Radiant Floor Cooling System With Displacement Ventilation

This thesis introduced the theory and characteristic of radiant floor cooling and displacement ventilation, presented the displacement ventilation can enhance the convection heat transfer between floor surface and space in floor radiant cooling system, and condensation can be effectively prevented.The thesis used FLUENT software, based on computational fluid dynamics and heat transfer theory,numerically simulated temperature field of the inner of floor.The thesis introduced the test in radiant floor house in Huazhong University of science and technology. The test measured the temperature field and speed field at the condition of radiant floor cooling without ventilation and radiant floor cooling integrated with displacement ventilation. The test showed the temperature field is very uniformity, especially without displacement ventilation. And testified the bigger the proportion of convection heat transfer, the less the uniformity.The thesis used AirPak software,based on computational fluid dynamics and heat transfer theory, numerically simulates temperature field and speed field of indoor. And the result of simulation was very similar to the result of test. When there is heat source, simulated temperature field and speed field of indoor at the condition of radiant floor cooling and radiant floor cooling integrated with displacement ventilation. The temperature field was very uniform, except the round of heat source. And the direction of air speed around heat source was upwards because of the action of buoyancy. When there was displacement ventilation, we can see the airflow felled to the floor and flow close to floor, except at the neighborhood of heat source.From the nephogram of PMV and PPD, we can see it was very comfortable at both radiant floor cooling with or without displacement ventilation.From the nephogram of relative humidity, we can see condensation can be effectively prevented.This thesis classified various control methods for the radiant floor cooling system and the characteristic of them, and the methods of preventing condensation.