WO2021111468A1

WO2021111468A1 - System and method for measuring various parameters of riverine/ canal water flow

Info

Publication number: WO2021111468A1
Application number: PCT/IN2020/050996
Authority: WO
Inventors: Jagadeshwaran Loganathan; Prakash Jonnalagadda
Original assignee: Mcwane India Private Limited
Priority date: 2019-12-07
Filing date: 2020-12-03
Publication date: 2021-06-10

Abstract

A system and method for measuring parameters of water flow in rivers has two parts viz., to calculate the river sediment area wherein the flow is to be measured and also measuring the instantaneous velocity of the flow. By finding the area and velocity of the flow the water discharge can be calculated it is the product of them. It involves continuous monitoring of these values so that flow rate of the water body can be measured. Bathymetric echo sounding technique is used to measure the sediment area of the water body. It involves the surveying of the river area by sonar. Using a motor control, the sensor is rotated at different positions to cover the entire width of the river. The velocity measurement of the river is done in various methods such as using a Doppler effect ultrasonic sensor, impeller or a conduit with transceivers on top and bottom.

Description

INTRODUCTION : -

This invention relates to the field of Hydrology. Further, the invention relates to the measurement of various parameters of riverine flow. Furthermore, this invention relates to appropriate and accurate measurement of water in open channels. Still further the invention relates to that of a system and method for determining the various flow parameters of water in wider cross section water bodies without surface contact and hence not obstructing the flow of water thereby. Still furthermore, the invention relates to measure the depth and flow of water in canals of wider cross section by using echo sounding as well as sensors based on Doppler effect.

BACKGROUND OF INVENTION: -

As it can be seen that nowadays as a result of increase in demands from various sectors like agriculture, municipal needs, industry, and domestic consumers, there is a need for water users to conserve, use, and share water wisely and judiciously too. Towards achieving that objective, it is imperative that appropriate and nearly accurate measurement of water in open channels is an important first step. The importance of knowing not only the quality, but quantity of water becomes more apparent in nowadays practice. Traditional methods of water quantity measurements involve the use if weirs and flumes to measure the discharge of water. However, these methods are not possible and are rendered inadequate when the given water body whose flow parameters etc are to be measured has a wider cross section area, as this makes it very difficult and time consuming for the installation of flumes and weirs. Hence it becomes more pragmatic and sagacious that sensors can be used to detect the flow of the water bodies. These are advantageous as they involve measurement without any physical contact with the water body, hence, do not disturb the continuous flow of the water and making the flow unabated.

Echo sounding is a technique for measuring water depths by transmitting acoustic pulses from the sensor into the water surface and listening for their reflection (or echo) from the marine sediment floor. This technique has been used since the early twentieth century to provide the vital depth input that are helpful in mapping the water bodies and their calculating their areas. There are several ways to measure the velocity of the flow. Doppler effect sensors are used to measure the liquid’s velocity by studying the variation in the frequency when the particles in the flow are detected. Another method is to use an impeller and calculate the velocity of the flow using its RPM. The velocity of the flow can also be calculated using a conduit and two transceivers inside the liquid medium

OBJECT OF THE INVENTION: -

Its prime object of the invention is to provide a system and method for the near accurate calculation of various parameters of riverine flow.

It is still further an object of the invention to provide a method for measuring the flow parameters of water over rivers, canals with larger cross sectional area without any surface contact over water and thus not obstructing the continuous flow of water.

It is yet another object of the invention to provide a method for calculation of the discharge of water at any given instant in a canal, riverine system wherein there is continuous flow of water by adopting methods like Bathymetric Echo sounding system as well as SONAR ( Sound Navigation Ranging) techniques. Furthermore, it is yet another object of the invention to provide the agreeable and accurate measured parameters of water flow over open channels and rivers by adopting Doppler effect sensors and more importantly without obstructing the flow of water.

Description of the Invention with respect to the accompanying drawings : -

Fig 1 depicts the block diagram of the process and method involved in the measurement of flow parameters in open channels and riverine systems with larger cross sectional area

Fig 3 Shows the usage of Doppler effect Ultrasonic sensor for determining the velocity of water flow in open channels and riverine systems with SONAR

Fig 4 Showing the usage of Doppler effect Ultrasonic sensor for determining the velocity of water flow in open channels and riverine systems with Impeller

Fig 5 Showing the usage of a conduit and a pair of transceivers for determining of the velocity of water flow

Description of the Invention

The basic principle for measurement of discharge of water using this method can be thus explained

The river discharge can be calculated as,

Q = V x A where,

Q → Water flow rate or discharge(m³/s)

V → Velocity (m/s)

A → Area (m²) It can be further observed that the method employed here has two parts. The first one being to calculate the river sediment area where the flow is to be measured and the second one is used to measure the instantaneous velocity of the flow. By finding the area and velocity of the flow the water discharge can be calculated as the water discharge is the product of velocity and area. It involves continuous monitoring of these values so that instantaneously the flow rate of the water body can be measured. Bathymetric echo sounding technique is used to measure the sediment area of the water body. This method involves the surveying of the river area by using sonar. Using a motor control, the sensor is rotated at three different positions to cover the entire width of the river. The velocity measurement of the river can be done in various methods such as using a doppler effect ultrasonic sensor, an impeller or a conduit with transceivers on its top and bottom.

Sediment area measurement:

Sound waves are useful for remote sensing in a water environment because they can travel for hundreds of kilometers without significant attenuation. The level of attenuation of a sound wave is dependent on its frequency — high frequency sound is attenuated rapidly, while extremely low frequency sound can travel with much lesser attenuation throughout the water body. As acoustic energy travels well in water, it gets interrupted by a sudden change in medium, such as rock or sand. Hence such a technology can be used for mapping or profiling the river sediment area across the width of the water body.

A multibeam active sonar source is installed above the surface of the water at a significant height. This source is made to rotate sideways using a motor. Using this the sediment area of the water body is mapped at three different positions as shown. Velocity measurement:

The velocity of the stream can be measured by three methods:

• Using doppler effect ultrasonic sensor

• Using an impeller

Using a conduit and a pair of transceivers

Using doppler effect ultrasonic sensor:

Doppler Effect refers to the apparent change in wave frequency during the relative motion between a wave source and its observer.

Using high frequency sound transmission, the velocity of the water can be measured as it will be reflected to the sensor from particles or bubbles suspended in the liquid.

The echoes return at an altered frequency which is proportionate to flow velocity which can be measures as v = c (f_r - f_t)/(2 f_tcosΦ) where, fr and ft are the transmitted and received frequencies respectively, c - velocity of sound in fluid,

0 - angle between transmitted beam and flow direction

Using an impeller:

An impeller is a rotating component that is driven by the flow of water through it. An impeller can be installed inside the river as shown. As water flows through the impeller it rotates and the number of rotations is proportional to the water velocity. Hence using its RPM the velocity of the flow can be determined

Using a conduit and a pair of transceivers

This method is used to measure the velocity of a pipe or conduit. Hence such a structure can be installed inside the water body as shown. In this method the time taken for a sound wave to travel between a transmitter and receiver is measured. Two transceivers are located on the top and bottom of the water flow. The transmitters send ultrasonic waves in a particular frequency from one side to the other. The difference in frequency is proportional to the average fluid velocity which can be calculated using the formula,

V = [(t₂ - t₁) / (t₂ t₁)] (I / 2oosΦ) where, tl and t2 are the transmission upstream and downstream respectively, ∅ - angle between transmitted beam and flow direction I - distance between sensors or water head level

Claims

What is claimed is

1) A method for measuring the various parameters of riverine flow as well as in water channels of larger cross sectional area, without any physical surface contact with the water flow and not disturbing the flow of water, wherein, two steps are involved for measuring the discharge of water in any given instant ; the first one being to calculate the river sediment area where the flow is to be measured and the second one is used to measure the instantaneous velocity of the flow and then by finding the area and velocity of the flow the water discharge can be determined as the water discharge is the product of velocity and area using the expression Q = V x A where,

Q→ Water flow rate or discharge ( in Cubic metres per second)

V→ Velocity (m/s) ( in metres per second)

A→ Area (m²) ( in square metres)

2) The method for measuring of parameters of riverine flow, as claimed in claim 1, wherein Bathymetric echo sounding technique is used to measure the river sediment area of which involves the surveying of the river area by using SONAR ( Sound Navigation Ranging) techniques and by using a motor control, the sensor is rotated at three different positions to cover the entire width of the river

3) The method for measuring of parameters of riverine flow as claimed in claim 1 , wherein The velocity measurement of the river can be done in various methods such as using a Doppler effect ultrasonic sensor, an impeller or a conduit with transceivers on its top and bottom

4) The method of measuring of parameters of riverine flow as claimed in claim 1, wherein an impeller is a rotating component that is driven by the flow of water through it and can be installed inside the river and as water flows through the said impeller it rotates and the number of rotations is proportional to the water velocity and thus using its Revolutions per minute (RPM) the velocity of the flow can be determined

5) The method of measuring of parameters of riverine flow as claimed in claim wherein the method is used to measure the velocity in case of flow of water through a pipe or conduit, consists of a structure can be installed inside the water body and the said method the time taken for a sound wave to travel between a transmitter and receiver is measured for two transceivers that are located on the top and bottom of the water flow and ultrasonic waves in a particular frequency are sent by the said transmitter from one side to the other and the difference in frequency is proportional to the average fluid velocity which can be calculated using the formula, V = [(t₂ - t₁) / (t₂ t₁)] (I / 2oosΦ) where, tl and t2 are the transmission upstream and downstream respectively,

∅ ( theta) - angle between transmitted beam and flow direction I - distance between sensors or water head level

6) A measuring system for determining the water flow parameters of riverine systems, of larger cross sectional area, without any physical surface contact with the water flow and not disturbing the flow of water the said measuring system comprising, two steps for measuring the discharge of water in any given instant ; the first one being to calculate the river sediment area where the flow is to be measured and the second one is used to measure the instantaneous velocity of the flow and then by finding the area and velocity of the flow the water discharge can be determined as the water discharge is the product of velocity and area using the expression

Q = V x A where,

Q - - Water flow rate or discharge ( in Cubic metres per second)

V - - Velocity (m/s) ( in metres per second)

A - - Area (m²) ( in square metres)