| 摘要 |
<p>The present invention relates to a method for controlling the heating water circulation in a gas-fired water heater, consisting of at least one heat exchanger (2, 3) which is heated by a burner (1) and to which a heating water forward run pipe (8) with a temperature sensor (9) for forward run temperature regulation and a heating water return run pipe (7), in which there is a heating water circulating pump (6), are connected, the forward run temperature T2 being constantly controlled, and compared with a maximum forward run temperature Tmax stored in a regulating device (15) which is line-connected to an automatic firing machine (14) and the burner (1) being switched off in the event that this temperature is exceeded. In order to guarantee reliable switching off in the event of low water, it is envisaged according to the invention that the heating water temperature is measured at an additional point approximately in the centre between forward and return run pipe (7, 8) and the temperature difference DELTA T between the forward run temperature T2 and this heating water temperature T1 is determined. This temperature difference DELTA T is compared with a maximum temperature difference DELTA Tmax and a minimum temperature difference DELTA Tmin stored in the regulating device (15) and this temperature difference DELTA T is used as second switch-off criterion DELTA T < DELTA Tmin, in addition to the first switch-off criterion T2 - T1 > DELTA Tmax. <IMAGE></p> |
