Energy Flexibility Potential of Heating and Cooling Systems of a Nearly-Zero-Energy Office Building
Authors
Clementsen, Rógvi Klæmint Djurhuus ; Loukou, Evangelia ; Dia, Bianca Alexandra
Term
4. Term
Education
Publication year
2018
Pages
50
Abstract
Den stigende andel af vedvarende energi kræver energifleksible bygninger, der kan understøtte et smart elnet via efterspørgselsstyring. Denne afhandling undersøger energifleksibilitetspotentialet for tre varme- og køleløsninger i et nyt næsten-nulenergi kontorbyggeri: et nyt to-rørs varme- og kølesystem, et radiatorsystem med mekanisk ventilation til køling, samt et strålegulv (gulvvarme) med mekanisk ventilation. Hvert system blev simuleret i EnergyPlus i både en referencecase med faste setpunkter og en fleksibilitetscase, hvor setpunkter varierede efter elpris og køling blev aktiveret ved hjælp af vejrforudsigelser. Systemerne blev sammenlignet i Matlab med fire metrikker: evne til effektjustering, evne til energiforskydning, økonomisk fordel (årlig energikostnad) og termisk komfort. Resultaterne viser, at det nye to-rørs system opnåede de største energibesparelser og den højeste fleksibilitet, samtidig med den bedste termiske komfort, blandt andet ved at overføre overskudsvarme mellem zoner. Strålegulvet udviste også stor fleksibilitet, især i form af energiforskydning, som følge af indlejret varme i bygningens masse. Den fleksible setpunktsstyring reducerede komforten en smule for alle systemer, men ikke i et omfang der vurderes kritisk. Fremtidigt arbejde kan afprøve andre setpunktniveauer for at øge fleksibiliteten i radiator- og gulvvarmesystemer.
The growing share of renewable energy calls for energy-flexible buildings that can support a smart grid through demand response. This thesis assesses the energy flexibility potential of three heating and cooling configurations in a new nearly-zero-energy office building: a novel two-pipe heating and cooling system, a radiator system with mechanical ventilation for cooling, and a radiant floor heating system with mechanical ventilation. Each system was simulated in EnergyPlus under a reference case with fixed set-points and a flexibility case with set-points varying according to electricity prices and cooling activation guided by weather prediction. The systems were compared in Matlab using four metrics: ability of power adjustment, ability of energy shifting, economic benefit (annual energy cost), and indoor thermal comfort. Findings indicate that the novel two-pipe system delivered the highest energy savings and flexibility while maintaining the best thermal comfort, partly by transferring excess heat between zones. The radiant floor system also showed strong flexibility, particularly in energy shifting due to its embedded thermal mass. While flexible set-point control slightly reduced comfort across all systems, the impact was not considered critical. Future work could test alternative set-point levels to further increase flexibility in radiator and floor heating systems.
[This summary has been generated with the help of AI directly from the project (PDF)]
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