Numerical simulation method for scroll compressor pipeline vibration

Abstract

The present invention relates to the field of compressor pipeline vibration, and specifically to a scroll compressor pipeline vibration numerical simulation calculation method, which can simulate the compressor pipeline vibration situation closer to reality, greatly shorten the simulation calculation cycle, and optimize the pipeline-related scheme. The scroll compressor pipeline vibration numerical simulation calculation method of the present invention includes: establishing a scroll compressor numerical simulation calculation model, the calculation model includes a scroll compressor body and an air supply pipeline; simplifying the calculation model, adding constraints, and performing vibration response simulation numerical calculation, the constraints include compressor mechanical excitation load and fluid pulsation excitation load. The present invention is suitable for the calculation of scroll compressor pipeline vibration numerical simulation.

Description

Technical Field

[0001] The invention relates to the field of compressor pipeline vibration, and in particular to a numerical simulation calculation method for scroll compressor pipeline vibration. Background Art

[0002] Scroll compressors are widely used in large central air-conditioning systems. Compared with rotary compressors, scroll compressors run smoothly, with less vibration and noise. In general, in order to achieve a larger compression ratio in a low-temperature environment, scroll compressors use jet enthalpy increase technology, open air supply holes on the scroll compressor scroll disk, add an intermediate pressure air supply circuit, increase the system refrigerant mass flow, and improve the compression efficiency and capacity of the scroll compressor. The excitation load of the scroll compressor is complex. During the movement of the scroll disk, the scroll disk is subjected to the gas force of the compression chamber to generate a circumferential force, and is also subjected to the centrifugal force and the vertical force in the vertical direction. For the air supply pipeline, in addition to the mechanical vibration load generated by the scroll compressor, it is also subjected to the periodic pressure pulsation generated by the jet of the scroll compressor. The operating frequency range of the scroll compressor is wide, and generally the higher the operating frequency, the greater the vibration. The piping system structure of the scroll compressor of a large central air conditioner is relatively complex. The four-way valve assembly includes connecting pipes such as the suction pipeline, the exhaust pipeline, and the air supply pipeline. The inherent frequency of the pipeline system is multi-frequency, which is easy to overlap with the excitation load frequency of the scroll compressor, forming resonance and fluid-solid coupling vibration. Pipeline vibration can cause fatigue fracture of pipelines, leading to system failure. Generally, enterprises test pipeline stress through vibration stress test, and evaluate whether the pipeline design scheme is feasible based on the pipeline vibration stress value. This evaluation method that relies solely on experimental testing has a long cycle, high cost, low efficiency, and cannot predict the quality of the scheme in advance during the conceptual design stage. Summary of the invention

[0003] The purpose of the present invention is to provide a scroll compressor pipeline vibration numerical simulation calculation method, which can simulate the compressor pipeline vibration condition more closely to the actual situation, greatly shorten the simulation calculation cycle, and at the same time can optimize the pipeline-related schemes.

[0004] The present invention adopts the following technical scheme to achieve the above-mentioned purpose, and the numerical simulation calculation method of the vibration of the scroll compressor pipeline includes:

[0005] Establishing a numerical simulation calculation model of a scroll compressor, the calculation model includes a scroll compressor body and an air supply pipeline;

[0006] The calculation model is simplified, constraints are added, and vibration response simulation numerical calculation is performed, wherein the constraints include the compressor mechanical excitation load and the fluid pulsation excitation load.

[0007] Furthermore, in order to improve the accuracy of mechanical excitation load calculation, the specific method for determining the compressor mechanical excitation load includes:

[0008] Compressor mechanical excitation load F = [M Z D X D Y D Z ],M Z is the vertical moment load of the compressor body, D X is the displacement load of the compressor body in the X direction, D Y is the displacement load of the compressor body in the Y direction, D Z is the displacement load of the compressor body in the Z direction.

[0009] The relationship between displacement load and compressor operating frequency is:

[0010] D X =K X ×f,D Y =K Y ×f,D Z =K Z ×f, where K X , K Y , K Z is a constant, f is the operating frequency of the compressor, and the phase difference between the displacement loads in the three directions is n degrees, where n ≥ 90 degrees.

[0011] Furthermore, in order to improve the accuracy of the calculation of the fluid pulsation excitation load, the specific method for determining the fluid pulsation excitation load includes:

[0012] The pressure pulsation test is used to directly test the pressure pulsation data of the fluid inside the air supply pipeline, and the fluid pulsation excitation load P is fitted by the formula, P=A sin(wt+φ), A is the pressure pulsation load amplitude, and φ is the phase.

[0013] The specific methods of fluid pulsation excitation load loading include:

[0014] A fluid pulsation excitation load P is applied to the surface of the air supply pipeline. The load action direction is the fluid flow direction, and the loading position is each bend of the air supply pipeline.

[0015] Furthermore, the specific method for optimizing the compressor mechanical excitation load F includes:

[0016] The mechanical excitation load F of the compressor is optimized through experimental test data and simulation data. The experimental test data selects any one of the measurement values ​​of vibration acceleration, vibration displacement, vibration velocity, vibration stress and vibration strain. The measurement points include at least two points of the compressor perpendicular to each other in the circumferential direction, and the remaining points are measurement points at other positions on the surface of the compressor. In the simulation data, the measurement points at the same position are used as monitoring points, and the initial compressor mechanical excitation load F and the air supply pipeline fluid pulsation excitation load P are loaded. The same measurement value as the monitoring point is obtained from the simulation results, and the M in the load F is used as the monitoring point. Z , K X , K Y , K Z The variable is taken as the minimum difference between the simulation value and the measured value of the monitoring point, and the optimized target value is obtained through iterative simulation calculation to determine the optimized compressor mechanical excitation load F.

[0017] Furthermore, in order to optimize the pipeline structure, the simulation calculation method also includes: obtaining optimized compressor excitation load data through multiple iterative calculations, performing numerical simulation calculations on the pipeline system based on the optimized compressor excitation load data, and optimizing the pipeline structure.

[0018] The present invention adds constraints when performing numerical calculation of vibration response simulation: compressor mechanical excitation load and fluid pulsation excitation load, so that the vibration characteristics of the scroll compressor pipeline can be simulated closer to the actual situation; at the same time, the model structure is simplified, and complex fluid-solid coupling calculations are avoided, which greatly improves the simulation calculation efficiency and shortens the simulation calculation cycle; and an optimization method is provided to optimize the pipeline structure and improve the reliability of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flow chart of simulation optimization calculation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0022] The present invention provides a method for numerical simulation of the vibration of a scroll compressor pipeline, comprising:

[0023] Establishing a numerical simulation calculation model of a scroll compressor. In one embodiment of the present invention, the calculation model includes a scroll compressor body, a gas-liquid separator, an oil-liquid separator, an air intake pipeline, an exhaust pipeline, and an air supply pipeline;

[0024] The calculation model is simplified, constraints are added, and numerical calculations of vibration response simulation are performed. The constraints include the compressor mechanical excitation load and the fluid pulsation excitation load.

[0025] In one embodiment of the present invention, the mechanical excitation load is mainly generated by the mechanical vibration of the compressor body, and the fluid pulsation excitation load is mainly generated by the fluid in the air supply pipeline. Therefore, the specific method for determining the mechanical excitation load of the compressor of the present invention includes:

[0026] Compressor mechanical excitation load F = [M Z D X D Y D Z ],M Z is the vertical moment load of the compressor body, D X is the displacement load of the compressor body in the X direction, D Y is the displacement load of the compressor body in the Y direction, D Z is the displacement load of the compressor body in the Z direction.

[0027] The relationship between displacement load and compressor operating frequency is:

[0028] D X =K X ×f,D Y =K Y ×f,D Z =K Z ×f, where K X , K Y , K Z is a constant, f is the compressor operating frequency, and the phase difference of the displacement loads in the three directions is n degrees, n ≥ 90 degrees. This improves the accuracy of the mechanical excitation load calculation.

[0029] The specific methods for determining fluid pulsation excitation loads include:

[0030] The pressure pulsation test is used to directly test the pressure pulsation data of the fluid inside the air supply pipeline, and the fluid pulsation excitation load P is fitted by the formula, P = A sin (wt + φ), A is the pressure pulsation load amplitude, φ is the phase, which improves the accuracy of the calculation of the fluid pulsation excitation load.

[0031] The specific methods of fluid pulsation excitation load loading include:

[0032] A fluid pulsation excitation load P is applied to the surface of the air supply pipeline. The load action direction is the fluid flow direction, and the loading position is each bend of the air supply pipeline.

[0033] The specific method for optimizing the mechanical excitation load F of the compressor of the present invention includes:

[0034] The mechanical excitation load F of the compressor is optimized through experimental test data and simulation data. The experimental test data selects any one of the measurement values ​​of vibration acceleration, vibration displacement, vibration velocity, vibration stress and vibration strain. The measurement points include at least two points of the compressor perpendicular to each other in the circumferential direction, and the remaining points are measurement points at other positions on the surface of the compressor. In the simulation data, the measurement points at the same position are used as monitoring points, and the initial compressor mechanical excitation load F and the air supply pipeline fluid pulsation excitation load P are loaded. The same measurement value as the monitoring point is obtained from the simulation results, and the M in the load F is used as the monitoring point. Z , K X , K Y , K Z The variable is taken as the minimum difference between the simulation value and the measured value of the monitoring point, and the optimized target value is obtained through iterative simulation calculation to determine the optimized compressor mechanical excitation load F.

[0035] The simulation calculation method also includes: obtaining optimized compressor excitation load data through multiple iterative calculations, performing numerical simulation calculations on the pipeline system based on the optimized compressor excitation load data, and optimizing the pipeline structure, which greatly improves the optimization capability of the pipeline.

[0036] Among them, optimizing the pipeline structure specifically includes optimizing the entire pipeline structure of the scroll compressor body, gas-liquid separator, oil-liquid separator, intake pipeline, exhaust pipeline and air supply pipeline.

[0037] The flowchart of the simulation optimization calculation provided by the embodiment of the present invention is as follows: Figure 1 As shown, a numerical simulation calculation model of a scroll compressor is established, and then the initial value of the simulation load is loaded. Specifically, the initial compressor mechanical excitation load F and the air supply pipeline fluid pulsation excitation load P can be loaded. After the initial value of the load is loaded, a simulation calculation is performed to determine whether the simulation result meets the error requirement. If the requirement is met, a simulation optimization calculation is performed. Specifically, through multiple iterative calculations, the optimized compressor excitation load data is obtained. Based on the optimized compressor excitation load data, a numerical simulation calculation is performed on the pipeline system to optimize the pipeline structure. If the requirement is not met, the load is optimized and the loading simulation is performed again.

[0038] In summary, the present invention can simulate the vibration characteristics of the scroll compressor pipeline more closely to reality; at the same time, it simplifies the model structure, avoids complex fluid-solid coupling calculations, greatly improves the simulation calculation efficiency, and shortens the simulation calculation cycle; and provides an optimization method to optimize the pipeline structure and improve the reliability of the final product.

Claims

1. A numerical simulation calculation method for scroll compressor pipeline vibration, characterized in that: include: Establishing a numerical simulation calculation model of a scroll compressor, the calculation model includes a scroll compressor body and an air supply pipeline; Simplifying the calculation model, adding constraints, and performing numerical calculation of vibration response simulation, wherein the constraints include the compressor mechanical excitation load and the fluid pulsation excitation load; The specific methods for determining fluid pulsation excitation loads include: The pressure pulsation test is used to directly test the pressure pulsation data of the fluid inside the air supply pipeline, and the fluid pulsation excitation load P is fitted by the formula, P = Asin (wt + φ), A is the pressure pulsation load amplitude, φ is the phase; The specific methods for optimizing the compressor mechanical excitation load F include: The mechanical excitation load F of the compressor is optimized through experimental test data and simulation data. The experimental test data selects any one of the measurement values ​​of vibration acceleration, vibration displacement, vibration velocity, vibration stress and vibration strain. The measurement points include at least two points of the compressor perpendicular to each other in the circumferential direction, and the remaining points are measurement points at other positions on the surface of the compressor. In the simulation data, the measurement points at the same position are used as monitoring points, and the initial compressor mechanical excitation load F and the air supply pipeline fluid pulsation excitation load P are loaded. The same measurement value as the monitoring point is obtained from the simulation results, and the M in the load F is used as the monitoring point. Z , K X , K Y , K Z is a variable, and the minimum difference between the simulation value and the measured value of the monitoring point is taken as the target. Through iterative simulation calculation, the optimized target value is obtained, and the optimized compressor mechanical excitation load F is determined; The simulation calculation method also includes: obtaining optimized compressor excitation load data through multiple iterative calculations, performing numerical simulation calculations on the pipeline system based on the optimized compressor excitation load data, and optimizing the pipeline structure.

2. The scroll compressor pipeline vibration numerical simulation calculation method according to claim 1 is characterized in that: The specific methods for determining the mechanical excitation load of the compressor include: Compressor mechanical excitation load F = [M Z D X D Y D Z ],M Z is the vertical moment load of the compressor body, D X is the displacement load of the compressor body in the X direction, D Y is the displacement load of the compressor body in the Y direction, D Z is the displacement load of the compressor body in the Z direction.

3. The method for numerical simulation of scroll compressor pipeline vibration according to claim 2, characterized in that: The relationship between displacement load and compressor operating frequency is: D X =K X ×f,D Y =K Y ×f,D Z =K Z ×f, where K X , K Y , K Z is a constant, f is the operating frequency of the compressor, and the phase difference between the displacement loads in the three directions is n degrees, where n ≥ 90 degrees.

4. The method for numerical simulation of scroll compressor pipeline vibration according to claim 1, characterized in that: The specific methods of fluid pulsation excitation load loading include: A fluid pulsation excitation load P is applied to the surface of the air supply pipeline. The load action direction is the fluid flow direction, and the loading position is each bend of the air supply pipeline.

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