VÄjo energijÄ naudojanÄio turbininio ventiliatoriaus termodinaminis modelis
This dissertation studies, through application of experimental research and methods of systematic analysis, wind driven roof turbine ventilators, their mode of operation, effectiveness, and functionality. It furthermore looks into the possibilities to boost wind energy efficiency for ventilation purposes, based on stochastic variation of wind throughout the year-cycle. The aim of the dissertation is to prepare a theoretical model of turbine ventilator operation based on experimentally determined mechanical and aerodynamic characteristics. The thesis addresses the following objectives: preparing and executing an experimental research programme to structure the operating modes of the RTV into separate flow processes; carrying out a quantitative and qualitative comparison of the experimental characteristics of different RTVs of this type; proposing a structural breakdown concept reflecting the turbine ventilator construction and flow processes inside it; designing a thermodynamic model of turbine ventilator operation; and evaluating the possibilities to improve the efficiency of the use of wind energy by turbine ventilators. The dissertation consists of an introduction, three chapters, general conclusions, and lists of literature and scientific publications by the author on the topic of this dissertation. The introduction covers the formulation of the problem, the relevance of the thesis, describes the object of research, formulates the aim and tasks of the thesis, describes the research methodology, the scientific novelty of the thesis, defended statements, outlines the authorās publications and reports at science conferences on the topic of the dissertation, as well as the structure of the dissertation. Chapter 1 presents a review of wind-driven natural ventilation systems research and features the research tasks formulated on the basis of said review to allow achieving the aim of the research. Chapter 2 outlines the programme, methodology, and results of experimental research into turbine ventilators. Chapter 3 describes the thermodynamic model of operation of the turbine ventilator as developed on the grounds of experimental research. It also contains a theoretical assessment of boosting the functionality of the turbine ventilator when the device can accumulate excess wind energy.