Recycle

Inputs

• Fluid package: Fluid package assigned to the recycle loop. This must be the same as the Fluid package of a connected Input stream.
• Temperature (init. value): Initial temperature guess for the recycled stream.
• Pressure (init. value): Initial pressure guess for the recycled stream.
• Mass flow (init. value): Initial flow rate used to start the convergence.

Outputs

• Recycle stream updated each solver iteration until the connected units and streams satisfy the process specification.

Details

An initial guess with zero mass flow will usually be enough for the solver to converge. In that case, the values for initial temperature and pressure will not be used.

If possible, avoid placing the Recycle directly upstream of a mixer. The problem is that the mixed stream will have the lowest pressure of all incoming streams, so if the initial guess for the Recycle pressure is too low it will affect all pressures downstream of the mixer. This may trip up the solver. It's better to place the Recycle directly upstream of a unit operation that explicitly sets the pressure, e.g. the closest valve, compressor, expander, etc. upstream of the mixer.