A case study based on a medium sized hotel, with new plant including CHP.
Whitbread Country Club Hotels - Breadsall Priory Hotel
Highlighting that identification of problems comes before specification of solutions.
Our guarantee - If we are prepared to commit ourselves to a client after initial free consultation and inspection, we will develop, install and commission full monitoring and logging facilities for the site, free of charge. If, after this stage, the potential client rejects our proposals for improved control we will remove the monitoring system and no charge will be made.
Many boiler systems are designed for extreme conditions plus 10% just in case, this leads to significant inefficiencies under normal load conditions. Breadsall Priory was a case in point, but then so are around 80% of all sites. Figure one would normally show a schematic of the system (but we haven't got an image scanner yet). The boilers are Strebel RU2S11 models rated at 721kw (2.4m BTU) each. The system was installed to a good standard in 1989 with sequence control operating on return water temperature and with individual mixing valves on the zones and calorifiers. To all intents and purposes a sound basic system, but with one significant complaint - high fuel consumption.
AEC was commissioned at this stage to monitor the plant and diagnose the symptoms. Temperature sensors were installed on the return and flow headers in the boiler house, in the flues of each boiler and outside for an ambient temperature reading. The readings, together with boiler run times were then monitored and logged in the AEC LOCUS system (which has modem communications which allows remote software maintenance and monitoring). At this stage provision was also made for basic control over boiler firing.
Each boiler recorded twenty two starts in a four hour period, prior to our bringing them under control. The differential between flow and return temperature was less than 4 C and the flow temperature was operating well below its design temperature of 80 C. The return temperature was reacting less than 30 seconds after the flue temperatures started to rise on firing, despite very long flow and return pipework for heating . However, with one boiler alone the system recorded only eight starts in a four hour period.
The system was monitored over a ten day period. During the 240 hours boiler one operated for a period of 110 hours 30 mins and boiler two for 103 hours 54 mins. Overall run time was thus 44%.
A simple control algorithm was developed for boiler two and boiler one was isolated. Over 48 hours boiler one did not run, while boiler two operated 38% of the time. Overall controlled runtime was thus 19% in comparison with the previous 44%.
On this site, monitoring, diagnosis and simple control achieved overall fuel consumption savings in excess of 50% despite a falling ambient temperature.
Our Guarantee - We will normally quote on the basis of a guaranteed minimum saving prior to applying control, or on the basis of proven savings following application of control, failing acceptance we would always remove our systems at no cost to the client. No client has yet chosen this option.
Each site has unique needs and varying potential for further improvements, though many are standard for example in hotels the need for reliable and rapidly varying domestic hot water demands. We will provide full BEMS if warranted and are happy to provide consultancy regarding plant renewal etc.
In the case of Breadsall Priory further improvements have lead to extention to full boilerhouse energy management with a payback within four months of winter operation. Maintenance of the DHWS calorifiers and rebalancing of the system has been undertaken resulting in additional savings through rectification of the return temperature reaction times. The system now operates as designed and any deviation from the design parameters is recorded and can be acted upon. CO2 and NOx emissions have been reduced by over 50% and our relationship with the client continues.
Our Guarantee - All of our systems are now supplied with free parts and labour for ten years subject to a nominal annual maintenance fee. In the case of system failure control reverts to normal operating mode. However, the only microprocessor failure suffered to date followed a direct lightning strike.
We expect to be able to guarantee payback within six months to one year for clients with boilerhouses currently using 15,000 pounds sterling or more of fuel per annum.
Contact us now for an exploratory meeting!
Ring Tony Denny on 01444 892000 or 01825 712800
Or better compete our form for a quick response
This is really neat and using our Locus unit can save buildings with distributed electrical heating
e.g. Motels, Halls of Residence Etc a fortune - But unfortunately this part of our Web is still
"UNDER CONSTRUCTION" why not make a bookmark and call back or better compete our
form for a quick response.
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We have provided a number of complete Building Management Systems and work on a basis
of a measurable payback being available within one year - Otherwise we believe the system is
inefficient or we are - This service has covered a number of parcel sorting offices of a major
parcel handling operation - sadly we haven't yet got their permission to site their name - some
legal stuff - so you'll just have to trust us or better we can arrange an on-site demo or a remote
visit by modem from your desk (which is available) so please complete our form for a quick response.
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We have provided delivered diverse solutions - with PLCs - for example measuring projectile
deformation on impact - these PLCs are fast. There are huge numbers of control applications
which we can provide - limited only by your imagination. To this end we are alpha testing a new
software product which allows object oriented programming of control systems and generates
C code. This works on the Windows95 platform and can be learnt in minutes. In fact we
developed a robust chiller control application in 35 minutes - It took the competition 3 weeks
to achieve a lower spec - bugs and all. If this sounds at all interesting please complete our form for a quick response.
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