PhD Position in Chemical, materials and energy technology, Early stage researcher

Tallinn University of Technology, School of Engineering, Department of Energy Technology offers a 4-year PhD position in the field of chemical, materials and energy technology.

Proposed doctoral thesis topic:  "Modelling of large-scale heat pumps for district heating and cooling".

Supervisors: Professor Anna Volkova and Eduard Latõšov

Abstract

The aim of this research project is to develop model for large-scale heat pump integration into district heating and cooling system. This model should handle variable parameters of heat sources (waste heat, seawater, solar heat, etc.), heat pump configurations and operating conditions for district heating and cooling. The project will address following scientific questions: What will be the effect of heat pumps internal heat loss reduction on the efficiency of district heating/cooling systems? What is the realistic HP capacity potential considering the proximity to existing DH areas? Which investments are required, when large heat sources should be used to feed into existing DH? What is the potential of large heat pumps in district heating and its role in future energy sector in Estonia?

Description

In the EU, heating and cooling is responsible for half of the final energy consumption, from which around ¾ is produced by fossil fuels. Even though district heating (DH) accounts for only 12 % of the heat supplied to EU citiziens, the proportion varies greatly by country. Especially countries from the northern region have a high share of DH. The proportion of DH in Denmark, Sweden, Finland, Poland and the Baltic states is above 50 %. Therefore, transforming the DH sector in these regions is important, but also a great chance and help for achieving the ambitious climate goals.

Heat supplied by sustainable low-temperature DH networks can be considered as one of the best heat supply options for urban buildings due to lower heat losses and the possibility of using RES. A supply temperature between 50 oC to 60 oC is the most important feature of the 4th generation DH. Energy supply and transition systems and end users will benefit from a low temperature. Implementing power-to-heat (P2H) solutions is a good way to increase the flexibility of the energy system, as P2H options will help address both heat and electricity consumption fluctuations. Besides, when the electricity used for P2H comes from RES, then the use of P2H technologies, such as heat pumps (HPs), will help to introduce RES into the energy system.

One of the P2H options that has been used widely in Denmark is the use of large-scale HPs to supply DH. Since 2010, 106 HPs with a thermal capacity above 100 kW have been implemented in Denmark. The total installed thermal capacity of these HPs results into 368 MW and the trend is growing.

Large-heat pumps can become good solution for district heating and cooling decarbonization and increase of heat/cold produced from non-fuel sources.

Model development of large-scale heat pump integration both into district heating and district cooling syste will contribute to this sector transition towards sustainability and decarbonization.

Responsibilities and (foreseen) tasks

• Determination of the topology of a process for large heat pump integration into district heating/cooling system.
• Model development for the simulation of large-scale heat pump’s system-level dynamic behaviour modle implementation in programming environments such as for example Matlab or Modelica.
• In-depth characterization and analysis of the system-level behaviour under dynamic operating conditions using methods and concepts from nonlinear dynamics.
• Development of advanced (nonlinear) control strategies for regulation of the large heat pumps based on the above modelling and characterization of the system-level dynamics.
• Using optimization models to perform detailed calculations on the levelized cost of heating, when HPs are used in specific DH areas.
• Contribute to the organization of research and practitioner workshops where project findings are presented