Flame monitoring device and flame monitoring program

Abstract

To detect a sign of a flame failure that cannot be detected by monitoring a flame voltage and a flame current, a flame monitoring device is provided that includes an information acquisition unit that sequentially acquires a flame level indicating frequency of discharge of a flame detector caused by a flame of a main burner, and a flame level monitoring unit that monitors the flame level sequentially acquired by the information acquisition unit. The flame level monitoring unit detects a sign of a flame failure of the flame by detecting an occurrence of a specific period during which a state in which the flame level is less than a predetermined threshold value continues for a length of time equal to or more than a predetermined period and less than a flame response period.

1 . A flame monitoring device comprising:
 an information acquisition unit configured to sequentially acquire a flame level indicating frequency of discharge of a flame detector caused by a flame of a burner; and   a flame level monitoring unit configured to monitor the flame level sequentially acquired by the information acquisition unit;   
       wherein
 the flame level monitoring unit is further configured to detect a sign of a flame failure of the flame by detecting an occurrence of a specific period during which a state in which the flame level is less than a predetermined threshold value continues for a length of time more than or equal to a predetermined first period and less than a second period, and 
 the second period is a period having a length of time equal to or less than a period from an occurrence of the flame failure of the flame to the detection of the flame failure in a combustion system that controls the burner when it is assumed that the flame failure occurs. 
 
     
     
         2 . The flame monitoring device according to  claim 1 , wherein
 the flame level monitoring unit is further configured to execute a process of notifying that the sign is detected when the occurrence of the specific period is detected.   
     
     
         3 . The flame monitoring device according to  claim 2 , wherein
 the flame level monitoring unit is further configured to execute a process of notifying that the sign is detected when the number of occurrences of the specific period per certain period is larger than a predetermined number of times larger than or equal to two.   
     
     
         4 . The flame monitoring device according to  claim 2 , wherein
 the information acquisition unit is further configured to sequentially acquire flow rates of fuel and air that are supplied to the burner, and   the flame level monitoring unit is further configured to notify of the detection of the sign along with flow rate information indicating a relation between the flow rate of fuel and the flow rate of air in at least one of the specific periods and a certain period traced back from the specific period based on the flow rates of fuel and air that are sequentially acquired by the information acquisition unit.   
     
     
         5 . The flame monitoring device according to  claim 1 , wherein
 the information acquisition unit is further configured to sequentially acquire combustion information including at least the flame level in the combustion system, and   the flame level monitoring unit is further configured to:
 learn a relation between presence or absence of the occurrence of the flame failure and the combustion information by using, as training data, a variation in combustion information in a period traced back by a predetermined time from the actually occurring flame failure and a variation in combustion information for the predetermined time when no flame failure occurs from the combustion information sequentially acquired by the information acquisition unit; and 
 derive a possibility of the occurrence of the flame failure based on the variation in combustion information for the predetermined time from the combustion information sequentially acquired by the information acquisition unit and the learned relation, and execute a process based on the derived possibility. 
   
     
     
         6 . The flame monitoring device according to  claim 5 , wherein
 the flame level monitoring unit is further configured to learn the relation by using a variation in combustion information in a period traced back by the predetermined time from the specific period actually generated from the combustion information sequentially acquired by the information acquisition unit as the variation in combustion information in a period traced back by the predetermined time from the flame failure.   
     
     
         7 . The flame monitoring device according to  claim 5 , wherein
 the process based on the derived possibility includes at least one of a process of notifying of the possibility, a process of notifying that the possibility is larger than a predetermined value, and a process of stopping fuel supply to the burner when the possibility is larger than the predetermined value.   
     
     
         8 . The flame monitoring device according to  claim 3 , wherein
 the information acquisition unit is further configured to sequentially acquire flow rates of fuel and air that are supplied to the burner, and   the flame level monitoring unit is further configured to notify of the detection of the sign along with flow rate information indicating a relation between the flow rate of fuel and the flow rate of air in at least one of the specific periods and a certain period traced back from the specific period based on the flow rates of fuel and air that are sequentially acquired by the information acquisition unit.   
     
     
         9 . A non-transitory computer-readable storage medium storing a flame monitoring program for causing a computer to execute:
 an information acquisition step of sequentially acquiring a flame level indicating frequency of discharge of a flame detector caused by a flame of a burner; and   a flame level monitoring step of monitoring the flame level sequentially acquired by the information acquisition step;   
       wherein
 in the flame level monitoring step, a sign of a flame failure of the flame is detected by detecting an occurrence of a specific period during which a state in which the flame level is less than a predetermined threshold value continues for a length of time equal to or more than a predetermined first period and less than a second period, and 
 the second period is a period having a length of time equal to or less than a period from an occurrence of the flame failure of the flame to the detection of the flame failure in a combustion system that controls the burner when it is assumed that the flame failure occurs.