Method and device for evaluating resistance of air duct system of environmental test chamber online and electronic equipment

Abstract

The application discloses an environmental test chamber air duct system resistance online evaluation method and device and electronic equipment. The method comprises a system pre-calibration stage and an on-site measurement evaluation stage. The system pre-calibration stage is used for establishing a "current I-static pressure P-air volume Q" mapping relationship database containing fluid dynamics coupling influence between parallel air fans. In the on-site measurement evaluation stage, the air fan operation current corresponding to each resistance is collected under a pre-set parallel operation condition. The air fan operation current corresponding to each resistance is matched with the pre-calibrated mapping relationship database to obtain an "air volume Q-static pressure P" working point corresponding to each air fan operation current. Based on fluid mechanics principles, quadratic curve fitting is performed on the obtained multiple working points to obtain an actual resistance characteristic curve of the air duct system of the target environmental test chamber. The technical scheme provided by the application can effectively reduce the test resistance cost and improve the operation efficiency of the test chamber.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment control technology, and in particular to a method, apparatus, and electronic equipment for online evaluation of the resistance of the air duct system of an environmental test chamber. Background Technology

[0002] The forced air circulation system is a core component of environmental test chambers (such as high and low temperature test chambers and rapid temperature change test chambers). The resistance characteristics of the air duct system directly determine the temperature uniformity, temperature change rate, and overall energy efficiency within the chamber. Currently, air duct resistance is typically assessed by installing sensors such as Pitot tubes, micromanometers, or hot-wire anemometers inside the air duct, or by judging the resistance based on experience.

[0003] Installing sensors to measure has the following significant drawbacks:

[0004] 1. Intrusiveness and Interference: Installing sensors requires openings or inserting them into air ducts, which may alter the original flow field, affecting the accuracy of the assessment, and is not suitable for routine inspection of encapsulated equipment. 2. High Cost and Complex Operation: Dedicated sensors are expensive, the testing process is cumbersome, and requires professional personnel to operate. 3. Inability to Achieve Online Monitoring: Difficult to integrate into equipment control systems for periodic automatic diagnostics.

[0005] The method of estimating wind resistance based on empirical values ​​and then selecting fans can easily lead to insufficient airflow or excessive airflow margin in the environmental test chamber. Insufficient airflow can cause problems such as a decrease in the heating and cooling rate of the test chamber, poor uniformity, and liquid return from the compressor, while excessive airflow can cause unnecessary energy loss and increased costs.

[0006] Furthermore, for test chambers employing multiple fans operating in parallel, the overall performance is not simply the sum of the individual fan performance due to the strong hydrodynamic coupling and mutual influence between the fans. The methods described above are insufficient for easily and accurately evaluating the overall wind resistance characteristics of such a complex parallel system after actual assembly, which can lead to inappropriate fan selection. Summary of the Invention

[0007] This invention provides an online evaluation method, device, and electronic equipment for the air duct system resistance of an environmental test chamber, to solve the problem that existing technologies are unable to easily and accurately evaluate the overall air resistance characteristics of such complex parallel systems after actual assembly, which may lead to unreasonable fan selection.

[0008] According to one aspect of the present invention, an online evaluation method for the resistance of the air duct system of an environmental test chamber is provided, including a system pre-calibration stage and an on-site measurement and evaluation stage;

[0009] The system pre-calibration stage is used to establish a "current I-static pressure P-air volume Q" mapping relationship database that includes the fluid dynamic coupling effects between parallel fans. Specifically, it includes: installing the target model fan on the fan test platform, and collecting fan operating current, duct system static pressure, and total fan air volume data corresponding to each resistance level under pre-set parallel operation conditions by adjusting the resistance of the duct system; fitting IPQ curve clusters under the corresponding operating conditions based on the collected fan operating current, duct system static pressure, and total fan air volume data, and summarizing them to form a mapping relationship database.

[0010] The on-site measurement and evaluation phase is used to evaluate the resistance of the air duct system of the target environmental test chamber. Specifically, it includes: installing parallel fans of the same model as those used in the system pre-calibration phase into the air duct system of the target environmental test chamber, keeping the fan control mode consistent with that in the system pre-calibration phase; collecting the fan operating current corresponding to each resistance under pre-set parallel operation conditions; matching the fan operating current corresponding to each resistance with the pre-calibrated mapping relationship database to obtain the "air volume Q - static pressure P" operating point corresponding to each fan operating current; and performing quadratic curve fitting on the multiple operating points obtained based on fluid mechanics principles to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

[0011] Optionally, in the system pre-calibration stage, the pre-set parallel operation condition is a condition with a fixed fan operating frequency and a changing number of fans in parallel. The system pre-calibration stage specifically includes:

[0012] S1-1: Select a single target model wind turbine, install it on the wind turbine experimental test platform, and construct a standard test system;

[0013] S1-2: Control the fan to operate stably at a preset fixed frequency. Adjust the resistance of the air duct system by controlling the nozzle switch or air valve on the fan test platform. Collect the fan operating current, air duct system static pressure and total fan air volume data under different resistances. Based on the collected fan operating current, air duct system static pressure and total fan air volume data, fit the IPQ curve cluster of a single fan.

[0014] S1-3: Gradually increase the number of parallel fans of the same model, repeat the operation of step S1-2, collect the average operating current, static pressure of the duct system and total air volume of the parallel fans under different resistance conditions for each number of parallel fans, fit the IPQ curve clusters corresponding to different numbers of parallel fans, and summarize them to form a mapping relationship database.

[0015] Optionally, in the on-site measurement and evaluation phase, the pre-set parallel operation condition is a condition where the operating frequency of the fans is fixed and the number of parallel fans in operation is changed. The on-site measurement and evaluation phase specifically includes:

[0016] S3-1: Install multiple parallel fans of the same model as those used in the system pre-calibration stage into the air duct system of the target environmental test chamber, and keep the fan operating frequency consistent with the preset fixed frequency of the system pre-calibration stage;

[0017] S3-2: First, start a single fan. After it stabilizes, collect the current operating current I1 of the fan. Then, increase the number of parallel fans started in sequence. After each adjustment, wait for the fan to stabilize and collect the average operating current IN of the parallel fans under the corresponding operating condition. N is the number of fans connected in parallel, and N is an integer ≥2.

[0018] S3-3: Match each current data with the pre-calibrated IPQ curve cluster corresponding to the number of parallel units, and obtain the "air volume Q - static pressure P" operating point (QN, PN) corresponding to each group of currents by interpolation or table lookup.

[0019] S3-4: The least squares method is used to perform quadratic curve fitting on the multiple operating points obtained to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

[0020] Optionally, in the system pre-calibration stage, the pre-set parallel operation condition is a condition with a fixed number of parallel fans and a changing fan operating frequency. The system pre-calibration stage specifically includes:

[0021] S2-1: Select a preset number of wind turbines of the same model and install them in parallel on the wind turbine test platform to construct a standard test system;

[0022] S2-2: Control all parallel fans to operate stably at the first preset frequency. By adjusting the resistance of the duct system, collect the fan operating current, duct system static pressure and total fan air volume data corresponding to different resistances. Based on the collected fan operating current, duct system static pressure and total fan air volume data, fit the IPQ curve cluster at this frequency.

[0023] S2-3: Keep the number of parallel fans constant, gradually adjust the operating frequency of the fans, repeat the operation of step S2-2, collect the average current of the parallel fans, the static pressure of the duct system and the total air volume of the fans under different operating frequencies and different resistance conditions, fit the IPQ curve clusters corresponding to different operating frequencies, and summarize them to form a mapping relationship database.

[0024] Optionally, in the on-site measurement and evaluation phase, the pre-set parallel operation condition is a condition with a fixed number of parallel fans and varying fan operating frequencies. The on-site measurement and evaluation phase specifically includes:

[0025] S4-1: Install the same model and number of parallel fans as those used in the system pre-calibration stage into the air duct system of the target environmental test chamber;

[0026] S4-2: Control all parallel fans to start at the first preset frequency. After the operation is stable, collect the average operating current I1' of the parallel fans under this condition. Adjust the operating frequency of all fans in sequence. After each adjustment, wait for the fans to run stably, and collect the average operating current In' of the parallel fans under the corresponding frequency condition, where n is the operating frequency of the fans.

[0027] S4-3: Match each collected current data with the pre-calibrated IPQ curve cluster corresponding to the operating frequency, and obtain the "air volume Q-static pressure P" operating point (Qn', Pn') corresponding to each group of currents by interpolation or table lookup.

[0028] S4-4: The least squares method is used to perform quadratic curve fitting on the multiple operating points obtained to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

[0029] Optionally, it also includes a drag characteristic test procedure for the target drag components within the duct system, specifically including:

[0030] S5-1: Install a target resistance component of the first specification in the air duct system of the target environment test chamber, and obtain the resistance of the air duct system of that specification through the system pre-calibration stage and the on-site measurement and evaluation stage.

[0031] S5-2: Keeping other components in the duct system unchanged, only change the specifications of the target resistance component, and repeat the operation of step S5-1 to obtain the resistance of the duct system under different specifications;

[0032] S5-3: Subtract the resistance corresponding to different specifications to obtain the resistance increment corresponding to the different specifications of the target resistance component;

[0033] S5-4: Based on the correspondence between the resistance increment and the change in the target resistance component's specifications, the "specification-resistance increment" characteristic curve of the target resistance component is obtained by fitting.

[0034] Optionally, the target resistance component is an evaporator inside the air duct of the environmental test chamber, and the specification change is a change in the number of pipe rows of the evaporator.

[0035] Optionally, the actual resistance characteristic curve satisfies the following relationship: ,in This represents the drag coefficient of the air duct system.

[0036] According to another aspect of the present invention, an online evaluation device for the air duct system resistance of an environmental test chamber is provided, comprising a system pre-calibration module and an on-site measurement and evaluation module;

[0037] The system pre-calibration module is used to establish a "current I-static pressure P-air volume Q" mapping relationship database that includes the fluid dynamic coupling effect between parallel fans. Specifically, it includes: installing the target model fan on the fan test platform, adjusting the resistance of the duct system, and collecting the fan operating current, duct system static pressure, and total fan air volume data corresponding to each resistance under pre-set parallel operation conditions; fitting the IPQ curve cluster under the corresponding operating conditions based on the collected fan operating current, duct system static pressure, and total fan air volume data, and summarizing them to form the mapping relationship database;

[0038] The on-site measurement and evaluation module is used to evaluate the resistance of the air duct system of the target environmental test chamber. Specifically, it includes: installing parallel fans of the same model as those used in the system pre-calibration stage into the air duct system of the target environmental test chamber, keeping the fan control mode consistent with that in the system pre-calibration stage; collecting the fan operating current corresponding to each resistance under pre-set parallel operation conditions; matching the fan operating current corresponding to each resistance with the pre-calibrated mapping relationship database to obtain the "air volume Q - static pressure P" operating point corresponding to each fan operating current; and performing quadratic curve fitting on the multiple operating points obtained based on fluid mechanics principles to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

[0039] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0040] At least one processor; and

[0041] A memory communicatively connected to the at least one processor; wherein,

[0042] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the online evaluation method for the air duct system resistance of the environmental test chamber according to any embodiment of the present invention.

[0043] The technical solution provided by this invention utilizes the easily measurable electrical signal of the fan operating current, combined with a mapping relationship database pre-established during the pre-calibration stage, to accurately back-calculate the resistance operating point of the duct system in a parallel fan environmental test chamber. This allows for the fitting of the resistance curve of the entire duct system, providing crucial data for fan selection and performance optimization. It solves the problem of existing technologies' difficulty in easily and accurately evaluating the overall wind resistance characteristics of such complex parallel systems after actual assembly, which can lead to unreasonable fan selection. The technical solution provided by this invention requires no damage or installation of any external fluid sensing devices, achieving non-invasive measurement. This method can be easily integrated into the test chamber software control, enabling periodic automatic operation, completing health checks and alarms for the duct system, resulting in low maintenance costs and online and self-diagnostic capabilities. The technical solution provided by this invention effectively reduces the cost of resistance testing and improves the operating efficiency of the test chamber.

[0044] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 A flowchart of an online evaluation method for the air duct system resistance of an environmental test chamber, provided as an embodiment of the present invention;

[0047] Figure 2 A flowchart of the system pre-calibration stage in an online evaluation method for the resistance of an environmental test chamber's duct system, provided in an embodiment of the present invention;

[0048] Figure 3 A flowchart illustrating the on-site measurement and evaluation stage of an online evaluation method for the air duct system resistance of an environmental test chamber, provided in an embodiment of the present invention;

[0049] Figure 4 A schematic diagram of the actual resistance characteristic curves under the conditions of fixed frequency and changing number of parallel fans in an online evaluation method for the resistance of the air duct system of an environmental test chamber provided in an embodiment of the present invention;

[0050] Figure 5 A flowchart of the system pre-calibration stage in another method for online evaluation of the air duct system resistance of an environmental test chamber provided in an embodiment of the present invention;

[0051] Figure 6 A flowchart of the on-site measurement and evaluation stage in another online evaluation method for the air duct system resistance of an environmental test chamber provided in an embodiment of the present invention;

[0052] Figure 7 A schematic diagram of the actual resistance characteristic curves under the condition of fixed parallel number and changing operating frequency in an online evaluation method for the resistance of the air duct system of an environmental test chamber provided in an embodiment of the present invention;

[0053] Figure 8 A flow chart for testing the resistance characteristics of a target resistance component within the air duct system of an environmental test chamber, provided as an embodiment of the present invention;

[0054] Figure 9 A schematic diagram of the structure of an online resistance assessment device for an environmental test chamber's air duct system provided in an embodiment of the present invention;

[0055] Figure 10 This is a schematic diagram of the electronic device used in an online evaluation method for the air duct system resistance of an environmental test chamber, as provided in an embodiment of the present invention. Detailed Implementation

[0056] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0057] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0058] Figure 1This is a flowchart illustrating an online evaluation method for the air duct system resistance of an environmental test chamber, provided by an embodiment of the present invention. This embodiment is applicable to the online evaluation of the air duct system resistance of test chambers with multiple fans operating in parallel. The method can be executed by an online evaluation device for the air duct system resistance of an environmental test chamber. This device can be implemented in hardware and / or software and can be configured in any electronic device with communication capabilities. See also... Figure 1 This method includes a system pre-calibration stage and an on-site measurement and evaluation stage.

[0059] S110, System Pre-calibration Stage: This stage establishes a "Current I-Static Pressure P-Air Volume Q" mapping relationship database that includes the fluid dynamic coupling effects between parallel fans. Specifically, this includes: installing the target model fan on the fan test platform; adjusting the resistance of the duct system; collecting fan operating current, duct system static pressure, and total fan air volume data corresponding to each resistance level under pre-set parallel operation conditions; fitting IPQ curve clusters under the corresponding operating conditions based on the collected fan operating current, duct system static pressure, and total fan air volume data; and summarizing these data to form the mapping relationship database.

[0060] The system pre-calibration stage is a one-time pre-laboratory task. Only one calibration is needed for parallel combinations of the same model and specifications of fans, and the database can be reused for all subsequent environmental test chambers of the same model. Its core function is to transform the difficult-to-measure airflow and resistance parameters, which require intrusive sensor installation, into a strong binding relationship with the easily collectable, non-invasive fan current signals. The fluid dynamic coupling effect between parallel fans refers to the fact that when multiple fans are connected in parallel to supply air to the same duct, the airflow between the fans interferes with each other, causes turbulent collisions, and competes for airflow. This results in the overall performance of multiple fans in parallel not being a simple sum of "single fan performance × number of fans." Traditional methods are insufficient to easily and accurately assess the overall resistance characteristics of such complex parallel systems after actual assembly. Here, "inclusion" means that this calibration stage measures the overall measured data of multiple fans operating in parallel, fully incorporating all mutual interference and coupling effects between fans into the data, rather than using single-fan data for theoretical summation, thus fundamentally ensuring the accuracy of the parallel system evaluation. In the "Current I-Static Pressure P-Air Volume Q" mapping database, I represents the input operating current of the fan motor, which can be directly read by the built-in electrical control system of the environmental test chamber without the need for any additional sensors; P represents the static pressure of the duct that the fan needs to overcome, which is the resistance of the duct system; and Q represents the total air volume actually output by the fan under the corresponding resistance. The mapping relationship means that for a specific fan model, a specific parallel combination, and stable operating conditions, there is a unique and definite correspondence between current I, static pressure P, and air volume Q. As long as the stable current value is known, the corresponding static pressure P and air volume Q can be uniquely identified. The database is a standardized set of this correspondence.

[0061] The target model of the fan refers to the same model of fan that must be selected from the actual installed fans in the subsequent environmental test chamber to ensure that the calibration data is completely matched with the field application. The fan test platform is a specialized piece of equipment with industry standards. It can accurately control the duct resistance and simultaneously and accurately collect three core data types: air volume, static pressure, and current. It eliminates interference from the field environment and obtains the most reliable original benchmark data. Adjusting the resistance of the duct system is achieved by controlling devices such as air valves and nozzle switches on the fan test platform to simulate the full-scenario load of the duct from extremely low resistance to high resistance. This is equivalent to simulating all possible duct resistance conditions that the fan may encounter in the field. The pre-set parallel operation conditions can be preset according to test requirements. This is the core of the "multi-mode" of this invention. It includes two modes: Mode 1: Fixed fan operating frequency, changing the number of fans in parallel (e.g., 1, 2, 3, 4); Mode 2: Fixed number of fans in parallel, changing the fan operating frequency (e.g., 30Hz, 35Hz, 40Hz, 45Hz, 50Hz). Setting these operating conditions in advance ensures that identical conditions are used during subsequent on-site testing, guaranteeing accurate matching of current data to the database. Collecting corresponding data means that for each adjustment of the resistance level, three sets of bound data—the fan operating current, the duct system static pressure, and the total fan airflow—are simultaneously collected under that stable operating condition, forming calibrated raw discrete data points.

[0062] Fitting IPQ curve clusters involves connecting discrete points into a continuous, smooth curve using mathematical fitting (such as the least squares method). A curve cluster refers to the collection of multiple independent IPQ curves corresponding to different operating conditions (different numbers of parallel units / different operating frequencies). For example, one fan corresponds to one curve, two fans in parallel correspond to one curve, and so on. Summarizing and forming a mapping database means integrating and archiving all IPQ curve clusters under preset operating conditions into a complete, searchable database. During subsequent on-site assessments, simply inputting the collected current into the database allows for quick reverse lookup of the corresponding airflow and duct resistance, providing a unique benchmark for on-site evaluation.

[0063] This step is the core foundation for the non-invasive, online duct system resistance assessment of this invention. Essentially, it involves establishing a unique database of correspondences between "fan operating current" and "duct resistance and total fan output" for the fans (including multiple parallel combinations) used in the subsequent environmental test chamber in a controlled standard laboratory environment. Furthermore, this database incorporates the mutual interference of airflow between multiple parallel fans (fluid dynamic coupling) into the measured data in advance, completely solving the problems of the inability to simply superimpose the performance of parallel fans and the inability to accurately measure air resistance on-site using traditional methods.

[0064] S120. On-site measurement and evaluation phase: This phase is used to evaluate the resistance of the duct system of the target environmental test chamber. Specifically, this includes: installing parallel fans of the same model as those used in the system pre-calibration phase into the duct system of the target environmental test chamber, maintaining the fan control mode consistent with the system pre-calibration phase; collecting the fan operating current corresponding to each resistance under pre-set parallel operation conditions; matching the fan operating current corresponding to each resistance with the pre-calibrated mapping database to obtain the "airflow Q - static pressure P" operating point corresponding to each fan operating current; and performing quadratic curve fitting on the multiple operating points obtained based on fluid mechanics principles to obtain the actual resistance characteristic curve of the duct system of the target environmental test chamber.

[0065] In this process, parallel fans of the same model as those used in the system pre-calibration phase are installed in the duct system of the target environmental test chamber. Maintaining the fan control mode consistent with the pre-calibration phase is a fundamental prerequisite for the entire field test. The core principle is to ensure complete alignment between the field operating conditions and the laboratory pre-calibration conditions, avoiding data mismatch. Consistent control modes mean that the fan's operating mode during field testing must be exactly the same as that used in the system pre-calibration phase. For example, if the pre-calibration used a "fixed fan frequency, changed number of parallel units" mode, the same frequency must be fixed on-site, and the operating conditions can be switched by changing the number of fans in operation. Conversely, if the pre-calibration used a "fixed number of parallel units, changed fan frequency" mode, the same number of fans must be fixed on-site, and the operating conditions can be switched by adjusting the fan operating frequency. Only with completely consistent control modes can the current data collected on-site accurately match the mapping relationship database formed during the system pre-calibration phase, ensuring the accuracy of the reverse-engineering results from the outset. Non-invasive characteristics: This step is a normal product installation of the fan, which does not require any modification to the air duct or the fan, and will not change the original flow field. This is different from the invasive operation of traditional methods that require drilling holes to insert sensors.

[0066] Under pre-set parallel operation conditions, the operating current of the fans corresponding to each resistance is collected. This step is the core manifestation of the low cost and ease of implementation of this invention. No additional testing equipment is required throughout the process; it can be completed using only the device's built-in electrical control system. The pre-set parallel operation conditions are multiple sets of test conditions that correspond one-to-one with the system pre-calibration stage. The purpose is to obtain multiple different real working resistance points of the duct system, providing sufficient effective data for subsequent curve fitting. For example, in the variable number of fans scheme: a fixed 50Hz frequency is used, and four sets of conditions are set sequentially: "1 fan on, 2 fans on, 3 fans on, and 4 fans on"; in the variable frequency scheme: all four fans are fixed to be on, and five sets of conditions are set sequentially: "30Hz, 35Hz, 40Hz, 45Hz, and 50Hz". Collecting the fan operating current corresponding to each resistance level means that the actual working resistance of the duct system changes with each switch in operating conditions, and the stable operating current of the fan also changes accordingly. After the fan has started up and is running smoothly (avoiding errors from transient startup current), the current data can be read directly through the equipment's built-in electrical control system without the need for any additional sensors. Note that "each resistance level" here does not refer to actively modifying the duct to adjust the resistance on-site, but rather to allowing the duct system to naturally exhibit different working resistance states by switching operating conditions. No modifications are required to the finished equipment, perfectly adapting to the daily inspection of the already packaged equipment.

[0067] The operating current of each fan corresponding to each resistance is matched with a pre-calibrated mapping database to obtain the "airflow Q - static pressure P" operating point corresponding to each fan's operating current. This step achieves the reverse deduction of "current → airflow + resistance," accurately solving for airflow and static pressure, which are difficult to measure on-site, using easily acquired current signals. Matching principle: The system pre-calibration stage has verified that under specific operating conditions, there is a unique and definite correspondence between the stable operating current of the fan and the airflow Q and static pressure P, and this relationship already includes fluid coupling interference between parallel fans. For each stable current value measured on-site, a unique set of airflow Q and static pressure P can be found in the pre-calibrated IPQ curve family under the same operating condition through table lookup or linear interpolation. For example, if two fans are running at a fixed frequency of 50Hz on-site, and the average current is measured to be 2A, the 2A current is uniquely matched with the air volume Q2 and static pressure P2 in the pre-calibration database for the curve "50Hz, 2 fans in parallel". This set of data is a measured point on the duct resistance curve. Note that each set (Q, P) is the actual operating point of the current duct system under this condition. The static pressure P is the total resistance of the duct system that the fan needs to overcome, which includes the resistance of all components in the duct, such as the evaporator, dampers, and housing structure, as well as the coupling effect between the parallel fans. It is the core data for subsequent fitting of the resistance curve.

[0068] Based on fluid mechanics principles, quadratic curve fitting is performed on multiple acquired operating points to obtain the actual resistance characteristic curve of the duct system of the target environmental test chamber. This step transforms discrete measured operating points into a complete resistance characteristic curve that can be used for fan selection, performance optimization, and online monitoring. The core principle of fluid mechanics is that for fixed-structure duct systems like environmental test chambers, the classic law of flow resistance within pipes is that the resistance of the duct system is directly proportional to the square of the airflow volume, as shown in the formula: ,in The resistance coefficient of the duct system is the theoretical basis for quadratic curve fitting, ensuring the scientific validity of the fitting results. Quadratic curve fitting refers to obtaining multiple discrete operating points (Q, P) through multiple sets of operating conditions, and then using mathematical fitting methods such as the least squares method to find a quadratic curve that best fits all measured points. This allows for the calculation of a unique resistance coefficient k, ultimately yielding the specific resistance characteristic curve for the duct system. With this curve, researchers can accurately select fans, completely avoiding issues such as poor temperature performance and compressor liquid return due to insufficient airflow, or energy waste due to excessive airflow margin. Furthermore, this method can be integrated into equipment control systems for periodic automatic testing, enabling online health diagnosis and alarms for faults such as duct dust accumulation, blockage, and component deformation, solving the technical problem of traditional methods being unable to achieve online monitoring.

[0069] The technical solution provided by this invention utilizes the easily measurable electrical signal of the fan operating current, combined with a mapping relationship database pre-established during the pre-calibration stage, to accurately back-calculate the resistance operating point of the duct system in a parallel fan environmental test chamber. This allows for the fitting of the resistance curve of the entire duct system, providing crucial data for fan selection and performance optimization. It solves the problem of existing technologies' difficulty in easily and accurately evaluating the overall wind resistance characteristics of such complex parallel systems after actual assembly, which can lead to unreasonable fan selection. The technical solution provided by this invention requires no damage or installation of any external fluid sensing devices, achieving non-invasive measurement. This method can be easily integrated into the test chamber software control, enabling periodic automatic operation, completing health checks and alarms for the duct system, resulting in low maintenance costs and online and self-diagnostic capabilities. The technical solution provided by this invention effectively reduces the cost of resistance testing and improves the operating efficiency of the test chamber.

[0070] Figure 2 This is a flowchart of the system pre-calibration stage in an online evaluation method for the resistance of an environmental test chamber's duct system, provided in an embodiment of the present invention. Optionally, in the system pre-calibration stage, the pre-set parallel operation condition is a condition with a fixed fan operating frequency and varying the number of parallel fans. See [link to documentation]. Figure 2 The system pre-calibration phase specifically includes:

[0071] S1-1: Select a single target model wind turbine, install it on the wind turbine experimental test platform, and construct a standard test system.

[0072] The target model of the fan refers to the actual fan model that will be installed in the environmental test chamber to be evaluated, not any arbitrary model. The motor electrical characteristics, impeller aerodynamic characteristics, and rated parameters of the fan are highly specific; the "current-static pressure-airflow" correspondence is completely different for different fan models. Only by selecting a model that is completely consistent with the on-site installation can the pre-calibrated database be directly reused in subsequent on-site evaluations, ensuring the accuracy of data matching. A single fan is the benchmark starting point for the parallel fan calibration of this invention. The core of this invention targets multi-parallel fan systems. First, a benchmark characteristic curve without coupling interference is obtained through single-fan calibration. Then, the number of parallel fans is gradually increased for testing. This not only fully captures the "performance changes caused by the fluid dynamic coupling between multiple fans after parallel connection" but also ensures that the test data for different numbers of parallel fans are based on the same benchmark fan, avoiding errors caused by batch differences, ultimately forming a complete curve cluster covering all scenarios from single to multiple parallel connections.

[0073] The wind turbine testing platform mentioned here refers to a specialized calibration-grade testing device that conforms to national / industry standards for wind turbine performance testing. It is also the core hardware carrier for the calibration process of this invention, rather than ordinary ductwork fixtures. Installing the wind turbine on this platform addresses three key issues:

[0074] It can achieve precise and interference-free adjustment of resistance under all working conditions: The platform comes with standard nozzle groups, adjustable air valves and other actuators, which can accurately and continuously adjust the air duct resistance, simulating the full-scenario operation of the fan from zero resistance to high resistance. This is something that finished environmental test chambers cannot achieve, and it is also a prerequisite for obtaining a complete "IPQ" curve.

[0075] It can achieve high-precision measurement of core parameters: The platform integrates calibrated high-precision air volume, static pressure and current sensors, which can accurately measure the three types of core data required for calibration, completely avoiding sensor errors and flow field interference problems in on-site measurement, and ensuring that the original calibration data has traceability and reliability.

[0076] It can eliminate additional interference and obtain pure reference characteristics of the fan: The platform's standardized air duct can eliminate the resistance interference of additional components such as evaporators, heaters, and box structures in the environmental test chamber, and measure the "electrical-aerodynamic" coupling characteristics of the fan itself, providing pure reference data for subsequent superimposed parallel interference and on-site operating conditions.

[0077] Building a standard testing system refers to integrating wind turbine drive, operating condition regulation, data acquisition, and data storage into a closed-loop standardized testing system that can be automatically controlled, synchronously acquired, and repeatedly operated.

[0078] S1-2: Control the fan to operate stably at a preset fixed frequency. Adjust the resistance of the duct system by controlling the nozzle switch or air valve on the fan test platform. Collect the fan operating current, duct system static pressure and total fan air volume data under different resistances. Based on the collected fan operating current, duct system static pressure and total fan air volume data, obtain the IPQ curve cluster of a single fan.

[0079] The preset fixed frequency can be set in advance according to the test requirements, and its value must be completely consistent with the operating frequency of the fan in the subsequent on-site measurement and evaluation stage. For example, the preset fixed frequency can be set to 50Hz. The IPQ curve cluster is a two-dimensional continuous mapping curve of "current I → static pressure P" and "current I → air volume Q" established under the fixed frequency with the fan operating current as the core independent variable.

[0080] Specifically, adjusting the resistance of the duct system by controlling the nozzle switches or valves on the fan test platform means precisely changing the flow area of ​​the duct by switching different numbers of nozzles or adjusting the opening of the valves. The smaller the flow area, the stronger the duct throttling effect and the greater the system resistance; conversely, the larger the flow area, the smaller the system resistance. This method allows for continuous and precise adjustment of the duct resistance from extremely low to high resistance without additional flow field interference. After each resistance level is adjusted and the fan reaches a steady state, three sets of data must be collected simultaneously at the same time point: the fan operating current, the duct system static pressure, and the total fan air volume. These data points form a one-to-one correspondence of raw data points. Only synchronous collection can ensure that the three sets of parameters are completely matched, thoroughly avoiding parameter misalignment caused by operating condition fluctuations and ensuring that the mapping logic of "one current value uniquely corresponds to one set of static pressure and air volume" holds true. The laboratory measurements yield a finite number of independent data points for discrete resistance levels. Through mathematical fitting, these independent data points are connected into a continuous and smooth characteristic curve, enabling precise interpolation and querying of any current value.

[0081] S1-3: Gradually increase the number of parallel fans of the same model, repeat the operation of step S1-2, collect the average operating current, static pressure of the duct system and total air volume of the parallel fans under different resistance conditions for each number of parallel fans, fit the IPQ curve clusters corresponding to different numbers of parallel fans, and summarize them to form a mapping relationship database.

[0082] The requirement of "same model of fan" means that the fan model used must be exactly the same as the one used in the single-unit calibration in step S1-2 and in subsequent on-site installation. The core reason is that only when the rated parameters, impeller aerodynamic characteristics, and motor electrical characteristics of the same model of fan are completely consistent can the operating conditions of each fan be guaranteed to be balanced during parallel operation. This avoids uneven current and airflow distribution caused by performance differences between different models of fans, ensuring that the calibration data is stable and reliable and can be fully matched with the on-site installation conditions. Gradually increasing the number of parallel fans of the same model means starting with a single fan and stacking them one by one to carry out full-process testing, rather than directly testing a fixed number of fans. Collecting data on different resistance conditions for each number of parallel fans means that for each number of parallel fans (2, 3, 4, etc.), the resistance conditions must be tested across the entire range from extremely low resistance to high resistance, just like the single-unit calibration. Data is collected synchronously at each resistance level to ensure that the calibration data covers all possible operating scenarios on-site and avoids situations where there is no corresponding calibration data for the on-site conditions. Average operating current refers to the average operating current of parallel fans at the same point in time, as well as the average cumulative operating current of parallel fans over a period of time. For example, if two fans are connected in parallel, at 1 second, the operating current of fan 1 is 1A and the operating current of fan 2 is 1.1A. The average operating current is then 1.05A. At 2 seconds, the operating current of fan 1 is 1.1A and the operating current of fan 2 is 1A, with an average operating current of 1.05A. At 3 seconds, the operating current of fan 1 is 1A and the operating current of fan 2 is 0.9A, with an average operating current of 0.95A, and so on. After one minute, there will be 60 sets of average operating currents. Therefore, the average operating current over the one-minute time period is the average of these 60 sets of average operating currents. The IPQ curve cluster corresponding to different numbers of parallel wind turbines refers to the fact that for each number of parallel turbines (1, 2, 3, 4, etc.), an independent and continuous IPQ characteristic curve is generated based on measured data and through industry-standard fitting methods such as the least squares method. The collection of all curves is the curve cluster.

[0083] Figure 3 This is a flowchart of the on-site measurement and evaluation stage in an online evaluation method for the air duct system resistance of an environmental test chamber provided in an embodiment of the present invention. Optionally, in the on-site measurement and evaluation stage, the pre-set parallel operation condition is a condition with a fixed fan operating frequency and varying number of parallel fans in operation. See [link to documentation]. Figure 3 The on-site measurement and evaluation phase specifically includes:

[0084] S3-1: Install multiple parallel fans of the same model as those used in the system pre-calibration stage into the air duct system of the target environmental test chamber, and keep the fan operating frequency consistent with the preset fixed frequency of the system pre-calibration stage.

[0085] The requirement of using the same fan model as the system pre-calibration stage is crucial because only when the fan model installed on-site is completely identical to that used in the laboratory pre-calibration can the unique correspondence between "current-static pressure-airflow" remain valid on-site, allowing the pre-calibration database to be directly reused. If the models do not match, all subsequent data matching and resistance calculations will suffer fundamental deviations. Multiple parallel fans refer to the total number of fans installed on-site, which must be consistent with the number of fans connected in parallel during the system pre-calibration stage.

[0086] S3-2: First, start a single fan. After it stabilizes, collect the current operating current I1 of the fan. Then, increase the number of parallel fans started in sequence. After each adjustment, wait for the fan to stabilize and collect the average operating current IN of the parallel fans under the corresponding operating conditions. N is the number of fans connected in parallel, and N is an integer ≥2.

[0087] Among them, the current operating current I1 is the only steady-state operating current of a single fan under the current target duct system. It corresponds to the benchmark data that can be directly queried in the pre-calibration database. Subsequently, the first measured operating point (Q1, P1) on the duct resistance curve can be reversed.

[0088] Specifically, start a single fan first. Once it stabilizes, collect the current operating current of that fan through the equipment's built-in electrical control system. Gradually increase the number of parallel fans activated. After each adjustment, once the fans stabilize, collect the average operating current IN of the parallel fans under the corresponding operating condition. For example, when two fans are activated, collect the steady-state current of each fan and take the arithmetic mean to obtain I2; when three fans are activated, collect the steady-state current of each fan and take the arithmetic mean to obtain I3, and so on. N always equals the total number of fans currently actually activated. The value range of N must be consistent with the number of parallel fans in the system pre-calibration phase.

[0089] S3-3: Match each current data with the pre-calibrated IPQ curve cluster corresponding to the number of parallel units, and obtain the "air volume Q - static pressure P" operating point (QN, PN) corresponding to each group of currents by interpolation or table lookup.

[0090] Specifically, on-site matching must strictly adhere to the "one-to-one correspondence of operating conditions" rule: the current I1 of a single wind turbine collected on-site can only be matched with the IPQ curve corresponding to "same fixed frequency, 1 wind turbine" in the pre-calibration; the average operating current I2 of 2 wind turbines in parallel can only be matched with the IPQ curve corresponding to "same fixed frequency, 2 wind turbines"; and so on, the average operating current IN of N wind turbines in parallel must be matched with the dedicated curve corresponding to the number of parallel turbines N, and matching across different numbers of turbines is absolutely prohibited. The core purpose of this rule is to ensure that the on-site operating conditions are completely consistent with the calibration operating conditions, so that the mapping relationship of currents is fully effective, and to fundamentally avoid orders of magnitude errors caused by mismatched operating conditions.

[0091] Each group (QN, PN) represents a measured operating point on the resistance curve of the current duct system. The value of N must strictly correspond one-to-one with the number of parallel current collection units in S3-2: I1 corresponds to N=1, and the operating point is (Q1, P1); I2 corresponds to N=2, and the operating point is (Q2, P2); and so on. Each current data can be used to deduce an independent and non-interfering operating point.

[0092] S3-4: The least squares method is used to perform quadratic curve fitting on the multiple operating points obtained to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

[0093] Specifically, the acquired multiple working points (QN, PN) are substituted into... The theoretical formula is used to calculate the drag coefficient k that minimizes the sum of squared errors at all operating points, thus obtaining a specific drag characteristic formula for this duct. Then, plotting this formula as a continuous curve in the "airflow-static pressure" coordinate system yields the actual resistance characteristic curve of the target air duct. See details... Figure 4 , Figure 4 This is a schematic diagram of the actual resistance characteristic curves under the conditions of fixed frequency and changing the number of parallel fans in an online resistance evaluation method for the air duct system of an environmental test chamber provided in an embodiment of the present invention.

[0094] Figure 5 A flowchart of the system pre-calibration stage in another online evaluation method for the air duct system resistance of an environmental test chamber provided in this embodiment of the invention. Optionally, in the system pre-calibration stage, the pre-set parallel operation condition is a condition with a fixed number of parallel fans and a changed fan operating frequency. See [link to documentation]. Figure 5 The system pre-calibration phase specifically includes:

[0095] S2-1: Select a preset number of wind turbines of the same model and install them in parallel on the wind turbine test platform to construct a standard test system.

[0096] The preset number of units can be set in advance according to testing requirements, and it must be completely consistent with the total number of wind turbines in the on-site measurement and evaluation phase. For example, the preset number of units can be set to 4. The standard testing system integrates four major modules: frequency conversion drive, operating condition adjustment, synchronous data acquisition, and process control into a closed-loop standardized testing system that can operate automatically, has precise and controllable operating conditions, and allows for repeatable data.

[0097] S2-2: Control all parallel fans to operate stably at a first preset frequency. By adjusting the resistance of the duct system, collect data on fan operating current, duct system static pressure and total fan air volume under different resistances. Based on the collected data on fan operating current, duct system static pressure and total fan air volume, obtain a cluster of IPQ curves at that frequency.

[0098] The first preset frequency can be pre-set according to testing requirements, usually the rated operating frequency of the fan, such as 50Hz. This frequency must be completely consistent with the frequency setting in the subsequent field testing phase. The fan operating current is the average operating current of all fans operating in parallel. The duct system static pressure is the total static pressure of the duct that the entire parallel fan system needs to overcome, i.e., the actual total resistance of the duct. The total fan air volume is the total air volume output by the parallel fan system under this resistance condition. The IPQ curve cluster at this frequency is a specific characteristic curve for a fixed number of parallel units at this particular frequency.

[0099] The specific operational logic is the same as S1-2 in the aforementioned embodiments, and will not be repeated here.

[0100] S2-3: Keep the number of parallel fans constant, gradually adjust the operating frequency of the fans, repeat the operation of step S2-2, collect the average current of the parallel fans, the static pressure of the duct system and the total air volume of the fans under different operating frequencies and different resistance conditions, fit the IPQ curve clusters corresponding to different operating frequencies, and summarize them to form a mapping relationship database.

[0101] The operating frequency of the fan can be 30Hz, 35Hz, 40Hz, 45Hz, or 50Hz.

[0102] Specifically, for each adjusted operating frequency, a full range of resistance conditions, from extremely low to high resistance, must be tested, similar to single-frequency calibration, with data collected synchronously at each resistance level. The average current of the parallel fans is the average operating current of all parallel-operating fans at each frequency and resistance level. For each adjusted frequency, an independent, continuous, and smooth IPQ characteristic curve is fitted based on the measured data at that frequency. The curves for all frequencies are then aggregated to form a cluster of IPQ curves for a "fixed number of parallel units, multiple frequencies".

[0103] Figure 6 A flowchart of the on-site measurement and evaluation stage in another online evaluation method for the air duct system resistance of an environmental test chamber provided in this embodiment of the invention. Optionally, in the on-site measurement and evaluation stage, the pre-set parallel operation condition is a condition with a fixed number of parallel fans and a changed fan operating frequency. See [link to relevant documentation]. Figure 6 The on-site measurement and evaluation phase specifically includes:

[0104] S4-1: Install the same model and number of parallel fans as those used in the system pre-calibration stage into the air duct system of the target environmental test chamber.

[0105] S4-2: Control all parallel fans to start at the first preset frequency. After the operation is stable, collect the average operating current I1' of the parallel fans under this condition. Adjust the operating frequency of all fans in sequence. After each adjustment, wait for the fans to run stably, and collect the average operating current In' of the parallel fans under the corresponding frequency condition, where n is the operating frequency of the fans.

[0106] The first preset frequency is consistent with the frequency in the system pre-calibration stage in S2-2.

[0107] Specifically, the operation logic of this step is the same as that of step S2-2, and will not be repeated here.

[0108] S4-3: Match each collected current data with the pre-calibrated IPQ curve cluster corresponding to the operating frequency, and obtain the "air volume Q - static pressure P" operating point (Qn', Pn') corresponding to each group of currents by interpolation or table lookup.

[0109] This step is consistent with the logic of S3-3, and will not be repeated here.

[0110] S4-4: The least squares method is used to perform quadratic curve fitting on the multiple operating points obtained to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

[0111] This step is logically consistent with steps S3-4, and will not be repeated here.

[0112] The actual resistance characteristic curve for this step is the actual resistance characteristic curve under the condition of changing the operating frequency while keeping the number of parallel units fixed. See details below. Figure 7 , Figure 7 This is a schematic diagram of the actual resistance characteristic curves under the condition of fixed parallel number and changing operating frequency in an online resistance evaluation method for the air duct system of an environmental test chamber provided in an embodiment of the present invention.

[0113] Correspondingly, through the operational logic of the above two modes, the resistance characteristics of other target resistance components within the air duct system of the environmental test chamber can be obtained. Figure 8 A flow chart for testing the resistance characteristics of a target resistance component within the air duct system of an environmental test chamber, provided in an embodiment of the present invention, is shown below. Figure 8 Specifically, it includes:

[0114] S5-1: Install the first-specification target resistance component in the air duct system of the target environment test chamber, and obtain the resistance of the air duct system under this specification through the system pre-calibration stage and the on-site measurement and evaluation stage.

[0115] Among them, "target resistance component" refers to the core functional component that generates air resistance within the duct, and is also the object whose resistance needs to be quantified separately. For example, the target resistance component could be an evaporator. The first specification refers to the baseline initial specification of the component. For example, the first specification of the evaporator is the number of pipe rows in the evaporator. The component of the first specification needs to be installed in its actual working position within the duct to completely reproduce the real flow field environment of the entire machine during normal operation, rather than simply placing the component on a test bench for testing. Then, the entire process of system pre-calibration + on-site measurement and evaluation is completely reused, using completely consistent operating conditions, methods, and accuracy standards to measure the resistance Pz1 of the duct system under this specification.

[0116] S5-2: Keeping all other components in the duct system unchanged, only change the specifications of the target resistance component, and repeat step S5-1 to obtain the resistance of the duct system under different specifications.

[0117] Specifically, within the duct system, all elements except the target resistance component remain completely fixed, with the only variable being the specifications of the target resistance component. For example, by changing only the number of pipe rows in the evaporator, gradually replacing it from 1 row to 2 / 3 / 4 / 5 / 6 rows, the corresponding resistances Pz2, Pz3, Pz4, Pz5, and Pz6 are obtained.

[0118] S5-3: Subtract the resistance corresponding to different specifications to obtain the resistance increment corresponding to the change of different specifications of the target resistance component.

[0119] For example, △P1=Pz2-Pz1, △P2=Pz3-Pz1, △P3=Pz4-Pz1, △P4=Pz5-Pz1, △P5=Pz6-Pz1.

[0120] S5-4: Based on the correspondence between the resistance increment and the change in the target resistance component's specifications, the "specification-resistance increment" characteristic curve of the target resistance component is obtained by fitting.

[0121] Specifically, the obtained △P1-△P5 is plotted on the "increased number of rows - resistance" curve, and the corresponding curve is approximately fitted to obtain the "specification - resistance increment" characteristic curve of the target resistance component. If it is an evaporator, then the curve is the relationship curve between increasing the number of rows of the evaporator and the corresponding increase in resistance.

[0122] Optionally, the target resistance component is the evaporator inside the air duct of the environmental test chamber, and the specification change is the change in the number of pipe rows of the evaporator.

[0123] The technical solution provided by this invention utilizes the easily measurable electrical signal of the fan operating current, combined with a mapping relationship database pre-established during the pre-calibration stage, to accurately back-calculate the resistance operating point of the duct system in a parallel fan environmental test chamber. This allows for the fitting of the resistance curve of the entire duct system, providing crucial data for fan selection and performance optimization. It solves the problem of existing technologies' difficulty in easily and accurately evaluating the overall wind resistance characteristics of such complex parallel systems after actual assembly, which can lead to unreasonable fan selection. The technical solution provided by this invention requires no damage or installation of any external fluid sensing devices, achieving non-invasive measurement. This method can be easily integrated into the test chamber software control, enabling periodic automatic operation, completing health checks and alarms for the duct system, resulting in low maintenance costs and online and self-diagnostic capabilities. The technical solution provided by this invention effectively reduces the cost of resistance testing and improves the operating efficiency of the test chamber.

[0124] Figure 9 A schematic diagram of an online resistance assessment device for an environmental test chamber's duct system provided in an embodiment of the present invention is shown below. Figure 9 The device includes a system pre-calibration module 910 and a field measurement and evaluation module 920;

[0125] The system pre-calibration module 910 is used to establish a "current I-static pressure P-air volume Q" mapping relationship database that includes the fluid dynamic coupling effect between parallel fans. Specifically, it includes: installing the target model fan on the fan test platform, and collecting the fan operating current, duct system static pressure and total fan air volume data corresponding to each resistance under the pre-set parallel operation conditions by adjusting the resistance of the duct system; fitting the IPQ curve cluster under the corresponding operating conditions based on the collected fan operating current, duct system static pressure and total fan air volume data, and summarizing them to form the mapping relationship database.

[0126] The on-site measurement and evaluation module 920 is used to evaluate the resistance of the air duct system of the target environmental test chamber. Specifically, it includes: installing parallel fans of the same model as those used in the system pre-calibration stage into the air duct system of the target environmental test chamber, keeping the fan control mode consistent with that in the system pre-calibration stage; collecting the fan operating current corresponding to each resistance under the pre-set parallel operation conditions; matching the fan operating current corresponding to each resistance with the pre-calibrated mapping relationship database to obtain the "air volume Q - static pressure P" operating point corresponding to each fan operating current; and performing quadratic curve fitting on the multiple operating points obtained based on fluid mechanics principles to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

[0127] The online resistance assessment device for the air duct system of an environmental test chamber provided in this embodiment of the invention can execute the online resistance assessment method for the air duct system of an environmental test chamber provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0128] Figure 10 This is a schematic diagram of the electronic device used in an online evaluation method for the air duct system resistance of an environmental test chamber, as provided in an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0129] like Figure 10 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 and a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded into the RAM 13 from storage unit 18. The RAM 13 can also store various programs and data required for the operation of the electronic device 10. The processor 11, the ROM 12, and the RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0130] Multiple components in electronic device 10 are connected to input / output I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of monitors, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0131] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, central processing unit (CPU), graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as an online evaluation method for the resistance of an air duct system in an environmental test chamber.

[0132] In some embodiments, the online evaluation method for the air duct system resistance of an environmental test chamber can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via read-only memory ROM 12 and / or communication unit 19. When the computer program is loaded into random access memory RAM 13 and executed by processor 11, one or more steps of the online evaluation method for the air duct system resistance of an environmental test chamber described above can be performed. Alternatively, in other embodiments, processor 11 can be configured in any other suitable manner to perform the online evaluation method for the air duct system resistance of an environmental test chamber.

[0133] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transferring data and instructions to the storage system, the at least one input device, and the at least one output device.

[0134] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0135] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0136] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device for displaying information to a user; and a keyboard and pointing device through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with a user; for example, feedback provided to the user can be any form of sensory feedback; and input from the user can be received in any form.

[0137] The systems and technologies described herein can be implemented in computing systems that include backend components, middleware components, or frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium. Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0138] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0139] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0140] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for online evaluation of the resistance of the air duct system in an environmental test chamber, characterized in that, This includes the system pre-calibration phase and the on-site measurement and evaluation phase; The system pre-calibration stage is used to establish a "current I-static pressure P-air volume Q" mapping relationship database that includes the fluid dynamic coupling effects between parallel fans. Specifically, this includes: installing the target model fan on the fan test platform, adjusting the resistance of the duct system, and collecting data on the fan operating current, duct system static pressure, and total fan air volume corresponding to each resistance level under pre-set parallel operation conditions; fitting the collected fan operating current, duct system static pressure, and total fan air volume data to obtain a cluster of IPQ curves under the corresponding operating conditions, and summarizing them to form a mapping relationship database. The on-site measurement and evaluation phase is used to evaluate the resistance of the air duct system of the target environmental test chamber. Specifically, it includes: installing parallel fans of the same model as those used in the system pre-calibration phase into the air duct system of the target environmental test chamber, keeping the fan control mode consistent with that in the system pre-calibration phase; collecting the fan operating current corresponding to each resistance under pre-set parallel operation conditions; matching the fan operating current corresponding to each resistance with the pre-calibrated mapping relationship database to obtain the "air volume Q - static pressure P" operating point corresponding to each fan operating current; and performing quadratic curve fitting on the multiple operating points obtained based on fluid mechanics principles to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

2. The method according to claim 1, characterized in that, In the system pre-calibration phase, the pre-set parallel operation condition is a condition with a fixed fan operating frequency and a changing number of fans in parallel. The system pre-calibration phase specifically includes: S1-1: Select a single target model wind turbine, install it on the wind turbine experimental test platform, and construct a standard test system; S1-2: Control the fan to operate stably at a preset fixed frequency. Adjust the resistance of the air duct system by controlling the nozzle switch or air valve on the fan test platform. Collect the fan operating current, air duct system static pressure and total fan air volume data under different resistances. Based on the collected fan operating current, air duct system static pressure and total fan air volume data, fit the IPQ curve cluster of a single fan. S1-3: Gradually increase the number of parallel fans of the same model, repeat the operation of step S1-2, collect the average operating current, static pressure of the duct system and total air volume of the parallel fans under different resistance conditions for each number of parallel fans, fit the IPQ curve clusters corresponding to different numbers of parallel fans, and summarize them to form a mapping relationship database.

3. The method according to claim 2, characterized in that, In the on-site measurement and evaluation phase, the pre-set parallel operation condition is a condition with a fixed fan operating frequency and varying number of parallel fans in operation. The on-site measurement and evaluation phase specifically includes: S3-1: Install multiple parallel fans of the same model as those used in the system pre-calibration stage into the air duct system of the target environmental test chamber, and keep the fan operating frequency consistent with the preset fixed frequency of the system pre-calibration stage; S3-2: First, start a single fan. After it stabilizes, collect the current operating current I1 of the fan. Then, increase the number of parallel fans started in sequence. After each adjustment, wait for the fan to stabilize and collect the average operating current IN of the parallel fans under the corresponding operating condition. N is the number of fans connected in parallel, and N is an integer ≥2. S3-3: Match each current data with the pre-calibrated IPQ curve cluster corresponding to the number of parallel units, and obtain the "air volume Q - static pressure P" operating point (QN, PN) corresponding to each group of currents by interpolation or table lookup. S3-4: The least squares method is used to perform quadratic curve fitting on the multiple operating points obtained to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

4. The method according to claim 1, characterized in that, In the system pre-calibration phase, the pre-set parallel operation condition is a condition with a fixed number of parallel fans and varying fan operating frequencies. The system pre-calibration phase specifically includes: S2-1: Select a preset number of wind turbines of the same model and install them in parallel on the wind turbine test platform to construct a standard test system; S2-2: Control all parallel fans to operate stably at the first preset frequency. By adjusting the resistance of the duct system, collect the fan operating current, duct system static pressure and total fan air volume data corresponding to different resistances. Based on the collected fan operating current, duct system static pressure and total fan air volume data, fit the IPQ curve cluster at this frequency. S2-3: Keep the number of parallel fans constant, gradually adjust the operating frequency of the fans, repeat the operation of step S2-2, collect the average current of the parallel fans, the static pressure of the duct system and the total air volume of the fans under different operating frequencies and different resistance conditions, fit the IPQ curve clusters corresponding to different operating frequencies, and summarize them to form a mapping relationship database.

5. The method according to claim 4, characterized in that, In the on-site measurement and evaluation phase, the pre-set parallel operation condition is a condition with a fixed number of parallel fans and varying fan operating frequencies. The on-site measurement and evaluation phase specifically includes: S4-1: Install the same model and number of parallel fans as those used in the system pre-calibration stage into the air duct system of the target environmental test chamber; S4-2: Control all parallel fans to start at the first preset frequency. After the operation is stable, collect the average operating current I1' of the parallel fans under this condition. Adjust the operating frequency of all fans in sequence. After each adjustment, wait for the fans to run stably, and collect the average operating current In' of the parallel fans under the corresponding frequency condition, where n is the operating frequency of the fans. S4-3: Match each collected current data with the pre-calibrated IPQ curve cluster corresponding to the operating frequency, and obtain the "air volume Q-static pressure P" operating point (Qn', Pn') corresponding to each group of currents by interpolation or table lookup. S4-4: The least squares method is used to perform quadratic curve fitting on the multiple operating points obtained to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

6. The method according to claim 1, characterized in that, It also includes the resistance characteristic testing procedures for target resistance components within the duct system, specifically including: S5-1: Install a target resistance component of the first specification in the air duct system of the target environment test chamber, and obtain the resistance of the air duct system of that specification through the system pre-calibration stage and the on-site measurement and evaluation stage. S5-2: Keeping other components in the duct system unchanged, only change the specifications of the target resistance component, and repeat the operation of step S5-1 to obtain the resistance of the duct system under different specifications; S5-3: Subtract the resistance corresponding to different specifications to obtain the resistance increment corresponding to the different specifications of the target resistance component; S5-4: Based on the correspondence between the resistance increment and the change in the target resistance component's specifications, the "specification-resistance increment" characteristic curve of the target resistance component is obtained by fitting.

7. The method according to claim 6, characterized in that, The target resistance component is the evaporator inside the air duct of the environmental test chamber, and the specification change refers to the change in the number of pipe rows of the evaporator.

8. The method according to claim 3 or 5, characterized in that, The actual resistance characteristic curve satisfies the following relationship: ,in This represents the drag coefficient of the air duct system.

9. An online evaluation device for the air duct system resistance of an environmental test chamber, characterized in that, It includes a system pre-calibration module and an on-site measurement and evaluation module; The system pre-calibration module is used to establish a "current I-static pressure P-air volume Q" mapping relationship database that includes the fluid dynamic coupling effects between parallel fans. Specifically, it includes: installing the target model fan on the fan test platform, adjusting the resistance of the duct system, and collecting data on the fan operating current, duct system static pressure, and total fan air volume corresponding to each resistance level under pre-set parallel operation conditions; fitting the IPQ curve cluster under the corresponding operating conditions based on the collected fan operating current, duct system static pressure, and total fan air volume data, and summarizing them to form the mapping relationship database; The on-site measurement and evaluation module is used to evaluate the resistance of the air duct system of the target environmental test chamber. Specifically, it includes: installing parallel fans of the same model as those used in the system pre-calibration stage into the air duct system of the target environmental test chamber, keeping the fan control mode consistent with that in the system pre-calibration stage; collecting the fan operating current corresponding to each resistance under pre-set parallel operation conditions; matching the fan operating current corresponding to each resistance with the pre-calibrated mapping relationship database to obtain the "air volume Q - static pressure P" operating point corresponding to each fan operating current; and performing quadratic curve fitting on the multiple operating points obtained based on fluid mechanics principles to obtain the actual resistance characteristic curve of the air duct system of the target environmental test chamber.

10. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the online evaluation method for the air duct system resistance of the environmental test chamber according to any one of claims 1-8.

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