热湿地区用的辐射冷顶板加置换通风系统_secret.docVIP

Radiational panel cooling system with continuous natural crossventilation for hot and humid regions Abstract This paper investigates a hybrid cooling system, utilizing wind-driven cross ventilation and radiation panel cooling in an office setting .The characteristics of the indoor environment are examined using computational fluid dynamics (CFD) simulation, which is coupled with a radiation heat transfer simulation, and HVAC control in which the PMV value for a human model in the center of the room is controlled to attain the target value.The system is devised with an energy-saving strategy, which utilizes stratified room air with a vertical temperature gradient. The cooled air settles down within the lower part of the room, while the hot and humid air passes through the upper region of the room, sweeping out the heat and contaminants generated indoors. This strategy is found to be quite energy-efficient in the intermediate seasons of spring and autumn in Japan. Even under hot and humid outdoor conditions, the hybrid system coupled with radiation cooling would bring significant energy savings are possible compared with a hybrid system coupled with under floor air-conditioning. 1. Introduction Wind-driven cross ventilation is considered to be a promising energy-effective strategy, since it utilizes nature’s power. Adjusting the indoor environment by natural cross ventilation was the traditional method in hot and humid regions of Asia including Japan. However, in modern buildings, where certainty, reliability, and efficiency are preferred, the use of wind-driven cross ventilation alone is inadequate. A hybrid air conditioning system with controlled natural ventilation, or a combination of natural ventilation with mechanical air conditioning is considered to be able to overcome the deficiency of wind-driven cross ventilation ,and has significant energy-reducing effects .Many studies have been conducted on natural ventilation systems and hybrid air-conditioning systems