The dissertation on completion of the Doctor of Philosophy degree on specialty 144 − Heat power engineering. National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute" Ministry of Education and Science of Ukraine, Kyiv, 2023.
The introduction of the dissertation provides the relevance of the topic and the connection of the work with research projects, plans and topics. The purpose, scientific task, object, subject and methods of research are presented, the scientific novelty is defined, the practical value of the obtained results is confirmed by implementing acts, the data on approbation of the dissertation and available publications where personal contribution is outlined are presented.
In the first section of the dissertation current data on the energy status of the construction sector are analyzed, building as a complex energy system is considered, modern approaches to energy performance determination and current trends in energy efficiency are reviewed, as well as organization of engineering systems operation and the main factors influencing the choice of the optimal operation mode for heating and ventilation system are outlined.
In the second section of the dissertation the methods for energy performance of buildings dynamic modes determination which include the development of energy models based on specialized software and experimental approaches to assess the indicators of thermal comfort in buildings are presented. Three author's energy models are presented, two of which are based on EnergyPlus software and one is based on Ansys Fluent. Also, methods of conducting two experimental researches at an intermittent heating mode in residential premise are described: monitoring of internal temperature dynamics and CO2 concentration dynamics.
In the third section of the dissertation the analysis of engineering systems operation modes influence on energy performance of studied premises on the basis of the created in the EnergyPlus software environment models is carried out. The results of experimental researches applied in energy models are presented. The influence of solar heat gains and air exchange mode on the energy performance of the residential premise is estimated by modeling. The results of intermittent heating mode energy efficiency analysis for residential premise and public building are given.
The influence of the radiation component of solar heat gains on the thermal condition of the apartment with different cardinal direction of enclosing structures was studied by analyzing the energy modeling results of heat load and temperature on the inner surfaces of external and internal walls under constant and intermittent heating modes. The analysis of air exchange impact on energy performance was conducted on the basis of few approaches to air exchange setting inside residential premises according to the values required by the current norms (EN 16798-1:2019, ASHRAE Std 62.2:2019 and DBN V. 2.2-15:2019), and according to the results of an experimental study of the air change rate in these premises.
In the fourth section of the dissertation the energy performance of the heat emission system is determined on the basis of CFD-modeling. The results of the room heating and cooling rate study during intermittent heating mode are presented. On the basis of the created model the part efficiency level for a vertical temperature profile is analyzed.
The research results were transferred for use in NGO «Association of Energy Auditors of Ukraine», and State Enterprise “The State Research Institute of Building Constructions”. Results are also used in the educational process of the Igor Sikorsky Kyiv Polytechnic Institute at the Department of Thermal and Alternative Energy. The practical significance of the obtained results is confirmed by the implementing acts.
Keywords: energy efficiency, energy consumption, building, energy performance, engineering systems, heating system, building energy modeling, ventilation, EnergyPlus, simulation, Ansys Fluent, CFD-model, heat emission system, heat transfer.
