JP3425269B2 - Variable speed water supply - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable speed water supply device,
In particular, it relates to a so-called direct connection type variable speed water supply device, which is directly connected to a terminal water supply device from a water distribution pipe via a pressure pump.

[0002]

2. Description of the Related Art FIG. 1 shows a system outline of a direct connection type variable speed water supply system. For example, an inflow pipe 12 is connected to a water distribution pipe 11 which is a main water pipe, and a suction side of a pressurizing pump 13 is connected to this inflow pipe. A water meter 15 that integrates the amount of water used is connected to the inflow pipe 12. Pressure pump 1
A discharge pipe 18 connected to a terminal water supply device 17 is connected to the discharge side of 3. The discharge pipe 18 has a flow rate detector 19 for detecting a small amount of water in which almost no water is used, and a discharge for accumulating and storing the discharged water so as not to frequently repeat the start and stop of the pump. The side pressure tank 20 and the like are connected.

The flow rate detector 19 is a detector for detecting the flow rate. In particular, when a small amount of water is detected, the operation of the pump is stopped in order to prevent the shutoff operation of the pump. The signal Fs for performing the above is transmitted to the control unit 22. An inflow pressure detector 2 is provided on the inflow side of the pressurizing pump 13.
1 is connected, and the pressure P on the inflow side of the pressurizing pump 13 is
s is detected and its signal is sent to the control unit 22. Similarly, a discharge pressure detector 23 is provided on the discharge side of the pressurizing pump 13, and sends a discharge side pressure signal Pd to the control unit 22.

The pump 13 is driven at a variable speed by an electric motor (variable speed means) 25 having a frequency / voltage converter (inverter) connected to a three-phase AC commercial power source. The control unit 22 includes the inflow pressure detector 21 and the discharge pressure detector 2
A signal is sent to the variable speed means 25 based on the signals Pd and Ps of No. 3 to accelerate or decelerate the rotation speed of the pump 13 to an arbitrary speed.

Japanese Unexamined Patent Publication Nos. 5-118280 and 5
According to Japanese Patent Application Laid-Open No. 263444/1993 and Japanese Patent Application Laid-Open No. 5-240186, by maintaining a constant pressure on the discharge side of the pressurizing pump, it is possible to constantly supply stable and constant pressure water to the terminal water supply device. A technique for increasing or decreasing the speed of is disclosed. Further, in order to prevent the water pressure from decreasing in the water distribution pipe, when the pressure on the inflow side of the pump decreases, the speed of the pump is reduced or stopped to prevent the pressure decrease on the water distribution pipe side. Etc. are disclosed.

In such a direct connection type variable speed water supply device,
There are various merits as compared with the conventional method of connecting a water storage tank to a water distribution pipe and distributing the water stored in the water storage tank to the terminal water supply equipment by using a pressure pump. The merit is that since the water tank is not provided on the inflow side of the pressurizing pump, the water supply device can be downsized as a whole and the installation area can be reduced. It is preferable for hygiene because water is not stored. Since the water pressure of the water distribution pipe can be used as it is on the suction side of the pressurizing pump, the head of the pressurizing pump is lowered, and energy can be saved accordingly.

Also in such a direct connection type variable speed water supply device,
The flow rate detector detects that the amount of water used in the terminal water supply device is small, operates the pump at a relatively high operating speed for a certain period of time, accumulates pressure in the pressure tank, and then stops the pump. There are cases where the water volume stop operation is performed.
When the speed of the pump is controlled to a constant discharge pressure, water is no longer used on the terminal water supply equipment side, and when the amount of water becomes almost zero, the pump will be shut off. If the pump shuts off continuously, the pump will generate heat and must be stopped.
The so-called small water amount stop operation starts. The condition for restarting the pump is when the discharge pressure falls below the target discharge pressure. However, if the pump is stopped immediately after detecting a small amount of water, the discharge pressure Pd immediately falls below the target discharge pressure, and the pump frequently operates. The start and stop will be repeated. Therefore, immediately before stopping the pump, the rotational speed of the pump is increased to accumulate the pressure in the discharge side pressure tank at a pressure slightly higher than the target discharge pressure and then stop the pump. In this way, even if some water is used, it takes time for the pressure to drop to the target discharge pressure, so that the pump can be stopped for a long time.

[0008]

The small water flow stop operation causes the number of times of starting and stopping the pressurizing pump to be extremely large when the usage of water is intermittent, such as in residential equipment with a small number of residents. May increase. Such frequent start-up and stop of the pressurizing pump inevitably involves pressure fluctuations on the pump discharge side, so that the water pressure in the terminal water supply device frequently changes, resulting in discomfort to the user side.

The present invention has been made in view of the above-mentioned circumstances, and in the direct connection type variable speed water supply apparatus, it is possible to perform a stable small water amount stop operation without frequently repeating the start and stop of the pump. An object is to provide a variable speed water supply device.

[0010]

The variable speed water supply apparatus of the present invention is connected to an inflow pipe connected to a water distribution pipe, a pressurizing pump connected to the inflow pipe, and a discharge side of the pressurizing pump. a discharge pipe connected to terminal water supply device, a front Stories and pressure tank provided on the discharge pipe, the discharge pressure detector for detecting a delivery pressure of the pressure pump connected to the discharge pipe, the pressure pump A variable speed drive means for driving the pump at a variable speed, and a control means for controlling the pump. The control means, when it is determined that the small water amount state continues for a certain time (A),
It is determined whether the time from the low water stopped the previous certain time has elapsed (D) above, if the elapsed, low water stop for stopping the pressure pump after accumulating before Symbol pressure tank It is characterized by performing an operation.

Further, the variable speed water supply apparatus of the present invention determines whether or not the time from the previous stop of the small amount of water has passed a certain time (D) or more, and when it has not passed, the pressurizing pump. slightly increase the operating speed of the discharge pressure by the discharge pressure detector confirms that no fixed time (B) decreases, before Symbol low water stop operation for stopping the pressure pump after accumulated in the pressure tank It is characterized by performing.

[0012]

SUMMARY OF] According to the onset bright, the flow rate detector is a predetermined time (A)
Stopping the pump after detecting that the water volume is low
To judge. Small amount of water is at least a certain time (A)
Continued, and more than a certain time (D) since the last time when a small amount of water was stopped
If the time has elapsed, operate at the pressure accumulation speed for a certain time (C), and
Stop the pump. As a result, the pump can be reliably operated to stop the small water amount only when the amount of water used is completely small on the terminal water supply device side.

[0013] Next, when the time from the low water stopped the previous certain time has not elapsed (D) above, slightly increases the operating speed of the pump, whether a certain time the discharge pressure is reduced ( B) By watching the situation, it is confirmed whether or not the state of small water continues. By this observation, the number of times the unnecessary pumps are stopped can be significantly reduced, and the pumps can be reliably stopped only when the small water volume state in which little water is used is certain. Therefore, the number of times of starting and stopping the pump due to the operation of stopping a small amount of water is increased in an apartment house or the like having a small number of residents, which is a conventional problem, and the frequency of giving discomfort to the user is extremely reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

Also in this embodiment, the system configuration in which the pressurizing pump 13 is directly connected to the water distribution pipe 11 and the water is directly connected to the terminal water supply device 17 from the water distribution pipe 11 without passing through the water storage tank is as shown in FIG. Then, the pressurizing pump 13 controls the discharge pressure by the variable speed means 25 such as an inverter so as to increase or decrease the pump rotation speed so that the water supply pressure to the terminal water supply device 17 becomes constant by the signal of the discharge pressure detector 23. . Further, when the inflow pressure drops, inflow pressure control is performed to reduce or stop the pump rotation speed by the variable speed means 25 so that the water distribution pipe is not adversely affected and the pressure does not drop below a predetermined set pressure. Be seen. Then, the discharge pressure control is switched to the inflow pressure control when the inflow pressure Ps becomes equal to or lower than the selected set pressure.

FIG. 2 shows the configuration of the control portion of the variable speed water supply system according to an embodiment of the present invention. The inflow pressure detector 21 inputs the pressure Ps on the inflow side of the pressurizing pump 13 to the control unit 22, and the discharge pressure detector 23 inputs the pressure Pd on the discharge side of the pressurizing pump 13. The control target value of the discharge pressure Pd is usually set to 2-3 kg / cm ² . Inflow pressure Ps The control target value of is usually set to about 1 kg / cm ² so as not to adversely affect the water distribution pipe. Inflow pressure Ps of inflow pressure detector When there is a possibility that the water pressure will decrease and the water distribution pipe will be adversely affected, the discharge pressure control is switched to the inflow pressure control. The control unit 22 controls the inflow pressure P
variable speed drive means (inverter) for speed command for accelerating or decelerating the pump 13 according to the values of s and discharge pressure Pd.
Give to 25.

Further, when the flow rate detector 19 is in a small amount of water state, that is, when almost no water is used, a signal Fs is sent to the control section 22. On the other hand, various parameters for controlling the operation of the pump are input to the control unit 22.
These parameters are the operating speed at the time of accumulating the small amount of water stopped operation, the differential speed at which the operating speed of the pump is slightly increased during the wait-and-see operation, and timer A, timer B, timer C, timer D, etc., which are time parameters. . Here, as for the differential speed of the pump operation, when the flow rate detector detects that the flow rate detector is in a small amount of water for a certain period of time (A) and it is judged that the pump is stopped, the operating speed of the pump is slightly increased to perform a wait-and-see operation. The difference to be increased is the difference speed, which is set to 2 Hz in this embodiment.

In the present embodiment, the timer A is set to about 60 seconds, and when the flow rate detector determines that the signal Fs indicating that the water amount is small continues for this time, the timer A is set as described above. Perform a wait-and-see operation with the pump operating speed slightly increased. The timer B is the time for continuing the wait-and-see operation with the pump operating speed slightly increased, and is about 2 minutes in the present embodiment. It is determined whether or not the discharge pressure Pd drops within this time. The timer C is the time for performing the pressure accumulation operation of the small water amount stop operation, and is set to about 20 seconds in this embodiment. The timer D stops the operation of the pump under a certain condition when a certain time or more has elapsed since the last time when the small amount of water was stopped, but this is the certain time, and in this embodiment, it takes about 5 minutes. is there.

FIG. 3 shows a flow of the small water amount stopping operation of the first embodiment of the present invention. First, the output signal of the flow rate detector 19 is read, and in the case of a small amount of water, the flow rate detector 19
The contact signal Fs is received from. Next, it is determined whether or not the small water amount state continues for the time set by the timer A (about 60 seconds in this embodiment). If “NO”, the pump is not stopped and the operation is continued. If it is determined that the amount of water flow has continued for the timer A time,
The pump speed is increased by the differential speed (here, 2 Hz) to perform the wait-and-see operation. Then, it is determined whether the discharge pressure is maintained for the time of the timer B (about 2 minutes in this embodiment). Whether or not the discharge pressure P _d decreases is determined by the measured value from the discharge pressure detector 23. If the discharge pressure does not decrease for the time of the timer B (here, about 2 minutes), it is determined that the water amount is small and the pump pressure accumulation operation is started. In the pump pressure accumulating operation, the operation speed of the pump is operated at a predetermined pressure accumulating operation speed for a time period (about 20 seconds in this case) set by the timer C, and after the pressure is accumulated in the pressure tank 22, the pump is stopped. If the discharge pressure is not maintained for the time of timer B, that is, if the discharge pressure decreases within this time, it is determined that water is being used and the small water amount stop operation is not started. Instead, continue pump operation.

FIG. 4 shows a flow of a small water amount stopping operation of the second embodiment of the present invention. In the present embodiment, in addition to the steps of the first embodiment described above, the small water amount stop operation is performed in consideration of the case where a certain time or more has elapsed since the previous small water amount stop. That is, first, when a signal Fs indicating that a small amount of water is supplied from the flow rate detector 19, it is determined whether or not the small amount of water continues for the time of the timer A (about 60 seconds in this embodiment). If yes,
It is determined whether or not the time since the last small water amount stop operation has passed a certain time D (about 5 minutes in this embodiment) or more. If "YES", the small water flow signal Fs is 2
Since it has continued for about 5 minutes and more than 5 minutes have passed since the last small water amount stop, the small water amount stop operation is started. If "NO", is the pump operating speed slightly increased by the differential speed and the discharge pressure is maintained for the time set for timer B (about 2 minutes) as in the first embodiment? Perform a wait-and-see operation to determine whether or not. When the discharge pressure does not decrease here, the small water amount stop operation is started. A small amount of water stopping operation is performed by operating the pump at a predetermined accumulating operation speed for a certain time C
After operating for about 20 seconds to accumulate the pressure in the pressure tank 22, the pump 13 is stopped. As a result of the wait-and-see operation, if the discharge pressure is “NO”, the small water amount stop operation is not performed and the pump operation is continued. Also, the time of the timer A which is the first judgment (about 60 seconds), the small water amount signal Fs
Even if does not continue, the small water flow stop operation is not performed and the pump operation is continued.

The above embodiment is only an example, and the set time of the timers A, B, C, D, etc., or the differential speed of increase during the wait-and-see operation, etc., is appropriately set according to the system configuration to be applied. It should be changed.

[0022]

As described above, according to the first aspect of the present invention, the operation for stopping a small amount of water is performed by the above-mentioned flow.
The operating speed of the pump is slightly increased to perform a wait-and-see operation for determining whether or not the discharge pressure is decreased. Further, according to the second aspect of the present invention, the small water amount stop operation is performed in consideration of the elapsed time from the previous small water amount stop. As a result, it is possible to reduce the number of unnecessary stoppages of the pump in the small water stop operation,
The problem that the start and stop of the pump is frequently repeated when a small amount of water is stopped, which gives a user a discomfort, has been solved. Further, while solving the problem, the pump can be surely stopped when the small water amount state is sufficiently continued, so that the deadline operation time of the pump is reduced,
Energy saving operation can be performed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a system configuration of a direct connection type variable speed water supply device.

FIG. 2 is an explanatory diagram showing a configuration of a control unit of each embodiment of the present invention.

FIG. 3 is a control flow chart of a small water amount stopping operation according to the first embodiment of the present invention.

FIG. 4 is a control flow chart of a small water amount stopping operation according to the second embodiment of the present invention.

[Explanation of symbols]

19 Flow rate detector 22 Control unit 23 Discharge pressure detector 25 Variable speed means (inverter) Ps Inflow pressure Pd discharge pressure Fs Small water amount detection signal

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F04B 49/00-49/10 F04B 23/00-23/14 F04D 15/00-15/02

Claims (2)

(57) [Claims] [1 claim] an inflow pipe connected to a water pipe, a pressure pump connected to the inlet pipe, a discharge pipe connected to this is connected to the discharge side of the pressure pump end water equipment, pre A pressure tank provided in the discharge pipe, a discharge pressure detector for detecting the discharge pressure of a pressurizing pump connected to the discharge pipe, a variable speed drive means for driving the pressurizing pump at a variable speed, and the pump. When it is determined that the small amount of water continues for a certain period of time (A) , the control unit has a certain period of time (D) or more since the last small amount of water stopped. to whether judges that, if the elapsed, variable speed water supply apparatus, wherein the performing the low water stop operation of stopping the pressure pump after accumulating before Symbol pressure tank. 2. A judgment is made as to whether or not the time from the previous stop of a small amount of water has passed a certain time (D) or more, and if it has not passed, the operating speed of the pressurizing pump is slightly increased, claim 1, characterized in that the discharge pressure by the discharge pressure detector confirms that no fixed time (B) decreases, low water stop operation for stopping the pressure pump after accumulating before Symbol pressure tank Variable speed water supply device described.