A Research On Operating Strategy For Mixed-mode Cooling In Office Buildings In Hot-summer And Cold-winter Area

The emerge and development of air-conditioning technology brings great convenience for mankind’s creating comfort built environment independently, while it also leads such problems to be solved as huge building energy consumption, deterioration of indoor air quality and sick building. Mixed-mode cooling is such a cooling method that uses different cooling methods to meet occupants’ requirement for thermal comfort and reduce energy consumption and operating cos t according to different weather condition in summer. This thesis researches operating strategy for mixed-mode office buildings in Zhuzhou, belonging to hot-summer and cold-winter area, and aims to provide reference for the application of mixed-mode cooling.At first, the domestic and foreign research status on mixed-mode cooling is reviewed. It concludes whether the expected effect is reached lies in effective operating strategy based on analyzing and summarizing the previous research results. This thesis will research the operating strategy in the following three aspects.As a kind of low energy cooling method, ventilation cooling directly affects the building energy consumption. This research first accounts the principle of different ventilation modes, classical model, method and conclusion and the function of ventilation, which will found a theoretical basis for subsequent theoretical analysis.It chooses demanded air flow rate that meets the requirement of thermal comfort and indoor air quality as operating parameter for mixed-mode cooling, based on thermal comfort standards in free-running buildings, IAQ standards and theory of heat balance.Then it takes a typical office building in Zhuzhou as an example, determines the thermal comfort temperature range and sets up the operating strategy based on analysis of typical meteorological year data. It analyzes the effectiveness of the operating strategy through the establishment of building model and relevant theoretical calculation.Finally, it uses De ST to simulate the thermal process of building model, including the room temperature under natural ventilation and hybrid ventilation and the potential of energy conservation, to verify the effectiveness of the strategy set up in this thesis.This thesis researches the operating parameters and strategy for mixed-mode cooling through theoretical calculation combined with numerical simulation, which can provide reference for the application of mixed-mode cooling technology in the field of building energy conservation.