CN117110653A - Flow velocity meter calibration method and device based on constant uniform flow - Google Patents
Flow velocity meter calibration method and device based on constant uniform flow Download PDFInfo
- Publication number
- CN117110653A CN117110653A CN202311186956.0A CN202311186956A CN117110653A CN 117110653 A CN117110653 A CN 117110653A CN 202311186956 A CN202311186956 A CN 202311186956A CN 117110653 A CN117110653 A CN 117110653A
- Authority
- CN
- China
- Prior art keywords
- water
- flow
- overflow
- tank
- groove
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 405
- 238000004891 communication Methods 0.000 claims description 2
- 238000005259 measurement Methods 0.000 abstract description 11
- 238000012795 verification Methods 0.000 abstract description 8
- 230000003068 static effect Effects 0.000 abstract description 3
- 239000007788 liquid Substances 0.000 description 27
- 230000001105 regulatory effect Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000003028 elevating effect Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P21/00—Testing or calibrating of apparatus or devices covered by the preceding groups
- G01P21/02—Testing or calibrating of apparatus or devices covered by the preceding groups of speedometers
- G01P21/025—Testing or calibrating of apparatus or devices covered by the preceding groups of speedometers for measuring speed of fluids; for measuring speed of bodies relative to fluids
Landscapes
- Measuring Volume Flow (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
Abstract
The invention relates to the technical field of flow velocity measurement, in particular to a flow velocity meter calibration method and a device based on constant uniform flow, wherein the flow velocity meter calibration method comprises an overflow water tank and a water flow tank, a water inlet pipe is connected to a water inlet end of the overflow water tank, and a water outlet end of the overflow water tank is connected to a water inlet end of the water flow tank; the characteristic of constant uniform flow in an open channel is utilized, the existing method that the flow rate meter is driven by the verification vehicle to run at a constant speed in static water flow to indirectly obtain a constant flow rate is abandoned, so that the flow rate of the water flow of the water inlet pipe entering the water flow tank through the overflow water tank is constant, the measurement requirement of the flow rate meter on the constant flow rate is directly realized, the calibration time is saved, the calibration efficiency of the flow rate meter is improved, the structure is simple, the scale is small, and the field can be greatly saved; meanwhile, constant uniform flow in the water flowing groove is more stable, so that the stability of the calibration result of the flow velocity meter is improved, and the calibration precision of the flow velocity meter is also improved.
Description
Technical Field
The invention relates to the technical field of flow velocity measurement, in particular to a flow velocity meter calibration method and a device based on constant uniform flow.
Background
In liquid flow measurement, the flow rate is the most important parameter, and even small changes in conditions can cause changes in the flow regime of the medium, and hence in the flow rate. At present, due to the establishment of various liquid flow standard devices and the continuous application of new technologies by manufacturers, the technology for measuring the liquid flow in a closed pipeline is mature, and the precision of the corresponding pipeline flowmeter is high and can reach 0.1% at most; in open channels, river channels and running pipes, the main flow measuring instrument is various open channels, weirs and measuring grooves, the flow velocity is mainly measured by a flow velocity meter, and the flow measuring instrument is used for measuring the flow of water bodies such as rivers, lakes, channels and the like. At present, the most widely used in flow velocity measurement in China is a rotor type flow velocity meter.
The current calibrating device of the flow velocity meter is mainly in a linear open groove mode, and the principle of the calibrating device is that a speed-adjustable calibrating vehicle is adopted to drag the flow velocity meter to run on the open groove at a constant speed, so that a flow velocity calibrating result of the flow velocity meter is obtained. At present, in all the current flowmeter calibration devices, the length of a straight open groove is about 100m, the width is about 4m, and the distance is required for adding a closed space and the like, so that the occupied area is large, and the field requirement on a detection mechanism is extremely high; the verification vehicle is high in cost, high in maintenance difficulty and high in calibration cost; the tracing of the flow velocity meter in the flow velocity meter calibrating device is to finish the repeated measurement of the same data of the flow velocity meter under the same measuring condition by adopting an indirect metering verification method through a universal counter and a secondary steel tape which are calibrated by the country, and the similar indication value is provided according to a metering standard, so that the calibrating efficiency is low.
Disclosure of Invention
The invention aims to provide a constant uniform flow-based flowmeter calibration method and a device thereof, which abandon the method of tracing the source of the existing flowmeter through a length-time system, and adopt a flow system to trace the magnitude of the flowmeter, thereby improving the working efficiency.
The technical problem of the invention is as follows:
the utility model provides a current meter calibrating device based on invariable uniform flow, its characterized in that includes overflow water tank and launder, overflow water tank's inlet end is connected with the inlet tube, and overflow water tank's play water end is connected with the inlet end of launder.
Further limited, the flowmeter calibrating device based on constant uniform flow further comprises a lifting table, wherein the lifting table is positioned at the water outlet end of the water flow groove, the water outlet end of the overflow water tank is movably connected with the water inlet end of the water flow groove through a connecting piece, and the lifting table is used for adjusting the angle between the water flow groove and the horizontal direction.
Further defined, the connection is a compensator or an expansion joint.
Further limited, the overflow water tank water inlet end is positioned below the overflow water tank water outlet end, an overflow port is formed in the side wall of the overflow water tank, the overflow port is positioned above the overflow water tank water inlet end, and the water depth of the water flow tank is adjusted according to the size of the opening of the overflow port.
Further defined, the constant uniform flow-based flow meter calibration device further includes an overflow valve disposed at the overflow port for adjusting the size of the water flow through the overflow port.
Further defined, the constant uniform flow based flow meter calibration device further comprises a level gauge disposed on and in communication with the flow channel.
Further defined, the constant uniform flow-based flow meter calibration device further comprises a total water inlet flow meter and an overflow water flow meter, wherein the total water inlet flow meter is arranged on the water inlet pipe, the overflow port is connected with an overflow pipe, and the overflow water flow meter is arranged on the overflow pipe.
Further limited, the constant uniform flow-based current meter calibration device further comprises a water return tank, the overflow water tank is arranged in the water return tank, the water inlet pipe penetrates through the water return tank to be connected with the overflow water tank, the water outlet end of the overflow pipe and the water outlet end of the water return tank are both located right above the water return tank, and the lifting platform is located on the outer side of the water return tank.
The flowmeter calibration method based on the constant uniform flow is characterized by comprising the following steps of:
s1, installing a to-be-detected flow velocity meter on a water flow tank, and injecting water into an overflow water tank at a constant speed through a water inlet pipe;
s2, adjusting the water depth of the water flowing groove through an overflow valve;
s3, setting the water flow speed in the water flow groove, and adjusting an included angle in the horizontal direction of the water flow groove through the lifting table according to the water flow speed set in the water flow groove;
s4, determining the flow of the water flowing groove according to the difference value between the flow of the water inlet pipe and the flow of the overflow pipe, and determining the real-time flow velocity of the water flowing groove according to the flow of the water flowing groove;
s5, calibrating the flow velocity meter to be detected by comparing the real-time flow velocity of the water flowing groove with the measured flow velocity of the flow velocity meter to be detected.
Further defined, the step S3 specifically includes:
s31, calculating the overflow cross section area of the water flow groove and the wet circumference of the water flow groove according to the width of the water flow groove and the water depth of the water flow groove;
s32, calculating to obtain the hydraulic radius of the launder according to the flow cross section area and the wet circumference of the launder;
s33, calculating according to the hydraulic radius of the water flowing groove to obtain the relative roughness of the water flowing groove;
s34, calculating to obtain a resistance coefficient of the launder according to the relative roughness of the launder;
s35, setting the water flow speed of the water flow tank, and calculating to obtain the hydraulic loss in the water flow tank according to the resistance coefficient of the water flow tank, the length of the water flow tank and the set water flow speed of the water flow tank;
s36, calculating to obtain an included angle between the water flowing groove and the horizontal direction according to the hydraulic loss of the set water flowing groove and the length of the water flowing groove;
s37, determining the lifting height of the lifting table according to the length of the water flowing groove, and adjusting the deflection angle of the water flowing groove.
The invention has the beneficial effects that:
1. according to the invention, the characteristic of constant uniform flow in an open channel is utilized, the existing method that a flow rate meter is driven by a verification vehicle to run at a constant speed in static water flow is abandoned, so that the flow rate of the water flow of a water inlet pipe is constant after entering the water flow tank through an overflow water tank, the measurement requirement of the flow rate meter on the constant flow rate is directly realized, the overflow water at the other position is measured by using a standard flow meter, and the instantaneous flow in the water flow tank is obtained by comparing the standard flow meter with the total water inlet flow meter to obtain a difference value, so that the flow rate value is obtained, the time is saved, the calibration efficiency of the flow rate meter is improved, the structure is simple, the scale is small, and the field can be greatly saved; meanwhile, constant uniform flow in the water flowing groove is more stable, so that the stability of the calibration result of the flow velocity meter is improved, and the calibration precision of the flow velocity meter is also improved.
2. According to the invention, the inclination angle of the water flow groove can be adjusted through the lifting table, so that the water flow speed in the water flow groove is controlled, the calibration of the flow rate instrument under different water flow states is realized, the structure is simple, the operation is convenient, the whole volume is reduced, the occupied area is reduced, the cost is low, the detection function is complete, and the device is suitable for popularization and use.
3. Through setting up the overflow valve and can be through the height of height determination water launder water level of adjusting the overflow valve to can realize the calibration work of current meter under different water level states, easy operation adjusts conveniently, the water that overflows from the overflow water tank flows through the overflow pipe simultaneously, can accurately obtain the flow in the water launder through overflow flow and the inflow flow that total inflow flowmeter gathered of overflow flowmeter, make the flow calculation of water launder more accurate.
Drawings
FIG. 1 is a schematic diagram of a front view of a constant uniform flow based flow meter calibration device of the present invention;
FIG. 2 is a schematic top view of a constant uniform flow based flow meter calibration device of the present invention;
FIG. 3 is a schematic diagram showing the overall structure of a constant uniform flow-based flow meter calibration device according to the present invention;
FIG. 4 is a schematic diagram of the cross-sectional structures of the communicating channel and the flow channel of the present invention;
1-overflow water tank; 2-a launder; 3-lifting platform; 4-a water inlet pipe; 5-overflow pipe; 6-overflow valve; 7-a liquid level meter; 8-a total water inlet flowmeter; 9-overflow water flow meter; 10-a water return tank; 11-communicating grooves.
Detailed Description
Example 1
The constant uniform flow in the open channel is characterized in that the flow velocity is unchanged along the way, the streamline is a series of parallel straight lines, and the flow velocity distribution of the water depth, the section and the like of the open channel are unchanged along the flow. Its section average flow velocity and kinetic energy correction coefficient are such that section average kinetic energyAlso along the flow.
Referring to fig. 1 to 3, the present embodiment provides a flow meter calibration device based on constant uniform flow, comprising an overflow water tank 1, a water flow tank 2 and a lifting table 3; in the initial state, the water flowing groove 2 is horizontally arranged, the head end of the water flowing groove 2 is movably connected with the water outlet of the overflow water tank 1 through a connecting piece, the tail end of the water flowing groove 2 is connected with the lifting table 3, the lifting table 3 is arranged at the bottom of the water flowing groove 2, the lifting table 3 can be selectively contacted and connected with the bottom of the water flowing groove 2, at the moment, the two opposite sides of the water flowing groove 2 are provided with baffle plates, the lifting table 3 is arranged between the two baffle plates, and the water flowing groove 2 is prevented from shaking on the lifting table 3; the top of the preferable lifting table 3 is hinged with the bottom of the water flowing groove 2, and the lifting table 3 is lifted and lowered to directly drive the tail end of the water flowing groove 2 to rotate up and down in a vertical plane by taking the center of the connecting piece as the center of a circle; it should be noted that, when the lifting platform 3 is hinged to the bottom of the water trough 2, since the tail end of the water trough 2 moves up and down along the axis direction of the lifting platform 3 when rotating up and down, the head end of the water trough 2 is close to or far away from the overflow water tank 1 when the water trough 2 rotates, at this time, the connecting piece adopts a component capable of providing rotation and movement, at this time, the connecting piece can be a compensator or an expansion joint, the head end of the water trough 2 can rotate and move relative to the overflow water tank 1 while the tail end of the water trough 2 rotates, so that the lifting platform 3 drives the water trough 2 to deflect up and down, thereby adjusting the deflection angle of the water trough 2 and the horizontal direction through the lifting platform 3, further adjusting the included angle between the water trough 2 and the horizontal direction, and simultaneously enabling the water in the overflow water tank 1 to keep being connected with the overflow water tank 1 when rotating up and down through the lifting platform 3, ensuring that water in the overflow water tank 1 can still flow into the water trough 2 after the tail end of the water trough is adjusted up and down, and water flow out of the water is avoided.
Further, the connecting piece can be a rubber tube, at this time, in order to avoid the running water tank 2 to lead to its head end downward sloping because of the dead weight, thereby cause the contained angle between running water tank 2 and the horizontal direction to have the deviation with the height-adjusting of elevating platform 3, consequently, need set up the lift bracing piece at running water tank 2 head end, the lift bracing piece sets up in the bottom of running water tank 2, the bottom surface contact of lift bracing piece top and running water tank 2, the top of lift bracing piece can be selected as spherical structure or cylinder structure, guarantee the steady rotation of running water tank 2, thereby realize the contained angle regulation of running water tank 2 and horizontal direction through adjusting the height of running water tank 2 head end and/or tail end.
The tail end of the water flow groove 2 is downwards regulated, and the speed of water flow in the water flow groove 2 is regulated by controlling the deflection angle of the water flow groove 2, so that the measurement and calibration of the flow velocity meter to be detected under different water flow speed states are realized; in order to facilitate the post calibration calculation, the interior of the launder 2 is preferably of a cuboid structure.
In order to realize the calibration of the flow rate meter to be detected under different liquid level height states, the overflow port is preferably formed in the overflow water tank 1, the overflow port is formed in the periphery of the overflow water tank 1, the upper edge of the overflow port is flush with the upper edge of the overflow water tank 1, the water outlet of the overflow water tank 1 is positioned on the opposite side of the overflow port, the water inlet flow of the overflow water tank 1 is fixed, the liquid level height of the overflow water tank 1 is regulated by regulating the height of the bottom of the overflow port, thereby regulating the liquid level height of the overflow water tank 1, entering the water flow channel 2 from the overflow water tank 1, the water inlet flow rate is the same, namely the water inlet flow rate is the same, the flow rate in the water flow channel 2 can be obtained by obtaining the overflow flow rate of the overflow port, the water flow channel 2 can be obtained when the width and the liquid level height of the overflow water tank 2 are known, in order to realize the measurement of different flow rates, the overflow port is avoided to be formed in each overflow water tank 1, further preferably, the overflow valve 6 is arranged on the overflow port, the overflow valve 6 is movably connected with the overflow port through regulating the height of the overflow water level bottom of the overflow water tank 1, the overflow valve 6 is movably connected with the overflow port, the overflow water level 6 is flush with the water level 6 when the water level 1 is flush with the water level 1, and the water level 1 is controlled from the water level 1, and the water level 6 is more preferably flush with the water level 1, and the water level 1 is more conveniently discharged from the overflow valve 1.
Further, referring to fig. 4, in order to conveniently obtain the height of the liquid level in the water flowing tank 2, the flowmeter calibration device based on constant uniform flow preferably further comprises a liquid level meter 7, the liquid level meter 7 is arranged on the water flowing tank 2 to obtain the real-time liquid level in the water flowing tank 2, in order to avoid interference caused by constant uniform flow of the liquid level meter 7 in the water flowing tank 2, a communicating groove 11 is preferably arranged on the side wall of the water flowing tank 2, the communicating groove 11 is communicated with the bottom of the water flowing tank 2, the liquid level in the communicating groove is guaranteed to be identical with the liquid level in the water flowing tank 2 by utilizing the principle of a communicating vessel, at the moment, the liquid level meter 7 is arranged in the communicating groove 11 to determine the real-time liquid level in the water flowing tank 2, the constant uniform flow in the water flowing tank 2 is guaranteed to be stable and reliable, and high-precision calibration of the flowmeter is realized.
Furthermore, in order to calculate the water flow in the water flow tank 2, a difference value obtained by subtracting the overflow flow from the water flow is selected as the water flow in the water flow tank 2, and the flowmeter calibration device based on constant uniform flow preferably further comprises a total water inlet flowmeter 8 and an overflow water flowmeter 9, wherein the total water inlet flowmeter 8 is arranged on the water inlet pipe 4, and the overflow water flowmeter 9 is arranged on the overflow pipe 5, so that the corresponding flow is obtained; the flow rate of the water flow in the water flowing tank 2 can be monitored in real time by arranging the specific tube sensor in the water flowing tank 2, so that the calibration precision is further improved.
Further, in order to avoid waste of water resources, the preferred flowmeter calibration device based on constant uniform flow further comprises a water return tank 10, wherein the water return tank 10 is arranged below the overflow water tank 1, so that water overflowed from the overflow water tank 1 is discharged into the water return tank 10 through the overflow pipe 5, at the moment, the water outlet end of the overflow pipe 5 is positioned above the water return tank 10, the tail end of the water return tank 2 is a water outlet end, water discharged from the water outlet end of the water return tank 2 flows into the water return tank 10, namely, the water outlet end of the water return tank 2 is positioned above the water return tank 10, and meanwhile, the lifting table 3 is positioned outside the water return tank 10, so that the service life of the lifting table 3 is prolonged; at this moment, one end of the water inlet pipe 4 stretches into the total water tank, the other end of the water inlet pipe 4 penetrates through the side wall of the water return tank 10 to be connected with the water inlet of the overflow water tank 1, water in the total water tank is pumped into the overflow water tank 1 through the water pump, the water outlet end of the water return tank 10 is connected with the total water tank, waste of water is avoided, recycling of water is achieved, and resources and cost are saved.
When the flow meter to be detected is used, the flow in the flow channel 2 is calculated and regulated according to the requirement, then the included angle between the flow channel 2 and the horizontal direction is regulated, constant uniform flow can be obtained in the flow channel 2, the flow meter to be detected is installed in the flow channel 2, the calibration of the flow meter to be detected can be realized, the calibration efficiency is high when the flow meter to be detected is installed, the calibration result is more stable, and the calibration precision is improved; compared with the existing method for measuring the static flow channel, the method does not need to utilize the existing distance-length system to drive the flowmeter to move by using the verification vehicle to obtain the measurement result of the flowmeter to be detected, and then calculates by calculating and selecting the value which is close to the constant speed time period, so that the time for driving the flowmeter to be detected to move is long in order to ensure the accuracy of the result, and the calibration efficiency of the flowmeter to be detected is greatly reduced; meanwhile, the verification vehicle is used for driving the to-be-detected flow velocity meter to move so that the to-be-detected flow velocity meter and the water flow form relative flow velocity, and the verification vehicle is required to be capable of driving at a constant speed, so that the difficulty is high, the stability of the constant speed driving is low, and the accuracy of a verification result obtained through the existing distance-time system is low.
Example 2
Based on embodiment 1, the present embodiment provides a method for using a flowmeter calibration device based on constant uniform flow, including the following steps:
s1, injecting water into an overflow water tank 1 at a constant speed through a water inlet pipe 4, and installing a to-be-detected flow velocity meter on a water flow tank 2;
in step S1, water in the total water tank is pumped into the overflow water tank 1 by the water pump, the water flow tank 2 is horizontally placed, the flow stability in the overflow pipe 5 and the flow stability in the water inlet pipe 4 are determined by observing the numerical change of the total water inlet flowmeter 8 and the numerical change of the overflow water flowmeter 9, at this time, the flow in the water flow tank 2 is stable, and then the flow rate meter to be detected is connected to the water flow tank 2 according to the detection requirement to be detected.
S2, adjusting the water depth in the water flowing groove 2 by adjusting the height of the overflow valve 6;
in step S2, firstly, determining the water depth of the to-be-detected flow meter to be tested, then gradually adjusting the height of the overflow valve 6, namely, adjusting the position of the bottom end of the overflow port on the overflow water tank 1, further realizing the adjustment of the liquid level of the overflow water tank 1, controlling the liquid level in the water flow tank 2, and meanwhile, by means of the liquid level meter 7, normally selecting to connect the to-be-detected flow meter to the opposite side of the liquid level meter 7, ensuring that the liquid level value of the liquid level meter 7 is the liquid level of the to-be-detected flow meter, and installing the liquid level meter 7 in the communicating groove 11 on the side wall of the water flow tank 2, further accurately obtaining the liquid level height of the corresponding position, namely, the water depth in the water flow tank 2.
S3, setting the water flow speed of the water flow tank 2, and adjusting the inclination angle of the water flow tank 2 according to the water flow speed of the water flow tank 2;
in step S3, determining the test flow rate of the flow meter to be detected, namely determining the flow rate of the water flowing channel 2, calculating to obtain the deflection angle of the water flowing channel 2, and when the connecting piece is a compensator or an expansion joint, driving the water flowing channel 2 to deflect downwards by a corresponding angle in a vertical plane by adjusting the height of the lifting table 3; when the connecting piece is a rubber tube, the height of the lifting support rod can be selectively kept and the height of the lifting platform 3 can be reduced so as to deflect the water flow tank 2 downwards, the height of the lifting support rod can be selectively raised so as to keep the height of the lifting platform 3 to deflect the water flow tank 2 downwards, and the height of the lifting support rod can be selectively raised and the height of the lifting platform 3 can be reduced so as to deflect the water flow tank 2 downwards, wherein when the lifting support rod is raised, the head end of the water flow tank 2 is required to be ensured not to be higher than the position of the connecting port of the rubber tube and the overflow water tank 1, and the water flow in the overflow water tank 1 can be ensured to flow to the water flow tank 2 stably and reliably; through the deflection adjustment of the water flowing groove 2, the flow velocity in the water flowing groove 2 is correspondingly adjusted, so that the to-be-detected flow velocity meter test under the corresponding flow velocity state is completed.
S4, determining the flow of the water flowing tank 2 according to the difference value between the flow of the water inlet pipe and the flow of the overflow pipe, and determining the real-time flow velocity of the water flowing tank 2 according to the determined flow of the water flowing tank 2;
in step S4, the flow in the water flow tank 2 is obtained by making a difference between the display result of the total water inlet flow meter 8 and the display result of the overflow water flow meter 9, and then the real-time flow rate of the water flow tank 2 can be obtained by combining the length and width dimensions and the water level depth in the water flow tank 2.
S5, calibrating the flow velocity meter to be detected by comparing the real-time flow velocity with the measured flow velocity of the flow velocity meter to be detected.
And finally, in the step S5, comparing the calculated real-time flow rate with the flow rate obtained by measuring the flow rate by the flow meter, and completing the calibration of the flow meter.
Specifically, step S3 includes the following steps:
s31, calculating the flow cross section A of the water flowing groove 2 and the wet circumference χ of the water flowing groove 2 according to the width of the water flowing groove 2 and the water depth in the water flowing groove 2;
A＝x*h
χ＝x*h*2
wherein x is the width of the water flowing groove 2, h is the water depth in the water flowing groove 2, and the water depth in the water flowing groove 2 is measured by the liquid level meter 7.
S32, calculating the hydraulic radius R of the launder 2 according to the flow cross section area of the launder 2 and the wet circumference of the launder 2;
s33, calculating the relative roughness K of the launder 2 according to the hydraulic radius of the launder 2 and the roughness of the inner wall of the launder 2 s ；
Wherein g is gravity acceleration, n is the roughness of the inner wall of the launder 2, and the roughness of the inner wall can be obtained according to the material of the launder 2.
S34, calculating a resistance coefficient lambda of the launder 2 according to the relative roughness of the launder 2;
λ＝0.185(K s /d) 1/3
wherein d=4r.
S35, setting the water velocity of the water flowing in the water flowing tank 2, and calculating the hydraulic loss h in the water flowing tank 2 according to the resistance coefficient of the water flowing tank 2, the length of the water flowing tank 2 and the set water velocity of the water flowing tank f ；
Where L is the length of the flume 2 and V is the set flume water flow rate.
S36, calculating to obtain an included angle theta between the water flowing groove 2 and the horizontal direction according to the hydraulic loss of the water flowing groove 2 and the length of the water flowing groove 2;
s37, determining the lifting height of the lifting table 3 according to the length of the water flowing groove 2, and realizing the rotation of the water flowing groove 2 to a corresponding inclination angle by adjusting the deflection angle of the water flowing groove 2.
For further explanation, examples are given by way of specific experiments:
the length L of the launder 2 was selected to be 10m, the width x of the launder 2 was 0.5m, i.e., the width between the inner walls of the launder 2 was 0.5m, and the depth h of water in the launder 2 measured by the level gauge 7 was 0.25m by adjusting the overflow valve 6, and the launder 2 used stainless steel as the inner wall, with the inner wall roughness n=0.012.
At this time, the calculation results in:
the flow cross-sectional area a=x×h=0.5×0.25=0.125 m of the flow channel 2 2 ；
Wet week χ=x×h×2=0.5+0.25×2=1m of the launder 2;
hydraulic radius of the flume 2
Relative roughness of the launder 2
Wherein g is 9.8m/s 2 According to the moid diagram of the pipeline experiment, the experimental result is that the experimental result meets λ=0.185 (K s /d) 1/3 When K is s Since/d is approximately 0.001 to 0.05, K is calculated s /d, where d=4r=0.5m, i.eMeets the above requirement, thereby calculating the resistance coefficient lambda=0.185 (K s /d) 1/3 ＝0.185×0.0015 1/3 ＝0.021。
When the water flow velocity v=1 in the water flow tank 2 is setIn m/s, the hydraulic loss in the launder 2 is obtained
Inclination angle of the launder 2
Based on the total flow q measured by the total inlet flow meter 8 on the inlet pipe 4 Total (S) Equal to the overflow flow q measured by the overflow water flowmeter 9 on the overflow pipe 5 Overflow valve And the flow rate q in the water flowing groove 2 Groove(s) The sum can be calculated to obtain q Groove(s) ＝q Total (S) -q Dividing into Then according to q Groove(s) ＝A×V Real world X3600 s can be calculated
V measured according to the flow velocity meter to be measured Measuring And V is equal to Real world Calculating to finish the water level and V of the to-be-detected flow velocity meter at 0.25m Real world And the calibration under the flow speed state is carried out, so that the measurement of the to-be-detected flow rate meter under different water levels and different flow speed states is realized by changing the position of the overflow valve 6 and the angle of the water flowing groove 2, and the calibration of the to-be-detected flow rate meter is finally completed.
Claims (10)
1. The utility model provides a current meter calibrating device based on invariable uniform flow, its characterized in that includes overflow water tank (1) and water launder (2), the inlet end of overflow water tank (1) is connected with inlet tube (4), and the outlet end of overflow water tank (1) is connected with the inlet end of water launder (2).
2. The constant uniform flow-based flow meter calibration device according to claim 1, further comprising a lifting table (3), wherein the lifting table (3) is located at the water outlet end of the water flow tank (2), the water outlet end of the overflow water tank (1) is movably connected with the water inlet end of the water flow tank (2) through a connecting piece, and the lifting table (3) is used for adjusting the angle between the water flow tank (2) and the horizontal direction.
3. The constant uniform flow based flow meter calibration device of claim 2, wherein the connection is a compensator or an expansion joint.
4. The constant uniform flow-based flow velocity meter calibration device according to claim 2, wherein the water inlet end of the overflow water tank (1) is positioned below the water outlet end of the overflow water tank (1), an overflow port is formed in the side wall of the overflow water tank (1), the overflow port is positioned above the water inlet end of the overflow water tank (1), and the water depth of the water flow tank (2) is adjusted according to the opening size of the overflow port.
5. The constant uniform flow based flow meter calibration device of claim 4, further comprising an overflow valve (6), the overflow valve (6) being disposed at the overflow port for adjusting the size of the water flow through the overflow port.
6. The constant uniform flow-based flow meter calibration device of claim 5, further comprising a level gauge (7), the level gauge (7) being disposed on the flow channel (2) and in communication with the flow channel (2).
7. The constant uniform flow-based flow meter calibration device according to claim 6, further comprising a total water inlet flow meter (8) and an overflow flow meter (9), wherein the total water inlet flow meter (8) is arranged on the water inlet pipe (4), wherein the overflow port is connected with the overflow pipe (5), and wherein the overflow flow meter (9) is arranged on the overflow pipe (5).
8. The constant uniform flow-based flow meter calibration device according to claim 7, further comprising a water return tank (10), wherein the overflow water tank (1) is arranged in the water return tank (10), the water inlet pipe (4) penetrates through the water return tank (10) to be connected with the overflow water tank (1), the water outlet end of the overflow pipe (5) and the water outlet end of the water return tank (2) are both positioned right above the water return tank (10), and the lifting table (3) is positioned outside the water return tank (10).
9. A constant uniform flow based flow meter calibration method, characterized by the constant uniform flow based flow meter calibration device of claim 5 or 6, comprising the steps of:
s1, installing a to-be-detected flow velocity meter on a water flowing tank (2), and injecting water into an overflow water tank (1) at a constant speed through a water inlet pipe (4);
s2, adjusting the water depth of the water flowing groove (2) through an overflow valve (6);
s3, setting the water flow speed in the water flow groove (2), and adjusting the included angle between the water flow groove (2) and the horizontal direction through the lifting table (3) according to the water flow speed set in the water flow groove (2);
s4, determining the flow of the water flowing groove (2) according to the difference value between the flow of the water inlet pipe and the flow of the overflow pipe, and determining the real-time flow velocity of the water flowing groove (2) according to the flow of the water flowing groove (2);
s5, calibrating the flow velocity meter to be detected by comparing the real-time flow velocity of the water flowing groove (2) with the measured flow velocity of the flow velocity meter to be detected.
10. The method for calibrating a flow meter based on constant uniform flow according to claim 9, wherein said step S3 is specifically:
s31, calculating the flow cross section of the water flowing groove (2) and the wet circumference of the water flowing groove (2) according to the width of the water flowing groove (2) and the water depth of the water flowing groove (2);
s32, calculating the hydraulic radius of the water flowing groove (2) according to the flow cross section area of the water flowing groove (2) and the wet circumference of the water flowing groove (2);
s33, calculating according to the hydraulic radius of the water flowing groove (2) to obtain the relative roughness of the water flowing groove (2);
s34, calculating to obtain a resistance coefficient of the water flowing groove (2) according to the relative roughness of the water flowing groove (2);
s35, setting the water flow speed of the water flow groove (2), and calculating to obtain the hydraulic loss in the water flow groove (2) according to the resistance coefficient of the water flow groove (2), the length of the water flow groove (2) and the set water flow speed of the water flow groove;
s36, calculating an included angle between the water flowing groove (2) and the horizontal direction according to the hydraulic loss of the water flowing groove (2) and the length of the water flowing groove (2);
s37, determining the lifting height of the lifting table (3) according to the length of the water flowing groove (2) and adjusting the deflection angle of the water flowing groove (2).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211448619.XA CN115856357A (en) | 2022-11-18 | 2022-11-18 | Constant uniform flow-based current meter calibration method and device |
| CN202211448619X | 2022-11-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117110653A true CN117110653A (en) | 2023-11-24 |
Family
ID=85664174
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211448619.XA Pending CN115856357A (en) | 2022-11-18 | 2022-11-18 | Constant uniform flow-based current meter calibration method and device |
| CN202311186956.0A Pending CN117110653A (en) | 2022-11-18 | 2023-09-14 | Flow velocity meter calibration method and device based on constant uniform flow |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211448619.XA Pending CN115856357A (en) | 2022-11-18 | 2022-11-18 | Constant uniform flow-based current meter calibration method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (2) | CN115856357A (en) |
-
2022
- 2022-11-18 CN CN202211448619.XA patent/CN115856357A/en active Pending
-
2023
- 2023-09-14 CN CN202311186956.0A patent/CN117110653A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| CN115856357A (en) | 2023-03-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105588796B (en) | A kind of device of accurate quick measure soil permeability coefficient | |
| CN202614752U (en) | Device for simulating bottom sediment erosion and transmission features of variable-slope rectangular water tank | |
| CN202048938U (en) | Trench weir type flow meter | |
| CN207675606U (en) | A kind of compact reservoir dynamic imbibition row drive simulator | |
| CN209690137U (en) | Coarse-grained soil permeability critical gradient deformeter | |
| CN216593940U (en) | Pressure measuring pipe exhaust device | |
| CN111005347B (en) | Multifunctional test system for optimizing design of water flow structure in front of water inlet of hydropower station | |
| CN221528671U (en) | Flow velocity meter calibrating device based on constant uniform flow | |
| CN111678855A (en) | Ring cutter infiltration test device | |
| CN117110653A (en) | Flow velocity meter calibration method and device based on constant uniform flow | |
| CN202976607U (en) | Orifice/mouthpiece experimental apparatus | |
| CN214310485U (en) | Landslide disaster runoff and motion process simulation test equipment | |
| CN205449184U (en) | Positive displacement liquid automatic measurement device | |
| CN204666329U (en) | A kind of air-flow is taken liquid and is taken sand visual experimental apparatus | |
| CN118190733A (en) | Sampling system for measuring runoff sediment content and flow velocity and sediment content measuring system | |
| CN108318664B (en) | Slope runoff-soil body permeation coupling test method | |
| CN114738297B (en) | Cavitation testing system of intelligent open-loop centrifugal pump | |
| CN201678988U (en) | Measuring weir with variable elevation of weir crest | |
| CN116625439A (en) | Real-time monitoring device for drainage flow under hydraulic and hydroelectric engineering | |
| CN113464108B (en) | Physical model experimental method for water flooding failure type water invasion development | |
| CN105466527A (en) | Thin sheet flow roll wave measurement system and method based on electromagnetic sensors | |
| CN214621403U (en) | System for calibrating millimeter wave radar flowmeter and testing performance | |
| CN104501893A (en) | Wide-range high-precision automatic runoff yield measurement system | |
| CN213580585U (en) | Full-automatic test device for measuring seepage and drag force coefficient of fluctuating water flow | |
| CN114779372A (en) | Method and device for carrying out precision correction on tipping bucket type rainfall sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |