Condensate drain, sensor device, and method for detecting the state of a flow path

A condensate drain for controlling the flow-through of fluids, in particular the condensate drain for discharging liquid condensate, with

• a housing with an inlet flange and an outlet flange,
• a flow path formed between the inlet flange and the outlet flange,
• a closure element, which is arranged in the flow path and which is configured for selectively blocking or releasing the flow path, respectively, and
• a sensor device fastened to the housing for monitoring the operating state of the condensate drain,
• wherein the sensor device has a coupling assembly for coupling to the housing as well as a sensor for detecting structure-borne sound and/or for detecting a temperature of the coupling assembly and/or of the housing,
• wherein the sensor device is arranged downstream from the closure element and is configured to detect at least one of the following:
• a leakage of the condensate drain by detecting the structure-borne sound of the coupling assembly and/or of the housing,
• a blockage of the flow path by detecting the temperature of the coupling assembly and/or of the housing.