Public Defence in Energy Technology, M.Sc. Tianchen Xue

Ground source heat pumps (GSHPs) are an efficient solution for the decarbonization of building heating and cooling systems. In Nordic countries, integrating a backup energy source with GSHP, such as district heating, offers a solution for enhancing long-term sustainability and economic viability of heating systems. This doctoral dissertation investigates methods in the system modeling, sizing, and control of a hybrid GSHP system coupled with district heating in an educational building complex in Finland. The thesis analyzes simplification methods for borehole field modeling, design methods for hybrid GSHP systems, a cost-optimal control strategy for system operation, and demand response control strategies for utilizing the thermal storage capacity of building thermal mass. The results demonstrate the viability of using simplified borehole field models without sacrificing accuracy. Furthermore, increasing the supply cold water temperature level of air handling unit and lowering indoor air heating and cooling temperature setpoints will improve long-term operational performance of the borehole fields. The utilization of cost-optimal control and demand response strategies is an effective way to reduce energy costs and enhance building energy flexibility. The findings provide valuable insights and practical guidance for utilizing hybrid GSHP systems in Nordic countries. 

Doctoral Student: Tianchen Xue

Opponent: Prof. Laurent Georges, Norwegian University of Science and Technology

Opponent: Prof. Livia Mazzarella, Politecnico di Milano, Italy

Custos: Prof. Risto Kosonen, Aalto University School of Engineering, Department of Energy and Mechanical Engineering 

The public defense will be organized in Lecture Hall 216, Otakaari 4 and online on Zoom.

The thesis is publicly displayed 10 days prior to the defense in the publication archive Aaltodoc of Aalto University. 

Contact information of doctoral student: 

Doctoral theses in the School of Engineering: https://aaltodoc.aalto.fi/handle/123456789/49