|
The Deaerator model simulates deaeration of water. The model actually acts as a direct heater with a vent. Removal of dissolved oxygen is not modelled.
The Deaerator model heats condensate and make-up water to a specified temperature by direct addition of steam. Make-up water is added to the flow in the Condensate Inlet to achieve the required flow in the Feedwater Outlet. The Feedwater Outlet is assumed to be fixed flow (given).
The Feedwater Outlet and Steam Vent stream pressures are set as the minimum inlet pressure. The Steam Vent stream is optional and it is assumed to be saturated.
The flow of steam required to heat the condensate/make-up water mixture to the specified temperature is calculated, along with the Steam Vent flow, and assigned to the Steam Inlet stream.
|
What do you want to see?
|
 |
Data Description
|
Data |
Unit |
Description |
|
Set |
Item |
Type |
Native |
|
Equipment Properties |
FeedTemp |
Temperature |
F |
The Feedwater Temperature is assigned to the Feedwater Outlet stream. |
|
VentFrac |
Fraction or Percent |
Fraction |
Steam to Vent as a fraction of the Steam Inlet flow. |
The Feedwater Temperature and minimum inlet pressure are assigned to the Feedwater Outlet and the resulting specific enthalpy is calculated. The minimum inlet pressure is assigned to the Steam Vent and the specific enthalpy at saturation is calculated.
The Steam Inlet flow is calculated from:
Fsteam = ( Ffeedwater * ( hfeedwater - hmake-up ) + Fcondensate * ( hmake-up - hcondensate ) ) / ( fvent * ( hmake-up - hvent ) - hmake- up
+ hsteam )
The Steam Vent flow is calculated from:
Fvent = fvent * Fsteam
The Make-Up Water flow is calculated from:
Fmake-up = Ffeedwater + Fvent - Fcondensate - Fsteam
where:
Fsteam is the Steam Inlet flow
Ffeedwater is the Feedwater Outlet flow
Fcondensate is the Condensate Inlet flow
Fvent is the Steam Vent flow
Fmake-up is the Make-Up Water flow
hfeedwater is the Feedwater Outlet enthalpy
hmake-up is the Make-Up Water enthalpy
hcondensate is the Condensate enthalpy
hvent is the Steam Vent enthalpy
hsteam is the Steam Inlet enthalpy
fvent is the fraction of Steam to Vent
No steam needed!
Solution: The feed water temperature is set too low.
Excess condensate!
Solution: The condensate flow is higher than the feed water flow.
Solution: check if all the streams are connected to the equipment.
Solution: Set the Temperature for the feed water.
Errors