Effects Of Air Outlet Locations On The Characteristics Of Warm Air Heating System

It has been estimated that energy consumption of building accounts for more than27%of the total energy consumption in our country and increases by Certain speed, including energy consumption of air conditioning accounts for more than60%. Therefore, researchers have pay more attention to efficient utilization of energy. For large space buildings, heating in winter is not easy to guarantee results, thus leading to increased heating energy consumption. Compared with the traditional heating mode using radiative heating, heat reduction can improve the vertical temperature distribution of high-large space, which is reducing space heating energy consumption in winter.Hot air induces the effect of buoyancy due to large space sizes. The amount of heat consumption in the upper part of building space, which caused lack of heat energy in the bottom of workspace and the whole space featured down-cold and up-hot. Although there is sufficient heating energy, it can’t make demand of heating temperature in the bottom of large space and there exists loss of large quantity of energy in the top, resulting in the increase of air conditioning load. Meanwhile the effect of heating is difficult to realized. As mentioned above, decrease heat supply can reduce the difference of temperature between the upper and lower parts in winter for high-large spaces. The reasonable air distribution can ensure the full use of heat contained in the jet and suppress heat convection between the upper and lower part of the space.In the present study, through the experiments to collect experimental data firstly, for a preliminary study on the characteristics of small heating space, and verify the accuracy of the calculation method with the experimental data, the commercial FLUENT software was used to simulate the distribution of flow field and temperature field by numerical simulation, then Investigate the thermal comfort and energy efficiency in different air supply conditions.The results show that, the lower outlet location, the higher energy utilization of the heating room in the lower region, with the same load and supply air condition,the higher the temperature and the thermal comfort of interior staff. Lower return can improve air flow directly into the space ratio of staff, the higher the outlet location, the lower return play a significant role in the Lower space for the temperature and the gain of the utilization coefficient of energy; the airflow velocity of the active area were significantly greater than the return air, but cannot affect human thermal comfort. The temperature difference between the upper and lower regions of space with tall height increases send increasing outlet, the heating energy consumption will also increase accordingly, when the outlet location increase on the8.5meter and with the return air, effective temperature difference is much smaller than the lower limit of thermal comfort, even with the high cost of energy, it is also difficult to meet the personnel requirements of the active area of thermal comfort.