JPH0988836A - Variable pressure water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically correct the discharge pressure of a pump to an effective pressure by providing a memorizing device for memorizing pressure in a water supply pipe and the rotating speed of the pump at the optional number of revolutions of the pump in a variable water supply equipment provided with a plurality of pumps and a driving circuit for driving the pumps. SOLUTION: In a water supply equipment for supplying water to a building or an apartment house, a suction pipe 3 and a discharge pipe 4 are connected to pumps 1, 2 and a pressure sensor 5 is mounted in the discharge pipe 4. A speed changing means 6 is connected to each of the pumps 1, 2 and a controller 7 for calculating suitable discharge pressure and the number of revolutions is disposed and a data table which always memorizes discharge pressure at every number of revolutions is stored in the controller 7, which adjusts the discharge pressure by itself to realize a suitable pressure control even if there is a difference between the maximum capacity and the using point specified by a user. In addition, it retrieves a following pump whose starting/stopping water quantity is sufficiently different from the required water quantity to prevent an unnecessary following pump from being operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller for adjusting the amount of water in a water supply facility equipped with a plurality of pumps.

[0002]

2. Description of the Related Art A pressurizing device for supplying water to a building, an apartment house, etc. operates at a pressure required for a small amount of water, and at a pressure with a pipe resistance loss that increases in proportion to the amount of water used Is used. In this method, since a flow meter for estimating the amount of water used is expensive, a method of calculating the amount of water used by the discharge pressure of the pressurizing device and the operating frequency of the variable speed pump is generally used.

[0003]

However, when the pump is used at the midpoint of the pump capacity as shown in FIG. 3, the point of the maximum water supply amount is converted into the maximum operating frequency. Therefore, the discharge pressure is set in each case. Had to be adjusted accordingly. The present invention has been made in view of the above problems,
An object of the present invention is to provide a feed water pressurizing device that operates at an appropriate discharge pressure and water amount according to the place where the feed water pressure device is used, regardless of the relationship between the pump capacity and the point of use.

[0004]

According to the present invention, a plurality of pumps, water supply pipes connected to the discharge side of these pumps, pressure detection means connected to the water supply pipes, a drive circuit for driving the pumps, It is provided with a control means for controlling the pump, and has a feature that the discharge pressure of the pump is automatically corrected to an efficient pressure by constantly storing the maximum operating speed of the pump.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to a performance diagram of FIG. 2 by taking as an example a water supply pressurizing device composed of two pumps as shown in FIG. A suction pipe 3 and a discharge pipe 4 are connected to each of the pumps 1 and 2, and a sensor 5 for measuring pressure is installed in the discharge pipe. Also, pump 1,
2 is provided with a variable speed means 6 and a control device 7 for calculating an appropriate discharge pressure and rotation speed. In addition, this control device 7
Has a built-in data table that constantly stores the discharge pressure for each rotation speed.

If the point of use of this water supply pressurizing device is point A, the discharge pressure of the pump will be the following (1 formula) and (2)
Since it is calculated by the equation), when the water amount is Q1, it becomes P1. In the case of operating one pump SV = (PM-PL) / (Nmax-NB) × (NX-NB) + PL (1 formula) In the case of operating two pumps SV = (PH-PM) / (Nmax-NM) × (NX-NM) + PM (Formula 2) SV: Target discharge pressure PH: Maximum water supply pressure PM:
Target pressure for starting / stopping the following pump PL: Minimum maintenance pressure NB: Number of revolutions at which pump can maintain PL in dead state NM: Number of revolutions at which pump can maintain PM in dead state However, this pressure P1 does not satisfy the required pressure Therefore, the pump is accelerated and the discharge pressure is adjusted to P2.
zmax is stored and Nmax in the above formulas (1) and (2)
To. When the pump operates again and the maximum rotation speed Hz2 exceeds the maximum rotation speed Hz1 up to now, substitution work is performed in the same manner. Further, this maximum rotation speed is set as the upper limit operation rotation speed of the first operation pump.

[0007]

The variable speed water supply device of the present invention has the following effects. Even if there is a gap between the maximum capacity of the pump and the point of use specified by the user, the self-adjustment function of the discharge pressure can realize optimum pressure control. With the adjustment function of the above and self, the self-retrieval of the starting / stopping water amount Q2 of the follow-up pump that is sufficiently different from the required water amount Q1 can prevent the unnecessary operation of the follow-up pump, thus extending the service life of the pump motor. You can

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a water supply pressurizing device including two pumps.

FIG. 2 is the above performance curve diagram.

FIG. 3 is a performance curve diagram of a conventional example.

[Explanation of symbols]

 1, 2 pumps 4 discharge pipes 5 sensors 6 variable speed means 7 control device

Claims (2)

[Claims] 1. A plurality of pumps, water supply pipes connected to the discharge sides of these pumps, pressure detection means connected to the water supply pipes, motors connected to the pumps and driving the pumps, and means for changing the pump rotation speed. In the variable water supply device for detecting the pump rotation speed, a variable speed water supply pressurizing device is provided, which is provided with a storage device for storing the pressure in the water supply pipe and the pump rotation speed at an arbitrary pump rotation speed. 2. The variable speed feed water pressurizing device according to claim 1, wherein the storage device stores the pressure in the feed pipe at the time of shutting off the pump for each rotation speed.