Research On Indoor Thermal Environment Of Radiant Floor Cooling

Along with the deve1pment of economy and the enhancement of people 1iving standard, energy consumption of air-conditioning increases unceasingly. The thermal comfort and indoor air quality was concerned by people. Currently, the hybrid air-conditioning system of chilled panel and displacement ventilation was considered to be one of the economical, energy conservative,comfortable air- conditioning modes and arouses more and more research interests.The Mechanism and characteristic of the radiant floor are discussed. The mathematical/physical models and the simulation method for the indoor thermal environment with floor radiant cooling system are introduced in this thesis. There are two parts in the calculation space, one is the floor unit, and the other is the room. The heat exchange in the floor part, and radiation as well as convection in the room are discussed.The model of floor coil established by PRO/E, is imported into CFD——Airpak. The boundary conditions of the room are setted in the Airpak software. The results of simulation compared with test results are agreeable.Test results show that: the upright temperature distribution is not even while the radiant floor coil and the fan coil were running together. The numerical simulation data simulated by Airpak are agree with the tested data.The numerical simulation results show that: under the condition of the same supply water temperature, the indoor air temperature and the floor temperature decline with the increase of the water flow rate; under the condition of the same supply and return water temperature difference, the indoor air temperature and the floor temperature decline with the increase of the water flow rate; under the condition of the same water volume, the indoor air temperature and the floor temperature rise with the increase of the water flow rate; under the condition of the same supply and return water temperature difference, the indoor air temperature and the floor temperature rise with increase of the water flow rate. Under the condition of the same cooling rate and supply water temperature, the impact of water flow rate on the indoor air temperature is more than the impact of the supply and return water temperature difference. The change of the outdoor air temperature has little impact on the indoor air temperature, it means that the radiant cooling floor system has self-adjusted function as well as the radiant heating floor system.