An analysis of 50 void fraction correlations available in the literature was performed to describe two-phase flow mechanism inside two helical double-pipe vertical evaporators. The evaporators considered water as working fluid connected in countercurrent so the change of phase was carried out...

Asphalt pavements subject to solar radiation can reach high temperatures causing not only environmental problems such as the heat island effect on cities but also structural damage due to rutting or hardening as a result of thermal cycles. Asphalt solar collectors are doubly effective active...

Direct steam generation (DSG) process in the absorber tubes of parabolic-trough solar collectors is experiencing an important development in the last decade. This concentrated solar technology can be used in solar fields for electricity production or industrial-process heat supply. The modeling...

Phase change materials (PCMs) can store large amounts of heat or cooling in a small amount of material, they potentially have less weight and volume compared with other thermal energy storage materials. Thermal energy storage applications such as solar hot water systems and off peak...

Thermal energy storage (TES) is a technology with a high potential for different thermal applications. It is well known that TES could be the most appropriate way and method to correct the gap between the demand and supply of energy and therefore it has become a very attractive technology. In...

Thermal energy storage systems for both heat and cold are necessary for many industrial processes. High energy density and high power capacity are desirable properties of the storage. The use of latent heat increases the energy density of the storage tank with high temperature control close to...

This paper describes a global analysis to determine the increase in annual energy output attained by a PV system with an integrated phase change material (PCM) layer. The PCM acts as a heat sink and limits the peak temperature of the PV cell thereby increasing efficiency. The simulation uses a...

The use of renewable energies in Spain is growing; nevertheless, up to now, a very low use of geothermal energy is found. In this paper, the use of low enthalpy geothermal energy that consists of converting mine galleries in underground heat exchangers is described and analysed. The system would...

This paper presents a non-tubular heat exchanger for use in a Stirling solar engine micro co-generation unit that is being developed by the University of Oviedo and the technological research centre Tekniker Foundation. The engine has been designed using scaling criteria, which imply a case of...

A cylindrical bubbling fluidized bed reactor having 2 kg/h pyrolysis capacity was developed and using this reactor fast pyrolysis of lignocellulosic biomass was carried out to obtain biocrude oil. In the fast pyrolysis system, a commonly used spiral quenching heat exchanger with electrostatic...