Hybrid commercial vehicle urea heating thawing control system and control method

Abstract

The application provides a kind of hybrid commercial vehicle urea heating thaw control system and control method, including urea tank heating circuit, electric drive electric control cooling circuit and engine cooling circuit, the electric drive electric control cooling circuit and engine cooling circuit are connected with urea tank heating circuit, while through temperature sensor set on above-mentioned three circuits to decide to adopt heating, heat preservation, prevent over temperature three modes to urea tank, can make low temperature environment under hybrid power vehicle in pure electric mode, the waste heat of electric drive electric control system is delivered to urea tank, and urea is heated thaw in advance;In hybrid mode, it can be achieved that the waste heat of electric drive electric control system and engine system is delivered to urea tank, realizes common heating, improves heating efficiency, while reducing energy consumption.

Description

Technical Field

[0001] This invention relates to the field of urea heating and thawing, and specifically to a control system and method for urea heating and thawing in hybrid commercial vehicles. Background Technology

[0002] To meet the China VI emission standards, commercial vehicle diesel engines widely adopt SCR (Selective Catalytic Reduction) technology in their aftertreatment systems. Urea, as a reducing agent, can freeze at low ambient temperatures, causing the SCR to fail to inject urea and resulting in excessive emissions. Therefore, it is necessary to heat and insulate the urea tank to ensure the normal use of urea.

[0003] There are currently two methods for heating urea in the urea tank: electric heating and heating with engine hot water. However, because the amount of urea that needs to be heated and thawed in the urea tank is large, the power consumption of electric heating is high. When using engine hot water for heating and thawing, there are problems such as slow engine water temperature rise and low urea thawing efficiency in low-temperature environments. Especially for hybrid electric commercial vehicles, the strategy of keeping the engine running is usually adopted to ensure timely urea thawing in low-temperature environments, which also leads to increased fuel consumption.

[0004] Therefore, there is an urgent need for a heating system that can ensure the urea defrosting efficiency of hybrid commercial vehicles while reducing energy consumption in low-temperature environments. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a urea heating and defrosting control system and method for hybrid commercial vehicles, overcoming the low efficiency of defrosting with a single heat source (engine hot water) and the high energy consumption caused by the engine not stopping in pure electric mode in hybrid vehicles. The technical solution provided by this invention is as follows:

[0006] A hybrid commercial vehicle urea heating and defrosting control system, comprising:

[0007] A urea tank heating circuit, the urea tank heating circuit including an inlet and an outlet;

[0008] An electric drive and control cooling circuit has an opening forming a first outlet and a first inlet, and the opening is located at the rear end of the vehicle's high-voltage motor. The first outlet is connected to the inlet, and the first inlet is connected to the outlet. A three-way valve is provided between the first outlet, the inlet, and the first inlet, and a first solenoid valve is provided between the outlet and the first inlet.

[0009] An engine cooling circuit includes a second outlet and a second inlet formed by the opening of the engine cooling circuit, with the opening located at the rear end of the vehicle engine. The second inlet is connected to the outlet, and the second outlet is connected to the inlet. A second solenoid valve is provided between the engine and the second outlet.

[0010] In some embodiments, the three-way valve includes a first interface connected to the first outlet, a second interface connected to the first inlet, and a third interface connected to the inlet.

[0011] In some embodiments, the electric drive and electronic control cooling circuit further includes a second temperature sensor for detecting the temperature of the coolant in the electric drive and electronic control cooling circuit, the second temperature sensor being located between the vehicle's high-voltage motor and the three-way valve.

[0012] In some embodiments, the three-way valve is controlled by the vehicle controller to control the valve body position.

[0013] In some embodiments, the electric drive and control cooling circuit passes through the vehicle's high-voltage controller, high-voltage motor, electric drive radiator, and electric water pump.

[0014] In some embodiments, the engine cooling circuit further includes a third temperature sensor for detecting the temperature of the coolant in the engine cooling circuit, the third temperature sensor being located between the vehicle engine coolant outlet and the second solenoid valve.

[0015] In some embodiments, the second solenoid valve is controlled by the vehicle's aftertreatment control unit to control its opening and closing states.

[0016] In some embodiments, the engine cooling circuit passes through the vehicle engine and the engine radiator.

[0017] In some embodiments, the heating circuit of the urea tank is provided with a first temperature sensor for detecting the temperature inside the urea tank.

[0018] A control method for a hybrid commercial vehicle urea heating and defreezing control system is provided for controlling the hybrid commercial vehicle urea heating and defreezing control system. The method is characterized in that it includes pure electric mode control logic and hybrid mode control logic.

[0019] The pure electric mode control logic specifically includes:

[0020] Obtain the temperature inside the urea tank and the temperature of the coolant in the electric drive and control cooling circuit, and determine:

[0021] When the temperature of the coolant in the electric drive and control cooling circuit is lower than the set temperature threshold that allows the three-way valve to open, the first outlet and the inlet of the three-way valve are closed, the first outlet and the first inlet are connected, and the first solenoid valve is closed at the same time.

[0022] When the temperature inside the urea tank is lower than the urea crystallization temperature threshold, and the temperature of the coolant in the electric drive and control cooling circuit is higher than the set temperature threshold that allows the three-way valve to open, the first outlet and the inlet of the three-way valve are connected, the first outlet and the first inlet are closed, the first solenoid valve is opened, and the valve body position between the first outlet and the inlet of the three-way valve is controlled to be 100%.

[0023] When the temperature inside the urea tank is higher than the urea insulation temperature threshold, and the temperature of the coolant in the electric drive and control cooling circuit is higher than the set temperature threshold that allows the three-way valve to open, the first outlet and the inlet of the three-way valve are connected, the first solenoid valve is opened, and the valve body position between the first outlet and the inlet of the three-way valve is controlled to be 50%.

[0024] When the temperature inside the urea tank exceeds the urea overheating temperature threshold, the first outlet and the inlet of the three-way valve are closed, the first outlet and the first inlet are connected, and the first solenoid valve is closed.

[0025] The hybrid mode control logic specifically includes:

[0026] Obtain the temperature inside the urea tank and the temperature of the coolant in the engine cooling circuit, and determine:

[0027] When the temperature inside the urea tank is lower than the urea crystallization temperature threshold, and the temperature of the coolant in the engine cooling circuit is higher than the set temperature threshold that allows the second solenoid valve to open, the second solenoid valve opens, the first outlet and the inlet of the three-way valve are connected, the first outlet and the first inlet are closed, and the first solenoid valve opens.

[0028] When the temperature inside the urea tank is higher than the urea insulation temperature threshold, the second solenoid valve is closed, and the first outlet and the first inlet of the three-way valve are connected. The first solenoid valve is opened, and the valve body position between the first outlet and the first inlet of the three-way valve is controlled to be 50%.

[0029] When the temperature of the urea tank exceeds the overheating temperature threshold of the urea tank, the second solenoid valve is closed, and at the same time, the first outlet and the inlet of the three-way valve are closed, the first outlet and the first inlet are connected, and the first solenoid valve is closed. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a urea heating and defrosting control system for a hybrid commercial vehicle provided in an embodiment of the present invention;

[0032] Figure 2 This is a detailed enlarged view of a three-way valve in a urea heating and defrosting control system for a hybrid commercial vehicle, provided in an embodiment of the present invention.

[0033] In the diagram: 1. Urea tank heating circuit; 11. Urea tank; 12. First temperature sensor; 13. Inlet; 14. Outlet; 101. Urea pump; 102. SCR processor; 2. Electric drive and control cooling circuit; 21. First inlet; 22. Electric water pump; 23. Second temperature sensor; 24. First outlet; 25. Three-way valve; 251. First interface; 252. Second interface; 253. Third interface; 26. First solenoid valve; 201. Electric drive radiator; 202. High-voltage controller; 203. High-voltage motor; 3. Engine cooling circuit; 31. Second outlet; 32. Second inlet; 33. Third temperature sensor; 34. Second solenoid valve; 301. Engine; 302. Engine radiator. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] See Figure 1 This invention provides a urea heating and defrosting control system for hybrid commercial vehicles, which can utilize the waste heat from the electric drive system and the engine system to heat and keep the urea tank 11 warm. The system includes: a urea tank heating circuit 1, which runs through the urea tank 11 inside the vehicle and has an inlet 13 and an outlet 14; an electric drive and electronic control cooling circuit 2 and an engine cooling circuit 3, which are both connected to the inlet 13 and the outlet 14 of the urea tank heating circuit 1 to transfer heat to the urea tank 11.

[0036] Specifically, the electric drive and control cooling circuit 2 has an opening forming a first outlet 24 and a first inlet 21. This opening is located at the rear end of the high-voltage motor 203 inside the vehicle. The first outlet 24 is connected to the inlet 13, and the first inlet 21 is connected to the outlet 14, so that the electric drive and control cooling circuit 2 and the urea tank heating circuit 1 are connected to form a circulation channel. After the coolant in the electric drive and control cooling circuit 2 absorbs the heat from the high-voltage controller 202 and the high-voltage motor 203, it flows to the urea tank heating circuit 1. The high-voltage controller 202 in the figure includes an MCU (motor controller), a DC-DC converter, and a PDU (high-voltage distribution box). In order to control the flow of coolant, a three-way valve 25 is also provided at the opening. The three-way valve 25 is connected to the first outlet 24, the first inlet 21, and the inlet 13. When the coolant in the electric drive and electronic control cooling circuit 2 flows to the three-way valve 25, the vehicle controller controls the opening and closing state of the three-way valve 25, thereby adjusting the flow direction and flow rate of the coolant. A first solenoid valve 26 is also provided between the first inlet 21 and the outlet 14 to control the connection and disconnection of the above two circuits.

[0037] The three-way valve 25 has a first interface 251 connected to the first outlet 24, a second interface 252 connected to the first inlet 21, and a third interface 253 connected to the inlet 13. A second temperature sensor 23 is provided on the electric drive and control cooling circuit 2 to detect the temperature of the coolant in the electric drive and control cooling circuit 2. The second temperature sensor 23 is located between the rear end of the high-voltage motor 203 and the first outlet 24. A first temperature sensor 12 is provided on the urea tank heating circuit 1 to detect the temperature in the urea tank 11. The two temperature sensors cooperate with each other to determine the opening state of the three-way valve 25.

[0038] Specifically, when the coolant temperature in the electric drive and electronic control cooling circuit 2 is lower than the pre-set allowable opening temperature threshold of the three-way valve 25, the first outlet 24 and the first inlet 21 of the three-way valve 25 are connected, while the first outlet 24 and the inlet 13 are closed, and the coolant circulates only within the electric drive and electronic control cooling circuit 2. When the temperature in the urea tank 11 is lower than the urea crystallization temperature threshold, and the coolant temperature in the electric drive and electronic control cooling circuit 2 is higher than the pre-set allowable opening temperature threshold of the three-way valve 25, the first outlet 24 and the first inlet 21 of the three-way valve 25 are closed, while the first outlet 24 and the inlet 13 are open, and the first solenoid valve 26 is opened. At this time, the coolant in the electric drive and electronic control cooling circuit 2 flows into the urea tank heating circuit 1, completes the heat release process in the urea tank 11, and then flows back into the electric drive and electronic control cooling circuit 2 from the outlet 14 to complete the heating cycle. When the temperature inside the urea tank 11 exceeds the urea insulation temperature threshold, and the coolant temperature in the electric drive and control cooling circuit 2 exceeds the pre-set allowable opening temperature threshold of the three-way valve 25, the first outlet 24 and the first inlet 21, as well as the first outlet 24 and the inlet 13, are both connected, and the control valve positions are set to 50% and 50%, thereby controlling the flow rate of coolant entering the urea tank heating circuit 1 to achieve the insulation function. When the temperature inside the urea tank 11 exceeds the urea overheating temperature threshold, the first outlet 24 and the inlet 13 in the three-way valve 25 are closed, the first outlet 24 and the second inlet are connected, the first solenoid valve 26 is closed, and heating of the urea tank 11 is stopped.

[0039] The above heating modes are the working principle when the vehicle is in pure electric mode. When the vehicle switches to hybrid mode, the engine starts to work, and the engine cooling circuit 3 participates in the heating operation of the urea tank 11.

[0040] The engine cooling circuit 3 also has an opening to form a second outlet 31 and a second inlet 32. This opening is located at the rear end of the engine 301 inside the vehicle. The second outlet 31 is connected to the inlet 13, and the second inlet 32 ​​is connected to the outlet 14, so that the engine cooling circuit 3 and the urea tank heating circuit 1 are connected to form a circulation channel. The coolant in the engine cooling circuit 3 can flow into the urea tank heating circuit 1. A second solenoid valve 34 is also provided between the second inlet 32 ​​and the outlet 14, which is a switch to connect or disconnect the two circuits.

[0041] A third temperature sensor 33 is installed on the engine cooling circuit 3 to detect the temperature of the coolant in the engine cooling circuit 3. The third temperature sensor 33 is located between the coolant outlet of the engine 301 and the second solenoid valve 34 to obtain the temperature of the coolant flowing out of the engine 301. The third temperature sensor 33 cooperates with the first temperature sensor 12 to determine the opening state of the second solenoid valve 34.

[0042] Specifically, when the temperature inside the urea tank 11 is lower than the urea crystallization temperature threshold, and the temperature of the coolant in the engine cooling circuit 3 is higher than the set temperature threshold for allowing the second solenoid valve 34 to open, the second solenoid valve 34 is opened, the first outlet 24 and the inlet 13 in the three-way valve 25 are connected, the first outlet 24 and the first inlet 21 are closed, the first solenoid valve 26 is opened, and the engine cooling circuit 3 and the electric drive and electronic control cooling circuit 2 are opened simultaneously to heat the urea tank 11 together. When the temperature inside the urea tank 11 exceeds the urea insulation temperature threshold, the second solenoid valve 34 is closed. At the same time, the first outlet 24 and inlet 13 of the three-way valve 25 are connected, and the first outlet 24 and the first inlet 21 are connected. The first solenoid valve 26 is opened, and the valve body position between the first outlet 24 and inlet 13 of the three-way valve 25 is controlled at 50%, and the valve body position between the first outlet 24 and the first inlet 21 is controlled at 50%. The electric drive and electronic control cooling circuit 2 performs insulation work. When the temperature inside the urea tank 11 exceeds the urea overheating temperature threshold, the second solenoid valve 34 is closed. At the same time, the first outlet 24 and inlet 13 of the three-way valve 25 are closed, and the first outlet 24 and the first inlet 21 are connected. The first solenoid valve 26 is closed, and the engine cooling circuit 3 and the electric drive and electronic control cooling circuit 2 are closed.

[0043] The urea heating and defrosting control system of this hybrid commercial vehicle can determine whether to use heating, heat preservation, or overheating prevention mode for the urea tank 11 based on different driving modes and the temperature inside the urea tank 11. The heated urea enters the SCR after-processor 102 through the urea pump 101 for catalytic reduction reaction. The overall structure is simple. While using the waste heat of the electric drive and control system and the engine system to heat the urea tank 11, the urea tank 11 can also reduce the temperature of the coolant. When the coolant returns to its respective circuit, it increases the heat dissipation efficiency of the engine 301 and the high-voltage motor 203, realizes heat exchange, and further reduces energy consumption.

[0044] This invention provides a control method for a urea heating and defrosting control system of a hybrid commercial vehicle, used to control the urea heating and defrosting control system of the hybrid commercial vehicle, including pure electric mode control logic and hybrid mode control logic to cope with different driving modes.

[0045] Specifically, the pure electric mode control logic includes the following steps:

[0046] The vehicle is powered on, and the temperature inside the urea tank 11 and the temperature of the coolant in the electric drive and electronic control cooling circuit 2 are read and obtained. Based on the temperature, the following judgments are made:

[0047] When the temperature of the coolant in the electric drive and electronic control cooling circuit 2 is lower than the pre-set allowable opening temperature threshold of the three-way valve 25, the first outlet 24 and the inlet 13 of the three-way valve 25 are closed, the first outlet 24 and the first inlet 21 are connected, and the first solenoid valve 26 is closed at the same time.

[0048] When the temperature inside the urea tank 11 is lower than the urea crystallization temperature threshold, and the temperature of the coolant in the electric drive and electronic control cooling circuit 2 is higher than the set allowable opening temperature threshold of the three-way valve 25, the first outlet 24 and the inlet 13 of the three-way valve 25 are connected, the first outlet 24 and the first inlet 21 are closed, the first solenoid valve 26 is opened, and the valve body position between the first outlet 24 and the inlet 13 of the three-way valve 25 is 100%. The electric drive and electronic control cooling circuit 2 and the urea tank heating circuit 1 are connected, and the heating of the urea tank 11 begins.

[0049] When the temperature inside the urea tank 11 is higher than the urea insulation temperature threshold, and the temperature of the coolant in the electric drive and electronic control cooling circuit 2 is higher than the set allowable opening temperature threshold of the three-way valve 25, the first outlet 24 and the inlet 13 of the three-way valve 25 are connected, the first outlet 24 and the first inlet 21 are connected, the first solenoid valve 26 is opened, and the valve body position between the first outlet 24 and the inlet 13 of the three-way valve 25 is controlled to be 50%, and the valve body position between the first outlet 24 and the first inlet 21 is controlled to be 50%, thereby reducing the flow of coolant into the urea tank heating circuit 1 and achieving insulation work;

[0050] When the temperature of the urea tank 11 is higher than the urea overheating temperature threshold, the first outlet 24 and inlet 13 of the three-way valve 25 are closed, the first outlet 24 and the first inlet 21 are connected, the first solenoid valve 26 is closed, the electric drive and control cooling circuit 2 and the urea tank heating circuit 1 are disconnected to prevent the urea in the urea tank 11 from overheating.

[0051] The hybrid mode control logic includes the following steps:

[0052] Obtain the temperature inside the urea tank 11 and the temperature of the coolant in the engine cooling circuit 3, and determine:

[0053] When the temperature inside the urea tank 11 is lower than the urea crystallization temperature threshold, and the temperature of the coolant in the engine cooling circuit 3 is higher than the set allowable opening temperature threshold of the second solenoid valve 34, the aftertreatment control unit inside the vehicle opens the second solenoid valve 34. At this time, the engine cooling circuit 3 is connected to the urea tank heating circuit 1. The coolant in the engine cooling circuit 3 absorbs the heat from the engine 301 and flows into the urea tank heating circuit 1. At the same time, the first outlet 24 and the inlet 13 in the three-way valve 25 are connected, the first outlet 24 and the first inlet 21 are closed, the first solenoid valve 26 is opened, and the electric drive and electronic control cooling circuit 2 also joins the heating work. The two work together to improve the heating efficiency.

[0054] When the temperature inside the urea tank 11 is higher than the urea insulation temperature threshold, it indicates that there is no risk of urea crystallization. At this time, the aftertreatment unit controls the closure of the second solenoid valve 34, disconnects the engine cooling circuit 3 and the urea tank heating circuit 1, connects the first outlet 24 and the inlet 13 in the three-way valve 25, connects the first outlet 24 and the first inlet 21, opens the first solenoid valve 26, and controls the valve body position between the first outlet 24 and the inlet 13 in the three-way valve 25 to 50%, and the valve body position between the first outlet 24 and the first inlet 21 to 50%, and the electric drive and electronic control cooling circuit 2 performs the insulation work.

[0055] When the temperature of the urea tank 11 exceeds the urea overheating temperature threshold, the second solenoid valve 34 closes, simultaneously closing the first outlet 24 and inlet 13 of the three-way valve, connecting the first outlet 24 and the first inlet 21, and closing the first solenoid valve 26, thus disconnecting the engine cooling circuit 3 and the electric drive and electronic control cooling circuit 2 from the urea tank heating circuit 1, stopping the heating of the urea tank 11, and preventing the urea from deteriorating due to excessive temperature.

[0056] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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 application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0057] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A control method for a urea heating and defrosting control system in a hybrid commercial vehicle, characterized in that, The control system includes: Urea tank heating circuit (1), the urea tank heating circuit (1) includes an inlet (13) and an outlet (14); An electric drive and control cooling circuit (2) has an opening forming a first outlet (24) and a first inlet (21), and the opening is located at the rear end of the vehicle high-voltage motor (203). The first outlet (24) is connected to the inlet (13), the first inlet (21) is connected to the outlet (14), and a three-way valve (25) is provided between the first outlet (24), the inlet (13) and the first inlet (21). A first solenoid valve (26) is provided between the outlet (14) and the first inlet (21). An engine cooling circuit (3) has an opening forming a second outlet (31) and a second inlet (32), and the opening is located at the rear end of the vehicle engine (301). The second inlet (32) is connected to the outlet (14), the second outlet (31) is connected to the inlet (13), and a second solenoid valve (34) is provided between the engine (301) and the second outlet (31). The control method includes pure electric mode control logic and hybrid mode control logic; The pure electric mode control logic specifically includes: Obtain the temperature inside the urea tank (11) and the temperature of the coolant in the electric drive and control cooling circuit (2), and determine: When the temperature of the coolant in the electric drive and control cooling circuit (2) is lower than the pre-set temperature threshold that allows the three-way valve (25) to open, the first outlet (24) and the inlet (13) of the three-way valve (25) are closed, the first outlet (24) and the first inlet (21) are connected, and the first solenoid valve (26) is closed. When the temperature inside the urea tank (11) is lower than the urea crystallization temperature threshold, and the temperature of the coolant in the electric drive and control cooling circuit (2) is higher than the set temperature threshold that allows the three-way valve (25) to open, the first outlet (24) and the inlet (13) of the three-way valve (25) are connected, the first outlet (24) and the first inlet (21) are closed, the first solenoid valve (26) is opened, and the valve body position between the first outlet (24) and the inlet (13) of the three-way valve (25) is controlled to be 100%. When the temperature inside the urea tank (11) is higher than the urea insulation temperature threshold, and the temperature of the coolant in the electric drive and control cooling circuit (2) is higher than the set temperature threshold that allows the three-way valve (25) to open, the first outlet (24) and the inlet (13) of the three-way valve (25) are connected, the first outlet (24) and the first inlet (21) are connected, the first solenoid valve (26) is opened, and the valve body position between the first outlet (24) and the inlet (13) of the three-way valve (25) is controlled to be 50%, and the valve body position between the first outlet (24) and the first inlet (21) is 50%; When the temperature inside the urea tank (11) is higher than the urea overheating temperature threshold, the first outlet (24) and the inlet (13) of the three-way valve (25) are closed, the first outlet (24) and the first inlet (21) are connected, and the first solenoid valve (26) is closed. The hybrid mode control logic specifically includes: Obtain the temperature inside the urea tank (11) and the temperature of the coolant in the engine cooling circuit (3), and determine: When the temperature inside the urea tank (11) is lower than the urea crystallization temperature threshold, and the temperature of the coolant in the engine cooling circuit (3) is higher than the set temperature threshold that allows the second solenoid valve (34) to open, the second solenoid valve (34) is opened, the first outlet (24) and the inlet (13) of the three-way valve (25) are connected, the first outlet (24) and the first inlet (21) are closed, and the first solenoid valve (26) is opened; When the temperature inside the urea tank (11) is higher than the urea insulation temperature threshold, the second solenoid valve (34) is closed, the first outlet (24) and the inlet (13) of the three-way valve (25) are connected, the first outlet (24) and the first inlet (21) are connected, the first solenoid valve (26) is opened, and the valve body position between the first outlet (24) and the inlet (13) of the three-way valve (25) is controlled to be 50%, the valve body position between the first outlet (24) and the first inlet (21) is controlled to be 50%; When the temperature inside the urea tank (11) is higher than the urea overheating temperature threshold, the second solenoid valve (34) is closed, and at the same time, the first outlet (24) and the inlet (13) of the three-way valve (25) are closed, the first outlet (24) and the first inlet (21) are connected, and the first solenoid valve (26) is closed.

2. The control method for a hybrid commercial vehicle urea heating and defrosting control system as described in claim 1, characterized in that, The three-way valve (25) includes a first interface (251) connected to the first outlet (24), a second interface (252) connected to the first inlet (21), and a third interface (253) connected to the inlet (13).

3. The control method for a hybrid commercial vehicle urea heating and defrosting control system as described in claim 1, characterized in that, The electric drive and control cooling circuit (2) also includes a second temperature sensor (23) for detecting the temperature of the coolant in the electric drive and control cooling circuit (2). The second temperature sensor (23) is located between the vehicle high-voltage motor (203) and the three-way valve (25).

4. The control method for a hybrid commercial vehicle urea heating and defrosting control system as described in claim 3, characterized in that, The three-way valve (25) is controlled by the vehicle controller to control the position of the valve body.

5. The control method for a hybrid commercial vehicle urea heating and defrosting control system as described in claim 1, characterized in that, The electric drive and control cooling circuit (2) passes through the vehicle's high-voltage controller (202), high-voltage motor (203), electric drive radiator (201) and electric water pump (22).

6. The control method for a hybrid commercial vehicle urea heating and defrosting control system as described in claim 1, characterized in that, The engine cooling circuit (3) also includes a third temperature sensor (33) for detecting the temperature of the coolant in the engine cooling circuit (3), the third temperature sensor (33) being located between the coolant outlet of the vehicle engine (301) and the second solenoid valve (34).

7. The control method for a hybrid commercial vehicle urea heating and defrosting control system as described in claim 6, characterized in that, The second solenoid valve (34) is controlled by the vehicle's after-treatment control unit to control its opening and closing states.

8. The control method for a hybrid commercial vehicle urea heating and defrosting control system as described in claim 7, characterized in that, The engine cooling circuit (3) passes through the vehicle engine (301) and the engine radiator (302).

9. The control method for a hybrid commercial vehicle urea heating and defrosting control system as described in claim 1, characterized in that, The heating circuit (1) of the urea tank is equipped with a first temperature sensor (12) for detecting the temperature inside the urea tank.

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