Simple model and control strategy of earth-to-air heat exchangers
The worldwide energy situation forces industrialized countries to reduce their energy consumption, especially in the building sector, which makes up a high proportion of the total consumption. Techniques such as earth-to-air heat exchangers must therefore be developed and managed to meet this challenge. Yet earth-to-air heat exchangers provide better performance when linked to efficient control strategies.
Cooling and preheating with buried pipe systems: monitoring, simulation and economic aspects
On basis of extensive monitoring and simulation work, we examine the fundamental difference between winter preheating and summer cooling potential of buried pipe systems under Central European climate, as well from an energetic as from an economic point of view. Care is taken to account for exhaustive energy balances, taking into account sensible and latent heat exchanges, as well as diffusion through soil.
Prediction of liquid phase hold-up in random packed beds
Experimental data on liquid phase hold-up in packed beds consisting of Raschig rings, Lessing rings and spheres are presented. A generalized correlation has been proposed for predicting the liquid phase hold-up in terms of packing density equivalent spherical diameter, liquid viscosity, density and flow rate.