The Ventilation Character Study Of Underfloor Distribution System With Multi-zone Model

Due to the advantages in the aspects of improving the indoor air quality and the energy-saving in all kinds of ventilation or air conditioning systems, underfloor air distribution system(UFAD) is appreciated by researchers and technicians of all nations. The designing approaches and standards relating to the traditional system of air distribution can not satisfy the specialty of UFAD. Hence, from the angle of realistic application, mainly based on the fundamental experiments, this project focuses on the experimental research on the characteristics of UFAD by the way of CFD. The important work and achievements are as follows:(1) For the first time studies the ventilation characteristics of the room of UFAD system, analyze the importance of the following factors in the designing of underfloor airflow organization, such as air supply inlet type, the temperature and speed of air distribution, generated quantity of heat source. The correlation analysis model between the ventilation efficiency and the above factors is founded.(2) Through experimental and numerical simulation researches on the influence of cooling wall on the ventilation characteristics and the air flow characteristics of UFAD system firstly. The research makes know: the heat plume generated by indoor heat source, the horizontal airflow generated by inducement air, the dropflow of the cooling wall and horizontal convection airflow produced by the temperature difference between the major indoors air and the air near to the cooling wall are the major influence factors on the indoor delamination of temperature and air flow in the room of UFAD with inner heat source and cooling wall.(3) Based on the traditional zone-model, regard the room of underfloor air distribution with the cooling wall and inner heat source as the research object, comprehending the processes of wall heat conduction, heat exchange of convection dropflow, heat radiation, and exchange of convection heat by the inner control volume, we put forwards three fundamental models,"dropflow model","heat plume model", and"heat-mass balance model". So the multi-zone balance model of heat-mass, based on UFAD system is established.(4) Based on the multi-zone balance model of heat-mass in the room of UFAD system, the simulation computation program is produced to describe the delamination...