JPS59162395A - Device for monitoring state of operation of pump - Google Patents

Abstract

PURPOSE:To provide a pump operation state monitoring device capable of early detecting the trouble of measuring machinery, by measuring outputs in the state of operation of the pump, calculating theoretical values for the pump's characteristics, and comparing the theoretical values with the measured values. CONSTITUTION:The lift (h), discharge flow rate (q) and mean rotational frequency (n) of a pump are calculated as measured values on the basis of outputs found out by a reservoir water level detector, a sent water pressure detector, a sent water flow rate detector and a pump rotational frequency detector. Two of the measured values are applied to a pump characteristic theoretical value calculator to compute the other value as a theoretical value, which is compared with the corresponding measured value to detect the abnormality of the measured value in terms of the difference between the compared values.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention relates to an operating state monitoring device for pump equipment, and in particular to a monitoring device for measurement signals when controlling pump rotation speed, water supply pressure and flow rate. It is related to.

In general, measurement signals in pump equipment are monitored in a wide variety of ways, including upper and lower limit monitoring, deviation monitoring, rate of change monitoring, monitoring within a specified area, and monitoring for disconnection or power cutoff, etc., to improve the reliability of the equipment. There is. In this case, there are many measurement signals such as flow rate, pressure, water level, number of traces, etc., and in order to monitor each of them, processing is performed using a large number of measuring instruments such as transmitters, converters, and calculators. There is. For this reason,
With this type of monitoring device, failure of the measuring device itself poses a problem. In other words, there is no problem in the case of an instrument failure that causes a large signal change that can be detected by upper/lower limit monitoring or deviation monitoring, but it is impossible to detect failures in other conditions, such as holding the same value or increasing error. In many cases, if this state remains, the measurement signal monitoring function may stop.

[Purpose of the invention]

Measure the various output characteristics of the pump under operating conditions, calculate the theoretical value of the pump characteristic from these measurement signals using the pump characteristic calculation formula, compare the theoretical value of the pump characteristic with the actual value, and calculate the difference based on the amount of difference. It is an object of the present invention to provide a pump operating state monitoring device capable of early detecting an abnormality in an actual measurement value, that is, a failure of a measuring device.

[Key points of the invention]

The configuration of the present invention will be explained based on FIG.

That is, in the present invention, a reservoir water level detection means, a water supply pressure detection means, a water supply flow rate detection means, and a pump rotation speed detection means are provided, and based on the output detected by these detection means v. The pump head value (h), discharge flow rate value (q), and average rotation speed value (n) are IL.
On the other hand, bomb characteristic theoretical value calculation means is provided, and two ilM of each of the above-mentioned actual measurement values are calculated in this calculation means.
is input and one other value is calculated as the theoretical value, and the resulting theoretical value and the actual measured value are compared in correspondence with each other using the pump characteristic abnormality determination means, and the abnormality of each actual measured value is determined from the difference amount. It is characterized by detecting.

In the above-mentioned pump operating state monitoring device, the pump characteristic theoretical value calculation means is calculated using the following formula (%) (where h is the head value, q is the discharge flow rate value, nrIi is the average rotational speed value, and A-E is the pump mechanical In the pump characteristic equation shown by n, the head value, the discharge flow rate value,
It is preferable to configure it with an arithmetic circuit that substitutes two values among the rotational speed average values and calculates the other value as a theoretical value.

In addition, the means for determining abnormalities in pump characteristics is the actual head value.

Compares the corresponding theoretical value and actual measured value for each discharge flow rate value and rotational speed average value, determines each abnormality of each actual value individually, and activates the abnormality alarm output means for each actual value based on the determination result. It is preferable that the

[Embodiment J of the Invention Next, an embodiment of the pump operating state monitoring device according to the present invention will be described in detail below with reference to the accompanying drawings.

First, the output characteristics of a pump are generally flow rate (H) - head (Q
) curve, and has the following relationship based on the lift height h, the discharge flow rate q, and the rotation speed n.

h= F(q-n)=Anz-Bnq-C(1-q)2
-D, 2-E... (1) In the above formula (1), A, B, C, D, and E are constants determined from mechanical properties. That is, based on the pump characteristic equation shown in equation (1) above, if the vertical axis is the head 11, the horizontal axis is the flow rate q, and the rotation speed n is the parameter, a characteristic curve as shown in Fig. 2 can be obtained. Ran.゛Also,
In this case, the pump operation is performed at the intersection (A, B
.

C), the numerical values of the head h, flow rate q, and rotation speed n at the actual pump operating point should satisfy the above formula (1).

Therefore, in the present invention, by actually measuring the head, flow rate q, and rotation speed n, and substituting two of these measured values into the pump characteristic equation (1), one of the remaining The value can be obtained as a theoretical value. Therefore, by comparing the theoretical values obtained in this way with the actual measured values, abnormalities in the actual measured values can be detected. This figure shows a pump system for actually measuring the number n. That is, FIG. 6 shows a plurality of pumps PU from the water distribution reservoir 10.
, ~PUk is a pump system that supplies water to a pipe 14 having a predetermined pipe resistance characteristic R via a pump equipment 12 consisting of pumps 12, 12, 12, 12, 12, 12, 12, and 12. In this case, the water distribution reservoir 10 is provided with a water level detection means 16, each pump of the pump equipment 12 is provided with a rotation speed detection means 18, and the piping 14 is provided with a water supply pressure detection means 20 and a water supply flow rate detection means 22, respectively. . However, the water level value L1 detected by the water level detection means 16
and the water supply pressure value 1 detected by the water supply pressure detection means 20
)o into the head value generating means 24 to obtain the formula h=po-L.
Lifting head value hf: Calculate based on i. In addition, the water supply flow rate value Qo detected by the water supply flow rate detection means 22 is inputted to the discharge flow rate value generation means 26, and based on the following formula q = q, )/k (where k is the number of pumps in operation). The discharge flow rate value q of 11 units of pumps is falsified. Furthermore, rotation speed detection means 18
The rotational speed n, ~nk detected in is input to the rotational speed average value generation means 28, and the average rotational speed n of the pump is calculated based on the following formula n=Σn/'k (where k is the number of pumps in operation). Calculate. In this way, the head value generation means 24
, the pump head value h, the discharge flow rate value q, and the rotation speed average value n calculated by the discharge flow rate value generation means 26 and the rotation speed average value generation means 28 are grasped as actual measured values during operation of the pump equipment.

FIG. 4 shows the response to the pump characteristic equation (1) based on the actual measured value h+qe'' calculated by the head value generation means 24, the discharge flow rate value generation means 26, and the rotational speed average value generation means 28 described above. Theoretical values of pump characteristics H, Q,
This figure shows a circuit that calculates N and determines all abnormalities in the actual measured value h* qe''. That is, in FIG.
Reference symbol 60 indicates pump characteristic theoretical value calculation means, and 62
indicates pump characteristic abnormality determination means. The pump characteristic theoretical value calculation means 60 is configured as an arithmetic circuit that performs calculation processing of the pump characteristic formula (1), and calculates each of the actual measured values h+ q+
The actual measured values output from the means 24, 26, and 28 for generating ``, q, and n are input, and the other value is calculated as the theoretical value. In the characteristic theoretical value calculating means 60, the actual measured value h*
Theoretical values fi, Q, and N corresponding to ``qe'' can be calculated. In this way, the theoretical values 1 (, Q, and N are the actual values The actual value obtained by the generating means 24°26.28,
Together with q and n, they are input to the pump characteristic abnormality determining means 62, and the corresponding theoretical values and actual measured values are compared to determine whether each actual measured value is abnormal.

Therefore, a flowchart for determining an abnormal state by the pump characteristic abnormality determining means 32 is shown in FIG.

First, the theoretical head value H calculated by the pump characteristic theoretical value calculation means 30 and the measured head value S are compared, and if they are equal, it is normal, and the execution of the characteristic abnormality determination program is immediately terminated. However, if a difference occurs in the comparison between the theoretical head value H and the measured head value, the theoretical discharge flow rate Q The theoretical discharge flow rate value Q and the measured discharge flow rate value q are compared, and if they are equal, an abnormality in the measured head value is detected.

Further, when a difference occurs in the comparison between the theoretical discharge flow rate value Q' and the measured discharge flow rate value q, or after an abnormality in the measured head value is detected, the pump characteristic theoretical value calculation means 30
The theoretical discharge flow rate value Q calculated in step 1 is compared with the measured discharge flow rate value q, and if they are equal, the process moves to the next step. but,
If the amount of wheat occurs in the comparison between the theoretical discharge flow rate value Q and the measured discharge flow rate value q, the theoretical rotation speed average is calculated based on the pump characteristic formula (1) from the theoretical discharge flow rate value Q and the measured head value. The value N' is calculated, and the theoretical rotation speed average value N' is compared with the measured rotation speed average value n. If they are equal, an abnormality in the measured discharge flow rate value q is detected.

Further, if the theoretical discharge flow rate value Q and the measured discharge flow rate value q are equal, if a difference occurs in the comparison between the theoretical rotation speed average value N' and the measured rotation speed average value n, and the actual measured discharge flow rate value After the abnormality i of q is detected, the theoretical rotational speed average value N calculated by the pump characteristic theoretical value calculation means 30 and the measured rotational speed average value n are compared, and if they are equal, it is determined as a characteristic abnormality and the characteristic abnormality determination program Terminate execution.

However, if a difference occurs in the comparison between the theoretical rotation speed average value N and the measured rotation speed average value n, it is determined based on the pump characteristic formula (1) from the theoretical rotation speed average value N and the measured discharge flow rate value q. calculate the theoretical head value d', and calculate the theoretical head value H'
and the measured lift value, and if they are equal, an abnormality in the measured rotational speed average value n is detected, and the execution of the characteristic abnormality determination program is terminated. If a difference is found in the comparison between the theoretical head value H and the measured head value, it is determined that a characteristic abnormality has occurred and the execution of the characteristic abnormality determination program is terminated.

As described above, when the execution of a program is terminated based on the determination result of a characteristic abnormality, it is generally the case that an abnormality of the measured head value and/or an abnormality of the measured discharge flow rate value q has occurred in the previous step.

In this manner, when the pump characteristic abnormality determination means 62 detects an abnormality for the actual measurement values hr q#, it generates an abnormality signal for each actual measurement value hr q#'', and the abnormality alarm output means 64 energizes and issues an abnormality alarm as well as controls the operation and shutdown of the pump equipment.

〔Effect of the invention〕

As is clear from the above-mentioned examples, the theoretical value is calculated from the measured value consisting of the pump head value, discharge flow rate value, and rotation speed average value indicating the pump characteristics, and the theoretical value and the actual measured value, which have been elaborated by the samurai, are compared correspondingly. If a difference occurs, it can be detected by detecting an abnormality in the actual measured value.

In addition to monitoring the characteristics of pump equipment, it is possible to diagnose and detect subtle failures in measuring equipment, which allows early countermeasures to be taken against failures of measuring equipment, improving the accuracy of pump operating status monitoring equipment, and The reliability of this type of monitoring device can be improved. Further, according to the present invention, the process from calculating ylL of the measured value indicating the pump characteristics to determining the abnormality of the pump characteristics (the part surrounded by the chain line in FIG. 4) can be easily realized by a microcomputer.

The device of the present invention has the above-mentioned measured pump characteristics.

If an abnormality in any one of the signals q and n is detected, the theoretical value 11. By using Q and N as substitutes for actual measured values, it can be effectively utilized as a back-amplification method for measured values in an automatic control system. Furthermore, by combining the pipe resistance characteristics as a control element, it becomes possible to simulate the entire pump operation characteristics.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing the configuration of a pump operating state monitoring device according to the present invention, FIG. 2 is a pump characteristic curve diagram obtained by a pump characteristic equation applied to the present invention, and FIG. 6 is a pump characteristic curve diagram of a pump according to the present invention. System diagram showing the configuration arrangement of the pump system implementing the operating state monitoring device and the pump characteristic detection means, No. 4
The figure is a block circuit diagram showing the configuration and arrangement of the means for calculating the measured pump characteristic value and the theoretical value based on the detected value detected by the pump characteristic detecting means shown in FIG. Figure 5 shows the abnormality determination program 70 executed by the pump characteristic abnormality determination means shown in Figure 4.
- Chart diagram. 10-...Water distribution pond 12...Pump equipment 14...
・Piping 16...Water level detection means 18...
Rotation speed detection means 20... Water supply pressure detection means 122
... Water supply flow rate detection means 24 ... Head value generation means 2
6...Discharge flow rate value generation means 7
28.--Rotation speed average value generation means
d60...Pump characteristic theoretical value calculation means
62... Pump characteristic abnormality determination means 64... Abnormal alarm output means Patent applicant: Fuji Electric Manufacturer: 8, Iyoyu'f% m '11B'/$', 7'), - 1 Yu

Claims (1)

[Scope of Claims] (1) Water level detection means for detecting the water level of the reservoir, water pressure detection means for detecting the pressure of water sent from the pump equipment, and detection of the flow rate of the water sent from the pump equipment. A water supply flow rate detection means, a pump rotation speed detection means of the pump equipment, and a head value generation means for calculating a pump head value based on the output of the water level detection means and the output of the water supply pressure detection means and generating a signal thereof. , a discharge flow rate value generation means for calculating a discharge flow rate value of the pump based on the output of the water supply flow rate detection means and generating a signal thereof; and a discharge flow rate value generating means for calculating a pump discharge flow rate value based on the output of the water supply flow rate detection means, and an average value of the rotation speed of the pump based on the output of the pump rotation speed detection means. A rotation speed average value generation means for calculating and generating a signal thereof, and actual measured values obtained from each generation means for the head value, discharge flow f, and rotation speed average value are input, and the pump is adjusted based on the pump characteristic formula. a theoretical pump characteristic value calculating means for calculating a theoretical characteristic value, and a pump characteristic theoretical value ξ calculated by the pump/characteristic theoretical value calculating means, each generating means for the head value, discharge flow rate value, and rotation speed average value. A pump characteristic abnormality determining means inputs the obtained actual measured value and compares the theoretical value and the actual measured value to determine an abnormality in the actual measured value from the obtained difference amount, and an output of the pump characteristic abnormality determining means A pump operating state monitoring device comprising an abnormality alarm output means for outputting an abnormality alarm based on. In the pump operating state monitoring device recited in claim 1, the pump characteristic theoretical value calculating means is calculated by the following formula % formula % (where h is the head value, q is the discharge flow rate value, and n is the rotation (number average value, A-E is the mechanical characteristic constant of the pump).
A pump operating state monitoring device comprising an arithmetic circuit that substitutes two values out of the rotational speed average value and calculates the other value as a theoretical value. (6) In the pump operating state monitoring device according to claim 1, the pump characteristic abnormality determining means determines the corresponding theoretical values and actual measured values for the pump head value, the discharge flow rate value, and the rotational speed average value, respectively. A pump operating state monitoring device configured to compare the values, individually determine abnormalities in each actual measured value, and energize an abnormality alarm output means for each actual measured value based on the determination result.