Gas shutoff device

• US 8,386,084 B2
• Filed: 03/07/2008
• Issued: 02/26/2013
• Est. Priority Date: 07/12/2007
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Koba, Yasuo, Ueki, Kouichi, Asano, Kazutaka, Ootani, Takuhisa
• Primary Examiner(s): Ali, Mohammad
• Assistant Examiner(s): WHITTINGTON, ANTHONY T
• Application Number:
  US12/668,754
• Publication Number:
  US 20100170582A1
• Time in Patent Office: 1,817 Days
• Field of Search: 700/282, 702/45, 137/382, 604/540
• US Class Current: 700/282
• CPC Class Codes: F23K 2400/201 Control devices
• CPC Class Codes: F23K 2900/05001 Control or safety devices in gaseous or liquid fuel supply lines
• CPC Class Codes: F23K 5/005 from a central source to a plurality of burners
• CPC Class Codes: Y10T 137/7062 Valve guards
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve

Abstract

An object is to prevent a mistaken shutoff caused by the mistaken registration of an appliance of which an amount of gas used changes. An individual flow registration maintenance unit maintains a registered flow rate deleted due to an increase/decrease in flow rate, again, performs determination on the flow rate maintained when a new flow rate is registered or a flow rate added with the maintained flow rate, and in the case where it is regarded to be the same, re-register the maintained flow rate.

Claims

1. A gas shutoff device for monitoring use statuses of a plurality of gas appliances connected to a pipe provided by being passed through a gas meter, and shutting the supply of gas when an error occurs, comprising:

a flow measurement unit for measuring an amount of gas passing through;

an individual appliance calculation unit for calculating a change in individual flow rate of an appliance among the plurality of gas appliances based on a flow signal of the flow measurement unit and outputting the calculated change in individual flow rate of the appliance;

an individual appliance registration maintenance unit for outputting a maximum individual flow signal output from the individual appliance calculation unit;

an abnormal flow determination unit for determining an abnormal flow rate from the individual appliance registration maintenance unit; and

a notification unit for giving a warning notification of an error upon receiving an error signal from the abnormal flow determination unit or a shutoff unit for shutting a gas passageway,

wherein the individual appliance registration maintenance unit includes a registration unit and a maintenance unit, wherein the individual appliance registration maintenance unit registers flow rates in the registration unit when an individual calculation flow rate output from the individual appliance calculation unit is an increased flow rate, and deletes an individual calculation flow rate that is regarded as the same after being compared with the registration flow rates from the registration unit and at the same time, registers the deleted flow rates in the maintenance unit when the individual calculation flow rate output from the individual appliance calculation unit is a decreased flow rate.

2. A program stored on a non-transitory memory for causing a computer to function as all or parts of the units of the shutoff device according to claim 1.

3. A gas shutoff device comprising:

a flow detection unit for measuring a flow rate in a passage;

a flow calculation unit for converting a detection value of the flow detection unit into instantaneous flow rates;

an average timekeeping unit for counting an averaging time to obtain an average flow rate from the instantaneous flow rates;

an average flow calculation unit for averaging the instantaneous flow rates obtained by the flow calculation unit at every predetermined time period,

a flow storage unit for storing the average flow rate values obtained by the average flow calculation unit;

a flow change detection unit for determining whether or not there is a change in flow rate from the stored average values of the average flow calculation unit and the flow storage unit;

a flow registration unit for obtaining a change in the flow rate and registering the flow rate at the time of detecting the change from the flow change detection unit;

a flow difference correction estimation unit for calculating a flow rate difference between the average flow rate obtained at every average time and the sum of registered flow rates and, in the case where there is the flow rate difference, re-correcting the registered flow rate value in the flow registration unit by an amount of the flow rate difference so as to be re-registered in the flow registration unit;

a monitoring correction unit for performing use time monitoring correction in the case where the maximum registered flow rate value in the flow registration unit is corrected by the flow difference correction estimation unit;

a time monitoring value storage unit for storing a monitoring value for monitoring the registered flow rate value in the flow registration unit that is re-registered by the flow difference correction estimation unit;

a use time error determination unit for determining an error by comparing the monitoring value with the registered flow rate value in the flow registration unit that is re-registered by the flow correction estimation unit and in the case where there is a signal output from the monitoring correction unit, not determining an update of the use time monitoring, and

a shutoff unit for shutting the passage when the error is confirmed by the error determination unit.

4. A gas shutoff device comprising:

a flow detection unit for measuring a flow rate in a passage;

a flow calculation unit for converting a detection value of the flow detection unit into a flow rate,

an average flow calculation unit for averaging instantaneous flow rates obtained by the flow calculation unit;

a flow storage unit for storing the average flow rate values obtained by the average flow calculation unit;

a flow change detection unit for determining whether or not there is a change in flow rate from the stored values of the average flow calculation unit and the flow storage unit;

a flow registration unit for obtaining and registering a change in flow rate when the flow change detection unit determines that there is a change in flow rate;

a registration flow storage unit for storing the average flow rate at the time of registration of the change in flow rate by the flow registration unit;

a flow estimation unit for, when the flow change detection unit subsequently determines whether or not there is a change in flow rate, calculating a flow rate difference between the average flow rate at the time of determination and the average flow rate of the registration flow storage unit, and when there is a flow rate difference, outputting the average flow rate of the registration flow storage unit to the flow registration unit for the calculation of registered flow rate values;

a monitoring value storage unit for storing a monitoring value for monitoring the flow rate registered in the flow registration unit;

an error determination unit for determining an error by comparing the monitoring value with the registered flow rate value; and

a shutoff unit for shutting the passage when error is confirmed by the error determination unit.