The Optimization Of Control Modes Of VAV Air Condtion Systems Combined With VWV Systems

It is a pressing problem to effectively reduce the energy consumption of air-conditioning system which is in the majority of the building's energy. It includes air system and chilled water system in a typical and integrated air-conditioning system. And to optimize the two parts is one of the potent measures to energy savings. The air-conditioning system operates in lower loads mostly. For the air system, VAV system can make changes to follow the load and is good for energy savings, so it is availably applied and researched, and it comes out several control modes. For the chilled water system, it also comes out several control modes due to make the cold source's flux match to the terminal apparatus' needs and reduce the cost of circulations. Facing to several modes, it has important meanings to find a best assembled mode to satisfy the different load, which is aimed at reducing the time for response.It analyses the sensitivity of cool coil, and points out the relationships between variables such as air inlet temperature, air flux and chilled water flux, and formulize them, and also prepare for bringing air system and chilled water system in an air-conditioning system. Bring a new one which is named return water temperature prediction mode in existing modes, and in this new mode, it brings in feed forward idea in order to response earlier. Simulate an VAV system with Matlab/simulink software in four ways such as return water temperature control mode, improved return water temperature control mode, variable pressure control mode and return water temperature prediction mode, and shows that these four modes are all feasible from the supply air flux, water flux, indoor air temperature and supply air temperature, for they these four factors adjust themselves periodically when the outdoor air temperature changes periodically, supply air flux, water flux, indoor air temperature and supply air temperature adjust themselves periodically when the outdoor air temperature changes periodically. It shows these four ways are available in air system and water system when people adjust them by frequency conversion. Confirms that the return water temperature prediction mode has the forward feed function, and it is advanced through to objective function contrast...