Cold start system and control method for a pure methanol engine

Abstract

This application discloses a cold start system and control method for a pure methanol engine, relating to the field of methanol engine cold start. The system includes: an auxiliary power supply unit, a one-way isolation module, an intake air heating device, a secondary fuel tank, an independent secondary fuel circuit, a pressure relief valve, a secondary fuel tank heating module, and a controller. The auxiliary power supply unit is electrically connected to the main power supply unit via the one-way isolation module and supplies power to both the intake air heating device and the secondary fuel tank heating module. The controller controls the switching between the independent secondary fuel circuit and the main fuel circuit based on fault conditions. This application achieves intake air heating and fuel heating during cold start based on the intake air heating device and the secondary fuel tank heating module. The auxiliary power supply unit is electrically connected to the main power supply unit via the one-way isolation module, isolating the heating power reduction caused by voltage drop in the main power supply unit during cold start. Finally, by setting up the secondary fuel tank, the independent secondary fuel circuit, and the pressure relief valve, the system serves as a backup for the main fuel circuit, improving the reliability and safety of cold start.

Description

Technical Field

[0001] This application relates to the field of methanol engine cold start technology, and in particular to a cold start system and control method for a pure methanol engine. Background Technology

[0002] Currently, the cold start of pure methanol engines in low-temperature environments (-40℃~10℃) usually adopts a starting method that combines intake air heating and fuel enrichment injection. That is, by setting up intake air heating devices and fuel tank heating devices, the engine intake air and fuel are heated during cold starts, thereby shortening the start-up time of pure methanol engines in low-temperature environments by increasing the intake air temperature and increasing the methanol vaporization concentration.

[0003] However, existing starting methods have the following problems: First, the power supply stability of existing heating devices is difficult to guarantee, resulting in poor preheating effects and a low cold start success rate. Second, the fuel tank and pipelines used for storing and transporting methanol fuel are prone to temperature and pressure runaway during the preheating process, posing safety hazards. Once a malfunction occurs, it will affect the normal operation of the entire fuel supply system. Therefore, existing cold start methods for pure methanol engines suffer from poor starting reliability and low safety. Summary of the Invention

[0004] In view of the above problems, this application provides a cold start system and control method for a pure methanol engine to improve the reliability and safety of cold start. The specific solution is as follows:

[0005] The first aspect of this application provides a cold start system for a pure methanol engine, the pure methanol engine including an engine body, an intake manifold, a main fuel line, a main fuel tank, and a main power supply unit, the cold start system for the pure methanol engine including:

[0006] Auxiliary power supply unit, one-way isolation module, intake air heating device, auxiliary fuel tank, independent auxiliary oil circuit, pressure relief valve, auxiliary fuel tank heating module and controller;

[0007] The auxiliary power supply unit is electrically connected to the main power supply unit through the unidirectional isolation module. The unidirectional isolation module allows the main power supply unit to charge the auxiliary power supply unit and prevents the auxiliary power supply unit from discharging in reverse to the main power supply unit.

[0008] The auxiliary power supply unit is electrically connected to the intake heating device and the auxiliary fuel tank heating module, respectively;

[0009] The auxiliary fuel tank heating module is disposed inside and / or outside the auxiliary fuel tank, and the intake heating device is disposed inside and / or outside the intake pipe;

[0010] The fuel outlet of the auxiliary fuel tank is connected to the first end of the independent auxiliary oil circuit, and the second end of the independent auxiliary oil circuit is connected to the fuel inlet of the engine body. The independent auxiliary oil circuit is equipped with an electromagnetic on / off valve. Under cold start conditions, the electromagnetic on / off valve is open, and if the auxiliary fuel tank and the independent auxiliary oil circuit are fault-free, the main oil circuit is closed. Under cold start conditions, if the auxiliary fuel tank and / or the independent auxiliary oil circuit are faulty, the electromagnetic on / off valve is closed, and the main oil circuit is open.

[0011] The pressure relief valve is located in the auxiliary fuel tank;

[0012] The controller is communicatively connected to the intake heating device, the auxiliary fuel tank heating module, and the electromagnetic on / off valve, respectively.

[0013] In one possible implementation, the auxiliary power supply unit includes:

[0014] An energy storage device, wherein the unidirectional isolation module is connected in series between the positive terminal of the energy storage device and the positive terminal of the main power supply unit.

[0015] In one possible implementation, the unidirectional isolation module is a diode or a unidirectional relay.

[0016] In one possible implementation, the pressure relief valve is a mechanical pressure relief valve or an electrically controlled pressure relief valve.

[0017] In one possible implementation, when the pressure relief valve is the electrically controlled pressure relief valve, the pressure relief valve further includes:

[0018] A temperature sensor and a pressure sensor are disposed inside the auxiliary fuel tank;

[0019] The temperature sensor, the pressure sensor, and the pressure relief valve are all communicatively connected to the controller.

[0020] In one possible implementation, the auxiliary fuel tank employs an insulation structure, the insulation structure comprising:

[0021] From the outside in, it consists of an outer layer of galvanized steel sheet, a rock wool insulation layer, and an inner layer of fluororubber.

[0022] In one possible implementation, the cold start system of the pure methanol engine further includes:

[0023] Waste heat recovery pipeline, which includes an exhaust heat exchange section, a preheating heat exchange section and a circulating pump;

[0024] The exhaust heat exchange section is located in the exhaust heat pipe of the engine body, the preheating heat exchange section is located in the intake pipe and the auxiliary fuel tank, and the circulating pump drives the heat exchange medium in the waste heat recovery pipe to circulate in the exhaust heat exchange section and the preheating heat exchange section.

[0025] The circulating pump is communicatively connected to the controller.

[0026] In one possible implementation, the cold start system of the pure methanol engine further includes:

[0027] A fuel recovery pipeline, wherein an on / off valve is installed in the fuel recovery pipeline;

[0028] The first end of the fuel recovery pipeline is connected to the exhaust port of the pressure relief valve, and the second end of the fuel recovery pipeline is connected to the fuel recovery inlet at the top of the main fuel tank.

[0029] A second aspect of this application provides a control method for a cold start system of a pure methanol engine, applied to a controller in a cold start system as described in the first aspect and any implementation thereof, comprising:

[0030] Under cold start conditions, and with no faults in the auxiliary fuel tank and independent auxiliary oil circuit, control the operation of the auxiliary fuel tank heating module and the intake air heating device, control the opening of the independent auxiliary oil circuit, control the shut-off of the main oil circuit, and control the cold start of the engine body.

[0031] In the cold start condition, and in the event of a failure of the auxiliary fuel tank and / or the independent auxiliary oil circuit, the auxiliary fuel tank heating module is shut down, the intake air heating device is operated, the independent auxiliary oil circuit is shut down, the main oil circuit is opened, and the engine body is cold started.

[0032] In one possible implementation, controlling the operation of the auxiliary fuel tank heating module and the intake air heating device under cold start conditions, provided that the auxiliary fuel tank and the independent auxiliary fuel line are fault-free, includes:

[0033] Obtain ambient temperature and engine coolant temperature signals;

[0034] Based on the ambient temperature signal and the engine coolant temperature signal, the target heating power level of the auxiliary fuel tank heating module and the intake air heating device is determined, and the auxiliary fuel tank heating module and the intake air heating device are controlled to operate with the operating parameters corresponding to the target heating power level.

[0035] In one possible implementation, the control method for the cold start system further includes:

[0036] Monitor engine speed and engine coolant temperature;

[0037] When the engine speed is within the preset idle speed range and the engine coolant temperature is not lower than the stable operating coolant temperature threshold, the independent auxiliary oil circuit and the main oil circuit are controlled to alternately open and close.

[0038] In one possible implementation, the cold start system of the pure methanol engine further includes:

[0039] Waste heat recovery pipeline, which includes an exhaust heat exchange section, a preheating heat exchange section and a circulating pump;

[0040] The exhaust heat exchange section is located in the exhaust heat pipe of the engine body, the preheating heat exchange section is located in the intake pipe and the auxiliary fuel tank, and the circulating pump drives the heat exchange medium in the waste heat recovery pipe to circulate in the exhaust heat exchange section and the preheating heat exchange section.

[0041] The circulating pump is communicatively connected to the controller;

[0042] The control method for the cold start system further includes:

[0043] Upon detecting an engine shutdown command, the circulating pump is controlled to run at a preset speed for a preset duration.

[0044] In one possible implementation, after controlling the auxiliary fuel tank heating module and the intake air heating device to operate with operating parameters corresponding to the target heating power level, the method further includes:

[0045] Monitor the operating status parameters of the engine body during a preset cold start period;

[0046] If the operating status parameters do not meet the preset successful start conditions, control the engine body to pause the start and increment the start failure count by 1;

[0047] If the number of failed starts does not exceed a preset start count threshold, the engine body is controlled to cold start again.

[0048] If the number of failed starts exceeds the preset start count threshold, the preset operating parameter adjustment amount is added to the operating parameters corresponding to the target heating power level, and the auxiliary fuel tank heating module and the intake air heating device are controlled to operate with the added operating parameters, and the engine body is controlled to start cold again.

[0049] By employing the above technical solution, this application provides a cold start system and control method for a pure methanol engine. By configuring an auxiliary power supply unit electrically connected to both the intake air heating device and the auxiliary fuel tank heating module, the intake air heating device and the auxiliary fuel tank heating module do not rely on the main power supply unit for power during cold starts. Furthermore, by configuring the auxiliary power supply unit electrically connected to the main power supply unit through a one-way isolation module, the one-way isolation module allows the main power supply unit to charge the auxiliary power supply unit while preventing the auxiliary power supply unit from discharging back to the main power supply unit. This avoids the risk of a voltage drop in the auxiliary power supply unit's bus due to a voltage drop in the main power supply unit caused by the starter motor running during cold starts, ensuring the stable operation of the intake air heating device and the auxiliary fuel tank heating module. This solves the problem of unreliable power supply stability for heating devices in existing technologies and improves the success rate of cold starts. Moreover, by configuring the auxiliary fuel tank heating module inside and / or outside the auxiliary fuel tank, and the intake air heating device inside and / or outside the intake pipe, heating of the intake air and methanol fuel is achieved, further enhancing the success rate of cold starts. Subsequently, by configuring the fuel outlet of the auxiliary fuel tank to connect to the first end of the independent auxiliary oil circuit, and the second end of the independent auxiliary oil circuit to connect to the fuel inlet of the engine body, and configuring it solenoid on / off valve in the independent auxiliary oil circuit to conduct and the main oil circuit to close during cold start conditions, and in the event of a failure in the auxiliary fuel tank and / or the independent auxiliary oil circuit during cold start conditions, the solenoid on / off valve to close and the main oil circuit to conduct, a backup redundancy design is achieved, improving the reliability of cold start. Finally, by configuring a pressure relief valve to be located in the auxiliary fuel tank, in the event of a failure in the auxiliary fuel tank and / or the independent auxiliary oil circuit, the pressure relief valve is used to create a pressure release channel, disrupting the internal overpressure environment of the auxiliary fuel tank and / or the independent auxiliary oil circuit under fault conditions, reducing the risk of component damage, and improving the safety of cold start. It is evident that the cold start system for a pure methanol engine provided in this application improves the reliability and safety of cold start for pure methanol engines. Attached Figure Description

[0050] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0051] Figure 1 A schematic diagram of the structure of a cold start system for a pure methanol engine provided in this application;

[0052] Figure 2 This application provides a schematic diagram of the structure of an existing fuel heating system;

[0053] Figure 3 A schematic diagram of the connection circuit between an auxiliary power supply unit and a main power supply unit provided in this application;

[0054] Figure 4 A schematic diagram of the overall structure of a cold start system for a pure methanol engine provided in this application;

[0055] Figure 5 A flowchart of a control method for a cold start system of a pure methanol engine provided in this application;

[0056] Figure 6 This is a schematic diagram of the structure of an electronic device provided in this application. Detailed Implementation

[0057] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the scope of this application.

[0058] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0059] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0060] The first aspect of this application provides a cold start system for a pure methanol engine. The pure methanol engine includes an engine body 1, an intake manifold 2, a main fuel line 3, a main fuel tank 4, and a main power supply unit 5. A schematic diagram of the cold start system for the pure methanol engine is shown below. Figure 1 As shown, the cold start system of this pure methanol engine includes:

[0061] Auxiliary power supply unit 6, unidirectional isolation module 7, intake air heating device 8, auxiliary fuel tank 9, independent auxiliary oil circuit 10, pressure relief valve 11, auxiliary fuel tank heating module 12, and controller 13;

[0062] The auxiliary power supply unit 6 is electrically connected to the main power supply unit 5 through a one-way isolation module 7. The one-way isolation module 7 allows the main power supply unit 5 to charge the auxiliary power supply unit 6 and prevents the auxiliary power supply unit 6 from discharging in reverse to the main power supply unit 5.

[0063] The auxiliary power supply unit 6 is electrically connected to the intake air heating device 8 and the auxiliary fuel tank heating module 12, respectively.

[0064] The auxiliary fuel tank heating module 12 is located inside and / or outside the auxiliary fuel tank 9, and the intake air heating device 8 is located inside and / or outside the intake pipe 2;

[0065] The fuel outlet of the auxiliary fuel tank 9 is connected to the first end of the independent auxiliary oil circuit 10, and the second end of the independent auxiliary oil circuit 10 is connected to the fuel inlet of the engine body 1. An electromagnetic on / off valve 14 is provided in the independent auxiliary oil circuit 10. Under cold start conditions, the electromagnetic on / off valve 14 is open, and if the auxiliary fuel tank 9 and the independent auxiliary oil circuit 10 are fault-free, the main oil circuit 3 is closed. Under cold start conditions, if the auxiliary fuel tank 9 and / or the independent auxiliary oil circuit 10 are faulty, the electromagnetic on / off valve 14 is closed, and the main oil circuit 3 is open.

[0066] Pressure relief valve 11 is located in auxiliary fuel tank 9;

[0067] The controller 13 is communicatively connected to the intake air heating device 8, the auxiliary fuel tank heating module 12, and the electromagnetic on / off valve 14.

[0068] It should be noted that, in practical applications, the aforementioned pure methanol engine can be an existing pure methanol engine, and the connection relationships of the engine body 1, intake pipe 2, main fuel line 3, main fuel tank 4, and main power supply unit 5 can be as follows: Figure 1 As shown, the configuration can also be determined based on the actual scenario, and only the engine body 1, intake pipe 2, main oil line 3, main fuel tank 4 and main power supply unit 5 mentioned above are required.

[0069] In one possible implementation, the main power supply unit 5 mentioned above can be a battery or capacitor that supplies power to the vehicle.

[0070] It should be noted that, in practical application scenarios, in addition to the devices and components included in the cold start system of the pure methanol engine provided in the first aspect of this application, the controller 13 can also communicate with the vehicle's own sensors to obtain the basic parameters required for control, such as ambient temperature sensor, engine controller, fuel temperature sensor, etc.

[0071] It should be noted that, in practical applications, the auxiliary power supply unit 6 is used to supply power to the intake air heating device 8 and the auxiliary fuel tank heating module 12. This application configures the auxiliary power supply unit 6 to be electrically connected to both the intake air heating device 8 and the auxiliary fuel tank heating module 12, thereby enabling the intake air heating device 8 and the auxiliary fuel tank heating module 12 to heat the engine intake air and methanol fuel without relying on the main power supply unit during cold starts, thus improving the success rate of cold starts.

[0072] It should be noted that, in practical applications, the aforementioned one-way isolation module 7 is a device used to restrict the direction of current flow between the auxiliary power supply unit 6 and the main power supply unit 5. After the pure methanol engine starts successfully, the current generated by the main power supply unit 5 can flow to the auxiliary power supply unit 6, thereby using the main power supply unit 5 to charge the auxiliary power supply unit 6. However, during the start-up process of the pure methanol engine, if the main power supply unit 5 experiences a significant voltage drop, the one-way isolation module 7 prohibits the auxiliary power supply unit 6 from charging the main power supply unit 5 in reverse, thereby ensuring that the auxiliary power supply unit 6 retains the power required for the operation of the heating device. This application configures the auxiliary power supply unit 6 to be electrically connected to the main power supply unit 5 via a unidirectional isolation module 7. The unidirectional isolation module 7 allows the main power supply unit 5 to charge the auxiliary power supply unit 6 and prevents the auxiliary power supply unit 6 from discharging back to the main power supply unit 5. This avoids the risk of the auxiliary power supply unit 6 generating electricity in reverse due to the voltage drop of the main power supply unit 5 caused by the start-up motor during cold start, which would lead to a drop in the bus voltage of the auxiliary power supply unit 6. This ensures the stable operation of the intake heating device 8 and the auxiliary fuel tank heating module 12, thereby solving the problem of the difficulty in ensuring the power supply stability of the heating device in the prior art and improving the success rate of cold start.

[0073] It should be noted that, in practical applications, the aforementioned intake heating device 8 is used to heat the gas within the intake manifold 2. The location of the intake heating device 8 can be selected based on the fuel injection position of the pure methanol engine. For example, when the fuel injection position is inside the intake manifold, the gas flowing in the intake manifold 2 is a mixture of air and methanol fuel. To prevent potential localized hot spots generated by the intake heating device 8 from igniting the mixture within the intake manifold 2, the intake heating device 8 can be located outside the intake manifold 2. Conversely, when the fuel injection position is inside the cylinder, the gas flowing in the intake manifold 2 is air. In this case, to improve heating efficiency, the intake heating device 8 can be located inside the intake manifold 2. It is understood that the above description only illustrates possible locations for the intake heating device 8 and does not impose excessive limitations or elaborate on specific locations or suitable pure methanol engine types.

[0074] In one possible implementation, the aforementioned intake heating device 8 can be a PTC positive temperature coefficient heater (model: PTC-200, power 200-500W, supports graded adjustment), which has self-limiting temperature characteristics (maximum operating temperature 150℃), effectively preventing local overheating damage to the intake pipe 2. This heater can be installed at the intake manifold inlet of the intake pipe 2 (close to the engine intake valve, shortening the preheating path and improving preheating efficiency), fixed with high-temperature resistant bolts, and electrically connected to the auxiliary power supply unit 6. A 10A fuse is connected in series in the circuit to prevent circuit overload damage. Its heating power can be controlled in real-time by the controller 13 according to the ambient temperature and engine coolant temperature, ensuring a balance between preheating effect and energy consumption.

[0075] It should be noted that, in practical applications, the aforementioned auxiliary fuel tank heating module 12 is used to heat the methanol fuel in the auxiliary fuel tank 9, making the methanol easier to atomize and burn, thereby helping to improve the start-up success rate. The auxiliary fuel tank heating module 12 is located inside and / or outside the auxiliary fuel tank 9; however, considering the flammable and explosive characteristics of methanol fuel, it is preferable that the auxiliary fuel tank heating module 12 is located outside the auxiliary fuel tank 9.

[0076] It should be noted that in practical applications, the aforementioned auxiliary fuel tank 9 and independent auxiliary fuel line 10 constitute an independent fuel supply circuit. Due to the flammable and explosive nature of methanol fuel, to avoid the risk of backfire caused by a heating device located in a single fuel line igniting the methanol, existing pure methanol engines typically place the heating device in the fuel line, or install an on / off valve or additional heating container in a single fuel line. This ensures effective fuel heating while preventing backfire from spreading to the fuel tank and causing an explosion. For example, as... Figure 2 The diagram shows a structural schematic of an existing fuel heating system adapted to a current pure methanol engine. It includes a fuel tank 211, an oil line 212, a shut-off valve 213, a heating container 214, and an engine 215, arranged sequentially along the fuel flow direction. The heating container 214 collects and heats the methanol fuel flowing from the fuel tank 211, thus avoiding the problem of reduced heating efficiency due to excessively high fuel flow rates in the pipeline heating system. When backfire occurs in the heating container 214, the shut-off valve 213 is controlled to close to prevent the backfire from spreading to the fuel tank 211. However, since the heating container 214 is located in the only oil line, and backfire could damage the heating container and pipeline, there is also a risk of the heating container 214 reigniting. In this case, to avoid further damage to the engine system, the only option is to shut down the engine for maintenance, severely impacting starting reliability and safety. This application configures the fuel outlet of the auxiliary fuel tank 9 to be connected to the first end of the independent auxiliary oil circuit 10, and the second end of the independent auxiliary oil circuit 10 to be connected to the fuel inlet of the engine body 1. Under cold start conditions, the solenoid on / off valve 14 in the independent auxiliary oil circuit 10 is turned on and the main oil circuit 3 is turned off. Under cold start conditions, and in the event of a failure of the auxiliary fuel tank and / or the independent auxiliary oil circuit, the solenoid on / off valve 14 is turned off and the main oil circuit 3 is turned on, thus realizing a backup redundancy design of dual independent oil circuits and improving the reliability of cold start.

[0077] In one possible implementation, the aforementioned independent auxiliary oil circuit 10 can be made of methanol-resistant rubber tubing to avoid continuous corrosion of the pipeline by methanol.

[0078] In one possible implementation, the auxiliary fuel tank 9 is also made of a methanol-resistant material. Its top features a filler neck with a sealing cap and an interface to the pressure relief valve 11, while its bottom has a fuel release port for easy maintenance. It also includes built-in temperature and pressure sensors. When installing the auxiliary fuel tank 9, it must be kept away from other heat-generating components such as the exhaust manifold to avoid residual heat interference that could cause internal pressure increases. The volume of the auxiliary fuel tank 9 is smaller than that of the main fuel tank 4 to reduce the risk of detonation in special circumstances by decreasing fuel storage.

[0079] It should be noted that, in practical applications, the aforementioned pressure relief valve is used to discharge methanol vapor from the auxiliary fuel tank 9. Due to the volatile nature of methanol, when the auxiliary fuel tank heating module 12 heats the methanol fuel in the auxiliary fuel tank 9, some methanol will evaporate, leading to an increase in pressure and methanol vapor concentration within the auxiliary fuel tank 9. If the methanol vapor concentration and pressure are too high, there is a risk of ignition by the auxiliary fuel tank heating module 12, affecting the safety of the cold start process. Therefore, this application configures a pressure relief valve 11 in the auxiliary fuel tank 9 to actively discharge methanol vapor when the pressure in the auxiliary fuel tank 9 increases, thereby reducing the risk of methanol vapor ignition and improving the safety of cold starts.

[0080] It should be noted that, in practical application scenarios, the controller 13 mentioned above can be an independent controller device, or it can be an electronic control unit (ECU), a vehicle control unit (VCU), a micro controller unit (MCU), etc.

[0081] This application configures an auxiliary power supply unit to be electrically connected to both the intake air heating device and the auxiliary fuel tank heating module. This allows the intake air heating device and auxiliary fuel tank heating module to operate independently of the main power supply unit during cold starts. Furthermore, the auxiliary power supply unit is electrically connected to the main power supply unit via a unidirectional isolation module. This unidirectional isolation module allows the main power supply unit to charge the auxiliary power supply unit while preventing the auxiliary power supply unit from discharging back into the main power supply unit. This avoids the risk of a voltage drop in the main power supply unit during a cold start, which could lead to reverse power generation in the auxiliary power supply unit and a drop in the auxiliary power supply unit's bus voltage. This ensures the stable operation of the intake air heating device and auxiliary fuel tank heating module, thus solving the problem of unstable power supply to heating devices in existing technologies and improving the success rate of cold starts. Moreover, by configuring the auxiliary fuel tank heating module inside and / or outside the auxiliary fuel tank, and the intake air heating device inside and / or outside the intake pipe, heating of the intake air and methanol fuel is achieved, further enhancing the success rate of cold starts. Subsequently, by configuring the fuel outlet of the auxiliary fuel tank to connect to the first end of the independent auxiliary oil circuit, and the second end of the independent auxiliary oil circuit to connect to the fuel inlet of the engine body, and configuring it solenoid on / off valve in the independent auxiliary oil circuit to conduct and the main oil circuit to close during cold start conditions, and in the event of a failure in the auxiliary fuel tank and / or the independent auxiliary oil circuit during cold start conditions, the solenoid on / off valve to close and the main oil circuit to conduct, a backup redundancy design is achieved, improving the reliability of cold start. Finally, by configuring a pressure relief valve to be located in the auxiliary fuel tank, in the event of a failure in the auxiliary fuel tank and / or the independent auxiliary oil circuit, the pressure relief valve is used to create a pressure release channel, disrupting the internal overpressure environment of the auxiliary fuel tank and / or the independent auxiliary oil circuit under fault conditions, reducing the risk of component damage, and improving the safety of cold start. It is evident that the cold start system for a pure methanol engine provided in this application improves the reliability and safety of cold start for pure methanol engines.

[0082] In one possible implementation, the auxiliary power supply unit 6 described above includes:

[0083] The energy storage device, with a unidirectional isolation module 7 connected in series between the positive terminal of the energy storage device and the positive terminal of the main power supply unit 5.

[0084] It should be noted that, in practical applications, the aforementioned energy storage devices can be batteries used to provide electrical energy. For example, mass-produced 12V or 24V batteries, adapted to the specific engine model, with a capacity of 60-100Ah, can be selected to independently power the intake air heating device 8 and the auxiliary fuel tank heating module 12.

[0085] It should be noted that, in practical application scenarios, the connection circuit diagram between the auxiliary power supply unit 6 and the main power supply unit 5 can be as follows: Figure 3As shown, the positive terminal (A+) of the main power supply unit 5 is electrically connected to the anode of the unidirectional isolation module 7, the cathode of the unidirectional isolation module 7 is electrically connected to the positive terminal (B+) of the energy storage device of the auxiliary power supply unit 6, and the negative terminal (A-) of the main power supply unit 5 is electrically connected to the negative terminal (B-) of the energy storage device of the auxiliary power supply unit 6.

[0086] In one possible implementation, the energy storage device can also be electrically connected to a generator driven by a pure methanol engine, so that after the pure methanol engine starts, the engine drives the generator (output voltage 13.5V / 28V) to charge the energy storage device, and the charging current is controlled within a preset value (such as 5-10A) to avoid damage to the energy storage device due to overcharging.

[0087] In one possible implementation, the unidirectional isolation module 7 is a diode or a unidirectional relay.

[0088] It should be noted that, in practical applications, the aforementioned unidirectional isolation module 7 can use a diode with unidirectional conductivity to restrict the direction of current flow. Alternatively, a unidirectional relay can be used to enable conduction when current flows from the main power supply unit 5 to the auxiliary power supply unit 6, and to deactivate when current flows from the auxiliary power supply unit 6 to the main power supply unit 5. This unidirectional relay can be a directional relay or a polarity relay.

[0089] In one possible implementation, the pressure relief valve 11 is a mechanical pressure relief valve or an electrically controlled pressure relief valve.

[0090] It should be noted that in practical applications, the aforementioned mechanical pressure relief valve can automatically relieve pressure when the vehicle is powered off, improving safety without generating additional energy consumption.

[0091] In one possible implementation, when the pressure relief valve 11 is an electrically controlled pressure relief valve, the pressure relief valve 11 further includes:

[0092] Temperature and pressure sensors are located inside the auxiliary fuel tank 9.

[0093] Temperature sensor, pressure sensor and pressure relief valve 11 are all communicatively connected to controller 13.

[0094] In one possible implementation, by configuring the temperature sensor, pressure sensor, and pressure relief valve 11 to communicate with the controller 13, the electronically controlled pressure relief valve 11 can release pressure in advance under controlled conditions, thereby mitigating the risk of fuel tank overpressure and improving cold start reliability. Specifically, the temperature sensor can be a PT100 model (measuring range -50℃ to 150℃, accuracy ±1℃), and the pressure sensor can be an MPX5010 model (measuring range 0-1MPa, accuracy ±0.01MPa). The sensor probes are tightly fitted to the inner wall of the auxiliary fuel tank (e.g., threaded fixing, IP67 sealing rating, suitable for the harsh environment of the auxiliary fuel tank).

[0095] In one possible implementation, the auxiliary fuel tank 9 employs an insulation structure, which includes:

[0096] From the outside in, it consists of an outer layer of galvanized steel sheet, a rock wool insulation layer, and an inner layer of fluororubber.

[0097] It should be noted that in practical applications, methanol, being a polar solvent, has a strong swelling and corrosive effect on many general-purpose rubber materials (such as nitrile rubber and natural rubber). Long-term use can lead to seal failure and even material dissolution, resulting in fuel contamination. Fluororubber, due to the high bond energy and chemical stability of fluorine atoms introduced into its molecular chain, effectively resists methanol corrosion, ensuring the inner lining maintains structural integrity and sealing even during long-term immersion or contact with high concentrations of methanol vapor. For example, in this application, the thickness of the fluororubber inner layer can be designed to be 1mm to 2mm, ensuring corrosion resistance while avoiding increased costs and hindered heat conduction due to excessive thickness. If ordinary rubber is used instead of fluororubber, although it may exhibit some sealing performance in the short term, it will rapidly expand in volume, decrease in hardness, and propagate cracks in a methanol environment, ultimately leading to fuel leakage and the risk of short circuits in the heating module.

[0098] It should be noted that in practical applications, rock wool, as an inorganic fiber material, contains a large number of static air pores, has an extremely low thermal conductivity (typically between 0.03 W / (m·K) and 0.04 W / (m·K)), and possesses excellent high-temperature resistance and fire resistance. In this application, the thickness of the rock wool insulation layer is preferably 5 mm to 8 mm, which is the optimal engineering solution based on the balance between engine compartment space constraints and insulation requirements. When the auxiliary fuel tank 9 is in a heated state, the rock wool layer effectively prevents the loss of internal heat to the external environment, significantly shortening the preheating time and reducing the energy consumption burden of the auxiliary power supply unit 6. When the engine generates high-temperature radiation during operation, the rock wool layer also acts as a heat shield, preventing external heat from intruding into the tank and preventing methanol from generating abnormal high pressure due to environmental overheating. Compared with organic insulation materials such as polyurethane foam, rock wool not only has a higher heat resistance temperature (up to 600℃ or higher), but also does not release toxic fumes or support combustion when encountering unexpected high temperatures, further improving the safety of the system.

[0099] It should be noted that, in practical applications, the aforementioned galvanized steel sheet combines the high strength of steel with the electrochemical corrosion resistance of zinc, enabling it to withstand vibrations, impacts, debris splashes, and oil and salt spray corrosion within the engine compartment, protecting the fragile internal rock wool and fluororubber layers from physical damage. Simultaneously, the steel sheet shell provides a rigid framework for the entire composite structure, facilitating the secure installation of the auxiliary fuel tank 9 in the designated location using brackets or clamps. In specific implementations, the thickness of the galvanized steel sheet can be selected from 0.8mm to 1.5mm depending on the tank volume and stress conditions, and the surface zinc coating should meet automotive-grade corrosion protection standards. It should be understood that while galvanized steel sheet is preferred in this application, in other embodiments, aluminum alloy or stainless steel sheets can be selected based on lightweight requirements, as long as they provide equivalent mechanical protection and sealing functions.

[0100] In one possible implementation, the cold start system for a pure methanol engine provided in this application further includes:

[0101] Waste heat recovery pipeline, which includes exhaust heat exchange section, preheating heat exchange section and circulating pump;

[0102] The exhaust heat exchange section is located in the exhaust heat pipe of the engine body 1, and the preheating heat exchange section is located in the intake pipe 2 and the auxiliary fuel tank 9. The circulating pump drives the heat exchange medium in the waste heat recovery pipe to circulate in the exhaust heat exchange section and the preheating heat exchange section.

[0103] The circulating pump is connected to the controller 13 via communication.

[0104] It should be noted that in real-world applications, vehicles may experience short-term shutdowns (e.g., highway vehicles parked at service areas). Since the duration of the shutdown is uncertain, if the auxiliary power supply unit 6 continues to drive the intake air heating device 8 and the auxiliary fuel tank heating module 12, there is a risk that the auxiliary power supply unit 6 may run out of power if the shutdown time is slightly longer. This could result in the auxiliary power supply unit 6 being unable to heat up during a subsequent cold start due to power failure, thus reducing the success rate of cold starts. Therefore, this application configures an exhaust heat exchange section within the exhaust heat pipe of the engine body 1. This allows the exhaust heat exchange section to heat the heat exchange medium by utilizing the heat emitted from the exhaust heat pipe. A circulating pump drives the heat exchange medium in the waste heat recovery pipe to circulate between the exhaust heat exchange section and the preheating heat exchange section. This allows the preheating heat exchange section to heat and insulate the intake pipe 2 and the auxiliary fuel tank 9. This reduces the energy consumption of the auxiliary power supply unit 6 during short vehicle stops, while preventing excessive cooling of the intake pipe 2 and the auxiliary fuel tank 9, thus improving the success rate of cold starts. Furthermore, because the preheating heat exchange section slows down the cooling of the intake pipe 2 and the auxiliary fuel tank 9, it reduces the energy consumption of the intake heating device 8 and the auxiliary fuel tank heating module 12 during cold starts.

[0105] In one possible implementation, the aforementioned exhaust heat exchange section is typically made of high-temperature resistant stainless steel tubing (e.g., diameter Φ16mm to Φ20mm), tightly wrapped or attached to the outer surface of the engine exhaust manifold using high-temperature resistant clamps. The clamp spacing can be controlled between 5cm and 8cm to ensure good thermal contact. To further improve heat collection efficiency and prevent high-temperature radiation damage to other wiring harnesses or plastic components in the engine compartment, a high-temperature resistant aluminum alloy heat shield can also be installed on the exterior of the exhaust heat exchange section. This allows the exhaust heat exchange section to efficiently absorb the high-temperature heat energy of 600℃ to 800℃ from the surface of the exhaust manifold, while also providing thermal shielding. The preheating heat exchange section is divided into two parallel or series branches, respectively covering the intake pipe 2 and the auxiliary fuel tank 9. The length of the section covering the intake pipe 2 is preferably half the total length of the intake pipe, and it must be tightly fitted to ensure heat exchange efficiency. The area covering the auxiliary fuel tank 9 is preferably not less than 80% of the surface area of ​​the auxiliary fuel tank to ensure uniform heating of the tank. Between the preheating heat exchange section and the heated component, a rock wool insulation layer with a thickness of 3mm to 5mm is also provided. This insulation layer can not only reduce the loss of heat to the environment, but also buffer vibration and provide sound insulation.

[0106] In one possible implementation, the cold start system for a pure methanol engine provided in the first aspect of this application further includes:

[0107] Fuel recovery pipeline, with on / off valves installed in the fuel recovery pipeline;

[0108] The first end of the fuel recovery pipeline is connected to the exhaust port of the pressure relief valve 11, and the second end of the fuel recovery pipeline is connected to the fuel recovery inlet at the top of the main fuel tank 4.

[0109] It should be noted that in practical applications, methanol is toxic. If the pressure relief valve 11 directly releases methanol vapor into the air, it will not only pollute the environment but also waste energy. Therefore, this application configures a fuel recovery pipeline with its first end connected to the exhaust port of the pressure relief valve 11 and its second end connected to the fuel recovery inlet at the top of the main fuel tank 4, thereby collecting methanol vapor when the pressure relief valve 11 releases pressure. Furthermore, in low-temperature environments, the methanol vapor entering the fuel recovery pipeline liquefies into liquid methanol upon cooling.

[0110] To facilitate understanding of the cold start system for a pure methanol engine provided by the first aspect and any implementation thereof of this application, an example of a possible implementation of this application is described below:

[0111] like Figure 4 The diagram shown is a schematic representation of the overall structure of a cold start system for a pure methanol engine, including:

[0112] The auxiliary power supply unit 6, the one-way isolation module 7, the intake heating device 8, the auxiliary fuel tank 9, the independent auxiliary oil circuit 10, the electromagnetic on / off valve 14 installed in the independent auxiliary oil circuit 10, the pressure relief valve 11, the auxiliary fuel tank heating module 12, the controller 13, the exhaust heat exchange section 15, the first preheating heat exchange section 16, the second preheating heat exchange section 17, the circulation pump 18, the heat conduction pipe 22, the fuel recovery pipe 19, and the on / off valve 20 installed in the fuel recovery pipe 19, the pure methanol engine includes the engine body 1, the intake pipe 2, the main oil circuit 3, the main fuel tank 4, the main power supply unit 5, and the exhaust pipe 21.

[0113] The exhaust end of the intake pipe 2 is connected to the intake port of the engine body 1. The fuel outlet of the main fuel tank 4 is connected to the first fuel input end of the engine body 1 through the main oil line 3. The fuel outlet of the auxiliary fuel tank 9 is connected to the second fuel input end of the engine body 1 through the independent auxiliary oil line 10. The pressure relief valve 11 is located in the auxiliary fuel tank 9. The exhaust port of the pressure relief valve 11 is connected to the recovery fuel inlet of the main fuel tank 4 through the fuel recovery pipe 19. The auxiliary fuel tank heating module 12 is located outside the auxiliary fuel tank 9. The intake heating device 8 is located outside the intake pipe 2. The exhaust heat exchange section 15 is located outside the exhaust pipe 21. The first preheating heat exchange section 16 is located outside the exhaust pipe 21. The second preheating heat exchange section 17 is located outside the auxiliary fuel tank 9. The circulating pump 18 is connected to the exhaust heat exchange section 15, the first preheating heat exchange section 16, and the second preheating heat exchange section 17 through the heat conduction pipe 22.

[0114] The main power supply unit 5 is electrically connected to the auxiliary power supply unit 6 through the unidirectional isolation module 7. The auxiliary power supply unit 6 is electrically connected to the intake heating device 8, the auxiliary fuel tank heating module 12 and the circulation pump 18 respectively.

[0115] The controller 13 is communicatively connected to the intake air heating device 8, the auxiliary fuel tank heating module 12, the electromagnetic on / off valve 14, and the on / off valve 20.

[0116] A second aspect of this application provides a control method for a cold start system of a pure methanol engine, applied to a controller in a cold start system as described in the first aspect of this application and any implementation thereof, comprising:

[0117] Under cold start conditions, and with no faults in the auxiliary fuel tank and independent auxiliary oil circuit, control the operation of the auxiliary fuel tank heating module and intake air heating device, control the opening of the independent auxiliary oil circuit, control the shut-off of the main oil circuit, and control the cold start of the engine body.

[0118] In the event of a cold start and a failure of the auxiliary fuel tank and / or independent auxiliary oil circuit, the auxiliary fuel tank heating module is shut down, the intake air heating device is operated, the independent auxiliary oil circuit is shut down, the main oil circuit is opened, and the engine body is controlled to start cold.

[0119] In one possible implementation, the presence or absence of faults in the aforementioned auxiliary fuel tank and independent auxiliary fuel circuit can be determined using an independently configured fault detection module. This is achieved by establishing electrical connections between the fault detection module and the aforementioned intake heating device 8, auxiliary fuel tank heating module 12, various types of sensors, electromagnetic on / off valve 14, on / off valve 20, and pressure relief valve 11, and by periodically checking the status of each device upon detecting a vehicle power-on signal.

[0120] In one possible implementation, under cold start conditions and with no faults in the auxiliary fuel tank and independent auxiliary fuel line, controlling the operation of the auxiliary fuel tank heating module and intake air heating device includes:

[0121] Obtain ambient temperature and engine coolant temperature signals;

[0122] Based on ambient temperature and engine coolant temperature signals, the target heating power levels of the auxiliary fuel tank heating module and the intake air heating device are determined, and the auxiliary fuel tank heating module and the intake air heating device are controlled to operate with the operating parameters corresponding to the target heating power levels.

[0123] It should be noted that, in practical applications, the aforementioned target heating power level is based on calibrated operating parameters that allow the auxiliary fuel tank heating module and intake air heating device to support successful cold starts of the engine with low energy consumption under different ambient and engine coolant temperatures. Since the difficulty of cold starting a pure methanol engine varies under different ambient and engine coolant temperatures, the temperature difference that the auxiliary fuel tank heating module and intake air heating device need to overcome also varies. Therefore, this application determines the target heating power level of the auxiliary fuel tank heating module and intake air heating device based on ambient and engine coolant temperature signals, and controls them to operate with the operating parameters corresponding to the target heating power level. This achieves improved heating of methanol fuel and intake air while reducing energy consumption, thereby increasing the success rate of cold starts for pure methanol engines.

[0124] It should be noted that, in practical applications, the aforementioned target heating power level can be obtained based on calibration tests of different vehicle models in different environments. This application provides an example of such a level:

[0125] When the ambient temperature signal is less than -10℃ and the engine coolant temperature signal is less than 0℃, or when the ambient temperature signal is less than -30℃ and the engine coolant temperature signal is less than 10℃, the cold start is the most difficult. At this time, the target heating power level is the highest. The corresponding operating parameters for this level are: operating power 500W, running time 3~5 minutes.

[0126] When the ambient temperature signal is less than -30℃ and the engine coolant temperature signal is not less than 10℃, or when the ambient temperature signal is not less than -30℃ and less than -10℃ and the engine coolant temperature signal is not less than 0℃ and less than 10℃, or when the ambient temperature signal is not less than -10℃ and the engine coolant temperature signal is less than 0℃, the cold start difficulty is moderate. The target heating power level at this time is medium. The corresponding operating parameters are: operating power 300W, running time 2~3 minutes.

[0127] When the ambient temperature signal is not less than -30℃ and less than -10℃, and the engine coolant temperature signal is not less than 10℃, or when the ambient temperature signal is not less than -10℃ and the engine coolant temperature signal is not less than 0℃ and less than 10℃, the cold start difficulty is the lowest. At this time, the target heating power level is low, and the corresponding operating parameters are: operating power 200W, running time 1~2 minutes.

[0128] In one possible implementation, the control method for the cold start system provided in the second aspect of this application further includes:

[0129] Monitor engine speed and engine coolant temperature;

[0130] When the engine speed is within the preset idle speed range and the engine coolant temperature is not lower than the stable operating coolant temperature threshold, the independent auxiliary oil circuit and the main oil circuit are alternately switched on and off.

[0131] It should be noted that in practical applications, when the engine speed is within the preset idle range and the engine coolant temperature is not lower than the stable operating coolant temperature threshold, it indicates that the pure methanol engine has successfully started and is operating stably. At this time, since the fuel supply of the pure methanol engine is still provided by the auxiliary fuel tank and the independent auxiliary fuel circuit, and the volume of the auxiliary fuel tank is smaller than that of the main fuel tank, if fuel is still supplied by the auxiliary fuel tank for a long time, the amount of methanol in it will decrease. If the fuel in the auxiliary fuel tank is completely consumed, it will result in no fuel supply during the next cold start. Therefore, this application configures the independent auxiliary fuel circuit and the main fuel circuit to alternately open and close when the engine speed is within the preset idle range and the engine coolant temperature is not lower than the stable operating coolant temperature threshold, so that the main fuel tank consumes fuel during the pure methanol engine operation, thereby reducing the consumption of fuel in the auxiliary fuel tank and improving the reliability of the next cold start.

[0132] Furthermore, since the stable operation of the engine is directly related to the stability of the fuel supply, fluctuations in fuel supply caused by differences in valve action rates during the alternating opening and closing of the independent auxiliary fuel circuit and the main fuel circuit can easily affect the stable operation of the engine, and may even lead to engine stalling. Therefore, during the alternating opening and closing of the independent auxiliary fuel circuit and the main fuel circuit, the conduction rate of the main fuel circuit can be limited to be consistent with the shut-off rate of the independent auxiliary fuel circuit (e.g., the valve action rate of both fuel circuits is 0.1L / min), thereby avoiding the risk of engine stalling of the pure methanol engine due to fuel supply fluctuations and improving the cold start success rate and reliability of the pure methanol engine.

[0133] In one possible implementation, since the auxiliary fuel tank does not need further heating after the main fuel line is open and the independent auxiliary fuel line is completely shut off, the residual heat from the auxiliary fuel tank heating module will cause the methanol in the auxiliary fuel tank to continue evaporating for a period of time, resulting in an increase in the gas pressure inside the auxiliary fuel tank. Therefore, after detecting that the independent auxiliary fuel line is completely shut off, the pressure relief valve can be controlled to perform a pressure relief action for a preset duration, and the pressure relief valve will be closed when the gas pressure drops below a preset safe pressure threshold and / or the fuel temperature drops below a preset safe temperature threshold.

[0134] In one possible implementation, the cold start system for a pure methanol engine provided in the first aspect of this application further includes:

[0135] Waste heat recovery pipeline, which includes exhaust heat exchange section, preheating heat exchange section and circulating pump;

[0136] The exhaust heat exchange section is located in the exhaust heat pipe of the engine body, and the preheating heat exchange section is located in the intake pipe and the auxiliary fuel tank. The circulating pump drives the heat exchange medium in the waste heat recovery pipe to circulate in the exhaust heat exchange section and the preheating heat exchange section.

[0137] The circulating pump is connected to the controller via communication.

[0138] The control method for the cold start system provided in the second aspect of this application further includes:

[0139] Upon detecting an engine shutdown command, the circulating pump is controlled to run at a preset speed for a preset duration.

[0140] It should be noted that in practical applications, the aforementioned engine shutdown command indicates that the shutdown of the pure methanol engine is caused by a stall fault, rather than by the driver's voluntary action. In this case, the vehicle needs to stop briefly. Therefore, this application configures the circulating pump to run at a preset speed for a preset duration upon detecting an engine shutdown command. This utilizes the engine's waste heat to insulate the intake manifold and auxiliary fuel tank, preventing rapid cooling of the intake manifold and auxiliary fuel tank from causing a decrease in cold start success rate and increased energy consumption.

[0141] In one possible implementation, after controlling the auxiliary fuel tank heating module and the intake air heating device to operate with operating parameters corresponding to the target heating power level, the method further includes:

[0142] Monitor the operating status parameters of the engine body during the preset cold start period;

[0143] If the operating status parameters do not meet the preset successful start conditions, control the engine to pause the start and increment the start failure count by 1.

[0144] If the number of failed starts does not exceed the preset start count threshold, control the engine to cold start again;

[0145] If the number of failed starts exceeds the preset start count threshold, the preset operating parameter adjustment amount is added to the operating parameters corresponding to the target heating power level, and the auxiliary fuel tank heating module and intake air heating device are controlled to operate with the added operating parameters, and the engine body is controlled to start cold again.

[0146] In one possible implementation, the above-mentioned operating state parameters may be the engine speed and engine coolant temperature, and the above-mentioned preset successful start condition is that the engine speed is in the preset idle speed range and the engine coolant temperature is not lower than the stable operating coolant temperature threshold.

[0147] It should be noted that in practical applications, calibration tests cannot fully calibrate the temperatures that may occur in real-world environments. Therefore, there are instances where multiple heating attempts based on the operating parameters corresponding to the target heating power level fail to start the pure methanol engine. To adapt to different ambient temperatures and improve cold start success rate and reliability, this application monitors the engine's operating status parameters during a preset cold start period. If the operating status parameters do not meet the preset successful start conditions, the engine is paused from starting, and the number of failed starts is incremented. If the number of failed starts exceeds a preset start count threshold, a preset operating parameter adjustment is applied to the operating parameters corresponding to the target heating power level. The auxiliary fuel tank heating module and intake air heating device are then controlled to operate with the added operating parameters, and the engine is cold-started again. This further increases the heating temperature of the auxiliary fuel tank heating module and intake air heating device in cases of multiple unsuccessful starts, thereby offsetting the impact of extreme low temperatures on cold start reliability.

[0148] It should be noted that, in practical application scenarios, for situations where devices or equipment cannot operate due to faults in low-temperature environments, in order to improve cold start reliability, the control method for the cold start system of the pure methanol engine provided in the second aspect of this application also includes fault redundancy control logic, which includes one or more of the following control logics:

[0149] If a fault is detected in the intake heating device and the exhaust temperature is not lower than the ambient temperature, the circulation pump is controlled to run for a preset time to improve the success rate of cold start.

[0150] If a circulation pump malfunction is detected and the intake air heating device is not malfunctioning, the intake air heating device will continue to run for a preset time after the control is stopped.

[0151] If a pressure relief valve malfunction is detected, the independent auxiliary oil circuit and the main oil circuit are alternately switched on and off, fuel is supplied from the main fuel tank, and an alarm signal is issued.

[0152] In the event of a malfunction in the temperature and pressure sensors, the pressure relief valve will be triggered periodically, and an alarm signal will be issued.

[0153] To facilitate understanding of the control method for the cold start system provided in the second aspect of this application, an example of a possible implementation of this application is described below:

[0154] like Figure 5 The diagram shows a flowchart of a control method for a cold start system of a pure methanol engine. The specific operation steps of this control method are as follows:

[0155] Step S501: Upon detecting a vehicle power-on signal, perform a vehicle fault self-check. This triggers step S502.

[0156] Step S502: Determine if there is a startup-related fault. If yes, trigger step S503; otherwise, trigger step S504.

[0157] Step S503: Execute the fault redundancy control logic.

[0158] Step S504: Determine the target heating power level of the auxiliary fuel tank heating module and the intake air heating device based on the obtained ambient temperature signal and engine coolant temperature signal. Then trigger step S505.

[0159] Step S505: Control the auxiliary fuel tank heating module and the intake air heating device to operate according to their respective operating parameters. This triggers step S506.

[0160] Step S506: Control the cold start of the pure methanol engine and monitor the engine speed and engine coolant temperature. Then trigger step S507.

[0161] Step S507: Determine whether the engine has started successfully based on engine speed and engine coolant temperature. If yes, trigger step S508; otherwise, trigger step S509.

[0162] In step S508, when the engine speed is within the preset idle speed range and the engine coolant temperature is not lower than the stable operating coolant temperature threshold, the independent auxiliary oil circuit and the main oil circuit are alternately switched on and off, and the auxiliary fuel tank heating module and intake air heating device are shut down. This triggers step S510.

[0163] Step S509: Control the engine to pause starting and increment the start failure count by 1. Then trigger step S511.

[0164] Step S510: Determine whether an engine stop command has been received. If not, repeat step S510; if yes, trigger step S512.

[0165] Step S511: Determine whether the number of startup failures exceeds a preset startup count threshold. If yes, trigger step S513; otherwise, trigger step S505.

[0166] Step S512: Control the circulating pump to run at a preset speed for a preset time.

[0167] Step S513: Add a preset operating parameter adjustment amount to the operating parameters corresponding to the target heating power level to update the operating parameters. Then trigger step S505.

[0168] This application also provides an electronic device for executing a control method for a cold start system of a pure methanol engine provided in the second aspect of this application and any implementation thereof. (Reference) Figure 6 The diagram illustrates a structural schematic suitable for implementing the electronic devices in the embodiments of this application. The electronic devices in the embodiments of this application may include, but are not limited to, ECU (Electronic Control Unit), VCU (Vehicle Control Unit), MCU (Micro Controller Unit), HCU (Hybrid Control Unit), etc. Figure 6 The electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0169] like Figure 6 As shown, the electronic device may include a processing unit (e.g., a central processing unit, a graphics processing unit, etc.) 601, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from a storage device 608 into a random access memory (RAM) 603. When the electronic device is powered on, the RAM 603 also stores various programs and data required for the operation of the electronic device. The processing unit 601, ROM 602, and RAM 603 are interconnected via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0170] Typically, the following devices can be connected to I / O interface 605: input devices 606 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 607 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 608 including, for example, memory cards, hard drives, etc.; and communication devices 609. Communication device 609 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 6 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown. More or fewer devices may be implemented or have alternatively.

[0171] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. In addition, in the device embodiment drawings provided in this application, the connection relationship between modules indicates that they have a communication connection, which can be implemented as one or more communication buses or signal lines.

[0172] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware, or it can be implemented by special-purpose hardware including application-specific integrated circuits, special-purpose CPUs, special-purpose memory, special-purpose components, etc. Generally, any function performed by a computer program can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be diverse, such as analog circuits, digital circuits, or special-purpose circuits. However, for this application, software program implementation is more often the preferred implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium, such as a computer floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk, or optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, training equipment, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0173] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product.

[0174] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, training device, or data center to another website, computer, training device, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

Claims

1. A cold start system for a pure methanol engine, characterized in that, The pure methanol engine includes an engine body (1), an intake pipe (2), a main fuel line (3), a main fuel tank (4), and a main power supply unit (5). The cold start system of the pure methanol engine includes: Auxiliary power supply unit (6), one-way isolation module (7), intake air heating device (8), auxiliary fuel tank (9), independent auxiliary oil circuit (10), pressure relief valve (11), auxiliary fuel tank heating module (12) and controller (13); The auxiliary power supply unit (6) is electrically connected to the main power supply unit (5) through the unidirectional isolation module (7). The unidirectional isolation module (7) allows the main power supply unit (5) to charge the auxiliary power supply unit (6) and prevents the auxiliary power supply unit (6) from discharging in reverse to the main power supply unit (5). The auxiliary power supply unit (6) is electrically connected to the intake heating device (8) and the auxiliary fuel tank heating module (12) respectively; The auxiliary fuel tank heating module (12) is located inside and / or outside the auxiliary fuel tank (9), and the intake heating device (8) is located inside and / or outside the intake pipe (2); The fuel outlet of the auxiliary fuel tank (9) is connected to the first end of the independent auxiliary oil circuit (10), and the second end of the independent auxiliary oil circuit (10) is connected to the fuel inlet of the engine body (1). The independent auxiliary oil circuit (10) is equipped with an electromagnetic on / off valve (14). Under cold start conditions, the electromagnetic on / off valve (14) is open, and if the auxiliary fuel tank (9) and the independent auxiliary oil circuit (10) are not faulty, the main oil circuit (3) is closed. Under cold start conditions, if the auxiliary fuel tank (9) and / or the independent auxiliary oil circuit (10) are faulty, the electromagnetic on / off valve (14) is closed, and the main oil circuit (3) is open. The pressure relief valve (11) is located in the auxiliary fuel tank (9). The controller (13) is communicatively connected to the intake heating device (8), the auxiliary fuel tank heating module (12), and the electromagnetic on / off valve (14).

2. The cold start system according to claim 1, characterized in that, The auxiliary power supply unit (6) includes: The energy storage device, wherein the unidirectional isolation module (7) is connected in series between the positive terminal of the energy storage device and the positive terminal of the main power supply unit (5).

3. The cold start system according to claim 1 or 2, characterized in that, The unidirectional isolation module (7) is a diode or a unidirectional relay.

4. The cold start system according to claim 1, characterized in that, The pressure relief valve (11) is a mechanical pressure relief valve or an electrically controlled pressure relief valve.

5. The cold start system according to claim 4, characterized in that, When the pressure relief valve (11) is the electrically controlled pressure relief valve, the pressure relief valve (11) further includes: Temperature sensor and pressure sensor, the temperature sensor and the pressure sensor are disposed inside the auxiliary fuel tank (9); The temperature sensor, the pressure sensor, and the pressure relief valve (11) are all communicatively connected to the controller (13).

6. The cold start system according to claim 1, characterized in that, The auxiliary fuel tank (9) adopts an insulation structure, which includes: From the outside in, it consists of an outer layer of galvanized steel sheet, a rock wool insulation layer, and an inner layer of fluororubber.

7. The cold start system according to claim 1, characterized in that, The cold start system of the pure methanol engine also includes: Waste heat recovery pipeline, which includes an exhaust heat exchange section, a preheating heat exchange section and a circulating pump; The exhaust heat exchange section is located in the exhaust heat pipe of the engine body (1), the preheating heat exchange section is located in the intake pipe (2) and the auxiliary fuel tank (9), and the circulating pump drives the heat exchange medium in the waste heat recovery pipe to circulate in the exhaust heat exchange section and the preheating heat exchange section. The circulating pump is communicatively connected to the controller (13).

8. The cold start system according to any one of claims 1, 4, or 5, characterized in that, The cold start system of the pure methanol engine also includes: A fuel recovery pipeline, wherein an on / off valve is installed in the fuel recovery pipeline; The first end of the fuel recovery pipeline is connected to the exhaust port of the pressure relief valve (11), and the second end of the fuel recovery pipeline is connected to the fuel recovery inlet at the top of the main fuel tank (4).

9. A control method for a cold start system of a pure methanol engine, applied to a controller in a cold start system as described in any one of claims 1 to 8, characterized in that, include: Under cold start conditions, and with no faults in the auxiliary fuel tank and independent auxiliary oil circuit, control the operation of the auxiliary fuel tank heating module and the intake air heating device, control the opening of the independent auxiliary oil circuit, control the shut-off of the main oil circuit, and control the cold start of the engine body. In the cold start condition, and in the event of a failure of the auxiliary fuel tank and / or the independent auxiliary oil circuit, the auxiliary fuel tank heating module is shut down, the intake air heating device is operated, the independent auxiliary oil circuit is shut down, the main oil circuit is opened, and the engine body is cold started.

10. The control method for the cold start system according to claim 9, characterized in that, The control of the auxiliary fuel tank heating module and the intake air heating device under cold start conditions, provided that the auxiliary fuel tank and independent auxiliary fuel circuit are fault-free, includes: Obtain ambient temperature and engine coolant temperature signals; Based on the ambient temperature signal and the engine coolant temperature signal, the target heating power level of the auxiliary fuel tank heating module and the intake air heating device is determined, and the auxiliary fuel tank heating module and the intake air heating device are controlled to operate with the operating parameters corresponding to the target heating power level.

11. The control method for the cold start system according to claim 9 or 10, characterized in that, The control method for the cold start system further includes: Monitor engine speed and engine coolant temperature; When the engine speed is within the preset idle speed range and the engine coolant temperature is not lower than the stable operating coolant temperature threshold, the independent auxiliary oil circuit and the main oil circuit are controlled to alternately open and close.

12. The control method for the cold start system according to claim 9, characterized in that, The cold start system of the pure methanol engine also includes: Waste heat recovery pipeline, which includes an exhaust heat exchange section, a preheating heat exchange section and a circulating pump; The exhaust heat exchange section is located in the exhaust heat pipe of the engine body, the preheating heat exchange section is located in the intake pipe and the auxiliary fuel tank, and the circulating pump drives the heat exchange medium in the waste heat recovery pipe to circulate in the exhaust heat exchange section and the preheating heat exchange section. The circulating pump is communicatively connected to the controller; The control method for the cold start system further includes: Upon detecting an engine shutdown command, the circulating pump is controlled to run at a preset speed for a preset duration.

13. The control method for the cold start system according to claim 10, characterized in that, After controlling the auxiliary fuel tank heating module and the intake air heating device to operate at the operating parameters corresponding to the target heating power level, the method further includes: Monitor the operating status parameters of the engine body during a preset cold start period; If the operating status parameters do not meet the preset successful start conditions, control the engine body to pause the start and increment the start failure count by 1; If the number of failed starts does not exceed a preset start count threshold, the engine body is controlled to cold start again. If the number of failed starts exceeds the preset start count threshold, the preset operating parameter adjustment amount is added to the operating parameters corresponding to the target heating power level, and the auxiliary fuel tank heating module and the intake air heating device are controlled to operate with the added operating parameters, and the engine body is controlled to start cold again.

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