JPH1164055A - Flow-measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the safety of a flow-measuring instrument by discriminating the appropriateness of the state used for a fluid by means of an abnormality discriminating means, based on the outputs of a flow rate computing means and a temperature computing means. SOLUTION: In an abnormality discriminating means 14, a critical value which is discriminated as appropriate in advance is stored. The discriminating means 14 discriminates an abnormal state not only from flow rate conditions, but also from temperature conditions. For a flow rate measuring instrument, such as a gas meter, water meter, etc., used for a household lifeline, the temperature in the pipeline varies depending upon the outside air temperature, because the pipeline is normally laid outdoors. The abnormality discriminating means 14 stores the appropriate value of the temperature of a fluid which is expected under a normal laying condition and, when the temperature found by means of a temperature computing means 12 deviates from the range, the means 14 discriminates that an abnormal temperature rise occurs in the pipeline due to the breakage of the pipeline, a fire, etc., and, for a water pipe, discriminates that certain abnormality, such as the freezing, etc., has occured in the route of the pipeline. Then the discriminating means 14 informs the user or supplier of the abnormality through an informing means 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid measuring device, and more particularly to a device for measuring a flow rate of a fluid such as fuel gas such as city gas and LP gas, tap water, and the like, which is used in general households.

[0002]

2. Description of the Related Art Among conventional measuring devices of this type, those for supplying gas to the home are disclosed in Japanese Patent Publication No. Hei.
As described in Japanese Patent Application Laid-Open Publication No. H10-209, there are many proposals with a gas accident prevention function. The operation will be described with reference to FIG. The gas supplied from the gas pipe 1 is integrated into the gas meter 3 via the shut-off valve 2 and then supplied to appliances in the house. On the other hand, each time a fixed amount of gas passes through the inside of the gas meter 3, a pulse signal is output from the flow rate measuring device 4, and the control device 5 counts the pulse signal per unit time to change the flow rate per time. You can know.

The control device 5 stores in advance a limit value determined to be appropriate as a gas usage method. The limit value is, for example, the maximum allowable amount of the instantaneous flow rate when a plurality of appliances are used, the limit value of the time for continuous use without a change in the flow rate, and the like. The former is a value set for accident prevention, assuming that the hose connected to the gas appliance is disconnected, and the latter is assumed to forget to turn off the appliance. When the control device 5 detects a use condition exceeding the stored limit value, the control device 5 activates the shutoff valve 2 to stop the gas supply, and displays the reason for determining the shutoff on the display device 6. I do. In this way, it is possible to prevent a gas accident from occurring.

[0004]

However, the main purpose of the above-mentioned conventional flowmeter is to monitor the user so that the user does not carelessly or intentionally fall into an abnormal use state.
It did not consider the environmental conditions around the fluid. Therefore, even when a fluid temperature abnormality occurs, the user or the supplier cannot recognize it at all, and there is a problem in terms of safety.

[0005] In addition, the conditions for shutting off the gas are determined under uniform conditions irrespective of the surrounding environment such as the season and time.
There is a case where so-called unnecessary interruption occurs, which is a problem in terms of convenience for the user.

[0006]

According to the present invention, in order to solve the above-mentioned problems, the abnormality judging means judges whether or not the use condition of the fluid is proper based on the outputs of the flow rate calculating means and the temperature calculating means. Has become.

According to the present invention, it is possible to measure the temperature, which is the physical property value of the fluid itself, and it is possible to detect an abnormal state of the fluid itself.

[0008] In addition, the limit value of the use continuation time for each gas appliance used is changed according to the value of the temperature calculation means.

According to the above-mentioned invention, the limit value can be determined according to the actual condition of the used equipment for each season or time, so that unnecessary cutoff can be reduced.

[0010]

A flow meter according to a first aspect of the present invention includes a flow rate detecting means for detecting a flow rate of a fluid passing through a pipe, and a flow rate calculating means for calculating a flow rate of the fluid from an output of the flow rate detecting means. Means, temperature detecting means for detecting the temperature of the fluid, temperature calculating means for calculating the temperature of the fluid from the output of the temperature detecting means, flow rate determined by the flow rate calculating means, and temperature determined by the temperature calculating means. Abnormality judgment means for judging an abnormality when deviated from a predetermined appropriate condition, and notifying means for notifying the judgment result of the abnormality judgment means to the outside, wherein the abnormality judgment means is the temperature calculation means. If the temperature obtained in step is out of the predetermined range, the notification means is activated.

Then, the abnormality detecting means judges whether the temperature of the fluid is appropriate, and if the temperature is abnormal, the abnormality is notified by the notifying means, so that safety can be improved.

According to a second aspect of the present invention, in the flow rate measuring device, the abnormality determining means determines that the fluid is abnormal if the temperature of the fluid is outside a predetermined range, and the first determining means determines that the fluid is abnormal. A second determining unit that determines an abnormal level according to the flow rate of the fluid when it is determined that the abnormality is present, wherein the notifying unit employs a different notification method according to the abnormal level determined by the abnormality determining unit.

[0013] Then, in the event of an abnormality, according to the value of the flow rate,
Since the notification method by the notification means is changed, the degree of abnormality can be notified, and the safety can be further improved.

According to a third aspect of the present invention, in the flow rate measuring device, the fluid used is a liquid, and the first determining means determines that the liquid is abnormal when the temperature of the liquid is equal to or lower than the freezing temperature or lower.
The second determination means is configured to increase the abnormal level as the liquid flow rate decreases.

Then, when the freezing temperature is reached, the abnormal level is increased as the flow rate becomes smaller, so that the pipe freezing can be detected and avoided in advance.

The flow rate measuring device according to a fourth aspect of the present invention is characterized in that the fluid used is a gas, and a shut-off means for stopping gas supply is provided, and the abnormality determining means has a high abnormality level determined by the second determining means. The configuration is such that the shut-off means is operated only at the time.

If the degree of abnormality is high, the supply of gas is shut off, so that safety can be further improved.

According to a fifth aspect of the present invention, there is provided a flow rate measuring device for detecting a flow rate of a gas passing through a pipe, a flow rate calculating means for calculating a gas flow rate from an output of the flow rate detecting means, Temperature detecting means for detecting the temperature of the gas, temperature calculating means for calculating the temperature of the gas from the output of the temperature detecting means, the flow rate determined by the flow rate calculating means, and the temperature determined by the temperature calculating means are determined in advance. It is provided with an abnormality determining means for determining an abnormality when deviating from a predetermined appropriate condition, and a shutoff means for stopping gas supply, and the abnormality determining means is provided on the downstream side of the apparatus based on the flow rate obtained by the flow rate calculating means. Estimating means for estimating the used gas appliance, storage means for storing a limit value of the continuous use time for each used equipment, and time measuring means for measuring the continuous use time of the appliance estimated by the estimating means,
Shutoff determining means for determining that an abnormality has occurred when the value measured by the timekeeping means exceeds a value determined by the storage means, and activating the shutoff means, wherein the limit value stored in the storage means is determined by the temperature calculation means. It changes in accordance with the temperature.

Then, the season and time are estimated from the pipe ambient temperature, and the combination of the equipment used, the season, and the time is used.
Since the limit value of the use time can be determined, unnecessary cutoff can be reduced.

There is provided a physical quantity detecting means for detecting a physical quantity correlated with both the flow rate and the temperature of the fluid in the pipe, and the physical quantity detecting means has a function of both a flow rate detecting means and a temperature detecting means. ing.

[0021] The safety and convenience can be improved without adding a new temperature sensor.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a configuration diagram of a flow rate measuring apparatus of Embodiment 1.

The gas having passed through the pipe flows in the fluid flow path 7 in the direction of the arrow. Reference numeral 8 denotes a physical quantity detection unit that detects the flow rate and temperature of the fluid, and is configured by ultrasonic vibrators 9 and 10 that transmit and receive ultrasonic waves to and from the flow path 7 and a detection circuit 11. That is, the first vibrator 9 is arranged on the upstream side of the flow and the second vibrator 10 is arranged on the downstream side, and the ultrasonic wave transmitted from the first vibrator 9 has a propagation time T1 at which the ultrasonic wave reaches the second vibrator 10. And the propagation time T2 at which the ultrasonic wave transmitted from the second transducer 4 reaches the first transducer 3 is determined by the detection circuit 11
Is measured by Further, the time T measured by the detection circuit 11 is
The fluid flow rate is calculated by the flow rate calculating means 12 and the fluid temperature is calculated by the temperature calculating means 13 based on T1 and T2. 14 is an abnormality determining means for monitoring the use condition of the fluid from the temperatures obtained by the flow rate calculating means 12 and the temperature calculating means 13 and performing an abnormality determination;
Reference numeral 15 denotes a notifying means for notifying outside when the abnormality determining means 9 detects an error, which is attached indoors through a signal line and notifies the abnormality by voice.

Next, the operation will be described. First,
The principle of measuring the flow rate and the temperature will be described. The sound velocity in the stationary fluid is C, the flow velocity is V, the first vibrator 9 and the second vibrator 1
L is the distance of 0, θ is the angle between the propagation axis of the ultrasonic wave and the central axis of the flow path, T1 is the propagation time of the ultrasonic wave from the first vibrator 9 to the vibrator 10, and Assuming that the propagation time of the ultrasonic wave to the first vibration 9 is T2, T1 and T2 have the following values, respectively.

T1 = L / (C + vcos θ) (1) T2 = L / (C−vcos θ) (2) Accordingly, the flow velocity V is obtained as follows using the equations (1) and (2).

V = (1 / T1-1 / T2) × (1/2 cos θ) (3) Further, assuming that the cross-sectional area of the flow path is S, the flow rate Q is expressed by the following equation (4).
Can be obtained by using

Q = S · v (4) The sound speed C can be obtained as follows from the equations (1) and (2).

C = 2L / (T1 + T2) (5) Further, since the sound speed c and t have a relationship of C = 331.5 + 0.607t (m / sec) (6), using the equation (7), The temperature t can be determined.

T = (C−331.5) /0.607 (7) Therefore, the detection unit 5 detects T1 and T2, and using the result, the flow rate calculation unit 3 calculates the equation (3) and The flow rate Q is obtained using Expression (4), and the temperature calculation unit obtains the temperature t using Expressions (5) and (7). In this embodiment, the method of directly measuring T1 and T2 is used. However, there is a method of repeating the transmission and reception of the ultrasonic wave a plurality of times and using the average value in order to improve the detection accuracy. With the idea, it is possible to determine the flow rate and the temperature.

Next, the operation of the abnormality determining means 14 will be described. The abnormality determination means 14 stores in advance a limit value that is determined to be appropriate as a gas usage method. The method of determining the abnormal use of gas from the flow rate condition is the same as in the conventional example, and thus the description is omitted. Abnormality determination means 14
Determines the abnormal state not only from the flow rate condition but also from the temperature condition. In the case of a flow rate measuring device used in a domestic life line such as a gas meter or a water meter, the temperature inside the pipe depends on the outside air temperature condition because it is usually installed outdoors. Further, it is considered that the supply pressure of the fluid is also within a predetermined range determined by the trader. Therefore, the temperature range in the pipe is naturally limited. Therefore,
The abnormality determining means 14 stores an appropriate value of the fluid temperature, which can be considered in a normal installation state, and if the temperature calculated by the temperature calculating means 12 is out of this range, the piping may be damaged due to a broken pipe, a fire, or the like. It is considered that some abnormality has occurred in the piping route, such as abnormal temperature rise in the case of water or in the case of water supply, freezing in the piping. Therefore, the abnormality determining means 14 uses the notifying means 15
Through these, these abnormalities can be notified to the user or the supplier.

In the present embodiment, the notification method of the notification means 15 is by voice, but the same effect can be obtained by a configuration in which the notification is made visually by display. Further, the same effect can be obtained even in a configuration in which information is transmitted to a security base station through a telephone line.

(Embodiment 2) FIG. 2 is a configuration diagram of a flow rate measuring apparatus according to Embodiment 2. FIG. 3 is a characteristic diagram for explaining the operation of the abnormality determining means 14. The difference from the first embodiment is
The abnormality judging means 14 has a first judging means 16 and a second judging means 17 therein, and the first judging means 16 judges an abnormal temperature of the fluid. The level is set, and the notifying unit 15 changes the notifying method based on the determination result of the second determining unit. The components having the same reference numerals as those in the first embodiment have the same structure, and a description thereof will be omitted.

Next, the operation will be described. The degree of danger increases as the numerical value of the abnormal level illustrated in FIG. 3 increases. As shown in the figure, each time the flow rate increases, the abnormal level becomes 1,
It has increased to a few, and the degree of danger has increased. Here, according to the determined danger level, the notification means 15
Changes. A warning sound is generated intermittently from the notification means 15, and the intermittent cycle becomes shorter as the abnormal level increases. The user can recognize the degree of danger by the warning sound.

(Embodiment 3) FIG. 4 is a characteristic diagram for explaining the operation of the abnormality determining means 14 when the flow rate measuring device described in Embodiment 2 is applied to a water meter. The configuration diagram in the present embodiment is the same as that in FIG.

In the case of a water meter, it can be used for detecting freezing of piping. The abnormality determining unit 14 notifies the abnormality through the notifying unit 10 when the temperature falls below 0 ° C. or a temperature in the vicinity thereof. Then, every time the flow rate decreases, the abnormal level increases to 1, 2, and 3, and the degree of danger increases. That is, after the water temperature reaches the freezing temperature, it is determined that the smaller the flow rate, the higher the risk of freezing. here,
The sound emitted by the notification means 10 changes according to the determined abnormal level. Therefore, the user can prevent the freezing by appropriately adjusting the opening of the water supply cull in accordance with the sound of the notification means 15.

(Embodiment 4) FIG. 5 is a configuration diagram of a flow rate measuring apparatus according to Embodiment 4. The difference from the second embodiment is that a shutoff unit 2 that operates to shut off the gas when the abnormality level determined by the abnormality determination unit 14 is high is provided. In addition,
The components having the same reference numerals as those of the second embodiment have the same structure, and the description is omitted.

Next, the operation will be described. When the abnormal level shown in FIG. 3 becomes 2 or more, the shutoff means 12 operates and the supply of gas is stopped. Therefore, even if the user does not notice the content notified by the notification means 15, the gas supply is stopped, and the gas is not continuously used in a dangerous state. For example, when the invention is applied in the event of a fire described in the second embodiment, the lower limit flow rate (for example, 3 l) at which Q1 shown in FIG.
/ H) and setting the abnormal level 2 or higher as the cutoff condition, the gas supply is cut off even if the use of the gas is recognized even a little. Therefore, the gas appliance stops when a fire occurs, so that damage caused by the spread of fire can be prevented.

(Embodiment 5) FIG. 6 is a configuration diagram of a flow rate measuring apparatus according to Embodiment 4. FIG. 7 is an explanatory diagram of a tool estimating method of the estimating means 18. Further, FIG.
FIG. 7 is a characteristic diagram showing a relationship between a limit value and a gas temperature for each use tool set in FIG. The difference from the first embodiment is that the abnormality determining means 14 estimates the gas equipment used downstream of the flow meter from the flow rate output from the flow rate calculating means 12 and the limit value of the usage continuation time for each used tool. Storage means 19 for storing
A timer 20 for measuring the continuous use time of the appliance estimated by the estimator, a value determined by the storage 19 and the timer 20
When the latter is greater than the former by comparing the values of the above, a cut-off determining means 21 for operating the cut-off means 2 is provided. The components having the same reference numerals as those in the first embodiment have the same structure, and a description thereof will be omitted.

Next, the operation will be described. Estimation means 1
8 estimates the equipment to be used based on the degree of change in the flow rate obtained by the flow rate calculating means 12. A method for estimating a device will be described with reference to FIG. As shown in FIG. 7, the flow rate is 0 → QS
When the flow changes from Qt to Qu, at time T1, the use of the appliance A with the flow rate QS starts, and at time T2, the flow rate (Qt-Q
s), the use of the appliance B is started, and at time t3, the flow rate (Qu
It is determined that the device C of -Qt) has stopped using. Time t
Since two instruments A and B were used between 2 and t3, the instrument C is either A or B. At this time, since Qu-Qt is a value close to Qs, the appliance continuously used after time T3 is B.

As described above, the estimating means 18 estimates the equipment to be used in accordance with the prescribed rules while sequentially monitoring the change pattern of the flow rate. Then, the cutoff determining means 21 measures the use time for each of the estimated used appliances, and when the use time exceeds the limit value of the use continuation time for each appliance stored in the storage means 19,
The shutoff means 2 is operated to stop the gas supply. At this time,
The limit value stored in the storage unit 19 is rewritten according to the temperature obtained by the temperature calculation unit 13. For example, heaters such as gas fan heaters are generally used only in winter. Furthermore, it is considered that the case of continuous use increases as the temperature decreases. Therefore, as shown in FIG. 8, the limit value is set so as to decrease as the temperature increases.

In the first to sixth embodiments, both the flow rate detection and the temperature detection are possible by using a pair of ultrasonic transducers. However, the flow rate detection means and the temperature detection means are separately provided. The same effect can be obtained even with such a configuration.
However, when an ultrasonic transducer is used, the safety and convenience are improved by using only the flow rate detecting element, which is an essential component of the flow rate measuring device, without adding a new temperature detecting element. There is an effect that the improvement can be achieved.

[0043]

As apparent from the above description, the flow rate measuring device of the present invention has the following effects.

In the flow rate measuring device according to the first aspect, when the fluid temperature deviates from an appropriate condition, the abnormality is notified by the notifying means, so that an abnormality can be determined from the fluid and its surrounding temperature, so that the safety can be improved. There is.

In the flow rate measuring device according to the second aspect, when the fluid and its ambient temperature deviate from appropriate conditions, the abnormality notification method is changed according to the magnitude of the fluid flow rate, so that the degree of abnormality can be identified. Therefore, a countermeasure can be easily taken.

In addition, the flow rate measuring device according to the third aspect determines that the abnormal level is higher as the flow rate decreases as the fluid temperature approaches the freezing temperature, and informs the user that the level is abnormal. .

Further, in the flow rate measuring device according to the fourth aspect, when the abnormal level is large, the gas supply is stopped by operating the shut-off means, so that the gas accident can be prevented beforehand.

Further, in the flow rate measuring device according to claim 5, since the limit value of the continuous use of the tool used is changed according to the temperature, the usable time is changed according to the surrounding environment.
There is an effect that unnecessary interruption is eliminated, and convenience for the user can be enhanced.

Further, the flow rate measuring device according to claim 6 can detect both the flow rate and the temperature by the physical quantity detecting means. Has the effect of improving safety and improving convenience.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a flow rate measurement device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a flow rate measurement device according to a second embodiment of the present invention.

FIG. 3 is an operation characteristic diagram of a second determination unit of the apparatus.

FIG. 4 is an operation characteristic diagram of a second determination unit according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a flow measurement device according to a fourth embodiment of the present invention.

FIG. 6 is a configuration diagram of a flow measurement device according to a fifth embodiment of the present invention.

FIG. 7 is an operation characteristic diagram of an estimation unit of the apparatus.

FIG. 8 is an operation characteristic diagram of a storage unit of the device.

FIG. 9 is a configuration diagram of a conventional flow measurement device.

[Explanation of symbols]

 2 Blocking means 8 Physical quantity detecting means 12 Flow rate calculating means 13 Temperature calculating means 14 Abnormality detecting means 15 Notification means 16 First determining means 17 Second determining means 18 Estimating means 19 Storage means 20 Clocking means 21 Blocking determining means

Claims (6)

[Claims] 1. A flow rate detecting means for detecting a flow rate of a fluid passing through a pipe, a flow rate calculating means for calculating a flow rate of a fluid from an output of the flow rate detecting means, a temperature detecting means for detecting a temperature of the fluid, A temperature calculating means for calculating the temperature of the fluid from the output of the temperature detecting means, a flow rate obtained by the flow rate calculating means, and a temperature obtained by the temperature calculating means deviating from a predetermined appropriate condition. Is provided with an abnormality determining means for determining an abnormality, and a notifying means for notifying the determination result of the abnormality determining means to the outside, wherein the abnormality determining means is provided when the temperature obtained by the temperature calculating means is out of a predetermined range. If
A flow measurement device for operating the notification means. An abnormality determining means for determining whether the temperature of the fluid is abnormal if the temperature of the fluid is out of a predetermined range; and determining whether the temperature of the fluid is abnormal when the first determining means determines that the temperature is abnormal. 2. The flow rate measuring device according to claim 1, further comprising: a second determining unit that determines an abnormal level by using a different notifying method according to the abnormal level determined by the abnormal determining unit. 3. 3. The fluid used is a liquid, the first judging means judges that the temperature of the liquid is abnormal at or below the freezing temperature or lower, and the second judging means increases the abnormal level as the liquid flow rate decreases. The flow measurement device according to claim 2. 4. A method according to claim 2, wherein the fluid used is a gas, and a shut-off means for stopping the supply of the gas is provided, and the abnormality judging means activates the shut-off means only when the abnormality level judged by the second judging means is high. The flow measurement device as described. 5. A flow rate detecting means for detecting a flow rate of a gas passing through a pipe, a flow rate calculating means for calculating a gas flow rate from an output of the flow rate detecting means, a temperature detecting means for detecting a gas temperature, Temperature calculating means for calculating the temperature of the gas from the output of the temperature detecting means, the flow rate determined by the flow rate calculating means, and the temperature determined by the temperature calculating means deviates from a predetermined appropriate condition. Is provided with abnormality determination means for determining an abnormality, and shutoff means for stopping gas supply,
The estimating means for estimating the used gas appliance on the downstream side of the apparatus based on the flow rate obtained by the flow rate calculating means,
Storage means for storing a limit value of the continuous use time for each used appliance, time measurement means for measuring the continuous use time of the appliance estimated by the estimation means, and a value measured by the time measurement means being determined by the storage means A flow rate measuring device comprising: a cutoff judging means for judging an abnormality when it exceeds the threshold value and activating the shutoff means, wherein a limit value stored in the storage means changes according to the temperature obtained by the temperature calculation means. 6. A physical quantity detecting means for detecting a physical quantity having a correlation with both a flow rate and a temperature of a fluid in a pipe, wherein the physical quantity detecting means has both functions of a flow rate detecting means and a temperature detecting means. Item 6. The flow measuring device according to any one of Items 1 to 5.