JPS59121299A - Fluid leakage detecting device - Google Patents

Abstract

PURPOSE:To eliminate the irregularity in the time interval of reading from respective counters of inlet side and outlet side by a method wherein a counting time is set by a clock device and the data of flow amount is obtained by counting a flow amount pulse signal at every counting times by the counters. CONSTITUTION:The counting time of the counter CT is made constant by the clock devices CL of counting units C1, C2 provided at the outside of controlling units 12, 22, further, the countings of the first and second counters CT11, 21, CT12, 22 are effected alternately by a gate circuit G to obtain the flow amount data. Accordingly, the deviation of reading times of the flow amount data due to the fluctuation of the number of another processing program may be eliminated and, therefore, the irregularity of the time intervals of reading from respective counters of the inlet side and the outlet side may be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a fluid leakage detection device for detecting fluid leakage from a fluid transport line.

For example, in oil pipelines, the following laws (for example, the Oil Pipeline Business Act, the Fire Service Act) and the like require monitoring of oil leaks in the piping system due to the need for safety. There are two methods for detecting oil leaks: the line path method or flow rate difference method, which detects based on the difference in flow rate between the inlet and outlet sides of the pipeline, and the flow rate difference method uses analog transmission and digital transmission. It is broadly divided into methods.

First, leakage detection using an analog transmission method will be explained. FIG. 1 is a configuration diagram of a conventional fluid leakage detection device. First, the volumetric flow rate Q1 on the inlet side and outlet side of the piping system line L
．． Qo is the first and second flow transmitter F, , Fo
It is measured at the same time. and a second flow rate transmitter F on the outlet side. The flow rate pulse signal is FS-modulated by telemeter TE2 (pulse frequency telemeter) and sent as a pulse train signal via communication line F to telemeter TE on the entrance side.
transmitted to I. Then, a flow balancer (trade name), that is, a flow rate difference calculator FB calculates the flow rate between the inlet side and the outlet side of the piping system line L every predetermined time T based on the flow rate pulse signals from the first and second flow rate oscillators F, , Fo. A comparison is made with the alarm set value QS1 and the new set value Qs□, which have different flow rates. FIG. 2 is a diagram showing the flow rates at which alarm and cutoff signals are generated. As shown in Figure 2, the predetermined time T
The flow rate difference statistical value 9 (Ql-Q.) is the alarm setting value Qs1.
, when the new cutoff value QS2 is exceeded, an alarm indicator (not shown) will issue an alarm cutoff signal.

Such a device has a simple circuit configuration, is low cost, and has a low volumetric flow rate Qip Q on the inlet and outlet sides.
Although it has advantages such as being able to read o simultaneously,
It has the following drawbacks. That is, the telemeter T E
Since TE 1, TE 2 uses the audio frequency band, the transmission speed is limited to a maximum of 1200 s. This reduces the pulse width of the transmitted signal to 1/1200 (
See), it is impossible to transmit a pulse number exceeding 600 (-radius 1%5ec) even if the on/off ratios are equal.

Furthermore, as the transmission speed increases, the pulse width to be transmitted becomes narrower, making the transmitted signal more susceptible to external noise and the like.

However, since there is no erroneous υ detection function for removing erroneous signals due to external noise, etc., it is difficult to remove external noise.

From the above, when this method is adopted, the number of flow pulses is 100[)Vs, taking into account its on/off ratio, etc.
ec] or more. However, this type of fluid leakage detection device is difficult to apply when the number of pulses of the flow rate signal exceeds 100 [)%Vw ec ).

Next, leakage detection using the digital transmission method will be explained. FIG. 3 is a configuration diagram of a conventional fluid leak detection device. First, similar to the device shown in FIG.
QIy is counted by each counter 11, 21 of the output side measuring section 20, and then the flow rate data is calculated by the controllers 12, 22 of the stowed program method every predetermined time T.
Each Q0 is stored in a portion of memory 13.23.

The data is then transmitted to the communication control unit 14 of the inlet side measuring unit 1o via the outlet side flow rate data and stored in a part of the memory 13.

After that, the command from the control unit 12 is calculated by adding the stored flow rate data to f=Q, -LQo at line 0.
0, and if this calculation result is larger than the preset value Q8, an alarm signal is output from the output section 15 and the alarm indicator 16 lights up.

The counters 11, 21 of such devices are usually 12 bits and can only count up to 4095 in binary notation. Therefore, if the number of pulses of the flow Ji% pulse signal is about lQQQ(4)v7y/11ee), the counters 11 and 21 will overflow in about 4 seconds. For this reason, memory 13g is performed as follows. Figure 4 is a diagram showing the sampling time (predetermined time T), where QI is the inlet flow rate/'P pulse signal, A is the sampling time of the inlet flow rate signal, and B and C are the outlet flow pulses. A case where the sampling time of the signal is delayed H and a case where the signal is synchronized are shown, and QO shows the outlet side flow rate pulse signal. For example, if the sampling time T is 30 seconds and the outlet side flow rate QO is 1000 [) Y8e c :], then the counters 11 and 21 are divided into 10 times every 3 seconds to 1000 [) Y8e c :] so that the counters 11 and 21 do not overflow. =30000
−? The flow rate data of the pulse is stored in the memory 21 and transmitted to the memory 13 via the communication control unit 24.14 every 30 seconds6. Since it depends on the 12.22 program, it is constant and fast, but it varies depending on the number of programs being processed at a certain time. For example, if the number of emitted pulses of each flow rate transmitter on the inlet side and outlet side is 1000 [At
1secC], the sampling time T on the inlet side is 15
[yy+gec:) If it is long, the sampling time T on the exit side is 15 [m5ec], and if it is short, the time difference is 30 [m5ec].
5ec], resulting in a difference of 3Qzf russ as a sipulus number. If 1 no 9 rus is equivalent to 1k, it would be detected that a leak of 307 occurred with a time difference of 30 seconds.
Erroneous measurements are still a cause of false alarms and are inconvenient. Conventionally, this has been dealt with by giving priority to the operating mode of the reading processing program for the counters 11 and 21 over other programs, but this method does not allow for the process monitoring cycle of the normal monitoring program in the process computer system. The disadvantage was that it was long.

The present invention has been made based on the above-mentioned circumstances, and eliminates variations in the reading time interval between the reading points of each counter on the inlet and outlet sides of a piping system line, and also eliminates variations in the sampling time for collecting flow rate data. It is an object of the present invention to provide a fluid leak detection device that can be eliminated and prevent erroneous measurements and false alarms.

An embodiment of the present invention will be described below with reference to FIGS. 5 to 7. Note that the same parts as in FIG. 3 are given the same reference numerals and detailed explanations will be omitted.

FIG. 5 is a configuration diagram of a fluid leak detection device according to the present invention. As shown in FIG. 5, this fluid leakage detection device is constructed by replacing the counters 11 and 21 shown in FIG. 3 with inlet side and outlet side counting sections C1 and C2, respectively. The inlet side and outlet side counters CI, C2 are composed of a clock device CL as a counting time setting means, a dirt circuit G, and a counter CT as a counting means. Clock device C
L is for outputting a dart pulse for a predetermined time (for example, 3 seconds) to set the counting time of the counter CT. The dart circuit G is a case G1z through which the dart pulse from the clock device CL sends a flow rate pulse signal during the rHJ repeating period.

G21, and a gate G that sends a flow rate pulse signal during the period when the dart pulse is at the "L" level.12. G22 and Knot Dart G13, which reverses the Dart 9 Luss. G23. Counter CT has gate Gll,
A 12-bit first counter CTI 1 , Cr21 that counts the flow rate/volume signal from G21, and a gate G
12, Count the flow rate and 7 pulse signals from G22 12
Bit second counter CT12. Cr22 and a 1-bit counter CT that counts the clock signal from the clock device CL.13. Cr23 and Knot Dart G13
．． 1-pin counter CT14 that counts the Gutnosols from G23. It is composed of Cr24. Further, this fluid leakage detection device includes a calculation unit (a calculation unit) that calculates the difference in flow rate between the inlet side and the outlet side of the piping system line based on the flow rate data read from the counter CT and stored in a part of the memory 13゜23. (not shown) is provided. The control units 11 and 21 also include first and second counters CT.
11, CTzi, CTC,? .

A clock device for time data is built in, which adds time data representing the time corresponding to the flow rate data sent from the CT 22 to the memories 13, 23.

Next, the operation of the apparatus configured as described above will be explained. Incidentally, since the counting sections CI and C2 have the same configuration, the operation thereof will be explained with respect to the exit side counting section C2, and the explanation of the inlet side counting section c1 will be omitted. FIG. 6 is a waveform diagram of each part in the exit side counting section c2. Fluid is pumped into a piping system line (not shown), and each flow rate is detected by first and second flow rate transmitters on the inlet side and the outlet side. Then, a flow rate pulse signal QO as shown in FIG. 6 is input from the outlet side flow rate transmitter to the outlet side counting section C2. Here, the clock device CL of this counting section C2 outputs a dart pulse g of a predetermined period (3 seconds) shown in FIG. 6, and sends it to each dart 021 to G23 and counters cT21 to CT24.

As a result, the first counter CT21 calculates the period of the dart pulse g1 (7) rHJ level to the dart G21, that is, the period of time tl, t3 . The flow rate signal Q01 of the period t5 is counted. On the other hand, the second counter CT
22 is goo)G, 2. ? In other words, the "H" level period of the signal g2, which is the inversion of the dart pulse g, is tO, t2 . L4...Count the flow rate/1000 Lus signal QO2 for the period. That is, the first and second counters CT21. The CT 22 alternately counts the flow rate/gurus signal QO at predetermined time intervals. The counter CT23 receives the signal g3 shown in FIG. 6, and the counter CT24 receives the signal g4.
Count each. The counted flow rate data is sent to each counter CT21 along with time data from a time data clock device built into the control unit 22 according to a command from the control unit 22.
, Dart G21. against CT22. It is stored in a part of the memory 23 during the off period of G22. Figure 7 shows memory 2
FIG. 3 is a diagram showing the contents of data stored in FIG. As shown in FIG. 7, time data TDo is added to flow rate data CDo-CDn.
-TDn is attached and stored in the memory 23.

The flow rate data CD stored in the memory 23 in this way
When o-CDn reaches a predetermined amount, the flow rate data CDo-CDn is read out from the memory 23 according to a command from the control unit 22, and is sent from the communication control unit 24 to the communication control unit 14 on the entrance side via the communication line LN. The data is sent and further stored in a part of the memory 13 on the entrance side. Then, the outlet side flow rate data CDo to CDn is transmitted according to the command from the inlet side control unit.
The difference in flow rate between the inlet side and the outlet side is determined in the calculating section based on the flow rate data on the inlet side and the flow rate data on the inlet side determined in the same manner as the flow rate data on the outlet side. That is, a flow rate difference calculation is performed.

As a result, the calculated flow rate difference is set to the preset value Q
If the value is larger than 8, an alarm signal is outputted from the output section 15 and an alarm is displayed on the alarm display 16.

According to the device configured in this manner, the counting time of the υ counter CT is kept constant by the clock device CL of the counting unit CI and C2 provided outside the control unit 12.23 of the stward program type, and the counting time of the υ counter CT is kept constant, and the counting time of the υ counter CT is kept constant. Since the flow data is obtained by alternately counting the first and second counters CT11, 21, CT12, 22 by the circuit G, there is no difference in reading time of the flow data due to variations in the number of different processing programs. This makes it possible to accurately read and calculate a high-speed flow rate signal, eliminating the possibility of false alarms due to fluctuations in the data collection cycle. 12 on the first and second counters CT11, 21, CTl2, 22
Even if a bit type is used, there will be no overflow.

Also, add time data to the flow rate data and take notes! J13
, 23, the calculation can be performed with a desired delay time provided to each flow rate data on the inlet side and outlet side of the piping system line.

Note that the present invention is not limited to the above embodiment. For example, in the above embodiment, time data is sent to the control unit 12.
．． The time data is obtained from the clock device built in 22, but 1. This may be obtained from each clock device CL of the counting units CI and C2.

And the time of the time data is also the start-up time of Dart Zorus G.
Either falling edge may be used. Furthermore, each flow rate data may be numbered in addition to the time data.

In the embodiment described above, the flow rate difference between the inlet side and the outlet side is determined by the arithmetic unit on the inlet side, but this may be done on both the inlet side and the outlet side.

Further, although flow rate data is continuously obtained using the counters CTII, 21 and CTl2°22, a set of counters may be used to obtain flow rate data intermittently.

However, this device may be suitable for detecting leaks not only in oil pipelines but also in pipelines for various chemical products (liquids), water supply and sewage pipelines, etc.

According to the present invention, the counting time is set by the clock device of the counting section which is the counting means, and after each counting time, the flow rate pulse signal is counted by the counter to obtain the flow rate data. Since the flow rate difference between the flow rate and It is possible to provide a fluid leakage detection device that improves leakage detection ability by preventing erroneous measurements and false alarms.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional fluid leakage detection device using an analog transmission method, Figure 2 is a diagram for explaining the operating functions of the device shown in Figure 1, and Figure 3 is a diagram showing a fluid leakage detection device using a conventional digital transmission method. FIG. 4 is a diagram for explaining the operation of the device shown in FIG. 3, FIG. 5 is a configuration diagram showing an embodiment of the fluid leak detection device according to the present invention, and FIG. 6 is a diagram showing the configuration of the detection device. The waveform diagram of each part of the counting section in this device, and FIG. 7 are schematic diagrams of the flow rate data stored in the memory. , 15... Output section, 16... Alarm indicator, C... Inlet side counting section, C2... Outlet side counting section, CL.
... Time opening device, G... route circuit, Gll, GI2
．． G21. G22...Dart, G13. G23...
Knot gate, CT...counter, CTJ 1, C
T21...first counter, CT12. CT22...
-Second counter. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Σ(Qi-Qo)

Claims (3)

[Claims] (1) In a fluid leakage detection device that detects fluid leakage from the difference between cumulative flow values at predetermined time intervals on the inlet side and outlet side of a fluid transport line, a first a second flow rate transmitter that detects the flow rate on the outlet side of the fluid transport line; counting means for counting the flow rate pulse signals of the counting means, counting time setting means for setting the counting time of these counting means, and storage means for storing the flow rate data sicanted by the counting means;
Transfer means for transferring a predetermined amount of flow rate data stored in the storage means to the storage means on either the inlet side or the outlet side of the fluid transport line; the counting means; the counting time setting means; a control unit that controls a transfer means; a calculation unit that calculates a difference in cumulative flow values between an inlet side and an outlet side of the transport line based on flow rate data in a storage means on the side transferred by the transfer means; An alarm indicator that issues an alarm if the cumulative flow rate requested by the calculation means is larger than a preset set flow rate difference; A fluid leak detection device comprising: time detection means for adding time data to data. (2) The fluid leak detection device according to claim (1), wherein the calculation means is provided on either the inlet side or the outlet side of the fluid transport line. (3) The counting means is configured such that either one of the counting means
and a first and a second counter, the other counting the flow pulse signal from the second flow transmitter and transmitting the counted value to the storage means. The fluid leakage detection device according to scope (1).