Measurement device for volute casing assemblies taking into account the effects of circumferential asymmetry

Abstract

A measurement device for a volute casing assembly is provided that takes into account the effects of circumferential asymmetry. [Solution] The system comprises a spiral passage (1), a diffuser pipe (2), an outlet extension (3) and a tongue (4) which are connected in series, and flow field measurement points (100, 200, 300) are spaced apart along the fluid flow direction within the spiral passage, the diffuser pipe and the outlet extension, and the diffuser pipe is connected to both the tongue and the outlet of the spiral passage, and the spacing between adjacent flow field measurement points in the region close to the tongue is smaller than the spacing between adjacent flow field measurement points in the region far from the tongue.

Description

[Technical Field]

[0001] The present invention belongs to the technical field of compressors, and more particularly to a measuring device for a volute casing assembly that takes into account the effects of circumferential asymmetry. [Background technology]

[0002] Centrifugal compressors are the core components of multi-stage centrifugal compressors or axial-centrifugal compressors in commonly used compressed air energy storage systems (using air, carbon dioxide, nitrogen, etc. as working fluids). The volute casing is the core stationary component of the centrifugal compressor. Its spiral passage collects the working fluid flowing out of the impeller or diffuser and directs it to the outlet passage through a gradually widening cross-sectional design, while gradually converting the kinetic energy of the high-speed working fluid flowing in from upstream into pressure potential energy. Its deceleration and pressure boosting performance, as well as the degree of internal flow loss, have a significant impact on the overall efficiency, pressure ratio, and variable operating condition range of the centrifugal compressor.

[0003] Most of the conventional technologies involve measuring the external characteristics of the volute casing or simulation analysis that is not based on the actual environment of the entire machine. There is little scientific research on the flow mechanisms inside the volute casing, making it impossible to perform more efficient optimization design of the volute casing's performance or highly accurate performance prediction.

[0004] Currently, the most commonly used methods in impeller machinery research are experimental measurement and numerical simulation. Each has its own advantages and disadvantages, but they complement each other. While the former is highly reliable, it requires expensive measurement systems and has limited data collection capabilities. The latter saves time and money and provides more detailed information about the flow field, but its reliability leaves room for improvement. This study employs experimental methods to conduct external characteristic tests and internal flow field measurements on the entire machine inlet and outlet, the inlet and outlet and interior of the adjustable inlet guide vanes, the inlet and outlet and interior of the impeller, the disc cavity, the blade tip clearance, the interior and upstream and downstream of the booster passage of the adjustable diffuser, and the interior and upstream and downstream of the booster passage of the volute casing. Numerical methods are used to simulate the internal flow field structure of the entire machine and each pneumatic component, and a comprehensive study is conducted on the centrifugal compressor from the perspective of overall performance and flow field details, particularly the analysis of the internal flow field of the volute casing, taking into account the effects of circumferential asymmetry.

[0005] Therefore, there is a need for a measurement device for a volute casing assembly that can take into account the effects of circumferential asymmetry. Summary of the Invention [Means for solving the problem]

[0006] The objective of the present application is to design a measuring device for analyzing the internal flow field of a volute casing, which can take into account the influence of circumferential asymmetry, and this objective is achieved by the following technical solutions:

[0007] The present application provides a measurement device for a volute casing assembly that takes into account the influence of circumferential asymmetry, and includes a helical passage, a diffuser pipe, an outlet extension, and a tongue, which are sequentially connected to each other, and flow field measurement points are provided at intervals along the fluid flow direction in the helical passage, the diffuser pipe, and the outlet extension, and the diffuser pipe is connected to both the tongue and the outlet of the helical passage.

[0008] Furthermore, the spacing between adjacent flow field measurement points in the region close to the tongue is smaller than the spacing between adjacent flow field measurement points in the region far from the tongue.

[0009] Furthermore, the diffuser pipe includes a first diffuser pipe section and a second diffuser pipe section, the first diffuser pipe section being connected to both the tongue section and the outlet of the spiral passage, and the second diffuser pipe section being connected to an end of the first diffuser pipe section remote from the spiral passage.

[0010] Additionally, the flow field measurement points include third measurement points spaced apart along the length of the first diffuser pipe section.

[0011] Furthermore, the interval between the third measurement points located in the measurement point densified region is smaller than the interval between the third measurement points located outside the measurement point densified region.

[0012] Furthermore, the flow field measurement points include a fourth group of measurement points spaced apart along the length of the second diffuser pipe section.

[0013] Furthermore, the interval between the fourth measurement points located in the measurement point densified region is smaller than the interval between the fourth measurement points located outside the measurement point densified region.

[0014] Furthermore, each fourth measurement point group includes a plurality of fourth measurement points located on the same plane, one of which is located on the central axis of the diffuser pipe, and the remaining fourth measurement points are located at intervals along the circumferential direction of the fourth measurement point on the central axis and along the radial direction of the diffuser pipe.

[0015] Additionally, the flow field measurement points include a fifth measurement point located between the inlet and outlet of the outlet extension.

[0016] Furthermore, one of the fifth measurement points is located on a central axis of the outlet extension, and the remaining fifth measurement points are located at intervals along a circumferential direction of the fifth measurement point on the central axis and along a radial direction of the outlet extension, and the spacing between the fifth measurement points located within the measurement point densification region is smaller than the spacing between the fifth measurement points located outside the measurement point densification region. [Brief explanation of the drawings]

[0017] Various additional benefits and advantages will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are intended to illustrate preferred embodiments and are not intended to limit the present application. Like reference numerals refer to like elements throughout the accompanying drawings. [Figure 1] FIG. 1 is a flowchart illustrating the main steps of a method for analyzing the internal flow field of a volute casing taking into account the effects of circumferential asymmetry according to one embodiment of the present application. [Figure 2] FIG. 2 is a flowchart illustrating some steps of a method for analyzing the internal flow field of a volute casing taking into account the effect of circumferential asymmetry according to one embodiment of the present application. [Figure 3] FIG. 3 shows a partial simulation model of adjustable inlet guide vanes according to one embodiment of the present application. [Figure 4] FIG. 4 shows a partial simulation model of an impeller according to one embodiment of the present invention. [Figure 5] FIG. 5 shows a partial simulation model of a disk cavity of an impeller according to one embodiment of the present application. [Figure 6] FIG. 6 shows a partial simulation model diagram of a variable diffuser according to one embodiment of the present invention. [Figure 7] FIG. 7 shows a simulation model diagram of a volute casing according to one embodiment of the present invention. [Figure 8] FIG. 8 is a first simulation diagram of a centrifugal compressor according to an embodiment of the present application. [Figure 9]FIG. 9 is a second simulation diagram of the centrifugal compressor according to an embodiment of the present application. [Figure 10] FIG. 10 is a third simulation diagram of the centrifugal compressor according to an embodiment of the present application. [Figure 11] FIG. 11 is a fourth simulation diagram of the centrifugal compressor according to an embodiment of the present application. [Figure 12] FIG. 12 is a structural schematic diagram illustrating the arrangement of internal flow field measurement points of the volute casing in the booster passage of the volute casing according to one embodiment of the present application. [Figure 13] FIG. 13 is a schematic diagram illustrating an arrangement of fourth measurement points in the second diffuser pipe section according to one embodiment of the present application. [Figure 14] FIG. 14 is a schematic diagram illustrating the placement of the fifth measurement point on the outlet extension according to one embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0018]

[0023] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are illustrated in the accompanying drawings, the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more complete understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0019] It should be understood that the terminology used herein is for the purpose of describing particular example embodiments and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a," "an," and "said" as used herein are intended to include the plural forms as well. The terms "comprise," "contain," and "have" are inclusive and thus specify the presence of stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0020] In this specification, terms such as "first" and "second" may be used to describe multiple elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Unless otherwise clearly indicated by the context, terms such as "first" and "second" and other numerical terms do not imply an order or sequence when used in this specification. Furthermore, unless explicitly specified or limited in the description of this specification, the terms "provide" and "connect" should be understood in a broad sense, for example, to mean a fixed connection, a detachable connection, an integral connection, a direct connection, or an indirect connection via an intermediate medium. A person skilled in the art can understand the specific meaning of the above terms in this specification on a case-by-case basis.

[0021] For ease of description, spatially relative terms such as "top," "bottom," "inside," "outside," "end," "side," etc. may be used herein to describe the relationship of one element or feature to another element or feature shown in the figures. Such spatially relative terms are intended to encompass different orientations of the features in use or operation than those shown in the figures.

[0022] Hereinafter, examples of the present application will be described in conjunction with FIGS. 1 to 14 of the present specification.

[0023] As shown in FIG. 1, according to an embodiment of the present invention, a method for analyzing the internal flow field of a volute casing considering the influence of circumferential asymmetry is disclosed, and this method is applied to the volute casing of a centrifugal compressor of a new pressure storage system; constructing a full passage simulation model of the entire centrifugal compressor; Executing a simulation of all operating conditions of the entire passage area based on a complete passage simulation model of the centrifugal compressor, preset fluid parameters, and preset boundary conditions; According to the numerical results of the simulation, obtain the external performance and internal flow characteristics of the whole centrifugal compressor, and further analyze and select a measurement point densification area set up for measuring the internal flow field of the volute casing; providing internal flow field measurement points of the volute casing at intervals along the fluid flow direction within the pressure booster passage of the volute casing, and making the intervals between the measurement points located in the measurement point densification region smaller than the intervals between the measurement points located outside the measurement point densification region; Based on the measurement system of the entire centrifugal compressor and the internal flow field, measuring the flow passing through the internal and upstream / downstream flow fields of the booster passage of the volute casing, obtaining flow parameters and environmental parameters at each internal flow field measurement point of the volute casing, and comparing and verifying the numerical results of the simulation using the measurement experiment results; For the full-circumferential passage simulation model of the entire machine, simulations are performed under all operating conditions in the entire passing flow area, and when measuring the flow inside the booster passage of the volute casing and the flow fields upstream and downstream, it is necessary to take into account the influence of the circumferential asymmetry caused by the tongue 4 of the volute casing.

[0024] In this paper, a method for analyzing the internal flow field of a volute casing, taking into account the effects of circumferential asymmetry, is developed. Simulations are performed under all operating conditions in the entire pass-through region for the entire centrifugal compressor. Based on the numerical results of the simulation, the external performance and internal flow characteristics of the entire centrifugal compressor are obtained, and a high-density measurement point region for measuring the internal flow field of the volute casing is analyzed and selected. In the measurement experiment phase, flow field measurement points are spaced along the fluid flow direction within the booster passage of the volute casing. The spacing between the flow field measurement points in the high-density measurement region is made smaller than the spacing between the flow field measurement points outside the high-density measurement region. This allows for a higher density of flow field measurement points in the high-density measurement region, enabling more and more accurate collection of fluid data within the high-density measurement region. Finally, measurements are performed on the flow passing through the booster passage of the volute casing and the upstream and downstream flow fields, and flow and environmental parameters are obtained at each flow field measurement point. The numerical results of the simulation are compared and verified with the measurement experiment results. Therefore, in this paper, we combine simulation and experimental measurement, and in conjunction with theoretical analysis, carry out overall performance evaluation and local quantitative analysis of the centrifugal compressor, deeply study the loss mechanism of the flow field inside the booster passage of the volute casing and the upstream and downstream, and fully consider the influence of the circumferential asymmetry caused by the tongue, thereby improving the comprehensiveness, credibility, and reliability of the measurement results.

[0025] Specifically, the volute casing, as the rearmost through-flow component of a centrifugal compressor, collects the outlet airflow from the centrifugal impeller and variable diffuser and sends it to the outlet passage of the entire compressor. The cross-sectional area of ​​the passage gradually increases in the circumferential and flow directions, further decelerating and pressurizing the airflow. Its three-dimensional asymmetric geometric configuration creates strong three-dimensional turbulence characteristics within it. Under off-design conditions, pressure distortions tend to occur circumferentially around the inlet of the volute casing. These pressure distortions develop circumferentially around the volute casing passage and propagate to upstream components, affecting the flow stability of the centrifugal impeller and variable diffuser. The structural types of volute casings are classified into circular, trapezoidal, horseshoe, rectangular, and compound shapes according to the cross-sectional shape of the flow passage; symmetric and asymmetric shapes according to the inlet position; and inner, outer, and intermediate shapes according to the radial position. Losses include friction loss (which accounts for a relatively large proportion as the inner wall surface is generally rough), impact loss in the area where the tongues 4 are located, internal leakage loss caused by gaps between the tongues 4, and secondary flow loss (which accounts for the largest proportion) at the cross section through which the flow passes. Under variable operating conditions, friction loss and impact loss caused by large flow rates increase, while secondary flow loss and internal leakage loss caused by small flow rates increase, resulting in relatively large flow losses under small flow rate operating conditions. The research object in this embodiment of the present invention is the circular outer volute casing at the tangential inlet of a centrifugal compressor.

[0026] In some embodiments, as shown in FIG. 2 , the step of constructing a full passage simulation model of the entire centrifugal compressor includes: constructing a full-circle aisle simulation model of the entire aircraft entrance aisle; Building a full-circle passage simulation model of the adjustable inlet guide vane and placing it inside the full-circle passage simulation model of the entire machine inlet passage; Building a full-circle passage simulation model of the centrifugal impeller and arranging it downstream of the full-circle passage simulation model of the adjustable inlet guide vanes; constructing a full-circle passage simulation model of the variable diffuser and arranging it downstream of the full-circle passage simulation model of the centrifugal impeller; constructing a full-circumferential passage simulation model of the volute casing in consideration of the influence of the circumferential asymmetry caused by the tongue portion 4, and arranging the full-circumferential passage simulation model downstream of the full-circumferential passage simulation model of the variable diffuser; The method includes a step of constructing a full-circumferential passage simulation model of the entire outlet passage, and connecting the full-circumferential passage simulation model of the outlet passage and the full-circumferential passage simulation model of the volute casing.

[0027] According to the above method, a full-circle passage simulation model of the entire inlet passage, a full-circle passage simulation model of the adjustable inlet guide vane, a full-circle passage simulation model of the impeller, a full-circle passage simulation model of the variable diffuser, a full-circle passage simulation model of the volute casing, and a full-circle passage simulation model of the entire outlet passage are established, that is, a full-circle passage simulation model of the entire centrifugal compressor is established, and simulation is carried out based on the full-circle passage simulation model of the entire centrifugal compressor, thereby improving the accuracy and reliability of the simulation results.

[0028] In some embodiments, the step of constructing a full-circle passage simulation model of the entire centrifugal compressor further includes the step of constructing a full-circle passage simulation model of a disk cavity of the centrifugal impeller, and connecting the leakage flow inlet of the full-circle passage simulation model of the disk cavity with the main flow outlet of the full-circle passage simulation model of the centrifugal impeller, taking into account the influence of the leakage flow of the disk cavity of the centrifugal impeller.

[0029] During the actual operation of a centrifugal compressor, a part of the main flow will leak from the disk cavity of the impeller. Therefore, in the simulation stage, the present application takes into account the influence of the leakage flow from the disk cavity of the impeller, and when constructing a full-circle passage simulation model of the centrifugal compressor, it also constructs a full-circle passage simulation model of the disk cavity of the impeller, and connects the leakage flow inlet of the full-circle passage simulation model of the disk cavity with the main flow outlet of the full-circle passage simulation model of the impeller, thereby improving the accuracy of the simulation results.

[0030] In some embodiments, the step of performing a simulation of all operating conditions of the entire pass-through area based on the entire pass-through simulation model of the centrifugal compressor, the preset fluid parameters, and the preset boundary conditions includes the step of building an entire pass-through area calculation model of the centrifugal compressor coupled with the disk cavity, and performing simulations of all operating conditions with different main flow rate and / or different rotation speed of the centrifugal impeller and / or different angles of the adjustable inlet guide vanes and / or different angles of the variable diffuser.

[0031] A calculation model of the entire throughflow basin of the centrifugal compressor coupled with a disk cavity is constructed, and simulations of all operating conditions with different main flow rates and / or different rotational speeds of the impeller and / or different angles of the adjustable inlet guide vanes and / or different angles of the variable diffuser are performed, thereby obtaining simulation data under different operating conditions of the entire centrifugal compressor coupled with a disk cavity and improving the comprehensiveness of the simulation data.

[0032] In some embodiments, the step of constructing a full-circumferential passage simulation model of an impeller cavity of a centrifugal impeller includes the following steps: divide the disk cavity into a periodic, fully orthogonal hexahedral structure mesh using mesh preprocessing software, and match the mesh nodes of the leakage flow inlet of the full-circumferential passage simulation model of the disk cavity with the mesh nodes of the main flow outlet of the full-circumferential passage simulation model of the centrifugal impeller; close the leakage flow outlet of the full-circumferential passage simulation model of the disk cavity, and densify the meshes of the communication surface between the leakage flow inlet and the main flow outlet, the moving wall surface and stationary wall surface of the disk cavity, and the seal structure of the leakage flow outlet; set the interior and moving wall surface of the disk cavity as a rotating region, and set the stationary wall surface of the disk cavity as a stationary region; select the mixing plane method as the mesh interactive calculation method for the communication surface between the leakage flow inlet and the main flow outlet.

[0033] According to the above method, the constructed full-circumferential passage simulation model of the disk cavity is more compatible with the full-circumferential passage simulation model of the impeller, and the leakage flow inlet / outlet, moving wall surface and stationary wall surface of the disk cavity are processed accordingly, so that the constructed full-circumferential passage simulation model of the disk cavity is more suitable for practical use.

[0034] Specifically, as shown in FIG. 5, FIG. 5 is a partial simulation model diagram of a disk cavity of an impeller according to one embodiment of the present application, and all the dark areas are mesh densification areas of the disk cavity.

[0035] In some embodiments, the step of constructing a full-circumference passage simulation model of the volute casing includes using mesh preprocessing software to perform tetrahedral unstructured mesh division of the volute casing with solid walls having boundary layers, densifying the mesh of the boundary layers, and partially densifying the mesh of the tongue 4.

[0036] By using the above method, a simulation model of the entire circumferential passage of the volute casing is constructed, and the mesh at a specific position of the volute casing is densified to improve the accuracy of the simulation.

[0037] Specifically, as shown in FIG. 7, FIG. 7 is a simulation model diagram of a volute casing according to one embodiment of the present application, and all the dark areas are mesh densification areas of the volute casing.

[0038] The construction of a full-circumferential passage simulation model of the adjustable inlet guide vanes, impeller, and variable diffuser of a centrifugal compressor can be performed by referring to the disk cavity and volute casing methods, as shown in Figures 3, 4, and 6. Figure 3 is a partial simulation model diagram of an adjustable inlet guide vane according to an embodiment of the present invention, Figure 4 is a partial simulation model diagram of an impeller according to an embodiment of the present invention, and Figure 6 is a partial simulation model diagram of a variable diffuser according to an embodiment of the present invention. The dark areas in Figures 3, 4, and 6 are all mesh densification areas. Specifically, using mesh pre-processing software, the three parts of the adjustable inlet guide vanes, impeller, and variable diffuser are divided into a complete hexahedral structure mesh, with a body-fit H-type mesh used on the wall surface and an O-type mesh used at the boundary between the leading and trailing edges of the blade and the wall surface and the blade tip gap.

[0039] In this application, when constructing a full-circle passage simulation model of a centrifugal compressor, it is necessary to combine the same mesh topology with a coarse mesh densification configuration to verify the independence of the mesh number for the full-circle passage mesh of the throughflow area of ​​the whole machine constructed 1:1 based on the original structural parameters of the research object.

[0040] In some embodiments, the preset fluid parameters include fluid flow parameters and environmental parameters, where the fluid flow parameters include at least one of pressure, temperature, velocity, flow rate, vibration displacement, phase concentration, viscosity, Reynolds number, and surface tension of the fluid, and the fluid environmental parameters include at least one of sound pressure decibels, humidity, surface roughness, and wear of an environment in which the fluid is located.

[0041] The flow parameters reflect the flow characteristics of the fluid, and the environmental parameters reflect the characteristics of the environment in which the fluid is located, and since fluid detection includes both the flow parameters of the fluid and the environmental parameters of the fluid, the obtained fluid data is more accurate and comprehensive.

[0042] Specifically, pressure includes static pressure, total pressure, and differential pressure, temperature includes static temperature and total temperature, velocity includes mean velocity, instantaneous velocity, absolute velocity, relative velocity, and peripheral velocity, flow rate includes volumetric flow rate and mass flow rate, vibration displacement includes low frequency, medium frequency, and high frequency, phase concentration includes gas-liquid and liquid-solid, viscosity includes Newtonian and non-Newtonian, Reynolds number includes laminar flow, transitional flow, and turbulent flow, and surface tension includes static and dynamic.

[0043] Specifically, sound pressure decibels include fluid noise, mechanical noise, and electromagnetic noise, humidity includes absolute humidity and relative humidity, surface roughness includes average roughness and maximum height, and wear amount includes abrasive particles, adhesion, and fatigue.

[0044] In this embodiment, the fluid may be a medium in a gas phase, a liquid phase, or a gas-liquid two-phase flow, such as air, carbon dioxide gas, nitrogen gas, or helium gas.

[0045] In some embodiments, the predefined boundary conditions include an inlet boundary condition, an outlet boundary condition, an all-contact wall boundary condition, a periodic boundary condition, a rotating stationary interference boundary condition, and a turbulence model boundary condition.

[0046] In the analysis stage of the simulation, the accuracy of the simulation results can be improved by restricting the parameters related to the preset boundary conditions.

[0047] Specifically, the inlet boundary conditions are set to the designed total temperature and total pressure boundaries, with turbulence intensity along the axial airflow direction at 5%. The outlet boundary conditions are set to the mean static pressure at the start of the calculation, and the back pressure is gradually increased. As the total pressure ratio gradually increases, the designed mass flow rate is applied. When the total pressure ratio begins to decrease, it is considered that the compressor is approaching its numerical stall point. All contact wall boundary conditions are set to adiabatic and no-slip boundary conditions on the blade surfaces and casing walls. The periodic boundary conditions are as follows: For single-passage calculations, the adjustable inlet guide vanes, impeller, disk cavity, and variable diffuser all select a single-blade passage, and rotating periodic surfaces are used along the circumferential boundaries on both sides of the passage. The full-circumference model is obtained by rotating and copying the single-blade model. The rotating-stationary interference treatment boundary conditions are as follows: Commonly used boundary methods include the mixing plane method, the frozen rotor method, and the transient rotor-stator method. In single-passage systems, the mixing plane method averages the upstream boundary physical quantities circumferentially and transfers them to the downstream boundary, ignoring the effects of circumferential asymmetry. In full-passage systems, the frozen rotor method analyzes the rotor in a rotating coordinate system and the stator in a stationary coordinate system, transferring information between the rotor and stator by interpolation, while taking into account the effects of circumferential asymmetry on the upstream and downstream flow fields. The turbulence model boundary conditions are as follows: The SST turbulence model is used, and the mass, momentum, and energy equations are discretized using second-order upwind finite difference. At least 10 mesh points are placed in the laminar sublayer region, and the wall function y+ is preferably close to 1.

[0048] In some embodiments, the step of obtaining the external performance and internal flow characteristics of the entire centrifugal compressor based on the numerical results of the simulation, and further analyzing and selecting a measurement point densification area provided for measuring the internal flow field of the volute casing, comprises: According to the numerical results of the simulation, analyzing the loss mechanism of the whole centrifugal compressor and the internal flow characteristics of each subcomponent under different operating conditions, and obtaining the external performance and internal flow characteristics of the whole centrifugal compressor; and intentionally capturing localized area locations where the internal flow field characteristics of the volute casing exhibit at least one of distortion, transition, and singularity as measurement point densification areas.

[0049] Through the numerical results of the simulation, the loss mechanism of the entire centrifugal compressor and the internal flow characteristics of each subcomponent under different operating conditions are analyzed, the loss mechanism of the entire compressor and the internal flow characteristics of each subcomponent under fluctuating operating conditions are evaluated, the areas where the internal flow field characteristics of the volute casing show obvious changes, including but not limited to distortion, transition and singularity, are intentionally captured, and the areas where the local characteristics change significantly are used as measurement point densification areas to analyze the coupling characteristics and internal flow structure of each through-flow part under fluctuating operating conditions, where emphasis is placed on the analysis of the internal flow field characteristics of the volute casing.

[0050] As shown in Figures 8 to 11, Figure 8(a) shows simulation data of static pressure changes when a fluid flows through a centrifugal compressor, and Figure 8(b) shows simulation data of total pressure changes when a fluid flows through a centrifugal compressor. Figure 9(c) shows simulation data of static temperature changes when a fluid flows through a centrifugal compressor, and Figure 9(d) shows simulation data of total temperature changes when a fluid flows through a centrifugal compressor. Figure 10(e) shows simulation data of density changes when a fluid flows through a centrifugal compressor, and Figure 10(f) shows simulation data of Mach number changes when a fluid flows through a centrifugal compressor. Figure 11(g) shows simulation data of viscosity changes when a fluid flows through a centrifugal compressor, and Figure 11(h) shows simulation data of turbulent kinetic energy changes when a fluid flows through a centrifugal compressor.

[0051] Each circled location or area with significant gradient change represents a localized area where the fluid exhibits at least one of distortion, transition, and singularity, i.e., a measurement point density area. The area surrounded by circles 1, 2, 3, 4, and 5 shows the impact of the circumferential asymmetry of the tongue 4 on upstream fluid parameters such as the impeller inlet, outlet, booster passage, and dynamic and static clearances. As can be seen, the closer to the tongue 4, the greater the impact of the circumferential asymmetry from the tongue 4. At the same time, due to the impeller's ability to circumferentially equalize the fluid, the impact of the circumferential asymmetry of the tongue 4 on the impeller is much smaller than the impact at other locations. Generally, along the spiral passage 1, starting from the tongue 4, the flow parameter distributions of both the upstream through-flow components close to the tongue 4 and the upstream through-flow components far from the tongue 4 show the greatest circumferential asymmetry, but the distribution of each flow parameter is quite different at the circumferential position or pneumatic component most affected by the circumferential asymmetry of the volute casing. The static pressure, total pressure, static temperature, total temperature, and density distributions all use the tongue 4 as the reference point. The maximum circumferential asymmetry is observed in the direction opposite to the main flow at the trailing edge, passage, leading edge, and impeller trailing and leading edges of the diffuser at two locations: close to the tongue 4 (after the fluid has passed through the tongue 4) and far from the tongue 4 (symmetrical location). (i.e., the location where the spacing between adjacent flow field measurement points in the region close to the tongue 4 is smaller than the spacing between adjacent flow field measurement points in the region far from the tongue 4). The Mach number distribution exhibits the greatest circumferential asymmetry only at the trailing edge of the impeller at two locations: close to the tongue 4 (when the fluid flows through the tongue 4) and away from the tongue 4 (symmetrical location). The viscosity and turbulent kinetic energy distributions exhibit the greatest circumferential asymmetry at the front and rear diffuser-impeller interfaces in the opposite direction to the main flow direction: close to the tongue 4 (before the fluid flows through the tongue 4) and away from the tongue 4 (symmetrical location). This is because the tongue 4 exhibits the greatest circumferential asymmetry of the volute casing, and its effect propagates upstream in the opposite direction to the fluid flow direction, causing the distribution of each flow parameter to exhibit different circumferential response effects and hysteresis.

[0052] In some embodiments, a measurement device for a volute casing assembly is needed that takes into account the effects of circumferential asymmetry, wherein the step of arranging internal flow field measurement points of the volute casing in a booster passage of the volute casing at intervals along a fluid flow direction includes a helical passage 1, a diffuser pipe 2, and an outlet extension 3 that are sequentially connected, and the step of arranging internal flow field measurement points of the volute casing in a booster passage of the volute casing at intervals along the fluid flow direction includes arranging internal flow field measurement points of the volute casing in the helical passage 1, the diffuser pipe 2, and the outlet extension 3 at intervals along the fluid flow direction.

[0053] The measurement device for the volute casing assembly, which takes into account the influence of circumferential asymmetry, sets up internal flow field measurement points in the volute casing in the spiral passage 1, the diffuser pipe 2, and the outlet extension 3, respectively, and uses these internal flow field measurement points in the volute casing to detect and obtain fluid flow parameters and environmental parameters in the spiral passage 1, the diffuser pipe 2, and the outlet extension 3. By analyzing the fluid flow parameters and environmental parameters, the internal fluid performance of the assembly of the spiral passage 1, the diffuser pipe 2, and the outlet extension 3 of the volute casing can be analyzed.

[0054] As shown in FIG. 12 , in some embodiments, a projection of the spiral passage 1 along the central axis thereof forms an inner ring line 11 and an outer ring line 12. The distance between the inner ring line 11 and the outer ring line 12 gradually increases along the fluid flow direction and is equal to the width of the cross-section of the spiral passage 1. The flow field measurement points include a plurality of first measurement points 100 spaced apart along the inner ring line 11. The spacing between the first measurement points 100 located in the measurement point densification region is smaller than the spacing between the first measurement points 100 located outside the measurement point densification region. The first measurement points 100 are used to detect flow parameters and environmental parameters of the fluid flowing along the spiral passage 1.

[0055] By arranging multiple first measurement points 100 at intervals in the spiral passage 1 along the inner ring line 11, and making the intervals between the first measurement points 100 located in the measurement point densification area smaller than the intervals between the first measurement points 100 located outside the measurement point densification area, it is possible to obtain more fluid data within the measurement point densification area, thereby better detecting changes in the fluid flow characteristics while taking installation costs into consideration. The first measurement points 100 detect flow parameters and environmental parameters of the fluid flowing along the spiral passage 1, and can obtain changes in the flow characteristics of the fluid flowing along the inner ring line 11 of the spiral passage 1.

[0056] The outer ring line 12 overlaps with the contour line of the spiral casing, and the inner ring line 11 overlaps with the boundary line between the upstream fluid and the spiral casing. In other words, the inner ring line 11 is closer to the upstream impeller, which has the ability to equalize the fluid in the circumferential direction, and the outer ring line 12 is farther from the upstream impeller. Therefore, the flow field near the inner ring line 11 is less affected by the circumferential asymmetry of the tongue 4 than the flow field near the outer ring line 12.

[0057] 12 , in some embodiments, the flow field measurement points include a plurality of second measurement points 200 spaced apart along the outer ring line 12, with the spacing between the second measurement points 200 located in the measurement point densification region being smaller than the spacing between the second measurement points 200 located outside the measurement point densification region. The second measurement points 200 are used to detect flow parameters and environmental parameters of the fluid flowing along the spiral passage 1.

[0058] By arranging multiple second measurement points 200 at intervals in the spiral passage 1 along the outer ring line 12, and making the intervals between the second measurement points 200 located in the measurement point densification area smaller than the intervals between the second measurement points 200 located outside the measurement point densification area, it is possible to obtain more fluid data within the measurement point densification area, thereby better detecting changes in the fluid flow characteristics while taking installation costs into consideration. The second measurement points 200 detect flow parameters and environmental parameters of the fluid flowing along the spiral passage 1, and can obtain changes in the flow characteristics of the fluid flowing along the outer ring line 12 of the spiral passage 1.

[0059] As shown in FIG. 12, the diffuser pipe 2 gradually widens along the direction of fluid flow, and can be configured as, for example, a trumpet pipe with a gradually increasing cross section, which plays a role in decelerating and increasing the pressure of the fluid passing through it.

[0060] In some embodiments, the diffuser pipe 2 includes a first diffuser pipe section 21 and a second diffuser pipe section 22, the first diffuser pipe section 21 being connected to both the tongue 4 of the measurement device of the volute casing assembly and the outlet of the helical passage 1, and the second diffuser pipe section 22 being connected to an end of the first diffuser pipe section 21 remote from the helical passage 1. The flow field measurement points include a plurality of third measurement points 300 spaced apart along the length of the first diffuser pipe section 21, the spacing between the third measurement points 300 located in the measurement point densification region being smaller than the spacing between the third measurement points 300 located outside the measurement point densification region. The third measurement points 300 are used to detect flow parameters and environmental parameters of the fluid flowing along the first diffuser pipe section 21.

[0061] A plurality of third measurement points 300 spaced apart along the length of the first diffuser pipe section 21 can detect the fluid flowing through the first diffuser pipe section 21. By making the intervals between the second measurement points 200 located in the measurement point densification region smaller than the intervals between the second measurement points 200 located outside the measurement point densification region, and thereby enabling acquisition of more fluid data within the measurement point densification region, it is possible to better detect changes in the fluid flow characteristics and analyze changes in the fluid flow characteristics along the first diffuser pipe section 21 while taking installation costs into consideration.

[0062] In some embodiments, the flow field measurement points include a group of multiple fourth measurement points 400 spaced along the length of the second diffuser pipe section 22, the spacing between the fourth measurement points 400 located in the measurement point densification region being smaller than the spacing between the fourth measurement points 400 located outside the measurement point densification region, and the fourth measurement points 400 are used to detect flow parameters and environmental parameters of the fluid flowing along the second diffuser pipe section 22.

[0063] A group of multiple fourth measurement points 400 spaced apart along the length of the second diffuser pipe section 22 detects the fluid flowing through the second diffuser pipe section 22. The spacing between the fourth measurement points 400 located in the high-density measurement area is smaller than the spacing between the fourth measurement points 400 located outside the high-density measurement area. This allows for more fluid data to be acquired within the high-density measurement area, enabling better detection of changes in the fluid flow characteristics while taking installation costs into consideration. This allows for acquisition of fluid flow parameters and environmental parameters, enabling analysis of changes in the characteristics of the fluid flowing along the second diffuser pipe section 22.

[0064] As shown in Figures 12 and 13, in some embodiments, each group of fourth measurement points 400 includes multiple fourth measurement points 400 located on the same plane, one of the fourth measurement points 400 is located on the central axis of the diffuser pipe 2, and the remaining fourth measurement points 400 are located at intervals along the circumferential direction of the fourth measurement point 400 on the central axis and along the radial direction of the diffuser pipe 2.

[0065] The multiple fourth measurement points 400 in each group are located on the same plane, one of the fourth measurement points 400 is provided on the central axis of the diffuser pipe 2, and the remaining fourth measurement points 400 are provided at intervals along the circumferential direction of the fourth measurement point 400 on the central axis and along the radial direction of the diffuser pipe 2. This makes it possible to detect the fluid flowing into multiple locations at the center, radially, and circumferentially of the second diffuser pipe section 22 and obtain multiple sets of detection data, improving detection accuracy.

[0066] Specifically, the diameter of the outlet extension 3 is equal to the outlet diameter of the second diffuser pipe section 22, and the inlet diameter of the first diffuser pipe section 21 is equal to the outlet diameter of the spiral flow path 1, making them easy to connect.

[0067] 12 and 14 , in some embodiments, the measurement points include a plurality of fifth measurement points 500 located in the same plane, and the fifth measurement points 500 are located between the inlet and the outlet of the outlet extension 3. One of the fifth measurement points 500 is located on the central axis of the outlet extension 3, and the remaining fifth measurement points 500 are located at intervals along the circumferential direction of the fifth measurement point 500 on the central axis and along the radial direction of the outlet extension 3. The intervals between the fifth measurement points 500 located in the measurement point densification region are smaller than the intervals between the fifth measurement points 500 located outside the measurement point densification region. The fifth measurement points 500 are used to detect flow parameters and environmental parameters of the fluid flowing along the outlet extension 3.

[0068] Note that a detection sensor is provided at each of the first measurement point 100, the second measurement point 200, the third measurement point 300, the fourth measurement point, and the fifth measurement point, and the flowing fluid can be detected by this detection sensor.

[0069] The detection sensor includes at least one of a contact sensor and a non-contact sensor.

[0070] The contact sensor may be at least one of a piezoresistive pressure sensor, a strain gauge pressure gauge, a thermocouple, a thermistor, a turbine flow meter, an electromagnetic flow meter, a differential pressure flow meter, a target flow meter, an accelerometer, a strain gauge, a conductivity sensor, a capacitance sensor, a rotational viscometer, a capillary viscometer, a multi-parameter composite sensor, a du Nouy method sensor, a plate method sensor, a contact microphone, a capacitance hygrometer, a stylus profiler, and a displacement sensor.

[0071] The non-contact sensor may be at least one of a piezoelectric pressure sensor, a capacitive pressure sensor, an infrared thermometer, an ultrasonic flow meter, a laser Doppler velocimeter (LDV), a non-contact electromagnetic flow meter, an ultrasonic flow meter, a laser vibrometer, a near-infrared spectrum sensor, a microwave sensor, a microwave / radio frequency sensor, a non-contact flow meter + viscosity sensor, a laser surface roughness sensor, a laser microphone, an infrared humidity sensor, a microwave humidity sensor, a laser interferometer, a white light interferometer, an ultrasonic thickness gauge, and an optical 3D scanner.

[0072] In some embodiments, the step of acquiring flow parameters and environmental parameters at each internal flow field measurement point of the volute casing and comparing and validating the numerical results of the simulation with the measurement experimental results includes: acquiring flow parameters and environmental parameters at measurement points provided in the spiral passage 1, the diffuser pipe 2 and the outlet extension 3; The processing results of the flow parameters and environmental parameters at each measurement point are compared with the numerical results of the simulation and analyzed, the comprehensive external performance of the whole machine under variable operating conditions and the internal loss distribution of the booster passage of the volute casing are evaluated, the internal flow loss mechanism of the volute casing is clarified, the influence of the circumferential asymmetry of the volute casing is analyzed, and the design direction of the optimization of the volute casing contour and the configuration of the tongue 4 is further guided.

[0073] By obtaining the flow parameters and environmental parameters at each measurement point installed in the spiral passage 1, the diffuser pipe 2, and the outlet extension 3, and comparing and analyzing the processing results of the obtained flow parameters and environmental parameters with the numerical results of the simulation, the comprehensive external performance of the whole machine under variable operating conditions and the internal flow field loss distribution of the spiral passage 1, the diffuser pipe 2, and the outlet extension 3 can be evaluated and analyzed, the internal flow loss mechanism of the booster passage of the volute casing can be clarified, and the design direction for optimizing the contour of the volute casing and the configuration of the tongue 4 can be guided.

[0074] In some embodiments, the centrifugal compressor includes an overall inlet passage, adjustable inlet guide vanes, a centrifugal impeller, a variable diffuser, a volute casing, and an overall outlet passage, wherein the adjustable inlet guide vanes are disposed within the overall inlet passage, the centrifugal impeller is disposed downstream of the adjustable inlet guide vanes, the variable diffuser is disposed downstream of the centrifugal impeller, the volute casing is disposed downstream of the centrifugal impeller, and the outlet passage is connected to the outlet of the volute casing.

[0075] The step of measuring the flow passing through the internal and upstream / downstream flow fields of the booster passage of the volute casing based on the overall and internal flow field measurement system of the centrifugal compressor includes: Designing and constructing a centrifugal compressor overall and internal flow field measurement system; External characteristic measurements and internal flow field measurements are carried out for the entire inlet passage inlet and outlet of the entire outlet passage, the inlet / outlet and interior of the adjustable inlet guide vane, the inlet / outlet and interior of the centrifugal impeller, the disk cavity of the centrifugal impeller, the blade tip clearance of the centrifugal impeller, the interior and upstream / downstream of the booster passage of the variable diffuser, and the interior and upstream / downstream of the booster passage of the volute casing under different main flow rates, different angles of the adjustable inlet guide vane, different rotational speeds of the centrifugal impeller, and different angles of the variable diffuser under all operating conditions.

[0076] During the actual operation of a centrifugal compressor, a part of the main flow will leak through the disk cavity and tip clearance of the centrifugal impeller. Therefore, in the measurement experiment stage of the present application, the influence of the leakage flow of the disk cavity and tip clearance of the centrifugal impeller is taken into consideration, and measurements of all operating conditions and all internal flow fields are carried out under different main flow rate, different angles of the adjustable inlet guide vane, different rotation speeds of the centrifugal impeller, and different angles of the variable diffuser, so as to improve the accuracy of the measurement experiment results.

[0077] In some embodiments, the objects affected by the circumferential asymmetry due to the tongue include at least one of the volute itself, the upstream and downstream internal flow fields, and the overall machine performance, and the extent of the impact includes at least one of the components, the area, and the degree.

[0078] By limiting the objects affected by the circumferential asymmetry due to the tongue to include at least one of the volute casing itself, the internal flow fields on the upstream and downstream sides, and the overall machine performance, it is possible to more comprehensively analyze the effect of the circumferential asymmetry due to the tongue on the internal flow field of the centrifugal compressor.

[0079] In this embodiment, the objects affected by the circumferential asymmetry due to the tongue include at least one of the volute casing itself, the upstream and downstream internal flow fields, and the overall machine performance, and the range of influence includes at least one of the parts, the area, and the degree.

[0080] The above is merely a preferred embodiment of the present application, and the scope of protection of the present application is not limited thereto. Any modifications or replacements that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application shall be included in the scope of protection of the present application. [Explanation of symbols]

[0081] 1 spiral passage 2 Diffuser pipe 3 Exit extension 4 Tongue 11 Inner Ring Line 12 Outer Ring Line 21 First diffuser pipe section 22 Second diffuser pipe section 100 1st measurement point 200 2nd measurement point 300 3rd measurement point 400 4th measurement point 500 5th measurement point

Claims

1. 1. A measuring device for a volute casing assembly taking into account the influence of circumferential asymmetry, comprising a spiral passage (1), a diffuser pipe (2), an outlet extension (3), and a tongue (4) that are sequentially connected to each other, wherein flow field measuring points are provided at intervals along the fluid flow direction within the spiral passage (1), the diffuser pipe (2), and the outlet extension (3), and the diffuser pipe (2) is connected to both the tongue (4) and the outlet of the spiral passage (1).

2. 2. The measuring device for a volute casing assembly taking into account the influence of circumferential asymmetry according to claim 1, characterized in that the spacing between adjacent flow field measuring points in the region close to the tongue (4) is smaller than the spacing between adjacent flow field measuring points in the region far from the tongue (4).

3. 2. The measuring device for a volute casing assembly taking into account the influence of circumferential asymmetry according to claim 1, characterized in that the diffuser pipe (2) includes a first diffuser pipe section (21) and a second diffuser pipe section (22), the first diffuser pipe section (21) being connected to both the tongue section (4) and the outlet of the spiral passage (1), and the second diffuser pipe section (22) being connected to an end of the first diffuser pipe section (21) remote from the spiral passage (1).

4. 4. The measurement device for a volute casing assembly taking into account the effects of circumferential asymmetry according to claim 3, characterized in that the flow field measurement points include third measurement points (300) spaced along the length of the first diffuser pipe section (21).

5. 5. The measuring device for a volute casing assembly taking into account the influence of circumferential asymmetry according to claim 4, wherein the intervals between the third measurement points (300) located within the measurement point densification region are smaller than the intervals between the third measurement points (300) located outside the measurement point densification region.

6. 4. The measurement device for a volute casing assembly taking into account the effect of circumferential asymmetry according to claim 3, wherein the flow field measurement points include a group of a plurality of fourth measurement points (400) spaced apart along the length of the second diffuser pipe section (22).

7. 7. The measuring device for a volute casing assembly taking into account the influence of circumferential asymmetry according to claim 6, wherein the interval between the fourth measurement points (400) located in the measurement point densification region is smaller than the interval between the fourth measurement points (400) located outside the measurement point densification region.

8. 8. The measuring device for a volute casing assembly taking into account the effect of circumferential asymmetry according to claim 7, wherein each group of fourth measurement points (400) includes a plurality of fourth measurement points (400) located on the same plane, one of which is provided on the central axis of the diffuser pipe (2), and the remaining fourth measurement points (400) are provided at intervals along the circumferential direction of the fourth measurement point (400) on the central axis and along the radial direction of the diffuser pipe (2).

9. 4. The measuring device for a volute casing assembly taking into account the influence of circumferential asymmetry according to claim 3, characterized in that the flow field measuring points include a fifth measuring point (500) located between the inlet and the outlet of the outlet extension (3).

10. 10. The measuring device for a volute casing assembly taking into account the effect of circumferential asymmetry according to claim 9, wherein one of the fifth measurement points (500) is provided on a central axis of the outlet extension (3), and the remaining fifth measurement points (500) are provided at intervals along a circumferential direction of the fifth measurement point (500) on the central axis and along a radial direction of the outlet extension (3), and the intervals between the fifth measurement points (500) located within the measurement point densification region are smaller than the intervals between the fifth measurement points (500) located outside the measurement point densification region.

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