Just a few decades ago, the water industry was not automated at all, but as technology has progressed so has the adoption of automation technology
By the 1990s many medium and pumping stations had installed SCADA (Supervisory Control and Data Acquisition) systems and there was a definite increase in efficiency.
However, engineers realised that there was still a lot of work to do and spent the noughties networking the various SCADA systems together. Huge amounts of data were being collected and transmitted to the head office computer systems but this did not create the step change in efficiency that many expected.
It was eventually realised that head office was not actually using much of this extra data. So now, a new concept is emerging. The idea is to let the users develop their own sub-systems and create an architecture that builds capability rather than warehouses data.
Scottish Water is rolling out a new system across the Highlands and Islands. Expressed in the simplest terms, field engineers who visit very remote sites are filing records on tablet PCs rather than on paper, but the deeper strategy is building a digital platform that will eventually network the whole organisation and all of its functions.
"We have run a pilot at over a hundred sites,” says Sheila Campbell-Lloyd, Waste Water Operations Manager for the North region. "With the old paper system, central records could be months out of date. Currently the graphics on the tablet PCs are similar to the old charts and everybody has really taken to them. They are collecting the same data and the software is producing reports on process results, task schedules, maintenance, energy, health and safety and environmental parameters.”
With plug-and-go technology this is perfectly achievable, as Jeremy Shinton of Mitsubishi Electric explained at the November 2012 Conference Driving Innovations in the Water Industry. "Manufacturing Enterprise Systems connect real time technical data into high level business systems and they are simple to implement using modular PLCs, such as Mitsubishi’s Q Series.”
Standard analytical softwaretools can then convert the raw data into reports, each formatted appropriately for the intended user. Once the data is transferred to head office, it is integrated with data from other pumping stations to produce management level reports.
LOW PRESSURE BLOWERS FOR AERATION
Anglian Water has chosen Atlas Copco’s low-pressure ZS blowers to supply air to the aeration diffusers at four of its wastewater treatment re-development sites. A total of 22 Atlas Copco ZS90 rotary screw blowers will be installed at the sites in Colchester, Letchworth, Bedford and Flag Fen (near Peterborough) as part of Anglian Water’s initiative to find innovative ways of reducing its energy costs.
Wastewater treatment plants use bacteria to break up waste which requires large quantities of air to be blown into aeration tanks. In a typical biological wastewater treatment plant, the blower system will account for up to 70% of energy usage. Anglian Water approached Hydrok, an aeration diffuser and IFAS specialist, about supplying submerged, high-efficiency, bubble aeration framework systems incorporating bio textile curtains and fixed bed media. These units improve the distribution of aeration air to maintain the desired level of dissolved oxygen within the wastewater containment system.
Hydrok matched their high efficiency diffuser technology with Atlas Copco ZS low pressure screw blowers, which make energy cost savings of up to 35% possible, for optimum performance.
IN WASTEWATER TREATMENT PLANTS, PROCESS VALVES ARE OFTEN ACTUATED ONLY INFREQUENTLY OR NOT AT ALL FOR LONG PERIODS OF TIME
In wastewater treatment plants, process valves are often actuated only infrequently or not at all for long periods of time. This leads to deposits and caking and thus to increased breakaway torques or forces. Pneumatic actuators can overcome this problem simply by increasing the air pressure; they also only require electricity for regulating and generating compressed air and act directly on the shut-off valve.
In Sindelfingen, Germany, the process valves with their pneumatic valve actuators DLP and DRD from Festo are distributed throughout the entire plant, sometimes in locations that are not easily accessible. There are six centrifugal pumps in the pumping cellar. Before pneumatic automation, the non-return valves had to be held open continuously via the pumps. This lowered the delivery rate by up to 10%. Now the new pneumatic automation of the existing knife gate valves has fully replaced the functionality of all non-return valves and thus increased operational reliability.
The Sindelfingen wastewater treatment plant now achieves the same pump delivery rate as before with significantly lower energy consumption, saving 89,469 kWh or €11,300 on energy costs per year.
Manganese exists in well water as a naturally occurring groundwater mineral, but may also be present due to underground pollution caused by industrial activity. Though the maximum allowed manganese concentration in tap water is 0.4mg/l, the colour, odour or taste may become noticeable in tap water at 0.05mg/l.
A manganese removal system for a water treatment plant in Indonesia using the (National Instruments) NI Developer Suite and NI CompactRIO hardware to develop a full SCADA system, features static and dynamic animation, an alarm log, real-time and historical data trending, a tabular database, setting parameters, and user-level security. There are two processes on the filter tank that run simultaneously: filtration and chemical injection.
"To optimise the control of the manganese removal system, we proposed developing an automation system using an NI cRIO-9073 real-time controller and a SCADA system based on LabVIEW,” said Thomas Ari Negara, of CV.Berkat Anugerah.
Just as the sophistication of automation systems in the water industry is increasing, so too in other utilities, leading to the term "Smart Grid". Generally speaking, the term "smart grid” refers to an advanced state of utility system infrastructure, operation, and processes. The smart grid advances the level of intelligence in a utility’s operation to include not only traditional "grid” aspects of the field, but also enterprise systems and processes such as CIS, work management, rates, and other future applications.
Smart grids vary in sophistication and intelligence levels and somewhat dependent on the utility’s present infrastructure, application needs, and vision.
The common themes of any smart grid design include:
- Automatic collection of datafrom multiple applications throughout the utility network, including end user premises. While the smartest grids will include end-user premises, this is not a prerequisite for a smarter grid.
- Adaptive integrated communication media that can handle data from multiple applications located throughout the utility infrastructure.
- Integration of application software suites so they share collected data in common dynamic databases.
One of the consequences of Smart Grids is an aggressive movement to retire proprietary SCADA protocols and replace them with DNP3 or IEC 61850, with Ethernet interfaces and TCP/IP, sometimes built with future applications in mind, such as a high speed backbone and mobile radio system.
FAULT LEVEL MONITORING
Outram Research, a specialist manufacturer of power quality monitors and analysers, is conducting trials with Scottish Power Energy Networks (SPEN) and Western Power Distribution (WPD) to test and validate an entirely original method to determine peak fault current on the electrical network.
The Outram Fault Level Monitor (FLM), which predicts the RMS and peak fault current by passively monitoring disturbances on the transmission and distribution networks during normal operation, is a more cost- effective and potentially more accurate approach than existing methods. The compact device allows users to take measurements on the live network and calculate a fault level value at that measurement point using both upstream and downstream information. The user is presented with a full fault level overview including real time fault level predictions, the trend and average values over a time period such as 30 minutes.
To date, the results are within 5% of the values produced by computer modelling, which has previously generated the most accurate fault level calculations available.
"The possibility of having an instrument that predicts the value of the maximum fault level on their networks, at every voltage level, is generating much interest among Distribution Network Operators (DNOs). The Outram FLM is the size of a lunchbox, so can be deployed quickly and easily and moved from site to site by a single engineer,” said John Outram managing director of Outram Research.
POWER STATION DCS UPGRADE
Keadby Power Station, at Scunthorpe in North Lincolnshire, began commercial operation in 1996 and is a 720-megawatt combined-cycle gas turbine generating facility.
When SSE management realized the facility’s Distributed Control System was approaching plant-wide obsolescence, the company chose Invensys Operations Management to upgrade the plant to a more flexible, scalable, and supportable solution.
"Although the existing system had been reliable in the past, problems were emerging,” said Hugh Ferguson, C&I engineer at Keadby Power Station and project manager for the DCS upgrade project. "An increasing number of components were either no longer available or no longer repairable. Plus, controller memory was near capacity and most of the data highway bandwidth was already utilized.”
Invensys Operations Management was selected because of its proven plug-in I/O card migration for the Westinghouse WDPF distributed control system, in-house simulation capabilities and the incorporation of a model- based plant simulator for application software testing and operator training. Invensys also demonstrated an extensive track record for supporting the Foxboro I/A Series Distributed Control System, a key component of the Invensys InFusion Enterprise Control System.
Eaton has launched an extendable single panel version of its Xiria switchgear range for Medium Voltage (MV) distribution networks. The Xiria E has been specifically developed for distribution substations for utilities and larger commercial and industrial applications, and enables easy and economical MV
switchgear configuration to meet the user’s exact requirements
The modular single panel can be extended with a simple coupling connection offering maximum flexibility and enabling easy future extension of secondary switchgear systems.
Xiria switchgear is designed around Eaton’s proven vacuum interrupters and solid insulation, technologies which provide an alternative to switchgear systems using Sulphur Hexafluoride (SF6) gas for insulation. The cost of ownership is also significantly reduced as no regular testing of gas pressure or other routine maintenance is needed and there is no end-of-life disposal cost.
AUTOMATIC VOLTAGE REGULATOR UPGRADE
ABB has won an order to supply a Dual Channel Automatic Voltage Regulator (AVR) for Eggborough Power Limited’s coal-fired power station in Goole, East Yorkshire.
The coal-fired plant first came on line in 1967 and became an independent business in 2010. From the 1990s to the present day,
a number of upgrades have been undertaken to improve environmental performance and to replace major components with more efficient modern designs. This now includes the upgrading of the power station’s AVRs.
ABB is manufacturing a complete replacement for the existing AVR equipment, based on its Unitrol 6080 Automatic Voltage Regulators with dual Auto channels and dual power converters replacing one of the existing single channel AVR units, whilst retaining the rotating exciters.
The Excitation Control Terminal and the Ethernet connection with OPC protocol are further options that allow simplified operation, monitoring and maintenance of the new Excitation System.
- Users are developing their own sub-systems and creating architectures that build capability rather than warehouse data
- Atlas Copco low-pressure ZS blowers supply air to aeration diffusers at wastewater treatment re- development sites
- Outram Fault Level Monitor (FLM) predicts the RMS and peak fault current on the electrical network