JP3596909B2 - Method of inspecting diaphragm of liquid supply system and apparatus therefor - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a diaphragm inspection method for a liquid supply system, which is suitable for diagnosing a deterioration state of a diaphragm provided in a pressure tank or the like of a water supply system, and an apparatus therefor.
[0002]
[Prior art]
A water supply system, which is a typical example of a liquid supply system, generally includes a liquid pump for sending water in a water receiving tank to each household via a water supply pipe, and a branch from the water supply pipe at a position immediately after the discharge side of the liquid pump. A pressure tank connected to the pressure tank, a pressure switch that detects a pressure in the pressure tank and outputs a predetermined signal, and a control device that controls the liquid pump based on a signal from the pressure switch. Here, the pressure switch outputs a signal for stopping the liquid pump when the pressure in the pressure tank rises above the pump stop pressure Poff, and turns off the liquid pump when the pressure falls below the pump start pressure Pon. It outputs a signal to stop. Further, a rubber diaphragm called a diaphragm is provided inside the pressure tank, and by sealing the air with the elastic diaphragm, the pressure tank is separated from water supplied and drained. High-pressure air is sealed in a closed state.
[0003]
Then, when tap water is used in each household when the supply of water from the liquid pump is stopped, the water in the pressure tank decreases accordingly, and the pressure of the sealed air gradually decreases. When the pump activation pressure Pon is reached, the pressure switch is actuated to activate the liquid pump, and water supply is resumed.
[0004]
By the way, in such a water supply system, the diaphragm in the pressure tank repeatedly expands and contracts with the start / stop of the liquid pump and the use of tap water, and the part fixing the diaphragm to the inner wall of the pressure tank is bent. When used for many years, there is a risk that the diaphragm itself will deteriorate or the above-mentioned fixed part of the diaphragm will deteriorate, and the air enclosed in the pressure tank will leak out, in which case not only normal water supply will not be possible In addition, the liquid pump may be repeatedly started and stopped frequently to cause a serious accident such as burning. Therefore, conventionally, after a predetermined period of time has elapsed, the diaphragm has been deemed to have deteriorated beyond an allowable range, and the entire pressure tank has been replaced.
[0005]
[Problems to be solved by the invention]
However, in practice, the deterioration of the diaphragm in the pressure tank differs depending on the use conditions, etc., and the diaphragm has not deteriorated much even after a predetermined period of the replacement cycle, or the rapidly deteriorated diaphragm passes for a predetermined period. The function may be deteriorated before. Therefore, as described above, the conventional method of replacing the entire pressure tank after a predetermined period has elapsed may wastefully replace a pressure tank that can still be used sufficiently, and unexpectedly. There is a disadvantage that the damage to the liquid pump caused by the rapid deterioration of the function of the diaphragm and the accident of water leakage from the pressure tank cannot be avoided.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and a first object of the present invention is to enable a simple and accurate diagnosis of a deterioration state of a diaphragm in a container such as a pressure tank and to appropriately replace the container. It is an object of the present invention to provide a method for inspecting a diaphragm of a liquid supply system, the timing of which can be grasped. A second object of the present invention is to provide a diaphragm inspection apparatus used for such an inspection.
[0007]
[Means for Solving the Problems]
The first object of the present invention is to provide a liquid supply system comprising a container connected to a discharge side of a liquid pump means and having a stretchable diaphragm therein, wherein a liquid discharged from the liquid pump means is supplied to the inside of the container. After the liquid is pumped into the container, the liquid is discharged under a predetermined condition through a discharge path for measurement communicated with the container while the liquid pump means and the inside of the container are shut off. The temporal change in the pressure of the liquid in the membrane is measured, and the measurement result is compared with a reference value obtained by measuring the same procedure at a time when the diaphragm is not deteriorated, to thereby check the deterioration state of the diaphragm. Achieved by making a diagnosis. In order to achieve the first object while the liquid supply system is operated, the liquid discharged from the liquid pump is injected into the container, and the supply of the liquid from the liquid pump is performed. After stopping, the time change of the pressure of the liquid in the container when the liquid is discharged under a certain condition through the discharge path for measurement communicated with the container, and the change of the liquid from the discharge path The temporal change of the pressure of the liquid in the container when the discharge is stopped is measured, and the temporal change of the pressure of the liquid in the container due to the discharge from the discharge path is measured based on the measurement results. The calculation may be performed, and the calculation result may be compared with a reference value obtained at a time when the diaphragm is not deteriorated to diagnose the deterioration state of the diaphragm.
[0008]
Further, the second object of the present invention is to provide a discharge path means having a discharge path for measurement communicated with the container and capable of discharging the liquid in the container under certain conditions, Switching means for switching between a state in which the liquid can be discharged and a state in which the liquid cannot be discharged; a measuring means for measuring a pressure value of the liquid flowing in the discharge path; and a pressure of the liquid in the container based on a measurement result of the measuring means. Diagnosing means for diagnosing the deterioration state of the diaphragm by comparing the time change of the diaphragm with a reference value.
[0009]
[Action]
When the liquid pump means and the inside of the container such as the pressure tank are shut off and the liquid is discharged under a certain condition through a discharge path for measurement communicated with the container, the liquid is sealed in the container. The pressure of the gas separated from the liquid by the diaphragm gradually decreases over time, but when the deterioration of the diaphragm progresses and the sealed gas leaks, compared to the case where the diaphragm is not deteriorated, The pressure change (how to decrease) of the sealed gas accompanying the discharge of the liquid from the discharge path becomes faster. Therefore, by measuring the temporal change of the pressure of the liquid substantially equivalent to the pressure of the sealed gas in the container, and comparing the measurement result with a reference value obtained when the diaphragm is not deteriorated, The state of deterioration of the diaphragm can be easily and accurately diagnosed.
[0010]
Further, if the liquid pump means and the inside of the container are not shut off, and the liquid can be discharged from other than the discharge path for measurement, the inside of the container when the liquid is discharged under a certain condition through the discharge path. The pressure change of the liquid is corrected with reference to the pressure change data when the drainage from the discharge path is stopped, and is compared with the reference value, whereby the diaphragm of the diaphragm is kept operating while the liquid supply system is operating. The deterioration state can be easily and accurately diagnosed.
[0011]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 is a schematic configuration diagram showing a diaphragm type water supply system according to the present invention and a diaphragm inspection device used therein, and FIG. 2 is a block diagram showing a main part of the diaphragm inspection device.
[0013]
In these figures, reference numeral 1 denotes a water receiving tank, 2 denotes a liquid pump connected to the water receiving tank 1, 3 denotes a water supply pipe extending from a discharge side of the liquid pump 2 to a water tap 7 of each household, Is an air chamber 4A that is branched from and connected to the water supply pipe 3 at a position immediately after the discharge side of the liquid pump 2 and seals air having a pressure higher than the atmospheric pressure, and a water chamber 4B that stores water supplied from the liquid pump 2. The pressure tank 5 having the following structure is provided in the pressure tank 4, and a diaphragm made of an elastic rubber also referred to as a diaphragm for separating the sealed air in the air chamber 4A from the water in the water chamber 4B. The pressure switch 6 detects a pressure in the water chamber and outputs a predetermined signal. The pressure switch 6 outputs a signal for stopping the liquid pump 2 when the water pressure in the water chamber 4B rises above the pump stop pressure Poff. And the water pressure is pump And it outputs a signal for starting the liquid pump 2 when drops below hydrodynamic pressure Pon. Reference numeral 8A denotes a gate valve which is normally opened and shuts off communication between the water supply pipe 3 and the pressure tank 4 when necessary, and 8B denotes a normally closed valve which is connected to the pressure tank 4 when necessary and a diaphragm inspection described later. A gate valve for communicating with the device. In addition, the code | symbol Qc in FIG. 1 has shown the tap water supplied to the water tap 7 of each household via the water supply pipe 3. FIG.
[0014]
Reference numerals 9 to 14 denote components of the diaphragm inspection apparatus, 9 denotes a pressure sensor, 10 denotes a processing apparatus, 11 denotes a ball valve, 12 denotes a control cock, 13 denotes a drain port, and 14 denotes a drain pipe. Here, the pressure sensor 9 is for measuring the water pressure in the drain pipe 14 extending from the discharge side of the gate valve 8B to the drain port 13, and opens and closes the ball valve 11 provided in the middle of the drain pipe 14. The operation switches whether the measurement water Qt flowing in the drain pipe 14 is discharged from the drain port 13 or not. Further, as shown in FIG. 2, the processing device 10 controls a timer 101 that measures an elapsed time after the ball valve 11 is opened, and controls switching between opening and closing of the ball valve 11 according to a signal from the timer 101. Opening / closing control means 103, a calculating unit 104 for calculating a measurement value sent from the timer 101 or the pressure sensor 9, a memory 102 for storing the calculation result, and an output means 105 for outputting a necessary calculation result. The arithmetic unit 104 is provided so that data stored in the memory 102 can be compared with each other.
[0015]
Although the diaphragm inspection apparatus shown in FIG. 2 is set so that the opening and closing operation of the ball valve 11 is automatically performed in response to a signal from the timer 101, the operation is manually performed while confirming the synchronization with the timer 101. The ball valve 11 may be opened and closed. As shown in FIG. 3, when a signal for stopping the liquid pump 2 is output from the pressure switch 6, the timer 101 is instructed to start a timing operation, and a partition not shown in FIG. If the control unit 106 for instructing the valve 8A to close is provided in the processing device 10, the measurement can be automatically started.
[0016]
The operation principle of such a water supply system is roughly as follows.
[0017]
Now, when the water supply is completed and the liquid pump 2 is stopped, when the tap cock 7 is opened, the water in the water chamber 4B receiving pressure from the sealed air in the air chamber 4A through the diaphragm 5 is removed. Since the water is pushed out of the pressure tank 4 into the water supply pipe 3, the tap water Qc is discharged from the tap cock 7, and the water pressure in the pressure tank 4 gradually decreases accordingly. Then, when the water pressure in the pressure tank 4 decreases to the pump starting pressure Pon, the pressure switch 6 operates to start the liquid pump 2 and water is sent from the pump 2 into the water chamber 4B of the pressure tank 4. Therefore, the water pressure in the pressure tank 4 gradually increases, and when this water pressure reaches the pump stop pressure Poff, the pressure switch 6 is operated to stop the liquid pump 2.
[0018]
Next, an inspection method for diagnosing the deterioration state of the diaphragm 5 using the above-described diaphragm inspection apparatus will be described. In the diaphragm inspection method according to the present invention, reference data is obtained in advance at a time when the diaphragm 5 is not deteriorated, and data obtained by measuring at an arbitrary time thereafter is compared with the reference data. It is to diagnose the deterioration state of.
[0019]
First, a first embodiment of the method of the present invention will be described with reference to FIGS.
[0020]
As shown in the flow chart of FIG. 4, in the first embodiment, the normally closed gate valve 8B is opened while the ball valve 11 is closed, and the gate valve 8A in the open state is initially set as shown in the flowchart of FIG. The supply of water into the pressure tank 4 through the process is completed, and the liquid pump 2 is stopped (S1). Thereafter, the gate valve 8A is closed (S2), and the water pressure in the drain pipe 14 substantially equivalent to the pressure of the sealed air in the pressure tank 4 is read by the pressure sensor 9, and the value is set to Poff (S3). Further, by opening the ball valve 11 with the opening degree of the control cock 12 kept constant, the measuring water Qt flowing through the drain pipe 14 is discharged from the drain port 13 under constant conditions, and the opening of the ball valve 11 is started. At the time of plugging, the timer 101 starts a timing operation (S4). When the drainage from the drain 13 is continued under a certain condition, the water in the pressure tank 4 decreases accordingly, and the water pressure in the drain pipe 14 gradually decreases. When a predetermined time t1 has elapsed since then, the pressure value is read by the pressure sensor 9, and the value is set to P1 (S5). The pressure value Poff at the start of the measurement and the pressure value P1 after the lapse of the time t1 are calculated by the calculation unit 104, and the calculation results are stored in the memory 102. The measurement result at the time when the measurement is not performed is stored as a reference value (S6).
[0021]
In the water supply system in which the reference value is stored in advance, when diagnosing the deterioration state of the diaphragm 5 after a certain period (for example, six months), first, the pressure value Poff at the start of the measurement and the pressure value Poff at the start of measurement are determined in the same procedure as above. The pressure value P1 after the lapse of the time t1 is measured and subjected to arithmetic processing, and the measurement result is stored in the memory 102 (S7), and the newly stored measurement result is compared with the already stored reference value. The operation is performed by the operation unit 104 (S8), and the deterioration state of the diaphragm 5 is diagnosed based on the result of the comparison operation (S9). If no significant deterioration is found in the diaphragm 5 as a result of the diagnosis, it is determined that there is no abnormality. However, if significant deterioration is found in the diaphragm 5, the contents of the deteriorated state are output from the output means 105 (S10). ), A re-examination of the next diagnosis time, the replacement time of the pressure tank 4, etc. is performed according to the degree of deterioration.
[0022]
FIG. 5 is a characteristic diagram showing an example of the measurement result according to the first embodiment, in which the abscissa represents the elapsed time since the ball valve 11 was opened, and the ordinate represents the pressure value measured by the pressure sensor 9. Is shown in That is, when the deterioration of the diaphragm 5 progresses and the leakage of the sealed air occurs, the pressure of the sealed air decreases due to the decrease in the water in the pressure tank 4 as compared with the case where the diaphragm 5 is not deteriorated. As described above, the change in pressure becomes faster, so that the gate valve 8A is closed and the ball valve 11 is opened when the water supply to the pressure tank 4 is completed as described above, and the drain pipe 14 is opened when the ball valve 11 is opened. By measuring the internal water pressure and the water pressure that decreases with the drainage from the drain port 13 after the elapse of the predetermined time t1, the deterioration state of the diaphragm 5 is reflected in the pressure change therebetween. Therefore, as shown in FIG. 5, when the deterioration of the diaphragm 5 has progressed to some extent, the water pressure in the drain pipe 14 indicating the water pressure in the pressure tank 4 is larger than that when the diaphragm 5 is not deteriorated (reference value). Decreases rapidly with the passage of time, and when the diaphragm 5 is further deteriorated, the temporal change of the water pressure becomes more rapid. Therefore, the deterioration state of the diaphragm 5 is determined from the pressure change. It becomes possible to grasp.
[0023]
In the first embodiment, the pressure sensor 9 constantly measures the water pressure in the drain pipe 14, and the arithmetic unit 104 to which these measured values are sent outputs a specific time signal from the timer 101. Since the signal (measured value) of the pressure sensor 9 is sometimes read, not only the pressure value Poff at the start of the measurement and the pressure value P1 after the lapse of the predetermined time t1 but also the pressure value between them are read. The temporal change of the water pressure may be obtained more accurately.
[0024]
Next, a second embodiment of the method of the present invention will be described with reference to FIGS. That is, the first embodiment is a diaphragm inspection method performed with the gate valve 8A closed, but the second embodiment described below opens the gate valve 8A to supply normal water to the water cock 12. This is a diaphragm inspection method performed while securing.
[0025]
In the second embodiment, first, a reference value is set in advance in the same procedure as in the first embodiment. Therefore, when measuring a reference value indicating a temporal change of the water pressure in the pressure tank 4 relying only on the drainage from the discharge port 13, the gate valve 8A is closed. When diagnosing the deterioration state of the diaphragm 5 after a certain period of time (for example, six months) for the water supply system for which the setting of the reference value has been completed, first, as a default setting, the ball valve 11 is normally closed, Opens the closed gate valve 8B, completes the supply of water into the pressure tank 4 via the open gate valve 8A, and stops the liquid pump 2 (U1). Thereafter, while the gate valve 8A is open, the water pressure in the drain pipe 14 is read by the pressure sensor 9, and the value is set to Poff (U2). Further, the timer 101 starts the timing operation, and the ball valve 11 is automatically opened by the signal output from the timer 101 via the opening / closing control means 103 to keep the opening of the control cock 12 constant. The measuring water Qt is discharged from the drain port 13 under constant conditions while keeping the state (U3). As a result, the drainage of Qt is continued from the drain 13 under a certain condition. However, since the gate valve 8A is open, there is also drainage of Qc from the water cock 12 and the drainage of Qt and Qc is accompanied by the drainage of Qt and Qc. The water in 4 decreases. Then, when a signal indicating that the predetermined time t1 has elapsed is output from the timer 101, the ball valve 11 is closed via the opening / closing control means 103 and the pressure value P1 of the pressure sensor 9 is read (U4). When the ball valve 11 is kept in the closed state in this way, the water pressure in the pressure tank 4 is reduced only by the drainage of Qc, but if a signal indicating that the predetermined time t2 has elapsed is output from the timer 101, Then, the ball valve 11 is opened again, and the pressure value P2 at that time is read (U5). Thereafter, every time a predetermined time elapses, the opening and closing of the ball valve 11 is repeated, and the pressure value is read by the pressure sensor 9 each time, whereby the pressure value is read by FIG. 7 and FIG. As shown by the solid line, the temporal change of the water pressure in the pressure tank 4 can be seen.
[0026]
Therefore, the operation of subtracting the pressure value when the ball valve 11 is closed (Y portion in FIG. 8) from the pressure value when the ball valve 11 is open (X portion in FIG. 8), that is, Qt and Qc By causing the calculation unit 104 to perform an operation of removing the pressure change relying only on the Qc drainage from the pressure change relying on the drainage, the pressure value when only Qt is drained under certain conditions (see FIG. 7). The broken line portion and the Z portion in FIG. 8) can be approximately obtained.
[0027]
In this way, if the temporal change of the water pressure in the pressure tank 4 which depends only on the drainage from the discharge port 13 is calculated and obtained, the subsequent procedure is the same as that of the first embodiment. That is, first, the calculation result is stored in the memory 102 as a measurement value (U6), and the calculation unit 104 compares the newly stored calculation result with the reference value already stored (U7), and then compares The state of deterioration of the diaphragm 5 is diagnosed based on the calculation result (U8). If the result of the diagnosis indicates significant deterioration of the diaphragm 5, the contents of the state of deterioration are output from the output means 105 (U9).
[0028]
In the second embodiment, the reference value is measured by closing the gate valve 8A. However, the same procedure as the flowchart of FIG. 6 is performed, that is, the gate valve 8A is opened to secure normal water supply to the water cock 12. Meanwhile, the reference value may be set.
[0029]
In the second embodiment, since the water hammer phenomenon may occur slightly when the ball valve 11 is opened and closed, the timing at which the calculation unit 104 reads the pressure value measured by the pressure sensor 9 is determined by the ball valve 11. If the arithmetic unit 104 is controlled so as to read the pressure values immediately before and after the opening / closing operation, instead of making the timings coincide with the timing of the opening / closing operation, more accurate measurement can be performed.
[0030]
Furthermore, in the first and second embodiments, elastic vinyl or bellows-like metal may be used as the diaphragm 5, a normal computer may be used as the processing device 10, and the timer 101 may be provided with a ball. The opening / closing control means 103 may be omitted by providing a function of controlling the opening / closing operation of the valve 11, or the control cock 12 may be omitted by providing the ball valve 11 with a throttle function.
[0031]
【The invention's effect】
As described above, according to the present invention, a temporal change in the pressure of a liquid substantially equivalent to the pressure of a sealed gas in a container such as a pressure tank is measured, and the measurement result is used to determine that the diaphragm in the container is deteriorated. By comparing the measured value with the reference value obtained at a time when it is not performed, the deterioration state of the diaphragm can be easily and accurately diagnosed, so that an excellent effect that an appropriate replacement time of the container can be grasped can be obtained. As a result, there is no danger of wasteful replacement of containers that can still be used, and serious accidents such as burnout of the liquid pump due to unexpectedly rapid deterioration of the function of the diaphragm can be avoided. The performance is also improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a diaphragm type water supply system according to the present invention and a diaphragm inspection apparatus used therein.
FIG. 2 is a block diagram showing a main part of the diaphragm inspection apparatus.
FIG. 3 is a block diagram showing a main part of an application example of the diaphragm inspection apparatus.
FIG. 4 is a flowchart showing a first embodiment of a diaphragm inspection method according to the present invention.
FIG. 5 is a characteristic diagram showing an example of a measurement result in the first example.
FIG. 6 is a flowchart showing a second embodiment of the diaphragm inspection method according to the present invention.
FIG. 7 is a characteristic diagram showing an example of a measurement result in the second example.
FIG. 8 is a partially enlarged view of FIG. 7;
[Explanation of symbols]
Reference Signs List 1 water receiving tank 2 liquid pump 3 water supply pipe 4 pressure tank 4A air chamber 4B water chamber 5 diaphragm (diaphragm)
6 Pressure switch 7 Water cock 8A, 8B Gate valve 9 Pressure sensor (measuring means)
10 Processing unit (diagnosis means)
11 Ball valve (switching means)
12 Control cock 13 Drain port 14 Drain pipe (drain passage)
101 timer 102 memory 103 opening / closing control means 104 arithmetic unit 105 output means

Claims (7)

A container connected to the discharge side of the liquid pump means and having a stretchable diaphragm therein; and when the liquid is discharged to the outside when the supply of the liquid from the liquid pump means is stopped, the container inside the container is In a liquid supply system in which the pressure of the gas separated from the liquid by the above-mentioned diaphragm is reduced by being enclosed in
After injecting the liquid discharged from the liquid pump means into the container, the liquid pump means and the inside of the container are shut off, and a certain amount is passed through a discharge path for measurement connected to the container. The liquid was discharged under the conditions, the temporal change in the pressure of the liquid in the container accompanying the discharge was measured, and the measurement result was obtained by measuring the same procedure when the diaphragm was not deteriorated. A method for inspecting a diaphragm of a liquid supply system, wherein a diagnosis of a state of deterioration of the diaphragm is performed as compared with a reference value. A container connected to the discharge side of the liquid pump means and having a stretchable diaphragm therein; and when the liquid is discharged to the outside when the supply of the liquid from the liquid pump means is stopped, the container inside the container is In a liquid supply system in which the pressure of the gas separated from the liquid by the above-mentioned diaphragm is reduced by being enclosed in
After injecting the liquid discharged from the liquid pump means into the container and stopping the supply of the liquid from the liquid pump means, a certain condition is passed through a discharge path for measurement communicated with the container. Measuring the temporal change of the pressure of the liquid in the container when the liquid is discharged, and the temporal change of the pressure of the liquid in the container when the discharge of the liquid from the discharge path is stopped, Based on these measurement results, a temporal change in the pressure of the liquid in the container due to the discharge from the discharge path is calculated, and the calculated result is a reference obtained by measuring the time when the diaphragm is not deteriorated. A method for inspecting a diaphragm of a liquid supply system, wherein a diagnosis of a state of deterioration of the diaphragm is performed as compared with a value. In the description of claim 2,
When obtaining the reference value, the liquid pump means and the inside of the container are shut off, and a temporal change in the pressure of the liquid in the container due to discharge from the discharge path is measured. A method for inspecting a diaphragm of a liquid supply system. In the description of claim 2,
When the reference value is obtained, the liquid pump means and the inside of the container are not shut off, and the temporal change of the pressure of the liquid in the container when the liquid is discharged under a certain condition through the discharge path. Measuring the temporal change of the pressure of the liquid in the container when the discharge of the liquid from the discharge path is stopped, and, based on these measurement results, measuring the pressure in the container by discharging from the discharge path. A method for inspecting a diaphragm of a liquid supply system, comprising calculating a temporal change of a pressure of a liquid. A container connected to the discharge side of the liquid pump means and having a stretchable diaphragm therein; and when the liquid is discharged to the outside when the supply of the liquid from the liquid pump means is stopped, the container inside the container is In a liquid supply system in which the pressure of the gas separated from the liquid by the above-mentioned diaphragm is reduced by being enclosed in
A discharge path means having a discharge path for measurement connected to the inside of the container and capable of discharging the liquid in the container under certain conditions; and a state in which the discharge path means can and cannot discharge the liquid. Switching means for switching to, a measuring means for measuring the pressure value of the liquid flowing in the discharge path, and comparing a temporal change in the pressure of the liquid in the container based on the measurement result of the measuring means with a reference value, A diagnosing means for diagnosing a deterioration state of the diaphragm. In the description of claim 5,
A diaphragm inspection apparatus for a liquid supply system, wherein diagnosis is performed by the diagnosis unit based on a pressure value measured by the measurement unit before and after the switching operation by the switching unit is performed. In the description of claim 5 or 6,
A diaphragm inspection apparatus for a liquid supply system, comprising: a timing unit for designating an operation timing of the switching unit.

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