface can be lowered more effectively, and heat is absorbed from the cylinder wall surface without generating too much heat energy of the exhaust gas, and superheated steam is generated. can do.
The stroke number corresponds to the number of the operation state in FIG.

  FIG. 5 shows another example of the heat insulating composite engine. A positive displacement heat insulating engine having an exhaust valve 27 and a scavenging hole 26 and an exhaust energy recovery device are combined, and the exhaust energy recovery device is the same as that of FIG. The structure of a positive displacement adiabatic engine is similar to a uniflow type two-cycle engine, but the difference from a normal two-cycle engine is that fuel is injected from the fuel injection nozzle 24 once every two revolutions, and the scavenging stroke is twice. Therefore, two peaks are provided in the cam 29 so that the exhaust valve 27 can be opened twice, and a steam or compressed air injection nozzle 25 for in-cylinder cooling is attached to the cylinder head 23.

In the first scavenging process, the exhaust gas and waste heat in the cylinder are absorbed and expanded air is generated. When the piston 21 reaches top dead center, steam or compressed air is injected, and the residual waste in the cylinder is lowered as the piston descends. Heat is absorbed and superheated steam or expanded air is generated. The exhaust valve 27 is opened and blown to the turbine 20 when the piston descends about three-fourths of the stroke of the exhaust gas and the expansion air of the first scavenging stroke and the superheated steam or the expansion air of the second scavenging stroke.
In addition, when applied to a gasoline engine, it is limited to the fuel cylinder direct injection method.

FIG. 6 is a shape diagram of the cam for the exhaust valve. There are two peaks with different shapes, and the shape is such that it is performed at the timing when two scavenging strokes are set. One process is completed with one rotation of the camshaft with respect to two rotations of the crankshaft.
Note that the numbers on the outer periphery of the cam substantially coincide with the operating state numbers in FIG.

FIG. 7 is an operational state diagram showing each process of scavenging, compression, fuel injection / explosion / expansion, scavenging and exhausting, steam or compressed air injection, and exhausting. Circle 1 is exhaust / scavenging, Circle 2 is compression, Circle 3 is fuel injection / explosion, Circle 4 is exhausted, Circle 5 is scavenging, Circle 6 is scavenging, Circle 7 is steam or compressed air injection , Circle 8 is exhaust In the process from circle 1 to circle 8, it is rotated twice and one process is completed.

FIG. 8 is a diagram showing the timing of scavenging, compression, fuel injection / explosion / expansion, scavenging / exhaust, steam or compressed air injection, and exhaust.
The stroke number corresponds to the number of the operation state in FIG.

Sectional drawing of the cylinder cooling system heat insulation composite engine which shows embodiment of this invention Cross-sectional plan view of the main part of an in-cylinder cooling type heat insulation composite engine Operation state diagram of each stroke from intake to exhaust Timing diagram of intake valve, exhaust valve, fuel injection and water or steam injection Sectional drawing of the in-cylinder cooling system heat insulation composite engine which shows another embodiment of this invention Cam shape with two ridges for exhaust valve Operational diagram of each stroke from scavenging to exhaust Scavenging hole, exhaust valve, fuel injection, steam or compressed air injection timing diagram

Explanation of symbols

1,21 ... Piston 2,22 ... Cylinder 3,23 ... Cylinder head 4,24 ... Fuel injection nozzle 5,25 ... Water or steam or compressed air injection nozzle 6 ... Suction Valve 26 ... Scavenging hole 7, 27 ... Exhaust valve 8, 28 ... Heat insulation 9 ... Exhaust energy recovery device 10, 20 ... Turbine 11 ... Compressor 12 ... Small gear 13 ... Shaft 14 ... Bearing 15 ... Casing 16 ... Gear train 17 ... Flywheel

Claims (2)

A positive displacement heat insulation engine that has intake / exhaust valves and performs intake / compression / expansion stroke and in-cylinder cooling stroke by exhaust / water or steam injection, and powers exhaust gas and superheated steam discharged from the positive displacement heat insulation engine In a 4-cycle adiabatic combined engine having an exhaust turbine as a source, a speed reducer, and an exhaust energy recovery device that transmits power to the crankshaft by a one-way clutch , an exhaust valve was opened and high-temperature and high-pressure exhaust gas was discharged before the end of the expansion stroke After that, the inside of the cylinder is cooled and the nozzle that injects water or steam to absorb the heat inside the cylinder to generate superheated steam, and the outside temperature and the exhaust temperature are measured so that the inside temperature becomes the set temperature. and controlling the injection quantity of water or steam, and covering the cylinder and cylinder head with a heat insulating material to prevent heat dissipation from the cylinder, the power and exhaust gas superheated steam And an exhaust turbine, the reduction gear for decelerating to fit the high-speed rotation of the exhaust turbine to the speed of the positive displacement heat insulating engine, the one-way clutch for transmitting power from the exhaust turbine in one direction to the crankshaft The four-cycle adiabatic composite engine comprising: A positive displacement heat-insulating engine having scavenging holes and exhaust valves for performing in-cylinder cooling / exhaust / scavenging stroke by compression, expansion, exhaust / scavenging stroke and steam or compressed air injection, and four-cycle heat insulation having the exhaust energy recovery device In a combined engine, a modified double cam corresponding to opening of an exhaust valve twice at different timings, a nozzle for injecting steam or compressed air for generating the superheated steam or expanded air, and injection of the steam or compressed air The four-cycle adiabatic composite engine according to claim 1, wherein the four-cycle adiabatic composite engine is configured by controlling an amount, covering with the heat insulating material, the exhaust turbine, the speed reducer, and the one-way clutch.

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