Supercharger protection method, device and vehicle

Abstract

The application discloses a supercharger protection method and device and a vehicle. The method comprises the following steps: obtaining the operation parameters of the supercharger; calculating the rotating speed of the supercharger according to the operation parameters; comparing the rotating speed of the supercharger with the maximum rated rotating speed of the supercharger, and determining the maximum fuel flow of the engine according to the size relationship. The technical scheme provided by the embodiment of the application constructs the anti-over-speed model of the supercharger through the operation parameters, recursively calculates the supercharger rotating speed of the future step and the fuel flow of the engine corresponding to the supercharger rotating speed of the future step according to the current rotating speed of the supercharger and the current fuel flow of the engine, compares the rotating speed of the supercharger with the maximum rated rotating speed of the supercharger, and determines the fuel flow of the engine corresponding to the supercharger rotating speed of the future step as the maximum fuel flow of the engine according to the size relationship, so that the supercharger over-speed can be identified in advance and prevented, and the damage of the supercharger can be effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a turbocharger protection method, device, and vehicle. Background Technology

[0002] With increasingly stringent fuel consumption and emission regulations, higher demands are being placed on diesel engines. Due to the complex operating environment of diesel engines, they require high performance and reliability. Turbochargers can improve the power performance of diesel engines and reduce exhaust emissions without changing engine displacement.

[0003] However, in high-altitude environments, as environmental pressure decreases, the turbocharger speed continuously increases. This means that diesel engines calibrated in plains areas still face the risk of turbocharger overspeeding and reaching the surge line in high-altitude areas, which can lead to turbocharger damage.

[0004] Existing turbocharger protection methods can only passively determine the engine's maximum fuel injection quantity by consulting the transient turbocharger protection calibration table. They cannot identify potential turbocharger overspeed situations in advance, and therefore cannot effectively prevent turbocharger damage. Summary of the Invention

[0005] This invention provides a turbocharger protection method, device, and vehicle to solve the problem in the prior art that it is impossible to detect the possibility of turbocharger overspeeding in advance.

[0006] According to one aspect of the present invention, a turbocharger protection method is provided, comprising:

[0007] Obtain the operating parameters of the turbocharger; wherein the operating parameters include intake manifold pressure, intake manifold temperature, compressor inlet pressure, compressor inlet temperature, first air flow rate of the turbocharger, atmospheric pressure, engine speed, engine fuel flow rate, turbine outlet pressure, and turbine outlet temperature.

[0008] Calculate the speed of the turbocharger based on the operating parameters;

[0009] The maximum fuel flow rate of the engine is determined by comparing the speed of the turbocharger with the maximum rated speed of the turbocharger.

[0010] Optionally, calculating the turbocharger speed based on the operating parameters includes:

[0011] The initial speed of the turbocharger is calculated based on the intake manifold pressure, the compressor inlet pressure, the compressor inlet temperature, and the first air flow rate of the turbocharger.

[0012] The first airflow rate of the turbocharger is calculated based on the initial speed of the turbocharger, the intake manifold pressure, the compressor inlet pressure, the compressor inlet temperature, the intake manifold temperature, and the engine speed.

[0013] The turbine torque is calculated based on the initial speed of the turbocharger, the first air flow rate of the turbocharger, the initial fuel flow rate of the engine, the turbine outlet pressure, and the turbine outlet temperature.

[0014] The compressor torque is calculated based on the initial speed of the turbocharger, the first air flow rate of the turbocharger, the inlet pressure of the compressor, and the inlet temperature of the compressor.

[0015] The speed of the supercharger is calculated based on the torque of the turbine, the torque of the compressor, the initial speed of the supercharger, and the moment of inertia of the supercharger.

[0016] Optionally, comparing the turbocharger's rotational speed with the turbocharger's maximum rated rotational speed, and determining the engine's maximum fuel flow rate based on this comparison, includes:

[0017] Calculate the upper limit and lower limit of the engine's fuel flow rate based on the engine's current fuel flow rate and the fuel flow rate calibration value.

[0018] The upper limit of the engine's fuel flow rate is used as the engine's initial fuel flow rate;

[0019] At the initial fuel flow rate, it is determined whether the speed of the turbocharger is less than the maximum rated speed of the turbocharger; if so, the upper limit of the fuel flow rate of the engine is determined as the maximum fuel flow rate of the engine.

[0020] Optionally, after determining whether the speed of the turbocharger is less than the maximum rated speed of the turbocharger, the method further includes:

[0021] If not, the lower limit of the engine's fuel flow rate is taken as the engine's initial fuel flow rate. Under the initial fuel flow rate, it is determined whether the turbocharger's rotational speed is greater than the turbocharger's maximum rated rotational speed. If yes, the lower limit of the engine's fuel flow rate is determined as the engine's maximum fuel flow rate.

[0022] Optionally, after determining whether the speed of the turbocharger is greater than the maximum rated speed of the turbocharger, the method further includes:

[0023] If not, a binary search method is used to iteratively calculate the turbocharger speed a preset number of times based on the upper limit and lower limit of the engine's fuel flow rate, and the fuel flow rate of the last preset number of times is determined as the engine's maximum fuel flow rate.

[0024] Optionally, after calculating the turbocharger speed based on the operating parameters, the method further includes:

[0025] The compressor pressure ratio and the second air flow rate of the turbocharger are determined by consulting the first calibration table based on the speed of the turbocharger.

[0026] The maximum opening value of the throttle valve is determined based on the pressure ratio and the second air flow rate.

[0027] Optionally, determining the maximum opening value of the throttle valve based on the pressure ratio and the second air flow rate includes:

[0028] Calculate the compressor outlet pressure based on the pressure ratio;

[0029] Calculate the intake manifold pressure based on the second airflow rate;

[0030] The pressure ratio of the throttle valve is calculated based on the outlet pressure of the gas turbine and the intake manifold pressure.

[0031] The maximum opening value of the throttle valve is determined based on the pressure ratio of the throttle valve and the second air flow rate.

[0032] Optionally, determining the maximum opening value of the throttle valve based on the pressure ratio of the throttle valve and the second air flow rate includes:

[0033] When the throttle valve pressure ratio and the second air flow rate satisfy a preset function, the throttle valve opening value corresponding to the preset function is determined as the maximum opening value of the throttle valve.

[0034] According to another aspect of the present invention, a turbocharger protection device is provided, comprising:

[0035] The acquisition module acquires the operating parameters of the turbocharger; wherein the operating parameters include the intake manifold pressure, intake manifold temperature, compressor inlet pressure, compressor inlet temperature, turbocharger first air flow rate, atmospheric pressure, engine speed, engine fuel flow rate, turbine outlet pressure, and turbine outlet temperature.

[0036] The calculation module is used to calculate the speed of the turbocharger based on the operating parameters;

[0037] The determination module is used to compare the speed of the turbocharger with the maximum rated speed of the turbocharger, and determine the maximum fuel flow rate of the engine based on the relationship between the speed and the maximum rated speed of the turbocharger.

[0038] According to another aspect of the present invention, a vehicle is provided, including the turbocharger protection device described in any embodiment of the present invention.

[0039] This invention provides a turbocharger protection method, device, and vehicle. The method involves acquiring the turbocharger's operating parameters; calculating the turbocharger's rotational speed based on these parameters; comparing the turbocharger's rotational speed with its maximum rated rotational speed; and determining the engine's maximum fuel flow rate based on this comparison. The technical solution provided by this invention constructs an overspeed prevention model for the turbocharger using operating parameters. Based on the turbocharger's current rotational speed and the engine's current fuel flow rate, it recursively calculates the turbocharger's rotational speed and the corresponding engine fuel flow rate at future increments of turbocharger rotational speed. By comparing the turbocharger's rotational speed with its maximum rated rotational speed, the fuel flow rate at the future increments of turbocharger rotational speed is determined as the engine's maximum fuel flow rate. This achieves the goal of identifying potential turbocharger overspeeding in advance and preventing turbocharger overspeeding, effectively avoiding turbocharger damage.

[0040] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0041] 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.

[0042] Figure 1 A flowchart of a turbocharger protection method provided in an embodiment of the present invention.

[0043] Figure 2 A flowchart of another turbocharger protection method provided in an embodiment of the present invention.

[0044] Figure 3 A flowchart of another turbocharger protection method provided in an embodiment of the present invention.

[0045] Figure 4 A flowchart of another turbocharger protection method provided in an embodiment of the present invention.

[0046] Figure 5A flowchart of another turbocharger protection method provided in an embodiment of the present invention.

[0047] Figure 6 This is a schematic diagram of a pressure vessel protection device provided in an embodiment of the present invention. Detailed Implementation

[0048] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0050] Figure 1 This is a flowchart illustrating a turbocharger protection method provided in an embodiment of the present invention. This embodiment is applicable to turbocharger protection. The method can be executed by a turbocharger protection device, which can be implemented in hardware and / or software. This turbocharger protection device can be configured in any electronic device with communication capabilities. See also... Figure 1 The method includes:

[0051] S110, Obtain the operating parameters of the turbocharger.

[0052] The operating parameters include intake manifold pressure, intake manifold temperature, compressor inlet pressure, compressor inlet temperature, turbocharger first airflow, atmospheric pressure, engine speed, engine fuel flow, turbine outlet pressure, and turbine outlet temperature.

[0053] Specifically, the sensor collects the operating parameters of the turbocharger in real time and stores the operating parameters in the vehicle's ECU (Electronic Control Unit). The operating parameters of the turbocharger can be obtained by retrieving the ECU. For example, the sensor can be a temperature sensor, a pressure sensor, etc., and this invention does not limit the type of sensor.

[0054] S120. Calculate the turbocharger speed based on the operating parameters.

[0055] Specifically, firstly, the operating parameters are fitted into a polynomial containing a functional relationship to construct an overspeed prevention model for the turbocharger. Secondly, the current turbocharger speed and the current engine fuel flow rate are calculated based on the operating parameters. Finally, the fuel flow rate limit is calculated based on the current engine fuel flow rate and calibration values. The fuel flow rate limit and the current turbocharger speed are then substituted into the polynomial containing the functional relationship to calculate the turbocharger speed. To predict whether there is a risk of overspeeding at future turbocharger speeds, a recursive step size of N is typically chosen, where N is generally less than 5. For each recursive step, a turbocharger speed is calculated, and the last calculated turbocharger speed is compared with the turbocharger's maximum rated speed. For example, if three recursive steps are used, the third calculated turbocharger speed is compared with the turbocharger's maximum rated speed.

[0056] S130. Compare the relationship between the turbocharger's rotational speed and the turbocharger's maximum rated rotational speed, and determine the engine's maximum fuel flow rate based on this relationship.

[0057] Specifically, firstly, using the fuel flow limit as the initial fuel flow value, the last calculated turbocharger speed is compared with the turbocharger's maximum rated speed. If the last calculated turbocharger speed is less than the turbocharger's maximum rated speed, the upper limit of the fuel flow is determined as the engine's maximum fuel flow. If the last calculated turbocharger speed is greater than the turbocharger's maximum rated speed, the lower limit of the fuel flow is used as the initial fuel flow value, and the turbocharger speed is iteratively calculated. The last calculated turbocharger speed is compared with the turbocharger's maximum rated speed. If the turbocharger speed is still greater than the turbocharger's maximum rated speed, the lower limit of the fuel flow is determined as the engine's maximum fuel flow. If the turbocharger speed is less than the turbocharger's maximum rated speed, a bisection method is used to search within the fuel flow limits, iterating 10 times. The iteration stops when the last calculated turbocharger speed, whether greater or less than the turbocharger's maximum rated speed, and the engine fuel flow corresponding to the last calculated turbocharger speed is determined as the engine's maximum fuel flow.

[0058] The technical solution provided by this invention involves acquiring the operating parameters of the turbocharger; calculating the turbocharger speed based on the operating parameters; comparing the turbocharger speed with the turbocharger's maximum rated speed; and determining the engine's maximum fuel flow rate based on this comparison. This invention constructs an overspeed prevention model for the turbocharger using the operating parameters. Based on the current turbocharger speed and the engine's current fuel flow rate, it recursively predicts the turbocharger speed and the corresponding engine fuel flow rate at future increments of turbocharger speed. By comparing the turbocharger speed with its maximum rated speed, the fuel flow rate at the future increments of turbocharger speed is determined as the engine's maximum fuel flow rate. This achieves the goal of identifying potential turbocharger overspeed in advance and preventing turbocharger overspeed, effectively avoiding turbocharger damage.

[0059] Figure 2 This is a flowchart illustrating another turbocharger protection method provided by an embodiment of the present invention. The embodiments of the present invention further refine the aforementioned embodiments based on the previous embodiments. See also... Figure 2 The method includes:

[0060] S210, Obtain the operating parameters of the turbocharger.

[0061] The operating parameters include intake manifold pressure, intake manifold temperature, compressor inlet pressure, compressor inlet temperature, turbocharger first airflow, atmospheric pressure, engine speed, engine fuel flow, turbine outlet pressure, and turbine outlet temperature.

[0062] S220. Calculate the initial speed of the turbocharger based on the intake manifold pressure, compressor inlet pressure, compressor inlet temperature, and the first air flow rate of the turbocharger.

[0063] Specifically, the initial speed of the turbocharger is calculated using the following formula;

[0064]

[0065] In the formula, N tc (0) represents the initial speed of the turbocharger; P im P is the intake manifold pressure. air T is the compressor inlet pressure; air M is the compressor inlet temperature. air denoted as the first airflow rate of the turbocharger; h is a function containing the relationship between the intake manifold pressure, compressor inlet pressure, compressor inlet temperature, and the first airflow rate of the turbocharger.

[0066] S230. Calculate the first airflow of the turbocharger based on the initial speed of the turbocharger, the intake manifold pressure, the compressor inlet pressure, the compressor inlet temperature, the intake manifold temperature, and the engine speed.

[0067] Specifically, the first air flow rate of the turbocharger is calculated using the following formula;

[0068]

[0069] In the formula, N tc The turbocharger's rotational speed is represented by k; the step size is represented by Ne; and the engine's rotational speed is represented by T. im g1 is the intake manifold temperature; g2 is a function containing the relationship between the turbocharger speed, intake manifold pressure, and compressor inlet pressure; g3 is a function containing the relationship between intake manifold pressure and engine speed.

[0070] S240. Calculate the turbine torque based on the turbocharger's initial speed, the turbocharger's first air flow, the engine's initial fuel flow, the turbine's outlet pressure, and the turbine's outlet temperature.

[0071] Specifically, the turbine torque is calculated using the following formula;

[0072]

[0073] In the formula, Tq tur M represents the torque of the turbocharger. f T represents the initial fuel flow rate of the engine. ex Turbine outlet temperature; P ex f1 is the turbine outlet pressure; f1 is a function relating the first airflow rate containing the turbocharger, the initial fuel flow rate of the engine, the turbine outlet pressure, and the turbine outlet temperature.

[0074] S250. Calculate the compressor torque based on the initial speed of the turbocharger, the first air flow rate of the turbocharger, the inlet pressure of the compressor, and the inlet temperature of the compressor.

[0075] Specifically, the compressor torque is calculated using the following formula;

[0076]

[0077] In the formula, Tq com f1 is the compressor torque; f2 is a function relating the initial speed of the turbocharger, the first air flow rate of the turbocharger, the inlet pressure of the compressor, and the inlet temperature of the compressor.

[0078] S260. Calculate the turbocharger speed based on the turbine torque, compressor torque, turbocharger initial speed, and turbocharger moment of inertia.

[0079] Specifically, the turbocharger speed is calculated using the following formula;

[0080] Ntc (k)=1 / J(Tq tur -Tq com )+N tc (k-1);

[0081] In the formula, J is the moment of inertia of the turbocharger.

[0082] S270. Compare the relationship between the turbocharger's rotational speed and the turbocharger's maximum rated rotational speed, and determine the engine's maximum fuel flow rate based on this relationship.

[0083] The embodiments of the present invention firstly distribute the air flow, turbine torque, compressor torque and turbocharger speed of the turbocharger based on torque balance. Based on the above parameters, an overspeed prevention model for the turbocharger is constructed. By comparing the relationship between the turbocharger speed and the turbocharger's maximum rated speed, and based on the relationship, the maximum fuel flow of the engine is determined, which further effectively prevents the turbocharger from overspeeding and thus effectively avoids turbocharger damage.

[0084] Figure 3 This is a flowchart illustrating another turbocharger protection method provided by an embodiment of the present invention. The embodiments of the present invention further refine the aforementioned embodiments based on the previous embodiments. See also... Figure 3 The method includes:

[0085] S310, Obtain the operating parameters of the turbocharger.

[0086] S320. Calculate the turbocharger speed based on the operating parameters.

[0087] S330. Calculate the upper limit and lower limit of the engine's fuel flow rate based on the engine's current fuel flow rate and the fuel flow rate calibration value.

[0088] The fuel flow rate calibration value can be preset.

[0089] Specifically, based on the current atmospheric pressure and the current engine speed, the current fuel flow rate of the engine can be determined by consulting the calibration table. The current fuel flow rate and the calibrated fuel flow rate are summed, and the sum is taken as the upper limit of the engine's fuel flow rate. The difference between the current fuel flow rate and the calibrated fuel flow rate is taken as the lower limit of the engine's fuel flow rate.

[0090] S340, Use the upper limit of the engine's fuel flow rate as the engine's initial fuel flow rate.

[0091] S350. Under the initial fuel flow rate, determine whether the turbocharger speed is less than the turbocharger's maximum rated speed; if yes, proceed to S360; if no, proceed to S370.

[0092] S360: The upper limit of the engine's fuel flow rate is determined as the engine's maximum fuel flow rate.

[0093] S370: The lower limit of the engine's fuel flow rate is used as the engine's initial fuel flow rate.

[0094] S380. Under the initial fuel flow rate, determine whether the turbocharger speed is greater than the turbocharger's maximum rated speed; if yes, proceed to S390; if no, proceed to S391.

[0095] S390. The lower limit of the engine's fuel flow rate is determined as the engine's maximum fuel flow rate.

[0096] S391. Using a bisection method, based on the upper limit and lower limit of the engine's fuel flow rate, the turbocharger speed is iteratively calculated a preset number of times, and the fuel flow rate of the last preset number of times is determined as the engine's maximum fuel flow rate.

[0097] The preset number of times can be set in advance. For example, the preset number of times can be set to 10.

[0098] Specifically, the upper and lower limits of the engine's fuel flow rate are used as an interval. The midpoint between the upper and lower limits is taken as the lower limit, forming a new interval with the upper limit. Then, the midpoint of the upper and lower limits is taken again as the lower limit, forming a new interval with the upper limit. This logic is repeated until the zero point is approached, obtaining a zero-point approximation. The turbocharger speed is calculated based on the zero-point approximation, regardless of whether the turbocharger speed is greater than or less than the turbocharger's maximum rated speed. The engine fuel flow rate corresponding to this turbocharger speed is determined as the engine's maximum fuel flow rate.

[0099] This invention first constructs an overspeed prevention model for the turbocharger based on the torque balance parameters, including airflow, turbine torque, compressor torque, and turbocharger speed. Then, it calibrates the current fuel flow rate of the turbocharger based on the current atmospheric pressure and engine speed. On this basis, it adds or subtracts an offset to form an actual maximum speed search range. The upper and lower boundaries of this range are used as the initial values ​​for the fuel flow rate in the iterative calculation. The maximum fuel flow rate of the engine is finally determined through bisection iterative calculation, which further effectively prevents turbocharger overspeed and thus effectively avoids turbocharger damage.

[0100] Figure 4 This is a flowchart illustrating another turbocharger protection method provided by an embodiment of the present invention. The embodiments of the present invention further refine the aforementioned embodiments based on the previous embodiments. See also... Figure 4 The method includes:

[0101] S410: Obtain the operating parameters of the turbocharger.

[0102] S420. Calculate the speed of the turbocharger based on the operating parameters.

[0103] S430. Compare the relationship between the turbocharger's rotational speed and the turbocharger's maximum rated rotational speed, and determine the engine's maximum fuel flow rate based on this relationship.

[0104] S440. Based on the turbocharger's rotational speed, consult the first calibration table to determine the compressor's pressure ratio and the turbocharger's second airflow rate.

[0105] Specifically, the compressor pressure ratio can be understood as the ratio between the compressor outlet pressure and the compressor inlet pressure. The first calibration table can be understood as a table showing the relationship between turbocharger speed, compressor pressure ratio, and turbocharger airflow. The second airflow rate can be understood as the airflow rate of the turbocharger when it is nearing surge.

[0106] Specifically, the first calibration table is consulted based on the turbocharger's speed, where each turbocharger speed corresponds to a compressor pressure ratio and a second air flow rate of the turbocharger.

[0107] S450. Determine the maximum opening value of the throttle valve based on the pressure ratio and the second air flow rate.

[0108] Specifically, the compressor outlet pressure is calculated based on the compressor pressure ratio, and the intake manifold pressure is calculated based on the second air flow rate. Since the throttle valve pressure ratio is equal to the ratio of the throttle valve inlet pressure to its outlet pressure, and since the throttle valve inlet pressure is equal to the compressor outlet pressure and the throttle valve outlet pressure is equal to the intake manifold pressure, the throttle valve pressure ratio is equal to the ratio between the compressor outlet pressure and the intake manifold pressure. The throttle valve opening can be determined based on the throttle valve pressure ratio and the second air flow rate. For each intensifier, the speed of rotation yields a throttle valve pressure ratio and an intensifier air flow rate. The minimum air flow rate and the minimum throttle valve pressure ratio are taken, and it is determined whether they satisfy a preset function. If they satisfy the preset function, the throttle valve opening calculated from the minimum air flow rate and the minimum throttle valve pressure ratio is determined as the maximum throttle valve opening value.

[0109] Figure 5 This is a flowchart illustrating another turbocharger protection method provided by an embodiment of the present invention. The embodiments of the present invention further refine the aforementioned embodiments based on the previous embodiments. See also... Figure 5 The method includes:

[0110] S510: Obtain the operating parameters of the turbocharger.

[0111] S520. Calculate the speed of the turbocharger based on the operating parameters.

[0112] S530. Compare the relationship between the turbocharger's rotational speed and the turbocharger's maximum rated rotational speed, and determine the engine's maximum fuel flow rate based on this relationship.

[0113] S540. Based on the turbocharger's rotational speed, consult the first calibration table to determine the compressor's pressure ratio and the turbocharger's second airflow rate.

[0114] S550, Calculate the compressor outlet pressure based on the pressure ratio.

[0115] Specifically, the compressor outlet pressure is calculated using the following formula;

[0116] p2_surge = pr_surge × p air ;

[0117] In the formula, p2_surge is the compressor outlet pressure; pr_surge is the compressor pressure ratio; p air This is the compressor inlet pressure.

[0118] S560, Calculate the intake manifold pressure based on the second airflow rate.

[0119] Specifically, the intake manifold pressure is calculated using the following formula;

[0120] pim_surge=M_surge÷[V / RT×Ne×30×Eff(Ne)];

[0121] In the formula, pim_surge is the intake manifold pressure; M_surge is the second airflow of the turbocharger; V is the engine displacement; T is the intake manifold temperature; and Eff is the charging efficiency.

[0122] S570. Calculate the pressure ratio of the throttle valve based on the compressor outlet pressure and the intake manifold pressure.

[0123] Specifically, since the pressure ratio of the throttle valve is equal to the ratio of the inlet pressure to the outlet pressure of the throttle valve, and since the inlet pressure of the throttle valve is equal to the outlet pressure of the compressor, and the outlet pressure of the throttle valve is equal to the intake manifold pressure, the pressure ratio of the throttle valve is equal to the ratio between the outlet pressure of the compressor and the intake manifold pressure.

[0124] S580. Determine the maximum opening value of the throttle valve based on the pressure ratio of the throttle valve and the second air flow rate.

[0125] Specifically, based on the number of calculations for the rotational speed, each rotational speed corresponds to a throttle valve pressure ratio and a second air flow rate. Each throttle valve pressure ratio and second air flow rate is used to calculate an expected throttle valve opening. The minimum second air flow rate in the number of calculations is compared with the throttle valve pressure ratio. When the minimum second air flow rate and the throttle valve pressure ratio satisfy a preset function, the throttle valve opening value corresponding to the preset function is determined as the maximum opening value of the throttle valve.

[0126] Optionally, the maximum opening value of the throttle valve can be determined based on the pressure ratio of the throttle valve and the second air flow rate, including:

[0127] When the throttle valve pressure ratio and the second air flow rate satisfy a preset function, the throttle valve opening value corresponding to the preset function is determined as the maximum opening value of the throttle valve.

[0128] Specifically, when the throttle valve pressure ratio and the second air flow satisfy the following formula, the throttle valve opening value corresponding to the preset function is determined as the maximum opening value of the throttle valve.

[0129]

[0130] In the formula, Min[M_surg]e is the minimum value of the second air flow rate; i is the number of rotational speeds; g3 is a preset function containing the correspondence between the second air flow rate and the throttle valve pressure ratio.

[0131] In this embodiment of the invention, based on the turbocharger overspeed prevention model, the compressor pressure ratio and air flow rate are obtained by querying the turbocharger near surge by the engine speed. Based on the compressor pressure ratio and air flow rate, an anti-surge model for the turbocharger is constructed. The throttle valve opening at the point where the turbocharger reaches surge is calculated when the fuel flow rate remains constant. The minimum air flow rate is compared with the throttle valve pressure ratio. When the minimum air flow rate and the throttle valve pressure ratio satisfy a preset function, the throttle valve opening value corresponding to the preset function is determined as the maximum opening value of the throttle valve. This can effectively prevent turbocharger surge and thus effectively avoid turbocharger damage.

[0132] Figure 6 This is a schematic diagram of a turbocharger protection device provided in an embodiment of the present invention, used to execute the turbocharger protection method provided in any embodiment of the present invention. See also... Figure 6 The device includes an acquisition module 610, a calculation module 620, and a determination module 630.

[0133] The acquisition module 610 is used to acquire the operating parameters of the turbocharger; wherein, the operating parameters include the pressure of the intake manifold, the temperature of the intake manifold, the inlet pressure of the compressor, the inlet temperature of the compressor, the first air flow of the turbocharger, the atmospheric pressure, the engine speed, the engine fuel flow, the turbine outlet pressure, and the turbine outlet temperature.

[0134] Calculation module 620 is used to calculate the speed of the turbocharger based on operating parameters;

[0135] The determination module 630 is used to compare the relationship between the turbocharger's rotational speed and the turbocharger's maximum rated rotational speed, and to determine the engine's maximum fuel flow rate based on this relationship.

[0136] The turbocharger protection device provided in the embodiments of the present invention can execute the turbocharger protection method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0137] Optionally, the calculation module includes:

[0138] The first calculation module is used to calculate the initial speed of the turbocharger based on the intake manifold pressure, compressor inlet pressure, compressor inlet temperature and the first air flow of the turbocharger;

[0139] The second calculation module is used to calculate the first air flow of the turbocharger based on the initial speed of the turbocharger, the intake manifold pressure, the compressor inlet pressure, the compressor inlet temperature, the intake manifold temperature, and the engine speed.

[0140] The third calculation module is used to calculate the turbine torque based on the turbocharger's initial speed, the turbocharger's first air flow, the engine's initial fuel flow, the turbine's outlet pressure, and the turbine's outlet temperature.

[0141] The fourth calculation module is used to calculate the compressor torque based on the initial speed of the turbocharger, the first air flow of the turbocharger, the inlet pressure of the compressor, and the inlet temperature of the compressor.

[0142] The fifth calculation module is used to calculate the speed of the turbocharger based on the torque of the turbine, the torque of the compressor, the initial speed of the turbocharger, and the moment of inertia of the turbocharger.

[0143] According to another aspect of the present invention, a vehicle is provided, including the turbocharger protection device provided in any embodiment of the present invention.

[0144] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0145] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for protecting a turbocharger, characterized in that, include Obtain the operating parameters of the turbocharger; wherein the operating parameters include intake manifold pressure, intake manifold temperature, compressor inlet pressure, compressor inlet temperature, first air flow rate of the turbocharger, atmospheric pressure, engine speed, engine fuel flow rate, turbine outlet pressure, and turbine outlet temperature. Calculate the speed of the turbocharger based on the operating parameters; The maximum fuel flow rate of the engine is determined by comparing the speed of the turbocharger with the maximum rated speed of the turbocharger. The step of comparing the turbocharger's rotational speed with its maximum rated rotational speed, and determining the engine's maximum fuel flow rate based on this comparison, includes: The upper limit and lower limit of the engine's fuel flow rate are calculated based on the engine's current fuel flow rate and the calibrated fuel flow rate. Specifically, the current fuel flow rate and the calibrated fuel flow rate are summed to obtain the upper limit of the engine's fuel flow rate, and the difference between the current fuel flow rate and the calibrated fuel flow rate is obtained to obtain the lower limit of the engine's fuel flow rate. The upper limit of the engine's fuel flow rate is used as the engine's initial fuel flow rate; At the initial fuel flow rate, determine whether the speed of the turbocharger is less than the maximum rated speed of the turbocharger; If so, the upper limit of the fuel flow rate of the engine is determined as the maximum fuel flow rate of the engine; If not, the lower limit of the engine's fuel flow rate is taken as the engine's initial fuel flow rate. Under the initial fuel flow rate, it is determined whether the turbocharger's speed is greater than the turbocharger's maximum rated speed. If so, the lower limit of the fuel flow rate of the engine is determined as the maximum fuel flow rate of the engine; If not, a binary search method is used to iteratively calculate the turbocharger speed a preset number of times based on the upper limit and lower limit of the engine's fuel flow rate, and the fuel flow rate of the last preset number of times is determined as the engine's maximum fuel flow rate.

2. The method according to claim 1, characterized in that, The step of calculating the turbocharger speed based on the operating parameters includes: The initial speed of the turbocharger is calculated based on the intake manifold pressure, the compressor inlet pressure, the compressor inlet temperature, and the first air flow rate of the turbocharger. The first airflow rate of the turbocharger is calculated based on the initial speed of the turbocharger, the intake manifold pressure, the compressor inlet pressure, the compressor inlet temperature, the intake manifold temperature, and the engine speed. The turbine torque is calculated based on the initial speed of the turbocharger, the first air flow rate of the turbocharger, the initial fuel flow rate of the engine, the turbine outlet pressure, and the turbine outlet temperature. The compressor torque is calculated based on the initial speed of the turbocharger, the first air flow rate of the turbocharger, the inlet pressure of the compressor, and the inlet temperature of the compressor. The speed of the supercharger is calculated based on the torque of the turbine, the torque of the compressor, the initial speed of the supercharger, and the moment of inertia of the supercharger.

3. The method according to claim 1, characterized in that, After calculating the turbocharger's rotational speed based on the operating parameters, the method further includes: The compressor pressure ratio and the second air flow rate of the turbocharger are determined by consulting the first calibration table based on the speed of the turbocharger. The maximum opening value of the throttle valve is determined based on the pressure ratio and the second air flow rate.

4. The method according to claim 3, characterized in that, Determining the maximum opening value of the throttle valve based on the pressure ratio and the second air flow rate includes: Calculate the compressor outlet pressure based on the pressure ratio; Calculate the intake manifold pressure based on the second airflow rate; The pressure ratio of the throttle valve is calculated based on the outlet pressure of the compressor and the intake manifold pressure. The maximum opening value of the throttle valve is determined based on the pressure ratio of the throttle valve and the second air flow rate.

5. The method according to claim 4, characterized in that, Determining the maximum opening value of the throttle valve based on the pressure ratio of the throttle valve and the second air flow rate includes: When the throttle valve pressure ratio and the second air flow rate satisfy a preset function, the throttle valve opening value corresponding to the preset function is determined as the maximum opening value of the throttle valve.

6. A turbocharger protection device for performing the turbocharger protection method as described in any one of claims 1-5, characterized in that, include The acquisition module acquires the operating parameters of the turbocharger; wherein, the operating parameters include the intake manifold pressure, intake manifold temperature, compressor inlet pressure, compressor inlet temperature, turbocharger first airflow rate, engine speed, engine fuel flow rate, turbine outlet pressure, and turbine outlet temperature. The calculation module is used to calculate the speed of the turbocharger based on the operating parameters; The determination module is used to compare the speed of the turbocharger with the maximum rated speed of the turbocharger, and determine the maximum fuel flow rate of the engine based on the relationship between the speed and the maximum rated speed of the turbocharger.

7. A vehicle, characterized in that, Includes the turbocharger protection device as described in claim 6.

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