Results for IPH Linear Direct Steam

Hi!

I'm simulating a water heating system using Linear Fresnel collector. Checking the field inlet and outlet temperatures in the Time Series tab, at the Results page, I noticed a behaviour for the inlet temperature that I don't really understand. Its temperature raises at the beggining of the day, drops to the value set in "Field inlet temperature", then pikes to a high value and starts decreasing. 
What could be the reason for this? It seems to happen with all sorts of input values and locations.
An image and a SAM file are beeing attached. 

Thank you.

Hi Giovani,

The heat sink component in the steam Linear Fresnel model requires that the field outlet temperature meets or exceeds a temperature close to the design outlet temperature. At field outlet temperatures colder than this threshold temperature, instead of sending the field outlet to the heat sink, the model instead recirculates the field outlet back to its inlet. So when the heat sink is not operating, the field is either warming up or cooling down, and the field inlet and outlet temperatures are the same.

Ty