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:
Feb. 13, 2001
Filed:
May. 08, 2000
Thomas B. Hartman, Marysville, WA (US);
Other;
Abstract
Methods of sequencing parallel units in HVAC systems are described to improve overall system operating efficiency. The improved method is applicable for sequencing parallel centrifugal pumps in a variable flow hydronic system, parallel fans in a variable air-flow system, and centrifugal chillers in an HVAC system having a plurality of variable speed drive centrifugal chillers arrange in parallel. The method calls for determining an operating point of the on-line units, comparing the current operating point to a natural curve of maximum efficiency, and adding or shedding units as required to move closest to an operating curve of optimal efficiency, without direct regard to actual loading. Natural operating curves relate head pressure and operating speed rather than load. Control logic that implements such operating characteristics often will result in operating more parallel units on-line that would be required by prior art to meet the load. However, in such cases, all of the on-line units are operated at lower speed resulting in lower overall system energy consumption.