An integrated two-way measurement elbow flowmeter

Abstract

The present invention discloses an integrated two-way measurement elbow flowmeter, which includes an elbow sensor, a first differential pressure transmitter, a second differential pressure transmitter and a secondary instrument. A first interface is provided inside the elbow sensor, and a second interface is provided outside the elbow sensor. The first interface forms a first interface angle with the end face of the elbow sensor, and the second interface forms a second interface angle with the end face of the elbow sensor. The first interface and the second interface are respectively connected to the first differential pressure transmitter through a first measurement pipeline. A third interface is further provided inside the elbow sensor, and a fourth interface is provided outside the elbow sensor. The third interface forms a third interface angle with the end face of the elbow sensor, and the fourth interface forms a fourth interface angle with the end face of the elbow sensor. The third interface and the fourth interface are respectively connected to the second differential pressure transmitter through a second measurement pipeline. The first differential pressure transmitter and the second differential pressure transmitter are respectively connected to the secondary instrument. This integrated two-way measurement elbow flowmeter has a wide installation and application range, high measurement accuracy and safety factor.

Description

Technical Field

[0001] The invention relates to a fluid flow monitoring device, in particular to an integrated bidirectional measuring elbow flow meter. Background Art

[0002] The elbow flowmeter is a flow measurement device that can measure the flow in the pipeline without being affected by the flow direction of the fluid, but it does not have the function of determining the specific direction in which the fluid flows. Therefore, when the forward and reverse flows are to be measured separately, it cannot meet the needs. In industrial applications, due to the influence of season, output and the location of the source of fluid transportation, the fluid in the pipeline often flows in both directions. At present, only one elbow flowmeter cannot measure the flow in each direction. The patent application number 201520076334.7 discloses a bidirectional measurement elbow flowmeter, including an elbow body, a temperature transmitter, a pressure transmitter, a first differential pressure transmitter, a throttling device, a second differential pressure transmitter and a secondary main meter. The temperature transmitter and the pressure transmitter are installed on the elbow body, the first differential pressure transmitter is installed at one end of the elbow body and is connected to the throttling device through a connecting pipe, and the second differential pressure transmitter is also installed at the other end of the elbow body through a connecting pipe. Although the bidirectional measurement elbow flowmeter measures the flow in two directions with only one elbow flowmeter, the patent requires a throttling device to achieve measurement during use. For installation conditions with strict requirements on installation space, installing another throttling device may not be able to meet the installation space requirements, and the throttling device will affect the measurement accuracy of the flowmeter to a certain extent. There is a risk of leakage at the connection between the throttling device and the straight pipe section, especially when pressure testing pressure pipelines or pipelines conveying corrosive, flammable, toxic and other media, there are many leak detection points, which increases the workload and has a low safety factor. Summary of the invention

[0003] The object of the present invention is to provide an integrated bidirectional measuring elbow flowmeter, which has a relatively wider installation and application range, can simultaneously measure fluid flow and flow direction, and has higher measurement accuracy and safety factor.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] An integrated two-way measurement elbow flowmeter, comprising an elbow sensor, a first differential pressure transmitter, a second differential pressure transmitter and a secondary instrument. A first interface is provided inside the elbow sensor, and a second interface is provided outside. The first interface forms a first interface angle with the end face of the elbow sensor, and the second interface forms a second interface angle with the end face of the elbow sensor. The first interface and the second interface are respectively connected to the first differential pressure transmitter through a first measurement pipeline. A third interface is further provided inside the elbow sensor, and a fourth interface is provided outside. The third interface forms a third interface angle with the end face of the elbow sensor, and the fourth interface forms a fourth interface angle with the end face of the elbow sensor. The third interface and the fourth interface are respectively connected to the second differential pressure transmitter through a second measurement pipeline. The first differential pressure transmitter and the second differential pressure transmitter are respectively connected to the secondary instrument.

[0006] Preferably, both the first interface angle and the second interface angle are 45°, the third interface angle is any angle between 18° and 32°, and the fourth interface angle is any angle between 58° and 72°.

[0007] Preferably, both the first interface angle and the second interface angle are 45°, the third interface angle is any angle between 58° and 72°, and the fourth interface angle is any angle between 18° and 32°.

[0008] Preferably, both the first interface angle and the second interface angle are 45°, the third interface angle is 22.5°, and the fourth interface angle is 67.5°.

[0009] Preferably, both the first interface angle and the second interface angle are 45°, the third interface angle is 67.5°, and the fourth interface angle is 22.5°.

[0010] Preferably, the first interface angle is any angle between 18° and 32°, the second interface angle is any angle between 58° and 72°, the third interface angle is any angle between 58° and 72°, and the fourth interface angle is any angle between 18° and 32°.

[0011] More preferably, the first interface angle is 22.5°, the second interface angle is 67.5°, the third interface angle is 67.5°, and the fourth interface angle is 22.5°.

[0012] In the above technical solution, the first pair of pressure measurement points composed of the first interface and the second interface on the inner and outer sides of the elbow sensor measure the first pressure difference, and the second pair of pressure measurement points composed of the third interface and the fourth interface on the inner and outer sides of the elbow sensor measure the second pressure difference. Through the secondary instrument, the first pressure difference and the second pressure difference are calculated and compared to obtain the flow rate of the fluid in the pipeline, and at the same time, the flow direction of the fluid in the pipeline is determined, and the flow rate and flow direction of the fluid in the pipeline are displayed. Through a large number of test data, two pairs of optimal pressure measurement points are obtained, and the measurement data of the two pairs of optimal pressure measurement points are mutually corrected to further improve the measurement accuracy. Since there is no need to cooperate with the installation and measurement of other pipeline components, the installation scope is wide, the leakage hidden danger is small, and the safety factor is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 FIG. is a schematic diagram of the integrated two-way measurement elbow flowmeter of the present invention;

[0014] Figure 2 FIG. is a schematic cross-sectional view of the elbow sensor when one pair of interface angles is 45°;

[0015] Figure 3 FIG. is a schematic cross-sectional view of the elbow sensor;

[0016] Figure 4 FIG. is the pressure distribution curves on the inner and outer sides of the elbow sensor when the medium flow velocity in the elbow sensor is 0.569 m / s;

[0017] Figure 5 FIG. is the pressure distribution curves on the inner and outer sides of the elbow sensor when the medium flow velocity in the elbow sensor is 1.080 m / s;

[0018] Figure 6 FIG. is the pressure distribution curves on the inner and outer sides of the elbow sensor when the medium flow velocity in the elbow sensor is 2.179 m / s;

[0019] Figure 7 FIG. is the pressure distribution curves on the inner and outer sides of the elbow sensor when the medium flow velocity in the elbow sensor is 3.218 m / s. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will be further described below with reference to the accompanying drawings:

[0021] The integrated two-way measurement elbow flowmeter includes an elbow sensor 10, a first differential pressure transmitter 20, a second differential pressure transmitter 30, and a secondary instrument 40. A first interface 21 is provided on the inner bus of the elbow sensor 10, and a second interface 22 is provided on the outer bus. The first interface 21 forms a first interface angle with the end face 11 of the elbow sensor, and the second interface 22 forms a second interface angle with the end face 11 of the elbow sensor. The first interface 21 and the second interface 22 form a first pair of pressure measurement points. The first interface 21 and the second interface 22 are respectively connected to the first differential pressure transmitter 20 through a first measurement pipeline 23. When the elbow sensor is currently in use, both the first interface angle and the second interface angle are 45°. In this way, there is no need to pay special attention to the installation direction of the elbow sensor and the interface angle when installing the elbow sensor. Similarly, a third interface 31 is also provided on the inner bus of the elbow sensor 10, and a fourth interface 32 is provided on the outer bus. The third interface 31 forms a third interface angle with the end face 11 of the elbow sensor, and the fourth interface 32 forms a fourth interface angle with the end face 11 of the elbow sensor. The third interface 31 and the fourth interface 32 form a second pair of pressure measurement points. The third interface 31 and the fourth interface 32 are respectively connected to the second differential pressure transmitter 30 through a second measurement pipeline 33. The first differential pressure transmitter 20 and the second differential pressure transmitter 30 are respectively connected to the secondary instrument 40. The secondary instrument 40 calculates and compares the first pressure difference and the second pressure difference measured by the first differential pressure transmitter 20 and the second differential pressure transmitter 30, and displays the flow rate and flow direction of the fluid in the pipeline. Here, it is stipulated that the fluid flowing into the elbow sensor 10 from the end face 11 of the elbow sensor is in the positive direction, and the fluid flowing out of the elbow sensor 10 from the end face 11 is in the reverse direction.

[0022] After a large number of pressure distribution simulation tests with different interface angles, among which Figures 4 - 7The fluid forward flow of the elbow sensor is selected. When the fluid medium has different flow rates and the angles of the inner and outer interfaces change, the pressure distributions inside and outside the elbow sensor are as follows: The upper curves in the figure are all the pressure distribution curves of the outer interface, and the lower curves are all the pressure distribution curves of the inner interface. The test data show that regardless of whether the fluid flow rate is changed, when the inner interface angle is in the range of 18° - 32°, the pressure change inside the elbow sensor is relatively stable and is all a small value. Especially when the inner interface angle is about 22.5°, it is the minimum value among all pressure values. When the inner interface angle is in the range of 58° - 72°, especially when the inner interface angle is about 67.5°, the pressure change inside the elbow sensor is also relatively stable and is all a large value. When the outer interface angle is in the range of 18° - 32°, especially when the outer interface angle is about 22.5°, the pressure change outside the elbow sensor is relatively stable and is all a small value. When the outer interface angle is in the range of 58° - 72°, the pressure change outside the elbow sensor is also relatively stable and is all a large value. Especially when the outer interface angle is about 67.5°, it is the maximum value among all pressure values. When the inner interface angle or the outer interface angle is 45°, the pressure changes inside and outside the elbow sensor are at the median value of other angles. The pressure difference value generated by this set of pressure measurement points is only related to the fluid flow rate and has nothing to do with the fluid flow direction. Therefore, when using it, there is no need to pay special attention to the installation direction and interface angle of the elbow sensor, and the installation and flow measurement calculation are relatively convenient. In this way, the angle combination of the inner interface angle between 18° - 32° and the outer interface angle between 58° - 72° is selected to form the first pair of pressure measurement points, and the first pressure difference is measured. When the fluid flows forward, the obtained pressure difference is a larger value than the pressure differences at other angles. When the fluid flows backward, the obtained pressure difference is a smaller value than the pressure differences at other angles. The angle combination of the inner interface angle between 58° - 72° and the outer interface angle between 18° - 32° is selected to form the second pair of pressure measurement points, and the second pressure difference is measured. When the fluid flows forward, the obtained pressure difference is a smaller value than the pressure differences at other angles. When the fluid flows backward, the obtained pressure difference is a larger value than the pressure differences at other angles. The secondary instrument 40 calculates the flow rate of the fluid in the pipeline by selecting the pressure difference of one of the pairs of pressure measurement points, and compares and discriminates the first pressure difference and the second pressure difference. When the first pressure difference is greater than the second pressure difference, the fluid is flowing forward. When the first pressure difference is less than the second pressure difference, the fluid is flowing backward. In this way, the data obtained from these two pairs of pressure measurement points with the combination of the larger value pressure difference and the smaller value pressure difference are more accurate than those at other angles. Especially for one pair of pressure measurement points with the inner interface angle of 22.5° and the outer interface angle of 67.5°, and the other pair of pressure measurement points with the inner interface angle of 67.5° and the outer interface angle of 22.5° combination, one pressure difference is the maximum value among the pressure differences at other angles, and one pressure difference is the minimum value among the pressure differences at other angles, and the obtained data are more accurate than those at other angles.

[0023] For other angles, such as when the inner interface angle is 0° - 17° or the outer interface angle is 73° - 90°, the pressure change slope on the inner or outer side of the elbow sensor is relatively large. With a slight change in the interface angle, the measured pressure difference value may change significantly, resulting in large fluctuations in the measurement result and inaccurate measurement results.

[0024] In Embodiment 1, both the first interface angle and the second interface angle are 45°. The first pressure difference is measured. The third interface angle is any angle between 18° and 32°, and the fourth interface angle is any angle between 58° and 72°. The second pressure difference is measured. In other cases, it is the same as the above situation. The secondary instrument 40 selects one of the pressure differences to calculate the flow rate of the fluid in the pipeline, and compares the two pressure difference values to obtain the fluid flow direction. When the fluid flows forward, the second pressure difference is a larger value compared to the pressure differences at other angles, and the first pressure difference is less than the second pressure difference; when the fluid flows backward, the second pressure difference is a smaller value compared to the pressure differences at other angles, and the first pressure difference is greater than the second pressure difference. It should be specifically noted that when the third interface angle is 22.5° and the fourth interface angle is 67.5°, and other cases are the same as the above situation, when the fluid flows forward, the second pressure difference is the maximum value compared to the pressure differences at other angles, and when the fluid flows backward, the second pressure difference is the smaller value compared to the pressure differences at other angles. The measurement result of the difference comparison is relatively accurate.

[0025] In Embodiment 2, both the first interface angle and the second interface angle are 45°. The third interface angle is any angle between 58° and 72°, and the fourth interface angle is any angle between 18° and 32. In other cases, it is the same as the above situation. When the fluid flows forward, the second pressure difference is a smaller value compared to the pressure differences at other angles, and the first pressure difference is greater than the second pressure difference; when the fluid flows backward, the second pressure difference is a larger value compared to the pressure differences at other angles, and the first pressure difference is less than the second pressure difference. It should be specifically noted that when the third interface angle is 67.5° and the fourth interface angle is 22.5°, and other cases are the same as the above situation, when the fluid flows forward, the second pressure difference is the smaller value compared to the pressure differences at other angles, and when flowing backward, the second pressure difference is the maximum value compared to the pressure differences at other angles. The measurement result of the difference comparison is relatively accurate.

[0026] In Embodiment 3, the first interface angle is any angle between 18° and 32°, the second interface angle is any angle between 58° and 72°, the third interface angle is any angle between 58° and 72°, and the fourth interface angle is any angle between 18° and 32°. In other cases, it is the same as the above situation. When the fluid flows forward, the first pressure difference is a larger value compared to the pressure differences at other angles, the second pressure difference is a smaller value compared to the pressure differences at other angles, and the first pressure difference is greater than the second pressure difference; when the fluid flows backward, the first pressure difference is a smaller value compared to the pressure differences at other angles, the second pressure difference is a larger value compared to the pressure differences at other angles, and the first pressure difference is less than the second pressure difference.

[0027] Example 4, the first interface angle is 22.5°, the second interface angle is 67.5°, the third interface angle is 67.5°, and the fourth interface angle is 22.5°. Other conditions are the same as those in the above embodiments. In this way, when the fluid flows forward, the first pressure difference is the maximum value compared with the pressure differences at other angles, and the second pressure difference is a smaller value compared with the pressure differences at other angles. When the fluid flows backward, the first pressure difference is a smaller value compared with the pressure differences at other angles, and the second pressure difference is the maximum value compared with the pressure differences at other angles. The flow direction determination method is the same as that in Example 3.

[0028] In the above embodiments, the flow rates in two directions are measured by a single elbow flowmeter, and no other pipeline components need to be added to the original pipeline. It is more applicable to installation conditions with strict requirements for installation space. Since no other separate flow direction discrimination devices need to be configured, the number of connection points is reduced, the corresponding leakage points become fewer, and the safety factor is higher.

[0029] This embodiment is only an illustration of the concept and implementation of the present invention, and does not limit it. Under the concept of the present invention, technical solutions without substantial transformation are still within the protection scope.

Claims

1. An integrated two-way measurement elbow flowmeter, comprising an elbow sensor, a first differential pressure transmitter, a second differential pressure transmitter and a secondary instrument. A first interface is provided inside the elbow sensor, and a second interface is provided outside. The first interface forms a first interface angle with the end face of the elbow sensor, and the second interface forms a second interface angle with the end face of the elbow sensor. The first interface and the second interface are respectively connected to the first differential pressure transmitter through a first measurement pipeline. It is characterized in that a third interface is further provided inside the elbow sensor, and a fourth interface is provided outside. The third interface forms a third interface angle with the end face of the elbow sensor, and the fourth interface forms a fourth interface angle with the end face of the elbow sensor. The third interface and the fourth interface are respectively connected to the second differential pressure transmitter through a second measurement pipeline. The first differential pressure transmitter and the second differential pressure transmitter are respectively connected to the secondary instrument; both the first interface angle and the second interface angle are 45°, the third interface angle is any angle between 18° and 32°, and the fourth interface angle is any angle between 58° and 72°; or both the first interface angle and the second interface angle are 45°, the third interface angle is any angle between 58° and 72°, and the fourth interface angle is any angle between 18° and 32°; or the first interface angle is any angle between 18° and 32°, the second interface angle is any angle between 58° and 72°, the third interface angle is any angle between 58° and 72°, and the fourth interface angle is any angle between 18° and 32°.

2. The integrated two-way measurement elbow flowmeter according to claim 1, It is characterized in that both the first interface angle and the second interface angle are 45°, the third interface angle is 22.5°, and the fourth interface angle is 67.5°.

3. The integrated two-way measurement elbow flowmeter according to claim 1, It is characterized in that both the first interface angle and the second interface angle are 45°, the third interface angle is 67.5°, and the fourth interface angle is 22.5°.

4. The integrated two-way measurement elbow flowmeter according to claim 1, It is characterized in that the first interface angle is 22.5°, the second interface angle is 67.5°, the third interface angle is 67.5°, and the fourth interface angle is 22.5°.

Images