Urea heating system and hybrid vehicle

Abstract

The application relates to the technical field of hybrid vehicles, and provides a urea heating system and a hybrid vehicle. The urea heating system comprises a urea tank, a power battery and a battery cooling circuit thereof, and a heating unit for improving the temperature of the urea tank. The heating unit comprises a first circulation circuit communicated between the battery cooling circuit and the urea tank; battery cooling liquid in the battery cooling circuit can be at least partially guided to the urea tank by the first circulation circuit to improve the temperature of the urea tank. The urea heating system provided by the application not only can heat the urea tank by means of an electric heating device, but also can guide part of the battery cooling liquid in the battery cooling circuit to the urea tank for heating, thereby avoiding the condition that the urea tank depends on the waste heat of an engine for heating and thawing, and thus a urea heating scheme suitable for a hybrid vehicle is provided.

Description

Technical Field

[0001] This application relates to the field of hybrid vehicle technology, and in particular to a urea heating system and a hybrid vehicle. Background Technology

[0002] To address NOx (nitrogen oxide) emissions during vehicle startup, vehicles are typically equipped with urea tanks. Urea is injected through nozzles to achieve the catalytic reduction of NOx. However, in extremely cold weather, urea is prone to freezing. Regulations require vehicle manufacturers to ensure that the urea in the vehicle can thaw and be used normally 70 minutes after the vehicle starts running, at an ambient temperature of 256K (-17℃). The freezing point of a standard urea solution is approximately -11℃. When the ambient temperature falls below the freezing point of urea, the urea solution in the tank will freeze. Therefore, in low temperatures, the urea system needs to be heated and thawed after the vehicle is started.

[0003] A vehicle's urea supply system typically includes a urea tank, a urea pump, and related piping. Defrost is usually achieved by heating the urea tank, pump, or piping. The urea tank often utilizes hot water from the engine for heating, but this method suffers from slow engine coolant temperature rise and low urea defrost efficiency in low-temperature environments. This is particularly problematic for hybrid electric commercial vehicles, which require a strategy of keeping the engine running continuously to ensure timely urea defrost in low temperatures, leading to increased fuel consumption.

[0004] Therefore, in the case of cold starts of hybrid vehicles where the engine cannot provide residual heat to heat urea because the vehicle is driven by an electric motor, there is an urgent need to provide a urea heating solution suitable for hybrid vehicles. Utility Model Content

[0005] In view of this, this application aims to provide a urea heating system to offer a urea heating solution suitable for hybrid vehicles.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows: A urea heating system includes a urea tank, a power battery and its battery cooling circuit, and a heating unit for raising the temperature of the urea tank; the heating unit includes a first circulation loop connected between the battery cooling circuit and the urea tank; the battery coolant in the battery cooling circuit can be at least partially diverted to the urea tank by the first circulation loop to raise the temperature of the urea tank.

[0007] Furthermore, the first circulation loop is connected to the battery cooling loop via a first electronically controlled three-way valve, and / or, the battery cooling loop is equipped with a first electronic thermostat.

[0008] Furthermore, a first temperature sensor is provided in the urea tank, and / or a second temperature sensor is provided in the coolant tank for providing the battery coolant to the battery cooling circuit.

[0009] Furthermore, it also includes an engine and its engine cooling circuit; the heating unit further includes a second circulation circuit connected between the engine cooling circuit and the urea tank; the engine coolant in the engine cooling circuit can be at least partially diverted to the urea tank by the second circulation circuit to increase the temperature of the urea tank.

[0010] Furthermore, the second circulation loop is connected to the engine cooling loop via a second electronically controlled three-way valve, and / or, the engine cooling loop is equipped with a second electronic thermostat, and / or, a third temperature sensor is configured in the coolant tank for supplying the engine cooling loop with the engine coolant.

[0011] Furthermore, it also includes a heat exchanger, a urea supply pump, and a supply pipeline connecting the urea tank and the urea supply pump; the engine cooling circuit and the battery cooling circuit both flow through the heat exchanger, and the supply pipeline has a first supply branch directly connected to the urea supply pump, and a second supply branch that flows through the heat exchanger and then to the urea supply pump.

[0012] Furthermore, a third electrically controlled three-way valve is provided at the branch point of the supply pipeline where the first supply branch and the second supply branch connect; and / or, a fourth temperature sensor is provided on the urea supply pump; and / or, a first electric heating device is provided on the first supply branch.

[0013] Furthermore, the urea tank includes a urea tank body and a water bath heating shell disposed on the outside of the urea tank body when it is submerged; heating pipes are arranged in a circuitous manner in the water bath heating shell, the heating pipes are arranged around the urea tank body, and the heating pipes are connected to the first circulation loop.

[0014] Furthermore, the heating unit also includes a second electric heating device, which includes at least two sets of heating resistance wires, the two sets of heating resistance wires being arranged vertically at intervals, and the heating pipeline being located between the two sets of heating resistance wires; and / or, the upper part of the water bath heating shell is provided with a water inlet, the lower part of the water bath heating shell is provided with a water outlet, and the heating pipeline is connected to the first circulation loop through the water inlet and the water outlet respectively.

[0015] Compared with related technologies, this application has the following advantages: (1) The urea heating system of this application is designed for vehicles equipped with power batteries and battery cooling circuits for cooling the power batteries. A first circulation circuit is configured in the heating unit for heating the urea tank. The battery coolant in the battery cooling circuit can be diverted to the urea tank. The heat brought by the circulating battery coolant is used to heat the urea tank, avoiding the situation where the urea tank relies solely on the residual heat of the engine for heating and defrosting. It can effectively meet the heating needs of the urea tank when the vehicle is started and driven by the motor but the engine has not yet started, thus providing a urea heating solution suitable for hybrid vehicles.

[0016] (2) By installing a first electrically controlled three-way valve on the battery cooling circuit, an interface for connecting to the first circulation circuit can be branched off from the battery cooling circuit. By controlling the on / off position of the first electrically controlled three-way valve in real time, the first circulation circuit can be connected when the urea tank needs the first circulation circuit to introduce battery coolant for heating, and the first circulation circuit can be disconnected when no flow is needed, so as to ensure good circulation of battery coolant in the battery cooling circuit. Installing a first electronic thermostat on the battery cooling circuit can cut off the flow of battery coolant in the battery cooling circuit when there is no cooling requirement for the power battery and the temperature of the battery coolant is low, thereby preventing the low-temperature battery coolant from flowing into the urea tank through the first circulation circuit.

[0017] (3) A first temperature sensor is installed in the urea tank to promptly monitor the temperature of the urea inside, thereby determining the heating requirements and their degree based on the urea temperature. This provides a control basis for starting the electric heating device and switching the valve position of the first electrically controlled three-way valve. A second temperature sensor is installed in the coolant tank used to hold the battery coolant to monitor the temperature of the battery coolant in real time. This allows the first electronic thermostat to be disconnected when the battery coolant temperature is low, preventing the low-temperature battery coolant from flowing into the urea tank through the first circulation loop and causing a drop in urea temperature.

[0018] (4) For vehicles equipped with engines, by setting a second circulation loop in the heating unit, the heat of the engine coolant in the engine cooling loop can be fully utilized, and the purpose of heating the urea in the urea tank can be achieved by using the engine coolant circulating in the second circulation loop.

[0019] (5) By setting a second electronically controlled three-way valve on the engine cooling circuit, an interface for connecting the second circulation circuit can be branched out from the engine cooling circuit. By controlling the valve position of the second electronically controlled three-way valve in real time, the second circulation circuit can be connected when the urea tank needs the second circulation circuit to introduce engine coolant for heating, or the second circulation circuit can be cut off when the second circulation circuit does not need to provide drainage, so as to ensure the good circulation state of engine coolant in the engine cooling circuit.

[0020] (6) By configuring a heat exchanger, heat dissipation conditions are provided for the engine cooling circuit and the battery cooling circuit mentioned above. The engine coolant circulating in the engine cooling circuit and the battery coolant circulating in the battery cooling circuit can dissipate the heat they carry to the outside through the heat exchanger, thereby ensuring the cooling effect of the engine and the power battery.

[0021] (7) A third electrically controlled three-way valve is installed at the branch of the first supply branch and the second supply branch of the supply pipeline. The two branches of the first supply branch and the second supply branch can be switched flexibly. When the waste heat at the heat exchanger needs to be used, the first supply branch can be closed and urea solution can be supplied to the urea supply pump only through the second supply branch. When the heat dissipation at the heat exchanger is not obvious, or when the urea temperature in the urea tank meets the requirements, the urea solution can be directly supplied to the urea supply pump only through the first supply branch, thereby improving the pumping efficiency of the urea solution.

[0022] (8) The urea tank adopts a water bath heating structure, which can effectively improve heating efficiency and heat transfer uniformity, so that the urea solution in the urea tank body is fully heated and heated to improve its defrosting efficiency. The circulation loop located in the water bath heating shell is set as a detour-arranged heating pipeline, which can avoid the mixing of coolant in the circulation loop with heating liquid in the water bath heating shell, and avoid the possible performance degradation or unnecessary chemical reactions caused by the mixing of liquids with different properties.

[0023] (9) The second electric heating device adopts a heating resistance wire heating method, which has technical advantages such as easy configuration and flexible and reliable on / off control. It can quickly heat up the heating liquid in the water bath heating shell. The inlet and outlet are distributed vertically, which allows the coolant with residual heat flowing into the circulation loop to flow quickly, improve the circulation speed, and thus improve the heating efficiency.

[0024] Another object of this application is to provide a hybrid vehicle equipped with the urea heating system described in this application. The hybrid vehicle of this application possesses the technical advantages of the aforementioned urea heating system. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application. The directional terms such as front / back, up / down, etc., used therein are only used to indicate relative positional relationships and do not constitute an improper limitation of this application. In the accompanying drawings: Figure 1 This is a schematic diagram of the piping system configuration of the urea heating system described in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the water bath heating shell described in the embodiments of this application; Figure 3 This is a schematic diagram of the overall system configuration of the urea heating system described in the embodiments of this application.

[0026] Explanation of reference numerals in the attached figures: 1. Coolant reservoir; 11. Engine coolant; 110. Third temperature sensor; 12. Battery coolant; 120. Second temperature sensor; 2. Engine; 20. Engine cooling circuit; 21. Second electronic thermostat; 22. Second electronically controlled three-way valve; 3. Power battery; 30. Battery cooling circuit; 31. First electronic thermostat; 32. First electronically controlled three-way valve; 4. Urea tank body; 40. Water bath heating shell; 400. First temperature sensor; 401. Water inlet; 402. Water outlet; 403. Heating pipe; 404. Second electric heating device; 405. Power supply interface; 41. Supply pipe; 410. Third electrically controlled three-way valve; 411. First supply branch; 412. Second supply branch; 42. Second circulation loop; 43. First circulation loop; 44. First electric heating device; 5. Heat exchanger; 6. Urea supply pump; 60. Nozzle; 600. Fourth temperature sensor; 7. Control unit; 700. Signal lines. Detailed Implementation

[0027] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0029] Furthermore, it should be stated in the description of this application that if terms such as "up," "down," "left," "right," "front," "back," "inner," or "outer" appear, they are based on the orientation or positional relationship shown in the accompanying drawings and are only for the purpose of describing this application and making the expression clear and concise, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0030] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joint," and "connector" should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application in light of the specific circumstances. The qualifying terms such as "first," "second," "A," "B," "C," and "D" appearing in the description of this application are merely for distinguishing similar features in different locations, attributions, or uses, in order to avoid ambiguity and confusion, and should not be construed as indicating or implying relative importance.

[0031] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] To address NOx (nitrogen oxide) emissions during vehicle startup, vehicles are typically equipped with urea tanks. Urea is injected through nozzles to achieve the catalytic reduction of NOx. However, in extremely cold weather, urea is prone to freezing. Regulations require vehicle manufacturers to ensure that the urea in the vehicle can thaw and be used normally 70 minutes after the vehicle starts running, at an ambient temperature of 256K (-17℃). For example, the vehicle's performance limiting system monitors the normal operation of the NOx control system in real time. If the urea heating system fails to thaw properly after 70 minutes, it will restrict the vehicle's normal operation and issue a fault alarm.

[0033] The freezing point of a 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 system needs to be heated and thawed after the vehicle is started.

[0034] A vehicle's urea supply system typically includes a urea tank, a urea pump, and related piping. Defrost is usually achieved by heating the urea tank, pump, or piping. The urea tank often utilizes hot water from the engine for heating, but this method suffers from slow engine coolant temperature rise and low urea defrost efficiency in low-temperature environments. This is particularly problematic for hybrid electric commercial vehicles, which require a strategy of keeping the engine running continuously to ensure timely urea defrost in low temperatures, leading to increased fuel consumption.

[0035] Electric heating is generally achieved using resistance heating wires for urea pumps and related pipelines. However, due to the large amount of urea that needs to be heated and thawed in the urea tank, the energy consumption of electric heating is high. Moreover, when the urea in the urea tank is an ice-water mixture (around -11℃), under specific ambient temperature and water flow conditions, the heat dissipation of the urea tank balances the water heating, causing the urea to thaw incomplete within 70 minutes. This results in the vehicle's speed and torque being limited, affecting not only the normal use of the vehicle but also its normal exhaust emissions.

[0036] Therefore, in the case of cold starts of hybrid vehicles where the engine cannot provide residual heat to heat urea because the vehicle is driven by an electric motor, there is an urgent need to provide a urea heating solution suitable for hybrid vehicles.

[0037] In view of the above-mentioned problems in the related technologies, this application innovatively proposes a brand-new urea heating system, which is particularly suitable for the urea heating needs of hybrid vehicles.

[0038] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0039] An embodiment of the first aspect of this application provides a urea heating system applied to a urea heating and defrosting scenario in a vehicle; an exemplary system configuration is as follows: Figure 1 , Figure 2 and Figure 3 As shown.

[0040] Overall, the urea heating system includes a urea tank, a power battery 3 and its battery cooling circuit 30, and a heating unit for raising the temperature of the urea tank. The heating unit includes a first circulation circuit 43 connecting the battery cooling circuit 30 and the urea tank; the battery coolant 12 in the battery cooling circuit 30 can be at least partially diverted to the urea tank through the first circulation circuit 43 to raise the temperature of the urea tank.

[0041] Based on the above overall design concept, for vehicles equipped with a power battery 3 and a battery cooling circuit 30 for cooling the power battery 3, a first circulation circuit 43 is configured in the heating unit for heating the urea tank. This circuit can divert a portion of the battery coolant 12 from the battery cooling circuit 30 to the urea tank. The heat generated by the circulating battery coolant 12 heats the urea tank, avoiding the situation where the urea tank relies solely on the residual heat of the engine 2 for heating and defrosting. This effectively addresses the heating needs of the urea tank at the beginning of vehicle startup, when the vehicle is driven by the electric motor and the engine is not yet running, thus providing a urea heating solution suitable for hybrid vehicles.

[0042] It should be noted that, based on the above overall design concept, the technical solution of this application can adopt a variety of different specific implementation structures, forms, or configuration sequences. For example, the first circulation loop 43 can be directly connected to the battery cooling loop 30 via a three-way valve, or it can be connected to the battery cooling loop 30 via a three-way control valve. The urea tank can be a conventional urea tank with heating pipes arranged inside, or it can be a double-layer urea tank, that is, a water bath heating shell 40 is set on the outside of the urea tank body 4, and the urea tank body 4 can be fixedly connected to the inner wall of the water bath heating shell 40 via connecting ribs; the water bath heating shell 40 should be filled with heating liquid for water bath, so that the urea tank body 4 is immersed in the heating liquid inside the water bath heating shell 40. Of course, for the case where the second electric heating device 404 is set in the heating liquid inside the water bath heating shell 40, the second electric heating device 404 should use electric heating components with good waterproof and insulation properties to avoid leakage in the heating liquid; for example, using electric heating rods or heating resistance wires with waterproof properties.

[0043] The specific arrangement and assembly method of the urea tank, first circulation loop 43, power battery 3, battery cooling loop 30, and the following supply pipeline 41, urea supply pump 6, engine 2, etc., can also be flexibly adjusted. For parts required for the overall implementation but not covered in the above overall setup, reasonable and flexible designs can be made by referring to mature setup methods in the field and the actual situation during implementation, which will not be elaborated here. The specific implementation scheme described below in this embodiment is only one of the many schemes that can be formed by the various combinations and variations mentioned above. In actual implementation, those skilled in the art can make flexible adjustments and improvements based on the actual situation. Obviously, the various schemes that can be formed by the combinations and variations of the above specific forms, as well as the specific implementation scheme of this embodiment, are all within the protection scope of this application.

[0044] The following will provide a detailed description of the solution proposed in this application. To facilitate a better understanding of the solution, it is necessary to first explain the heat source for urea heating and defrosting in the urea supply injection system of the vehicle before proceeding with the detailed description. The urea heating system of this application is applicable to various hybrid vehicle models, especially large hybrid commercial vehicles. Large hybrid commercial vehicles contain a large-displacement engine 2 and a high-power electric motor and its matching power battery 3. These two power sources can provide power for vehicle operation independently or work together to propel the vehicle.

[0045] When the power battery 3 is fully charged, the vehicle initially relies solely on the electric motor for propulsion, and the engine 2 does not need to be started. However, if the outside temperature is low and the urea in the urea tank is frozen, the frozen urea needs to be thawed within 70 minutes. Since the engine 2 has not yet started, it cannot provide residual heat for thawing the urea. The heating unit of the urea heating system in this application can be a second electric heating device 404 powered by the power battery 3 to heat the urea tank; or it can be the aforementioned first circulation loop 43, which relies on the battery coolant 12 in the battery cooling loop 30 of the power battery 3 to provide heat to heat the urea in the urea tank. This fully utilizes the heat from various components that can generate heat or residual heat to preheat the urea, enabling the urea to thaw in advance within a limited time, thereby reducing the impact of the urea not thawing in time on the normal operation of the vehicle and the normal emission of engine exhaust.

[0046] Continue as Figure 1 As shown, as a preferred exemplary implementation among various feasible solutions, the first circulation loop 43 of this embodiment is connected to the battery cooling loop 30 through the first electrically controlled three-way valve 32. By setting the first electrically controlled three-way valve 32 on the battery cooling loop 30, an interface for connecting the first circulation loop 43 can be branched out from the battery cooling loop 30. By controlling the valve position of the first electrically controlled three-way valve 32 in real time, the first circulation loop 43 can be connected when the urea tank needs the first circulation loop 43 to introduce battery coolant 12 for heating, and the first circulation loop 43 can be disconnected when the first circulation loop 43 does not need to provide drainage, so as to ensure the good circulation state of battery coolant 12 in the battery cooling loop 30.

[0047] Meanwhile, a first electronic thermostat 31 can be installed on the battery cooling circuit 30. By installing the first electronic thermostat 31 on the battery cooling circuit 30, the flow of the battery coolant 12 in the battery cooling circuit 30 can be cut off when the power battery 3 does not require cooling and the temperature of the battery coolant 12 is low, thereby preventing the low-temperature battery coolant 12 from flowing into the urea tank through the first circulation circuit 43.

[0048] For the specific configuration of the first electrically controlled three-way valve 32, there are, of course, various technical solutions to choose from; for example, a common electrically controlled three-way valve can be used, or an electrically adjustable three-way valve with an adjustable valve opening angle can be used, so that the flow rate of the battery coolant 12 introduced into the first circulation loop 43 is adjustable. However, in order to obtain better technical effects, preferably, the first electrically controlled three-way valve 32 in this embodiment is an electrically adjustable three-way valve, so that the opening size of the first electrically controlled three-way valve 32 can be adjusted according to the heating and temperature rise requirements of the urea tank, thereby reasonably controlling the flow rate of the battery coolant 12 diverted to the first circulation loop 43.

[0049] In addition, the urea tank in this embodiment is also equipped with a first temperature sensor 400. The first temperature sensor 400 in the urea tank can promptly understand the temperature of the urea in the urea tank, and then determine the heating requirements and the degree of requirements based on the temperature of the urea, so as to provide a control basis for the opening of the second electric heating device 404 and the valve position switching control of the first electric three-way valve 32.

[0050] To monitor the temperature of the battery coolant 12 in real time, a second temperature sensor 120 can be installed in the coolant tank 1, which supplies the battery coolant 12 to the battery cooling circuit 30. The second temperature sensor 120 in the coolant tank 1 allows for real-time monitoring of the battery coolant 12 temperature. This enables the first electronic thermostat 31 to be disconnected when the battery coolant 12 temperature is too low or too high, preventing the coolant 12 from flowing through the first circulation circuit 43 to the urea tank and causing the urea temperature to exceed the appropriate range. When the battery coolant 12 is within the appropriate range, the first electronic thermostat 31 can be activated, using the battery coolant 12 in the first circulation circuit 43 to heat and regulate the temperature of the urea in the urea tank, maintaining the urea temperature between 20°C and 25°C to meet the requirements for urea injection.

[0051] Still refer to Figure 1As shown, in hybrid vehicles, an engine 2 is also configured; therefore, the urea heating system of this application further includes the engine 2 and its engine cooling circuit 20. Based on this, the heating unit of this embodiment also includes a second circulation circuit 42 connecting the engine cooling circuit 20 and the urea tank; and the engine coolant 11 in the engine cooling circuit 20 can be at least partially diverted to the urea tank by the second circulation circuit 42 to increase the temperature of the urea tank. For vehicles equipped with an engine 2, by providing the second circulation circuit 42 in the heating unit, the heat of the engine coolant 11 in the engine cooling circuit 20 can be fully utilized, and the purpose of heating the urea in the urea tank can be achieved by using the engine coolant 11 circulating in the second circulation circuit 42.

[0052] Similar to the configuration of the first circulation loop 43 described above, as a preferred exemplary implementation among various feasible solutions, the second circulation loop 42 of this embodiment is connected to the engine cooling loop 20 via the second electronically controlled three-way valve 22. By setting the second electronically controlled three-way valve 22 on the engine cooling loop 20, an interface for connecting the second circulation loop 42 can be branched off from the engine cooling loop 20. By controlling the on / off position of the second electronically controlled three-way valve 22 in real time, the second circulation loop 42 can be connected when the urea tank needs the second circulation loop 42 to introduce engine coolant 11 for heating, and the second circulation loop 42 can be disconnected when it is not needed to provide drainage, so as to ensure a good circulation state of engine coolant 11 in the engine cooling loop 20.

[0053] Naturally, there are several different options for the specific configuration of the second electrically controlled three-way valve 22. Similar to the selection of the first electrically controlled three-way valve 32, a regular electrically controlled three-way valve can be used, or an electrically adjustable three-way valve with an adjustable valve opening angle can be used to make the flow rate of the engine coolant 11 introduced into the second circulation loop 42 adjustable. However, in order to obtain better technical results, the following configuration is preferred.

[0054] In this embodiment, the second electronically controlled three-way valve 22 is also an electronically adjustable three-way valve, so that the opening size of the second electronically controlled three-way valve 22 can be adjusted according to the heating and temperature rise requirements of the urea tank, thereby reasonably controlling the flow rate of the engine coolant 11 diverted to the second circulation loop 42.

[0055] Furthermore, it should be noted that the engine coolant 11 and battery coolant 12 can share a single coolant tank 1, or two separate coolant tanks 1 can be provided. Preferably, communication and mixing between the engine coolant 11 and battery coolant 12 should be avoided; therefore, when sharing a single coolant tank 1, the coolant tank 1 can be divided into two parts, one for holding the engine coolant 11 and the other for holding the battery coolant 12. Accordingly, the third temperature sensor 110 is installed in the compartment holding the engine coolant 11, and the second temperature sensor 120 is installed in the compartment holding the battery coolant 12.

[0056] Additionally, a second electronic thermostat 21 can be provided on the engine cooling circuit 20; and a third temperature sensor 110 can be provided in the coolant tank 1 that supplies engine coolant 11 to the engine cooling circuit 20. The second electronic thermostat 21 on the engine cooling circuit 20 can cut off the flow of engine coolant 11 within the engine cooling circuit 20 when there is no cooling requirement for the engine 2 and the engine coolant 11 temperature is low, thereby preventing the low-temperature engine coolant 11 from flowing into the urea tank through the second circulation loop 42. The third temperature sensor 110 in the coolant tank 1 that holds the engine coolant 11 can monitor the temperature of the engine coolant 11 in real time, so that the second electronic thermostat 21 can be disconnected when the engine coolant 11 temperature is too low or too high, preventing the low-temperature or excessively high-temperature engine coolant 11 from flowing into the urea tank through the second circulation loop 42 and causing the urea temperature to exceed the appropriate range. Similar to the first electronic thermostat 31 mentioned above, when the engine coolant 11 is within a suitable range, the second electronic thermostat 21 can be opened to use the engine coolant 11 in the second circulation loop 42 to heat and regulate the temperature of the urea in the urea tank, keeping the urea between 20°C and 25°C to meet the needs of urea injection.

[0057] like Figure 1 and Figure 3 As shown, in this embodiment, the urea heating system further includes a heat exchanger 5, a urea supply pump 6, and a supply pipeline 41 connecting the urea tank and the urea supply pump 6. The engine cooling circuit 20 and the battery cooling circuit 30 are both connected to the heat exchanger 5. The supply pipeline 41 has a first supply branch 411 directly connected to the urea supply pump 6, and a second supply branch 412 connected to the heat exchanger 5 and then to the urea supply pump 6.

[0058] By configuring the heat exchanger 5, while providing heat dissipation conditions for the aforementioned engine cooling circuit 20 and battery cooling circuit 30, the second supply branch 412 connecting the urea tank and the urea supply pump 6 can be routed through the heat exchanger 5. The heat exchanger 5 heats the pipeline to prevent it from freezing. The engine coolant 11 circulating in the engine cooling circuit 20 and the battery coolant 12 circulating in the battery cooling circuit 30 can both dissipate their heat to the outside through the heat exchanger 5, thereby ensuring the cooling effect of the engine 2 and the power battery 3. Based on the configuration of the heat exchanger 5, the supply pipeline 41 for outputting urea is divided into two branches: a first supply branch 411 and a second supply branch 412. The second supply branch 412 passes through the heat exchanger 5 and then reaches the urea supply pump 6. When the engine coolant 11 or battery coolant 12 carries a lot of heat and dissipates significantly at the heat exchanger 5, the urea solution passing through the second supply branch 412 can be further heated at the heat exchanger 5. Then, it is injected into the exhaust gas system through the urea supply pump 6 and its downstream nozzle 60. This not only makes full use of the waste heat at the heat exchanger 5, but also helps with the urea injection and exhaust gas treatment effect.

[0059] Based on the above configuration, preferably, a third electrically controlled three-way valve 410 can be installed at the branch of the supply pipeline 41 (i.e., the connection between the first supply branch 411 and the second supply branch 412). Installing the third electrically controlled three-way valve 410 at the branch of the first supply branch 411 and the second supply branch 412 of the supply pipeline 41 allows for flexible switching between the two branches. When it is necessary to utilize the waste heat at the heat exchanger 5, the first supply branch 411 can be closed, and only... Urea solution is supplied to urea supply pump 6 via the second supply branch 412. When heat dissipation at heat exchanger 5 is not significant, or when the urea temperature in urea tank already meets the requirements, urea solution can be directly supplied to urea supply pump 6 via the first supply branch 411, thereby improving the pumping efficiency of urea solution. At the same time, a first electric heating device 44 can be installed on the first supply branch 411 to ensure that the pipeline does not freeze. The first electric heating device 44 can be an electric heating belt, electric heating wire, etc.

[0060] At the same time, a fourth temperature sensor 600 can be installed on the urea supply pump 6 to monitor the temperature of the urea solution pumped by the urea supply pump 6 in real time, so as to reasonably adjust the heating status of each heating component in the heating unit and obtain the urea injection solution with the most suitable temperature.

[0061] Continue as Figure 1 and combined Figure 2As shown, as a preferred exemplary implementation among various feasible solutions, the urea tank in this embodiment includes a urea tank body 4 and a water bath heating shell 40 disposed outside the urea tank body 4; the urea tank body 4 is immersed in the water bath within the water bath heating shell 40. The water bath heating structure of the urea tank effectively improves heating efficiency and the uniformity of heat transfer, ensuring that the urea solution in the urea tank body 4 is fully heated and its temperature increased, thereby improving its defrosting efficiency.

[0062] Based on the above configuration, the second electric heating device 404 in this embodiment includes heating resistance wires disposed in the water bath heating shell 40. Preferably, the second electric heating device 404 includes at least two sets of heating resistance wires, which are arranged vertically at intervals, and the heating pipe 403 is laid between the two sets of heating resistance wires. The second electric heating device 404 adopts a heating method using heating resistance wires, which has technical advantages such as easy installation and flexible and reliable on / off control, and can quickly heat the heating liquid in the water bath heating shell 40. Furthermore, the heating resistance wires are preferably arranged in a twisted pair to reduce electromagnetic interference. Specifically, the two sets of heating resistance wires can be fixedly installed at the upper and lower positions of the heating pipe 403, which can supplement the heating of the outer area of ​​the heating pipe 403, realize the comprehensive heating of the water bath in the water bath heating shell 40, which is beneficial to accelerate the melting of urea, reduce the coexistence of urea solution and ice, and prevent pump damage caused by icing blockage at the urea supply pump 6.

[0063] To facilitate the circuit connection of the second electric heating device 404, a power supply interface 405 can be reserved on the outer wall of the water bath heating shell 40 to facilitate the convenient plug-in arrangement of the power supply line; by controlling the on / off of the power supply line of the second electric heating device 404, the heating state of the second electric heating device 404 can be flexibly controlled.

[0064] Based on the above configuration, the heating pipes 403 are arranged in a circuitous manner within the water bath heating shell 40 of this embodiment. The heating pipes 403 are connected to the first circulation loop 43 and can simultaneously connect to the second circulation loop 42. Thus, the heating pipes 403 constitute a part of both the first circulation loop 43 and the second circulation loop 42. Specifically, an inlet 401 can be provided at the upper part of the water bath heating shell 40, and an outlet 402 at the lower part. The heating pipes 403 are connected to the first circulation loop 43 and the second circulation loop 42 through the inlet 401 and the outlet 402, respectively. By arranging the circulation loop within the water bath heating shell 400 as a circuitous arrangement of heating pipes 403, the mixing of the coolant in the circulation loop with the heating liquid within the water bath heating shell 40 can be avoided, preventing potential performance degradation or unnecessary chemical reactions that might result from mixing liquids of different properties. The inlet 401 is positioned at a higher location, and the outlet 402 is positioned at a lower location. The coolant (battery coolant 12 and engine coolant 11) flowing into the circulation loop through the inlet 401, carrying residual heat, cools down after transferring heat to the water in the water bath heating shell 40, causing it to sink quickly and be discharged from the outlet 402. Both the inlet 401 and outlet 402 can be connected to the first circulation loop 43 and the second circulation loop 42 respectively via T-connectors. A water valve can be installed on the T-connector to prevent the engine coolant 11 and battery coolant 12 from heating each other.

[0065] It should be noted that, in addition to the first circulation loop 43 being connected in series with the heating pipe 403, when an engine 2, an engine cooling circuit 20, and a second circulation loop 42 are configured, the second circulation loop 42 should be connected in series with the heating pipe 403, so that the two circulation loops share one heating pipe 403, thereby reducing the number of heating pipes 403 to be laid. When the two circulation loops share the heating pipe 403, a tee structure can be installed at both the inlet 401 and the outlet 402 of the heating pipe 403, and two on / off control valves can be installed at the interfaces of the tee. The two interfaces of the tee are respectively connected to the second circulation loop 42 and the first circulation loop 43. By reasonably controlling the opening and closing of the corresponding on / off control valves, the on / off state of different circulation loops and the heating pipe 403 can be flexibly controlled.

[0066] Based on the above exemplary embodiments, as a preferred combination of the exemplary solutions, refer to Figures 1 to 3 As shown, when implementing the urea heating system of this application, the following overall layout scheme and its control method can be referred to: based on Figure 1 The urea heating system shown can use the vehicle's VCU (Vehicle Control Unit) as the control unit 7 of the system, such as... Figure 3 As shown, the third temperature sensor 110, the second temperature sensor 120, the first temperature sensor 400, the fourth temperature sensor 600, the second electronic thermostat 21, the second electrically controlled three-way valve 22, the first electronic thermostat 31, the first electrically controlled three-way valve 32, and the third electrically controlled three-way valve 410 are connected via signal line 700. This allows for real-time acquisition of the temperature of coolant, urea solution, etc., and the sending of control signals to control the operation of the relevant valves.

[0067] During system operation, signals such as the operating status of engine 2, the charge level of power battery 3, and the temperature of battery coolant 12 are acquired. Since the state of charge (SOC) of power battery 3 is below 20%, it cannot meet the vehicle's power needs. At this time, the vehicle enters charging mode or engine 2 direct drive charging mode. Charging stops once the SOC reaches 100%. Therefore, the various heating configurations in the heating unit can be utilized reasonably in the following situations.

[0068] When the temperature of the battery coolant 12 is ≤5℃, the vehicle is confirmed to be in a state requiring heating. After the vehicle starts, if the SOC is >28%, the vehicle is in pure electric driving mode, the engine 2 is in a stopped state, and the VCU controls the second electronic thermostat 21 and the first electronic thermostat 31 to close. When the SOC is between 26% and 28% and the VCU detects that the temperature of the battery coolant 12 is between 30℃ and 45℃, the VCU controls the first electronic thermostat 31 to open, the first electronically controlled three-way valve 32 to open to the first circulation loop 43, and at the same time the third electronically controlled three-way valve 410 to open to the first supply branch 411. By using the battery coolant 12 and the second electric heating device 404, the urea tank body 4 and pipelines are preheated; the urea is preheated and melted to meet the engine 2's urea injection requirements.

[0069] After engine 2 starts, the VCU controls the second electronic thermostat 21 and the first electronic thermostat 31 to open, continuing to use the first circulation loop 43 to heat the urea tank. Urea reaches the urea supply pump 6 through the first supply branch 411. After the engine coolant 11 reaches 45°C, the VCU controls the second electronic thermostat 21 to open and the first electronic thermostat 31 to close. The second electronic thermostat 21 opens to the second circulation loop 42 (the opening value of the second electronic thermostat 21 is determined based on the temperature detected by the third temperature sensor 110 and the first temperature sensor 400). At this time, part of the engine coolant 11 flowing through the engine cooling loop 20 heats the urea tank, and part flows through the heat exchanger 5 to dissipate heat. At the same time, it can heat the second supply branch 412 located at the heat exchanger 5. In this way, the effect of using the engine coolant 11 to heat the urea tank and urea pipeline is achieved. Simultaneously, the third electronically controlled three-way valve 410 opens to the second supply branch 412, using the engine coolant 11 flowing to the heat exchanger 5 to further heat the second supply branch 412. Based on the temperature values ​​collected by the VCU from the third temperature sensor 110 and the first temperature sensor 400, the opening of the second electronic thermostat 21 and the second electronically controlled three-way valve 22 are adjusted in real time to regulate the flow rate of the engine coolant 11 and change the heating state of the urea tank. This achieves closed-loop control of urea heating, ensuring that the temperature of the urea solution is controlled within the range of 20 to 25°C.

[0070] When the SOC is between 26% and 28% and the temperature of the battery coolant 12 detected by the VCU is less than 30°C, the engine 2 can be controlled to enter the drive and power generation mode; or, when the SOC is less than 25%, the engine 2 can be started in direct drive mode. At this time, the VCU controls the second electronic thermostat 21 and the first electronic thermostat 31 to close, and controls the third electronically controlled three-way valve 410 to open to the first supply branch 411 to supply urea to the urea supply pump 6; at the same time, the urea solution flowing through the pipeline is heated by the first electric heating device 44 (electric heating belt, electric heating wire, etc.) installed on the first supply branch 411 to prevent the pipeline from freezing. After the engine coolant 11 temperature rises to 45°C, the VCU controls the opening of the second electronic thermostat 21, shuts off the electric heating device on the first supply branch 411, and simultaneously opens the second electronically controlled three-way valve 22 to connect the second circulation loop 42. (The opening values ​​of the second electronic thermostat 21 and the second electronically controlled three-way valve 22 can be determined specifically based on the temperature values ​​collected by the third temperature sensor 110 and the first temperature sensor 400.) Part of the engine coolant 11 in the engine cooling circuit 20 flows to the urea tank through the second circulation loop 42 to heat the urea tank, and part flows through the heat exchanger 5 to dissipate heat, while also heating the second supply branch 412 located at the heat exchanger 5. Based on the temperature values ​​collected by the VCU from the third temperature sensor 110 and the first temperature sensor 400, the opening of the second electronic thermostat 21 and the second electronically controlled three-way valve 22 are adjusted in real time to regulate the flow rate of the engine coolant 11 and change the heating state of the urea tank. This achieves closed-loop control of urea heating and ensures that the temperature of the urea solution is controlled within the range of 20 to 25°C.

[0071] When the SOC of the power battery 3 is above 28%, and the vehicle is in pure electric driving mode, the engine 2 does not need to be started. The second electronic thermostat 21, the first electronic thermostat 31, and the second electric heating device 404 can be turned off, and the urea tank and its pipelines will no longer be heated. When the temperature of the engine coolant 11 is >5°C, the engine coolant 11 can provide residual heat for heating. The second electronic thermostat 21 and the second electronically controlled three-way valve 22 can be opened, and the first electronic thermostat 31 and the first electronically controlled three-way valve 32 can be closed. The urea tank is heated by the engine coolant 11, and the power battery 3 and its residual heat are no longer used to heat the urea tank.

[0072] When setting up the water bath heating shell 40, the inlet 401 should be positioned above the outlet 402 to accommodate the rising of high-temperature liquids and the sinking of low-temperature liquids, thereby increasing the circulation speed of the coolant. A three-way pipe with an on / off control valve is installed at both the inlet 401 and outlet 402 to prevent the engine coolant 11 and battery coolant 12 from mixing and heating each other. The second electric heating device 404 installed in the water bath heating shell 40 is preferably arranged in a twisted pair to reduce electromagnetic interference. The second electric heating device 404 can be fixed at both the top and bottom of the heating pipe 403 to supplement the water bath heating and accelerate urea melting, reducing the coexistence of urea solution and ice, and minimizing the risk of urea pump freezing damage.

[0073] In summary, the urea heating system of this embodiment, designed for vehicles equipped with a power battery 3 and a battery cooling circuit 30 for cooling the power battery 3, incorporates a second electric heating device 404 and a first circulation circuit 43 in the heating unit for heating the urea tank. This allows the urea tank to be heated not only by utilizing the power battery 3's power supply and the second electric heating device 404, but also by diverting a portion of the battery coolant 12 from the battery cooling circuit 30 to the urea tank. The heat generated by the circulating battery coolant 12 heats the urea tank, avoiding the situation where the urea tank relies solely on the residual heat of the engine 2 for heating and defrosting. This effectively addresses the heating needs of the urea tank at the start of vehicle operation, when the vehicle is driven by the electric motor but the engine is not yet running, thus providing a urea heating solution suitable for hybrid vehicles.

[0074] An embodiment of the second aspect of this application provides a hybrid vehicle equipped with the urea heating system provided in the embodiment of the first aspect of this application.

[0075] By equipping the hybrid vehicle with the urea heating system of this application, the vehicle's VCU can preheat the urea tank based on the SOC value of the power battery 3 and the detected temperatures of the coolant and urea solution. This helps to preheat the urea and completely defrost it, ensuring the reliability of the vehicle's engine emissions. When the vehicle is running, the heat between the power battery 3 and the engine 2 can be fully utilized to heat the urea tank, making efficient use of the vehicle's heat. When the urea in the urea tank is in a liquid-ice mixture but still flowable, the heat exchanger 5 can also heat the second supply branch 412, melting the urea solution while preventing icing of the urea supply pump 6 and its downstream pipelines.

[0076] When the temperature of the engine coolant 11 is low, the urea tank can be flexibly heated by electric heating through VCU control, avoiding the situation where urea heating depends entirely on starting the engine 2, which is beneficial to improving the economy of the engine 2.

[0077] As can be seen, by configuring the urea heating system of this application, the second electric heating device 404, engine coolant 11 circulation, or battery coolant 12 circulation can be flexibly used to heat the urea tank according to different vehicle operating states. This fully utilizes the heat generated by the power battery 3 and engine 2, and also ensures timely thawing of the urea, helping to preheat and completely thaw the urea and meet the vehicle's emission requirements. The VCU adopts different control strategies to heat the urea tank according to the SOC and urea solution temperature, which not only makes rational use of energy but also achieves the vehicle's energy-saving and emission-reduction goals.

[0078] The above description is merely a preferred embodiment of this application. Detailed explanations of configurations, examples of specific structural arrangements, and descriptions of assembly and connection methods are provided to ensure sufficient disclosure so that those skilled in the art can better implement this application, and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A urea heating system, characterized in that: It includes a urea tank, a power battery (3) and its battery cooling circuit (30), and a heating unit for raising the temperature of the urea tank; The heating unit includes a first circulation loop (43) connected between the battery cooling circuit (30) and the urea tank; the battery coolant (12) in the battery cooling circuit (30) can be at least partially diverted to the urea tank by the first circulation loop (43) to increase the temperature of the urea tank.

2. The urea heating system according to claim 1, characterized in that: The first circulation loop (43) is connected to the battery cooling loop (30) via the first electronically controlled three-way valve (32), and / or the battery cooling loop (30) is provided with a first electronic thermostat (31).

3. The urea heating system according to claim 1, characterized in that: The urea tank is equipped with a first temperature sensor (400), and / or the coolant tank (1) for supplying the battery coolant (12) to the battery cooling circuit (30) is equipped with a second temperature sensor (120).

4. The urea heating system according to claim 1, characterized in that: It also includes the engine (2) and its engine cooling circuit (20); The heating unit also includes a second circulation loop (42) connected between the engine cooling circuit (20) and the urea tank; the engine coolant (11) in the engine cooling circuit (20) can be at least partially diverted to the urea tank by the second circulation loop (42) to increase the temperature of the urea tank.

5. The urea heating system according to claim 4, characterized in that: The second circulation loop (42) is connected to the engine cooling loop (20) via the second electronically controlled three-way valve (22), and / or the engine cooling loop (20) is provided with a second electronic thermostat (21), and / or a third temperature sensor (110) is provided in the coolant tank (1) for supplying the engine coolant (11) to the engine cooling loop (20).

6. The urea heating system according to claim 4, characterized in that: It also includes a heat exchanger (5), a urea supply pump (6), and a supply pipeline (41) connecting the urea tank and the urea supply pump (6). The engine cooling circuit (20) and the battery cooling circuit (30) are both connected to the heat exchanger (5). The supply pipeline (41) has a first supply branch (411) that is directly connected to the urea supply pump (6) and a second supply branch (412) that is first connected to the heat exchanger (5) and then connected to the urea supply pump (6).

7. The urea heating system according to claim 6, characterized in that: The supply pipeline (41) is provided with a third electrically controlled three-way valve (410) at the connection between the first supply branch (411) and the second supply branch (412); and / or, The urea supply pump (6) is equipped with a fourth temperature sensor (600); and / or, The first supply branch (411) is equipped with a first electric heating device (44).

8. The urea heating system according to any one of claims 1 to 7, characterized in that: The urea tank includes a urea tank body (4) and a water bath heating shell (40) located outside the urea tank body (4); a heating pipe (403) is arranged in a meandering manner in the water bath heating shell (40), the heating pipe (403) is arranged around the urea tank body (4), and the heating pipe (403) is connected to the first circulation loop (43).

9. The urea heating system according to claim 8, characterized in that: The heating unit further includes a second electric heating device (404), which includes at least two sets of heating resistance wires, the two sets of heating resistance wires being arranged vertically at intervals, and the heating pipe (403) being located between the two sets of heating resistance wires; and / or, The upper part of the water bath heating shell (40) is provided with a water inlet (401), and the lower part of the water bath heating shell (40) is provided with a water outlet (402). The heating pipeline (403) is connected to the first circulation loop (43) through the water inlet (401) and the water outlet (402).

10. A hybrid vehicle, characterized in that: The hybrid vehicle is equipped with a urea heating system as described in any one of claims 1 to 9.

Images