Test system for Venturi tube

Abstract

The utility model provides a test system for a venturi tube, which comprises a water tank, a water pump, a surge tank, a venturi tube, a flow meter, a flow regulating valve and a weighing module which form a circulation loop along the water flow direction, the water pump is used for providing power for the circulation loop, the surge tank is used for ensuring that the pressure of water entering the venturi tube is stable, and the flow meter is used for measuring the pressure of water entering the venturi tube. The flow meter is used for detecting the flow of water flowing out of the Venturi tube, the flow regulating valve is used for regulating the flow of water in a pipeline, and the weighing module is used for weighing the mass of water during measurement; a pressure instrument is arranged at the inlet end of the Venturi tube and used for measuring the pressure value of the inlet end of the Venturi tube. By means of the test system, related data of the outflow coefficient of the Venturi tube can be obtained, and the test system can also be used for verifying the flow limiting function of the Venturi tube. And meanwhile, the surge tank is arranged on one side of the inlet end of the Venturi tube, so that the pressure in a circulation loop is stable when the outflow coefficient test and the flow limiting test are carried out, and the test result is not influenced.

Description

Technical Field

[0001] The utility model belongs to the technical field of designing a venturi tube outflow coefficient and cavitation, and particularly relates to a test system for a venturi tube. Background Art

[0002] The cavitation type Venturi is based on the Venturi, and the throat, contraction section and diffusion section of the Venturi are specially designed to enable it to have the flow limiting function under specific working conditions. After the production and manufacturing is completed, the Venturi needs to be tested for reduction performance under different working conditions to verify that the new type of Venturi tube meets the flow measurement and flow limiting functions in the process system, and the parameters that affect the product performance are obtained through the test, thereby optimizing the product structure and manufacturing process and reducing product costs.

[0003] The existing outflow coefficient test and the current limiting test are performed separately in different test systems, which requires the use of different operating systems, resulting in the disassembly and installation of the venturi tube, which leads to a long installation time. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a test system for a venturi tube, which is used to solve the problems in the prior art that each test needs to be done separately, resulting in a long time for disassembly and installation of the venturi tube and a relatively long time for the entire test.

[0005] To achieve the above-mentioned purpose and other related purposes, the utility model provides a test system for a venturi tube, comprising a water tank, a water pump, a pressure-stabilizing tank, a venturi tube, a flow meter, a flow regulating valve and a weighing module forming a circulation loop along the water flow direction, wherein the water pump is used to provide power to the circulation loop, the pressure-stabilizing tank is used to ensure the stability of the water pressure entering the venturi tube, the flow meter is used to detect the water flow out of the venturi tube, the flow regulating valve is used to regulate the water flow in the pipeline, and the weighing module is used to weigh the mass of water during measurement; differential pressure transmitters are provided on both sides of the venturi tube, and the differential pressure transmitter is used to measure the differential pressure value at both ends of the venturi tube, and the inlet end of the venturi tube is connected to a pressure meter.

[0006] Furthermore, the test system also includes a safety valve, one end of which is connected to the pressure-stabilizing tank, and the other end of which is connected to the water tank.

[0007] Furthermore, the test system also includes a temperature measuring instrument, and the temperature measuring instrument is arranged between the pressure-regulating tank and the venturi tube.

[0008] Furthermore, an on-off valve is provided between the pressure stabilizing tank and the venturi tube, and the on-off valve is used to control the on-off of the circulation loop.

[0009] Furthermore, the weighing module includes a water receiving container and a weighing sensor, and the weighing sensor is located at the bottom of the water receiving container.

[0010] Furthermore, a drain valve is provided at the bottom of the water receiving container.

[0011] Furthermore, the experimental system also includes a reversing valve, a first end of the reversing valve is connected to the flow regulating valve, a second end of the reversing valve is connected to the inlet of the water receiving container, and a third end of the reversing valve is connected to the water tank.

[0012] As described above, the utility model has the following beneficial effects: the differential pressure transmitter connected to the venturi tube can obtain the pressure difference value on both sides of the venturi tube, and then combine the value measured by the weighing module to obtain the outflow coefficient of the venturi tube. When verifying the flow limiting function of the venturi tube, when the venturi reaches the designed cavitation working condition, that is, the specific inlet pressure, temperature and flow rate at the flow limiting point, continue to increase the opening of the regulating valve, increase the flow in the pipeline, due to the cavitation effect of the venturi tube, the flow through the venturi tube remains unchanged, so the reading of the flow meter will not change at this time, then it can be judged that the venturi tube has a flow limiting function, and at this time due to the cavitation effect, the venturi tube has abnormal vibration and noise. At the same time, the present application sets a pressure stabilizing tank on one side of the inlet end of the venturi tube to ensure that the pressure in the circulation loop is stable when the outflow coefficient test and the flow limiting test are performed, and will not affect the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The utility model is a schematic diagram of the structure of the test system for the venturi tube.

[0014] Part Number Description

[0015] 1-water pump, 2-safety valve, 3-pressure regulating tank, 4-temperature measuring instrument, 5-pressure instrument, 6-on-off valve, 7-venturi tube, 8-flow meter, 9-flow regulating valve, 10-reversing valve, 11-water receiving container, 12-weighing sensor, 13-drain valve, 14-water tank. DETAILED DESCRIPTION

[0016] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0017] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the utility model without substantial change of the technical content.

[0018] In order to describe the present invention in detail, first, the test system for the venturi tube of the present invention is specifically described below.

[0019] like Figure 1 As shown, the present application provides a test system for a venturi tube, including a water tank 14, a water pump 1, a pressure-surge tank 3, a venturi tube 7, a flow meter 8, a flow regulating valve 9 and a weighing module forming a circulation loop along the water flow direction. The water pump 1 is used to provide power to the circulation loop to ensure the circulation of water in the circulation loop.

[0020] A safety valve 2 is also provided between the water tank 14 and the pressure-suppressing tank 3, which is equivalent to the safety valve 2 being provided in parallel with the water pump 1. The safety valve 2 is a normally closed valve. When the pressure in the circulation loop rises to exceed the specified value, the safety valve 2 opens, and the water flow discharged by the water pump 1 is discharged through the safety valve 2 or returned to the water tank 14, preventing the water flow pressure in the circulation loop or the pressure-suppressing tank 3 from exceeding the specified value. The safety valve 2 controls the pressure in the circulation loop not to exceed the specified value, and plays an important protective role in the circulation loop, especially in the operation of the pressure-suppressing tank 3.

[0021] The pressure stabilizing tank 3 is used to ensure the stability of the water pressure entering the venturi tube 7. The venturi tube 7 includes a contraction section, a throat and a diffusion section. The contraction section of the venturi tube 7 is connected to the pressure stabilizing tank 3, and the diffusion section of the venturi tube 7 is connected to the flow meter 8. During the test of the venturi tube 7, in the process of adjusting the flow regulating valve 9, due to the characteristics of the venturi tube 7 itself, the pressure in the circulation loop will fluctuate. If the pressure entering the venturi tube 7 is unstable, it may affect the test results and cause unstable test data. Therefore, the contraction section of the venturi tube 7 is connected to the pressure stabilizing tank 3, so that the pressure can be guaranteed to be stable when the water flows into the venturi tube 7.

[0022] The flow regulating valve 9 is used to regulate the water flow out of the venturi tube 7, and the flow meter 8 is used to detect the water flow out of the venturi tube 7. Therefore, the flow meter 8 is arranged on the side of the diffusion section of the venturi tube 7, and is mainly used for the flow limiting test of the venturi tube 7. The flow meter 8 of this embodiment adopts a high-precision standard instrument, and the fluid flow in the circulation pipeline system is changed by adjusting the opening of the flow regulating valve 9. The flow regulating valve 9 can be arranged on the side of the venturi tube 7 close to the contraction section or the side close to the diffusion section.

[0023] The inlet end of the venturi tube 7 is provided with a pressure meter 5, which is used to measure the pressure value entering the inlet end of the venturi tube 7. A differential pressure transmitter is connected to the venturi tube 7, and the differential pressure value between the inlet end and the outlet end of the venturi tube can be obtained through the differential pressure transmitter. The differential pressure transmitter is not drawn in the drawings of this embodiment, which is located at the inlet end and the outlet end of the venturi tube 7. Of course, some venturi tubes themselves have a pressure difference function.

[0024] The weighing module is used to weigh the mass of water during measurement. When conducting the outflow coefficient test, first adjust the pumping frequency of the water pump 1 and the flow control valve 9 to meet the test conditions, observe the data through the flow meter 8, and after the flow meter 8 stabilizes, weigh the water flowing through the Venturi tube 7 within the specified time, and record the mass data of the water flow within the specified time period.

[0025] Temperature will affect the measurement accuracy of the venturi tube 7, the pressure meter 5, the flow meter 8, etc. In addition, the temperature of the fluid will also affect the density and viscosity of the fluid. Therefore, the present application sets a temperature measuring instrument 4 in the circulation loop to detect the temperature of the water flow, so that the entire test process is within a relatively stable temperature range.

[0026] An on-off valve 6 is also provided between the pressure-stabilizing tank 3 and the venturi tube 7. The on-off valve 6 is used to control the on-off of the circulation loop. The on-off valve 6 can also be provided at other positions, but it is more effective to provide it before the contraction section of the venturi tube 7, which directly blocks the water flow from entering the venturi tube 7 before the test, thereby achieving a better effect during the test.

[0027] The weighing module of this embodiment is suitable for weighing the water flow in a specified time period. During the adjustment process of the water pump 1 and the flow regulating valve 9, the weighing module is not used, and the water flow does not need to pass through the weighing module. In order to obtain more accurate results, the weighing module adopts a high-precision weighing sensor 12. Therefore, for the convenience of debugging, a reversing valve 10 is arranged between the flow regulating valve 9 and the weighing module. The first end of the reversing valve 10 is connected to the flow regulating valve 9, the second end of the reversing valve 10 is connected to the inlet of the weighing module, and the third end of the reversing valve is connected to the water tank 14.

[0028] When the water pump 1 and the flow regulating valve 9 in the circulation loop are being debugged, the first end of the reversing valve 10 is connected to the third end, and the water flows directly back to the water tank 14 after passing through the flow regulating valve 9. After the water pump 1 and the flow regulating valve 9 are adjusted, when the outflow coefficient measurement test of the venturi tube 7 is carried out, the first end of the reversing valve 10 is connected to the second end, and the water flows through the flow regulating valve 9 and enters the weighing module, and the water flow during the test is weighed.

[0029] The weighing module includes a water receiving container 11 and a weighing sensor 12, and the weighing sensor 12 is located at the bottom of the water receiving container 11. A drain valve 13 is provided at the bottom of the water receiving container 11. When the test is completed, the drain valve 13 is opened to drain the water in the water receiving container 11. The second end of the reversing valve 10 is connected to the inlet of the water receiving container 11. In order to facilitate timing, a photoelectric sensor can be installed on the top of the water receiving container 11 to record the time when the water flow starts to enter the water receiving container 11 and the time when the water flow finally enters the water receiving container 11.

[0030] The test steps for the outflow coefficient test of the Venturi tube 7 are:

[0031] 1. Install the venturi tube 7 on the test loop, connect the differential pressure transmitter to the venturi tube 7, fill the water tank 14 with enough water for the test, and adjust the temperature measuring instrument 4, pressure instrument 5, flow meter 8, etc. on the test loop.

[0032] 2. Start the water pump 1 to drive the water in the water tank 14 to circulate in the entire circulation loop of the test.

[0033] 3. According to the test conditions of the Venturi, gradually adjust the frequency of the water pump 1 and the opening of the flow control valve 9 until the test conditions are met. Observe the flow meter 8, and perform real flow calibration within the set time period after the flow rate stabilizes. Measure the mass of the fluid flowing through the Venturi during this time period through the high-precision weighing sensor 12, and record the differential pressure value of the Venturi at this flow rate.

[0034] 4. Calculate the outflow coefficient using the Venturi outflow coefficient formula:

[0035]

[0036] In formula (1): q m is the mass flow rate, in kg / s; Δp is the differential pressure, which is the difference in results measured by the pressure instrument 5 on both sides of the venturi tube 7, in pa; d is the opening diameter of the throttling element, in m; β is the equivalent diameter ratio; ρ1 is the density of the measured fluid, which is the density of water in this embodiment, in kg / m 3 .

[0037] 5. Adjust the flow control valve 9. By repeating the above operation at different flow rates, the outflow coefficient C at different flow rates can be obtained. Finally, the flow measurement function of the Venturi tube 7 can be evaluated by calculation using the existing method.

[0038] 6. After the test is completed, turn off the water pump 1, drain the remaining water in the circulation loop, and perform maintenance.

[0039] Through the above steps, the outflow coefficient of the Venturi tube 7 can be obtained.

[0040] The technical solution for testing the current limiting function of the Venturi tube 7 is as follows:

[0041] 1. Install the Venturi tube 7 on the test loop. Fill the water tank 14 with enough water for the test. The temperature measuring instrument 4, pressure instrument 5, flow meter 8, etc. on the test loop have been adjusted.

[0042] 2. Start water pump 1 to drive the water in the pool to circulate in the entire circulation loop of the test.

[0043] 3. According to the test conditions of the Venturi, gradually adjust the frequency of the water pump 1 and the opening of the flow control valve 9 until the pressure and flow corresponding to the flow limit point are reached. The temperature of the fluid medium, the pressure at the inlet of the Venturi and the flow through the Venturi are recorded by the temperature meter 4, the pressure meter 5 and the flow meter 8, and the opening of the flow control valve 9 is recorded at the same time.

[0044] 4. Keep the pressure at the inlet of the Venturi unchanged and continue to increase the opening of the flow regulating valve 9. When the Venturi tube 7 reaches the flow limit point, as long as the pressure at the inlet of the contraction section of the Venturi tube 7 remains unchanged, the flow through the Venturi tube 7 will not change no matter how the flow in the pipeline is increased, and there is a harsh metal hammering sound in the Venturi tube 7, so it can be judged that the Venturi tube 7 is in a cavitation state at this time. At this time, the bubbles generated by cavitation burst and block the flow channel, so it can be judged that the Venturi tube 7 plays a flow limiting role.

[0045] 5. When it is necessary to conduct current limiting tests under multiple working conditions, start from the working condition with the lowest requirements for test conditions such as pressure and flow, and improve the test conditions one by one to ensure that all the expected test conditions can be completed by starting the test system once.

[0046] 6. After the test is completed, turn off the water pump 1, drain the remaining water in the test bench circuit, and perform maintenance.

[0047] Through the test system of the present application, the outflow coefficient test and the current limiting test of the Venturi tube 7 can be completed simultaneously without two separate systems, reducing the disassembly and installation of the Venturi tube 7. In addition, a pressure-stabilizing tank 3 is added to the test system of the present application. When the Venturi tube reaches the test condition, the pressure at the Venturi inlet end in the test loop will not fluctuate, and the test result is more accurate.

[0048] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A test system for a venturi tube, characterized in that: The invention comprises a water tank (14), a water pump (1), a pressure regulating tank (3), a venturi tube (7), a flow meter (8), a flow regulating valve (9) and a weighing module which form a circulation loop along the water flow direction. The water pump (1) is used to provide power for the circulation loop. The pressure regulating tank (3) is used to ensure the stability of the water pressure entering the venturi tube (7). The flow meter (8) is used to detect the water flow rate flowing out of the venturi tube (7). The flow regulating valve (9) is used to regulate the water flow rate flowing out of the venturi tube (7). The weighing module is used to weigh the mass of water during measurement. Differential pressure transmitters are arranged on both sides of the venturi tube (7). The differential pressure transmitters are used to measure the differential pressure value at both ends of the venturi tube (7). The inlet end of the venturi tube (7) is connected to a pressure meter (5).

2. The test system for a venturi tube according to claim 1, characterized in that: The test system further comprises a safety valve (2), one end of the safety valve (2) being connected to the pressure-stabilizing tank (3), and the other end of the safety valve (2) being connected to the water tank (14).

3. The test system for a venturi tube according to claim 1, characterized in that: The test system further comprises a temperature measuring instrument (4), wherein the temperature measuring instrument (4) is arranged between the pressure regulating tank (3) and the venturi tube (7).

4. The test system for a venturi tube according to claim 1, characterized in that: An on-off valve (6) is also provided between the pressure-stabilizing tank (3) and the venturi tube (7), and the on-off valve (6) is used to control the on-off of the circulation loop.

5. The test system for a venturi tube according to claim 1, characterized in that: The weighing module comprises a water receiving container (11) and a weighing sensor (12), wherein the weighing sensor (12) is located at the bottom of the water receiving container (11).

6. The test system for a venturi tube according to claim 5, characterized in that: A drainage valve (13) is provided at the bottom of the water receiving container (11).

7. The test system for a venturi tube according to claim 5, characterized in that: The test system further comprises a reversing valve (10), a first end of the reversing valve (10) being connected to the flow regulating valve (9), a second end of the reversing valve (10) being connected to the inlet of the water receiving container (11), and a third end of the reversing valve (10) being connected to the water tank (14).

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