Solar / Thermal Energy Technology Technology Offers

Unitat de Valorització de la URV posted this:
Licensing Manager at Fundació URV

The invention relates to a new solar thermally driven system that meets the heating and cooling demands of buildings. The system consists of a reversible absorption cycle which operates as a single effect absorption cycle in the cooling mode and as a heat transformer in the heating mode. Components of both cycles are the same, only the flow direction inside the system changes. In thermally driven systems, solar thermal collectors convert solar energy into thermal heat which can be used to run a thermally-activated device. Different types of thermally driven systems are available on the market, but among them, absorption systems are the most mature technology and are commercially available. The thermal collectors mostly used in solar absorption installations are flat plate or evacuated tubes. These thermal collectors produce hot water to drive the absorption machine in summer and produce chilled water. However, the hot water temperature obtained in winter with these solar collectors is too low to directly feed conventional heating systems but also is too low to drive the absorption machine in order to produce a higher temperature water stream to feed the heating system. So, in winter the hot water produced in the thermal collectors is heated up in a boiler before to feed the heating units. The invention proposes a new reversible solar driven absorption machine that in summer it would work as an absorption chiller, as the machines that we can find on the market today, but in winter it would work as a heat transformer. As heat transformer the absorption machine cycle can be driven with a heat source temperature of 40 °C to produce hot water at 60°C at an ambient temperature of 0°C. Furthermore, the lower the ambient temperature, the lower the activation temperature of the machine and higher the machine heating power. Components of both cycles are the same, only the flow direction inside the system and the connection with external devices changes. To allow the reversibility of the equipment and its operation in winter a new working pair, ammonia/lithium nitrate, has been selected because no rectifier is required and it does not present problems of refrigerant freezing at low condensing temperatures when the cycle operates as a heat transformer.
Solar driven absorption cycle for space heating and cooling