JPH05215581A - Momentary flow rate measuring device - Google Patents

Abstract

PURPOSE:To measure the change in a momentary flow rate accurately even if another gas fitting is used immediately after the gas fitting with a large momentary flow rate such as a gas type hot water supply device is extinguished. CONSTITUTION:The title device is constituted of a first momentary flow rate operation means 14 which operates when a flow rate above a certain momentary flow rate value exists and a second momentary flow rate operation means 16 which calculates a momentary flow rate according to the number of pulses which are input during a predetermined amount of time. The momentary flow rate can be measured accurately by using each momentary flow rate value which is obtained from two momentary flow rate operation means 14 and 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention, for example, monitors gas flow rate, estimates what kind of gas appliance is currently used depending on how the flow rate changes, and determines that the gas appliance is being used abnormally. The present invention relates to an instantaneous flow rate measuring device built in a gas meter or the like, which is a so-called microcomputer meter, configured to shut off gas when a judgment is made.

[0002]

2. Description of the Related Art An instantaneous flow rate measuring device used in a membrane gas meter will be described with reference to FIGS. FIG. 3 is a gas piping system diagram showing a state in which the membrane gas meter is attached to a home and connected to a gas appliance. 10 in FIG.
1 is a house, 102 is a membrane gas meter, 103 is a primary gas pipe, 104 is a secondary gas pipe, 105 is a gas fan heater, 106 is a gas table, 107 is a bathtub, 10
8 is a water heater. The membrane gas meter 102 displays an integrated value of the gas flow rates used in the gas appliances 105 to 108 connected to the secondary pipe 104, and monitors the gas usage status in each of the gas appliances 105 to 108, which is dangerous. When the usage status of gas is discovered, the gas shutoff valve built in the membrane gas meter 102 is operated to shut off the gas. FIG. 4 is a block diagram illustrating the function of the membrane gas meter 102.
In the figure, 1 is a disk that makes one revolution in association with one reciprocation of the film of the membrane gas meter 102, 2 is a plurality of magnets arranged on the disk 1, and 3 is a fixed magnetic field arranged near the disk 1 It is a magnetoresistive element that detects changes. For example, if the capacity of the film is 0.8 liters and the number of magnets 2 arranged on the disk 1 is 8, the pulse signal is output from the timing resistance element 3 at a rate of 1 pulse every 0.1 liter. Reference numeral 4 is an instantaneous flow rate measuring means for counting the pulse signals from the magnetoresistive element 3 and converting it into an instantaneous flow rate value. Reference numeral 5 is an integrating means, 6 is a storage means for sequentially storing the instantaneous flow rate value from the instantaneous flow rate measuring means 4, and 7 is a flow rate change detecting means, which is a gas meter based on a change in the instantaneous flow rate value measured by the instantaneous flow rate measuring means. The change in the flow rate flowing through 102 is detected. Reference numeral 8 is an individual flow rate estimating means for estimating the flow rate of each gas appliance currently used by using the output of the flow rate change detecting means 7. The safety means 9 is configured to shut off the gas when it is estimated from the information from the individual flow rate estimating means 8 that the gas is used in an abnormal manner such as forgetting to turn off the gas. Instrument-based accumulation means 10
Then, based on the information from the individual flow rate estimating means 8, the used flow rate is cumulatively displayed for each device.

FIG. 5 shows a conventional instantaneous flow rate measuring device used in a gas meter called the above-mentioned microcomputer meter.
A block diagram is shown in FIG. In the figure, 11 is a first timer means, 12 is a second timer means, 13 is a counting means, and 14 is an instantaneous flow rate calculating means. a is an input terminal to which the pulse signal from the magnetoresistive element 3 of FIG. 4 is input, b
Is an output terminal for outputting the instantaneous flow rate. FIG. 6 is an operation explanatory view for explaining the operation of the conventional instantaneous flow rate measuring means. The operation of the conventional instantaneous flow rate measuring device will be described with reference to FIGS. First, consider a case where the gas water heater 108 is extinguished from a state where the gas water heater 108 is used at 10,000 watts, and then the gas table 106 is ignited at 4000 watts after a while. Figure 6 for input a
A pulse signal corresponding to the instantaneous flow rate shown in is input. The first timer means 11 starts time measurement from the time when the pulse signal is input to the input a, and when the time T1 has elapsed, sends a signal notifying the elapse of T1 to the second timer means 12 and the counting means 13. Then, after the lapse of T1 time, the measurement of T1 time is started again by the first pulse signal.
In the counting means 13, the first timer means 11 starts the measurement of the T1 time, and at the same time, the count value so far is cleared and the counting of the number of pulses input to the input a is started. In the second timer means 12, T1 from the first timer means 11
When a signal indicating the passage of time is received, the time measuring operation is started, and when the time measuring operation is ended by the pulse signal that comes first after the start of time measuring, the measured time T2 is output to the instantaneous flow rate calculating means 14 at that time. When the instantaneous flow rate calculation means 14 receives the signal from the second timer means 12, the instantaneous flow rate is calculated by using the count value N of the counting means 13 and the previously known T1 time and the received T2 time information from the second timer means. Is proportional to the instantaneous frequency = N / (T1 + T
2) is calculated and output to the output terminal b. FIG. 6 shows the state of the operation. Then, as shown in FIG. 6, the gas water heater is turned off while the first timer means 11 is measuring the T1 time.
In this case, since the flow rate becomes zero, the rotation of the disk 1 shown in FIG. 4 stops and the pulse signal is not input to the input a.
Therefore, the time measurement by the second timer means 12 continues for a long time. Then, when the gas table 106 is next used, a pulse is again input to the input a, and the T2 time measurement by the second timer means 12 is completed. At this point, the instantaneous flow rate calculation means 14 calculates N / (T1 + T2), and FIG.
The instantaneous flow rate output is as shown by the output b.

[0004]

However, in the conventional structure as described above, when a gas appliance having a large instantaneous flow rate such as a water heater is used and the gas appliance is used again after a while after extinguishing the fire, As shown in FIG. 6, although the instantaneous flow rate is originally zero, since the average instantaneous flow rate is measured during (T1 + T2) time, the instantaneous flow rate value does not become zero and a considerably large value may remain. There were challenges.

The present invention has been made to solve the above problems, and has as its object to calculate the instantaneous flow rate more accurately.

[0006]

In order to achieve the above object, the instantaneous flow rate measuring device of the present invention starts time measurement from the time when a pulse signal is input and starts a predetermined time T1.
First timer means for producing an output after a lapse of time and restarting time measurement from the beginning with a pulse signal input after the lapse of the T1 time, and counting for starting counting of the pulse signal by a signal from the first timer means Means for measuring the time T2 from when a signal is generated by the first timer means until the next pulse signal is input, and second timer means for producing an output when the pulse signal is input,
Measured by the counting means, a third timer means for producing an output after a lapse of a predetermined time T3 from the signal for the first timer means, and for stopping the timer operation by the signal from the second timer means. Number of pulses N
And a first instantaneous flow rate calculation means for calculating N / (T1 + T2) corresponding to the instantaneous flow rate using the time (T1 + T2), and a pulse number N and a time T1 when a signal is generated from the third timer means. N / T1 and 1 / using T2
And a second instantaneous flow rate calculation means for calculating T2.

[0007]

According to the present invention, according to the above structure, the instantaneous flow rate value is output from the first instantaneous flow rate calculating means when there is a flow rate, and when the flow rate falls below a certain level, the instantaneous flow rate value is instantaneously detected by the number of pulses input within a predetermined time. The instantaneous flow rate value is output from the second instantaneous flow rate calculation means for calculating the flow rate.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. The same parts as those in the conventional example are designated by the same reference numerals. In FIG. 1, 11 is a first timer means, 1
2 is a second timer means, 13 is a counting means, and 14 is a first instantaneous flow rate calculating means. a is the magnetoresistive element 3 of FIG.
From the first instantaneous flow rate calculation means 14 and an output terminal from which the instantaneous flow rate is output. Reference numeral 15 is a third timer means, 16 is a second instantaneous flow rate calculation means, and 17 is an output means. The terminal c is an output terminal for outputting the instantaneous flow rate from the second instantaneous flow rate calculation means 16, and the terminal d is the output of the instantaneous flow rate measuring device of the present invention.
When the third timer means 15 receives a signal indicating that T1 time has elapsed from the first timer means 11, it starts time measurement. Then, when the preset T3 time has elapsed, a signal is output. The third timer means 15
Stops the time measurement by the signal from the second timer means 12. Therefore, when the next pulse is input to the input a in a time shorter than T3 time, an output is generated from the second timer means 12 and the time measurement of the third timer means 15 is stopped so that the output from the third timer means 15 is stopped. Does not happen. T
An output is generated in the third timer means 15 only when the pulse signal does not come within 3 hours. The second instantaneous flow rate calculation means 16 operates only when a signal is generated from the third timer means 15. When a signal is generated from the third timer means 15, the number of pulses N counted by the counting means, T1 time whose preset time is known, and T2 time measured by the second timer means 12 are respectively used to obtain N /
Two instantaneous flow rate values of T1 and 1 / T2 are calculated, and the instantaneous flow rate values are output to the output means 17 in the next stage in the order of N / T1 and 1 / T2. The output means 17 outputs a signal from the second instantaneous flow rate calculation means 16 when the second instantaneous flow rate calculation means 16 operates, and outputs a signal from the first instantaneous flow rate calculation means 14 at other times.

Next, an example of using an actual gas appliance will be shown and described. As for the usage status of the gas appliance, as in the conventional example, when the gas water heater 108 is extinguished from the state where the gas water heater 108 is used at 10,000 watts, and then the gas table 106 is ignited at 4000 watts after a while. think about. FIG. 2 shows a diagram for explaining the operation of the instantaneous flow rate measuring device of the present invention, which will be described with reference to FIGS. 1 and 2. When the gas water heater is extinguished, no pulse is generated and the third timer means 12 times out, and an output is produced after T3 hours. Then, the second instantaneous flow rate calculation means 16 starts to operate, and from the time T1 and the number of pulses N during the time T1 immediately before the pulse disappears, the instantaneous flow rate during this time = N / T1.
To calculate. Next, the second instantaneous flow rate calculation means 16 obtains the instantaneous flow rate during the time T2 using the time T2 until the next pulse measured by the second timer means 12 is input. That is, it is considered that one pulse is input during the time T2, and the instantaneous flow rate = 1 / T2 is calculated. Therefore, for the pulse input to the input terminal a, the signals from the output terminals b to d are as shown in FIG.

It should be noted that the second instantaneous flow rate calculation means 1 is provided so as to be able to cope with the case where a low-flow rate gas appliance such as a pilot fire, which is considered to have no pulse during T1 time, is used.
6 is configured to operate only when the number N of pulses during the time T1 is a predetermined value (for example, 2 pulses) or more.

In the embodiment shown in FIG. 1, the film type gas meter has been described as an example of the flow rate measuring means 1, but it may be applied to a so-called fluidic gas meter using a fluidic element, for example. Of course, it's not just about gas meters.

[0012]

As described above, according to the instantaneous flow rate measuring device of the present invention, if there is no pulse for a certain time T3, the instantaneous flow rate during the time T1 immediately before the pulse disappears and the time T2 until the next pulse. The gas flow is decomposed into the instantaneous flow rate between the two and the instantaneous flow rate for two periods to measure the instantaneous flow rate.Therefore, a gas appliance with a large flow rate is being used and extinguished. Even when used, there is an effect that the instantaneous flow rate can be measured more accurately.

[Brief description of drawings]

FIG. 1 is a block diagram of an instantaneous flow rate measuring device according to an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram illustrating an operation of the device.

[Figure 3] Gas piping system diagram in a general household

FIG. 4 is a block diagram when the same device is used in a membrane gas meter.

FIG. 5 is a block diagram of a conventional instantaneous flow rate measuring device.

FIG. 6 is an operation explanatory view explaining the operation of the apparatus.

[Explanation of symbols]

 11 First Timer Means 12 Second Timer Means 13 Counting Means 14 First Instantaneous Flow Rate Calculating Means 15 Third Timer Means 16 Second Instantaneous Flow Rate Calculating Means

Claims (1)

[Claims] 1. A first timer which starts time measurement from the time when a pulse signal is input, produces an output after a predetermined time T1 has elapsed, and restarts time measurement from the beginning with a pulse signal input after the time T1 has elapsed. Means, counting means for starting counting of the pulse signal by the signal from the first timer means, and time T2 from generation of a signal from the first timer means to input of the next pulse signal. The second timer means for producing an output when the pulse signal is input, and the second timer means for producing an output after a lapse of a predetermined T3 time after the signal is produced by the first timer means and the second timer means A third timer means for stopping the timer operation by a signal,
The number of pulses N measured by the counting means and the time (T1
N / (T1 + T) corresponding to the instantaneous flow rate by using + T2)
The second instantaneous flow rate calculating means for calculating 2) and the second instantaneous flow rate calculating means for calculating N / T1 and 1 / T2 using the pulse number N and the times T1 and T2 when a signal is generated from the third timer means. An instantaneous flow rate measuring device comprising an instantaneous flow rate calculating means.