A method, device, detection equipment and medium for detecting expansion joint compensation amount

Abstract

The embodiment of the present invention discloses a method, device, detection equipment and medium for detecting the compensation amount of an expansion joint. The method includes obtaining engine performance parameters, inputting them into a pre-built one-dimensional thermodynamic model, and outputting a one-dimensional thermodynamic boundary condition; determining the average convection heat transfer coefficient on the gas side and the average temperature of the gas side near the wall of the engine exhaust pipe according to the one-dimensional thermodynamic boundary condition, and inputting them into a pre-built heat transfer calculation finite element model, and outputting the temperature field of the engine exhaust pipe; inputting the temperature field of the engine exhaust pipe into a pre-built strength calculation finite element model, and outputting the axial and radial relative deformation between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe; based on the axial and radial relative deformation between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe, detecting whether the compensation amount of the expansion joint currently assembled in the engine exhaust pipe meets the required conditions of the expansion joint compensation amount. In order to accurately detect whether the expansion joint compensation amount meets the requirements.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of expansion joint compensation amount detection, and in particular, to a detection method, device, detection equipment and medium for the compensation amount of an expansion joint. Background Art

[0002] The exhaust system of an automobile is an important assembly for emission and noise reduction. It mainly consists of an exhaust pipe, a catalytic converter, a muffler, a tail pipe, etc. The exhaust pipe is an important component of the engine. It is connected to the engine cylinder head and collects the exhaust gas of each cylinder and guides it into the exhaust manifold, with a branched pipeline. The exhaust pipe is subjected to the action of high-temperature exhaust gas and is mainly cooled by air. The temperature of the pipe body is very high and it is easy to generate large thermal deformation. The expansion joint is connected to the end face of the segmented exhaust pipe and has the ability to compensate for axial and radial thermal deformation. When the exhaust pipe is in a high-temperature working state, the thermal deformation is large. If the compensation amount of the expansion joint between the segmented exhaust pipes is less than the thermal deformation amount of the exhaust pipe, the expansion joint is likely to be pulled off, leaking high-temperature gas and causing a failure. Summary of the Invention

[0003] The embodiments of the present invention provide a detection method, device, detection equipment and medium for the compensation amount of an expansion joint, so as to realize the detection of the relative deformation amount between the flange surfaces of the segmented exhaust pipe in the axial and radial directions, and accurately detect whether the compensation amount of the expansion joint meets the requirements.

[0004] In a first aspect, the embodiments of the present invention provide a detection method for the compensation amount of an expansion joint. The detection method for the compensation amount of an expansion joint includes:

[0005] Obtain engine performance parameters and input the engine performance parameters into a pre-established one-dimensional thermodynamic model to output one-dimensional thermodynamic boundary conditions;

[0006] Determine the average convective heat transfer coefficient on the gas side and the average temperature near the gas-side wall surface of the engine exhaust pipe according to the one-dimensional thermodynamic boundary conditions, and input the average convective heat transfer coefficient on the gas side and the average temperature near the gas-side wall surface into a pre-established finite element model for heat transfer calculation to output the temperature field of the engine exhaust pipe;

[0007] Input the temperature field of the engine exhaust pipe into a pre-established finite element model for strength calculation to output the relative deformation amount in the axial and radial directions between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe;

[0008] Based on the relative deformation amount in the axial and radial directions between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe, detect whether the compensation amount of the expansion joint currently assembled in the engine exhaust pipe meets the requirements for the compensation amount of the expansion joint.

[0009] Further, the engine performance parameters include the exhaust gas temperature in front of the turbine of the engine exhaust pipe, engine speed, engine torque, intake pressure, and intake air volume;

[0010] The one-dimensional thermodynamic boundary conditions include the exhaust gas temperature, exhaust gas pressure, and exhaust gas mass flow rate at the inlet of the cylinder head exhaust port corresponding to each crankshaft angle in the engine, as well as the exhaust gas temperature, exhaust gas pressure, and exhaust gas mass flow rate in front of the turbine.

[0011] Further, determining the average convective heat transfer coefficient on the gas side and the average temperature near the wall surface on the gas side of the engine exhaust pipe according to the one-dimensional thermodynamic boundary conditions includes:

[0012] Inputting the one-dimensional thermodynamic boundary conditions into a pre-established three-dimensional thermodynamic model to output the average convective heat transfer coefficient on the gas side and the average temperature near the wall surface on the gas side of the engine exhaust pipe.

[0013] Further, before inputting the temperature field of the engine exhaust pipe into a pre-established finite element model for strength calculation and outputting the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe, it further includes:

[0014] By setting an elastic device on the flange surface of the expansion joint currently assembled on the engine exhaust pipe, the axial stiffness of the currently assembled expansion joint is obtained.

[0015] Further, the axial and radial relative deformation amounts between the flange surfaces include the axial relative deformation amount between the flange surfaces, the first radial relative deformation amount, and the second radial relative deformation amount;

[0016] Inputting the temperature field of the engine exhaust pipe into a pre-established finite element model for strength calculation and outputting the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe includes:

[0017] Inputting the temperature field of the engine exhaust pipe and the axial stiffness of the currently assembled expansion joint into a pre-established finite element model for strength calculation to output the axial relative deformation amount, the first radial relative deformation amount, and the second radial relative deformation amount between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe.

[0018] Further, detecting whether the compensation amount of the expansion joint currently assembled on the engine exhaust pipe meets the expansion joint compensation amount requirement conditions based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe includes:

[0019] If the axial relative deformation amount is less than or equal to the axial compensation amount of the currently assembled expansion joint, and the first radial relative deformation amount is less than or equal to the radial compensation amount of the currently assembled expansion joint, and the second radial relative deformation amount is less than or equal to the radial compensation amount of the currently assembled expansion joint, it is considered that the compensation amount of the expansion joint currently assembled in the engine exhaust pipe meets the requirements of the expansion joint compensation amount;

[0020] If the axial relative deformation amount is greater than the axial compensation amount of the currently assembled expansion joint, or the first radial relative deformation amount is greater than the radial compensation amount of the currently assembled expansion joint, or the second radial relative deformation amount is greater than the radial compensation amount of the currently assembled expansion joint, it is considered that the compensation amount of the expansion joint currently assembled in the engine exhaust pipe does not meet the requirements of the expansion joint compensation amount.

[0021] Further, the detection method of the expansion joint compensation amount further includes:

[0022] If the compensation amount of the expansion joint currently assembled in the engine exhaust pipe does not meet the requirements of the expansion joint compensation amount, a warning signal for replacing the expansion joint is generated, and the warning signal for replacing the expansion joint is used to prompt the replacement of the expansion joint.

[0023] In a second aspect, an embodiment of the present invention further provides a detection device for the expansion joint compensation amount. The detection device for the expansion joint compensation amount includes:

[0024] A one-dimensional thermodynamic boundary condition output module, configured to obtain engine performance parameters, input the engine performance parameters into a pre-established one-dimensional thermodynamic model, and output one-dimensional thermodynamic boundary conditions;

[0025] A temperature field output module, configured to determine the average convective heat transfer coefficient on the gas side and the average temperature near the wall surface on the gas side of the engine exhaust pipe according to the one-dimensional thermodynamic boundary conditions, and input the average convective heat transfer coefficient on the gas side and the average temperature near the wall surface on the gas side into a pre-established finite element model for heat transfer calculation, and output the temperature field of the engine exhaust pipe;

[0026] A relative deformation amount output module, configured to input the temperature field of the engine exhaust pipe into a pre-established finite element model for strength calculation, and output the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe;

[0027] An expansion joint compensation amount detection module, configured to detect whether the compensation amount of the expansion joint currently assembled in the engine exhaust pipe meets the requirements of the expansion joint compensation amount based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe.

[0028] In a third aspect, an embodiment of the present invention further provides a detection device for the expansion joint compensation amount. The detection device for the expansion joint compensation amount includes:

[0029] One or more processors;

[0030] A storage device for storing a plurality of programs,

[0031] When at least one of the plurality of programs is executed by the one or more processors, the one or more processors implement a method for detecting the compensation amount of an expansion joint provided in the first aspect embodiment of the present invention.

[0032] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements a method for detecting the compensation amount of an expansion joint provided in the first aspect embodiment of the present invention.

[0033] The technical solution of the embodiment of the present invention is to obtain engine performance parameters, input the engine performance parameters into a pre-built one-dimensional thermodynamic model, and output one-dimensional thermodynamic boundary conditions; determine the average convective heat transfer coefficient on the gas side and the average temperature near the wall surface on the gas side of the engine exhaust pipe according to the one-dimensional thermodynamic boundary conditions, and input the average convective heat transfer coefficient on the gas side and the average temperature near the wall surface on the gas side into a pre-built finite element model for heat transfer calculation, and output the temperature field of the engine exhaust pipe; input the temperature field of the engine exhaust pipe into a pre-built finite element model for strength calculation, and output the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe; based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe, detect whether the compensation amount of the expansion joint currently assembled in the engine exhaust pipe meets the requirements of the expansion joint compensation amount. This solves the problem that the current exhaust pipe has large thermal deformation under high-temperature working conditions. If the compensation amount of the expansion joint between the segmented exhaust pipes is less than the thermal deformation amount of the exhaust pipe, it will cause the expansion joint to be easily broken and high-temperature gas to leak, resulting in failures, so as to realize the detection of the axial and radial relative deformation amounts between the flange surfaces of the segmented exhaust pipes, and accurately detect whether the expansion joint compensation amount meets the requirements. Description of the Drawings

[0034] Figure 1 It is a schematic structural connection diagram of a segmented exhaust pipe and an expansion joint;

[0035] Figure 2 It is a flowchart of a method for detecting the compensation amount of an expansion joint provided in Embodiment 1 of the present invention;

[0036] Figure 3 It is a flowchart of a method for detecting the compensation amount of an expansion joint provided in Embodiment 2 of the present invention;

[0037] Figure 4It is a structural diagram of a detection device for the compensation amount of an expansion joint provided in Embodiment 3 of the present invention;

[0038] Figure 5 It is a schematic diagram of the hardware structure of a detection device for the compensation amount of an expansion joint provided in Embodiment 4 of the present invention. Detailed implementation manners

[0039] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention.

[0040] In addition, it should also be noted that, for the sake of convenience of description, only parts related to the present invention are shown in the drawings rather than all the content. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations (or steps) as sequential processes, many of the operations can be implemented in parallel, concurrently or simultaneously. In addition, the order of the operations can be rearranged. When the operations are completed, the process can be terminated, but there can also be additional steps not included in the drawings. The process can correspond to a method, a function, a procedure, a subroutine, a subprogram, etc.

[0041] Taking a six-cylinder engine as an example, Figure 1 It is a schematic structural connection diagram of a segmented exhaust pipe and an expansion joint. Refer to Figure 1 , the expansion joint is connected to the end face of the segmented exhaust pipe and has the ability to compensate for the thermal deformation in the axial and radial directions of the segmented exhaust pipe. The exhaust pipe has a large thermal deformation under high-temperature working conditions. If the compensation amount of the expansion joint between the segmented exhaust pipes is less than the thermal deformation amount of the exhaust pipe, the expansion joint is likely to be pulled off, leaking high-temperature gas and causing a failure. Based on the above problems, the embodiments of the present invention propose a detection method, device, detection equipment and medium for the compensation amount of the expansion joint to solve the problems.

[0042] Embodiment 1

[0043] Figure 2 It is a flowchart of a detection method for the compensation amount of an expansion joint provided in Embodiment 1 of the present invention. This embodiment is applicable to the situation of adaptively detecting the compensation amount of the expansion joint pre-assembled on the segmented exhaust pipe. The detection method for the compensation amount of the expansion joint can be executed by a detection device for the compensation amount of the expansion joint, and the detection device for the compensation amount of the expansion joint can be implemented in the form of software and / or hardware. The detection method for the compensation amount of the expansion joint specifically includes the following steps:

[0044] S110. Obtain the engine performance parameters, input the engine performance parameters into a pre-established one-dimensional thermodynamic model, and output the one-dimensional thermodynamic boundary conditions.

[0045] Among them, the engine performance parameters include parameters related to engine performance such as the exhaust gas temperature in front of the turbine of the engine exhaust pipe, engine speed, engine torque, intake pressure, and intake air volume. This embodiment cannot list them all here. The engine performance parameters can be selected and set according to the actual working state of the engine.

[0046] The pre-established one-dimensional thermodynamic model can be a one-dimensional thermodynamic model established by first building the physical models of each system module of the engine, and then assigning parameters to the physical models of each module. After that, the actual cycle working process of each module can be mathematically described using differential equations, that is, data such as unsteady flow inside the engine and combustion and heat transfer inside the cylinder can be obtained through numerical calculations. Furthermore, the performance of the engine and the variation laws of each module parameter with the crankshaft angle or time can be obtained.

[0047] On this basis, the one-dimensional thermodynamic model can better reflect the working characteristics of the engine after being corrected by engine performance parameters such as the actual cycle intake air volume, engine speed, engine torque, intake pressure, and intake air volume of the engine.

[0048] Specifically, according to parameters related to engine performance such as the exhaust gas temperature in front of the turbine of the engine exhaust pipe, engine speed, engine torque, intake pressure, and intake air volume, input them into the one-dimensional thermodynamic model built by performance simulation, and output the one-dimensional thermodynamic boundary conditions.

[0049] Among them, the one-dimensional thermodynamic boundary conditions include the exhaust gas temperature, exhaust gas pressure, and exhaust gas mass flow rate at the inlet of the cylinder head exhaust port corresponding to each crankshaft angle in the engine, and the exhaust gas temperature, exhaust gas pressure, and exhaust gas mass flow rate in front of the turbine.

[0050] It should be noted that the one-dimensional thermodynamic boundary conditions obtain the exhaust gas temperature, exhaust gas pressure, exhaust gas mass flow rate at the inlet of the cylinder head exhaust port corresponding to each crankshaft angle in one working cycle (0 - 720° crankshaft angle) of the engine, and the exhaust gas temperature, exhaust gas pressure, and exhaust gas mass flow rate in front of the turbine.

[0051] S120. Determine the average convective heat transfer coefficient on the gas side and the average temperature near the gas side wall of the engine exhaust pipe according to the one-dimensional thermodynamic boundary conditions, and input the average convective heat transfer coefficient on the gas side and the average temperature near the gas side wall into a pre-established finite element model for heat transfer calculation, and output the temperature field of the engine exhaust pipe.

[0052] Based on the above embodiments, determining the average convective heat transfer coefficient on the gas side and the average temperature near the gas-side wall surface of the engine exhaust pipe according to the one-dimensional thermodynamic boundary conditions includes: inputting the one-dimensional thermodynamic boundary conditions into a pre-established three-dimensional thermodynamic model, and outputting the average convective heat transfer coefficient on the gas side and the average temperature near the gas-side wall surface of the engine exhaust pipe.

[0053] Among them, the three-dimensional thermodynamic model is a computational fluid dynamics model. First, a geometric entity model can be established, and on this basis, pre-processing work is carried out. Secondly, the geometric entity model is divided into qualified meshes that can meet the calculation requirements, so as to obtain the three-dimensional thermodynamic model.

[0054] The finite element model for heat transfer calculation can solve the influence of the temperature field on physical quantities such as temperature in the structure. Its basic principles involve heat analysis, thermal contact theory, and finite element analysis theory, etc. At present, the establishment of the finite element model for heat transfer calculation can be realized by using existing analysis software, and the results obtained by the existing analysis software have high accuracy. This embodiment will not be elaborated here.

[0055] Specifically, in this embodiment, the exhaust temperature, exhaust pressure, exhaust mass flow rate at the inlet of the cylinder head exhaust port corresponding to each crankshaft angle in one working cycle (0 - 720° crankshaft angle) of the engine obtained from the one-dimensional thermodynamic boundary conditions, and the exhaust temperature, exhaust pressure, and exhaust mass flow rate in front of the turbine are input into the pre-established three-dimensional thermodynamic model, and the average convective heat transfer coefficient on the gas side and the average temperature near the gas-side wall surface of the engine exhaust pipe are output. The average convective heat transfer coefficient on the gas side and the average temperature near the gas-side wall surface are input into the pre-established finite element model for heat transfer calculation, and the temperature field of the engine exhaust pipe is output.

[0056] S130: Input the temperature field of the engine exhaust pipe into the pre-established finite element model for strength calculation, and output the axial and radial relative deformation amounts between the flange surfaces of the expansion joints currently assembled on the engine exhaust pipe.

[0057] Among them, the finite element model for strength calculation can solve the influence of the temperature field on physical quantities such as stiffness in the structure. Its basic principles involve heat analysis, thermal contact theory, and finite element analysis theory, etc. At present, the establishment of the finite element model for strength calculation can be realized by using existing analysis software, and the results obtained by the existing analysis software have high accuracy. This embodiment will not be elaborated here.

[0058] On the basis of the above embodiments, before inputting the engine exhaust pipe temperature field into a pre-established finite element model for strength calculation and outputting the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe, the following steps are further included: obtaining the axial stiffness of the currently assembled expansion joint by setting an elastic force device on the flange surface of the expansion joint currently assembled on the engine exhaust pipe.

[0059] Among them, the elastic force device can be a spring or other components with elastic properties, and this embodiment does not impose any restrictions on this. The elastic force device is used to simulate the axial stiffness of the currently assembled expansion joint, that is, to simulate the axial stiffness of the pre-assembled expansion joint.

[0060] Specifically, on the above basis, by setting a spring on the flange surface of the expansion joint currently assembled on the engine exhaust pipe, the axial stiffness of the currently assembled expansion joint is obtained, and the axial stiffness of the currently assembled expansion joint and the engine exhaust pipe temperature field are input into a pre-established finite element model for strength calculation to obtain the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe.

[0061] Further, on the basis of the above embodiments, the axial and radial relative deformation amounts between the flange surfaces include the axial relative deformation amount between the flange surfaces, the first radial relative deformation amount, and the second radial relative deformation amount; specifically, inputting the engine exhaust pipe temperature field into a pre-established finite element model for strength calculation and outputting the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe includes: inputting the engine exhaust pipe temperature field and the axial stiffness of the currently assembled expansion joint into a pre-established finite element model for strength calculation and outputting the axial relative deformation amount, the first radial relative deformation amount, and the second radial relative deformation amount between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe.

[0062] Among them, the axial relative deformation amount is the axial relative deformation amount between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe, that is, the relative deformation amount in the X direction of the expansion joint currently assembled on the engine exhaust pipe, the first radial relative deformation amount is the radial relative deformation amount between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe, that is, the relative deformation amount in the Y direction of the expansion joint, and the second radial relative deformation amount is the radial relative deformation amount between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe, that is, the relative deformation amount in the Z direction of the expansion joint.

[0063] S140. Detect whether the compensation amount of the expansion joint currently assembled on the engine exhaust pipe meets the requirements of the expansion joint compensation amount based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe.

[0064] On the basis of the above embodiments, it is detected whether the compensation amount of the expansion joint currently assembled on the engine exhaust pipe meets the requirements of the expansion joint compensation amount based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe, including:

[0065] If the axial relative deformation amount is less than or equal to the axial compensation amount of the currently assembled expansion joint, and the first radial relative deformation amount is less than or equal to the radial compensation amount of the currently assembled expansion joint, and the second radial relative deformation amount is less than or equal to the radial compensation amount of the currently assembled expansion joint, it is considered that the compensation amount of the expansion joint currently assembled on the engine exhaust pipe meets the requirements of the expansion joint compensation amount;

[0066] If the axial relative deformation amount is greater than the axial compensation amount of the currently assembled expansion joint, or the first radial relative deformation amount is greater than the radial compensation amount of the currently assembled expansion joint, or the second radial relative deformation amount is greater than the radial compensation amount of the currently assembled expansion joint, it is considered that the compensation amount of the expansion joint currently assembled on the engine exhaust pipe does not meet the requirements of the expansion joint compensation amount.

[0067] It can be understood that when any one of the three conditions that the axial relative deformation amount is less than or equal to the axial compensation amount of the currently assembled expansion joint, the first radial relative deformation amount is less than or equal to the radial compensation amount of the currently assembled expansion joint, and the second radial relative deformation amount is less than or equal to the radial compensation amount of the currently assembled expansion joint is not satisfied, it can be considered that the compensation amount of the expansion joint currently assembled on the engine exhaust pipe does not meet the requirements of the expansion joint compensation amount. At this time, an expansion joint with a larger compensation amount needs to be replaced.

[0068] Further, on the basis of the above embodiments, the method for detecting the expansion joint compensation amount further includes: if the compensation amount of the expansion joint currently assembled on the engine exhaust pipe does not meet the requirements of the expansion joint compensation amount, a warning signal for replacing the expansion joint is generated, and the warning signal for replacing the expansion joint is used to prompt the replacement of the expansion joint.

[0069] It can be understood that the warning signal for replacing the expansion joint can be sent to those skilled in the art, and those skilled in the art can accurately know whether the compensation amount of the currently assembled expansion joint is appropriate according to the warning signal for replacing the expansion joint.

[0070] Further, the warning signal for replacing the expansion joint can be fed back in the form of sound and light warning or an interface pop-up box, etc., and this embodiment does not make any restrictions on this. At the same time, the result of detecting whether the requirements of the expansion joint compensation amount are met can be displayed and stored in a preset storage space.

[0071] The technical solution of the embodiment of the present invention obtains engine performance parameters, inputs the engine performance parameters into a pre-established one-dimensional thermodynamic model, and outputs one-dimensional thermodynamic boundary conditions; determines the average convective heat transfer coefficient on the gas side and the average temperature near the wall surface on the gas side of the engine exhaust pipe according to the one-dimensional thermodynamic boundary conditions, and inputs the average convective heat transfer coefficient on the gas side and the average temperature near the wall surface on the gas side into a pre-established finite element model for heat transfer calculation, and outputs the temperature field of the engine exhaust pipe; inputs the temperature field of the engine exhaust pipe into a pre-established finite element model for strength calculation, and outputs the axial and radial relative deformation amounts between the flange surfaces of the expansion joints currently assembled on the engine exhaust pipe; detects whether the compensation amount of the expansion joints currently assembled on the engine exhaust pipe meets the requirements of the expansion joint compensation amount based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joints currently assembled on the engine exhaust pipe. It solves the problem that the current exhaust pipe has large thermal deformation under high-temperature working conditions. If the compensation amount of the expansion joint between the segmented exhaust pipes is less than the thermal deformation amount of the exhaust pipe, it will easily lead to the breakage of the expansion joint and the leakage of high-temperature gas, so as to realize the detection of the axial and radial relative deformation amounts between the flange surfaces of the segmented exhaust pipes and accurately detect whether the expansion joint compensation amount meets the requirements.

[0072] Embodiment 2

[0073] Figure 3 It is a flowchart of a method for detecting the compensation amount of an expansion joint provided by Embodiment 2 of the present invention. This embodiment is optimized based on the above embodiment.

[0074] Correspondingly, the method of this embodiment specifically includes:

[0075] S210. Obtain engine performance parameters, and input the engine performance parameters into a pre-established one-dimensional thermodynamic model, and output one-dimensional thermodynamic boundary conditions.

[0076] Among them, the engine performance parameters include the exhaust temperature before the turbine of the engine exhaust pipe, the engine speed, the engine torque, the intake pressure, and the intake air volume;

[0077] The one-dimensional thermodynamic boundary conditions include the exhaust temperature, exhaust pressure, and exhaust mass flow rate at the inlet of the cylinder head exhaust port corresponding to each crankshaft angle in the engine, and the exhaust temperature, exhaust pressure, and exhaust mass flow rate before the turbine.

[0078] Specifically, according to the data collected from the engine test, that is, the engine performance parameters, input them into a pre-established one-dimensional thermodynamic model, and output the exhaust temperature, exhaust pressure, exhaust mass flow rate at the inlet of the cylinder head exhaust port corresponding to each crankshaft angle in one working cycle (0 - 720° crankshaft angle) of the engine, and the exhaust temperature, exhaust pressure, and exhaust mass flow rate before the turbine.

[0079] S220. Input the one-dimensional thermodynamic boundary condition into a pre-established three-dimensional thermodynamic model, and output the average convective heat transfer coefficient on the gas side and the average temperature near the wall on the gas side of the engine exhaust pipe.

[0080] S230. Input the average convective heat transfer coefficient on the gas side and the average temperature near the wall on the gas side into a pre-established finite element model for heat transfer calculation, and output the temperature field of the engine exhaust pipe.

[0081] S240. Obtain the axial stiffness of the currently assembled expansion joint by setting an elastic device on the flange surface of the expansion joint currently assembled on the engine exhaust pipe.

[0082] S250. Input the temperature field of the engine exhaust pipe and the axial stiffness of the currently assembled expansion joint into a pre-established finite element model for strength calculation, and output the axial relative deformation amount, the first radial relative deformation amount, and the second radial relative deformation amount between the flange surfaces of the currently assembled expansion joint of the engine exhaust pipe.

[0083] Exemplarily, a finite element model for strength calculation is built in structural simulation. An elastic device (such as a spring) is set between the flange surfaces of the segmented exhaust pipe to simulate the axial stiffness of the pre-assembled expansion joint, and the temperature field of the engine exhaust pipe obtained above is input to obtain the axial relative deformation amount (X direction) and the radial relative deformation amounts (Y direction and Z direction) between the flange surfaces of the segmented exhaust pipe, denoted as the axial relative deformation amount U1, the first radial relative deformation amount U2, and the second radial relative deformation amount U3.

[0084] S260. Determine whether the axial relative deformation amount is less than or equal to the axial compensation amount of the currently assembled expansion joint, and the first radial relative deformation amount is less than or equal to the radial compensation amount of the currently assembled expansion joint, and the second radial relative deformation amount is less than or equal to the radial compensation amount of the currently assembled expansion joint. If so, execute step S270; if not, execute step S280.

[0085] Exemplarily, compare the axial relative deformation amount U1, the first radial relative deformation amount U2, and the second radial relative deformation amount U3 between the flange surfaces of the segmented exhaust pipe with the axial compensation amount U1constant of the currently assembled expansion joint and the radial compensation amount U23constant of the currently assembled expansion joint. The axial relative deformation amount U1 ≤ the axial compensation amount U1constant of the currently assembled expansion joint, and the first radial relative deformation amount U2 ≤ the radial compensation amount U23constant of the currently assembled expansion joint, and the second radial relative deformation amount U3 ≤ the radial compensation amount U23constant of the currently assembled expansion joint. According to the above three conditions, it can be detected whether the compensation amount of the currently assembled expansion joint (i.e., the pre-assembled expansion joint) meets the requirements.

[0086] S270. It is considered that the compensation amount of the expansion joint currently assembled in the engine exhaust pipe meets the requirements for the compensation amount of the expansion joint.

[0087] S280. It is considered that the compensation amount of the expansion joint currently assembled in the engine exhaust pipe does not meet the requirements for the compensation amount of the expansion joint, and step S290 is executed.

[0088] S290. Generate a warning signal for replacing the expansion joint, and the warning signal for replacing the expansion joint is used to prompt the replacement of the expansion joint.

[0089] In the technical solution of the embodiment of the present invention, by comparing the relative deformation amounts in the axial and radial directions between the flange surfaces of the segmented exhaust pipe and the compensation amounts of the pre-assembled expansion joint of the segmented exhaust pipe in the axial and radial directions, it can be accurately detected whether the compensation amount of the pre-assembled expansion joint meets the requirements. Based on the engine test data, taking this relative deformation amount as the input for the simulation calculation of detecting the compensation amount of the expansion joint, it ensures the reliability of the simulation calculation result, has high calculation accuracy, and can accurately detect whether the compensation amount of the pre-assembled expansion joint meets the requirements.

[0090] Embodiment III

[0091] Figure 4 It is a structural diagram of a detection device for the compensation amount of an expansion joint provided in Embodiment III of the present invention. This embodiment is applicable to the situation of adaptively detecting the compensation amount of the expansion joint pre-assembled in the segmented exhaust pipe.

[0092] As Figure 4 shown, the detection device for the compensation amount of the expansion joint includes: a one-dimensional thermodynamic boundary condition output module 310, a temperature field output module 320, a relative deformation amount output module 330, and an expansion joint compensation amount detection module 340, where:

[0093] The one-dimensional thermodynamic boundary condition output module 310 is configured to obtain engine performance parameters, input the engine performance parameters into a pre-established one-dimensional thermodynamic model, and output one-dimensional thermodynamic boundary conditions;

[0094] The temperature field output module 320 is configured to determine the average convective heat transfer coefficient on the gas side and the average temperature of the near-wall surface on the gas side of the engine exhaust pipe according to the one-dimensional thermodynamic boundary conditions, and input the average convective heat transfer coefficient on the gas side and the average temperature of the near-wall surface on the gas side into a pre-established finite element model for heat transfer calculation, and output the temperature field of the engine exhaust pipe;

[0095] The relative deformation amount output module 330 is configured to input the temperature field of the engine exhaust pipe into a pre-established finite element model for strength calculation, and output the relative deformation amounts in the axial and radial directions between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe;

[0096] The expansion joint compensation amount detection module 340 is configured to detect whether the compensation amount of the expansion joint currently assembled in the engine exhaust pipe meets the requirements of the expansion joint compensation amount based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe.

[0097] The detection device for the expansion joint compensation amount in this embodiment obtains engine performance parameters, inputs the engine performance parameters into a pre-established one-dimensional thermodynamics model, and outputs one-dimensional thermodynamics boundary conditions; determines the average convective heat transfer coefficient on the gas side and the average temperature of the near-wall surface on the gas side of the engine exhaust pipe according to the one-dimensional thermodynamics boundary conditions, and inputs the average convective heat transfer coefficient on the gas side and the average temperature of the near-wall surface on the gas side into a pre-established finite element model for heat transfer calculation to output the temperature field of the engine exhaust pipe; inputs the temperature field of the engine exhaust pipe into a pre-established finite element model for strength calculation to output the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe; and detects whether the compensation amount of the expansion joint currently assembled in the engine exhaust pipe meets the requirements of the expansion joint compensation amount based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe. This solves the problem that the current exhaust pipe has large thermal deformation under high-temperature working conditions. If the compensation amount of the expansion joint between the segmented exhaust pipes is less than the thermal deformation amount of the exhaust pipe, it will easily cause the expansion joint to break and leak high-temperature gas, resulting in failures, so as to realize the detection of the axial and radial relative deformation amounts between the flange surfaces of the segmented exhaust pipes and accurately detect whether the compensation amount of the expansion joint meets the requirements.

[0098] Based on the above embodiments, the engine performance parameters include the exhaust gas temperature in front of the turbine of the engine exhaust pipe, the engine speed, the engine torque, the intake pressure, and the intake air volume;

[0099] The one-dimensional thermodynamics boundary conditions include the exhaust gas temperature, exhaust gas pressure, and exhaust gas mass flow rate at the inlet of the cylinder head exhaust port corresponding to each crankshaft angle in the engine, and the exhaust gas temperature, exhaust gas pressure, and exhaust gas mass flow rate in front of the turbine.

[0100] Based on the above embodiments, determining the average convective heat transfer coefficient on the gas side and the average temperature of the near-wall surface on the gas side of the engine exhaust pipe according to the one-dimensional thermodynamics boundary conditions includes:

[0101] Inputting the one-dimensional thermodynamics boundary conditions into a pre-established three-dimensional thermodynamics model to output the average convective heat transfer coefficient on the gas side and the average temperature of the near-wall surface on the gas side of the engine exhaust pipe.

[0102] Based on the above embodiments, before inputting the engine exhaust pipe temperature field into the pre-established finite element model for strength calculation and outputting the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe, the following steps are further included:

[0103] By setting an elastic device on the flange surface of the expansion joint currently assembled on the engine exhaust pipe, the axial stiffness of the currently assembled expansion joint is obtained.

[0104] Based on the above embodiments, the axial and radial relative deformation amounts between the flange surfaces include the axial relative deformation amount between the flange surfaces, the first radial relative deformation amount, and the second radial relative deformation amount;

[0105] Inputting the engine exhaust pipe temperature field into the pre-established finite element model for strength calculation and outputting the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe includes:

[0106] Inputting the engine exhaust pipe temperature field and the axial stiffness of the currently assembled expansion joint into the pre-established finite element model for strength calculation, and outputting the axial relative deformation amount, the first radial relative deformation amount, and the second radial relative deformation amount between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe.

[0107] Based on the above embodiments, detecting whether the compensation amount of the expansion joint currently assembled on the engine exhaust pipe meets the requirements of the expansion joint compensation amount based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe includes:

[0108] If the axial relative deformation amount is less than or equal to the axial compensation amount of the currently assembled expansion joint, and the first radial relative deformation amount is less than or equal to the radial compensation amount of the currently assembled expansion joint, and the second radial relative deformation amount is less than or equal to the radial compensation amount of the currently assembled expansion joint, it is considered that the compensation amount of the expansion joint currently assembled on the engine exhaust pipe meets the requirements of the expansion joint compensation amount;

[0109] If the axial relative deformation amount is greater than the axial compensation amount of the currently assembled expansion joint, or the first radial relative deformation amount is greater than the radial compensation amount of the currently assembled expansion joint, or the second radial relative deformation amount is greater than the radial compensation amount of the currently assembled expansion joint, it is considered that the compensation amount of the expansion joint currently assembled on the engine exhaust pipe does not meet the requirements of the expansion joint compensation amount.

[0110] Based on the above embodiments, the detection device for the expansion joint compensation amount further includes:

[0111] If the compensation amount of the expansion joint currently assembled in the engine exhaust pipe does not meet the requirements of the expansion joint compensation amount, a warning signal for replacing the expansion joint is generated, and the warning signal for replacing the expansion joint is used to prompt the replacement of the expansion joint.

[0112] The detection device for the expansion joint compensation amount provided in each of the above embodiments can execute the detection method for the expansion joint compensation amount provided in any embodiment of the present invention, and has corresponding functional modules and beneficial effects for executing the detection method for the expansion joint compensation amount.

[0113] Embodiment 4

[0114] Figure 5 is a schematic structural diagram of a detection device for the expansion joint compensation amount provided in Embodiment 4 of the present invention. As Figure 5 shown, the detection device for the expansion joint compensation amount includes a processor 410, a memory 420, an input device 430, and an output device 440; the number of processors 410 in the detection device for the expansion joint compensation amount can be one or more, Figure 5 and one processor 410 is taken as an example here; the processor 410, the memory 420, the input device 430, and the output device 440 in the detection device for the expansion joint compensation amount can be connected through a bus or other means, Figure 5 and taking the connection through the bus as an example here.

[0115] The memory 420, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as program instructions / modules corresponding to the detection method for the expansion joint compensation amount in the embodiments of the present invention (for example, the one-dimensional thermodynamic boundary condition output module 310, the temperature field output module 320, the relative deformation amount output module 330, and the expansion joint compensation amount detection module 340 in the detection device for the expansion joint compensation amount). The processor 410 executes various functional applications and data processing of the detection device for the expansion joint compensation amount by running the software programs, instructions, and modules stored in the memory 420, that is, implements the above detection method for the expansion joint compensation amount.

[0116] The memory 420 may mainly include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the terminal, etc. In addition, the memory 420 may include a high-speed random access memory, and may further include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some instances, the memory 420 may further include a memory remotely provided with respect to the processor 410, and these remote memories can be connected to the detection device for the expansion joint compensation amount through a network. Examples of the above network include, but are not limited to, the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0117] The input device 430 can be used to receive input digital or character information and generate key signal inputs related to user settings and function control of the detection device for the expansion joint compensation amount. The output device 440 can include display devices such as a display screen.

[0118] Embodiment Five

[0119] Embodiment Five of the present invention also provides a storage medium containing computer-executable instructions, and the computer-executable instructions are used to execute a method for detecting the expansion joint compensation amount when executed by a computer processor. The method for detecting the expansion joint compensation amount includes:

[0120] Obtain engine performance parameters, input the engine performance parameters into a pre-established one-dimensional thermodynamic model, and output one-dimensional thermodynamic boundary conditions;

[0121] Determine the average convective heat transfer coefficient on the gas side and the average temperature near the wall surface on the gas side of the engine exhaust pipe according to the one-dimensional thermodynamic boundary conditions, and input the average convective heat transfer coefficient on the gas side and the average temperature near the wall surface on the gas side into a pre-established finite element model for heat transfer calculation to output the temperature field of the engine exhaust pipe;

[0122] Input the temperature field of the engine exhaust pipe into a pre-established finite element model for strength calculation to output the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe;

[0123] Detect whether the compensation amount of the expansion joint currently assembled in the engine exhaust pipe meets the requirements of the expansion joint compensation amount based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe.

[0124] Of course, the computer-executable instructions of a storage medium provided by the embodiments of the present invention are not limited to the method operations as described above, and can also execute related operations in the method for detecting the expansion joint compensation amount provided by any embodiment of the present invention.

[0125] From the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software and necessary general hardware. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present invention, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk or optical disc of a computer, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0126] It should be noted that in the embodiments of the above detection device for the expansion joint compensation amount, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of mutual distinction and do not limit the protection scope of the present invention.

[0127] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for detecting the compensation amount of an expansion joint, characterized in that: include: Acquire engine performance parameters, input the engine performance parameters into a pre-built one-dimensional thermodynamic model, and output one-dimensional thermodynamic boundary conditions, wherein the one-dimensional thermodynamic boundary conditions include exhaust temperature, exhaust pressure, and exhaust mass flow rate at the inlet of the cylinder head exhaust passage corresponding to each crankshaft angle in the engine and exhaust temperature, exhaust pressure, and exhaust mass flow rate before the turbine; Determine the average convection heat transfer coefficient on the air side and the average temperature of the air side near the wall of the engine exhaust duct according to the one-dimensional thermodynamic boundary condition, input the average convection heat transfer coefficient on the air side and the average temperature of the air side near the wall into a pre-built finite element model for heat transfer calculation, and output the temperature field of the engine exhaust duct; By arranging an elastic device on the flange surface of the expansion joint currently assembled on the engine exhaust pipe, the axial stiffness of the currently assembled expansion joint is obtained; The temperature field of the engine exhaust pipe is input into a pre-built strength calculation finite element model, and the relative axial and radial deformations between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe are output; wherein the relative axial and radial deformations between the flange surfaces include the axial relative deformation between the flange surfaces, the first radial relative deformation, and the second radial relative deformation, the first radial relative deformation is the relative deformation of the expansion joint in the Y direction, and the second radial relative deformation is the relative deformation of the expansion joint in the Z direction; The method comprises: inputting the temperature field of the engine exhaust pipe into a pre-built strength calculation finite element model, and outputting the axial and radial relative deformations between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe, including: inputting the temperature field of the engine exhaust pipe and the axial stiffness of the currently assembled expansion joint into a pre-built strength calculation finite element model, and outputting the axial relative deformation, the first radial relative deformation, and the second radial relative deformation between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe; Based on the relative axial and radial deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe, it is detected whether the compensation amount of the expansion joint currently assembled on the engine exhaust pipe meets the expansion joint compensation amount requirement conditions.

2. The method for detecting the compensation amount of the expansion joint according to claim 1, characterized in that: The engine performance parameters include the pre-turbine exhaust temperature of the engine exhaust pipe, the engine speed, the engine torque, the intake pressure and the intake volume.

3. The method for detecting the compensation amount of the expansion joint according to claim 1, characterized in that: Determining the average air-side convection heat transfer coefficient and the average air-side near-wall temperature of the engine exhaust duct according to the one-dimensional thermodynamic boundary condition includes: The one-dimensional thermodynamic boundary conditions are input into a pre-built three-dimensional thermodynamic model, and the average convection heat transfer coefficient on the gas side and the average temperature near the gas side wall of the engine exhaust duct are output.

4. The method for detecting the compensation amount of an expansion joint according to claim 1, characterized in that: The method comprises: detecting whether the compensation amount of the expansion joint currently assembled on the engine exhaust pipe meets the required conditions of the expansion joint compensation amount based on the relative axial and radial deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe, including: If the axial relative deformation is less than or equal to the axial compensation of the currently assembled expansion joint, and the first radial relative deformation is less than or equal to the radial compensation of the currently assembled expansion joint, and the second radial relative deformation is less than or equal to the radial compensation of the currently assembled expansion joint, then it is considered that the compensation of the expansion joint currently assembled on the engine exhaust pipe meets the expansion joint compensation requirement; If the axial relative deformation is greater than the axial compensation of the currently assembled expansion joint, or the first radial relative deformation is greater than the radial compensation of the currently assembled expansion joint, or the second radial relative deformation is greater than the radial compensation of the currently assembled expansion joint, then it is considered that the compensation of the expansion joint currently assembled in the engine exhaust pipe does not meet the required conditions for the expansion joint compensation.

5. The method for detecting the compensation amount of the expansion joint according to claim 4, characterized in that: The method for detecting the expansion joint compensation amount also includes: If the compensation amount of the expansion joint currently assembled in the engine exhaust pipe does not meet the expansion joint compensation amount requirement, an expansion joint replacement warning signal is generated, and the expansion joint replacement warning signal is used to prompt the replacement of the expansion joint.

6. A device for detecting the compensation amount of an expansion joint, characterized in that: include: A one-dimensional thermodynamic boundary condition output module is used to obtain engine performance parameters, input the engine performance parameters into a pre-built one-dimensional thermodynamic model, and output one-dimensional thermodynamic boundary conditions, wherein the one-dimensional thermodynamic boundary conditions include the exhaust temperature, exhaust pressure, and exhaust mass flow rate at the inlet of the cylinder head exhaust passage corresponding to each crankshaft angle in the engine and the exhaust temperature, exhaust pressure, and exhaust mass flow rate before the vortex; A temperature field output module is used to determine the average convection heat transfer coefficient on the air side and the average temperature of the air side near the wall of the engine exhaust duct according to the one-dimensional thermodynamic boundary condition, and input the average convection heat transfer coefficient on the air side and the average temperature of the air side near the wall into a pre-built heat transfer calculation finite element model to output the temperature field of the engine exhaust duct; An axial stiffness determination module, configured to obtain the axial stiffness of the currently assembled expansion joint by setting an elastic device on the flange surface of the expansion joint currently assembled on the engine exhaust pipe; A relative deformation output module is used to input the temperature field of the engine exhaust pipe into a pre-built strength calculation finite element model, and output the axial and radial relative deformations between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe; wherein the axial and radial relative deformations between the flange surfaces include the axial relative deformation between the flange surfaces, the first radial relative deformation, and the second radial relative deformation, the first radial relative deformation is the relative deformation of the expansion joint in the Y direction, and the second radial relative deformation is the relative deformation of the expansion joint in the Z direction; The relative deformation output module is specifically used to: input the temperature field of the engine exhaust pipe and the axial stiffness of the currently assembled expansion joint into a pre-built strength calculation finite element model, and output the axial relative deformation, the first radial relative deformation, and the second radial relative deformation between the flange surfaces of the expansion joint currently assembled in the engine exhaust pipe; The expansion joint compensation amount detection module is used to detect whether the compensation amount of the expansion joint currently assembled on the engine exhaust pipe meets the expansion joint compensation amount requirement conditions based on the axial and radial relative deformation amounts between the flange surfaces of the expansion joint currently assembled on the engine exhaust pipe.

7. A device for detecting the compensation amount of an expansion joint, characterized in that: The detection device of the expansion joint compensation amount includes: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for detecting the compensation amount of the expansion joint as described in any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, a method for detecting the compensation amount of an expansion joint as described in any one of claims 1 to 5 is implemented.

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