A convection transport visualization technique is suggested to analyze the indoor air environment (IAE). A two-dimensional and laminar displacement ventilated room with discrete heat and contaminant sources is numerically investigated. Based on the governing equations, three convection transport functions, i.e. streamfunction, heatfunction, and massfunction, are derived to describe the fluid, heat, and contaminant transport processes, respectively. Main attentions are focused on the effects of the strength of heat source (Gr), the strength of contaminant source (Br), the strength of external ventilation (Re), and the positions of inlet/outlet openings on IAE. Numerical results illustrated that the abstract transport behaviors of the fluid, heat, and contaminant indoors are clearly exhibited by the convection transport functions which provides a simple but practical means of assessing IAE.

A direct-fired absorption chiller systes more heat nenrgy than a vapour-comlpression chiller system of slmilar capacity. The combined tise of fuel energy and electricity consumption an important criterion is its performance evaluation. Many current research efforts on absorption chiller system are related to the search of an optimal supervisory control stategy to minimize the energy costs System simulation has been a contventional approach for the investigation. However. the task of developing an accurater system model through the component-modelling approach can be tedious Oversimplification in the process, and the nonlinear structure of the equation set as result. are often the limitations for raching reliable conveging solutions. The system-based artificial neural network (ANN) modelling approach appears to be an atternative. This article describes the process of deriving an ANN model of a commercial direct-fired double-effect absorption chiller system. The techniques and the ways to overcome the diffculties ln the training orocess are discussed.