A flow test device for testing low vacuum

Abstract

The utility model discloses a flow testing arrangement for testing low vacuum, including equipment test board and low vacuum generating mechanism, the equipment test board includes test compressor, the air inlet end of test compressor is connected with the connecting pipe, the part of connecting pipe is close to test compressor and is connected with the thermometer, low vacuum generating mechanism includes support frame and sets up low vacuum generator on support frame, the air outlet end of low vacuum generator is detachably connected with the one end of connecting pipe far from test compressor, and the air inlet end is provided with air intake control member, air intake control member is used for changing air intake and calculating air intake, the part of low vacuum generator close to air inlet end is connected with pressure gauge, the utility model discloses simple structure, low in cost, convenient operation, adapts to the situation that the testing precision is not high, and the practicality is high.

Description

Technical Field

[0001] This utility model relates to the field of compressor testing, and in particular to a flow testing device for testing low vacuum. Background Technology

[0002] Volumetric flow rate is one of the core performance parameters of a compressor, as it relates to the compressibility of the gas, its operating conditions, and the compression process itself. The most accurate and commonly used method for measuring volumetric flow rate is using a differential pressure flow meter, which requires the use of equipment such as a venturi tube. While accurate, this method is costly and not very suitable for applications where high measurement accuracy is not required. Utility Model Content

[0003] In order to overcome the shortcomings of the prior art, this utility model provides a flow testing device for testing low vacuum, which has the advantage of high practicality.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A flow testing device for testing low vacuum includes a test bench and a low vacuum generating mechanism. The test bench includes a test compressor. The inlet end of the test compressor is connected to a connecting pipe. A thermometer is connected to the portion of the connecting pipe near the test compressor. The low vacuum generating mechanism includes a support frame and a low vacuum generator mounted on the support frame. The outlet end of the low vacuum generator is detachably connected to the end of the connecting pipe away from the test compressor. An inlet flow control element is provided at the inlet end. The inlet flow control element is used to change the inlet flow and calculate the inlet flow. A pressure gauge is connected to the portion of the low vacuum generator near the inlet end.

[0005] By adopting the above technical solution, after completing the preparation work, once the test compressor reaches the test conditions (speed, etc.), the intake air volume is reduced by the intake air volume control component, thereby generating negative pressure in the low vacuum generator. The pressure gauge monitors the pressure in the low vacuum generator in real time. After the negative pressure condition is achieved, the test is conducted for a period of time to stabilize the intake air temperature. The thermometer is used to detect the intake air temperature, and the intake air volume is calculated according to the intake air volume control component. Finally, the volumetric flow rate is calculated using a calculation table. This flow rate testing device has a simple structure, low cost, and convenient operation. It is suitable for situations where the testing accuracy is not high and has high practicality.

[0006] Optionally, the air intake control component includes a nozzle mounting plate and a nozzle assembly mounted on the nozzle mounting plate; the nozzle assembly includes a plurality of metering nozzles; the metering nozzles have air inlets; and each metering nozzle corresponds to a set air intake volume.

[0007] By adopting the above technical solution, during the testing process, the corresponding metering nozzles can be sealed with thick rubber plates, which makes it convenient to change the air intake volume. At the same time, since each metering nozzle corresponds to a set air intake volume, the air intake volume can be quickly calculated based on the unsealed metering nozzles, which is beneficial for calculation.

[0008] Optionally, all the metering nozzles are divided into multiple nozzle groups. The metering nozzles in the same nozzle group have the same orifice diameter at the air inlet, while the metering nozzles in different nozzle groups have different orifice diameters at the air inlet.

[0009] By adopting the above technical solution, the metering nozzles on the corresponding sides can be sealed in an orderly manner according to the actual situation. When the required negative pressure is far away, the metering nozzle with a larger orifice can be sealed, so that the required negative pressure can be approached quickly. When the required negative pressure is approached, the metering nozzle with a smaller orifice can be sealed, so that the required negative pressure is more accurate.

[0010] Optionally, the metering nozzle is screwed onto the nozzle mounting plate.

[0011] By adopting the above technical solution, the metering nozzle is installed on the nozzle mounting plate by screwing, which facilitates the disassembly and assembly of the metering nozzle and subsequent maintenance.

[0012] Optionally, the low vacuum generator includes a first tube, a second tube, and a third tube; the second tube connects the first tube and the third tube; the air intake control element is located at the end of the first tube away from the second tube; the end of the third tube away from the second tube is connected to the connecting pipe; the diameter of the first tube is larger than the diameter of the third tube.

[0013] By adopting the above technical solution, the diameter of the first tube is larger than that of the third tube. This type of tube, which is thicker at the front and thinner at the back, is more likely to generate negative pressure than a tube with the same diameter, thus improving testing efficiency.

[0014] Optionally, the low vacuum generator is oscillatingly connected to the support frame; the oscillation center axis of the low vacuum generator is parallel to the center axis of the gas outlet end of the low vacuum generator; a limiting member is provided between the low vacuum generator and the support frame; the limiting member is used to restrict the oscillation of the low vacuum generator.

[0015] By adopting the above technical solution, the height of the low vacuum generator end can be changed by the combination of swing and limiting components, which facilitates connection with the connecting pipe. In addition, different test compressors can be used.

[0016] Optionally, the limiting component includes a swing limiting plate, an inner support base, a swing limiting post, and a limiting nut; the swing limiting plate is fixed on the support frame and has a swing arc groove formed therein; the central axis of the swing arc groove is collinear with the swing central axis of the low vacuum generator; the inner support base is fixed on the low vacuum generator; the swing limiting post is fixed on the inner support base and slidably disposed within the swing arc groove; the limiting nut is screwed onto the swing limiting post; the swing limiting plate is located between the inner support base and the limiting nut.

[0017] By adopting the above technical solution, during testing, the limit nut and the inner support seat tighten the swing limit plate, so that the low vacuum generator will not swing unexpectedly, which helps to improve the stability of the test; when it is necessary for the low vacuum generator to swing, the limit nut can be loosened slowly, so that the low vacuum generator will not swing rapidly and avoid causing impact.

[0018] Optionally, the swing center axis of the low vacuum generator passes through its center of mass.

[0019] By adopting the above technical solution, since the swing center of the low vacuum generator passes through its center of mass, there will be no torque due to eccentricity, and the limiting component will not bear excessive external force, thus making the position of the low vacuum generator more accurate.

[0020] Optionally, the low vacuum generator can be detachably connected to the support frame and has several lifting rings evenly distributed on it.

[0021] By adopting the above technical solution, the presence of the lifting ring allows the overhead crane to bear the weight of the low vacuum generator and move it, thus reducing the operational intensity for the operator.

[0022] Optionally, the bottom of the support frame is provided with several casters with brakes.

[0023] By adopting the above technical solution, the low vacuum generating mechanism can be moved to the corresponding side position using the casters, which improves the flexibility of the test; at the same time, since the casters are equipped with brakes, the parking position of the low vacuum generating mechanism is more stable. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of this utility model.

[0025] Figure 2 This is a schematic diagram of the structure of this utility model.

[0026] Figure 3 This is a structural schematic diagram of the support frame of this utility model.

[0027] Figure 4This is a schematic diagram of the low vacuum generator of this utility model.

[0028] Figure 5 This is a schematic diagram of the exploded structure of the air intake control component of this utility model.

[0029] Figure 6 This is a cross-sectional structural diagram of the metering nozzle of this utility model.

[0030] Figure 7 This is a schematic diagram of the connecting pipe of this utility model.

[0031] Explanation of reference numerals in the attached figures: 10. Support frame; 11. Swing support frame; 12. Swing limiting plate; 120. Swing arc groove; 20. Low vacuum generator; 21. First tube body; 211. Pressure detection nozzle; 212. Inner support seat; 213. Swing limit post; 214. Limit nut; 215. Rotating rod; 22. Air intake control component; 221. Nozzle mounting plate; 2211. Air inlet; 2212. Air intake connecting pipe; 222. Metering nozzle; 2220. Air inlet; 2221. External threaded part; 2222. Rotating part; 23. Second tube body; 24. Third tube body; 25. Third tube body; 30. Test bench; 40. Test the compressor; 50. Connecting pipe; 51. Thermometer; 60. Exhaust pipe; 70. Pressure gauge; 71. Valve; 72. Test pipeline. Detailed Implementation

[0032] The following is in conjunction with the appendix Figures 1-7 The present invention will be described in further detail below.

[0033] Example 1: A flow testing device for testing low vacuum is disclosed, referencing... Figure 1 and Figure 2 The system includes a test bench and a low-vacuum generating mechanism. The test bench includes a test frame 30, on which a test compressor 40 is bolted. The inlet of the test compressor 40 is connected to a connecting pipe 50 via a flange, and the outlet is connected to an exhaust pipe 60 via a flange. The low-vacuum generating mechanism includes a support frame 10 and a low-vacuum generator 20 mounted on the support frame 10. The outlet of the low-vacuum generator 20 is connected to the end of the connecting pipe 50 away from the test compressor 40 via a flange. To facilitate movement of the low-vacuum generating mechanism, four casters with brakes are installed at the bottom of the support frame 10.

[0034] refer to Figure 4The low vacuum generator 20 includes a first tube 21, an air intake control element 22, a second tube 23, and a third tube 24; the two ends of the second tube 23 are connected to the first tube 21 and the third tube 24 respectively through flanges; the air intake control element 22 is located at the end of the first tube 21 away from the second tube 23; the end of the third tube 24 away from the second tube 23 is connected to the connecting pipe 50 through a flange; the diameter of the first tube 21 is larger than the diameter of the third tube 24.

[0035] refer to Figures 4-6 The intake volume control component 22 includes a nozzle mounting plate 221 and a nozzle assembly mounted on the nozzle mounting plate 221; the nozzle mounting plate 221 is connected to the first pipe body 21 via a flange; the nozzle assembly includes a plurality of metering nozzles 222; the metering nozzles 222 have an axially penetrating air inlet 2220; each metering nozzle 222 corresponds to a set intake volume; in order to improve the smoothness of intake, the inlet of the air inlet 2220 is funnel-shaped and the outlet is cylindrical groove-shaped.

[0036] refer to Figure 5 The metering nozzle 222 consists of an external threaded portion 2221 and a hexagonal rotating portion 2222; the external threaded portion 2221 and the rotating portion 2222 are coaxially arranged; the nozzle mounting plate 221 has a threaded hole that mates with the external threaded portion 2221; in order to improve the connection stability of the metering nozzle 222, in other embodiments, the nozzle mounting plate 221 has a plurality of air inlet holes 2211, and a plurality of air inlet connecting pipes 2212 are formed on the end face of the nozzle mounting plate 221 away from the first tube body 21; the air inlet connecting pipes 2212 mate with the air inlet holes 2211 one by one and are coaxially arranged with the air inlet holes 2211 on the corresponding side; the inner cylindrical surface of the air inlet connecting pipes 2212 has an internal thread that mates with the external threaded portion 2221 of the metering nozzle 222.

[0037] refer to Figure 5 To detect the pressure of the first tube 21, a pressure testing nozzle 211 is connected to the upper end of the first tube 21, and a pressure gauge 70 is fixed on the support frame 10. The pressure gauge 70 and the pressure testing nozzle 211 are connected through a test pipeline 72. The pressure gauge 70 is a mercury pressure gauge, but other pressure gauges can also be used. To control the gas entering and exiting the pressure gauge 70, a valve 71 is installed on the test pipeline 72. The valve 71 is a ball valve. To make the measurement more accurate, the distance between the pressure testing nozzle 211 and the end face of the nozzle mounting plate 221 away from the first tube 21 is the same as the inner diameter of the first tube 21.

[0038] refer to Figure 7To detect the intake air temperature, a thermometer 51 is connected to the end of the connecting pipe 50 near the test compressor 40. The thermometer 51 is a bimetallic mercury thermometer, but other thermometers can also be used. For more accurate measurements, the distance between the flange face connecting the connecting pipe 50 to the outlet end of the low vacuum generator 20 and the thermometer 51 is twice the inner diameter of the connecting pipe 50.

[0039] Example 2: The difference between Example 2 and Example 1 is as follows: (Refer to...) Figure 3 and Figure 4 To facilitate the connection between the low vacuum generator 20 and the connecting pipe 50, the low vacuum generator 20 is oscillatingly connected to the support frame 10; the oscillation center axis of the low vacuum generator 20 is parallel to the center axis of the outlet end of the low vacuum generator 20; a limiting element is provided between the low vacuum generator 20 and the support frame 10; the limiting element is used to restrict the oscillation of the low vacuum generator 20; Reference Figure 4 The end of the low vacuum generator 20 is bent to make it L-shaped and the bend is rounded. The swing center axis of the low vacuum generator 20 is parallel to the center axis of the end of the low vacuum generator 20.

[0040] To facilitate the disassembly of the low vacuum generator 20, a pair of coaxially arranged horizontal rotating rods 215 are formed on the first tube 21; the axial direction of the rotating rods 215 passes through the axis of the first tube 21; a pair of swing support frames 11 are formed on the support frame 10 for the rotating rods 215 to be inserted from top to bottom, and the cross-section of the swing support frame 11 is a U-shape with the opening facing upward. In order to prevent the low vacuum generator 20 from generating torque due to eccentricity, the pair of rotating rods 215 pass through the center of mass of the low vacuum generator 20.

[0041] refer to Figure 3 and Figure 4 The limiting components include a swing limiting plate 12, an inner support base 212, a swing limiting post 213, and a limiting nut 214. The swing limiting plate 12 is fixed on the support frame 10 and has a swing arc groove 120 formed therein. The central axis of the swing arc groove 120 is collinear with the swing center axis of the low vacuum generator 20. The inner support base 212 is fixed on the low vacuum generator 20. The swing limiting post 213 is fixed on the inner support base 212 and slidably disposed within the swing arc groove 120. The limiting nut 214 is screwed onto the swing limiting post 213. The swing limiting plate 12 is located between the inner support base 212 and the limiting nut 214. To make the limiting more stable, there are two inner support bases 212, two swing limiting posts 213, and two limiting nuts 214.

[0042] To reduce the workload of operators and facilitate the adjustment of the low vacuum generator 20, several lifting rings 25 are evenly distributed on the low vacuum generator 20. In this way, during adjustment, the weight of the low vacuum generator 20 can be supported by a crane and the low vacuum generator 20 can be moved.

[0043] The specific procedures for testing are as follows: Step 1: After completing the power-on preparation work of the equipment test bench, move the low vacuum generator to the side of the equipment test bench, and then adjust the angle of the low vacuum generator 20 so that the third tube 24 is connected to the flange of the connecting tube 50.

[0044] Step 2: Install metering nozzle 222, thermometer 51 and pressure gauge 70; Step 3: After the compressor 40 is turned on and reaches the test operating speed, seal the inlet of the metering nozzle 222 with a thick rubber plate according to the required intake negative pressure to reduce the intake volume and generate negative pressure. At this time, first seal the large-diameter nozzle, and adjust to seal the small nozzle when it is close to the required negative pressure to achieve the required intake negative pressure. Step 4: After applying negative pressure, test for a period of time to allow the intake air temperature to stabilize. Record the size and number of unsealed metering nozzles and the intake air temperature at this time. Use a calculation table to calculate the volumetric flow rate.

[0045] The total intake air volume is calculated by summing the number of unsealed metering nozzles and the intake air volume of each nozzle at different temperatures. This total intake air volume is then corrected using conversion correction factors (composed of atmospheric pressure conversion factor, pressure ratio conversion factor, gas conversion factor, and nozzle efficiency conversion factor). The volumetric flow rate is then calculated after determining the air density under the measurement conditions.

[0046] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A flow rate testing device for testing low vacuum, characterized in that: The device includes a test bench and a low vacuum generating mechanism. The test bench includes a test compressor (40). The inlet end of the test compressor (40) is connected to a connecting pipe (50). A thermometer (51) is connected to the part of the connecting pipe (50) near the test compressor (40). The low vacuum generating mechanism includes a support frame (10) and a low vacuum generator (20) mounted on the support frame (10). The outlet end of the low vacuum generator (20) is detachably connected to the end of the connecting pipe (50) away from the test compressor (40). An intake volume control device (22) is provided at the inlet end. The intake volume control device (22) is used to change the intake volume and calculate the intake volume. A pressure gauge (70) is connected to the part of the low vacuum generator (20) near the intake end.

2. The flow testing device for testing low vacuum according to claim 1, characterized in that: The air intake control component (22) includes a nozzle mounting plate (221) and a nozzle assembly mounted on the nozzle mounting plate (221); the nozzle assembly includes a plurality of metering nozzles (222); the metering nozzles (222) have air inlets (2220); each metering nozzle (222) corresponds to a set air intake volume.

3. The flow testing device for testing low vacuum according to claim 2, characterized in that: All the metering nozzles (222) are divided into multiple nozzle groups. The metering nozzles (222) in the same nozzle group have the same orifice diameter of the air inlet (2220). The metering nozzles (222) in different nozzle groups have different orifice diameters of the air inlet (2220).

4. A flow testing device for testing low vacuum according to claim 2, characterized in that: The metering nozzle (222) is screwed onto the nozzle mounting plate (221).

5. A flow testing device for testing low vacuum according to claim 1, characterized in that: The low vacuum generator (20) includes a first tube (21), a second tube (23), and a third tube (24); the second tube (23) connects the first tube (21) and the third tube (24); the air intake control element (22) is located at the end of the first tube (21) away from the second tube (23); the end of the third tube (24) away from the second tube (23) is connected to the connecting pipe (50); the diameter of the first tube (21) is larger than the diameter of the third tube (24).

6. The flow testing device for testing low vacuum according to claim 1, characterized in that: The low vacuum generator (20) is oscillatingly connected to the support frame (10); the oscillation center axis of the low vacuum generator (20) is parallel to the center axis of the outlet end of the low vacuum generator (20); a limiting member is provided between the low vacuum generator (20) and the support frame (10); the limiting member is used to restrict the oscillation of the low vacuum generator (20).

7. A flow testing device for testing low vacuum according to claim 6, characterized in that: The limiting component includes a swing limiting plate (12), an inner support base (212), a swing limiting post (213), and a limiting nut (214); the swing limiting plate (12) is fixed on the support frame (10) and has a swing arc groove (120); the central axis of the swing arc groove (120) is collinear with the swing center axis of the low vacuum generator (20); the inner support base (212) is fixed on the low vacuum generator (20); the swing limiting post (213) is fixed on the inner support base (212) and slidably disposed in the swing arc groove (120); the limiting nut (214) is screwed onto the swing limiting post (213); the swing limiting plate (12) is located between the inner support base (212) and the limiting nut (214).

8. A flow testing device for testing low vacuum according to claim 6, characterized in that: The swing center axis of the low vacuum generator (20) passes through its center of mass.

9. A flow testing device for testing low vacuum according to claim 1, characterized in that: The low vacuum generator (20) is detachably connected to the support frame (10) and a number of lifting rings (25) are evenly distributed on the low vacuum generator (20).

10. A flow testing device for testing low vacuum according to claim 1, characterized in that: The bottom of the support frame (10) is provided with several casters with brakes.

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