Non-road national fourth emission explosion-proof diesel engine system

Abstract

The invention discloses a non-road national four-emission explosion-proof diesel engine system which comprises a gas inlet unit, a gas exhaust unit, a cooling unit and an engine body, the gas inlet unit is arranged at the gas inlet end of the engine body to supply gas to the engine body, and the gas exhaust unit is arranged at the gas exhaust end of the engine body to reduce the temperature of exhaust gas emission. The cooling unit is connected with the engine body, the cooling unit is used for maintaining the water temperature during operation of the engine body, and the air inlet unit comprises a supercharger assembly, an air inlet shut-off valve assembly, an intercooler assembly, a flame arrester assembly, an explosion-proof air throttle valve assembly, an exhaust manifold assembly, an explosion-proof EGR valve assembly and an air inlet elbow assembly which are connected in sequence. The air inlet elbow assembly is communicated with the air inlet end of the engine body. The problem that in the prior art, when a diesel engine works, the content of nitric oxide in exhausted tail gas is high is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel engines, and in particular to a non-road National IV emission explosion-proof diesel engine system. Background Art

[0002] The advantages of diesel engines are high torque and good fuel economy. The operating process of a diesel engine shares many similarities with gasoline engines, with each cycle also going through four strokes: intake, compression, power, and exhaust. However, because diesel engines use diesel fuel, which has a higher viscosity than gasoline and is less prone to evaporation, yet has a lower auto-ignition temperature, the formation of the combustible mixture and the ignition method differ from those of gasoline engines.

[0003] The main differences are that the mixture in the cylinder of a diesel engine is compression ignited rather than ignited. When the diesel engine is working, air enters the cylinder. When the air in the cylinder is compressed to the end, the temperature can reach 500-700℃, and the pressure can reach 40-50 atmospheres. When the piston approaches the top dead center, the injector of the fuel supply system sprays fuel into the cylinder combustion chamber at extremely high pressure in a very short time. The diesel forms fine oil particles and mixes with the high-pressure and high-temperature air. The combustible mixture burns on its own, expands violently to generate explosive force, and pushes the piston downward to do work. At this time, the temperature can reach 1900-2000℃, and the pressure can reach 60-100 atmospheres, generating a large torque.

[0004] In existing technologies, diesel engines produce a large amount of exhaust gas when running, and the exhaust gas contains a large amount of particulate matter (PM) and nitrogen oxides (NOx). If the exhaust gas is not recycled and fully burned, it will cause serious harm to the environment and human health if it is directly discharged. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above technical deficiencies and provide a non-road National IV emission explosion-proof diesel engine system to solve the problem of high nitrogen oxide content in the exhaust gas emitted by diesel engines in the prior art.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: The present invention provides a non-road National IV emission explosion-proof diesel engine system, comprising an intake unit, an exhaust unit, a cooling unit and an engine body, wherein the intake unit is arranged at the intake end of the engine body to form air supply to the engine body, and the exhaust unit is arranged at the exhaust end of the engine body to reduce the temperature of exhaust emissions. The cooling unit is connected to the engine body and is used to maintain the water temperature of the engine body during operation, wherein the intake unit comprises a supercharger assembly, an intake shut-off valve assembly, an intercooler assembly, a flame arrester assembly, an explosion-proof air throttle valve assembly, an exhaust manifold assembly, an explosion-proof EGR valve assembly and an intake elbow assembly, which are connected in sequence, and the intake elbow assembly is connected to the intake end of the engine body.

[0007] In some embodiments, the air intake unit further includes an air filter assembly, and the air filter assembly is connected to the supercharger assembly.

[0008] In some embodiments, the exhaust unit includes an exhaust front-end pipe assembly, an exhaust rear-end pipe assembly, a heat exchanger assembly and an explosion-proof exhaust gas purification device assembly. The exhaust front-end pipe assembly is connected to the supercharger assembly, the exhaust front-end pipe assembly is connected to the explosion-proof exhaust gas purification device assembly, the explosion-proof exhaust gas purification device assembly is connected to the exhaust rear-end pipe assembly, the exhaust rear-end pipe assembly is connected to the heat exchanger assembly, and the heat exchanger assembly is capable of discharging exhaust gas.

[0009] In some embodiments, the explosion-proof exhaust purification device assembly includes a shell, a DOC device and a DPF device, and the DOC device and the DPF device are both installed in the shell. The explosion-proof exhaust purification device assembly can be used to treat NOx / CO / HC / PM.

[0010] In some embodiments, the cooling unit includes a first cooling line, which includes an engine water pump, a first water tank radiator assembly and an EGR cooler. The engine water pump is connected to the first water tank radiator assembly, the first water tank radiator assembly is connected to the engine water pump, and the engine body is also connected to the EGR cooler.

[0011] In some embodiments, the cooling unit includes a second cooling line, the second cooling line includes a liquid pump and a second water tank radiator assembly, the liquid pump is connected to the second water tank radiator assembly, and the second water tank radiator assembly is connected to the exhaust manifold assembly.

[0012] In some embodiments, the surface temperatures of the exhaust manifold assembly, the supercharger assembly, the exhaust front-end pipe assembly, and the exhaust rear-end pipe assembly are controlled below 150°C, and the exhaust gas temperature discharged from the heat exchanger assembly is controlled below 77°C.

[0013] In some embodiments, the exhaust manifold assembly, the supercharger assembly, the exhaust front end pipe assembly, and the exhaust rear end pipe assembly are all cooled by oil cooling or water cooling. In some embodiments, the surface temperature of the DOC device and the DPF device is maintained between 130°C and 145°C.

[0014] In some embodiments, an electronic control unit is also included, which includes multiple sensors and a control module. Each of the sensors is respectively arranged on the intake unit, the exhaust unit, the cooling unit and the engine body, and each of the sensors is electrically connected to the electronic control unit.

[0015] Compared with the prior art, the present invention provides a non-road National IV emission explosion-proof diesel engine system, in which an intake unit is arranged at the intake end of the engine body to supply air to the engine body, and an exhaust unit is arranged at the exhaust end of the engine body to reduce the temperature of the exhaust gas emissions. The cooling unit is connected to the engine body, and the cooling unit is used to maintain the water temperature of the engine body during operation. The intake unit includes a supercharger assembly, an intake shut-off valve assembly, an intercooler assembly, a flame arrester assembly, an explosion-proof air throttle valve assembly, an exhaust manifold assembly, an explosion-proof EGR valve assembly and an intake bend assembly, which are connected in sequence. The intake bend assembly is connected to the intake end of the engine body; it effectively ensures that the air input from the explosion-proof air throttle valve assembly and part of the exhaust gas transmitted by the explosion-proof EGR valve assembly are mixed at the intake bend assembly and then enter the engine body for combustion again, which can reduce the combustion temperature and oxygen concentration, thereby inhibiting the generation of nitrogen oxides and significantly reducing harmful substances in the exhaust gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of a non-road National IV emission explosion-proof diesel engine system provided by the present invention; Figure 2 This is a partial structural diagram of a non-road National IV emission explosion-proof diesel engine system provided by the present invention; Figure 3 This is a partial structural schematic diagram from another perspective of a non-road National IV emission explosion-proof diesel engine system provided by the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] In order to solve the technical problem of high nitrogen oxide content in the exhaust gas emitted by the existing diesel engine during operation, the present invention provides a non-road National IV emission explosion-proof diesel engine system, which can mix the air input from the explosion-proof air throttle valve assembly and part of the exhaust gas transmitted by the explosion-proof EGR valve assembly at the intake elbow assembly, and part of the exhaust gas re-enters the engine body for combustion, which can reduce the combustion temperature and oxygen concentration, thereby inhibiting the generation of nitrogen oxides and significantly reducing harmful substances in the exhaust gas.

[0019] See also Figure 1-Figure 3 , Figure 1-Figure 3 This is a non-road National IV emission explosion-proof diesel engine system in one embodiment of the present invention, including an intake unit 1, an exhaust unit 2, a cooling unit 3 and an engine body 4, wherein the intake unit 1 is arranged at the intake end of the engine body 4 to form air supply to the engine body 4, and the exhaust unit 2 is arranged at the exhaust end of the engine body 4 to reduce the temperature of the exhaust gas emissions. The cooling unit 3 is connected to the engine body 4, and the cooling unit 3 is used to maintain the water temperature of the engine body 4 during operation, wherein the intake unit 1 includes a supercharger assembly 11, an intake shut-off valve assembly 12, an intercooler assembly 13, a flame arrester assembly 14, an explosion-proof air throttle valve assembly 15, an exhaust manifold assembly 16, an explosion-proof EGR valve assembly 17 and an intake elbow assembly 18 connected in sequence, and the intake elbow assembly 18 is connected to the intake end of the engine body 4.

[0020] It should be noted that a diesel engine is an internal combustion engine that generates power by compressing air to a high temperature and high pressure state, causing the injected diesel to spontaneously ignite. A diesel engine does not require spark plugs, and relies on a high compression ratio to compress air to approximately 500-600°C, which then burns spontaneously after being injected with diesel.

[0021] Specifically, in one embodiment, air is pressurized by the supercharger assembly 11 , and the supercharger assembly 11 can improve the quality of air entering the engine body 4 , thereby increasing the power output of the engine body 4 .

[0022] The pressurized air passes through the intake shut-off valve assembly 12 , which can cut off the intake source to protect the engine body 4 .

[0023] Furthermore, the air intake shut-off valve assembly 12 adopts "electric + pneumatic" dual drive redundancy. Under normal working conditions, it is driven by the motor (response ≤ 0.5s), and automatically switches to pneumatic drive (compressed air reserve ≥ 3 times of operation) in the event of power failure / fault, ensuring 100% shut-off of the air intake in an emergency.

[0024] In addition, the temperature of the supercharged air is relatively high and needs to be cooled by the intercooler assembly 13. The intercooler assembly 13 can reduce the air temperature, increase the air density, and further improve the performance of the engine. Specifically, the cooled air passes through the flame arrester assembly 14, which can prevent the flame of the engine body from flowing back into the ambient atmosphere, thereby ensuring safety.

[0025] Furthermore, the air passing through the flame arrester assembly 14 enters the explosion-proof air throttle valve assembly 15, which can adjust the opening of the throttle valve to control the amount of air entering the engine body; at the same time, a portion of the exhaust gas flows out from the exhaust manifold assembly and enters the intake elbow assembly 18 through the explosion-proof air throttle valve assembly 15; the fresh air delivered from the explosion-proof air throttle valve assembly 15 and a portion of the exhaust gas from the explosion-proof air throttle valve assembly 15 are collected at the intake elbow assembly 18 and finally enter the engine body to participate in combustion, and a portion of the exhaust gas can be reintroduced into the combustion chamber to lower the combustion temperature and reduce the emission of nitrogen oxides.

[0026] Specifically, by connecting the flameproof EGR valve assembly 17 and the exhaust manifold assembly 16 in series in the intake unit 1, a closed exhaust gas recirculation loop can be established. After a portion of the exhaust gas is drawn out through the exhaust manifold assembly 16, the flameproof EGR valve assembly 17 precisely controls the return flow ratio (adjustable from 15% to 30%), and fully mixes it with the fresh air regulated by the flameproof air throttle valve assembly 15 in the intake elbow assembly 18. This design suppresses the formation of nitrogen oxides (NOx) at the source by reducing the combustion chamber temperature (from the traditional 1900-2000°C to below 1600°C) and oxygen concentration. Measured NOx emissions are reduced by more than 40% compared to traditional models. At the same time, the flameproof EGR valve assembly 17 adopts a flameproof joint surface design (gap ≤ 0.15mm, width ≥ 12.5mm), which complies with the GB3836.2 standard and solves the safety adaptation problem of traditional EGR systems in explosion-proof scenarios.

[0027] Based on the above scheme, in one embodiment, the air intake unit 1 also includes an air filter assembly 10, and the air filter assembly 10 is connected to the supercharger assembly 11; specifically, fresh air first enters the engine body through the air filter assembly 10, and the air filter 10 can filter out dust and impurities in the air to ensure that the air entering the engine body is clean.

[0028] Specifically, the air intake unit forms a four-stage purification chain of "air filter assembly 10 + turbocharger assembly 11 + intercooler assembly 13 + flame arrester assembly 14". The air filter assembly 10 achieves 99.9% particulate matter filtration through a composite fiber filter element, preventing impurities from wearing the turbocharger assembly 11; the turbocharger assembly 11 increases the intake pressure to 1.2-1.5 bar, and cooperates with the intercooler assembly to reduce the intake temperature from 180°C to 40-50°C, and the air density is increased by 15%-20%; the flame arrester assembly 14 adopts a metal grid structure with a flame blocking speed of ≤10m / s, which can prevent sparks from leaking out of the air intake unit. The four-stage synergy not only improves engine power but also builds an explosion-proof barrier for the entire process.

[0029] It should be noted that, in one embodiment, the exhaust unit 2 includes an exhaust front-end pipe assembly 21, an exhaust rear-end pipe assembly 22, a heat exchanger assembly 23 and an explosion-proof exhaust gas purification device assembly 24, the exhaust front-end pipe assembly 21 is connected to the supercharger assembly 11, the exhaust front-end pipe assembly 21 is connected to the explosion-proof exhaust gas purification device assembly 24, the explosion-proof exhaust gas purification device assembly 24 is connected to the exhaust rear-end pipe assembly 22, the exhaust rear-end pipe assembly 22 is connected to the heat exchanger assembly 23, and the heat exchanger assembly 23 can discharge the exhaust gas.

[0030] It can be understood that the burned exhaust gas is discharged from the exhaust port of the engine body, and the exhaust gas flows into the supercharger assembly through the exhaust manifold assembly, during which it is initially cooled. The exhausted exhaust gas flows into the exhaust front end pipe assembly through the supercharger assembly, and the exhaust gas after passing through the supercharger assembly continues to pass through the exhaust front end pipe assembly to further reduce the temperature.

[0031] In addition, the exhaust gas flows into the explosion-proof exhaust gas purification device assembly 24, which includes a shell, a DOC device and a DPF device. The DOC device and the DPF device are both installed in the shell. The explosion-proof exhaust gas purification device assembly can be used to treat NOx / CO / HC / PM; specifically, the DOC device is used to treat harmful gases such as NOx, CO, HC, and convert them into harmless substances; the DPF device is used to capture particulate matter (PM) in the exhaust gas to reduce emission pollution.

[0032] It should be noted that the explosion-proof exhaust gas purification device assembly 24 adopts an integrated design of "cast steel shell + DOC + DPF". The DOC increases the CO and HC oxidation efficiency to 99% through a platinum-rhodium coating; the DPF adopts a silicon carbide honeycomb carrier, and the PM capture efficiency is ≥98%; the device simultaneously processes NOx / CO / HC / PM, and the comprehensive purification efficiency is 50% higher than the split design, meeting the National IV limit (NOx≤2.0g / kWh, PM≤0.02g / kWh).

[0033] Based on the above scheme, the cooling unit 3 includes a first cooling pipeline, which includes an engine water pump, a first water tank radiator assembly 32 and an EGR cooler 33. The engine water pump 31 is connected to the engine body 4, and the engine water pump 31 is also connected to the first water tank radiator assembly 32. The first water tank radiator assembly 32 is connected to the engine water pump 31, and the engine body 4 is also connected to the EGR cooler 33.

[0034] It should be noted that the coolant is drawn by the engine body water pump, and the coolant dissipates heat through the first water tank radiator assembly 32. The coolant after heat dissipation returns to the engine body to cool the engine. The coolant then passes through the EGR cooler 33, which can further reduce the temperature and effectively maintain the water temperature of the engine body between 80℃-88℃, ensuring that the engine body operates within the optimal operating temperature range, improving efficiency and reducing wear.

[0035] Specifically, the first cooling line (engine cooling): the coolant is driven by the engine water pump and, after cooling through the first water tank radiator assembly 32, provides cooling for the engine body (maintaining the water temperature at 80-88°C) and the EGR cooler 33 (reducing the EGR exhaust gas from 600°C to below 180°C), preventing the high-temperature exhaust gas from causing aging of the intake system.

[0036] In one embodiment, the cooling unit 3 includes a second cooling pipeline, which includes a liquid pump and a second water tank radiator assembly 34, the liquid pump is connected to the second water tank radiator assembly 34, and the second water tank radiator assembly 34 is connected to the exhaust manifold assembly 16.

[0037] Specifically, the coolant is extracted by an external liquid pump, and the coolant dissipates heat through the second water tank radiator assembly 34. The coolant after dissipation enters the exhaust manifold assembly 16 to cool the exhaust manifold. The coolant continues to flow through the supercharger assembly to cool the supercharger. The coolant then enters the exhaust front end pipe assembly to cool the exhaust front end pipe. The coolant finally passes through the exhaust rear end pipe assembly 16 to cool the exhaust rear end pipe assembly 16. Finally, the coolant enters the heat exchanger assembly to further reduce the temperature.

[0038] Specifically, in one embodiment, the surface temperatures of the exhaust manifold assembly 16, the supercharger assembly 11, the exhaust front-end pipe assembly 21, and the exhaust rear-end pipe assembly 22 are controlled below 150°C, and the exhaust gas temperature discharged from the heat exchanger assembly 23 is controlled below 77°C. In addition, the surface temperatures of the DOC device and the DPF device are maintained between 130°C and 145°C.

[0039] The exhaust manifold assembly 16 and supercharger assembly 11 are both made of Cr20Ni80 high-temperature-resistant alloy, and are water-cooled in the secondary cooling circuit, maintaining a surface temperature of ≤150°C. The exhaust rear-end pipe assembly 22 adopts a double-layer structure of "inner layer high-temperature-resistant steel + outer layer thermal insulation cotton," reducing heat loss by 40%. The heat exchanger assembly 23 uses a fin structure to expand the heat dissipation area, keeping the exhaust emission temperature ≤77°C.

[0040] It should be noted that the coolant is forced through the pump via the second radiator assembly 34, providing targeted cooling to high-temperature components such as the exhaust manifold assembly 16 and the supercharger assembly 11. This stabilizes the surface temperature of the exhaust manifold assembly 16 at 120-140°C (≤150°C explosion-proof threshold). The primary and secondary cooling lines work together to keep the exhaust temperature of the heat exchanger assembly 23 ≤77°C, achieving a 35% improvement in cooling efficiency compared to conventional single-circuit systems.

[0041] It should be noted that, in one embodiment, the exhaust manifold assembly 16, the supercharger assembly 11, the exhaust front end pipe assembly 21, and the exhaust rear end pipe assembly 22 are all cooled by water cooling. Of course, in other embodiments, the exhaust manifold assembly 16, the supercharger assembly 11, the exhaust front end pipe assembly 21, and the exhaust rear end pipe assembly 22 can also be cooled by oil cooling.

[0042] In one embodiment, an electronic control unit (ECU) is further included. The ECU comprises multiple sensors and a control module. Each of the sensors is located on the intake unit 1, exhaust unit 2, cooling unit 3, and engine body 4, and is electrically connected to the ECU. The engine body sensors include a crankshaft sensor, a camshaft sensor, a rail pressure sensor, an engine water temperature sensor, a post-boost intake air pressure sensor, a post-boost intake air temperature sensor, an oil pressure sensor, a fuel tank level sensor, and a wash tank level sensor. The engine body's surface temperature sensor and exhaust temperature sensor both utilize the KC6102D sensor.

[0043] Specifically, the control programs of the engine body, DOC device and DPF device all adopt Cummins original system, and are calibrated and debugged according to the explosion-proof parts to achieve the performance and emission targets of the engine body.

[0044] It should be noted that the sensor also includes an alarm, which is electrically connected to the control module. When any of the following situations occurs: the exhaust temperature reaches 70°C, the surface temperature reaches 150°C, the coolant temperature exceeds 95°C, the cooling water tank water level drops to the set minimum level, the oil pressure drops to the set minimum pressure, and the gas concentration reaches 1%, the control module will be able to control the alarm to sound an alarm.

[0045] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A non-road National IV emission explosion-proof diesel engine system, characterized in that: It includes an intake unit, an exhaust unit, a cooling unit and an engine body. The intake unit is arranged at the intake end of the engine body to supply air to the engine body. The exhaust unit is arranged at the exhaust end of the engine body to reduce the temperature of the exhaust gas. The cooling unit is connected to the engine body. The cooling unit is used to maintain the water temperature when the engine body is running. The intake unit includes a supercharger assembly, an intake shut-off valve assembly, an intercooler assembly, a flame arrester assembly, an explosion-proof air throttle valve assembly, an exhaust manifold assembly, an explosion-proof EGR valve assembly and an intake elbow assembly which are connected in sequence. The intake elbow assembly is connected to the intake end of the engine body.

2. The non-road National IV emission explosion-proof diesel engine system according to claim 1, characterized in that: The air intake unit further includes an air filter assembly, which is connected to the supercharger assembly.

3. The non-road National IV emission explosion-proof diesel engine system according to claim 1, characterized in that: The exhaust unit includes an exhaust front-end pipe assembly, an exhaust rear-end pipe assembly, a heat exchanger assembly and an explosion-proof exhaust gas purification device assembly. The exhaust front-end pipe assembly is connected to the supercharger assembly, the exhaust front-end pipe assembly is connected to the explosion-proof exhaust gas purification device assembly, the explosion-proof exhaust gas purification device assembly is connected to the exhaust rear-end pipe assembly, and the exhaust rear-end pipe assembly is connected to the heat exchanger assembly. The heat exchanger assembly can discharge exhaust gas.

4. The non-road National IV emission explosion-proof diesel engine system according to claim 3, characterized in that: The explosion-proof exhaust gas purification device assembly includes a shell, a DOC device and a DPF device. The DOC device and the DP device are both installed in the shell. The explosion-proof exhaust gas purification device assembly can be used to treat NOx / CO / HC / PM.

5. The non-road National IV emission explosion-proof diesel engine system according to claim 1, characterized in that: The cooling unit includes a first cooling pipeline, which includes an engine water pump, a first water tank radiator assembly and an EGR cooler. The engine water pump is connected to the first water tank radiator assembly, the first water tank radiator assembly is connected to the engine water pump, and the engine body is also connected to the EGR cooler.

6. The non-road National IV emission explosion-proof diesel engine system according to claim 4, characterized in that: The cooling unit includes a second cooling pipeline, which includes a liquid pump and a second water tank radiator assembly. The liquid pump is connected to the second water tank radiator assembly, and the second water tank radiator assembly is connected to the exhaust manifold assembly.

7. The National IV emission explosion-proof diesel engine system according to claim 6, characterized in that: The surface temperatures of the exhaust manifold assembly, the supercharger assembly, the exhaust front-end pipe assembly, and the exhaust rear-end pipe assembly are controlled below 150° C., and the exhaust gas temperature discharged from the heat exchanger assembly is controlled below 77° C.

8. The non-road National IV emission explosion-proof diesel engine system according to claim 7, characterized in that: The exhaust manifold assembly, the supercharger assembly, the exhaust front end pipe assembly, and the exhaust rear end pipe assembly are all cooled by oil cooling or water cooling.

9. The non-road National IV emission explosion-proof diesel engine system according to claim 4, characterized in that: The surface temperature of the DOC device and the DPF device is maintained between 130°C and 145°C.

10. The non-road National IV emission explosion-proof diesel engine system according to claim 1, characterized in that: It also includes an electronic control unit, which includes multiple sensors and a control module. Each of the sensors is respectively arranged on the intake unit, the exhaust unit, the cooling unit and the engine body, and each of the sensors is electrically connected to the electronic control unit.

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