JP6723105B2 - Drainage system and drainage method - Google Patents

Description

The present invention relates to a drainage system and a drainage method for draining water using a plurality of pumps.

A pump station for draining water with a plurality of pumps is known (for example, Patent Document 1). The pump operates by receiving the power of the prime mover. A diesel engine or a gas turbine is used as the prime mover.

Although a diesel engine is inexpensive, if light load operation (including no load operation) continues for a long time, carbon and unburned fuel may be accumulated in the exhaust pipe, which may cause an explosion or a fire. As a countermeasure, a scavenging operation is required in which the actual load operation is performed after the light load operation to scaveng the exhaust pipe. Since scavenging operation increases the maintenance work of the pump, it is often necessary to use a gas turbine that is more expensive than a diesel engine.

Japanese Patent No. 5475607

The present invention has been made in view of such problems, and an object of the present invention is to provide a drainage system and a drainage method capable of shortening the time of light load operation.

According to one aspect of the present invention, a plurality of pump equipment, and a control device, each of the plurality of pump equipment, a prime mover, a pump, and when the power is turned on, transmits the power of the prime mover to the pump, And a power transmission means that does not transmit the power of the prime mover to the pump when turned off, and the controller controls the power of any pump equipment based on the light load operating time of the prime mover in each of the plurality of pump equipment. A drainage system is provided that controls whether the transmission means is turned on.
Since it is controlled which of the pump power transmission means is turned on based on the light load operating time, the light load operating time of the prime mover can be shortened.

It is preferable that the control device turns on the power transmission means of the pump facility having the longest light load operation time.
As a result, the light load operation of the prime mover can be shortened.

It is desirable that the control device controls which power transmission means of which pump equipment is turned on based on the actual load operating time of each of the plurality of pump equipment.
As a result, the load can be distributed among a plurality of pump facilities.

It is preferable that the control device does not turn on the power transmission means of the pump facility having the longest actual load operation time.
As a result, the load can be distributed among a plurality of pump facilities.

It is preferable that the control device starts timing of the actual load operating time of the prime mover in the pump facility in which the power transmission means is turned on.
As a result, it is possible to reliably measure the actual load operation time.

It is desirable that the control device reset the light load operation time for the pump equipment in which the power transmission means is turned on.
As a result, the light load operation time can be reliably measured.

The prime mover is preferably a diesel engine.
This reduces the cost of the prime mover.

According to another aspect of the present invention, each includes a prime mover, a pump, and a power transmission unit that transmits power of the prime mover to the pump when turned on and does not transmit power of the prime mover to the pump when turned off. A drainage method for performing drainage using a plurality of pump equipments, comprising turning on a power transmission means of one of the pump equipments based on a light load operating time of a prime mover in each of the plurality of pump equipments. Will be provided.

It is possible to shorten the light load operating time of the prime mover because the power transmission means of which pump equipment is turned on is controlled based on the light load operating time.

The block diagram showing the schematic structure of the drainage system concerning one embodiment. The block diagram which shows the detail of the pump equipment 100a. The flowchart which shows the control at the time of pump start. The flowchart which shows the control at the time of a pump stop.

Hereinafter, embodiments according to the present invention will be specifically described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a drainage system according to an embodiment. This drainage system is installed in, for example, a drainage station to discharge the water in the suction water tank 50 to a discharge water tank (not shown), and includes a plurality of pump facilities 100a and 100b and a control device 200. Although FIG. 1 and the following will describe an example in which two pump facilities 100a and 100b are provided, there may be three or more pump facilities. Hereinafter, unless otherwise specified, the pump facilities 100a and 100b have the same configuration, and therefore the pump facility 100a will be mainly described.

The pump equipment 100a includes a prime mover 1a, a clutch 21a, a pump 3a, and the like.

The prime mover 1a rotates its output shaft 11a. The prime mover 1a may be a gas turbine, but in the present embodiment, an inexpensive diesel engine can also be applied.

The clutch 21a is provided between the prime mover 1a and the pump 3a, and controls whether or not the power (torque) of the prime mover 1a is transmitted to the pump 3a. That is, the clutch 21a switches whether to directly or indirectly fit the output shaft 11a of the prime mover 1a and the main shaft 31a of the pump 3a. When the clutch 21a engages both shafts (hereinafter, "clutch 21a is turned on"), power is transmitted, and the engagement of both shafts is released (hereinafter, "clutch 21a is turned off"). Power will not be transmitted. In this sense, the clutch 21a can be said to be power transmission means.

The pump 3a is, for example, a vertical shaft mixed flow pump, and drainage is performed by receiving the power of the prime mover 1a and rotating an impeller (not shown) fixed to the main shaft 31a.

Here, when the clutch 21a is off, the prime mover 1a is in a no-load operation with no rotation. When the prime mover 1a is a diesel engine, carbon and unburned fuel accumulate inside when light load operation (including no load operation, the same applies hereinafter) of 30% or less is performed for a long time. However, in the present embodiment, since the time of light load operation is shortened as described later, an inexpensive diesel engine can be applied as the prime mover 1a.

The control device 200 has light load operation timers 51a and 51b for measuring the light load operation times of the prime movers 1a and 1b in the respective pump equipments 100a and 100b, and which pumps are operated based on the light load operation times of the prime movers 1a and 1b. It controls whether the clutches 21a and 21b in the equipment 100a and 100b are turned on. Desirably, the control device 200 has actual load operation timers 52a and 52b for measuring the actual load operation time of the prime movers 1a and 1b, and also considers the actual load operation time of the prime movers 1a and 1b in the respective pump facilities 100a and 100b. .. As a result, the control device 200 can arbitrarily change the drainage start order of the plurality of pump facilities 100a and 100b.

FIG. 2 is a configuration diagram showing details of the pump equipment 100a, in which a control device 200 is drawn in addition to a main component, a prime mover 1a, a speed reducer 2a including a clutch 21a and a pump 3a.

The pump 3a is installed on the pump installation floor 51 above the suction water tank 50 via the pump base 52. The pump 3a has a main shaft 31a, a casing 32a, and an impeller 33a.

The casing 32a is disposed in the suction water tank 50 and has a pump casing 322a having a lower end connected to the suction bell mouth 321a, a suspension pipe 323a connected to an upper portion thereof, and a bent discharge pipe 324a connected to an upper portion thereof. It is composed of a discharge pipe 326a connected to the tip of the discharge valve 325a. A check valve 327a is provided at the tip of the discharge pipe 326a.

The main shaft 31a passes through the bent discharge pipe 324a and is disposed inside the suspension pipe 323a and the pump casing 322a, and is rotatably supported. An impeller 33a is attached to the lower part of the main shaft 31a.

A prime mover 1a and a speed reducer 2a are arranged above the pump 3a. The reduction gear 2a is, for example, an orthogonal shaft bevel gear reduction gear, and has a clutch 21a, an input shaft 22a, and a bevel gear 23a. The clutch 21a is provided between the input shaft 22a of the speed reducer 2a and the output shaft 11a of the prime mover 1a, and switches whether or not to fit both shafts. The bevel gear 23a is connected to the input shaft 22a and the main shaft 31a of the pump 3a. When the power from the prime mover 1a is transmitted to the input shaft 22a via the clutch 21a, the bevel gear 23a rotates, which causes the main shaft 31a of the pump 3a to rotate.

FIG. 3 is a flowchart showing the control at the time of starting the pump. Hereinafter, an example will be described in which the prime movers 1a and 1b of the pump equipment 100a and 100b are full-speed full-water-level standby pumps that are operating regardless of the water level of the suction water tank 50.

In this case, the prime movers 1a and 1b of the pump equipment 100a and 100b are first started (step S1). However, when the water level is low, the clutches 21a and 21b are off, and the standby operation, that is, the light load operation is performed. Therefore, the control device 200 turns on the light load operation timers 51a and 51b of the respective prime movers 1a and 1b and starts counting the light load operation time when the prime movers 1a and 1b are started (step S2).

When the water level in the suction water tank 50 detects that the water level in the suction water tank 50 has reached the predetermined starting water level (YES in step S3), the control device 200 causes one pump facility (hereinafter referred to as pump facility 100a) to be operated. Select (step S4).

Then, the control device 200 confirms whether or not the light load operation time of the prime mover 1a in the selected pump equipment 100a is the longest by referring to the light load operation timers 51a and 51b (step S5).

When it is the longest (YES in step S5), the control device 200 issues a command for turning on the clutch 21a of the pump equipment 100a (step S6A). As a result, the clutch 21a is turned on and the pump 3a is started, and the prime mover 1a of the pump equipment 100a transitions from light load operation to actual load operation.

In this way, by performing the actual load operation of the prime mover 1a having the longest light load operating time first, it is possible to realize the actual load operation that also serves as the scavenging operation (operation for scavenging the exhaust pipe of the prime mover 1a). ..

On the other hand, when the light load operation time of the prime mover 1a in the selected pump equipment 100a is not the longest (NO in step S5), the control device 200 refers to the actual load operation timers 52a and 52b to select the selected pump equipment 100a. It is confirmed whether the actual load operating time of the prime mover 1a in 100a is the longest (step S7).

If it is the longest, the cumulative operating time of the pump equipment 100a is long, and therefore the clutch 21a of the pump equipment 100a is not turned on in order to distribute the load to other pump equipment. Then, the control device 200 selects another pump facility (here, the pump facility 100b) (step S8). Then, the control device 200 performs the processes of steps S5, S7, and S9 described above until the pump equipment whose step S5 is YES or the later-described step S9 is NO is specified.

On the other hand, when the actual load operation time of the prime mover 1a in the selected pump equipment 100a is not the longest (NO in step S7), the control device 200 refers to the light load operation timers 51a and 51b to select the selected pump equipment 100a. It is confirmed whether the light load operation time of the prime mover 1a at 100a is the second longest (step S9).

When it is the second longest (YES in step S9), the control device 200 selects another pump equipment 100b without turning on the clutch 21a of the pump equipment 100a (step S8).

On the other hand, if it is not the second longest (NO in step S9), the control device 200 issues a command to turn on the clutch 21a of the pump equipment 100a (step S6A). As a result, the clutch 21a is turned on and the pump 3a is started, and the prime mover 1a in the pump equipment 100a transitions from the light load operation to the actual load operation.

In addition, in step S6A, the prime mover 1a in the selected pump facility 100a transitions to actual load operation. Therefore, the control device 200 turns on the corresponding actual load operation timer 52a to start the accumulation of the actual load operation time of the prime mover 1a in the pump equipment 100a, and turns off the light load operation timer 51a to generate the prime mover 1a in the pump equipment 100a. The light load operation time is stopped and the time is reset (step S6B).

With the above, the first pump facility starts draining. After that, when the water level in the suction water tank 50 further rises and reaches the next starting water level, the processing from step S3 is performed.

FIG. 4 is a flowchart showing control when the pump is stopped. Hereinafter, the pump facility 100a will be described as draining water.

When the water level in the suction water tank 50 decreases and reaches the stop water level (YES in step S11), the control device 200 issues a command to turn off the clutch 21a of the pump facility 100a that is draining water (step S12).

As a result, the pump 3a of the pump equipment 100a stops and the prime mover 1a transitions from the actual load operation to the light load operation. Therefore, the control device 200 turns off the corresponding actual load operation timer 52a to stop the accumulation of the actual load operation time of the prime mover 1a, and turns on the light load operation timer 51a to count the light load operation time of the prime mover 1a. It starts (step S13).
With the above, drainage of the pump equipment 100a is stopped.

As described above, in the present embodiment, the light load operation time of the prime mover in each pump equipment is timed, and the clutch of the pump equipment having the prime mover having the longest light load operation time is preferentially selected and turned on. Therefore, the light load operation time of each pump facility can be shortened. As a result, scavenging operation becomes unnecessary and an inexpensive diesel engine can be applied as a prime mover.
It should be noted that the present embodiment is applicable not only to the case where the pump equipment 100a, 100b is the full speed/all water level preceding standby pump but also to the case of a normal pump.

The above-described embodiments are described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above-described embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but should be the broadest scope according to the technical idea defined by the claims.

1a, 1b Motor 21a, 21b Clutch 3a, 3b Pump 100a, 100b Pump equipment 200 Control device 51a, 51b Light load operation timer 52a, 52b Real load operation timer

Claims (8)

A plurality of pump equipment and a control device,
Each of the plurality of pump equipment,
Prime mover,
A pump,
And a power transmission unit that transmits the power of the prime mover to the pump when turned on, and does not transmit the power of the prime mover to the pump when turned off,
The said control apparatus is a drainage system which controls which power transmission means of which pump equipment is turned on based on the light load operating time of the prime mover in each of said some pump equipment. The drainage system according to claim 1, wherein the control device turns on the power transmission means of the pump facility having the longest light load operation time. The drainage system according to claim 1 or 2, wherein the control device controls which power transmission means of which pump facility is turned on, based on the actual load operation time of each of the plurality of pump facilities. The drainage system according to claim 3, wherein the control device does not turn on the power transmission means of the pump facility having the longest actual load operation time. The drainage system according to claim 3 or 4, wherein the control device starts timing of the actual load operation time of the prime mover in the pump facility in which the power transmission unit is turned on. The drainage system according to any one of claims 1 to 5, wherein the control device resets the light load operation time for the pump equipment in which the power transmission means is turned on. The drainage system according to claim 1, wherein the prime mover is a diesel engine. Drainage is performed using a plurality of pump facilities, each of which has a prime mover, a pump, and a power transmission means that transmits power of the prime mover to the pump when turned on and does not transmit power of the prime mover to the pump when turned off. Drainage method
A drainage method of turning on a power transmission means of one of the pump facilities based on a light load operating time of a prime mover in each of the plurality of pump facilities.