Two-stage thermal protection method for an expansion tank

Abstract

The application discloses a two-stage thermal protection method for an expansion water tank. The method can comprise: triggering thermal load Count calculation enabling; determining an operation area, including a safe area and a non-safe area; and performing two-stage thermal protection according to the operation area. The application does not need to replace heat-resistant materials, reduces thermal load and vehicle machine delay power-off pop-up window prompting through mechanical and electrical cooperation, and reduces the risk of thermal melting and cracking of the expansion water tank and the component procurement cost.

Description

Technical Field

[0001] This invention relates to the field of vehicle control, and more specifically, to a two-stage thermal protection method for an expansion tank. Background Technology

[0002] After an engine has been running under heavy load for an extended period, a sudden shutdown will cause the engine temperature to continue to rise. High-temperature steam will flow downwards from the cooling pipes through the expansion tank inlet, sweeping across the expansion tank wall. If the high-temperature steam exceeds the expansion tank's withstand temperature, it can cause the tank wall to thin, creating a risk of cracking under internal pressure.

[0003] There are several traditional directions for optimizing the thermal protection of expansion tanks:

[0004] 1. Using materials with higher temperature resistance will increase costs;

[0005] 2. Adjusting the pipeline and water pump operation strategy; this solution cannot be applied to projects using mechanical cooling water pumps.

[0006] Currently, a two-stage thermal protection method for expansion tanks still needs to be developed.

[0007] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0008] This invention proposes a two-stage thermal protection method for expansion tanks, which eliminates the need to replace heat-resistant materials. By reducing heat load through electromechanical coordination and providing delayed power-off pop-up reminders from the vehicle's infotainment system, the risk of thermal melting and cracking of the expansion tank and the cost of component procurement are reduced.

[0009] This disclosure provides a two-stage thermal protection method for an expansion tank, including:

[0010] Enable the heat load count calculation;

[0011] Determine the operating area, including safe and unsafe areas;

[0012] Two levels of thermal protection are implemented for the operating area.

[0013] Preferably, enabling the heat load count calculation includes:

[0014] If the engine coolant temperature is ≥Count, the coolant temperature threshold is enabled; if the range extender power is ≥Count, the range extender power threshold is enabled; if the catalytic converter exhaust temperature is ≥Count, the catalytic converter exhaust temperature threshold is enabled; and if the thermal protection switches from active to inactive, then the thermal load Count calculation is enabled.

[0015] Preferably, determining the operating area includes:

[0016] By conducting engine shutdown temperature rise tests at different engine speeds, the torque critical point at which the outlet water temperature rise after shutdown does not exceed 135 degrees Celsius was found, thus determining the safe and unsafe operating ranges of the engine.

[0017] Preferably, based on the non-safe zone, different risk zones are divided according to the exhaust temperature before the catalytic converter, including:

[0018] Risk Level 1 Zone: When the exhaust temperature before the catalytic converter exceeds 900 degrees, the heat load count increases by 5 at each timing interval;

[0019] Risk Level 2 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 850 degrees and less than or equal to 900 degrees, the heat load count is increased by 3 at each timing moment;

[0020] Risk Level 3 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 800 degrees and less than 850 degrees, the heat load count is increased by 2 at each timing moment;

[0021] Risk Level 4 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 700 degrees and less than 800 degrees, the heat load count is incremented by 1 at each timing moment.

[0022] Preferably, based on the safe zone, a heat load count reduction zone is set based on the catalytic converter exhaust temperature and engine torque safety margin. When the speed and torque enter 20 Nm below the boundary of the safe zone and the catalytic converter exhaust temperature is less than 700 degrees, the heat load count is reduced by 1 in each timing cycle.

[0023] Preferably, the area not covered by the above division is defined as a transition area, and the heat load count remains unchanged.

[0024] Preferably, when the heat load count value is greater than or equal to the first-level thermal protection entry count calibration threshold, the first-level thermal protection is entered.

[0025] Preferably, the control strategy for the first-stage thermal protection includes:

[0026] Activate the high-load engine shutdown prevention request;

[0027] The correction coefficient for the requested engine torque is obtained by looking up the heat load count value and vehicle speed table, and the reduction of heat load is displayed by reducing the engine operating load.

[0028] Preferably, after entering the first-level thermal protection, when the heat load count value is greater than or equal to the count calibration threshold for entering the second-level thermal protection, the second-level thermal protection is entered.

[0029] Preferably, the control strategy for the second-stage thermal protection includes:

[0030] Activate the high-load engine shutdown prevention request;

[0031] The correction coefficient for the requested engine torque is obtained by looking up the heat load count value and vehicle speed table, and the reduction of heat load is displayed by reducing the engine operating load.

[0032] When in Park (P) mode, a pop-up window on the vehicle's infotainment system will prompt the user to delay power-off.

[0033] Its beneficial effects are as follows:

[0034] This invention calculates the cumulative thermal load hazard based on different regions defined by the engine operating area and exhaust temperature. When the cumulative thermal load hazard exceeds a set threshold, the first-level protection reduces the thermal load before power-off by preventing engine shutdown and requesting a reduction in engine operating load. The second-level protection prompts the user to delay power-off via a pop-up window on the vehicle's infotainment system, reducing the risk of thermal melting and cracking of the expansion tank caused by high-temperature steam after power-off and reducing component procurement costs.

[0035] The method of the present invention has other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0036] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same parts.

[0037] Figure 1 A flowchart illustrating the steps of a two-stage thermal protection method for an expansion tank according to an embodiment of the present invention is shown.

[0038] Figure 2 A schematic diagram of the heat load count calculation enable logic according to an embodiment of the present invention is shown.

[0039] Figure 3A schematic diagram of the interaction of a heat load count module according to an embodiment of the present invention is shown.

[0040] Figure 4 A schematic diagram of a safe area and an unsafe area according to an embodiment of the present invention is shown.

[0041] Figure 5 A simplified diagram for calculating heat load count according to an embodiment of the present invention is shown.

[0042] Figure 6 A simplified flowchart of a thermal protection pop-up notification is shown according to an embodiment of the present invention. Detailed Implementation

[0043] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0044] To facilitate understanding of the solutions and effects of the embodiments of the present invention, a specific application example is given below. Those skilled in the art should understand that this example is merely for the purpose of understanding the present invention, and any specific details therein are not intended to limit the present invention in any way.

[0045] Example 1

[0046] Figure 1 A flowchart illustrating the steps of a two-stage thermal protection method for an expansion tank according to an embodiment of the present invention is shown.

[0047] like Figure 1 As shown, the two-stage thermal protection method for the expansion tank includes:

[0048] Step 101: Enable the calculation of heat load Count;

[0049] Step 102: Determine the operating area, including safe areas and unsafe areas;

[0050] Step 103: Implement two-stage thermal protection for the operating area.

[0051] In one example, the enable for triggering the heat load count calculation includes:

[0052] If the engine coolant temperature is ≥Count, the coolant temperature threshold is enabled; if the range extender power is ≥Count, the range extender power threshold is enabled; if the catalytic converter exhaust temperature is ≥Count, the catalytic converter exhaust temperature threshold is enabled; and if the thermal protection switches from active to inactive, then the thermal load Count calculation is enabled.

[0053] In one example, determining the operating region includes:

[0054] By conducting engine shutdown temperature rise tests at different engine speeds, the torque critical point at which the outlet water temperature rise after shutdown does not exceed 135 degrees Celsius was found, thus determining the safe and unsafe operating ranges of the engine.

[0055] In one example, based on the pre-catalytic converter exhaust temperature, different risk zones are defined within the non-safe zone, including:

[0056] Risk Level 1 Zone: When the exhaust temperature before the catalytic converter exceeds 900 degrees, the heat load count increases by 5 at each timing interval;

[0057] Risk Level 2 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 850 degrees and less than or equal to 900 degrees, the heat load count is increased by 3 at each timing moment;

[0058] Risk Level 3 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 800 degrees and less than 850 degrees, the heat load count is increased by 2 at each timing moment;

[0059] Risk Level 4 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 700 degrees and less than 800 degrees, the heat load count is incremented by 1 at each timing moment.

[0060] In one example, based on the safety zone, a heat load count reduction zone is set based on the catalytic converter exhaust temperature and engine torque safety margin. When the speed and torque enter 20 Nm below the safety zone boundary and the catalytic converter exhaust temperature is less than 700 degrees, the heat load count is reduced by 1 in each timing cycle.

[0061] In one example, the area not covered by the above division is defined as a transition area, and the heat load count remains unchanged.

[0062] In one example, when the heat load count value is greater than or equal to the first-level thermal protection entry count calibration threshold, the first-level thermal protection is activated.

[0063] In one example, the control strategy for the first-stage thermal protection includes:

[0064] Activate the high-load engine shutdown prevention request;

[0065] The correction coefficient for the requested engine torque is obtained by looking up the heat load count value and vehicle speed table, and the reduction of heat load is displayed by reducing the engine operating load.

[0066] In one example, after entering the first-level thermal protection, if the heat load count value is greater than or equal to the count calibration threshold for entering the second-level thermal protection, the second-level thermal protection will be activated.

[0067] In one example, the control strategy for the second-stage thermal protection includes:

[0068] Activate the high-load engine shutdown prevention request;

[0069] The correction coefficient for the requested engine torque is obtained by looking up the heat load count value and vehicle speed table, and the reduction of heat load is displayed by reducing the engine operating load.

[0070] When in Park (P) mode, a pop-up window on the vehicle's infotainment system will prompt the user to delay power-off.

[0071] Figure 2 A schematic diagram of the heat load count calculation enable logic according to an embodiment of the present invention is shown.

[0072] Specifically, the heat load count calculation enable module is as follows: Figure 2 As shown, the calculations are primarily based on engine coolant temperature, range extender power, and catalytic converter exhaust temperature. When the thermal protection switches from active to inactive, the thermal load count calculation is reset to enable.

[0073] Figure 3 A schematic diagram of the interaction of a heat load count module according to an embodiment of the present invention is shown.

[0074] Figure 4 A schematic diagram of a safe area and an unsafe area according to an embodiment of the present invention is shown.

[0075] Heat load count module such as Figure 3 As shown, it mainly consists of two parts: a running region determination module and a count calculation module based on the running region. The running region determination module is as follows: Figure 4 As shown, based on engine speed and actual engine torque, two main parts are initially divided: a safe zone and an unsafe zone.

[0076] By conducting engine shutdown temperature rise tests at different engine speeds, the torque critical point at which the outlet water temperature rise after shutdown does not exceed 135 degrees Celsius was found, thus determining the safe and unsafe operating range of the engine.

[0077] Based on the non-safe zone, the following four different levels of risk zones are divided according to the exhaust temperature before the catalytic converter:

[0078] Risk Level 1 Zone: When the exhaust temperature before the catalytic converter exceeds 900 degrees Celsius (calibrable), the heat load count is increased by 5 at each timing interval (calibrable).

[0079] Risk Level 2 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 850 degrees Celsius (calibrable) and less than or equal to 900 degrees Celsius (calibrable), the heat load count is incremented by 3 at each timing interval (calibrable).

[0080] Risk Level 3 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 800 degrees Celsius (calibrable) and less than 850 degrees Celsius (calibrable), the heat load count is incremented by 2 at each timing point (calibrable).

[0081] Risk Level 4 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 700 degrees Celsius (calibrable) and less than 800 degrees Celsius (calibrable), the heat load count is incremented by 1 at each timing point (calibrable).

[0082] Based on the safe zone, a heat load count reduction zone is set according to the catalytic converter exhaust temperature and engine torque safety margin: when the speed and torque enter 20Nm below the boundary of the safe zone (calibrable) and the catalytic converter exhaust temperature is less than 700 degrees (calibrable), the heat load count is reduced by 1 in each timing cycle (calibrable).

[0083] The areas not covered by the above divisions are defined as transition areas: in the transition areas, the heat load Count remains unchanged from the previous time point.

[0084] Figure 5 A simplified diagram for calculating heat load count according to an embodiment of the present invention is shown.

[0085] The main calculation logic of the heat load count module is as follows: Figure 5 As shown, it is also necessary to consider resetting the heat load Count value when the thermal protection is deactivated and when the power is turned off for 15 hours.

[0086] The first stage of thermal protection is activated when the following conditions are met:

[0087] (1) When the heat load count value is greater than or equal to the first-level thermal protection entry count calibration threshold, the first-level thermal protection is entered.

[0088] The exit conditions for the first-level thermal protection are designed as follows: The exit conditions are set to take effect when any one of the following conditions is met:

[0089] (1) When the heat load count value is less than the first-level thermal protection exit count calibration threshold;

[0090] (2) The range extender power is less than the calibration threshold and continues for more than the calibration time;

[0091] (3) The exhaust temperature before the catalyst is lower than the calibrated threshold and continues to exceed the calibrated time;

[0092] (4) 15 electricity.

[0093] When the first level of thermal protection is activated, the following post-processing protection is performed:

[0094] (1) Activate the high-load engine shutdown prohibition request to avoid sudden shutdown after high-load operation;

[0095] (2) Reduce engine heat load (based on the heat load count value and vehicle speed, the correction coefficient of the requested engine torque is obtained by looking up the table (not exceeding 1), and the heat load is reduced by reducing the engine operating load).

[0096] Entering or exiting the second-level thermal protection is similar to the logic of the first-level thermal protection, except that the calibrated thresholds are more stringent, and the prerequisite for entering the second-level thermal protection is that the conditions for entering the first-level thermal protection must be met.

[0097] Figure 6 A simplified flowchart of a thermal protection pop-up notification is shown according to an embodiment of the present invention.

[0098] When entering the second stage of thermal protection, the following post-processing protection is performed:

[0099] (1) Activate the high-load engine shutdown prohibition request to avoid sudden shutdown after high-load operation;

[0100] (2) Reduce engine thermal load (based on the thermal load Count value and vehicle speed, the correction coefficient for the requested engine torque is obtained by looking up the table (not exceeding 1), and the thermal load is reduced by reducing the engine load);

[0101] (3) In P gear, such as Figure 6 As shown, the vehicle's infotainment system will prompt the user to delay power-off via a pop-up window. The specific wording may vary depending on the actual vehicle.

[0102] Those skilled in the art should understand that the above description of the embodiments of the present invention is only intended to illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any of the examples given.

[0103] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A two-stage thermal protection method for an expansion tank, characterized in that, include: Enable the heat load count calculation; Determine the operating area, including safe and unsafe areas; Two-stage thermal protection is implemented for the operating area; The enable for triggering the heat load count calculation includes: If the engine coolant temperature is ≥Count, the coolant temperature threshold is enabled; if the range extender power is ≥Count, the range extender power threshold is enabled; if the catalytic converter exhaust temperature is ≥Count, the catalytic converter exhaust temperature threshold is enabled; and if the thermal protection switches from active to inactive, then the thermal load Count calculation is enabled. The operating area to be determined includes: By conducting engine shutdown temperature rise tests at different engine speeds, the torque critical point at which the outlet water temperature rise after shutdown does not exceed 135 degrees Celsius was found, thus determining the safe and unsafe operating range of the engine. In addition to the unsafe zone, different risk zones are defined based on the exhaust temperature before the catalytic converter, including: Risk Level 1 Zone: When the exhaust temperature before the catalytic converter exceeds 900 degrees, the heat load count increases by 5 at each timing interval; Risk Level 2 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 850 degrees and less than or equal to 900 degrees, the heat load count is increased by 3 at each timing moment; Risk Level 3 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 800 degrees and less than 850 degrees, the heat load count is increased by 2 at each timing moment; Risk Level 4 Zone: When the exhaust temperature before the catalytic converter is greater than or equal to 700 degrees and less than 800 degrees, the heat load count is incremented by 1 at each timing moment; Among them, when the heat load count value is greater than or equal to the first-level thermal protection entry count calibration threshold, the first-level thermal protection is entered; When entering the first-level thermal protection, if the heat load count value is greater than or equal to the count calibration threshold for entering the second-level thermal protection, the second-level thermal protection will be activated.

2. The two-stage thermal protection method for expansion tanks according to claim 1, wherein, Based on the safe zone, a heat load count reduction zone is set according to the catalytic converter exhaust temperature and engine torque safety margin. When the speed and torque enter 20Nm below the boundary of the safe zone and the catalytic converter exhaust temperature is less than 700 degrees, the heat load count is reduced by 1 in each timing cycle.

3. The two-stage thermal protection method for expansion tanks according to claim 2, wherein, Areas not covered by the above divisions are defined as transition areas, where the heat load count remains unchanged.

4. The two-stage thermal protection method for expansion tanks according to claim 1, wherein, The control strategy for the first-level thermal protection includes: Activate the high-load engine shutdown prevention request; The correction coefficient for the requested engine torque is obtained by looking up the heat load count value and vehicle speed table, and the reduction of heat load is displayed by reducing the engine operating load.

5. The two-stage thermal protection method for expansion tanks according to claim 1, wherein, The control strategies for the second-level thermal protection include: Activate the high-load engine shutdown prevention request; The correction coefficient for the requested engine torque is obtained by looking up the heat load count value and vehicle speed table, and the reduction of heat load is displayed by reducing the engine operating load. When in Park (P) mode, a pop-up window on the vehicle's infotainment system will prompt the user to delay power-off.

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