General product description

With the VERD program you can design and simulate forced-flow pure substances evaporators of the following type.

·         Vaporisation in the tubes

·         Vaporisation in the shell

·         Horizontal evaporators

·         Vertical evaporators with upward or downward flow

·         Double-pipe heat exchangers

The calculation is performed in increments. For each increment the local heat fluxes, the local types of flow and the sectional pressure loss are determined.

The variables can either be calculated from a series (company standard, DIN standard) or in free form. A detailed editable tubesheet is created.

The properties are stored in separate program modules. The basic version includes the properties of water and ammonia. Further substances can be provided on request. Unpublished reference heat transfer coefficients can be calculated using critical data.

The constructive shell-side and tube-side layout of the heat exchanger can be specified according to the TEMA code or according to a company standard. The TEMA code can be selected as general option, whereas the company standard has to be administered by the user with the help of given editable dimensions.

The detailed tubesheet  can be created by the user in a dialog or generated by the program and then adapted to special requirements. The data can be saved as a DXF file for use in a CAD program such as AutoCAD.

For the calculation of the heat transfer different operation modes are considered:

·         Vaporization in or around the tubes

·         Vertical / horizontal

·         Convective boiling or nucleate boiling

The module selects and uses the calculation formulation according to the operation mode. In addition to that the incrementation along the evaporator length is considered for the vaporization in the tubes. For each increment the local heat transfer coefficient and the local pressure loss is calculated.

Physical properties are provided in the various properties modules. Properties for further substances can be created with the corresponding modules.

The physical properties of water and steam are provided by the H2O module according to the International seam table of the IAPWS.

The reference heat transfer coefficient α₀ required for the vaporisation can be looked up in a table which you can call up with the F3 function key.

For the vaporization of substances, which are not included in this table we recommend to use the additional module HABA. The HABA module makes it possible to generate the required reference variables for any media.