CONSORCIO – GRUPOS DE INVESTIGACIÓN
UNED-STEM Group of the National University of Distance Education
The research group Thermal, Energy and Environment Systems (STEM) was born in 2007 with the common objective of contributing to the advancement and improvement in the production and management of thermal energy and thermal electricity, in order to reduce the demand for exhaustible resources, streamline consumption, processes and contribute to sustainable development.
The main lines of research developed by the group are as follows:
- Thermal and optical characterisation of concentrated solar collectors, as well as the proposal of new designs.
- Analysis and simulation of solar thermal plants: optics, receivers, storage systems and power blocks.
- Thermodynamic and thermo-economic optimisation of combined cycles: conventional technologies (CCGT) and hybrid technology with solar energy (ISCC).
- Design, simulation and development of absorption machines for the production of solar cooling in buildings.
- Energy saving and emissions reduction in buildings.
The experience and training acquired by the group in relation to the objectives of the ACES2030-CM research program are discussed in short below:
With regards to Objective 1, the working group has extensive experience in power cycles and in the coupling between the solar subsystem and the electric power production subsystem. Research in this field has generated many publications, including those dealing with coupling to combined cycles; solar-only plants with thermal storage; or power cycle optimisation (Rankine, Brayton or ORC). Among the relevant projects in this topic, it is worth highlighting the CENIT CONSOLl+DA project, which deepened the use of Rankine cycles with steam and ORC type cycles in solar thermal plants. Two National Projects have also been carried out: ENE2012-37950-C02-01 and ENE2015-70515-C2-1-R (the last is still ongoing) on combined cycles hybridised with solar energy. In addition, two doctoral theses have been directed in this topic.
With respect to tower receivers, the working group has participated in the design of a superheated steam receiver. for Abengoa. Tools have also been developed to analyse heat transfer in cavities and tube receivers, which can be easily extrapolated to the tower. A doctoral thesis on volumetric receivers has been directed and another thesis on the performance of concentrated solar receivers has also been presented recently. Finally, it is worth noting that work has also been done on the part of the optics of heliostats, having directed a thesis in this field. This experience is also valid for Objective 3 of the project.
In line with Objective 2, the working group has extensive experience in the design of Fresnel collectors, both in monotube and multitube. Regarding this latest design, UNED has collaborated with UPM and OHL (Industrial on the Futuro Solar project) that culminated in the construction of a Fresnel prototype with multi-tube receiver on the UPM technology campus. We have also collaborated with the UPM on numerous patents, most of them related to Fresnel collectors. Recent research with Fresnel collectors has focused on the production of process heat. Finally, it is worth noting that the work of the group in the field of solar cooling, with numerous publications, among which it stands out having participated in two patents with the CSIC in 2008.