A test method and test equipment for a rail vehicle air conditioning unit condensing air volume

Abstract

The application discloses a kind of test method and test equipment of rail vehicle air conditioning unit condensing air volume, it is related to the air conditioning test technical field of rail vehicle, the steps of test method include: S1, the current environmental parameter of environmental wind tunnel is adjusted to set environmental parameter;S2, the current wind speed of environmental wind tunnel is adjusted to preset high wind speed, so that the air conditioning unit in environmental wind tunnel is in high-speed test environment;S3, actual refrigeration pressure of air conditioning unit under high-speed test environment is obtained;S4, under the premise that current environmental parameter remains unchanged, the current wind speed of environmental wind tunnel is adjusted to preset low wind speed, so that air conditioning unit is in low-speed test environment;S5, adjust the condensing air volume of air conditioning unit, until the current refrigeration pressure of air conditioning unit under low-speed test environment reaches actual refrigeration pressure;S6, under low-speed test environment, the condensing air volume of air conditioning unit is obtained.The refrigeration pressure corresponding to high-speed working condition is reproduced under low-speed working condition, and the condensing air volume is quantitatively measured.

Description

Technical Field

[0001] This invention relates to the field of air conditioning testing technology for rail vehicles, and particularly to a testing method and testing equipment for the condensate air volume of rail vehicle air conditioning units. Background Technology

[0002] In the design of air conditioning systems for rail vehicles, to adapt to high-speed operating conditions and improve energy efficiency, air conditioning units are gradually adopting ram-jet air conditioning technology. This involves installing a dedicated ram-jet air inlet on the roof, utilizing relative airflow to increase the condenser's air intake and reduce intake resistance, thereby improving condensing heat exchange efficiency and the overall energy efficiency ratio. However, since the condenser chamber is usually located on the exterior of the roof, it is difficult to manually approach and measure it during high-speed operation, and it is also impossible to directly obtain the condensing air volume. Due to the lack of dynamic measurement methods, the performance boundaries of ram-jet air conditioning under real operating conditions have long been difficult to quantify, resulting in the inability to accurately assess the working state of system components, which seriously restricts the development of performance optimization, fault diagnosis, and control strategies.

[0003] To evaluate the actual air intake performance of a ramjet air conditioner during vehicle operation, its condensing air volume needs to be quantitatively measured. Current engineering practices primarily employ two indirect testing methods: First, wind speed sensors are placed at the inlet and outlet of the condenser cavity, and the local wind speed is converted into volumetric air volume based on the effective flow area of ​​the measurement cross-section. Second, pressure sensors are placed at the inlet and outlet of the condenser cavity, and the corresponding air volume is indirectly derived by monitoring the cooling pressure at each measuring point and comparing it with a preset operating condition pressure benchmark. Both methods achieve air volume assessment through indirect parameter measurement. However, because the condenser cavity typically houses two high-speed rotating condenser fans, the surrounding flow field is highly complex, chaotic, and lacks regularity, severely interfering with the wind speed and pressure measuring points. This results in neither method being able to accurately measure the true condensing air volume of the ramjet air conditioner. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method and equipment for testing the condensing air volume of a rail vehicle air conditioning unit. Using the condensing air volume as a key variable, the method reproduces the refrigeration pressure conditions corresponding to the high-speed operating conditions under low-speed operating conditions, effectively quantifying the condensing air volume, which is originally difficult to measure directly, and achieving accurate measurement of the condensing air volume. This solves the technical problem in the prior art of accurately quantifying the changes in condensing air volume under different operating conditions.

[0005] To achieve the above objectives, the present invention provides a method for testing the condensate air volume of an air conditioning unit in a rail vehicle, comprising the following steps:

[0006] S1. Adjust the current environmental parameters of the environmental wind tunnel to the set environmental parameters;

[0007] S2. Adjust the current wind speed of the environmental wind tunnel to the preset high wind speed so that the air conditioning unit in the environmental wind tunnel is in a high-speed test environment;

[0008] S3. Obtain the actual cooling pressure of the air conditioning unit under high-speed testing conditions;

[0009] S4. Under the premise that the current environmental parameters remain unchanged, adjust the current wind speed of the environmental wind tunnel to a preset low wind speed so that the air conditioning unit is in a low-speed test environment.

[0010] S5. Adjust the condenser air volume of the air conditioning unit until the current cooling pressure of the air conditioning unit under the low-speed test environment reaches the actual cooling pressure.

[0011] S6. Obtain the condensate air volume of the air conditioning unit under low-speed test conditions.

[0012] In some embodiments, between step S3 and step S4, the steps further include:

[0013] S31. Under high-speed testing conditions, adjust the current air supply volume of the air conditioning unit to the rated air supply volume;

[0014] S32. Within a set time period, record the current environmental parameters of each test point of the air conditioning unit under high-speed testing environment at specified intervals.

[0015] S33. Under high-speed testing conditions, determine whether the current air supply volume of the air conditioning unit has reached the rated air supply volume. If it has not reached the rated air supply volume, proceed to step S31. If it has reached the rated air supply volume, determine whether the difference between two consecutive recorded current environmental parameters is within the preset threshold range. If it is not within the preset threshold range, proceed to step S2. If it is within the threshold range, proceed to step S4.

[0016] In some embodiments, between step S5 and step S6, the steps further include:

[0017] S51. Under low-speed test conditions, adjust the current air supply volume of the air conditioning unit to the rated air supply volume;

[0018] S52. Within a set time period, record the current environmental parameters of each test point of the air conditioning unit under low-speed test conditions at specified intervals.

[0019] S53. Under low-speed test conditions, determine whether the current air supply volume of the air conditioning unit has reached the rated air supply volume. If it has not reached the rated air supply volume, proceed to step S51. If it has reached the rated air supply volume, determine whether the difference between the current environmental parameters recorded twice consecutively is within the set threshold range. If it is not within the threshold range, proceed to step S4. If it is within the threshold range, proceed to step S6.

[0020] In some embodiments, step S1 includes:

[0021] S11. The air inlet, condenser air inlet, fresh air inlet, return air inlet and supply air outlet of the air conditioning unit are used as detection points, and temperature and humidity sensors are installed at each detection point.

[0022] S12. Use various temperature and humidity sensors to detect the current temperature and humidity at each detection point in the environmental wind tunnel;

[0023] S13. Determine whether the current temperature and humidity at each detection point have reached the set temperature and humidity. If yes, the condenser air intake temperature and humidity of the air conditioning unit remain unchanged; if not, adjust the condenser air intake temperature and humidity.

[0024] In some embodiments, step S2 includes:

[0025] S21, Input preset high wind speed;

[0026] S22. Adjust the speed of the condenser fan of the air conditioning unit and measure the actual wind speed in the environmental wind tunnel in real time;

[0027] S24. Compare the actual wind speed with the preset high wind speed. If they are the same, stop adjusting the speed of the condenser fan; if not, continue adjusting the speed of the condenser fan.

[0028] In some embodiments, before adjusting the current air volume of the air conditioning unit to the rated air volume, the step further includes:

[0029] Use an air volume hood placed at the air outlet of the air conditioning unit to measure the current air volume of the air conditioning unit.

[0030] In some embodiments, adjusting the current air supply volume of the air conditioning unit to the rated air supply volume includes the following steps:

[0031] Adjust the current frequency of the condenser fan in the air conditioning unit;

[0032] And / or, adjust the cross-sectional area of ​​the condenser outlet of the air conditioning unit.

[0033] In some embodiments, the current environmental parameters include the condenser inlet air temperature and humidity, the return air temperature and humidity, the supply air temperature and humidity, the refrigeration pipe pressure of the air conditioning unit, and the rated current of the air conditioning unit.

[0034] In some embodiments, adjusting the condenser air volume of the air conditioning unit involves adjusting the speed of the condenser fan of the air conditioning unit.

[0035] This invention also provides a testing device for the condensate air volume of a rail vehicle air conditioning unit, applied to the aforementioned testing method for the condensate air volume of a rail vehicle air conditioning unit, comprising:

[0036] The parameter adjustment module is used to adjust the current environmental parameters of the environmental wind tunnel to the set environmental parameters;

[0037] The high wind speed adjustment module is used to adjust the current wind speed of the environmental wind tunnel to a preset high wind speed, so that the air conditioning unit in the environmental wind tunnel is in a high-speed testing environment.

[0038] The pressure acquisition module is used to acquire the actual cooling pressure of the air conditioning unit under high-speed testing conditions;

[0039] The low wind speed adjustment module is used to adjust the current wind speed of the environmental wind tunnel to a preset low wind speed while keeping the current environmental parameters unchanged, so that the air conditioning unit is in a low-speed test environment.

[0040] The air volume adjustment module is used to adjust the condenser air volume of the air conditioning unit until the current cooling pressure of the air conditioning unit in the low-speed test environment reaches the actual cooling pressure.

[0041] The air volume acquisition module is used to acquire the condensate air volume of the air conditioning unit under low-speed testing conditions.

[0042] Compared with the prior art, the test method for condensing air volume of rail vehicle air conditioning units provided by the present invention aims to solve the problem that it is difficult to accurately quantify the changes in condensing air volume under different operating conditions in the prior art.

[0043] This invention uses the wind speed in an environmental wind tunnel as a simulation variable, placing the air conditioning unit inside the wind tunnel to ensure that its heat exchange state is only affected by the wind speed in the wind tunnel. By changing the wind speed, high-speed and low-speed test environments are established respectively, thereby establishing a mapping relationship between the cooling pressure and condensing air volume of the air conditioning unit, and realizing accurate measurement of the condensing air volume of the air conditioning unit under different operating environments.

[0044] Specifically, the wind speed in the environmental wind tunnel is set to a preset high speed. After the air conditioning unit stabilizes, its actual cooling pressure is obtained as the benchmark pressure for the high-speed test environment, thus reflecting the condensing air volume of the air conditioning unit under high-speed operating conditions. Subsequently, the wind speed in the environmental wind tunnel is reduced to a preset low speed to simulate the condensing air intake conditions of a rail vehicle operating at low speed. Due to the reduced wind speed, the heat exchange efficiency of the air conditioning unit decreases, and the cooling pressure shifts. In this state, the present invention uses the cooling pressure as a feedback signal and the condensing air volume as the adjustment target. By increasing the condensing air volume, the air conditioning unit maintains the actual cooling pressure under the high-speed test environment, and the condensing air volume of the air conditioning unit is measured under this state.

[0045] This invention uses condenser airflow as an adjustment mechanism to reconstruct the refrigeration pressure state corresponding to a high-speed test environment in a low-speed test environment. Although the external wind speed is reduced, the condenser heat exchange effect is restored to the high-speed operating level by actively adjusting the condenser airflow. This indirectly achieves the reproduction of the high-speed operating condition under a low-speed test environment, thereby completing the quantification and measurement of condenser airflow.

[0046] In summary, this invention simulates the actual working environment of air conditioning units in rail vehicles operating at both high and low speeds. Using condensing air volume as the key variable, it reproduces the refrigeration pressure conditions corresponding to high-speed conditions under low-speed conditions, thereby effectively quantifying the condensing air volume, which is originally difficult to measure directly, and achieving accurate measurement of condensing air volume. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0048] Figure 1 This is a flowchart illustrating a specific embodiment of the method for testing the condensate air volume of a rail vehicle air conditioning unit.

[0049] Figure 2 This is another flowchart of a method for testing the condensate air volume of a rail vehicle air conditioning unit according to a specific embodiment of the present invention;

[0050] Figure 3 This is a diagram showing the state of the environmental wind tunnel when it is covered by the air conditioning unit.

[0051] Figure 4 This is a structural diagram of the air conditioning unit;

[0052] Figure 5 for Figure 4 A magnified view of a portion of the image.

[0053] The attached figures are labeled as follows:

[0054] Environmental wind tunnel 1, air conditioning unit 2, stamping air inlet 21, condenser air inlet 22, fresh air inlet 23, return air inlet 24 and supply air outlet 25. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0056] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0057] This invention discloses a method for testing the condensing air volume of an air conditioning unit in a rail vehicle. Using the wind speed in an environmental wind tunnel 1 as a simulated variable, the air conditioning unit 2 is placed in the environmental wind tunnel 1, as shown in the attached diagram. Figure 3 As shown, this ensures that its heat exchange state is only affected by the wind speed in the ambient wind tunnel 1. By changing the wind speed, high-speed and low-speed test environments are established respectively, thereby establishing the mapping relationship between the cooling pressure and condensing air volume of the air conditioning unit 2, and realizing accurate measurement of the condensing air volume of the air conditioning unit 2 under different operating environments.

[0058] As attached Figure 1 As shown, the steps of the test method for the condensate air volume of a rail vehicle air conditioning unit include:

[0059] S1. Adjust the current environmental parameters of environmental wind tunnel 1 to the set environmental parameters, so that all environmental parameters remain constant. Use environmental wind tunnel 1 to build a constant environment, simplify the complex multivariate coupling problem into a single variable evaluation, remove the transient response interference caused by changes in boundary conditions, and ensure that all environmental factors except the independent variable remain unchanged during the test, so that the collected data can accurately reflect the real steady-state performance.

[0060] Environmental parameters can be referenced such as temperature, humidity and solar radiation intensity. Among them, the temperature range of environmental wind tunnel 1 is 35℃±1℃, the humidity is 50% RH, and the solar radiation intensity is 1000 W / m².

[0061] S2. Adjust the current wind speed of environmental wind tunnel 1 to a preset high wind speed, placing the air conditioning unit 2 inside the environmental wind tunnel 1 in a high-speed test environment. This simulates a forced convection heat transfer environment under high-speed operating conditions, thereby evaluating the coupled influence of airflow velocity on the heat transfer effect and surface temperature field distribution of the air conditioning unit 2. During this process, environmental parameters remain constant, thus accurately isolating the dynamic heat exchange characteristics caused by wind speed changes and separately capturing the true steady-state performance of the tested object when it reaches thermal equilibrium under different flow velocities. This ensures that the performance parameters collected under high-speed operating conditions have good reproducibility. The preset high wind speed can reach 80 m / s, but is not limited to this; it can be adjusted according to the actual operating conditions of the rail vehicle.

[0062] S3. Obtain the actual refrigeration pressure of air conditioning unit 2 under high-speed test environment; specifically, pressure sensors are arranged on the refrigeration pipes of air conditioning unit 2. By collecting pressure data in real time and combining it with the thermodynamic properties of the refrigerant, the saturation temperature corresponding to the current pressure is dynamically calculated. Then, by comparing the difference between the actual wall temperature and the saturation temperature of the refrigeration pipe, the phase change state of the refrigerant in the evaporator and condenser is accurately determined. Based on this dynamic, the pressure of the refrigeration pipe is kept stable by adjusting the opening of the expansion valve or the compressor frequency, providing an accurate reference pressure for the subsequent low-speed test environment.

[0063] S4. Under the premise that the current environmental parameters remain unchanged, adjust the current wind speed of the environmental wind tunnel 1 to the preset low wind speed. By actively reducing the condenser air intake speed, a stable low-speed test environment is constructed for the air conditioning unit 2, which is conducive to reproducing the real heat exchange state of the air conditioning unit 2 at low speed or idling speed, thereby effectively verifying the cooling capacity of the air conditioning unit 2 in a weak convection environment.

[0064] S5. Adjust the condenser airflow of air conditioning unit 2 until the current cooling pressure of air conditioning unit 2 in the low-speed test environment reaches the actual cooling pressure. In the established low-speed test environment, by gradually adjusting the condenser airflow of air conditioning unit 2, the heat exchange efficiency of the condenser is changed, thereby dynamically adjusting the pressure of the refrigeration pipeline until the current cooling pressure stably drops to the preset actual cooling pressure, realizing the pressure calibration of the low-speed test environment, thus simulating the real pressure response of air conditioning unit 2 when operating at low frequency.

[0065] S6. Under low-speed testing conditions, obtain the condensing air volume of air conditioning unit 2. By directly measuring the airflow through the condenser, the abstract heat dissipation capacity is transformed into quantifiable engineering parameters, thereby establishing a mathematical relationship between the operating state of the rail vehicle and the heat load of air conditioning unit 2, improving the reliability of air conditioning unit 2 under low-speed testing conditions. For example, if the condensing air volume under a certain low-speed condition is measured to be 2000 m³ / h, it means that in environmental wind tunnel 1, only the same air volume needs to be provided by a fan to accurately reproduce the air conditioning heat load of the vehicle under specific low-speed conditions such as congested road conditions.

[0066] This invention sets the wind speed in the environmental wind tunnel 1 to a preset high wind speed. After the air conditioning unit 2 stabilizes, its actual cooling pressure is obtained as a benchmark pressure for the high-speed test environment, thus reflecting the condensing airflow of the air conditioning unit 2 under high-speed operating conditions. Subsequently, the wind speed in the environmental wind tunnel 1 is reduced to a preset low wind speed to simulate the condensing air intake conditions under low-speed operation of a rail vehicle. Due to the reduced wind speed, the heat exchange efficiency of the air conditioning unit 2 decreases, and the cooling pressure shifts. In this state, this invention uses the cooling pressure as a feedback signal and the condensing airflow as the adjustment target. By increasing the condensing airflow, the air conditioning unit 2 maintains the actual cooling pressure under the high-speed test environment, and the condensing airflow of the air conditioning unit 2 is measured under this state.

[0067] This invention uses condenser airflow as an adjustment mechanism to reconstruct the refrigeration pressure state corresponding to a high-speed test environment in a low-speed test environment. Although the external wind speed is reduced, the condenser heat exchange effect is restored to the high-speed operating level by actively adjusting the condenser airflow. This indirectly achieves the reproduction of the high-speed operating condition under a low-speed test environment, thereby completing the quantification and measurement of condenser airflow.

[0068] In summary, this invention simulates the actual working environment of the air conditioning unit 2 under high-speed and low-speed operation of a rail vehicle, using condensing air volume as the key variable. It reproduces the refrigeration pressure conditions corresponding to the high-speed operation under low-speed conditions, thereby effectively quantifying the condensing air volume, which is originally difficult to measure directly, and achieving accurate measurement of condensing air volume.

[0069] In a preferred embodiment, between step S3 and step S4, the following steps are further included:

[0070] S31. Under high-speed testing conditions, adjust the current airflow of air conditioning unit 2 to the rated airflow. At high speeds, although the condenser dissipates heat well due to sufficient airflow, the heat exchange capacity of the evaporator is indirectly affected by vehicle speed, causing fluctuations in the actual airflow of the blower, which in turn interferes with the outlet air temperature and cooling effect. By precisely adjusting the blower voltage, the airflow at the outlet is stabilized at the rated airflow, simulating the heat exchange state of air conditioning unit 2 under full load. This helps to evaluate the heat exchange capacity of the evaporator or condenser at the rated airflow and simultaneously verify the energy consumption characteristics of the fan under high-speed operation, providing crucial test data to ensure that the performance of air conditioning unit 2 meets the standards under rated conditions.

[0071] S32. Within a set time period, record the current environmental parameters of each detection point of the air conditioning unit 2 under high-speed test environment at specified intervals; by constructing high-resolution time-series data of operating condition changes, quantitatively analyze the fluctuation characteristics and spatial distribution uniformity of environmental parameters under high-speed air supply conditions, verify the stability of the air conditioning unit 2 in response to environmental disturbances when operating at rated air volume, and provide accurate data support for subsequent evaluation of heat exchange performance, effectively avoiding data misreading and performance misjudgment caused by transient fluctuations.

[0072] Specifically, after the formal test of the environmental wind tunnel 1, the current environmental parameters such as temperature, humidity, and wind speed of the environmental wind tunnel 1 are kept stable for 30 minutes. Then, during the 10-minute period, the current environmental parameters are recorded every minute. During this period, the temperature fluctuation should not exceed ±1℃, and the humidity and pipeline pressure fluctuation should not exceed 5%. If the fluctuation is large, it is necessary to continue to measure until the requirements are met.

[0073] S33. Under high-speed testing conditions, determine whether the current air supply volume of air conditioning unit 2 has reached the rated air supply volume. If it has not reached the rated air supply volume, proceed to step S31. If it has reached the rated air supply volume, determine whether the difference between the current environmental parameters recorded twice consecutively is within the preset threshold range. If it is not within the threshold range, proceed to step S2. If it is within the threshold range, proceed to step S4.

[0074] In the high-speed test environment, the current airflow at the outlet of air conditioning unit 2 is measured using a wind speed sensor and compared with the set rated airflow. If the current airflow is lower than the rated airflow, the blower speed is gradually increased by adjusting the input voltage of the blower until the current airflow reaches the rated airflow, ensuring the standardization of the heat exchange boundary conditions on the evaporator side. If the current airflow reaches the rated airflow, two consecutive environmental parameters are collected, such as condenser inlet air temperature, evaporator outlet air temperature, and refrigeration pressure, and the difference between the two records is calculated. If the difference of any current environmental parameter exceeds a preset threshold, it indicates that thermal equilibrium has not yet been reached. In this case, the high-speed adjustment step needs to be returned, the wind speed stabilized at the preset high wind speed, and the stabilization time extended to eliminate transient effects. If the difference between two consecutive current environmental parameters is within the threshold range, it indicates that thermal equilibrium has been reached. At this time, the wind speed of environmental wind tunnel 1 is adjusted to the preset low wind speed, and the test proceeds to the next operating condition.

[0075] This invention ensures that each operating condition switch is based on a repeatable baseline state by first determining the air volume, then judging the steady state, and finally switching the operating condition through a logical closed loop. This not only eliminates the interference of evaporator-side air volume fluctuations on cooling performance, but also avoids collecting distorted data due to transient response through steady-state criteria, thereby improving the accuracy and efficiency of multi-condition progressive testing.

[0076] In a preferred embodiment, between step S5 and step S6, the following steps are further included:

[0077] S51. Under low-speed testing conditions, the current air volume of air conditioning unit 2 is adjusted to the rated air volume. When the rail vehicle is at low speed or idling, the natural airflow through the condenser is almost zero, leading to a sharp increase in refrigeration pressure, increased compressor power consumption, and decreased refrigeration efficiency. If the evaporator's air volume is insufficient at this time, the heat exchange effect will be further weakened. Based on this problem, by adjusting the blower to stabilize the air volume at the rated air volume, it is equivalent to applying the rated evaporation load while bearing the maximum condensing pressure. This exposes the true matching relationship between the condenser heat dissipation area, compressor displacement, expansion valve opening, and evaporator capacity. This not only verifies whether the evaporator still has sufficient cooling capacity to cool the rated air volume to the target temperature under low speed and high load, but also accurately quantifies the cooling capacity loss caused by the reduction in vehicle speed by comparing the cooling effect with that under high-speed conditions. This provides key test basis for evaluating the performance of air conditioning unit 2 under rated conditions.

[0078] S52. Within a set time period, record the current environmental parameters of each detection point of air conditioning unit 2 under low-speed test conditions at specified intervals. Through continuous and equally spaced data sampling, the dynamic response process of air conditioning unit 2 under low-speed, high-load conditions is transformed into a quantifiable and analyzable time-series dataset, thereby revealing its stability under extreme thermal environments. By synchronously recording key parameters such as condenser inlet air temperature, evaporator outlet air temperature, high-pressure, low-pressure, and compressor power consumption every few minutes, a dynamic curve is formed. By analyzing the pressure fluctuation period and amplitude, it is determined whether the compressor displacement adjustment is smooth and whether the fan start-stop is too frequent, avoiding a decrease in the reliability of air conditioning unit 2 due to oscillations, and providing accurate data support for subsequent evaluation of heat exchange performance.

[0079] Similarly, after the formal test of the environmental wind tunnel 1, the current environmental parameters such as temperature, humidity, and wind speed of the environmental wind tunnel 1 are kept stable for 30 minutes. Then, during the 10-minute period, the current environmental parameters are recorded every minute. During this period, the temperature fluctuation should not exceed ±1℃, and the humidity and pipeline pressure fluctuation should not exceed 5%. If the fluctuation is large, it is necessary to continue to measure until the requirements are met.

[0080] S53. Under low-speed test conditions, determine whether the current air supply volume of air conditioning unit 2 has reached the rated air supply volume. If it has not reached the rated air supply volume, proceed to step S51. If it has reached the rated air supply volume, determine whether the difference between the current environmental parameters recorded twice consecutively is within the set threshold range under low-speed test conditions. If it is not within the threshold range, proceed to step S4. If it is within the threshold range, proceed to step S6.

[0081] In a low-speed testing environment, by judging and adjusting the airflow to the rated value, the impact of evaporator-side airflow fluctuations on the system's cooling capacity was eliminated, ensuring that the condenser-side heat dissipation demand was in a stable baseline state. If the current airflow reaches the rated airflow, the difference between two consecutive environmental parameters is collected and compared. If the difference exceeds a preset threshold, it indicates that thermal equilibrium has not yet been reached. In this case, the low-speed adjustment step needs to be returned to, and the airflow speed is stabilized at the preset high speed, with the stabilization time extended to eliminate transient effects and avoid collecting distorted data before stabilization. If the difference is within the threshold range, it indicates that thermal equilibrium has been reached, and only then is the condenser airflow measured.

[0082] This invention ensures high accuracy of the obtained condensing air volume through a closed-loop logic of first determining the air volume, then judging the steady state, and finally measuring the air volume. This allows it to truly reflect the minimum heat dissipation capacity required to maintain thermal balance under low-speed, high-load conditions. In this way, it can truly reflect the matching limit of the condenser and the fan under extreme conditions, providing reliable data support for evaluating the performance of the air conditioning unit 2 under rated conditions.

[0083] As a preferred embodiment, as shown in the appendix Figure 2As shown, step S1 includes:

[0084] S11, as attached Figure 4 and 5 As shown, the ram air inlet 21, condenser air inlet 22, fresh air inlet 23, return air inlet 24, and supply air inlet 25 of the air conditioning unit 2 are used as detection points, and temperature and humidity sensors are arranged at each detection point. By constructing a full-path monitoring network, a refined analysis and energy balance calculation of the heat treatment process of the air conditioning unit 2 can be achieved. The temperature and humidity sensors installed at the ram air inlet 21 and condenser air inlet 22 capture the air state at the condenser inlet in real time, providing a benchmark for assessing the impact of changes in oncoming wind speed on condensation heat dissipation efficiency. The temperature and humidity sensors installed at the fresh air inlet 23 and return air inlet 24 monitor the external fresh air load and the internal return air load, respectively, and accurately calculate the mixing ratio and mixing point enthalpy. The temperature and humidity sensor installed at the supply air inlet 25 directly quantifies the output cold air temperature and humidity to verify whether the target supply air parameters have been achieved. By measuring the temperature and humidity differences at each measurement point, the heat exchange capacity of the condenser, the cooling capacity of the evaporator, and the proportion of fresh air load are calculated, providing comprehensive data support for the performance optimization and fault early warning of air conditioning unit 2.

[0085] S12. Use various temperature and humidity sensors to detect the current temperature and humidity at each detection point in the environmental wind tunnel 1; collect temperature and humidity data from different detection points in a distributed manner, and eliminate the uneven distribution of temperature and humidity fields inside the environmental wind tunnel 1 by constructing a gridded detection system, so as to provide reliable data support for accurate comparison of environmental parameters on both sides and ensure the repeatability of steady-state criteria.

[0086] Due to factors such as airflow organization, thermal boundary layer, and equipment heat dissipation, slight differences in temperature and humidity may exist in different spatial locations within the environmental wind tunnel 1. Relying solely on single-point measurements for steady-state determination can easily lead to misjudgments due to local fluctuations at the measuring point. To address this issue, this invention collects temperature and humidity data from multiple points, including the pressurized air inlet 21, condenser air inlet 22, fresh air inlet 23, return air inlet 24, and supply air inlet 25. This allows for the calculation of the mean and variance of each measuring point, accurately reflecting the overall uniformity of the wind tunnel environment. Furthermore, by using the comprehensive characteristic value of the multi-point data as the judgment benchmark when comparing two consecutive records, the risk of false triggering caused by transient fluctuations at a single point is effectively avoided. This multi-point gridded monitoring ensures that every judgment is based on both spatial uniformity and temporal stability, providing reliable environmental boundary protection for subsequent critical operations such as condition switching, airflow adjustment, and condenser airflow acquisition.

[0087] S13. Determine whether the current temperature and humidity at each detection point have reached the set temperature and humidity. If yes, the condenser inlet air temperature and humidity of air conditioning unit 2 remains unchanged; if not, adjust the condenser inlet air temperature and humidity. Through closed-loop control, the fan speed is adjusted to eliminate the influence of environmental disturbances on the condenser inlet air state, ensuring that the condenser inlet air temperature and humidity remain constant. This allows the condenser air volume measured under the premise of constant condenser inlet air temperature and humidity to truly represent the heat dissipation requirements of air conditioning unit 2 under specific operating conditions, providing a reliable basis for the performance evaluation of air conditioning unit 2.

[0088] As a preferred embodiment, as shown in the appendix Figure 2 As shown, step S2 includes:

[0089] S21, Input preset high wind speed;

[0090] S22. Adjust the speed of the condenser fan of the air conditioning unit 2 and measure the actual wind speed of the environmental wind tunnel 1 in real time;

[0091] S24. Compare the actual wind speed with the preset high wind speed. If they are the same, stop adjusting the speed of the condenser fan; if not, continue adjusting the speed of the condenser fan.

[0092] This invention employs a closed-loop control method to automatically adjust the actual wind speed in the environmental wind tunnel 1 by regulating the rotational speed of the condenser fan, ensuring a stable actual wind speed and providing reliable data support for the measurement of condenser airflow. Furthermore, the entire testing process eliminates the need for repeated manual adjustments to the frequency converter, resulting in a high degree of automation and testing efficiency. Of course, the air duct adjustment method is the same under low-speed testing conditions.

[0093] As a preferred embodiment, before adjusting the current air volume of the air conditioning unit 2 to the rated air volume, the step further includes: using an airflow hood at the air outlet 25 of the air conditioning unit 2 to measure the current air volume of the air conditioning unit 2. This solves the problem of inaccurate indoor heat exchange measurement caused by outdoor wind speed fluctuations in traditional testing, achieving accurate air volume calibration in dynamic environments. Furthermore, the connection between the airflow hood and the air outlet 25 must be strictly sealed to prevent leakage and inaccurate measurement values.

[0094] In a preferred embodiment, adjusting the current airflow of air conditioning unit 2 to its rated airflow involves the following steps: adjusting the current frequency of the condenser fan of air conditioning unit 2, thereby changing the rated speed of the condenser fan, which in turn changes the heat exchange capacity of the condenser, thereby adjusting the pipeline cooling pressure and indirectly affecting the airflow of the indoor evaporator. And / or, adjusting the cross-sectional area of ​​the condenser outlet of air conditioning unit 2, such as adjusting the mesh, louvers, valves, etc., to change the air outlet area of ​​the condenser, thereby changing the airflow resistance and flow rate of the condenser, thus affecting the heat exchange efficiency and indirectly adjusting the airflow.

[0095] In a preferred embodiment, the current environmental parameters include the condenser inlet air temperature and humidity at the condenser inlet 22, the return air temperature and humidity at the return air inlet 24, the supply air temperature and humidity at the supply air inlet 25, the refrigeration pipe pressure of the air conditioning unit 2, and the rated current of the air conditioning unit 2. The condenser inlet air temperature and humidity, as the inlet boundary of the condenser, determines the basic load on the heat dissipation side; the return air temperature and humidity reflect the actual thermal and humidity state of the passenger compartment or equipment compartment, and are the source load that the evaporator needs to handle; the supply air temperature and humidity directly quantifies the cooling output effect of the system. The refrigeration pipe pressure, as an internal response parameter of the system, maps the matching relationship between the compressor operating point, condensing efficiency, and evaporation capacity in real time; the rated current reflects the real-time load of the compressor and fan from the energy consumption perspective, providing a direct basis for energy efficiency assessment. This invention, through multi-dimensional detection, ensures that each state switch of the air conditioning unit 2 is based on a comprehensive benchmark, providing reliable data support for subsequent condenser airflow measurement.

[0096] In a preferred embodiment, adjusting the condensing airflow of air conditioning unit 2 involves the following steps: adjusting the rotational speed of the condenser fan in air conditioning unit 2 to directly control the airflow through the condenser, thereby achieving precise adjustment of condensing pressure and heat dissipation capacity. This invention, by calibrating the correspondence between different rotational speeds and condensing airflow, transforms abstract rotational speed signals into quantifiable airflow data, providing crucial information for subsequent condensing airflow measurement.

[0097] Furthermore, by measuring the output air volume of the condenser fan under different voltages, frequencies, or duty cycles, a complete speed-air volume characteristic curve can be plotted, establishing a mapping relationship between speed and airflow. Without the need for additional airflow sensors, the current condenser airflow can be estimated in real time by detecting the speed.

[0098] This invention also provides a testing device for the condensate air volume of a rail vehicle air conditioning unit, applied to the aforementioned testing method for the condensate air volume of a rail vehicle air conditioning unit, comprising:

[0099] The parameter adjustment module is used to adjust the current environmental parameters of the environmental wind tunnel 1 to the set environmental parameters;

[0100] The high wind speed adjustment module is used to adjust the current wind speed of the environmental wind tunnel 1 to a preset high wind speed, so that the air conditioning unit 2 in the environmental wind tunnel 1 is in a high-speed test environment.

[0101] The pressure acquisition module is used to acquire the actual cooling pressure of air conditioning unit 2 under high-speed testing conditions;

[0102] The low wind speed adjustment module is used to adjust the current wind speed of the environmental wind tunnel 1 to a preset low wind speed while keeping the current environmental parameters unchanged, so that the air conditioning unit 2 is in a low-speed test environment.

[0103] The air volume adjustment module is used to adjust the condenser air volume of the air conditioning unit 2 until the current cooling pressure of the air conditioning unit 2 in the low-speed test environment reaches the actual cooling pressure.

[0104] The air volume acquisition module is used to acquire the condensate air volume of air conditioning unit 2 under low-speed test environment.

[0105] To address the technical challenge of directly measuring condensate airflow in rail vehicle air conditioning units 2 during operation due to installation space limitations and airflow disturbances, this study simulates the actual operating environment of the air conditioning system at different vehicle speeds, using condensate airflow as the core control variable. Under low-speed conditions, the pipeline cooling pressure under high-speed conditions is artificially replicated by adjusting the fan speed, thus establishing an equivalent relationship between pressure and airflow. Based on this, the difficult-to-measure condensate airflow can be transformed into a quantifiable parameter of the easily controlled and measurable fan motor speed, ultimately achieving accurate measurement of this parameter.

[0106] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0107] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for testing the condensate air volume of an air conditioning unit in a rail vehicle, characterized in that the steps include... include: S1. Adjust the current environmental parameters of the environmental wind tunnel to the set environmental parameters; S2. Adjust the current wind speed of the environmental wind tunnel to a preset high wind speed so that the air conditioning unit in the environmental wind tunnel is in a high-speed test environment; S3. Obtain the actual cooling pressure of the air conditioning unit under the high-speed test environment; S4. Under the premise that the current environmental parameters remain unchanged, adjust the current wind speed of the environmental wind tunnel to a preset low wind speed so that the air conditioning unit is in a low-speed test environment. S5. Adjust the condenser air volume of the air conditioning unit until the current cooling pressure of the air conditioning unit under the low-speed test environment reaches the actual cooling pressure; S6. Under the low-speed test environment, obtain the condensate air volume of the air conditioning unit.

2. The method for testing the condensate air volume of a rail vehicle air conditioning unit according to claim 1, characterized in that, Between step S3 and step S4, the steps further include: S31. Under the high-speed test environment, adjust the current air supply volume of the air conditioning unit to the rated air supply volume; S32. Within a set time period, record the current environmental parameters of each detection point of the air conditioning unit under the high-speed test environment at specified intervals. S33. Under the high-speed test environment, determine whether the current air supply volume of the air conditioning unit has reached the rated air supply volume. If it has not reached the rated air supply volume, proceed to step S31. If it has reached the rated air supply volume, determine whether the difference between the current environmental parameters recorded twice consecutively is within the preset threshold range. If it is not within the preset threshold range, proceed to step S2. If it is within the threshold range, proceed to step S4.

3. The method for testing the condensate air volume of a rail vehicle air conditioning unit according to claim 1, characterized in that, Between step S5 and step S6, the steps also include: S51. Under the low-speed test environment, adjust the current air supply volume of the air conditioning unit to the rated air supply volume; S52. Within the set time period, record the current environmental parameters of each detection point of the air conditioning unit under the low-speed test environment at specified intervals. S53. Under the low-speed test environment, determine whether the current air supply volume of the air conditioning unit has reached the rated air supply volume. If it has not reached the rated air supply volume, proceed to step S51. If it has reached the rated air supply volume, determine whether the difference between the current environmental parameters recorded twice consecutively is within the set threshold range. If it is not within the threshold range, proceed to step S4. If it is within the threshold range, proceed to step S6.

4. The method for testing the condensate air volume of a rail vehicle air conditioning unit according to claim 1, characterized in that, Step S1 includes: S11. The air inlet, condenser air inlet, fresh air inlet, return air inlet and supply air outlet of the air conditioning unit are used as detection points, and temperature and humidity sensors are arranged at each detection point. S12. Use the temperature and humidity sensors to detect the current temperature and humidity at each of the detection points in the environmental wind tunnel; S13. Determine whether the current temperature and humidity at each detection point have reached the set temperature and humidity. If yes, the condenser air intake temperature and humidity of the air conditioning unit remain unchanged; if no, adjust the condenser air intake temperature and humidity.

5. The method for testing the condensate air volume of a rail vehicle air conditioning unit according to claim 1, characterized in that, Step S2 includes: S21. Input the preset high wind speed; S22. Adjust the speed of the condenser fan of the air conditioning unit and measure the actual wind speed of the environmental wind tunnel in real time; S24. Compare whether the actual wind speed is consistent with the preset high wind speed. If yes, stop adjusting the speed of the condenser fan; if no, continue adjusting the speed of the condenser fan.

6. The test method for condensate air volume of a rail vehicle air conditioning unit according to claim 2 or 3, characterized in that, Before adjusting the current air supply volume of the air conditioning unit to the rated air supply volume, the step further includes: The current air volume of the air conditioning unit is measured using an air volume hood at the air outlet of the air conditioning unit.

7. The method for testing the condensate air volume of a rail vehicle air conditioning unit according to claim 2 or 3, characterized in that, The specific steps for adjusting the current air supply volume of the air conditioning unit to the rated air supply volume include: Adjust the current frequency of the condenser fan of the air conditioning unit; And / or, adjust the cross-sectional area of ​​the condenser outlet of the air conditioning unit.

8. The method for testing the condensate air volume of a rail vehicle air conditioning unit according to claim 4, characterized in that, The current environmental parameters include the condenser inlet air temperature and humidity, the return air temperature and humidity, the supply air temperature and humidity, the refrigeration pipeline pressure of the air conditioning unit, and the rated current of the air conditioning unit.

9. The method for testing the condensate air volume of a rail vehicle air conditioning unit according to claim 2 or 3, characterized in that, The specific steps for adjusting the condenser air volume of the air conditioning unit are as follows: adjust the speed of the condenser fan of the air conditioning unit.

10. A testing device for the condensate air volume of a rail vehicle air conditioning unit, characterized in that, The test method for the condensate air volume of the rail vehicle air conditioning unit according to any one of claims 1 to 9 includes: The parameter adjustment module is used to adjust the current environmental parameters of the environmental wind tunnel to the set environmental parameters; The high wind speed adjustment module is used to adjust the current wind speed of the environmental wind tunnel to a preset high wind speed, so that the air conditioning unit in the environmental wind tunnel is in a high-speed test environment. The pressure acquisition module is used to acquire the actual cooling pressure of the air conditioning unit under high-speed testing conditions; The low wind speed adjustment module is used to adjust the current wind speed of the environmental wind tunnel to a preset low wind speed, so that the air conditioning unit is in a low-speed test environment, while keeping the current environmental parameters unchanged. The air volume adjustment module is used to adjust the condenser air volume of the air conditioning unit until the current cooling pressure of the air conditioning unit under the low-speed test environment reaches the actual cooling pressure. The air volume acquisition module is used to acquire the condensate air volume of the air conditioning unit under the low-speed test environment.

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