JP2012242257A - Gas shut-off device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent erroneous shut-off by monitoring abnormal measurement in ultrasonic flow rate measurement.SOLUTION: A gas shut-off device comprises: flow rate detection means 1 for measuring flow rates; means for calculating instantaneous flow rates or an average flow rate; abnormal measurement determination means 13 for monitoring whether or not there is abnormality in the flow rate detection means 1 and determining that there is abnormal measurement when abnormality is detected; timer means 15 for counting a predetermined time; use state storage means 16 for storing a use state within a predetermined time period on the basis of the average flow rate; appropriate use condition change means 17 for changing appropriate use conditions according to contents of the use state storage means 16; period time counting means 18 for starting operations of the abnormal measurement determination means 13 after a predetermined time period is counted; abnormality determination means 19 for determining whether or not there is abnormality on the basis of the calculated average flow rate and resetting appropriate conditions by the appropriate use condition change means 17; and shut-off means 20 for shutting off supply of gas when it is determined that there is abnormality by the abnormality determination means 19.

Description

  The present invention relates to a gas shut-off device, and more particularly to a gas shut-off device that performs flow rate measurement with ultrasonic waves and performs safety monitoring.

  Conventionally, as this type of gas shut-off device, there is one as shown in FIG. 3 (for example, see Patent Document 1).

  The configuration of the gas cutoff device of Patent Document 1 will be briefly described with reference to FIG.

  Two transducers TD1 and TD2 are arranged opposite to each other so as to be separated from each other by a distance L in the gas flow path and form an angle θ with respect to the gas flow direction Y. A gas shut-off valve 101 is provided on the upstream side of both transducers TD1, TD2. Each transducer TD1, TD2 is connected to a transmission circuit 104 and a reception circuit 105 via transducer I / F circuits 102, 103. Under the control of the microcomputer (μCOM) 106, the transmission circuit 104 drives one of the transducers TD1 and TD2 to generate an ultrasonic wave. The μCOM 106 includes a CPU 106a that performs various processes, a ROM 106b that stores programs, and a read-only memory RAM 106c. The reception circuit 105 processes the reception signals from the other transducers TD1 and TD2 that have received the ultrasonic signal that has passed through the gas flow path. A display 107 is connected to the μCOM 106.

  Next, the operation of the configuration of the conventional gas cutoff device will be described. The μCOM 106 measures the gas flow rate at each sampling time using the two transducers TD1 and TD2, and performs instantaneous flow rate measurement processing. Further, the CPU 106a of the μCOM 106 performs a flow rate measurement process and a measurement abnormality determination process for determining whether or not an accurate flow rate measurement can be performed. The propagation time after the peak value of the received ultrasonic wave signal exceeds the threshold is measured. The gain is adjusted so as to exceed the threshold, but the μCOM 106 determines that accurate flow velocity measurement cannot be performed when the ultrasonic wave exceeding the threshold cannot be received even if the gain is maximized.

  After canceling the shipping mode, the CPU 106a performs a return process for confirming the return safety of the gas shut-off valve, and functions as a mixture determination unit and a stop unit. After the shipment mode is released, it is determined that a mixed state has occurred between the reception of the ultrasonic signal and the detection of the absence of mixing of supply gas and air based on the instantaneous flow rate calculated from the ultrasonic signal. Then stop judging the flow rate abnormality. After exiting this stop process, a return safety confirmation process is performed based on the determination of the flow rate abnormality.

  Further, the CPU 106a shifts to the shipping mode, the first learning mode for confirming the return safety of the gas shut-off valve, and after the first learning mode is finished, and after the third predetermined time has elapsed from the start of the first learning mode, the CPU 106a sets the third predetermined value. While performing the operation according to a plurality of modes including the second learning mode that waits for the flow of gas exceeding the flow rate, the mixture determination means is in the shipping mode, while in the first learning mode performed immediately after the shipping mode is released, Alternatively, during the second learning mode that is performed immediately after the shipment mode is released, it is determined that mixing has occurred. Accordingly, the measurement abnormality of the flow velocity measuring unit is stopped during the shipping mode, the first learning mode, or the second learning mode in which gas replacement work or mixing may occur.

Further, when the CPU 106a shifts to the second learning mode immediately after the release of the shipping mode, the CPU 106a has a mixture determination unit that starts detection of the presence / absence of mixing based on the state in which measurement is not possible by the flow rate measurement unit or the flow rate measured by the flow rate measurement unit. Even when the mixture determination means detects the absence of mixing even in the second learning mode immediately after the release of the shipping mode, the mixture determination means determines that no mixing has occurred and does not wait for the end of the second learning mode. Start measuring abnormality quickly.

Japanese Patent No. 4199106

  However, in the gas shut-off device having the above-described conventional configuration, at the time of return safety confirmation after the release of the shipping mode, the mixture of air and supply gas is judged based on the reception state of ultrasonic waves and the instantaneous flow rate, and the judgment of the flow rate abnormality is stopped. However, it is not disclosed how to handle the abnormal flow value at the time of stopping. In addition, the gas company may cancel the shipment mode after installation, but may purge the air with only some gas appliances, and other gases such as air remain in other piping There is. In this case, the gas flow path naturally mixes with a gas other than the supply gas as time elapses. Therefore, even in the second learning mode after the release of the shipping mode, the gas replacement is completed, and it cannot be said that the mixed judgment is completed, and the flow measurement unit is made of different gas due to the convection of the air in another gas pipe or water heater pipe. There is a problem that a mixed state occurs, which is erroneously used for learning data, and as a result may be erroneously determined to be mixed gas, resulting in erroneous blockage.

  The present invention solves the above-described problems, and provides a highly convenient gas shut-off device that does not erroneously shut off even if a mixed state with a different gas occurs in a gas flow path.

  In order to solve the above-described conventional problems, a gas shut-off device according to the present invention is a gas shut-off device that shuts off the supply of gas when an abnormality occurs, a flow rate detecting means for amplifying and detecting a flow rate signal, and the flow rate detecting means. A flow rate calculating means for calculating an instantaneous flow rate from the detected value, an average flow rate calculating means for obtaining an average flow rate from the instantaneous flow rate obtained by the flow rate calculating means, and a plurality of determination values for determining signal amplification adjusted by the flow rate detecting means Amplifying degree determining means, a measurement abnormality determining means for monitoring whether there is an abnormality in the flow rate detecting means and detecting an abnormality, a measuring abnormality determining means, a timer means for measuring a predetermined time, and during the time measurement of the timer means The usage state storage means for storing the usage state of the gas from the average flow rate obtained by the average flow rate calculation means, and the appropriate usage conditions are changed according to the contents of the usage state storage means. Comparing the condition changing means, the period measuring means for starting the operation of the measurement abnormality determining means after measuring a predetermined period, the average flow rate obtained by the average flow rate calculating means, and the appropriate condition set by the appropriate condition changing means The abnormality determining means for determining the presence / absence of abnormality, and the interruption means for cutting off the gas supply when the measurement abnormality determining means determines that the measurement abnormality is present or when the abnormality determination means establishes the abnormality determination.

  According to the above invention, even if the gas can be supplied during the shipping mode or after the shipping mode is released, the measurement abnormality determining means is in a function invalid state, and the timer is started after the shipping mode is released by the starting means and the use state is changed. While being observed, the flow rate value measured at an amplification level greater than or equal to a predetermined value even in the invalid state is not stored in the use state storage means, and the mixed state in the gas supply pipe by the period measurement means separately from the use state observation timer When a predetermined period of time to avoid an abnormal state due to occurrence has elapsed, the measurement abnormality determination means is switched to function effective, and the gas piping is not fully filled in the gas piping in an empty house state in a newly built house etc. However, a long period is set, it is homogenized during the set period, it is moved into the supply gas using gas appliances at the time of the time measurement by means of the time measuring means, and the period has passed The measurement abnormality judgment means becomes effective with a margin, and the usage status monitoring timer and the period measurement for measurement abnormality are monitored independently, so there is no problem of accidentally shutting off when returning from shipping mode, Safety monitoring can be performed reliably, accurately and safely.

  After installing the gas shut-off device of the present invention, after a gas consumer operates the gas appliance easily before moving in and checks for gas leaks, etc., the timer starts and the usage pattern is observed and the usage status is memorized. Even if the mixed state of the different gases in the gas pipe is canceled and homogenized, the function of the measurement abnormality judgment means is disabled for a long period of time, and the function is switched over with a margin after a long period of time. As a result, it is possible to monitor the abnormality of the original flow rate detection means or the measurement system as in the conventional example. It is possible to prevent erroneous interruption during the return safety confirmation by enabling the measurement abnormality determination means at an early stage.

Control block diagram of gas shutoff device in embodiment 1 of the present invention Control block diagram of gas cutoff device in embodiment 2 Control block diagram of a conventional gas shut-off device

  A first invention is a gas shut-off device that shuts off the supply of gas when an abnormality occurs, a flow rate detecting means for amplifying and detecting a flow rate signal, and a flow rate calculating means for calculating an instantaneous flow rate from a detection value of the flow rate detecting means. Average flow rate calculation means for obtaining an average flow rate from the instantaneous flow rate obtained by the flow rate calculation means, amplification degree determination means having a plurality of determination values for determining signal amplification adjusted by the flow rate detection means, and the flow rate detection means A measurement abnormality determining means for monitoring the presence or absence of an abnormality and determining a measurement abnormality when an abnormality is detected; a timer means for timing a predetermined time; and an average flow rate obtained by the average flow rate calculating means during the time counting of the timer means More usage state storage means for storing the usage state of the gas, appropriate condition changing means for changing the appropriate usage condition according to the contents of the usage state storage means, and after counting a predetermined period, A period measuring means for starting operation of the abnormality determining means, an average flow rate determined by the average flow rate calculating means, and an abnormality determining means for determining presence / absence of an abnormality in comparison with an appropriate condition set by the appropriate condition changing means; When the measurement abnormality determining means determines that a measurement abnormality has occurred, or when the abnormality determination means establishes an abnormality determination, the apparatus includes a shut-off means that shuts off the gas supply.

  Even if the gas can be supplied after the shipment mode is released or after the shipment mode is released, the measurement abnormality determination means is in the function invalid state, and the timer is started after the shipment mode is released by the starting means and invalidated while observing the use state. A predetermined period in which a flow rate value with an amplification degree greater than or equal to a predetermined value is not stored in the use state storage means even in a state, and erroneous determination or erroneous shutoff due to an abnormal state due to the mixed state occurring in the gas supply pipe is avoided by the period measuring means After the lapse of time, the measurement abnormality judgment means is switched to function effective, and even if the gas piping is not fully filled in the gas pipe in a newly built house etc., a long period is set Homogenized during the set period, moved in during the timekeeping by the timekeeping means, changed to supply gas using the gas appliance, and after the period passed Since the effect, there is no problem that be cut off when returning from accidentally shipping mode, it can be performed safely security surveillance without operators to unnecessary spending.

  According to a second aspect of the invention, in the first aspect of the invention, there is provided a retry determination means for restarting the time counting in the period time measuring means when the amplification degree of the flow rate detecting means is not less than a predetermined value after the operation of the time period measuring means is started. It is provided.

Then, when the pipe is in a mixed state due to convection while the period is being counted by the period measuring means, the retry timing determining means resets the period to start misjudgment or error due to an abnormal state caused by the mixed state in the gas supply pipe. Even if it is left in a state where the gas piping is not sufficiently filled in the gas pipe in an empty house state in a newly built house, etc., after a predetermined period of avoiding shut-off, the measurement abnormality determination means is switched to function effectively. The period is set, homogenized during the set period, moved by the timekeeping means during the timekeeping, used as a gas appliance and changed to supply gas at a stroke, and the measurement abnormality judgment means becomes effective after the period has elapsed, so it is shipped incorrectly. There is no problem of blocking when returning from the mode, and the operator can perform safety monitoring safely without unnecessary dispatch.

  The third invention is a program for causing a computer to execute all or part of the means of the shut-off device of the first or second invention.

  And since it is a program, a part or all of the gas interruption | blocking apparatus of this invention can be easily implement | achieved using a microcomputer etc. Also, program distribution and installation can be simplified by recording on a recording medium or distributing a program using a communication line.

(Embodiment 1)
FIG. 1 is a control block diagram of the gas shutoff device according to Embodiment 1 of the present invention. The same number is attached | subjected to the equivalent to FIG.

  Although not shown, the gas shut-off device is installed in the garden of each household, and after passing through this gas shut-off device, it is piped to the place where various gas appliances used in each home are installed, and gas is supplied. The The internal configuration of the gas cutoff device includes a flow path and a control device. The flow path is connected to a supply port for supplying gas to each gas appliance through the inlet side flow path from the inlet of the gas shut-off device, through the flow path at the bottom, and through the outlet side flow path.

  FIG. 1 is a control block diagram of the gas cutoff device. The flow rate detection unit 1 includes an upstream side transceiver 2, a downstream side transceiver 3, a switching unit 4, a transmission unit 5, a reception unit 6, a propagation time measurement unit 7, an amplitude determination unit 8, and an amplification degree adjustment unit 9. The upstream side transmitter / receiver 2 that transmits or receives ultrasonic waves and the downstream side transmitter / receiver 3 that also receives or transmits ultrasonic waves can be switched between transmission and reception by the switching means 4. The upstream transmitter / receiver 2 and the downstream transmitter / receiver 3 that transmit and receive ultrasonic signals are attached to face the upstream and downstream of the flow path.

  Transmitting means for outputting an ultrasonic signal is connected to the upstream-side transceiver 2 or downstream-side transceiver 3 and the switching means 4 receives the ultrasonic signal via the upstream-side transceiver 2 or downstream-side transceiver 3. Received by means 6.

  First, an ultrasonic signal is transmitted by the upstream transmitter / receiver 2 by the transmitter 5 and received by the downstream transmitter / receiver 3, and a propagation time is measured by the propagation time measuring unit 7 for the received signal from the receiver 6. Next, switching is performed by the switching means 4, and similarly, an ultrasonic signal is transmitted from downstream to upstream, and the propagation time is measured. Then, the ultrasonic wave propagation time difference between the upstream side transceiver 2 and the downstream side transceiver 3 is obtained every predetermined period (for example, every 2 seconds).

  The ultrasonic signal received by the receiving means 6 determines whether or not the signal amplitude has an appropriate magnitude by the amplitude determining means 8, but if it is too large or too small, an error is caused in the propagation time measurement, so that the appropriate magnitude is obtained. It adjusts with the amplification degree adjustment means 9 so that it may become. Then, the next receiving means 6 receives the ultrasonic signal from the transmitting means 5 with the adjusted amplification degree.

  The propagation time measured and determined for each predetermined period is converted into an instantaneous flow rate by the flow rate calculation means 10. The instantaneous flow rate is input to the average flow rate calculation means 11, and a predetermined number of instantaneous flow rates are collected and calculated as an average flow rate value. On the other hand, the amplification degree adjusting means 12 monitors the amplification degree for adjusting the amplitude level of the ultrasonic signal of the flow rate detection means 1. Usually, when the flow rate is large or the flow path through which the ultrasonic waves pass is not a homogeneous medium, the sensitivity of ultrasonic signal reception decreases, and the amplification degree tends to increase.

  The measurement abnormality determination unit 13 determines whether there is an abnormality in the flow rate detection unit 1. For example, when the amplification level of the amplification level determination unit 12 is equal to or greater than a predetermined value, it is determined that the ultrasonic reception signal is abnormally lowered for some reason. Further, in the flow rate detection means 1, when the ultrasonic signal is transmitted from the upstream side transceiver 2 and cannot be received by the downstream side transceiver 3, or the ultrasonic signal is received by the downstream side transceiver 3 and the propagation time measuring means 7 is received. If a propagation time other than the original supply gas or air is detected, it is determined that foreign gas is mixed, and it is determined that the flow rate measurement using ultrasonic waves cannot be performed correctly.

  The starting means 14 is composed of, for example, a reed switch called a test switch, and the shipping mode state is canceled when the gas company is operated by a magnet or the like and an operation signal is input. The activation means 14 may be brought into a shipping mode state by operating. Further, when the shipping mode is canceled and the return switch (not shown) is operated to return, the normal state is reached in which the gas appliance can be used after the return safety confirmation time has elapsed.

  The timer means 15 starts counting for a predetermined time when the activation signal output from the activation means 14 is input. The predetermined time may be set in advance or may be arbitrarily set, for example, a span such as one week or one month. Simultaneously with the start of operation of the timer means 15, the use state storage means 16 stores the total flow rate, the increased flow rate, and the continuous use time based on the gas usage pattern, that is, the average flow rate from the average flow rate calculation means 11. However, when the measurement abnormality determination unit 13 is in an invalid state, the flow rate is not stored in the use state storage unit 16 when the amplification level determined by the amplification level determination unit 12 described later is equal to or greater than a predetermined value. Only the flow rate measured with the degree of amplification is stored.

  The usage state storage means 16 stores and updates the maximum values of the total flow rate, the increased flow rate, and the continuous usage time of the measured gas usage patterns. When the timer means 15 finishes counting, the final data is output from the appropriate condition changing means.

  When the activation unit 14 is operated, an activation signal is also input to the period timing unit 18 for permitting the operation of the measurement abnormality determination unit 13, and the period measurement unit 18 starts timing for a predetermined period. Normally, the measurement abnormality determination means 13 is ineffective and does not activate abnormality determination. The gas shut-off device installed by the gas company is in the normal shipping mode state, is released from the shipping mode state by operating the starter 14, and when the normal gas appliance is used, the timer unit 15 and the time counting The means 18 starts counting. When the time measurement for a predetermined period is completed, the measurement abnormality determination means 13 switches to function enable and performs the presence / absence of abnormality determination regarding various measurements.

  The amplification degree determination means 12 has a large instantaneous flow rate obtained by the flow rate calculation means 10 while the measurement abnormality determination means 13 is disabled, and the amplification degree determination means shows a value greater than or equal to a predetermined value even when the gas appliance is not used. When the shipment mode is canceled, it is determined that the supply gas and other gases are sufficiently mixed in the piping, and the instantaneous flow rate at that time is not used. The measured instantaneous flow rate is adopted and output to the average flow rate calculation means 11.

  The amplification degree judging means 12 has a plurality of judgment values. For example, the upstream side transceiver 2 or the downstream side transceiver 3 can be used to determine the flow rate when dust or the like is gradually accumulated and the upstream side transceiver 2 cannot measure the flow rate. Since the ultrasonic signal cannot be received when the transmitter / receiver 3 on the downstream side is disconnected, the amplification level adjustment means 9 adjusts to increase the amplification level to obtain the maximum amplification level. In such a case, the flow rate cannot be measured. It has a judgment value for judging.

Also, even if the flow rate detection means 1 is normal, if the gas pipe is in a mixed state with a different gas such as air, the ultrasonic wave propagates between media of different densities during flow rate detection, causing refraction and reflection. Therefore, the ultrasonic signal that has reached the receiving means 6 becomes a very small level when the amplitude determining means 8 determines the level of the ultrasonic signal. Therefore, the amplification degree is increased in order to increase the signal level by the amplification degree adjusting means 9. As a result, the above-mentioned dust detection level is exceeded, and the determination value that cannot be measured may be exceeded. Although the gas appliance is originally in a stopped state, when a mixed state occurs, a high flow rate such as an appliance flow rate may be exhibited.

  Then, the abnormality determination means 19 monitors the appliances used at the obtained average flow rate or monitors whether there is an abnormality in the current flow rate detection means 1. The abnormality determining means 19 stores an initial value such as a time limit value for use time corresponding to each flow rate range of the initial set value or a monitor determination value for the maximum use flow rate. For example, when a hose that supplies gas to a gas stove or the like is disconnected for some reason, an abnormally large flow rate occurs, but the total flow cutoff value for monitoring such a condition and the maximum use of gas appliances normally used Stored is a time limit for shutting down a use time that defines a time limit for use time corresponding to a case where the use time is much longer than the time.

  By comparing and determining the set value and the average flow value by the abnormality determination means 19, the flow value does not exceed the maximum use flow value, or the use time of the gas appliance is the time limit for continuous use corresponding to the registered flow rate. Monitor whether it exceeds the limit. Further, when the timer unit 15 completes counting, the abnormality determination unit 19 compares the output value from the appropriate use condition changing unit 17 and selects the smaller cutoff determination value to reset it as the proper use condition.

  When the abnormality determining means 19 determines that an abnormality has been established, a cutoff signal is sent to the cutoff means 20 to stop the gas supply. In addition, the notification communication means 21 displays the shut-off state and shut-off content on a liquid crystal display element and the like, and notifies the center of the gas company that is monitoring the safety of the gas by communication such as a telephone line.

  Next, the operation of the gas shut-off device configured as described above will be described. The gas shut-off device is in the shipping mode when it is newly constructed or replaced by inspection. The shipping mode is canceled by the gas company before the gas customer moves in and starts using the gas appliance. That is, in the starter 14, the shipping mode state is canceled by operating a switch called a test switch, for example, and the shutoff unit 20 is returned by a return operation. After returning, the gas appliance is used to check for gas leaks. By this check, a different gas different from the supply gas such as air in the pipe is purged.

  However, in some cases, the shipping mode state has already been released from the non-occupancy stage so that the gas appliance can be used immediately. In such a case, for example, there may be a case where the gas in the pipe is not sufficiently filled with the supply gas because the air in the pipe may not be sufficiently purged by using only a gas table with a gas appliance. Become.

  When the flow rate is measured under such conditions in the pipe, the upstream side transmitter / receiver 2 and the downstream side transmitter / receiver 2 are mixed with different gases such as supply gas and air by convection as time passes. The ultrasonic wave transmitted from the device 3 or the like propagates in the mixed gas, refraction occurs, and the signal level received by the receiving means 6 becomes small.

When such a state is detected by the amplitude determination unit 8 of the flow rate detection unit 1, the amplification level adjustment unit 9 increases the amplification level so as to increase the signal level. However, since the mixed state continues, the amplification level becomes abnormal. Get higher. In addition, because of the mixed state, the amplitude of the ultrasonic signal is not stable, and the level fluctuation always occurs. In this state, the propagation time of the ultrasonic signal is measured as a detected value, and this signal is sent to the flow rate calculation means 10 and converted into an instantaneous flow rate. Since the level of the received signal between the devices 3 fluctuates and the signal propagation time constantly fluctuates, the propagation time value measured by the propagation time measuring means 7 changes even though the gas appliance is not used at all. As a result, the flow rate value obtained by the flow rate calculation means 10 varies.

  Although the gas shut-off device is generally installed in a shipping mode state, the shipping mode may be canceled and restored depending on the installation work form. Normally, the function of the measurement abnormality determination unit 13 is in an invalid state, and the timer unit 15 and the period measuring unit 18 count the timer after the start unit 14 becomes in a state in which normal supply gas can be used from the shipping mode release state. Start.

  Although the period of the period measuring means 18 can be changed by communication or the like, for example, a period of several weeks or the like is set. During the operation of the timer means 15, the use state is stored from the flow rate from the average flow rate calculation means 11. When the timer means 15 and the period measuring means 18 are in operation, an output signal of a predetermined amplification degree or more is output from the amplification degree determination means 12, and a signal in a mixed state with a gas other than the supply gas is output. The instantaneous flow rate of the flow rate calculation means 10 is not used. For example, the instantaneous flow rate measured with the amplification level in the normal state before the output signal of the amplification degree determination means 12 is determined to be abnormal is used and output to the average flow rate calculation means 11. . In other words, the flow rate when the amplification degree determination means 12 determines that there is an abnormality is not stored in the use state storage means 16.

  When the timer means 15 completes counting, a new cutoff judgment value (total flow cutoff, increased flow cutoff or usage time cutoff judgment value) is supplied to the abnormality judgment means 19 by the appropriate usage condition changing means 17 from the stored value in the usage state storage means 16. Is output. On the other hand, when the predetermined period is measured by the period measuring means 18, the function of the measurement abnormality determining means 13 is switched to valid. That is, when a gas customer moves in during this predetermined period, the inside of the supply pipe is sufficiently purged with the supply gas and switched to the supply gas while the measurement abnormality determination means 13 is disabled by using the gas appliance. The measurement abnormality judgment function is switched from disabled to enabled in the status. Therefore, the mixed state with other gases is eliminated, and abnormal flow measurement in the mixed state does not occur.

  After the measurement abnormality determination means 13 becomes effective, when the amplification degree determination means 12 becomes a predetermined level or more, the upstream transmitter / receiver 2 or the downstream transmitter / receiver 3 is deteriorated over time or cannot be normally measured due to dust or the like. There is a high possibility that the road is in a road condition. Therefore, when such a state is detected by the measurement abnormality determination means 13, a signal is output to the abnormality determination means 19, and when the abnormality determination means 19 determines that an abnormality has been established, a cutoff signal is sent to the cutoff means 20 to stop the gas supply. .

  In addition, the notification communication means 21 displays the shut-off state and shut-off content on a liquid crystal display element and the like, and notifies the center of the gas company that is monitoring the safety of the gas by communication such as a telephone line. The gas company can immediately take countermeasures such as replacing the gas shut-off device, and can quickly avoid abnormal conditions.

  On the other hand, the average flow rate calculation means 11 calculates the instantaneous flow rate obtained by the flow rate calculation means 10 as an average flow rate value for each predetermined number. The abnormality determination means 19 stores a time limit value for use time corresponding to each flow rate region, a monitor determination value for the maximum use flow rate, or the like. For example, when a hose that supplies gas to a gas stove or the like is disconnected for some reason, an abnormally large flow rate occurs.To monitor such a condition, the total flow cutoff value or the Stored is a time limit for use time interruption that defines a time limit for use time corresponding to a case where the use time is much longer than the maximum use time for normal use.

When the timer unit 15 completes the counting, the abnormality determination unit 19 compares the new cutoff determination value output from the proper use condition changing unit 17 with the initial set value, and adopts the smaller set value as the new cutoff determination value. . By comparing and determining the shutoff determination value and the average flow rate value by the abnormality determination means 19, the flow rate value does not exceed the maximum use flow rate value or the usage time of the gas appliance is limited to the continuous use corresponding to the registered flow rate. It monitors whether the time is exceeded or not, and outputs a cut-off signal when it exceeds.

  In the present embodiment, when the measurement time determining means 13 of the measurement abnormality determining means 13 and the timer means 15 for obtaining appropriate use conditions operate independently, the gas consumer is not moved in. Since the timer unit 15 starts to operate after the activation unit 14 is operated, the usage pattern observation is started and stored in the usage state storage unit 16. Therefore, even if an abnormal gain is detected due to the mixed state of the supply gas and air, and an abnormal flow rate is detected, only the flow rate measured with the normal gain remains and the abnormal flow rate value is not used. When the means 15 completes the counting, the proper use condition changing means 17 can prevent an abnormal cutoff judgment value from being set.

  Further, even if the non-occupancy continues and the timer means 15 is completed during that period, the period measuring means 18 sets the period until the mixed state in the supply pipe is switched to a homogeneous state by convection. Since the measurement abnormality determination means 13 is switched from invalid to effective, the measurement abnormality is not erroneously determined. Piping conditions and piping conditions differ depending on each gas customer, and once the supply gas and other gases are mixed, an abnormal amplification state appears due to temperature, but it is used to determine the cutoff value. Since the timer means 15 which is a pattern observation timer and the period measuring means 18 for determining the mixed state cancellation are independent, the measurement abnormality determining means 13 may be erroneously enabled at an early stage, leading to erroneous interruption or erroneous determination. Absent.

  Note that the configuration used in the present embodiment is an example, and the usage pattern is not limited to the present embodiment.

  As described above, the measurement abnormality determination means 13 of the gas cutoff device is in a function invalid state regardless of the presence or absence of gas mixing in the supply pipe, and the timer means 15 is a timer for obtaining appropriate conditions for various cutoff judgment values. When a predetermined period by the period measuring means 18 in which a period until the mixed state is canceled and becomes a homogeneous gas state has elapsed, the measurement abnormality determining means 13 becomes functional, and the function of the flow rate detecting means 1 is normal. It is possible to prevent the flow rate detection means 1 from erroneously measuring the flow rate under the mixed gas, erroneously judging that the flow rate detection means 1 is abnormal, and erroneously shutting off. In addition, since the gas shut-off device operates normally, the safety and reliability are extremely high, and there is an effect that the gas business operator is not required to be activated due to erroneous shut-off and is highly usable.

(Embodiment 2)
FIG. 2 is a control block diagram of the gas cutoff device according to Embodiment 2 of the present invention. The same number is attached | subjected to the equivalent to FIG.1 and FIG.3.

  FIG. 2 is a control block diagram of the shut-off device. The retry determination unit 22 is input when the amplification level determination unit 12 that monitors the signal level of the ultrasonic signal of the flow rate detection unit 1 has reached an amplification level equal to or greater than a predetermined value after the period measurement unit 18 is activated. Then, the timer means 15 for observing the usage pattern determines that an abnormal mixed state has occurred even though the counting is proceeding, and starts the time counting of the period measuring means 18 to zero. That is, after the shipment mode is released, it is determined that the air purge in the supply gas piping is not sufficient and is in a mixed state with a different gas other than the supply gas, and the function validity switching of the measurement abnormality determination means 13 is further delayed.

Next, the operation of the gas shut-off device configured as described above will be described. The gas shut-off device is in the shipping mode when it is newly constructed or replaced by inspection. The shipping mode is canceled by the gas company before the gas customer moves in and starts using the gas appliance. That is, the shipping unit state is canceled by the operation of a switch called a test switch, for example, by the starting unit 14, and the blocking unit 20 is returned by the return operation. After returning, the gas appliance is used to check for gas leaks. By this check, a different gas different from the supply gas such as air in the pipe is purged.

  However, in some cases, the shipping mode state has already been released from the non-occupancy stage so that the gas appliance can be used immediately. In such a case, for example, there may be a case where a gas appliance having only a gas table is used and the ignition in the pipe is not sufficiently purged and the air is not sufficiently purged, and the gas pipe is not sufficiently filled with the supply gas.

  When the flow rate is measured under such conditions in the pipe, the upstream side transmitter / receiver 2 and the downstream side transmitter / receiver 2 are mixed with different gases such as supply gas and air by convection as time passes. The ultrasonic wave transmitted from the device 3 or the like propagates in the mixed gas, refraction occurs, and the signal level received by the receiving means 6 becomes small. When such a state is detected by the amplitude determination unit 8 of the flow rate detection unit 1, the amplification level adjustment unit 9 increases the amplification level so as to increase the signal level. However, since the mixed state continues, the amplification level becomes abnormal. Get higher.

  In addition, because of the mixed state, the amplitude of the ultrasonic signal is not stable, and level fluctuations always occur. In this state, the propagation time of the ultrasonic signal is measured as a detected value, and this signal is sent to the flow rate calculation means 10 and converted into an instantaneous flow rate. Since the level of the received signal between the devices 3 fluctuates and the signal propagation time constantly fluctuates, the propagation time value measured by the propagation time measuring means 7 changes even though the gas appliance is not used at all. As a result, the flow rate value obtained by the flow rate calculation means 10 varies.

  Although the gas shut-off device is generally installed in a shipping mode state, the shipping mode may be canceled and restored depending on the installation work form. Usually, the function of the measurement abnormality determination means 13 is in an invalid state. The timer means 15 and the period measuring means 18 start the timer counting after the starting means 14 makes it possible to use normal supply gas from the shipping mode release state. Although the period of the period measuring means 18 can be changed by communication or the like, for example, a period of several weeks or the like is set. During the operation of the timer means 15, the use state is stored from the flow rate from the average flow rate calculation means 11.

  When an output signal of a predetermined amplification level or higher is output from the amplification level determination unit 12 while the timer unit 15 or the period measuring unit 18 is in operation, a signal in a mixed state with a gas other than the supply gas is output. The instantaneous flow rate of the flow rate calculation means 10 at that time is not used, for example, the instantaneous flow rate measured with the amplification degree in the normal state before the output signal of the amplification degree determination means 12 is determined to be abnormal is used. Output. The flow rate when the amplification degree determination means 12 determines that the above is not stored in the use state storage means 16.

  When the timer means 15 completes counting, a new cutoff judgment value (total flow cutoff, increased flow cutoff or usage time cutoff judgment value) is supplied to the abnormality judgment means 19 by the appropriate usage condition changing means 17 from the stored value in the usage state storage means 16. Is output.

On the other hand, when the passage of the predetermined period is timed by the time keeping means 18, the function of the measurement abnormality determining means 13 is effectively switched. In other words, if a gas customer moves in during this predetermined period, the use of gas appliances causes the supply piping to be sufficiently purged with supply gas during the invalid period, and the measurement abnormality determination function is disabled when the supply gas is switched. To switch to valid. The mixed state with other gases is eliminated, and abnormal flow measurement in the mixed state does not occur. After that, when the amplification degree determination means 12 is equal to or higher than a predetermined level, there is a high possibility that the upstream transmitter / receiver 2 or the downstream transmitter / receiver 3 has deteriorated over time or has become a flow path state in which normal measurement is difficult due to dust or the like. . Therefore, when such a state is detected by the measurement abnormality determination means 13, a signal is output to the abnormality determination means 19, and when the abnormality determination means 19 determines that an abnormality has been established, a cutoff signal is sent to the cutoff means 20 to stop the gas supply. .

  In addition, the notification communication means 21 displays the shut-off state and shut-off content on a liquid crystal display element and the like, and notifies the center of the gas company that is monitoring the safety of the gas by communication such as a telephone line. The gas company can immediately take countermeasures such as replacing the gas shut-off device, and can quickly avoid abnormal conditions.

  On the other hand, the average flow rate calculation means 11 calculates the instantaneous flow rate obtained by the flow rate calculation means 10 as an average flow rate value for each predetermined number. As for the obtained average flow rate, the abnormality determining means 19 stores a time limit value for use time corresponding to each flow rate region, a monitor determination value for the maximum use flow rate, or the like. For example, when a hose that supplies gas to a gas stove or the like is disconnected for some reason, an abnormally large flow rate occurs.To monitor such a condition, the total flow cutoff value or the Stored is a time limit for use time interruption that defines a time limit for use time corresponding to a case where the use time is much longer than the maximum use time for normal use.

  When the timer means 15 completes counting, the appropriate use condition changing means 17 compares the new set value with the initial set value, and the smaller set value is adopted as the new set value. By comparing and determining the set value and the average flow value by the abnormality determination means 19, the flow value does not exceed the maximum use flow value, or the use time of the gas appliance is the time limit for continuous use corresponding to the registered flow rate. Is monitored, and if it exceeds, a shutoff signal is output.

  The period measuring means 18 for switching functions of the measurement abnormality determining means 13 and the timer means 15 for obtaining appropriate use conditions are operated independently, and the starting means 14 is operated when the gas consumer is not moved in. Thereafter, since the timer unit 15 starts to operate, observation of the use pattern is started and stored in the use state storage unit 16. Even if an abnormal amplification degree and an abnormal flow rate are detected depending on the mixed state of the supply gas and air, only the flow rate measured with the normal amplification degree remains, and the abnormal flow rate value is not used. However, when the count is completed, the proper use condition changing means 17 can prevent an abnormal cutoff judgment value from being set.

  Furthermore, even if the occupancy continues and the timer means 15 is completed during that period, the predetermined period counted by the period timing means 18 is a sufficient period until the mixed state in the supply pipe is switched to a homogeneous state by convection. It is set, and after that period, the measurement abnormality determining means 13 is switched from invalid to valid, so that it is not erroneously determined as a measurement abnormality. That is, the piping state and piping conditions differ depending on each gas customer, and once the supply gas and other gas are mixed, an abnormal amplification state appears due to convection due to temperature. Since the period of mixed state elimination independent of the timer means 15 for observing the usage pattern for determining the cutoff value is set as the period for timing, the erroneous measurement cutoff judgment means 13 is erroneously enabled early. And never misjudged.

  Then, after the timer unit 15 starts counting, when an output signal having an abnormal amplification level is received from the amplification level determination unit 12, it is determined that the piping is in a mixed state with a different gas other than the supply gas, and a retry determination is made. The count of the period measuring means 18 is once reset by means 22 and time is again measured. Therefore, it is determined by the timer means 15 that a gas consumer has moved in and the gas appliance has been used, and the abnormal mixing state has not been eliminated, so that the mixing state is released and the gas is changed to a completely homogeneous gas by convection. To extend the period to do.

  Note that the configuration used in the present embodiment is an example, and the usage pattern is not limited to the present embodiment.

As described above, the measurement abnormality determining means 13 of the gas shut-off device is in a function invalid state regardless of the presence or absence of gas mixing in the supply pipe, and is mixed separately from the timer for obtaining appropriate conditions for various shut-off determination values. Whether the measurement abnormality determining means 13 is enabled and the function of the flow rate detecting means 1 is operating normally when a predetermined period of time is set by the period counting means 18 in which the period until the state is eliminated and the gas state becomes homogeneous is set. Whether or not can be monitored.

  Therefore, the flow rate detection means 1 can erroneously measure the flow rate under the mixed gas, erroneously determine that there is an abnormality in the flow rate detection means 1 and prevent erroneous interruption, and operate the gas cutoff device normally. Safety and reliability are extremely high, and there is an effect that it is easy to use without causing the gas company to unnecessarily be dispatched due to erroneous interruption.

  As described above, the gas shutoff device according to the present invention is for preventing measurement abnormality due to different gas in the supply pipe at the time of installation, and can be applied to all flow measuring devices such as water meters. is there.

DESCRIPTION OF SYMBOLS 1 Flow rate detection means 10 Flow rate calculation means 11 Average flow rate calculation means 12 Amplification degree determination means 13 Measurement abnormality determination means 15 Timer means 16 Usage state storage means 17 Appropriate use condition change means 18 Period measurement means 19 Abnormality determination means 20 Blocking means 22 Retry Judgment means

Claims (3)

A gas shut-off device that shuts off the gas supply when an abnormality occurs,
A flow rate detecting means for amplifying and detecting a flow rate signal;
A flow rate calculation means for calculating an instantaneous flow rate from a detection value of the flow rate detection means;
Average flow rate calculating means for obtaining an average flow rate from the instantaneous flow rate obtained by the flow rate calculating means;
Amplification degree determination means having a plurality of determination values for determining signal amplification adjusted by the flow rate detection means,
A measurement abnormality determination unit that monitors the presence or absence of abnormality of the flow rate detection unit and determines a measurement abnormality when an abnormality is detected;
Timer means for measuring a predetermined time;
During the time counting of the timer means, a usage state storage means for storing the usage state of the gas from the average flow rate obtained by the average flow rate calculation means,
Appropriate condition changing means for changing appropriate use conditions according to the contents of the use state storage means;
A period timing means for starting the measurement abnormality determining means after timing a predetermined period; and
An abnormality determination unit that determines the presence or absence of an abnormality by comparing the average flow rate obtained by the average flow rate calculation unit with the appropriate condition set by the appropriate condition change unit;
When the measurement abnormality determining means determines that the measurement abnormality is present, or when the abnormality determination means establishes the abnormality determination, a shut-off means that shuts off the gas supply,
Gas shut-off device with 2. The gas shut-off device according to claim 1, further comprising a retry determination unit that restarts the time measurement in the period time measuring unit when the amplification degree of the flow rate detecting unit is equal to or greater than a predetermined value after the operation of the period time measuring unit is started. A program for causing a computer to function as all or part of means of the shut-off device according to claim 1.

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