A urea nozzle system to prevent crystallization and clogging

Abstract

This application discloses a urea nozzle system to prevent crystallization blockage, used to reduce crystallization at the connection between the urea nozzle and the catalyst. The method includes: a catalyst, a urea nozzle, a heat insulation gasket, a urea injection pipe, a coolant inlet pipe, and a coolant return pipe; the urea nozzle is connected to the catalyst via the heat insulation gasket; the urea nozzle has three openings, respectively connecting to the urea injection pipe, the coolant return pipe, and the coolant inlet pipe; the connection between the urea injection pipe and the urea nozzle is located at the highest position, and a first straight pipe section is provided at the connection between the urea injection pipe and the urea nozzle; the coolant return pipe is positioned higher than the coolant inlet pipe; a second straight pipe section is provided at the connection between the coolant return pipe and the urea nozzle, and a third straight pipe section is provided at the connection between the coolant inlet pipe and the urea nozzle.

Description

Technical Field

[0001] This embodiment relates to the field of engines, and more particularly to a urea nozzle system for preventing crystallization and blockage. Background Technology

[0002] In existing technologies, both vehicle-mounted China VI and non-road T4 systems inject urea into the catalytic converter. Under the catalytic action of the catalyst, urea reacts with nitrogen oxides to generate harmless nitrogen gas, thus reducing nitrogen oxide emissions. The urea nozzle is installed on the catalytic converter through which engine exhaust flows. If the vehicle frequently idles for extended periods or runs at high exhaust temperatures before being turned off, residual urea in the nozzle cavity will, under high-temperature conditions (above 150°C), produce a hard, water-insoluble crystalline substance called biuret.

[0003] Biuret crystals have high hardness and are chemically stable, making them difficult to decompose and prone to clogging. When urea injection is required during vehicle operation, the clogged nozzle prevents injection. Common practices for handling urea nozzle clogging include: First, the user removes the urea nozzle and manually cleans the crystals from the nozzle orifice. This method disrupts normal vehicle operation and may not completely clean the crystals from the tiny nozzle orifice, requiring frequent cleaning as it doesn't resolve the problem. Second, the urea nozzle is replaced directly. This method also disrupts normal vehicle operation, increases parts costs, and requires frequent nozzle replacements as it doesn't resolve the problem. Summary of the Invention

[0004] This application provides a urea nozzle system to prevent crystallization blockage, thereby reducing the occurrence of crystallization at the connection between the urea nozzle and the catalyst.

[0005] This application provides a urea nozzle system for preventing crystallization blockage, comprising:

[0006] Catalyst, urea nozzle, heat insulation gasket, urea injection pipe, coolant inlet pipe, coolant return pipe;

[0007] The urea nozzle is connected to the catalyst via the heat insulation pad;

[0008] The urea nozzle is provided with three openings, which are respectively connected to the urea injection pipe, the coolant return pipe and the coolant inlet pipe;

[0009] The connection between the urea injection pipe and the urea nozzle is located at the highest position, and a first straight pipe section is provided at the connection between the urea injection pipe and the urea nozzle.

[0010] The coolant return pipe is positioned higher than the coolant inlet pipe;

[0011] A second straight pipe section is provided at the connection between the coolant return pipe and the urea nozzle, and a third straight pipe section is provided at the connection between the coolant inlet pipe and the urea nozzle.

[0012] Optionally, the first straight pipe section is provided with a first upward tilt angle, the second straight pipe section is provided with a second upward tilt angle, the angle of the second upward tilt angle is smaller than the first upward tilt angle, and the third straight pipe section is provided with a downward tilt angle.

[0013] Optionally, the length of the first straight pipe section is greater than 150 mm, and the first straight pipe section contains 10 mL of urea solution.

[0014] Optionally, the second upward tilt angle is greater than 35°, and the interior of the second straight pipe section contains at least 20 mL of coolant.

[0015] Optionally, the downward tilt angle is greater than 0°, and the third straight pipe section contains at least 20 mL of coolant.

[0016] Optionally, the catalyst is provided with a nozzle seat, and the heat insulation gasket is provided between the nozzle seat and the urea nozzle. The nozzle seat is used to fix the urea nozzle.

[0017] Optionally, the nozzle seat is provided with a threaded hole, and the nozzle seat is fixed to the catalyst by bolts.

[0018] Optionally, the first straight pipe section, the second straight pipe section, and the third straight pipe section are respectively connected to the urea injection pipe, the coolant return pipe, and the coolant inlet pipe via locking connections.

[0019] Optionally, the nozzle seat is provided with a threaded hole, and the urea nozzle is connected to the nozzle seat by screws.

[0020] Optionally, the heat insulation pad is a mica pad, and the material of the heat insulation pad is silicate resin.

[0021] As can be seen from the above technical solutions, a straight pipe section is set at the connection between the urea injection pipe, the coolant return pipe, the coolant inlet pipe and the urea nozzle. This straight pipe section can hold a certain amount of liquid. This liquid can still cool the connection between the urea nozzle and the catalyst after the engine stops working. Furthermore, the urea nozzle and the catalyst are separated by a heat insulation gasket, thereby preventing the formation of water-insoluble urea crystals in the urea nozzle due to high temperature. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of one embodiment of a urea nozzle system for preventing crystallization blockage in this application. Detailed Implementation

[0023] This application provides a urea nozzle system to prevent crystallization blockage, thereby reducing the occurrence of crystallization at the connection between the urea nozzle and the catalyst.

[0024] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0025] Please see Figure 1 This application provides an embodiment of a urea nozzle system for preventing crystallization blockage, comprising:

[0026] 1. Catalyst; 2. Urea nozzle; 3. Heat insulation gasket; 4. Urea injection pipe; 5. Coolant inlet pipe; 6. Coolant return pipe;

[0027] The urea nozzle 2 is connected to the catalyst 1 via the heat insulation pad 3;

[0028] The urea nozzle 2 is provided with three openings, which are respectively connected to the urea injection pipe 4, the coolant return pipe 6 and the coolant inlet pipe 5;

[0029] The connection port between the urea injection pipe 4 and the urea nozzle 2 is located at the highest position, and a first straight pipe section 41 is provided at the connection point between the urea injection pipe 4 and the urea nozzle 2.

[0030] The coolant return pipe 6 is positioned higher than the coolant inlet pipe 5;

[0031] A second straight pipe section 61 is provided at the connection between the coolant return pipe 6 and the urea nozzle 2, and a third straight pipe section 51 is provided at the connection between the coolant inlet pipe 5 and the urea nozzle 2.

[0032] Specifically, the urea nozzle 2 is installed on the catalyst 1 through which the engine exhaust flows. In this embodiment, in order to prevent the urea nozzle 2 from being exposed to high temperatures and causing crystallization, a heat insulation gasket 3 is provided in the urea nozzle 2 and the catalyst 1 so that when the engine is turned off or due to other abnormal use conditions, the ambient temperature of the urea in the urea nozzle 2 is reduced, thereby reducing the probability of urea forming biuret crystals.

[0033] The urea nozzle 2 has a total of three ports, which are connected to the urea injection pipe 4, the coolant inlet pipe 5, and the coolant return pipe 6, respectively. The port of the urea injection pipe 4 is located at the top of the urea nozzle 2 and is connected through the first straight pipe section 31. The end of the first straight pipe section 31 connected to the urea nozzle has a straight opening, which is perpendicular to the urea nozzle 2. The straight opening extends obliquely to the tail end of the first straight pipe section 41 and is connected to the urea injection pipe 4.

[0034] The interfaces of the coolant inlet pipe 5 and the coolant return pipe 6 extend from the side of the urea nozzle 2. The two interfaces are at the same height and are connected to the second straight pipe section 61 and the second straight pipe section 51 respectively by tightening nuts.

[0035] The first straight pipe section 41 is provided with a first upward tilt angle, the second straight pipe section 61 is provided with a second upward tilt angle, the angle of the second upward tilt angle is smaller than the first upward tilt angle, and the third straight pipe section 51 is provided with a downward tilt angle.

[0036] Specifically, the first upward tilt angle is greater than the second upward tilt angle. In actual practice, the position of the first straight pipe section 41 is higher than that of the second straight pipe section 61. The tilt angle of the third straight pipe section 5 is a downward tilt angle, and its position is the lowest. In this embodiment, the main function of the straight pipe section is to store liquid. The straight pipe section acts as a connector to connect the urea injection pipe 4, the coolant inlet pipe 5, and the coolant return pipe 6 to the urea nozzle 2, respectively.

[0037] The first straight pipe section 41 has a length greater than 150 mm, and the first straight pipe section 41 contains 10 mL of urea solution.

[0038] Specifically, the first straight section 41 can store at least 10 ml of urea solution, the purpose of which is to reduce the heating efficiency of urea by increasing the mass of urea solution, thereby reducing the possibility of crystal formation.

[0039] The second upward tilt angle is greater than 35°, and the second straight pipe section 61 contains at least 20 mL of coolant.

[0040] 20 ml of coolant is normally stored inside the second straight pipe section 61. The coolant in the second straight pipe section 61 will not return to the coolant return pipe 6 when the engine is abnormally shut off. This is so that in actual use, if the catalytic converter has not yet cooled down after the engine is shut off, it can be cooled down by the coolant inside the second straight pipe section 61, thereby reducing the probability of urea crystallization caused by the high temperature of the catalytic converter.

[0041] The second upward inclination angle of the second straight pipe section 61 is at least greater than 35° to ensure that the coolant can be cooled when the engine is turned off.

[0042] The downward tilt angle is greater than 0°, and the third straight pipe section 51 contains at least 20 mL of coolant.

[0043] Specifically, the internal volume of the third straight pipe section 51 is at least equal to that of the second straight pipe section 61, so as to retain the coolant flowing down from the second straight pipe section 61 and prevent the coolant from standing still in the high-temperature area for a long time, which would cause the temperature to rise.

[0044] In practice, the coolant return pipe 6 is positioned at a high level and the second upward tilt angle is greater than 35°, allowing the coolant return pipe 6 and the coolant inlet pipe 5 to form a cooling pipeline with a low inlet and a high outlet. The reverse flow of coolant can improve cooling efficiency and help reduce nozzle temperature.

[0045] The catalyst 1 is provided with a nozzle seat 21, and the heat insulation gasket 3 is provided between the nozzle seat 21 and the urea nozzle 2. The nozzle seat 21 is used to fix the urea nozzle 2.

[0046] The nozzle seat 21 is provided with a threaded hole, and the nozzle seat 21 is fixed to the catalyst by bolts.

[0047] Specifically, the nozzle seat 21 is used to fix the urea nozzle 2. The nozzle seat 21 is fixed to the catalyst 1 by bolts. The heat insulation gasket 3 is set between the nozzle seat 21 and the urea nozzle 2 to avoid direct contact between the high-temperature metal nozzle seat 21 and the urea nozzle 2, thereby reducing the temperature rise of the urea nozzle.

[0048] The first straight pipe section 41, the second straight pipe section 61 and the third straight pipe section 51 are respectively connected to the urea injection pipe 4, the coolant return pipe 6 and the coolant inlet pipe 5 by locking.

[0049] Specifically, the first straight pipe section 41, the second straight pipe section 61, and the third straight pipe section 51 are two separate pipe sections from the urea injection pipe 4, the coolant return pipe 6, and the coolant inlet pipe 5, respectively. When connecting them, they need to be fitted or locked in other ways. In the embodiment of this application, the first straight pipe section 41, the second straight pipe section 61, and the third straight pipe section 51 are respectively connected to the urea injection pipe 4, the coolant return pipe 6, and the coolant inlet pipe 5 by corresponding locking.

[0050] The nozzle seat 21 is provided with a threaded hole, and the urea nozzle 2 is connected to the nozzle seat 21 by screws.

[0051] The nozzle holder 21 has threaded holes on both sides. The purpose of the threaded holes is to fit screws. During the assembly process, the urea nozzle 2 is placed into the nozzle holder 21 and fixed by tightening the screws.

[0052] The heat insulation pad 3 is a mica pad, and the material of the heat insulation pad is silicate resin.

[0053] A heat insulation gasket 3 is provided on the urea nozzle 21. The heat insulation gasket 3 is located between the nozzle seat 21 and the urea nozzle 2. Its function is to prevent the high-temperature metal nozzle seat 21 from directly contacting the urea nozzle 2, thereby reducing the rate of temperature rise of the nozzle. At the same time, the heat insulation gasket 2 is a mica gasket made of silicate resin material with a heat transfer coefficient of less than 0.15W / (mK), which improves the heat insulation effect of the urea nozzle 2. Specifically, the effective temperature range of the heat insulation gasket 2 is less than 800 degrees Celsius, which includes all exhaust temperature ranges of the catalytic converter under engine operating conditions, and it will not be damaged by high temperature.

[0054] As can be seen from the above technical solutions, a straight pipe section is set at the connection between the urea injection pipe, the coolant return pipe, the coolant inlet pipe and the urea nozzle. This straight pipe section can hold a certain amount of liquid. This liquid can still cool the connection between the urea nozzle and the catalyst after the engine stops working. Furthermore, the urea nozzle and the catalyst are separated by a heat insulation gasket, thereby preventing the formation of water-insoluble urea crystals in the urea nozzle due to high temperature.

[0055] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

Claims

1. A urea nozzle system to prevent crystallization plugging, characterized by, The application relates to a catalytic converter, a urea nozzle, a heat insulation pad, a urea injection pipe, a cooling liquid inlet pipe and a cooling liquid return pipe. The urea nozzle is connected with the catalytic converter through the heat insulation pad. The urea nozzle is provided with three openings which are respectively connected with the urea injection pipe, the cooling liquid return pipe and the cooling liquid inlet pipe. The connecting port of the urea injection pipe and the urea nozzle is arranged at the highest position, and a first straight pipe section is arranged at the connecting position of the urea injection pipe and the urea nozzle. The first straight pipe section is provided with a first upward inclination angle, the second straight pipe section is provided with a second upward inclination angle, the angle of the second upward inclination angle is smaller than that of the first upward inclination angle, and the third straight pipe section is provided with a downward inclination angle. The position of the cooling liquid return pipe is higher than that of the cooling liquid inlet pipe. The second straight pipe section is arranged at the connecting position of the cooling liquid return pipe and the urea nozzle, and the third straight pipe section is arranged at the connecting position of the cooling liquid inlet pipe and the urea nozzle. The catalytic converter is provided with a nozzle seat, the heat insulation pad is arranged between the nozzle seat and the urea nozzle, and the nozzle seat is used for fixing the urea nozzle. The length of the first straight pipe section is greater than 150 mm, and the first straight pipe section contains 10 mL of urea solution.

2. The urea nozzle system of claim 1, wherein, The second upward inclination angle is greater than 35 DEG, and the second straight pipe section contains at least 20 mL of cooling liquid.

3. The urea nozzle system of claim 1, wherein, The downward inclination angle is greater than 0 DEG, and the third straight pipe section contains at least 20 mL of cooling liquid.

4. The urea nozzle system of claim 1, wherein, The nozzle seat is provided with screw holes, and the nozzle seat is fixed on the catalytic converter through bolts.

5. The urea nozzle system of claim 1, wherein, The first straight pipe section, the second straight pipe section and the third straight pipe section are respectively connected with the urea injection pipe, the cooling liquid return pipe and the cooling liquid inlet pipe through buckles.

6. The urea nozzle system according to any one of claims 1 to 5, characterized in that The nozzle seat is provided with screw holes, and the urea nozzle is connected with the nozzle seat through screws.

7. The urea nozzle system according to any one of claims 1 to 5, characterized in that The heat insulation pad is a mica pad, and the material of the heat insulation pad is silicate resin.

8. The urea nozzle system of any one of claims 1 to 5, wherein, ​

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