CFD prediction of heat transfer in heated or cooled concrete floors in laying areas for pig

Abstract

Abstract. Two-dimensional CFD modelling was used to gain knowledge on how the presence of laying pigs affects the heat transfer in heated or cooled concrete solid floor laying areas. The study included three different floor types; A) an insulated concrete ground floor, B) an uninsulated concrete floor element with no insulation underneath, and C) a concrete floor element with insulation underneath,. All three floor types where investigated both with and without simulated pigs covering 50 % of the laying area, and all 6 combinations where investigated in both heating and cooling mode. For heating the study showed that the presence of pigs caused a significant reduction of heat transfer to the floor, and likewise a significant increase in water temperature required to transfer heat to the floor. For cooling, the presence of animals caused a significant increase in cooling effect (heat removal) and caused a large cooling even when the water temperature was of the same magnitude as the air temperature. Without either heating or cooling, the study showed a higher surface temperature on insulated floors compared with uninsulated floors and in addition, the insulation reduced the energy consumption for floor heating by about 60 percent. Finally, the study showed that that more than 50 % of the steady state change of the floor surface temperature, caused by changed pipes temperature, takes place during the first hour after the water temperature are changed.