JP2016160769A - Pump system operation method, pump system, and pump replacement method for pump system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump system that can inhibit air suction of a pump due to generation of swirl and discharge a large amount of water when a water level is high by a low-cost and simple configuration and method.SOLUTION: In the pump system, a return water pipe (30) is provided with a return water valve (31) and a valve control part (40) is provided to control the return water valve (31) according to a water level in the suction water tank (2).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pump system operation method, a pump system, and a pump replacement method of the pump system.

  A pump such as a vertical shaft pump is used to pump rainwater stored in a water absorption tank and drain it into a river or the sea.

  When the water in the water absorption tank is pumped by the pump, if a vortex is generated on the surface of the water, the pump sucks air, causing problems such as a decrease in pump discharge amount and damage due to pump vibration.

  The vortex is generated under predetermined conditions depending on the shape of the water absorption tank, the pump capacity, the water level in the water absorption tank, and the like. Therefore, in the conventional pump station, the dimensions of the water absorption tank are designed according to the pump capacity in consideration of preventing the generation of vortices. Moreover, in the conventional pump station, the vortex | eddy_current prevention apparatus for preventing generation | occurrence | production of a vortex was sometimes provided in the bottom face, side wall, etc. of the water absorption tank.

  In recent years, an existing pump may be replaced with a large-capacity pump in order to cope with a sudden rise in the water level of the water absorption tank due to a sudden heavy rain. If the existing pump is replaced with a large-capacity pump without changing the shape of the water absorption tank, the water level where no vortex is generated rises compared to before the pump replacement. The stop water level is often not changed. Therefore, considering the pump capacity, there are many opportunities to operate the pump with the water level in the water absorption tank being low. When the pump is operated at a low water level, a vortex is likely to occur on the water surface, and the pump can easily suck air.

  In addition, when a vortex preventing device is newly provided on the bottom surface of the water absorption tank, the pump is stopped for a certain period of time and a large-scale work such as a mud draining work is involved, which takes time and labor and increases the cost.

  Patent Document 1 describes an eddy current generation prevention device in which an injection jet is provided on the outer periphery of a pumping pipe, and a part of the water flowing in the pumping pipe is jetted from the jet jet toward the water surface near the suction port of the pump.

  In Patent Document 2, a vortex is detected by image recognition by providing a camera on the ceiling of the water absorption tank, and pressure is applied toward the vortex from pressure water injection holes provided radially on the outer peripheral portion of the pump according to the generation of the vortex. A vortex suction prevention method for jetting water is described.

  According to the eddy current generation preventing device of Patent Document 1 and the vortex suction preventing method of Patent Document 2, the vortex can be collapsed or the generation of the vortex can be prevented, and the air suction of the pump can be prevented.

Japanese Utility Model Publication No. 56-77699 (published June 24, 1981) JP 6-317299 A (published November 15, 1994)

  Here, considering the situation of the pump station, when the water level in the water absorption tank is high, vortices are unlikely to occur. On the other hand, since the water level in the water absorption tank is high, it is necessary to drain more water.

  In the eddy current generation preventing device of Patent Document 1, since a part of the water flowing in the pumping pipe is jetted toward the water surface regardless of the water level of the water absorption tank, a sufficient amount of water is discharged when the water level in the water absorption tank is high. Cannot be obtained.

  In the method of Patent Document 2, it is necessary to provide a camera on the ceiling of the water absorption tank in order to detect vortices, which increases the manufacturing cost of the pump system.

  The present invention has been made in view of the above-mentioned problems, and its object is to suppress pump air suction due to the generation of vortices by a low-cost and simple configuration and method, and to supply a large amount of water at high water levels. An object of the present invention is to provide an operation method of a pump system capable of draining, a pump system, and a pump replacement method of the pump system.

  In order to solve the above problems, a pump system operating method according to aspect 1 of the present invention includes a pump for pumping water in a water absorption tank, a discharge pipe for discharging water pumped by the pump, and the discharge pipe. And a water return pipe provided so that at least a part of the water pumped up by the pump can be returned to the water absorption tank, and a method for operating the pump system, wherein the water level of the water absorption tank is detected In the detection step, when the water level in the water absorption tank is lower than a predetermined water level, at least a part of the water pumped up by the pump is returned to the vortex generation area in the water absorption tank through the return pipe. And a water return step.

  According to the above method, according to the water level of the water absorption tank, the water level of the water absorption tank is returned by a simple method of returning at least part of the water pumped up by the pump toward the vortex generation region through the water return pipe. Accordingly, the generation of vortices can be prevented, the pump air suction due to the generation of vortices can be suppressed, and a large amount of water can be drained from the water absorption tank when the water level is high.

  The operation method of the pump system according to aspect 2 of the present invention may be an operation method in which the water return amount is increased in the water return step as the water level of the water absorption tank is lowered in the water return step.

  Whirlpools are likely to occur when the water level in the water absorption tank is low, but according to the above method, the water return amount and the discharge amount can be adjusted appropriately according to the decrease in the water level of the water absorption tank. The generation of vortices can be prevented.

  The operation method of the pump system according to aspect 3 of the present invention is the operation method according to aspect 1 or 2, wherein the predetermined water level is a water level at which a predetermined vortex is generated based on a result of verification in advance. May be.

  According to said method, when it becomes the water level which is easy to generate | occur | produce a vortex, it can return to a vortex generating area | region via a return pipe. Therefore, it is possible to appropriately adjust the water return amount and the discharge amount according to the ease with which the vortex is generated.

  Moreover, in order to solve said subject, the pump system which concerns on aspect 4 of this invention is the pump which pumps the water in a water absorption tank, the discharge pipe which discharges the water which the said pump pumped, and the said discharge pipe And a water return pipe that is provided so that at least a part of the water pumped by the pump can be returned to the water absorption tank, and the water absorption tank is provided with a water level gauge. The water return pipe is directed to a vortex generation region in the water absorption tank, and the water return pipe is provided with a water return valve, and controls the water return valve according to the water level of the water absorption tank. A valve control unit is provided.

  According to the above configuration, by controlling the water return valve according to the water level of the water absorption tank, at least a part of the water pumped from the water absorption tank is returned toward the vortex generation region according to the water level of the water absorption tank. The generation of vortices can be prevented.

  This makes it possible to prevent the generation of vortices according to the water level of the water absorption tank, and to suppress the intake of air into the pump due to the generation of vortices, thanks to the low cost and simple configuration of the water return pipe and valve control unit provided with a water return valve. In addition, when the water level is high, a large amount of water can be drained from the water absorption tank.

  The pump system according to aspect 5 of the present invention is the bottom part of the aspect 4 provided so that at least a part of the water branched from the discharge pipe and pumped by the pump can be returned to the bottom part of the water absorption tank. The bottom water return pipe is provided with a bottom water return valve, and the valve control unit is configured to control the bottom water return valve according to the water level of the water absorption tank. Also good.

  According to the above configuration, by controlling the bottom water return valve according to the water level of the water absorption tank, at least part of the water pumped from the water absorption tank according to the water level of the water absorption tank is returned to the vortex generation region. can do.

  Thereby, the air suction of the pump by generation | occurrence | production of the underwater vortex generated from the bottom face of the water absorption tank can be suppressed. Moreover, the mud accumulated on the bottom of the water absorption tank can be wound up, the mud can be sucked up together with the water pumped up and discharged to the outside of the water absorption tank through the discharge pipe.

  Moreover, in order to solve said subject, the pump replacement method of the pump system which concerns on aspect 6 of this invention is the existing pump which pumps up the water in a water absorption tank, and the discharge pipe which discharges the water which the said existing pump pumped up A pump system for exchanging the existing pump with a new pump, an exchange step for exchanging the existing pump with the new pump; and Depending on the water return tank extension step to add a return pipe that can return a part of the water pumped by the new pump to the vortex generation area in the water absorption tank and the water level of the water absorption tank. And a valve control unit expansion step of adding a valve control unit for controlling a water return valve provided in the water return pipe.

  Replacing the pump may increase the chances of operating at low water levels and, as a result, may increase the chance of vortices.

  However, according to the above method, when the pump is replaced, a vortex is provided according to the water level of the water absorption tank by a low-cost and simple method of adding a water return pipe provided with a water return valve and a valve control unit. The pump system can suppress the air suction of the pump due to the generation of water and can discharge a large amount of water from the water absorption tank when the water level is high.

  A pump replacement method for a pump system according to aspect 7 of the present invention is the pump replacement method for a pump system according to aspect 6 above, including an estimation step for estimating the vortex generation region by testing or analysis, wherein the return pipe extension step Then, the pump replacement method of adding the water return pipe so that water can be returned to the water absorption tank toward the vortex generation region estimated in the estimation step may be used.

  According to said method, it can be set as the pump system provided with the water return pipe | tube which can return water toward the vortex generation area | region estimated by the test or analysis. Thereby, generation | occurrence | production of a vortex can be prevented effectively.

  In the pump replacement method for a pump system according to aspect 8 of the present invention, in the aspect 7, the estimation step may include a water level estimation step for estimating a water level when a vortex is generated in the vortex generation region.

  According to said method, the water level of a water absorption tank when a vortex is easy to generate can be estimated, and a water return valve can be controlled based on the estimated result. Thereby, generation | occurrence | production of a vortex can be prevented effectively, without reducing the waste_water | drain amount when it is hard to generate | occur | produce a vortex.

  ADVANTAGE OF THE INVENTION According to this invention, the pump system which can suppress the air suction of the pump by generation | occurrence | production of a vortex by a low-cost and simple structure and can drain a lot of water at the time of a high water level, the operating method of a pump system, and a pump A system pump replacement method can be provided.

It is a side view which shows the structure of the principal part of the pump system which concerns on Embodiment 1 of this invention. It is a side view of the pump system which shows the relationship between the operating state of the pump system which concerns on Embodiment 1 of this invention, and a water level. It is a side view which shows the structure of the principal part of the pump system which concerns on Embodiment 2 of this invention. It is a side view which shows the structure of the principal part of the pump system which concerns on Embodiment 3 of this invention. It is a side view of the pump system which shows the relationship between the driving | running state of the pump system which concerns on Embodiment 3 of this invention, and a water level.

Embodiment 1
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.

<Configuration of pump system>
FIG. 1 is a side view illustrating a configuration of a main part of the pump system according to the present embodiment.

  The pump system 1 is for draining the water in the water absorption tank 2 to the outside. In the following description, the pump system 1 that supplies water in the water absorption tank 2 to the discharge water tank 3 will be described.

  The pump system 1 includes a pump 10 for pumping water in the water absorption tank 2 through a bell mouth 11, a discharge pipe 20 for discharging water pumped by the pump 10 to the discharge water tank 3, and a management operation branched from the discharge pipe 20. The pipe 60 for operation, the valve control part 40 for driving the pump 10, and the water level meter 50 for detecting the water level of the water absorption tank 2 are provided.

  For example, a vertical shaft pump can be used as the pump 10.

  The management operation pipe 60 is branched from the discharge pipe 20 at the branching portion 62, the management operation valve 61 is provided in the pipe line, and the tip is directed to the water absorption tank 2.

  Further, a water return pipe 30 branched from the upstream side of the management operation valve 61 is provided in the pipeline of the management operation pipe 60.

  The tip of the water return pipe 30 is directed to the vortex generation area, which is an area where the vortex S is likely to be generated, in the inside of the water absorption tank 2, whereby the water return pipe 30 receives at least a part of the water pumped by the pump 10. It is provided so that water can be returned toward the vortex generation area.

  In the pump system 1, the management operation pipe 60 is not an essential configuration, and the water return pipe 30 may be branched from the discharge pipe 20. Moreover, you may use the water return pipe | tube 30 as piping for management operation in the case of management operation.

  A discharge valve 21 is provided in the discharge pipe 20. Further, the water return pipe 30 is provided with a water return valve 31. Each of the discharge valve 21 and the water return valve 31 may be of various types that are conventionally known, and may be capable of switching between two states, a fully closed state and a fully open state. The flow rate of the discharge pipe 20 and the water return pipe 30 may be adjustable by controlling the above.

  The valve control unit 40 controls the water return valve 31 according to the water level of the water absorption tank 2 detected using the water level gauge 50. Further, the valve control unit 40 may control the discharge valve 21 according to the water level of the water absorption tank 2, and may further control the start / stop of the pump 10.

  The specific configuration of the water level meter 50 is not particularly limited, and may be any type of water level meter such as a frict type water level meter, an electrode type water level meter, and a pressure type water level meter, Any of continuous measurement type water level meters may be used, but a continuous measurement type throwing water level meter which is a general water level meter can be suitably used.

<Vortex generation area>
When the water in the water absorption tank 2 is pumped by the pump 10, the water in the water absorption tank 2 flows toward the pump 10. At this time, vortices (air suction vortices) may be generated depending on the speed of water flow. Since the vortex is likely to be generated when the flow of water is fast, the vicinity of the pump 10 around the pump 10 where the flow of water becomes fast becomes a vortex generation region where the vortex is likely to be generated.

  The tip of the water return pipe 30 is directed to the vortex generation region as described above, and water can be returned toward the vortex generation region. As a result, the water flow in the vortex generation region can be disturbed, and as a result, the generation of vortices can be prevented.

  The position of the vortex generation region in the water absorption tank 2 and the water level of the water absorption tank 2 when the vortex is generated are estimated or obtained in advance by verification of a water tank experiment, simulation, trial operation, actual machine operation, and the like. For example, specifically, it can be estimated by a test using a simulated water tank based on a vortex test based on the pump suction water tank model test method of the TSJS002 standard of the turbo machinery association, or by analysis by a computer. Therefore, before installing the pump system 1, the vortex generation water level and the vortex generation region are verified and estimated in advance by tests and computer analysis, and the tip of the water return pipe 30 is estimated when the pump system 1 is installed. It is preferably directed to the generated vortex generation region.

  A nozzle may be provided at the tip of the water return pipe 30. By selecting this nozzle, it is possible to accurately inject water toward the vortex generation region and to inject water toward a wide range of vortex generation regions.

  For example, the nozzle provided at the tip of the water return pipe 30 may eject water in a fan shape in plan view. Further, the nozzle provided at the tip of the water return pipe 30 may be configured to be able to change the injection direction according to the water level of the water absorption tank 2, or by rotating at a predetermined cycle, water can be supplied in multiple directions. You may inject. As a result, water can be returned more reliably toward the vortex generation region, and vortex generation can be prevented more reliably.

  Moreover, as shown in FIG. 1, it is preferable that the front-end | tip part of the water return pipe 30 is orient | assigned to the diagonal direction with respect to the water surface of a vortex generating area | region. As a result, water can be injected in an oblique direction with respect to the water surface, and the injected water is incident on a wider range of water surface than in the case of vertical injection. The flow can be disturbed.

<Operation of pump system>
FIG. 2 is a side view of the pump system showing the relationship between the operating state of the pump system of the present embodiment and the water level.

  The pump 10 is activated when it is equal to or higher than the starting water level, which is a predetermined water level equal to or higher than the pump stop water level shown in FIG. 2, and the explanation regarding the valve opening / closing state added in the figure is for valve opening / closing control during pump activation. An example is shown. In this embodiment, the pump starting water level is described as a high water tank level.

  When the water level in the water absorption tank 2 is low, when the flow rate of water toward the pump 10 in the water absorption tank 2 is high, or when a drift occurs, an air suction vortex is generated from the water surface. In addition, when the flow rate of water toward the pump 10 in the water absorption tank 2 is high or when a drift occurs, an underwater vortex is generated from the wall surface of the water absorption tank 2.

  In the pump system 1, the valve control unit 40 opens the water return valve 31 when the water level of the water absorption tank 2 becomes low, and returns water toward the vortex generation region through the water return pipe 30.

  Hereinafter, the operation method of the pump system 1 will be specifically described.

  The operation method of the pump system 1 first detects the water level of the water absorption tank 2 using the water level meter 50 (detection step). And according to the detected water level, at least a part of the water pumped up by the pump 10 is returned to the vortex generation region via the return pipe 30 (returning step).

  Specifically, as shown in FIG. 2, the valve control unit 40 opens the water return valve 31 when the water level of the water absorption tank 2 is equal to or lower than the water level h1 (predetermined water level). Further, when the water level rises and the water level in the water absorption tank 2 exceeds the water level h1 and rises to the water level h2, the valve control unit 40 closes the water return valve 31.

  By controlling the water return valve 31 in this way, the pump system 1 directs at least a part of the water pumped up by the pump 10 to the vortex generation region via the water return pipe 30 according to the water level of the water absorption tank 2. Return water. Thereby, generation | occurrence | production of a vortex can be prevented and it can prevent that the pump 10 sucks a vortex.

  In addition, as shown in FIG. 2, when the water level of the water absorption tank 2 rises to the water level h2, the water return valve 31 is closed to increase the amount of water supplied from the water absorption tank 2 to the discharge water tank 3, thereby absorbing the water. A sudden rise in the water level in the water tank 2 can be suppressed. If a water level difference is provided in the opening and closing of the water return valve 31 as described above, frequent opening and closing of the valve can be prevented, and failure of the valve, particularly failure of the valve drive unit can be prevented.

  The position of the water level h1 and the vortex generation region may be set based on the result of verifying the water level and region where vortices are likely to be generated in advance through tests and analysis such as trial operation, actual operation, water tank experiment, and simulation at the pump station. preferable.

  By controlling the water return valve 31 as described above, as shown in FIG. 2, when the water level is higher than the start water level (pump stop water level) and lower than the predetermined water level (h1), the water return pipe 30 is directed toward the vortex generation region. When the water level is equal to or higher than the predetermined water level (h2), water is not injected from the water return pipe 30. When the water level rises from the water level h1 to the water level h2, the water return valve 31 is opened to inject water, and when the water level h2 is reached, the water return valve 31 is closed to stop water injection. Further, when the water level is lowered from the water level h2 to the water level h1, the water return valve 31 is kept closed and does not inject water. When the water level h1 is reached, the water return valve 31 is opened and water is injected.

  As described above, the water return valve 31 is opened, and at least a part of the water pumped from the water absorption tank 2 by the pump 10 is jetted from the water return pipe 30 toward the vortex generation region, thereby preventing the generation of vortices. In addition, air suction of the pump due to the generation of vortices can be suppressed, and problems such as a decrease in pump discharge amount and damage due to pump vibration can be suppressed.

  When the water level is higher than h2, the water return valve 31 is closed and the pump 10 pumps as much water as is pumped from the water absorption tank 2 to the discharge water tank 3, thereby absorbing the maximum amount of water that can be supplied. The water can be drained from the water tank 2 and the rise in the water level of the water absorption tank 2 can be suppressed.

  That is, according to the pump system 1, the low-cost and simple configuration of the water return pipe 30 provided with the water return valve 31 and the valve control unit 40 suppresses the air suction of the pump 10 due to the generation of vortices and the high water level. Sometimes the maximum amount of water can be drained from the water absorption tank 2 to the discharge water tank 3.

  Moreover, the pump system 1 stops when the water level of the water absorption tank 2 falls and becomes below the stop water level. However, when the pump is stopped, it takes time to start again due to overheating of the motor, cooling water supply to the engine, etc., and if there is a sudden heavy rain after stopping the pump, the pump will not start in time and the water absorption tank There is a risk of water overflowing. Therefore, it is preferable that the stop frequency of the pump 10 is low.

  According to the pump system 1 of the present embodiment, at least a part of the water absorbed from the water absorption tank 2 can be returned to the water absorption tank 2 according to the water level of the water absorption tank 2. Thereby, the effect that the rapid fall of the water level of the water absorption tank 2 can be suppressed and the stop frequency of the pump 10 can be reduced is also obtained.

  The valve control unit 40 is not limited to a configuration that can control the open / close state of the water return valve 31 in two stages, that is, an open state and a closed state. For example, the valve control unit 40 may be configured to adjust the opening degree of the water return valve 31. Thereby, the amount of returned water can be adjusted according to the water level of the water absorption tank 2, the amount of returned water can be increased as the water level of the water absorption tank 2 decreases, and the water level of the water absorption tank 2 can be further stabilized. 1 can be driven.

<Replacing the pump>
The pump system 1 of the present embodiment may be configured by modifying an existing pump system including the pump 10 and the discharge pipe 20. In particular, it is preferable to employ the pump replacement method when the pump system is modified in accordance with the opportunity to replace the existing pump with a larger capacity pump (new pump).

  In such a pump replacement method, a process of replacing an existing pump with a new pump (exchange step) and a flow path of the discharge pipe 20 are branched so that a part of the water pumped by the new pump is directed to the vortex generation region. A step of adding a return pipe 30 capable of returning water (return pipe extension step), a step of adding a valve control unit 40 for controlling a return valve 31 provided in the return pipe 30 (valve control unit extension step), ,including.

  When an existing pump is replaced with a large-capacity pump, there is a great demand to operate the pump without changing the water level at which the existing pump is operated or stopped. In this way, when the existing pump is operated or stopped, the new large-capacity pump has more opportunities to operate the pump system at a low water level, so there may be more opportunities to generate vortices in the vortex generation region. .

  However, according to the above-described pump replacement method, when the pump is replaced, the low-cost and simple method of adding the water return pipe 30 provided with the water return valve 31 and the valve control unit 40 causes the vortex to be generated. The pump system 1 can suppress the air suction of the pump and can drain the maximum amount of water that can be supplied from the water absorption tank 2 to the discharge water tank 3 when the water level is high.

  In such a pump replacement method, the discharge pipe 20 may be replaced in accordance with the replacement of the pump, or an existing one may be used without replacing the discharge pipe 20.

  Further, in the step of installing the valve control unit 40, a function of controlling the water return valve 31 may be added to the valve control unit 40 of the existing pump system, or the valve control unit of the existing pump system is returned to the water return unit. The valve control unit 40 having a function of controlling the valve 31 may be replaced. The valve control unit 40 may have a control function other than the valve, such as starting / stopping the pump 10.

  Further, when the management operation pipe 60 is provided in the existing pump system, the water return pipe 30 may be branched from the management operation pipe 60, or the management operation pipe 60 may be diverted as the water return pipe 30. May be. Thereby, the expense concerning the extension of the return pipe 30 can be held down.

  Further, before replacing the pump 10, verification of water tank experiments, simulation, trial operation, actual operation, etc., specifically, based on a vortex test based on the pump suction water tank model test method of the turbo machinery association standard TSJS002, It is preferable to estimate the vortex generation region (estimation step) by performing a test using a water absorption tank or analyzing with a computer, and direct the tip of the water return pipe 30 to the estimated region. Thereby, it can be set as the pump system provided with the water return pipe | tube which can return water toward the eddy generation area estimated by the test and analysis, and can suppress the air suction of the pump by generation | occurrence | production of a vortex effectively. .

  Furthermore, when estimating the vortex generation region, it is preferable to estimate the water level of the water absorption tank 2 when the vortex is generated (water level estimation step). Thereby, the valve control unit 40 can be controlled based on the water level when the vortex is likely to occur, and the water return amount and the discharge amount can be adjusted appropriately. Thereby, the air suction of the pump by generation | occurrence | production of a vortex can be suppressed effectively.

  In this embodiment, as an example of the estimation step, it has been described by a test or simulation using a simulated water absorption tank. However, any method can be used as long as the vortex generation region and the vortex generation water level can be estimated. Also good.

[Embodiment 2]
Another embodiment of the present invention will be described with reference to FIG. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  FIG. 3 is a side view showing a configuration of a main part of the pump system of the present embodiment.

  As shown in FIG. 3, the pump system 101 further includes a bottom water return pipe 70 in addition to the same configuration as the pump system 1 of the first embodiment.

  The bottom water return pipe 70 branches from the water return pipe 30 downstream of the water return valve 31, and the tip thereof is directed to the bottom of the water absorption tank 2. More specifically, the tip of the bottom water return pipe 70 is directed to the bottom of the water absorption tank 2 immediately below the bell mouth 11 of the pump 10. Thereby, the bottom water return pipe 70 can inject at least part of the water pumped by the pump 10 toward the bottom of the water absorption tank 2. The destination of the bottom water return pipe 70 is not limited to the position immediately below the bell mouth 11 but may be directed to a place where the mud M tends to stay. Thereby, the water absorption tank 2 can be made more beautiful.

  According to the pump system 101 of the present embodiment, by controlling the water return valve 31 according to the water level of the water absorption tank, at least a part of the water pumped from the water absorption tank 2 according to the water level of the water absorption tank 2 is swirled. Water can be returned toward the generation area and the bottom of the water absorption tank 2.

  As a result, the water flow in the vortex generation region can be disturbed, and as a result, the generation of vortices can be prevented.

  Further, the mud M staying at the bottom of the water absorption tank 2 is wound up, the mud M is sucked up together with the water pumped up by the pump 10, and can be discharged to the outside of the water absorption tank 2 through the discharge pipe 20. The bottom can be cleaned. Moreover, the air suction of the pump 10 by generation | occurrence | production of the underwater vortex S1 which generate | occur | produces from the bottom face of the water absorption tank 2 can be suppressed.

[Embodiment 3]
Another embodiment of the present invention will be described with reference to FIGS. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  FIG. 4 is a side view showing a configuration of a main part of the pump system of the present embodiment.

  As shown in FIG. 4, the pump system 201 includes a bottom water return pipe 80 and a bottom water return valve 81 in addition to the same configuration as the pump system 1 of the first embodiment, and the valve control unit 40 includes Instead, a valve control unit 140 is provided.

  The bottom water return pipe 80 branches off from the management operation pipe 60, and the tip thereof is directed to the bottom of the water absorption tank 2. The bottom water return pipe 80 is provided with a bottom water return valve 81. Thereby, the bottom water return pipe 80 can inject at least a part of the water pumped by the pump 10 toward the bottom of the water absorption tank 2.

  The valve control unit 140 controls the water return valve 31 and the bottom water return valve 81 according to the water level of the water absorption tank 2 detected using the water level gauge 50. Further, the valve control unit 140 may control the discharge valve 21 according to the water level of the water absorption tank 2 or may control the start / stop of the pump 10.

<Operation of pump system>
FIG. 5 is a side view of the pump system showing the relationship between the operating state of the pump system of the present embodiment and the water level.

  As shown in FIG. 5, in the pump system 201 of this embodiment, the valve control unit 140 controls the water return valve 31 and the bottom water return valve 81 so that the water return valve 31 is turned on when the water level is equal to or higher than the pump stop water level. By opening the bottom water return valve 81 in the open state, water is injected from the water return pipe 30 toward the vortex generation region, and when the water level is equal to or higher than the first predetermined water level, the water return valve 31 is closed and the bottom water return water is returned. By opening the valve 81, water is jetted from the bottom water return pipe 80 toward the bottom of the water absorption tank 2.

  Thus, the pump system 201 of the present embodiment injects water to the bottom at the first predetermined water level or higher where the possibility of vortex generation is low. At this time, water is not injected from the water return pipe 30 by closing the water return valve 31.

  Thereby, the muddy water sucked up by the pump 10 by jetting water toward the bottom is discharged to the outside of the water absorption tank through the discharge pipe 20 without returning water to the water absorption tank 2 through the water return pipe 30. can do. Thus, the bottom of the water absorption tank 2 can be efficiently cleaned at a water level where vortices are unlikely to be generated, and water can be jetted toward the vortex generation region at the water level where vortices are generated. If there is a concern about the occurrence of underwater vortices, the bottom water return valve 81 may be opened to prevent underwater vortices regardless of the water level.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  In the description of each of the above embodiments, the turbomachinery association TSJS002 (vortex test based on the pump suction water tank model test method) is given as an example as a test using a simulated water tank, but the test method in the present invention is not limited to the above. Other test methods may be employed.

  1, 3, and 4, the tip of the water return pipe 30 is in water, and the water return pipe 30 is illustrated to inject water from the water toward the vortex generation region. However, the spraying may be performed on the water surface or from the water surface toward the vortex generation region.

  In the description of each of the above embodiments, the pump activation water level has been described as the water tank high water level. However, the pump activation may be performed manually, and the pump may be activated at any water level.

  The present invention can be used as a pump system for draining rainwater.

DESCRIPTION OF SYMBOLS 1, 101, 201 Pump system 2 Water absorption tank 10 Pump 20 Discharge pipe 30 Return pipe 31 Return valve 40, 140 Valve control part 70, 80 Bottom return pipe 81 Bottom return valve

Claims (8)

A pump for pumping the water in the water absorption tank;
A discharge pipe for discharging water pumped by the pump;
A return pipe that branches off from the discharge pipe and is provided so that at least a portion of the water pumped by the pump can be returned to the water absorption tank, and a method for operating a pump system comprising:
A detection step of detecting the water level of the water absorption tank;
When the water level of the water absorption tank is lower than a predetermined water level, the return water that returns at least a part of the water pumped up by the pump toward the vortex generation region in the water absorption tank through the return pipe And a step of operating the pump system.   The method of operating a pump system according to claim 1, wherein in the water return step, the amount of water returned is increased as the water level of the water absorption tank decreases.   3. The operation method of a pump system according to claim 1, wherein the predetermined water level is a water level at which a vortex determined based on a result verified in advance is generated. A pump for pumping the water in the water absorption tank;
A discharge pipe for discharging water pumped by the pump;
A return pipe that branches off from the discharge pipe and is provided so that at least a part of the water pumped by the pump can be returned to the water absorption tank,
The water tank is provided with a water level gauge,
The water return pipe is directed to the vortex generation region in the water absorption tank,
The return pipe is provided with a return valve,
A pump system comprising: a valve control unit that controls the water return valve in accordance with a water level of the water absorption tank. A bottom water return pipe that is branched from the discharge pipe and provided so as to be able to return at least a portion of the water pumped by the pump toward the bottom of the water absorption tank,
The bottom water return pipe is provided with a bottom water return valve,
The pump system according to claim 4, wherein the valve control unit controls the bottom water return valve in accordance with a water level of the water absorption tank. In a pump system comprising an existing pump for pumping water in a water absorption tank and a discharge pipe for discharging water pumped by the existing pump, the pump replacement method of the pump system for replacing the existing pump with a new pump. ,
A replacement step of replacing the existing pump with the new pump;
A return pipe expansion step for branching the flow path of the discharge pipe to the discharge pipe and adding a return pipe capable of returning a part of the water pumped by the new pump toward the vortex generation region in the water absorption tank When,
A pump control method for a pump system, comprising: a valve control unit expansion step for adding a valve control unit for controlling a water return valve provided in the water return pipe according to a water level of the water absorption tank. The pump replacement method for a pump system according to claim 6, comprising an estimation step of estimating the vortex generation region by a test or analysis.
A pump replacement method for a pump system, wherein, in the return pipe extension step, the return pipe is added so that water can be returned toward the vortex generation region estimated in the estimation step.   8. The pump replacement method for a pump system according to claim 7, wherein the estimation step includes a water level estimation step for estimating a water level when a vortex is generated in the vortex generation region.

Images