Model Library
Heat Transfer
The library Heat Transfer is especially designed for detailed, geometry-based modeling
of different types of heat exchangers for steady-state and dynamic simulation. It serves
as a thermal connection between the SimulationX fluid libraries. Each heat exchanger
model can be coupled with elements from the hydraulics, pneumatics and Thermal-Fluid
libraries. Application areas include power plants, heat pumps, district heating systems,
air-conditioning systems, solar and geothermal hot water heating, oil and gas applications,
train and airplane ventilation as well as chillers.
The focus of this document is on steady-state simulations for a variety of heat exchangers.
Models for the simulation of dynamic effects as well as a library containing basic elements
for general modeling of heat transfer and pressure drop will be available in the near future.
The sub-library Steady State Heat Exchangers contains ready-to-use heat exchangers of
different types, all using the NTU (Number of Transfer Units) method for fast calculations.
These include real-time applications like controller testing and training simulators. Furthermore, the Steady State Heat Exchanger models can be used for parameter influence
studies and for system models with long-term heat transfer focus.
For realistic physical modeling, a large selection of heat transfer and pressure drop correlations for different geometries and flow conditions are provided.
• Detailed geometry
based modeling of
heat exchangers
• Large selection
of heat transfer
and pressure drop
correlations
• Real-time capable
using the NTU
method
• Connectors to
the Hydraulics,
Pneumatics and
Thermal-Fluid
libraries
• Ready to use heat
exchanger models
+ basic elements
for own models and
libraries
Fig. 1: Example model of a heat pump with an internal heat exchanger
SimulationX 3.6 – Library Sheet: Heat Transfer
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Accessories
The sub-library Accessories contains a large selection of heat transfer and pressure drop correlations as well as
specific functions such as heat conduction, transitions and characteristic numbers, as well as material properties and
connectors
Heat transfer correlations represent the heat transfer properties for different geometries and conditions
Fig. 2: Available heat transfer correlations
SimulationX 3.6 – Library Sheet: Heat Transfer
3|5
Heat conduction, transitions and characteristic numbers, as well as material properties and connectors serve for
physically realistic modelling.
Fig. 3: Additional functions and models in Accessories
A collection of temperature-dependent material properties (density, specific heat capacity and thermal conductivity)
are provided under Materials in the sub-library Accessories.
Fig. 4: Material properties in Accessories
SimulationX 3.6 – Library Sheet: Heat Transfer
4|5
Pressure drop correlations represent the pressure drop properties in heat transfer prodesses for different geometries
and conditions.
Fig. 5: Available pressure drop correlations
Steady State Heat Exchangers
The library Steady State Heat Exchangers contains different types of ready-to-use heat exchangers using the
NTU-method (RT applications). These elements are intended for fast calculations. Features of the steady-state heat
exchangers are:
• Compatible to all SimulationX fluid libraries
• Customizable geometry, material and flow arrangements
• Value for alpha can be set or calculated depending on geometry and flow conditions
• Valid for one-phase and two-phase regions
• Contain a variety of physics-based pressure drop and heat transfer correlations
• Constant or time varying definition of fouling factors
• Possible to define custom heat transfer or pressure loss correlations
5|5
Fin and Tube Heat
Exchanger
• Different flow arrangements in one element
• Linear pressure drop or calculated fin and tube pressure drop
depending on geometry and flow conditions
• User defined number of tube rows and tubes per row
• Free definition of fin thickness and spacing
• Two phase flow possible in the tubes
Double Pipe Heat
Exchanger
• Linear pressure drop or calculated fin and channel pressure drop
depending on geometry and flow conditions
• Selection for module design between hairpin and straight pipe
• Use several modules in parallel or series within one heat exchanger
element
• Two phase flow possible in the inner pipe
• Use one or more inner pipes
• Inner tubes with or without outer fins
Microchannel Heat
Exchanger
• Linear pressure drop or calculated pipe pressure drop depending on
geometry and flow conditions
• User defined number of extruded tubes, flow channels and passes
• Two phase flow possible in the extruded tubes
• Free definition of fin thickness and spacing
Plate Heat Exchanger
• Linear pressure drop or calculated plate pressure drop depending on
geometry and flow conditions
• User defined number of passes
• Two phase flow possible on one side of the heat exchanger
• Free definition of Chevron angle
Shell and Tube Heat
Exchanger
• Linear pressure drop or calculated shell and tube pressure drop
depending on geometry and flow conditions
• User defined tube layout angle, pitch and number of passes
• Free definition of number of tubes and baffles
Fluids
esd n/
The sub-library Fluids contains fluid functions that are used in the elements of the Heat Transfer library. These fluids
are calculated in the same way as the fluids in the SimulationX libraries Hydraulics, Pneumatics and Thermal-Fluid to
ensure compatibility with the Heat Transfer library.
Basic Elements
rin r S
t
The sub-library Basic Elements will be released with a forthcoming version of the Heat Transfer library. It will contain
basic models that can be used either as stand-alone elements or as part of a heat exchanger, as done in the models
from the sub-library Dynamic Heat Exchangers.
T Hea
i
Dynamic Heat Exchangers
Dynamic Heat Exchangers will be released with a forthcoming version of the Heat Transfer library. This sub-library will
contain complex heat exchanger models with dynamic behavior. These heat exchangers are used if the dynamics of
the heat exchanger (for example heat capacity of the wall between the fluids) are of interest.
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SimulationX 3.6 – Library Sheet: Heat Transfer
Stand
02/2014_2