Method for determining pump flow without the use of traditional sensors
US7945411B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 2006 |
| Grant date | May 17, 2011 |
| Priority date | — |
| Expiry date | Mar 13, 2030 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04D27/001
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A technique for determining pump flow without using traditional sensors features steps and modules for creating a calibrated power curve at closed valve conditions at several speeds; calculating coefficients from a normalized power curve based on a pump's power ratio; and solving a polynomial power equation for flow at the current operating point. The calibrated power curve may be created by increasing the speed of the pump from a minimum speed to a maximum speed and operating the pump with a closed discharge valve. This data is used to correct published performance for shutoff power and best efficiency point power at rated speed in order to determine the pump's power ratio. It is also used to accurately determine closed valve power at the current operating speed. The pump's power ratio is determined by the equation: Pratio=Pshutoff @100%/PBEPcorr. The polynomial power equation may, for example, include a 3rd order polynomial equation developed using coefficients from the normalized power versus flow curve, and corrections may be made for speed, hydraulic efficiency and specific gravity in the polynomial power equation. Complex roots may be determined to solve the 3rd order polynom…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.