The TEPSS tool consists of modular and reusable components that are interconnected to form an energy system where the performance can quickly be simulated and optimized by varying TE and system design parameters. TEPSS uses an object oriented programming approach where each component is created at the outset of a simulation.
Consider the gas turbine power generation system below where a thermoelectric power unit could be used to generate electrical power as well as recuperate heat from the exhaust stream to improve overall system performance.
Each system component will have an object that contains a physical and economic model based on specific user provided physical parameters such as fin length, TE module leg length, and material properties. These models can be simple expressions based on empirical characterization or a detailed implicit analytical or numerical model. These objects are then integrated to form a system such as the one shown below.
The components are coupled using domain state vectors or nodes such as fluids, electric, or mechanical. These domain vectors describe the state of the system and are objects themselves created at the beginning of a simulation. In the case of a fluid node, the mass flow rate, pressure, temperature and dependent fluid properties are provided and interconnect component objects. The structure of the interconnection is currently provided by the user through a text file.
TEPSS solves for the state vectors that satisfy all the system component models for a given set of physical parameters. An optimization shell will be placed around the simulation and will vary user specified parameters to optimize some cost functions such as system efficiency, material cost required to provide a desired power, net present value or other cost metric the user is interested in optimizing. Each component object will have a costing function to aid in optimizing overall system design and screen potential applications.
TEPSS is being developed to be general in nature and to allow users to create new components in addition to a core set of component models in almost any desired configuration. For this reason a system simulation may have a complex set of coupled nonlinear equations. Currently TEPSS is being developed within the MATLAB environment to make use of the many nonlinear and robust solvers with the capability of handling a range of constraint conditions.