Urea pump assembly, selective catalytic reduction system and vehicle

Abstract

The utility model provides a urea pump assembly, a selective catalytic reduction system and a vehicle, and belongs to the technical field of selective catalytic reduction systems, the urea pump assembly comprises a pump unit, a filter module, a first heating module and a second heating module; the pump unit is communicated with the filtering module through a fluid channel; the first heating module is arranged on the periphery of the fluid channel and used for outputting heat to the fluid channel. The second heating module is arranged on the filtering module and used for outputting heat into the filtering module. The first heating module is mainly used for heating a urea solution flowing through the fluid channel, the urea solution is prevented from being crystallized or frozen at low temperature, the fluidity of urea is improved, and the situation that pumping resistance is increased or pressure buildup is unstable due to local freezing is avoided; the second heating module is directly integrated on the filtering module and outputs heat into the filtering module, so that the problem of urea freezing in a filtering area is solved in a targeted mode, filter element blockage is avoided, stable urea flow and system pressure are maintained, and the response speed of the system is increased.

Description

Technical Field

[0001] This utility model belongs to the technical field of selective catalytic reduction systems, and more specifically, relates to a urea pump assembly, a selective catalytic reduction system, and a vehicle. Background Technology

[0002] Vehicles use urea to reduce harmful nitrogen oxides in exhaust gases into nitrogen and water, achieving safe emissions. The freezing point of standard urea solution is approximately -11°C. When the ambient temperature is below the freezing point of urea, the urea solution in the urea tank will freeze. Therefore, at low temperatures, the urea needs to be heated to thaw after the vehicle is started.

[0003] Currently, automotive urea pump assemblies are connected to a filter module and also integrate a heating module. When the ambient or urea temperature drops below a certain level, the heating module activates to heat and defrost the urea at a specific power. However, the following problem exists: urea closer to the heating module defrosts first, while urea near the filter module and inside the filter module cannot defrost completely, leading to unstable pressure build-up. Utility Model Content

[0004] The purpose of this invention is to provide a urea pump assembly, a selective catalytic reduction system, and a vehicle, aiming to solve the problem of unstable pressure build-up caused by uneven urea thawing within the proximity filter module and the filter module in the prior art.

[0005] To achieve the above objectives, in a first aspect, this utility model provides a urea pump assembly, including a pump unit and a filter module, wherein the pump unit and the filter module are connected through a fluid channel; the urea pump assembly further includes a first heating module and a second heating module;

[0006] The first heating module is disposed on the periphery of the fluid channel and is used to output heat to the fluid channel; the second heating module is disposed on the filter module and is used to output heat to the interior of the filter module.

[0007] The beneficial effects of the urea pump assembly provided by this utility model are as follows: The first heating module of the urea pump assembly is arranged around the fluid channel and is mainly used to heat the urea solution flowing through the fluid channel to prevent it from crystallizing or freezing at low temperatures, improve the urea fluidity, and avoid increased pumping resistance or unstable pressure build-up due to local freezing; the second heating module is directly integrated into the filter module and outputs heat to the inside of the filter module to specifically solve the problem of urea freezing in the filter area, so as to avoid filter element blockage, maintain stable urea flow and system pressure, and improve the system response speed.

[0008] Compared with existing technologies, this invention utilizes the coordinated operation of a first heating module and a second heating module to eliminate the cold zone in the filter module of traditional solutions, resulting in more uniform urea thawing, reducing pressure build-up delays or pressure fluctuations caused by filter module freezing, and ensuring urea injection accuracy. The urea pump assembly provided by this invention is adaptable to lower ambient temperatures, extending the reliability of vehicles under low-temperature conditions.

[0009] In one possible implementation, the filtering module includes:

[0010] Filter screen; and

[0011] A frame is installed inside the filter screen to expand the filter screen so that the filter screen forms a filter cavity.

[0012] The filter screen has a degree of freedom of deformation, allowing for partial bending, stretching, or compression when not installed. This facilitates matching the direction of the fluid channel or spatial constraints. By adjusting the shape of the filter screen, the fit between the first heating module and the periphery of the fluid channel can be optimized, ensuring heating efficiency.

[0013] The frame is made of metal or high-strength plastic and is used to support the filter screen to prevent it from collapsing, ensure the stable shape of the filter chamber, and avoid structural loosening caused by urea flow impact or temperature changes.

[0014] In some embodiments, the second heating module is disposed within the filter cavity, and the second heating module has a wire outlet that passes through the frame and is sealed to the frame.

[0015] The frame, serving as a rigid support structure for the filter screen, provides a stable base for the cable outlet, preventing wiring harness displacement due to vehicle vibration or fluid impact. Furthermore, the integrated design of the cable outlet and frame allows for pre-assembly of the second heating module and filter module before overall installation, reducing assembly steps. Moreover, the centralized fixing of the cable outlet to the frame facilitates rapid fault location and detection without disassembling the entire filter screen.

[0016] In some embodiments, the second heating module includes a second housing and a second heating module filled inside the second housing; the second housing is distributed in a meandering manner.

[0017] The second housing serves as the encapsulation shell for the second heating module, providing insulation and heat conduction. The second housing employs a sealed design to prevent urea solution from seeping into the heating module, thus avoiding short circuits or component corrosion.

[0018] The second shell is distributed in a meandering pattern (such as serpentine, spiral, or mountain-shaped), which can increase the surface area of ​​the second shell, thereby increasing the heat conduction area of ​​the second shell. This enables uniform heating of the urea solution inside the filter module, avoids local overheating or cold zones, improves heat exchange efficiency, and shortens the melting time of urea during low-temperature startup.

[0019] In one possible implementation, the urea pump assembly further includes an integrated base, on which the first heating module, the pump unit, and the filter module are respectively fixed.

[0020] The integrated base is the core load-bearing structure of the urea pump assembly. The three major functional components, namely the first heating module, the pump unit, and the filter module, are centrally fixed through the sinking groove, achieving a compact layout to reduce the length of pipeline connections and reduce fluid resistance. Furthermore, it enables standardized assembly, with each module installed in its pre-positioned position, simplifying the assembly process on the production line.

[0021] In some embodiments, the integrated base is provided with a socket, and the second heating module has a wire outlet, which is fixedly disposed in the socket.

[0022] The outgoing wire is simultaneously fixed to both the frame and the integrated housing connector, forming a two-point lock to prevent the wiring harness from loosening due to vehicle vibration. Furthermore, the connector allows the second heating module to connect to the external wiring harness. This facilitates electrical connection to the second heating module, and centralized wiring makes diagnostic interface connections easier; the second heating module's current signal can be directly transmitted to the ECU via the connector. On the other hand, during maintenance, the second heating module can be disconnected simply by plugging and unplugging the connector, without needing to disassemble the filter chamber.

[0023] In some embodiments, the integrated base is further provided with a sensor mounting position for mounting a temperature sensor and / or a liquid level sensor.

[0024] By also mounting the temperature sensor and / or level sensor on the integrated housing, the volume of the separate package can be reduced, and the sensor wiring harness can be routed through the pre-embedded channels of the integrated housing.

[0025] In one possible implementation, the fluid channel includes a first channel and a second channel, wherein the inlet end of the first channel is connected to the outlet of the filter module, and the outlet end of the first channel is connected to the inlet of the pump unit; the inlet end of the second channel is connected to the outlet of the pump unit, and the outlet end of the second channel is fixed on the integrated base.

[0026] The first heating module is arranged around the first channel, the pump unit and the second channel.

[0027] The first channel directly connects the outlet of the filter module to the inlet of the pump unit, ensuring that the urea solution filtered by the filter module is free of impurities before entering the pump unit, thus protecting the precision plunger / gear pump of the pump unit from wear. The first heating module surrounds the first channel and prioritizes heating the urea solution that is about to enter the pump unit, preventing the low-temperature viscosity increase from causing difficulty in pump suction.

[0028] The second channel connects the pump unit outlet to the integrated base outlet, stably delivering the high-pressure urea solution generated by the pump unit to the injection system; the first heating module also extends to the periphery of the second channel to maintain the temperature of the high-pressure urea solution and prevent secondary crystallization before injection.

[0029] Secondly, this utility model embodiment also provides a selective catalytic reduction system, including a urea tank, a urea pipeline, a urea nozzle, and the aforementioned urea pump assembly; the urea pump assembly is disposed on the urea pipeline, one end of the urea pipeline is connected to the urea tank, the other end of the urea pipeline is connected to the inlet end of the urea nozzle, and the outlet end of the urea nozzle is connected to the exhaust pipe of the engine.

[0030] The selective catalytic reduction system provided by this utility model, by adopting the above-mentioned urea pump assembly, utilizes the first heating module and the second heating module to work together to eliminate the cold zone of the filter module in the traditional solution, making the urea thawing more uniform, reducing the pressure build-up delay or pressure fluctuation caused by the freezing of the filter module, and ensuring the accuracy of urea injection.

[0031] Thirdly, this utility model embodiment also provides a vehicle including the above-described selective catalytic reduction system.

[0032] The vehicle provided by this utility model, due to the adoption of the above-mentioned selective catalytic reduction system, allows the urea pump assembly to adapt to lower ambient temperatures, thus expanding the vehicle's reliability under low-temperature conditions. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A three-dimensional structural schematic diagram of the urea pump assembly provided in an embodiment of this utility model;

[0035] Figure 2 A cross-sectional structural schematic diagram of the urea pump assembly provided in an embodiment of this utility model;

[0036] Figure 3A cross-sectional structural schematic diagram of the second heating module of the urea pump assembly provided in this embodiment of the utility model;

[0037] Figure 4 This is a schematic diagram of the selective catalytic reduction system provided in an embodiment of the present invention.

[0038] In the picture:

[0039] 1. Pump unit;

[0040] 2. Filter module; 21. Filter screen; 22. Frame;

[0041] 3. Fluid channel; 31. First channel; 32. Second channel;

[0042] 4. First heating module;

[0043] 5. Second heating module; 51. Second housing; 52. Second heating module;

[0044] 6. Integrated base; 61. Socket; 62. Connecting pipe; 63. Sensor mounting position;

[0045] 7. Urea tank;

[0046] 8. Urea pipeline;

[0047] 9. Urea nozzle. Detailed Implementation

[0048] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0049] It should be noted that when an element is referred to as being "set on" another element, it can be directly on or indirectly on that other element. It should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0050] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a number" means two or more, unless otherwise explicitly specified.

[0051] A diesel engine (compression ignition engine) is an internal combustion engine that uses compressed air to generate high temperatures, causing injected diesel fuel to ignite and produce power. Its core characteristics are high pressure, high compression ratio, and spark plug-free ignition. It is mainly used in trucks, ships, construction machinery, and some passenger cars.

[0052] Because diesel engines use compression ignition, the combustion chamber is hot and oxygen-rich. These conditions promote the reaction of nitrogen (N2) and oxygen (O2) in the air to produce nitrogen oxides (NOx, including NO and NO2). NOx is a major component of air pollution, contributing to acid rain, photochemical smog, and harming the human respiratory system. Existing technologies can reduce emissions through exhaust gas recirculation (EGR). Specifically, this involves introducing some exhaust gas into the combustion chamber to lower the combustion temperature and reduce NOx formation. However, this method sacrifices engine efficiency and power and cannot meet stringent emission standards on its own. Furthermore, relying solely on EGR may increase particulate matter emissions, and its effectiveness is limited under high-load conditions.

[0053] Selective Catalytic Reduction (SCR) is a key aftertreatment technology for reducing nitrogen oxide (NOx) emissions from diesel engine exhaust. It works by injecting a urea solution into the exhaust pipe, where a catalyst converts harmful NOx into harmless nitrogen (N2) and water (H2O). SCR can reduce NOx emissions by more than 90% without affecting engine combustion efficiency. Therefore, while ensuring power and fuel economy, SCR is currently the most effective NOx aftertreatment technology.

[0054] A selective catalytic reduction (SCR) system typically includes a urea tank, urea pump, urea piping, urea injectors, an SCR catalyst carrier, a NOx sensor, an exhaust temperature sensor, and a control unit. The urea tank stores a 32.5% high-purity urea solution. The urea pump pressurizes the solution and delivers it to the urea injectors via the urea piping. The urea injectors precisely inject the atomized urea solution into the exhaust pipe. The SCR catalyst carrier is a ceramic / metal substrate coated with a vanadium-based (V₂O₅-WO₃ / TiO₂) or zeolite catalyst to promote the NOx reduction reaction. The NOx sensor monitors the NOx concentration before and after the catalyst, enabling closed-loop control. The exhaust temperature sensor ensures that the SCR operates within its optimal operating temperature window of 200–450°C. The control unit calculates the urea injection quantity based on engine operating conditions and communicates with the engine ECU.

[0055] "Pressure building up" in an SCR system refers to the process by which the urea pump draws urea solution from the urea tank and establishes a stable high pressure in the urea pipeline through a pressurization device. The purpose of pressure building up is to ensure that urea can be precisely injected into the exhaust pipe in atomized form, fully mix with the exhaust gas, and efficiently reduce NOx in the SCR catalytic converter.

[0056] The freezing point of standard urea solution is about -11°C. When the ambient temperature is lower than the freezing point of urea, the urea solution in the urea tank will freeze. Therefore, at low temperatures, the urea system needs to be heated and thawed after the vehicle is started.

[0057] Currently, automotive urea pump assemblies are connected to a filter module and also integrate a heating module. When the ambient or urea temperature drops below a certain level, the urea pump will heat and defrost at a specific power. However, this defrosting method can lead to unstable pressure build-up in the SCR system. The specific reasons are as follows:

[0058] 1. The heating module integrated into the urea pump typically prioritizes heating the urea near the pump body, while the filter module, being farther from the heat source, thaws more slowly. While the liquid urea inside the pump can be pressurized, ice crystals or semi-frozen urea remain within the filter module, increasing flow resistance.

[0059] 2. Ice crystals in partially thawed urea solution can clog the filter module, causing a decrease in flow rate. During the initial pressure build-up, some liquid urea can pass through the filter module's screen, resulting in a brief pressure increase. As ice crystals accumulate, the filter's permeability decreases, requiring the pump to generate more power to maintain pressure, ultimately leading to pressure fluctuations or failure to build up pressure.

[0060] 3. If the urea upstream of the filter module is not completely thawed, the urea pump may draw in discontinuous liquid flow, causing dry running or cavitation, which may damage the pump's sealing components.

[0061] To resolve the above issues, please refer to the following: Figures 1 to 3The urea pump assembly provided by this utility model will now be described. The urea pump assembly includes a pump unit 1, a filter module 2, a first heating module 4, and a second heating module 5; the pump unit 1 and the filter module 2 are connected through a fluid channel 3; the first heating module 4 is disposed on the periphery of the fluid channel 3 and is used to output heat to the fluid channel 3; the second heating module 5 is disposed on the filter module 2 and is used to output heat to the interior of the filter module 2.

[0062] It should be noted that this urea pump assembly is used in a selective catalytic reduction system. The selective catalytic reduction system also includes a urea tank 7, a urea pipeline 8, a urea nozzle 9, and a control unit. The urea pump assembly is installed on the urea pipeline 8. One end of the urea pipeline 8 is connected to the urea tank 7, and the other end of the urea pipeline 8 is connected to the inlet end of the urea nozzle 9. The outlet end of the urea nozzle 9 is connected to the exhaust pipe of the engine.

[0063] The urea pump assembly provided by this utility model has a first heating module 4 arranged around the fluid channel 3, which is mainly used to heat the urea solution flowing through the fluid channel 3 to prevent it from crystallizing or freezing at low temperatures, improve the urea flowability, and avoid increased pumping resistance or unstable pressure build-up due to local freezing. The second heating module 5 is directly integrated into the filter module 2 and outputs heat to the filter module 2 to specifically solve the problem of urea freezing in the filtration area, so as to avoid filter blockage, maintain stable urea flow and system pressure, and improve the system response speed.

[0064] Compared with existing technologies, this invention utilizes the coordinated operation of the first heating module 4 and the second heating module 5 to eliminate the cold zone of the filter module 2 in traditional solutions, resulting in more uniform urea thawing, reducing pressure build-up delays or pressure fluctuations caused by the freezing of the filter module 2, and ensuring urea injection accuracy. The urea pump assembly provided by this invention is adaptable to lower ambient temperatures, extending the reliability of vehicles under low-temperature conditions.

[0065] The filter module 2 is a key purification unit in the urea pump assembly. It is used to filter particulate matter (such as metal scraps, crystal precipitates, etc.) in the urea solution, prevent the nozzle and SCR catalyst from clogging, avoid impurities from entering the precision mechanical structure of the pump unit 1, and reduce the risk of wear and leakage.

[0066] Preferably, the filter module 2 can use a filter element for filtration. The urea solution enters the housing of the filter module 2, and the liquid passes through the multi-layer filter media of the filter element to intercept particulate matter. Alternatively, the filter module 2 can use a filter screen for filtration, where the urea solution is filtered out of impurities through the filter screen. This embodiment does not limit the specific structure of the filter module 2, as long as it can filter the urea solution and install the second heating module 5.

[0067] The fluid channel 3 connects not only the pump unit 1 and the filter module 2, but also the pump unit 1 and the urea pipeline 8. The purified urea solution is pumped from the pump unit 1 into the urea pipeline 8 through the fluid channel 3 and flows to the urea nozzle 9.

[0068] The first heating module 4 is located around the fluid channel 3, and can be considered as enclosing or covering the outside of the fluid channel 3. The first heating module 4 can employ a PTC heating element bonding method, where a positive temperature coefficient PTC heating element is bonded to the outer wall of the fluid channel 3, and a cover is placed around the fluid channel to reduce heat loss; alternatively, a shell can be placed around the fluid channel, with PTC heating elements distributed inside the shell. During low-temperature startup, the PTC heating element rapidly heats up to the set temperature, and the heat is conducted through the fluid channel 3 to the internal urea solution, keeping it in a liquid state.

[0069] The first heating module 4 can also employ a heating element wound around a heating wire. A high-temperature resistant heating wire is spirally wound around the outer wall of the fluid channel 3, and the outer layer is wrapped with heat-insulating material to reduce heat loss. When the temperature sensor detects that the urea solution temperature is less than 5°C, the heating wire is energized and heated. The heat is conducted through the fluid channel 3 to the internal urea solution, keeping it in a liquid state.

[0070] The second heating module 5 can be placed directly inside the filter module 2. For example, for cartridge filtration, an electric heating ring can be embedded in the inlet / outlet flange of the filter module 2 to ensure rapid heat transfer to the cartridge. For mesh filtration, an independent heating element can be installed inside the filter chamber, in which case it is necessary to ensure that the heating element is insulated from the filter chamber. Alternatively, the second heating module 5 can be placed on the outer surface of the filter module 2 to transfer heat to the inner cavity of the filter module 2 through heat conduction.

[0071] It should be noted that whether the first heating module 4 and the second heating module 5 are activated and for how long are determined by the control unit of the selective catalytic reduction system. The control unit determines the operating status of the first heating module 4 and the second heating module 5 based on the monitored system pressure data, as well as the ambient temperature and urea temperature values.

[0072] In some embodiments, the filtering module 2 described above may employ, for example... Figure 3 The structure shown is described in the following document. Figure 3 The filter module 2 includes a filter screen 21 and a frame 22; the frame 22 is installed inside the filter screen 21 and is used to open the filter screen 21 so that the filter screen 21 forms a filter cavity.

[0073] The filter screen 21 can be made of metal wire mesh or high-density polymer mesh. The mesh opening size is precisely calculated to intercept solid impurities in the urea solution, such as dust, crystal particles, and pipeline residues. The filter screen 21 has a degree of freedom of deformation, allowing for partial bending, stretching, or compression when not installed. This facilitates matching the direction or spatial constraints of the fluid channel 3. By adjusting the shape of the filter screen 21, the fit between the first heating module 4 and the periphery of the fluid channel 3 can be optimized, ensuring heating efficiency. It should be noted that the mesh openings of the filter screen 21 are preferably rhomboid or hexagonal, allowing for moderate stretching or compression during deformation to prevent breakage.

[0074] After the shape of the filter screen 21 is determined, the structure of the frame 22 is designed. The frame 22 must match the contour of the shaped filter screen 21 to avoid support failure. The frame 22 is a metal or high-strength plastic frame used to support the filter screen 21, prevent it from collapsing, ensure the stable shape of the filter chamber, and avoid structural loosening caused by urea flow impact or temperature changes.

[0075] It should be noted that, as a specific embodiment, the skeleton 22 can not only serve as a support for the filter screen 21, but also as a sealing structure to seal part of the filter screen 21, so that the filter screen 21 retains only the inlet end and the outlet end. The inlet end is connected to the pipe storing the urea solution, and the outlet end is connected to the inlet of the fluid channel 3.

[0076] In another embodiment, the frame 22 is only used to support the filter screen 21 and does not serve as a sealing structure. A cover can be installed around the filter screen 21, and the cover has an inlet end and an outlet end that communicate with the inner cavity of the filter screen 21. The inlet end is connected to the pipe storing the urea solution, and the outlet end is connected to the inlet of the fluid channel 3.

[0077] In some embodiments, the second heating module 5 is disposed within the filter chamber. The second heating module 5 has a wire outlet end that passes through the frame 22 and is sealed to the frame 22. The second heating module 5 is preferably an independent electrically heated module, while the electrically heated module is generally connected to a wire harness. In this embodiment, the wire outlet end of the wire harness is disposed on the frame 22, and the rigidity of the frame 22 itself ensures the stability of the wire outlet position.

[0078] If the cable outlet is directly fixed to the flexible filter screen 21, long-term vibration can easily lead to fatigue fracture or seal failure of the cable harness connector. The frame 22, as a rigid support structure for the filter screen 21, provides a stable base for the cable outlet, preventing displacement of the cable harness due to vehicle vibration or fluid impact. If the frame 22 is made of a high-strength plastic frame, it can also act as a non-conductive material, preventing short circuits between the cable harness and the filter screen 21.

[0079] Furthermore, the integrated design of the cable outlet and the frame 22 allows the second heating module 5 and the filter module 2 to be pre-assembled and then installed as a whole, reducing the assembly steps. Moreover, the cable outlet is centrally fixed on the frame 22, which facilitates quick location and detection in case of failure without having to disassemble the entire filter screen 21.

[0080] Specifically, the frame 22 is provided with a wire-through hole, through which the wire end passes. The wire-through hole is provided with a sealing ring or potting compound to achieve a seal.

[0081] In some embodiments, the second heating module 5 described above may also employ, for example... Figure 3 The structure shown is described in the following document. Figure 3 The second heating module 5 includes a second housing 51 and a second heating module 52 filled inside the second housing; the second housing 51 is distributed in a meandering manner.

[0082] The second housing 51 serves as the encapsulation shell for the second heating module 52, providing insulation and heat conduction. The second housing 51 employs a sealed design to prevent urea solution from seeping into the heating module, thus avoiding short circuits or component corrosion. Since the second housing 51 directly contacts the urea solution within the filter chamber, it must also possess high thermal conductivity and corrosion resistance.

[0083] The second heating module can be a PTC heating element, directly attached to the inner wall of the second housing 51, which transfers heat to the urea solution through the second housing 51. Alternatively, it can be a thick-film heating circuit, in which conductive paste is printed on the surface of the housing to form a heating loop.

[0084] The second housing 51 is distributed in a meandering manner (such as serpentine, spiral, mountain-shaped, etc.), which can increase the surface area of ​​the second housing 51, that is, increase the heat conduction area of ​​the second housing 51, realize uniform heating of the urea solution inside the filter module 2, avoid local overheating or cold areas, improve heat exchange efficiency, and shorten the melting time of urea when starting at low temperature.

[0085] In addition, the second housing 51, which is distributed in a meandering manner, can also guide the urea solution to form turbulence in the filter cavity. The flow scouring reduces the adhesion of the urea solution to the filter screen surface, and impurities are not easily deposited on the surface of the second housing 51.

[0086] In some embodiments, the urea pump assembly described above may also employ, for example... Figure 1 and Figure 2 The structure shown is described in the following document. Figure 1 and Figure 2 The urea pump assembly also includes an integrated base 6, on which the first heating module 4, pump unit 1, and filter module 2 are respectively fixed. Preferably, the integrated base 6 has a recessed groove, in which the first heating module 4, pump unit 1, and filter module 2 are all located.

[0087] The integrated base 6 is the core load-bearing structure of the urea pump assembly. The three major functional components, namely the first heating module 4, the pump unit 1, and the filter module 2, are centrally fixed through the sinking groove to achieve a compact layout, reduce the length of pipeline connections, and reduce fluid resistance. Furthermore, it enables standardized assembly, with each module installed in its predetermined position, simplifying the assembly process on the production line.

[0088] The enclosed structure of the sinking trough can limit the lateral displacement of each module and adapt to the high-frequency vibration during vehicle operation; the edge of the sinking trough can be designed with reinforcing ribs to prevent the integrated base 6 from cracking due to the working pulse pressure of the pump unit 1.

[0089] Preferably, please refer to Figure 1 Based on the above embodiments, the integrated base 6 is provided with a socket 61, and the second heating module 5 has a wire outlet end, which is fixedly disposed in the socket 61. The wire outlet end of the second heating module 5 is not only sealed and connected to the frame 22, but also fixedly disposed in the socket 61 of the integrated base 6, so as to realize the connection with the external wiring harness through the socket 61.

[0090] Specifically, connector 61 serves as the connection point between the second heating module 5 and the vehicle wiring harness, and can be designed to prevent mis-connection, ensuring quick and accurate connection. Connector 61 integrates a waterproof sealing ring to prevent water leakage and short circuits during car washes or rain / snow.

[0091] The outgoing wire is simultaneously fixed to the frame 22 and the connector 61 of the integrated base 6, forming a two-point lock to prevent the wiring harness from loosening due to vehicle vibration. Furthermore, the connector 61 connects the second heating module 5 to the external wiring harness. This facilitates electrical connection to the second heating module 5, and centralized wiring makes diagnostic interface connection easier; the current signal from the second heating module 5 can be directly transmitted to the ECU through the connector 61. On the other hand, during maintenance, the second heating module 5 can be disconnected simply by plugging and unplugging the connector 61, without needing to disassemble the filter chamber.

[0092] In some embodiments, the integrated base 6 described above may also adopt the following: Figure 1 The structure shown is described in the following document. Figure 1 The integrated base 6 is also provided with a sensor mounting position 63, which is used to mount a temperature sensor and / or a liquid level sensor.

[0093] A temperature sensor is used to monitor the temperature of the urea solution in the urea tank 7 in real time, forming a closed-loop control with the first module and the second heating module 5 to prevent the urea solution from overheating or insufficiently thawing. A level sensor is used to detect the level of the urea solution in the urea tank 7. When the detected level is lower than a preset value, a low level alarm is triggered, cutting off the power to the first heating module 4 and the second heating module 5 to prevent damage from dry burning.

[0094] Mounting the temperature sensor and / or level sensor onto the integrated housing 6 reduces the size of individual packages, and the sensor wiring harness can be routed through the pre-embedded channels in the integrated housing 6. Additionally, a buffer structure, such as a silicone gasket, can be designed at the sensor mounting position 63 to attenuate the impact of high-frequency vibrations on measurement accuracy.

[0095] In some embodiments, the fluid channel 3 and the first heating module 4 may also employ, for example... Figure 2 The structure shown is described in the following document. Figure 2 The fluid channel 3 includes a first channel 31 and a second channel 32. The inlet end of the first channel 31 is connected to the outlet of the filter module 2, and the outlet end of the first channel 31 is connected to the inlet of the pump unit 1. The inlet end of the second channel 32 is connected to the outlet of the pump unit 1, and the outlet end of the second channel 32 is fixed on the integrated base 6. The first heating module 4 is arranged around the first channel 31, the pump unit 1 and the second channel 32.

[0096] The first channel 31 is directly connected to the outlet of the filter module 2 and the inlet of the pump unit 1, ensuring that the urea solution without impurities after being filtered by the filter module 2 enters the pump unit 1, and protecting the precision plunger / gear pump of the pump unit 1 from wear; the first heating module 4 surrounds the first channel 31 and prioritizes heating the urea solution that is about to enter the pump unit 1, preventing the low-temperature viscosity from increasing and causing difficulty in pump suction.

[0097] The second channel 32 connects the outlet of the pump unit 1 to the outlet of the integrated base 6, stably delivering the high-pressure urea solution generated by the pump unit 1 to the injection system; the first heating module 4 also extends to the periphery of the second channel 32 to maintain the temperature of the high-pressure urea solution and prevent secondary crystallization before injection.

[0098] The integrated base 6 is also provided with a connecting port 62, and the liquid outlet end of the second channel 32 is fixed at the connecting port 62.

[0099] Please see Figure 4 Based on the same inventive concept, this application also provides a selective catalytic reduction system, including a urea tank 7, a urea pipeline 8, a urea nozzle 9, and the aforementioned urea pump assembly; the urea pump assembly is disposed on the urea pipeline 8, one end of the urea pipeline 8 is connected to the urea tank 7, the other end of the urea pipeline 8 is connected to the inlet end of the urea nozzle 9, and the outlet end of the urea nozzle 9 is connected to the exhaust pipe of the engine.

[0100] The urea tank 7 is used to store and supply 32.5% high-purity urea solution. The urea pump assembly pressurizes the urea solution in the urea tank 7 and delivers it to the urea nozzle 9 through the urea pipeline 8. The urea nozzle 9 atomizes the urea solution into tiny particles through precision spray holes and sprays them precisely into the exhaust pipe to increase the contact area with the exhaust gas.

[0101] In addition to the above, the selective catalytic reduction system also includes an SCR catalyst carrier, a NOx sensor, an exhaust temperature sensor, and a control unit. The SCR catalyst carrier is a ceramic / metal substrate coated with a vanadium-based or zeolite catalyst to promote the NOx reduction reaction. The NOx sensor monitors the NOx concentration before and after the catalyst, enabling closed-loop control. The exhaust temperature sensor ensures that the SCR operates within its optimal operating temperature window of 200–450°C. The control unit calculates the urea injection quantity based on engine operating conditions and communicates with the engine ECU.

[0102] The selective catalytic reduction system provided by this utility model, by adopting the above-mentioned urea pump assembly, utilizes the first heating module 4 and the second heating module 5 working together to eliminate the cold zone of the filter module 2 in the traditional solution, making the urea thawing more uniform, reducing the pressure build-up delay or pressure fluctuation caused by the freezing of the filter module 2, and ensuring the accuracy of urea injection.

[0103] Based on the same inventive concept, this application also provides a vehicle including the above-described selective catalytic reduction system.

[0104] The vehicle provided by this utility model, due to the adoption of the above-mentioned selective catalytic reduction system, allows the urea pump assembly to adapt to lower ambient temperatures, thus expanding the vehicle's reliability under low-temperature conditions.

[0105] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A urea pump assembly comprising a pump unit (1) and a filter module (2), said pump unit (1) and said filter module (2) being in fluid communication through a fluid passage (3); characterized in that, The urea pump assembly also includes a first heating module (4) and a second heating module (5); The first heating module (4) is disposed on the periphery of the fluid channel (3) and is used to output heat to the fluid channel (3); the second heating module (5) is disposed on the filter module (2) and is used to output heat to the interior of the filter module (2).

2. The urea pump assembly of claim 1, wherein, The filtering module (2) includes: Filter screen (21); and The frame (22) is installed inside the filter screen (21) to open the filter screen (21) so that the filter screen (21) forms a filter cavity.

3. The urea pump assembly of claim 2, wherein, The second heating module (5) is disposed in the filter cavity. The second heating module (5) has a wire outlet end that passes through the frame (22) and is sealed to the frame (22).

4. The urea pump assembly of claim 3, wherein, The second heating module (5) includes a second housing (51) and a second heating module (52) filled inside the second housing (51); the second housing (51) is distributed in a meandering manner.

5. The urea pump assembly as described in claim 1, characterized in that, The urea pump assembly also includes an integrated base (6), on which the first heating module (4), the pump unit (1) and the filter module (2) are respectively fixed.

6. The urea pump assembly of claim 5, wherein, The integrated base (6) is provided with a socket (61), and the second heating module (5) has a wire outlet, which is fixedly installed in the socket (61).

7. The urea pump assembly of claim 5, wherein, The integrated base (6) is also provided with a sensor mounting position (63), which is used to mount a temperature sensor and / or a liquid level sensor.

8. The urea pump assembly of claim 5, wherein, The fluid channel (3) includes a first channel (31) and a second channel (32). The inlet end of the first channel (31) is connected to the outlet of the filter module (2), and the outlet end of the first channel (31) is connected to the inlet of the pump unit (1). The inlet end of the second channel (32) is connected to the outlet of the pump unit (1), and the outlet end of the second channel (32) is fixed on the integrated base (6). The first heating module (4) is arranged around the first channel (31), the pump unit (1) and the second channel (32).

9. A selective catalytic reduction system characterized by, The urea pump assembly includes a urea tank (7), a urea pipeline (8), a urea nozzle (9), and a urea pump assembly as described in any one of claims 1-8; the urea pump assembly is disposed on the urea pipeline (8), one end of the urea pipeline (8) is connected to the urea tank (7), the other end of the urea pipeline (8) is connected to the inlet end of the urea nozzle (9), and the outlet end of the urea nozzle (9) is connected to the exhaust pipe of the engine.

10. A vehicle characterized by comprising: Includes the selective catalytic reduction system as described in claim 9.

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