Mike Ferris, Emerson Process Management, USA
W ireless technology presents opportunities for the power industry to implement applications that they simply could not justify with traditional wired technology. Wireless enables access to remote devices and opens up blind spots in a facility where measurements are not taken as often as they should be. By adopting wireless, operators, maintenance, IT personnel, and plant management gain convenient access to information previously unattainable.
Wireless technology is being used to determine thermal efficiencies at Federal Electrical Commission power generation facilities in Mexico.
Using wireless becomes even more attractive when you consider the major savings that can be achieved compared with a wired installation. Smart wireless can save up to 90 per cent of installed cost per point compared with wired analogue points on installations in existing facilities. These savings are primarily due to the inherent reduction in cabling, cable containment, junction boxes and marshalling cabinets that are required for a wired installation.
But, there are other savings to be made. In-depth studies of real-world projects show that, in small or large capital projects, today’s smart wireless technology currently results in engineering, construction and start-up savings of up to 35 per cent compared with wired analogue points in a greenfield installation.
Total project savings using wireless start to approach those of fieldbus installations. Further, wireless offers benefits that are incremental to cost savings as it increases flexibility and shortens schedules, due to ease of use.
Potential wireless applications are extensive and include automating operator rounds, increasing measurement points, gaining cost-effective access to plant diagnostic information and making measurements on rotating or moving plant equipment. For example, the opportunity now exists for wireless vibration sensors to give a continuous real-time indication of the reliability of more equipment throughout the plant. Previously, wiring costs meant that some equipment was only monitored whenever dictated by the schedule of measurement rounds.
When it comes to enhancing overall workforce productivity, wireless technology delivers in another important way by providing mobile, instant access to key information wherever plant staff might be. Workers can access desktop applications and perform tasks à‚— including viewing and responding to alarms from the field. The locations of personnel and physical assets in the plant can be tracked at all times.
Security systems can track and ensure authorized plant access and wireless video systems can not only guard the facility but keep a cost-effective eye on the process. Of course many of these applications are possible without wireless technologies, but wiring costs or technical limitations often make them impractical.
Clearly applying wireless across the whole plant can bring enormous benefits, but as one might expect, some companies may hesitate to make an upfront investment before they have tried and tested wireless and achieved some benefits. When looking to implement a wireless solution you can begin at the plant level and work down to the field, or at the field level and work up. Wireless field networks are extremely low powered to enable the use of battery-powered devices that operate for many years on the same battery. These solutions are also extremely secure and reliable, using open standards such as 802.15.4 and WirelessHART.
Of course, security and reliability are just as important at the plant level. Here wireless plant networks are based on open standards, such as 802.11 (“Wi-Fi”) that provide the security, reliability, high bandwidth, flexibility and expansion capabilities required by your business and operational applications.
Emerson’s smart wireless technology allows the user to start anywhere, based on highest priority needs. The user is not required to invest in an expensive wireless infrastructure throughout their facility to try out a simple monitoring application.
Gateways, devices, access points and software use wireless communication standards and have gone through rigorous coexistence testing. This ensures that wherever the user starts in the architecture, they can seamlessly and easily expand later as budget grows and confidence in the technology evolves.
For example, if additional measurements would help the user improve plant maintenance or reduce energy usage, they can build a sensor network at the field level, starting with just a single gateway and a few measurement devices. If the user needs to provide mobile access to plant information, then they can set up plant-level wireless access points so workers can get the information they need, wherever they are. If both types of applications are important, then implement them both at once, using the plant-through-field strength of the unified smart wireless architecture.
E.ON Kingsnorth: wireless monitoring of water usage
Emerson has applied wireless technology in numerous power industry applications across the world, applications such as helping E.ON UK to accurately monitor and measure treated water usage, thus allowing trending at its Kingsnorth oil and coal fired power station.
Using wireless transmitters, E.ON is now able to collect flow measurement data from new flowmeters installed throughout the turbine hall. The self-organizing wireless network delivers the data for trending in an OSIsoft PI historian that helps personnel monitor water usage within the system.
Smart wireless transmitters are ideal for temporary measurement applications.
E.ON Kingsnorth, a 1940 MW generating facility located on the Medway Estuary in Kent, UK, needed a solution to monitor and measure water usage within its main plant. They decided to install new non-intrusive ultrasonic flow meters to carry out this task. The high cost of wiring associated with a conventional cabled solution, and a desire to embrace the latest networking technology, led E.ON to evaluate wireless technologies that could meet their needs.
“E.ON is keen to adopt the very latest technology to help improve productivity, efficiency and availability, and wireless technology provides the ideal networking solution to access the flow measurement data from the turbine building without having to install new cabling,” said Chet Mistry, team leader, E.ON Uwith
Having initially undertaken extensive trials of Emerson’s Smart Wireless technology, E.ON selected the solution because it offered high levels of reliability and long transmitting distance, as well as the ability to add additional devices to the network without the need for additional infrastructure.
The turbine hall at Kingsnorth is around 500 m long and presents a difficult working environment as it houses large turbines, vast amounts of metal piping and a number of metal walkways that could interfere with the wireless signal. Such an environment would not be suitable for a line-of-sight wireless solution, but the smart wirele ss self-organizing technology encountered no problems in terms of routing data back to the gateway or reliability of connection.
“We have great confidence in the technology. The self-organizing net work provides redundant routes for the data to pass back to the gateway. The resulting wireless mesh network delivers high reliability,” said Simon Lark, C&I engineer, E.ON UK.
With self-organizing technology, each wireless device can act as a router for other nearby devices, passing messages along until they reach their destination. If there is an obstruction, transmissions are simply re-routed along the network until a clear path to the gateway is found.
As conditions change or new obstacles are encountered in a plant, such as temporary scaffolding, new equipment, or a parked lorry, these wireless networks simply reorganize and find a way to get their signals through. All of this happens automatically, without any involvement by the user. This self-organizing technology optimizes data reliability while minimizing power consumption. It also reduces the effort and infrastructure necessary to set up a successful wireless network.
Turbine halls with their large turbines, vast amounts of metal piping and large number of metal walkways present a tough challenge for wireless.
“We were initially a little sceptical of the claims made for wireless, especially considering the environment we would be placing it in. But installation was quick and easy and we just switched them on and they all worked,” said Simon Lark.
Fourteen wireless transmitters have been installed to provide access to flow percentage readings from the new non-intrusive ultrasonic flow meters monitoring different sections of the turbine hall. The wireless devices are transmitting flow measurement data every fifteen seconds to the gateway, situated in the main administration building on the other side of the road from the turbine hall.
“The gateway is situated in a windowless room within the main building. Despite being totally surrounded by brick walls, when switched on the wireless transmitters were all clearly visible and immediately connected to the gateway,” said Simon Lark.
Using an ethernet, the data is sent from the gateway to Emerson’s AMS Suite predictive maintenance software that manages the wireless transmitters and uses its OPC server to import the flow data into the PI data historian. From here, operators view trends and pinpoint where any loss of flow takes place.
The 14 transmitters took around two hours to configure and then less than six hours to fully install in the plant. In contrast a wired solution would have taken between one and two weeks to complete.
“This initial installation of wireless is providing us with valuable experience,” said Chet Mistry. “We are now hoping to be able to use this experience to apply the technology to a range of applications, including accessing valve diagnostic information.”
LAPEM: wireless for temporary thermal efficiency monitoring
Wireless technology is also being employed very successfully by the Laboratory Analysis group (LAPEM) of Mexico’s Federal Electrical Commission (CFE) in helping to determine thermal efficiencies at power generating units throughout Mexico. LAPEM has five analysis teams that set up temporary measurement facilities at each of the 140 power plants, although they cannot cover 100 per cent of the plants due to the time required for each.
In contrast to traditional wired measurements, one team’s easy establishment of a temporary wireless network in power plants made it possible to increase its productivity and plant coverage by 10 per cent. This led to an annual revenue increase of $512 000 for LAPEM. It has also improved the revenue of the CFE by pushing higher output for each plant while reducing costs.
Emerson’s Rosemount wireless transmitters provide access to flow percentage readings from non-intrusive ultrasonic flow meters.
The ease of use and the reliable performance of Emerson’s wireless system resulted in a decision by the Laboratory Analysis group to equip all five of its analytical teams with wireless instrumentation.
Their productivity is expected to increase by another 40 per cent with faster turnaround time between services. As a result, all five teams should perform 25 more assessment services per year, producing an extra $1.375 million annually without adding personnel. Each of the 140 power units can now be visited and analyzed every other year.
“In the past, we could only cover about 50 plants per year,” said Oscar Martinez Mejia of LAPEM. “We needed to reduce turnaround time at each plant in order to reach every plant on a two-year cycle. Smart wireless made it possible for the team equipped with wireless devices to cut their on-site time by one-third, enabling them to complete more services in a year’s time and proving the value of wireless.”
When this group of technicians and engineers arrive at a plant, they install seven to 25 wireless instruments, depending on the size of the unit (350 MW, 300 MW, 160 MW and smaller), plus a gateway to receive key flow, pressure and temperature measurements, which are fed to a thermal efficiency model. The model is used to determine the heat rate of the unit and the efficiency of such equipment as condensers, cooling towers, boilers, turbines and auxiliary equipment as well as energy losses. This information helps the analytical team define problems that a plant needs to correct to maximize production efficiency.
“It takes 15 days to install and commission wired instruments, take the readings and tear down the setup,” Martinez Mejia said. “Then, another week is needed for reporting and other activities before a team can move on to the next plant. In the future, they will be able to cover 75 plants per year, because the onsite work can be done in just ten days using wireless devices.”
Smart wireless self-organizing networks start functioning as soon as the devices are mounted and batteries installed, and this reduces the effort necessary to set up a reliable wireless network in the dense power plant infrastructure, as demonstrated so effectively by the LAPEM team.
Huaneng Dandong, China: wireless in upgrade project
Smart wireless has also been deployed as part of an upgrade project at Unit 1 of the 700 MW power Huaneng Dandong power plant located near the city of Dandong in Liaoning Province, China.
Emerson has updated the controls with its PlantWeb digital plant architecture, migrating its previous-generation WDPF control system to the Ovation expert control system.
The project also includes the deployment of smart wireless technology featuring wireless pressure and temperature transmitters used to measure the cycle water temperature.
Wireless technology is being used extensively in the process industries to help solve common problems and provide access to information that was previously out of economic or technical reach. Now we are seeing how wireless is gaining momentum in the power generation industry as forward-thinking organizations seek out technologies that can help them best achieve their operational and financial objectives.