Method for calculating service life of turbocharger impeller by introducing temperature factor

Abstract

The invention discloses a turbocharger impeller service life calculation method introducing a temperature factor. The turbocharger impeller service life calculation method comprises the following steps of S10, collecting temperature data T when an impeller works; the rotating speed of the rotating shaft during working is collected; s20, the vehicle-mounted system obtains a data life curve, cycle period data and stress / strain data; s30, according to the collected temperature data T and stress / strain data, the vehicle-mounted system retrieves the corresponding cycle number in the impeller stress and material data life curve at the temperature, retrieves the cycled data N of the impeller at the temperature in the stored cycle period data, solves the damage D at the temperature, and then solves the residual damage value P; and once the residual damage value P is less than 10%, the vehicle-mounted system prompts to give an alarm for maintenance or replacement. According to the method, excessive risk and conservative judgment of residual damage under a single temperature condition can be avoided, and the service time of the impeller is prolonged to the maximum extent.

Description

Technical Field

[0001] The invention belongs to the technical field of turbocharger life detection, and in particular relates to a turbocharger impeller life calculation method introducing a temperature factor. Background Art

[0002] A turbocharger is a device used in automobile engines. It increases the power output of the engine by compressing the air entering the engine. It is widely used in mid-range and high-end cars. The specific structure of a turbocharger includes a rotating shaft and turbine impellers and compressor impellers located at both ends of the rotating shaft. During operation, the turbine impeller and the compressor impeller rotate at high speed, and the turbine impeller is also affected by high-temperature exhaust gas and is in a high-temperature working state. Therefore, it is very important to predict the service life of the impeller. When the service life is insufficient, it needs to be replaced in time to avoid accidents.

[0003] In the prior art, the traditional turbine impeller life detection is to install a sensor at the turbine end to monitor the turbine box inlet temperature. This temperature sensor only provides the vehicle-mounted CPU with the highest temperature during operation to roughly calculate the service life, but does not monitor the temperature throughout the entire process. It is also impossible to identify the life at different temperatures. Therefore, the error in the life calculation is large and needs to be improved.

[0004] It can be seen that the life monitoring and identification method in the prior art does not recognize temperature, and the life curves of different temperatures are very different. Calculating different temperatures according to the same temperature curve will cause over- and under-judgment of life. Therefore, the present application has made improvements in this direction. Summary of the invention

[0005] In view of the above shortcomings in the prior art, the present invention provides a method for calculating the life of a turbocharger impeller by introducing temperature factors. The method takes into account the influence of temperature and obtains the corresponding cycle life of the stress or strain at multiple different temperatures according to their life curves, thereby making the life calculation result more accurate. The present invention is solved by the following technical solutions.

[0006] A method for calculating the life of a turbocharger impeller by introducing a temperature factor comprises the following steps: S10: collecting temperature data T of the impeller when it is working by means of a temperature sensor arranged near the impeller in the turbocharger; collecting the rotation speed of the shaft when it is working by means of a rotation speed sensor arranged in the turbocharger; S20: obtaining the life curve of the impeller stress and material data of the turbocharger at different temperatures by an on-board system; obtaining the stored cycle data by the on-board system; obtaining the stress / strain data of the impeller at different rotation speeds by the on-board system; S30: retrieving the on-board system according to the collected temperature data T and stress / strain data The impeller stress at the temperature corresponds to the number of cycles in the material data life curve, and the cycle data N of the impeller at the temperature in the stored cycle data is retrieved, and the damage D at the temperature is calculated by Miner damage theory, and then the remaining damage value P is calculated; during the operation of the turbocharger, the temperature sensor continuously collects temperature data T and shaft speed according to the program settings, and transmits the data to the vehicle-mounted system to calculate the remaining damage value P; once the remaining damage value P is less than 10%, the vehicle-mounted system prompts an alarm for maintenance or replacement; S40: the vehicle-mounted system updates the cycle data of the working state to the stored cycle data.

[0007] Furthermore, in this application, step S30 includes the following specific methods: Obtain temperature data T1, T2, ..., Tn, and the shaft speed at the corresponding temperature; The vehicle-mounted system retrieves the impeller stress and material data life curves at these temperatures, and obtains the stress / strain data of the impeller at different shaft speeds, and obtains the corresponding cycle numbers L1, L2, ..., Ln in the life curve of the corresponding temperature according to the stress / strain data. Obtain the impeller cycle data N1, N2, ..., Nn at these temperatures and speeds respectively, Miner damage theory is used to calculate the damage of the corresponding cycles under these temperature conditions: D1=N1 / L1, D2=N2 / L2, ..., Dn=Nn / Ln, Then find the remaining damage value P=1-(D1+D2+…Dn); When P is less than 10%, the vehicle system will prompt an alarm for maintenance or replacement.

[0008] Furthermore, in the present application, the interval of the temperature data acquired by the temperature sensor is 15°C~20°C.

[0009] Furthermore, in the present application, the temperature sensor is used to detect the temperature of the turbine impeller.

[0010] Compared with the prior art, the present invention has the following beneficial effects: the working temperature of the impeller in the turbocharger is continuously monitored to obtain damage values ​​at different temperatures, these damage values ​​are accumulated to calculate the residual damage value, and an alarm is issued when the residual damage value is too low; this method is more accurate in calculating the life of the turbine impeller, avoids overly risky and conservative judgment of the residual damage under a single temperature condition, and maximizes the service life of the impeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of a life curve in one embodiment of the present invention. DETAILED DESCRIPTION

[0012] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0013] In the following embodiments, the same or similar reference numerals throughout represent the same or similar components or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0014] The present application discloses a turbocharger impeller life calculation method that introduces temperature factors, comprising the following steps: S10: collecting temperature data T of the impeller during operation through a temperature sensor disposed near the impeller in the turbocharger; collecting shaft speed during operation through a speed sensor disposed in the turbocharger; S20: the vehicle-mounted system obtains the impeller stress and material data life curve of the turbocharger at different temperatures; the vehicle-mounted system obtains the stored cycle data; the vehicle-mounted system obtains the stress / strain data of the impeller at different shaft speeds; S30: the vehicle-mounted system adjusts the temperature data T and stress / strain data according to the collected temperature data T and stress / strain data. Take the impeller stress at this temperature and the corresponding cycle number in the material data life curve, call the impeller's cycle data N at this temperature in the stored cycle data, calculate the damage D at this temperature through Miner damage theory, and then calculate the remaining damage value P; during the operation of the turbocharger, the temperature sensor continuously collects temperature data T and shaft speed according to the program settings, and transmits the data to the vehicle system to calculate the remaining damage value P; once the remaining damage value P is less than 10%, the vehicle system prompts an alarm for maintenance or replacement; S40: the vehicle system updates the cycle data of this working state to the stored cycle data.

[0015] In this method, the temperature data obtained by the temperature sensor is at an interval of 15° C. to 20° C. The temperature sensor is used to detect the temperature of the turbine impeller, because the turbine impeller is affected by the engine exhaust gas, the temperature changes greatly, and the temperature may even reach 700° C. during operation.

[0016] In a specific implementation of the present application, step S30 includes the following specific methods: Obtain temperature data T1, T2, ..., Tn, and the shaft speed at the corresponding temperature; The vehicle-mounted system retrieves the impeller stress and material data life curves at these temperatures, and obtains the stress / strain data of the impeller at different shaft speeds, and obtains the corresponding cycle numbers L1, L2, ..., Ln in the life curve of the corresponding temperature according to the stress / strain data. Obtain the impeller cycle data N1, N2, ..., Nn at these temperatures and speeds respectively, Miner damage theory is used to calculate the damage of the corresponding cycles under these temperature conditions: D1=N1 / L1, D2=N2 / L2, ..., Dn=Nn / Ln, Then find the remaining damage value P=1-(D1+D2+…Dn); When P is less than 10%, the vehicle system will prompt an alarm for maintenance or replacement.

[0017] See also Figure 1 ,from Figure 1 It can be seen that different temperatures have different life curves. The two different life curves of T1 and T2 in the figure can be obtained from the data according to the different shaft speeds under the two working conditions. The corresponding stress / strain parameters can then be obtained from Figure 1 The curve in can obtain the cycle numbers L1 and L2 under two working conditions. In this way, the cycle number L data under different temperatures and speeds can be obtained.

[0018] In this application, the life curve data package and the stress / strain data package corresponding to the speed can be provided by the turbocharger manufacturer, or by the car manufacturer, pre-stored in the vehicle system, or downloaded from the network server. The cycle data of the impeller at the corresponding temperature and speed is the actual use of the vehicle, which is recorded in the vehicle system according to the actual working condition of the turbocharger and continuously updated and accumulated, such as: 10 minutes of work at a specific temperature and speed is recorded as one cycle, or other quantitative cycle calculation methods can be used. Miner damage theory is also a known technology.

[0019] A specific embodiment is given below.

[0020] After the vehicle is started, the turbocharger begins to work, and the temperature of the impeller starts to rise from 40°C, and along with the exhaust gas temperature, it reaches up to 800°C, and then drops to 200°C. In this process, the interval of the temperature data obtained by the temperature sensor is set to 20°C, and 68 corresponding temperatures and the speed at the temperature are collected, and then the corresponding 68 cycle numbers L1~L68 are obtained according to the life curve data, and then the corresponding 68 cycle data N1~N68 are obtained from the cycle data.

[0021] Based on these data, the corresponding damage D1~D68 is calculated, and finally the remaining damage value P=1-(D1+D2+...D68) is obtained. When P is less than 10%, the on-board system prompts an alarm for maintenance or replacement.

[0022] It can be seen from the above description that the method in the present application continuously monitors the operating temperature of the impeller in the turbocharger, obtains damage values ​​at different temperatures, accumulates these damage values ​​to calculate the residual damage value, and issues an alarm when the residual damage value is too low; this method is more accurate in calculating the life of the turbine impeller, avoids the overly risky and conservative judgment of the residual damage under a single temperature condition, and maximizes the service life of the impeller.

[0023] The protection scope of the present invention includes but is not limited to the above embodiments. The protection scope of the present invention shall be based on the claims. Any replacement, deformation, and improvement of the technology that can be easily thought of by technicians in this field shall fall within the protection scope of the present invention.

Claims

1. A method for calculating the life of a turbocharger impeller by introducing temperature factors, characterized in that: The following steps are involved: S10: collecting temperature data T of the impeller during operation through a temperature sensor disposed near the impeller in the turbocharger; collecting shaft speed during operation through a speed sensor disposed in the turbocharger; S20: The vehicle-mounted system obtains the impeller stress and material data life curve of the turbocharger at different temperatures; The on-board system obtains the stored cycle data; The onboard system acquires stress / strain data of the impeller at different shaft speeds; S30: The vehicle-mounted system retrieves the impeller stress at the temperature and the corresponding cycle number in the material data life curve according to the collected temperature data T and stress / strain data, retrieves the cycle data N of the impeller at the temperature in the stored cycle period data, calculates the damage D at the temperature by Miner damage theory, and then calculates the remaining damage value P; During the operation of the turbocharger, the temperature sensor continuously collects temperature data T and shaft speed according to the program settings, and transmits the data to the vehicle system to calculate the remaining damage value P; once the remaining damage value P is less than 10%, the vehicle system prompts an alarm for maintenance or replacement; S40: The vehicle-mounted system updates the cycle data of the current working state to the stored cycle data.

2. The method for calculating the life of a turbocharger impeller by introducing temperature factors according to claim 1, characterized in that: Step S30 includes the following specific methods: Obtain temperature data T1, T2, ..., Tn, and the shaft speed at the corresponding temperature; The vehicle-mounted system retrieves the impeller stress and material data life curves at these temperatures, and obtains the stress / strain data of the impeller at different shaft speeds, and obtains the corresponding cycle numbers L1, L2, ..., Ln in the life curve of the corresponding temperature according to the stress / strain data. Obtain the impeller cycle data N1, N2, ..., Nn at these temperatures and speeds respectively, Miner damage theory is used to calculate the damage of the corresponding cycles under these temperature conditions: D1=N1 / L1, D2=N2 / L2, ……， Dn=Nn / Ln, Then find the remaining damage value P=1-(D1+D2+…Dn); When P is less than 10%, the vehicle system will prompt an alarm for maintenance or replacement.

3. The method for calculating the life of a turbocharger impeller by introducing temperature factors according to claim 2, characterized in that: The temperature data obtained by the temperature sensor has an interval of 15℃~20℃.

4. The method for calculating the life of a turbocharger impeller by introducing temperature factors according to claim 3, characterized in that: The temperature sensor is used to detect the temperature of the turbine impeller.

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