JP2006161337A - Method for detecting abnormality in pressure tank, and water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for detecting an abnormality in a pressure tank, which enables the accurate detection of the abnormality in the pressure tank, such as a decrease in sealing pressure, and a water supply system which has the function of detecting the abnormality in the pressure tank. <P>SOLUTION: In the method for detecting the abnormality in the pressure tank, a pump stop time from the stop of a pump 14 of the water supply system 10 to the restart of the pump 14 is measured; the pump stop time is compared with a predetermined reference time; the result of this comparison is recorded as the result of the detection of the abnormality when the pump stop time is shorter than the reference time; and it is determined that the abnormality occurs in the pressure tank 36 when the result of the detection of the abnormality is recorded a plurality of times. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pressure tank abnormality detection method and a water supply device, and more particularly to a pressure tank abnormality detection method and a pressure tank abnormality detection used in a water supply device for driving a pump to supply water to a building such as an apartment house. The present invention relates to a water supply device having a function.

  In medium-rise or high-rise buildings such as apartment buildings and office buildings, water supply devices that use tap water from the water mains with a pump to supply to the end of the water supply (water taps, water heaters, etc.) are used. . Usually, the amount of water to be supplied by the water supply apparatus varies greatly depending on the amount of water used at the demand destination. For example, the amount of supplied water is greatly reduced in a time zone where the amount of water used is small, such as at night. For this reason, from the viewpoint of energy saving, the pump is stopped when the amount of water used falls below a certain level. At this time, without stopping the pump immediately, the operation speed of the pump is temporarily increased to hold water in a pressure tank provided in the water supply apparatus. By doing in this way, even if it does not start a pump again, water is supplied to a customer from a pressure tank for a while.

  As water is used, the water in the pressure tank decreases, and the water pressure in the water supply pipe inside the building (that is, the pressure on the discharge side of the pump) decreases. And when this discharge side pressure falls below to the starting pressure of a pump, a pressure sensor will detect this and a pump will be restarted. Thereafter, when the amount of water used again decreases, the pump is accelerated and accumulated in the pressure tank, and then the pump is stopped. In this way, the stop and restart of the pump are repeated based on the amount of water used and the discharge side pressure of the pump.

  As a pressure tank used for a water supply apparatus, a diaphragm type pressure tank having a diaphragm (partition wall) disposed therein is generally used. The pressure tank is filled with air in advance, and the water flowing into the pressure tank compresses the air through the diaphragm. A check valve is disposed between the pressure tank and the pump, and the water pressure in the water supply pipe is maintained at a high level even after the pump is stopped by the check valve and the pressure tank.

  However, when a diaphragm type pressure tank is used for a long time in an excessively pressurized state, the diaphragm deteriorates faster than normal use and may be damaged in some cases. If the diaphragm is damaged and the air in the pressure tank is exhausted, the pressure in the water supply pipe drops rapidly due to the use of water and drops below the starting pressure in a very short time. For this reason, the problem that the starting frequency of a pump increases and the lifetime of a pump becomes short arises. Therefore, when an abnormality occurs in the pressure tank, it is necessary to quickly detect this and repair or replace the pressure tank as necessary.

  The present invention has been made in view of such circumstances, and a pressure tank abnormality detection method capable of accurately detecting an abnormality of a pressure tank such as a decrease in enclosed pressure and a water supply having such an abnormality detection function. An object is to provide an apparatus.

  In order to achieve the above-described object, one aspect of the present invention is a pressure tank abnormality detection method for measuring a pump stop time from when a pump of a water supply device is restarted to when the pump is restarted. When the stop time is compared with a predetermined reference time, and the pump stop time is shorter than the reference time, the comparison result is recorded as an abnormality detection result, and the abnormality detection result is recorded a plurality of times. It is determined that an abnormality has occurred in the pressure tank.

In a preferred aspect of the present invention, when the abnormality detection result is continuously recorded a plurality of times, it is determined that an abnormality has occurred in the pressure tank.
In a preferred aspect of the present invention, it is determined that an abnormality has occurred in the pressure tank when the number of times the abnormality detection result is recorded within a predetermined monitoring period reaches a predetermined number.
In a preferred aspect of the present invention, the reference time is the shortest time from when the pump is stopped to when it is restarted when the pressure tank is functioning normally.
In a preferred aspect of the present invention, the determination is performed on the condition that a difference between a lower limit value of the target pressure of the pump and a suction side pressure of the pump is a predetermined reference value or more.

  Another aspect of the present invention is a pressure tank abnormality detection method for measuring a pressure drop time until a discharge side pressure of a pump of a water supply device drops from a stop pressure of the pump to a start pressure of the pump, The pressure drop time is compared with a predetermined reference time. When the pressure drop time is equal to or shorter than the reference time, 1 is added to the count, and when the count reaches a predetermined reference number, It is determined that an abnormality has occurred.

In a preferred aspect of the present invention, the determination is performed on the condition that a difference between a lower limit value of the target pressure of the pump and a suction side pressure of the pump is a predetermined reference value or more.
In a preferred aspect of the present invention, the reference time is a shortest time until the discharge-side pressure decreases from the stop pressure to the start pressure when the pressure tank is functioning normally. To do.

  Another aspect of the present invention is a pressure tank abnormality detection method, in which the discharge side pressure of the pump at the first time point and the second time point during the period from when the pump of the water supply device is stopped to when it is restarted. The pressure difference from the discharge side pressure of the pump is calculated, the pressure difference is compared with a predetermined reference pressure difference, and if the pressure difference is greater than or equal to the reference pressure difference, an abnormality has occurred in the pressure tank. It is characterized by judging that it exists.

In a preferred aspect of the present invention, the reference pressure difference is a pressure difference between the discharge side pressure at the first time point and the discharge side pressure at the second time point, which is measured when the pressure tank is not functioning normally. It is characterized by being.
In a preferred aspect of the present invention, when the pressure difference is equal to or greater than the reference pressure difference, 1 is added to the count, and when the count reaches a predetermined reference number, an abnormality occurs in the pressure tank. It is characterized by judging.
In a preferred aspect of the present invention, the determination is performed on the condition that a difference between a lower limit value of the target pressure of the pump and a suction side pressure of the pump is a predetermined reference value or more.

Another aspect of the present invention is a pressure tank abnormality detection method for monitoring the rotational speed of a pump of a water supply device, and when the pump is restarted before the rotation of the pump is completely stopped. It is determined that an abnormality has occurred in the pressure tank.
According to a preferred aspect of the present invention, when the pump restarts before the rotation of the pump is completely stopped, 1 is added to the count, and when the count reaches a predetermined reference number, It is determined that an abnormality has occurred.
In a preferred aspect of the present invention, the determination is performed on the condition that a difference between a lower limit value of the target pressure of the pump and a suction side pressure of the pump is a predetermined reference value or more.

  In another aspect of the present invention, a pump, a motor for driving the pump, a discharge pipe provided on the discharge side of the pump, a pressure tank connected to the discharge pipe, and the discharge pipe are provided. A check valve, a pressure detector for detecting the pressure in the discharge pipe, a water amount detector for detecting that the water volume in the discharge pipe has reached a predetermined underwater volume, and a discharge pressure of the pump being a predetermined pressure And a controller that controls the rotational speed of the motor so that the discharge pressure of the pump is reduced when the amount of water in the discharge pipe reaches the predetermined excessive water amount. The pump is stopped by raising the pressure to a predetermined stop pressure, and the pump is restarted when the pressure in the discharge pipe drops from the stop pressure to a predetermined start pressure. When the pump stops until The pump stop time is compared with a predetermined reference time, and when the pump stop time is shorter than the reference time, the comparison result is recorded as an abnormality detection result, and a plurality of the abnormality detection results are recorded. The water supply apparatus is configured to determine that an abnormality has occurred in the pressure tank when the number of times is recorded.

  In another aspect of the present invention, a pump, a motor for driving the pump, a discharge pipe provided on the discharge side of the pump, a pressure tank connected to the discharge pipe, and the discharge pipe are provided. A check valve, a pressure detector for detecting the pressure in the discharge pipe, a water amount detector for detecting that the water volume in the discharge pipe has reached a predetermined underwater volume, and a discharge pressure of the pump being a predetermined pressure And a controller that controls the rotational speed of the motor so that the discharge pressure of the pump is reduced when the amount of water in the discharge pipe reaches the predetermined excessive water amount. The pump is stopped by raising the pressure to a predetermined stop pressure, and the pump is restarted when the pressure in the discharge pipe decreases from the stop pressure to a predetermined start pressure. The pressure in the discharge pipe is changed to the stop pressure. Decreases to the starting pressure from The pressure drop time until the pressure drop is measured, the pressure drop time is compared with a predetermined reference time, and if the pressure drop time is less than or equal to the reference time, 1 is added to the count, and the count is equal to the predetermined reference time The water supply device is configured to determine that an abnormality has occurred in the pressure tank when the number is reached.

  In another aspect of the present invention, a pump, a motor for driving the pump, a discharge pipe provided on the discharge side of the pump, a pressure tank connected to the discharge pipe, and the discharge pipe are provided. A check valve, a pressure detector for detecting the pressure in the discharge pipe, a water amount detector for detecting that the water volume in the discharge pipe has reached a predetermined underwater volume, and a discharge pressure of the pump being a predetermined pressure And a controller that controls the rotational speed of the motor so that the discharge pressure of the pump is reduced when the amount of water in the discharge pipe reaches the predetermined excessive water amount. The pump is stopped by raising the pressure to a predetermined stop pressure, and the pump is restarted when the pressure in the discharge pipe drops from the stop pressure to a predetermined start pressure. In the meantime The pressure difference between the pressure in the discharge pipe at the time point and the pressure in the discharge pipe at the second time point is calculated, the pressure difference is compared with a predetermined reference pressure difference, and the pressure difference is greater than or equal to the reference pressure difference. In this case, the water supply device is configured to determine that an abnormality has occurred in the pressure tank.

  In another aspect of the present invention, a pump, a motor for driving the pump, a discharge pipe provided on the discharge side of the pump, a pressure tank connected to the discharge pipe, and the discharge pipe are provided. A check valve, a pressure detector for detecting the pressure in the discharge pipe, a water amount detector for detecting that the water volume in the discharge pipe has reached a predetermined underwater volume, and a discharge pressure of the pump being a predetermined pressure A control unit that controls the rotation speed of the motor so as to be maintained at a predetermined value, and a rotation speed detector that detects the rotation speed of the pump, and the control unit has a water amount in the discharge pipe of the predetermined value. When the amount of water is too small, the pump discharge pressure is increased to a predetermined stop pressure to stop the pump, and when the pressure in the discharge pipe decreases from the stop pressure to a predetermined start pressure. Restart the pump, When the pump before the rotation of the serial pump is completely stopped it is restarted is a water supply apparatus characterized by being configured to determine an abnormality in the pressure tank has occurred.

  According to the present invention, it is possible to accurately detect a decrease in the enclosed pressure of air caused by a diaphragm breakage or the like, or a breakage of the pressure tank itself. Therefore, the pressure tank in which an abnormality is detected can be repaired or replaced quickly, and the pump start-up frequency can be reduced to extend the life of the pump.

  Hereinafter, an embodiment of a pressure tank abnormality detection method according to the present invention will be described in detail with reference to FIGS. 1 to 9, the same or corresponding components are denoted by the same reference numerals and / or names, and redundant description is omitted.

  FIG. 1 is a schematic diagram showing a water supply apparatus, and FIG. 2 is a graph showing an operating characteristic curve of a pump in the water supply apparatus shown in FIG. In FIG. 2, the horizontal axis represents the amount of water, and the vertical axis represents the pressure (head or head). As shown in FIG. 1, the water supply apparatus 10 includes a pump 14 connected to the water main 12, a motor 16 that drives the pump 14, an inverter 18 that controls the rotational frequency of the motor 16, and an inverter 18. And a control unit 20 for controlling various devices. The motor 16 is connected to the control unit 20, and the rotation speed of the motor 16 or the pump 14 is controlled by the control unit 20 by an output signal from an optical or magnetic rotary encoder (rotation speed detector) 15 provided in the motor 16. Monitored.

The pump 14 of the water supply apparatus 10 is connected to an upstream water supply pipe 22 extending from the water main pipe 12, and a discharge pipe 26 is connected to the discharge side of the pump 14. The discharge pipe 26 has a check valve 28 for preventing water from flowing back from the discharge side to the suction side when the pump 14 is stopped, and maintaining the pressure in the discharge pipe 26. A flow switch (water amount detector) 30 for detecting that the amount of water has decreased is provided. The flow switch 30, water is set amount discharged to the discharge pipe 26 from the pump 14 to operate with less than (a predetermined under-water) Q _min, emit under-water detection signal. The flow switch 30 is connected to the control unit 20, and an excessive water amount in the discharge pipe 26 is monitored by the control unit 20 by an output signal of the flow switch 30. The number of pumps is not limited to one, and a plurality of pumps may be arranged in the water supply apparatus 10.

  As shown in FIG. 1, a pressure sensor (pressure detector) 34 that detects water pressure in the discharge pipe 26 (discharge side pressure of the pump 14) and water in the discharge pipe 26 are stored in the discharge pipe 26. A pressure tank 36 is attached via branch pipes 38 and 39, respectively. The pressure sensor 34 is connected to the control unit 20, and the water pressure in the discharge pipe 26 is monitored by the control unit 20 based on the output signal of the pressure sensor 34.

  The discharge pipe 26 of the water supply apparatus 10 is connected to a downstream water supply pipe 42 extending to a water supply terminal 40 of a consumer such as a building or a condominium, and the water of the water main 12 is supplied to the consumer by the water supply apparatus 10 described above. It has become so. These water supply terminals 40 are, for example, a water heater, a water faucet, a flush valve for toilet cleaning, etc. provided in each of the branched downstream water supply pipes 42.

Here, as shown in FIG. 1, an input panel 44 having a display unit such as a liquid crystal screen and a numeric keypad or an increase / decrease button is attached to the control unit 20. Through this input panel 44, the operator can set the upper limit value (upper limit pressure) P _U and lower limit value (lower limit pressure) P _L of the target pressure, the stop pressure P ₀ when the amount of water is too low, the upper limit pressure P _U and the lower limit pressure P. The differential pressure P _D with respect to _L and other information necessary for control can be input. For example, information necessary for the control can be input by pressing a touch panel or a button on the liquid crystal screen of the input panel 44. Moreover, the upper limit pressure P _U and the lower limit pressure P _L are, for example, the conditions when the pump 14 is installed, that is, the height of the building that supplies water, the length of the pipe to the water tap, the pipe resistance, and the discharge to be guaranteed The pressure can be set and changed via the input panel 44 in consideration of the pressure in the pipe.

  As shown in FIG. 1, the control unit 20 includes a central processing unit (CPU) 46, an internal memory 48, and a timer 49. Information input from the input panel 44 is stored in the internal memory 48 via the CPU 46. Is remembered. Inside the control unit 20, a gate control signal of the motor 16 is calculated, and this gate control signal is sent to the inverter 18 to drive the gate transistor in the inverter 18. The inverter 18 sends a speed control signal to the electrically connected motor 16 to drive the pump 14 at a predetermined rotational speed. In driving the pump 14, for example, the pump 14 can be efficiently operated at high speed by controlling the AC voltage steplessly by pulse width modulation (PWM) or pulse amplitude modulation (PAM).

  The control unit 20 performs variable speed control of the rotational speed (rotational frequency) of the pump 14 via the inverter 18 based on information input from the input panel 44, an output signal from the pressure sensor 34, and the like. That is, the control unit 20 controls the inverter 18 to apply a predetermined AC voltage or DC voltage to the motor 16 to increase or decrease the speed of the motor 16. As the rotation of the motor 16 increases, the discharge amount of the pump 14 increases. At this time, the water pressure in the discharge pipe 26 increases, but the discharge side pressure is sequentially detected by the pressure sensor 34, and the control unit 20 ensures that the pressure detected by the pressure sensor 34 matches the target pressure. The rotation speed of the pump 14 is feedback-controlled.

Here are used the water in the water supply terminal 40 of the consumer, when the detection pressure detected falls starting pressure P ₁ below, which is set in advance by the pressure sensor 34, pump 14 of the water supply device 10 is started. When the pump 14 is driven by the motor 16, the water in the water main pipe 12 is sucked into the pump 14 through the upstream water supply pipe 22 and discharged to the discharge pipe 26 with a predetermined pressure. The water discharged to the discharge pipe 26 is supplied to the water supply terminal 40 on the demand side through the downstream water supply pipe 42. The water pumped up by the pump 14 is pressurized to a pressure that can sufficiently supply water to the water supply terminal 40a provided at the highest position in a middle-rise house, a high-rise house, a commercial building, or the like.

If the amount of water used at the feed end 40 decreases during operation of the pump 14 and the flow amount is less than the set amount _Qmin and the flow switch 30 operates, the operation of the pump 14 is stopped. When the pump 14 is stopped, sufficient water is stored in the pressure tank 36 by temporarily increasing the operation speed of the pump 14 to discharge and increasing the pressure. Finally, the pump 14 is stopped in a state where the water in the pressure tank 36 is pressurized to a predetermined stop pressure P _0.

Thereafter, when the water is used in the water supply terminal 40, but some time is supplied water from the pressure tank 36, the less water pressure tank 36, the detected pressure of the pressure sensor 34 below starting pressure P ₁ described above When lowered, the pump 14 is started again.

  In addition, you may make it cancel the insufficient water amount detection signal from the flow switch 30 in the fixed time after the start-up of the pump 14 is started. By doing in this way, even if it is a case where water does not flow for a while after the pump 14 starts due to various conditions of the water supply equipment, the pump 14 is stopped by detecting the insufficient water amount. Can be prevented. Further, when the discharge pressure of the pump 14 is lower than a predetermined value, the control unit 20 may be programmed not to perform the stop process of the pump 14 even if the excessive water amount detection signal is sent from the flow switch 30. Good. By doing in this way, the discharge pressure during operation of the pump 14 can be kept from becoming lower than a predetermined value at all times, and the frequency of the stop process due to the insufficient amount of water can be lowered.

  Here, as described above, the control unit 20 controls the rotational speed of the pump 14 so that the pressure detected by the pressure sensor 34 matches the target pressure. The discharge pressure constant control for controlling the rotation speed of the pump 14 so that the discharge pressure becomes constant, or the target value of the discharge pressure of the pump 14 is sequentially calculated so that the end pressure of the pipe becomes constant, and this target value The estimated terminal pressure constant control for controlling the rotational speed of the pump 14 is performed so that the discharge pressure of the pump 14 coincides with the output pressure. Of these control methods, constant terminal pressure constant control will be described.

  The estimated end pressure is an estimate of the pressure at the highest point and / or the longest pipe end 40a, and this end 40a dominates the target discharge pressure of the pump 14. The discharge pressure of the pump 14 that makes the pressure at this end constant is calculated as the target pressure, and the rotational speed of the pump 14 is controlled so that the discharge pressure of the pump 14 becomes the target pressure.

In FIG. 2, curves N _{1 to} N ₄ indicate the operation characteristics of the pump 14 at each rotation speed, and N ₁ is a characteristic curve at the maximum rotation speed of the pump 14. Here, the resistance curve R is a pipe loss in accordance with the amount of water used from the pump 14 to the water supply terminal 40, and is a curve proportional to the square of the amount of water used Q with the point where the water amount is 0 as the origin.

  In the estimated terminal pressure constant control, the control is performed in consideration of the pipe loss (indicated by the resistance curve R) according to the amount of water used, so that the target pressure is sequentially calculated along the resistance curve R. The calculated target pressure is temporarily stored in the internal memory 48 of the control unit 20. The control unit 20 controls the rotational speed of the pump 14 so that the discharge pressure of the pump 14 becomes the calculated target pressure.

2, the operating point of the maximum rotational speed is the point A _1, the pressure in this respect A ₁ is the upper limit pressure P _U, the amount of water has a Q _1. By reducing the rotational speed of the pump 14, the operating point, the point A ₂ from point A _1, moves on resistance curve R passing through the point A _3. For example, as shown in FIG. 2, the target pressure Px at the time of the water amount Qx is calculated along the resistance curve R, and the rotation speed of the pump 14 is set so that the discharge pressure of the pump 14 becomes the target pressure Px. The

When the amount of water is less than the set amount Q _min and the flow switch 30 is operated, the pump 14 stop process is started. In this pump stopping process, from the discharge to the target pressure along the resistance curve R described above the target value of the pressure of the pump 14 is temporarily changed to the stop pressure P ₀ set in advance. As a result, the rotational speed of the pump 14 is increased, and finally, the discharge pressure of the pump 14 reaches the stop pressure P ₀ and the pump 14 is stopped. In addition, it is preferable that the stop process of the pump 14 is started only after the flow of the flow switch 30 is continued for a certain period of time. For example, the duration of the state of the insufficient water amount can be sequentially changed according to the operation state of the pump 14 immediately before. By doing in this way, the frequency of the stop process of the pump 14 and the starting process of the subsequent pump 14 can be reduced, and the durability of the apparatus can be improved and the life can be extended.

The control unit 20 can calculate the stop pressure P ₀ based on the upper limit pressure P _U and the lower limit pressure P _L stored in the internal memory 48. For example, the stop pressure P ₀ is calculated to be a value equal to or higher than the upper limit pressure P _U. The control unit 20, starting pressure P ₁ of the pump 14 is also adapted to be calculated, for example, the lower limit pressure P _L started and so that a slight underpressure than the equivalent pressure or lower pressure P _L pressure P ₁ Is calculated.

It is also possible to calculate the lower limit pressure P _L from the upper limit pressure P _U entered. For example, if the highest position of the water supply terminal 40 is a fifth floor building, the upper limit pressure _{P U} and 14m, the upper limit pressure _{P U} about 15% lower 12m or lower limit pressure _{P L.} The reason why the lower limit pressure P _L is set to be about 15% lower than the upper limit pressure P _U is that the pipe resistance is estimated to be about 15%.

For example, the upper limit pressure P _U and the ratio D% may be input via the input panel 44 of the control unit 20 described above, and the lower limit pressure P _L may be obtained by P _L = P _U − (P _U × D%). . Alternatively, the upper limit pressure P _U and the differential pressure P _D may be input, and the lower limit pressure P _L may be obtained by P _L = P _U −P _D. If the upper limit pressure P _U and the lower limit pressure P _L are set to the same value, the discharge pressure constant control can be performed. In this case, the stop pressure P ₀ is P _U (= P _L ) and the starting pressure is P _U -P _D , so that excessive pressurization by the pump 14 is not performed.

As described above, the water supply apparatus 10 has a function of stopping the operation of the pump 14 when the amount of water used is small. The pressure tank 36 and the check valve 28 are used to maintain the water pressure in the discharge pipe 26 after the pump 14 is stopped. As shown in FIG. 1, a diaphragm (partition wall) 41 made of an elastic material such as rubber is disposed inside the pressure tank 36, and an air chamber 47 defined by the diaphragm 41 has an air chamber 47. Pressurized air is sealed in advance. When the rotational speed of the pump 14 is increased when the amount of water is equal to or less than the set amount Q _min , the water flowing through the discharge pipe 26 flows into the pressure tank 36 through the branch pipe 39, and enters the air chamber 47 through the diaphragm 41. Compress the air. Since the check valve 28 is disposed between the pump 14 and the pressure tank 36, the pressure in the discharge pipe 26 is maintained by the compressed air in the pressure tank 36.

However, if the sealed pressure in the pressure tank 36 decreases due to damage to the diaphragm 41 or the like, the pressure in the discharge pipe 26 rapidly decreases even when a small amount of water is used, and the starting pressure P ₁ is reached in a very short time. To reach. For this reason, not only the stop time of the pump 14 is shortened, but the start frequency of the pump 14 is increased and the life of the pump 14 is shortened. Therefore, in order to solve such a problem, in the present embodiment, an abnormality of the pressure tank 36 is detected by a method described below, and an alarm is issued to prompt repair or replacement of the pressure tank 36.

When the flow switch 30 detects that the amount of water used has decreased and the amount of water flowing through the discharge pipe 26 has reached the set amount (minimum flow rate) Q _min , the control operation of the control unit 20 is a discharge pressure constant control or estimation. Shift from constant terminal pressure control to pump stop control. That is, the control unit 20 instructs the inverter 18 to increase the rotation speed (operation speed) of the pump 14, increases the discharge pressure of the pump 14, and sends water into the pressure tank 36. When the discharge pressure of the pump 14 reaches the stop pressure P ₀ , the control unit 20 transmits a pump stop command to the inverter 18 to stop the pump 14. At this time, the control unit 20 starts measuring the pump stop time from the time when the pump 14 (or the motor 16) stops.

When water is used in a state where the pump 14 is stopped, the water stored in the pressure tank 36 is sent to the consumer, whereby the pressure in the discharge pipe 26 (the pump 14 detected by the pressure sensor 34). The pressure on the discharge side) decreases. When the use of water is continued, the discharge side pressure further decreases and eventually reaches the starting pressure P ₁ of the pump 14. If discharge pressure is detected by the pressure sensor 34 be decreased to the starting pressure P _1, the control unit 20 issues a pump start command to the inverter 18, thereby the pump 14 is restarted. A rotary speed signal indicating that the pump 14 has started is sent from the rotary encoder 15 to the control unit 20. Upon receiving this signal, the control unit 20 finishes measuring the pump stop time, and the pump 14 is actually stopped. Time.

  The control unit 20 compares the pump stop time with a preset reference time (set time), and determines whether or not the pump stop time is shorter than the reference time. This reference time is the shortest pump stop time from when the pump 14 is stopped to when it is restarted, which is measured in advance when the pressure tank 36 is functioning normally. It is determined according to the capacity of 36. This reference time is input in advance to the internal memory 48 of the control unit 20 via the input panel 44.

  That the pump stop time is shorter than the reference time means that the sealed pressure of the pressure tank 36 has decreased, that is, some abnormality (failure) has occurred in the pressure tank 36. Therefore, it can be determined that the pressure tank 36 is not functioning normally by detecting that the actual stop time of the pump 14 is shorter than the reference time. However, there is a risk of misjudgment with only one detection. Therefore, in this embodiment, when it is detected that the pump stop time is shorter than the reference time, the detection result is recorded in the internal memory 48 of the control unit 20, and the detection result is recorded a plurality of times. For the first time, it is determined that an abnormality has occurred in the pressure tank 36. The causes of the abnormality in the pressure tank 36 include a decrease in air pressure (enclosed pressure) due to the breakage of the diaphragm 41, air leakage from the air valve, damage to the outer wall of the pressure tank 36, and the like.

  Here, the abnormality detection method for the pressure tank according to the first embodiment of the present invention will be described with reference to FIG. FIG. 3 is a flowchart showing the pressure tank abnormality detection method according to the first embodiment of the present invention. As shown in FIG. 3, the control unit 20 measures a pump stop time from when the pump 14 is stopped to when it is restarted (step 1). Next, the pump stop time is compared with the reference time (step 2). If it is determined that the pump stop time is shorter than the reference time (YES in step 2), the result of the comparison is used as one abnormality detection result. Is recorded in the internal memory 48 (step 3). On the other hand, when the pump stop time is longer than the reference time (NO in step 2), it is not determined that the pressure tank 36 is abnormal.

  The control unit 20 monitors the number of times the abnormality detection result is recorded. If the number of times the abnormality detection result is recorded reaches a predetermined number (a reference number) (YES in step 4), the pressure tank 36 has an abnormality. Judgment is made (step 5). On the other hand, if the number of times the abnormality detection result is recorded is less than the predetermined number (NO in step 4), it is not determined that the pressure tank 36 is abnormal.

Here, as a precondition that the difference between the suction side pressure of the lower pressure P _L and the pump 14 is a predetermined reference value (set value) or more, it is preferable to perform the determination of abnormality of the pressure tank 36. This is due to the following reason. That is, when the water supply apparatus 10 is directly connected to the water main pipe 12 without going through the water receiving tank, the suction side pressure of the pump 14 (the water pressure in the upstream water supply pipe 22 detected by a pressure sensor not shown) is the lower limit pressure P. _It may have risen to the vicinity of _L. In such a case, even if the pressure tank 36 is out of order, the discharge-side pressure gradually decreases as if the pressure tank 36 is functioning normally. As a result, the stop time of the pump 14 becomes long, and it is impossible to accurately determine whether or not the pressure tank 36 is functioning normally. For this reason, it is preferable to perform the abnormality determination of the pressure tank 36 in terms of the difference between the suction side pressure of the lower pressure P _L and the pump 14 was determined to be greater than or equal to a predetermined reference value. This reference value is set based on the air filling pressure when the pressure tank 36 is normal.

  Thus, according to the present embodiment, it is possible to accurately detect that an abnormality has occurred in the pressure tank 36 by confirming that the abnormality detection result has been recorded a plurality of times. In this case, when the abnormality detection result is continuously recorded a predetermined number of times, it may be determined that an abnormality has occurred in the pressure tank 36, or the abnormality detection result is recorded within a predetermined monitoring period. When the number of times reaches a predetermined number, it may be determined that an abnormality has occurred in the pressure tank 36.

  Next, a second embodiment of the present invention will be described. The operation of the present embodiment not specifically described is the same as that of the first embodiment described above, and the graph showing the configuration of the water supply apparatus 10 shown in FIG. 1 and the operating characteristic curve of the pump 14 shown in FIG. Also applies.

In the present embodiment, an abnormality in the pressure tank 36 is detected according to the following method. First, the control unit 20 the time was reduced from the stop pressure P ₀ to the starting pressure P ₁ (pressure detected by the pressure sensor 34) the discharge pressure of the pump 14 is measured. This measured time is stored in the internal memory 48 as a pressure drop time. At this time, the control unit 20, the difference between the suction side pressure of the lower pressure P _L and the pump 14 (water pressure upstream in the water supply pipe 22) is equal to or greater than a predetermined reference value, i.e., described in the first embodiment Make sure that the prerequisites are met.

The control unit 20 compares the pressure drop time with a preset reference time, and determines whether or not the pressure drop time is shorter than the reference time. This reference time is the shortest pressure drop time when the discharge side pressure drops from the stop pressure P ₀ to the start pressure P ₁ measured in advance when the pressure tank 36 is functioning normally, It is determined according to the maximum usage amount, the capacity of the pressure tank 36, and the like. This reference time is input in advance to the internal memory 48 of the control unit 20 via the input panel 44. If it is determined that the pressure drop time is shorter than the reference time, 1 is added to the count of a counter (counter) (not shown) incorporated in the controller 20. Then, when the count (the total number determined that the pressure drop time is shorter than the reference time) reaches a predetermined reference number, it is determined that an abnormality has occurred in the pressure tank 36.

Here, the abnormality detection method of the pressure tank 36 in this embodiment is demonstrated in detail using FIG. FIG. 4 is a flowchart showing a pressure tank abnormality detection method according to the second embodiment of the present invention. As shown in FIG. 4, when the discharge pressure of the pump 14 reaches the stop pressure P ₀ , the control unit 20 stops the pump 14 and simultaneously starts measuring the pressure drop time of the discharge side pressure (step 1). ). Then, the discharge pressure is determined whether decreased to below starting pressure P ₁ of the pump 14 (Step 2). When the discharge pressure has not decreased to the starting pressure P ₁ (NO in step 2), the stopped state of the pump 14 is maintained. If the discharge pressure drops to below starting pressure P ₁ (YES in step 2), and ends the measurement of the pressure drop time (Step 3).

Next, the control unit 20 checks whether or not the reference number to be compared with the count is 0 (step 4). The reference number is input in advance from the input panel 44 by the operator. When the reference number is 0 (YES in Step 4), the count is cleared to 0, and then the pump 14 is restarted (Step 10). ). In this case, the abnormality detection of the pressure tank 36 is not performed. On the other hand, unless the reference number 0 (NO in Step 4), the difference between the suction side pressure of the lower pressure P _L and the pump 14 is equal to or more than a predetermined reference value is determined by the control unit 20 ( Step 5). If the difference between the lower limit pressure P _L and the suction side pressure is smaller than a predetermined reference value (Step NO 5), and clears the count to 0, then the pump 14 is restarted (step 10). On the other hand, (YES in Step 5) If the difference between the lower limit pressure P _L and the suction side pressure is equal to or greater than the reference value, the routine goes to the subsequent Step 6.

  In step 6, the pressure drop time and the reference time are compared. When the pressure drop time is equal to or shorter than the reference time, that is, when the pump 14 restarts instantaneously (YES in step 6), 1 is added to the count (step 7). On the other hand, when the pressure drop time is longer than the reference time (NO in step 6), the count is cleared to 0, and then the pump 14 is restarted (step 10). When the count reaches the reference number (YES in step 8), the control unit 20 determines that an abnormality has occurred in the pressure tank 36 (step 9). In this case, even if it is determined that an abnormality has occurred in the pressure tank 36, the pump 14 is restarted from the viewpoint of avoiding water cut (step 10), and the operation of the pump 14 itself is continued. On the other hand, when the count is smaller than the reference number (NO in step 8), the pump 14 is restarted without determining that an abnormality has occurred in the pressure tank 36 (step 10). Also in this embodiment, since it is determined that an abnormality has occurred in the pressure tank 36 only after the count (the total number determined that the pressure drop time is shorter than the reference time) reaches the predetermined reference number, the determination is reliable. And accuracy can be improved.

  Next, a third embodiment of the present invention will be described with reference to FIGS. 5 (a) and 5 (b). FIG. 5A and FIG. 5B are graphs showing changes in discharge-side pressure from when the pump is stopped until it is restarted. The operation of the present embodiment not specifically described is the same as that of the first embodiment described above, and the graph showing the configuration of the water supply apparatus 10 shown in FIG. 1 and the operating characteristic curve of the pump 14 shown in FIG. Also applies.

In the present embodiment, an abnormality in the pressure tank 36 is detected according to the following method. 5A and 5B, the discharge side pressure from when the pump 14 is stopped to when it is restarted is indicated by a curve L ′. As shown in FIG. 5A, the discharge side pressure at a predetermined first time point t _F is after the time point t ₀ when the pump 14 is stopped and before the time point t ₁ ′ when the pump 14 is restarted. calculating a P _F 'and the discharge-side pressure _{P S} in the predetermined second time point _{t S'} pressure differential _P F of the _{'-P S'.} Then, the pressure difference P _F ′ −P _S ′ is compared with a predetermined reference pressure difference, and if the pressure difference P _F ′ −P _S ′ is equal to or larger than the reference pressure difference, an abnormality occurs in the pressure tank 36. Judge that This determination is made before the pump 14 is restarted.

The reference pressure difference is determined based on a change in the discharge side pressure measured when the pressure tank 36 is not functioning normally. Specifically, when the pressure tank 36 is not functioning normally due to a decrease in the sealed pressure or the like, the discharge-side pressure of the pump 14 from when the pump 14 is started (t ₀ ) to when it is restarted (t ₁ ). (Indicated by the curve L) is measured in advance by the pressure sensor 34 and stored in the internal memory 48 of the control unit 20. Then, a pressure difference _P F -P _S between the discharge side pressure _{P S} in the discharge-side pressure _{P F} and the second time point _{t S} at the first time point _{t F,} which is referred to as the reference pressure difference.

In the example shown in FIG. 5 (a), the pressure difference _P F _{'-P S'} is larger than the reference pressure difference _P F -P _S, is determined by the control unit 20 that an abnormality in the pressure tank 36 has occurred . On the other hand, in the example shown in FIG. 5 (b), the pressure difference _P F _{'-P S'} is smaller than the reference pressure difference _P F -P _S, the control unit 20 the pressure tank 36 is functioning properly To be judged. Control unit 20, the difference between the suction side pressure of the lower pressure P _L and the pump 14 (water pressure upstream in the water supply pipe 22) is equal to or greater than a predetermined reference value, i.e. the assumptions described in the first embodiment It is preferable to make the above determination after confirming that the above is satisfied.

Usually, if the pressure tank 36 is not functioning normally, the start frequency of the pump 14 increases. Therefore, in order to reduce the starting frequency of the pump 14, it is preferable to provide a certain delay period from when the water amount reaches the minimum flow rate _Qmin to when the pump stop process is started. In this case, when it is determined by the abnormality detection method that an abnormality has occurred in the pressure tank 36, the delay period is preferably set to the longest value. Further in this case, when it is determined that an abnormality in the pressure tank 36 has occurred, it is preferable to increase the value of the starting pressure P _1.

Here, when the pressure difference P _F ′ −P _S ′ is greater than or equal to the reference pressure difference P _F −P _S , 1 is added to the count of the 20 counters (counter) of the control unit, and this count (ie, , it is determined that the abnormality in the pressure tank 36 has occurred when the total number of the pressure difference P _{F '-P S'} is determined to be the reference pressure difference P _F -P _S or higher) has reached a predetermined reference number You may do it. Also, as in the first embodiment, when the pressure difference P _{F '-P S'} is the reference pressure difference P _F -P _S or records each time the abnormality detection result in the internal memory 48, the abnormal When the detection result is continuously recorded a predetermined number of times, it may be determined that an abnormality has occurred in the pressure tank 36. By doing in this way, the reliability and precision of judgment can be improved.

  Next, a fourth embodiment of the present invention will be described. The operation of the present embodiment not specifically described is the same as that of the first embodiment described above, and the graph showing the configuration of the water supply apparatus 10 shown in FIG. 1 and the operating characteristic curve of the pump 14 shown in FIG. Also applies.

As described in the first embodiment, when the flow switch 30 detects that the amount of water has reached the set amount Q _min , the control unit 20 causes the inverter 18 to increase the rotational speed (operating speed) of the pump 14. In this way, the discharge pressure of the pump 14 is increased and water is sent into the pressure tank 36. When the discharge pressure of the pump 14 reaches the stop pressure P ₀ , the control unit 20 transmits a pump stop command to the inverter 18 to stop the pump 14.

At this time, the rotation of the impeller of the pump 14 does not stop immediately due to inertia, but completely stops after a certain time has elapsed since the pump stop command was transmitted to the inverter 18. Usually, if functioning properly the pressure tank 36, the discharge-side pressure after rotation is completely stopped the pump 14 reaches the starting pressure P _1, the pump 14 is restarted. However, the pressure tank 36 is not functioning properly because of such as a decrease in gas pressure, discharge pressure is decreased to rapidly starting pressure P _1, the pump 14 before the rotation of the pump 14 is completely stopped is May restart. Therefore, in this embodiment, the rotation speed of the pump 14 (motor 16) is monitored by the control unit 20 via the rotary encoder 15, and the discharge side pressure is set to the stop pressure P ₀ before the rotation of the pump 14 is completely stopped. when the pump 14 is lowered to the starting pressure P ₁ and restart, it is determined that the abnormality in the pressure tank 36 has occurred.

In this case, the control unit 20, the difference between the suction side pressure of the lower pressure P _L and the pump 14 (water pressure upstream in the water supply pipe 22) is equal to or greater than a predetermined reference value, i.e., described in the first embodiment It is preferable to make the above determination after confirming that the preconditions are satisfied. In addition, when the pump 14 is restarted before the rotation of the pump 14 is completely stopped, the count 1 is added to the counter (counting unit) of the control unit 20, and this count (that is, the rotation of the pump 14 is completely completed). It may be determined that an abnormality has occurred in the pressure tank 36 when the total number of pumps 14 restarted before stopping) reaches a predetermined reference number. Furthermore, when the pump 14 is restarted before the rotation of the pump 14 is completely stopped as in the first embodiment, the monitoring result is recorded in the internal memory 48 each time, and the monitoring result is continuously recorded. It may be determined that an abnormality has occurred in the pressure tank 36 when it has been recorded a predetermined number of times. By doing in this way, the reliability and precision of judgment can be improved.

  In the above-described example, the water supply apparatus 10 including one pump 14 has been described. However, the first to fourth embodiments described above can also be applied to a water supply apparatus including a plurality of pumps as described below. It is. FIG. 6 is a front view showing an example of the structure of the water supply apparatus 10 having two pumps, and FIG. 7 is a plan view of FIG. As shown in FIGS. 6 and 7, the water supply apparatus 10 includes two pumps 14 installed on the base 50, two motors 16 that drive the pumps 14, and the rotational speed of each motor 16. And a control unit 20 for controlling.

  Each pump 14 is provided with a suction pipe 24 for sucking water from the upstream water supply pipe and a discharge pipe 26 for discharging pressurized water. Each discharge pipe 26 is provided with a flow switch 30 that detects that the amount of water in the discharge pipe 26 is less than a predetermined amount. When the flow switch 30 is arranged in the vertical discharge pipe, if the vertical discharge pipe is arranged in the same direction as the axial direction of the motor 16, the influence of the flow due to the fluid discharged from the pump 14 can be avoided and stable. Detection is possible. Further, these discharge pipes 26 are joined to a joining pipe 32. A pressure tank 36 is installed on the base 50 between the two pumps 14, and the pressure tank 36 is connected to the junction pipe 32. Further, the junction pipe 32 is provided with a pressure sensor 34 for detecting the pressure of the discharged water.

  In the water supply apparatus 10 having such a configuration, the water sucked from the suction pipe 24 is pressurized by the pump 14, is then discharged from the discharge port 52 through the junction pipe 32, and is supplied through the downstream water supply pipe. To be supplied. Here, the rotational speed of each motor 16 is variably controlled so that the discharge pressure of the pump 14 becomes a predetermined target pressure.

  In order to prevent vibration of the entire water supply apparatus 10, it is preferable to form a notch hole (not shown) at an arbitrary position of the base 50. An anti-vibration effect can be obtained by forming such a notch hole at the resonance point of vibration. Further, by providing a rib (not shown) on the base 50, a further vibration isolation effect can be obtained. The shape of the cutout hole may be any shape as long as it does not have a corner portion where another resonance point is generated. For example, a circular or elliptical cutout hole can be provided.

  8 and 9 are examples of a water supply apparatus 110 including five pumps, FIG. 8 is a front view, and FIG. 9 is a plan view. As shown in FIGS. 8 and 9, the water supply device 110 controls five pumps 114 a and 114 b installed on the base 150, motors 116 that drive the respective pumps, and the rotation speed of each motor 116. And a control unit 120.

  A suction pipe 124 for sucking water from the upstream water supply pipe and a discharge pipe 126 for discharging pressurized water are attached to each pump 114a, 114b. Each discharge pipe 126 is provided with a flow switch 130 for detecting that the amount of water in the discharge pipe 126 is less than a predetermined amount. When the flow switch 30 is arranged in the vertical discharge pipe, if the vertical discharge pipe is arranged in the same direction as the axial direction of the motor 16, the influence of the flow caused by the fluid discharged from the pump 14 can be avoided. Stable detection is possible.

  The water supply apparatus 110 shown in FIGS. 8 and 9 includes a first junction pipe 132a connected to the discharge pipe 126 of the three pumps 114a and a second junction pipe 132b connected to the discharge pipe 126 of the pump 114b. It has a structure in which two are connected. In this way, by connecting an arbitrary number of additional units 133b composed of one pump 114b to the base unit 133a composed of three pumps 114a in the arrangement direction of the pumps 114a, the user's request can be met. It is possible to easily configure a water supply device having a corresponding number of pumps.

  Further, the first joining pipe 132a is provided with a pressure sensor 134 for detecting the pressure of the discharged water. A pressure tank 136 is installed on the base 150, and the pressure tank 136 is connected to the first junction pipe 132a. Thus, by installing the pressure tank 136 in parallel with the pumps 114a and 114b in the lower part of the control unit 120, it is possible to prevent water in the pressure tank 136 from being applied to the control unit 120 during maintenance and replacement of the pressure tank 136. Is done.

  In this example, a blind flange 154 is attached to the end of the first joining pipe 132a, and a discharge port 152 is formed at the end of the second joining pipe 132b on the opposite side. In addition, the blind flange 154 may be attached to the end of the second merge pipe 132b, and the discharge port 152 may be formed at the end of the first merge pipe 132a.

  In the water supply apparatus 110 having such a configuration, the water sucked from the suction pipe 124 is pressurized by the pumps 114a and 114b, and then discharged from the discharge port 152 through the merge pipes 132a and 132b, and is supplied to the downstream water supply pipe. It is supplied to the water supply terminal via Here, the rotation speed of each motor 116 is variably controlled so that the discharge pressure of the pumps 114a and 114b becomes a predetermined target pressure.

In large buildings such as relatively high-rise apartment buildings and buildings where boosting with pumps is indispensable, abnormal pump stoppages are directly connected to water outage, so it is essential to have multiple pumps and a backup function. is there. The abnormality detection methods according to the first to fourth embodiments described above can be applied to both the pressure tank 36 shown in FIGS. 6 and 7 and the pressure tank 136 shown in FIGS. 8 and 9. .
In addition, in the above-mentioned embodiment, although the case where the water supply apparatus was directly connected to the water main was demonstrated, it is not restricted to this, For example, the water receiving tank which stores tap water once upstream of a water supply apparatus is used. It is good also as installing and supplying the water stored by this water-receiving tank to each consumer with a water supply apparatus.
Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.

It is a schematic diagram which shows a water supply apparatus. It is a graph which shows the driving | operation characteristic curve of the pump in the water supply apparatus shown in FIG. It is a flowchart which shows the abnormality detection method of the pressure tank which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the abnormality detection method of the pressure tank which concerns on the 2nd Embodiment of this invention. FIG. 5A and FIG. 5B are graphs showing changes in discharge-side pressure from when the pump is stopped until it is restarted. It is a front view which shows the example of the structure of the water supply apparatus provided with the two pumps. FIG. 7 is a plan view of FIG. 6. It is a front view which shows the example of the structure of the water supply apparatus provided with five pumps. It is a top view of FIG.

Explanation of symbols

10, 110 Water supply device 12 Water main 14, 114a, 114b Pump 15 Rotary encoder (rotation speed detector)
16, 116 Motor 18 Inverter 20, 120 Control unit 22 Upstream water supply pipe 24, 124 Suction pipe 26, 126 Discharge pipe 28 Check valve 30, 130 Flow switch (water quantity detector)
32, 132a, 132b Merge pipes 34, 134 Pressure sensor (pressure detector)
36, 136 Pressure tanks 38, 39 Branch pipe 40 Water supply terminal 41 Diaphragm 42 Downstream water supply pipe 44 Input panel 46 CPU
47 Air chamber 48 Internal memory 49 Timer 50, 150 Base 52, 152 Discharge port

Claims (19)

A pressure tank abnormality detection method,
Measure the pump stop time from when the water supply pump is stopped until it is restarted,
Compare the pump stop time with a predetermined reference time,
If the pump stop time is shorter than the reference time, record the result of the comparison as an abnormality detection result,
An abnormality detection method for a pressure tank, comprising: determining that an abnormality has occurred in the pressure tank when the abnormality detection result is recorded a plurality of times.   The pressure tank abnormality detection method according to claim 1, wherein when the abnormality detection result is continuously recorded a plurality of times, it is determined that an abnormality has occurred in the pressure tank.   The pressure tank abnormality according to claim 1, wherein when the number of times the abnormality detection result is recorded within a predetermined monitoring period reaches a predetermined number, it is determined that an abnormality has occurred in the pressure tank. Detection method.   The reference time is the shortest time from when the pump is stopped to when it is restarted when the pressure tank is functioning normally. An abnormality detection method for a pressure tank as described in 1.   5. The determination according to claim 1, wherein the determination is made on the condition that a difference between a lower limit value of the target pressure of the pump and a suction side pressure of the pump is a predetermined reference value or more. The abnormality detection method of the pressure tank of description. A pressure tank abnormality detection method,
Measure the pressure drop time until the discharge side pressure of the pump of the water supply device drops from the stop pressure of the pump to the start pressure of the pump,
Comparing the pressure drop time with a predetermined reference time;
If the pressure drop time is less than or equal to the reference time, add 1 to the count,
An abnormality detection method for a pressure tank, comprising: determining that an abnormality has occurred in the pressure tank when the count reaches a predetermined reference number.   7. The pressure tank abnormality according to claim 6, wherein the determination is made on the condition that a difference between a lower limit value of the target pressure of the pump and a suction side pressure of the pump is a predetermined reference value or more. Detection method.   The said reference time is the shortest time until the said discharge side pressure falls from the said stop pressure to the said starting pressure when the said pressure tank is functioning normally, The Claim 6 or 7 characterized by the above-mentioned. The abnormality detection method of the pressure tank of description. A pressure tank abnormality detection method,
Calculating the pressure difference between the discharge side pressure of the pump at the first time point and the discharge side pressure of the pump at the second time point during the period from when the pump of the water supply device is stopped to restarting,
Comparing the pressure difference with a predetermined reference pressure difference;
An abnormality detection method for a pressure tank, comprising determining that an abnormality has occurred in the pressure tank when the pressure difference is equal to or greater than the reference pressure difference.   The reference pressure difference is a pressure difference between the discharge side pressure at the first time point and the discharge side pressure at the second time point, which is measured when the pressure tank is not functioning normally. The pressure tank abnormality detection method according to claim 9. If the pressure difference is greater than or equal to the reference pressure difference, add 1 to the count,
The pressure tank abnormality detection method according to claim 9 or 10, wherein when the count reaches a predetermined reference number, it is determined that an abnormality has occurred in the pressure tank.   The determination is performed on the condition that a difference between a lower limit value of a target pressure of the pump and a suction side pressure of the pump is a predetermined reference value or more. An abnormality detection method for a pressure tank as described in 1. A pressure tank abnormality detection method,
Monitor the rotational speed of the water supply pump,
An abnormality detection method for a pressure tank, comprising: determining that an abnormality has occurred in the pressure tank when the pump is restarted before the rotation of the pump is completely stopped. If the pump restarts before the pump rotation stops completely, add 1 to the count,
The pressure tank abnormality detection method according to claim 13, wherein when the count reaches a predetermined reference number, it is determined that an abnormality has occurred in the pressure tank.   The pressure tank according to claim 13 or 14, wherein the determination is made on condition that a difference between a lower limit value of a target pressure of the pump and a suction side pressure of the pump is a predetermined reference value or more. Anomaly detection method. A pump,
A motor for driving the pump;
A discharge pipe provided on the discharge side of the pump;
A pressure tank connected to the discharge pipe;
A check valve provided in the discharge pipe;
A pressure detector for detecting the pressure in the discharge pipe;
A water amount detector for detecting that the amount of water in the discharge pipe has reached a predetermined underwater amount;
A control unit for controlling the rotation speed of the motor so that the discharge pressure of the pump is maintained at a predetermined pressure;
With
The controller is
When the amount of water in the discharge pipe reaches the predetermined underwater amount, the discharge pressure of the pump is increased to a predetermined stop pressure to stop the pump,
Restarting the pump when the pressure in the discharge pipe drops from the stop pressure to a predetermined starting pressure;
Measure the pump stop time from when the pump is stopped until it is restarted,
Compare the pump stop time with a predetermined reference time,
If the pump stop time is shorter than the reference time, record the result of the comparison as an abnormality detection result,
A water supply apparatus configured to determine that an abnormality has occurred in the pressure tank when the abnormality detection result is recorded a plurality of times. A pump,
A motor for driving the pump;
A discharge pipe provided on the discharge side of the pump;
A pressure tank connected to the discharge pipe;
A check valve provided in the discharge pipe;
A pressure detector for detecting the pressure in the discharge pipe;
A water amount detector for detecting that the amount of water in the discharge pipe has reached a predetermined underwater amount;
A control unit for controlling the rotation speed of the motor so that the discharge pressure of the pump is maintained at a predetermined pressure;
With
The controller is
When the amount of water in the discharge pipe reaches the predetermined amount of underwater, the pump is stopped by increasing the discharge pressure of the pump to a predetermined stop pressure,
Restarting the pump when the pressure in the discharge pipe drops from the stop pressure to a predetermined starting pressure;
Measuring the pressure drop time until the pressure in the discharge pipe drops from the stop pressure to the start pressure,
Comparing the pressure drop time with a predetermined reference time;
If the pressure drop time is less than or equal to the reference time, add 1 to the count,
A water supply apparatus configured to determine that an abnormality has occurred in the pressure tank when the count reaches a predetermined reference number. A pump,
A motor for driving the pump;
A discharge pipe provided on the discharge side of the pump;
A pressure tank connected to the discharge pipe;
A check valve provided in the discharge pipe;
A pressure detector for detecting the pressure in the discharge pipe;
A water amount detector for detecting that the amount of water in the discharge pipe has reached a predetermined underwater amount;
A control unit for controlling the rotation speed of the motor so that the discharge pressure of the pump is maintained at a predetermined pressure;
With
The controller is
When the amount of water in the discharge pipe reaches the predetermined underwater amount, the discharge pressure of the pump is increased to a predetermined stop pressure to stop the pump,
Restarting the pump when the pressure in the discharge pipe drops from the stop pressure to a predetermined starting pressure;
Calculating the pressure difference between the pressure in the discharge pipe at the first time point and the pressure in the discharge pipe at the second time point between the stop and restart of the pump;
Comparing the pressure difference with a predetermined reference pressure difference;
A water supply apparatus configured to determine that an abnormality has occurred in the pressure tank when the pressure difference is greater than or equal to the reference pressure difference. A pump,
A motor for driving the pump;
A discharge pipe provided on the discharge side of the pump;
A pressure tank connected to the discharge pipe;
A check valve provided in the discharge pipe;
A pressure detector for detecting the pressure in the discharge pipe;
A water amount detector for detecting that the amount of water in the discharge pipe has reached a predetermined underwater amount;
A control unit for controlling the rotation speed of the motor so that the discharge pressure of the pump is maintained at a predetermined pressure;
A rotational speed detector for detecting the rotational speed of the pump;
With
The controller is
When the amount of water in the discharge pipe reaches the predetermined underwater amount, the discharge pressure of the pump is increased to a predetermined stop pressure to stop the pump,
Restarting the pump when the pressure in the discharge pipe drops from the stop pressure to a predetermined starting pressure;
A water supply apparatus configured to determine that an abnormality has occurred in the pressure tank when the pump is restarted before the rotation of the pump is completely stopped.

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