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:
Sep. 01, 1987
Filed:
Nov. 21, 1985
Doyoung Han, North Syracuse, NY (US);
Merle A Renaud, Onalaska, WI (US);
American Standard Inc., New York, NY (US);
Abstract
A control and method for varying the capacity of a centrifugal chiller system used to cool a liquid to a setpoint temperature. The control permits the user to select the setpoint, the control gain, and two variables that determine a first deadband and a second relatively wider deadband about the setpoint. If the absolute value of the difference (error) between the actual fluid temperature and the setpoint is increasing, the control uses the first deadband, and conversely, if the error is decreasing, it uses the second deadband to vary chiller capacity. The control also permits the user to select a limit for various operating parameters associated with protective shutdown of the system to avoid catastrophic failure, and adjusts the chiller capacity according to one of two predefined functions of the deviation of the operating parameter from its limit, dependent on whether that deviation is greater or less than a predefined deadband.