Influence Of Indoor Partition On Air Distribution Of Ceiling-Mounted Cassette Type Indoor Unit

The ceiling-mounted cassette type indoor unit is widely used in different type buildings. Normally, there are furniture and separators inside the room, which will change the air distribution and have influence on thermal comfort and energy consumption. For studies on the air distribution of ceiling-mounted cassette type indoor unit is few, and studies of influence of partitions on it is fewer, it is necessary to study the influence of partitions on the air distribution of ceiling-mounted cassette type indoor unit.In this study, we used experiments and CFD simulation methods. According to the different positions of partition and mainstream direction of air supply, four layouts were designed in order to study the influence of partitions on the air distribution of ceiling-mounted cassette type indoor unit. The distributions of indoor temperature and velocity were gotten by experiments, as well as boundary conditions, which were used for CFD simulation.In order to achieve accurate simulation, infiltrate flow load should be considered, so the tracer-gas single point measuring method was used to measure the air infiltration rate of room, and a mathematical model for the air infiltration rate of the inside wall was made based on the measured air infiltration rate by experiments, a prediction formula was got using the least square method. Based on the predication formula, infiltrated flow load of different temperature differences between indoor and outdoor can be calculated.When CFD is used to simulate and evaluate the air distribution, whether evaluate indexes are scientific is very important. So it is necessary to modify the original air distribution evaluation indexed. In this study, the evaluation indexes were modified based on CFD simulation and an example was used to show it was accurate and scientific to use the modified indexes.FLUENT was used to simulate the indoor air distribution of different layouts, considering infiltrate flow load and modified evaluation indexes. For the partition can have influence on not only the whole room air distribution, but also different zones of the room, according to the real position, the test room was divided into several zones, in which the modified indexes were calculated. Several air distribution designing advises were given by combining whole and regional analysis methods to study the influence of partition on the air distribution of ceiling-mounted cassette type indoor unit.