JP5306881B2 - Control device and control method for manhole pump device - Google Patents

Description

  The present invention relates to a control device and a control method for a manhole pump device.

  Natural flow sewage transport pipes buried in the ground at a downward slope are connected to a manhole pump device at predetermined intervals.

  The manhole pump device measures the manhole that stores the sewage flowing in from the inflow pipe at the end of the sewage transport pipe, the submersible pump that pumps the sewage stored in the manhole to the outflow pipe, and the level of the sewage stored in the manhole. A water level sensor is provided.

  Such a manhole pump device includes a control unit that starts the submersible pump when the water level measured by the water level sensor reaches a predetermined pump start water level, and stops the submersible pump when the pump stop water level lower than the pump start water level is reached. A control device is installed.

  The submersible pump installed in the manhole is selected from a model with a small capacity from the viewpoint of cost, power consumption, space saving, etc., so it may be operated with a high head and a small amount of water on the pump performance curve. is there.

  As the sewage is pumped to the outflow pipe by the submersible pump activated at the pump activation water level and the water level decreases, the head height increases and the amount of pumped water decreases.

  However, the sewage may contain a wide variety of solid foreign matters such as paper and cloth. If such solid foreign matters get entangled with the impeller, the submersible pump may be blocked.

  Therefore, in Patent Document 1, an intermediate water level is set between the pump start water level and the pump stop water level, and when the water level reaches the intermediate water level, the submersible pump is stopped for a predetermined time and then restarted. A technique for removing entangled foreign matter is disclosed.

Japanese Patent Application Laid-Open No. 07-91389

  However, when the driven submersible pump is temporarily stopped and restarted, the water level may be lower than the pump starting water level and the lift may be large, resulting in a large current during startup and a significant increase in motor life. There was a problem that the start frequency which affects was increased.

  It is also possible to remove the foreign matter entangled with the impeller by temporarily stopping the submersible pump and driving it in the reverse direction. In this case, the impeller bolts fastened to the main shaft loosen and the main shaft There is also a problem that the impeller may be detached from the wheel.

  In addition, when the head is increased and the amount of pumped water is reduced, there is a possibility that the foreign matter may stay in the pump casing without being pumped to the outflow pipe even if the impeller does not get tangled.

  In particular, in submersible pumps equipped with non-clog type impellers, there is a low risk of foreign objects getting entangled with the impellers. There was a problem that there was a high possibility of doing.

  In view of the above-described problems, an object of the present invention is to provide a control device and a control method for a manhole pump device in which foreign matter is not entangled with the impeller or stays in the pump casing without causing clogging without increasing the activation frequency. Is to provide

In order to achieve the above-mentioned object, the first characteristic configuration of the submersible pump device according to the present invention is, as described in claim 1 of the claims, a manhole for storing sewage flowing in from the inflow pipe, and a manhole Is installed in a manhole pump device equipped with a submersible pump that pumps the sewage stored in the outflow pipe and a water level sensor that measures the level of sewage stored in the manhole, and the water level measured by the water level sensor starts the specified pump When the water level is reached, the submersible pump is started, and when the pump stop water level lower than the pump start water level is reached, the control unit for the manhole pump device includes a control unit that stops the submersible pump. during water level after the start up reaches pump stop level, the first rotary control for driving the water pump at a predetermined constant rotational speed, higher than the steady state rotation speed rotation In lies in a combination of the second rotary control including a control for driving controlling the water pump.

The control unit starts the submersible pump and starts the first rotation control for driving the submersible pump at a predetermined steady rotational speed until the water level reaches the pump stop water level, and the first rotational control for driving the submersible pump at a rotational speed higher than the steady rotational speed . By controlling the submersible pump by freely combining two-rotation control, the flow velocity around the impeller and the pump casing is changed, and the flow state is changed, so that foreign matter is entangled with the impeller, and the pump casing The occurrence of clogging due to stagnation of foreign matter can be avoided and the sewage can be pumped well.

And even if the pumping water amount decreases due to the rise in the head due to the lowering of the water level, it is possible to increase the pumping water amount by driving at the steady rotational speed by driving at a rotational speed higher than the steady rotational speed. Even if the foreign matter stays in the pump casing, the effect of the pressure feeding can be increased and the foreign matter can be discharged effectively.

In the second characteristic configuration, as described in claim 2 , in addition to the first characteristic configuration described above, the second rotation control is performed by driving the submersible pump at the first rotation number and then starting from the first rotation number. It is in the point including the control which drives at high 2nd rotation speed.

  For example, by driving the impeller at a first rotational speed lower than the steady rotational speed, it is possible to weaken the force that the foreign matter gets entangled with the impeller, and to remove the foreign matter from the impeller. By driving at a second rotational speed higher than the number, the detached foreign matter can be effectively discharged. In addition, when foreign matter stays in the pump casing, driving the impeller at the first rotation speed decreases the flow velocity around the impeller and the pump casing, and the foreign matter stays in a different state. To do. Thereafter, by driving the impeller at a second rotational speed higher than the first rotational speed, the foreign matter whose staying state has changed can be effectively discharged on the sewage flow. The first rotational speed is not limited to a rotational speed lower than the steady rotational speed, and may be the same rotational speed as the steady rotational speed or a rotational speed higher than the steady rotational speed.

The third feature structure, as described in the claim 3, in addition to the first feature configuration described above, the second rotary control includes a control for driving the water pump at a first rotational speed, the first rotational speed It is in the point which repeats the control which drives with a higher 2nd rotation speed.

  By repeating the control driven at the first rotational speed and the control driven at the second rotational speed higher than the first rotational speed, the flow velocity in the pump casing changes and the sewage is repeatedly fluctuated and the force applied to the foreign matter is reduced. The foreign matter that is changed and entangled with the impeller is likely to be detached and is more likely to be discharged. In addition, when foreign matter stays in the pump casing, driving the impeller at the first rotation speed decreases the flow velocity around the impeller and the pump casing, and the foreign matter stays in a different state. To do. Thereafter, by driving the impeller at a second rotational speed higher than the first rotational speed, the foreign matter whose staying state has changed can be effectively discharged on the sewage flow.

The fourth characteristic configuration is that, as described in claim 4 , in addition to the second or third characteristic configuration described above, the second rotational speed is higher than the rated rotational speed.

  When the second number of rotations is higher than the rated number of rotations, the discharge amount at the same head can be increased, so that the effect of pumping is increased and foreign matter is easily discharged.

In the fifth feature configuration, as described in claim 5 , in addition to any of the second to fourth feature configurations described above, the first rotational speed is a rise connected to the discharge port of the submersible pump. It is in the point set to the rotation speed more than the rotation speed which can ensure the discharge pressure higher than the discharge pressure which waterfall generate | occur | produces in piping.

  If the submersible pump is stopped and water is dropped, energy will be needed to pump the sewage that has fallen when it is restarted. If the first rotation speed is set to a rotation speed that is higher than the discharge pressure at which a discharge pressure higher than the discharge pressure at which falling water is generated in the rising pipe can be secured, the rotation speed is then increased while removing foreign matter entangled with the impeller. Even in such a case, power consumption can be effectively suppressed.

In the sixth feature configuration, as described in claim 6 , in addition to any of the second to fifth feature configurations described above, the control unit is configured so that the drive time at the second rotation speed is the first rotation speed. It is in the point which controls so that it may become longer than the drive time by.

  Even if the discharge flow rate decreases during the drive time at the first rotational speed, and the foreign matter staying in the pump casing or the foreign matter in the discharge pipe sinks in the pipe, the second rotational speed Can be pumped downstream by increasing the driving time.

In the seventh feature configuration, as described in claim 7 , in addition to any of the second to sixth feature configurations described above, the control unit includes a driving time based on the first rotation speed and a second rotation speed. There is a timer setting unit that variably sets the driving time by.

  By variably setting the driving time based on the first rotation speed and the driving time based on the second rotation speed by the timer setting unit, control according to the state of the sewage flowing into the manhole and the capacity of the submersible pump becomes possible.

In the eighth feature configuration, as described in claim 8 , in addition to any of the first to seventh feature configurations described above, the control unit determines that the water level measured by the water level sensor is the pump activation water level. The point is to switch to the second rotation control after reaching the intermediate water level set during the pump stop water level.

  After reaching the intermediate water level, switching to the second rotation control including the control to drive at a rotation speed different from the steady rotation speed, changing the state of the flow around the impeller, entanglement of the foreign object to the impeller, The possibility of clogging due to staying in the pump casing can be reduced.

In the ninth feature configuration, as described in claim 9 , in addition to the eighth feature configuration described above, the intermediate water level is set closer to the pump stop water level than the central water level of the pump start water level and the pump stop water level. There is in point.

  When the water level is lowered and the head is increased, the amount of water to be pumped is reduced, foreign objects are easily entangled with the impeller, and the foreign objects are easily retained in the pump casing without being pumped to the outflow pipe. Therefore, if the intermediate water level is set closer to the pump stop water level than the central water level between the pump start water level and the pump stop water level, the rotation speed of the submersible pump can be changed in the region where such foreign matter is entangled or stays frequently. The flow around the vehicle can be fluctuated, and the foreign matter can be separated from the impeller, or the foreign matter staying in the pump casing can be efficiently pumped.

The tenth characterizing feature of the can, as noted in the claim 10, in addition the first above Fifth any feature configuration of an intermediate level of a plurality of stages between the pump start level and the pump stops water level It is set, and the control unit switches to the second rotation control after the water level measured by the water level sensor reaches the uppermost intermediate water level after starting the submersible pump, and then switches the rotation speed every time it reaches each set water level. It is in.

  As the water level falls, the head rises and the pumping amount of the submersible pump decreases. In the meantime, the impeller is entangled with foreign matter, and the pumping amount may further decrease. Therefore, by detecting that the water level has reached the uppermost intermediate water level by the control unit, the control unit is switched to the second rotation control, and the rotation speed of the submersible pump is controlled to decrease or increase. The removal of the foreign matter from the impeller and the pumping of the staying foreign matter within the pump casing are achieved. Since such rotation speed switching is performed every time the intermediate water level reaches a plurality of stages, the rotation speed can be switched at an appropriate time according to the amount of residual water.

The eleventh characteristic configuration is a submersible pump provided with a non-clog type impeller in addition to any of the first to tenth characteristic configurations described above, as described in claim 11. There is a point.

  If it is a submersible pump equipped with a non-clog type impeller, there is a low possibility that foreign matter will get entangled with the impeller, but if the head becomes high and the pumped water amount decreases, the foreign matter will stay in the impeller and pump casing. It becomes easy to do. In such a case, the staying foreign matter can be effectively pumped together with the sewage by the second rotation control described above.

Characteristic feature of the control method of the manhole pump apparatus according to the present invention, as described in the claim 12, a manhole for storing the sewage flowing in from the inflow tube, a water pump for pumping sewage stored in manhole outlet pipe It is installed in a manhole pump device equipped with a water level sensor that measures the level of sewage stored in the manhole, and when the water level measured by the water level sensor reaches a predetermined pump activation water level, the submersible pump is activated. A control method of a manhole pump device that stops a submersible pump when a low pump stop water level is reached, and after the submersible pump is started until the water level reaches the pump stop water level, the submersible pump is driven at a predetermined steady rotational speed. control the first rotary control for driving the water pump in combination a second rotary control including the control of driving at higher than normal rotational speed rpm To the point that there is.

  As described above, according to the present invention, there is provided a control device and a control method for a manhole pump device in which foreign matter is not entangled with the impeller and does not stay in the pump casing and cause clogging without increasing the activation frequency. Can now be offered.

Explanatory drawing of the manhole pump apparatus by this invention Illustration of submersible pump (A) is a cross-sectional view of a non-clog type impeller, (b) is a cross-sectional view taken along the line AA in FIG. 2 (a). Illustration of the control unit (A) is a performance curve diagram of the submersible pump, (b) is an explanatory diagram of rotation speed switching control. (A) is a time chart of the second rotation control (b) is a time chart of the second rotation control showing another embodiment, (c) is a time chart of the second rotation control showing another embodiment. (A) is a second rotation control time chart showing another embodiment, (b) is a second rotation control time chart showing another embodiment, and (c) is a second rotation control time chart showing another embodiment.

  Below, the control apparatus and control method of the manhole pump apparatus by this invention are demonstrated. As shown in FIG. 1, a manhole pump device 10 includes a manhole 11 that stores sewage flowing in from an inflow pipe 12, and a submersible pump 20 that pumps the sewage stored in the manhole 11 to an outflow pipe 14 via a rising pipe 13. And the water level sensor 15 which measures the water level of the sewage stored in the manhole 11 is provided. In the vicinity of the manhole pump device 10, a control device 50 including a control unit 51 that controls the start and stop of the submersible pump 20 is installed.

  A power supply line 57 for supplying power to the submersible pump 20 is wired between the control device 50 and the submersible pump 20, and a water level detection signal line 58 is wired between the control device 50 and the water level sensor 15.

  The water level sensor 15 is an injection pressure type or bubble type water level sensor, and is installed at the bottom of the manhole 11 so as to continuously detect the level of sewage stored in the manhole 11. Further, in preparation for failure of the water level sensor 15, a backup float type water level sensor 16 is installed at a height that causes an abnormally high water level, and the water level sensor 15 and the water level sensor 16 are configured to detect the abnormally high water level HHWL. Yes. In addition, you may comprise so that a water level may be measured with other well-known water level sensors, such as detecting a water level whenever it becomes a predetermined water level, using a float type water level sensor as a water level sensor.

  As shown in FIG. 2, the submersible pump 20 includes an electric motor 30, a non-clog impeller 22 supported on one end of an electric motor shaft 33 of the electric motor 30, a pump casing 21 that houses the impeller 22, and a pump casing. A connection casing 23 for connecting the motor 21 and the motor 30 is provided.

  As shown in FIG. 3, the impeller 22 has a spiral blade plate 22d fixed between a side plate 22a in which a suction opening is formed and a main plate 22c in which an opening 22b into which the motor shaft 33 is inserted is formed. ing.

  The electric motor 30 includes an electric motor frame 31, a stator 32 disposed on an inner peripheral wall of the electric motor frame 31, an electric motor shaft 33, and a rotor 34 disposed on the electric motor shaft 33, and the electric motor shaft 33 is an upper ball. The impeller 22 is supported at one end by the bearing 35 and the lower ball bearing 36, and the electric power from the control device 50 is transmitted to the electric motor 30 through the feeder line 57, and the electric motor shaft 33 is rotated. The impeller 22 is configured to rotate.

  When the impeller 22 rotates, water is sucked from a suction port 24 formed in the lower part of the pump casing 21, passes through the inside of the impeller 22, and is discharged from a discharge port 25 formed in a part of the peripheral wall. 13 is pumped to the outflow pipe 14 through 13.

  As shown in FIG. 4, the control device 50 receives a microcomputer 52, a control unit 51 having an inverter circuit 53 controlled by the microcomputer, and a monitor signal output from the control unit 51 to input a manhole. A communication unit 54 for wirelessly communicating the state to the outside is provided. The microcomputer 52 controls the inverter circuit 53 based on the water level measured by the water level sensor 15 to control the rotation speed of the electric motor 30.

  When the water level sensor 15 detects the pump activation water level HWL, the control unit 51 activates the electric motor 30 (hereinafter also referred to as “activate the submersible pump”), starts discharging the sewage by the submersible pump 20, and stops the pump. When the water level LWL is measured, the electric motor 30 is stopped after the predetermined time has elapsed, that is, after the time required for pumping the amount of water corresponding to the water level from the stop water level LWL to the vicinity of the suction port 24, and the submersible pump 20 Stop the discharge of sewage.

FIG. 5A shows a characteristic curve showing the relationship among the discharge amount Q of the submersible pump 20, the total head H, the shaft power T, and the pump efficiency η. When the rated rotational speed N0 and the arbitrary rotational speed N are set, the discharge amount is Q0 and Q, the lift is H0 and H, and the shaft power is T0 and T, respectively.
Q / Q0 = N / N0
H / H0 = (N / N0) ²
T / T0 = (N / N0) ³
There is a relationship. Therefore, for example, when the operating point is set so that the flow rate Q0 indicating the maximum efficiency η0 is obtained at the total head H0 corresponding to the pump starting water level HWL, the rotational speed N0 at that time is determined, and correspondingly The shaft power T0 is obtained.

When the drive frequency f, voltage V, current I, and constant C are determined by the inverter circuit 53, the drive frequency f0 for securing the shaft power T0 is expressed by the following equation.
T0 = C × (V / f0) × I

  When the values of voltage and current supplied from the commercial power supply are set to predetermined values equal to or lower than the rated power, the driving frequency f0, that is, the rotation speed of the submersible pump 20 is determined. As the electric motor 30, a synchronous electric motor, an induction electric motor or the like is used, and the rotation speed of the electric motor 30 is determined in accordance with the drive frequency f0 by the inverter circuit 53.

  After starting the submersible pump 20, the control part 51 performs the 1st rotation control which drives the rotation speed corresponding to the specification point of the submersible pump 20 as steady rotation speed N0, and starts the drainage of the sewage in the manhole 11. . The steady rotational speed N0 is set to the same value as the rated rotational speed or a value lower than the rated rotational speed.

  If the head at the pump activation water level HWL is H0, the discharge amount at the time S0 when the submersible pump 20 is activated is Q0, the shaft power is T0, and the pump efficiency is η0.

  When the sewage in the manhole 11 is pumped by the first rotation control after the submersible pump 20 is started, the water level in the manhole 11 is lowered, and the head is increased accordingly, and the sewage level measured by the water level sensor 15 is the intermediate water level. When the head rises to Hn at the time Sn when NWL is detected, the shaft power decreases to Tn, the pump efficiency decreases to ηn, and the discharge amount decreases to Qn. As the discharge amount decreases, the foreign matter becomes difficult to be pumped by the submersible pump 20, and a state in which the foreign matter tends to stay in the casing 21 or the rising pipe 13 occurs. The foreign matter is a solid foreign matter such as a resin piece, a piece of cloth or paper mixed in the sewage.

  When the lift increases from H0 to Hn and the discharge amount decreases from Q0 to Qn, the pump efficiency also decreases to ηn, but the shaft power Tn is in a state with a margin in terms of power compared to T0. By utilizing such electric power and the margin of the electric motor, the submersible pump 20 can be driven at a rotational speed NH higher than the steady rotational speed N0 within the range of the rated output of the motor. Note that at the time Sh when the submersible pump 20 is driven at the rotation speed NH when the head is Hn, a discharge amount Qh greater than Qn is obtained.

  As shown in FIG.5 (b), the control part 51 starts the submersible pump 20, performs 1st rotation control, and when the head becomes high from predetermined time, for example, H0 to Hn, the submersible pump 20 Is switched to the second rotation control that is driven at a rotation speed NH higher than the steady rotation speed N0 (indicated by a solid line in the figure), thereby increasing the amount of sewage pumped and retaining foreign matter in the pump casing 21. Can be pumped together with sewage.

  In addition, when the control unit 51 switches from the first rotation control to the second rotation control that is driven at a rotation speed smaller than the steady rotation speed N0 (indicated by a broken line in the figure), the blades are reduced by the decrease in the rotation speed. The flow rate of the sewage around the wheel 22 is decelerated, the water flow in the pump casing 21 fluctuates, and the force applied to the foreign matter entangled with the impeller 22 during the first rotation control changes and is effectively separated. be able to.

  Thereafter, by increasing the rotation speed of the submersible pump 20, it is possible to pump the foreign matter detached from the impeller 22 together with the sewage.

  That is, the controller 51 determines from the first rotation control that drives the submersible pump 20 at a predetermined steady rotational speed until the water level reaches the pump stop water level LWL after the submersible pump 20 is started. It is configured to switch to the second rotation control that is driven at a different rotation speed.

  Switching of the rotational speed controlled by the control unit 51 is not limited to stepwise switching, and may be set as appropriate, such as continuous switching, for example, switching of the rotational speed along a sine curve.

  Further, the controller 51 starts the submersible pump 20 and starts the submersible pump 20 at a predetermined steady rotational speed until the water level reaches the pump stop water level LWL. You may comprise so that a submersible pump may be controlled combining the 2nd rotation control containing the control driven by a different rotational speed.

  Hereinafter, specific examples of the first rotation control and the second rotation control executed by the control unit 51 will be described in detail.

  As shown in FIG. 6 (a), when the water level measured by the water level sensor exceeds the pump activation water level HWL, the control unit 51 activates the submersible pump 20 and drives it at a predetermined steady rotational speed N0. Execute rotation control.

  When the water level measured by the water level sensor 15 reaches the intermediate water level NWL, the control is switched to the second rotation control, and is driven at the first rotation speed NL lower than the steady rotation speed N0 for a predetermined time T1, and then higher than the first rotation speed NL. Driven for a predetermined time T2 at the second rotational speed NH.

  Thereafter, when the pump stop water level LWL is detected, the submersible pump 20 is stopped after a predetermined time T3. The predetermined time T3 is a time required for pumping the amount of water corresponding to the water level from the stop water level LWL to the vicinity of the suction port 24 at the steady rotation speed N0.

  That is, after being driven at a predetermined first rotational speed NL, it is driven at a second rotational speed NH higher than the first rotational speed NL, and the driving time T2 based on the second rotational speed NH is the driving time based on the first rotational speed NL. It is controlled to be longer than T1.

  Even if the discharge flow rate decreases during the drive time T1 at the first rotational speed NL and the foreign matter staying in the pump casing 21 or the foreign matter in the discharge rising pipe 13 settles in the pipe, By extending the driving time T2 at the two rotation speed NH, it can be pumped downstream. The driving time T1 needs to be secured for several seconds, and the driving time T2 may be set in the range of 10 seconds to several tens of seconds.

  The first rotation speed NL is set to be equal to or less than the steady rotation speed N0, but is equal to or higher than the rotation speed at which a discharge pressure higher than the discharge pressure at which falling water is generated in the rising pipe 13 connected to the discharge port 25 of the submersible pump 20 can be secured. It is preferable that the number of rotations is set.

  The minimum rotation speed at which the impeller 22 of the submersible pump 20 continues to rotate, for example, the inverter circuit 53 is set to a rotation speed of about 5% or more of the rated rotation speed. This is because the current does not increase unless the submersible pump 20 is stopped even if water falls in the rising pipe 13.

  When the submersible pump 20 is stopped and water falls in the rising pipe 13, when the submersible pump 20 is started again, energy is required to pump the sewage that has fallen, but the first rotation speed NL is dropped by the rising pipe 13. If it is set to a rotation speed that is higher than the rotation speed at which a discharge pressure higher than the discharge pressure generated can be secured, even if the rotation speed is increased next, while removing the foreign matter entangled with the impeller, This is because power consumption can be effectively suppressed.

  The first rotational speed NL is set to an arbitrary value in a range of about 70% or more of the rated rotational speed, for example, and the second rotational speed NH is an arbitrary value in a range of about 110% or lower of the rated rotational speed, for example. Can be set to Here, the rated rotational speed is a rotational speed determined from the commercial power supply frequency and the number of poles of the motor. For example, if the commercial power supply frequency is 60 Hz and the number of poles of the motor is 4, the speed is 1800 rpm. The second rotational speed NH may be a rotational speed higher than the rated rotational speed at which the drive frequency by the inverter circuit 53 is the commercial power supply frequency of 60 Hz or 50 Hz. Usually, the drive frequency by the inverter circuit has a drive capability up to about 110% of the commercial power supply frequency.

  The intermediate water level NWL is set closer to the pump stop water level LWL than the central water level of the pump start water level HWL and the pump stop water level LWL. When the water level is lowered and the head is increased, the amount of water to be pumped is reduced, and foreign objects are easily entangled with the impeller 22, and the foreign substances are easily retained in the pump casing 21 without being pumped to the outflow pipe. This is because the second rotation control is executed in such a situation.

  In addition to executing the switching to the second rotation control by detecting the intermediate stop water level NWL, the current of the armature winding of the electric motor 30 is measured to detect that the current value has decreased below a predetermined value and to perform the second rotation. Switching to control may be performed.

  In addition, as shown by the broken line blowing in FIG. 6A, when the rotation speed is switched, if the switching is performed in a stepwise manner, the electric motor 30 cannot cope with the rotation. Also, soft start and soft stop control for gradually increasing or decreasing the frequency is performed when the submersible pump 20 is started or stopped.

  Furthermore, the rotation speed may be switched to the first rotation speed NL or the second rotation speed NH in a sine wave form. That is, the rotational speed may be switched in a sine wave shape so that the first rotational speed NL is a negative peak rotational speed and the second rotational speed NH is a positive peak rotational speed. Similarly, the rotation speed may be switched in a triangular wave shape so that the first rotation speed NL is a negative peak rotation speed and the second rotation speed NH is a positive peak rotation speed.

  As shown in FIG. 6B, the second rotation control is performed so that the control for driving the submersible pump 20 at the first rotation speed NL and the control for driving at the second rotation speed NH higher than the first rotation speed NL are repeated. May be executed.

  By repeatedly decreasing and increasing the rotational speed, the flow velocity in the pump casing 21 is changed, the sewage is repeatedly fluctuated, the force applied to the foreign matter is changed, and the foreign matter entangled with the impeller 22 is easily separated and discharged. Is more likely. In addition, the more rapid the change in the rotational speed, the larger the change in the flow velocity, and the easier it is for the foreign matter to leave and to be discharged.

  At this time, the first rotation speed NL and the second rotation speed NH do not need to be fixed, and the second rotation speed NL is higher or lower than the first rotation speed NL for the first time. It may be set to be. Since the head rises due to the drop in the water level, if the second first rotation speed is set higher than the first rotation speed NL for the first time, a significant decrease in the pumping amount can be prevented. Similarly, the second rotation speed NH for the second time may be set higher or lower than the first second rotation speed NH.

  As shown in FIG. 6C, the control for driving the submersible pump 20 at the second rotational speed NH and the control for driving at the first rotational speed NL lower than the second rotational speed NH are executed at the initial stage of the second rotational control. You may repeat this. In this case, the foreign matter staying in the pump casing 21 is pumped by the initial drive at the second rotational speed NH, and then the foreign matter entangled with the impeller 22 and the like is detached by the drive at the first rotational speed NL. Further, the separated foreign matter is pumped by driving at the second rotational speed NH.

  As shown in FIG. 7 (a), the control for driving the submersible pump 20 at the first rotational speed NL at the initial stage of the second rotational control, and then the second lower than the first rotational speed NL and lower than the steady rotational speed N0. Control that is driven at the rotation speed NH may be executed.

  In any case, it is particularly preferable to drive at the second rotation speed NH after driving at the first rotation speed NL.

  The controller 51 preferably includes a timer setting unit 55 (see FIG. 4) that variably sets the driving time based on the first rotational speed and the driving time based on the second rotational speed. By variably setting the driving time T1 based on NL and the driving time T2 based on the second rotational speed NH, control according to the state of sewage flowing into the manhole 11 and the capacity of the submersible pump 20 becomes possible.

  Specifically, the timer value input by the administrator via the timer setting unit 55 is configured to be stored in the memory, and the microcomputer 52 performs the first rotation speed NL based on the timer value stored in the memory. And the drive time of the second rotation speed NH may be controlled. The timer value may be 0.

  Further, as shown in FIGS. 7B and 7C, a plurality of intermediate water levels NWL1, NWL2,... Are set between the pump start water level HWL and the pump stop water level LWL, and the control unit 51 After the pump 20 is started, the water level measured by the water level sensor switches to the second rotation control after reaching the uppermost intermediate water level NWL1, and then the rotation speed is switched each time it reaches each set water level NWL2, NWL3,. You may comprise as follows. In this case, it is preferable to use an injection pressure type or bubble type water level sensor capable of continuously detecting the water level as the water level sensor.

  As the water level decreases, the head rises and the pumping amount of the submersible pump 20 decreases. In the meantime, the impeller is entangled with foreign matter, and the pumping amount may further decrease. Therefore, after the control unit 51 detects that the water level has reached the uppermost intermediate water level NWL1, the control unit 51 is switched to the second rotation control, and the rotation speed of the submersible pump 20 is controlled to decrease or increase. As a result, the detachment of the foreign matter from the impeller and the pumping of the staying foreign matter within the pump casing 21 are achieved. Since such switching of the rotational speed is performed every time the intermediate water levels NWL1, NWL2,... Reach a plurality of stages, the rotational speed can be switched at an appropriate time according to the residual water amount.

  The driving time at each rotational speed is determined by the water levels set as the intermediate water levels NWL1, NWL2,. For example, as shown in FIG. 7C, the driving time at the first rotation speed NL is determined by the water level difference between the intermediate water levels NWL1 and NWL2, the water level difference between NWL3 and NWL4, and driving at the second rotation speed NH. The time is determined by the water level difference between the intermediate water levels NWL2 and NWL3 and the water level difference between NWL4 and LWL.

  With the above configuration, the manhole 11 that stores the sewage flowing in from the inflow pipe 12, the submersible pump 20 that pumps the sewage stored in the manhole 11 to the outflow pipe 14, and the water level of the sewage stored in the manhole 11 are measured. The submersible pump 20 is started when the water level measured by the water level sensor 15 reaches a predetermined pump start water level HWL, and the pump stop water level LWL lower than the pump start water level HWL. Is a control method of the manhole pump device 10 that stops the submersible pump 20 when the water level is reached, and after the submersible pump 20 is started, the submersible pump 20 is kept at a predetermined steady rotational speed N0 until the water level reaches the pump stop water level LWL. The first rotation control that is driven by the first rotation control and the second rotation control that includes the control that is driven at a rotation speed different from the steady rotation speed N0. Control method for manhole pump apparatus 10 for controlling the water pump 20 combined can be performed.

  In the embodiment described above, the configuration in which the rotation speed of the submersible pump is variably controlled by the inverter circuit has been described. However, the circuit that variably controls the rotation speed of the submersible pump is not limited to the inverter circuit, and a known drive circuit is appropriately employed. can do. For example, when an induction motor is employed as the motor, the rotational speed can be switched by variably controlling the slip ratio of the rotor using a microcomputer.

  In the above-described embodiment, the case of the submersible pump provided with the non-clog type impeller has been described, but it is a known submersible pump of a submersible pump provided with a vortex type impeller, a screw type impeller, or the like. The present invention can also be applied.

  In particular, in the case of a submersible pump equipped with an impeller with a complicated shape compared to a non-clog impeller, such as a vortex impeller, foreign matter is likely to get entangled with the impeller, and the submersible pump is controlled by the control unit. From the first rotation control for driving the submersible pump at a predetermined steady rotation speed to the second rotation control for driving at a rotation speed different from the steady rotation speed until the water level reaches the pump stop water level after starting Thus, by changing the state of the flow around the impeller, there is a high effect of reducing the possibility of tangling of foreign matters to the impeller and the occurrence of clogging due to retention in the pump casing.

  In the above-described embodiment, the configuration in which the control device 50 is installed in the vicinity of the manhole 11 has been described. However, a configuration in which the control device 50 is built in the submersible pump 20 may be used.

  The specific configuration of the control device and the control method for the manhole pump device described above is not limited to the description of the above-described embodiment, and it goes without saying that the design can be changed as appropriate within the scope of the effects of the present invention. Nor.

10: Manhole pump device 12: Inflow pipe 11: Manhole 13: Rising pipe 14: Outflow pipe 15, 16: Water level sensor 20: Submersible pump 21: Pump casing 22: Impeller 22a: Side plate 22b: Opening 22c: Main plate 22d: Blade Plate 23: Connection casing 24: Suction port 25: Discharge port 30: Electric motor 31: Electric motor frame 32: Stator 33: Electric motor shaft 34: Rotor 35: Upper ball bearing 50: Controller 51: Control unit 52: Microcomputer 53 : Inverter circuit 54: Communication unit 55: Timer setting unit 57: Feed line 58: Water level detection signal line H: Lifting head T: Shaft power η: Pump efficiency N0: Steady speed NL: First speed NH: Second speed T1: Drive time T2: Drive time HWL: Pump start water level LWL: Pump stop water level NWL: Intermediate water level

Claims (12)

It is installed in a manhole pump equipped with a manhole that stores sewage flowing in from the inflow pipe, a submersible pump that pumps the sewage stored in the manhole to the outflow pipe, and a water level sensor that measures the water level of the sewage stored in the manhole. A manhole pump device having a control unit that starts a submersible pump when the water level measured by the water level sensor reaches a predetermined pump start water level and stops the submersible pump when a pump stop water level lower than the pump start water level is reached. A control device,
The controller controls the first rotation control for driving the submersible pump at a predetermined steady rotational speed and the control for driving at a rotational speed higher than the steady rotational speed until the water level reaches the pump stop water level after starting the submersible pump. by combining the second rotary control including a control device for manhole pumping device for controlling the water pump. 2. The control device for a manhole pump device according to claim 1 , wherein the second rotation control includes a control for driving the submersible pump at a second rotation speed higher than the first rotation speed after being driven at the first rotation speed.   2. The control device for a manhole pump device according to claim 1, wherein the second rotation control repeats control for driving the submersible pump at a first rotation speed and control for driving at a second rotation speed higher than the first rotation speed. The control device for a manhole pump device according to claim 2 or 3 , wherein the second rotational speed is higher than the rated rotational speed. The first rotational speed, any claims 2 to 4, a higher discharge pressure than discharge pressure of man overboard the connected rising pipe to the discharge port of the water pump is generated is set to the speed of the above rotational speed can be secured A control device for a manhole pump according to claim 1. The control unit for a manhole pump according to any one of claims 2 to 5 , wherein the control unit controls the driving time based on the second rotational speed to be longer than the driving time based on the first rotational speed. The control unit for a manhole pump according to any one of claims 2 to 6 , wherein the control unit includes a timer setting unit that variably sets a driving time based on the first rotational speed and a driving time based on the second rotational speed. The manhole pump according to any one of claims 1 to 7 , wherein the control unit switches to the second rotation control after the water level measured by the water level sensor reaches an intermediate water level set between the pump start water level and the pump stop water level. Control device for the device. The control device for a manhole pump device according to claim 8 , wherein the intermediate water level is set closer to the pump stop water level than the central water level of the pump start water level and the pump stop water level. A multi-stage intermediate water level is set between the pump start water level and the pump stop water level, and the controller controls the second rotation after the water level measured by the water level sensor reaches the uppermost intermediate water level after the submersible pump is started. The control device for a manhole pump device according to any one of claims 1 to 5 , wherein the number of rotations is switched each time the set water level is reached. The control device for a manhole pump device according to any one of claims 1 to 10 , wherein the submersible pump is a submersible pump provided with a non-clog type impeller. It is installed in a manhole pump equipped with a manhole that stores sewage flowing in from the inflow pipe, a submersible pump that pumps the sewage stored in the manhole to the outflow pipe, and a water level sensor that measures the water level of the sewage stored in the manhole. The control method of the manhole pump device starts the submersible pump when the water level measured by the water level sensor reaches a predetermined pump start water level, and stops the submersible pump when the pump stop water level lower than the pump start water level is reached,
A first rotation control for driving the submersible pump at a predetermined steady rotation speed and a control for driving at a higher rotation speed than the steady rotation speed until the water level reaches the pump stop water level after starting the submersible pump. control method for manhole pumping device for controlling the water pump by combining rotation control.

Images