?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F240%2F&rft.title=Freeze+protection+in+gasholders&rft.creator=Hewitt%2C+Ian&rft.creator=Taroni%2C+Michele&rft.creator=Slim%2C+Anja&rft.creator=Byatt-Smith%2C+John&rft.creator=Ockendon%2C+John&rft.creator=Howell%2C+Peter&rft.creator=Bauer%2C+Robert&rft.creator=Somani%2C+Sapna&rft.creator=Blyth%2C+Mark&rft.creator=Parau%2C+Emilian&rft.creator=Purvis%2C+Richard&rft.creator=Parker%2C+David&rft.creator=Hjorth%2C+Poul&rft.creator=Duursma%2C+Gail&rft.subject=Energy+and+utilities&rft.subject=None%2FOther&rft.description=In+cold+weather%2C+the+water+seals+of+gasholders+need+protection+from+freezing+to+avoid+compromising+the+seal.+These+holders+have+a+large+reservoir+of+%22tank+water%22+at+the+base+which+is+below+ground.+At+present+freeze-protection+is+achieved+by+external+heating+of+the+seal+water+which+is+in+a+slotted+channel+called+a+cup.+Electrical+heating+or+circulation+of+heated+tank+water+to+the+cup+are+examples+of+systems+presently+used.%0D%0A%0D%0AThe+tank+water+has+a+large+thermal+capacity+and+National+Grid+wishes+to+investigate+whether+circulation+of+the+tank+water+without+external+heating+could+provide+sufficient+energy+input+to+avoid+freezing.+Only+tanks+in+which+the+tank+water+is+below+ground+are+investigated+in+the+report.+The+soil+temperature+under+the+reservoir+at+depth+of+10m+and+lower+is+almost+constant.&rft.date=2008&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F240%2F1%2FNationalGrid-FreezeProtectionInGasholders.pdf&rft.identifier=++Hewitt%2C+Ian+and+Taroni%2C+Michele+and+Slim%2C+Anja+and+Byatt-Smith%2C+John+and+Ockendon%2C+John+and+Howell%2C+Peter+and+Bauer%2C+Robert+and+Somani%2C+Sapna+and+Blyth%2C+Mark+and+Parau%2C+Emilian+and+Purvis%2C+Richard+and+Parker%2C+David+and+Hjorth%2C+Poul+and+Duursma%2C+Gail++(2008)+Freeze+protection+in+gasholders.++%5BStudy+Group+Report%5D+++++