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Who
A combined Babcock-Ministry of Defence team has introduced a technology-based energy-saving initiative at the Devonport shipyard in Plymouth, generating savings of £335,000.
Technology
Key to these energy savings have been efficiency improvements to the steam system used to heat the majority of buildings on the Devonport site. The system uses steam generated by two boiler houses and distributed through 10km of pressurised steam pipes. A review found opportunities to improve efficiency and reduce gas usage in the boiler.
Five goals were identified: producing steam with as little input fuel as possible; distributing steam with minimal heat loss; controlling steam demand in buildings; ensuring minimal loss of water and heat when condensed steam is returned to the boilers and ensuring the steam distribution system is correctly sized.
Boiler economisers have been reinstated so that exhaust gas is diverted to pre-heat the feed water going into the boilers. That results in less gas being needed for heating the water in the boiler and is expected to generate savings of £100,000 this winter.
Insulating lagging on the steam distribution pipes has been renewed, reducing heat loss and generating savings in the region of £75,000. New steam traps have been installed, enabling condensed steam to be bled from the steam main and recycled for re-use in the boiler, resulting in £50,000 savings.
New computer systems and valves have been installed to control the heating in 10 buildings for “intelligent” heating (gauged to outside temperature and building occupancy) and saving £60,000 a year, it is estimated.
Finally, a full site survey has been undertaken and disused sections of steam mains and redundant lengths of pipework have been disconnected, producing savings of a further £50,000.
Application
Similar ventures are being undertaken by multi-functional Babcock/MoD teams in lighting and motor controls. They are also working with local councils to address waste disposal issues and with one of the bidders on a proposed combined heat and power (CHP) plant for the Devonport site. The CHP project would build and operate an energy-from-waste plant that converts household waste into a cost-effective, environmentally friendly alternative energy supply.