Generatori Stirling per edifici zero energy: sistemi di tri-generazione

Responsabili di progetto

Francescosaverio Marra, Chin-hsiang Cheng

Accordo

TAIWAN - NSTC - National Science and Technology Council

Bando

CNR/MoST biennio 2018-2019 2018-2019

Dipartimento

Ingegneria, ICT e tecnologie per l'energia e i trasporti

Area tematica

Ingegneria, ICT e tecnologie per l'energia e i trasporti

Stato del progetto

Nuovo

Proposta di ricerca

Environment preservation, energy and growing economy are becoming strongly interconnected themes requiring new solutions to be exploited. An example of this interconnection is the demand for the development of almost zero-energy buildings, i.e. buildings capable to be almost autonomous from external energy supply or at least not dependent on the energy supply from utilities.
This demand is driven by the fact that buildings contribute for a very large share to the global energy demand and to the emission of pollutants in the atmosphere.
Apart from the measures able to lower the energy consumption of the building (thermal insulation, efficient electric appliances and lightening, etc.), several systems have been developed to provide the energy required for the activities carried out in the building: solar photovoltaic panels are probably the most common, able to provide electric power during daylight hours, and similarly solar thermal panels, that can be adopted to provide ambient heating and sanitary hot water. Other systems are also available to reduce the power consumption for ambient cooling. Nevertheless, large energy storage systems (like heat storage and batteries) are required to be integrated in the system to supply the energy during hour of unavailability of daylight or insufficient solar irradiation.
As a result, the actual conception of a zero energy building is a very complex system formed by several subsystems, with the consequence that costs are very high and reliability relatively low.
The aim of this research program is to deepen the possibility to employ the Stirling engine and cooler technology to lower the number of components required in a near zero-energy building, increase the efficiency and contemporary raise the reliability of the overall system. Stirling cooler could be used to convert mechanical work into heating and cooling effects and produce the temperature difference by the expanding and compressing the working fluid. Similar concept of the Stirling cooler could also be adopted to develop a heat pump. Compared to the traditional vapor-compression refrigeration systems, the Stirling coolers are of higher efficiency and with no components like compressor, expansion valve, evaporator, or condensers. Therefore, they are considered to be clean cooling devices. On the other hand, Stirling engine is an external combustion engine, which is compatible with a variety of thermal sources, such as solar radiation, waste heat, geothermal energy, combustion, and so on. With the heat input to the hot end of the engine, the Stirling engine could be operated to produce mechanical work/electricity at a high thermal efficiency. In principle the Stirling machines are capable to provide all the forms of energy (heat, cool and electricity) that form the almost total energy load of a building. Furthermore, they can be easily adapted to several sources of energy. A system able to generate heat from the combustion of different forms of renewable fuels and/or concentrated solar power and very effectively transfer the thermal energy to the engine has been recently developed in the Istituto di Ricerche sulla Combustione - CNR (IRC-CNR). In addition, IRC-CNR has been working on the combustion technology with fluidized bed that can be adopted to enhance the efficiency of Stirling engine. On the other hand, a solar-driven combined heating, power and cooling (CHPC) system (or tri-generation system) based on integration of Stirling engine and cooler has been developed at National Cheng Kung University (NCKU) for years. It is then of very great potential to develop a joint collaboration project between CNR and NCKU in order to explore the tri-generation systems based on Stirling technology for the zero-energy buildings. Besides, it is expected that with the help of the fluidized bed, the heat transfer in cooling operation mode could be largely increased; however, the issue has not yet been explored.

Obiettivi della ricerca

The research program aims to:
1) Explore the possibility to adopt the fluidized bed technology to effectively cool-down a stream of air used to fluidize a bed cooled by a Stirling engine;
2) Explore the possibility to increase the engine efficiency consequent to the increased heat transfer coefficients both in the power production and cooling modes;
3) Evaluate the possibility to reduce the number of subsystems in a near zero-energy building;
4) Verify the proper dimensioning of such a system to identify the most advantageous application to near zero-energy buildings.
5) Evaluate the possibility to develop a solar-driven combined heat, power and cooling (CHPC) system based on Stirling engine technology.
The cooperation between the two involved institutions appears extremely profitable. IRC-CNR possess a long term expertise in the development of fluidized bed systems and fluidized bed combustion. Recently it has becoming to study the integration with Stirling engines for power production. The NCKU has a long term expertise in the development of Stirling engine/cooler technology, especially in application to the tri-generation systems. The program will therefore enable an extremely fruitful exchange of knowledge and will establish a base for a long term cooperation.
Results of this cooperation will be disseminated as publications in most relevant scientific journals and specialized conferences. Further visibility will be provided through the Institutional Web Site.

Ultimo aggiornamento: 04/09/2025