Operations guide24
- 1. 2-8 Sub-Flowsheet Property View 2-8 2.2.3 Transfer Basis Tab The transfer basis for each Feed and Product Stream is listed on the Transfer Basis tab. The transfer basis only becomes significant when the sub-flowsheet and Parent flowsheet’s fluid packages consist of different property methods. The transfer basis is used to provide a consistent means of switching between the different basis of the various property methods. Transfer Basis Description T-P Flash The Pressure and Temperature of the Material stream are passed between flowsheets. A new Vapour Fraction is calculated. VF-T Flash The Vapour Fraction and Temperature of the Material stream are passed between flowsheets. A new Pressure is calculated. VF-P Flash The Vapour Fraction and Pressure of the Material stream are passed between flowsheets. A new Temperature is calculated. P-H Flash The Pressure and Enthalpy of the Material stream are passed between flowsheets. User Specs You define the properties passed between flowsheets for a Material stream. None Required No calculation is required for an Energy stream. The heat flow is simply passed between flowsheets. Figure 2.5 The Transfer Basis is also useful in controlling VF, T or P calculations in column sub-flowsheet boundary streams with close boiling or nearly pure compositions.