NOxProtekt had been employed by their client Power Electrics to reduce the emissions of the engine to below that of the requirements of the Medium Combustion Plant Directive, and the Environmental Permitting Regulations for England and Wales 2018, for this critical generator application at a NHS hospital facility. Whilst NOxProtekt have a history of treating both new and existing diesel and gas engines for NOx reduction there is usually a set of data for both emissions output, exhaust flow and engine characteristics, however it was not the case when they were asked to look at this application the information was very limited given the age of the initial installation.

There was the added complexity of the special exhaust system and flue run within the installation, and the fact that these engines are historically referred to as a “dirty engine”, even by the Ministry Of Defence whom utilise the smaller variant of the engine in the Challenger Tank. (Engine production in Shrewsbury of 3000 series engines by MOD since 2002 (approx.)

NOxProtekt approached RODEng Consulting for assistance for our experience of these engines with two members of staff whom spent a combined 15??? years of testing and validation of generator packages with this specific family of engines, and the Managing Partner having worked on Torsional Vibration Analysis and viscous damper selection on this very engine model some 22 years ago which formed the basis of a paper he had written for his Chartership final engineering report to the Institute of Mechanical Engineers (IMechE).

Given RODEng history with this engine family we had the specific engine data sheets with flow rate, energy balance, consumption and emissions data for the specification of the same build age of engine.

The project also brought specific challenges for selection and installation of the equipment given the limited space available within the existing compact generator room with high levels of attenuation within a limited height space.

With collaborative design phase RODEng were able to assist NOxProtekt with the sizing and selection of the interconnecting pipework, rector and transition sections to enable laminar flow to the reactor surfaces whilst limiting resistance to flow and all while enhancing catalyst reaction to maximum conversion of NO & NO2. RODEng employed both theoretical and practical elements of design to consider the thermal expansion, fluid flow dynamics, vibration isolation and acoustic characteristics to ensure the project met its performance requirements for emissions reduction, whilst meeting the acoustic requirements of the project and all while maintaining engine full load performance and cooling to the generators original/existing? condition.

Through the management of structural, mechanical and electrical design phases RODEng were able to deliver a full design package to allow NOxProtekt to deliver and install a fully compliant SCR system with minimal interruption/disturbance to the critical function of the backup generation to the NHS Trust. Through the management of planned changeover to short term temporary power to the hospital site in association with Power Electrics.

In January 2021 NOxProtekt completed the successful commissioning of this SCR System to meet the requirements of the Environmental Permitting Regulations for England and Wales (2018) and the MCPD (Medium Combustion Plant Directive), and to emissions levels of less than 190mg/Nm3 @ 15% O2. Along with another newer FG Wilson P715-1 generator at a different/separate location on the same site.

The successful commissioning and validation of the SCR project is proof that with proper Engineering processes and application consideration even older higher emissions engine models can be successfully mitigated to the most stringent emissions requirements with professional high quality catalyst selection and application/engineering/smarts??? Blah, blah, blah.

NOxProtekt are due to attend site to complete the commissioning of another FG Wilson 2,200kVA (Perkins 4016 TAG2A) Generator in February as the final phase of the works on this NHS Site.

RODEng Consulting LLP are a partner of NOxProtekt Ltd, and provide Mechcanical, Electiral, Control and Civil works design and installation phase assistance to assist in NOxProtekt SCR installations.