JPH058619U - Automatic control system for variable speed pump - Google Patents

Abstract

(57) [Summary] [Purpose] To control the variable speed pump so that the sand removal efficiency can be kept good even if the inflow water amount increases rapidly. [Structure] The variable speed pump is controlled by the deviation c between the set water level S of the pump well water level setter 14 and the water level signal a of the pump well water level detector to control the water in the pump well 1 to the pressure regulating water tank or the discharge water tank 2.
The water level detector 11 is provided in the pressure regulating water tank or the discharge water tank, and the water level of the pump well 1 is controlled by making the set water level S of the pump well water level setter 14 proportional to the water level signal b of the water level detector 11. This will prevent the flow velocity in the pump well from declining when the inflow increases sharply.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an automatic control system for variable speed pumps in relay pump stations and drainage pump stations.

[0002]

[Prior Art]

 At the wastewater relay pumping station and drainage pumping station, the number of pumps is controlled or the water level of the pump well is controlled by a variable speed device according to the change in the amount of water flowing into the pump well.

FIG. 2 shows a conventional automatic control system for a variable speed pump. 2, reference numeral 1 denotes pump wells, 2 pressure water tank (or water discharge tank), 3 is the variable pump main number where to send the water pump well 1 in pressure water tank 2, 4 with the float 4 ₁ Float type water level meter, 7 is a pump Well controller for inputting the deviation c between the set value S of the water level setter 6 and the water level signal a from the signal converter 5 connected to the water level gauge 4, 8 is the controller 7 It is a variable speed device that controls the speed of the pump 3 by the output so that the pump well water level is maintained at the set water level.

With the urbanization of the river basin, the time of occurrence of a flood peak has been shortened. For this reason, in general, as a measure for operation during floods, the set water level of the pump well water level setting unit 6 is lowered to an allowable range to perform constant water level control of the pump well 1.

[0005]

[Problems to be solved by the device]

 The water level of pump well 1 has upper and lower limits, and the water flow rate is limited by the capacity of the pump and the capacity of the water pipe. Therefore, the original purpose of the conventional automatic control system for variable-speed pumps is to adjust the amount of inflow water. It was to change the pump well water level set value S to keep the flow velocity constant and to maintain good sand removal efficiency.

For this reason, as described above, when the pump well water level set value S is lowered to the allowable range and the constant water level control is performed before the water discharge peak, the flow velocity of the pump well 1 becomes faster when the inflow water amount increases rapidly. There is a problem that the sand removal efficiency becomes poor.

The present invention has been made in view of the above problems of the related art, and an object of the present invention is to provide a variable speed pump capable of maintaining good sand removal efficiency even when the amount of inflow water increases rapidly. To provide an automatic control system of.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the automatic control system of the variable speed pump according to the present invention controls the variable speed pump by controlling the difference between the set water level of the pump well water level setter and the water level signal of the pump well water level detector to control the water in the pump well. In the case of sending to the pressure control water tank or discharge water tank, install a water level detector in the pressure control water tank or discharge water tank, and make the set water level of the pump well water level setter proportional to the water level signal of the pressure water tank or discharge water tank water level detector. It will be.

[0009]

[Action]

 The pump well set water level changes in proportion to the water level signal of the water level detector in the pressure control water tank or the discharge water tank. Since the variable speed pump is controlled so that the pump well water level is set to this pump well set water level, the pump well water level is proportional to the water level of the pressure control tank or discharge water tank. For this reason, the pump well water level is usually well above the lower limit, so that the flow velocity in the pump well does not become so high even if the inflow of water increases rapidly. Therefore, sand removal efficiency can be kept good even if the inflow of water increases sharply.

[0010]

【Example】

 An embodiment of the present invention will be described with reference to FIG. Note that the same components as those shown in FIG. 2 are designated by the same reference numerals, and the duplicated description thereof will be omitted.

In FIG. 1, 11 is a float type water level gauge provided in the pressure regulating water tank 2, 12 is a signal converter for outputting a water level signal b connected to the water level gauge 11, and 13 is a water level of the signal converter 5. An upper limit water level detection circuit that detects that the water level of the pump well 1 has reached the upper limit water level (HWL) from the signal a and outputs an output d until the water level drops to a predetermined water level, and 14 is a water level signal below the upper limit water level (H WL). It is a pump well water level setter that outputs a set water level S proportional to b and lowers the set water level S when the high water level detection circuit 13 outputs d.

Since the pump well set water level S constantly changes in proportion to the water level signal b of the pressure regulating water tank 2 and the water level of the pump well 1 does not become so low, the sand removal efficiency is improved. You can drive well.

When the inflow of the pump well 1 suddenly increases due to the water discharge, the variable speed control of the pump is performed by the set water level S proportional to the water level of the pressure regulating water tank 2 until the pump well water level reaches the upper limit water level (H WL). It Although the pump well water level rises due to the lack of discharge capacity of the pumps, etc., the flow velocity of the pump well does not increase so much due to the rise of this water level and the deepening of the pump well water level. For this reason, even if there is a rapid inflow containing a large amount of sand at the initial stage of water discharge, it will flow into a place where the water level in pump well 1 is not too low, so sand removal efficiency will be kept good.

Although the amount of inflow water decreases with the passage of time, when the water level of the pump well 1 reaches the upper limit water level (HW L), the output d is output from the upper limit water level detection circuit 13 and the set water level S is lowered. .. Therefore, the pump 3 becomes close to full operation, and the pump well water level is prevented from exceeding the upper limit water level.

When the pump well water level decreases to a predetermined water level, the upper limit detection output d disappears, and variable speed control is performed by the set water level S proportional to the original water level of the pressure regulating water tank 2.

[0016]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects.

(1) Since the set water level in the pump well is changed in proportion to the water level in the pressure regulating water tank or the water discharge tank, the flow velocity can be kept almost constant, so that the sand removal efficiency is kept good.

(2) Since the set water level of the pump well does not fall to the allowable range at the time of water discharge, sand removal efficiency does not deteriorate even if the inflow water amount increases rapidly.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of an automatic control system for a variable speed pump according to an embodiment of the present invention.

FIG. 2 is a structural explanatory view of an automatic control system for a conventional variable speed pump.

[Explanation of symbols]

1 ... Pump well, 2 ... Pressure regulation water tank or water discharge tank, 3 ... Variable speed pump, 4, 11 ... Water level gauge, 5, 12 ... Signal converter, 6,
14 ... Pump well water level setting device, 7 ... Controller, 8 ... Variable speed device, 13 ... Upper limit water level detection circuit.

Claims (1)

[Claims for utility model registration] [Claim 1] A variable speed pump is controlled by the difference between the set water level of the pump well water level setter and the water level signal of the pump well water level detector to control the water in the pump well The water level detector is provided in the pressure regulating water tank or the discharge water tank, and the set water level of the pump well water level setting device is made proportional to the water level signal of the pressure water tank or the discharge water tank water level detector. Automatic control system for variable speed pump.