Search

Your search keyword '"Orehounig, Kristina"' showing total 182 results
Start Over Author "Orehounig, Kristina"
182 results on '"Orehounig, Kristina"'

48. Design and Assessment of District Heating Systems with Solar Thermal Prosumers and Thermal Storage

Author

Wang, Danhong, Carmeliet, Jan, and Orehounig, Kristina

Subjects
district heating networks, solar thermal collectors, lcsh:T, thermal storage, distributed solar prosumers, district heating network, simulation modeling, lcsh:Technology
Abstract

In this study, a holistic energy, economic and environmental assessment was performed on a prosumer-based district heating system, including scenarios with varying district size, retrofitting stages and system configurations. A modeling framework was built which comprises a thermal network design and simulation model; a building energy demand model for districts; and supply and storage technology models that allow assessing system solar fraction, equivalent annual cost and greenhouse gas emissions of district heating systems (DHS). Furthermore, the approach allows comparing the performance of a DHS with individual heating systems (IHS) for the district with the same set of technology options (rooftop-mounted solar thermal collectors, gas boilers and thermal storage tanks). The framework was applied to a Swiss case study. The results of the case study show that DHS often outperform IHS; however, parameters such as the district size, the retrofitting stage of buildings and the system configuration have impacts on the performance of the DHS. The most important parameter lies in the adequate selection of the storage volume over solar collector area ratio, which indicates that DHS solutions are only advantageous if they are properly sized. Smaller districts and districts with retrofitted buildings especially benefit from DHS solutions in terms of energy, economic and environmental performance. Maximum solar fractions of 50% (non-retrofitted case) and 63% (retrofitted case) were reached with the DHS solutions., Energies, 14 (4), ISSN:1996-1073

Published
2021

49. Advancing the Thermal Network Representation for the Optimal Design of Distributed Multi-Energy Systems

Author

Wang, Danhong, Li, Xiang, Marquant, Julien, Carmeliet, Jan, and Orehounig, Kristina

Subjects
district heating networks, distributed multi-energy systems, simulation model, mixed-integer linear programming, optimization model
Abstract

This paper investigates modeling methods with thermal network representation under the scope of the optimal design and operation of Distributed Multi-Energy System (D-MES). Two modeling approaches are compared: A Mixed‐Integer Linear Programming (MILP) optimization model and a district heating network (DHN) simulation model. The MILP model was developed for the simultaneous design of the network layout, the sizing, and locations of energy generation and storage technologies to minimize both costs and carbon emissions. The thermal network is represented with a simplified linear approximation. The DHN simulation model is a thermal-hydraulic model to address the non-linear operational performance regarding hourly heat losses, pumping energy, and temperature distribution along with the network. The discrepancies in the network’s costs and operational performances from the two models are identified. The MILP model is further improved by adding new constraints. Results from both MILP models are compared and demonstrated with a case study. It reveals that the state-of-art MILP-model with simplified network representation suffices for optimal selection and sizing for most of the technologies. Although more computationally intensive, the refined model can address the operational issues with distributed design solutions., Frontiers in Energy Research, 9, ISSN:2296-598X

Published
2021
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results