Replacement of old ground-source heat pumps – a techno-economic study
The goal of this project is to asses the techno-economic performance of heat pumps connected to undersized ground heat exchangers.
Background
The coefficient of performance (COP) of heat pumps (HPs) has been increasing in the last two decades; therefore, a new ground source heat pump (GSHP) is able to satisfy the heating demand of a building with less electricity than 20 years ago and a higher heat extraction from the ground instead. To satisfy the higher heat demand from the ground, newly installed GSHPs have bigger ground heat exchangers compared to older systems.
However, when an old system reaches its end of life, usually only the HP is replaced, but the ground heat exchanger, being the most expensive part of the system, is not. Therefore, the ground heat exchanger is undersized for the new installation and its higher heat extraction leads to low underground temperature. As the underground temperature decrease, the performance of the system decrease and the operational cost increases.
Goal
The student will simulate the operation of newly replaced HPs in a GSHP system to assess how the wrong sizing of the ground heat exchanger affects the overall techno-economic performance of the system.
Preliminary plan
Prerequisites
The student is expected to have knowledge of heat transfer and thermodynamics, and basic experience with programming (for example Matlab, Python).
Location and duration of the project
The project is to be performed at the Department of Energy Technology at KTH Stockholm Campus. The project should start around January/February 2022 (VT-2022) and is expected not to exceed 6 months. Specific starting date to be discussed.
Supervision and contact
Supervisor
Examiner
