Transient temperature was within 10 deg. F of saturation

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Transient temperature was within 10 deg. F of saturation temperature at X seconds.

Explanation

The temperature at some point in the system approached saturation conditions during the transient simulation. It does not necessarily mean that condensation occurred or that the results cannot be trusted; however, the user should investigate accordingly. Fluid property calculations close to saturation conditions may result in model convergence issues.

Required Action

The user should review the results to verify that saturation conditions were never reached. Flow must remain superheated at all times in the simulation (no two-phase flow or condensation) as stated in the engineering assumptions. A useful method of checking for condensation is to create various Transient Pipe graphs at different locations in the system and display the "Temperature Static" and "Temperature Saturation" parameters using the same units and axis range. Prime locations to check for saturation would be at the pipe inlets/outlets next to junctions like valves that have transient events. One of the graph parameters can be added as a secondary y-axis to create a stacked graph which overlays both series. Double click the empty box in front of the parameter name, or select the parameter row and click the right facing blue arrow above the parameters to indent it and make it a secondary y-axis. Then, verify that the Static Temperature does not drop below the Saturation Temperature for any time step.

If saturation conditions are never reached at any location throughout the entire transient simulation, then this Caution can be disregarded.