REMOTE SYSTEM FOR DETECTING LEAKAGE OF GAS USING ANALYSIS OF GAS USAGE PATTERN
Technical Field The present invention relates to a remote system for detecting leakage of gas provided to a home or a business place (hereinafter, referred to as a consuming house) and informing a user of the gas leakage, and more particularly, to a remote system for remotely monitoring gas usage from a gas meter and detecting whether gas leaks.
Background Art
For human lives and actions in a home or business place, various resources such as electricity, gas, water, and hot water are needed. In particular, liquefied natural gas (LNG) is widely used for heating and cooking. LNG is natural gas that has been condensed into a liquid. The primary component of natural gas is methane. It may also contain paraffin hydrocarbon such as ethane. 1 kg methane has a volume of about 1.4 m3 in a gas state in an atmospheric pressure of 1 bar at 00C. When the 1 kg methane is cooled down to -162°C, the methane is liquefied and has a volume of 0.0024 m3. In other words, when methane is liquefied, its volume is reduced to about 1/600. Accordingly, natural gas is provided to each consuming house in a liquid state.
A company providing LNG to a consuming house installs a gas meter for measuring the amount of gas provided to the consuming house and charges the consuming house for the use of gas according to a figure measured by the gas meter. When the company has many consuming houses, it is not proper that a person (i.e., a meterman) reads gas meters one by one to charge each consuming house for the use of gas because of labor costs or inaccuracy in reading. To overcome this problem, many remote meter reading systems have been proposed.
Meanwhile, when gas provided to each consuming house is not normally used but leaks due to troubles in a boiler or gas range or a breakage in a pipe, even a small spark generated by the operation of an electrical switch may cause a big fire. Accordingly, a device such as a gas sensor, which generates an alarm sound when gas leaking without combustion is sensed so that a user in a consuming house can know gas leakage, has been developed. However, to install such gas sensor, it costs separately. In addition, when nobody is present in the consuming house for a long time, an appropriate management cannot be performed.
Disclosure of the Invention
The present invention provides a remote system for detecting leakage of gas using analysis of a gas usage pattern, which uses an existing remote gas meter reading system, thereby reducing additional installation costs, and informs a user of gas leakage through a call center system and/or remotely interrupts the supply of gas when the leakage of gas is determined based on a result of comparing a normal gas usage pattern with a current gas usage pattern, thereby preventing an accident.
According to an aspect of the present invention, there is provided a remote system for detecting leakage of gas using analysis of a gas usage pattern. The remote system includes a gas meter installed in a consuming house to measure a gas usage; a remote meter reader receiving metric information from the gas meter, generating and storing meter read information in each predetermined time slot in a memory, comparing a gas usage in a current time slot with an average gas usage in the same time slot, determines whether gas is leaking, and transmitting the meter read information and gas leakage information to a remote meter reading server; a wired/wireless communication network transmitting information between the remote meter reader and the remote meter reading server; a remote meter reading server which is connected with the remote meter reader through the wired/wireless
communication network, manages meter read information for each consuming house, and generates a report request message including corresponding consuming house information in response to gas leakage information; and a call center system receiving the report request message from the remote meter reading server, calling one or more telephone numbers included in the consuming house information, and delivering an alarming message in voice.
The remote system may further include a gas circuit breaker which is installed at a gas supply pipe to each consuming house. The gas circuit breaker receives a gas-cutoff signal from the remote meter reader and blocks the gas pipe to stop supply of gas to the consuming house. When a gas-cutoff command is received through the call center system, the remote meter reading server transmits the gas-cutoff command to the remote meter reader. In response to the gas-cutoff command, the remote meter reader generates a gas-cutoff signal for controlling the gas circuit breaker.
The remote meter reading server may calculate an average gas usage in each predetermined time slot during a predetermined period while managing the meter read information for each consuming house and may periodically download the average gas usage to the remote meter reader.
The gas meter may include a plurality of digit wheels showing a gas usage and a sensor generating a sensing signal when a magnet attached to a predetermined region of one digit wheel among the plurality of digit wheels approaches the sensor by rotation of the digit wheel. The remote meter reader receives the sensing signal from the sensor as the metric information and generates the meter read information by digitizing the sensing signal.
The remote meter reader may generate a message indicating erroneous meter reading when a difference between a time of generation of a current sensing signal and a time of generation of a previous sensing
signal is less than a predetermined minimum pulse generation time and may transmit the message to the remote meter reading server.
The remote system may further include two pulse connection lines for transmitting the sensing signal and one or two monitoring lines for checking breaking down of either of the pulse connection lines. The two pulse connection lines and the one or two monitoring lines are connected between the gas meter and the remote meter reader. When the breaking down of either of the pulse connection line is confirmed, the remote meter reader generates a message indicating the breaking down and transmits the message to the remote meter reading server.
Brief Description of the Drawings
FIG. 1 illustrates a remote system for detecting leakage of gas according to an embodiment of the present invention. FIG. 2 illustrates connection between a gas meter and a remote meter reader, which are included in the remote system according to the embodiment illustrated in FIG. 1.
FIG. 3 illustrates a pulse connection line and a monitoring line between the gas meter and the remote meter reader, which are included in the remote system according to the embodiment illustrated in FIG. 1.
FIG. 4 illustrates a remote meter reader embedded in a gas meter and a gas circuit breaker controlled by the remote meter reader, according to an embodiment of the present invention.
FIG. 5 is a graph illustrating the relation between an average gas usage in each time slot and a portion of a gas usage on a certain day which is different from the average gas usage.
Best mode for carrying out the Invention
Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.
Referring to FIG. 1 , a remote system 1 for detecting leakage of gas according to a first embodiment of the present invention includes a gas meter 10, a remote meter reader 20, a wired/wireless communication network 30, a remote meter reading server 40, and a call center system 50.
The gas meter 10 is installed in a consuming house and measures usage of gas provided to the consuming house. Referring to FIG. 2, the gas meter 10 includes a plurality of digit wheels 110 showing a gas usage outside. In the first embodiment of the present invention, the gas meter 10 expresses a number with four digits to the left of the decimal point and three digits to the right of the decimal point. A magnet 110b is attached near a region to which "0" is written in a digit wheel 110a corresponding to the third decimal place among the seven digit wheels 110. A sensor 120 is installed in a predetermined area close to the digit wheel 110a. When the digit wheel 110a rotates and the magnet 110b attached to the digit wheel 110a approaches the sensor 120, the sensor 120 generates a sensing signal. The sensor 120 may be implemented as a reed switch that is turned ON and OFF according to the approach and withdrawal of the magnet 110b attached to the digit wheel 110a and generates a pulse signal.
The remote meter reader 20 receives as metric information the sensing signal from the sensor 120 included in the gas meter 10 and generates meter read information by digitizing the sensing signal. The remote meter reader 20 may be installed inside or outside a housing of the gas meter 10. The remote meter reader 20 includes a power supply 210, a memory 230, a processor 220, and a transceiver 240. The power supply 210 supplies electric power to each element of the remote meter reader 20. Since it is necessary to continuously recognize the sensing signal received from the gas meter 10 even in case of power failure, it is preferable that the power supply 210 includes a battery. Accordingly, the power supply 210 supplies electric power from a power
supply circuit in a normal state and electric power from the battery in case of power failure. The processor 220 may be implemented using a microprocessor and firmware. The processor 220 receives the sensing signal from the gas meter 10, generates meter read information in a predetermined time slot, and stores the meter read information in the memory 230. In addition, the processor 220 compares a gas usage in a current time slot with a gas usage pattern in the same time slot and determines whether gas is leaking. The gas usage pattern is an average gas usage in each time slot and is generated using a usage pattern algorithm provided in the processor 220. The transceiver 240 transmits the meter read information stored in the memory 230 to the remote meter reading server 40 at a predetermined instant of time or at the request of the remote meter reading server 40. In addition, when the processor 220 generates gas leakage information, the transceiver 240 immediately transmits the gas leakage information to the remote meter reading server 40.
The processor 220 included in the remote meter reader 20 receives the sensing signal from the gas meter 10 and generates a message indicating erroneous meter reading when a difference between a time of generation of a current sensing signal and a time of generation of a previous sensing signal is less than a predetermined minimum pulse generation time stored in the memory 230. The message indicating erroneous meter reading is transmitted by the transceiver 240 included in the remote meter reader 20 to the remote meter reading server 40. Referring to FIG. 3, two pulse connection lines 150a and 150b for transmitting a sensing signal and one or two monitoring lines 160 for checking the breaking down of the pulse connection lines 150a and 150b are connected between the gas meter 10 and the remote meter reader 20. When the breaking down of the pulse connection line 150a or 150b is confirmed, the processor 220 included in the remote meter reader 20 generates a message indicating the breaking down and the transceiver
240 included in the remote meter reader 20 transmits the message to the remote meter reading server 40.
The wired/wireless communication network 30 transmits information between the remote meter reader 20 and remote meter reading server 40. The wired/wireless communication network 30 may be implemented as a ZigBee network, a code-division multiple access (CDMA) network, a global system for mobile communication (GSM) network, a digital subscriber line (DSL) network, a wide area network (WAN), Internet, or a combination thereof. The remote meter reading server 40 is connected with the remote meter reader 20 through the wired/wireless communication network 30 and manages meter read information received from the remote meter reader 20 for each consuming house. When the remote meter reading server 40 receives gas leakage information from the remote meter reader 20, it generates a report request message including corresponding consuming house information and transmits the report request message to the call center system 50.
The call center system 50 receives the report request message from the remote meter reading server 40, sequentially calls one or more telephone numbers (e.g., a home phone number, a resident's mobile phone number, and the resident's office phone number) included in consuming house information, and delivers an alarming message in voice. In other words, when the call is not answered within a predetermined period of time when the call center system 50 calls the home phone number, the call center system 50 calls the mobile phone number and then calls the office phone number. In addition, the call center system 50 repeats calling in order predetermined number of times until the call is answered.
Meanwhile, the remote system 1 for detecting leakage of gas according to the first embodiment of the present invention may further include a gas circuit breaker 60 installed at a gas supply pipe 70, as
illustrated in FIG. 4. The gas circuit breaker 60 receives a gas-cutoff signal from the remote meter reader 20 (which is embedded in a gas meter in FIG. 4) and blocks the gas supply pipe 70 to stop the supply of gas to a consuming house. Here, the call center system 50 transmits the alarming message to a user and receives confirmation on remote gas-cutoff from the user. When the call center system 50 receives a gas-cutoff command from the user, the call center system 50 transmits the gas-cutoff command to the remote meter reader 20 through the remote meter reading server 40 and the wired/wireless communication network 30. In response to the gas-cutoff command, the remote meter reader 20 generates the gas-cutoff signal to control the gas circuit breaker 60.
The appearance of a remote system for detecting leakage of gas according to a second embodiment of the present invention is the same as that according to the first embodiment of the present invention. However, according to the first embodiment of the present invention, the remote meter reader 20 receives a sensing signal, generates and stores meter read information in each time slot in the memory 230, generates a gas usage pattern using a usage pattern algorithm provided therein based on accumulated meter read information, compares the gas usage pattern with a current gas usage, and determines whether gas is leaking. Accordingly, the processor 220 included in the remote meter reader 20 must have sufficient performance to periodically calculate the gas usage pattern. Unlikely, according to the second embodiment of the present invention, a remote meter reader is not provided with the usage pattern algorithm that periodically generates the gas usage pattern but periodically downloads a gas usage pattern from a remote meter reading server and stores/manages it in a memory. In addition, the remote meter reading server manages meter read information for each consuming house, which is received from the remote meter reader. The
remote meter reading server is provided with the usage pattern algorithm, which generates a gas usage pattern (e.g., an average gas usage in each time slot) based on accumulated meter read information. The remote meter reading server periodically downloads the gas usage pattern to the corresponding remote meter reader.
As described above, the second embodiment is the same as the first embodiment, with the exception of the functions of the remote meter reader and the remote meter reading server, and thus redundant descriptions of other elements of the remote system according to the second embodiment of the present invention will be omitted.
Hereinafter, the operations of the remote system 1 for detecting leakage of gas according to the first embodiment of the present invention will be described in detail.
When a user uses gas supplied to a consuming house in which the user resides, the digit wheels 110 of the gas meter 10 rotates in proportion to usage. Then, the sensor 120 included in the gas meter 10 generates a sensing signal in response to the approach of the magnet 110b attached to the digit wheel 110a. The remote meter reader 20 receives the sensing signal from the sensor 120 included in the gas meter 10, digitizes the sensing signal, generates meter read information in each predetermined time slot, and stores the meter read information in the memory 230.
The remote meter reader 20 receives the sensing signal from the gas meter 10, generates a message indicating erroneous meter reading when a difference between a time of generation of the current sensing signal and a time of generation of a previous sensing signal is less than a predetermined minimum pulse generation time stored in the memory 230, and transmits the message to the remote meter reading server 40. When the breaking down of the pulse connection line 150a or 150b is confirmed, the remote meter reader 20 generates a message indicating
the breaking down and transmits the message to the remote meter reading server 40.
The following describes the minimum pulse generation time in detail. A particular class is given to the gas meter 10 according to gas usage. For example, the gas meter 10 belonging to the first class has a maximum gas flow of 1 m3 per hour. The gas meter 10 belonging to the second class has a maximum gas flow of 2 m3 per hour. The gas meter 10 belonging to the third class has a maximum gas flow of 3 m3 per hour. The gas meter 10 belonging to the seventh class has a maximum gas flow of 7 m3 per hour. When the gas meter 10 belongs to the first class and has three digit wheels to the right of the decimal point, since a ratio of rotation speed of a digit wheel to rotation speed of an immediate left digit wheel is 10 to 1 , a digit wheel corresponding to a second decimal place cannot rotate more than 10 times per hour. In addition, whenever the magnet 110b attached to the digit wheel 110a corresponding to the third decimal place makes one rotation, one pulse is generated. Accordingly, a minimum time for one pulse is 36 seconds, which is stored in the memory 230 as the minimum pulse generation time for the first-class gas meter 10. The remote meter reader 20 compares a current gas usage with a gas usage pattern that has been calculated using the usage pattern algorithm provided therein and determines whether gas is leaking. Referring to FIG. 5, an average gas usage is denoted by a bold solid line. A portion of gas usage on a day, which is different from the average gas usage, is denoted by a bold dotted line and is estimated as corresponding to leaking gas. The remote meter reader 20 immediately transmits gas leakage information to the remote meter reading server 40.
Thereafter, in response to the gas leakage information, the remote meter reading server 40, which manages the meter read information received through the wired/wireless communication network 30 for each consuming house, generates a report request message including
corresponding consuming house information and transmits the report request message to the call center system 50. In response to the report request message from the remote meter reading server 40, the call center system 50 calls one or more telephone numbers included in the consuming house information and delivers an alarming message in voice.
Here, the call center system 50 transmits the alarming message to the user and receives confirmation on remote gas-cutoff from the user. When the call center system 50 receives a gas-cutoff command from the user, the call center system 50 transmits the gas-cutoff command to the remote meter reader 20 through the remote meter reading server 40 and the wired/wireless communication network 30. In response to the gas-cutoff command, the remote meter reader 20 generates the gas-cutoff signal to control the gas circuit breaker 60. In response to the gas-cutoff signal from the remote meter reader 20, the gas circuit breaker 60 blocks the gas supply pipe 70 to stop gas supply to the consuming house. The gas circuit breaker 60 and the gas-cutoff command corresponding thereto may be independently implemented between different gas devices (e.g., a gas range and a gas boiler) used in the consuming house.
Hereinafter, the operations of the remote system for detecting leakage of gas according to the second embodiment of the present invention will be described. For clarity of the description, the same reference numerals are used for the same elements in the first and second embodiments of the present invention.
When a user uses gas supplied to a consuming house in which the user resides, the digit wheels 110 of the gas meter 10 rotates in proportion to usage. Then, the sensor 120 included in the gas meter 10 generates a sensing signal in response to the approach of the magnet 110b attached to the digit wheel 110a. The remote meter reader 20 receives the sensing signal from the sensor 120 included in the gas
meter 10, digitizes the sensing signal, generates meter read information in each predetermined time slot, and stores the meter read information in the memory 230.
The remote meter reader 20 receives the sensing signal from the gas meter 10, generates a message indicating erroneous meter reading when a difference between a time of generation of the current sensing signal and a time of generation of a previous sensing signal is less than a predetermined minimum pulse generation time stored in the memory 230, and transmits the message to the remote meter reading server 40. When the breaking down of the pulse connection line 150a or 150b is confirmed, the remote meter reader 20 generates a message indicating the breaking down and transmits the message to the remote meter reading server 40.
When erroneous meter reading or the breaking down of the pulse connection line 150a or 150b does not occur, the remote meter reader 20 transmits the meter read information stored in the memory 230 to the remote meter reading server 40 at a predetermined instant of time or at the request of the remote meter reading server 40.
The remote meter reading server 40 manages the meter read information, which is received through the wired/wireless communication network 30, for each consuming house. The remote meter reading server 40 is provided with a usage pattern algorithm, which generates a gas usage pattern based on accumulated meter read information. The remote meter reading server 40 periodically downloads the gas usage pattern to the corresponding remote meter reader 20 so that the gas usage pattern is stored and managed in the memory 230.
The remote meter reader 20 compares a current gas usage with the gas usage pattern that has been downloaded from the remote meter reading server 40 and stored in the memory 230 and determines whether gas is leaking. The remote meter reader 20 generates and transmits gas leakage information to the remote meter reading server 40.
In response to the gas leakage information, the remote meter reading server 40 generates a report request message including corresponding consuming house information and transmits the report request message to the call center system 50. In response to the report request message from the remote meter reading server 40, the call center system 50 calls one or more telephone numbers included in the consuming house information and delivers an alarming message in voice.
Here, the call center system 50 transmits the alarming message to the user and receives confirmation on remote gas-cutoff from the user. When the call center system 50 receives a gas-cutoff command from the user, the call center system 50 transmits the gas-cutoff command to the remote meter reader 20 through the remote meter reading server 40 and the wired/wireless communication network 30. In response to the gas-cutoff command, the remote meter reader 20 generates the gas-cutoff signal to control the gas circuit breaker 60. In response to the gas-cutoff signal from the remote meter reader 20, the gas circuit breaker 60 blocks the gas supply pipe 70 to stop gas supply to the consuming house. While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes may be made therein without departing from the scope of the invention. Therefore, the above-described embodiments will be considered not in restrictive sense but in descriptive sense only. The scope of the invention will be defined not by the above description but by the appended claims, and it will be construed that all differences made within the scope defined by the claims are included in the present invention.
Industrial Applicability
According to the present invention, since an existing remote gas meter reading system is used, not only an accident due to leakage of gas is prevented but also additional installation costs can be reduced. Moreover, the present invention reports gas leakage to a person concerned even when nobody resides in a consuming house and can automatically cut off the supply of gas at a remote place at the request of the person concerned.