JPH08277782A - Variable speed water feeding device - Google Patents

Abstract

PURPOSE: To enable the stable stopping operation of a pump with water quantity small without frequently repeating its start and stop by performing test operation to judge the presence or absence of the decrease of discharge pressure while slightly increasing the operating speed of the pump. CONSTITUTION: A control unit 22 reads an output signal of a flow rate detector 19, and receives a contact signal Fs in the small water quantity state. It judges whether the small water quantity state is continued for the time set by a timer A or not. When the judged result is NO, the operation is continues without stop-operating a pump. When the judged result is YES, the pump speed is increased only by the specified differential speed, and test operation is performed. Whether discharge pressure Pd detected by a discharge pressure detector 23 is maintained for the time of a timer B or not is judged. When the discharge pressure Pd is not decreased, the pump is operated at the specified pressure accumulating operating speed for the time set by a timer C, pressure is accumulated in a pressure tank, and the pump is stopped. When the discharge pressure Pd is decreased, it is judged that water is used, and the operation of the pump is continued.

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. Also, in order to prevent the water pressure from decreasing in the 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 on the distribution pipe side from decreasing. 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 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 it is possible to perform a stable small water amount stopping operation in a direct-coupling type variable speed water supply apparatus 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 the terminal water supply device, a flow rate detector connected to the discharge pipe for detecting a small amount of water, a pressure tank provided in the discharge pipe, and a pressure pump connected to the discharge pipe. A discharge pressure detector for detecting the discharge pressure of the pump, a variable speed drive means for driving the pressurizing pump at a variable speed, and a control means for controlling the pump. When it is detected that the state continues for a certain time (A), the operating speed of the pressurizing pump is slightly increased so that the discharge pressure detector does not lower the discharge pressure for a certain time (B). Check the pressure pump at the accumulator operating speed When a small water amount stop operation is performed in which the operation is performed for a constant time (C) and the pressure pump is stopped after accumulating pressure in the pressure tank, and the flow rate detector does not continue to be in a small water amount state for a constant time (A), and When the discharge pressure decreases during a certain time (B) when the operating speed of the pressurizing pump is slightly increased, it is determined that it is not in a small water amount state, and control for not stopping the operation of the pressurizing pump is performed. Is characterized by.

The variable speed water supply apparatus according to the second aspect of the present invention is
An inflow pipe connected to the water distribution pipe, a pressurizing pump connected to the inflow pipe, a discharge pipe connected to the discharge side of the pressurizing pump and connected to the terminal water supply device, and connected to the discharge pipe. A flow rate detector for detecting a small amount of water, a pressure tank provided on the discharge pipe, a discharge pressure detector for detecting the discharge pressure of a pressurizing pump connected to the discharge pipe, and the pressurizing pump. Variable speed driving means for variable speed driving and control means for controlling the pump are provided, and the control means includes an inflow pipe connected to the water distribution pipe, a pressurizing pump connected to the inflow pipe, and the pressurizing pump. A discharge pipe connected to the discharge side of the pump and connected to the terminal water supply device, a flow rate detector connected to the discharge pipe for detecting a small amount of water, a pressure tank provided in the discharge pipe, and the discharge pipe Discharge to detect the discharge pressure of the pressure pump connected to the A force detector, a variable speed drive unit for driving the pressurizing pump at a variable speed, and a control unit for controlling the pump are provided, and the control unit is configured such that the flow rate detector is in a small water amount state for a certain time (A). When it is detected that it is continuing, the time since the last small water stop was a fixed time (D)
It is judged whether or not the time has elapsed, and if so, the pressurizing pump is operated at the pressure accumulating operation speed for a certain time (C).
When a small amount of water stopping operation is performed to stop the pressurizing pump after operating and accumulating pressure in the pressure tank, and when the time from the previous small amount of water stop has not elapsed for a certain time (D) or more, The operating speed of the pressurizing pump is slightly increased, and it is confirmed by the discharge pressure detector that the discharge pressure does not decrease for a certain period of time (B). The pressurizing pump is operated at the accumulated pressure operating speed for a certain period of time (C). A small water amount stop operation is performed to stop the pressurizing pump after accumulating pressure in the pressure tank, and the pump operation is not stopped when the flow amount detector does not continue the small water amount state for a certain time (A). The control is performed, and when the discharge pressure decreases during the certain time (B), it is determined that the state is not a small water amount state, and the control of not stopping the operation of the pressurizing pump is performed.

[0012]

According to the first aspect of the present invention, when the flow rate detector detects that the amount of water is small for a certain period (A), the operating speed of the pump is slightly increased and the discharge pressure is not lowered. Perform a wait-and-see operation to confirm this for a certain time (C). If the discharge pressure does not decrease at this stage, the pump is operated for a fixed time (C) at a predetermined pressure accumulation operation speed, and after the pressure is accumulated in the pressure tank, a small water amount stop operation is performed. At this stage, if the discharge pressure decreases, it is determined that the water amount is not small, and the pump operation is not stopped. Therefore, first, since the operation stop of the pump cannot be judged unless the small amount of water continues for at least a certain time (A), the effect of not frequently stopping the pump for intermittent use of water on the terminal water supply equipment side There is. Then, by slightly increasing the operating speed of the pump and observing whether or not the discharge pressure is decreasing for a certain period of time (B), it is possible to further confirm whether or not water is used on the end device side. The number of stops can be further reduced. Therefore, the pump can be reliably stopped with a small amount of water only when the amount of water used is completely small on the side of the terminal water supply device.

Further, in the second aspect of the present invention, first, similarly to the first aspect, it is judged whether or not the pump is stopped after detecting that the flow rate detector is in a small amount of water state for a certain period (A). A small amount of water continues for at least a certain time (A),
In addition, the pump will not be judged to have stopped for a certain period of time (D) or more since the last time when a small amount of water was stopped, so the effect of not frequently stopping the pump for intermittent use of water on the terminal water supply equipment side is obtained. is there. Next, if the time from the previous stop of the small amount of water has not elapsed for a certain time (D) or more, the operating speed of the pump is slightly increased to determine whether the discharge pressure is decreased for a certain time (B). By looking at it, confirm whether or not the state of small water volume 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 terminal water supply device 17 is directly connected to 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. . In addition, when the inflow pressure is reduced, 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 P
s 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 gives a speed command for accelerating or decelerating the pump 13 to the variable speed drive means (inverter) 25 according to the values of the inflow pressure Ps and the discharge pressure Pd.

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 measurement 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 the timer B (about 2 minutes) as in the first embodiment described above. 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. In addition, as a result of the wait-and-see operation, when 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 part 23 Discharge pressure detector 25 Variable speed means (inverter) Ps Inflow pressure Pd Discharge pressure Fs Small water amount detection signal

Claims (2)

[Claims] 1. An inflow pipe connected to a water distribution pipe, a pressurizing pump connected to the inflow pipe, a discharge pipe connected to a discharge side of the pressurizing pump and connected to an end water supply device, A flow rate detector connected to the discharge pipe for detecting a small amount of water, 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, and A variable speed driving means for driving the pressurizing pump at a variable speed and a control means for controlling the pump are provided, and the control means is such that the flow rate detector continues to be in a small water amount state for a certain time (A). If it is detected, the operating speed of the pressurizing pump is slightly increased, and it is confirmed by the discharge pressure detector that the discharge pressure does not decrease for a certain time (B). Time (C)
When a small amount of water is stopped by operating and storing the pressure in the pressure tank, the pressure pump is stopped, and when the small amount of water in the flow rate detector does not continue for a certain time (A), and A certain period of time when the operating speed was slightly increased (B)
A variable speed water supply device, characterized in that, when the discharge pressure drops during the operation, it is determined that the amount of water is not small, and control is performed so as not to stop the operation of the pressurizing pump. 2. An inflow pipe connected to a water distribution pipe, a pressurizing pump connected to the inflow pipe, a discharge pipe connected to a discharge side of the pressurizing pump and connected to a terminal water supply device, A flow rate detector connected to the discharge pipe for detecting a small amount of water, 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, and A variable speed driving means for driving the pressurizing pump at a variable speed and a control means for controlling the pump are provided, and the control means is such that the flow rate detector continues to be in a small water amount state for a certain time (A). When it is detected, it is judged whether or not the time from the previous stop of the small amount of water has passed a certain time (D) or more, and if it has passed, the pressurizing pump is operated at the pressure accumulation operating speed for a certain time. (C) After operating, pressure is accumulated in the pressure tank, A small water amount stop operation for stopping the pump is performed, and if the time from the previous small water amount stop has not elapsed for a certain time (D) or more, the operating speed of the pressurizing pump is slightly increased to It is confirmed by the discharge pressure detector that the discharge pressure does not decrease for a certain time (B), the pressure pump is operated at a pressure accumulation operation speed for a certain time (C), and the pressure pump is stopped after the pressure is accumulated in the pressure tank. If the flow rate detector does not continue to operate for a certain amount of time (A), the pump operation is controlled so that it does not stop, and again for the certain amount of time (B). A variable speed water supply device, characterized in that, when the discharge pressure drops during the operation, it is determined that the amount of water is not small, and control is performed so as not to stop the operation of the pressurizing pump.