| 摘要 |
PURPOSE:To achieve the stability of pump terminal pressure control and the enhancement of control accuracy by carrying out feed water control so as to keep the feed water pressure in response to the variation of water quantity used within a required hysteresis which is prescribed from the resistance curve of a feed pipe line and in view of the stability and accuracy of pressure control. CONSTITUTION:The FH curve denotes the upper limit of a resistance curve in which a hysteresis (a) is added to a target resistance curve F of a feed water pipe line in view of the stability and accuracy of pressure control, and the FL curve denotes the lower limit of the above. and, the speed difference between the maximum speed Nmax and minimum speed Nmim is divided into 5 equal parts to give respective speeds N1 through N3, and, making the pressures at the points of intersection of a resistance curve F predicted previously from the bore diameter, material, shape and the like with the Q-H performance curves A through E of a pump corresponding to these operating speeds to be the standard values HT, H1, H2, H3 and HI of the target pressure at the respective speeds, these values are used for the correction data of the target pressure, and are corrected by the registor (not shown in the Figure) of a microcomputer mu. And the stability of control and the enhancement of control accuracy is achieved by keeping the feed water pressure within the hysteresis of the resistance curve of the feed water pipe line.
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