A low-temperature cold-start fuel pretreatment device, method, fuel supply system device, electronic device, and medium

Abstract

This invention relates to a fuel pretreatment device, method, fuel supply system, electronic equipment, and medium for low-temperature cold start. The fuel pretreatment device includes a fuel filter, an electrically heated PTC self-regulating fuel preheating section, and an exhaust waste heat recovery type fuel preheater, arranged along a low-pressure fuel supply pipeline. The inlet of the low-pressure fuel supply pipeline is connected to the fuel tank, and the outlet is connected to a bypass passage and the main fuel line, respectively. The outlet of the bypass passage is connected to the fuel tank via a first solenoid valve and an electric auxiliary circulation pump, while the outlet of the main fuel line is connected to a high-pressure fuel pump via a second solenoid valve. The engine ECU collects signals from an ambient temperature sensor and a fuel temperature sensor in the fuel tank, and controls the electric heating element and the PTC ceramic heating element via relays. This invention gradually warms the entire fuel tank through circulating preheating, and maintains the fuel temperature after startup using exhaust waste heat. It can cover the cold start requirements of various fuels, reduce overall vehicle power consumption, and adapt to the differences in the physical properties of different fuels without requiring hardware replacement.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine fuel supply technology, specifically to a fuel pretreatment device, method, fuel supply system device, electronic equipment, and medium for low-temperature cold start. Background Technology

[0002] Many liquid fuels face varying degrees of cold-start difficulties in low-temperature environments, with the physical properties of these challenges differing depending on the fuel type. For example, methanol has a flash point of 11°C, a boiling point of 64.7°C, and a kinematic viscosity of 0.56–0.60 mm³ at 20°C. 2 / s, saturated vapor pressure at 20℃ is 13kPa. During low-temperature cold starts, it is prone to problems such as high latent heat of vaporization, low viscosity leading to insufficient oil absorption, and water precipitation resulting in ice crystals. Ethanol has a flash point of 13℃, a boiling point of 78.4℃, and a kinematic viscosity of 1.1~1.5mm at 20℃. 2 / s, saturated vapor pressure at 20℃ is 6kPa, and it is prone to problems such as high latent heat of vaporization, poor atomization at low temperatures, and hygroscopicity during cold starts; propanol has a flash point of 15℃, a boiling point of 97℃, and a kinematic viscosity of 2.0~2.5mm at 20℃. 2 / s, saturated vapor pressure at 20℃ is 2kPa, and it is prone to high viscosity and decreased low-temperature fluidity during cold starts; butanol has a flash point of 35℃, a boiling point of 117℃, and a kinematic viscosity of 2.6~3.5mm at 20℃. 2 / s, saturated vapor pressure at 20℃ <1kPa, prone to high flash point and significant viscosity increase during cold start at low temperatures; gasoline flash point is -43℃, boiling point is 30~210℃, kinematic viscosity at 20℃ is 0.45~0.55mm 2 / s, saturated vapor pressure at 38℃ is 60kPa, and it is prone to problems such as low flash point, easy volatilization, and poor atomization at low temperatures during cold starts; diesel fuel has a flash point of 52~96℃, a boiling point of 180~370℃, and a kinematic viscosity of 3.0~4.5mm at 20℃. 2 / s, saturated vapor pressure at 38℃ <1kPa, prone to problems such as sharp increase in viscosity at low temperature, poor fluidity, and wax crystallization during low-temperature cold start.

[0003] Currently, traditional diesel engine cold starts mainly rely on intake air preheating or coolant preheating, but these methods do not directly affect the fuel lines and suffer from problems such as incomplete heating, lack of circulating preheating, and incompatibility with various fuels. Therefore, providing a fuel pretreatment device and method with a unified thermal management architecture to cover the cold start requirements of multiple fuels is a technical problem that needs to be solved. Summary of the Invention

[0004] To address the above problems, the present invention aims to provide a fuel pretreatment device, method, fuel supply system device, electronic equipment, and medium for low-temperature cold start. Compared with the prior art, the fuel pretreatment device provided by the present invention combines a fuel filter, an electrically heated PTC self-limiting temperature fuel preheating section, and an exhaust waste heat recovery type fuel preheater arranged along the fuel flow path, which can cover the cold start requirements of various fuels.

[0005] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a fuel pretreatment device for low-temperature cold start, the fuel pretreatment device comprising: a fuel filter, an electrically heated PTC self-regulating fuel preheating section, and an exhaust waste heat recovery type fuel preheater arranged sequentially from the inlet to the outlet of a low-pressure fuel supply pipeline; the inlet of the low-pressure fuel supply pipeline is connected to a fuel tank, the outlet of the low-pressure fuel supply pipeline is connected to a bypass passage and a main fuel line respectively, the outlet of the bypass passage is connected to an electric auxiliary circulation pump via a first solenoid valve, the outlet of the electric auxiliary circulation pump is connected to the fuel tank, and the outlet of the main fuel line is connected to a high-pressure fuel pump via a second solenoid valve; the fuel pretreatment device further comprises an engine ECU, the signal input terminal of the engine ECU is connected to an ambient temperature sensor and a fuel temperature sensor in the fuel tank, and the signal output terminal of the engine ECU is connected to the electrically heated element of the fuel filter and the PTC ceramic heating element of the electrically heated PTC self-regulating fuel preheating section respectively via relays.

[0006] This invention addresses problems such as difficulty in high-pressure fuel pump suction, filter icing and blockage, and pipeline air resistance caused by increased fuel viscosity in low-temperature environments. The invention integrates a fuel filter, an electrically heated PTC self-regulating fuel preheating section, and an exhaust waste heat recovery fuel preheater sequentially on the low-pressure fuel supply pipeline between the fuel tank and the high-pressure fuel pump. A cold start circulation loop is established via a first solenoid valve and an electric auxiliary circulation pump. The fuel filter incorporates an electric heating element to prevent ice crystal blockage. The electrically heated PTC self-regulating fuel preheating section uses a PTC ceramic heating element to heat the fuel. The exhaust waste heat recovery fuel preheater uses exhaust heat to heat the fuel after engine startup. Positioning the exhaust waste heat recovery fuel preheater after the electrically heated PTC self-regulating fuel preheating section avoids reverse heat dissipation during cold starts. Through this arrangement, the electric auxiliary circulation pump circulates in the loop before cold starts, gradually warming the fuel in the fuel tank. Furthermore, the engine control unit (ECU) determines whether to enter the cold start pretreatment mode based on temperature data from the ambient temperature sensor and the fuel temperature sensor in the fuel tank, and controls the engine to start only when the fuel temperature at the high-pressure fuel pump inlet reaches a set threshold. The fuel pretreatment device provided by this invention is suitable for various fuels such as methanol, ethanol, propanol, butanol, gasoline, and diesel. By adjusting the Curie temperature of the PTC ceramic heating element and the start-up threshold, it can adapt to the differences in the physical properties of different fuels.

[0007] In this invention, the electric auxiliary circulation pump can be selected as needed, including but not limited to any one of gear pump, diaphragm pump or vane pump, with a rated flow rate of 30% to 60% of the maximum oil suction flow rate of the high-pressure oil pump; the material of the electric auxiliary circulation pump is compatible with the fuel used, and the internal metal parts of the pump body are made of stainless steel 316L or corrosion-resistant engineering plastics.

[0008] The electric heating element of the fuel filter includes a PTC positive temperature coefficient heating plate and / or a PTC positive temperature coefficient heating rod.

[0009] In this invention, the fuel filter can adopt a spin-on structure, and the heating power of its internal electric heating element is 50-200W, which is controlled by the engine ECU according to the ambient temperature.

[0010] At least two PTC ceramic heating elements are wrapped around the outer wall of the electric heating PTC self-limiting fuel preheating section.

[0011] The outer wall of the electrically heated PTC self-regulating fuel preheating section is wrapped with three PTC ceramic heating elements, which are located in the upstream, middle and downstream sections of the electrically heated PTC self-regulating fuel preheating section, respectively. The Curie temperature of the PTC ceramic heating elements increases along the fuel flow direction.

[0012] In this invention, by controlling the PTC self-regulating fuel preheating section with multiple PTC ceramic heating elements whose Curie temperatures increase along the fuel flow direction, and by uniformly supplying power to a relay controlled by the engine ECU, gradient heating can be achieved. Specifically, the Curie temperature can be designed in segments according to different fuel types, which can reduce fuel temperature fluctuations and improve temperature uniformity. For example, when the fuel is methanol, the Curie temperature is 20–25°C upstream, 25–30°C midway, and 30–35°C downstream; when the fuel is ethanol, the Curie temperature is 20–30°C upstream, 25–35°C midway, and 30–40°C downstream; when the fuel is propanol, the Curie temperature is 25–35°C upstream, 30–40°C midway, and 35–45°C downstream; when the fuel is butanol, the Curie temperature is 30–40°C upstream, 35–45°C midway, and 40–50°C downstream; when the fuel is gasoline, the Curie temperature is 10–20°C upstream, 15–25°C midway, and 20–30°C downstream; and when the fuel is diesel, the Curie temperature is 5–15°C upstream, 10–20°C midway, and 15–25°C downstream.

[0013] The PTC ceramic heating element is a PTC ceramic ring.

[0014] The PTC ceramic ring is wrapped with an insulating sleeve.

[0015] A fuel temperature sensor is installed at the outlet of the electric heating PTC self-limiting fuel preheating section, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU.

[0016] The exhaust waste heat recovery fuel preheater includes a heat pipe array, which includes an evaporation section and a condensation section. The evaporation section extends into the exhaust manifold of the engine or is attached to the outer wall of the exhaust manifold and is thermally coupled to the exhaust heat source. The condensation section extends into the fuel heat exchange chamber of the exhaust waste heat recovery fuel preheater to preheat the fuel.

[0017] The outer surface of the evaporation section is provided with fins.

[0018] Several baffles are provided inside the fuel heat exchange chamber to allow the fuel to flow along a serpentine path over the outer surface of the condensation section.

[0019] The outlet of the exhaust waste heat recovery fuel preheater is equipped with a fuel temperature sensor, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU.

[0020] In this invention, the working medium in the heat pipe array of the exhaust waste heat recovery fuel preheater is water or ethanol, with a filling rate of 30% to 50%. The shell material of the heat pipe array is stainless steel 316L or nickel-based alloy. Fins are provided on the outer surface of the evaporation section. Several baffles are provided in the fuel heat exchange chamber so that the fuel flows along a serpentine path over the surface of the condensation section. The residence time of the fuel in the fuel heat exchange chamber is 1 to 2 seconds.

[0021] The fuel pretreatment device also includes a storage battery that supplies power to the electric heating element and the PTC ceramic heating element via a relay.

[0022] A fuel temperature sensor is installed at the inlet of the high-pressure oil pump, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU.

[0023] A fuel temperature sensor is installed at the inlet of the electric auxiliary circulation pump, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU.

[0024] Secondly, the present invention provides a pretreatment method for low-temperature cold start, wherein the pretreatment method employs the fuel pretreatment device for low-temperature cold start described in the first aspect of the present invention; the pretreatment method includes the following steps: S1, the engine ECU reads signals from the ambient temperature sensor and the fuel temperature sensor in the fuel tank; S2, if the fuel temperature in the fuel tank is less than the first temperature threshold and the driver issues a start request, the engine ECU enters the cold start pre-processing mode: closes the main fuel line, opens the bypass line, starts the electric auxiliary circulation pump, and the engine ECU controls the relay to turn on the electric heating element and the PTC ceramic heating element. At this time, the exhaust waste heat recovery fuel preheater does not preheat and continuously monitors the fuel temperature at the high-pressure fuel pump inlet. S3, when the fuel temperature at the high-pressure oil pump inlet is greater than or equal to the second temperature threshold, the engine ECU controls the relay to shut off the electric heating element and the PTC ceramic heating element, continues to circulate for the first duration until the fuel temperature is uniform, then stops the electric auxiliary circulation pump, closes the bypass passage, and opens the main oil circuit; S4, the engine ECU authorizes engine start.

[0025] In this invention, the engine ECU reads the ambient temperature and the temperature of the fuel in the fuel tank. If the fuel temperature in the fuel tank is less than a first temperature threshold and the driver requests to start the engine, the engine ECU determines that it is entering a cold start pre-processing mode. It circulates and heats the fuel through a bypass path, an electric auxiliary circulation pump, an electric heating element, and a PTC ceramic heating element, while continuously monitoring the fuel temperature at the high-pressure fuel pump inlet. When the fuel temperature at the high-pressure fuel pump inlet is greater than or equal to a second temperature threshold, the heating by the electric heating element and the PTC ceramic heating element is stopped. The circulation continues for a first duration to ensure temperature uniformity. Then, the fuel is delivered to the high-pressure fuel pump through the main fuel circuit to start the engine. In this invention, the first and second temperature thresholds can be adjusted according to different fuels, thereby adapting to the usage requirements of different fuels.

[0026] The first temperature threshold is set according to the type of fuel.

[0027] In this invention, the first temperature threshold refers to the lowest fuel temperature at which the engine is allowed to start, i.e., the trigger temperature of the cold start pretreatment mode. Below this temperature, the fuel's fluidity or atomization characteristics are insufficient to support normal starting, and it needs to be set according to different fuel types.

[0028] The fuel includes any one or a combination of at least two of alcohols, gasoline, or diesel.

[0029] The alcohols include any one or a combination of at least two of methanol, ethanol, propanol or butanol.

[0030] The first temperature threshold of the alcohol is -5 to 0°C, for example, it can be -5°C, -4°C, -3°C, -2°C, -1°C or 0°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0031] The first temperature threshold of the gasoline is -10 to 0°C, for example, it can be -10°C, -9°C, -8°C, -7°C, -6°C, -5°C, -4°C, -3°C, -2°C, -1°C or 0°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0032] The first temperature threshold of the diesel fuel is -15 to 0°C, for example, it can be -15°C, -12°C, -10°C, -8°C, -6°C, -4°C, -2°C or 0°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0033] The second temperature threshold is set according to the type of fuel.

[0034] In this invention, the second temperature threshold refers to the target temperature at which the engine ECU permits the engine to start after the fuel temperature at the high-pressure oil pump inlet reaches this value, i.e., the termination temperature of the cold start pretreatment mode, which needs to be set separately according to different fuel types.

[0035] The second temperature threshold for methanol is 10 to 15°C, for example, it can be 10°C, 11°C, 12°C, 13°C, 14°C or 15°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0036] The second temperature threshold for the ethanol is 10 to 20°C, for example, it can be 10°C, 12°C, 13°C, 14°C, 16°C, 18°C ​​or 20°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0037] The second temperature threshold of the propanol is 15 to 25°C, for example, it can be 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C or 25°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] The second temperature threshold of the butanol is 20 to 30°C, for example, it can be 20°C, 22°C, 24°C, 26°C, 28°C or 30°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0039] The second temperature threshold of the gasoline is 5 to 10°C, for example, it can be 5°C, 6°C, 7°C, 8°C, 9°C or 10°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0040] The second temperature threshold for the diesel fuel is 5 to 15°C, for example, it can be 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C or 15°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0041] The first duration is 10 to 20 seconds, for example, it can be 10 seconds, 12 seconds, 14 seconds, 16 seconds, 18 seconds or 20 seconds, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0042] The PTC ceramic heating element adopts a graded power operation mode: when the battery voltage is higher than the lower voltage limit, the PTC ceramic heating element adopts a full power operation mode; when the battery voltage is lower than the lower voltage limit, the PTC ceramic heating element adopts a half power operation mode.

[0043] In this invention, the PTC ceramic heating element adopts a graded power operation mode, that is, it operates at full power when the battery voltage is higher than the lower voltage limit, and operates at half power when the battery voltage is lower than the lower voltage limit. The above control can prevent battery overload.

[0044] In the full-power operation mode, when the heating rate of the PTC self-limiting fuel preheating section is continuously less than the preset rate within the second time period, the engine ECU determines that the PTC ceramic heating element is faulty and enters the degradation mode; the degradation mode includes: raising the first temperature threshold to the third temperature threshold and issuing a maintenance prompt.

[0045] In this invention, under normal operating conditions, the heating rate should reach a preset rate. When the heating rate of the PTC self-limiting fuel preheating section is continuously less than the preset rate for a second duration, the engine ECU determines that the PTC ceramic heating element is faulty and enters a degradation mode. In degradation mode, by raising the first temperature threshold to the third temperature threshold, the insufficient heating capacity is compensated for with a higher starting temperature threshold when the PTC ceramic heating element partially fails, sacrificing some cold start convenience in exchange for the engine still being able to start. At the same time, the engine ECU sends a maintenance prompt to the instrument panel or remote terminal.

[0046] The second duration is 30 to 60 seconds, for example, it can be 30 seconds, 35 seconds, 40 seconds, 45 seconds, 50 seconds, 55 seconds or 60 seconds, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0047] The third temperature threshold is 5 to 10°C, for example, it can be 5°C, 6°C, 7°C, 8°C, 9°C or 10°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0048] The pretreatment method further includes: S5, after the engine starts, the exhaust waste heat recovery fuel preheater is turned on to preheat the fuel, and the engine ECU continuously monitors the fuel temperature at the high-pressure oil pump inlet and the fuel temperature at the exhaust waste heat recovery fuel preheater outlet. When the fuel temperature at the exhaust waste heat recovery fuel preheater outlet is greater than the second temperature threshold, the electric heating element and the PTC ceramic heating element are kept in standby mode; when the fuel temperature at the high-pressure oil pump inlet is less than the second temperature threshold, the engine ECU controls the relay to turn on the PTC ceramic heating element.

[0049] In this invention, the exhaust waste heat recovery fuel preheater operates after the engine starts. When the fuel temperature at the outlet of the exhaust waste heat recovery fuel preheater is greater than a second temperature threshold, the fuel temperature is maintained by the exhaust waste heat recovery fuel preheater, eliminating the need for electric heating elements and PTC ceramic heating elements. When the fuel temperature at the high-pressure fuel pump inlet is less than the second temperature threshold, the PTC ceramic heating element is then activated for heating. This invention, through the exhaust waste heat recovery fuel preheater, utilizes exhaust waste heat to replace electric heating after engine start, achieving a seamless switch from "electric heating-dominated" to "waste heat-dominated" heat source, reducing overall vehicle power consumption. Simultaneously, temperature monitoring enables the PTC ceramic heating element to be activated on demand, avoiding unnecessary energy consumption.

[0050] Thirdly, the present invention provides an engine fuel supply system device, the engine fuel supply system device comprising a low-temperature cold start fuel pretreatment device as described in the first aspect of the present invention.

[0051] In this invention, the engine fuel supply system device, by employing the aforementioned low-temperature cold start fuel pretreatment device, can be adapted to a variety of different fuel systems.

[0052] Fourthly, the present invention provides an electronic device comprising: a processor; and a memory storing executable code, wherein when the executable code is executed, the processor performs a preprocessing method for low-temperature cold start as described in the second aspect of the present invention.

[0053] Fifthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a processor to execute the preprocessing method for low-temperature cold start as described in the second aspect of the present invention.

[0054] Compared with the prior art, the present invention has the following beneficial effects: (1) In the fuel pretreatment device provided by the present invention, in order to address the problems of high pressure oil pump difficulty in oil suction, filter icing blockage and pipeline air resistance caused by the increase of fuel viscosity in low temperature environment, the present invention integrates a fuel filter, an electric heating PTC self-limiting temperature fuel preheating section and an exhaust waste heat recovery fuel preheater in sequence on the low pressure fuel supply pipeline between the fuel tank and the high pressure oil pump, and sets up a cold start circulation loop through a first solenoid valve, an electric auxiliary circulation pump, etc. In the cold start pretreatment mode, the preheating relies entirely on electricity and does not depend on the engine waste heat, thus solving the heat source problem.

[0055] (2) In the fuel pretreatment device provided by the present invention, the bypass passage driven by the electric auxiliary circulation pump can heat up the entire tank of fuel through circulation preheating, rather than just heating the pipeline, so that the fuel temperature will not drop rapidly after startup.

[0056] (3) In the fuel pretreatment device provided by the present invention, the exhaust waste heat recovery type fuel preheater is set after the electric heating PTC self-limiting temperature fuel preheating section, which can avoid reverse heat dissipation during cold start.

[0057] (4) The fuel pretreatment device and engine fuel supply system provided by the present invention can switch between various fuels such as methanol, ethanol, propanol, butanol, gasoline and diesel by adjusting the parameters of the engine ECU such as temperature threshold through a set of hardware, without the need for hardware replacement. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the fuel pretreatment device provided in Embodiment 1 of the present invention; Among them, 101-fuel tank; 102-fuel filter; 103-electrically heated PTC self-limiting temperature fuel preheating section; 104-exhaust waste heat recovery type fuel preheater; 105-second solenoid valve; 106-first solenoid valve; 107-high pressure oil pump; 108-electric auxiliary circulation pump; 109-main oil circuit; 110-bypass passage.

[0059] Figure 2 This is a schematic diagram of the connection between the engine ECU and each temperature sensor provided in Embodiment 1 of the present invention; Among them, 201-engine ECU; 202-first temperature sensor; 203-second temperature sensor; 204-third temperature sensor; 205-fourth temperature sensor; 206-fifth temperature sensor; 207-sixth temperature sensor. Detailed Implementation

[0060] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0061] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0063] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0064] One specific embodiment of the present invention provides a low-temperature cold start fuel pretreatment device, the fuel pretreatment device comprising: a fuel filter, an electrically heated PTC self-regulating fuel preheating section, and an exhaust waste heat recovery type fuel preheater arranged sequentially from the inlet to the outlet of a low-pressure fuel supply pipeline; the inlet of the low-pressure fuel supply pipeline is connected to a fuel tank, the outlet of the low-pressure fuel supply pipeline is connected to a bypass passage and a main fuel line respectively, the outlet of the bypass passage is connected to an electric auxiliary circulation pump via a first solenoid valve, the outlet of the electric auxiliary circulation pump is connected to the fuel tank, and the outlet of the main fuel line is connected to a high-pressure fuel pump via a second solenoid valve; the fuel pretreatment device further comprises an engine ECU, the signal input terminal of the engine ECU is connected to an ambient temperature sensor and a fuel temperature sensor in the fuel tank, and the signal output terminal of the engine ECU is connected to the electrically heated element of the fuel filter and the PTC ceramic heating element of the electrically heated PTC self-regulating fuel preheating section respectively via relays.

[0065] In this invention, the low-temperature barrier is addressed sequentially along the fuel flow path: an electric heating element is installed in the fuel filter to prevent ice crystal blockage; a gradient heating PTC self-limiting temperature fuel preheating section provides gradient heating; and an exhaust waste heat recovery fuel preheater utilizes engine exhaust waste heat to maintain the temperature, gradually warming the entire fuel tank through circulation. This invention is inclusive of the differences in the physical properties of different fuels; the only differences between different fuels are in the PTC Curie temperature setting and the start-up temperature threshold, requiring no changes to the hardware structure.

[0066] In this invention, under cold start pretreatment mode, the main oil circuit is cut off. Fuel is driven by an electric auxiliary circulation pump to circulate in a cold start preheating loop: fuel tank → fuel filter → electrically heated PTC self-limiting temperature fuel preheating section → exhaust waste heat recovery fuel preheater → bypass passage → fuel tank. This gradually raises the temperature of the entire fuel tank, rather than only heating a portion of the pipeline. Furthermore, the electric auxiliary circulation pump has a suction capacity of 30% to 60% of the maximum suction capacity of the high-pressure oil pump. The electric auxiliary circulation pump can be any of a gear pump, diaphragm pump, or vane pump, with materials compatible with the fuel used. Internal metal components of the pump body are made of 316L stainless steel or corrosion-resistant engineering plastics.

[0067] In some embodiments, the electric heating element of the fuel filter includes a PTC positive temperature coefficient heating plate and / or a PTC positive temperature coefficient heating rod.

[0068] In this invention, the fuel filter adopts a spin-on structure, internally integrating a PTC positive temperature coefficient heating plate and / or a PTC positive temperature coefficient heating rod. When the ambient temperature is lower than a set value, the engine ECU activates the electric heating element to prevent ice formation and blockage on the filter element surface (for alcohol fuels) or wax crystallization (for diesel fuels). The internal electric heating element has a heating power of 50–200W and operates only in cold start pretreatment mode or at extremely low ambient temperatures. The fuel filter housing is made of 316L stainless steel, and the seals are made of fluororubber with a fluorine content ≥70wt%, exhibiting good resistance to swelling from methanol, ethanol, propanol, butanol, gasoline, and diesel fuel.

[0069] In some embodiments, at least two PTC ceramic heating elements are wrapped around the outer wall of the electrically heated PTC self-regulating fuel preheating section.

[0070] In some embodiments, the outer wall of the electrically heated PTC self-regulating fuel preheating section is wrapped with three PTC ceramic heating elements, which are located in the upstream, middle and downstream sections of the electrically heated PTC self-regulating fuel preheating section, respectively. The Curie temperature of the PTC ceramic heating elements increases along the fuel flow direction.

[0071] In this invention, the PTC ceramic heating element has self-limiting temperature characteristics, eliminating the need for an additional temperature controller. By arranging three sections of PTC ceramic heating elements along the pipeline axis, the high temperature difference in the upstream section allows for full-power heating operation. As the fuel heats up in the downstream section, the corresponding Curie temperature also increases, enabling automatic power adjustment. This invention utilizes gradient heating to match the heating power distribution with the fuel temperature gradient, preventing localized overheating that could lead to fuel vaporization (especially for low-boiling-point fuels). Furthermore, the PTC ceramic ring is externally encased in a heat-insulating sleeve. Taking methanol as an example, at an ambient temperature of -20℃ and a flow rate of 15L / min, using three progressively increasing Curie temperatures (22℃, 28℃, and 33℃) reduces the fuel temperature fluctuation range from ±6℃ to ±2℃ compared to using a single uniform Curie temperature (28℃), significantly improving temperature uniformity.

[0072] The fuel pretreatment device provided by this invention is designed based on the common physical properties of different liquid fuels, such as viscosity changes at low temperatures, precipitate blockage, and latent heat of vaporization. Different fuels have quantitative differences in the above physical properties, but the trend is the same: low temperature leads to decreased fluidity, and external heating is required. Moreover, the same hardware structure can be adapted to different fuels at the same time, and only the parameters need to be adjusted according to the fuel, as shown in Table 1.

[0073] Table 1 In this invention, the engine ECU can identify signals based on fuel type, specifically by automatically switching the above parameter groups through a filler port sensor or manual selection by the driver.

[0074] In some embodiments, the PTC ceramic heating element is a PTC ceramic ring.

[0075] In some embodiments, the PTC ceramic ring is externally wrapped with a heat-insulating sleeve.

[0076] In some embodiments, a fuel temperature sensor is installed at the outlet of the electrically heated PTC self-limiting fuel preheating section, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU.

[0077] In some embodiments, the exhaust waste heat recovery fuel preheater includes a heat pipe array, which includes an evaporation section and a condensation section. The evaporation section extends into the exhaust manifold of the engine or is attached to the outer wall of the exhaust manifold and is thermally coupled to the exhaust heat source. The condensation section extends into the fuel heat exchange chamber of the exhaust waste heat recovery fuel preheater to preheat the fuel.

[0078] In this invention, the evaporation section of the heat pipe array in the exhaust waste heat recovery fuel preheater extends directly into the engine's exhaust manifold, directly contacting the high-temperature flue gas, resulting in a significantly higher heat exchange efficiency than methods that attach the heat pipes to an external wall. The working medium of the heat pipe array is water or ethanol, with a filling rate of 30%–50%. The shell material of the heat pipe array is 316L stainless steel or a nickel-based alloy (which has higher resistance to corrosive fuels). Fins are provided on the outer surface of the evaporation section of the heat pipe array to increase the heat exchange area. The condensation section extends into the fuel heat exchange chamber, which is equipped with several baffles to extend the fuel residence time, which is 1–2 seconds.

[0079] In this invention, the exhaust waste heat recovery fuel preheater is positioned after the electrically heated PTC self-regulating fuel preheating section and before the high-pressure fuel pump. The reason is that during the initial cold start phase, the exhaust manifold temperature is the same as the ambient temperature, and the heat pipe array is not working. If it is placed before the electrically heated PTC self-regulating fuel preheating section, the low-temperature heat pipe array will act as a radiator, lowering the fuel temperature. Comparative tests show that in a -20℃ environment, when the heat pipe array is placed before the electrically heated PTC self-regulating fuel preheating section, the cold fuel first flows through the low-temperature heat pipe cavity, and the fuel temperature drops by 1-2℃. When the heat pipe array is placed after the electrically heated PTC self-regulating fuel preheating section (i.e., the scheme of this invention), the fuel first passes through the electrically heated PTC self-regulating fuel preheating section to raise its temperature before entering the heat pipe cavity, avoiding reverse heat dissipation during the initial cold start phase. Under both layouts, 3 minutes after engine start-up, the fuel temperature at the high-pressure fuel pump inlet of the scheme of this invention is 4℃ higher than that of the scheme where the heat pipe array is placed before the PTC self-regulating fuel preheating section.

[0080] In some embodiments, fins are provided on the outer surface of the evaporation section.

[0081] In some embodiments, the fuel heat exchange chamber is provided with several baffles to allow the fuel to flow along a serpentine path over the outer surface of the condensation section.

[0082] In some embodiments, a fuel temperature sensor is installed at the outlet of the exhaust waste heat recovery fuel preheater, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU.

[0083] In some embodiments, the fuel pretreatment device further includes a battery that supplies power to the electric heating element and the PTC ceramic heating element via a relay.

[0084] In some embodiments, a fuel temperature sensor is installed at the inlet of the high-pressure oil pump, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU.

[0085] In some embodiments, a fuel temperature sensor is installed at the inlet of the electric auxiliary circulation pump, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU.

[0086] One specific embodiment of the present invention provides a pretreatment method for low-temperature cold start, wherein the pretreatment method employs a fuel pretreatment device for low-temperature cold start; the pretreatment method includes the following steps: S1, the engine ECU reads signals from the ambient temperature sensor and the fuel temperature sensor in the fuel tank; S2, if the fuel temperature in the fuel tank is less than the first temperature threshold and the driver issues a start request, the engine ECU enters the cold start pre-processing mode: closes the main fuel line, opens the bypass line, starts the electric auxiliary circulation pump, and the engine ECU controls the relay to turn on the electric heating element and the PTC ceramic heating element. At this time, the exhaust waste heat recovery fuel preheater does not preheat and continuously monitors the fuel temperature at the high-pressure fuel pump inlet. S3, when the fuel temperature at the high-pressure oil pump inlet is greater than or equal to the second temperature threshold, the engine ECU controls the relay to shut off the electric heating element and the PTC ceramic heating element, continues to circulate for the first duration until the fuel temperature is uniform, then stops the electric auxiliary circulation pump, closes the bypass passage, and opens the main oil circuit; S4, the engine ECU authorizes engine start.

[0087] In some embodiments, the first temperature threshold is set according to the type of fuel.

[0088] In some embodiments, the fuel includes any one or a combination of at least two of alcohols, gasoline, or diesel.

[0089] In some embodiments, the alcohols include any one or a combination of at least two of methanol, ethanol, propanol, or butanol.

[0090] In some embodiments, the first temperature threshold of the alcohol is -5 to 0°C, for example, it can be -5°C, -4°C, -3°C, -2°C, -1°C or 0°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0091] In some embodiments, the first temperature threshold of the gasoline is -10 to 0°C, for example, it can be -10°C, -9°C, -8°C, -7°C, -6°C, -5°C, -4°C, -3°C, -2°C, -1°C or 0°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0092] In some embodiments, the first temperature threshold of the diesel fuel is -15 to 0°C, for example, it can be -15°C, -12°C, -10°C, -8°C, -6°C, -4°C, -2°C or 0°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0093] In some embodiments, the second temperature threshold is set according to the type of fuel.

[0094] In some embodiments, the second temperature threshold of the methanol is 10 to 15°C, for example, it can be 10°C, 11°C, 12°C, 13°C, 14°C or 15°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0095] In some embodiments, the second temperature threshold of the ethanol is 10 to 20°C, for example, it can be 10°C, 12°C, 13°C, 14°C, 16°C, 18°C ​​or 20°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0096] In some embodiments, the second temperature threshold of the propanol is 15 to 25°C, for example, it can be 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C or 25°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0097] In some embodiments, the second temperature threshold of the butanol is 20 to 30°C, for example, it can be 20°C, 22°C, 24°C, 26°C, 28°C or 30°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0098] In some embodiments, the second temperature threshold of the gasoline is 5 to 10°C, for example, it can be 5°C, 6°C, 7°C, 8°C, 9°C or 10°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0099] In some embodiments, the second temperature threshold of the diesel fuel is 5 to 15°C, for example, it can be 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C or 15°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0100] In some embodiments, the first duration is 10 to 20 seconds, for example, it can be 10 seconds, 12 seconds, 14 seconds, 16 seconds, 18 seconds or 20 seconds, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0101] In some embodiments, the PTC ceramic heating element adopts a graded power operation mode: when the battery voltage is higher than the lower voltage limit, the PTC ceramic heating element adopts a full power operation mode, and when the battery voltage is lower than the lower voltage limit, the PTC ceramic heating element adopts a half power operation mode.

[0102] In some embodiments, under the full-power operation mode, when the heating rate of the PTC self-limiting fuel preheating section is continuously less than a preset rate for a second duration, the engine ECU determines that the PTC ceramic heating element is faulty and enters a degraded mode; the degraded mode includes: raising the first temperature threshold to a third temperature threshold and issuing a maintenance prompt.

[0103] In some embodiments, the second duration is 30 to 60 seconds, for example, it can be 30 seconds, 35 seconds, 40 seconds, 45 seconds, 50 seconds, 55 seconds or 60 seconds, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0104] In some embodiments, the third temperature threshold is 5 to 10°C, for example, it can be 5°C, 6°C, 7°C, 8°C, 9°C or 10°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0105] In some embodiments, the pretreatment method further includes: S5, after the engine starts, the exhaust waste heat recovery fuel preheater is turned on to preheat the fuel, the engine ECU continuously monitors the fuel temperature at the high-pressure oil pump inlet and the fuel temperature at the exhaust waste heat recovery fuel preheater outlet, when the fuel temperature at the exhaust waste heat recovery fuel preheater outlet is greater than a second temperature threshold, the electric heating element and the PTC ceramic heating element are kept in standby mode; when the fuel temperature at the high-pressure oil pump inlet is less than the second temperature threshold, the engine ECU controls the relay to turn on the PTC ceramic heating element.

[0106] In this invention, the engine ECU reads the ambient temperature and the temperature of the fuel in the fuel tank to determine whether to enter the cold start pre-processing mode. After entering the pre-processing mode, the PTC ceramic heating element is started in a graded power operation mode according to the lower limit of the battery voltage. When the battery voltage is higher than the lower limit, the PTC ceramic heating element adopts the full power operation mode. When the battery voltage is lower than the lower limit, the PTC ceramic heating element adopts the half power operation mode. The fuel temperature at the high-pressure fuel pump inlet is monitored. If the exhaust waste heat is sufficient to maintain the standby of the electric heating element and the PTC ceramic heating element, the PTC ceramic heating element is restarted. Otherwise, the PTC ceramic heating element is restarted, and a fault diagnosis is added: if the temperature rise is too slow, the PTC ceramic heating element is determined to be faulty, the first temperature threshold is raised to the third temperature threshold, and maintenance is prompted.

[0107] One specific embodiment of the present invention provides an engine fuel supply system device, the engine fuel supply system device including the low temperature cold start fuel pretreatment device.

[0108] In this invention, the engine fuel supply system device, by employing the aforementioned low-temperature cold start fuel pretreatment device, can be adapted to a variety of different fuel systems.

[0109] One specific embodiment of the present invention provides an electronic device, the electronic device comprising: a processor; and a memory, the memory storing executable code, which, when executed, causes the processor to perform the low-temperature cold start preprocessing method.

[0110] One specific embodiment of the present invention provides a computer-readable storage medium storing computer instructions, the computer instructions being used to cause a processor to execute the aforementioned low-temperature cold start preprocessing method.

[0111] Example 1 This embodiment provides a low-temperature cold start fuel pretreatment device, such as... Figure 1 and Figure 2 As shown, the fuel pretreatment device includes: a fuel filter 102, an electrically heated PTC self-regulating fuel preheating section 103, and an exhaust waste heat recovery type fuel preheater 104, sequentially arranged from the inlet to the outlet of the low-pressure fuel supply pipeline; the inlet of the low-pressure fuel supply pipeline is connected to the fuel tank 101, and the outlet of the low-pressure fuel supply pipeline is connected to a bypass passage 110 and a main fuel line 109 respectively; the outlet of the bypass passage 110 is connected to an electric auxiliary circulation pump 108 via a first solenoid valve 106, the outlet of the electric auxiliary circulation pump 108 is connected to the fuel tank 101, and the outlet of the main fuel line 109 is connected to a high-pressure fuel pump 107 via a second solenoid valve 105; the fuel pretreatment device also includes an engine ECU 201, the signal input terminal of which is connected to an ambient temperature sensor (denoted as the first temperature sensor 202) and a fuel temperature sensor (denoted as the second temperature sensor 203) in the fuel tank 101; the engine ECU... The signal output terminal of 201 is connected via relays to the electric heating element of the fuel filter 102 and the PTC ceramic heating element of the PTC self-regulating fuel preheating section 103. Wherein: The engine parameters are: 6 cylinders, 15.9L displacement, 800bar rail pressure, and the maximum oil suction capacity of the high-pressure pump is about 40L / min (1900r / min).

[0112] The fuel filter 102 is a spin-on type with a filter element precision of 10μm. It has a built-in PTC positive temperature coefficient heating plate and a power of 100W under a rated voltage of 24V. Its on / off state is controlled by a relay controlled by the engine ECU 201.

[0113] The electrically heated PTC self-regulating fuel preheating section 103 consists of three PTC ceramic heating elements, located in the upstream, middle, and downstream sections respectively. Their Curie temperatures increase along the fuel flow direction, reaching 22°C, 28°C, and 33°C respectively. Each section is 40mm long with an inner diameter of 12mm, and the total heating power at a rated voltage of 24V is 400W. The piping is made of 316L stainless steel (12×1.5mm), and the PTC ceramic ring is wrapped with an aluminum silicate heat-insulating sleeve. A fuel temperature sensor (referred to as the third temperature sensor 204) is installed at the outlet of the electrically heated PTC self-regulating fuel preheating section 103, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU 201.

[0114] The exhaust waste heat recovery fuel preheater 104 consists of a heat pipe array composed of four stainless steel-water heat pipes. The evaporation section is 80 mm long and inserted into the exhaust manifold, with fins. The condensation section is 100 mm long and extends into an aluminum fuel heat exchange chamber. The fuel heat exchange chamber has a volume of 800 mL and is equipped with three baffles. The working fluid of the heat pipe array is water, with a filling rate of 40%. A fuel temperature sensor (referred to as the fourth temperature sensor 205) is installed at the outlet of the exhaust waste heat recovery fuel preheater 104, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU 201.

[0115] The electric auxiliary circulation pump 108 is a diaphragm pump with a displacement of 15L / min (37.5% of the maximum oil suction capacity of the high-pressure pump of 40L / min) and is driven by a 24V DC motor.

[0116] Additionally, a storage battery (not shown in the figure) is included, which supplies power to the electric heating element and the PTC ceramic heating element via a relay (not shown in the figure). A fuel temperature sensor (denoted as the fifth temperature sensor 206) is installed at the fuel inlet of the high-pressure fuel pump 107, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU 201. A fuel temperature sensor (denoted as the sixth temperature sensor 207) is installed at the inlet of the electric auxiliary circulation pump, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU 201.

[0117] Taking methanol as an example, this embodiment also provides a pretreatment method for low-temperature cold start of the above-mentioned fuel pretreatment device, the pretreatment method including the following steps: S1, the engine ECU 201 reads the signal from the first temperature sensor 202 and obtains T_amb=-25℃, and the signal from the second temperature sensor 203 T_tank=-22℃.

[0118] S2, if the fuel temperature T_tank in fuel tank 101 is less than the first temperature threshold (0℃) and the driver issues a start request, then the engine ECU 201 enters the cold start pre-processing mode: closes the second solenoid valve 105 of the main fuel line 109, opens the first solenoid valve 106 of the bypass passage 110, starts the electric auxiliary circulation pump 108, and the engine ECU... The 201 control relay turns on the electric heating element (100W heating power under 24V rated voltage) and the PTC ceramic heating element (400W heating power under 24V rated voltage). At this time, the exhaust waste heat recovery fuel preheater 104 does not preheat and continuously monitors the fuel temperature at the inlet of the high-pressure oil pump 107. During this process, the electric heating PTC self-limiting fuel preheating section 103 heats up to 15°C in about 30 seconds. After the circulating return oil mixes with the cold fuel, the inlet temperature of the electric auxiliary circulation pump 108 is about -10°C. After 120 seconds, the overall temperature of the oil tank 101 heats up to -5°C. The outlet temperature of the electric heating PTC self-limiting fuel preheating section 103 is about 28°C. After 180 seconds, the fuel temperature T_pump_in at the inlet of the high-pressure oil pump 107 stabilizes at about 22°C. At this time, the engine is not started, and all heating is done through electric heating.

[0119] S3, when the fuel temperature T_pump_in at the inlet of the high-pressure oil pump 107 stabilizes at about 22°C and exceeds the second temperature threshold (15°C), turn off the electric heating element and the PTC ceramic heating element, continue to circulate for 15 seconds until the fuel temperature is uniform, then stop the electric auxiliary circulation pump 108, close the bypass passage 110, and open the main oil passage 109.

[0120] S4, Engine ECU 201 permits engine start.

[0121] S5, about 2 minutes after the engine starts, the exhaust temperature rises to above 200°C, the exhaust waste heat recovery fuel preheater 104 turns on to preheat the fuel, the engine ECU 201 continuously monitors the fuel temperature at the inlet of the high-pressure oil pump 107 and the fuel temperature at the outlet of the exhaust waste heat recovery fuel preheater 104, T_pump_in is maintained above 20°C, and the PTC ceramic heating element is on standby.

[0122] In this embodiment, the total heating power of the electric heating element and the PTC ceramic heating element is 500W (under 24V rated voltage), the 24V system current is about 20.8A, the battery capacity is 80Ah, the cold start pretreatment mode works for a maximum of 3 minutes, consuming about 1.04Ah of power, which does not affect the start-up.

[0123] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A fuel pretreatment device for low-temperature cold start, characterized in that, The fuel pretreatment device includes: a fuel filter, an electrically heated PTC self-regulating fuel preheating section, and an exhaust waste heat recovery fuel preheater, which are arranged sequentially from the inlet to the outlet of the low-pressure fuel supply pipeline. The inlet of the low-pressure fuel supply pipeline is connected to the fuel tank, and the outlet of the low-pressure fuel supply pipeline is connected to the bypass passage and the main oil passage respectively. The outlet of the bypass passage is connected to the electric auxiliary circulation pump via the first solenoid valve. The outlet of the electric auxiliary circulation pump is connected to the fuel tank, and the outlet of the main oil passage is connected to the high-pressure oil pump via the second solenoid valve. The fuel pretreatment device also includes an engine ECU. The signal input terminal of the engine ECU is connected to an ambient temperature sensor and a fuel temperature sensor in the fuel tank. The signal output terminal of the engine ECU is connected to the electric heating element of the fuel filter and the PTC ceramic heating element of the PTC self-limiting fuel preheating section via relays.

2. The fuel pretreatment device according to claim 1, characterized in that, The electric heating element of the fuel filter includes a PTC positive temperature coefficient heating plate and / or a PTC positive temperature coefficient heating rod; Preferably, at least two PTC ceramic heating elements are wrapped around the outer wall of the electrically heated PTC self-limiting fuel preheating section; Preferably, the outer wall of the electrically heated PTC self-regulating fuel preheating section is wrapped with three PTC ceramic heating elements, which are located in the upstream, middle and downstream sections of the electrically heated PTC self-regulating fuel preheating section, respectively. The Curie temperature of the PTC ceramic heating elements increases along the fuel flow direction. Preferably, the PTC ceramic heating element is a PTC ceramic ring; Preferably, the PTC ceramic ring is wrapped with a heat-insulating sleeve. Preferably, a fuel temperature sensor is installed at the outlet of the electric heating PTC self-limiting fuel preheating section, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU.

3. The fuel pretreatment apparatus according to claim 1 or 2, characterized in that, The exhaust waste heat recovery fuel preheater includes a heat pipe array, which includes an evaporation section and a condensation section. The evaporation section extends into the exhaust manifold of the engine or is attached to the outer wall of the exhaust manifold and is thermally coupled to the exhaust heat source. The condensation section extends into the fuel heat exchange chamber of the exhaust waste heat recovery fuel preheater to preheat the fuel. Preferably, fins are provided on the outer surface of the evaporation section; Preferably, a plurality of baffles are provided in the fuel heat exchange chamber to allow the fuel to flow along a serpentine path over the outer surface of the condensation section; Preferably, a fuel temperature sensor is installed at the outlet of the exhaust waste heat recovery fuel preheater, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU; Preferably, the fuel pretreatment device further includes a storage battery, which supplies power to the electric heating element and the PTC ceramic heating element via a relay; Preferably, a fuel temperature sensor is installed at the inlet of the high-pressure oil pump, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU; Preferably, a fuel temperature sensor is installed at the inlet of the electric auxiliary circulation pump, and the signal output terminal of the fuel temperature sensor is connected to the engine ECU.

4. A pretreatment method for low-temperature cold start, characterized in that, The pretreatment method employs the low-temperature cold start fuel pretreatment device as described in any one of claims 1 to 3; the pretreatment method includes the following steps: S1, the engine ECU reads signals from the ambient temperature sensor and the fuel temperature sensor in the fuel tank; S2, if the fuel temperature in the fuel tank is less than the first temperature threshold and the driver issues a start request, the engine ECU enters the cold start pre-processing mode: closes the main fuel line, opens the bypass line, starts the electric auxiliary circulation pump, and the engine ECU controls the relay to turn on the electric heating element and the PTC ceramic heating element. At this time, the exhaust waste heat recovery fuel preheater does not preheat and continuously monitors the fuel temperature at the high-pressure fuel pump inlet. S3, when the fuel temperature at the high-pressure oil pump inlet is greater than or equal to the second temperature threshold, the engine ECU controls the relay to shut off the electric heating element and the PTC ceramic heating element, continues to circulate for the first duration until the fuel temperature is uniform, then stops the electric auxiliary circulation pump, closes the bypass passage, and opens the main oil circuit; S4, the engine ECU authorizes engine start.

5. The pretreatment method according to claim 4, characterized in that, The first temperature threshold is set according to the type of fuel; Preferably, the fuel comprises any one or a combination of at least two of alcohols, gasoline, or diesel. Preferably, the alcohols include any one or a combination of at least two of methanol, ethanol, propanol or butanol; Preferably, the first temperature threshold of the alcohol is -5 to 0°C; Preferably, the first temperature threshold of the gasoline is -10 to 0°C; Preferably, the first temperature threshold of the diesel fuel is -15 to 0°C; Preferably, the second temperature threshold is set according to the type of fuel; Preferably, the second temperature threshold of the methanol is 10–15°C; Preferably, the second temperature threshold of the ethanol is 10–20°C; Preferably, the second temperature threshold of the propanol is 15–25°C; Preferably, the second temperature threshold of the butanol is 20–30°C; Preferably, the second temperature threshold of the gasoline is 5 to 10°C; Preferably, the second temperature threshold of the diesel fuel is 5–15°C; Preferably, the first duration is 10 to 20 seconds.

6. The pretreatment method according to claim 4 or 5, characterized in that, The PTC ceramic heating element adopts a graded power operation mode: when the battery voltage is higher than the lower voltage limit, the PTC ceramic heating element adopts a full power operation mode; when the battery voltage is lower than the lower voltage limit, the PTC ceramic heating element adopts a half power operation mode. Preferably, in the full-power operation mode, when the heating rate of the PTC self-limiting fuel preheating section is continuously less than the preset rate for a second duration, the engine ECU determines that the PTC ceramic heating element is faulty and enters the degradation mode; the degradation mode includes: raising the first temperature threshold to the third temperature threshold and issuing a maintenance prompt. Preferably, the second duration is 30–60 seconds; Preferably, the third temperature threshold is 5 to 10°C.

7. The pretreatment method according to any one of claims 4 to 6, characterized in that, The pretreatment method further includes: S5, after the engine starts, the exhaust waste heat recovery fuel preheater is turned on to preheat the fuel, and the engine ECU continuously monitors the fuel temperature at the high-pressure oil pump inlet and the fuel temperature at the exhaust waste heat recovery fuel preheater outlet. When the fuel temperature at the exhaust waste heat recovery fuel preheater outlet is greater than the second temperature threshold, the electric heating element and the PTC ceramic heating element are kept in standby mode; when the fuel temperature at the high-pressure oil pump inlet is less than the second temperature threshold, the engine ECU controls the relay to turn on the PTC ceramic heating element.

8. An engine fuel supply system device, characterized in that, The engine fuel supply system includes a fuel pretreatment device for low-temperature cold start as described in any one of claims 1 to 3.

9. An electronic device, characterized in that, The electronic device includes: a processor; and a memory storing executable code, which, when executed, causes the processor to perform the preprocessing method for low-temperature cold start as described in any one of claims 4 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that are used to cause a processor to execute a preprocessing method for low-temperature cold start as described in any one of claims 4 to 7.

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