Optimisation methods and computer codes were needed to find the proper sizing of the selected technologies taking the studied Process constraints and technology sizes available on the market into account. The optimisation criterion or objective function to be minimised is chosen among those available, i.e. minimum of energy, or of energy, or of cost.
This result is a set of enhancements (Foreground) of three independent existing software (Background). The developments have been based on available software from other project partners, as written here above; for the developments of interfaces necessary for the integration with the IEST databases, following information is to be given:
-Partner 3 did focus on the heat pumps technologies.
-Partner 6 on heat exchangers.
-Partner 4 on all the technologies except heat exchangers.
These three tools are used for engineering studies in the field of RUE (rational use of energy). These three Partners, 3-4-6, can be considered, as references in this field, because they belong to the scientific units whose knowledge constitute the state of the art in this field. Therefore the foreground developed is a clear plus with respect to the former state of the art. The robustness of MILP is well known, even when the number of constraints is big; this is the case when the insertion of several IEST in a complex process is attempted.
The use of the MILP method necessitates though, that the process and IEST constraints (modelling equations) are linear. The linear model of the process is readily obtained by a tool of Belsim, called EASY (Energy Analysis and SYnthesis) and the coding of the mathematical models of the IEST have been made linear too, before to store these in the technology databases. Without going too much in the details, for property protection reasons, let us mention that the possibility exists to use another Belsim's software, called VALI, to linearise the process model in the vicinity of the nominal process working conditions, during the sequential approach to the integration solution (Process-IEST). With respect to the current state of the art, this MILP implementation has a competitive advantage. This is why the developers are convinced of the added value of the methodology and tools developed.