KR100953683B1 - Homogeneous Charge Compression Ignition Engine System with Burned Gas Generator - Google Patents

Abstract

The compression ignition engine system according to the present invention includes an engine that is ignited by a compression ignition method, an intake pipe for supplying fuel and air to the engine, and a combustion gas connected to the intake pipe to supply heated combustion gas into the intake pipe. It includes a generator and an exhaust pipe for exhausting the exhaust gas burned by the engine.

Compression Ignition, Combustion Gas Generator, Catalyst Carrier, Electric Heater

Description

Homogeneous Charge Compression Ignition Engine System with Burned Gas Generator

The present invention relates to a compression ignition engine system, and more particularly, to a compression ignition engine system provided with a combustion gas generator.

In order to improve the fuel efficiency of internal combustion engines, various technologies are being researched as a technique for increasing the lean limit and reducing emissions such as nitrogen oxides (NOx), but the most promising technique is the Homogeneous Charge Compression Ignition (HCCI) Combustion technology.

Premixed compression ignition combustion technology utilizes the self-ignition characteristics of the fuel to compress and ignite the fuel air mixer in the combustion chamber without using a spark plug.

In order to compress and ignite the fuel mixer, a high-temperature and high-pressure atmosphere must be established. Therefore, research on preheating the premixer and research on the use of internal exhaust gas recirculation (EGR) have been conducted. Is being considered. However, when the compression ratio is increased, it is difficult to apply it to an engine having a variable compression ratio because the operating range is limited due to a pumping loss or the like under high power operating conditions.

The biggest problem with premixed compression ignition combustion is that it is not possible to operate in all areas. In general, pre-compression compression ignition operation is possible only in some areas except for the start-up or full-load area and the existing combustion method such as electric ignition.

Therefore, in order to generally apply premixed compression ignition combustion, it is necessary to solve the problem of expansion of the operating range and switching of the combustion method according to the operating conditions.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention to provide a compression ignition engine system including a combustion gas generating unit.

In order to achieve the above object, a compression ignition engine system according to an embodiment of the present invention is an engine that is ignited by compression ignition, an intake pipe for supplying fuel and air to the engine, and is connected to the intake pipe, It may include a combustion gas generating unit for supplying the combustion gas heated in the intake pipe, and the exhaust pipe discharged from the exhaust gas burned by the engine.

The combustion gas generating unit may include a catalyst carrier having an oxidation catalyst layer formed on a surface thereof, and the catalyst carrier may include a plurality of through holes.

In addition, the catalyst carrier may be made of any one selected from the group consisting of ceramic honeycomb, ceramic bead, ceramic foam, ceramic fiber, metal foam, metal fiber, and metal powder. have.

The combustion gas generator may include an electric heater for heating fuel and the catalyst carrier, and the electric heater may include a coil or a positive temperature coefficient (PTC).

In addition, the combustion gas generating unit includes a housing forming an outer shape, the housing may be formed with an oxidant inlet hole and a fuel inlet containing oxygen. An air induction pipe may be installed in the oxidant inlet hole, and the air induction pipe may communicate with the intake pipe. In addition, the intake pipe is provided with a throttle valve for adjusting the amount of air flowing into the engine, the air induction pipe may be installed in front of the throttle valve.

An air induction pipe may be installed in the oxidant inlet, and the air induction pipe may be connected to a compressed air tank in which air is stored. have.

The combustion gas generator may include a high voltage electrode and a ground electrode to generate plasma, and the combustion gas generator may further include an igniter to burn fuel heated by the plasma.

The combustion gas generator may further include an evaporator capable of evaporating fuel, and the combustion gas generator may further include an igniter to burn fuel heated by the evaporator.

Compression and ignition engine system according to an embodiment of the present invention can supply the combustion gas heated to the intake cylinder of the engine to stably heat the fuel flowing into the engine. Accordingly, compression ignition can be easily performed even when the temperature inside the engine is low.

In addition, the compression ignition engine system according to an embodiment of the present invention includes a catalyst carrier and an electric heater, so that the electric heater may preheat the fuel, and the catalyst carrier may oxidize the preheated fuel, thereby more stably burning the fuel. have.

In addition, the compression ignition engine system according to an embodiment of the present invention is less polluted by heating the fuel using a plasma, it is possible to heat the high temperature it is easy to generate a high temperature combustion gas.

In addition, the compression ignition engine system according to an embodiment of the present invention may include an evaporator to more efficiently evaporate fuel and burn the evaporated fuel through an igniter.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Like reference numerals in the present specification and drawings denote like elements.

1 is a block diagram showing a compression ignition engine system according to a first embodiment of the present invention.

Referring to FIG. 1, an engine system according to the present embodiment includes an engine 100 that burns fuel to generate kinetic energy, and an intake pipe that provides a passage through which fuel and air flow into the engine 100. 145, an exhaust pipe 120 connected to the engine 100 to provide a passage through which exhaust gas is discharged, a fuel injector 141 installed at the intake pipe 145 to inject fuel, and And a combustion gas generator 150 connected to the intake pipe 145 and supplying the combustion gas heated to the engine 100.

In this embodiment, the engine 100 refers to a conventional internal combustion engine that performs mechanical work by burning fuel. The engine 100 includes a cylinder chamber 110 and a piston rod reciprocating and installed in the cylinder chamber 110 and a connecting rod 114 and a flywheel 116 connected to the piston 112. In addition, a cylinder head 132 is installed at an upper portion of the cylinder chamber 110, and an intake valve 131 and an exhaust valve 135 for controlling intake and exhaust are installed at the cylinder head 132.

In the present embodiment, an engine system using gasoline fuel as a fuel is described as an example, but the present invention is not limited thereto, and a fuel such as diesel may be applied.

An air filter 147 is provided in the intake pipe 145 to purify the air necessary for combustion, and a throttle valve 143a for controlling the amount of air sucked in the rear of the air filter 147 (based on the air traveling direction). ) Is located inside the throttle body 143 is installed. In the present specification, the upstream side is referred to as the front side or the front side, and the downstream side is referred to as the rear side or the rear side based on the air flow.

In general, in the gasoline premixed compression ignition engine, since the compression ratio is lower than that of the diesel engine, it is difficult to compress and ignite the fuel by pure compression stroke alone. Therefore, the high-temperature exhaust gas generated after combustion is confined in the cylinder chamber 110 during the exhaust and intake strokes or flowed back from the exhaust pipe 120 to facilitate premixed compression ignition by using the energy of the exhaust gas. However, it is difficult to realize premixed compression ignition because it is virtually impossible to trap hot combustion gases in the combustion chamber because the temperature of the exhaust gas is low at low speed and low load conditions at the beginning of the startup, and the consumption of fuel and air is high under high load conditions. it's difficult.

In order to solve such a problem, the present engine system includes a combustion gas generator 150 generating high temperature combustion gas. The combustion gas generating unit 150 includes an air induction pipe 158 connected to the intake pipe 145, a fuel injector 156 supplying fuel into the combustion gas generating unit 150, and an oxidation catalyst on the surface of the combustion gas generating unit 150. Is applied to oxidize the fuel to support the catalyst carrier 152, and the catalyst carrier 152 is installed adjacent to the catalyst carrier 152 and the electric heater 154 for heating the fuel.

The air guide pipe 158 is connected to the intake pipe 145 in front of the throttle body 143. Since the flow of air is disturbed by the throttle valve 143a, a relatively large pressure is generated in front of the throttle body 143. Accordingly, the combustion gas generator 150 easily generates air by using a pressure difference. Can be introduced into.

In this embodiment, the air induction pipe 158 is connected to the intake pipe 145 as an example, but the present invention is not limited thereto.

Therefore, as shown in FIG. 2, the air induction pipe 158 may be connected to a separate air tank 155, where the air tank 155 may be a compressed air tank. In addition, as shown in FIG. 3, the air induction pipe 158 may be connected to the exhaust pipe 120.

4 is a cutaway perspective view illustrating a combustion gas generating unit according to the first embodiment. The combustion gas generating unit will be described in more detail with reference to FIG. 4.

The combustion gas generator 150 includes a cylindrical housing 153 and a bottom plate 157 coupled to the housing 153 to form a bottom of the housing 153. The housing 153 has a combustion gas discharge hole 153a for discharging the combustion gas into the intake pipe 145, and an oxidant inlet hole connected to the air induction pipe 158 to introduce air into the outer circumferential surface of the housing 153. 153b is formed. The bottom plate 157 is formed with a fuel inlet hole 157a through which fuel is introduced.

In the housing 153, a catalyst carrier 152 having an oxide catalyst coated on the surface thereof is installed. The catalyst carrier 152 is made of ceramic, and a honeycomb in which hexagonal through holes 152a are continuously formed. ) Is formed into a type.

However, the structure of the catalyst carrier 152 is only one embodiment of the present invention, and the present invention is not limited thereto. Therefore, the catalyst carrier may be made of ceramic beads, ceramic foams, ceramic fibers, metal foams, metal fibers, metal powders, and the like.

The catalyst carrier 152 serves to oxidize fuel by reacting the fuel with the catalyst when the fuel passes through the through hole 152a. The oxidized fuel is converted into hot combustion gases. In order for the fuel and catalyst to react well, the temperature of the fuel and catalyst carrier 152 must be high. To this end, in this embodiment, the electric heater 154 is installed adjacent to the catalyst carrier 152 so that the electric heater 154 heats the catalyst carrier 152 and the fuel.

The electric heater 154 includes a support 154a fixed to the inner wall of the housing 153 and a coil 154b connected to the support 154a. The electric heater 154 heats the air and fuel introduced into the housing 153 and the catalyst carrier 152 to stably oxidize the fuel.

However, the above-described electric heater structure is exemplary, and the present invention is not limited thereto. Therefore, the electric heater 154 may be made of a positive temperature coefficient (PTC) or the like capable of heating air and fuel.

As such, when the electric heater 154 and the catalyst carrier 152 are installed in the housing 153, the fuel introduced into the housing 153 is primarily heated by the electric heater 154 and the catalyst carrier 152. It is oxidized by) to change into hot combustion gas.

When the combustion gas is introduced into the intake pipe 145, the combustion gas and the fuel may be mixed to increase the temperature of the fuel, and may be more easily compressed and ignited in the cylinder chamber 110.

5 is a cutaway perspective view illustrating a combustion gas generator according to a second exemplary embodiment of the present invention.

Referring to FIG. 5, the combustion gas generator 250 according to the present exemplary embodiment includes a housing 253 forming an external shape and a bottom plate 257 coupled to the housing 253. The housing 253 has a combustion gas discharge hole 253a through which combustion gas is discharged and a fuel inlet hole 253b through which fuel is introduced.

In addition, a high voltage electrode 254 charged with a high voltage is inserted into the bottom plate 257 through the insulator 256.

A ground electrode 258 is installed around the combustion gas discharge hole 253a, whereby a plasma is generated between the high pressure electrode 254 and the ground electrode 258. A fuel injection pipe 210 for injecting fuel into a region where plasma is generated is provided at a portion adjacent to the end of the high voltage electrode 254. Accordingly, the fuel introduced into the housing 253 through the fuel injection pipe 210 is heated by the plasma.

In addition, an igniter 252 is installed at a portion adjacent to the combustion gas discharge hole 253a, and the igniter 252 serves to burn fuel heated by plasma.

Accordingly, the combustion gas heated by the plasma and combusted by the igniter 252 may be supplied into the intake pipe 145, and the combustion gas is mixed with the fuel to raise the temperature of the fuel.

6 is a cutaway perspective view illustrating a combustion gas generator according to a third exemplary embodiment of the present invention.

Referring to FIG. 6, the combustion gas generator 350 according to the present exemplary embodiment includes a housing 353 and an evaporator 360 installed in the housing 353.

The housing 353 has a combustion gas discharge hole 353a through which the combustion gas is discharged and an air inlet 353b. The housing 353 is provided with a bottom plate 357 forming a bottom of the housing 353, and a fuel inlet 357a through which fuel flows is installed in the bottom plate 357.

The evaporator includes a case 361 and a torch 363 installed in the case to generate a flame, and an upper surface of the case 361 is provided such that the air heated by the torch 363 can be discharged into the housing 353. Pores 361a are formed.

Accordingly, the fuel introduced into the housing 353 is directly heated and evaporated by the evaporator 360.

An igniter 352 is installed at a portion adjacent to the combustion gas discharge hole 353a, and the igniter 352 serves to generate combustion gas by burning the vaporized fuel.

The combustion gas generated in the combustion gas generating unit as described above is supplied to the intake pipe 145, and the combustion gas supplied to the intake pipe 145 flows into the cylinder chamber 110 together with the fuel. At this time, the combustion gas increases the temperature of the fuel so that the fuel is more easily compressed and ignited.

As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to this, It can be variously modified and implemented in a claim, a detailed description of an invention, and the attached drawing.

1 is a schematic diagram illustrating a compression ignition engine system according to a first embodiment of the present invention.

2 is a schematic diagram illustrating a compression ignition engine system according to a modification of the first embodiment of the present invention.

3 is a schematic diagram illustrating a compression ignition engine system according to another modified example of the first embodiment of the present invention.

4 is a cutaway perspective view illustrating a combustion gas generator according to a first exemplary embodiment of the present invention.

5 is a cutaway perspective view illustrating a combustion gas generator according to a second exemplary embodiment of the present invention.

6 is a cutaway perspective view illustrating a combustion gas generator according to a third exemplary embodiment of the present invention.

[Explanation of symbols on the main parts of the drawings]

100: engine 110: cylinder chamber

120: exhaust pipe 141: fuel injector

143: throttle body 143a: throttle valve

145: intake pipe 150, 250, 350: combustion gas generating unit

152: catalyst carrier 154: electric heater

156: fuel injector 158: air induction pipe

254: high voltage electrode 258: ground electrode

360: burner

Claims (17)

In the pre-mixed compression ignition engine system for gasoline, the exhaust gas supplied to the engine with fuel and ignited by compression ignition, An engine ignited by compression ignition; An intake pipe for supplying fuel and air to the engine; A combustion gas generator connected to the intake pipe and configured to supply a heated combustion gas into the intake pipe; And Exhaust pipe for exhaust gas exhausted from the engine Including The combustion gas generating unit comprises a catalyst carrier having an oxidation catalyst layer formed on a surface and an electric heater for heating the fuel and the catalyst carrier. delete According to claim 1, The catalyst carrier is a compression ignition engine system having a plurality of through holes. According to claim 1, The catalyst support is a compression ignition engine system consisting of a ceramic honeycomb (ceramic honeycomb). According to claim 1, The catalyst support is a compression ignition engine system comprising any one selected from the group consisting of ceramic beads, ceramic foam, ceramic fiber, metal foam, metal fiber, metal powder. delete According to claim 1, The electric heater includes a coil ignition engine system. According to claim 1, The electric heater is a compression ignition engine system including a positive temperature coefficient (PTC). According to claim 1, The combustion gas generating unit comprises a housing forming an external shape, the housing is a compression ignition engine system formed with an oxidant inlet hole and a fuel inlet containing oxygen. The method of claim 9, An air induction pipe is connected to the oxidant inlet, and the air induction pipe is in communication with the intake pipe. The method of claim 10, The intake pipe is provided with a throttle valve for adjusting the amount of air flowing into the engine, And the air induction pipe is installed in front of the throttle valve. The method of claim 9, And an air induction pipe is installed in the oxidant inlet hole, and the air induction pipe is connected to a compressed air tank in which air is stored. The method of claim 9, And an air induction pipe is installed in the oxidant inlet hole, and the air induction pipe is connected to the exhaust pipe. An engine ignited by compression ignition; An intake pipe for supplying fuel and air to the engine; A combustion gas generator connected to the intake pipe and configured to supply a heated combustion gas into the intake pipe; And Exhaust pipe for exhaust gas exhausted from the engine Including; The combustion gas generating unit has a high voltage electrode and a ground electrode to generate a plasma, And the combustion gas generating unit has an igniter to combust fuel heated by plasma. delete delete An engine ignited by compression ignition; An intake pipe for supplying fuel and air to the engine; A combustion gas generator connected to the intake pipe and configured to supply a heated combustion gas into the intake pipe; And Exhaust pipe for exhaust gas exhausted from the engine Including; And the combustion gas generating unit has an igniter to combust an evaporator and fuel heated by the evaporator.

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