Automobile exhaust purifier

Abstract

The invention relates to the technical field of automobile exhaust purification, in particular to an automobile exhaust purifier which comprises a heat preservation shell, a first pipeline and a second pipeline are fixedly installed in the heat preservation shell, a first spray head and a second spray head are installed outside the heat preservation shell, the first spray head communicates with the first pipeline, the second spray head communicates with the second pipeline, and the first pipeline communicates with an external urea pump. The second pipeline communicates with an external water pump, and a switching device is arranged on the heat preservation shell. Compared with an existing automobile exhaust purifier, after the first spray head for spraying urea is blocked, the standby second spray head is switched to continue to work through the switching device, and the blocked spray head is automatically cleaned through the water pump; the problem that the torque of a vehicle can only be limited to guarantee that tail gas discharged by the vehicle is qualified after an existing nozzle is blocked by urea crystallization is solved, safety accidents caused by the limited torque of the truck after the urea nozzle is crystallized in the uphill process of the truck are avoided, and the life safety of a driver is guaranteed while the tail gas treatment effect is guaranteed to reach the standard.

Description

Technical Field

[0001] This invention relates to the field of automotive exhaust purification technology, specifically to an automotive exhaust purifier. Background Technology

[0002] Diesel engines, compared to gasoline engines, offer higher thermal efficiency, lower fuel consumption, and lower carbon emissions, making them widely used in trucks. However, due to the limitations of cylinder temperature and pressure during diesel combustion, diesel engines release large amounts of NO, which is harmful to the atmospheric environment. X With the full implementation of the China VI emission standards for diesel engines, the NOx emissions from diesel engines have increased. X The emission limits are higher. Furthermore, because the China VI emission standard requires the use of the WHTC and WHSC cycles, compared to the previous ETC and ESC cycles, it introduces significantly more cold start and low-load conditions, resulting in a substantial decrease in diesel engine exhaust temperature and an increase in NOx emissions. X The difficulty of elimination.

[0003] Currently, domestic diesel engines mainly utilize exhaust aftertreatment systems to treat NO. x The gas is processed. Among these processes, an SCR system is used to treat NO. X During the elimination process, a reducing additive needs to be sprayed into the exhaust pipe. Current automotive SCR systems typically use a 32.5% (by mass) urea solution as the reducing additive. After being sprayed into the pipe through a urea nozzle, the urea solution undergoes evaporation and pyrolysis, releasing ammonia (NH3) and isocyanate (NHCO). Subsequently, the ammonia (NH3) reacts with NO... X To carry out the reaction, NO X Reducing it to neutral N2, thereby achieving the control of NO X Elimination.

[0004] However, urea solutions are prone to crystallization at low temperatures, especially during cold starts and low-load conditions following WHTC and WHSC cycles. When the temperature inside the exhaust pipe drops significantly, the urea solution cannot be completely pyrolyzed after being sprayed from the nozzle, easily leading to crystal formation. This is particularly problematic in winter when temperatures are low, or when trucks travel long distances at high altitudes due to large temperature differences between day and night, making urea crystallization and nozzle blockage more likely. Crystallization adhering to the nozzle can easily clog it. When the nozzle is blocked and unable to spray urea solution, the truck's urea system detects an anomaly. To ensure qualified emissions, the system will limit the truck's torque, causing the vehicle to malfunction. If the truck is climbing a hill while the torque is being limited, a safety accident is more likely.

[0005] To address this issue, a vehicle exhaust purifier is proposed to solve the problem of safety accidents caused by crystallization and blockage of urea nozzles in trucks. Summary of the Invention

[0006] The purpose of this invention is to provide an automotive exhaust purifier that addresses the inconvenience of timely repair when urea nozzles become clogged during long-distance truck transport, and the contradiction of having to limit truck torque to ensure exhaust emissions meet national standards when urea nozzles are clogged. This invention utilizes two nozzles with a switching device. When one nozzle becomes clogged, the device automatically switches to the backup nozzle, ensuring a stable and continuous injection of urea solution into the truck's exhaust pipe for exhaust purification. It also automatically cleans clogged nozzles, ensuring that even when a nozzle is blocked by urea crystals, the truck's exhaust emissions still meet standards. This guarantees normal vehicle operation and prevents torque limitation due to urea nozzle blockage during uphill driving, thus avoiding potential safety accidents.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] An automotive exhaust purifier, comprising:

[0009] The insulation shell is a sealed cylinder made of 310 stainless steel, high-chromium-nickel austenitic stainless steel, or other heat-resistant metal materials. Inside the insulation shell are two pipes, Pipe 1 and Pipe 2, which are metal pipes made of the same material as the insulation shell. Pipe 1 and Pipe 2 are of the same size. Sprayer 1 and Sprayer 2 are installed outside the insulation shell. Sprayer 1 is connected to Pipe 1, and Sprayer 2 is connected to Pipe 2. Pipe 1 is connected to an external urea pump, and Pipe 2 is connected to an external water pump. The insulation shell is equipped with a switching device, which can be a solenoid valve, such as a two-position four-way solenoid valve, or other solenoid valves with the same function. Alternatively, the switching device can be any other device or mechanism capable of switching Pipe 1 from being connected to the urea pump to being connected to the water pump, and vice versa. The insulation shell is fixedly installed on the truck's exhaust pipe. Nozzle one and nozzle two are inserted into the exhaust pipe. During normal use, the urea pump pumps a urea solution into the connected pipe and sprays it into the exhaust pipe from one of the nozzles. Inside the exhaust pipe, the urea undergoes thermal decomposition to form ammonia gas, which ultimately reacts with NO in the exhaust pipe. x The reaction is carried out to remove NO from the car's exhaust. x Purification is carried out.

[0010] When the urea solution sprayed from nozzle 1 crystallizes and blocks it due to prolonged use or temperature and pressure issues inside the exhaust pipe, the truck's urea system detects the abnormal pressure of the urea pump. It then activates a switching device, connecting the urea pump to pipe 2 and the water pump to pipe 1. As the urea pump continues to pump urea solution into the exhaust pipe, the solution sprays out from nozzle 2, continuing to treat the truck's exhaust gases. This ensures the quality of exhaust gas treatment and eliminates the need to limit torque to reduce emission rates. This avoids the safety risks associated with sudden torque restrictions during heavy-duty uphill driving, thus guaranteeing both effective exhaust gas treatment and the truck's driving safety.

[0011] After the solenoid valve switches, the water pump can start, pumping cleaning water into pipe one. The water flows into pipe one, cleaning its interior and diluting the urea solution inside, dissolving urea crystals inside pipe one and at the nozzles, thus restoring unobstructed flow to pipe one. By setting a standard pressure value for the water pump as a benchmark, when the pump detects normal pressure, it indicates that nozzle one is unobstructed and can spray liquid normally. At this point, the solenoid valve can be actuated to return to its original state, reconnecting the urea pump to pipe one and the water pump to pipe two, and then the water pump is immediately shut off. This system allows for continued purification of exhaust gas inside the exhaust pipe even when nozzles are clogged, while simultaneously cleaning clogged nozzles. This eliminates the need for trucks to stop for urea nozzle maintenance, improving the convenience and automation of the urea system.

[0012] To improve the cleaning effect, the water from the pump can be heated to 60-70℃ using a heating device, which helps to dissolve urea crystals faster and better, making it easier to unclog clogged nozzles.

[0013] Preferably, the first and second nozzles are vertically arranged along the axis of the insulation shell, with a spacing of 2-3 cm between them. The arrangement of the first and second nozzles along the axis of the insulation shell saves space. The insulation shell is cylindrical, designed to reduce wind resistance during exhaust gas emission. However, the cylindrical shape makes it difficult to arrange two nozzles parallel to each other in the radial direction. If two nozzles were to be arranged side-by-side in the radial direction, the distance between them would be very small to avoid occupying too much internal space in the exhaust pipe and to ensure smooth exhaust. During use, the urea sprayed from the nozzles... The water mist formed by the aqueous solution will cause a certain degree of swirling eddies, which is one of the situations where urea crystals are formed on the nozzle. In order to prevent the spare nozzle two from being adhered to by the urea crystals sprayed by nozzle one, setting the spare nozzle two to be 2-3 cm away from nozzle one can effectively avoid this situation. At the same time, setting it to 2-3 cm also allows nozzle two to effectively spray the urea aqueous solution into the entire exhaust pipe when in use, so that the water mist of the urea aqueous solution covers the cross section of the exhaust pipe as much as possible, ensuring the effectiveness of exhaust gas treatment when using nozzle two.

[0014] At the same time, nozzle one and nozzle two should be oriented in the same direction, both facing the exhaust pipe. Orienting the nozzles towards the exhaust pipe effectively reduces the possibility of them being clogged by dust particles generated from fuel combustion, while also maximizing the area covered by the urea spray, ensuring effective exhaust gas treatment.

[0015] Preferably, the insulation shell is provided with a compensation device for driving the insulation shell and its nozzles (nozzle 1 and nozzle 2) to move linearly along the axis of the insulation shell. The compensation device can be an electric push rod, an electric cylinder, a pneumatic cylinder, or other device or mechanism capable of driving linear motion. The compensation device is used to compensate for nozzle 2's movement towards the center of the exhaust pipe when nozzle 1 is blocked and nozzle 2 is activated as a backup urea solution sprayer. By setting the compensation distance of the compensation device to the distance between nozzle one and nozzle two, nozzle two can be positioned in its original location during use. This allows nozzle two to better and more evenly spray the urea solution into the exhaust pipe, resulting in better exhaust gas purification. After nozzle one is cleared, the compensation device resets nozzle one and nozzle two, allowing nozzle one to function as the urea solution spray nozzle again. Although the extension of the insulation shell into the exhaust pipe temporarily occupies space during the use of nozzle two, this is only temporary. The retracted insulation shell releases the space occupied by the insulation shell, ensuring smooth exhaust flow.

[0016] Preferably, the compensation device includes a sliding sleeve fitted over the outside of the insulation shell. The sliding sleeve and the insulation shell are slidable relative to each other along the axial direction. The material of the sliding sleeve is the same as that of the insulation shell. The sliding sleeve has two sliding grooves, each along the axial direction of the insulation shell. Two sliders that cooperate with the sliding grooves are fixedly installed on the insulation shell. The two sliders are slidably installed inside the two sliding grooves. A spring is provided between each slider and the bottom of the sliding groove. The spring is a compression spring, and each spring is a high-temperature resistant spring, capable of withstanding temperatures above 350°C. In its natural state, the spring always holds the slider locked at the top of the sliding groove. The range of motion of each slider inside the sliding groove is the same as the interval between nozzle one and nozzle two. A water bladder is provided between the top of the insulation shell and the sliding sleeve, and the water bladder is connected to pipe one via pipe four.

[0017] After nozzle one becomes clogged, the pressure inside pipe one increases. Because nozzle one cannot spray urea solution, the urea solution will flow towards the water bladder. After the water bladder is filled with liquid, it will expand and squeeze the insulation shell towards the axis of the exhaust pipe. The two springs one are compressed under the pressure of the water bladder, and nozzle two moves towards the axis of the exhaust pipe until it can no longer move. The urea system will detect the blockage in pipe one and control the solenoid valve to start. After the urea solution enters pipe two, it will be sprayed out from nozzle two. At this time, nozzle two is located in the original position of nozzle one under the action of the water bladder squeezing the insulation shell, ensuring that the urea solution mist sprayed by nozzle two can fully contact the exhaust gas and ensure the exhaust gas purification effect.

[0018] After the solenoid valve is activated, water is pumped into pipe one. The water dilutes the urea solution already inside pipe one, increasing its solubility and clearing crystals from the pipe. The pump then maintains pressure in pipe one, during which time the urea solution is continuously sprayed from nozzle two until nozzle one is cleared (i.e., the pressure inside pipe one automatically decreases). A pressure-maintaining time setting can be configured. If the time exceeds the set value, the urea system will alert the truck driver to inspect and repair nozzle one to ensure equipment stability. Alternatively, if repair is inconvenient during a long journey, nozzle two can continue to be used until a repair shop is found.

[0019] Using a water bladder as a compensation device, instead of a motor, cylinder, or push rod, can effectively save on equipment production and maintenance costs. It eliminates the need for an additional power source. Furthermore, using a water bladder as a compensation device provides higher synchronization, allowing the insulation shell to automatically extend when the nozzle becomes clogged. This also reduces control costs and difficulty.

[0020] Preferably, the water bladder is made of silicone rubber, which can operate within a temperature range of -70℃ to 300℃. The temperature range of the truck's exhaust pipe is 150℃ to 300℃, and silicone rubber meets the requirements of this working environment. The height of the water bladder after installation also needs to be carefully designed. After installation, the water bladder must be higher than the exhaust pipe wall to allow it to dissipate heat effectively under the influence of external airflow during truck operation, ensuring its service life. Furthermore, the bottom of the fully inflated water bladder should be 1-2cm higher than the exhaust pipe wall. This 1-2cm height prevents the water bladder from being continuously heated by vehicle exhaust while still allowing it to be cooled by external airflow, reducing its temperature during use. Combined with the urea solution inside the water bladder, this absorbs heat, ensuring its effectiveness. Simultaneously, the 1-2cm height prevents the insulation shell and sliding sleeve from becoming too bulky, minimizing their space occupation and interference with other truck equipment, thus improving the equipment's practicality.

[0021] Preferably, the sliding sleeve is provided with a baffle, the baffle being made of the same material as the insulation shell. The baffle blocks the second nozzle and, together with the insulation shell, forms a cavity with an opening at the bottom. When the first nozzle is not clogged, the baffle blocks the second nozzle, further preventing the urea solution sprayed from the first nozzle from forming eddies and adhering to the second nozzle, thus preventing urea from crystallizing and clogging the second nozzle. Because the second nozzle is not constantly in operation, dust generated from fuel combustion inside the exhaust pipe can easily clog the unused second nozzle. The baffle further prevents dust from fuel combustion in the exhaust pipe from adhering to the second nozzle and causing clogging. Since the first nozzle is in a long-term use state, the urea solution can clean the dust at the nozzle when sprayed, so clogging is not likely and does not require blocking. When the first nozzle is clogged, due to the compensation device, the second nozzle is pushed back to the original position of the first nozzle; at this time, the baffle will not obstruct the spraying of the second nozzle. Meanwhile, after urea crystals adhere to nozzle two, when nozzle two is blocked by the baffle again, because nozzle two is continuously heated inside the pipe, more heat will accumulate in nozzle two between the baffle and the insulation shell, making the temperature environment of nozzle two higher than that of nozzle one. When the temperature of nozzle two exceeds 320℃, the urea crystals adhering to nozzle two will pyrolyze, which helps the pyrolysis byproducts of urea pyrolysis, such as biuret and melamine, to release more ammonia gas to purify truck exhaust gas. At the same time, it can also slow down the crystallization of urea pyrolysis byproducts on nozzle two to a certain extent.

[0022] Preferably, the baffle is slidably mounted on the sliding sleeve along the axis of the sliding sleeve, and the baffle can slide out of the exhaust pipe of the truck along the axis of the insulation shell. An electromagnet is provided on the top of the baffle, and a second spring is provided between the electromagnet and the baffle. The second spring is a common compression spring, and in its natural state, the second spring always keeps the baffle pressed towards the inside of the exhaust pipe. A third pipe is provided between the first pipe and the second pipe, and the third pipe connects the first pipe and the second pipe. A valve is provided on the third pipe, and the valve can be a common solenoid valve, which only needs to control the opening and closing of the third pipe. The valve is electrically connected to the electromagnet. During use, the exhaust status of the exhaust pipe can be monitored (such as monitoring the temperature of the exhaust pipe, or monitoring the emission rate of the exhaust gas in the exhaust pipe, or monitoring the NO in the exhaust gas). x (The content of urea), in conjunction with the existing urea system inspection, activates the electromagnet. When the electromagnet is activated, the baffle is pulled outwards towards the exhaust pipe. The distance the baffle is pulled out is set to the diameter of nozzle two. Spring two is compressed, at which point nozzle two is fully exposed inside the exhaust pipe. Subsequently, the valve opens, and pipe three connects pipe two to pipe one. Because pipe one is now connected to the urea pump, after pipe three connects pipe one and pipe two, the urea solution can enter the interior of pipe two and be sprayed out from nozzle two, thereby increasing the input of urea into the exhaust pipe and increasing the removal of NO in truck exhaust. x This treatment method can further ensure the purification effect of exhaust gas when the truck is under heavy load, thus further improving the practicality of nozzle two.

[0023] Preferably, heat insulation sheets are provided at both the top and bottom of the water bladder. These sheets are made of aerogel, asbestos, alumina, or other heat-insulating materials, and are 1-2 mm thick. The sheets are adhesively attached to both sides of the water bladder to provide insulation when the water bladder contacts the top of the sliding sleeve and the top of the insulation shell. Because the sleeve and insulation shell are made of metal, they have high thermal conductivity and easily transfer the temperature of the exhaust pipe to the water bladder. Although the water bladder is made of heat-resistant material, and its position allows for timely heat dissipation from the water bladder and the surrounding sleeve and insulation shell, the temperature of the sleeve and insulation shell remains high. To further extend the service life of the water bladder and prevent damage and leakage, heat insulation sheets are designed to replace the water bladder in direct contact with the sleeve and insulation shell, thus further ensuring the service life of the water bladder and guaranteeing the practicality and operational stability of the equipment. The cross-sectional area of ​​pipe four is half that of pipe one, which it connects to. This is to prevent the urea solution inside pipe one from primarily entering the water bladder and increasing the water pressure during normal operation of nozzle one. Instead, the urea solution is primarily released from the nozzle, preventing the increased water pressure in the bladder from compressing spring one and pushing the insulation shell into the exhaust pipe, thus avoiding the occupation of the exhaust pipe's internal space. It also prevents the spare nozzle two from being blocked by dust after the insulation shell extends into the exhaust pipe. The cross-sectional area of ​​pipe four is half that of pipe one, rather than smaller, because urea crystals may also form in the water bladder. A sufficiently large opening ensures that the crystals are smoothly discharged when the water bladder is compressed by spring one, guaranteeing the effectiveness of the water bladder and thus ensuring the overall operational stability of the equipment.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. The automotive exhaust purifier of this invention, compared with existing exhaust purifiers that clean truck exhaust by spraying urea, is equipped with two nozzles for spraying urea (nozzle one and nozzle two). One nozzle is connected to a urea pump for supplying urea, and the other is connected to a water pump for supplying cleaning solution. A switching device is also provided between the two nozzles. When the nozzle for spraying urea becomes clogged, the switching device switches the clogged nozzle to be connected to the water pump and the unclogged nozzle to be connected to the urea pump. This allows the water pump to automatically clean the clogged nozzle, allowing the urea solution to continue to be sprayed into the exhaust pipe from the unclogged nozzle, continuing to purify the truck exhaust. This solves the problem that existing nozzles, when clogged by urea crystals, can only limit the vehicle's torque to ensure that the vehicle's exhaust emissions meet standards. This avoids safety accidents caused by the truck being restricted in torque due to urea crystallization when the urea nozzle is clogged during uphill driving. It ensures that the truck's exhaust emissions meet national standards while also protecting the life and property safety of the truck driver.

[0026] 2. The automotive exhaust purifier of this invention, based on the aforementioned beneficial effects, further includes a compensation device. This compensation device allows the second spare nozzle to move back to the original position of the first nozzle after the first nozzle becomes clogged. This ensures that the second nozzle, when spraying urea solution into the truck's exhaust pipe, achieves the same effect as the first nozzle, guaranteeing that temporary exhaust treatment using the second nozzle also meets national standards. After the first nozzle is cleared, a switching device switches the nozzle spraying urea solution back to the first nozzle, and the compensation device retracts the second nozzle, reducing its impact on the exhaust pipe's internal space and ensuring the truck's exhaust performance. The compensation device further ensures the exhaust treatment effect after the first nozzle becomes clogged, improving the equipment's reliability.

[0027] 3. The automotive exhaust purifier of the present invention also includes a protective device to protect the second nozzle when it is not in use, preventing it from being clogged by dust generated from incomplete combustion of engine fuel due to prolonged disuse. It also includes an electromagnet that can move the protective device, and a valve connecting the two nozzles. When the truck has a high exhaust volume, the electromagnet can drive the protective device to release the protection of the second nozzle and open the valve, connecting the first and second nozzles. This allows urea solution to be sprayed simultaneously from both nozzles to purify the vehicle exhaust. This not only solves the problem of torque limitation caused by urea crystals clogging the nozzles, but also further ensures the exhaust purification effect of the truck under high load. Attached Figure Description

[0028] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0029] Figure 2 This is a schematic diagram of the internal structure of the nozzle during normal operation in this invention;

[0030] Figure 3 This is a schematic diagram of the internal structure of the nozzle after it becomes clogged in this invention;

[0031] Figure 4 For the present invention Figure 3 Enlarged view of A in the middle;

[0032] Figure 5 This is a schematic diagram of the compensation device of the present invention;

[0033] Figure 6 This is a schematic diagram of the internal structure of Embodiment 2 of the present invention.

[0034] In the diagram: 1. Insulation shell; 2. Pipe 1; 3. Pipe 2; 4. Nozzle 1; 5. Nozzle 2; 6. Urea pump; 7. Water pump; 8. Compensation device; 801. Sliding sleeve; 802. Slide groove; 803. Sliding block; 804. Spring 1; 805. Water bladder; 806. Pipe 4; 9. Baffle; 10. Electromagnet; 11. Spring 2; 12. Pipe 3; 13. Valve; 14. Heat insulation sheet; 15. Switching device; 16. Exhaust pipe. Detailed Implementation

[0035] Example 1:

[0036] refer to Figures 1 to 5 The sliding sleeve 801 is made of 310 stainless steel. It is a C-shaped cylinder with a thickness of 2mm and an inner diameter of 3cm. The sliding sleeve 801 is vertically fixed to the exhaust pipe 16 along its diameter. A groove 802 is provided on both the left and right sides of the sliding sleeve 801, each groove being 4cm long. The insulation shell 1 is also made of 310 stainless steel, with an outer diameter of 3cm, the same as the inner diameter of the sliding sleeve 801. A pipe 2 is installed inside the insulation shell 1, entering from the top and exiting from the... The pipe 12 extends horizontally from the side wall of the insulation shell 1. The minimum distance between the point where the pipe 12 extends from the side wall of the insulation shell 1 and the bottom of the insulation shell 1 is 3mm. A nozzle 14 is fixedly installed at one end of the pipe 12 extending from the side wall of the insulation shell 1. A pipe 23 is also fixedly installed inside the insulation shell 1. The layout of pipe 23 is the same as that of pipe 12. A nozzle 25 is fixedly installed at the end of pipe 23 extending out of the insulation shell 1. The nozzles 14 and 25 are arranged parallel to the axis of the insulation shell 1. The nozzles 14 and 25 face the same direction. The center distance between the nozzles 14 and 25 is 3cm. The materials of pipe 12 and pipe 23 are the same as those of the insulation shell 1.

[0037] Two sliders 803 are welded to the left and right sides of the exterior of the insulation shell 1. The two sliders 803 are slidably installed inside the two sliding grooves 802, corresponding to the two sliding grooves 802. A spring 804 is installed between each slider 803 and the bottom of the sliding groove 802. The spring 804 is a compression spring made of Inconel X-750 steel wire and is a high-temperature resistant spring. The deformation displacement of the spring 804 after full compression is 3 cm. A water bladder 805 is installed between the top of the insulation shell 1 and the top of the sliding sleeve 801. The water bladder 805 is made of high-temperature resistant silicone rubber and has a wall thickness of 1 mm. The water bladder 805 is connected to pipe 2 via pipe 4 806. The diameter of pipe 4 806 is half the diameter of pipe 2. The opening of pipe 4 806 is inclined towards the bottom of the insulation shell 1 and connected to pipe 2, forming a "Y"-shaped interface. This "Y"-shaped interface effectively prevents urea solution from entering the water bladder 805 before the nozzle 4 is blocked. The volume of the water bladder 805 after it is fully inflated ensures that it can compress the insulation shell 1 and move it, and that the spring 804 is fully compressed.

[0038] A heat insulation sheet 14 is glued to the top and bottom of the water bladder 805. Each heat insulation sheet 14 is 2mm thick and is made of aerogel.

[0039] After the sliding sleeve 801 is fixedly installed, the bottom of the sliding groove 802 opened on the sleeve should be 1cm higher than the outer diameter of the exhaust pipe 16. This will ensure that the water bag 805 is 2cm away from the outer diameter of the exhaust pipe 16 after it is fully inflated, thus ensuring the service life of the water bag 805.

[0040] Pipes 1-2 and 2-3 on the insulation shell 1 extend out of the top of the sleeve and can slide relative to each other inside the sleeve along with the insulation shell 1. Pipes 1-2 and 2-3 are connected to a switching device 15. The switching device 15 uses a two-position four-way solenoid valve. Pipe 1-2 is connected to the 0 port of the solenoid valve, and pipe 2-3 is connected to the P port of the solenoid valve. The A port of the solenoid valve is connected to an external urea pump 6. The urea pump 6 uses a 32.5% urea solution. The B port of the solenoid valve is connected to an external water pump 7. The water pump 7 uses hot water at a temperature of 60℃.

[0041] A baffle 9 is slidably installed at the notch of the "C"-shaped sleeve. The baffle 9 is made of the same material as the sleeve. The baffle 9 can slide out along the notch of the sleeve toward the outside of the exhaust pipe 16 of the truck. The baffle 9, together with the notch of the sleeve, forms a complete cylinder around the sleeve. In the initial position, the baffle 9 just blocks the nozzle 2 5. An electromagnet 10 is installed on the top of the baffle 9. The electromagnet 10 is fixedly installed on the outside of the exhaust pipe 16. The magnetic pole of the electromagnet 10 is aligned with the top of the baffle 9. A spring 2 11 is installed between the top of the baffle 9 and the magnetic pole of the electromagnet 10. The spring 2 11 is a common compression spring. The spring 2 11 always presses the baffle 9 toward the inside of the exhaust pipe 16.

[0042] A pipe 12 is fixedly installed between pipe 12 and pipe 23. Pipe 12 is located outside the exhaust pipe 16. Pipe 12 connects pipe 12 and pipe 23. A valve 13 is also installed on pipe 12 to control the opening or closing of pipe 12. The valve 13 is electrically controlled and is electrically connected to the electromagnet 10.

[0043] The specific workflow is as follows:

[0044] Before nozzle 14 is blocked: two springs 1804 push the two sliders 803 on the side wall of the insulation shell 1 to the top of the two grooves 802, the insulation shell 1 remains retracted inside the sleeve, the baffle 9 blocks nozzle 25, nozzle 14 is in the center of the exhaust pipe 16, both nozzle 14 and nozzle 25 are facing the exhaust direction of the exhaust pipe 16, and the water bag 805 is squeezed by the insulation shell 1.

[0045] After the truck starts, the urea pump 6 pumps the urea solution into the pipe 2, and sprays it out from the nozzle 4 through the pipe 2 to form a urea spray. Under the action of the exhaust gas, the urea spray is hydrolyzed into ammonia and water. The ammonia reacts with the NOx in the exhaust gas and converts it into harmless N2, thus purifying the NOx in the truck exhaust gas.

[0046] When nozzle 4 becomes clogged: urea solution is pumped into pipe 2, but it cannot be sprayed out from nozzle 4. When the urea system detects abnormal pressure inside pipe 2, urea pump 6 controls the backflow of urea solution inside pipe 2. Then, a solenoid valve is activated, switching the connection between urea pump 6 and pipe 3. After the solenoid valve is activated, urea pump 6 is connected to pipe 2, while water pump 7 is connected to pipe 2. Water pump 7 then controls the entry of cleaning water into pipe 2. Because nozzle 4 is clogged, the water cannot be sprayed out after entering pipe 2 and instead enters the water bladder 805, which then begins to inflate. As the water expands, the expanding water bladder 805 presses against the insulation shell 1 towards the inside of the exhaust pipe 16, compressing the spring 804 until it can no longer be compressed. At this point, the water pump 7 begins to maintain pressure. The insulation shell 1 moves 3cm towards the inside of the exhaust pipe 16, and the nozzle 5 is removed from the obstruction of the baffle 9. The nozzle 5 is now located at the original position of the nozzle 4. At this time, the urea pump 6 pumps urea solution into the pipe 3, which is then sprayed out from the nozzle 5 to continue cleaning the exhaust gas inside the exhaust pipe 16. Once the exhaust gas of the truck can continue to be purified, there is no need to limit the torque of the truck. When the urea crystals in pipe 2 and nozzle 4, which are under pressure, dissolve and nozzle 4 can spray solution, the pressure in pipe 2 begins to decrease. Water pump 7 returns the water inside pipe 2 to water pump 7, and urea pump 6 also returns the urea solution in pipe 3. Spring 804 and insulation shell 1 reset, and nozzle 5 is blocked again by baffle 9. Then the solenoid valve closes, and urea pump 6 pumps urea solution back into pipe 2. The urea solution is then sprayed again into the exhaust pipe 16 at nozzle 4. This achieves continuous spraying of urea solution after nozzle 4 becomes clogged and automatic cleaning of the clogged nozzle 4.

[0047] If pipe 2 does not depressurize within 30 minutes during the cleaning process of nozzle 4, the internal pressure of pipe 2 will continue to be maintained. The system can then remind the truck driver to find a repair shop for timely maintenance when passing through the city. During the malfunction of nozzle 4, nozzle 5 will take over the operation.

[0048] Example 2:

[0049] like Figure 6Unlike Example 1, nozzle 4 did not become clogged during use. The truck system detected that the exhaust volume of exhaust pipe 16 exceeded the normal level by 30%, indicating that the truck engine was operating under overload. To ensure the purification effect on the exhaust gas, the system controlled the electromagnet 10 to start. After the electromagnet 10 started, it attracted the baffle 9 towards the outside of exhaust pipe 16, and the baffle 9 attracted by the electromagnet 10 no longer blocked nozzle 5. After the electromagnet 10 started, valve 13 started, connecting pipe 2 and pipe 3. When urea pump 6 pumped urea solution into pipe 2, the urea solution could enter pipe 3 from pipe 2 through pipe 3 12 and be sprayed out from nozzle 5, so that nozzles 25 and 4 sprayed urea solution at the same time, ensuring the purification effect of NOx in the vehicle exhaust gas. When the vehicle engine resumes normal operation, valve 13 first closes to isolate pipe 2 and pipe 3. Then, water pump 7 turns on, pumping hot water into pipe 3 for 20 seconds. The hot water compresses the urea solution inside pipe 3 and forces it to spray out from nozzle 5, ensuring that the urea solution does not remain in pipe 3. After the time is up, water pump 7 returns the water inside pipe 3. Then, electromagnet 10 is de-energized, and baffle 9 resets under the action of spring 11, blocking nozzle 5. During the cleaning of pipe 3, nozzle 4 continues to continuously spray urea solution to purify the truck's exhaust, ensuring the purification effect.

[0050] The functions and implementation processes not described in this embodiment are the same as in Embodiment 1, so they will not be elaborated further.

[0051] The above two embodiments are merely illustrative examples among the many embodiments of the present invention. Various variations can be made without departing from the principles of the present invention. Embodiments created by those skilled in the art through modifications to the present invention without creative effort are also within the scope of protection of the present invention.

Claims

1. An automobile exhaust purifier, characterized by comprising: include: The insulation shell (1) is cylindrical. Inside the insulation shell (1) are fixedly installed pipes 1 (2) and 2 (3) for conveying urea solution. On the outside of the insulation shell (1) are nozzles 1 (4) and 2 (5). Nozzle 1 (4) is connected to pipe 1 (2), nozzle 2 (5) is connected to pipe 2 (3), pipe 1 (2) is connected to an external urea pump (6), and pipe 2 (3) is connected to an external water pump (7). A switching device (15) is provided on the insulation shell (1). The switching device (15) can switch pipe 1 (2) to be connected to urea pump (6) or water pump. The switching device (15) can also switch pipe 2 (3) to be connected to urea pump (6) or water pump (7).

2. The automobile exhaust purifier according to claim 1, characterized in that: The first nozzle (4) and the second nozzle (5) are vertically arranged along the axis of the insulation shell (1), and the interval between the first nozzle (4) and the second nozzle (5) is 2-3 cm.

3. The automobile exhaust purifier according to claim 2, characterized in that: The insulation shell (1) is provided with a compensation device (8) for driving the insulation shell (1) and the nozzle one (4) and nozzle two (5) thereon to move linearly along the axis of the insulation shell (1). The displacement of the nozzle one (4) and nozzle two (5) under the drive of the compensation device (8) is the same as the distance between the nozzle one (4) and nozzle two (5).

4. The automobile exhaust purifier according to claim 3, characterized in that: The compensation device (8) includes a sliding sleeve (801) disposed outside the insulation shell (1). The sliding sleeve (801) is provided with two sliding grooves (802). Two sliders (803) that cooperate with the sliding grooves (802) are fixedly installed on the insulation shell (1). A spring (804) is provided between each slider (803) and the bottom of the sliding groove (802). The range of motion of each slider (803) inside the sliding groove (802) is the same as the interval between the nozzle (4) and the nozzle (5). A water bag (805) is provided between the top of the insulation shell (1) and the sliding sleeve (801). The water bag (805) is connected to the pipe (2) by the pipe (4) (806).

5. The automobile exhaust purifier according to claim 4, characterized in that: The water bladder (805) is made of silicone rubber. After the water bladder (805) is fully expanded, the bottom of the water bladder (805) that contacts the heat insulation shell (1) is 1-2 cm higher than the outside of the exhaust pipe (16).

6. The automobile exhaust purifier according to claim 4, characterized in that: A baffle (9) is provided on the sliding sleeve (801), which is used to block the second nozzle (5) when the first nozzle (4) is not blocked.

7. The automobile exhaust purifier according to claim 6, characterized in that: The baffle (9) is slidably mounted on the sliding sleeve (801) along the axial direction of the sliding sleeve (801). An electromagnet (10) is provided on the top of the baffle (9). A spring (11) is provided between the electromagnet (10) and the baffle (9). A pipe (12) is provided between the pipe (2) and the pipe (3). The pipe (12) connects the pipe (2) and the pipe (3). A valve (13) is provided on the pipe (12). The valve (13) is electrically connected to the electromagnet (10).

8. The automobile exhaust purifier according to claim 4, characterized in that: Heat insulation sheets (14) are provided on the contact surface between the water bladder (805) and the top of the sliding sleeve, and on the contact surface between the water bladder (805) and the top of the heat insulation shell (1). The cross-sectional area of ​​the fourth pipe (806) is half that of the first pipe (2) connected to it.

Images