We were approached by our customer, a manufacturer and supplier of sugar, aggregates, tomatoes, animal feed, Bioethanol, TOPSOIL and LimeX in addition to generating electricity, to survey the original control equipment and recommend improvements to reliability issues. Of the large number of British Sugar factories, those used within the production of electricity use a combined heat and power generation system that produces steam and electricity used to power its factories and the excess, approximately 50MWh per factory is exported to the grid and sold to electricity supply companies.
During 2010 and 2011, one of the turbines tripped and shutdown many times causing major problems across the production processes. Our customer therefore sought a significant increase in reliability.
The requirements for the new system, conveyed to us by British Sugar consist of the removal of the existing ten year old Woodwood 505 governor system and its associated hydraulic pipework and valves, and replacing with the new Woodwood 505 and CPCII mounted in purpose built panel, the CPC-II offers far great reliability than that of the originally installed CPC-I. We would also be fitting a HMI505 view for remote control and monitoring. The original Dr Horn over speed equipment became unreliable, thus was replaced with the Woodward Protech TPS over speed module.
To complete this project, engineers Jon, Karl and Chris attended site to record all information and measurements necessary for us to install the new 505 panel and CPC-II system. Our Technician Kevin worked on the cabinet at our works.
Technician Chris attended site to fit the CPC-II and complete all pipework. The original CPC bracket was in poor condition consisting of a plastic box which was worn and broken. We designed and made a new bracket for the CPC-II which was moved back to make space for the new, much more robust bracket, far more suitable for the design.
Upon completion of the all remaining elements to the British sugar upgrade, the final stage consisted of comprehensive functional testing of all components to the set, emergency stop tests, overspeed trip testing and a final testing of the turbine onload.
The ProTech TPS was tested to ensure it functioned correctly. The TPS is a 2 out of 3 system in which there are three independent modules; if any two give the same value it results in a functional output. If one module fails therefore, the system can still function and an alert of the failed module will be issued. The correct functioning of the three dual MPUs was also tested to ensure all three read correctly with the turbine turning over an electric motor at 263 RPM.
We also tested the 505 overspeed trip and the mechanical overspeed trip. The CPC-II (Current to Pressure Converter) was the final module to be tested. It is wired to the 505 control that positions the steam inlet valve to desired position depending on speed and load. All data is feeds back to the HMI enabling the status of equipment to be monitored.
Lastly we ensure a final testing of the turbine onload took place, which generated MW and exported 4MW to the National Grid. The final test was very successful and stable.