CN105822484A - Microwave excitation ignition control device for HCCI engine and control method - Google Patents

Abstract

The invention discloses a microwave-excited HCCI engine ignition control device and a control method, belonging to the technical field of internal combustion engines; the control device includes: a repetitive pulse power supply, a microwave source, a microwave distributor, a waveguide device and a microwave plug; the repetitive pulse power supply is connected to an engine control unit and a microwave source, the microwave source is sequentially connected to a microwave distributor, a waveguide device and a microwave plug, and the microwave plug is arranged on the cylinder head. The ignition control method is as follows: at the initial stage of air intake, the fuel injector sprays fuel into the combustion chamber to form a homogeneous mixture; the engine control unit sends out instructions to the repetitive pulse power supply to send pulse electric energy, which is converted into microwave pulses by the microwave source; The pulse is transmitted to the microwave plug through the waveguide device; the microwave pulse is directly transmitted to the combustion chamber of the cylinder that needs to be ignited through the microwave plug to stimulate the ignition. The invention has the advantages of effectively solving the problem of difficult ignition control of the HCCI engine, accelerating the combustion speed of the mixed gas, and helping to improve the thermal efficiency of the engine.

Description

A microwave excitation HCCI engine ignition control device and control method

technical field

The invention relates to the technical field of internal combustion engines, in particular to a microwave-excited HCCI engine ignition control device and control method.

Background technique

At present, with the rapid growth of the number of automobiles, the resource and environmental problems are becoming more and more serious.

In traditional automobiles, the thermal efficiency of gasoline engines is only 30%, and the efficiency is lower under small and medium loads, and it has high hydrocarbon and CO emissions. Although the diesel engine has high thermal efficiency, fuel is injected into the cylinder, causing uneven mixing in the cylinder, resulting in high NOX and particulate matter emissions. So since the end of the last century, the new combustion mode HCCI (Homogeneous Charge Compression Ignition, homogeneous charge compression ignition) engine has been extensively studied.

HCCI engine fuel and air are evenly mixed, and the emission is good, and the compression ignition method is adopted, and the compression ratio is high, which helps to improve thermal efficiency. Although the HCCI engine has great potential for energy saving and emission reduction, there are still many problems: the HCCI engine has no direct way to control the combustion time. The initial gas temperature and pressure, the compression ratio of the engine, the piston speed and the heat transfer of the combustion chamber. Therefore, it is difficult to control the combustion phase, which is the biggest problem in the current HCCI.

At present, the ignition control methods of HCCI engines mainly include the use of direct intake heating, high compression ratio, the use of fuels that are more prone to spontaneous combustion, external residual exhaust gas circulation (EGR) or internal EGR. These technologies that change the combustion boundary can realize the ignition of the HCCI engine within a certain range, but the changes in the external environment and working conditions make it difficult to control the combustion phase, and it will be very time-consuming and laborious to calibrate the HCCI control strategy for each environment and each working condition work, which limits the application of HCCI engines.

Contents of the invention

Aiming at the problems of complex ignition control and low reliability of the current HCCI engine, the present invention provides a microwave-excited HCCI engine ignition control device and a control method, which uses microwave radiation space ignition to control the ignition of the HCCI engine, thereby igniting the hybrid of the HCCI engine. gas, greatly simplifying the combustion control of the HCCI engine.

A microwave-excited HCCI engine ignition control device, by introducing microwaves into the combustion chamber, igniting the mixed gas in the combustion chamber to achieve rapid combustion; specifically includes: repetitive pulse power supply, microwave source, microwave distributor, waveguide device and microwave stuffed.

The repetitive pulse power supply is connected to the engine control unit and the microwave source at the same time, the microwave source is connected to the microwave distributor, the microwave distributor is connected to the waveguide device, the waveguide device is connected to the microwave plug, and the microwave plug is arranged on the cylinder head.

The engine control unit sends instructions to the repetitive pulse power supply, and the repetitive pulse power supply outputs the pulse electric energy required by the microwave source, and drives the microwave source to generate microwave pulses. After receiving the instructions from the engine control unit, the microwave distributor transmits the microwave pulses to the Microwave plugs are accurately delivered to the cylinders that need to be ignited.

A kind of microwave excitation HCCI engine ignition control method, concrete steps are as follows:

Step 1. The microwave source is connected to the microwave plug through the microwave distributor and the waveguide device, and the microwave plug is installed on the cylinder head;

Step 2. At the beginning of the intake stroke, the fuel injector sprays a certain amount of fuel into the combustion chamber, and the fuel evaporates in the combustion chamber to form a homogeneous mixture;

Step 3, the engine control unit sends an instruction to the repetitive pulse power supply, and the repetitive pulse power supply sends pulse electric energy;

Step 4, the pulse electric energy is converted into a microwave pulse through a microwave source;

Step 5. The microwave distributor accepts the instruction from the engine control unit, and transmits the microwave pulse to the microwave plug through the waveguide device;

Step 6: The microwave pulse is directly transmitted to the combustion chamber of the cylinder that needs to be ignited through the microwave plug to stimulate ignition.

The energy of the gas in the cylinder becomes larger, the temperature rises, and the number of active molecules increases. The microwave pulse is transmitted into the corresponding cylinder, which breaks down the mixture and stimulates the ignition.

The advantages of the present invention are:

1), a microwave excitation HCCI engine ignition control device, which effectively solves the difficult problem of HCCI engine ignition control.

2), a microwave excitation HCCI engine ignition control method, the HCCI ignition control mode requires little modification to the engine, easy to implement, and low cost.

3), a kind of microwave excitation HCCI engine ignition control method, this ignition mode can accelerate the combustion speed of mixture gas, is conducive to improving the thermal efficiency of engine.

Description of drawings

Fig. 1 is the connection schematic diagram of microwave excitation HCCI engine ignition control device of the present invention;

Fig. 2 is the schematic diagram of microwave excitation HCCI engine ignition control device of the present invention;

Fig. 3 is a flow chart of the ignition control method of the microwave-excited HCCI engine of the present invention.

1-piston, 2-cylinder, 3-cylinder head, 4-intake valve, 5-exhaust valve, 6-intake port, 7-exhaust port, 8-microwave plug, 9-injector;

detailed description

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

The following examples illustrate the invention but are not intended to limit the scope of the invention.

A microwave excitation HCCI engine ignition control device of the present invention is mainly used in the ignition control of HCCI gasoline engines, and a set of microwave ignition system is arranged on the homogeneous compression ignition gasoline engine, as shown in Figure 1: including repetitive pulse power supply, microwave source, Microwave distributors, waveguides and microwave plugs.

The repetitive pulse power supply is connected to the engine control unit and the microwave source at the same time, the microwave source is connected to the microwave distributor, the microwave distributor is connected to the waveguide device, the waveguide device is connected to the microwave plug, and the microwave plug is arranged on the cylinder head.

The repetitive pulse power supply is modified by using the existing high-voltage generating circuit of the engine, and outputs the pulse electric energy required by the microwave source at an appropriate time according to the instructions of the engine control unit, and the pulse electric energy is converted into microwave pulses through the microwave source.

The microwave distributor accepts the instructions from the engine control unit, transmits the microwave to the microwave plug through the waveguide device at an appropriate time, and accurately transmits the microwave pulse to a certain combustion chamber that needs to ignite the cylinder through the microwave plug to stimulate ignition and combustion Mixed gas in the chamber: When a cylinder needs to be ignited, the microwave channel of the cylinder is opened by the microwave distributor, and all the microwave pulses are transmitted to the cylinder.

The present invention takes the microwave space ignition system applied to the vehicle as an example, and the microwave-triggered HCCI combustion engine combustion system provided is shown in Figure 2. The combustion chamber is composed of a piston 1, a cylinder 2, a cylinder head 3, and an intake valve 4. The cavity formed by the exhaust valve 5. The gas enters the combustion chamber from the intake port 6, and the exhaust gas after combustion is discharged from the combustion chamber through the exhaust port 7. The microwave plug 8 is arranged on the cylinder head 3, meanwhile, the fuel injector 9 is also arranged on the cylinder head, and is biased toward the side of the intake valve. At the same time, in order to realize the controllable combustion speed of the HCCI engine, the maximum combustion speed is reduced by introducing external exhaust gas circulation.

The process of microwave triggering HCCI combustion is as follows: At the beginning of the intake stroke, the fuel injector 9 injects a certain amount of fuel, and the fuel evaporates in the combustion chamber to form a homogeneous mixture; when the engine crankshaft sensor detects the engine phase, piston 1 is compressed to the upper At the stop point, the engine control unit controls the repetitive pulse power supply to generate high-power pulse electric energy, which is converted into microwave pulses. The microwave distributor controls the introduction of microwave pulses into the combustion chamber of the cylinder 2 that needs to be ignited, and quickly realizes multi-point simultaneous ignition in space. , the mixture burns rapidly.

A microwave excitation HCCI engine ignition control method, as shown in Figure 3, the specific steps are as follows:

Step 1. The microwave source is connected to the microwave plug through the microwave distributor and the waveguide device, and the microwave plug is installed on the cylinder head;

Step 2. At the beginning of the intake stroke, the fuel injector sprays a certain amount of fuel into the combustion chamber, and the fuel evaporates in the combustion chamber to form a homogeneous mixture;

Step 3, the engine control unit sends an instruction to the repetitive pulse power supply, and the repetitive pulse power supply sends pulse electric energy;

According to the instructions of the engine control unit, when the engine crankshaft sensor detects the engine phase and the piston is compressed to the top dead center, the repetitive pulse power supply excites and generates high-power pulses, and outputs the pulse electric energy required by the microwave source;

Step 4, the pulse electric energy is converted into a microwave pulse through a microwave source;

Step 5. The microwave distributor accepts the instruction from the engine control unit, and transmits the microwave pulse to the microwave plug through the waveguide device;

Step 6, the microwave pulse is directly transmitted to the combustion chamber of the cylinder that needs to be ignited through the microwave plug to stimulate the ignition;

When the gas in the cylinder gets more energy, the temperature rises, and the number of active molecules increases, the microwave energy is transmitted to the corresponding cylinder, breaking down the mixed gas and stimulating the ignition.

In the microwave control method of HCCI combustion of the present invention, at the end of the compression stroke, high-energy microwave pulses are introduced into the combustion chamber to heat and excite the mixture in the combustion chamber, so that the gas in the entire combustion chamber approaches or reaches the spontaneous combustion condition in a short time, and realizes the combustion of the mixture. Rapid combustion does not require the complex and unreliable combustion control methods of conventional HCCI engines, and realizes reliable control of the combustion phase of HCCI gasoline engines, overcomes the current difficulty in ignition control of homogeneous compression ignition gasoline engines, and effectively solves the problem of HCCI gasoline engines technical bottleneck.

Claims (4)

1. A microwave excitation HCCI engine ignition control device is characterized in that, comprising: repetitive pulse power supply, microwave source, microwave distributor, waveguide device and microwave plug; The repetitive pulse power supply is connected to the engine control unit and the microwave source at the same time, the microwave source is connected to the microwave distributor, the microwave distributor is connected to the waveguide device, the waveguide device is connected to the microwave plug, and the microwave plug is set on the cylinder head; The engine control unit sends instructions to the repetitive pulse power supply, and the repetitive pulse power supply outputs the pulse electric energy required by the microwave source, and generates microwave pulses through the microwave source. After receiving the instructions from the engine control unit, the microwave distributor transmits the microwave pulses to the The microwave plug is accurately transmitted to the cylinder that needs to be ignited. By introducing microwave pulses into the combustion chamber, it excites and ignites the mixed gas in the combustion chamber to achieve rapid combustion. 2. A kind of microwave excitation HCCI engine ignition control device as claimed in claim 1, is characterized in that, described repetitive pulse power supply utilizes the existing high voltage generation circuit of engine to refit. 3. application a kind of microwave excitation HCCI engine ignition control method of HCCI engine ignition control device as claimed in claim 1 is characterized in that, concrete steps are as follows: Step 1. The microwave source is connected to the microwave plug through the microwave distributor and the waveguide device, and the microwave plug is installed on the cylinder head; Step 2. At the beginning of the intake stroke, the fuel injector sprays a certain amount of fuel into the combustion chamber, and the fuel evaporates in the combustion chamber to form a homogeneous mixture; Step 3, the engine control unit sends an instruction to the repetitive pulse power supply, and the repetitive pulse power supply sends pulse electric energy; Step 4, the pulse electric energy is converted into a microwave pulse through a microwave source; Step 5. The microwave distributor accepts the instruction from the engine control unit, and transmits the microwave pulse to the microwave plug through the waveguide device; Step 6: The microwave pulse is directly transmitted to the combustion chamber of the cylinder that needs to be ignited through the microwave plug to stimulate ignition. 4. a kind of microwave excitation HCCI engine ignition control method as claimed in claim 3 is characterized in that, in described step 6: microwave pulse is transmitted in the combustor that needs to ignite cylinder, excites and ignites in the combustor Mixed gas: When a cylinder needs to be ignited, the microwave channel of the cylinder is opened by the microwave distributor, and all the microwave pulses are transmitted to the cylinder.