Biodiesel filtering system and method and mining excavator

Abstract

The invention discloses a biodiesel filtering system and method and a mining excavator, and the system comprises a filling pipeline which is connected between a refueling vehicle and a vehicle oil tank, and is provided with a diesel coarse filter; the filtering pipeline comprises a first pipeline and a second pipeline, the first pipeline is connected between a vehicle oil tank and an engine, an oil-water separator, a fuel oil primary refined filter, a fuel oil water-containing sensor and a three-way electromagnetic valve are sequentially installed on the first pipeline, the second pipeline is connected between the three-way electromagnetic valve and the engine in parallel, and a fuel oil secondary refined filter is installed on the second pipeline; the oil-water separator comprises a fuel lift pump, a water level sensor and a water discharge electromagnetic valve; and the vehicle control unit is respectively connected with the water level sensor, the water discharge electromagnetic valve, the fuel oil water content sensor, the three-way electromagnetic valve and the instrument. According to the invention, real-time and accurate detection of the water content of the biodiesel is realized, the filtering level of refined filtration of the biodiesel can be adjusted in time, and the quality of the biodiesel entering an engine is accurately controlled.

Description

Technical Field

[0001] The present invention relates to a biodiesel filtration system, method and mining excavator, belonging to the technical field of fuel filtration for construction machinery. Background Art

[0002] In the field of diesel application, the problem of moisture has always been a key factor affecting the reliability of the fuel system. Compared with ordinary diesel, biodiesel usually has a higher water content due to production processes and raw material characteristics. In the humid Southeast Asian region, the popularity of biodiesel in construction machinery has been continuously increasing and it has become one of the mainstream power fuels. However, after high-water-content biodiesel enters the fuel injector, it is extremely easy to cause faults such as component wear and jamming. Therefore, an efficient and reliable biodiesel filtration system is crucial for ensuring the normal operation of the engine.

[0003] Currently, conventional diesel filtration systems on the market mostly adopt a combined structure of "oil-water separator + diesel fine filter". This system is maintained and serviced based on a preset fixed cycle, for example, the filter element is replaced every 500 hours or after filtering a certain volume of fuel cumulatively. Such a solution can meet the basic filtration requirements when dealing with ordinary diesel.

[0004] However, facing the special properties of biodiesel, conventional diesel filtration systems expose significant limitations: (1) The high water content of biodiesel far exceeds that of ordinary diesel, and the separation efficiency and accuracy of existing filtration systems are insufficient to completely remove moisture, resulting in residual moisture continuously eroding the precision components of the fuel injector, accelerating abnormal wear, and then triggering a series of faults such as a decrease in engine power and a sharp increase in fuel consumption, seriously shortening the service life of the engine. (2) Due to differences in raw materials (such as waste oil and palm oil) and production processes of biodiesel, the quality is uneven, and the key indicators such as impurity content and water ratio fluctuate greatly. This makes it difficult to estimate the actual load of the filter element, and the mode of maintenance and service according to a fixed cycle can no longer adapt to its complex working conditions. Premature replacement of the filter element will cause waste of resources, while delayed replacement may increase the risk of damage to the fuel system due to filter element blockage or failure. Summary of the Invention

[0005] In view of the problems existing in the above-mentioned prior art, the present invention provides a biodiesel filtration system, method and mining excavator.

[0006] To achieve the above object, a biodiesel filtration system adopted by the present invention includes:

[0007] A filling pipeline, connected between a refueling vehicle and a vehicle fuel tank, on which a diesel coarse filter is installed, and the diesel coarse filter is used for preliminarily filtering moisture and impurities in biodiesel;

[0008] Filter pipeline, including a first pipeline and a second pipeline. The first pipeline is connected between the vehicle fuel tank and the engine. An oil-water separator, a primary fuel filter, a fuel water content sensor, and a three-way solenoid valve are successively installed on the first pipeline in the direction from the vehicle fuel tank to the engine. The second pipeline is connected in parallel between the three-way solenoid valve and the engine, and a secondary fuel filter is installed on the second pipeline. The oil-water separator includes a fuel lift pump, a water level sensor, and a drain solenoid valve.

[0009] The vehicle controller is respectively connected to the water level sensor, the drain solenoid valve, the fuel water content sensor, the three-way solenoid valve, and the instrument. The water level sensor is used to monitor the water level in the water accumulation cup of the oil-water separator in real time and transmit the water level information to the vehicle controller. When the water level > the set value, the vehicle controller controls the drain solenoid valve to drain water after the vehicle stops. The fuel water content sensor is used to detect the fuel water content and transmit it to the vehicle controller. When the water content ≤ the engine set value, the vehicle controller controls the three-way solenoid valve to make the fuel flow to the engine through the three-way solenoid valve. When the water content > the engine set value, the vehicle controller controls the three-way solenoid valve to make the fuel flow to the engine through the secondary fuel filter.

[0010] As an improvement, a first differential pressure sensor is provided on the pipeline on the outlet side of the primary fuel filter, and a second differential pressure sensor is provided on the pipeline on the outlet side of the secondary fuel filter. The first and second differential pressure sensors are respectively connected to the vehicle controller. The first and second differential pressure sensors are used to detect the oil inlet resistance and transmit it to the vehicle controller.

[0011] When the oil inlet resistance detected by the first differential pressure sensor > the set value, the instrument is triggered by the vehicle controller to display the maintenance alarm information of the primary fuel filter.

[0012] When the oil inlet resistance detected by the second differential pressure sensor > the set value, the vehicle controller first judges whether the oil inlet resistance detected by the first differential pressure sensor is greater than the set value. If the oil inlet resistance detected by the first differential pressure sensor ≤ the set value at this time, the vehicle controller triggers the instrument to display the maintenance alarm information of the secondary fuel filter. If the oil inlet resistance detected by the first differential pressure sensor > the set value at this time, the vehicle controller triggers the instrument to first display the maintenance alarm information of the primary fuel filter. After the filter element of the primary fuel filter is maintained, it is then judged according to the oil inlet resistance situation detected by the second differential pressure sensor whether to trigger the instrument to display the maintenance alarm information of the secondary fuel filter.

[0013] As an improvement, after the filter element of the primary fuel filter is maintained, if the oil inlet resistance detected by the second differential pressure sensor > the set value, the vehicle controller triggers the instrument to display the maintenance alarm information of the secondary fuel filter. If the oil inlet resistance detected by the second differential pressure sensor ≤ the set value, the vehicle controller does not display the maintenance alarm information.

[0014] As an improvement, it further comprises a heat dissipation pipeline connected between the engine and the vehicle fuel tank, and a fuel radiator is installed on the heat dissipation pipeline.

[0015] As an improvement, the diesel coarse filter is provided with a drain ball valve for manually draining water when the water level in the water cup is high and for replacing the filter element when the refueling resistance is large.

[0016] As an improvement, when the water level in the water cup in the oil-water separator is greater than the set value, the instrument displays a high water level alarm message.

[0017] A second aspect of the present invention further provides a biodiesel filtration method, based on the biodiesel filtration system, comprising the following steps:

[0018] Perform preliminary filtration of the added biodiesel through a diesel coarse filter;

[0019] Use the oil-water separator for secondary filtration and control the water release solenoid valve to release water according to the water level sensor data;

[0020] The water content in the fuel is detected by the fuel water sensor, and the three-way solenoid valve is controlled to adjust the fuel to flow directly into the engine through the three-way solenoid valve or to flow into the engine after passing through the secondary fine filter of the fuel.

[0021] As an improvement, the following steps are also included: judging the filter element maintenance timing based on the oil inlet resistance detected by the pressure difference sensor on the outlet side of the first-level fuel fine filter and the second-level fuel fine filter.

[0022] As an improvement, the step of determining when to perform filter element maintenance includes:

[0023] When the fuel inlet resistance after the first-stage fine filtration is greater than the set value, the filter element of the first-stage fine filtration of the fuel should be maintained;

[0024] When the fuel inlet resistance after the second-level fine filtration is greater than the set value, combined with the fuel inlet resistance after the first-level fine filtration, it is determined that the filter element of the first-level fine filtration and / or the filter element of the second-level fine filtration of the fuel should be maintained.

[0025] According to a third aspect of the present invention, a mining excavator is provided, on which the biodiesel filtration system is installed.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention sets a fuel water content sensor in the filtration pipeline to realize real-time and accurate detection of the water content of biodiesel. The sensor transmits the acquired water content data to the vehicle controller. The vehicle controller controls the three-way solenoid valve to timely adjust the filtration level of biodiesel fine filtration, accurately controlling the quality of biodiesel entering the engine.

[0028] 2. The present invention respectively sets highly sensitive differential pressure sensors on the pipelines after the primary fuel filtration and the secondary fuel filtration, which can monitor the fuel inlet resistance in real time and accurately. The differential pressure data is transmitted to the controller, and the controller analyzes and processes the data: when the inlet resistance exceeds the preset limit, the instrument displays an alarm message, accurately grasping the maintenance time of the biodiesel fine filter element, greatly reducing the maintenance cost, effectively avoiding the risk of abnormal wear of the engine caused by filter element blockage, and prolonging the service life of the engine.

[0029] 3. The present invention adds a large-flow coarse filter in the biodiesel filling pipeline, which can maintain high filtration performance. This coarse filter can effectively filter out most of the water and impurities in the biodiesel, avoiding a large amount of water precipitation at the bottom of the vehicle fuel tank, causing faults such as filter system pressure or abnormal wear when entering the engine.

[0030] 4. The oil-water separator of the present invention is provided with a water level sensor and a drain solenoid valve. The data of the water level sensor is transmitted to the vehicle controller in real time. When the water level in the water accumulation cup of the oil-water separator exceeds the highest liquid level, the instrument displays an alarm message. At the same time, after shutdown, the controller controls the drain solenoid valve to open for draining water, and controls the solenoid valve to close after draining water, realizing automatic draining water after shutdown, which can avoid other faults caused by abnormal operation of the drain solenoid valve during operation, and at the same time can reduce the manual draining cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0033] Figure 2 It is a flowchart of the method of the present invention;

[0034] Figure 3 It is a control principle diagram of the present invention;

[0035] In the figure: 1. Diesel coarse filter, 2. Vehicle fuel tank, 3. Oil-water separator, 3-1. Fuel lift pump, 3-2. Water level sensor, 3-3. Drain solenoid valve, 4. Primary fuel filter, 5. First differential pressure sensor, 6. Fuel water content sensor, 7. Three-way solenoid valve, 8. Secondary fuel filter, 9. Second differential pressure sensor, 10. Fuel radiator. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the technical solutions of this application will be described in detail through specific embodiments below. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. Without conflict, the technical features in the embodiments of this application and the embodiments can be combined with each other.

[0037] Embodiment 1

[0038] As Figure 1 、 Figure 2 and Figure 3 shown, a biodiesel filtration system includes a vehicle controller, a filling pipeline and a filtration pipeline; the filling pipeline is connected between a fuel tanker and a vehicle fuel tank 2, and a diesel coarse filter 1 is installed thereon. The diesel coarse filter 1 is used to preliminarily filter moisture and impurities in biodiesel. Since the filling gun has a large flow rate and a short filling time, the diesel coarse filter 1 has the characteristics of a large flow rate, a relatively large volume and a general filtration accuracy.

[0039] The filtration pipeline includes a first pipeline and a second pipeline. The first pipeline is connected between the vehicle fuel tank 2 and the engine. An oil-water separator 3, a fuel primary fine filter 4, a fuel water content sensor 6 and a three-way solenoid valve 7 are sequentially installed on the first pipeline in the direction from the vehicle fuel tank 2 to the engine. The second pipeline is connected in parallel between the three-way solenoid valve 7 and the engine, and a fuel secondary fine filter 8 is installed on the second pipeline. The oil-water separator 3 includes a fuel lift pump 3-1, a water level sensor 3-2 and a drain solenoid valve 3-3. The fuel lift pump 3-1 is connected to the vehicle controller through an engine controller. The engine controller can obtain the operating parameters such as the engine speed and load in real time, and accurately control the speed of the fuel lift pump 3-1 according to the actual working requirements of the engine. Through the connection between the vehicle controller and the engine controller and the fuel lift pump 3-1, the pressure in the fuel pipeline can be dynamically monitored and adjusted.

[0040] The vehicle controller is respectively connected to the water level sensor 3-2, the drain solenoid valve 3-3, the fuel water content sensor 6, the three-way solenoid valve 7 and the instrument. The water level sensor 3-2 is used to monitor the water level in the water accumulation cup of the oil-water separator 3 in real time and transmit the water level information to the vehicle controller. When the water level > the set value, the vehicle controller controls the drain solenoid valve 3-3 to drain water after the vehicle stops, which can avoid excessive water accumulation causing water to mix into the fuel, prevent problems such as incomplete engine combustion, power decline and component corrosion caused by too high fuel water content, and ensure that the fuel entering the engine always maintains good quality.

[0041] The fuel water sensor 6 detects the water content in the fuel and transmits it to the vehicle controller. When the water content is less than or equal to the engine's set value, the vehicle controller controls the three-way solenoid valve 7 to allow the fuel to flow through the valve to the engine. When the water content is greater than the engine's set value, the vehicle controller controls the valve 7 to allow the fuel to flow through the secondary fine filter 8 to the engine. This regulation method effectively removes excess water from the fuel, reducing the risk of water-related failures such as injector clogging and reduced combustion efficiency, thereby ensuring stable engine operation.

[0042] In some embodiments, as Figure 1 As shown, a first differential pressure sensor 5 is provided on the pipeline on the outlet side of the first-level fuel fine filter 4, and a second differential pressure sensor 9 is provided on the pipeline on the outlet side of the second-level fuel fine filter 8. The first and second differential pressure sensors are respectively connected to the vehicle controller. The first differential pressure sensor 5 is used to detect the oil inlet resistance on the outlet side of the first-level fuel fine filter 4, and the second differential pressure sensor 9 is used to detect the oil inlet resistance on the outlet side of the second-level fuel fine filter 8. Each differential pressure sensor transmits the detected oil inlet resistance to the vehicle controller.

[0043] When the oil inlet resistance detected by the first differential pressure sensor 5 is greater than the set value, the vehicle controller triggers the instrument to display the maintenance alarm information of the first-level fuel fine filter 4, and the filter element of the first-level fuel fine filter 4 is maintained;

[0044] When the oil inlet resistance detected by the second differential pressure sensor 9 is greater than the set value, the vehicle controller first determines whether the oil inlet resistance detected by the first differential pressure sensor 5 is greater than the set value. If the oil inlet resistance detected by the first differential pressure sensor 5 is less than or equal to the set value, the vehicle controller triggers the instrument to display the maintenance alarm information of the secondary fuel filter 8. If the oil inlet resistance detected by the first differential pressure sensor 5 is greater than the set value, the vehicle controller triggers the instrument to first display the maintenance alarm information of the primary fuel filter 4 and simultaneously performs maintenance operations on the filter element of the primary fuel filter 4.

[0045] After the filter element of the primary fuel filter 4 is maintained, it is then determined whether to trigger the maintenance alarm information of the secondary fuel filter 8 on the instrument according to the inlet oil resistance detected by the second differential pressure sensor 9. Specifically, after the filter element of the primary fuel filter 4 is maintained, if the inlet oil resistance detected by the second differential pressure sensor 9 > the set value, the vehicle controller triggers the instrument to display the maintenance alarm information of the secondary fuel filter 8. If the inlet oil resistance detected by the second differential pressure sensor 9 ≤ the set value, the vehicle controller does not display the maintenance alarm information. In the present invention, high-sensitivity differential pressure sensors are respectively arranged in the pipelines after the primary fuel filter and the secondary fuel filter, which can monitor the inlet oil resistance of the fuel in real time and accurately. The differential pressure data is transmitted to the controller, and the controller analyzes and processes the data. When the inlet oil resistance exceeds the preset limit, the instrument displays the alarm information, accurately grasping the maintenance time of the biodiesel fine filter element, which can greatly reduce the maintenance cost, effectively avoid the risk of abnormal wear of the engine caused by filter element blockage, and extend the service life of the engine.

[0046] In some embodiments, such as Figure 1 shown, it further includes a cooling pipeline, and the cooling pipeline is connected between the engine and the vehicle fuel tank 2, and a fuel radiator 10 is installed on the cooling pipeline. When the engine is working, the high-temperature fuel flows into the fuel radiator 10 through the cooling pipeline, and the fuel temperature is reduced by using air convection or coolant circulation (depending on the type of radiator), and then flows back to the vehicle fuel tank 2 to form a temperature closed-loop control.

[0047] In some embodiments, the diesel pre-filter 1 is provided with a drain ball valve. When the water level in the water accumulation cup of the diesel pre-filter 1 is relatively high, the ball valve is manually opened to drain water. At the same time, when the refueling resistance is large, the filter element is replaced.

[0048] In some embodiments, when the water level in the water accumulation cup of the oil-water separator 3 > the set value, the instrument displays the high water level alarm information to remind the operator to process the accumulated water in time, avoiding water entering the engine along with the fuel and ensuring the normal operation of the power system.

[0049] Embodiment 2

[0050] As Figures 1-3 shown, a biodiesel filtering method, based on the biodiesel filtering system described in Embodiment 1, includes the following steps:

[0051] When the mining excavator needs to refuel, the refueling vehicle uses a filling gun to fill the biodiesel into the vehicle fuel tank 2 through the filling pipeline. The biodiesel filling pipeline described in the present invention is provided with a diesel pre-filter 1, and the diesel pre-filter 1 can filter out a large amount of water in the biodiesel. The biodiesel has been preliminarily filtered when it reaches the vehicle fuel tank 2;

[0052] When the engine starts and the vehicle begins to operate, biodiesel first reaches the oil-water separator 3 from the vehicle fuel tank 2 for filtration. The oil-water separator 3 is equipped with a fuel lift pump 3-1. Under the action of the fuel lift pump 3-1, diesel reaches the oil-water separator 3. The oil-water separator 3 is configured with a water level sensor 3-2 and a drain solenoid valve 3-3. The water level sensor 3-2 transmits the water level signal in the water accumulation cup of the oil-water separator 3 to the vehicle controller in real time. When the water level L is greater than the set value H, the instrument displays a high water level alarm message. At the same time, the vehicle controller controls the drain solenoid valve 3-3 to open for draining water after the vehicle stops. After the water is drained, the drain solenoid valve 3-3 closes.

[0053] The diesel filtered by the oil-water separator 3 passes through a pipeline to the primary fuel filter 4 for further filtration. A fuel water content sensor 6 is provided on the diesel pipeline after primary fine filtration. The fuel water content sensor 6 detects the water content percentage signal in the fuel and transmits it to the vehicle controller. When the detected value S ≤ the engine set value S0, the vehicle controller controls the three-way solenoid valve 7 to directly flow to the engine through the original path. When the detected value S > the engine set value S0, the vehicle controller controls the original path of the three-way solenoid valve 7 to close and the path flowing to the secondary fuel filter 8 to open to filter the water in the fuel again, and then continue to flow to the engine, and the injector injects fuel for normal combustion operation. This route can effectively control the filtration level of biodiesel, making the filtered biodiesel meet the usage requirements of the engine, reducing abnormal wear of the engine, and prolonging the service life of the engine.

[0054] A first differential pressure sensor 5 is provided on the fuel pipeline after the primary fuel filter 4. The signal of the first differential pressure sensor 5 is transmitted to the vehicle controller in real time. When the inlet oil resistance P1 detected by the first differential pressure sensor 5 > the set value P0, the instrument displays a maintenance alarm message, and the filter element of the primary fuel filter 4 is maintained after parking.

[0055] A second differential pressure sensor 9 is also provided on the fuel pipeline after the secondary fuel filter 8. The signal of the second differential pressure sensor 9 is transmitted to the vehicle controller in real time. When the inlet oil resistance P2 detected by the second differential pressure sensor 9 > the set value P0, the vehicle controller makes a further judgment. If P1 ≤ P0 at this time, the filter element of the secondary fuel filter 8 is maintained after the vehicle stops. When P1 > P0, the filter element of the primary fuel filter 4 is maintained after the vehicle stops first, and then the relationship between P2 and P0 at this time is continuously judged. If P2 ≤ P0, it continues to operate. If P2 > P0, the filter element of the secondary fuel filter 8 is maintained after the vehicle stops.

[0056] The present invention outputs the fuel inlet resistance data to the controller through a differential pressure sensor, which can accurately identify the maintenance time of the fuel fine filter element, neither causing cost waste due to premature maintenance nor delaying maintenance, and avoiding the entry of inferior biodiesel into the engine, which may cause abnormal wear of the engine and increase the risk of failure.

[0057] Embodiment 3

[0058] A mining excavator, on which the biodiesel filtering system described above is installed.

[0059] In addition, those skilled in the art can understand that although some of the embodiments described herein include certain features contained in other embodiments rather than other features, the combination of features of different embodiments also means that it is within the protection scope of the present invention and forms different embodiments. For example, in the above embodiments, those skilled in the art can use them in a combined manner according to the known technical solutions and the technical problems to be solved in this application.

Claims

1. A biodiesel filtration system, characterized in that: include: A filling pipeline is connected between a refueling truck and a vehicle fuel tank (2), and a diesel coarse filter (1) is installed on the filling pipeline. The diesel coarse filter (1) is used for preliminarily filtering water and impurities in biodiesel; A filter pipeline comprises a first pipeline and a second pipeline, wherein the first pipeline is connected between a vehicle fuel tank (2) and an engine, and an oil-water separator (3), a primary fuel fine filter (4), a fuel water sensor (6), and a three-way solenoid valve (7) are sequentially installed on the first pipeline in a direction from the vehicle fuel tank (2) to the engine, and the second pipeline is connected in parallel between the three-way solenoid valve (7) and the engine, and a secondary fuel fine filter (8) is installed on the second pipeline, wherein the oil-water separator (3) comprises a fuel lift pump (3-1), a water level sensor (3-2), and a water drain solenoid valve (3-3); The vehicle controller is respectively connected to the water level sensor (3-2), the water discharge solenoid valve (3-3), the fuel water content sensor (6), the three-way solenoid valve (7) and the instrument. The water level sensor (3-2) is used to monitor the water level of the water storage cup in the oil-water separator (3) in real time and transmit the water level information to the vehicle controller. When the water level is greater than the set value, the vehicle controller controls the water discharge solenoid valve (3-3) to discharge water after the vehicle stops. The fuel water content sensor (6) is used to detect the fuel water content and transmit the information to the vehicle controller. When the water content is less than or equal to the engine set value, the vehicle controller controls the three-way solenoid valve (7) to allow the fuel to flow to the engine through the three-way solenoid valve (7). When the water content is greater than the engine set value, the vehicle controller controls the three-way solenoid valve (7) to allow the fuel to flow to the engine through the fuel secondary fine filter (8).

2. A biodiesel filtration system according to claim 1, characterized in that: A first differential pressure sensor (5) is provided on the pipeline at the outlet side of the first-stage fine filter (4) of the fuel, and a second differential pressure sensor (9) is provided on the pipeline at the outlet side of the second-stage fine filter (8) of the fuel. The first and second differential pressure sensors are respectively connected to the vehicle controller, and the first and second differential pressure sensors are used to detect the oil inlet resistance and transmit it to the vehicle controller. When the oil inlet resistance detected by the first differential pressure sensor (5) is greater than a set value, the vehicle controller triggers the instrument to display a maintenance alarm message for the first-level fine filter (4) of the fuel; When the oil inlet resistance detected by the second differential pressure sensor (9) is greater than the set value, the vehicle controller first determines whether the oil inlet resistance detected by the first differential pressure sensor (5) is greater than the set value. If the oil inlet resistance detected by the first differential pressure sensor (5) is less than or equal to the set value, the vehicle controller triggers the instrument to display the maintenance alarm information of the secondary fuel filter (8). If the oil inlet resistance detected by the first differential pressure sensor (5) is greater than the set value, the vehicle controller triggers the instrument to display the maintenance alarm information of the primary fuel filter (4). After the filter element of the primary fuel filter (4) is maintained, the vehicle controller determines whether to trigger the instrument to display the maintenance alarm information of the secondary fuel filter (8) based on the oil inlet resistance detected by the second differential pressure sensor (9).

3. A biodiesel filtration system according to claim 2, characterized in that: When the filter element of the first-stage fine filter (4) of the fuel is maintained, if the oil inlet resistance detected by the second differential pressure sensor (9) is greater than a set value, the vehicle controller triggers the instrument to display a maintenance alarm message of the second-stage fine filter (8); if the oil inlet resistance detected by the second differential pressure sensor (9) is less than or equal to the set value, the vehicle controller does not display the maintenance alarm message.

4. A biodiesel filtration system according to claim 1, characterized in that: It also includes a heat dissipation pipeline connected between the engine and the vehicle fuel tank (2), and a fuel radiator (10) is installed on the heat dissipation pipeline.

5. The biodiesel filtration system according to claim 1, characterized in that: The diesel coarse filter (1) is provided with a drain ball valve, which is used for manually draining water when the water level in the water cup is high and for replacing the filter element when the refueling resistance is large.

6. The biodiesel filtration system according to claim 1, characterized in that: When the water level in the water storage cup of the oil-water separator (3) is greater than the set value, the instrument displays a high water level alarm message.

7. A biodiesel filtration method, characterized in that: The biodiesel filtration system according to any one of claims 1 to 6 comprises the following steps: Performing preliminary filtration on the added biodiesel through a diesel coarse filter (1); The oil-water separator (3) is used for secondary filtration, and the water discharge solenoid valve (3-3) is controlled to discharge water according to the data of the water level sensor (3-2); The water content of the fuel is detected by a fuel water sensor (6), and the three-way solenoid valve (7) is controlled to adjust the fuel to flow directly into the engine through the three-way solenoid valve (7) or to flow into the engine after passing through the fuel secondary fine filter (8).

8. A biodiesel filtration method according to claim 7, characterized in that: The following steps are also included: The maintenance time of the filter element is determined based on the oil inlet resistance detected by the pressure difference sensor on the outlet side of the fuel first-level fine filter (4) and the fuel second-level fine filter (8).

9. A biodiesel filtration method according to claim 8, characterized in that: The step of determining when to perform filter element maintenance includes: When the oil inlet resistance after the first-stage fine filter (4) of the fuel is greater than the set value, the filter element of the first-stage fine filter (4) of the fuel is maintained; When the oil inlet resistance after the secondary fuel filter (8) is greater than the set value, combined with the oil inlet resistance after the primary fuel filter (4), it is determined that the filter element of the primary fuel filter (4) or / and the filter element of the secondary fuel filter (8) should be maintained.

10. A mining excavator, characterized in that: The mining excavator is equipped with the biodiesel filtration system according to any one of claims 1 to 6.

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