A look at how the theory of wireless technology is put into practice
Wireless technology can be seen in everyday use in personal communications, whether that’s mobile phones or computer accessories. But industrial wireless applications, originally stemming from the need to have real-time control over a network system, are still developing.
Industries, especially process industries, have yet to take full advantage of wireless technology’s ability to improve production and security, minimize costs and extend the lifetime of new and existing equipment.
In fact, wireless instrument technology – based on radio signal rather than hard-wired communication – has aroused as much interest as it has skepticism. There are questions about the reliability and security of wireless networks. However, the reduced installation costs it represents and the potential for improved cost effectiveness are tempting to most industries.
The list of requirements then is clear. For wireless technology to really take hold in an industrial setting it needs to be robust, reliable, cost effective and totally secure.
So if wireless is the new frontier of optimisation and safety, how is it being applied? UME takes a look at two examples of real world applications.
Provides employees in the field with secure roaming access to real-time control systems, enterprise applications, documents, and other information via wireless hand-held devices and hardened Mil Spec and NEMA 4-rated tablet personal computers.
Field Data Logging
Enables personnel to quickly and accurately upload device and equipment status and diagnostic data to maintenance systems from the field.
Provides a means to accurately identify physical location of personnel in real time, notify first responders of safety shower activation, provide ‘man-down’ notification for emergency services, and remote evacuation alarming.
Uses RFID technology to provide identification and location of fixed and rolling assets with optional visualisation on a hand-held device.
Wireless technology can provide the flexibility to implement any combination of mobile video, fixed surveillance cameras, intrusion detectors, and proximity sensors as required to cost-effectively extend the reach of physical security throughout a building, plant, or even an entire complex.
Wireless connection to remote sensors provides incremental measurements (tank levels, temperatures, pH, vibration, flow etc.) to provide a richer real-time database. this can be used to support highly effective model-based predictive maintenance strategies.
Provides secure integration of multiple wireless technologies (including both VoIP and high-speed back haul communications) to connect people, facilities, and systems in a cost-effective and reliable manner.
CASE STUDY: FLOW
Wireless technology from Emerson has allowed power generation company E.ON UK to monitor and measure the use of the treated water at its Kingsnorth dual-fired power station.
Wireless transmitters in a self-organising network are used to pinpoint water usage using flow data, allowing trending and analysis to formulate target values. The project uses Emerson’s Rosemount wireless transmitters to collect the flow measurement data from flowmeters installed throughout the turbine hall.
E.ON Kingsnorth, a 1 940 MW generating, needed a way 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 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 UK.
Initially the technology was trialed to establish the viability of its use in the environment of the turbine hall. A long transmitting distance, reliability and the ability to add additional devices to the network, without the need for more infrastructure, all contributed to the trials success.
The turbine hall at Kingsnorth is around 500 m long and presents a difficult working environment for wireless, as it houses large turbines, vast amounts of metal piping and a number of metal walkways that could interfere with the signal. Such an environment would not be suitable for a line of sight solution.
“We have great confidence in the technology. The self-organising network 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.
The ‘self-organising’ technology allows each wireless device to 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 construction trailer, these wireless networks simply reorganise and find a way to get their signals through.
All of this happens automatically, without any involvement by the user. This self-organising technology optimises data reliability while minimising power consumption.
“We were initially a little skeptical of the claims made for wireless, especially considering the environment. But installation was quick and easy and we just switched them on and they all worked,” said Lark.
Fourteen Rosemount 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 Rosemount wireless transmitters are transmitting flow measurement data every fifteen seconds to an Emerson Smart Wireless 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 Lark.
The fourteen transmitters took around two hours to configure and then less than six hours to install. 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.”
CASE STUDY: VIBRATION
According to a US Energy Information Association study, operating costs at refineries represent approximately 23% of the gross margin. Maintenance expense is responsible for 24% of those operating costs.
Condition based maintenance programmes have the potential to reduce maintenance costs by 15%.
In the past, purchasing a machine condition monitoring system for essential or general-purpose machinery required a large initial commitment and investment from the customer. Most customers monitor ‘essential’ and ‘general purpose’ equipment with manual data collection programmes and portable instruments.
Over the past 15 to 20 years, however, maintenance and reliability experts have not always been able to meet their objectives using this methodology on machinery that fell into the ‘essential assets’ category.
In order to reach the reliability associated with a continuous scanning system, a large amount of field wiring had to be installed to transmit the signal to the data acquisition computer.
Companies that used a portable data collector on ‘essential’ and ‘general purpose’ assets had a much smaller initial hardware cost, but a much more considerable human resource expense. In order to take readings at scheduled frequencies, plants would need to commit personnel and a significant time commitment.
This commitment became more acute for remote machines or machines installed in hazardous locations or those located in areas that were not readily accessible.
GE Energy’s Bently Nevada Essential Insight.mes system was developed to address these issues. The facilities where this technology was prototyped, and later proven, are some of the most difficult anywhere, combining extremely challenging environments for radio frequency (RF) communication interference and aggressive chemical and atmospheric conditions. This ability provided customer confidence that the system is robust, reliable, and field-proven.
The technology has the potential to remotely monitor rotating equipment, where using handheld monitors is dangerous or difficult and has been further tested at ‘Uthmaniyah Gas-Oil Separation Plant-10 (UGOSP-10)’.
In the South Ghawar Producing Department (SGPD), the trial was conducted on the UGOSP’s air-compressor motors to monitor vibration, a key indicator of the equipment’s status. The trial was used to test the wireless sensor technology for its effectiveness in predictive maintenance and its feasibility.
“The trial highlights SGPD’s continuous efforts to capitalise on new technologies to improve plant reliability and optimise operational costs,” said a member of the South Ghawar Engineering Division team.
The Essential Insight.mesh system, while not designed for continuous real-time monitoring, is suited for use where it would be difficult or dangerous to monitor with handheld data collectors, or where frequent samplings are required. Cost savings are expected over hard-wired systems with similar diagnostic features.
In most instances, the wireless technology can be installed and commissioned with no interruption in plant operations. The wireless sensor network is battery-powered and can be configured to measure vibration or temperature.
The setup at Uthmaniyah GOSP-10 involved five sensors, a wireless network gateway and a laptop.
Magnetically mounted vibration sensors were installed on two air-compressor motors. The remaining sensors were used as repeaters in locations throughout the plant to set up the mesh network architecture and to strengthen the signals. The laptop and wireless network receiver were installed in a room over 75 ms from the air compressors.
The trial equipment operated unattended for four weeks. Engineers concluded that the wireless monitoring technology is a feasible alternative to handheld or hardwired monitoring. The instrument engineer leading the trial commented: “A wireless monitoring system like this is particularly attractive for essential machines, which demand a more frequent monitoring rate than a portable system can deliver.”