A design method of a continuous wind tunnel distributed compressor system overall scheme

Abstract

The application discloses a design method of a continuous wind tunnel distributed compressor system overall scheme, relates to the field of continuous wind tunnel design, and first obtains a mass flow resistance loss relation curve and converts the mass flow resistance loss relation curve into a converted flow total pressure ratio relation curve of a compressor system; maximum operation power is determined, and lowest isentropic efficiency requirements of each working condition are calculated. A lowest efficiency working condition point is selected as a first-stage compressor design constraint point, serial compressors are designed one by one, and working condition coverage ranges are evaluated; if all working conditions are not covered, a serial compressor is added, iteration is completed through overlapping working condition point selection, load distribution and efficiency calculation, and all working conditions are covered. Finally, whether parallel replacement is needed at each serial position is judged according to processing and manufacturing capacity, parallel numbers are determined, a serial-parallel distributed compressor system overall scheme is output, and the problem that the distributed compressor system lacks a systematic design method is solved, thereby providing scientific guidance for continuous wind tunnel high-speed, wide-speed-range and fine development.

Description

Technical Field

[0001] This invention relates to the field of continuous wind tunnel design, and more specifically, to a design method for an overall scheme of a continuous wind tunnel distributed compressor system. Background Technology

[0002] Continuous wind tunnels are indispensable ground-based testing facilities supporting the development of aerospace vehicles. The compressor system is the heart of a continuous wind tunnel, and is the core key to establishing the target flow field and ensuring the safe operation of the wind tunnel. Currently, the high-speed and wide-speed-range characteristics of aerospace vehicles are becoming increasingly prominent, requiring continuous wind tunnels to possess high-speed, wide-speed-range, and precise testing capabilities.

[0003] The demand for high-speed, wide-range, and precise testing capabilities in continuous wind tunnels requires that the compressor systems of such wind tunnels provide ultra-high total pressure ratios and ultra-large flow rates, enabling safe, stable, and efficient operation within a wide range of total pressure ratios and flow rates.

[0004] A single large or ultra-large compressor driving a continuous wind tunnel is a conventional technical solution in the design of continuous wind tunnel compressor systems (referred to as the single compressor system technical solution). Due to factors such as the limited range of efficient and stable operation of a single compressor, the complex vibration characteristics of long shaft systems, the difficulty in processing and manufacturing ultra-large structural components, and the large investment amount, the single compressor system technical solution is difficult to apply to continuous wind tunnels with high speed, wide speed range characteristics, and strong fine-tuning testing capabilities.

[0005] To meet the evolving demands for high-speed, wide-speed-range, and refined testing capabilities in continuous wind tunnels, while also considering the requirements for low-risk, low-investment, high feasibility, and maturity in engineering development, a distributed compressor system technical solution (including a compressor system technical solution based on multiple small compressors connected in parallel, hereinafter referred to as the parallel distributed compressor system technical solution, see...) is proposed. Figure 1 ), a compressor system technical solution based on multiple compressors driven in series (hereinafter referred to as the series distributed compressor system technical solution, see Figure 2 The parallel distributed compressor system technology scheme coupled with the series distributed compressor system technology scheme (hereinafter referred to as the series-parallel distributed compressor system technology scheme, see...) Figure 3 It has become a feasible, potential, and highly competitive technical solution for future continuous wind tunnel compressor systems.

[0006] Currently, the development of distributed compressor system technology is still in its early stages. Related design methods, especially overall scheme design methods (mainly including designing and determining the number of compressors in parallel distributed compressor systems and the number of compressors in series distributed compressor systems), have not yet been formed. There is a lack of a scientific and systematic design logic to guide how to determine the number of series compressors, the number of parallel compressors, and the layout of series-parallel combinations. This leads to design decisions relying on experience, making it difficult to guarantee the rationality, economy, and feasibility of the scheme. Summary of the Invention

[0007] The purpose of this invention is to provide a design method for a continuous wind tunnel distributed compressor system, in order to solve the problem of the lack of a systematic design method in the prior art.

[0008] To achieve the above-mentioned objectives, this invention provides a design method for a continuous wind tunnel distributed compressor system, the method comprising:

[0009] Step 1: Based on the number of operating points, total pressure in the steady section, and total temperature in the steady section of the wind tunnel, obtain the mass flow rate-drag loss relationship curve of the wind tunnel;

[0010] Step 2: Convert the mass flow rate-resistance loss relationship curve into the equivalent flow rate-total pressure ratio relationship curve of the wind tunnel distributed compressor system;

[0011] Step 3: Obtain the maximum operating power of the driving wind tunnel;

[0012] Step 4: Based on the maximum operating power, the mass flow rate at each operating point, the total pressure ratio obtained in Step 2, and the total temperature in the steady section, calculate the minimum isentropic efficiency requirement of the wind tunnel distributed compressor system at each operating point.

[0013] Step 5: Select the operating point with the lowest isentropic efficiency of the wind tunnel distributed compressor system across the entire operating range as the design constraint operating point of the first compressor, and take the lowest isentropic efficiency requirement corresponding to this operating point as the target isentropic efficiency requirement of the first compressor.

[0014] Step 6: Iteratively design the i-th compressor to ensure that the isentropic efficiency of the i-th compressor at the design constraint operating point is not less than the target isentropic efficiency requirement determined in Step 5 or Step 13. The initial value of i is 1, which is updated according to the number of compressors in the series distributed compressor system to be designed.

[0015] Step 7: Evaluate the aerodynamic performance of the i-th compressor, obtain the anti-surge line and blockage line of the i-th compressor, and determine the operating condition range that can be met when the first to the i-th compressors are running in a matched manner based on the reduced flow rate-total pressure ratio relationship curve.

[0016] Step 8: If the current operating condition range covers all operating conditions, let the total number of compressors in the series distributed compressor system be i, and then execute step 15; if the current operating condition range does not cover all operating conditions, determine the uncovered operating condition range, and then execute step 9.

[0017] Step 9: Arrange the (i+1)th compressor in series after the i-th compressor along the airflow direction. Sort the currently covered operating points in ascending order of comprehensive surge margin, and select the first K operating points as overlapping operating points.

[0018] Step 10: Select the operating point with the largest comprehensive surge margin from the overlapping operating points as the design constraint point of the (i+1)th compressor, and determine the equivalent flow rate and total pressure ratio of the design constraint point;

[0019] Step 11: Based on the reduced flow rate and total pressure ratio of the design constraint point, determine the load distribution of each compressor when the first to the (i+1)th compressors are operated in series to meet the performance requirements of the design constraint point and the uncovered operating conditions, including the total pressure ratio and reduced flow rate of each compressor.

[0020] Step 12: Based on the load distribution results determined in Step 11 and the aerodynamic performance of the first to the i-th compressors, determine the power consumption of each compressor and the total power consumption when the first to the i-th compressors are connected in series to meet the performance requirements of the design constraint point.

[0021] Step 13: Based on the reduced flow rate at the design constraint point and the total power consumption, calculate the minimum isentropic efficiency requirement for the (i+1)th compressor when it is running at the design constraint point, and use the minimum isentropic efficiency requirement as the target isentropic efficiency requirement for the (i+1)th compressor.

[0022] Step 14: Update i to i+1, return and repeat steps 6 to 14 until the current working condition range in step 8 has covered all working conditions.

[0023] Step 15: Based on the processing and manufacturing capabilities and operational economic requirements, determine whether any compressor in the series distributed compressor system needs to be replaced by a parallel distributed compressor system, and determine the number of parallel compressors after replacement;

[0024] Step 16: Determine the overall scheme of the wind tunnel distributed compressor system as a series-parallel distributed compressor system. The number of compressors connected in series in the series-parallel distributed compressor system is determined by step 8, and the number of parallel compressors at each compressor series position in the series-parallel distributed compressor system is determined by step 15.

[0025] The lack of a systematic design methodology for distributed compressor systems in existing technologies leads to reliance on experience in determining the number of series compressors, the number of parallel compressors, and the series-parallel combination layout, which fails to guarantee the rationality, economy, and feasibility of the design. To address this issue, this method constructs a closed-loop design logic through 16 steps: Steps 1-4 transform wind tunnel aerodynamic requirements into compressor system performance constraints; Steps 5-14 determine the number of series compressors through iterative design, employing overlapping operating points and load distribution strategies to ensure smooth operating condition coverage; Step 15 assesses parallel replacement requirements based on manufacturing capabilities and determines the number of parallel compressors; Step 16 outputs the overall scheme for the series-parallel distributed compressor system. This provides a complete design process from wind tunnel operating condition requirements to the overall scheme of the series-parallel distributed compressor system, scientifically determining the number of series compressors and the number of parallel compressors at each series location, ultimately outputting M1+M2+…+M N The overall scheme of the serial-parallel distributed compressor system.

[0026] Preferably, the conversion operation in step 2 is performed using the following formula:

[0027] ;

[0028] ;

[0029] in, To convert the flow rate, For quality flow, To stabilize the total temperature of the section, To stabilize the total pressure in the section, The total pressure ratio, This is for resistance loss.

[0030] Specifically, the specific mathematical conversion relationship between the wind tunnel mass flow rate-drag loss curve and the compressor system equivalent flow rate-total pressure ratio curve enables subsequent steps to be designed based on the accurate compressor system performance curve.

[0031] The preferred method for calculating the minimum isentropic efficiency requirement is as follows:

[0032] ;

[0033] in, For the lowest isentropic efficiency, The specific heat capacity at constant pressure of the working fluid. For quality flow, To stabilize the total temperature of the section, The total pressure ratio, The specific heat ratio of the working fluid. This is the maximum operating power.

[0034] This formula establishes a quantitative relationship between maximum operating power, mass flow rate, total temperature, total pressure ratio and efficiency requirements, making design constraints quantifiable and calculable.

[0035] Preferably, the value of K is 1 or 2.

[0036] Preferably, in step 11, the load distribution adopts the principle of equal pressure ratio distribution. If the distributed working point is located below the compressor blockage line, the total pressure ratio of the corresponding compressor is increased so that it is located above the blockage line.

[0037] Among them, the equal pressure ratio distribution principle is that the total pressure ratio borne by each compressor in the series system is equal, which simplifies the distribution logic and makes the load of each compressor balanced;

[0038] Blockage line adjustment: If the allocated operating point is below the blockage line (i.e., the flow rate is too high and exceeds the stable range), the total pressure ratio allocated to the compressor should be appropriately increased to move the operating point above the blockage line and ensure the stability of compressor operation.

[0039] Preferably, the minimum isentropic efficiency requirement for the (i+1)th compressor during operation at the design constraint point is calculated as follows:

[0040] ;

[0041] in, Let be the minimum isentropic efficiency of the (i+1)th compressor when it operates at the design constraint point. The specific heat capacity at constant pressure of the working fluid. To design the reduced flow rate at the constraint point, To stabilize the total temperature of the section, The total pressure ratio allocated to the (i+1)th compressor The specific heat ratio of the working fluid. For maximum operating power, This represents the total power consumption of the first to the i-th compressors.

[0042] Preferably, the criteria for determining whether a parallel distributed compressor system is needed in step 15 include: the compressor's disc diameter, casing diameter, or coupling power exceeding the processing, manufacturing, or technological maturity capabilities.

[0043] Among them, the impeller diameter reflects the processing difficulty of the turbomachinery; when it exceeds domestic processing capabilities, parallel replacement is required. The casing diameter reflects the processing and transportation capabilities of the casing; when these capabilities are exceeded, parallel replacement is required. The coupling power reflects the technological maturity of the transmission system; when it exceeds the capabilities of existing products, parallel replacement is required. The criteria for determining parallel replacement are clarified, including whether the compressor's impeller diameter, casing diameter, or coupling power exceeds the processing, manufacturing, or technological maturity capabilities, making the judgment standards specific and quantifiable.

[0044] Preferably, when it is determined that a parallel distributed compressor system is needed as a replacement, the number of parallel compressors is determined based on manufacturing capabilities or coupling power capacity. Clarifying that the number of parallel compressors is determined based on manufacturing capabilities or coupling power capacity ensures that the key dimensions or power specifications of each parallel compressor after replacement fall within an achievable range, thus guaranteeing the engineering feasibility of the solution.

[0045] Preferably, the serial-parallel distributed compressor system is represented as follows: Where N is the number of compressors connected in series in the serial-parallel distributed compressor system. These represent the number of parallel compressors at the 1st, 2nd, ..., Nth compressor series positions in the series-parallel distributed compressor system, respectively. For any... , =1 indicates a single compressor. >1 indicates that by Two compressors are connected in parallel. (Using...) The mathematical expression clearly defines the structure of the serial-parallel distributed compressor system.

[0046] Preferably, the isentropic efficiency of the i-th compressor at the design constraint operating point in step 6 is equal to the target isentropic efficiency requirement. If the design efficiency is much higher than the target efficiency, it means that the compressor performance is excessive, and the number of stages can be appropriately reduced or the design difficulty can be reduced; if the design efficiency is slightly lower than the target efficiency, the number of stages needs to be increased or the design needs to be improved; the iteration is carried out with the goal of equality, so that the compressor performance just meets the requirements, without generating redundancy, thereby reducing the number of units in series and reducing system complexity and cost.

[0047] One or more technical solutions provided by this invention have at least the following technical effects or advantages:

[0048] It provides a complete design process from wind tunnel requirements to serial-parallel scheme output, filling the gap in the design methodology of distributed compressor systems.

[0049] Based on quantitative parameters such as wind tunnel drag characteristics, compressor aerodynamic performance, and power constraints, a clear judgment logic and calculation formula were established to avoid the blindness of experience-based design.

[0050] By using overlapping operating points and load distribution strategies, the series system can smoothly cover all operating conditions, avoiding sudden changes in operating conditions or operational instability.

[0051] While meeting performance requirements, the design difficulty of the compressor is controlled by the minimum isentropic efficiency requirement, and the processing and manufacturing pressure of a single compressor is reduced by parallel replacement, thus effectively balancing performance and cost. Attached Figure Description

[0052] The accompanying drawings, which are provided to further illustrate embodiments of the invention and constitute a part of this invention, are not intended to limit the scope of the invention.

[0053] Figure 1 This is a schematic diagram of a parallel distributed compressor system;

[0054] Figure 2 This is a schematic diagram of a series distributed compressor system;

[0055] Figure 3 This is a schematic diagram of a series-parallel distributed compressor system;

[0056] Figure 4 Wind tunnel mass flow rate -Drag loss Schematic diagram of the relationship curve;

[0057] Figure 5 Converted flow rate for compressor system -Total pressure ratio Schematic diagram of the relationship curve;

[0058] Figure 6 A schematic diagram showing the minimum isentropic efficiency requirements of the compressor system at various operating points;

[0059] Figure 7 A schematic diagram showing the aerodynamic performance and operating condition coverage of compressor #1;

[0060] Figure 8 This is a schematic diagram showing the aerodynamic performance and operating condition coverage of compressor #2;

[0061] Figure 9 This is a schematic diagram showing the coverage of the series operation of compressors #1 and #2.

[0062] Figure 10 A schematic diagram of a 2+1 series-parallel distributed compressor system for a wind tunnel.

[0063] Figure 11 This is a flowchart illustrating the design method for a continuous wind tunnel distributed compressor system. Detailed Implementation

[0064] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, where there is no conflict, the embodiments of the present invention and the features thereof can be combined with each other.

[0065] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0066] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0067] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0068] Example 1;

[0069] This invention, through analysis, reveals the current need for a design method for the overall design of continuous wind tunnel distributed compressor systems. This method provides scientific and effective guidance for the overall design decision of continuous wind tunnel distributed compressor systems, supporting the further development of continuous wind tunnels towards higher speeds, wider speed ranges, and greater precision.

[0070] Please refer to Figure 11 , Figure 11 This is a flowchart illustrating a design method for a continuous wind tunnel distributed compressor system. Embodiment 1 of the present invention provides a design method for a continuous wind tunnel distributed compressor system, characterized in that the method includes:

[0071] Step 1: Based on the number of operating points, total pressure in the steady section, and total temperature in the steady section of the wind tunnel, obtain the mass flow rate-drag loss relationship curve of the wind tunnel;

[0072] Step 2: Convert the mass flow rate-resistance loss relationship curve into the equivalent flow rate-total pressure ratio relationship curve of the wind tunnel distributed compressor system;

[0073] Step 3: Obtain the maximum operating power of the driving wind tunnel;

[0074] Step 4: Based on the maximum operating power, the mass flow rate at each operating point, the total pressure ratio obtained in Step 2, and the total temperature in the steady section, calculate the minimum isentropic efficiency requirement of the wind tunnel distributed compressor system at each operating point.

[0075] Step 5: Select the operating point with the lowest isentropic efficiency of the wind tunnel distributed compressor system across the entire operating range as the design constraint operating point of the first compressor, and take the lowest isentropic efficiency requirement corresponding to this operating point as the target isentropic efficiency requirement of the first compressor.

[0076] Step 6: Iteratively design the i-th compressor to ensure that the isentropic efficiency of the i-th compressor at the design constraint operating point is not less than the target isentropic efficiency requirement determined in Step 5 or Step 13. The initial value of i is 1, which is updated according to the number of compressors in the series distributed compressor system to be designed.

[0077] Step 7: Evaluate the aerodynamic performance of the i-th compressor, obtain the anti-surge line and blockage line of the i-th compressor, and determine the operating condition range that can be met when the first to the i-th compressors are running in a matched manner based on the reduced flow rate-total pressure ratio relationship curve.

[0078] Step 8: If the current operating condition range covers all operating conditions, let the total number of compressors in the series distributed compressor system be i, and then execute step 15; if the current operating condition range does not cover all operating conditions, determine the uncovered operating condition range, and then execute step 9.

[0079] Step 9: Arrange the (i+1)th compressor in series after the i-th compressor along the airflow direction. Sort the currently covered operating points in ascending order of comprehensive surge margin, and select the first K operating points as overlapping operating points.

[0080] Step 10: Select the operating point with the largest comprehensive surge margin from the overlapping operating points as the design constraint point of the (i+1)th compressor, and determine the equivalent flow rate and total pressure ratio of the design constraint point;

[0081] Step 11: Based on the reduced flow rate and total pressure ratio of the design constraint point, determine the load distribution of each compressor when the first to the (i+1)th compressors are operated in series to meet the performance requirements of the design constraint point and the uncovered operating conditions, including the total pressure ratio and reduced flow rate of each compressor.

[0082] Step 12: Based on the load distribution results determined in Step 11 and the aerodynamic performance of the first to the i-th compressors, determine the power consumption of each compressor and the total power consumption when the first to the i-th compressors are connected in series to meet the performance requirements of the design constraint point.

[0083] Step 13: Based on the reduced flow rate at the design constraint point and the total power consumption, calculate the minimum isentropic efficiency requirement for the (i+1)th compressor when it is running at the design constraint point, and use the minimum isentropic efficiency requirement as the target isentropic efficiency requirement for the (i+1)th compressor.

[0084] Step 14: Update i to i+1, return and repeat steps 6 to 14 until the current working condition range in step 8 has covered all working conditions.

[0085] Step 15: Based on the processing and manufacturing capabilities and operational economic requirements, determine whether any compressor in the series distributed compressor system needs to be replaced by a parallel distributed compressor system, and determine the number of parallel compressors after replacement;

[0086] Step 16: Determine the overall scheme of the wind tunnel distributed compressor system as a series-parallel distributed compressor system. The number of compressors connected in series in the series-parallel distributed compressor system is determined by step 8, and the number of parallel compressors at each compressor series position in the series-parallel distributed compressor system is determined by step 15.

[0087] The specific objectives of this invention include: establishing a quantitative design logic based on wind tunnel aerodynamic parameters and compressor performance characteristics; providing methods for determining the number of series compressors, the number of parallel compressors, and the series-parallel combination layout; taking into account manufacturing feasibility, operational economy, and technological maturity while meeting the full operating requirements of the wind tunnel; and providing scientific and effective methodological guidance for the overall design of continuous wind tunnel distributed compressor systems, supporting the development of wind tunnels towards higher speeds, wider speed ranges, and greater precision.

[0088] The objective of this invention is achieved through the following technical solution:

[0089] Objective 1: To establish a systematic design logic:

[0090] This method constructs a complete process from wind tunnel condition analysis, conversion curve calculation, efficiency constraint determination, series iterative design, load allocation to series-parallel combination through 16 steps. Each step has clear input, output and judgment conditions, forming a closed-loop logic.

[0091] Objective 2: Determine the number of compressors in series:

[0092] This is achieved through an iterative loop from steps 5 to 14: Step 5 selects the operating point with the lowest isentropic efficiency as the design constraint point for the first compressor; Step 6 designs the i-th compressor to meet the efficiency requirements; Step 7 evaluates the operating condition coverage of the designed compressors; Step 8 determines whether it covers all operating conditions. If it does not cover all operating conditions, steps 9 to 14 are executed to add the next compressor in series; the loop continues until all operating conditions are covered, and the number of compressors in series N is determined by step 8.

[0093] Objective 3: Determine the number of compressors to be connected in parallel:

[0094] Step 15 achieves the following: Based on the processing and manufacturing capabilities (disc diameter, casing diameter, coupling power), it is determined whether each series position needs to be replaced by parallel connection; the number of parallel units is calculated through capability matching, so that the key parameters of each parallel compressor after replacement fall within the achievable range.

[0095] Objective 4: To balance manufacturing feasibility and economic efficiency.

[0096] Step 3 incorporates engineering investment, power resources, and technical complexity into the determination of the power limit to control investment risks from the source; Step 6 sets the design goal of efficiency equal to the minimum requirement to avoid over-design and reduce the cost of a single compressor; Step 15 introduces the assessment of processing and manufacturing capabilities to ensure that the design scheme is engineering feasible.

[0097] Objective 5: To provide scientific methodological guidance:

[0098] Steps 2, 4, and 13 provide explicit mathematical transformations and calculation formulas; steps 9 and 10 define the selection strategy for overlapping load points (sorted by surge margin, taking the top K points, and then selecting the point with the largest margin); step 11 provides specific principles for load distribution (equal pressure ratio distribution, plugging line adjustment); step 16... The final solution should be clearly expressed in a formal manner.

[0099] The technical principle of this invention is as follows:

[0100] The technical principle of this invention can be summarized as a four-step logic: demand decomposition—level-by-level matching—load allocation—serial-parallel combination.

[0101] 1. Requirements Decomposition:

[0102] The overall performance requirements of the wind tunnel (number of operating points, total pressure in the steady section, total temperature, etc.) are converted into the reduced flow-total pressure ratio characteristic curve required by the compressor system, and the minimum isentropic efficiency requirement of the compressor system at each operating point is calculated based on the maximum operating power constraint.

[0103] 2. Hierarchical matching:

[0104] Starting from the most demanding operating point (the point of lowest isentropic efficiency), the first, second, ... Nth series compressors are designed sequentially, ensuring that the efficiency of each compressor at its design constraint point is not lower than the minimum efficiency requirement of the system, thereby ensuring that the series system can cover as many operating conditions as possible.

[0105] 3. Load Distribution:

[0106] When the designed series compressors cannot cover all operating conditions, the design constraint points of the new compressors are determined by the overlapping operating point selection strategy. The load (total pressure ratio and equivalent flow rate) of each compressor during series operation is determined by the equal pressure ratio distribution principle or the calculation method of the adaptation target, and then the power consumption and efficiency requirements are calculated.

[0107] 4. Serial-parallel combination:

[0108] After the series connection scheme is determined, based on manufacturing capabilities (such as disc diameter, casing diameter, and coupling power limitations) and operational economics, it is determined whether the compressors at each series position need to be replaced by parallel connections, and the number of units connected in parallel is determined, ultimately forming... The overall scheme of the serial-parallel distributed compressor system.

[0109] The macroscopic requirements of the wind tunnel are decomposed into quantifiable design targets for individual compressors. The number of series and parallel connections is determined through iterative optimization, so that the overall system achieves the optimal balance between performance, manufacturing, and cost.

[0110] Among them, the continuous wind tunnel distributed compressor system refers to a compressor system assembly that uses multiple relatively small compressors connected in parallel, series or series-parallel combination to drive the operation of a continuous wind tunnel, so as to meet the wind tunnel's requirements for ultra-large flow rate, ultra-high total pressure ratio and wide operating range.

[0111] The mass flow rate-drag loss curve describes the mass flow rate in a continuous wind tunnel loop. Total pressure loss generated by airflow through the wind tunnel loop The curve showing the functional relationship between (i.e., drag loss) and the total pressure in the steady section is determined by the geometric characteristics of the wind tunnel. and the total temperature of the stable section The combined determination reflects the flow resistance characteristics of the wind tunnel loop under different operating conditions.

[0112] The maximum operating power of the drive wind tunnel is determined as follows: By surveying the product specifications, market prices, and technological maturity of motor and frequency converter manufacturers, combined with the project investment budget, the maximum operating power of the drive wind tunnel is determined. Specifically, this can be achieved by surveying domestic motor and frequency converter manufacturers to obtain the rated power series of existing mature products, denoted as {P1, P2, ..., Pn}, where n is the total number of power levels obtained from the survey. The technological maturity, delivery cycle, and market price corresponding to each power level are confirmed. Based on the project investment budget B, an acceptable upper limit Cmax for the purchase cost of a single motor and frequency converter is set. Power levels whose purchase cost does not exceed Cmax are selected from {P1, P2, ..., Pn}, forming a candidate power set {Pc1, Pc2, ..., Pcm}, where m is the total number of candidate power levels. The power level with the highest technological maturity (i.e., the most existing engineering application cases and the most complete reliability data) is selected from the candidate power set as the recommended power Prec. If the technological maturity is similar, the power level with the highest power is selected to improve the system capacity margin. The maximum operating power Mmax = Prec is then determined. If the project investment budget is relatively generous and mature products with higher power ratings are available, the upper limit of power required for full-condition operation can be directly selected based on the overall performance requirements of the wind tunnel. However, it is necessary to ensure that there are already mature application cases for this power rating to avoid technical risks. Other existing methods can also be used to obtain the maximum operating power of the wind tunnel; this embodiment of the invention does not impose any limitations on this method.

[0113] Among them, the series distributed compressor system refers to a compressor system structure in a continuous wind tunnel distributed compressor system in which multiple compressors are arranged in series along the airflow direction to jointly bear the total pressure ratio required by the wind tunnel loop. The compressor system structure meets the wind tunnel's requirement for ultra-high total pressure ratio by superimposing the pressure ratios of each compressor.

[0114] Among them, the series-parallel distributed compressor system refers to the combination of parallel distributed compressor systems and series distributed compressor systems in a continuous wind tunnel distributed compressor system. That is, multiple parallel units are connected in series along the airflow direction to form a hybrid structure of parallel first, then series, or a combination of series and parallel, which can meet the wind tunnel's requirements for large flow rate and high total pressure ratio.

[0115] The following is a detailed introduction to this method:

[0116] Embodiment 1 of this invention provides a design method for the overall design of a continuous wind tunnel distributed compressor system, which solves the problem of the lack of a design method for the overall design of a continuous wind tunnel distributed compressor system. It provides scientific and effective methodological guidance for the design decision of the overall scheme of the continuous wind tunnel distributed compressor system, and supports the further development of continuous wind tunnels towards high speed, wide speed range and precision (for the sake of simplification, the wind tunnel compressor system is abbreviated as compressor system in this section).

[0117] To achieve the objectives stated in this invention, this invention provides a design method for the overall design of a continuous wind tunnel distributed compressor system. Steps (1) to (4) obtain the design input and design constraints of the compressor system; steps (5) to (14) design the series configuration of the compressor system; step (15) analyzes whether the i-th compressor in the series compressor configuration needs to be designed in parallel and determines the number of compressors in parallel. The method includes the following steps:

[0118] (1) Based on wind tunnel characteristics (number of operating points) Total pressure in the stable section and total temperature (etc.) to obtain wind tunnel mass flow rate -Drag loss The relationship curve is used as the basis for calculating the compressor system design input in step (2). For specific implementation methods, please refer to the "Practical Fluid Resistance Handbook". The embodiments of this invention will not be described in detail.

[0119] (2) The wind tunnel mass flow rate -Drag loss Relationship curve converted to compressor reduced flow rate -Total pressure ratio The relationship curve serves as input for the overall design of the compressor system. The transformed relationship is: , ;

[0120] (3) Based on factors such as the estimated project investment, the technical complexity of the motor and frequency converter system, and the cost of test operation, determine the maximum operating power of the drive wind tunnel. (Determine the maximum operating power based on the investment budget and the current market prices of motors and frequency converters. Generally, the power of the motor should not exceed the maximum power already developed, in order to improve the maturity of the technology. The specific power can also be determined by surveying domestic motor and frequency converter manufacturers.) Obtain the input for the overall design of the compressor system.

[0121] (4) Based on steps (1), (2) and (3), obtain the design input for the overall compressor scheme and calculate the minimum isentropic efficiency of the compressor. Requirements, as design constraints for the compressor system, In the formula, The specific heat capacity at constant pressure of the working fluid. express of Power of 1 The specific heat ratio of the working fluid;

[0122] (5) Select the high flow rate and low total pressure ratio operating point as the design constraint operating point of the first compressor (compressor #1) (based on the essential characteristics of compressor operation, the high flow rate and low total pressure ratio operating point has the lowest efficiency. Therefore, as long as the efficiency at the lowest efficiency point meets the minimum efficiency requirement, the efficiency of the compressor across the entire operating range can be guaranteed). Clarify the minimum isentropic efficiency requirement of the compressor at the design constraint operating point. The subscript min indicates the minimum value. Indicates correspondence # Compressor, which is equal to 1 here. The minimum isentropic efficiency requirement of compressor #1 is given directly by step (4).

[0123] (6) Design #compressor( , The initial value is 1, and it is updated in subsequent iterations. (The number of compressors in a series distributed compressor system) until the isentropic efficiency of the compressor at the design constraint operating point is not less than the minimum isentropic efficiency. In practice, the isentropic efficiency at the compressor design constraint operating point can be equal to the minimum isentropic efficiency as the design objective, so as to reduce the number of compressors in the series distributed compressor system.

[0124] (7) Complete the first #Compressor aerodynamic performance evaluation (comprehensive aerodynamic performance evaluation of compressors is often completed using numerical calculation methods, which can be done using commercial software. Common commercial software includes Ansys CFX, Numeca, etc., see the corresponding commercial software's user manual for details), obtain #Compressor's anti-surge line and blockage line (the anti-surge line and blockage line together determine the compressor's stable operating range, see...) Figure 4 According to the converted flow rate ( -Total pressure ratio ( Relationship curve, determine 1#~ #The operating range that the compressor can meet during operation (Operating Condition 1 to Operating Condition 2) (The obtained compressor comprehensive performance curve and converted flow rate) -Total pressure ratio ( Plot the relationship curves on a single graph (see details). Figure 8Operating conditions outside the anti-surge and blockage lines are considered unacceptable, while those within the anti-surge and blockage lines are considered acceptable.

[0125] (8) If ,make And jump to step (15), if This clarifies the operating conditions that are not yet covered (operating conditions). ~Working conditions ), proceed to step (9);

[0126] (9) Then, along the direction of the airflow, in #Compressor arranged in series #Compressor; Select distance 1#~ #When compressors are operated in series, they can cover the operating point with the smallest overall surge margin. Each operating point is used as an overlap operation operating point ( Generally, 1 to 2 is taken.

[0127] (10) Select the working point with the largest overall surge margin (farthest from the surge line) among the overlapping working points as the working point. #Design constraints of the compressor (denoted as) (Operating point), specifying the equivalent flow rate corresponding to this design constraint point as: The total pressure ratio is ;

[0128] (11) Clarify 1#~ #Compressors operate in series to meet the requirements Operating conditions and uncovered operating conditions (operating conditions) ~Working conditions The load distribution of each compressor under performance requirements. That is, 1#~ #When the compressor is running in series at a certain operating point #compressor( The total pressure ratio of the distribution ( ) and the corresponding equivalent flow rate ( In practice, when #1~ #Compressor series operation meets operating conditions When considering performance requirements, the load distribution can be calculated using formula (1) or other existing calculation methods that match the design objectives. Generally, the method provided in formula (1) can be used for calculation (where the superscript is...). This indicates the operating point number, where the subscript j represents the j-th compressor and the subscript l represents the l-th compressor, with a value range of [value missing]. , If the work point In If the compressor is blocked below the line, appropriately increase the total pressure ratio. The value is adjusted to ensure the operating point is above the compressor blockage line;

[0129] (1)

[0130] (12) According to 1#~ #The aerodynamic performance of the compressor, clarify #1~ #Compressors operate in series to meet the requirements Power consumed by each compressor at the operating point performance requirement. , , indicating 1#~ #Any one of the compressors, and #1~ #Total power consumed by the compressor , ;

[0131] (13) Calculate and clarify the i+1# compressor at Minimum isentropic efficiency requirement at operating point :

[0132] ;

[0133] in, Let be the minimum isentropic efficiency of the (i+1)th compressor when it operates at the design constraint point. The specific heat capacity at constant pressure of the working fluid. To design the reduced flow rate at the constraint point, To stabilize the total temperature of the section, The total pressure ratio allocated to the (i+1)th compressor The specific heat ratio of the working fluid. For maximum operating power, This represents the total power consumption of the first to the i-th compressors.

[0134] (14) Update The specific value is Repeat steps (6) to (14).

[0135] (15) Based on the requirements of processing and manufacturing, and the economic efficiency of compressor system operation, analyze and clarify the characteristics of series distributed compressor systems. #Whether the compressor needs to be replaced by a parallel distributed compressor system and the number of compressors in the parallel distributed compressor system (this can be determined by surveying domestic processing and manufacturing capabilities, such as the ability to process the largest compressor disc and the largest compressor casing, or by surveying the capabilities of domestic coupling manufacturers to determine whether parallel connection is necessary. For example, if the disc diameter of the i-th series compressor is designed to be 1.0 meters, but the maximum processing capacity in China is only 0.8 meters, then the i-th series compressor needs to be designed as two parallel units, so that the disc diameter of each compressor can be reduced to 0.72 meters; or if the power of the coupling of the i-th compressor is designed to be 2MW, but it is found that the maximum R&D capacity of the coupling is only 1.5MW, then the i-th compressor needs to be designed as two parallel units, so that the power of a single coupling can be reduced to 1MW). , The compressors are numbered as follows: #compressor, );

[0136] (16) The overall scheme of the continuous wind tunnel compressor system is determined as follows: The series-parallel distributed compressor system (the subscript N represents the number of units connected in series, and M represents the number of units connected in parallel in each series unit (M=1 means a single unit, M>1 means M units connected in parallel, N is determined by step (8)). Determined by step (15).

[0137] Example 2;

[0138] Based on Embodiment 1, Embodiment 2 of the present invention describes the method with specific examples:

[0139] A continuous wind tunnel (wind tunnels can be divided into temporary and continuous types; this method is applicable to continuous wind tunnels; there are many types of compressors, this method is used for axial compressors and centrifugal compressors) has a stable section total pressure of 100 kPa and a stable section total temperature of 323 K. The wind tunnel operating conditions include 16 operating points, numbered sequentially as operating point 1 to operating point 16 (see...) Figure 5 Based on this invention, the overall scheme of the wind tunnel distributed compressor system is determined. The specific implementation steps are as follows:

[0140] (1) Based on the geometric characteristics of the wind tunnel and the total pressure of the steady section corresponding to each working point and total temperature Range to obtain wind tunnel mass flow rate -Drag loss Relationship curve, such as Figure 5 As shown;

[0141] (2) The wind tunnel mass flow rate -Drag loss Relationship curve converted to equivalent flow rate of wind tunnel compressor system -Total pressure ratio Relationship curve, such as Figure 6 As shown;

[0142] (3) Based on factors such as the estimated investment cost of the project, the power resources at the wind tunnel construction site, the technical complexity of the motor and frequency converter system, and the test operation cost, the maximum operating power of the wind tunnel is determined to be 1.6MW;

[0143] (4) Based on the maximum operating power limit of the wind tunnel and the mass flow rate, total pressure ratio, and total temperature characteristics of each test under each operating condition, calculate the minimum isentropic efficiency of the wind tunnel compressor system at each operating point. Requirements, such as Figure 7 As shown;

[0144] (5) Select operating point 1 as the design constraint point of compressor #1. According to step (4), the minimum isentropic efficiency requirement of the compressor at this operating point should not be lower than 77.37%.

[0145] (6) The design scheme of compressor No. 1 was obtained through iterative design. The compressor has 5 stages, the compressor disc diameter is 0.9 meters, the maximum diameter of the compressor casing is 1.5 meters, and the efficiency at the design constraint point is 77.68%.

[0146] (7) Calculate the aerodynamic performance of compressor #1, obtain the anti-surge line and blockage line of compressor #1, and based on the aerodynamic performance of compressor #1, determine whether the aerodynamic performance of compressor #1 meets the requirements of operating points 1 to 10 when operating alone. See Figure 8 ;

[0147] (8) It can be seen that the single compressor technical solution cannot safely meet the requirements of the wind tunnel operation under all working conditions. Along the airflow direction, the second compressor is arranged in series after the first compressor, and the working condition point 10 is selected as the overlapping working condition point.

[0148] (9) Since there is only one overlapping working condition point, this point is selected as the design constraint point of compressor #2. Based on step (2), the equivalent flow rate of this point is 0.005548 and the total pressure ratio is 2.94.

[0149] (10) When the series operation of compressors 1# and 2# meets the performance requirements of the overlapping operating point, the total pressure ratio allocated to compressor 1# is 1.715, and the corresponding equivalent flow rate is 0.005548; the total pressure ratio allocated to compressor 2# is 1.715, and the corresponding equivalent flow rate is 0.003235; the allocation of operating points 11-16 is shown in the figure. Figure 8 The specific calculation can be performed using the aforementioned load distribution formula;

[0150] (11) Based on the aerodynamic performance of compressor #1, it is calculated that when compressors #1 and #2 are connected in series to meet the performance requirements of operating point 10, the power consumed by compressor #1 is 0.79166MW;

[0151] (12) When compressors 1# and 2# are connected in series to meet the performance requirements of operating point 10, the minimum isentropic efficiency requirement of compressor 2# is 70.55%;

[0152] (13) Based on the design point constraints, the aerodynamic design scheme of compressor #2 (hub diameter 0.65 m, casing diameter 1.08 m, compressor stage 7) was obtained according to steps (6) to (8) in the instruction manual. It was found that compressors #1 and #2 can meet the performance requirements of operating conditions 10-16 when running in parallel. The isentropic efficiency at the design constraint point is 71.34%. See Figure 9 ;

[0153] (14) It can be seen that the series distributed compressor system with compressors #1 and #2 arranged in series can meet the performance requirements of the wind tunnel under all working conditions. Therefore, step (15) in Example 1 is executed.

[0154] (15) The survey found that the existing processing capacity can meet the processing of a 0.7-meter diameter disc and a 1.5-meter casing. Therefore, compressor #1 needs to be replaced with a parallel distributed compressor system based on multiple compressors connected in parallel. Based on the disc processing capacity, it was calculated that compressor #1 can be replaced with a parallel distributed compressor system based on two smaller compressors connected in parallel. At this time, the disc diameter of a single compressor is reduced to 0.675 meters, which is feasible. The calculation method is to calculate the disc diameter of a single parallel compressor based on the principle of area equivalence, and then take the final branch after considering the processing margin, or use other reasonable calculations. The embodiments of this invention will not be described in detail.

[0155] (16) The overall scheme of the continuous wind tunnel compressor system is determined to be a 2+1 series-parallel distributed compressor system, such as Figure 10 As shown.

[0156] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0157] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A design method for a continuous wind tunnel distributed compressor system, characterized in that, The method includes: Step 1: Based on the number of operating points, total pressure in the steady section, and total temperature in the steady section of the wind tunnel, obtain the mass flow rate-drag loss relationship curve of the wind tunnel; Step 2: Convert the mass flow rate-resistance loss relationship curve into the equivalent flow rate-total pressure ratio relationship curve of the wind tunnel distributed compressor system; Step 3: Obtain the maximum operating power of the driving wind tunnel; Step 4: Based on the maximum operating power, the mass flow rate at each operating point, the total pressure ratio obtained in Step 2, and the total temperature in the steady section, calculate the minimum isentropic efficiency requirement of the wind tunnel distributed compressor system at each operating point. Step 5: Select the operating point with the lowest isentropic efficiency of the wind tunnel distributed compressor system across the entire operating range as the design constraint operating point of the first compressor, and take the lowest isentropic efficiency requirement corresponding to this operating point as the target isentropic efficiency requirement of the first compressor. Step 6: Iteratively design the i-th compressor to ensure that the isentropic efficiency of the i-th compressor at the design constraint operating point is not less than the target isentropic efficiency requirement determined in Step 5 or Step 13. The initial value of i is 1, which is updated according to the number of compressors in the series distributed compressor system to be designed. Step 7: Evaluate the aerodynamic performance of the i-th compressor, obtain the anti-surge line and blockage line of the i-th compressor, and determine the operating condition range that can be met when the first to the i-th compressors are running in a matched manner based on the reduced flow rate-total pressure ratio relationship curve. Step 8: If the current operating condition range covers all operating conditions, let the total number of compressors in the series distributed compressor system be i, and then execute step 15; if the current operating condition range does not cover all operating conditions, determine the uncovered operating condition range, and then execute step 9. Step 9: Arrange the (i+1)th compressor in series after the i-th compressor along the airflow direction. Sort the currently covered operating points in ascending order of comprehensive surge margin, and select the first K operating points as overlapping operating points. Step 10: Select the operating point with the largest comprehensive surge margin from the overlapping operating points as the design constraint point of the (i+1)th compressor, and determine the equivalent flow rate and total pressure ratio of the design constraint point; Step 11: Based on the reduced flow rate and total pressure ratio of the design constraint point, determine the load distribution of each compressor when the first to the (i+1)th compressors are operated in series to meet the performance requirements of the design constraint point and the uncovered operating conditions, including the total pressure ratio and reduced flow rate of each compressor. Step 12: Based on the load distribution results determined in Step 11 and the aerodynamic performance of the first to the i-th compressors, determine the power consumption of each compressor and the total power consumption when the first to the i-th compressors are connected in series to meet the performance requirements of the design constraint point. Step 13: Based on the reduced flow rate at the design constraint point and the total power consumption, calculate the minimum isentropic efficiency requirement for the (i+1)th compressor when it is running at the design constraint point, and use the minimum isentropic efficiency requirement as the target isentropic efficiency requirement for the (i+1)th compressor. Step 14: Update i to i+1, return and repeat steps 6 to 14 until the current working condition range in step 8 has covered all working conditions. Step 15: Based on the processing and manufacturing capabilities and operational economic requirements, determine whether any compressor in the series distributed compressor system needs to be replaced by a parallel distributed compressor system, and determine the number of parallel compressors after replacement; Step 16: Determine the overall scheme of the wind tunnel distributed compressor system as a series-parallel distributed compressor system. The number of compressors connected in series in the series-parallel distributed compressor system is determined by step 8, and the number of parallel compressors at each compressor series position in the series-parallel distributed compressor system is determined by step 15.

2. The design method for a continuous wind tunnel distributed compressor system according to claim 1, characterized in that, The conversion operation in step 2 is performed using the following formula: ； ； in, To convert the flow rate, For quality flow, To stabilize the total temperature of the section, To stabilize the total pressure in the section, The total pressure ratio, This is for resistance loss.

3. The design method for a continuous wind tunnel distributed compressor system according to claim 1, characterized in that, The minimum isentropic efficiency requirement is calculated as follows: ； in, For the lowest isentropic efficiency, The specific heat capacity at constant pressure of the working fluid. For quality flow, To stabilize the total temperature of the section, The total pressure ratio, The specific heat ratio of the working fluid. This is the maximum operating power.

4. The design method for a continuous wind tunnel distributed compressor system according to claim 1, characterized in that, The value of K is either 1 or 2.

5. The design method for a continuous wind tunnel distributed compressor system according to claim 1, characterized in that, In step 11, the load distribution adopts the principle of equal pressure ratio distribution. If the operating point after distribution is located below the compressor blockage line, the total pressure ratio of the corresponding compressor is increased so that it is located above the blockage line.

6. The design method for a continuous wind tunnel distributed compressor system according to claim 1, characterized in that, The minimum isentropic efficiency requirement for the (i+1)th compressor when operating at the design constraint point is calculated as follows: ； in, Let be the minimum isentropic efficiency of the (i+1)th compressor when it operates at the design constraint point. The specific heat capacity at constant pressure of the working fluid. To design the reduced flow rate at the constraint point, To stabilize the total temperature of the section, The total pressure ratio allocated to the (i+1)th compressor. The specific heat ratio of the working fluid. For maximum operating power, This represents the total power consumption of the first to the i-th compressors.

7. The design method for a continuous wind tunnel distributed compressor system according to claim 1, characterized in that, The criteria for determining whether a parallel distributed compressor system is needed in step 15 include: the compressor's disc diameter, casing diameter, or coupling power exceeding the processing, manufacturing, or technological maturity capabilities.

8. The design method for a continuous wind tunnel distributed compressor system according to claim 7, characterized in that, When it is determined that a parallel distributed compressor system is needed as an alternative, the number of parallel compressors is determined based on the processing and manufacturing capabilities or the power capacity of the coupling.

9. The design method for a continuous wind tunnel distributed compressor system according to claim 1, characterized in that, The serial-parallel distributed compressor system is represented as follows: Where N is the number of compressors connected in series in the serial-parallel distributed compressor system. These represent the number of parallel compressors at the 1st, 2nd, ..., Nth compressor series positions in the series-parallel distributed compressor system, respectively. For any... , =1 indicates a single compressor. >1 indicates that by Two compressors are connected in parallel.

10. The design method for a continuous wind tunnel distributed compressor system according to claim 1, characterized in that, In step 6, the isentropic efficiency of the i-th compressor at the design constraint operating point is equal to the target isentropic efficiency requirement.

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