Products > Discipline: Space and Aeronautics > Library: ECLSS
ECLSS LIBRARY
The ECLSS library provides a set of components to design and analyse the most typical equipment and processes of the Environmental Control and Life Support Systems in manned spacecrafts.
Features
EcosimPro is the European Space Agency (ESA) official tool to support Environmental Control and Life Support Systems (ECLSS) analysis.
ECLSS modelling involves multi-disciplinary simulation, since ECLS operations consider a very wide range of different phenomena such as fluid flow, chemical reactions, electrochemical reactions, heat transfer and biological processes.
The ECLSS library is an EcosimPro professional library which provides a set of components to simulate the most typical process units, equipment and processes of the ECLS systems, such as cabins, crews, heat exchangers, pipes, pumps, reactors, electrolysers etc.
This library is mainly adapted to the thermo-hydraulic analysis of air cabin loops of conventional ECLSS, but special case fluid flow problems like venting lines or pressure regulators can also be analysed.
The ECLSS library enables you to simulate heat transfer, chemical reaction and mass/energy balance, and to analyse system pressure drop based on any manned spacecraft.
Models built with the library components assume that mass flow and heat flow is 1-dimensional. The intensive variables like pressure, temperature or compositions, are assumed average values in the control volumes or nodes considered (lumped modelling). The majority of components are able to evaluate reverse flow. Moreover, one or more types of fluids can be considered in the system, depending on the fluid loops in the ECLSS.
The library includes thermodynamic functions to calculate the properties of the following two types of working fluids:
- Perfect gas mixtures with or without water, where water can condense in solid or liquid phase and whose pressure must be in the region of atmospheric pressure or lower
- Real fluids like pure gases, water and pure liquid refrigerants
The intuitive EcosimPro graphical tool offers user friendly drag-and drop methodology and input data editors that help to build the flow sheet for the ECLSS model and specify the input data and parameters.
EcosimPro enables the user to easily develop new components or modify existing components in order to provide the ECLSS components with the required level of fidelity. This can be done graphically through a simple, user friendly interface, or through EcosimPro’s object-orientated language which makes it possible to re-use existing codes.
The library has been designed so that the process control system can be included using the standard CONTROL library and so that the system’s thermal control system (TCS) can be included using the standard THERMAL library. These two libraries are provided with EcosimPro.
The ECLSS library enables you to carry out trade studies and preliminary designs of ECLS systems, and to determine the component, subsystem and system off-design performance. Furthermore, it enables you to perform long duration transient analyses with reasonable CPU time consumption.
Components
The library includes a wealth of ECLSS components and boundary condition components to build the system simulation model:
- Cabin: It represents a standard air volume or cabin. It takes into account the phenomena of deposition of the condensed liquid water and ice and the evaporation of the water film on the cabin wall. The cabin model is usually connected to submodels representing parts of the Air Management subsystem or to other cabins using hatches, and it can be connected to the thermal control system submodel and to the crew component
- Crew: It represents crew members, and some of the phenomena that have been taken into account in the formulation of this component type are: metabolic activity, breathing, evaporative and sensible heat losses from skin, skin blood flow, predictions of thermal comfort and thermal sensation...
- Fittings: There are some friction components to take into account pressure losses in the system such as: Expanders, Reducers, Grids, Wyes, Tees, Orifices, MitreBend, etc
- Pipes: There are several models of pipes with different levels of complexity to take into account thermal delay, bends, or molecular flow in venting lines
- Valves: The library includes several valve models to represent check valves, pressure regulator valves, liquid and gas valves...
- Boundary conditions: The library contains a set of components to specify the system boundary conditions; eg, temperature, composition of the working fluid, pressure, mass flow...
- Sensors: The library includes a set of sensors which can be used to implement ECLSS control loops
- Other components: The library also contains models of equipment normally found in ECLS systems, such as pumps, fans, tanks, filters, and models of more specific ECLS equipment, such as chemical reactors, fuel cell stack, electrolyser, membrane, LiOH cartridges...