Water flow heating device with protection function

Abstract

The present application provides a water flow heating device with a protection function, including: a heating cylinder, a heating wire disposed in the heating cylinder and a water flow temperature sensor, and a protection circuit respectively connected with the heating wire and the water flow temperature sensor; the protection circuit includes a first voltage comparator, an environmental thermal conductivity detection circuit for detecting an environmental thermal conductivity of the water flow temperature sensor and a protection switch for switching on and off the heating wire; the water flow temperature sensor is connected with an input terminal of the first voltage comparator and the environmental thermal conductivity detection circuit, respectively; an output terminal of the first voltage comparator is connected with the protection switch; and the environmental thermal conductivity detection circuit is connected with an enable terminal of the heating wire. The present application can prohibit the heating wire from being turned on when the water flow is not full or slow, and can also cut off the power supply of the heating wire when an internal temperature of the heating cylinder is too high, thus improving the stability and safety of equipment operation.

1 . A water flow heating device with a protection function comprising: a heating cylinder, a heating wire disposed in the heating cylinder and a water flow temperature sensor, and a protection circuit respectively connected with the heating wire and the water flow temperature sensor;
 the protection circuit includes a first voltage comparator, an environmental thermal conductivity detection circuit for detecting an environmental thermal conductivity of the water flow temperature sensor and a protection switch for switching on and off the heating wire; the water flow temperature sensor is connected with an input terminal of the first voltage comparator and the environmental thermal conductivity detection circuit, respectively; an output terminal of the first voltage comparator is connected with the protection switch; and the environmental thermal conductivity detection circuit is connected with an enable terminal of the heating wire.   
     
     
         2 . The water flow heating device according to  claim 1 , wherein the protection switch comprises a first relay and a second relay; contact terminals of the first relay are respectively connected to a live wire and one end of the heating wire; contact terminals of the second relay are respectively connected to a neutral wire and the other end of the heating wire; and the output terminals of the first voltage comparator are respectively connected to a coil terminal of the first relay and a coil terminal of the second relay. 
     
     
         3 . The water flow heating device according to  claim 1 , further comprising a protection temperature sensor disposed on an outer surface of the heating cylinder; the protection circuit further includes a second voltage comparator; and the protection temperature sensor is connected with an input terminal of the second voltage comparator, and an output terminal of the second voltage comparator is connected with the protection switch. 
     
     
         4 . The water flow heating device according to  claim 1 , further comprising a thermoswitch disposed on the outer surface of the heating cylinder, wherein the protection switch is connected to an internal power supply through the thermoswitch. 
     
     
         5 . The water flow heating device according to  claim 4 , wherein an operating temperature of the thermoswitch is 60° C.±2° C. 
     
     
         6 . The water flow heating device according to  claim 1 , wherein the heating cylinder is a hollow cylinder disposed horizontally. 
     
     
         7 . The water flow heating device according to  claim 6 , wherein one side of the heating cylinder is provided with a water inlet, and the other side of the heating cylinder opposite to the water inlet is provided with a water outlet. 
     
     
         8 . The water flow heating device according to  claim 7 , wherein sizes of the water inlet and the water outlet are equal to a cross section of the heating cylinder. 
     
     
         9 . The water flow heating device according to  claim 1 , wherein the heating wire is disposed at a bottom of the heating cylinder. 
     
     
         10 . The water flow heating device according to  claim 1 , wherein the heating wire has a double U shape.