DIERS Benchmarks

Two-phase Frozen Flow

The DIERS two-phase frozen flow involves saturated water at 72.2 psia relieving pressure with 5 psia being a nitrogen blanket.  The flow is frozen meaning that there is no flashing of the saturated water.  The water is saturated at 67.5 psia.  The water will not flash but the nitrogen will expand as the pressure decrease as it flows through the inlet pipe, enters the nozzle and exits the discharge pipe.  The physical properties are based on saturated water at its partial pressure of 67.5 and the nitrogen gas based on its specific volume changes as it enters inlet pipe, the relief nozzle, and exits the discharge pipe.   The saturated water properties at 67.5 psia and 300.5 o F,  remain constant throughout the flow path.  Only the nitorgen will expand.

Mach II Results for Nitorgen blanket              Downlaod

For the next case of two-phase frozen flow instead of a nitrogen blanket the blanket will be steam at a pressure of 72.5 psia.  The water will remain sub-cooled at 67.5 psia.  Only the steam will expand and the water will remain without flashing. The steam properties will be taken at each pressure increment.

Mach II   Results for Steam blanket                Download. 

Frozen Flow

Flow rate (lbs/hr)              Choke (psia)           Quality (x)            Inlet dP / %Pset             Outlet dP /% Pset         Piping

       240,500                              39.6                      0.01                         ----------                           ----------                     nozzle N

       230,103                              37.8                      0.01                         3.2 / 6.1                            3.3 / 6.3                     4 X 6  N

       237,559                              39.0                      0.01                         0.93 /1.8                          3.6 / 6.9                     6 X 6  N

      188,425                               42.7                      0.01                           ---------                             ---------                      nozzle  S

      179,058                               40.7                     0.01                           3.3 / 6.3                             2.3 / 4.4                    4 X 6    S

      184,861                               42.0                     0.01                           1.3 / 2.5                             2.5 / 4.8                     6 X 6   S