Submersible pump

Abstract

To provide a submersible pump that can easily and appropriately set start and stop timing of operation of a submersible pump body, and stably operate the submersible pump body at a low water level.SOLUTION: A submersible pump 10 comprises a submersible pump body 110, a first detection part 121 for detecting a first water level, a second detection part 122 for detecting a second water level lower than the first water level, and a submersible pump control part 130 for controlling operation of the submersible pump body 110. The submersible pump control part 130 has a measurement mode and an automatic operation mode. In the measurement mode, the operation of the submersible pump body 110 is started at the first water level, and stop timing for stopping the operation of the submersible pump body 110 is set on the basis of the detection of the first water level and the detection of the second water level. In the automatic operation mode, the operation of the submersible pump body 110 is started on the basis of the detection of the second water level, and the operation of the submersible pump body 110 is stopped on the basis of the stop timing.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a submersible pump. [Background technology]

[0002] Conventionally, submersible pumps have been used at construction sites for purposes such as draining spring water. Submersible pumps use a motor to draw up water and drain it, but the operation of the submersible pump starts and stops depending on the amount of water (water level) accumulated in the boiler room (water tank).

[0003] For example, Patent Documents 1 and 2 disclose techniques relating to submersible pumps equipped with an automatic operation function based on water level control.

[0004] Specifically, the submersible pump disclosed in Patent Document 1 operates the motor based on a water level determination signal from a water level detector, and stops the motor after a calculated operating time determined from past stop times and operating times.The submersible pump disclosed in Patent Document 2 uses a water level detector to detect multiple water levels, including a stop water level and an operating water level, and operates and stops the motor based on these levels. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-220895 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-315367 Summary of the Invention [Problem to be solved by the invention]

[0006] However, while conventional submersible pumps attempt to achieve optimal automatic operation by calculating the start and stop timing of the submersible pump while monitoring changes in the water level, the control and mechanism are complex.

[0007] Additionally, submersible pumps are required to operate automatically and energy-efficiently, and to operate the submersible pump itself stably at low water levels.

[0008] Therefore, the present invention aims to provide an underwater pump that can easily and appropriately set the start and stop timing of the underwater pump main body, and can operate the underwater pump main body stably at low water levels. [Means for solving the problem]

[0009] An underwater pump according to one embodiment of the present invention comprises a submersible pump main body, a first detection unit installed directly or indirectly on the submersible pump main body and configured to detect a first water level and a second detection unit installed directly or indirectly on the submersible pump main body and configured to detect a second water level lower than the first water level, and a submersible pump control unit that controls the operation of the submersible pump main body, wherein the submersible pump control unit has a measurement mode that measures the timing to stop operation of the submersible pump main body and an automatic operation mode that automatically controls the operation and stop of the submersible pump main body, and in the measurement mode, starts operation of the submersible pump main body based on detection of the first water level by the first detection unit, and sets the stop timing to stop operation of the submersible pump main body based on detection of the first water level by the first detection unit and detection of the second water level by the second detection unit, and in the automatic operation mode, starts operation of the submersible pump main body based on detection of the second water level by the second detection unit, and stops operation of the submersible pump main body based on the stop timing.

[0010] In the above aspect, the underwater pump control unit may, in measurement mode, measure the water level drop time from when the first water level is detected by the first detection unit to when the second water level is detected by the second detection unit, and set the stop timing based on the water level drop time.

[0011] In the above aspect, the stop timing may include the time from when the second water level is detected by the second detection unit to when operation of the submersible pump main body is stopped.

[0012] In the above aspect, the measurement frequency for operating and stopping the submersible pump body in measurement mode may be every predetermined number of operations for operating and stopping the submersible pump body in automatic operation mode, or every predetermined time.

[0013] In the above aspect, the measurement frequency may be changed in accordance with a change in the water level drop time measured in the measurement mode.

[0014] In the above aspect, when the change in the water level drop time measured in the measurement mode is within a threshold value, the measurement frequency may be reduced or maintained.

[0015] In the above aspect, in the measurement mode, the submersible pump control unit may start operation of the submersible pump main body based on the detection of a first water level by the first detection unit, and then reset the measurement of the water level drop time if the first water level is further detected by the first detection unit before the second water level is detected by the second detection unit.

[0016] In the above aspect, when the submersible pump is powered on, the submersible pump control unit may start operating the submersible pump main body immediately or after a predetermined time has elapsed in response to the first detection unit detecting a water level above the first water level and / or the second detection unit detecting a water level above the second water level.

[0017] In the above aspect, the submersible pump control unit may start operation of the submersible pump main body in the measurement mode if the first water level is not detected by the first detection unit for a predetermined time after the second water level is detected by the second detection unit. [Effects of the Invention]

[0018] According to the present invention, an underwater pump can be provided that can easily and appropriately set the start and stop timing of the underwater pump main body and can operate the underwater pump main body stably at low water levels. [Brief explanation of the drawings]

[0019] [Figure 1]1 is a schematic diagram showing the configuration of a submersible pump 10 according to an embodiment of the present invention. [Figure 2] 1 is a functional block diagram showing the functions of a submersible pump control unit 130 that controls the operation of a submersible pump main body 110 according to an embodiment of the present invention. [Figure 3] FIG. 10 is a diagram for explaining how the submersible pump main body 110 is operated in measurement mode. [Figure 4] FIG. 10 is a diagram for explaining how the submersible pump main body 110 operates in automatic operation mode. [Figure 5] 10 is a flowchart showing the flow of processing in a submersible pump control method M10 executed by a submersible pump 10 according to one embodiment of the present invention. [Figure 6] 10 is a flowchart showing the flow of processing in a measurement frequency change method M110 for changing the measurement frequency. [Figure 7] FIG. 10 is a diagram for explaining how the submersible pump main body 110 is operated when the amount of water accumulated in the boiler room exceeds the first water level h1. [Figure 8] This is a diagram for explaining how the submersible pump main body 110 is operated when the amount of water accumulated in the boiler room exceeds the second water level h2. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the embodiment described below is merely a specific example for carrying out the present invention and is not intended to limit the scope of the present invention. Furthermore, to facilitate understanding of the description, the same components in each drawing will be designated by the same reference numerals wherever possible, and duplicate descriptions may be omitted.

[0021] <One embodiment> [Submersible pump configuration] Figure 1 is a schematic diagram showing the configuration of a submersible pump 10 according to one embodiment of the present invention. As shown in Figure 1, the submersible pump 10 includes a submersible pump main body 110, a water level detection member 120 (a first detection unit 121 and a second detection unit 122), and a submersible pump control unit (not shown).

[0022] For example, the submersible pump 10 is installed in a boiler room (water tank). The operation and stop of the submersible pump main body 110 is controlled by a submersible pump control unit based on the water level detected by a water level detection member 120 installed in the submersible pump main body 110. In this way, the submersible pump 10 uses an automatic operation function to discharge water from the boiler room.

[0023] The submersible pump body 110 has a water intake port and a water discharge port, and is configured to rotate the impeller by driving the motor with the submersible pump control unit, thereby discharging water accumulated in the boiler compartment.

[0024] The water level detection member 120 may be attached directly to the submersible pump body 110, or may be attached indirectly to the submersible pump body 110 via an attachment or the like.

[0025] The water level detection member 120 includes a first detection unit 121 and a second detection unit 122, and the first detection unit 121 and the second detection unit 122 are each composed of, for example, an electrode, and the water level in the boiler area can be detected by establishing electrical conductivity between the electrode and a GND electrode (not shown) on the submersible pump main body 110 side through the water (liquid) accumulated in the boiler area.

[0026] By installing the water level detection member 120 directly or indirectly on the submersible pump main body 110, the first detection unit 121 detects that the water level in the boiler room has reached the first water level h1, and the second detection unit 122 detects that the water level in the boiler room has reached the second water level h2 (first water level h1 > second water level h2).

[0027] More specifically, the first detection unit 121 turns on when the water level in the boiler room rises and reaches the first water level h1, and then turns off when the water level drops below the first water level h1 as the submersible pump main body 110 operates.

[0028] The second detection unit 122 turns on when the water level in the boiler room rises and reaches the second water level h2, and then turns off when the water level drops below the second water level h2 as the submersible pump main body 110 operates.

[0029] Here, the submersible pump 10 has a measurement mode and an automatic operation mode as operation modes for operating the submersible pump main body 110. The measurement mode operates the submersible pump main body 110 to measure the timing to stop operation of the submersible pump main body 110, and the automatic operation mode automatically controls the operation and stop of the submersible pump main body 110, and details of each mode will be described later.

[0030] The first detection unit 121 functions as a starting electrode for starting the operation of the submersible pump main body 110 in the measurement mode.

[0031] The second detection unit 122 functions as a measurement electrode for measuring the time from when the submersible pump main body 110 operates and the water level drops, causing the first detection unit 121 to turn off, until the water level drops further and the second detection unit 122 turns off, and also functions as a starting electrode for starting operation of the submersible pump main body 110 in the automatic operation mode.

[0032] [Submersible pump operation and shutdown control] 2 is a functional block diagram showing the functions of the submersible pump control unit 130 that controls the operation of the submersible pump main body 110 according to one embodiment of the present invention. As shown in FIG. 2, the submersible pump control unit 130 includes an operation mode setting means 131, a first water level detection means 132, a second water level detection means 133, a submersible pump control means 134, and a stop timing setting means 135.

[0033] The submersible pump control unit 130 is, for example, a processor provided in the submersible pump main body 110, and controls the driving of the motor to operate and stop the submersible pump main body 110 based on the on and off states of the first detection unit 121 and the second detection unit 122.

[0034] The operation mode setting means 131 sets the measurement mode or the automatic operation mode as the operation mode for operating the submersible pump main body 110. For example, when the submersible pump 10 is installed and operated for the first time, the measurement mode is set to operate the submersible pump main body 110, and thereafter the automatic operation mode is set to operate the submersible pump main body 110.

[0035] Thereafter, the frequency at which the submersible pump main body 110 is operated in the measurement mode (measurement frequency) may be every predetermined number of times that the submersible pump main body 110 is operated in the automatic operation mode, or every predetermined time. For example, the submersible pump main body 110 may be operated in the measurement mode every 10 times that the submersible pump main body 110 is operated in the automatic operation mode, or may be operated in the measurement mode once a day (at the start of work or at a specific time).

[0036] The first water level detection means 132 detects that the water level in the boiler room has reached the first water level h1 using the first detection unit 121. For example, the first water level detection means 132 may detect that the water level in the boiler room has risen to reach the first water level h1 and that the first detection unit 121 has changed from an off state to an on state, or may detect that the water level in the boiler room has fallen to reach the first water level h1 and that the first detection unit 121 has changed from an on state to an off state.

[0037] The second water level detection means 133 detects that the water level in the boiler room has reached the second water level h2 by the second detection unit 122. For example, the second water level detection means 133 may detect that the water level in the boiler room has risen to reach the second water level h2 and that the second detection unit 122 has changed from the off state to the on state, or may detect that the water level in the boiler room has fallen to reach the second water level h2 and that the second detection unit 122 has changed from the on state to the off state.

[0038] The submersible pump control means 134 controls the driving of the motor so as to operate and stop the submersible pump main body 110 according to the operation mode set by the operation mode setting means 131.

[0039] For example, in the measurement mode, the submersible pump control means 134 starts operation of the submersible pump main body 110 based on the detection of the first water level h1 by the first water level detection means 132, and stops operation of the submersible pump main body 110 based on the stop timing set by the stop timing setting means 135.

[0040] In addition, in the automatic operation mode, the submersible pump control means 134 starts operation of the submersible pump main body 110 based on the detection of the second water level h2 by the second water level detection means 133, and stops operation of the submersible pump main body 110 based on the stop timing set by the stop timing setting means 135.

[0041] In the measurement mode, the stop timing setting means 135 calculates the stop timing for stopping the operation of the submersible pump main body based on the detection of the first water level h1 by the first water level detection means 132 and the detection of the second water level h2 by the second water level detection means 133.

[0042] Specifically, the stop timing setting means 135 calculates the stop timing for stopping operation of the submersible pump main body 110 based on the detection of the start of measurement by the first water level detection means 132 and the detection of the end of measurement by the second water level detection means 133.

[0043] Measurement start detection is detecting that the first detection unit 121 has changed from an on state to an off state, and specifically, that the water level in the boiler basin has risen to a first water level h1, causing the first detection unit 121 to detect that it has changed from an off state to an on state, and that after operation of the submersible pump main body 110 has started, the water level in the boiler basin has dropped to the first water level h1, causing the first detection unit 121 to change from an on state to an off state. Measurement end detection is detecting that the water level in the boiler basin has further dropped to a second water level h2, causing the second detection unit 122 to change from an on state to an off state.

[0044] The stop timing setting means 135 measures the time (water level drop time) from when the measurement start is detected to when the measurement end is detected, and measures the time it takes for the water level in the boiler room to drop from the first water level h1 to the second water level h2 due to the operation of the submersible pump main body 110.

[0045] For example, if it takes time t for the water level in the boiler basin to drop from a first water level h1 to a second water level h2, the stop timing setting means 135 may calculate the stop timing based on the distance d from the first water level h1 to the second water level h2 and the distance from the second water level h2 to the stop position of the submersible pump main body 110. If the relationship between the distance d and the distance from the second water level h2 to the stop position of the submersible pump main body 110 is 1:2, the stop timing setting means 135 may calculate the stop timing to be twice the measured water level drop time t, and may calculate the stop timing to be twice the time t after the second water level detection means 133 detects the end of measurement.

[0046] It is preferable that the stopping position be near the drainage limit, and may be determined based on, for example, the lowest operational water level (LWL) of the equipment pump and the lowest continuous operating water level (CWL) of the construction machinery pump, and further, consideration may be given to reducing the possibility of dry operation even if the submersible pump 10 is installed at an angle in the boiler yard.

[0047] Furthermore, the water level detection by the first detection unit 121 and the second detection unit 122 is determined by the contact and separation of the electrodes, but it may also be determined by the contact and separation of the electrodes continuing for a predetermined time (for example, 1 second), which can reduce false detections.

[0048] [Measurement mode] FIG. 3 is a diagram for explaining how the submersible pump main body 110 is operated in the measurement mode.

[0049] In FIG. 3(A), the amount of water in the boiler room is small, the water level is below the second water level h2, and the first detection unit 121 and the second detection unit 122 are in the OFF state.

[0050] In Figure 3(B), the amount of water in the boiler basin increases, causing the water level to rise, and the first detection unit 121 changes from an OFF state to an ON state, causing the first water level detection means 132 to detect the first water level h1. As a result, the submersible pump control means 134 starts operating the submersible pump main body 110. Note that as the amount of water in the boiler basin increases and the water level rises, the second detection unit 122 changes from an OFF state to an ON state. As a result, the second water level detection means 133 detects the second water level h2, but in measurement mode, the submersible pump main body 110 does not start operating at this point (it skips over this).

[0051] When the submersible pump main body 110 starts operating, the amount of water in the boiler decreases, the water level drops, and the first detector 121 changes from an ON state to an OFF state, causing the first water level detector 132 to detect the first water level h1. This causes the stop timing setting means 135 to start measuring the water level drop time.

[0052] In Figure 3(C), the amount of water in the boiler tank further decreases, causing the water level to drop, and the second detection unit 122 changes from an ON state to an OFF state, causing the second water level detection means 133 to detect the second water level h2. As a result, the stop timing setting means 135 ends measurement of the water level drop time, calculates the water level drop time t required for the water level to drop by the distance d from the first water level h1 to the second water level h2, and further calculates and sets the stop timing based on the water level drop time t. For example, if the relationship between the distance d and the distance from the second water level h2 to the stop position of the submersible pump main body 110 is 1:2, the stop timing may be set to twice the water level drop time t after the second water level detection means 133 detects the second water level h2.

[0053] In Figure 3(D), the amount of water in the boiler room further decreases, causing the water level to drop, and as described above, the submersible pump control means 134 stops operation of the submersible pump main body 110 at the stop timing set by the stop timing setting means 135. In other words, the submersible pump control means 134 stops operation of the submersible pump main body 110 after a time that is twice the water level drop time t has elapsed since the second water level detection means 133 detected the second water level h2.

[0054] In this way, in the measurement mode, the first detection unit 121 functions as a starting electrode to start operation of the submersible pump main body 110, the second detection unit 122 functions as a measurement electrode to measure the water level drop time, and the stop timing for stopping operation of the submersible pump main body 110 is calculated and set after the second detection unit 122 changes from the on state to the off state.

[0055] [Autonomous driving mode] FIG. 4 is a diagram for explaining how the submersible pump main body 110 operates in the automatic operation mode.

[0056] In FIG. 4(A), the amount of water in the boiler room is small, the water level is below the second water level h2, and the first detection unit 121 and the second detection unit 122 are in the OFF state.

[0057] 4(B), the amount of water in the boiler basin increases, causing the water level to rise, and the second detection unit 122 changes from an OFF state to an ON state, causing the second water level detection means 133 to detect the second water level h2. As a result, the submersible pump control means 134 starts operating the submersible pump main body 110.

[0058] Then, when the submersible pump main body 110 starts operating, the amount of water in the boiler room decreases and the water level drops, and the second detection unit 122 changes from an on state to an off state, causing the second water level detection means 133 to detect the second water level h2.

[0059] In Figure 4 (C), the amount of water in the boiler room further decreases, causing the water level to drop, and at the stop timing set by the stop timing setting means 135 in measurement mode (after twice the water level drop time t has elapsed since the second water level detection means 133 detected the second water level h2), the submersible pump control means 134 stops operation of the submersible pump main body 110.

[0060] In this way, in the automatic operation mode, the second detection unit 122 functions as a starting electrode to start operation of the submersible pump main body 110, and operation of the submersible pump main body 110 is stopped at the stop timing set in the measurement mode, at which operation of the submersible pump main body 110 is stopped after the second detection unit 122 changes from the on state to the off state.

[0061] [Submersible pump control method] Next, a method for controlling the operation of the submersible pump main body 110 in the submersible pump 10 will be specifically described in detail.

[0062] 5 is a flowchart showing the flow of processing of a submersible pump control method M10 executed by the submersible pump 10 according to one embodiment of the present invention. Each step of the submersible pump control method M10 is executed by a processor included in the submersible pump control unit 130.

[0063] In step S110, the submersible pump control unit 130 determines the operation mode. For example, if the measurement frequency is set in advance so that the pump operates in the measurement mode every 10 times in the automatic operation mode, the measurement mode or the automatic operation mode may be determined based on the measurement frequency.

[0064] If it is determined in step S110 that the device is to operate in the measurement mode, the process proceeds to step S120.

[0065] In step S120, the first water level detection means 132 monitors whether the first detection unit 121, which detects the first water level h1, changes from an off state to an on state, and detects (start-up detection) that the first detection unit 121 has changed from an off state to an on state ("Yes" in step S110), and proceeds to processing in step S130.

[0066] In step S130, the submersible pump control means 134 starts the operation of the submersible pump main body 110 based on the start detection by the first water level detection means 132.

[0067] In step S140, the first water level detection means 132 monitors whether the first detection unit 121, which detects the first water level h1, changes from an on state to an off state, and detects that the first detection unit 121 has changed from an on state to an off state (detects the start of measurement) (“Yes” in step S140), and proceeds to processing in step S150.

[0068] In step S150, the stop timing setting means 135 starts measurement for calculating the stop timing based on the detection of the start of measurement by the first water level detection means 132. Specifically, the stop timing setting means 135 may store the time of the detection of the start of measurement.

[0069] Note that, considering that operation of the submersible pump main body 110 is started based on start detection and the water level in the boiler room drops immediately thereafter, measurement start detection may be detected immediately based on start detection, for example. That is, the time of start detection may be stored as the time of measurement start detection, or a predetermined time after the time of start detection (for example, the time when drainage actually begins due to operation of the submersible pump main body 110) may be stored as the time of measurement start detection.

[0070] In step S160, the second water level detection means 133 monitors whether the second detection unit 122 that detects the second water level h2 changes from an ON state to an OFF state, and when it detects that the second detection unit 122 has changed from an ON state to an OFF state (detection of measurement end) (“Yes” in step S160), it proceeds to the processing of step S170. Note that if the water level rises and it is detected that the first detection unit 121 has changed from an OFF state to an ON state before it is detected that the second detection unit 122 has changed from an ON state to an OFF state (detection of measurement end), it may reset the measurement, and may start measurement again by detecting again that the first detection unit 121 has changed from an ON state to an OFF state (detection of measurement start).

[0071] In step S170, the stop timing setting means 135 calculates the stop timing based on the detection of the end of measurement by the second water level detection means 133. Specifically, the stop timing setting means 135 calculates the water level drop time required for the water level in the boiler bay to drop from the first water level h1 to the second water level h2 based on the time of the detection of the start of measurement stored in step S150 and the time of the detection of the end of measurement in step S160.

[0072] Then, the stop timing setting means 135 calculates the stop timing according to the calculated water level drop time. For example, if the relationship between the distance from the first water level h1 to the second water level h2 and the distance from the second water level h2 to the stop position of the submersible pump body 110 is 1:2, the stop timing setting means 135 may calculate the stop timing to be twice the calculated water level drop time from the time when the measurement end is detected in step S160.

[0073] In step S180, the submersible pump control means 134 monitors whether the stop timing calculated in step S170 has arrived, and if the stop timing has arrived ("Yes" in step S180), the process proceeds to step S190.

[0074] In step S190, the submersible pump control means 134 stops the operation of the submersible pump main body 110.

[0075] On the other hand, if it is determined in step S110 that the vehicle will operate in the automatic driving mode, the process proceeds to step S161.

[0076] In step S161, the second water level detection means 133 monitors whether the second detection unit 122, which detects the second water level h2, changes from an off state to an on state, and detects (start-up detection) that the second detection unit 122 has changed from an off state to an on state ("Yes" in step S161), and proceeds to processing of step S131.

[0077] In step S131, the submersible pump control means 134 starts the operation of the submersible pump main body 110 based on the start detection by the second water level detection means 133.

[0078] In step S181, the submersible pump control means 134 monitors whether the stop timing calculated in step S170 has arrived, and if the stop timing has arrived ("Yes" in step S181), the process proceeds to step S191.

[0079] In step S191, the submersible pump control means 134 stops the operation of the submersible pump main body 110.

[0080] As described above, according to the submersible pump 10 and submersible pump control method M10 of one embodiment of the present invention, in measurement mode, the first detection unit 121 and the second detection unit 122 are used to measure the water level drop time, thereby setting an appropriate stop timing for stopping operation of the submersible pump main body 110, and in automatic operation mode, the second detection unit 122 is made to function as a starting electrode, and the stop timing set in measurement mode is used, thereby enabling energy-saving automatic operation and operation of the submersible pump main body 110 at a stable low water level.

[0081] In this embodiment, the measurement frequency is preset to operate in measurement mode, for example, every 10 times when operating in automatic driving mode, but the measurement frequency may be changed depending on the situation.

[0082] 6 is a flowchart showing the process flow of a measurement frequency change method M110 for changing the measurement frequency. As shown in FIG. 6, the measurement frequency change method M110 includes steps S111 to S117, and each step is executed by a processor included in the submersible pump control unit 130.

[0083] In step S111, the submersible pump main body 110 is operated in the measurement mode. For example, when the submersible pump 10 is installed and operated for the first time, the operation mode is set to the measurement mode and the submersible pump main body 110 is operated.

[0084] In step S112, the submersible pump main body 110 is operated in the automatic operation mode. For example, the submersible pump main body 110 is operated in the automatic operation mode using the stop timing that was set when the submersible pump main body 110 was operated in the measurement mode in step S111.

[0085] In step S113, it is determined whether operation of the submersible pump main body 110 has been repeated a predetermined number of times in the automatic operation mode. For example, the frequency of operation in the measurement mode (measurement frequency) may be preset to every 10 operations in the automatic operation mode. In this case, if operation in the automatic operation mode has been repeated 10 times in step S113, the process proceeds to step S114.

[0086] In step S114, the submersible pump main body 110 is operated in measurement mode. Specifically, as described with reference to Fig. 5, the water level drop time is calculated (steps S150, S160), and a stop timing is set according to the water level drop time (step S170).

[0087] In step S115, it is determined whether the water level drop time is stable. For example, if the change in the water level drop time calculated when the submersible pump main body 110 is operated in the measurement mode is within a threshold, it is determined that the water level drop time is stable, and the process may proceed to step S116 ("Yes" in step S115). On the other hand, if the change in the water level drop time exceeds the threshold, more specifically, if the difference from the water level drop time calculated when the submersible pump main body 110 was operated in the previous measurement mode exceeds the threshold, the process may proceed to step S117 ("No" in step S115).

[0088] In addition, the change in the water level drop time can be determined by comparing the water level drop time calculated in the previous measurement mode and the water level drop time calculated in the current measurement mode, or by comparing the water level drop time for several times to determine whether the water level drop time is stable.

[0089] In step S116, the frequency of operation in measurement mode (measurement frequency) is reduced or maintained. For example, the measurement frequency for operation in measurement mode, which was set to every 10 operations in automatic operation mode, may be reduced to every 15 or 20 operations, or maintained at every 10 operations. Also, if the change in the water level drop time determined in step S115 is extremely small, the measurement frequency may be significantly reduced, and the degree of maintenance or reduction may be set according to the degree of change in the water level drop time.

[0090] In step S117, the frequency of operation in measurement mode (measurement frequency) is increased. For example, the measurement frequency for operation in measurement mode, which was set to every 10 operations in automatic operation mode, is increased to every 5 operations, every operation, etc. Furthermore, if the change in the water level drop time determined in step S115 is extremely large, the measurement frequency may be increased significantly (every operation, etc.), and the degree of increase may be set according to the degree of change in the water level drop time.

[0091] [Variation 1] Next, the operation control of the submersible pump main body 110 in the case where water has already accumulated in the boiler room when the submersible pump 10 is installed in the boiler room will be described.

[0092] Figure 7 is a diagram for explaining how the submersible pump main body 110 is operated when the amount of water accumulated in the boiler room exceeds the first water level h1. As shown in Figure 7, when the submersible pump 10 is installed in the boiler room (water tank), water has already accumulated in the boiler room exceeding the first water level h1.

[0093] When the submersible pump 10 is powered on, the submersible pump control unit 130 immediately and forcibly starts operation of the submersible pump main body 110 based on the detection by the first water level detection means 132 of a first water level h1 or higher (the first detection unit 121 is on) and the detection by the second water level detection means 133 of a second water level h2 or higher (the second detection unit 122 is on). Note that if the first detection unit 121 is on, the second detection unit 122 is also on, so the state of the second detection unit 122 does not need to be determined. However, if the first detection unit 121 is on and the second detection unit 122 is off, a malfunction of at least one of the first detection unit 121 and the second detection unit 122, contamination of the detection unit including the electrodes, or sensitivity effects (described later) may be suspected, and an alert may be output to notify the user of the abnormality.

[0094] Then, as operation of the submersible pump main body 110 begins, the amount of water in the boiler decreases, the water level drops, and the first detection unit 121 changes from an ON state to an OFF state, causing the first water level detection means 132 to detect the first water level h1 (corresponding to the processing of step S140 in FIG. 5). As a result, the stop timing setting means 135 starts measuring the water level drop time (corresponding to the processing of step S150 in FIG. 5). Thereafter, the same processing as in the measurement mode (steps S160 to S190 in FIG. 5) is performed.

[0095] In this way, after forcibly starting operation of the submersible pump main body 110, the water level drop time is measured, and the stop timing is set by the stop timing setting means 135, similar to the processing described using Figure 5.

[0096] As a result, even if the water level in the boiler room (tank) has already exceeded the first water level h1 when the submersible pump 10 is installed, the second detection unit 122 functions as a starting electrode in automatic operation mode, and the stop timing set in measurement mode is used, allowing the submersible pump main body 110 to operate in an energy-saving automatic manner and at a stable low water level.

[0097] [Variation 2] Figure 8 is a diagram illustrating how the submersible pump main body 110 is operated when the amount of water accumulated in the boiler room exceeds the second water level h2. As shown in Figure 8, when the submersible pump 10 is installed in the boiler room (water tank), the water in the boiler room has already exceeded the second water level h2. However, the water has not yet reached the first water level h1.

[0098] In the submersible pump control unit 130, when the power supply of the submersible pump 10 is turned on, the first water level detection means 132 does not detect a water level above the first water level h1 (the first detection unit 121 is in the off state) and the second water level detection means 133 detects a water level above the second water level h2 (the second detection unit 122 is in the on state), and based on this, the submersible pump control means 134 forcibly starts operation of the submersible pump main body 110 after a predetermined time has elapsed.

[0099] Then, as operation of the submersible pump main body 110 begins, the amount of water in the boiler room decreases, and for example, the submersible pump control means 134 stops operation of the submersible pump main body 110 based on a timer (a pre-set time). The timer may be set so that the water accumulated in the boiler room is drained and the water level falls to at least below the second water level h2. The timer may be set to start when the second water level detection means 133 detects the second water level h2 (when the second detection unit 122 changes from an on state to an off state). In this case, the operation mode in which the submersible pump main body 110 is next operated is set to the measurement mode.

[0100] On the other hand, if the amount of water in the boiler increases and the water level rises before the predetermined time has elapsed to forcibly start operation of the submersible pump main body 110, and the first detection unit 121 changes from an OFF state to an ON state, causing the first water level detection means 132 to detect the first water level h1 (corresponding to the processing of step S120 in Figure 5), the submersible pump control means 134 will start operation of the submersible pump main body 110 in measurement mode (corresponding to the processing of step S130 in Figure 5). Thereafter, the same processing as in measurement mode (steps S140 to S190) will be performed.

[0101] 8 may occur during operation of the submersible pump main body 110 in measurement mode. Specifically, when the submersible pump main body 110 is operated in measurement mode, the amount of water in the boiler basin increases and exceeds the second water level h2, but does not reach the first water level h1.

[0102] In this case as well, the submersible pump control means 134 may forcibly start operation of the submersible pump main body 110 after a predetermined time has elapsed.

[0103] As described above, even if the water level in the boiler pit exceeds the first water level h1 and / or the second water level h2 and the submersible pump main body 110 does not operate, the submersible pump main body 110 can be forcibly started to operate, thereby appropriately responding to the situation so that the submersible pump main body 110 operates at a stable, low water level.

[0104] Furthermore, in the present invention, the first detection unit 121 and the second detection unit 122 are each composed of, for example, an electrode, and although excessive sensitivity may result in false detection of the water level in the boiler chamber when, for example, water droplets adhere thereto, the first detection unit 121 may be more sensitive than the second detection unit 122. In the embodiment of the present invention, the first detection unit 121 functions as a starting electrode in the measurement mode, but in the automatic operation mode, if the first detection unit 121 detects a water level of h1 or higher, it is preferable to forcibly start operation of the submersible pump main body 110.

[0105] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those illustrated and can be modified as appropriate. Furthermore, configurations shown in different embodiments can be partially substituted or combined with each other. [Explanation of symbols]

[0106] 10...Submersible pump, 110...Submersible pump main body, 120...Water level detection member, 121...First detection unit, 122...Second detection unit, 130...Submersible pump control unit, 131...Operation mode setting means, 132...First water level detection means, 133...Second water level detection means, 134...Submersible pump control means, 135...Stop timing setting means, M10...Submersible pump control method, M110...Measurement frequency change method

Claims

1. A submersible pump body, A first detection unit that is directly or indirectly installed on the submersible pump body and detects a first water level and a second detection unit that detects a second water level that is lower than the first water level; an underwater pump control unit that controls the operation of the underwater pump body; The submersible pump control unit A measurement mode measures the timing to stop the operation of the submersible pump body, and an automatic operation mode automatically controls the operation and stop of the submersible pump body, In the measurement mode, operation of the submersible pump body is started based on the detection of the first water level by the first detection unit, and a stop timing for stopping the operation of the submersible pump body is set based on the detection of the first water level by the first detection unit and the detection of the second water level by the second detection unit, In the automatic operation mode, the operation of the submersible pump body is started based on the detection of the second water level by the second detection unit, and the operation of the submersible pump body is stopped based on the stop timing. Submersible pump.

2. In the measurement mode, the submersible pump control unit measuring a water level drop time from when the first water level is detected by the first detection unit to when the second water level is detected by the second detection unit; The stop timing is set based on the water level drop time.

2. The submersible pump of claim 1.

3. The stop timing includes the time from when the second water level is detected by the second detection unit to when the operation of the submersible pump body is stopped, 3. The submersible pump of claim 2.

4. The measurement frequency for operating and stopping the submersible pump body in the measurement mode is every predetermined number of times for operating and stopping the submersible pump body in the automatic operation mode, or every predetermined time.

3. The submersible pump of claim 2.

5. changing the measurement frequency in accordance with a change in the water level drop time measured in the measurement mode; 5. The submersible pump of claim 4.

6. When the change in the water level drop time measured in the measurement mode is within a threshold value, the measurement frequency is reduced or maintained.

6. The submersible pump according to claim 5.

7. In the measurement mode, the submersible pump control unit After starting operation of the submersible pump body based on the detection of the first water level by the first detection unit, if the first water level is further detected by the first detection unit before the second water level is detected by the second detection unit, the measurement of the water level drop time is reset.

3. The submersible pump of claim 2.

8. When the power supply of the submersible pump is turned on, the submersible pump control unit starts operation of the submersible pump body immediately or after a predetermined time has elapsed in response to detection by the first detection unit of the first water level or higher and / or detection by the second detection unit of the second water level or higher.

2. The submersible pump of claim 1.

9. In the measurement mode, the submersible pump control unit If the first water level is not detected by the first detection unit for a predetermined time after the second water level is detected by the second detection unit, operation of the submersible pump body is started.

2. The submersible pump of claim 1.

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