Hotel Atrium Calculation Research And Optimization Of Air Distribution

Hotel atrium is a kind of large construction with massive volume and high space. Because of large space, the air distribution inside the atrium is complicated and will has a significant influence on comfort and energy consumption. Therefore a proper and reasonable air-conditioning system is of great important to improve the environment in large space. This paper carries out a systemic investigation on air distribution in the atrium by taking a hotel in Chongqing as the research object. The air-conditioning system, which combines nozzle-supply and floor-supply is numerically investigated by FLUENT. The influence of supply angle on the air distribution under constant air flow rate in summer condition is also discussed and finally the optimal supply angel is got which can provide an accurate reference for the operation of AC system. The numerical model are validated against the test results of field measurement, which shows good agreement and confirm the reliability of numerical computation. For the problems and deficiencies found in field measurement, such as uneven air distribution in summer and energy waste in winter, improvement method was proposed and the corresponding numerical simulations were carried out. Some important parameters of numerical computation and field measurement, such as temperature and velocity distribution PMV and PPD distribution are analyzed and compared in this paper, results showed that:(1) Air-supply angle has a certain influence on the temperature and velocity distribution inside the atrium. A reasonable air-supply angle can obviously conduct to the optimization of air distribution and improvement of air conditioning effect. The optimal air-supply angle in summer to be found is+7°, which makes the human activity zone, two meters from the ground, meets the temperature and velocity requirements and has the most uniform air distribution. The optimal angle in winter is-15°, under which condition the temperature in human activity zone can meet the design requirements, speed is slightly higher than the design value.(2) Trends of simulation results are consistent with field measurement and the comparison between them shows great agreement, which confirms the validity and reliability of the application of CFD simulation in large space buildings.(3) Using the improved method, the stratified air-conditioning model with bilateral air-supply in summer condition is much more economical and energy efficient than the original design with only one way air-supply. The improved method can satisfy the design requirements and make the atrium’s temperature lower than that of original design even with smaller amount of air supply. By using the improved one, an uniform air distribution and high comfortable degree in human activity area can be got, and the average value of PMV and PPD also meets the ISO7730standards. (4) Using the improved method, the radiant floor heating combined with bilateral floor board air-supply in winter conditions is much more energy efficient and comfortable than the original design of stratified air-conditioning model with one side air-supply combined with bilateral floor board air-supply. Parameters such as temperature and velocity distribution, PMV and PPD distribution all meet the design requirements, an uniform air distribution and high comfortable degree can be got, and the vertical temperature distribution is in accord with ergonomic. The radiant floor heating has less invalid heat loss and2℃lower design temperature than the stratified air-conditioning, and is more energy efficient.