ANALYSING BOREHOLE ENERGY SYSTEM INFLUENCE ON A HEAT RECOVERY UNIT IN WINTER TIME
Stockunaite, Karolina (2018)
Stockunaite, Karolina
Kaakkois-Suomen ammattikorkeakoulu
2018
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-201805158138
https://urn.fi/URN:NBN:fi:amk-201805158138
Tiivistelmä
This investigation studies how AHU system is influenced by the heat gained from the vertical boreholes besides the certain H-building. Chosen H-building is a part of XAMK campus and located in Mikkeli, Finland. The idea of this thesis is to understand how big impact the direct energy (no heat pump) from the ground has to the liquid coupled heat recovery unit at cold season.
One of the main concern is to evaluate the influence of the energy the boreholes via needle heat exchanger give to the supply air and to compare result when the outdoor air is not preheated (when there is no needle heat exchanger). At this point, having boreholes system as a preheater, the temperature ratio of the HRU might get reduced. However, as the supply air entering the HRU is warmer, it is believed the limitation of the exhaust air should last shorter when compared to the system without any preheater.
Structure of the investigation consist of both theoretical and practical parts. In the first part, the reader is familiarized with the main information the research is related to – about ground source energy, needle heat exchanger, liquid coupled heat recovery unit and brief review about control systems installed in the investigated air handling unit system.
Results were gained after estimations based on the collected data. In order to avoid getting inaccurate results some parameters were accepted as constant values. Results were presented in tables and graphic forms. In the end, it was concluded that having borehole energy system as a preheater for the outdoor air, can lead to some savings as this type of energy gives free preheating and the need for using district heating is reduced.
One of the main concern is to evaluate the influence of the energy the boreholes via needle heat exchanger give to the supply air and to compare result when the outdoor air is not preheated (when there is no needle heat exchanger). At this point, having boreholes system as a preheater, the temperature ratio of the HRU might get reduced. However, as the supply air entering the HRU is warmer, it is believed the limitation of the exhaust air should last shorter when compared to the system without any preheater.
Structure of the investigation consist of both theoretical and practical parts. In the first part, the reader is familiarized with the main information the research is related to – about ground source energy, needle heat exchanger, liquid coupled heat recovery unit and brief review about control systems installed in the investigated air handling unit system.
Results were gained after estimations based on the collected data. In order to avoid getting inaccurate results some parameters were accepted as constant values. Results were presented in tables and graphic forms. In the end, it was concluded that having borehole energy system as a preheater for the outdoor air, can lead to some savings as this type of energy gives free preheating and the need for using district heating is reduced.