High-antiknock methanol cracking gas engine system utilizing waste gas backflow
Through the exhaust gas return system and knock sensor, the spark plug ignition is delayed, and the fuel and exhaust gas ratio is adjusted, the knock problem of methanol cracking gas engine is solved, and high explosion resistance and high power are achieved while reducing NOx emissions.
Patent Information
- Application Number
- CN202420919796.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-29
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-04-29
AI Technical Summary
Methanol cracking gas engines are prone to cause knocking, resulting in damage to engine components. The prior art is difficult to effectively solve the knocking problem of high-power methanol cracking gas engines, limiting the upper limit of engine power to below 300kW.
The exhaust gas return system is adopted to detect engine vibration through knock sensors, delay the ignition time of the spark plug, and adjust the ratio of fuel and exhaust gas, use exhaust gas to dilute oxygen, reduce the combustion speed in the cylinder, suppress the occurrence of knock, and at the same time, cool and increase the waste gas. The pressure regulator reduces NOx emissions.
The high explosion resistance of methanol cracking gas engine is achieved, with a power of more than 500kW, meeting the high power demand and improving NOx emission.
Smart Images
Figure CN222184928U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of methanol cracking gas engines, in particular to a high-explosion-resistant methanol cracking gas engine system utilizing exhaust gas reflux. Background Art
[0002] Engine knock is an abnormal combustion phenomenon, which is mainly manifested by high-frequency and large-amplitude fluctuations in the cylinder pressure and increased engine vibration. The main reason for its occurrence is that after the engine spark plug ignites, part of the unburned fuel in the cylinder produces uncontrolled spontaneous combustion or deflagration. The flame diffusion at the deflagration point and the compression of the pre-flame gas cause the temperature and pressure of the deflagration point to rise. If the deflagration speed is fast and there is enough pre-flame gas to produce deflagration, the high-pressure vibration pulse wave generated can cause some components of the engine or the entire engine to vibrate. Accumulated or severe knock can cause serious accidents such as damage to the engine piston, cylinder head, valve and piston ring.
[0003] Methanol cracking gas contains more than 60% hydrogen, which has a fast combustion speed and a short combustion duration, and there is almost no ignition delay during ignition. The minimum ignition energy of hydrogen is extremely small, only 15.1μJ, while the ignition energy of a general spark plug is not less than 50 mJ, and the ignition duration is not less than 0.5ms. The ignition energy is more than 3300 times greater than the former. It is precisely because hydrogen has a wide combustion range and a fast diffusion speed that it is very easy to cause knock combustion in a methanol cracking gas engine.
[0004] Research on methanol cracking gas engines is generally based on methanol cracking gas engines for road traffic, and high-power methanol cracking gas engines above 500kW have not yet appeared on the market. The knock of methanol cracking gas engines can no longer be solved by simply relying on the delay of spark plug ignition time. Knock will occur when the engine power exceeds 300kW, resulting in the general power of methanol cracking gas engines on the market being below 300kW, which cannot meet the market demand for high-power methanol cracking gas engines above 500kW. Therefore, there is an urgent need for a system that uses exhaust gas reflux to improve the anti-knock performance of methanol cracking gas engines. Summary of the invention
[0005] In order to solve the above-mentioned problems, the utility model provides a high explosion-proof methanol cracking gas engine system using exhaust gas reflow.
[0006] In a first aspect, the present invention provides a highly explosion-resistant methanol cracking gas engine system utilizing exhaust gas reflow, which adopts the following technical solution:
[0007] A system for improving the anti-knock performance of a methanol cracking gas engine by utilizing an exhaust gas reflow method, comprising an engine unit and an engine control unit, wherein the engine unit comprises a spark plug, a sensor, an engine cylinder, a fuel intake pipeline, an air intake pipeline, an exhaust gas reflow pipeline and a mixed gas pipeline, the engine control unit is connected to the spark plug and the sensor, the fuel intake pipeline is connected to the engine cylinder, the air intake pipeline and the exhaust gas reflow pipeline are combined and connected to the mixed gas pipeline, and the mixed gas pipeline is connected to the engine cylinder.
[0008] Furthermore, the engine unit also includes a first intake manifold, a second intake manifold and an engine exhaust pipe, the first intake manifold of the engine cylinder is connected to the outlet of the fuel intake pipeline, the engine cylinder is connected to the outlet of the mixed gas pipeline through the second intake manifold, and the engine exhaust pipe is connected to the inlet of the exhaust gas reflow pipeline.
[0009] Furthermore, the gas intake pipeline includes a methanol cracking gas inlet, a solenoid valve, a pressure regulating valve and a gas throttle valve, the methanol cracking gas inlet is connected to the solenoid valve, the solenoid valve outlet is connected to the pressure regulating valve through a pipeline, the pressure regulating valve outlet is connected to the gas throttle valve, the gas throttle valve outlet is connected to the engine gas intake manifold, and each outlet of the engine gas intake manifold is connected to the engine cylinder.
[0010] Furthermore, the mixer pipeline includes a mixer and a mixed gas throttle valve, the mixer adopts a venturi tube structure, the mixer outlet is connected to the mixed gas throttle valve, and the mixed gas throttle valve outlet is connected to the engine cylinder through a second intake manifold.
[0011] Furthermore, the air intake pipeline includes an air inlet, an air filter, an air throttle valve, a supercharger compressor and an air cooler, the air inlet is connected to the air filter, the air filter outlet is connected to the air throttle valve, the air throttle valve outlet is connected to the inlet of the supercharger compressor, the air outlet of the supercharger compressor is connected to the air cooler, and the air cooler is connected to the first inlet of the mixer pipeline.
[0012] Furthermore, the exhaust gas reflow pipeline includes an engine exhaust pipe, an exhaust gas reflow valve, an exhaust gas cooler and a supercharger turbine, the first end of the engine exhaust pipe is connected to the exhaust gas reflow valve inlet, the exhaust gas reflow valve outlet is connected to the exhaust gas cooler, and the exhaust gas cooler is connected to the second inlet of the mixer pipeline.
[0013] Furthermore, the second end of the engine exhaust pipe is connected to a supercharger turbine, and part of the exhaust gas is discharged through the supercharger turbine.
[0014] Furthermore, a knock sensor is installed on the engine cylinder of the engine unit, and the knock sensor is connected to the engine control unit. The knock sensor converts vibration into an electrical signal and transmits it to the engine control unit. The engine control unit receives the electrical signal and sends a signal instruction to the spark plug of the engine unit.
[0015] Furthermore, the engine control unit has a built-in filter, which receives a sensor signal, filters the sensor signal to shield background noise, and outputs an electrical signal with a knock frequency.
[0016] Furthermore, the engine control unit is connected to the spark plug, gas shut-off valve, air shut-off valve, exhaust gas reflow valve and mixture shut-off valve of the engine unit, and the engine control unit outputs signals to the spark plug, gas shut-off valve, air shut-off valve, exhaust gas reflow valve and mixture shut-off valve.
[0017] In summary, the present invention has the following beneficial technical effects:
[0018] The present invention solves the knock problem of the methanol cracking gas engine by using a high anti-knock methanol cracking gas engine system that utilizes exhaust gas recirculation to control the time of delayed spark plug ignition, adjust the fuel and adjust the ratio of the recirculated exhaust gas and air, so that the engine power can reach more than 500kW to meet market demand. At the same time, the exhaust gas recirculation method is used to improve the NOx emission of the engine. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a schematic diagram of a highly explosion-resistant methanol cracking gas engine system utilizing exhaust gas reflow according to Example 1 of the utility model.
[0020] Among them: 1. Solenoid valve; 2. Pressure regulating valve; 3. Gas throttle valve; 4. Engine cylinder; 5. Engine exhaust pipe; 6. Mixed gas throttle valve; 7. Mixer; 8. Exhaust gas cooler; 9. Air cooler; 10. Supercharger compressor; 11. Air throttle valve; 12. Air filter; 13. Exhaust gas return valve; 14. Knock sensor; 15. Spark plug; 16. Engine control unit; 17. Supercharger turbine. DETAILED DESCRIPTION
[0021] The utility model is further described in detail below in conjunction with the accompanying drawings.
[0022] Example 1
[0023] Reference Figure 1A highly anti-explosion methanol cracking gas engine system utilizing exhaust gas reflow in this embodiment includes an engine unit and an engine control unit 16, wherein the engine unit includes a spark plug 15, a knock sensor 14, an engine cylinder 4, a fuel intake pipeline, an air intake pipeline, an exhaust gas reflow pipeline and a mixed gas pipeline, the engine control unit is connected to the spark plug 15 and the sensor 14, the fuel intake pipeline is connected to the engine cylinder 4, the air intake pipeline and the exhaust gas reflow pipeline are combined and connected to the mixed gas pipeline, and the mixed gas pipeline is connected to the engine cylinder 4.
[0024] The engine unit also includes a first intake manifold, a second intake manifold and an engine exhaust pipe 5, the first intake manifold of the engine cylinder is connected to the outlet of the fuel intake pipeline, the engine cylinder is connected to the outlet of the mixed gas pipeline through the second intake manifold, and the engine exhaust pipe is connected to the inlet of the exhaust gas reflow pipeline.
[0025] The gas intake pipeline includes a methanol cracking gas inlet, a solenoid valve 1, a pressure regulating valve 2 and a gas throttle valve 3. The methanol cracking gas inlet is connected to the solenoid valve 1, the outlet of the solenoid valve 1 is connected to the pressure regulating valve 2 through a pipeline, the outlet of the pressure regulating valve 2 is connected to the gas throttle valve 3, and the outlet of the gas throttle valve 3 is connected to the engine gas intake manifold, and each outlet of the engine gas intake manifold is connected to the engine cylinder 4.
[0026] The mixer pipeline includes a mixer 7 and a mixed gas throttle valve 6. The mixer 7 adopts a venturi tube structure. The outlet of the mixer is connected to the mixed gas throttle valve 6. The outlet of the mixed gas throttle valve 6 is connected to the engine cylinder 4 through a second intake manifold.
[0027] The air intake pipeline includes an air inlet, an air filter 12, an air throttle valve 11, a supercharger compressor 10 and an air cooler 9, the air inlet is connected to the air filter 12, the air outlet of the air filter 12 is connected to the air throttle valve 11, the outlet of the air throttle valve 11 is connected to the inlet of the supercharger compressor 10, the air outlet of the supercharger compressor 10 is connected to the air cooler 9, and the air cooler 9 is connected to the first inlet of the mixer pipeline.
[0028] The exhaust gas reflow pipeline includes an engine exhaust pipe 5, an exhaust gas reflow valve 13, an exhaust gas cooler 8 and a supercharger turbine 17. The first end of the engine exhaust pipe 5 is connected to the air inlet of the exhaust gas reflow valve 13, the air outlet of the exhaust gas reflow valve 13 is connected to the exhaust gas cooler 8, and the exhaust gas cooler 8 is connected to the second inlet of the mixer pipeline.
[0029] The second end of the engine exhaust pipe is connected to the supercharger turbine 17, and part of the exhaust gas is discharged through the supercharger turbine. The exhaust gas discharged from the engine exhaust pipe 5 is divided into two paths, one is discharged through the supercharger turbine 17, and the other is mixed with fresh air in the mixer 7.
[0030] After the engine is started, the methanol cracking gas enters the pressure regulating valve 2 through the solenoid valve 1, and is then output to the gas throttle valve 3 through the pressure regulating valve 2. The gas enters the gas intake manifold through the gas throttle valve 3, and finally flows into the engine cylinder 4, where it is mixed with the air. After the air is filtered through the air filter 12, it enters the supercharger compressor 10 through the air throttle valve 11, and is then cooled through the air cooler 9. After cooling, it enters the mixer 7 to mix with the refluxed exhaust gas. The mixed gas flows into the engine cylinder 4 through the air intake manifolds of each cylinder, where it is mixed with the gas.
[0031] A knock sensor 14 is installed on each cylinder to convert all engine vibrations into electrical signals and transmit them to the engine control unit. The engine control unit performs knock detection and independently controls the ignition timing of each cylinder according to the situation to suppress or eliminate the occurrence of knock.
[0032] The built-in filter of the engine control unit filters out the background noise, leaving the signal with the knock frequency. After filtering, when the signal strength of a cylinder exceeds the preset limit, that is, exceeds the knock threshold, the engine control unit delays the ignition time of the corresponding knock cylinder through the ignition control system, so that the cylinder can be cooled, shortening the time that the gas after work remains in the cylinder, and avoiding the recurrence of knock. The denser the knock frequency, the noisier the signal, the more explosion points occur in the cylinder, and the more the ignition time is delayed.
[0033] The engine control unit is connected to the spark plug 15, the gas shutoff valve 3, the air shutoff valve 12, the exhaust gas recirculation valve 13 and the mixture shutoff valve 6 of the engine unit and outputs a signal to the engine unit.
[0034] When the system detects knock, the engine control unit first delays the ignition time of the knocking cylinder to reduce the knock tendency. If the delay in ignition time cannot make the engine get rid of knock, the engine control unit will issue a command to gradually open the opening of the exhaust gas return valve 13, adjust the amount of exhaust gas entering the mixer 7, and the exhaust gas mixes with the air and enters the cylinder, and then mixes with the fuel gas. Due to the introduction of exhaust gas, the combustion speed in the cylinder is reduced, and the occurrence of knock is suppressed.
[0035] Part of the exhaust gas is introduced into the intake pipe to increase the exhaust gas component in the mixed gas. The exhaust gas dilutes the fresh air to reduce the oxygen concentration and destroy the oxygen-rich condition. Since the triatomic molecules such as carbon dioxide contained in the exhaust gas have a large specific heat capacity, the maximum combustion temperature in the cylinder is reduced, destroying the high temperature condition, thereby reducing the NOx content. The refluxed exhaust gas is cooled by the exhaust gas cooler 8 and then sent to the intake end to further reduce the intake temperature, which is conducive to reducing NOx emissions.
[0036] The above are all preferred embodiments of the present utility model, and are not intended to limit the protection scope of the present utility model. Therefore, any equivalent changes made based on the structure, shape, and principle of the present utility model should be included in the protection scope of the present utility model.
Claims
1. A highly anti-explosion methanol cracking gas engine system utilizing exhaust gas reflow, characterized in that: The invention comprises an engine part and an engine control part, wherein the engine part comprises a spark plug, a sensor, an engine cylinder, a fuel intake line, an air intake line, an exhaust gas return line and a mixed gas line, the engine control part is connected to the spark plug and the sensor, the fuel intake line is connected to the engine cylinder, the air intake line and the exhaust gas return line are combined and connected to the mixed gas line, and the mixed gas line is connected to the engine cylinder.
2. A highly anti-explosion methanol cracking gas engine system using exhaust gas reflow according to claim 1, characterized in that: The engine unit also includes a first intake manifold, a second intake manifold and an engine exhaust pipe. The first intake manifold of the engine cylinder is connected to the outlet of the fuel intake pipeline, the engine cylinder is connected to the outlet of the mixed gas pipeline through the second intake manifold, and the engine exhaust pipe is connected to the inlet of the exhaust gas reflow pipeline.
3. The high explosion-proof methanol cracking gas engine system using exhaust gas reflow according to claim 1, characterized in that: The fuel intake pipeline includes a methanol cracking gas inlet, a solenoid valve, a pressure regulating valve and a gas throttle valve. The methanol cracking gas inlet is connected to the solenoid valve, the solenoid valve outlet is connected to the pressure regulating valve through a pipeline, the pressure regulating valve outlet is connected to the gas throttle valve, the gas throttle valve outlet is connected to the engine gas intake manifold, and each gas outlet of the engine gas intake manifold is connected to the engine cylinder.
4. A highly anti-explosion methanol cracking gas engine system using exhaust gas reflow according to claim 1, characterized in that: The mixed gas pipeline includes a mixer and a mixed gas throttle valve. The mixer adopts a venturi tube structure. The outlet of the mixer is connected to the mixed gas throttle valve. The outlet of the mixed gas throttle valve is connected to the engine cylinder through a second intake manifold.
5. The high explosion-proof methanol cracking gas engine system using exhaust gas reflow according to claim 1, characterized in that: The air intake pipeline includes an air inlet, an air filter, an air throttle valve, a supercharger compressor and an air cooler. The air inlet is connected to the air filter, the air filter outlet is connected to the air throttle valve, the air throttle valve outlet is connected to the inlet of the supercharger compressor, the air outlet of the supercharger compressor is connected to the air cooler, and the air cooler is connected to the first inlet of the mixed gas pipeline.
6. A highly anti-explosion methanol cracking gas engine system using exhaust gas reflow according to claim 1, characterized in that: The exhaust gas reflow pipeline includes an engine exhaust pipe, an exhaust gas reflow valve, an exhaust gas cooler and a supercharger turbine. The first end of the engine exhaust pipe is connected to the exhaust gas reflow valve inlet, the exhaust gas reflow valve outlet is connected to the exhaust gas cooler, and the exhaust gas cooler is connected to the second inlet of the mixed gas pipeline.
7. A highly anti-explosion methanol cracking gas engine system using exhaust gas reflow according to claim 6, characterized in that: The second end of the engine exhaust pipe is connected to the supercharger turbine, and part of the exhaust gas is discharged through the supercharger turbine.
8. The high explosion-proof methanol cracking gas engine system using exhaust gas reflow according to claim 1, characterized in that: A knock sensor is installed on the engine cylinder of the engine part, and the knock sensor is connected to the engine control part. The knock sensor converts vibration into an electrical signal and transmits it to the engine control part. The engine control part receives the electrical signal, and the engine control part sends a signal instruction to the spark plug of the engine part.
9. The high explosion-proof methanol cracking gas engine system using exhaust gas reflow according to claim 1, characterized in that: The engine control unit has a built-in filter, which receives a sensor signal, filters the sensor signal to shield background noise, and outputs an electrical signal with a knock frequency.
10. The high explosion-proof methanol cracking gas engine system using exhaust gas reflow according to claim 1, characterized in that: The engine control unit is connected to the spark plug, gas shutoff valve, air shutoff valve, exhaust gas reflow valve and mixed gas shutoff valve of the engine unit, and the engine control unit outputs signals to the spark plug, gas shutoff valve, air shutoff valve, exhaust gas reflow valve and mixed gas shutoff valve.