(19)
(11) EP 1 914 493 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
08.06.2011 Bulletin 2011/23

(43) Date of publication A2:
23.04.2008 Bulletin 2008/17

(21) Application number: 07118087.1

(22) Date of filing: 09.10.2007
(51) International Patent Classification (IPC): 
F25B 31/00(2006.01)
F25B 13/00(2006.01)
 F25B 49/02(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR
Designated Extension States:
AL BA HR MK RS

(30) Priority: 11.10.2006 JP 2006277481

(71) Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
Tokyo 108-8215 (JP)

(72) Inventors:
  • Watanabe, Satoshi
    1, Aza Takamichi, Iwatsuka-cho, Nakamura-ku Nagoya Aichi 453-8515 (JP)
  • Maeno, Masashi
    1, Aza Takamichi, Iwatsuka-cho, Nakamura-ku Nagoya Aichi 453-8515 (JP)
  • Isozumi, Shinichi
    3-1, Asahi, Nishibiwajima-cho Kiyosu Aichi 452-8561 (JP)
  • Mitoma, Keisuke
    3-1, Asahi, Nishibiwajima-cho Kiyosu Aichi 452-8561 (JP)

(74) Representative: Bongiovanni, Simone et al
STUDIO TORTA Via Viotti 9
10121 Torino
10121 Torino (IT)

   


(54) Air-conditioning apparatus


(57) An air-conditioning apparatus (1) capable of reliably recovering lubricant accumulated in indoor units (3A,3B,3C) and their refrigerant circuit, regardless of the refrigerant-pipe length differences of the indoor units connected to each other, has been desired, and includes an operating unit (22) configured to carry out liquid return at each indoor unit, to carry out an oil-recovery operation for recovering lubricant accumulated in the refrigerant circuit, and to complete the oil-recovery operation when liquid return is detected at the outdoor unit (2). The operating unit includes a detecting unit configured to detect the refrigerant pipe length of each of the indoor units, a storing unit configured to store the refrigerant pipe lengths detected by the detecting unit, and a control unit configured to change the operation time during the oil-recovery operation on the basis of the refrigerant pipe length of each of the indoor units stored in the storing unit.







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