Engine cold start air intake preheating system

Abstract

The utility model relates to an engine cold start intake preheating system, including intake manifold, bypass pipeline and electronic control unit, the intake manifold is the U type pipeline of one end open, one end closed, and the open end is equipped with the throttle, and the open end and the closed end are equipped with bypass pipeline, the bypass pipeline is equipped with bypass control valve and axial flow fan in, the straight pipe of intake manifold closed end is equipped with a plurality of nozzles, and the elbow pipe before intake manifold inserts intake heater, the closed end of intake manifold and the rear of intake heater all are equipped with temperature sensor, temperature sensor, bypass control valve, axial flow fan, throttle, intake heater, nozzle all connect electronic control unit and be controlled by it, the utility model discloses through the preheating of intake, makes fuel to evaporate atomization in the intake passage, forms the combustible mixture, drives the airflow in the intake system with constant rate circulation through axial flow fan, makes the gas flow in the intake passage provide good heat dissipation for heater.

Description

Technical Field

[0001] This utility model belongs to the field of engine cold start technology, and specifically relates to an engine cold start intake air preheating system. Background Technology

[0002] With the increasing urgency of global energy structure transformation and carbon emission reduction, low-carbon alternative fuels such as methanol, ethanol, and ammonia have received widespread attention in engine applications due to their clean combustion characteristics and sustainable production potential. However, the physicochemical properties of these fuels, such as the high latent heat of vaporization of methanol and ethanol, and the high ignition energy and slow flame propagation speed of ammonia, result in problems such as slow evaporation, difficulty in mixture formation, insufficient ignition energy, and poor combustion stability in low-temperature environments, which seriously restrict the reliable starting of engines under low-temperature conditions.

[0003] Even for traditional gasoline and diesel engines, cold starts present a severe challenge in extreme environments such as high altitudes and frigid zones. Low temperatures increase engine oil viscosity, reduce battery performance, and enhance combustion chamber heat dissipation, further exacerbating starting difficulties. This often manifests as prolonged starting time, multiple ignition failures, and worsened emissions during the cold start phase.

[0004] To improve cold start performance, existing technologies often employ auxiliary measures such as intake air preheating, coolant heating, and the addition of fuel heaters or fuel tank systems (e.g., methanol-gasoline dual-fuel switching). While these methods can improve performance under certain conditions, they still have significant limitations: First, the system structure is complex and costly, and their adaptability to specific fuel types is generally limited; second, during the preheating stage, since the engine has not yet started, there is a lack of airflow in the intake manifold, and the heat generated by the heating device (such as the PTC heating grille) cannot be dissipated in time, easily causing its surface temperature to exceed the safety threshold, triggering overheat protection or even burning out, affecting starting reliability; in addition, traditional intake air preheating schemes usually rely on the natural intake process after the engine starts to deliver heated air to the cylinders, but in the initial few working cycles of starting, the air temperature in the area near the intake valve is still low, and the fuel cannot fully evaporate and form an ideal combustible mixture, resulting in incomplete initial combustion, affecting the smoothness and success rate of starting.

[0005] Therefore, there is an urgent need in the existing technology for an engine cold start technology that can adapt to multiple fuel types, achieve rapid and reliable cold start under different environmental conditions, and effectively overcome problems such as overheating of the heating device and uneven intake air temperature distribution. Utility Model Content

[0006] This utility model provides an engine cold start intake air preheating system to solve the technical problems existing in the prior art. By preheating the intake air, the fuel can be evaporated and atomized in the intake manifold to form a combustible mixture, thus realizing reliable cold start of the engine at low temperatures and solving the problem of difficult cold start of the engine.

[0007] This utility model includes the following technical solution: an engine cold start intake air preheating system, including an intake manifold, a bypass pipe, and an electronic control unit; the intake manifold is a U-shaped pipe with one end open and the other end closed, with a throttle valve at the open end and a bypass pipe between the open and closed ends; a bypass control valve and an axial fan are provided in the bypass pipe; several nozzles are provided on the straight pipe at the closed end of the intake manifold, and an intake heater is embedded in front of the bend of the intake manifold; temperature sensors are provided at the closed end of the intake manifold and after the intake heater; the temperature sensors, bypass control valve, axial fan, throttle valve, intake heater, and nozzles are all connected to and controlled by the electronic control unit.

[0008] Furthermore, the intake manifold forms a parallel circuit with the bypass pipeline through the throttle valve and bypass control valve.

[0009] Furthermore, the bypass control valve is located on the side near the closed end of the intake manifold, and the axial fan is located on the side near the open end of the intake manifold.

[0010] Furthermore, the spacing between the nozzles is equal.

[0011] Furthermore, when the ambient temperature, engine coolant temperature, and intake air temperature are all lower than preset values, the engine is determined to be in a cold start state, and the intake air heater starts to work.

[0012] Furthermore, a first temperature sensor is provided on the inner wall of the closed end of the intake manifold, and a second temperature sensor is provided on the inner wall behind the intake heater.

[0013] Furthermore, the temperature difference between the first temperature sensor and the second temperature sensor is ≤20℃.

[0014] Furthermore, when the temperature detected by the second sensor exceeds the preset upper limit, the throttle valve closes, the bypass control valve opens, and the axial fan starts and begins circulating heating.

[0015] Furthermore, when the temperature detected by the first temperature sensor exceeds a preset upper limit, the cyclic heating stops, the axial fan is turned off, the bypass control valve is closed, and the throttle valve is opened.

[0016] Furthermore, the electronic control unit is equipped with a PID algorithm module to dynamically adjust the speed of the axial fan and the power of the electric heater.

[0017] The advantages and positive effects of this utility model are as follows: This invention solves the problem of low air temperature near the intake valve during the initial stage of cold start with intake heating. Unlike traditional solutions that rely on the engine's own intake to deliver hot air from the heating area to the cylinder after startup, this system uses a bypass circuit for forced circulation and a closed-loop heater to ensure uniform heating and circulation of air within the intake system. This achieves full preheating of the intake pipe before cold start, ensuring that the intake temperature reaches the fuel evaporation and atomization requirements during the first cycle of engine cold start. This avoids the problem of insufficient air temperature and inability to form a combustible mixture during the first 3-5 cycles, which is common in traditional solutions.

[0018] This invention utilizes an axial fan to drive airflow within the intake system at a constant rate, ensuring effective heat dissipation for the heater. Simultaneously, real-time feedback from first and second temperature sensors dynamically adjusts the heating power and fan speed, avoiding the risk of localized overheating associated with traditional heating methods. It also solves the problem of heater overheating and burnout during cold start preheating, preventing localized overheating and thermal damage, and extending the lifespan of core components. Existing heating devices (such as heating grilles) experience heater surface temperatures exceeding a set threshold during the preheating phase (3-5 minutes) when the engine is stationary and there is no air flow in the intake, leading to heating interruption or burnout.

[0019] This invention uses intake air heating to ensure complete fuel evaporation and atomization, reducing unburned fuel and harmful gas emissions during cold starts and improving combustion efficiency. At the same time, it ensures uniform distribution of hot air, reduces unevenness between cylinders, optimizes combustion efficiency during engine cold starts, and reduces emissions.

[0020] This utility model adopts a parallel design of bypass pipeline and intake manifold, which does not require major changes to the original engine structure, can be adapted to most spark-ignition engines, and reduces the modification cost; it has a compact structure and strong compatibility. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model; In the diagram, 1-first temperature sensor; 2-bypass control valve; 3-axial fan; 4-bypass line; 5-nozzle; 6-intake manifold; 7-second temperature sensor; 8-intake heater; 9-throttle valve; 10-electronic control unit. Detailed Implementation

[0022] To further disclose the invention content, features, and effects of this utility model, the following examples are provided in conjunction with the accompanying drawings for detailed description. In the following description of the embodiments, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this patent and simplifying the description. They do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this patent.

[0023] In the following description of the embodiments, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0024] Example: See Appendix Figure 1 An engine cold start intake air preheating system includes an intake manifold 6, a bypass pipe 4, and an electronic control unit 10. The intake manifold 6 is a U-shaped pipe with one open end and one closed end. A throttle valve 9 is provided at the open end, and a bypass pipe 4 is provided between the open end and the closed end. A bypass control valve 2 and an axial flow fan 3 are provided in the bypass pipe 4. The intake manifold 6 forms a parallel circuit with the bypass pipe 4 through the throttle valve 9 and the bypass control valve 2. The bypass control valve 2 is located near the closed end of the intake manifold 6, and the axial flow fan 3 is located near the open end of the intake manifold 6.

[0025] The intake manifold 6 has several nozzles 5 on its straight end, and an intake heater 8 is embedded in front of the bend of the intake manifold 6; the nozzles 5 are spaced equally. Temperature sensors are located at the closed end of the intake manifold 6 and behind the intake heater 8. The temperature sensors, bypass control valve 2, axial fan 3, throttle valve 9, intake heater 8, and nozzles 5 are all connected to and controlled by an electronic control unit 10. The electronic control unit 10 is equipped with a PID algorithm module to dynamically adjust the speed of the axial fan 3 and the power of the electric heater 8. When the ambient temperature, engine coolant temperature, and intake air temperature are all below preset values, the engine is determined to be in a cold start state, and the intake heater 8 begins to operate.

[0026] A first temperature sensor 1 is installed on the inner wall of the closed end of the intake manifold 6, and a second temperature sensor 7 is installed on the inner wall behind the intake heater 8. The temperature difference between the first temperature sensor 1 and the second temperature sensor 7 is ≤20℃. When the temperature detected by the second temperature sensor 7 is greater than a preset upper limit value, the throttle valve 9 closes, the bypass control valve 2 opens, and the axial fan 3 starts and begins circulating heating. When the temperature detected by the first temperature sensor 1 is greater than the preset upper limit value, circulating heating stops, the axial fan 3 closes, the bypass control valve 2 closes, and the throttle valve 9 opens.

[0027] Working process: Air enters the system through the intake manifold 6. The electronic control unit 10 acquires the ambient temperature, the temperature collected by the first temperature sensor 1, and the engine coolant temperature. When the ambient temperature is simultaneously lower than the preset value T, the system will automatically adjust the temperature accordingly. 环境 (25℃) The engine coolant temperature is lower than the preset value T. 环境 (20℃) and intake air temperature below T 进气1 At 25℃, the engine is determined to be in a cold start state.

[0028] During the cold start preheating phase, the intake air heater 8 is first turned on via the electronic control unit 10, with the initial power set to full power mode (e.g., 2kW); the temperature T is monitored in real time via the second temperature sensor 7. 加热器 If T 加热器 If the temperature exceeds the preset upper limit T1 (e.g., 150℃), in order to prevent the intake heater 8 from overheating, the throttle valve 9 is closed and the bypass control valve 2 is opened to connect the bypass circuit 4, forming a closed-loop airflow channel in the intake system.

[0029] After the axial fan 3 starts, it drives air to circulate along the bypass circuit 4, dissipating heat from the intake heater 8 while simultaneously heating the air within the system. The air is uniformly heated to a preset temperature as it passes through the intake heater 8. During heating, the electronic control unit 10 receives real-time feedback data from the second temperature sensor 7 and the first temperature sensor 1 near the intake heater 8, and dynamically adjusts the speed of the axial fan 4 and the power of the intake heater 8 using a PID algorithm. When the temperature collected by the first temperature sensor 1 reaches the set fuel atomization threshold, the electronic control unit 10 stops the axial fan 3, reduces the power of the intake heater 8, closes the bypass control valve 2, switches to intake manifold 6, and simultaneously opens the throttle valve 9 to the starting position. The engine is then started, and the preheated high-temperature air in the intake system directly vaporizes and atomizes the injected fuel, which then enters the engine cylinder. The electronic control unit 10 continues to control the intake heater 8 to heat the cold air drawn into the intake manifold 6, achieving efficient cold start and warm-up of the engine.

[0030] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the claims. These modifications all fall within the protection scope of the present invention.

Claims

1. An engine cold start intake air preheating system, characterized in that: It includes an intake manifold, a bypass pipe, and an electronic control unit; the intake manifold is a U-shaped pipe with one end open and the other end closed, with a throttle valve at the open end and a bypass pipe between the open and closed ends; the bypass pipe contains a bypass control valve and an axial fan; several nozzles are provided on the straight pipe at the closed end of the intake manifold, and an intake heater is embedded in front of the bend of the intake manifold; temperature sensors are provided at the closed end of the intake manifold and after the intake heater, and the temperature sensors, bypass control valve, axial fan, throttle valve, intake heater, and nozzles are all connected to and controlled by the electronic control unit.

2. The engine cold start intake air preheating system according to claim 1, characterized in that: The intake manifold forms a parallel circuit with the bypass pipeline through the throttle valve, bypass control valve, and bypass pipeline.

3. The engine cold start intake air preheating system according to claim 1, characterized in that: The bypass control valve is located on the side near the closed end of the intake manifold, and the axial fan is located on the side near the open end of the intake manifold.

4. The engine cold start intake air preheating system according to claim 1, characterized in that: The distance between the nozzles is equal.

5. The engine cold start intake air preheating system according to claim 1, characterized in that: When the ambient temperature, engine coolant temperature, and intake air temperature are all lower than preset values, the engine is determined to be in a cold start state, and the intake air heater starts to work.

6. The engine cold start intake air preheating system according to claim 1, characterized in that: A first temperature sensor is provided on the inner wall of the closed end of the intake manifold, and a second temperature sensor is provided on the inner wall behind the intake heater.

7. The engine cold start intake air preheating system according to claim 6, characterized in that: The temperature difference between the first temperature sensor and the second temperature sensor is ≤20℃.

8. The engine cold start intake air preheating system according to claim 6, characterized in that: When the temperature detected by the second sensor exceeds the preset upper limit, the throttle valve closes, the bypass control valve opens, and the axial fan starts and begins circulating heating.

9. An engine cold start intake air preheating system according to claim 6, characterized in that: When the temperature detected by the first temperature sensor exceeds the preset upper limit, the circulating heating stops, the axial fan is turned off, the bypass control valve is closed, and the throttle valve is opened.

10. An engine cold start intake air preheating system according to any one of claims 1-9, characterized in that: The electronic control unit is equipped with a PID algorithm module to dynamically adjust the speed of the axial fan and the power of the electric heater.

Images