Heating device and method for operating the same

Abstract

A heating device includes: a fluid reservoir; a heat exchanger whose feed line is hydraulically connected to the fluid reservoir geodetically deeper than its return line; a pump situated in the feed line or the return line; a bypass hydraulically connected to the feed line and to the return line, the bypass bypassing the heat exchanger and the pump; and a three-way valve situated in the connection of the bypass to the feed line or in the connection of the bypass to the return line. Based on a comparison of a setpoint temperature with a first fluid temperature determined in the return line between the heat exchanger and the bypass, the three-way valve is switched into a first switch position in which the bypass is at least partially open, or the three-way valve is switched into a second switch position in which the bypass is closed.

1 - 10 . (canceled) 
     
     
         11 . A heating device, comprising:
 a fluid reservoir;   a heat exchanger, wherein a feed line of the heat exchanger is hydraulically connected to the fluid reservoir geodetically deeper than a return line of the heat exchanger;   a pump situated in one of the feed line or the return line;   a bypass hydraulically connected to the feed line and to the return line, wherein the bypass bypasses the heat exchanger and the pump; and   a three-way valve situated one of (i) in the connection of the bypass to the feed line, or (ii) in the connection of the bypass to the return line.   
     
     
         12 . The heating device as recited in  claim 11 , wherein the heat exchanger is a condenser of a heat pump. 
     
     
         13 . The heating device as recited in  claim 12 , wherein the three-way valve is a controllable valve. 
     
     
         14 . The heating device as recited in  claim 11 , wherein a first temperature sensor is situated in the return line between the heat exchanger and the bypass for detecting a first fluid temperature in the return line. 
     
     
         15 . The heating device as recited in  claim 14 , wherein the three-way valve is activated by a control unit storing a setpoint temperature, wherein the control unit is connected in a data-communicating way to the first temperature sensor. 
     
     
         16 . A method for operating a heating device having: a fluid reservoir; a heat exchanger, wherein a feed line of the heat exchanger is hydraulically connected to the fluid reservoir geodetically deeper than a return line of the heat exchanger; a pump situated in one of the feed line or the return line; a bypass hydraulically connected to the feed line and to the return line, wherein the bypass bypasses the heat exchanger and the pump; and a three-way valve situated one of (i) in the connection of the bypass to the feed line, or (ii) in the connection of the bypass to the return line, wherein the method comprises:
 a) activating the pump and flow of fluid through the heat exchanger,   b) transferring heat to the fluid in the heat exchanger,   c) determining a first fluid temperature in the return line between the heat exchanger and the bypass,   d) comparing the first fluid temperature with a setpoint temperature,   e1) if the first fluid temperature is lower than the setpoint temperature, switching the three-way valve into a first switch position in which the bypass is at least partially open, and   e2) if the first fluid temperature is higher than the setpoint temperature, switching the three-way valve into a second switch position in which the bypass is closed.   
     
     
         17 . The method as recited in  claim 16 , further comprising:
 f) deactivating the pump if a third fluid temperature in the feed line upstream from the bypass is higher than the setpoint temperature.   
     
     
         18 . The method as recited in  claim 16 , wherein the bypass is completely open in the first switch position of the three-way valve. 
     
     
         19 . The method as recited in  claim 16 , wherein a hysteresis is taken into account during a change between the switch positions of the three-way valve. 
     
     
         20 . The method as recited in  claim 17 , further comprising:
 g) override switching of the three-way valve into the second switch position if it is not necessary to maintain the setpoint temperature in a draw-off zone situated geodetically on top in the fluid reservoir.