Engine exhaust gas reheating system
The engine exhaust gas reheating system, which uses a mixed exhaust gas heating system consisting of an electric heater and an air pump, solves the problem of the exhaust gas temperature of the particulate filter (DPF) not meeting the standard, and achieves efficient regeneration of exhaust gas and energy saving and emission reduction.
Patent Information
- Application Number
- CN202410816744.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-24
- Publication Date
- 2026-02-24
AI Technical Summary
In existing technologies, the exhaust gas temperature of a particulate filter (DPF) may not reach the regeneration temperature required during each trip, resulting in poor regeneration performance. Furthermore, the active regeneration process is fuel-intensive, costly, and produces exhaust gases that are detrimental to energy conservation and emission reduction.
An engine exhaust gas reheating system is adopted, which uses a mixed exhaust gas heating system consisting of an electric heater and an air pump to ensure that the exhaust gas temperature reaches the temperature required for regeneration when the engine starts. The system includes the circuit connection of components such as electric heater, air solenoid valve, air pump, and solid-state relay to achieve automatic regulation of exhaust gas temperature.
By ensuring that the exhaust gas temperature exceeds the temperature required for the regeneration of the particulate filter (DPF) each time the engine is started, efficient exhaust gas regeneration is achieved, reducing fuel consumption and costs, and minimizing harmful exhaust emissions.
Smart Images
Figure CN121556966A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an engine exhaust gas reheating system that heats a mixture of fresh air and engine exhaust gas to raise the temperature of the mixture. Background Technology
[0002] Currently, the known technology is that GPF regeneration essentially restores the filtration performance of the Gas Permeable Filter (GPPF). It uses high temperatures to cause a chemical reaction and combustion of fine particles in the GPF, after which the deposited particulate matter is expelled. GPF regeneration is divided into active and passive regeneration. Passive GPF regeneration occurs during normal driving when the driver releases the accelerator pedal, cutting off fuel supply and allowing a large amount of oxygen to enter the GPF for a chemical reaction and regeneration. Active GPF regeneration occurs when passive regeneration is ineffective, requiring high-speed driving. This involves driving at a minimum speed of 80 km / h, then releasing the accelerator pedal to allow the vehicle to coast, repeating this cycle for 30 minutes. During active GPF regeneration, the engine control unit (ECU) increases fuel injection to retard the ignition timing, causing the exhaust temperature to reach an overheated state, thus achieving regeneration. During the parking regeneration process, the engine idles at a higher speed to increase the exhaust temperature upstream of the DOC. Once the upstream DOC temperature is reached, the HC injection system controls the exhaust temperature upstream of the DPF to around 600°C, ensuring that the particles accumulated in the DPF are fully burned off. After the parking regeneration time (approximately 30 minutes), the regeneration process is complete, the DPF indicator light goes out, and the engine idles back to normal.
[0003] The drawbacks of the above-mentioned regeneration technology are as follows: Since the exhaust gas temperature entering the DPF (Dual Particulate Filter) cannot exceed the required regeneration temperature for every trip, regeneration of the DPF is not guaranteed for every trip. For example, prolonged idling or low-speed driving, or short periods of high-speed driving, result in high exhaust resistance during the drive before DPF regeneration, preventing passive regeneration. During active GPF regeneration, to increase the exhaust gas temperature entering the DPF, the HC injection system controls the upstream exhaust temperature to approximately 600°C, leading to regeneration fuel consumption. Performing DPF regeneration while parked is significantly more expensive and generates more post-combustion exhaust gases, which is detrimental to energy conservation and emission reduction. Summary of the Invention
[0004] To overcome the drawback that the temperature of the exhaust gas entering the particulate filter (DPF) cannot exceed the required temperature for DPF regeneration every time the vehicle is driven, this invention provides an engine exhaust gas reheating system. The technical solution adopted in this invention consists of: a first air pipe, a second air pipe, an electric heater, an air solenoid valve, an air pump, a manual switch, a solid-state relay (SSR), resistors R1, R2, R3, R4, R5, R6, capacitors C1 and C2, transistors Q1, Q2, Q3, a parallel diode group, and a Zener diode DW.
[0005] The technical solution adopted by this invention to solve its technical problem is as follows: the outlet of the particulate filter (DPF) is connected to the rear exhaust pipe, and the inlet of the particulate filter (DPF) is connected to the front exhaust pipe; one end of the first air pipe is connected to the front exhaust pipe, and the other end of the first air pipe is connected to the outlet of the air solenoid valve; the inlet of the air solenoid valve is connected to one end of the second air pipe, and the other end of the second air pipe is connected to the outlet of the air pump; an electric heater is installed inside the front exhaust pipe; the current input terminal of the output circuit of the solid-state relay (SSR) is connected to the positive terminal of the power supply, and the current output terminal of the output circuit is connected to the positive terminal of the electric heater and the positive terminal of the air solenoid valve; the negative terminal of the electric heater is grounded, and the negative terminal of the air solenoid valve is grounded; the on terminal of the ignition switch is connected to one end of the manual switch 1, and the other end of the manual switch 1 is connected to one end of R3 and one end of R5; the other end of R3 is connected to the current input terminal of the input circuit of the solid-state relay (SSR); the current output terminal of the input circuit of the solid-state relay (SSR) is connected to the collector of Q1. The base of Q1 is connected to one end of R2. The other end of R2, the positive terminal of C1, is connected to the emitter of Q3, and the negative terminal of C1 is grounded. The emitter of Q1 is connected to the positive terminals of diodes D1 and Dn in a parallel diode group (the number of diodes is the same as the number of forward gears). SQ (gear indicator switch) 1 in a parallel gear position indicator switch group (the number of SQ switches is the same as the number of forward gears) is connected to the negative terminal of diode D1. One end of SQn is connected to the negative terminal of diode Dn, and the other end of SQ1 is connected to... The other end of SQn is grounded; the negative terminal of Zener diode DW is connected to the excitation circuit terminal of the generator, and the positive terminal of Zener diode DW is connected to one end of R1; the emitter of Q2 is connected to the other end of R1; the base of Q2 is connected to one end of R4, and the other end of R4 is connected to one end of R6 and the positive terminal of C1; the negative terminal of C2 is grounded, and the other end of R6 is connected to the terminal of the engine oil pressure alarm; the collector of Q2 is connected to the base of Q3; the collector of Q3 is connected to the other end of R5.
[0006] The beneficial effect of this invention is that it can electrically heat the engine exhaust gas for a set period of time each time the engine is started and the car is driven forward, so that the temperature of the mixed exhaust gas entering the particulate filter (DPF) exceeds the temperature required for the regeneration of the particulate filter (DPF). Attached Figure Description
[0007] In the diagram: 1. Manual switch, 2. Electric heater, 3. Excitation circuit terminal, 4. Parallel diode group, 5. Parallel gear position indicator switch group, 11. Fresh air pump, 12. Engine exhaust, 13. Air solenoid valve, 14. Rear exhaust pipe, 15. Second air pipe, 16. Air pump, 17. Engine oil pressure alarm, 18. Front exhaust pipe, 21. First air pipe.
[0008] The present invention will be further described below with reference to the accompanying drawings:
[0009] Figure 1 This is a schematic diagram illustrating the working principle of the engine exhaust gas reheating system of the present invention. Detailed Implementation
[0010] like Figure 1 As shown, the exhaust port of the particulate filter (DPF) is connected to the rear exhaust pipe 14, and the intake port of the particulate filter (DPF) is connected to the front exhaust pipe 18; one end of the first air pipe 21 is connected to the front exhaust pipe 18, and the other end of the first air pipe 21 is connected to the exhaust port of the air solenoid valve 13. The intake port of the air solenoid valve 13 is connected to one end of the second air pipe 15, and the other end of the second air pipe 15 is connected to the exhaust port of the air pump 16; an electric heater 2 is installed inside the front exhaust pipe 18; the current input terminal of the output circuit of the solid-state relay (SSR) is connected to the positive terminal of the power supply, and the current output terminal of the output circuit is connected to the positive terminal of the electric heater and the positive terminal of the air solenoid valve; the negative terminal of the electric heater is grounded, and the negative terminal of the air solenoid valve is grounded; the ON terminal of the ignition switch is connected to one end of the manual switch 1, and the other end of the manual switch 1 is connected to one end of R3 and one end of R5. The other end of R3 is connected to the current input terminal of the input circuit of the solid-state relay (SSR); the collector of Q1... Connect the current output terminal of the input circuit of the solid-state relay (SSR); connect the base of Q1 to one end of R2, connect the other end of R2 to the positive terminal of C1 and the emitter of Q3, and ground the negative terminal of C1; connect the emitter of Q1 to the positive terminals of diodes D1 and Dn in parallel diode group 4; connect SQ1 and SQn of parallel gear position indicator switch group 5 to the negative terminals of diodes D1 and Dn respectively, and ground the other end of SQ1 to the other end of SQn; voltage regulation. The negative terminal of diode DW is connected to terminal 3 of the generator's excitation circuit; the positive terminal of Zener diode DW is connected to one end of R1; the emitter of Q2 is connected to the other end of R1; the base of Q2 is connected to one end of R4; the other end of R4 is connected to one end of R6 and the positive terminal of C1; the negative terminal of C2 is grounded; the other end of R6 is connected to the terminal of engine oil pressure alarm 17; the collector of Q2 is connected to the base of Q3; the collector of Q3 is connected to the other end of R5.
[0011] The working process of this invention:
[0012] Condition 1: When the manual switch is in the off and non-energized state, the input circuit of the solid-state relay (SSR) is de-energized, and the output circuit of the solid-state relay (SSR) is also in the cut-off and non-conducting state, so that the air solenoid valve 13 and the electric heater 2 are de-energized.
[0013] In operating condition 2, the manual switch is in the closed energized state, supplying power to the input circuit of the solid-state relay (SSR). After the engine starts, the oil pressure pushes open the switch contacts of the engine oil pressure alarm 17, preventing R6 from grounding through the oil pressure alarm 17. At this time, the generator's excitation state changes from external excitation to self-excitation, causing the voltage at terminal 3 of the generator's excitation circuit to rise to a state where it can reverse-break down the Zener diode DW. The trigger current of Q2 then charges C2 from terminal 3 of the generator's excitation circuit through the Zener diode DW, R1, the emitter of Q2, the base of Q2, and R4, simultaneously triggering the emitter and collector of Q2 to be in a conducting state. Until C2 is nearly fully charged, causing the trigger current of Q2 to approach zero, the emitter and collector of Q2 are then triggered to be in a cut-off, non-conducting state. The trigger current of Q3 flows through the Zener diode DW, R1, the emitter and collector of Q2, and the base and emitter of Q3 into C1, simultaneously triggering the collector and emitter of Q3 to conduct. This allows the current charging C1 to flow through R5 and the collector and emitter of Q3. When C2 is nearly fully charged, causing the trigger current of Q2 to approach zero, it triggers the emitter and collector of Q2 to enter a non-conducting state. Consequently, no current flows through the base to the emitter of Q3, again triggering the collector and emitter of Q3 to enter a non-conducting state, and thus no current charges C1. When the vehicle is moving forward:
[0014] Under operating condition 2.1, when the vehicle enters the first set gear, SQ1 is closed and conducting. At this time, C1 discharges through R2, the base and emitter of Q1, diode D1, and SQ1 ground; subsequently, it triggers the collector and emitter of Q1 to conduct. At this time, the trigger current of the solid-state relay SSR can pass through manual switch 1, R3, the input circuit of the solid-state relay SSR, the collector and emitter of Q1, diode D1, and SQ1 ground; subsequently, it triggers the output circuit of the solid-state relay SSR to be in a conducting state. At this time, the operating current passes through... After the output circuit of the solid-state relay (SSR) outputs power to the air solenoid valve 13 and the electric heater 2 respectively, the fresh air 11 pumped out by the air pump 16 passes through the second air pipe 15, the air electric contact valve 13, and the first air pipe 21 into the front exhaust pipe 18. After mixing with the engine exhaust, the mixture is heated by the electric heater to a temperature exceeding that required for the regeneration of the particulate filter (DPF), so that the particles accumulated in the particulate filter (DPF) are fully burned off, and then discharged from the rear exhaust pipe 14 outside the particulate filter (DPF).
[0015] In condition 2.2, when the vehicle enters the nth set gear, SQn is closed and conducting. At this time, C1 discharges through R2, the base and emitter of Q1, diode Dn, and SQn ground; then, the collector and emitter of Q1 are connected; at this time, the trigger current of the solid-state relay SSR can pass through manual switch 1, R3, the input circuit of the solid-state relay SSR, the collector and emitter of Q1, diode Dn, and SQn ground; then, the output circuit of the solid-state relay SSR is triggered to be in a conducting state. At this time, the operating current is output through the output circuit of the solid-state relay SSR and supplies power to the air solenoid valve 13 and the electric heater 2 respectively. Then, fresh air 11 pumped from air pump 16 enters the front exhaust pipe 18 through the second air pipe 15, air electric contact valve 13, and first air pipe 21. After mixing with the engine exhaust, the mixture is heated by electric heater to a temperature exceeding that required for the regeneration of the particulate filter (DPF), so that the particles accumulated in the particulate filter (DPF) are fully burned off, and then discharged from the rear exhaust pipe 14.
[0016] In condition 2.3, when C1 approaches the state of complete discharge and the discharge current of C1 approaches zero, the collector and emitter of Q1 are immediately triggered to be in a cut-off and non-conducting state; then the trigger current of the solid-state relay SSR flowing through the input circuit of the solid-state relay SSR disappears, and the output circuit of the solid-state relay SSR is also triggered to be in a cut-off and non-conducting state, and the power supply to the air solenoid valve 13 and the electric heater 2 is stopped; thus, the air solenoid valve 13 is in a cut-off and non-air-flow state, and the electric heater 2 is in a non-heating state.
[0017] Condition 3: When the engine stops running, without the action of oil pressure, the switch contacts of the oil pressure alarm 17 close, allowing C2 to discharge through R6 and the oil pressure alarm 17 to ground.
Claims
1. An engine exhaust gas reheating system, comprising: one end of a first air pipe connected to a front exhaust pipe; the other end of the first air pipe connected to the outlet of an air solenoid valve; the inlet of the air solenoid valve connected to one end of a second air pipe; and the other end of the second air pipe connected to the outlet of an air pump. An electric heater is installed inside the front exhaust pipe. The current input terminal of the output circuit of a solid-state relay (SSR) is connected to the positive terminal of a power supply, and the current output terminal of the output circuit is connected to the positive terminals of the electric heater and the air solenoid valve. The negative terminal of the electric heater is grounded, and the negative terminal of the air solenoid valve is also grounded. The "on" terminal of the ignition switch is connected to one end of a manual switch 1, and the other end of the manual switch 1 is connected to one end of resistors R3 and R5. The other end of R3 is connected to the current input terminal of the input circuit of the solid-state relay (SSR). The current output terminal of the input circuit of the solid-state relay (SSR) is connected to the collector of Q1. The base of Q1 is connected to one end of resistor R2, and the other end of R2 is connected to C1. The positive terminal of Q3 is connected to the emitter of Q3, and the negative terminal of C1 is grounded. The emitter of Q1 is connected to the positive terminals of diodes D1 and Dn in the parallel diode group (the number of diodes is the same as the number of forward gears). The SQ (gear position indicator switch) 1 in the parallel gear position indicator switch group (the number of SQ is the same as the number of forward gears) is connected to the negative terminal of diode D1, one end of SQn is connected to the negative terminal of diode Dn, and the other end of SQ1 is grounded to the other end of SQn. The negative terminal of Zener diode DW is connected to the excitation circuit terminal of the generator, and the positive terminal of Zener diode DW is connected to one end of R1. The emitter of Q2 is connected to the other end of R1. The base of Q2 is connected to one end of R4, and the other end of R4 is connected to one end of R6 and the positive terminal of C1. The negative terminal of C2 is grounded, and the other end of R6 is connected to the terminal of the engine oil pressure alarm. The collector of Q2 is connected to the base of Q3. The collector of Q3 is connected to the other end of R5.
2. The engine exhaust gas reheating system according to claim 1, characterized in that: One end of the first air pipe is connected to the front exhaust pipe, and the other end of the first air pipe is connected to the air outlet of the air solenoid valve. The air inlet of the air solenoid valve is connected to one end of the second air pipe, and the other end of the second air pipe is connected to the air outlet of the air pump. An electric heater is installed inside the front exhaust pipe.