Method for efficient soot trapping

Abstract

The application discloses a soot efficient trapping method, and particularly relates to the following steps: fuel oil is injected into an oil injection tank through a peristaltic pump; when fuel oil of a soot generator submerges an oil pipe scale line, an electronic igniter switch is started, an oil nozzle starts to ignite and burn, and a vacuum pump is started, so that the soot generator is in a negative pressure state; soot generated by the soot generator enters a primary collector and a secondary collector to be collected; when the pressure of the secondary collector exceeds -1800 Pa or the pressure of the vacuum pump exceeds -2000 Pa, the trapping is ended; and the soot in the primary collector and the secondary collector is cleaned and collected. According to the method, the product generated after the fuel oil is burned in the soot generator is used as soot, the process that the combustion chamber of an engine generates soot in a working state is reduced to the maximum extent, the obtained soot product is not doped with other lubricating oil additive components, and raw material guarantee is provided for subsequent investigation on the dispersion performance of soot in lubricating oil.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of soot processing, and particularly relates to a soot high-efficiency capturing method. BACKGROUND

[0002] With the progress of engine technology and increasingly stringent environmental protection requirements, countries around the world have introduced increasingly stringent emission regulations to limit vehicle emissions, and the design of engines is developing towards high efficiency, energy saving and low emission. Engine manufacturers (OEM) have adopted new technologies such as delayed injection, exhaust gas recirculation (EGR) and particulate trap. However, under the condition of delayed fuel injection, fuel combustion is not sufficient, and unburned fuel due to flameout remains on the cylinder wall. In addition, lubricating oil also enters the combustion chamber through channels such as blow-by gas, valve stem seal and piston ring wiping, and oil vapor from the inner wall of the cylinder and the combustion chamber, and long-term accumulation forms soot. Soot particles enter the oil through the gap between the piston ring and the cylinder liner, and the further aggregation of soot particles in the oil forms larger particles, causing rapid growth of oil viscosity, clogging of the oil filter, forming abrasive particles, and causing serious wear of the friction pair. When the concentration of soot is high enough, it will precipitate, which is one of the reasons for the clogging of the filter, so the oil should have good dispersing properties to ensure that soot can be suspended in the oil even when the concentration is very high. Soot is an abnormal abrasive that can erode the boundary lubrication surface at high concentrations, which can cause serious engine wear. Some wear characteristics caused by soot include: tappet polishing, cam lobe wear, and piston ring wear. If too much soot accumulates in the lubricating oil, it will cause the oil viscosity to increase, and excessive oil viscosity will also exacerbate the wear of engine parts. Therefore, inhibiting the increase in oil viscosity caused by the increase in soot is an important indicator for evaluating the dispersing properties of the oil.

[0003] In the currently reported literature, the oil samples used to simulate the dispersing properties of lubricating oil are mostly soot in used oil or carbon black directly simulating soot. The soot in used oil is closest to the actual operating conditions of the engine, but it contains other lubricating oil additive components. Different types of additives have different structures, physicochemical properties such as acid and base, and different mechanisms of action on soot. When using such soot in used oil as a reference oil for lubricating oil dispersing property test, there is a lot of interference and uncertainty. Carbon black particles are inorganic substances, which are very different from the structure and composition of real soot, and there is a big gap in the distribution state in the oil. Moreover, carbon black particles have poor solubility and dispersion in oil, and are prone to agglomeration and sedimentation, which is the main reason for the inconsistency between simulation experiments and actual bench tests, directly affecting the effectiveness of the simulation dispersion method, and causing great obstacles to the early development of lubricating oil. SUMMARY

[0004] The application aims at providing a soot high-efficiency trapping method, and solves the problem of low soot trapping efficiency in the prior art.

[0005] The technical scheme adopted by the application is a soot high-efficiency trapping method, which is implemented according to the following steps:

[0006] Step 1: fuel oil is injected into an oil injection tank by a peristaltic pump, when the fuel oil of a soot generator submerges the oil pipe scale line 0, an electronic igniter switch is started, an oil nozzle starts to ignite and burn, the height of the outer flame of the burning flame is controlled between 1 cm and 2 cm, the moisture in the inverted U-shaped protective cover on the top of the oil injection tank is dried for 1 min, and then the height of the outer flame of the burning flame is controlled between 2.5 cm and 3 cm;

[0007] Step 2: a vacuum pump is started to be in a negative pressure state, soot particles generated by the soot generator enter a primary trap and a secondary trap in sequence for collection;

[0008] Step 3: the soot particles are filtered by a coarse filter screen and a fine filter screen in the primary trap in sequence, the soot particles are enriched in the primary trap, the coarse filter screen and the fine filter screen are blocked, the pressure in the primary trap gradually increases, the soot particles that are not filtered enter the secondary trap and are filtered by a filter cleaner, the filter cleaner is blocked after the soot particles are accumulated, the pressure in the secondary trap gradually increases, and when the pressure reaches a certain degree, the whole trapping process is ended, and the peristaltic pump and the electronic igniter are turned off;

[0009] Step 4: after the primary trap and the secondary trap are cooled to normal temperature, the soot in the primary trap and the secondary trap is cleaned and collected.

[0010] The application also has the characteristics that

[0011] In step 1, the pump speed of the peristaltic pump 8 is set to 11 mL / h-12 mL / h.

[0012] In step 2, the pressure of the primary trap is between-700 Pa and-800 Pa, the pressure of the secondary trap is between-1400 Pa and-1800 Pa, and the pressure of the vacuum pump 20 is between-1600 Pa and-2000 Pa.

[0013] In step 2, the temperature in the primary trap is kept between 95 ℃ and 100 ℃, and the temperature in the secondary trap is kept between 75 ℃ and 85 ℃.

[0014] In step 3, when the pressure of the secondary trap exceeds-1800 Pa or the pressure of the vacuum pump exceeds-2000 Pa, the vacuum pump stops working, and the whole trapping process is ended.

[0015] The application has the beneficial effects that

[0016] The efficient soot collection method of the present invention uses the product generated after the fuel oil is burned in the soot generator as soot, which maximizes the reproduction of the soot generation process in the combustion chamber of the engine under working conditions. The soot product obtained is not mixed with other lubricating oil additive components, which provides a raw material guarantee for subsequent evaluation of the dispersion performance of soot in lubricating oil. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the soot collection device of the present invention;

[0018] Figure 2 These are photographs of soot collected in the primary and secondary traps of this invention.

[0019] Figure 3 This is a dispersion diagram of soot and carbon black in oil products;

[0020] Figure 4 This is a diffusion diagram of soot test oil and carbon black test oil in oil products.

[0021] In the diagram, 1. Soot generator, 2. Fuel tank, 3. Fuel injector, 4. Fuel pipe, 5. Electronic igniter, 6. Inverted U-shaped protective cover, 7. Pipe, 8. Peristaltic pump, 9. Fuel tank, 10. Primary collection shell, 11. Coarse filter, 12. Fine filter, 13. First pressure gauge, 14. Secondary collection shell, 15. Filter, 16. Exhaust pipe, 17. Gas outlet pipe, 18. Dryer, 19. Gas pipe, 20. Vacuum pump, 21. Second pressure gauge. Detailed Implementation

[0022] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0023] The soot collection device of the present invention, such as Figure 1 As shown, the device includes a soot generator 1, which includes an oil filling tank 2. An oil nozzle 3 is fixedly inserted through the center of the top of the oil filling tank 2. The oil nozzle 3 is connected to an oil pipe 4, the end of which extends into the bottom of the oil filling tank 2. The oil pipe 4 has three graduation lines (-0.5mm, 0, +0.5mm) and a valve at its top. An electronic igniter 5 is located at the bottom of the oil nozzle 3. An inverted U-shaped protective cover 6 is installed on the top of the oil filling tank 2 to protect the oil nozzle 3. The top of the inverted U-shaped protective cover 6 is connected to the bottom of the primary collector via a conduit 7. The device also includes a peristaltic pump 8, whose inlet is connected to an oil delivery tank 9, and whose outlet extends into the oil filling tank 2.

[0024] The primary trap includes a primary trap housing 10. Inside the primary trap housing 10, multiple coarse filters 11 and fine filters 12 are alternately arranged from top to bottom. The spacing between the coarse and fine filters is 8-15 cm. The uppermost part of the primary trap housing 10 is the fine filter, and the lowermost part is the coarse filter. The conduit 7 is connected to the bottom of the coarse filter. The pore size of the coarse filter is 3-5 mm, and the pore size of the fine filter is 1-1.5 mm. A first pressure gauge 13 is also provided on the top of the primary trap housing 10.

[0025] The first-stage trapping housing 10 is provided with a heat transfer oil inlet and a heat transfer oil outlet at the bottom and top, respectively. The inner wall of the first-stage trapping housing 10 is also provided with a first temperature sensor; the first temperature sensor is electrically connected to the first controller.

[0026] The secondary trap includes a secondary trap housing 14, inside which a filter 15 is installed. The filter 15 can further filter the flue gas to ensure the performance and output pressure of the flue gas. The top of the primary trap housing 10 is connected to the secondary trap housing 14 through an exhaust pipe 16. The secondary trap housing 14 is connected to the bottom of the dryer 18 through an exhaust pipe 17. The top of the dryer 18 is connected to the vacuum pump 20 through an air pipe 19. A second pressure gauge 21 is also installed on the top of the secondary trap housing 14.

[0027] The secondary trap shell 14 is provided with a heat transfer oil inlet and a heat transfer oil outlet at the bottom and top, respectively. A second temperature sensor is also provided on the inner wall of the secondary trap shell 14. The second temperature sensor is electrically connected to the second controller.

[0028] The present invention provides a highly efficient soot collection method, based on the aforementioned soot collection device, and is implemented according to the following steps:

[0029] Step 1: Inject fuel oil into the fuel tank 2 using the peristaltic pump 8. When the fuel oil in the soot generator is submerged above the 0 mark on the fuel line 4, turn on the electronic ignition switch. The fuel injector 3 will start ignition and combustion. Adjust the height of the combustion flame using the valve on the fuel line 4. First, control the height of the outer flame between 1cm and 2cm. Preheat for about 1 minute with a low flame to dry the moisture inside the inverted U-shaped protective cover 6. Then, adjust the height of the outer flame between 2.5cm and 3cm.

[0030] The pumping speed of the peristaltic pump 8 is set to 11 mL / h to 12 mL / h. During the experiment, dynamic adjustments are made. The adjustment principle is as follows: when the fuel oil level in the fuel tank 2 is 0.5 mm higher than the scale line of the oil pipe 4, the pump speed is appropriately reduced; when the fuel oil level in the fuel tank 2 is -0.5 mm lower than the scale line of the oil pipe 4, the pump speed is appropriately increased.

[0031] Step 2: Start the vacuum pump 20 to put the entire collection device under negative pressure. The soot generated by the soot generator 1 enters the primary collector and the secondary collector in sequence.

[0032] The pressure of the primary trap is between -700 and -800 Pa, the pressure of the secondary trap is between -1400 and -1800 Pa, and the pressure of the vacuum pump 20 is between -1600 and -2000 Pa.

[0033] The temperature inside the primary trap is maintained at 95–100℃; the temperature inside the secondary trap is maintained at 75–85℃.

[0034] Fuel oil combustion produces a large amount of moisture. If not drained in time, this moisture mixes with the soot and clumps together, adhering to the filter screen of the trap and quickly clogging it, affecting the overall trapping efficiency of the device. After the test, the soot adhering to the trap filter is difficult to remove. Therefore, temperature control devices are installed on both traps to maintain a certain temperature inside their chambers, effectively draining the moisture and improving trapping efficiency. The drained moisture is ultimately absorbed by the dryer, preventing it from entering the vacuum pump 20.

[0035] Step 3: The soot particles are filtered sequentially by the coarse filter 11 and the fine filter 12 in the primary collector. The soot particles gradually accumulate in the primary collector. As the amount of accumulated soot particles increases, the accumulated soot particles slowly clog the coarse and fine filters, causing the pressure on the first pressure gauge 13 of the primary collector to gradually increase. Unfiltered soot particles enter the secondary collector and are filtered by the filter 15. The soot particles are slowly adsorbed on the filter 15. As the amount of adsorbed soot particles increases, the accumulated soot particles slowly clog the filter 15, causing the pressure on the second pressure gauge 21 of the secondary collector to gradually increase. When the pressure of the secondary collector exceeds -1800Pa or the pressure of the vacuum pump 20 exceeds -2000Pa, the vacuum pump 20 stops working, the entire collection process ends, and then the peristaltic pump 8 and the electronic igniter 5 are turned off.

[0036] Step 4: After the primary and secondary collectors have cooled to room temperature, clean and collect the soot inside the primary and secondary collectors.

[0037] The soot collected in the primary and secondary traps is as follows Figure 2 As shown, the soot particles collected in the primary collector are relatively large due to the filtration of the coarse and fine filters, while the unfiltered soot particles enter the secondary collector, where the soot particles are smaller.

[0038] Example 1: Comparative test of the solubility of soot and carbon black in oil products

[0039] The soot and comparative carbon black provided by this invention were added to API CK-4 15W-40 diesel engine oil at a ratio of 4.5%, respectively. The mixture was stirred at a constant temperature of 300 rpm for 2 hours in an oil bath at 150°C, and then left to stand at room temperature for 48 hours to observe its dispersion. The results are as follows: Figure 3 As shown, when it was first placed, the soot and carbon black were evenly dispersed in the oil. However, after standing in a room temperature environment for 48 hours, the carbon black showed a layering phenomenon in the oil, while the soot remained evenly dispersed in the oil.

[0040] Example 2: Comparative Test on the Dispersibility of Soot and Carbon Black in Oil Products

[0041] The soot and comparative carbon black provided by this invention were added to API CK-4 15W-40 diesel engine oil at a ratio of 4.5%, respectively. The mixture was heated and stirred at 150°C for 1.5 hours. While still hot, a drop of the test oil was placed on filter paper and placed in an oven at 80°C for 2 hours. The ratio of the diffusion zone to the oil zone was measured to obtain spot test data. A higher spot dispersion value indicates better low-temperature sludge dispersibility. Results are as follows... Figure 4 As shown, after maintaining a constant temperature of 80℃ for 2 hours, both the oil ring and diffusion ring of the test oil prepared with soot diffused outwards, while only the oil ring of the test oil prepared with carbon black diffused outwards, with almost no diffusion in the diffusion ring. Calculations showed that the spot dispersion value of the soot test oil was 65, while that of the carbon black test oil was 24. The results indicate that the soot prepared by this method is well miscible with the oil and diffuses outwards with the oil, eventually settling down. In contrast, carbon black does not dissolve well in the oil; when the oil diffuses, all the carbon black settles down, with almost no outward diffusion.

[0042] The soot collection method of the present invention has the following advantages compared with the prior art:

[0043] (1) The fuel oil is burned in the soot generator, which maximizes the reproduction of the soot generation process in the combustion chamber of the engine under working conditions. The soot obtained is not mixed with other lubricating oil additives, which provides a raw material guarantee for the subsequent investigation of the dispersion performance of soot in lubricating oil.

[0044] (2) Soot collection is carried out through a two-stage collector. First, soot with larger particle diameters is filtered and collected into the first-stage collector through a coarse filter and a fine filter to avoid subsequent pipeline blockage. Then, soot with fine particle diameters is filtered and collected through the second-stage collector filter, which improves the soot collection rate.

[0045] (3) The two collectors are equipped with temperature control devices to maintain a certain temperature in their chambers. This can effectively remove the large amount of water generated during the combustion of fuel oil, preventing it from mixing and clumping with the generated soot and sticking to the filter screen of the collector, thus greatly improving the collection efficiency. The discharged water is eventually absorbed by the dryer, preventing it from entering the vacuum pump.

Claims

1. A high-efficiency soot collection method, implemented using a soot collection device, specifically comprising: a soot generator, which includes an oil filling tank, with an oil nozzle fixedly inserted through the center of the top of the oil filling tank, the oil nozzle connected to an oil pipe, the end of the oil pipe extending into the bottom of the oil filling tank, the oil pipe having three graduation lines, a valve at the top of the oil pipe, an electronic igniter at the bottom of the oil nozzle, and an inverted U-shaped protective cover on the top of the oil filling tank; the top of the inverted U-shaped protective cover is connected to the bottom of the primary collector via a conduit; it also includes a peristaltic pump, the inlet of which is connected to an oil delivery tank, and the outlet of which extends into the oil filling tank; the primary collector includes a primary collector housing, inside which multiple coarse and fine filters are alternately arranged from top to bottom, with the fine filter at the top and the coarse filter at the bottom, a conduit connected below the coarse filter, and a first pressure gauge at the top of the primary collector housing; The primary trap shell has a heat transfer oil inlet and a heat transfer oil outlet at its bottom and top, respectively. A first temperature sensor is also installed on the inner wall of the primary trap shell. The first temperature sensor is electrically connected to a first controller. The secondary trap includes a secondary trap shell, inside which a filter is installed. The top of the primary trap shell is connected to the secondary trap shell via an exhaust pipe. The secondary trap shell is connected to the bottom of the dryer via an exhaust pipe, and the top of the dryer is connected to a vacuum pump via an exhaust pipe. A second pressure gauge is also installed on the top of the secondary trap shell. A heat transfer oil inlet and a heat transfer oil outlet are also provided at the bottom and top of the secondary trap shell, respectively. Its features are, The specific steps are as follows: Step 1: Inject fuel oil into the fuel tank using a peristaltic pump. When the fuel oil in the soot generator is submerged above the 0 mark on the fuel line, turn on the electronic igniter switch. The fuel injector will start to ignite and burn. Control the height of the outer flame of the combustion flame between 1cm and 2cm. Preheat for 1 minute to dry the moisture inside the inverted U-shaped protective cover on the top of the fuel tank. Then control the height of the outer flame of the combustion flame between 2.5cm and 3cm. Step 2: Start the vacuum pump to put it in a negative pressure state. The soot particles generated by the soot generator will enter the primary collector and the secondary collector in sequence for collection. Step 3: The soot particles are filtered sequentially by the coarse and fine filters in the primary trap. The soot particles accumulate in the primary trap, clogging the coarse and fine filters, causing the pressure inside the primary trap to gradually increase. Unfiltered soot particles enter the secondary trap and are filtered by the filter. The soot particles accumulate and clog the filter, causing the pressure inside the secondary trap to gradually increase. When the pressure reaches a certain level, the entire trapping process ends, and the peristaltic pump and electronic igniter are turned off. Step 4: After the primary and secondary collectors have cooled to room temperature, clean and collect the soot inside the primary and secondary collectors.

2. The method for efficient soot collection according to claim 1, characterized in that, In step 1, the pump speed of the peristaltic pump is set to 11 mL / h to 12 mL / h.

3. The method for efficient soot collection according to claim 1, characterized in that, In step 2, the pressure of the primary trap is between -700 and -800 Pa, the pressure of the secondary trap is between -1400 and -1800 Pa, and the pressure of the vacuum pump is between -1600 and -2000 Pa.

4. The method for efficient soot collection according to claim 1, characterized in that, In step 2, the temperature inside the primary trap is maintained between 95 and 100°C; the temperature inside the secondary trap is maintained between 75 and 85°C.

5. The method for efficient soot collection according to claim 1, characterized in that, In step 3, when the pressure of the secondary collector exceeds -1800 Pa or the pressure of the vacuum pump exceeds -2000 Pa, the vacuum pump stops working, and the entire collection process ends.

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