(19)
(11) EP 2 392 825 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
21.12.2011 Bulletin 2011/51

(43) Date of publication A2:
07.12.2011 Bulletin 2011/49

(21) Application number: 11166316.7

(22) Date of filing: 17.05.2011
(51) International Patent Classification (IPC): 
F04B 49/00(2006.01)
F04B 25/00(2006.01)
F04B 49/10(2006.01)
 F17C 9/02(2006.01)
F04B 49/06(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 RS SE SI SK SM TR
Designated Extension States:
BA ME

(30) Priority: 07.06.2010 JP 2010129956

(71) Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
Kobe-shi, Hyogo 651-8585 (JP)

(72) Inventors:
  • Takagi, Hitoshi
    Takasago-shi, Hyogo 676-8670 (JP)
  • Nagura, Kenji
    Takasago-shi, Hyogo 676-8670 (JP)

(74) Representative: TBK 
Bavariaring 4-6
80336 München
80336 München (DE)

   


(54) Method for controlling the operation of a multistage boil-off gas (BOG) compressor


(57) Method for controlling the operation of a BOG multistage compressor (8) including plural stages of compression sections (9,10), which are connected with each other, for compressing boil-off gas (BOG) generated from liquefied natural gas. The method comprises, in case of a predetermined condition, making a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section (load ratio) smaller than load ratios in case of conditions other than the predetermined condition. The said predetermined condition is, either a condition where the suction temperature of the low pressure stage compression section (9) is not lower than a first preset temperature, or a condition where the discharge temperature of the low pressure stage compression section (9) is not lower than a second preset temperature. This control method prevents the temperature of the low pressure stage compression section (9) from exceeding a maximum allowable temperature.







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