Applied Research, Air-conditioning System

Task Air-Conditioning (TAC) is an innovation to the traditional methods of air-conditioning, providing advantages such as excellent air quality and appreciable air quality, advanced personal satisfaction, great potential for energy saving, etc. However, it has not been used widely for the lack of research for appliance, especially in constitution, thermal comfort prediction and energy-use analysis of TAC. The task of this dissertation is an exploration to the domains above.TAC system is divided into task system, ambient system and centralized air-handling system in this dissertation. Existed and potential constitutions are concluded with sketches of different systems. The process, merits, demerits and applicability of different systems are analyzed.Artificial Neural Network (ANN) model for predicating thermal comfort index PMV of local environment in a workstation is developed. The 7938 groups of studying and testing data samples are chosen from the intervals of PMV and its parameters recommended by ISO 7730. The general parameters zone of local environment constructed by TAC is considered at the same time, as well as the standard comfort intervals of ASHRAE. The results of training and testing indicate that the ANN model can predicate PMV quickly and accurately.The energy models of TAC system and traditional variable air volume (VAV) air-conditioning system are developed for the chosen building model. Simple occupant behavior and control model, heat transfer between workstations and that between workstation and insignificant area are considered in the energy model of TAC. Under climate conditions of typical meteorological year of three cities in China and different characteristic parameters of TAC, horary energy use of two air-conditioning systems and the energy-saving ratios of TAC system compared with VAV system are calculated in 4380h a year , from which the characteristics of energy use of TAC are analyzed and discussed. The conclusions indicate that it needs integrated consideration of climatic conditions during runtime, parameters of sending air, type of official business, system collocation and strategies of operating and controlling to evaluate whether TAC system is more economical than the traditional systems.