A performance test bench for agricultural cleaning fan and its test method

Abstract

The present invention provides an agricultural cleaning fan performance test bench and a test method thereof, comprising a test bench, a test wind tunnel, a detection mechanism and a data acquisition system; the cleaning fan is installed on the test bench, and a slide rail is provided between the cleaning fan and the test bench for translating the cleaning fan; the test wind tunnel is connected to the air outlet of the cleaning fan; the detection mechanism comprises at least two types of sensors, the first type of sensor is installed on the test wind tunnel, and is used to detect the wind speed signal and wind pressure signal in the test wind tunnel; the second type of sensor is used to detect the speed signal and torque signal of the central axis of the cleaning fan; the data acquisition system is connected to the detection mechanism, and the data acquisition system converts the wind speed signal and the wind pressure signal into performance parameters, draws a performance curve, and is used to evaluate the fan performance. The present invention can reflect the performance of the cleaning fan through the performance curve.

Description

Technical Field

[0001] The invention relates to the field of performance testing of agricultural cleaning fans, and in particular to a performance test bench for agricultural cleaning fans and a test method thereof. Background Art

[0002] As an important part of the cleaning system of the combine harvester, the cleaning fan plays an important role in reducing the grain loss rate and impurity rate. Today's grain combine harvesters are constantly developing in the direction of large-scale and multi-purpose, which puts higher requirements on the performance of the fan in the cleaning system. The current field of cleaning fans lacks a complete performance test platform and test methods, resulting in slow development of fan manufacturing technology, which seriously restricts the efficiency and function of harvesting machinery. In order to ensure and improve the performance of cleaning fans, the performance test technology and methods of cleaning fans need to be further studied.

[0003] The prior art discloses a fan performance measurement system including a wind pressure detection device and a wind resistance adjustment device. The wind pressure detection device is used to detect the static pressure in the air duct; the wind resistance adjustment device is used to adjust the wind resistance in the air duct. The wind pressure detection device and the wind resistance adjustment device are connected to a control device. The control device adjusts the speed of the fan step by step according to the speed level required for the test. The control device records the detection data and generates performance curves at different fan speeds, thereby realizing automatic collection and recording of test data and improving test efficiency and accuracy. However, the fan installation panel of the device cannot adapt to fans of different sizes and models. In addition, it only tests the wind pressure in the air duct for curve drawing, lacks parameters such as wind speed, efficiency and power, and cannot fully reflect the performance of the tested fan, which has certain limitations.

[0004] The prior art discloses a test device for testing the performance of a fan, including a test box and a test box. A fan is arranged inside the test box, and the fan is connected to a frequency converter. A fan installation panel is arranged at the outer end of the test box for installing the fan. The installation panel is provided with an air inlet, and the air inlet is aligned with the fan port. The fan exhaust is introduced into the test box through an air duct. A flow sensor and a pressure sensor are arranged in the test box, which improves the accuracy of the fan performance test. However, the air duct and the test box in the device are not equal-section structures, the air flow uniformity is not good, and there may be turbulence caused by cross-section changes at the sampling point, which affects data collection.

[0005] The prior art discloses a multifunctional fan performance detection device, which is mainly composed of a measuring port, a front wind tunnel, a rear wind tunnel, a support frame and a rubber plug. The measuring port, the front wind tunnel and the rear wind tunnel are sequentially connected and supported by the support frame, and the rubber plug is installed in the corresponding holes of the front and rear wind tunnels. A detachable measuring port is used to realize experimental analysis of various types of fans. The device has the characteristics of low cost, wide application, good reconfigurability and strong comprehensiveness. However, the device can measure fewer airflow parameters, and the parameters reflecting the airflow state are too few to facilitate subsequent performance analysis.

[0006] The prior art discloses a combined fan performance test device, including a common section, a transition section and an air outlet, the common section includes an air inlet section, a rectifier grid, an oblique cone section and a straight cylinder section; the transition section includes an oblique cone section and a straight cylinder section, and the oblique cone section and the straight cylinder section; the end of the air outlet section is provided with an interface for connecting to the fan outlet; the common section is a section shared by multiple models of fans, the transition section and the common section are detachably connected, and the transition section and the air outlet section can be replaced according to different fan models, so as to realize the same test device, test the performance of fans of different models, and save the cost of fan performance testing. However, the device has too many sections, the diameter of the test air duct changes frequently, turbulence is prone to occur, and the measurement accuracy is affected.

[0007] The prior art discloses a fan performance test device, including a test device and a data processing device, wherein the test device includes a temperature test device, a pressure test device and a humidity test device, and the data processing device includes a storage module, an analysis module and a calculation module. The invention can eliminate interference values ​​through the data processing device to make the fan performance test result more accurate. However, the invention mainly considers the ventilation performance in environments such as power plants, so the parameters detected are mostly related to the working environment, and less attention is paid to the parameters of the airflow itself. Summary of the invention

[0008] In view of the deficiencies in the prior art, the present invention provides a performance test bench for agricultural cleaning fans. The cleaning fan to be tested is installed on a universal test bench, the air outlet is connected to a test wind tunnel, the speed regulating device adjusts the fan speed range according to the test requirements, the frame detection mechanism measures the shaft end speed and torque of the cleaning fan, the detection mechanism in the test wind tunnel measures the wind speed signal and wind pressure signal of the airflow generated by the fan, the data acquisition system converts the collected wind speed signal, wind pressure signal and torque signal into fan performance parameters and draws a performance curve, and the performance curve reflects the performance of the cleaning fan.

[0009] The present invention achieves the above technical objectives through the following technical means.

[0010] An agricultural cleaning fan performance test bench, comprising a test bench, a test wind tunnel, a detection mechanism and a data acquisition system;

[0011] A cleaning fan is installed on the test bench, and a slide rail is provided between the cleaning fan and the test bench for translation of the cleaning fan; the test wind tunnel is connected to the air outlet of the cleaning fan; the detection mechanism includes at least two types of sensors, the first type of sensor is installed on the test wind tunnel, and is used to detect the wind speed signal and wind pressure signal in the test wind tunnel; the second type of sensor is used to detect the speed signal and torque signal of the central axis of the cleaning fan; the data acquisition system is connected to the detection mechanism, and the data acquisition system converts the wind speed signal and wind pressure signal into performance parameters, draws a performance curve, and is used to evaluate the performance of the fan.

[0012] Furthermore, the test wind tunnel includes a connecting section, a flow stabilizing section, an attenuation section and a rectifying grid; the air inlet of the connecting section is connected to the air outlet, and the rectifying grid is installed between the connecting section and the flow stabilizing section; the air outlet of the flow stabilizing section is connected to the air inlet of the attenuation section.

[0013] Furthermore, the connecting section is arc-shaped; the flow stabilizing section is straight-cylindrical; the attenuation section is trumpet-shaped and opens outward; and the rectifying grid is a honeycomb structure.

[0014] Furthermore, the detection system includes a first Pitot tube, a second Pitot tube, a first wind speed sensor, a second wind speed sensor, a tracer rod, a torque sensor and a speed sensor; the first Pitot tube and the first wind speed sensor are respectively installed on the steady flow section, and the first Pitot tube and the first wind speed sensor are staggered and equidistantly distributed longitudinally; a number of measuring holes are equidistantly provided on the two diagonals on the upper surface of the attenuation section, the second Pitot tube is installed on the first diagonal, and the second wind speed sensor is installed on the second diagonal; a tracer rod is installed at the intersection of the two diagonals. The torque sensor is used to detect the torque of the central axis of the cleaning fan; the speed sensor is used to detect the speed of the output shaft of the cleaning fan.

[0015] Furthermore, the test bench includes a frame, a power drive mechanism and a speed control cabinet; the cleaning fan is installed on the frame through a slide rail; the power drive mechanism is installed on the frame to drive the cleaning fan; the speed control cabinet is located at the bottom of the frame, and the speed control cabinet is respectively connected to the cleaning fan and the power drive mechanism to adjust the speed of the cleaning fan.

[0016] A test method for an agricultural cleaning fan performance test bench comprises the following steps:

[0017] Cleaning fan parameter measurement: the input shaft torque of the cleaning fan is measured by the torque sensor, and the actual input shaft speed is measured by the speed sensor;

[0018] Test wind tunnel airflow parameter measurement: measuring wind pressure by the first Pitot tube and the second Pitot tube; measuring wind speed by the first wind speed sensor and the second wind speed sensor;

[0019] Performance determination: The data acquisition system analyzes and processes the sensor data to determine the fan performance.

[0020] Furthermore, by installing a first Pitot tube and a first wind speed sensor equidistantly on the steady flow section, the wind pressure and wind speed under the steady airflow state are obtained to calculate the fan efficiency;

[0021] By installing a second Pitot tube and a second wind speed sensor equidistantly on the diagonal line of the upper surface of the attenuation section, the wind pressure and wind speed under the airflow attenuation state are obtained, and the wind pressure and wind speed attenuation rates are calculated;

[0022] By installing a tracer rod on the upper surface of the wind tunnel attenuation section, the vertical airflow attenuation rate is obtained;

[0023] By adjusting the speed, the fan efficiency, wind pressure and wind speed attenuation rate and vertical airflow attenuation rate at different speeds are obtained as performance indicators. The relationship curve between the performance indicators and different levels of speed is plotted as a performance curve, and the fan performance is judged by the performance curve.

[0024] Furthermore, the wind volume Q is determined based on the wind speed V collected by the first wind speed sensor in the steady flow section, and the effective power P is obtained by combining the total pressure p in the steady flow section collected by the first Pitot tube. 有效 ; According to the torque sensor, the input shaft torque of the cleaning fan is measured, and the shaft power P is obtained 轴 , according to the effective power P 有效 With shaft power P 轴 The ratio of the two is the fan efficiency.

[0025] Furthermore, the wind speed attenuation rate is calculated by measuring the wind speed signal in the attenuation section using a plurality of second wind speed sensors installed equidistantly on the diagonal line of the attenuation section. for:

[0026] Where: n is the number of second wind speed sensors, V1 is the measurement value of the first second wind speed sensor near the air inlet of the attenuation section; V i is the measurement value of the i-th second wind speed sensor close to the air inlet of the attenuation section, i∈(1,n); L is the distance between adjacent second wind speed sensors;

[0027] The wind pressure attenuation rate is calculated based on the wind pressure signal in the attenuation section measured by several second Pitot tubes installed equidistantly on the diagonal line of the attenuation section. for:

[0028] Where: m is the number of second Pitot tubes, P1 is the measurement value of the first second Pitot tube near the air inlet of the attenuation section; P j is the measurement value of the jth second Pitot tube (8-2) close to the air inlet of the attenuation section, j∈(1,m); L' is the distance between adjacent second Pitot tubes (8-2).

[0029] Furthermore, five tracer bars are evenly spaced on the tracer rod, and the vertical airflow attenuation rate is calculated according to the deflection angle C of different tracer bars on the tracer rod. for: Among them: the first tracer bar, the second tracer bar, the third tracer bar, the fourth tracer bar and the fifth tracer bar are evenly distributed on the tracer rod from top to bottom, C1 is the deflection angle of the measurement value of the first tracer bar; C2 is the deflection angle of the measurement value of the second tracer bar; C3 is the deflection angle of the measurement value of the third tracer bar; C4 is the deflection angle of the measurement value of the fourth tracer bar; C5 is the deflection angle of the measurement value of the fifth tracer bar; D is the distance between adjacent tracer bars.

[0030] The beneficial effects of the present invention are:

[0031] 1. The agricultural cleaning fan performance test bench described in the present invention can be adapted to carry various types of cleaning fans for performance testing by adjusting the upper lower rail of the universal test bench.

[0032] 2. The agricultural cleaning fan performance test bench described in the present invention selects the corresponding test wind tunnel to carry out tests according to the different shapes of the cleaning fan outlets, thereby achieving the multi-purpose purpose of the test bench.

[0033] 3. The agricultural cleaning fan performance test method described in the present invention uses a combination of multiple sensors to detect the quality of the fan, which can ensure the accuracy of the test results.

[0034] 4. The agricultural cleaning fan performance test method described in the present invention fits a variety of cleaning fan airflow measurement parameters, thereby improving the reliability of the cleaning fan performance test. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings described below are some embodiments of the present invention. For ordinary technicians in this field, it is obvious that other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 It is a schematic diagram of the overall structure of the cleaning fan performance test bench described in the present invention.

[0037] Figure 2 This is a schematic diagram of the test bench frame structure of the present invention.

[0038] Figure 3 This is a schematic diagram of the installation of the cleaning fan described in the present invention.

[0039] Figure 4 This is a schematic diagram of the installation position of the torque and speed sensor described in the present invention.

[0040] Figure 5 This is a cross-sectional view of the test wind tunnel structure described in the present invention.

[0041] Figure 6 This is a top view of the installation of the Pitot tube and wind speed sensor described in the present invention.

[0042] Figure 7 Schematic diagram of the rectifier grid described in the present invention.

[0043] Figure 8 This is a connection block diagram of the cleaning fan performance test method described in the present invention.

[0044] Fig. 9 The present invention provides a flow chart of the test method for the cleaning fan performance.

[0045] In the figure:

[0046] 1-computer; 2-speed sensor; 3-1-first mounting seat; 3-2-second mounting seat; 4-torque sensor; 5-cleaning fan; 5-1-air outlet; 6-test wind tunnel; 7-1-first wind speed sensor; 7-2-second wind speed sensor; 8-1-first Pitot tube; 8-2-second Pitot tube; 9-data acquisition card; 10-tracer rod; 12-slide rail; 13-frequency control cabinet; 14-AC variable frequency motor; 15-frame; 16-universal wheel; 17-fan center shaft; 18-driven pulley; 19-belt; 20-driving pulley; 21-bearing seat; 22-mounting plate. DETAILED DESCRIPTION

[0047] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0048] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0049] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0050] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] like Figure 1 , Figure 3 , Figure 5 As shown, the agricultural cleaning fan performance test bench described in the present invention includes a test bench, a test wind tunnel 6, a detection mechanism and a data acquisition system; the cleaning fan 5 is installed on the test bench, and a slide rail 12 is provided between the cleaning fan 5 and the test bench for translation of the cleaning fan 5; the test bench adjusts the installation guide rail 12 according to the size of each type of cleaning fan and the test wind tunnel 6, and is used to install multiple types of cleaning fans for comparative testing; the test wind tunnel 6 is connected to the air outlet 5-1 of the cleaning fan 5; the detection mechanism includes at least two types of sensors 7, the first type of sensor is installed on the test wind tunnel 6, and is used to detect the wind speed signal and wind pressure signal in the test wind tunnel 6; the second type of sensor is used to detect the speed signal and torque signal of the central axis of the cleaning fan 5; the data acquisition system is connected to the detection mechanism, and the data acquisition system converts the wind speed signal and the wind pressure signal into performance parameters, draws a performance curve, and is used to evaluate the fan performance.

[0052] like Figure 1 , Figure 2 As shown, the test bench includes a frame 15, a cleaning fan 5, a power drive mechanism and a speed control cabinet 13. The frame 15 is a frame composed of a crossbeam, a slide rail 12 and a universal wheel 16. Figure 1, Figure 5 As shown, the cleaning fan 5 is installed on the frame 15 through the slide rail 12; the fan center axis 17 of the cleaning fan 5 is supported on the bearing seat 21. The power drive mechanism includes a belt 19, a motor 14 and a driving pulley 20; the motor 14 of the power drive mechanism is fixed to the bottom of the frame through a mounting plate 22, and the position can be adjusted according to the change of the fan size, so as to keep the driving pulley 20 at the output shaft end of the motor 14 and the driven pulley 18 at the fan shaft end in the same plane, and the driving pulley 20 of the motor output shaft is connected to the driven pulley 18 on the blade center axis through a belt 19, and the speed control cabinet 13 is arranged at the bottom of the frame, and the speed control cabinet 13 has a power switch and a fan speed adjustment switch, and the speed control cabinet 13 is respectively connected to the cleaning fan 5 and the power drive mechanism, and is used to adjust the fan theoretical speed according to the test requirements.

[0053] like Figure 5 , Figure 6 , Figure 7 As shown, the test wind tunnel 6 includes a connecting section 6-1, a steady flow section 6-2 and an attenuation section 6-3 in sequence according to the flow direction, which are used to converge and clean the airflow at the fan outlet 5-1 and be measured and analyzed by the detection mechanism. The air inlet of the connecting section 6-1 of the test wind tunnel is connected to the fan outlet 5-1, and is arc-shaped. The connecting section of appropriate size can be selected according to the size of the fan outlet, which is used to converge the airflow and pass it into the steady flow section for airflow detection; the steady flow section 6-2 is connected to the connecting section 6-1, and the steady flow section 6-2 is a straight cylinder, which is used to stabilize the airflow. Four measuring holes are equidistantly provided on the upper surface, which are used to install two first Pitot tubes 8-1 to measure wind pressure and two first wind speed sensors 7-1 to measure wind speed; the attenuation section 6-3 of the test wind tunnel is connected to the steady flow section 6-2, and is open outward. It is trumpet-shaped, and its side walls are made of plexiglass plates, which are used to diverge the airflow in the wind tunnel. Four measuring holes are equidistantly provided on the two diagonals of the upper surface, which are used to install four second Pitot tubes 8-2 and four second wind speed sensors 7-2 respectively. A measuring hole is provided in the middle of the diagonal to install a tracer rod 10 for analyzing the attenuation of wind speed and pressure. The rectifier grid 6-4 is installed at the connection between the connecting section and the stabilizing section, and is covered with honeycomb-shaped openings, which are used to break up the larger air masses at the air inlet to form evenly distributed small air masses, reduce turbulence, and make the wind field in the stabilizing section uniform and stable.

[0054] As shown in Figure 6, the detection system includes a first Pitot tube 8-1, a second Pitot tube 8-2, a first wind speed sensor 7-1, a second wind speed sensor 7-2, a tracer rod 10, a torque sensor 4 and a speed sensor; the first Pitot tube 8-1 and the first wind speed sensor 7-1 are respectively installed on the steady flow section 6-2, and the first Pitot tube 8-1 and the first wind speed sensor 7-1 are longitudinally staggered and equidistantly distributed; four measuring holes are equidistantly opened on the two diagonals on the upper surface of the attenuation section 6-3, four second Pitot tubes 8-2 are installed on the first diagonal, and four second wind speed sensors 7-2 are installed on the second diagonal; a tracer rod 10 is installed at the intersection of the two diagonals. The torque sensor 4 is installed on the frame through the second mounting seat 3-2, and is used to detect the torque of the central axis of the cleaning fan 5; the speed sensor 2 is installed on the frame through the first mounting seat 3-1, and is used to detect the speed of the output shaft of the cleaning fan 5.

[0055] The data acquisition system includes a signal acquisition module, a signal processing module and a judgment module. The signal acquisition module is connected to the detection mechanism and is used to receive the signal of the detection mechanism; the signal processing module is connected to the signal acquisition module and is used to process the wind pressure signal, wind speed signal and torque signal received by the signal acquisition module, convert them into total pressure, air volume and efficiency through formulas, combine the total pressure, air volume and efficiency into performance indicators through functions and draw relationship curves with different levels of rotational speeds; the judgment module is connected to the signal processing module and the signal acquisition module and is used to compare and analyze the relationship curves between performance indicators and different levels of rotational speeds, i.e., performance curves, compare and analyze the wind speed and wind pressure attenuation through wind speed signals collected by wind speed sensors at different distances from the air outlet, and judge the performance of the fan by the above means.

[0056] like Figure 8 and Fig. 9 As shown, the test method of the agricultural cleaning fan performance test bench of the present invention comprises the following steps:

[0057] Parameter measurement of the cleaning fan 5: the torque of the input shaft 17 of the cleaning fan 5 is measured by the torque sensor 4, and the actual speed of the input shaft 17 is measured by the speed sensor 2;

[0058] Measurement of airflow parameters in the test wind tunnel 6: measuring wind pressure through the first pitot tube 8-1 and the second pitot tube 8-2; measuring wind speed through the first wind speed sensor 7-1 and the second wind speed sensor 7-2;

[0059] The wind pressure and wind speed in the steady-state state of the airflow are obtained by installing the first Pitot tube 8-1 and the first wind speed sensor 7-1 equidistantly on the steady-flow section 6-2, and the fan efficiency is calculated. Specifically, the wind volume Q is determined according to the wind speed V collected by the first wind speed sensor 7-1 in the steady-flow section 6-2, and the effective power P is obtained by combining the total pressure p in the steady-flow section 6-2 collected by the first Pitot tube 8-1. 有效 According to the torque sensor 4 measuring the input shaft 17 of the cleaning fan 5, the shaft power P is obtained 轴 , according to the effective power P 有效 With shaft power P 轴 The ratio is the efficiency.

[0060] By installing the second Pitot tube 8-2 and the second wind speed sensor 7-2 equidistantly on the diagonal line of the upper surface of the attenuation section 6-3, the wind pressure and wind speed under the airflow attenuation state are obtained, and the wind pressure and wind speed attenuation rate are calculated; specifically, the wind speed signal in the attenuation section is measured by a plurality of second wind speed sensors 7-2 equidistantly installed on the diagonal line of the attenuation section 6-3, and the wind speed attenuation rate is calculated. for:

[0061] Wherein: V1 is the measurement value of the first second wind speed sensor 7-2 near the air inlet of the attenuation section 6-3; V2 is the measurement value of the second second wind speed sensor 7-2 near the air inlet of the attenuation section 6-3; V3 is the measurement value of the third second wind speed sensor 7-2 near the air inlet of the attenuation section 6-3; 4 is the measurement value of the fourth second wind speed sensor 7-2 near the air inlet of the attenuation section 6-3; L is the distance between adjacent second wind speed sensors 7-2;

[0062] The wind pressure attenuation rate is calculated by measuring the wind pressure signal in the attenuation section using a number of second Pitot tubes 8-2 installed equidistantly on the diagonal line of the attenuation section 6-3. for:

[0063] Among them: P1 is the measurement value of the first second Pitot tube 8-2 close to the air inlet of the attenuation section 6-3; P2 is the measurement value of the second second Pitot tube 8-2 close to the air inlet of the attenuation section 6-3; P3 is the measurement value of the third second Pitot tube 8-2 close to the air inlet of the attenuation section 6-3; P4 is the measurement value of the fourth second Pitot tube 8-2 close to the air inlet of the attenuation section 6-3; P5 is the measurement value of the fifth second Pitot tube 8-2 close to the air inlet of the attenuation section 6-3; L' is the distance between adjacent second Pitot tubes 8-2.

[0064] By installing a tracer rod 10 on the upper surface of the wind tunnel attenuation section 6-3, the vertical airflow attenuation rate is obtained. Specifically, five tracer bars are evenly distributed on the tracer rod 10, and the vertical airflow attenuation rate is calculated according to the deflection angle C of different tracer bars on the tracer rod 10. for: Wherein: the first tracer bar, the second tracer bar, the third tracer bar, the fourth tracer bar and the fifth tracer bar are evenly distributed on the tracer rod 10 from top to bottom, C1 is the deflection angle of the measurement value of the first tracer bar; C2 is the deflection angle of the measurement value of the second tracer bar; C3 is the deflection angle of the measurement value of the third tracer bar; C4 is the deflection angle of the measurement value of the fourth tracer bar; C5 is the deflection angle of the measurement value of the fifth tracer bar; D is the distance between adjacent tracer bars.

[0065] By adjusting the speed, the fan efficiency, wind pressure and wind speed attenuation rate and vertical airflow attenuation rate at different speeds are obtained as performance indicators. The relationship curve between the performance indicators and different levels of speed is plotted as a performance curve, and the fan performance is judged by the performance curve.

[0066] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0067] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An agricultural cleaning fan performance test bench, characterized in that: It includes a test bench, a test wind tunnel (6), a detection mechanism and a data acquisition system; A cleaning fan (5) is installed on the test bench, and a slide rail (12) is provided between the cleaning fan (5) and the test bench for translating the cleaning fan (5); the test wind tunnel (6) is connected to the air outlet (5-1) of the cleaning fan (5); the detection mechanism comprises at least two types of sensors (7), the first type of sensor is installed on the test wind tunnel (6) and is used to detect the wind speed signal and wind pressure signal in the test wind tunnel (6); the second type of sensor is used to detect the speed signal and torque signal of the central axis of the cleaning fan (5); the data acquisition system is connected to the detection mechanism, and the data acquisition system converts the wind speed signal and the wind pressure signal into performance parameters, draws a performance curve, and is used to evaluate the fan performance; The test wind tunnel (6) comprises a connecting section (6-1), a flow stabilizing section (6-2), an attenuation section (6-3) and a rectifying grid (6-4); the air inlet of the connecting section (6-1) is connected to the air outlet (5-1), and the rectifying grid (6-4) is installed between the connecting section (6-1) and the flow stabilizing section (6-2); the air outlet of the flow stabilizing section (6-2) is connected to the air inlet of the attenuation section (6-3); the detection system comprises a first Pitot tube (8-1), a second Pitot tube (8-2), a first wind speed sensor (7-1), a second wind speed sensor (7-2), a tracer rod (10), a torque sensor (4) and a rotation speed sensor; The first Pitot tube (8-1) and the first wind speed sensor (7-1) are respectively installed on the steady flow section (6-2), and the first Pitot tube (8-1) and the first wind speed sensor (7-1) are staggered and equidistantly distributed longitudinally; a plurality of measuring holes are equidistantly provided on two diagonals on the upper surface of the attenuation section (6-3), the second Pitot tube (8-2) is installed on the first diagonal, and the second wind speed sensor (7-2) is installed on the second diagonal; a tracer rod (10) is installed at the intersection of the two diagonals; the torque sensor (4) is used to detect the torque of the central shaft of the cleaning fan (5); and the speed sensor (2) is used to detect the speed of the output shaft of the cleaning fan (5); The connecting section (6-1) is arc-shaped; the flow stabilizing section (6-2) is straight-cylindrical; the attenuation section (6-3) is trumpet-shaped and opens outward; and the rectifying grid (6-4) is a honeycomb structure.

2. The agricultural cleaning fan performance test bench according to claim 1 is characterized in that: The test bench comprises a frame (15), a power drive mechanism and a speed regulating cabinet (13); a cleaning fan (5) is mounted on the frame (15) via a slide rail (12); the power drive mechanism is mounted on the frame (15) and is used to drive the cleaning fan (5); the speed regulating cabinet (13) is located at the bottom of the frame (15), and the speed regulating cabinet (13) is respectively connected to the cleaning fan (5) and the power drive mechanism and is used to adjust the rotation speed of the cleaning fan (5).

3. A test method for the agricultural cleaning fan performance test bench according to any one of claims 1-2, characterized in that: The steps include: Parameter measurement of the cleaning fan (5): measuring the torque of the input shaft (17) of the cleaning fan (5) through the torque sensor (4), and measuring the actual rotation speed of the input shaft (17) through the rotation speed sensor (2); Measurement of airflow parameters in the test wind tunnel (6): measuring wind pressure through the first Pitot tube (8-1) and the second Pitot tube (8-2); measuring wind speed through the first wind speed sensor (7-1) and the second wind speed sensor (7-2); Performance determination: The data acquisition system analyzes and processes the sensor data to determine the fan performance, specifically: By installing a first Pitot tube (8-1) and a first wind speed sensor (7-1) equidistantly on the steady flow section (6-2), the wind pressure and wind speed under the steady airflow state are obtained, and the fan efficiency is calculated; By installing a second Pitot tube (8-2) and a second wind speed sensor (7-2) equidistantly on the diagonal line of the upper surface of the attenuation section (6-3), the wind pressure and wind speed in the airflow attenuation state are obtained, and the wind pressure and wind speed attenuation rates are calculated; By installing a tracer rod (10) on the upper surface of the wind tunnel attenuation section (6-3), the airflow attenuation rate in the vertical direction is obtained; By adjusting the speed, the fan efficiency, wind pressure and wind speed attenuation rate and vertical airflow attenuation rate at different speeds are obtained as performance indicators. The relationship curve between the performance indicators and different levels of speed is plotted as a performance curve, and the fan performance is judged by the performance curve.

4. The test method of the agricultural cleaning fan performance test bench according to claim 3 is characterized in that: The wind volume Q is determined based on the wind speed V collected by the first wind speed sensor (7-1) of the steady flow section (6-2), and the effective power P is obtained by combining the total pressure p in the steady flow section (6-2) collected by the first Pitot tube (8-1). 有效 ; According to the torque sensor (4) measuring the input shaft (17) torque of the cleaning fan (5), the shaft power P is obtained 轴 , according to the effective power P 有效 With shaft power P 轴 The ratio is the efficiency.

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