The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 21, 2020
Filed:
Mar. 14, 2014
Daikin Applied Americas Inc., Minneapolis, MN (US);
Nobuhiro Umeda, Fishersville, VA (US);
Takatoshi Takigawa, St Louis Park, MN (US);
Fumiaki Onodera, Minnetonka, MN (US);
Nobutoshi Kozono, Osaka, JP;
DAIKIN APPLIED AMERICAS INC., Minneapolis, MN (US);
Abstract
A refrigerating apparatus includes a centrifugal compressor, suction and discharge capacity control mechanisms that control capacity of the compressor by changing opening degrees of the suction and discharge capacity control mechanisms, and a controller that compares a compressor-specific surge curve with an isentropic head to perform rotational speed control of the compressor, rotational speed adjustment control of the compressor in order to avoid surge, and emergency shutdown control of the compressor upon detection of surge. The compressor-specific surge curve is stored in the controller in advance, and is defined by an actual rotational speed of the compressor and opening degrees of the suction and discharge capacity control mechanisms. The isentropic head is calculated based on a suction pressure, a discharge pressure, and a suction temperature during operation.