TPCS - Two-Phase Capillary Systems

Applications

Simulation of Loop Heat Pipes (LHP) and Capillary Pumped Loops (CPL) in two phases

  • Transient simulation of two-phase capillary pumped systems.
    Simulation of single or multi evaporator loops
  • Reverse flow and transitions between flooded, two-phase, dry-out and standby conditions
Related papers
Fact sheet

Description

TPCS, which stands for Two-Phase Capillary Systems, is an EcosimPro toolkit for the simulation of Loop Heat Pipes (LHP) and Capillary Pumped Loops (CPL). The operating principle of a TPCS heat transfer device is based on the evaporation and condensation of a working fluid, which uses the capillary pumping forces to ensure the fluid circulation.

Models using TPCS toolkit calculates the transient response of a thermo-fluid system in correspondence with the boundaries and geometry defined in the model. Steady conditions can be calculated after a transient simulation under constant boundary conditions. On the other hand, sensitivity studies of geometry and design parameters can be easily done using the EcosimPro Monitor tool.

The TPCS toolkit provides a large palette of components (represented by icons) to be inserted (drag and drop) in a model. There is no limitation concerning the system topology to be modelled; on the contrary, building a model is easily done by inserting the respective components as they are integrated in a real system.

Features

The main characteristics of TPCS toolkit are:

TPCS toolkit simulates fluid networks and equipment improving the numerical schemes classically used in other codes, dealing in particular with 1D pipe wall friction and two-phase flow at porous media.

TPCS components have been validated against test results under liquid, gas or two-phase conditions depending on the current P/T conditions of the working fluid, the fluid phase being determined by the code.

Complex topologies of loop heat pipes with one or more evaporator and/or pumping systems, where the heat transfer and the system controls are coupled, can be evaluated with this library just by linking graphically the concerned components in a particular system model.

Typical LHP applications are: Space applications, Avionics cooling, Airplane anti-icing system for the engine cowl using waste semiconductor engine heat, etc.

User Cases

The image below shows a multi-evaporator, multi-condenser design (MER-LHP) developed by Iberespacio. MER-LHP was developed as a demonstrator of the multi-evaporator and multi-condenser concept, enabling high flexibility in terms of heat collection at different sources and at different heat load levels due to its multi-evaporator architecture. The capability of adding several condensers allows to create enhanced radiator layouts in typical configuration such as North/South and East/West, shared within the same system.

The following plot shows an example of test results obtained for a standard performance case on the previous system:

The TPCS/EcosimPro model representative of the previous hardware system is depicted below:

The results obtained using the TPCS thermal model match those obtained during hardware test campaign:

An example of last power step correlation and some system temperatures are presented in next table:

Thermal model results are stable and the different steady state scenarios are reached. Steady state temperatures correspond to those obtained from hardware with minor error. Evaporators’ temperatures vary between 37°C to 57°C for the power sequence whereas the remote compensation chamber is maintained around 40°C.