(19)
(11) EP 2 348 196 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
Note: Bibliography reflects the latest situation

(15) Correction information:
Corrected version no 1 (W1 A2)

(48) Corrigendum issued on:
28.09.2011 Bulletin 2011/39

(43) Date of publication:
27.07.2011 Bulletin 2011/30

(21) Application number: 10173147.9

(22) Date of filing: 18.08.2010
(51) International Patent Classification (IPC): 
F01K 7/34(2006.01)
F22D 1/28(2006.01)
F01D 1/28(2006.01)
 F01K 13/02(2006.01)
F01D 21/14(2006.01)
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR
Designated Extension States:
BA ME RS

(30) Priority: 18.08.2009 JP 2009189423

(71) Applicant: Hitachi Ltd.
Tokyo 100-8280 (JP)

(72) Inventors:
  • Hirakawa, Yosuke
    Tokyo 100-8220 (JP)
  • Sudo, Mitsuru
    Tokyo 100-8220 (JP)
  • Hiraga, Ichiro
    Tokyo 100-8220 (JP)
  • Teranishi, Tsugutomo
    Ibaraki (JP)

(74) Representative: MERH-IP Matias Erny Reichl Hoffmann 
Paul-Heyse-Strasse 29
80336 München
80336 München (DE)

   


(54) Turbine protection device and method for controlling a steam turbine


(57) An object of the present invention is to provide a turbine protection device which can interrupt steam flowing backward from a deaerator (5) to a turbine (2) completely even if a check valve (3a) provided between the deaerator (5) and the turbine (2) can not interrupt the steam flowing between the deaerator (5) and the turbine (2) completely. In order to achieve the above object, a control unit (11) sends commands to a shutdown valve device (12) so as to close the shutdown valve device (12) when a differential pressure resulted from subtracting a pressure of a extraction steam from a pressure within the deaerator (5) becomes equal to or greater than a first predetermined value. As a result, the steam flowing backward from the deaerator (5) to the turbine (2) is interrupted by a stop valve of the shutdown valve device (12).