Elbow flow measuring device

Abstract

The invention relates to the technical field of flow monitoring, in particular to a bent pipe flow measuring device which comprises a right-angle bent pipe and an M-shaped thin pipe, the right-angle bent pipe is composed of a main pipeline, an upper arc, a middle arc and a lower arc, and the two ends of the thin pipe are communicated with the upper arc and the lower arc respectively. The thin pipe is fixedly connected with a first boss and a second boss, the first boss is provided with a liquid adding port, the second boss is provided with an exhaust port, the liquid adding port and the exhaust port are detachably connected with plugging covers, and the liquid adding port and the exhaust port are communicated with the thin pipe. Fluid passes through the right-angle bent pipe, the same fluid is injected into the thin pipe, the flow velocity of the fluid in the upper arc and the lower arc of the right-angle bent pipe is inconsistent, so that pressure difference is generated, the fluid in the thin pipe can generate height difference, and the fluid flow is reversely pushed out through the height difference and the pipe diameter of the right-angle bent pipe; and an external power supply or a battery is not needed, and the installation efficiency is improved, so that the monitoring efficiency of the fluid flow velocity is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flow monitoring, in particular to a bend pipe flow measuring device. BACKGROUND

[0002] Flow is the most important parameter of fluid transportation system. For example, the flow of water pump, through the flow, it can be known that how much water is transported in a specified time. Therefore, the detection of flow is extremely important. The common flow detection device has turbine flowmeter, electromagnetic flowmeter and ultrasonic flowmeter, which can be used for monitoring the flow of fluid transportation system, so as to calculate the amount of transported fluid.

[0003] In the prior art, although the turbine flowmeter, the electromagnetic flowmeter and the ultrasonic flowmeter can monitor the flow of the fluid transportation system, the turbine flowmeter and the electromagnetic flowmeter need to be installed on the pipeline, and the fluid passes through the inside of the turbine flowmeter and the electromagnetic flowmeter, which is extremely complex to install. The ultrasonic flowmeter needs to be installed outside the pipe wall. All of them need external power supply or battery, which is not conducive to improving the monitoring efficiency of the fluid transportation system.

[0004] In summary, how to solve the problem that the existing flowmeter needs external power supply or battery and is complex to install, which is not conducive to improving the monitoring efficiency of the fluid transportation system, has become a technical problem to be solved by the technical personnel in the field. Therefore, it is necessary to provide a bend pipe flow measuring device. SUMMARY

[0005] To solve the above problems, the present application provides a bend pipe flow measuring device. The fluid passes through the right-angle bend pipe, the same fluid is injected into the thin pipe, the pressure difference is generated due to the inconsistent flow rate of the fluid in the upper arc and the lower arc of the right-angle bend pipe, the fluid in the thin pipe generates height difference, the fluid flow is calculated by the height difference and the pipe diameter of the right-angle bend pipe, without using external power supply or battery, and the installation efficiency is improved, thereby improving the monitoring efficiency of the fluid flow rate.

[0006] In order to achieve the above purpose, the technical scheme of the present application is as follows: a bend pipe flow measuring device, comprising a right-angle bend pipe composed of a main pipe, an upper arc, a middle arc and a lower arc, and an M-shaped thin pipe, the two ends of the thin pipe are communicated with the midpoint positions of the upper arc and the lower arc. The middle part of the thin pipe is U-shaped and transparent. The thin pipe is fixedly connected with a first boss and a second boss, the first boss is provided with a liquid adding port, and the second boss is provided with an exhaust port. The liquid adding port and the exhaust port are detachably connected with a blocking cover, and the liquid adding port and the exhaust port are communicated with the thin pipe.

[0007] The technical principle of the above scheme is as follows: the device calculates the fluid flow based on the Bernoulli equation, and measures the flow by using the pressure difference caused by the flow rate difference of the fluid in the elbow. When the fluid flows through the elbow, the flow rate of the upper arc is fast and the pressure is low, and the flow rate of the lower arc is slow and the pressure is high. According to the Bernoulli equation, the pressure difference is transmitted through the connected M-shaped thin tube, so that the fluid in the thin tube forms a height difference H. By measuring H and combining the geometric parameters of the elbow, the fluid flow can be derived.

[0008] The above scheme has the following beneficial effects:

[0009] 1. The existing flow testing device usually needs an external power supply or a battery, which limits its application in power-free or outdoor environments. However, the present application uses a pure mechanical structure design to realize flow measurement by converting the kinetic energy and potential energy of the fluid itself, completely without the need for an external power supply. This feature enables it to adapt to outdoor, remote or temporary installation scenarios, significantly expanding the application range of the flow measurement device.

[0010] 2. The present application observes the height difference of the fluid level in the middle of the thin tube through the transparent material, and derives the fluid flow by measuring the height difference of the fluid in the thin tube combined with the geometric parameters of the elbow. The calculation process is simple, reduces the risk of human error and can meet the demand for accurate flow control and adjustment.

[0011] 3. In the present application, there are no electrical components in the elbow and the thin tube, which avoids the situation of precision decline or equipment failure caused by mechanical wear during long-term use, and improves the stability of the device in measuring fluid flow.

[0012] Further, the surface of the middle of the thin tube is engraved with scale marks.

[0013] Beneficial effect: Through the scale marks, the staff can more accurately observe the liquid level difference H of the fluid in the thin tube, thereby improving the accuracy of the staff in measuring the fluid flow in the elbow.

[0014] Further, the upper arc radius is R, the lower arc radius is r, and the main pipe diameter is D, and the main pipe diameter satisfies D=R-r.

[0015] Beneficial effect: Through the geometric constraint of D=R-r, the flow rate of the fluid in the upper arc R is accelerated, and the flow rate of the fluid in the lower arc r is correspondingly reduced, thereby significantly amplifying the pressure difference. The pressure difference makes the fluid in the M-shaped thin tube form a more obvious height difference H, directly improving the sensitivity and resolution of flow measurement, especially suitable for low flow rate or small flow rate scenarios.

[0016] Further, the device calculates the flow Q based on the Bernoulli equation, and the flow calculation formula is:

[0017]

[0018] wherein D is the diameter of the main pipe, in m. V C is the flow rate of the fluid in the middle circular arc, in m / s. R is the radius of the upper circular arc, in m. r is the radius of the lower circular arc, in m. H is the height difference of the fluid in the thin tube, in m. h is the height difference between the centers of the upper and lower circular arcs, in m. g is the acceleration of gravity.

[0019] Beneficial effect: By combining the geometric parameters of the right-angle elbow and fluid mechanics, the height difference h between the centers of the upper and lower circular arcs and the height difference H of the fluid level in the thin tube are utilized to accurately calculate the fluid flow in the right-angle elbow, thereby improving the accuracy of fluid flow measurement in the right-angle elbow.

[0020] Further, the material of the thin tube except the middle part is stainless steel seamless steel pipe. When the diameter D of the main pipe is greater than 50 mm, the inner diameter of the thin tube is greater than 10 mm. When the diameter D of the main pipe is less than 50 mm, the inner diameter of the thin tube is not greater than 0.2 times the diameter D of the main pipe.

[0021] Beneficial effect: The stainless steel seamless steel pipe has excellent corrosion resistance and can resist the corrosion of water, gas, oil and weak corrosive media, avoiding measurement errors or fluid contamination caused by pipe wall rust. When D > 50 mm, the inner diameter of the thin tube is > 10 mm, which can reduce the flow resistance of the fluid in the thin tube. When D < 50 mm, the inner diameter of the thin tube is ≤ 0.2D, which can amplify the pressure difference signal by reducing the flow area. Thus, the measurement sensitivity at low flow rate is improved.

[0022] Further, it further comprises a support assembly for fixing the right-angle elbow, and the support assembly comprises a support frame, and the right-angle elbow is fixedly connected with the support frame.

[0023] Beneficial effect: When the fluid passes through the right-angle elbow, the support frame can suppress the vibration frequency of the right-angle elbow and reduce the liquid surface fluctuation in the thin tube, thereby improving the measurement accuracy. Through the rigid constraint of the support frame, the right-angle elbow will not be deviated due to external force when the fluid passes through the right-angle elbow for a long time, thereby ensuring the stability of the measurement.

[0024] Further, a flexible layer is fixedly connected at the connection between the right-angle elbow and the support frame.

[0025] Beneficial effect: The flexible layer can absorb the vibration energy generated when the fluid passes through the right-angle elbow, reducing the liquid surface fluctuation in the thin tube caused by mechanical vibration due to fluid impact, thereby improving the measurement accuracy of the height difference H.

[0026] Further, the vertical part of the right-angle elbow is always perpendicular to the ground.

[0027] Beneficial effect: the design of the vertical part being perpendicular to the ground makes the flow direction of the fluid in the elbow consistent with the direction of gravity, reduces the flow rate gradient caused by gravity, thereby reducing the fluctuation of the pressure difference H and improving the measurement stability. And the vertical design makes the fluid height difference H in the thin tube completely driven by the fluid pressure difference, eliminating the interference of the gravity component caused by the inclination of the elbow.

[0028] Further, the inner wall of the elbow and the thin tube are fixedly connected with a corrosion-proof layer.

[0029] Beneficial effect: the corrosion-proof layer protects the elbow and the thin tube, effectively prolongs the service life of the elbow and the thin tube, reduces the erosion of the fluid to the elbow and the thin tube, and thereby reduces the calculation error of the fluid flow.

[0030] Further, the support frame is further fixedly connected with a level.

[0031] Beneficial effect: the level can display the horizontal state of the support frame in real time, so that the vertical part of the elbow is always perpendicular to the ground, improving the measurement accuracy of the fluid flow.

[0032] Additional aspects and advantages of the application will be set forth in part in the following description, will become apparent from the following description, or will be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a perspective view of the elbow flow measuring device of the application.

[0034] Figure 2 is a front view of the elbow flow measuring device of the application.

[0035] Figure 3 is Figure 2 is a partial enlarged view of part A.

[0036] The reference signs in the drawings of the specification include: 1, elbow; 2, thin tube; 3, support frame; 4, level; 5, exhaust port; 6, liquid inlet; 7, scale mark; 8, main pipeline; 9, upper arc; 10, middle arc; 11, lower arc. DETAILED DESCRIPTION

[0037] The following will be further described in detail through specific embodiments:

[0038] Example 1:

[0039] As shown in the accompanying drawings Figure 1 and Figure 2As shown: a flow measuring device of elbow pipe, including a right angle elbow pipe 1, the right angle elbow pipe 1 is composed of main pipe 8, upper circular arc 9, middle circular arc 10 and lower circular arc 11, and also includes M-shaped thin tube 2, both ends of the thin tube 2 are communicated with the midpoint positions of the upper circular arc 9 and the lower circular arc 11 respectively. The middle part of the thin tube 2 is U-shaped and is of transparent material, and the transparent material is selected as organic glass in the embodiment.

[0040] Combining Figure 3 As shown, the first boss and the second boss are fixedly connected on the thin tube 2, the liquid adding port 6 is opened on the first boss, and the exhaust port 5 is opened on the second boss, the liquid adding port 6 and the exhaust port 5 are detachably connected with the plugging cover, and the liquid adding port 6 and the exhaust port 5 are communicated with the thin tube 2. The scale mark 7 is engraved on the surface of the middle part of the thin tube 2.

[0041] The radius of the upper circular arc 9 is R, the radius of the lower circular arc 11 is r, the diameter of the main pipe 8 is D, and the diameter of the main pipe 8 satisfies D=R-r.

[0042] The device calculates the flow Q based on Bernoulli equation, and the flow calculation formula is:

[0043]

[0044] Wherein D is the diameter of the main pipe 8, and the unit is m. C V is the flow velocity of the fluid in the middle circular arc 10, and the unit is m / s. R is the radius of the upper circular arc 9, and the unit is m. r is the radius of the lower circular arc 11, and the unit is m. H is the height difference of the fluid in the thin tube 2, and the unit is m. h is the height difference between the centers of the upper circular arc 9 and the lower circular arc 11, and the unit is m. g is the acceleration of gravity.

[0045] The material of the thin tube 2 except the middle part is stainless steel seamless steel pipe, when the diameter D of the main pipe 8 is greater than 50mm, the inner diameter of the thin tube 2 is greater than 10mm. When the diameter D of the main pipe 8 is less than 50mm, the inner diameter of the thin tube 2 is not greater than 0.2 times of the diameter D of the main pipe 8. The vertical part of the right angle elbow pipe 1 is always perpendicular to the ground. The inner walls of the right angle elbow pipe 1 and the thin tube 2 are bonded with anticorrosive layer, and the anticorrosive layer is selected as epoxy resin coating in the embodiment.

[0046] The specific implementation process is as follows: taking Figure 2 For example, first of all, the staff can fix the right angle elbow pipe 1 on the pipe which needs to be measured for fluid flow, and then fix the thin tube 2 on the right angle elbow pipe 1, at this time, the exhaust port 5 and the liquid adding port 6 of the thin tube 2 are communicated with the right angle elbow pipe 1.

[0047] Taking Figure 3For example, the staff can communicate the pipeline which needs to measure the fluid flow with the elbow 1, inject the fluid which needs to measure the flow through the liquid inlet 6 on the top of the tube 2, and discharge the gas in the elbow 1 and the tube 2 through the exhaust port 5 to reduce the influence of the bubbles on the fluid flow.

[0048] The epoxy coating can effectively reduce the corrosion of the fluid on the elbow 1 and the tube 2 when the fluid passes through the elbow 1 and the tube 2, thereby prolonging the service life of the elbow 1 and the tube 2 and ensuring the accuracy of the fluid flow measurement.

[0049] When the fluid flows in the pipeline and passes through the elbow 1, the flow rate is relatively fast at the upper arc 9 of the elbow 1 due to the characteristics of the fluid, and according to Bernoulli equation, the pressure is low where the flow rate is high. On the contrary, the flow rate is small at the lower arc 11 of the elbow 1, and the pressure is high. Thus, a pressure difference is formed between the upper arc 9 and the lower arc 11 of the elbow 1.

[0050] The upper arc 9 and the lower arc 11 of the elbow 1 are communicated with the tube 2, and the middle part of the tube 2 is U-shaped and made of organic glass. Since there is a pressure difference between the upper arc 9 and the lower arc 11 of the elbow 1, the pressure difference is transmitted through the communicated tube 2, and the fluid in the tube 2 forms a height difference H under the action of the pressure at this time. The staff can accurately measure the height difference H through the scale mark 7.

[0051] The greater the fluid flow, the greater the difference in flow rate between the upper arc 9 and the lower arc 11 of the elbow 1, and the greater the corresponding pressure difference, so the height difference of the fluid in the tube 2 is more obvious.

[0052] In this embodiment, the diameter of the main pipeline 8 in the elbow 1 is set as D, D>50mm, and the inner diameter of the tube 2 is set as 20mm. Since D=R-r, the height difference between the centers of the upper arc 9 and the lower arc 11 is h, and through the trigonometric function, The radius of the middle arc 10 can be obtained as (r+D / 2).

[0053] The flow rate in the upper arc 9 is set as V A , the flow rate in the lower arc 11 is set as V B , and the flow rate in the middle arc 10 is set as V C .

[0054] Since the arc length of the upper arc 9 is LA=1 / 4*(2πR)=1 / 2πR.

[0055] The arc length of the lower arc 11 is LB=1 / 2πr.

[0056] The arc length of the center circular arc is Lc = 1 / 2π(r + D / 2) = 1 / 2π[r + (R - r) / 2] = 1 / 2π[r + (R - r) / 2)] = 1 / 4π(R + r) = 1 / 2(LA + LB).

[0057] That is, the arc length of the center circular arc is half of the sum of the upper circular arc 9 and the lower circular arc 11.

[0058] Because the flow rate is constant, the fluid near the upper circular arc 9 passes along the upper circular arc 9 at the same time as the fluid near the lower circular arc 11 passes along the lower circular arc 11. That is, the fluids at the two places have different displacements in the same time, and according to displacement = velocity * time, velocity = displacement / time, the ratio of the velocities is the ratio of the displacements because the time is the same.

[0059] That is, V A / V B = LA / LB = (1 / 4πR) / (1 / 4πr) = R / r.

[0060] Therefore, V A = V B *R / r.

[0061] Because the arc length of the center circular arc is half of the sum of the upper circular arc 9 and the lower circular arc 11, and the ratio of the velocities is the ratio of the displacements, V C = (V A + V B ) / 2.

[0062] Under the action of the fluid pressure difference, the liquid level in the fine tube 2 has a height difference H.

[0063] Because h is equal to the velocity head difference of the upper circular arc 9 and the lower circular arc 11 after superposition, H is always greater than h.

[0064] According to flow rate = flow area * flow velocity, the flow rate is

[0065] The flow rate obtained by the above formula is in cubic meters per second, m 3 / s. The value multiplied by 3600 is cubic meters per hour, m 3 / h.

[0066] Because h - H is a negative number, r 2 -R 2 is also a negative number, so the value of the flow rate Q can be calculated by taking the square root.

[0067] This invention utilizes the pressure difference of fluid flow velocity to cause a change in the height difference of the liquid level within the thin tube 2. Based on the flow rate calculation formula, the flow rate of the fluid within the right-angle bend 1 is calculated using its geometric parameters and height difference. This reduces reliance on external power supplies or batteries, simplifies installation, and improves the efficiency of fluid velocity measurement. The use of a mechanical structure for measurement enhances the stability of long-term fluid flow rate measurement.

[0068] Example 2:

[0069] like Figure 1 As shown, the difference from the above embodiment is that it also includes a support assembly for fixing the right-angle bend 1. The support assembly includes a support frame 3, and the right-angle bend 1 is bolted to the support frame 3. A flexible layer is bonded to the connection between the right-angle bend 1 and the support frame 3. In this embodiment, the flexible layer is selected as a rubber layer, and a level 4 is also screwed to the support frame 3.

[0070] The specific implementation process is as follows: After fixing the support frame 3 to the ground, the worker then fixes the right-angle bend 1 to the support frame 3 to maintain the stability of the right-angle bend 1. The worker can adjust the support angle of the support frame 3 using a level 4 to ensure that the support frame 3 is always parallel to the ground, thus ensuring that the vertical end of the right-angle bend 1 is always perpendicular to the ground.

[0071] With the support frame 3 always kept horizontal to the ground and the right-angle bend 1 stably fixed to the support frame 3, the fluid flow measurement can be started. The rubber layer reduces the influence of external forces on the right-angle bend 1, improves the stability of the right-angle bend 1, and thus improves the stability of the fluid flow measurement inside the right-angle bend 1.

[0072] Example 3:

[0073] In this embodiment, the flow measurement device with a bent pipe is compared with that of an electromagnetic flow meter.

[0074] Experiment 1:

[0075] Data from a test bench at a factory in Hunan Province shows a local gravitational acceleration of 9.81 m / s. 2 / s. A single-stage double-suction split-case pump, model 500MS59, with an electromagnetic flow meter installed 5m after the valve on the outlet pipeline, and then the bend pipe flow measuring device of this invention installed 5m after the electromagnetic flow meter to prevent the eddy current generated by the electromagnetic flow meter from affecting this device.

[0076] The outlet pipe diameter is DN500, which is 500mm = 0.5m. The bend diameter is D = 0.5m. The large arc diameter is R = 1.0m. The small arc diameter is r = 0.5m.

[0077] but:

[0078]

[0079] After the pump is started, the valve is adjusted to make the electromagnetic flowmeter reading to be about 1000m 3 / h, and the intermediate liquid level difference H=2.21m; the valve is adjusted to make the electromagnetic flowmeter reading to be about 1200m 3 / h, and the intermediate liquid level difference H=3.12m.

[0080] Error calculation table 1:

[0081]

[0082] Experiment 2:

[0083] Still using the device in example 1, the pump therein is replaced by a single-stage double-suction split pump, model 300MS26, the valve is adjusted to make the electromagnetic flowmeter reading to be about 1000m 3 / h, and the intermediate liquid level difference H=0.85m; the valve is adjusted to make the electromagnetic flowmeter reading to be about 1200m 3 / h, and the intermediate liquid level difference H=1.22m.

[0084] Error calculation table 2:

[0085]

[0086] Through comparison between error calculation table 1 and error calculation table 2, in both experiments, the maximum experimental error is -7.6%, and the minimum experimental error is -4.5%, both of which are within the range of ±10%, thus the bend flow measuring device meets the actual requirements, and can measure the fluid flow in the bend.

[0087] Obviously, the above examples are merely examples for clearly illustrating but not limiting the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A flow measuring device for a bend pipe, comprising a right angle bend pipe (1) consisting of a main pipe (8), an upper circular arc (9), a middle circular arc (10) and a lower circular arc (11), characterized in that, The M-shaped thin tube (2) is communicated with the midpoint of the upper circular arc (9) and the lower circular arc (11) respectively; The middle part of the thin tube (2) is U-shaped and made of transparent material; The first boss and the second boss are fixedly connected to the thin tube (2), the liquid adding opening (6) is arranged on the first boss, the exhaust opening (5) is arranged on the second boss, the liquid adding opening (6) and the exhaust opening (5) are detachably connected with the blocking covers, and the liquid adding opening (6) and the exhaust opening (5) are communicated with the thin tube (2).

2. The flow measuring device of claim 1, wherein, The scale mark (7) is engraved on the surface of the middle part of the thin tube (2).

3. The flow measuring device of claim 2, wherein, The radius of the upper circular arc (9) is R, the radius of the lower circular arc (11) is r, the diameter of the main pipeline (8) is D, and the diameter of the main pipeline (8) satisfies D = R - r.

4. The flow measuring device of claim 3, wherein, The device calculates the flow Q based on the Bernoulli equation, and the flow calculation formula is: where D is the diameter of the main pipe (8) in m; V C is the flow rate of the fluid in the middle circular arc (10) in m / s; R is the radius of the upper circular arc (9) in m; r is the radius of the lower circular arc (11) in m; H is the height difference of the fluid in the thin tube (2) in m; h is the height difference of the centers of the upper circular arc (9) and the lower circular arc (11) in m; and g is the acceleration of gravity.

5. The flow measuring device of claim 4, wherein, The material of the thin tube (2) except the middle part is a stainless steel seamless steel pipe, when the diameter D of the main pipeline (8) is greater than 50 mm, the inner diameter of the thin tube (2) is greater than 10 mm, and when the diameter D of the main pipeline (8) is less than 50 mm, the inner diameter of the thin tube (2) is not greater than 0.2 times the diameter D of the main pipeline (8).

6. The flow measuring device of claim 5, wherein, The support assembly is further used for fixing the right-angle elbow (1), and the support assembly comprises a support frame (3), and the right-angle elbow (1) is fixedly connected with the support frame (3).

7. The flow measuring device of claim 6, wherein, The connection part of the right-angle elbow (1) and the support frame (3) is fixedly connected with a flexible layer.

8. The flow measuring device of claim 7, wherein, The vertical part of the right-angle elbow (1) is always perpendicular to the ground.

9. The flow measuring device of claim 8, wherein, The inner walls of the right-angle elbow (1) and the thin tube (2) are fixedly connected with a corrosion-resistant layer.

10. The flow measuring device of claim 9, wherein, The support frame (3) is further fixedly connected with a level (4).

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