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Title:
ESTIMATED END PRESSURE CONSTANT CONTROL DEVICE FOR PUMP
Document Type and Number:
Japanese Patent JP3793885
Kind Code:
B2
Abstract:

PROBLEM TO BE SOLVED: To provide highly accurate estimated end pressure constant control by obtaining a flow rate signal based on a no-discharge pump head, a push-in pump head or check valve fixing loss head and performing accurate flow rate detection not affected by external disturbances.
SOLUTION: In a device for supplying water to an end faucet by single or parallel operations of pumps 13 and 23, induction motors 11 and 21 for variable-controlling the speeds of the pumps 13 and 23 are provided and these motors are controlled by an estimated end pressure constant control device 1 based on the outputs of pressure detectors 21 and 22. That is, by obtaining a no-discharge pump head, reducing a value obtained by reducing check valve fixing loss head from a push-in head from a discharge pressure head, subtracting the obtained value from the non-discharge head and dividing the head of this difference with a sum between a factor of squaring a pump flow rate and the check valve fixing loss head, a flow rate signal equivalent to the square of the flow rate is detected. A guarantee head signal is made by multiplying this flow rate signal by the factor and a control signal is outputted based on a pressure set value to which the signal is added.


Inventors:
Hironobu Tashiro
Tsuyoshi Tsuruta
Tetsuo Kono
Tanji Tomoyama
Application Number:
JP1274597A
Publication Date:
July 05, 2006
Filing Date:
January 27, 1997
Export Citation:
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Assignee:
Yaskawa Electric Co., Ltd.
International Classes:
F04D15/00; F04B23/04; F04B49/06; F04B49/08; (IPC1-7): F04D15/00; F04B23/04
Domestic Patent References:
JP10176673A
Attorney, Agent or Firm:
Akio Miyazaki
Masaaki Ogata
Nobuyuki Kaneda
Katsuhiro Ito
Ishibashi Masayuki