Heat exchanger and method for estimating remaining life of heat exchanger

Abstract

Dummy tubes are each provided near a gas inlet side and a gas outlet side of a heat recovery unit and near a gas discharge side of a re-heater via an intubation, and a heat medium is circulated in the dummy tube by a branched path which branches from a medium circulation path. The dummy tube is periodically extracted to check the quantity of thickness reduction of the surface thereof. Thus, it is possible to check the quantity of thickness reduction of the surface of the dummy tube, and determine the state of damage or the like of a heat transfer tube.

1 - 5 . (canceled) 
     
     
         6 . A heat exchanger having a plurality of heat transfer tubes for heat recovery or heat exchange, the heat exchanger comprising:
 a heat medium circulation path for supplying a heat medium to the plurality of heat transfer tubes;   a branched path branching from the heat medium circulation path;   a dummy tube for introducing the branched heat medium; and   a pump for returning the heat medium from the dummy tube to the heat medium circulation path.   
     
     
         7 . The heat exchanger according to  claim 6 ,
 wherein the dummy tube is a through tube passing through the heat exchanger or a U-shaped tube folded back in the middle of the heat exchanger.   
     
     
         8 . A heat exchanger having a plurality of heat transfer tubes for heat recovery or heat exchange, the heat exchanger comprising:
 a dummy tube provided in any one or both of a gas inlet side or a gas discharge side of the heat exchanger, the dummy tube having a filling liquid in which an electrically conductive medium is contained in a heat medium from a heat medium circulation path; and   a conductive sensor having a tip end immersed in the filling liquid.   
     
     
         9 . A method of estimating a remaining life of the heat exchanger according to  claim 6 , comprising:
 determining a thickness reduction condition of the heat transfer tube from degradation state of the dummy tube; and   predicting a replacement timing of the heat transfer tube.   
     
     
         10 . The heat exchanger according to  claim 6 , wherein the dummy tube is a bare tube. 
     
     
         11 . The heat exchanger according to  claim 6 , wherein the dummy tube is provided in any one or both of a gas inlet side or a gas discharge side of the heat exchanger.