Gas boiler having closed-type cistern tank

Abstract

A gas boiler having a closed cistern tank with no diaphragm, in which the volume of the cistern tank can be reduced, the closed cistern tank storing returned heating water and absorbing pressure changes of the heating water. The cistern tank having no diaphragm has an internal space that is isolated from the atmosphere, and includes a heating water inlet through which the heating water is introduced, a heating water outlet through which the heating water is discharged toward a circulation pump, a water level detecting sensor which detects the water level of the heating water stored in the cistern tank, and a safety valve for maintaining the pressure of an internal space of the cistern tank to less than a predetermined value.

1 . A gas boiler having a closed cistern tank in which returned heating water is stored and which absorbs pressure changes of the heating water, wherein the cistern tank
 has no diaphragm has an internal space isolated from the atmosphere, and includes
 a heating water inlet through which the heating water is introduced, 
 a heating water outlet through which the heating water is discharged toward a circulation pump, 
 a water level detecting sensor which detects the water level of the heating water stored in the cistern tank, and 
 a safety valve for maintaining the pressure of the internal space of the cistern tank at less than a predetermined value. 
   
     
     
         2 . The gas boiler according to  claim 1 , wherein the safety valve is located on an uppermost end portion of the cistern tank and discharges air before discharging the heating water. 
     
     
         3 . The gas boiler according to  claim 1 , wherein the cistern tank is located adjacent to an entrance of the circulation pump such that air separation is performed in the cistern tank. 
     
     
         4 . The gas boiler according to  claim 1 , wherein the water level detecting sensor is installed so that a lower end of the water level detecting sensor is adjacent to a bottom surface of the cistern tank. 
     
     
         5 . The gas boiler according to  claim 1 , wherein, when the water level detecting sensor detects that the water level is proper, the circulation pump is normally operated even when the internal pressure of the cistern tank is less than atmospheric pressure. 
     
     
         6 . The gas boiler according to  claim 2 , wherein the cistern tank is located adjacent to an entrance of the circulation pump such that air separation is performed in the cistern tank. 
     
     
         7 . The gas boiler according to  claim 2 , wherein the water level detecting sensor is installed so that a lower end of the water level detecting sensor is adjacent to a bottom surface of the cistern tank. 
     
     
         8 . The gas boiler according to  claim 2 , wherein, when the water level detecting sensor detects that the water level is proper, the circulation pump is normally operated even when the internal pressure of the cistern tank is less than atmospheric pressure.