Nobuhiro Umeda

20100326130, Dec 30, 2010

Jan 30, 2009

12/865580

Yasutaka Takada - Osaka, JP
Nobuhiro Umeda - Minneapolis MN, US
Kenji Kinokami - Osaka, JP

F25B 1/10
F25D 11/00

62510, 62430

An economizer () is provided in a multistage compression refrigeration system including a refrigerant circuit in which a multistage compressor, a condenser, a multistage expansion mechanism, and an evaporator are sequentially connected. The economizer () includes: a tank () having an introducing portion () for introducing a refrigerant of the refrigerant circuit, a liquid outlet () for guiding a liquid refrigerant into the evaporator, and a gas outlet () for guiding a gas refrigerant into a medium pressure portion of the multistage compressor; and a float expansion valve (), which forms part of the multistage expansion mechanism and is attached to the liquid outlet (), and whose throttle amount is adjusted according to a level of the liquid refrigerant in the tank (). Multiple ones of the liquid outlet () and multiple ones of the float expansion valve () are provided.

20170097005, Apr 6, 2017

Oct 2, 2015

14/873671

- Minneapolis MN, US
Nobuhiro Umeda - Plymouth MN, US
Takatoshi Takigawa - St. Louis Park MN, US

F04D 27/02
F04D 25/06
F04D 27/00
F04D 29/28
F25B 1/04
F04D 29/44
F04D 29/058
F04D 29/052
F04D 29/05
F04D 17/10
F04D 29/42

A centrifugal compressor for a chiller includes a casing, an inlet guide vane, an impeller downstream of the inlet guide vane, a motor and a diffuser. The casing has inlet and outlet portions with the inlet guide vane disposed in the inlet portion. The impeller is rotatable about a rotation axis defining an axial direction, and the impeller is adjustably mounted within the casing along the axial direction between at least a first flow rate position and a second flow rate position. The motor rotates the impeller. The diffuser is disposed in the outlet portion downstream from the impeller with a outlet port of the outlet portion being disposed between the impeller and the diffuser.

20170097006, Apr 6, 2017

Oct 2, 2015

14/873573

- Minneapolis MN, US
Nobuhiro Umeda - Plymouth MN, US
Takatoshi Takigawa - St. Louis Park MN, US

F04D 27/02
F25B 31/02
F04D 17/10
F25B 1/053
F04D 27/00
F04D 29/058

A centrifugal compressor for a chiller includes a casing, an inlet guide vane, an impeller downstream of the inlet guide vane, a rotational magnetic bearing, a magnetic bearing sensor, a motor, a diffuser and a controller. The casing has inlet and outlet portions with the inlet guide vane disposed in the inlet portion. The impeller is attached to a shaft. The radial magnetic bearing rotatably supports the shaft. The magnetic bearing sensor detects at least one of a position signal indicative of the shaft's position and a current signal indicative of current supplied to the magnetic bearing. The motor rotates the shaft in order to rotate the impeller. The diffuser is disposed in the outlet portion downstream from the impeller. An outlet port of the outlet portion is disposed between the impeller and the diffuser. The controller is programmed to predict surge based on the position signal and/or the current signal.