JPH10103076A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make improvements in mean effective pressure without increasing the maximum pressure by preheating and precompressing air into high temperature and high pressure, generating high temperature-high pressure air, and filling this air into a combustion chamber together with fuel till a piston gets moving toward a bottom dead center and the measure of combustion chamber capacity comes to the specified capacity. SOLUTION: A piston 1 gets shifting toward a bottom dead center from a state that it is situated in a top dead center, and air-charging valve 3 is opened till the measure of capacity in a cylinder 2 comes to the specified capacity (when a compression ratio is set to ε, 1/ε times or so of the total capacity of the cylinder 2), and air of high temperature and high pressure (for example, 900K, 50 atmospheric pressure or so) passed through a preheating means 8 and a precompressing means 9 is introduced into the cylinder 2. Successively, fuel is injected into the cylinder 2 from a fuel injection mechanism 7 and thereby combustion is carried out, making this cylinder perform its adiabatic expansion till the piston 1 arrives at the bottom bead center. At this time when a two-stage combustion is carried out, an injection valve 5 is opened after fuel injection, the high temperature-high pressure air is introduced into the cylinder 2 from a two-stage combustion tank 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine used as a power source for automobiles, railways, ships, etc.
The present invention relates to an internal combustion engine capable of improving the average effective pressure Pm value (output / volume) without increasing the maximum pressure, improving the efficiency of pollution-free combustion, and improving the heat shielding effect.

[0002]

2. Description of the Related Art As a conventional reciprocating internal combustion engine, for example, a four-cycle internal combustion engine used for an automobile or the like is known.

A conventional four-cycle internal combustion engine includes a piston, a cylinder, a suction valve, a discharge valve, a spark plug, a fuel injection valve, and the like, which are reciprocated by a crankshaft and a connecting rod. One cycle is completed by two reciprocations of the piston. However, one cycle consists of four strokes: suction, compression, combustion expansion, and discharge.

A four-cycle internal combustion engine is roughly classified into a spark ignition engine and a compression ignition engine. In a spark ignition engine, a mixture of air and fuel is sucked in an intake stroke, and combustion is started by a spark at the beginning of a combustion expansion stroke. There is a difference in that only the air is sucked in the suction stroke of the compression ignition engine, and the combustion is started by injecting the fuel into the air heated to a high temperature in the compression stroke.

[0005] As an internal combustion engine, a two-cycle internal combustion engine in which one cycle is completed by one reciprocation of a piston is also known. In the two-cycle internal combustion engine, the average effective pressure Pm (output / volume) can be improved as compared with the four-cycle internal combustion engine. However, because it is difficult to improve the scavenging efficiency and the air supply efficiency, for example,
It is used only for small spark ignition engines.

[0006]

Since the thermal efficiency of a reciprocating internal combustion engine largely depends on the compression ratio, a certain level of compression ratio must be ensured. Requires a certain level or more, and it is desirable to increase the maximum pressure for this purpose. However, a high compression ratio and a high maximum pressure increase the maximum temperature, resulting in an increase in the amount of nitrogen oxides (NOx) in the exhaust gas, making it difficult to respond to recent social demands for low pollution. Further, the high maximum pressure of the diesel engine raises the level of noise and increases the weight of the engine due to the need to ensure the strength to withstand the pressure.

[0007] Therefore, in an internal combustion engine, it is desired to improve the average effective pressure Pm (output / volume) without increasing the maximum pressure.

Further, the present invention and the like have been conducting research on a technique for improving the thermal efficiency by recovering the waste heat pressure of an internal combustion engine, and include a technique relating to a heat shielding (high temperature) engine, and There is a technology related to a two-stage combustion engine. In such a heat shield engine and two-stage combustion engine, it is preferable to improve the heat shield effect and the two-stage combustion effect.

The present invention has been made in view of such conventional circumstances, and can improve the average effective pressure Pm (output / volume) without increasing the maximum pressure, and can improve the heat shielding effect, An object of the present invention is to provide an internal combustion engine that can improve the effect of stage combustion.

[0010]

According to the first aspect of the present invention,
Means for preheating and precompressing air to high temperature and high pressure (for example, about 900 K, 50 atm) to generate high temperature and high pressure air, a piston and a cylinder configured to have a small top dead center volume, and High-temperature and high-pressure air injecting means for injecting the high-temperature and high-pressure air into the cylinder until the volume in the cylinder reaches a predetermined volume, starting moving from the state located at the dead center toward the bottom dead center, After injecting the high-temperature and high-pressure air into the cylinder by the high-temperature and high-pressure air injection means, and before the piston reaches bottom dead center, fuel injection means for injecting fuel into the cylinder to cause combustion. Exhaust means for exhausting when the piston moves toward top dead center after reaching the bottom dead center, and is configured to be operated for two cycles.

According to a second aspect of the present invention, in the internal combustion engine according to the first aspect, the heat exchange with the exhaust gas is performed to preheat the air.

According to a third aspect of the present invention, in the internal combustion engine according to the first or second aspect, a preliminary compression of air is performed by using exhaust pressure.

According to a fourth aspect of the present invention, in the internal combustion engine according to the first to third aspects, the high-temperature and high-pressure air is injected into the cylinder during a combustion step of injecting fuel into the cylinder to cause combustion. And means for causing two-stage combustion.

According to a fifth aspect of the present invention, there is provided the internal combustion engine according to any one of the first to fourth aspects, further comprising a tank connected to a top of the cylinder via a valve mechanism and capable of storing the high-temperature and high-pressure air therein. Sometimes, the valve mechanism is opened, the tank is set to the top dead center volume, and four-cycle operation is performed.

According to a sixth aspect of the present invention, in the internal combustion engine according to the fifth aspect, the high-temperature and high-pressure air is introduced into the cylinder from the tank during a combustion step of injecting fuel into the cylinder to cause combustion. To generate two-stage combustion.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an internal combustion engine of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a schematic configuration of an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a piston, and 2 denotes a cylinder. These are volumes formed between the top of the piston 1 and the cylinder 2 when the piston 1 is located at the top dead center (top dead center volume). Is configured to be very small (substantially zero). At the top of the cylinder 2, a supply valve 3, an exhaust valve 4, a two-stage high-temperature and high-pressure air injection valve 5, a starting valve 6, and a fuel injection mechanism 7 are provided.

In FIG. 1, reference numeral 8 denotes preheating means for preheating air, and reference numeral 9 denotes precompression means for precompressing air. In the present invention, the preheating means 8 and the precompression means 9 preheat and precompress the air to a high temperature and a high pressure (for example, about 900 K and 50 atm), and send the air from the air supply valve 3 into the cylinder 2. ing.

As the preheating means 8, a heat exchanger for preheating air by using exhaust heat can be used. Further, as the pre-compression means 9, a turbine or a piston-cylinder mechanism for pre-compressing air using exhaust pressure can be used.

In FIG. 1, reference numeral 10 denotes a high temperature and high pressure air for injecting into the cylinder 2 from the high temperature and high pressure air injection valve 5 for two stage combustion to generate two stage combustion during the combustion process. A stage combustion tank 11, which is capable of storing high-temperature and high-pressure air therein, is used as a top dead center volume by opening a start valve 6 at the time of start.

It should be noted that the two-stage combustion tank 10 and the starting tank 11 may be shared as only one, and the opening and closing of the valve may be controlled to perform the starting and the two-stage combustion. In FIG. 1, reference numerals 12 to 14 denote valves, respectively. Inflow of high-temperature and high-pressure air into the two-stage combustion tank 10 and the starting tank 11,
This controls the exhaust from the system.

FIGS. 2A and 2B show the operation of the internal combustion engine having the above configuration, and FIG. 2A shows a state in which the piston 1 is located at the top dead center.

Then, from the state (a), as shown in (b), the piston 1 starts moving toward the bottom dead center until the volume in the cylinder 2 reaches a predetermined volume, and the air supply valve 3 is opened, and high temperature and high pressure (for example, 900
(K, about 50 atm). The above-mentioned predetermined volume means that the compression ratio is ε
(Usually about 6 to 16), it is about 1 / ε times the total volume of the cylinder 2.

After the high-temperature and high-pressure air is introduced into the cylinder 2 as described above, fuel is injected from the fuel injection mechanism 7 into the cylinder 2 as shown in FIG. The adiabatic expansion process is performed until 1 reaches the bottom dead center.

At this time, when performing two-stage combustion, after fuel injection, the high-temperature and high-pressure air injection valve 5 for two-stage combustion is opened, and
High-temperature, high-pressure air is injected into the cylinder 2 from the stage combustion tank 10, thereby performing the first stage combustion in an excess fuel state and the second stage combustion in an excess air state. Will be In this two-stage combustion, to suppress the generation of the NO _X by the reducing action of the fuel in the first stage of combustion, C in the combustion of the second stage (soot), CO, CH _X (hydrocarbons)
Etc. can be completely oxidized and burned.

Then, as shown in FIG.
After reaching the bottom dead center, the exhaust valve 4 is opened and the cylinder 2 is exhausted until the piston 1 rises and reaches the top dead center again as shown in (e). At this time, as described above, since the piston 1 and the cylinder 2 are configured so that the top dead center volume becomes substantially zero, exhaust gas does not remain in the cylinder 2.

The temperature of the exhaust gas is, for example, 900 to 1
The pressure is, for example, about 3 to 5 atm.

By repeating the above steps, two-cycle operation is performed. Further, the exhaust gas from the cylinder 2 is guided to the preheating means 8 and the precompression means 9 and is used for preheating and precompression of the air supply, and waste heat and waste pressure are collected.

When starting the internal combustion engine, the starting valve 6 is opened. As a result, the inside of the starting tank 11 is used as the top dead center volume, and four cycles are operated.

As described above, in the internal combustion engine of the present invention, 2
By performing the cycle operation, the average effective pressure Pm (output / volume) can be improved without increasing the maximum pressure.

Further, since the preheated and precompressed air is always introduced into the cylinder 2 at a high temperature and a high pressure (for example, about 900 K and 50 atm), the inside of the cylinder 2 is not cooled, and the heat shielding effect is reduced. Can be improved. Furthermore, the heat efficiency of the heat shield engine can be improved by recovering the amount of heat obtained by the heat shield as effective power by the waste heat pressure recovery means without being released together with the exhaust gas.

In general, if two-stage combustion is performed to eliminate pollution, loss increases and thermal efficiency decreases.
By recovering the waste heat and the waste pressure by the waste heat pressure recovery means, the thermal efficiency can be improved.

[0033]

As described above, according to the internal combustion engine of the present invention, the average effective pressure Pm (output / volume) can be improved without increasing the maximum pressure, and the heat shielding effect can be improved. Can be done.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing the operation of the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piston 2 ... Cylinder 3 ... Air supply valve 4 ... Exhaust valve 5 ... High-temperature and high-pressure air injection valve for two-stage combustion 6 ... Start valve 7 ... Fuel injection mechanism 8 ... Preheating means 9 ... Pre-compression means 10 ... Two-stage combustion tank 11 ... Starting tank

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code FI F02D 41/02 351 F02D 41/02 351 (71) Applicant 592073101 IBM Japan, Ltd. IBM Japan, Ltd. 3-chome, Roppongi, Minato-ku, Tokyo No. 12 (71) Applicant 000004237 NEC Corporation 5-7-1, Shiba, Minato-ku, Tokyo (72) Inventor Eiichi Goto 3-9-305, Tsujido East Coast, Fujisawa City, Kanagawa Prefecture (72) Inventor Kase Jin Shinto 710-67, Hirohama-cho, Machida-shi, Tokyo (72) Inventor Ding 2-1 Hirosawa, Wako-shi, Saitama Pref. RIKEN (72) Inventor Riki Amano 443-7 Yahata, Chigasaki-shi, Kanagawa

Claims (6)

[Claims] 1. Air is heated to high temperature and high pressure (for example, 900K, 50K).
Means for pre-heating and pre-compressing to about high pressure to generate high-temperature and high-pressure air, a piston and a cylinder configured to have a small top dead center volume, and a bottom dead state from a state where the piston is located at the top dead center. A high-temperature and high-pressure air injection means for injecting the high-temperature and high-pressure air into the cylinder until the volume in the cylinder reaches a predetermined volume, and After injecting the high-temperature and high-pressure air into the cylinder, before the piston reaches the bottom dead center, fuel injection means for injecting fuel into the cylinder to cause combustion, and the piston is moved to the bottom dead center. An internal combustion engine, comprising: exhaust means for exhausting when the vehicle moves toward top dead center after the vehicle has arrived, and is configured to be operated for two cycles. 2. The internal combustion engine according to claim 1, wherein the internal combustion engine is configured to perform heat exchange with exhaust gas to perform preheating of air. 3. The internal combustion engine according to claim 1, wherein a preliminary compression of air is performed using exhaust pressure. 4. The internal combustion engine according to claim 1, wherein the high-temperature and high-pressure air is injected into the cylinder during a combustion process in which fuel is injected into the cylinder to cause combustion. An internal combustion engine comprising: means for generating 5. The internal combustion engine according to claim 1, further comprising a tank connected to a top portion of the cylinder via a valve mechanism, and capable of storing the high-temperature and high-pressure air therein, wherein the valve mechanism is activated at the time of starting. Open the tank to top dead center volume,
An internal combustion engine configured to be operated for four cycles. 6. The internal combustion engine according to claim 5, wherein the high-temperature and high-pressure air is injected into the cylinder from the tank during a combustion step of injecting fuel into the cylinder to cause combustion. An internal combustion engine configured to produce staged combustion.