JPH055643A - Flow rate determination device - Google Patents

Abstract

(57) [Summary] [Purpose] Continuation of a small increase in flow rate by determining the change in flow rate by taking the difference between the flow rate sent from the flow rate measurement means and the stored flow rate stored in all individual flow rate storage means as the change flow rate. as well as,
It is an object of the present invention to provide a flow rate discriminating apparatus capable of recognizing a change in flow rate even if a small amount continues to decrease. [Structure] A flow rate measuring means 4 for measuring a flow rate of a fluid, a total individual flow rate storage means 21 for storing a total of individual flow rates, a measured flow rate sent from the flow rate measuring means 4 and the total individual flow rate storage means 21 are stored. The difference between the stored memory flow rates is the preset change determination reference value and the flow rate measuring means 4
Flow rate change presence / absence determining means 5 which outputs a signal if the flow rate is changed if it is larger than the product of the measured flow rate value sent from
It is possible to recognize the change of the flow rate as the flow rate continues to increase by a small amount and the flow rate continues to decrease.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate discriminating apparatus which is built in a gas meter and has a function of automatically cutting off gas supply when an abnormality such as forgetting to turn off a gas appliance occurs.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional flow rate discriminating apparatus has a rotor 1 built in a gas meter and rotating according to the flow rate passing through the meter, and a magnetic body 2 arranged on the rotor 1.
Flow rate measuring means 4 including a flow rate measuring part 3 which senses the magnetic force of the gas and measures the instantaneous flow rate of the gas at intervals of, for example, 30 seconds, and outputs the flow rate information, and the flow rate information from the flow rate information sent from the flow rate measuring means 4 Flow rate change presence / absence determining means 5 for determining change
Then, each time the flow rate change presence / absence determining means 5 detects a change in the flow rate, it is assumed that there is a change in the usage state of the gas appliance, and the individual flow rate corresponding to the amount of change is estimated to register and register a new gas appliance. The individual flow rate estimating means 6 for erasing and increasing / decreasing the registered individual flow rate, and the limit continuous use safe time during which the state in which no change in the gas flow rate is recognized according to the stored individual flow rate can be continued. A shutoff time control means 7 for setting and determining that an abnormal state has occurred when the set time has elapsed and issuing a shutoff signal for shutting off gas.
And a shut-off means 8 for shutting off the gas in response to a shut-off signal from the shut-off time control means 7.

FIG. 4 is a block diagram showing the structure of the flow rate change presence / absence determining means 5. The pre-change gas flow rate storage section 6 stores the previous gas flow rate. The change determination reference value storage unit 11 stores a change determination reference value in advance. In the flow rate change determination unit 10, the absolute value of the flow rate obtained by subtracting the previous gas flow rate stored in the pre-change gas flow rate storage unit 9 from the gas flow rate from the flow rate measurement unit 4 is the gas flow rate from the flow rate measurement unit 4. And a reference value for change determination stored in the change determination reference value storage unit 11 (for example, 3%), a signal is output that the flow rate has changed.

FIG. 5 is a block diagram showing the structure of the individual flow rate estimating means 6, in which the change estimating section 12 is a flow rate change determining section 10.
If the change in the gas flow rate detected in step 2 increases, it is estimated which gas appliance the flow rate is increasing or is registered.
Further, if the change in the gas flow rate detected by the flow rate change determination unit 10 is decreased, it is estimated which gas appliance is decreased or erased. The individual flow rate registration correcting unit 13 processes the result estimated by the change estimating unit 12. The individual flow rate storage unit 14 stores the individual flow rates as a result of processing by the individual flow rate registration correction unit 13 in descending order.

FIG. 6 is a block diagram showing the configuration of the cutoff time control means 7. The duration measuring unit 16 indicates whether the individual flow rate estimating means 6 registers or deletes one and stores the next registration or registration. Measure the duration of erasure and storage. The cutoff time storage unit for each flow rate section 17 stores the limit time (hereinafter referred to as cutoff time) for which it is determined that the gas appliance is normally used in the home for each flow rate section corresponding to each gas appliance. Set and store in advance.
The shutoff time setting unit 15 retrieves the time set in the flow rate segment corresponding to the maximum individual flow rate stored in the individual flow rate storage unit 14 of the individual flow rate estimation unit 6 from the flow rate segmented shutoff time storage unit 17. Set the cutoff time. The time comparison unit 18 compares the duration time that has elapsed without being measured by the duration time measurement unit 16 with the interruption time set by the interruption time setting unit 15, and if the duration time exceeds the interruption time, the interruption unit 8 is notified. Issue a close signal.

Details of the operation in the above configuration will be described with reference to the flowchart of FIG. FIG. 7 shows the entire operation. In the flow rate measurement in step 1, the flow rate Qmn (3
It is the flow rate measured by the flow rate measuring means 4 every 0 seconds, and Qmi
Indicates that it is the data measured at the i-th time), and ΔQ (the flow rate obtained by subtracting the i-1-th time flow rate Qmi-1 from the i-th time measured flow rate Qmi) in the flow rate change presence / absence determination in step 2. If the absolute value of is larger than 3% of the measured flow rate of Qmi, it is recognized that there is a change in the flow rate. If it is 3% or less, the procedure goes to step 1 to perform the next measurement. In step 3, if ΔQ is positive, it is estimated which device is increased or which device is added. If ΔQ is negative, it is estimated which device the flow rate is decreasing or the device is erasing. Then, the individual flow rates are corrected and stored in descending order. In step 4, set the cutoff time corresponding to the largest appliance. And
It is judged whether or not the cutoff time set in step 5 has been reached. If the cutoff time has been reached, it is judged that an abnormal state has occurred and a cutoff signal is issued. In step 5, the gas shutoff signal is used to shut off the gas. If a change in the flow rate is recognized before the set cutoff time is reached, return to the estimation of the individual flow rate in step 3 again, and when the maximum value is replaced, set the cutoff time corresponding to this new maximum individual flow rate. , If there is no change in the maximum individual flow rate, reset the cutoff time until then.

[0007]

However, in the above conventional configuration, the flow rate change presence / absence determining means 5 is used to determine the current flow rate value Q.
If the absolute value of ΔQ, which is the difference between mi and the preceding Qmi-1, is greater than 3% of the measured flow rate, it is determined that there is a change in the flow rate, and the individual flow rate estimation means that is an important constituent means of the flow rate determination device. 6 works. However, as shown in FIG. 8, when the absolute value of ΔQ continues to increase by 3% or less of the measured flow rate due to the influence of pressure fluctuation and proportional control of the water heater, the conventional flow rate change presence / absence determining means 5 Cannot be detected, and the increased flow rate cannot be registered as an individual flow rate. But,
In the above-described conventional configuration, the flow rate change presence / absence determining means 5 uses 3% of the measured flow rate as a change rate change criterion. However, if the change rate criterion is made smaller, the flow rate change can always be recognized. There is a problem that the operating time of the flow rate estimating means 6 increases and the current consumption of the microcomputer increases.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a flow rate discriminating apparatus capable of accurately estimating individual flow rates and having low current consumption.

[0009]

In order to solve the above-mentioned problems, the flow rate determining device of the present invention sums up the flow rate measuring means for measuring the flow rate of the fluid and the individual flow rates stored in the individual flow rate storage section. The total individual flow rate storage unit including an adding unit and a storage unit that stores the total flow rate, and the difference between the measured flow rate sent from the flow rate measurement unit and the stored flow rate stored by the total individual flow rate storage unit A flow rate change determination unit that outputs a signal that the flow rate has changed if it is larger than the product of the change determination reference value stored in the change determination reference value storage unit and the measured flow rate value sent from the flow rate measuring means. Flow rate change presence / absence determining means, and change estimation for estimating whether or not the flow rate change presence / absence determining means detects a change in flow rate and outputs a signal, the change is registration of individual flow rate, deletion of registration, and increase / decrease in registered individual flow rate. Department An individual flow rate registration / correction unit for registering the individual flow rate, deleting the registration, and increasing / decreasing the registered individual flow rate according to the result of the change estimation unit, and an individual flow rate storage unit for storing the individual flow rate corrected by the individual flow rate registration / correction unit. It is provided with an individual flow rate estimating means.

[0010]

According to the present invention, with the above configuration, the difference between the gas flow rate sent from the flow rate measuring means and the stored flow rate stored in the total individual flow rate storage means is used as the change flow rate, and the change in the flow rate is determined by an appropriate change determination standard. As a result, the individual flow rate estimating means 3 operates intermittently and individually increases or decreases the flow rate by recognizing the flow rate change in a timely manner as the flow rate continues to increase or decrease by a small amount due to the influence of pressure fluctuations. It acts so as to be registered as a flow rate, and it is possible to reduce the current consumption of the microcomputer and to accurately estimate the individual flow rate.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. In FIG. 1, 4 is a flow rate measuring means, 19 is an addition section, 20 is a storage section, 21 is a total flow rate storage section, 5 is a flow rate change presence / absence determination section, 10 is a flow rate change determination section, and 11 is a change determination reference value storage. Reference numeral 12 is a change estimation unit, 13 is an individual flow rate registration correction unit, 14 is an individual flow rate storage unit, and 6 is an individual flow rate estimation means.

The flow rate measuring means 4 measures the instantaneous flow rate of the gas passing through the gas meter at intervals of 30 seconds, and the total individual flow rate storage means 21 sums the flow rates stored in the individual flow rate storage section 14 by the adding section 19 to obtain the total flow rate. Storage unit 20 as total individual flow rate Qt
Remember. The flow rate change presence / absence determining means 5 is the flow rate measuring means 4
The absolute value of the change flow rate ΔQt obtained by subtracting the total individual flow rate Qt stored in the storage unit 20 from the gas flow rate measured in step 3 is the gas flow rate measured by the flow rate measuring means 4 and the change determination reference value storage unit 11
If it is larger than the product of the change judgment reference value (3%) stored in, the gas flow rate is changed and a signal is output. The individual flow rate estimating means 6 estimates which gas appliance the flow rate is increasing or is registered if the flow rate change presence / absence determining means 5 detects a change in the gas flow rate and the change in the gas flow rate increases. If the change in gas flow rate decreases, a change estimating unit 12 that estimates which gas appliance is decreasing or deleting, and registration of individual flow rates, deletion of registration and registration based on the result of the change estimating unit 12 The individual flow rate registration / correction unit 13 for increasing / decreasing the individual flow rate, and the individual flow rate storage unit 14 stores the individual flow rate corrected by the individual flow rate registration / correction unit 13.

The details of the operation of the above configuration will be described with reference to the flowchart of FIG. FIG. 2 shows the entire operation. In the flow rate measurement in step 1, the flow rate Qmn (3
It is the flow rate measured by the flow rate measuring means 4 every 0 seconds, and Qmi
Indicates that it is the data measured at the i-th time), and the absolute value of ΔQt (flow rate obtained by subtracting all individual flow rates Qt from the i-th time measured flow rate Qmi) is measured in the flow rate change judgment in step 2. If it is larger than 3% of Qmi, it is recognized that there is a change in the flow rate. Go to step 3 and if it is 3% or less, step 1
Go to In the individual flow rate estimation in step 3, if ΔQt is positive, it is estimated which device is increased or which device is added. △
If Qt is negative, it is estimated which device is the flow reduction or the device is erased. Then, the individual flow rate is corrected and stored in Q1 to Q5 in descending order of flow rate. In the calculation of all individual flow rates in step 4, Qt = Q1 + Q2 + Q3 + Q4
Calculate + Q5.

In the above structure, the absolute value of the flow rate ΔQt obtained by subtracting the total individual flow rate Qt stored in the total individual flow rate storage means 21 from the measured flow rate sent from the flow rate measuring means 4 is 3% of the measured flow rate. If the flow rate is large, the flow rate change presence / absence determining means 5 detects the change in the flow rate, and the individual flow rate estimating means 6 which is an important constituent means of the flow rate determining device operates. For example, as shown in FIG. 8, the difference ΔQ, which is the difference between the current flow rate value Qmi and the previous flow rate Qmi-1, is 3% or less of the measured flow rate Qmi due to the influence of pressure fluctuation and proportional control of the water heater. If continues,
The flow rate change presence / absence judging means 2 recognizes a change when the absolute value of ΔQt is larger than 3% of the measured flow rate, that is, when the measured flow rate is Qmi + 3 in FIG. 8, and the individual flow rate estimating means 6 operates. Since the operation is intermittent, the flow rate determining device having the above configuration can accurately estimate the individual flow rate and reduce the current consumption of the microcomputer.

[0015]

As described above, the flow rate determining device of the present invention determines the change in flow rate by setting the difference between the flow rate sent from the flow rate measuring means and the stored flow rate stored in the total individual flow rate storage means as the change flow rate. By doing so, it becomes possible to timely recognize the change of the flow rate with respect to the continuous increase of the flow rate and the continuous decrease of the flow rate.

[Brief description of drawings]

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

FIG. 2 is a flowchart of the same flow rate determination device.

FIG. 3 is a block diagram of a conventional flow rate determination device.

FIG. 4 is a configuration diagram of the flow rate change presence / absence determining unit.

FIG. 5 is a block diagram of the individual flow rate estimating means.

FIG. 6 is a block diagram of the cutoff time control means.

FIG. 7 is a flowchart of the same flow rate determination device.

FIG. 8: Example of continuous increase in measured flow rate by small amount

[Explanation of symbols]

 4 flow rate measuring means 5 flow rate change presence / absence determination means 6 individual flow rate estimation means 10 flow rate change determination section 11 change determination reference value storage section 12 change estimation section 13 individual flow rate registration / correction section 14 individual flow rate storage section 19 adder section 20 storage section 21 all Individual flow rate storage means

Claims (1)

Claims: 1. A flow rate measuring means for measuring a flow rate of a fluid, an adding section for summing up individual flow rates stored in an individual flow rate storage section, and a storage section for storing the total flow rate. And the difference between the measured flow rate sent from the flow rate measuring means and the stored flow rate stored in the total individual flow rate storage means is set in advance and stored in the change determination reference value storage section. A flow rate change presence / absence determination means comprising a flow rate change determination part that outputs a signal that the flow rate has changed if it is larger than the product of the determination reference value and the measured flow rate value sent from the flow rate measurement means, and the flow rate change presence / absence determination means. Each time a change in the flow rate is detected and a signal is output, the change is registered as an individual flow rate, the registration is deleted, and a change estimation unit that estimates whether the registered individual flow rate is increased or decreased and the individual flow rate is registered according to the result of the change estimation unit, Register A flow rate discriminating device comprising an individual flow rate estimating means comprising an individual flow rate registration / correction unit for erasing and increasing / decreasing the registered individual flow rate, and an individual flow rate storage unit for storing the individual flow rate corrected by the individual flow rate registration / correction unit.