Research On Demand-oriented Mechanism For Building Non-uniform Indoor Environment

Traditionally, the built environment focuses on uniform environment with singleparameter requirement in the whole space; however, in many circumstances, differentparameters in multiple locations or local zones are required in one common indoorspace. Therefore, it is important to create an individual environment, i.e. a non-uniformenvironment oriented to different requirements. On the other hand, with the rapiddevelopment of the construction industry, the energy consumption of ventilation and airconditioning increases fast, and therefore it is meaningful to provide an energy efficientnon-uniform environment.In the dissertation, the fast prediction on effect of an arbitrary initial condition, theidentification of constant sources, the potential evaluation of airflow patterns in creatinga non-uniform environment, and the demand-oriented optimization of air supplyparameters were studied. The main contributions are as follows:(1) A fast prediction method for effect on the transient contaminant concentrationat an arbitrary location from an arbitrary initial condition was established on the basis ofspatial division and transient accessibility of sub-initial condition. The reliability of themethod was validated by both theoretical derivation and numerical validation. Theeffects of different numbers of sub-initial conditions on prediction accuracy wereanalyzed. Based on the transient accessibility of supply air, contaminant source andsub-initial condition, the expression for transient concentration can better deal with anarbitrary initial condition.(2) Experiments were conducted to study the reliability of the identificationmethod of multiple constant sources. The effects of different factors, including numberand positions of sensors, total sampling time and sampling interval on identificationaccuracy were investigated by experiments. The identification methods for two typicalscenarios with sources released at different times were further established andnumerically validated.(3) The index of difference potential by supply air (DPSA) was defined to evaluatethe potential of different airflow patterns in creating parameter difference between twoarbitrary locations or local zones. DPSA was then applied to evaluate the non-uniformpotential of different airflow patterns and a VAV system in a new project. (4) An optimization model oriented to individual parameters in multiple locationswas proposed and the applicability of the model was demonstrated through a numerialcase study. The optimal regulation method responding to changes of requiredparameters or releasing source parameters was investigated. A fast control strategy forrequired parameters was developed.(5) Based on the above research, the realization approaches for the non-uniformenvironment were discussed, and the design and control concept of multi-modeventilation was suggested. Through case studies, the creating process and results ofnon-uniform environment were demonstrated.The research achievements in the dissertation will provide theoretical supports inparameter distribution characteristics, source identification, and design and controlmethod of ventilation systems for creating a non-uniform environment.