• Energy Research

In order to reduce the required volume for thermal energy storage, a finned plate latent heat thermal energy storage system for domestic applications is presented in this paper. This innovative design allows the exchanging of energy between water and the RT60, used as the phase change material. The simulation of that system is covered by a validated mathematical model. The model, based on a simplified numerical approach, is used for the optimal design of the final prototype, which is compared with a conventional 500 l hot water tank usually integrated in domestic heating and domestic hot water applications. It is obtained that the resulting design is in the order of one half of the water tank volume, resulting in a more compact configuration which can be easily integrated in the space. This solution will bring a great opportunity for thermal storage especially in those applications where there is a lack of available space, as it is the case of residential flats.

[EN] This paper presents a method of subtracting the effect of atmospheric conditions from thermal response test (TRT) estimates by using data on the ambient air temperature. The method assesses effective ground thermal conductivity within 10% of the mean value from the test, depending on the time interval chosen for the analysis, whereas the estimated value can vary by a third if energy losses outside the borehole are neglected. Evaluating the same test data using the finite line-source (FLS) model gives lower values for the ground thermal conductivity than for the infinite line-source (ILS) model, whether or not heat dissipation to ambient air is assumed. This paper has been supported by the European Union Commission under projects GROUND-MED FP7-ENERGY-2007-2-TREN-218895, 043340, and Geotrainet - IEE/07/581; the Spanish Ministry of Education and Science under projects "Modelado y simulacion de sistemas energeticos complejos" (Programa Ramon y Cajal 2005) and ENE2008-00599/CON; by the Government of Valencia under project GV/2008/292; and by PAID-06-09/2734.