GOST R 51657.2-2000

Group P60

STATE STANDARD OF THE RUSSIAN FEDERATION

WATER ACCOUNTING ON HYDROMELIORATIVE AND WATER MANAGEMENT SYSTEMS

Methods for measuring the flow and volume of water. Classification

Water flow measurement in hydromelioration and water economics systems.
Methods of water flow measurement. classification

OKS 17.120
OKP 43 1100

Introduction date 2001-07-01

Foreword

1 DEVELOPED by the Technical Committee for Standardization TK 317 "Measurement of liquid flow rates in open watercourses and channels"

INTRODUCED by the Technical Committee for Standardization TC 317 "Measurement of liquid flow rates in open watercourses and canals" and the Department of Land Reclamation and Agricultural Water Supply of the Ministry of Agriculture of the Russian Federation

2 ADOPTED AND INTRODUCED BY Decree of the State Standard of Russia dated December 14, 2000 N 355-st

3 INTRODUCED FOR THE FIRST TIME

1 area of ​​use

1 area of ​​use

This standard establishes methods for measuring the flow and volume of water used at water metering points in irrigation and drainage systems and water management systems.

This standard does not apply to methods for measuring the flow, volume and quantity of liquids used for technological purposes of general industrial and petrochemical purposes.

This standard is applied to all water management organizations of various Ministries and departments that ensure the distribution of water resources between consumers, as well as in design bureaus, research institutes, design and industrial organizations that develop, test, manufacture and operate water metering equipment for open watercourses, canals and agribusiness facilities , pressure, semi-pressure and non-pressure pipelines and for irrigation and drainage pumping stations.

This standard should be used in conjunction with GOST 8.439 and GOST 15528.

2 Normative references

This standard uses references to the following standards:

GOST 8.439-81 State system for ensuring the uniformity of measurements. Water flow in pressure pipelines. Methodology for performing measurements using the area - speed method

GOST 8.563.1-97 State system for ensuring the uniformity of measurements. Measurement of flow and quantity of liquids and gases by the method of variable pressure drop. Diaphragms, ISA 1932 nozzles and Venturi tubes installed in filled round pipes. Specifications

GOST 8.563.2-97 State system for ensuring the uniformity of measurements. Measurement of flow and quantity of liquids and gases by the method of variable pressure drop. Method for performing measurements with narrowing devices

GOST 8.563.3-97 State system for ensuring the uniformity of measurements. Measurement of flow and quantity of liquids and gases by the method of variable pressure drop. Procedures and calculation module. Software

GOST 15528-86 Instruments for measuring the flow, volume or mass of flowing liquids and gases. Terms and Definitions

GOST R 51657.1-2000 Water accounting for irrigation and drainage and water management systems. Terms and Definitions

3 Definitions

This standard uses the terms and definitions in accordance with GOST R 51657.1.

4 General provisions

4.1 The classification of methods for measuring the flow and volume of water is made both for open channels and for pipelines, since in the general case, hydroreclamation and water management systems transport liquid both in open watercourses and canals (GOST 8.439,,), and in pipelines with pumping pumping stations GOST 8.563.1 - GOST 8.563.3.

4.2 To measure the flow and volume of water at water metering points located both in open channels and on pipelines, methods are mainly used that differ from each other in technical implementations, which are combined in Section 5.

4.3 For the purpose of approving the type of measuring instruments used for the technical implementation of methods for measuring the flow and volume of water, mandatory tests must be carried out.

5 Classification of methods for measuring water flows and volumes

According to the methods of obtaining the results of measurement, they are divided into direct and indirect.

5.1 Direct measurements of water flows and volumes for open channels and penstocks

Direct measurements are carried out by the following methods:

- volumetric, in which graduated reservoirs or exemplary liquid measuring devices, reserve capacities of full-scale sections of canals or small reservoirs are used;

- mass, in which a container is used, installed on an exemplary balance, in which the mass of liquid is measured over a given time interval.

Direct measurements are used, as a rule, to obtain high-precision data in research and development of flowmeters, metrological tests and calibration of measuring instruments, as well as in reference flowmeter installations and when accounting for liquids for commercial purposes.

5.2 Indirect measurements of water flows and volumes for open streams and canals

5.2.1 Depending on the fixed equipment, indirect measurements are made using:

- fixed gauging stations in natural stable or artificial unlined channels and lined sections of channels according to GOST 8.439;

- gauging structures and devices, including weirs, rapids, gauging flumes and special gauging devices (attachments, nozzles);

- graduated hydraulic structures.

5.2.2 Depending on the measured parameters, indirect measurements using fixed gauging stations in stable unlined or lined sections of the channels are carried out by the following methods:

- speed - area;

- slope - area;

- mixing.

When using hydrometric structures and devices, the following methods are used:

- level (pressure) - flow rate;

- level difference (pressure difference) - flow rate;

- speed - consumption.

Measurements of these parameters can be carried out in the usual way, i.e. of the entire passing flow, and in a partial way, in which only a given part of the flow is measured.

When using graduated hydraulic structures, the following methods are used:

- levels (heads) - opening of the control device - flow;

- level differences (pressure difference) - opening value of the control device - flow rate.

Indirect measurement methods are used as the main working means for determining the flow rate and volumes of water.

To select the required water measurement method, use GOST 8.439,.

5.3 Indirect methods for measuring flows in closed pipelines

5.3.1 Depending on the fixed equipment, indirect measurements are made using:

- measuring sections or sections of pipelines;

- narrowing devices, including diaphragms, nozzles and Venturi pipes according to GOST 8.563.1 - GOST 8.563.3;

- graduated hydromechanical equipment.

5.3.2 Depending on the measured parameters, indirect measurements using measuring sections or sections of pipelines are carried out by the following methods:

- area - speed according to GOST 8.439;

- pressure drop - area according to GOST 8.563.1 - GOST 8.563.3;

- mixing.

Parameter measurements are carried out as usual methods, i.e. for the entire flow passing in the pipe, and by partial methods, i.e. for a given part of the diverted (bypass) flow in a small diameter pipeline.

When using narrowing devices, measuring the parameters of pressure flows is carried out in the following ways according to GOST 8.563.1 - GOST 8.563.3:

- speed - consumption:

- pressure difference - flow rate.

When using graduated hydromechanical equipment for measurements, the following methods are used:

- pressure difference in the upstream and downstream - the value of the opening of the control device - flow;

- pressure difference between the characteristic points of hydromechanical equipment - opening values ​​of the control device - flow rate.

The latest measurement methods are approximate, because. hydromechanical equipment changes its characteristics over time.

Indirect measurement methods are used as the main working means for determining the flow and volume of water.

The definitions of the listed methods for measuring the flow and volume of water for pressure flows in pipelines are given in GOST 8.563.1 - GOST 8.563.3, GOST 15528 and.

APPENDIX A (informative). Bibliography

APPENDIX A
(reference)

MI 2406-97 GSI. Fluid flow in open channels of water supply and sewerage systems. Method for performing measurements using standard weirs and flumes

Manual for hydrometeorological stations and posts, issue 6. part II. Hydrological observations and work on small rivers. Gidrometeoizdat. L., 1972

Recommendations for the use of flow meters at reclamation pumping stations with a flow rate of up to 6 m/s . VNIIVODGEO Gosstroy of the USSR. M., 1986



The text of the document is verified by:
official publication
M.: IPK Standards Publishing House, 2001

For various technological needs and other needs, it is often necessary to determine the flow of water in a pipe and its dynamics over a period of time. For many cyclic processes, it is important to constantly monitor the flow of water and modern measurements are indispensable here.

CJSC "Expertise of utility networks" produces:

• measurement of water and wastewater flow in pressure and non-pressure (gravity) pipelines using portable ultrasonic flow meters (temporary installation of water meters),
• evaluates the accuracy of readings of the Customer's stationary flow meters. Measurements are made on pipes of various materials and with a diameter of 50 mm to 2 m.

Accurate determination of flow and quantity of liquid necessary in case of commercial disputes and litigation, for proper planning of reconstruction, selection of pumping units and pipe diameters, hydraulic calculations and modeling.

Measurement of liquid flow is an important measure in identifying the distribution of flows, checking the accuracy of stationary water meters. Measuring the flow of water and wastewater allows you to determine the degree of use (load) of water supply and sewerage networks.

Prices

Measurement of water consumption - from 20,000 rubles.
Prices

Equipment

In our work we use high-precision ultrasonic equipment. Each flowmeter set has a Certificate of Conformity (Certificate of Approval of the Type of Measuring Instruments), undergoes periodic verification (confirmed by the relevant documents). Before purchase, all our flow meters were selected based on the results of comparison of different brands of equipment, stability of readings even under adverse conditions, incl. on old pipes. This allows us to make accurate measurements on existing networks, determine the distribution of flows, water consumption of individual consumers, find sources of water loss, and carry out comparative measurements with existing stationary meters to assess the correctness of their readings.
We use the following equipment to measure water flow in pressurized water supply and heat supply (heating) networks:

• Portable Ultrasonic Flow Meter GE Panametrics PT878 (USA), 2 sets a. The device determines the speed and flow of liquid in the pipeline. The measurement error is in the range of 0.5-2%. The outer diameter of the pipeline can be 50-5000 mm. Each set is additionally equipped with a thickness gauge and various mounts: on chains and magnets.
• Flowmeter ChronoFlo (Hydreka, France) I). The main advantage of this device is a long-lived rechargeable battery (for 80 hours with the LCD screen on and backlight off).

Devices that determine the flow of water

Our company has modern ultrasonic equipment from well-known manufacturers, which allows you to accurately determine the flow of water. Depending on the features of the object, our specialists choose the optimal type of device. To install the equipment, it is not necessary to dismantle part of the pipeline.

An example of a survey area to detect hidden leaks.

The service is needed in situations

• Determining the flow in various sections of the network makes it possible to identify hidden leaks.
• Measuring the flow of water and wastewater allows you to determine the load on the pipeline, the possibility of increasing the flow (for example, connecting new subscribers).
• Measurements of the characteristics of the flow allow you to determine the actual values ​​of speed, flow, pipeline filling: maximum, minimum, average, accumulated. Based on the results of measurements, tables and graphs are formed
• Using measurements at different points in the network, you can identify an unknown connection.
• At industrial enterprises, control of water consumption is often important for compliance with the technological process, planning for modernization, optimizing modes, and saving resources.

We will accurately determine the flow of water and provide an opinion if you need to prove your case on this issue in court.

Advantages of our company:

• Determination of water flow is carried out using modern equipment, which has high accuracy.
• Departure on object in day of registration of the order is possible.
• Guaranteed high quality work at reasonable prices.
• If necessary, our specialists travel to the regions.
• After the measurements are taken, the customer is provided with a technical report, as well as recommendations for eliminating the identified problems in accounting for water consumption.

3.1 Instruments and equipment.

To measure the flow, in practice, a hydrometric meter GR-21M is used, the number of the meter is indicated on the blade propeller. Bladed propellers are No. 1 main - with a diameter of 12 cm and a geometric pitch of 20 cm, No. 2 - non-component, with a diameter of 12 cm, a geometric pitch of 50 cm. Be sure to indicate what the turntable is lowered into the water (rod, cable). The main parts of turntables:

1) The propeller or rotor is driven into a rotational state as a result of the force of the oncoming flow.

2) The axis on which the bladed propeller or murmur rotates. The axis serves to strengthen the bladed propeller, it can be movable, connected directly to the bladed propeller.

3) Turntable body. It serves as the basis for strengthening and placing individual parts of the turntable, for strengthening the turntable on a rod or cable. A desirable body shape is streamlined, creating the least resistance to flow.

4) Counting-contact mechanism. It serves to count the revolutions of the propellers.

5) Tail or rudder. The tail or rudder is used to install the turntable in the stream in the direction of the current, which is especially important when working with a cable.

Fig.2. Fig.3.

Floats are also used to measure water flow. Hydrometric floats are considered the most inaccurate way to measure water flow. For our river, surface floats were used, which were made in the form of circles sawn off from a dry log with a diameter of 5-15 cm and a thickness of 2-3 cm. No more than 4 pieces.

3.2. Methods for measuring water flow.

Water flow is the volume of water that has passed through a given cross section of a river flow in 1 s. For large watercourses - rivers, canals, spillways of hydraulic structures, etc. - Water consumption is expressed in cubic meters per second. The flow rate of small watercourses - springs, streams, wells, as well as laboratory flumes, is expressed in liters per second.

There are the following methods for calculating water consumption, they can be divided into two main groups:

1. Direct flow measurement.

2. Indirect flow measurement.

The direct measurement of the flow rate includes the so-called volumetric method, which is based on measuring the flow rate by means of measuring vessels substituted under a stream of water. The filling time of the measuring vessel is also measured. The flow rate is determined by dividing the volume of water in the vessel by the duration of filling.

Indirect measurement of water flow can be performed by various methods, the common feature of which is that they measure not the water flow itself, but individual elements of the flow, and the flow rate is obtained by calculation. These methods include:

a). Determination of flow using measuring devices: hydrometric flumes, weirs.

b). A mixing method that has several varieties (thermal, electrical and colorimetric).

in). Determining the flow rate from measured flow velocities and flow cross-sectional area is called the "velocity-area" method. We have used this method in practice. The cross-sectional area of ​​the flow is found from the results of depth measurements, and the velocity at individual points of the live section.

3.3. Measuring the flow rate of the hydrometric vertical.

Determination of water flow rates using hydrometric turntables is carried out using the "velocity-area" method. To ensure sufficient accuracy of flow measurement, it is necessary that a smoothly changing movement of water be observed in the selected area, the flow of water both in the root channel and on the floodplain should have a common direction along the entire width of the river. The flow rate in low water should be at least 0.15-0.25 m / s, which could be changed with a turntable. It is desirable that during floods and floods, the speeds do not exceed 3.0-4.0 m / s. In winter, the section of the river should be covered with a continuous ice cover. There should be no areas with stagnant water or reverse currents on the site. When choosing a site for temporary work, it is enough to take into account the convenience of the location in this period of the year.

A gauging cross-section across a river, in which water discharges are measured. The position of the hydrometric target is fixed on the plane by strong pillars - benchmarks.

The gauging section is divided perpendicular to the general direction of the river, focusing on the direction of the banks, since in order to correctly determine the flow rates, it is necessary that the cross section of the river along the alignment line be located normally to the average direction of the flow. As a rule, one gauging site is installed at the measurement site, coinciding with the site of the water metering station or located close to it. However, in some cases it is necessary to have two, and sometimes three sections. This is due to the fact that in different periods of the year the conditions for the flow of water can change significantly.

Determination of the direction of the hydrological section by means of a turntable that measures the direction of the current.

Work to determine the direction of the alignment is carried out in the following sequence:

1) on a pre-selected and fixed alignment, depth measurements are carried out, after which, in accordance with the width of the river and the outlines of the alignment profile, high-speed verticals are assigned in an amount of no more than 10-12;

2) on all high-speed verticals, the speeds and directions of the flow are measured, at one point at a depth of 0.6 h from the surface; the resulting vertical velocity is taken as the average vertical velocity.

3) water flow rates are calculated (we multiply the river speed by the area of ​​the water section) * see KG-3 Water flow rate for the GMCM-1 turntable

When measuring water flow with turntables, three methods are used - detailed, composite and abbreviated, which differ in the degree of detail of velocity measurements in a living section.

Before providing water flow measurement, it is necessary to check the serviceability of the hydrometric turntable, as well as the condition of all equipment of the hydrometric section. When measuring water flow, the following work is performed:

1) a description of the state of the river, weather, aquatic vegetation, the state of the riverbed, timber rafting, indicating the type of rafting, wind strength and direction, waves, water turbidity, the presence of ice phenomena.

2) observation of the water level.

3) depth measurements on the hydraulic section.

4) measurement of flow velocities on turntables.

When measuring speeds along each vertical, the following work is performed:

1) The state of the weather and the river is different.

2) The water level is determined (with significant changes) according to observations at the water meter for the beginning and end of work on the turntables.

3) Depth is measured on the vertical; in winter, the thickness of snow, ice, submerged ice and slush is additionally measured.

4) The working depth on the vertical is calculated and the depths are calculated, the vane is immersed in the speed measurement points.

5) The flow velocities are measured at individual points.

To measure the water consumption with the GR21-M turntable, you need to lower it by 0.6 depths in the central measuring vertical and count the number of calls. The first 2-3 signals are skipped without recording. This is necessary so that the bladed propeller acquires a rotation speed corresponding to the speed of the water flow. Then the stopwatch starts and after ≈ 100 sec. Calls are counted (one call - 20 turns). The number of calls is multiplied by 20 and this result is divided by the number of seconds, we get the number of revolutions per second:

According to the calibration table, we determine the speed:

V \u003d 0.0408 + 0.3233 * (0.2405) 2 \u003d 0.1185 m / s

Q \u003d 0.1185 * 2.2775 \u003d 0.27 m 3 / s

3.4 Measurement of water flow using surface floats.

In addition to the hydrometric turntable, the determination of the current velocity can be done with hydrometric floats. The method is based on registering the speed of a floating body-float. When determining the speed with floats, it is assumed that the current speed is equal to the speed of the float. To measure the water flow rate by surface floats above and below the hydrometric section, two additional sections are divided at equal distances so that the duration of the floats between the upper and lower sections is at least 20 seconds. At flow velocities of more than 2 m.sec, the duration of the float stroke may be less, but not less than 10 sec. The distance between the upper and lower gates must be measured with greater accuracy - twice with a steel tape. In windy weather, the use of surface floats is limited. When measuring velocities with floats, obtained in each case is the highest flow velocity on the float trajectory, this velocity is taken as the local velocity at the point of intersection of the alignment line and the float trajectory. Thin cords are pulled along the broken sections under water. One of the members of the brigade with a stopwatch becomes at the upper alignment, and two other members of the brigade become basically and lower. The student floats a little higher than the upper alignment, throwing it onto the midstream of the river from the shore. At the moment the float passes through the upper section, it turns on the stopwatch and watches the float. At the moment the float passes through the hydraulic gate, the observer monitors whether the float is on the midstream of the river. At the moment the float passes the lower alignment, the observer makes a signal (voice) and the student starts the stopwatch. Of all the floats pushed on the arrow, three floats are selected, showing the shortest duration of the course between the alignments. The extreme value of the duration of the stroke of these three floats should not differ from each other by more than 10%. The calculation of the flow rate measured by surface floats is given only by the highest flow rate according to the formula.

Measuring water flow with a hydrometer

Multipoint (Detailed) Method provides for the measurement of water flow along the increased against the usual number of high-speed verticals 10-15 with the measurement of speed at 5-10 points (surface; 0.2; 0.6; 0.8; ; 0.4; 0.6; 0.8; bottom-if the channel is not free) on each vertical. The multi-point method gives the most accurate flow rate.

main way, when the number of high-speed verticals decreases by 1.5-2 times compared to the detailed one, and the flow velocities are measured at 2-3 points on each vertical.

Integration way vertically it is used at depths of more than 1 m and current velocities of more than 0.2 m/s. The measurement is made using the integrated installation GR-101.

fast track it is used for rapid level changes during the measurement of water flow with intense channel deformation, in the presence of variable backwater and in other unfavorable conditions.

Shortcuts provide for the measurement of water flow at an average velocity at 1-2 representative verticals or a unit velocity at a point 0.2 of its working depth.

Water flow measurement with floats

Measurements with surface floats. The accuracy of float measurements is significantly lower than that of turntables. At intense ice drift, when spinner measurements become impossible, and individual ice floes serve as floats.

Measurement of water flow with deep-seated floats and integrator floats

Floats of this type are used to measure relatively low flow velocities (up to 0.15-0.20 m/s), when spinner measurements are not very reliable.

Water flow measurement hydraulically

It is used when it is not possible to measure the water flow in other ways. Water consumption is calculated by the formula

Q=VavF, Vav=C RJ,

where R is the hydraulic radius; J-longitudinal slope; C-speed coefficient or Chezy coefficient C=1/nR x-1.5 n at R<1 м;x-1,3 n при R>1m.

River Level Observations

The results of observations of the levels make it possible to establish the zones and duration of flooding of individual sections of the river valley, the speed of the flood wave along the river (in the event that “there are at least two water measuring posts in the river) and draw conclusions about the general nature of the change in the water content of the river during the year in a multi-year period, about the highest floods, etc.

Among these so-called characteristic levels, the levels of greatest practical interest are: 1) the highest annual, 2) spring ice drift, 3) autumn ice drift, 4) summer and autumn floods, 5) the lowest summer and winter.

river runoff - the movement of water in the form of a stream along a river bed.

Occurs under the influence of gravity. It is an essential element of the water cycle in nature, with the help of which water moves from land to oceans or areas of internal runoff. The quantitative value of the runoff per unit of time is called the water flow.

In hydrology, river runoff is usually understood as the volume of runoff - the volume of water that has passed through a certain target in a unit of time, most often a year. It combines surface runoff (formed as a result of precipitation and snowmelt) and groundwater runoff generated by groundwater. River runoff for the year is an objective indicator for determining the fullness of the river.

The main characteristic of river runoff is water flow.

All other characteristics of the river runoff, in fact, are derived from the corresponding water flow rates. Consider the most commonly used characteristics of river flow.

Runoff volume W (m 3, km 3) - the amount of water flowing from the catchment for any time interval (day, month, year, etc.).

Runoff module M (l / s * km 2) or q [m 3 / s * km 2)] - the amount of water flowing from a unit catchment area per unit time.

Runoff layer h (mm) - the amount of water flowing from the catchment area for any time interval, equal to the thickness of the layer, evenly distributed over the area of ​​this catchment area.

The runoff coefficient is the ratio of the runoff layer to the amount of precipitation that has fallen on the catchment area, which caused the runoff to occur.

Annual runoff is calculated in temperate climates for a hydrological year beginning in autumn (October 1 or November 1), when the moisture reserves in river basins passing from one year to another are low.

Two types of instruments are used to measure the flow velocity: electrical and mechanical. In many current measurements, both mechanical and electrical, an impeller rotating on an axis serves as a current velocity sensor, and a magnetic compass serves as a direction sensor. All these devices are based on measuring the number of revolutions of the impeller over a certain period of time. This is done using a mechanical (Ekman spinner) or electrical (Roberts current meter) counter. Recently, the Savokius rotor, whose revolutions are recorded by an electric meter, and Alekseev's letter-printing turntable have been widely used. In Alekseev's turntable, recording is carried out on tape using a special device after a certain number of turns of the turntable.

In the practice of limnologists, to determine the flow velocity, resistance thermometers-thermohydrometers are also used, based on the change in the resistance of thermocouples depending on the speed of the water flow surrounding these sensors. Recently, improved electrical recording meters of the speed and direction of currents - ACIT - have appeared.

In order to establish the nature of the relationship between costs and levels, it is necessary to carefully check and analyze the source materials. These include: 1) table "Measured water discharges" (WDI); 2) table "Daily water levels" (DWL); 3) combined cross-sectional profiles along the hydrometric alignment; 4) plan of the site of the post; 5) transverse profile along the hydraulic section to the level of high waters; 6) the technical work of the post; 7) literary and archival materials characterizing the regime of the river at the site of the hydrometric alignment.