Key points
It’s beginning to dawn on many that sustainability in the water industry is only achievable through a thorough understanding of the demands being placed on supplies. In this article Krishna Prashanth, Global Product Line Manager- Electromagnetic Flow Meters at ABB Measurement & Analytics, examines advances in high accuracy flowmeters and how they are helping in the drive to get water to those who need it most while minimising losses through leakage.
Water loss from distribution networks is a serious problem for water companies around the world as the global water supply is under increasing strain from the rise of urbanisation, industrialisation and the ever-increasing needs of agriculture. Governments therefore expect water utilities to ensure that every possible drop of water can be delivered to where it is needed.
This is a huge undertaking. It may sound like it should be simple, but accounting for every liter of water in pipelines that may stretch for thousands of kilometers across a country that may be remote, difficult to operate in or hard to access is a difficult and expensive task.
While some countries have made progress in tackling and fixing water network losses, many others are still experiencing water losses that can run into high double figures, which is unsustainable for both public health and business reasons.
A 2019 report by the International Water Association estimated that pipelines around the globe lose approximately 346 billion liters of treated water every day. These losses must be replaced, which requires more energy and resources that in turn add to the environmental burdens already caused by an energy hungry industrial world.
The costs to recover or prevent such losses also reduce revenue that could have been invested in upgrading networks. With these pressures and expectations, the global water industry must find the location of leaks, explain why they are happening and make clear what they will do to rectify the situation. It’s not often possible that all three can be achieved at the same time.
But there are new techniques and devices that can help change all that.
Improvement starts with measurement
Detecting lost water starts with choosing a method to measure water flow, a variety of which can be used depending on the application. These methods can range from constrictive methods such as flumes and weirs for open channel systems, to orifice, mechanical, ultrasonic or electromagnetic flowmeters for use in closed pipe systems. Each of these have advantages and disadvantages.
The second major factor in locating and mitigating water losses is deciding where to measure. Many water companies simply don’t measure in enough places to be able to get a full picture of their network.
Performing measurements as widely as possible gives utilities the maximum amount of data on the location and severity of water losses, and that data can subsequently be used to develop methods and strategies to resolve those losses.
Therefore, it’s imperative that any device used to measure flows must be as easy as possible to install, access and maintain as broadly as possible throughout a water pipeline network that passes through towns, cities, and remote areas that may be difficult to access.
One of the best methods to achieve this is the use of electromagnetic flowmeters, which offer several advantages including consistent accuracy and high reliability. They are also highly stable and can be used in a wide range of installations.
A major attraction of electromagnetic flowmeters is that they offer greatly enhanced accuracy with uncertainty as low as +/- 0.4% or better compared to other methods, as well as exhibiting a high level of all-important repeatability throughout their operational life. Accuracy at this level is crucial when measuring for lost water to determine what constitutes legitimate consumption versus leaks or other sources of loss.
Reliability is another important benefit of electromagnetic flowmeters. Because flowmeters have no moving parts, they do not suffer the wear and tear that of mechanical designs. This also reduces maintenance costs by avoiding the need for upstream filter sediment strainers.
Electromagnetic flowmeters can also handle distorted velocity profiles without affecting accuracy, which eliminates the need required by other technologies for defined lengths of pipeline upstream or downstream of the point of measurement as. That means that electromagnetic flowmeters can easily be installed in congested locations such as towns and cities.
The benefits of digital high accuracy flowmeters
Several new digital developments are now making electromagnetic high accuracy flowmeters even more attractive and cost effective.
One of these is the ability to use alternatives to conventional mains power, which enables flowmeters to be fitted anywhere. ABB launched the world’s first battery-powered device in the early 1990s, and its latest generation of AquaMaster electromagnetic flowmeters can be used in remote locations with no need for a mains power supply.
Because electromagnetic flowmeters are small, they open the possibility of achieving enhanced flow measurement in many more locations. Moreover, as because electromagnetic flowmeters have a significantly lower power consumption than conventional mains-powered devices, they also offer energy cost reductions that further reduce the cost of ownership.
Gathering and importing measurement data from the devices is another important aspect to water conservation and efficient delivery and manufacturers, including ABB, are looking at using Low Power Wide Area Network (LPWAN) band and Narrow Band Internet of Things (NB-IoT) technologies.
These allow rapid exchange of measurement, configuration and maintenance data with using greatly reduced power requirements. As these technologies continue to mature, they offer the enticing prospect of controlling and monitoring water supplies in near real-time.
Even more benefits are possible using Power over Ethernet (PoE), which uses the same cable for both power and communications. This improved flexibility enables high accuracy flowmeters to be installed wherever they are needed, making it ideal for industrial water measurement and control applications.
For this purpose, ABB has also developed a 4-wire Ethernet, which combines classic outputs with future communication protocols to ensure devices are future-proof.
High Accuracy Flowmeters with Ethernet connectivity increase simplicity, flexibility and reliability while providing access to previously inaccessible data such as density measurement, conductivity or concentration of the medium.
The time needed to commission, operate and maintain electromagnetic flowmeters – coupled with the skills and training of technicians and operators – is another factor in their total cost of ownership. ABB’s AquaMaster4 electromagnetic flowmeter offers Near Field Communications (NFC) technology, which allows users to download configuration settings and retrieve logger data by simply tapping the transmitter with a smart device such as a phone or tablet loaded with ABB’s Velox app. This enables a variety of operational, logging and diagnostic data to be downloaded, interrogated and shared.
The pressure is still on
It will be no surprise that pressure is a major cause of pipe bursts and water leaks, so effective pressure management is critical to achieve the best performance from a water distribution network. Although reducing pressure to reduce leakage can be a solution for some, it is not suitable for all areas, such as those in lower pressure areas where a further reduction could cause weak or interrupted water supplies. Getting more accurate data on pressure is the key to making the right choice on pressure level measurement and maintenance in a network.
Utilities are increasingly attracted by the prospect of combining flow and pressure measurement into one device. This is because it offers numerous benefits, one of which is simplifying the gathering, sharing and analysis of data.
Integrating the ability to collect and save two readings with one device means that users can download logged data and investigate flow and pressure activity for a specific period, which greatly improves the ability to assess and enhance total network performance.
Water sustainability transformed with high accuracy flowmeters
Optimising water network management is based on achieving the highest levels of flow and pressure measurement accuracy. This allows true consumption to be much better identified and understood, ensuring a utility can account for nearly every drop of water supplied.
To achieve that, highly accurate flowmeters can now help ensure that major investments in water supply infrastructures are wisely spent and that water, one of the world’s most precious resources, is far better managed for the benefit of all.
