JPH0771060A - Variable speed water supply device - Google Patents

Abstract

PURPOSE:To prolong equipment life and to promote energy conservation by automatically setting operating parameters regarding to small water volume stopping operation. CONSTITUTION:Pressure signals S1 on a pump discharge side of a pressure detection means and signals S2 of a small water volume detection means are inputted in a pump controlling means 7. Analog information such as discharge pressure from the controlling means 7, pressure frequency value, etc., and digital information such as a pump ON-OFF state, a wait and see operation state, a flow-switch opening and shutting state, etc., are inputted in a CPU 16 as operating parameters, and measuring monitor in an operating state is made. Those states are inputted in a fuzzy inference section 17, inference 1 or theory 2 is calculated in accordance with a rule 1 or a rule 2, a corrected amount of pressure frequency is added to the previous pressure frequency value by the inference 1, and new pressure frequency value is set. In accordance with the rule 2, small water volume detection hours such as wait and see operation hours confirming the continuation in a small water volume state with the theory 2, flow switch detection hours, etc., are set, and the operating parameters are sent to the controlling means 7 by a setting transmission 18.

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, the present invention relates to a variable speed water supply device having a small water volume stop function for stopping a water supply pump when the load is small.

[0002]

2. Description of the Related Art A variable speed water supply apparatus is a water supply apparatus capable of adjusting a flow rate and a discharge pressure by changing a rotation speed of a water supply pump for supplying water according to a load by a variable speed means such as an inverter. . FIG. 11 is an explanatory diagram showing the overall configuration of a conventional variable speed water supply device. This variable speed water supply device sucks water from the suction port 11, pressurizes it with the water supply pump 1, and supplies the load 20 with water. Water supply pump 1 for channel 10
On the discharge side, the small water amount detection means 3 for detecting that the flow rate of the water flow is a small amount of water below a certain value, the check valve 4, the pressure tank 5, and the discharge side pressure of the pump (the water pressure of the pressure tank). )
And a pressure detecting means 6 for detecting The pump 1 is driven by a frequency / voltage inverter which is a variable speed means 2 for changing the rotation speed, and the variable speed means 2 is controlled by a pump control means 7.

The pump control means 7 detects that the small water amount detection means 3 is below a certain value of the flow rate in the flow path 10, generates a small water amount detection signal, and holds a constant small water amount detection time. After confirming that the small amount of water continues, the small amount of water stopping function is provided to stop the water supply pump 1 after accumulating in the pressure tank 5 at a certain pressurizing pressure value or pressurizing frequency value for a certain period of time. Further, it has a pump starting pressure set value, and has a function of starting the water supply pump 1 when the pressure signal of the pressure detecting means 6 becomes equal to or lower than the pump starting pressure set value while the water supply pump is stopped.

Therefore, the operation of this variable speed water supply system is as follows. First, when the load 20 requires a medium water amount or a large water amount, the pump control means 7 uses the pressure signal S ₁ from the pressure detection means 6 to rotate the water supply pump 1 so that the pressure of the load becomes constant so that the load pressure becomes constant. Control means 2. When the load is a small amount of water, the above-described small amount of water stopping operation is performed in order to prevent heating due to the shutoff operation of the pump and to reduce unnecessary operating time (energy saving). That is, the small water amount detecting means 3 detects a small amount of water, generates a detection signal, holds a certain small amount of water detection time, and then accumulates pressure in the pressure tank 5 at a certain pressurizing pressure value or pressurizing frequency value for a certain period of time. After that, the water supply pump 1 is stopped. Then, a small amount of water is supplied from the pressure tank 5 to the load 20, and when the pressure in the pressure tank 5 becomes equal to or lower than a constant pump starting pressure set value, the water supply pump is restarted.

[0005]

However, all the parameters related to the conventional small water flow stop operation are constant values selected from the assumed load pattern. That is, the pressurizing pressure value or pressurizing frequency value when accumulating in the pressure tank is a constant value, and for confirming that the small water amount state continues after the small water amount detection means generates the small water amount detection signal. The small amount of water detection time was also constant. However, the load of the water supply device changes every moment, and the load pattern when the amount of water is small is not uniform. Therefore, the conventional small water volume stop operation cannot artificially change the operating parameters for load changes under all conditions, and cannot automatically cope with various load changes.

The purpose of the small water amount stop operation is to prevent the motor from being heated by the pump shutoff operation and to reduce the wasteful operation time. On the contrary, when the small water amount stop operation is too much (the frequency of starting and stopping the pump is increased. In addition, a rapid pressure increase due to accumulated pressure before a small amount of water is frequently required, which causes a problem to the mechanical life of the water supply device and causes a problem such as pressure fluctuation on the load side. Also, if the pressure rise value due to accumulated pressure before stopping a small amount of water is suppressed to a low level, there will be no sudden pressure rise on the load side, which will improve the usability of the water supply device. You will not be able to earn money, and the frequency of starting and stopping will increase.

The present invention has been made in view of the problems of the prior art.
While conflicting with the original purpose of the small water flow stop function, which is to prevent heating by the pump shutoff operation and reduce wasteful operation time, the start and stop frequency of the pump is reduced, and the rapid pressure rise due to the accumulated pressure before the small water flow stop is reduced. To provide a variable speed water supply device of energy saving type that achieves the objectives to some extent in good balance and reduces pressure fluctuations on the discharge side, is easy to use, extends the mechanical life of the pump, and reduces wasteful operation time as much as possible. That is the purpose.

[0008]

The pump control means is configured such that the small water amount detecting means generates a small water amount detection signal and holds the small water amount detection time for a certain amount of time, and then the pressure tank holds a certain pressurization pressure value for a certain period of time. Alternatively, after accumulating at the pressurization frequency value, it has a small water amount stop function for stopping the water supply pump and a pump starting pressure set value, and the pressure signal is sent by the discharge pressure detection means while the water supply pump is stopped. In a variable speed water supply device having a function of starting the water supply pump when the value becomes equal to or less than a set value, an operation including the pressurization frequency value and the small water amount detection time according to the load or the data of the latest operation status. It is characterized by comprising means for automatically setting parameters.

Further, the means for automatically setting the operating parameters is characterized by a fuzzy inference function.

[0010]

[Function] The fuzzy reasoning function automatically adjusts the pressurizing pressure value or pressurizing frequency value when accumulating pressure and the small water amount detection time for confirming the continuation of the small water amount state according to the load or the data of the most recent exercise condition. It is possible to adjust the optimum operating parameter corresponding to the variation of the load condition due to various variations. Therefore, it is possible to reduce wasteful operation time and contribute to energy saving.
Provided is a comfortable water supply system which avoids a sudden rise in pressure on the discharge side of the pump, extends the mechanical life of the water supply system, and has less pressure fluctuation on the load side.

[0011]

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

FIG. 1 is a block diagram showing the overall construction of a variable speed water supply system according to an embodiment of the present invention. As is apparent from FIG. 1, a water supply pump 1, a variable speed means 2 for changing the rotation speed of the water supply pump 1, a small water amount detecting means 3 and a check valve 4 provided on the discharge side of the water supply pump, and a check valve. The configuration including the pressure tank 5 and the pressure detection means 6 provided on the downstream side of the valve is the same as that of the variable speed water supply device described in the section of the related art. Further, the pump control means 7 causes the low water amount detection means 3 to generate a low water amount detection signal S ₂ and hold it for a certain low water amount detection time, then accumulate the pressure in the pressure tank 5 and thereafter stop the water supply pump 1. It has a water amount stop function and also has a pump starting pressure set value, and when the pressure signal S ₁ becomes less than or equal to the pump starting pressure set value by the pressure detection means 6 while the water supply pump 1 is stopped, the water feed pump 1 is started. It has the same starting function as the above-mentioned conventional technology.

In the water supply system of this embodiment, the pump control means 7 is operated to detect a small amount of water for confirming the continuation of a small amount of water, and a pressurizing pressure value or a pressurizing frequency value when accumulating pressure in the pressure tank. Operation parameter automatic setting means 1 for automatically setting the optimum value of the parameter according to the operation situation
5 is provided. Here, the operation status is, for example, the previous water supply pump operating time, the previous stop time, the number of times the small water amount detection signal is generated on the previous day, the previous pressurizing pressure value or pressurizing frequency value, or the like. Means 15 for automatically setting these operating parameters
Is based on the fuzzy inference function. It is equipped with a fuzzy inference unit and rules, extracts various results of driving conditions, extracts the results of inference according to the rules of fuzzy theory, and newly uses the values as operating parameters. Set.

The automatic setting means for operating parameters using fuzzy inference will be described in detail below. FIG. 2 is an explanatory diagram showing a hardware configuration of the automatic setting means 15 for operating parameters. In the pump control means 7, the pressure signal S ₁ on the pump discharge side (pressure tank) by the pressure detection means and the signal S of the small water quantity detection means for detecting whether or not the flow rate is a small water quantity.
₂ is entered. Then, from the pump control means 7, analog information (A / I) such as discharge pressure, pressurization frequency value, etc., pump
Digital information (D / I) of "1" or "0" such as an ON-OFF state, a wait-and-see operating state, and a flow switch open / close state is input to the CPU 16 as an operating parameter, and the operating state is measured and monitored. These operating parameters are input to the fuzzy inference unit 17 and the predetermined rule 1
Alternatively, inference 1 or inference 2 is calculated according to Rule 2, and the inference 1 adds the correction amount of the pressurizing frequency to the previous pressurizing frequency value to set a new pressurizing frequency value. Further, according to the rule 2, a small water amount detection time such as a wait-and-see operation time for confirming the continuation of the small water amount state by the inference 2 and a flow switch detection time is set. These set operating parameters are sent to the pump control means 7 by the set value transmission 18.

FIG. 3 shows Rule 1 of the correction amount of the pressurizing frequency value. What is input as the operation status is the pressurization frequency value at the time of the previous pressure accumulation and the previous small water volume stop time. In order to infer the current pressurization frequency correction amount from the previous pressurization frequency value and the previous stop time, these control contents are first described in a document, and the illustrated rule 1 is created.

In Rule 1, the vertical axis represents the previous stop time, the horizontal axis represents the previous pressurizing frequency, and the portion where the vertical axis and the horizontal axis intersect is the pressurizing frequency correction amount, which is the conclusion of the rule. For example, in FIG.
If the first row and the second column are combined, the rules are: if last stop time is short (NL) and last pressurization frequency is medium (ZR) then pressurization frequency correction amount is slightly increased (PS). Such a rule matrix is created by empirical knowledge with respect to set values for achieving desired operating conditions for all load conditions.

Further, in order to quantify the modifiers such as "large" and "small" expressing the state quantities and operation quantities of the above rules, a graph called membership function is made. In FIG. 4, (A) is a previous pressurizing frequency, (B) is a previous stop time, and (C) is a membership function indicating the pressurizing frequency correction amount. In the fuzzy reasoning section 17, the reasoning 1
Calculates the quantitative calculation result from the membership function of Rule 1, and outputs the correction amount of the pressurizing frequency value as a conclusion.

FIG. 5 shows Rule 2 of the wait-and-see operation time control. The wait-and-see operating time is the latter part of the small water amount detection time, and is a time for confirming the continuation of the small water amount state following the flow switch detection signal. The flow switch detection time, which precedes the small water amount detection time, is fixed. From the last stop time, the immediately preceding operation time, and the number of times of small water stop of the previous day, the wait-and-see operation time is inferred and a rule is created based on the following operating knowledge. If the previous stop time is short, the start frequency may increase, so the wait-and-run operation time is lengthened and the interval until the pump stops is lengthened. On the contrary, if the previous stop time is long, shorten the wait-and-see operation time. If the immediately preceding operation time is long, the frequency of starting is not likely to increase, so the wait-and-see operation time is shortened to reduce unnecessary operation time. On the contrary, when the immediately preceding operation time is short, the wait-and-see operation time is lengthened to prevent the start frequency from increasing. When the number of times of small water flow stop on the previous day is small, it can be inferred that the load fluctuation is small, so the wait time is shortened and the confirmation time of the small water flow state is shortened to reduce the wasteful operation time. On the contrary, if the number of small water stoppages on the previous day is high, increase the wait-and-see operation time and reduce the starting frequency.

FIG. 6 shows Rule 2 of the wait-and-see driving time control as a membership function. The inference 2 performs the same arithmetic processing as the inference 1 described above, obtains the optimum wait-and-see operating time as a conclusion, and transmits it to the pump control means 7 by the set value transmission 18. Example 1 is an example of a variable-speed water supply device in which inference 2 is performed by using this wait-and-see operating time control as rule 2.

FIG. 7 shows Rule 2 of the flow switch detection time control instead of the wait-and-see operation time control. The flow switch detection time is a part before the small water amount detection time, and when the flow switch is closed for a certain period of time, that is,
This is the time to start a wait-and-see operation by generating a detection signal when it is confirmed that a small amount of water has continued for a certain period of time. The wait-and-see operating time, which is the latter stage of the small water amount detection time, is fixed. The flow switch detection time is inferred from the last stop time, the immediately preceding operation time, and the number of times the flow switch is opened and closed, and rule 2 is created based on the following operating knowledge. If the previous stop time is short, the start frequency may increase, so the flow switch detection time is lengthened and the interval until the stop is lengthened. On the contrary, if the previous stop time is long, the flow switch detection time is shortened. When the immediately preceding operation time is long, the frequency of starting is not likely to increase, so the flow switch detection time is shortened to reduce unnecessary operation time. On the contrary, if the immediately preceding operation time is short, the flow switch detection time is set longer. When the number of times of opening and closing the flow switch is small, it can be estimated that the fluctuation of the water amount of the load is small. Therefore, the flow switch detection time is shortened to reduce the wasteful operation time. On the other hand, when the number of times the flow switch is opened and closed is large, the flow switch detection time is lengthened to reduce the starting frequency.

FIG. 8 shows this rule as a membership function. From the rule 2, the calculation process of the inference 2 for obtaining the optimum flow switch detection time is the same as that described above. In the second embodiment, the flow switch detection time control shown in FIGS.

FIG. 9 is a time chart showing the operation of the water supply pump obtained by the fuzzy inference unit 17 for the wait-and-see operation time and the correction amount of the pressurization frequency value in the small water amount detection time of the first embodiment. FIG. 10 is a time chart showing the operation of the water supply pump in which the fuzzy inference unit 17 finds the flow switch detection time and the pressurization frequency value correction amount of the small water amount detection time of the second embodiment.

From the result of the first embodiment by the automatic setting means of the operating parameters obtained by the fuzzy inference of the pressurization frequency and the wait-and-see operating time, the fuzzy inference function is used to reduce the number of times of small water stop (starting frequency). It was confirmed that the pressurizing frequency can be kept relatively low and the parameters can be adjusted and controlled without significantly increasing the operating time. Similarly, also from the result of the second embodiment by the automatic setting means of the operation parameter obtained by the fuzzy inference for the pressurizing frequency value and the flow switch detection time, the pressurizing frequency is lowered and the starting frequency is reduced as a whole. It was confirmed that there is an effect that the operating time can be reduced (or not increased so much).

In this embodiment, the inference unit performs the fuzzy inference based on the rule for setting the parameters of the small water amount detection time and the pressurization frequency, but the inference result is obtained in advance by another fuzzy controller. It is also possible to make a data table, set the small water amount detection time and the pressurization frequency value, and make a decision by referring to the value corresponding to the input value. Further, as the data for inputting the operation status, the number of times of small water stoppage, the pressure fluctuation state before the small water stoppage, and the like may be used. Further, the output may be a pressure fluctuation state detection time before stopping a small amount of water, a pressurization time, or the like. In the present invention, as the target setting means of the operating parameter,
Although it is not limited to fuzzy inference, fuzzy inference can be used to control to a desired operating state for all load conditions, and experience knowledge can be reflected in the control content.

[0025]

According to the present invention, it is possible to automatically set the operation parameters related to the operation of stopping the small amount of water of the variable speed water supply apparatus so that the desired operation state can be obtained regardless of any load fluctuation. That is, while satisfying the purpose of the small water volume stop operation such as prevention of heating by the pump shut-off operation and reduction of the operation time, there is a conflict with each other such as reduction of the operation stop (start) frequency and reduction of pressure rise due to accumulated pressure before the small water volume stop. The effect can be achieved in a balanced manner even under various operating conditions.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of a variable speed water supply apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a hardware configuration of an automatic setting means for operating parameters.

FIG. 3 is an explanatory diagram of Rule 1 of a pressurization frequency correction amount.

FIG. 4 is an explanatory diagram of a membership function of a rule of pressure frequency control.

FIG. 5 is an explanatory diagram of a rule of wait-and-see operation time control.

FIG. 6 is an explanatory diagram of a membership function of a rule of wait-and-see driving time control.

FIG. 7 is an explanatory diagram of a rule of flow switch detection time control.

FIG. 8 is an explanatory diagram of a membership function of a rule of flow switch detection time control.

FIG. 9 is a time chart of the rotation speed control of the pump (Example 1) in which the pressurization frequency and the wait-and-see operation time are obtained by fuzzy inference.

FIG. 10 is a time chart of pump speed control (Example 2) in which a pressurization frequency and a flow switch detection time are obtained by fuzzy inference.

FIG. 11 is an explanatory diagram showing the overall configuration of a conventional variable speed water supply device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water supply pump 2 Variable speed means 3 Small water amount detection means 4 Check valve 5 Pressure tank 6 Pressure detection means 7 Pump control means 10 Flow path 15 Automatic setting means for operating parameters 16 CPU 17 Fuzzy inference section

Claims (2)

[Claims] 1. A water supply pump, a variable speed means for changing the number of revolutions of the water supply pump, a small water amount detecting means and a check valve provided on the discharge side of the water supply pump, and a downstream side of the check valve. It comprises a pressure tank and a pressure detecting means provided, and a pump controlling means, wherein the pump controlling means generates a small water amount detecting signal by the small water amount detecting means, and holds the pressure for a certain small water amount detecting time. It has a function to stop the water supply pump after accumulating in the tank at a certain pressure pressure value or pressure frequency value for a certain period of time and a pump starting pressure set value, and the pressure is detected by the pressure detecting means while the water supply pump is stopped. In a variable speed water supply apparatus having a function of starting the water supply pump when the signal becomes equal to or lower than the pump starting pressure set value, the pressurizing frequency value, the Water volume Variable speed water supply apparatus characterized by comprising means for automatically setting the operating parameters including intellectual time. 2. The variable speed water supply apparatus according to claim 1, wherein the means for automatically setting the operation parameter is based on a fuzzy inference function.