National Grid Research
UK
Sine Environmental supported Project Environmental Solutions Limited and National Grid Gas on a number of research projects and subsequent updates to National Grid internal procedures. The research projects were funded under the Ofgem Network Innovation Allowance (NIA) scheme, which can be used by National Grid to fund smaller technical projects directly related to their network which have the potential to deliver financial benefits to National Grid and its customers. To find out more about the research studies and the tools that were developed click on the links below:
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Corrosion under pipework noise insulation
The challenge of corrosion under insulation (CUI) for above ground steel pipework has been long recognised by National Grid. Above ground pipework can represent a significant source of noise from above ground installations (AGIs) and in particular compressor installations. To reduce this noise insulation is frequently installed on exposed pipework. Unfortunately moisture can collect under the noise insulation and cause premature damage to the pipework. This study looked at recent technological developments in acoustic insulation products such as closed cell elastomeric foam, constrained layer damping, aerogels and viscoelastic polymers, as well as method of reducing noise within pipework as an alternative to acoustic insulation. The review focused on the materials’ acoustic properties, ability to prevent corrosion, ease of installation/inspection, lifespan and value for money. A toolkit has been developed which enables those specifying noise control products to determine the Best Available Technique (BAT) for a given situation, and the National Grid pipework cladding management procedure T/PM/PWC/10 was subsequently updated to reflect this emerging best practice.
Compressor cabinet noise study
(NGGT0112 Noise Mitigation Tool)
Noise produced by gas compressors can cause disturbance at neighbouring properties, and in some cases can lead to adverse health effects such as annoyance and sleep disturbance. Noise emissions are frequently a major factor in the design of compressor stations, but there are few resources which compare the noise performance of different approaches to compressor cab designs. Recent experience of National Grid is that bespoke noise mitigation measures have added significant cost and complexity to projects that was not initially identified in the project plans.
This research conducted interviews with representatives from National Grid OEM suppliers to find out how reducing noise emissions at source influenced their design processes for turbines, compressors and ancillary equipment. A database of compressor train noise sources and standard noise abatement packages was collated, enabling typical equipment noise emissions to be determined early in the feasibility stages of a project.
The study modelled three common compressor cab configurations using identical compressor train noise data to see how the cab configuration and associated ventilation arrangements affects noise emissions.
The outcome of these activities is a preferred cab configuration in respect of noise, and a repository of information which will enable early estimates of noise emissions and necessary noise control measures to be identified early in the project feasibility phase. The study identified updates that could be made to existing tender documents and specifications, plus new tools that could be developed to support the design of future gas compressor cabs.