Research On Theory And Method Of Air-conditioner Energy Saving Design Based On The Thermal Comfort

The rapid development of economy and the rising of people’s living standard have stimulated people’s requirement for an improved environment. While people are committed to create a comfortable living environment, we have consumed lots of energy and resources and caused damage to the ecological environment. Correct understanding of the relationship between comfort and energy saving, and achieving win-win between them are effective way to coordinate their contradiction.Incorporating the theory of quality function deployment(QFD) and axiomatic design(AD), the energy-saving design model of air conditioner based on thermal comfort is established, and two basic energy-saving design approaches are presented, including the direct method driven by the energy utility model and indirect method driven by function-structure decomposition and mapping. In order to coordinate thermal comfort and energy-saving in design process, the functional house of quality based on thermal comfort is set as the starting point, and the energy utility model is built to bring energy information to design process, and the optimal solution is obtained by design plans evaluation.Applying QFD method, the functional house of quality (HoQ) of the thermal comfort requirements is illustrated. Based on the analysis of physical, psychological and behavioral needs of human thermal comfort, the functional HoQ is established so the human thermal comfort demands are converted to the functional requirements of the product. Aiming at the problems of the fuzzy, imprecise and dynamic information and group decision making in HoQ, uncertain linguistic variables and rough analytic hierarchy process are applied to express and calculate the parameters in the each part of HoQ, and the importance degree of human thermal comfort demands and the priority result of product functions are obtained.Aiming at the problems of the fuzzy, imprecise and dynamic information and group decision making in HoQ, uncertain linguistic variables and rough analytic hierarchy process are applied to express and calculate the parameters in the each part of HoQ, and the importance degree of human thermal comfort demands and the priority result of product functions are obtained.Aiming at the functions which are related to thermal comfort demands and high energy consumption, in the view of saving energy directly, the energy utility model containing energy factors recognition, the extraction and application of energy design factors is built, and the methods of the energy design factors extraction, decoupling, and influence degree quantification are analyzed. Taking household air conditioner as an example, the energy design factors are extracted, two coupling factors, volumetric efficiency and heat transfer coefficient are decomposed, and the influence coefficient of energy design factors are calculated. Through changing the fan blade structure parameters, the supply air volume is targeted to optimize energy.Aiming at the functions which are low or unrelated with the energy consumption, the optimization design of structure is used to achieve energy-saving indirectly. The evaluation index and methods of energy saving indirectly are presented in terms of human thermal. Selecting the air outlets of household air conditioner as research object, three design plans are put forward, and the corresponding models are built and simulated using FLUENT12.0, the air outlet designs are evaluated adopting the evaluation index and simulation results in order to obtain the optimal design of the air outlets.