Catalyst temperature control method, device and system

Abstract

The invention relates to a catalytic converter temperature control method, device and system, and the method comprises the steps: monitoring the temperature tc of a catalytic converter and the temperature tl of cooling liquid in real time, and carrying out the dynamic comparison with preset thresholds t1 (light-off temperature), t2 (the lower limit of an optimal working interval) and t3 (the upper limit of the optimal working interval); and the connection state of the catalytic converter and the engine cooling system and graded heating of the catalytic converter heating device are accurately controlled. The method specifically comprises the following steps: when tc lt; when t1 is equal to t1, primary / secondary heating is started according to the relation between t1 and tc, and a cooling system is controlled to be merged; when t1 is smaller than or equal to tc lt; at t2, only first-stage heating is started; when t2 is less than or equal to tc lt; when t3, heating is stopped; and when tc is greater than or equal to t3, controlling the cooling system to cool. The method ensures that the catalyst is stably maintained in a high-efficiency catalytic working interval, the tail gas purification efficiency is remarkably improved, the requirements of national 6 and other strict environmental protection laws and regulations are effectively met, and the method is suitable for a light vehicle tail gas treatment system and has the advantages of being simple in structure, accurate in control, energy-saving and efficient.

Description

Technical Field

[0001] This invention belongs to the field of automotive exhaust emission control technology, specifically relating to a temperature control method, device, and system for a catalytic converter in a light-duty vehicle. Background Technology

[0002] With increasingly stringent environmental regulations and ever-improving emission standards for automobiles, the performance of the catalytic converter, a key component in vehicle exhaust treatment, is crucial for meeting emission standards. The catalytic efficiency of a catalytic converter is closely related to temperature. Under low-temperature conditions, the catalytic converter cannot function effectively, leading to excessive emissions. This is especially true for hybrid vehicles. When the vehicle's state of charge (SOC) is near its equilibrium point, the engine may frequently start and stop during operation due to load variations. In such cases, the catalytic converter's temperature may struggle to reach its efficient operating range, and frequent cold starts can accelerate carbon buildup and sulfide blockage. Under extremely high temperatures, the precious metal coating of the catalyst may sinter and deactivate, potentially leading to carrier blockage or even the risk of vehicle spontaneous combustion. Therefore, developing a thermal management system that can effectively control the temperature of the catalytic converter is of great significance for improving the environmental and safety performance of automobiles.

[0003] In the field of automotive exhaust emission control, existing technology CN205805684U discloses an automotive catalytic converter thermal management system, which achieves temperature regulation by connecting the catalytic converter in parallel to the engine cooling circuit. This system includes a catalytic converter, engine, coolant pump, radiator, and thermostat. The catalytic converter cooling circuit is connected in parallel with the engine's main cooling circuit and consists of a heat exchanger, control valve, and temperature sensor, utilizing engine coolant to cool the catalytic converter. However, this solution only provides cooling and lacks an active heating mechanism for the catalytic converter. It cannot quickly raise the catalytic converter temperature to its ignition point under low-temperature conditions (such as cold start), resulting in the catalytic converter operating in an inefficient state for extended periods, significantly reducing exhaust gas purification efficiency and failing to meet the stringent temperature requirements of the China VI emission standards for catalytic converter operation. Summary of the Invention

[0004] This invention provides a method, apparatus, and system for controlling the temperature of a catalyst, which aims to ensure stable operation of the catalyst within the high-efficiency catalytic conversion range by precisely regulating its operating temperature, thereby meeting increasingly stringent environmental regulations and improving exhaust gas purification efficiency.

[0005] In a first aspect, a method for controlling catalyst temperature is provided, including: The real-time catalytic converter temperature tc and coolant temperature tl are compared with the preset first temperature threshold t1, second temperature threshold t2 and third temperature threshold t3. Based on the comparison results, the catalyst is controlled to be connected to or disconnected from the engine cooling system, and the catalyst heating device is controlled to heat the catalyst in stages so that the catalyst is heated and maintained in the optimal operating temperature range. Wherein, the first temperature threshold t1 is the ignition temperature of the catalyst, the second temperature threshold t2 is the lower limit temperature of the optimal operating temperature range of the catalyst, and the third temperature threshold t3 is the upper limit temperature of the optimal operating temperature range of the catalyst.

[0006] In some embodiments, when the catalyst temperature tc < coolant temperature tl < first temperature threshold t1, the catalyst heating device is controlled to simultaneously activate primary heating and secondary heating, and the catalyst is controlled to be connected to the engine cooling system for heating until the catalyst temperature tc rises to the first temperature threshold t1.

[0007] This embodiment utilizes the residual heat of the engine coolant and the synergistic effect of dual-stage heating to effectively accelerate the heat accumulation process of the catalyst in a low-temperature environment, avoid heat loss due to low coolant temperature, ensure that the catalyst can quickly break through the ignition temperature threshold during the cold start phase, significantly shorten the high emission window period of exhaust gas, and improve the initial catalytic efficiency.

[0008] In some embodiments, when the coolant temperature tl ≤ catalyst temperature tc < first temperature threshold t1, the catalyst heating device is controlled to keep the primary and secondary heating on, and the connection between the catalyst and the engine cooling system is cut off until the catalyst temperature rises to the first temperature threshold t1.

[0009] This embodiment can block the absorption path of heat from the catalyst by the cooling system, maintain the efficient use of heating energy, solve the problem of reverse heat transfer caused by the intervention of the cooling system when the catalyst temperature is higher than that of the coolant, ensure that the catalyst can achieve a stable and rapid heating process under complex temperature gradients, and avoid ignition delay caused by heat loss.

[0010] In some embodiments, when the first temperature threshold t1 ≤ catalyst temperature tc < second temperature threshold t2, the connection between the catalyst and the engine cooling system is kept disconnected, and the catalyst heating device is controlled to turn on the first stage heating and turn off the second stage heating.

[0011] This embodiment enables a smooth temperature transition by reducing heating power, avoiding the risk of temperature overshoot caused by secondary heating when approaching the optimal operating range. It ensures that the catalyst maintains thermodynamic stability during the temperature rise process from the ignition point to the lower limit of the optimal operating range, prevents structural damage to the catalytic active material caused by temperature fluctuations, and improves the sustainability of catalytic conversion efficiency.

[0012] In some embodiments, when the second temperature threshold t2 ≤ catalyst temperature tc < third temperature threshold t3, the connection between the catalyst and the engine cooling system is kept disconnected, and the catalyst heating device is controlled to shut down the primary heating and secondary heating.

[0013] This embodiment can automatically terminate the heating process, avoiding energy redundancy caused by continuous input of heat energy within the optimal operating range. At the same time, by cutting off the cooling system to maintain the thermal inertia of the catalyst, the system can naturally maintain temperature balance without external intervention, effectively solving the problems of energy waste and catalyst overheating risk under high-temperature conditions, and ensuring that the catalyst is in a highly efficient catalytic state for a long time.

[0014] In some embodiments, when the catalyst temperature tc ≥ the third temperature threshold t3, the primary and secondary heating devices of the catalyst are kept off, and the catalyst is controlled to be connected to the engine cooling system for cooling until the catalyst temperature tc drops to the optimal operating range [t2, t3].

[0015] This embodiment enables precise temperature control of the catalyst by utilizing the heat exchange capacity of the engine cooling system, avoiding irreversible damage such as sintering of the catalyst coating or agglomeration of precious metals caused by high temperatures, solving the problem of a sharp drop in catalytic efficiency under overheating conditions, ensuring that the catalyst quickly returns to its optimal operating range after high-temperature operation, and maintaining the long-term stability of exhaust gas purification performance.

[0016] In some embodiments, when the catalyst temperature tc is in the optimal operating range [t2, t3), if the vehicle is operating under low load, when the catalyst temperature tc < the second temperature threshold t2, the connection between the catalyst and the engine cooling system is cut off, and the catalyst heating device is controlled to start the first stage of heating until the catalyst temperature tc rises to the optimal operating range [t2, t3).

[0017] This embodiment enables dynamic compensation for minor fluctuations in catalyst temperature under low-load conditions (such as low-speed urban driving). It achieves fine temperature regulation through localized primary heating, avoiding fluctuations in catalytic efficiency caused by the intervention of the cooling system or changes in ambient temperature. This improves the system's adaptability in complex driving scenarios and ensures that the catalyst maintains high-efficiency catalytic conversion capability under low-load conditions.

[0018] In some embodiments, based on the real-time acquired engine load and ambient temperature, a linear compensation function between the ambient temperature and the first temperature threshold t1, and a gradient adjustment rule between the engine load and the second temperature threshold t2 are constructed; the first temperature threshold t1 is dynamically adjusted according to the linear compensation function, and the second temperature threshold t2 is dynamically adjusted according to the gradient adjustment rule.

[0019] This embodiment enables dynamic adjustment. Through a linear compensation function of ambient temperature and a first temperature threshold t1, and a gradient adjustment rule of engine load and a second temperature threshold t2, the threshold parameters are matched to actual operating conditions in real time without altering the hardware architecture. Compared to embodiments with fixed thresholds, this embodiment effectively avoids the control rigidity problem of a single threshold under varying environments. It ensures that the catalyst can stably maintain its optimal catalytic efficiency range under typical operating conditions such as cold start, high load, and low temperature, avoiding structural damage to the catalytic active material or conversion efficiency decay caused by temperature fluctuations. Simultaneously, it reduces redundant switching of the cooling / heating system, improving the overall system energy efficiency.

[0020] Secondly, a catalyst temperature control device is provided, comprising: The temperature detection module is used to acquire the catalyst temperature tc and coolant temperature tl in real time. The control decision module is used to compare the catalyst temperature tc and the coolant temperature tl with preset first temperature threshold t1, second temperature threshold t2 and third temperature threshold t3, and generate control commands. The execution control module is used to control the catalyst to connect to or disconnect from the engine cooling system according to the control command, and to control the catalyst heating device to perform staged heating of the catalyst so that the catalyst is heated and maintained in the optimal operating temperature range. Wherein, the first temperature threshold t1 is the ignition temperature of the catalyst, the second temperature threshold t2 is the lower limit temperature of the optimal operating temperature range of the catalyst, and the third temperature threshold t3 is the upper limit temperature of the optimal operating temperature range of the catalyst.

[0021] Thirdly, a catalytic converter temperature control system is provided, which can be connected as a branch circuit to the vehicle's engine cooling system, including: The catalyst has cooling channels formed inside it; A catalytic converter solenoid valve, the inlet of which is connected to the engine cooling circuit; A first temperature sensor T1 is disposed on a pipeline used to connect the engine cooling circuit to the inlet of the catalyst solenoid valve; The second temperature sensor T2 is installed on the pipeline connecting the outlet of the catalyst solenoid valve and the inlet of the catalyst cooling channel; A catalyst heating device for staged heating of the catalyst; A catalyst temperature control device, the catalyst temperature control device being used to perform the catalyst temperature control method as described above.

[0022] Fourthly, a vehicle is provided that includes the catalytic converter temperature control device as described above.

[0023] The beneficial effects of the technical solution provided by this invention include: By employing a staged heating strategy and dynamic connection control logic, precise closed-loop management of the catalytic converter's operating temperature is achieved, resulting in significant technological advantages. Key benefits include: real-time monitoring and intelligent regulation ensure the catalytic converter consistently operates within its optimal operating temperature range, significantly improving catalytic conversion efficiency and effectively reducing exhaust emissions; the staged heating mechanism (coordinated primary and secondary heating) drastically shortens the response time of the catalytic converter from a cold state to ignition temperature, reducing the high-emission period during cold starts; the system possesses full-condition adaptability, intelligently matching complex operating scenarios such as low loads, high loads, and extreme environments, ensuring the catalytic converter maintains a highly efficient and stable operating state under any vehicle operating conditions; simultaneously, by optimizing the dynamic switching strategy between heating and cooling, energy waste is avoided and system overheating is prevented, improving overall energy efficiency and reliability, providing an efficient, energy-saving, and reliable solution to meet stringent environmental regulations such as China VI b. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 The main flowchart of the catalyst temperature control method provided in the embodiments of the present invention; Figure 2 A detailed control strategy diagram for the catalyst temperature control method provided in the embodiments of the present invention; Figure 3 This is a system diagram of a catalyst temperature control method provided in an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures: 1. Catalyst; 2. Catalyst heating device; 21. Primary heater; 22. Secondary heater; 3. First temperature sensor T1; 4. Second temperature sensor T2; 5. Catalyst solenoid valve; 6. Engine; 7. Engine water pump; 8. Engine radiator; 9. Thermostat; 10. Fluid reservoir. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a catalyst temperature control method, comprising: The real-time catalytic converter temperature tc and coolant temperature tl are compared with the preset first temperature threshold t1, second temperature threshold t2 and third temperature threshold t3. Based on the comparison results, the catalyst is controlled to be connected to or disconnected from the engine cooling system, and the catalyst heating device is controlled to heat the catalyst in stages so that the catalyst is heated and maintained in the optimal operating temperature range. Wherein, the first temperature threshold t1 is the ignition temperature of the catalyst, the second temperature threshold t2 is the lower limit temperature of the optimal operating temperature range of the catalyst, and the third temperature threshold t3 is the upper limit temperature of the optimal operating temperature range of the catalyst.

[0029] In some embodiments, when the catalyst temperature tc < coolant temperature tl < first temperature threshold t1, the catalyst heating device is controlled to simultaneously activate primary heating and secondary heating, and the catalyst is controlled to be connected to the engine cooling system for heating until the catalyst temperature tc rises to the first temperature threshold t1.

[0030] This embodiment utilizes the residual heat of the engine coolant and the synergistic effect of dual-stage heating to effectively accelerate the heat accumulation process of the catalyst in a low-temperature environment, avoid heat loss due to low coolant temperature, ensure that the catalyst can quickly break through the ignition temperature threshold during the cold start phase, significantly shorten the high emission window period of exhaust gas, and improve the initial catalytic efficiency.

[0031] In some embodiments, when the coolant temperature tl ≤ catalyst temperature tc < first temperature threshold t1, the catalyst heating device is controlled to keep the primary and secondary heating on, and the connection between the catalyst and the engine cooling system is cut off until the catalyst temperature rises to the first temperature threshold t1.

[0032] This embodiment can block the absorption path of heat from the catalyst by the cooling system, maintain the efficient use of heating energy, solve the problem of reverse heat transfer caused by the intervention of the cooling system when the catalyst temperature is higher than that of the coolant, ensure that the catalyst can achieve a stable and rapid heating process under complex temperature gradients, and avoid ignition delay caused by heat loss.

[0033] In some embodiments, when the first temperature threshold t1 ≤ catalyst temperature tc < second temperature threshold t2, the connection between the catalyst and the engine cooling system is kept disconnected, and the catalyst heating device is controlled to turn on the first stage heating and turn off the second stage heating.

[0034] This embodiment enables a smooth temperature transition by reducing heating power, avoiding the risk of temperature overshoot caused by secondary heating when approaching the optimal operating range. It ensures that the catalyst maintains thermodynamic stability during the temperature rise process from the ignition point to the lower limit of the optimal operating range, prevents structural damage to the catalytic active material caused by temperature fluctuations, and improves the sustainability of catalytic conversion efficiency.

[0035] In some embodiments, when the second temperature threshold t2 ≤ catalyst temperature tc < third temperature threshold t3, the connection between the catalyst and the engine cooling system is kept disconnected, and the catalyst heating device is controlled to shut down the primary heating and secondary heating.

[0036] This embodiment can automatically terminate the heating process, avoiding energy redundancy caused by continuous input of heat energy within the optimal operating range. At the same time, by cutting off the cooling system to maintain the thermal inertia of the catalyst, the system can naturally maintain temperature balance without external intervention, effectively solving the problems of energy waste and catalyst overheating risk under high-temperature conditions, and ensuring that the catalyst is in a highly efficient catalytic state for a long time.

[0037] In some embodiments, when the catalyst temperature tc ≥ the third temperature threshold t3, the primary and secondary heating devices of the catalyst are kept off, and the catalyst is controlled to be connected to the engine cooling system for cooling until the catalyst temperature tc drops to the optimal operating range [t2, t3].

[0038] This embodiment enables precise temperature control of the catalyst by utilizing the heat exchange capacity of the engine cooling system, avoiding irreversible damage such as sintering of the catalyst coating or agglomeration of precious metals caused by high temperatures, solving the problem of a sharp drop in catalytic efficiency under overheating conditions, ensuring that the catalyst quickly returns to its optimal operating range after high-temperature operation, and maintaining the long-term stability of exhaust gas purification performance.

[0039] In some embodiments, when the catalyst temperature tc is in the optimal operating range [t2, t3), if the vehicle is operating under low load, when the catalyst temperature tc < the second temperature threshold t2, the connection between the catalyst and the engine cooling system is cut off, and the catalyst heating device is controlled to start the first stage of heating until the catalyst temperature tc rises to the optimal operating range [t2, t3).

[0040] This embodiment enables dynamic compensation for minor fluctuations in catalyst temperature under low-load conditions (such as low-speed urban driving). It achieves fine temperature regulation through localized primary heating, avoiding fluctuations in catalytic efficiency caused by the intervention of the cooling system or changes in ambient temperature. This improves the system's adaptability in complex driving scenarios and ensures that the catalyst maintains high-efficiency catalytic conversion capability under low-load conditions.

[0041] In some embodiments, based on the real-time acquired engine load and ambient temperature, a linear compensation function between the ambient temperature and the first temperature threshold t1, and a gradient adjustment rule between the engine load and the second temperature threshold t2 are constructed; the first temperature threshold t1 is dynamically adjusted according to the linear compensation function, and the second temperature threshold t2 is dynamically adjusted according to the gradient adjustment rule.

[0042] An adaptive dynamic threshold adjustment mechanism based on driving conditions is introduced. By integrating multi-source operating parameters such as engine load and ambient temperature in real time, the setting logic of the temperature threshold is dynamically optimized, thereby significantly improving the system's adaptability and stability in complex operating environments. Due to the coupling relationship between the thermodynamic behavior of the catalyst and environmental factors, in low-temperature environments (such as ambient temperatures below 5°C), the surface activity of the catalyst material decreases due to reduced thermal motion. The first temperature threshold t1 needs to be raised to compensate for the activity decay and ensure rapid catalytic reaction during cold start. Under high-load conditions (such as vehicle acceleration or hill climbing), the engine exhaust temperature rises instantaneously. If the lower limit of the second temperature threshold t2 is kept fixed, the catalyst may frequently trigger cooling cycles due to temperature approaching the threshold, causing fluctuations in catalytic efficiency. Therefore, the second temperature threshold t2 needs to be dynamically lowered to widen the safe operating range and avoid unnecessary temperature intervention.

[0043] Regarding the linear compensation function for ambient temperature T_env and the first temperature threshold t1, the parameters are first set as follows: t1_base is the base ignition temperature threshold (e.g., 250°C) used under normal ambient temperature (e.g., ≥ 25°C). T_critical is the critical ambient temperature at which compensation is initiated (e.g., 25°C). k_comp is the linear compensation coefficient (unit: ℃ / ℃), which is a positive number. It represents the number of degrees that the first temperature threshold value t1 needs to be increased for every 1℃ decrease in ambient temperature T_env.

[0044] The defined linear compensation function is as follows: If T_env>= T_critical Then t1 = t1_base If T_env <T_critical Then t1 = t1_base + k_comp * (T_critical - T_env) Specifically, assume t1_base = 250℃, T_critical = 25℃, k_comp = 2 ℃ / ℃.

[0045] When T_env = 25℃, t1 = 250℃.

[0046] When T_env = 0℃, t1 = 250 + 2* (25 - 0) = 300℃.

[0047] When T_env = -5℃, t1 = 250 + 2 * (25 - (-5)) = 310℃.

[0048] Regarding the gradient adjustment rule for engine load L_engine and the second temperature threshold t2, the parameters are first set as follows: t2_base is the lower limit of the basic high temperature threshold used under low / medium load conditions (e.g., 780°C). L_low is the lower limit of the load rate, that is, the load point at which the second temperature threshold t2 is adjusted (e.g., 70%). L_high is the upper limit of the load rate, that is, when this load is reached, the second temperature threshold t2 drops to the lowest value (e.g., 95%). t2_min is the lowest value (e.g., 750°C) that the second temperature threshold t2 can be adjusted, serving as a safety boundary; k_grad is the gradient adjustment coefficient, which is calculated from (t2_base - t2_min) / (L_high - L_low).

[0049] If L_engine <= L_low Then t2 = t2_base If L_low <L_engine<L_high: Then t2 = t2_base - k_grad * (L_engine - L_low) If L_engine>= L_high: Then t2 = t2_min This embodiment enables dynamic adjustment. Through a linear compensation function of ambient temperature and a first temperature threshold t1, and a gradient adjustment rule of engine load and a second temperature threshold t2, the threshold parameters are matched to actual operating conditions in real time without altering the hardware architecture. Compared to embodiments with fixed thresholds, this embodiment effectively avoids the control rigidity problem of a single threshold under varying environments. It ensures that the catalyst can stably maintain its optimal catalytic efficiency range under typical operating conditions such as cold start, high load, and low temperature, avoiding structural damage to the catalytic active material or conversion efficiency decay caused by temperature fluctuations. Simultaneously, it reduces redundant switching of the cooling / heating system, improving the overall system energy efficiency.

[0050] This invention provides a catalyst temperature control device, comprising: The temperature detection module is used to acquire the catalyst temperature tc and coolant temperature tl in real time. The control decision module is used to compare the catalyst temperature tc and the coolant temperature tl with preset first temperature threshold t1, second temperature threshold t2 and third temperature threshold t3, and generate control commands. The execution control module is used to control the catalyst to connect to or disconnect from the engine cooling system according to the control command, and to control the catalyst heating device to perform staged heating of the catalyst so that the catalyst is heated and maintained in the optimal operating temperature range. Wherein, the first temperature threshold t1 is the ignition temperature of the catalyst, the second temperature threshold t2 is the lower limit temperature of the optimal operating temperature range of the catalyst, and the third temperature threshold t3 is the upper limit temperature of the optimal operating temperature range of the catalyst.

[0051] like Figure 3 As shown, an embodiment of the present invention provides a catalytic converter temperature control system, which can be connected as a branch circuit to the engine cooling system of a vehicle, including: Catalyst 1 has cooling channels formed inside it; Catalyst solenoid valve 5, the inlet of which is connected to the engine cooling circuit; The first temperature sensor 3 is disposed on the pipeline used to connect the engine cooling circuit and the inlet of the catalyst solenoid valve 5; The second temperature sensor 4 is installed on the pipeline connecting the outlet of the catalyst solenoid valve 5 and the inlet of the catalyst cooling channel; Catalyst heating device 2 is used for staged heating of the catalyst; A catalyst temperature control device, the catalyst temperature control device being used to perform the catalyst temperature control method as described above.

[0052] The catalyst heating device employs a novel, high-efficiency heating element, such as a microwave heating device. Furthermore, the catalyst heating device comprises at least two stages of heating, for example, a primary heater 21 and a secondary heater 22.

[0053] The engine cooling system includes a coolant circulation system and an engine radiator 8, used to cool the catalytic converter when the temperature is too high. One end of the engine radiator is connected to a thermostat 9, and the other end is connected to the inlet of the engine water pump 7. One end of the thermostat 9 is connected to the engine radiator 8, and the other end is connected to the outlet of the engine 6. The catalytic converter temperature control device intelligently controls heating and cooling operations based on data from the first temperature sensor T1 and the second temperature sensor T2.

[0054] like Figure 2 As shown in the figure, this embodiment of the invention provides a detailed control strategy for a catalyst temperature control method, and the specific control process is as follows: S1. During the start-up phase, after the vehicle starts, the temperature sensor collects the catalytic converter temperature tc, coolant temperature tl, and passenger compartment temperature tn in real time. The ECU receives the temperature signal and outputs control commands. When the catalytic converter temperature tc < tl < t1, the ECU issues a low-temperature command to control the catalytic converter solenoid valve to open. The primary and secondary heaters of the catalytic converter are turned on simultaneously. At this time, the catalytic converter is integrated into the engine cooling system. Since the coolant temperature tl is higher than tc, the catalytic converter can obtain heat from the cooling system, saving energy consumption. At the same time, the primary and secondary heaters are both in the on state, and the catalytic converter temperature rises rapidly until tc ≥ tl.

[0055] S2. After heating for a period of time, tl≤tc<t1. At this time, in order to make the catalyst temperature rise further to the ignition temperature point t1 and prevent the coolant from taking away the heat of the catalyst, the ECU controls the catalyst solenoid valve to close, the catalyst is disconnected from the cooling system, and the primary and secondary heaters of the catalyst remain on.

[0056] S3. When heated to t1≤tc<t2, since the catalyst has reached the ignition temperature, the temperature of the catalyst will rise during the catalytic conversion process. In order to save power consumption, the ECU controls the catalyst solenoid valve to remain closed to prevent the coolant from carrying away the heat of the catalyst. The primary heater of the catalyst remains on, and the secondary heater is closed.

[0057] S4. When heated to t2≤tc<t3, the catalyst reaches the optimal conversion efficiency operating temperature range. During the catalytic conversion process, the temperature of the catalyst will rise. In order to save power consumption, the ECU controls the catalyst solenoid valve to remain closed, and at the same time, the primary and secondary heaters of the catalyst are both turned off.

[0058] S5. When the catalytic converter temperature is within its optimal operating range, the temperature changes with vehicle load. If the vehicle is continuously operating under high load, the catalytic converter temperature will continue to rise. When t3 ≤ tc, the ECU issues a high-temperature command, controlling the catalytic converter solenoid valve to open. The catalytic converter is then connected to the engine cooling system, while the primary and secondary heaters remain closed. The coolant is used to lower the catalytic converter temperature to its optimal operating range (t2 ≤ tc < t3). Once the temperature drops to the optimal operating range, the solenoid valve closes.

[0059] S6. When the catalyst temperature is in the optimal operating range, if the vehicle is operating under low load, the catalyst will start to cool down. When the temperature drops to tc < t2, the ECU controls the catalyst solenoid valve to remain closed and the catalyst primary heater to turn on until the catalyst temperature is heated to the optimal operating range (t2 ≤ tc < t3), ensuring that the catalyst is always in the high-efficiency conversion range.

[0060] The detailed control strategy of the catalyst temperature control method provided in this invention can improve catalytic efficiency. By precisely controlling the catalyst temperature, it can keep the catalyst in its optimal working state, significantly improving catalytic efficiency and reducing exhaust emissions. The new heating element can quickly raise the catalyst temperature, shorten the time for the catalyst to reach the effective working temperature, and reduce exhaust emissions during the cold start phase. The system can adapt to different vehicle operating conditions and environmental conditions, ensuring that the catalyst can work stably under various conditions.

[0061] Furthermore, embodiments of the present invention provide a vehicle including the catalyst temperature control device as described above.

[0062] In the description of this invention, 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 the invention 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 the invention. 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 invention can be understood according to the specific circumstances.

[0063] It should be noted that in this invention, 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.

[0064] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. 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 the invention. Therefore, the present invention 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 method for controlling the temperature of a catalyst, characterized in that, include: The real-time catalytic converter temperature tc and coolant temperature tl are compared with the preset first temperature threshold t1, second temperature threshold t2 and third temperature threshold t3. Based on the comparison results, the catalyst is controlled to be connected to or disconnected from the engine cooling system, and the catalyst heating device is controlled to heat the catalyst in stages so that the catalyst is heated and maintained in the optimal operating temperature range. Wherein, the first temperature threshold t1 is the ignition temperature of the catalyst, the second temperature threshold t2 is the lower limit temperature of the optimal operating temperature range of the catalyst, and the third temperature threshold t3 is the upper limit temperature of the optimal operating temperature range of the catalyst.

2. The method according to claim 1, characterized in that, When the catalyst temperature tc < coolant temperature tl < first temperature threshold t1, the catalyst heating device is controlled to simultaneously activate primary heating and secondary heating, and the catalyst is controlled to be connected to the engine cooling system for heating until the catalyst temperature tc rises to the first temperature threshold t1.

3. The method according to claim 2, characterized in that, When the coolant temperature tl ≤ catalyst temperature tc < first temperature threshold t1, the catalyst heating device is controlled to keep the first-stage heating and second-stage heating on, and the connection between the catalyst and the engine cooling system is cut off until the catalyst temperature rises to the first temperature threshold t1.

4. The method according to claim 3, characterized in that, When the first temperature threshold t1 ≤ catalyst temperature tc < second temperature threshold t2, the connection between the catalyst and the engine cooling system is kept disconnected, and the catalyst heating device is controlled to turn on the first stage heating and turn off the second stage heating.

5. The method according to claim 4, characterized in that, When the second temperature threshold t2 ≤ catalyst temperature tc < third temperature threshold t3, the connection between the catalyst and the engine cooling system is kept disconnected, and the catalyst heating device is controlled to shut down the primary heating and secondary heating.

6. The method according to claim 5, characterized in that, When the catalyst temperature tc ≥ the third temperature threshold t3, the primary and secondary heating devices of the catalyst heating device are kept off, and the catalyst is controlled to be connected to the engine cooling system for cooling until the catalyst temperature tc drops to the optimal operating range [t2, t3].

7. The method according to claim 1, characterized in that, include: Based on the real-time acquired engine load and ambient temperature, a linear compensation function for the ambient temperature and the first temperature threshold t1 is constructed, as well as a gradient adjustment rule for the engine load and the second temperature threshold t2. The first temperature threshold t1 is dynamically adjusted according to the linear compensation function, and the second temperature threshold t2 is dynamically adjusted according to the gradient adjustment rule.

8. A catalyst temperature control device, characterized in that, include: The temperature detection module is used to acquire the catalyst temperature tc and coolant temperature tl in real time. The control decision module is used to compare the catalyst temperature tc and the coolant temperature tl with preset first temperature threshold t1, second temperature threshold t2 and third temperature threshold t3, and generate control commands. The execution control module is used to control the catalyst to connect to or disconnect from the engine cooling system according to the control command, and to control the catalyst heating device to perform staged heating of the catalyst so that the catalyst is heated and maintained in the optimal operating temperature range. Wherein, the first temperature threshold t1 is the ignition temperature of the catalyst, the second temperature threshold t2 is the lower limit temperature of the optimal operating temperature range of the catalyst, and the third temperature threshold t3 is the upper limit temperature of the optimal operating temperature range of the catalyst.

9. A catalytic converter temperature control system, which can be connected as a branch circuit to the engine cooling system of a vehicle, characterized in that, include: The catalyst has cooling channels formed inside it; A catalytic converter solenoid valve, the inlet of which is connected to the engine cooling circuit; A first temperature sensor T1 is disposed on a pipeline used to connect the engine cooling circuit to the inlet of the catalyst solenoid valve; The second temperature sensor T2 is installed on the pipeline connecting the outlet of the catalyst solenoid valve and the inlet of the catalyst cooling channel; A catalyst heating device for staged heating of the catalyst; A catalyst temperature control device for performing the method as described in any one of claims 1 to 7.

10. A vehicle, characterized in that, Includes the catalyst temperature control device as described in claim 8.

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