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Ntostoglou, E., Ddiba, D. I., Khatiwada, D., Martin, V., Engström, R. E., Henrysson, M. & Lasaridi, K. (2024). Understanding the interactions between biowaste valorisation and the Sustainable Development Goals: insights from an early transition stage. International Journal of Urban Sustainable Development, 16(1), 53-72
Open this publication in new window or tab >>Understanding the interactions between biowaste valorisation and the Sustainable Development Goals: insights from an early transition stage
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2024 (English)In: International Journal of Urban Sustainable Development, ISSN 1946-3138, E-ISSN 1946-3146, ISSN 1946-3138, Vol. 16, no 1, p. 53-72Article in journal (Refereed) Published
Abstract [en]

The valorisation of urban biowaste can contribute to a circular and sustainable resource management. However, biowaste valorisation is not inherently sustainable. This study employs the Sustainable Development Goals (SDGs) to investigate the sustainability implications of biowaste valorisation. A narrative literature review provided an overview of the current scientific knowledge on interactions between biowaste valorisation and selected SDG targets. Then stakeholder interviews yielded insights into such interactions in a national context. Our findings show the potential for 19 synergies and 11 trade-offs between biowaste valorisation and 20 selected SDG targets that are addressed in detail. Although the synergies outnumber the trade-offs, different context-dependencies influence the nature and strength of the interactions. We highlight three types of context-dependencies relating to governance. This study informs the scientific community and decision-makers on planning for sustainable biowaste valorisation that addresses context-dependencies. The insights can guide countries and cities at early transition stages towards biowaste valorisation.

Place, publisher, year, edition, pages
Taylor & Francis Group, 2024
Keywords
biobased resource recovery and biorefinery, circular bioeconomy, organic fraction of municipal solid waste, SDG interactions, urban biowaste valorization
National Category
Environmental Management
Identifiers
urn:nbn:se:kth:diva-344543 (URN)10.1080/19463138.2024.2319795 (DOI)001185037800001 ()2-s2.0-85188118633 (Scopus ID)
Note

QC 20240325

Available from: 2024-03-20 Created: 2024-03-20 Last updated: 2024-04-05Bibliographically approved
Nilsson, D., Karpouzoglou, T., Wallin, J., Blomkvist, P., Golzar, F. & Martin, V. (2023). Is on-property heat and greywater recovery a sustainable option? A quantitative and qualitative assessment up to 2050. Energy Policy, 182, 113727
Open this publication in new window or tab >>Is on-property heat and greywater recovery a sustainable option? A quantitative and qualitative assessment up to 2050
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2023 (English)In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 182, p. 113727-Article in journal (Refereed) Published
Abstract [en]

This article deals with ongoing attempts to recover heat and greywater at property level, based on an in-depth study of Stockholm, Sweden. We explore different socio-technical development paths from now up until 2050 using a novel combination of on-property technology case-studies, actor studies and system-level scenario evaluation, based on Artificial Neural Networks modelling. Our results show that the more conservative scenarios work in favour of large-scale actors while the more radical scenarios benefit the property owners. However, in the radical scenarios we identify disruptive effects on a system level due to disturbance on wastewater treatment plants, where incoming wastewater can be critically low for up to 120 days per year. At the same time, net energy savings are relatively modest (7.5% of heat demand) and economic gains for property owners small or uncertain. Current policies at EU and national level around energy-efficient buildings risk being counter-productive in cases when they push property owners to install wastewater heat recovery technology which, in places like Stockholm, can create suboptimal outcomes at the system level.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Heat and water recovery; Urban energy policy; System modelling; Future scenarios; Actor-driven disruption
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-334678 (URN)10.1016/j.enpol.2023.113727 (DOI)001051815500001 ()2-s2.0-85166184740 (Scopus ID)
Funder
Swedish Research Council Formas, 2018-00239
Note

QC 20230824

Available from: 2023-08-24 Created: 2023-08-24 Last updated: 2023-09-21Bibliographically approved
Manyumbu, E., Martin, V. & Chiu, J. N. (2023). Prospective PCM-Desiccant Combination with Solar-Assisted Regeneration for the Indoor Comfort Control of an Office in a Warm and Humid Climate-A Numerical Study. Energies, 16(14), Article ID 5391.
Open this publication in new window or tab >>Prospective PCM-Desiccant Combination with Solar-Assisted Regeneration for the Indoor Comfort Control of an Office in a Warm and Humid Climate-A Numerical Study
2023 (English)In: Energies, E-ISSN 1996-1073, Vol. 16, no 14, article id 5391Article in journal (Refereed) Published
Abstract [en]

Favorable thermal conditions within buildings are a necessity. Mechanical air conditioning, although effective, contributes a significant percentage of the world's total energy use, which contributes to global warming. In addition, the refrigerants used in air conditioning also contribute to global warming. Passive means to provide thermal comfort have therefore been considered as alternative solutions. Phase-change materials (PCMs) have been considered as one passive cooling option. Although this option achieves a certain degree of effectiveness, especially in warm and dry climatic conditions, its effectiveness in warm humid climates is subdued due to its inability to handle humidity. In the present study, the suitability of a novel passive comfort provision strategy that combines a PCM and a desiccant is assessed. The passive system operates in a cycle of two phases: the moderating phase and the regenerating phase. For the proposed strategy, the regeneration process first involves the external desiccant bed, then night air drying using the regenerated external bed; the dried air subsequently regenerates the internal wall surface. The study involves the modeling of the proposed strategy and simulation of its performance. The simulation results indicate the significant potential for providing satisfactory comfort and health conditions through application of a combination of a desiccant and a PCM.

Place, publisher, year, edition, pages
MDPI AG, 2023
Keywords
comfort, passive, desiccant, phase-change materials, simulation
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-333786 (URN)10.3390/en16145391 (DOI)001036094800001 ()2-s2.0-85166197598 (Scopus ID)
Note

QC 20230810

Available from: 2023-08-10 Created: 2023-08-10 Last updated: 2023-08-28Bibliographically approved
Kumar, S., Thakur, J., Cunha, J. M., Gardumi, F., Kok, A., Lisboa, A. & Martin, V. (2023). Techno-economic optimization of the industrial excess heat recovery for an industrial park with high spatial and temporal resolution. Energy Conversion and Management, 287, 117109, Article ID 117109.
Open this publication in new window or tab >>Techno-economic optimization of the industrial excess heat recovery for an industrial park with high spatial and temporal resolution
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2023 (English)In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 287, p. 117109-, article id 117109Article in journal (Refereed) Published
Abstract [en]

With increasing heating and cooling demands, decarbonisation of the heating and cooling sectors is key to achieving a carbon-neutral energy system. Using industrial excess heat in heating systems helps offset emissions by reducing the use of fossil fuels. While several studies have analysed the temperature of heat availability, the cost of extending or constructing the heating network and techno-economic feasibility, it is important to consider all aspects together to achieve a comprehensive design of industrial excess heat recovery. This study proposes a method to link an energy system optimisation tool with a spatial analysis tool and an exergy analysis tool to achieve a comprehensive design. An iterative soft link is implemented between the energy system model and the spatial analysis tool for high spatial and temporal resolution. The developed method is applied to a case study of an industrial park in Greece. Scenarios are developed to assess the robustness of the developed method and the system profitability of excess heat recovery. The scenarios indicated that the profitability of excess heat depends heavily on the price of natural gas with the share of excess heat increasing from 10% to 45% with a 20% increase in natural gas prices in cases where heat pumps are needed for temperature boosting. In cases where heat pumps are not needed, excess heat indicates higher system profitability with a share of around 40% and reduces the emissions by around 50 times. The method provides robust results in considered scenarios with convergence within four iterations.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Spatial analysis, Exergy analysis, District heating systems, Industrial excess heat, Energy system optimisation, Energy system model
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-329377 (URN)10.1016/j.enconman.2023.117109 (DOI)001001493900001 ()2-s2.0-85158060445 (Scopus ID)
Note

QC 20230620

Available from: 2023-06-20 Created: 2023-06-20 Last updated: 2023-06-26Bibliographically approved
da Silva, H. B., Thakur, J., Uturbe, W. & Martin, V. (2022). Analysis of Residential Rooftop Photovoltaic Systems Diffusion in India through a Bass Model Approach. JOURNAL OF SUSTAINABLE DEVELOPMENT OF ENERGY WATER AND ENVIRONMENT SYSTEMS-JSDEWES, 10(4), Article ID 1080423.
Open this publication in new window or tab >>Analysis of Residential Rooftop Photovoltaic Systems Diffusion in India through a Bass Model Approach
2022 (English)In: JOURNAL OF SUSTAINABLE DEVELOPMENT OF ENERGY WATER AND ENVIRONMENT SYSTEMS-JSDEWES, ISSN 1848-9257, Vol. 10, no 4, article id 1080423Article in journal (Refereed) Published
Abstract [en]

In this paper, the analysis of the diffusion of photovoltaic systems is performed using the Bass model. The historical data of installed rooftop photovoltaics are not enough for the model, as the installation of photovoltaics was almost non-existent; hence data of solar water heaters are utilised to calculate the parameters for the model. The trajectory of growth for solar water heaters in the market presents a congruence for the growth of solar photovoltaics due to inherent similarities in the technologies and their application. India was used as a case study of the application of this borrowing approach in a market where PV is also used to provide electricity to local communities. Data from India's solar water heater market were used, indicating an innovator parameter of 0.00105 and an imitator parameter of 0.12219. The study is significant as it forecasts the diffusion of photovoltaics in the market, which is essential for achieving India's Intended Nationally Determined Contributions goals and Renewable Energy targets. The results indicate that residential rooftop photovoltaic diffusion will tend to present slower in India than in other markets if no additional policies are implemented to foster this market.

Place, publisher, year, edition, pages
International Centre for Sustainable Development of Energy, Water and Environment Systems SDEWES, 2022
Keywords
PV, Market diffusion, Bass model, India, Residential market, Solar water heaters
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-321013 (URN)10.13044/j.sdewes.d8.0423 (DOI)000865954000004 ()2-s2.0-85139197423 (Scopus ID)
Note

QC 20221104

Available from: 2022-11-04 Created: 2022-11-04 Last updated: 2022-11-04Bibliographically approved
Chiu, J. N. & Martin, V. (2022). Industrial Applications of Thermal Energy Storage Systems. In: Andreas Hauer (Ed.), Advances in Energy Storage: Latest Developments from R&D to the Market. John Wiley & Sons
Open this publication in new window or tab >>Industrial Applications of Thermal Energy Storage Systems
2022 (English)In: Advances in Energy Storage: Latest Developments from R&D to the Market / [ed] Andreas Hauer, John Wiley & Sons, 2022Chapter in book (Other academic)
Abstract [en]

This chapter provides an overview of the application of thermal energy storage in industrial scale systems, e.g. steel works, pulp mills, and also power generation and district heating and cooling utilities. The purpose is to illustrate the benefits of integrating thermal energy storage in such processes, from both a technical functional and economical perspectives. Examples of such benefits are resource efficiency, stability of operation, and lowered cost of fuel.

Place, publisher, year, edition, pages
John Wiley & Sons, 2022
National Category
Energy Engineering Energy Systems
Identifiers
urn:nbn:se:kth:diva-315071 (URN)10.1002/9781119239390.ch32 (DOI)2-s2.0-85148181190 (Scopus ID)
Note

QC 20220819

Part of book: ISBN 9781119239352; 9781119239390

Available from: 2022-06-29 Created: 2022-06-29 Last updated: 2023-06-08Bibliographically approved
Shao, X.-F., Yang, S., Lin, J., Teng, H., Fan, L.-W., Chiu, J. N., . . . Martin, V. (2022). Polyvinylpyrrolidone (PVP)-enabled significant suppression of supercooling of erythritol for medium-temperature thermal energy storage. Journal of Energy Storage, 46, 103915, Article ID 103915.
Open this publication in new window or tab >>Polyvinylpyrrolidone (PVP)-enabled significant suppression of supercooling of erythritol for medium-temperature thermal energy storage
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2022 (English)In: Journal of Energy Storage, ISSN 2352-152X, E-ISSN 2352-1538, Vol. 46, p. 103915-, article id 103915Article in journal (Refereed) Published
Abstract [en]

The supercooling effect is deemed to be a crucial issue for thermal energy storage using phase change materials (PCMs). The exploration of promising additives plays a decisive role in effective suppression efforts for suppressing the supercooling effect of a PCM. The present work proposed a potential additive, polyvinylpyrrolidone (PVP), to reduce the supercooling of erythritol, which is the most promising polyol PCM candidate for medium temperature range. PVP with various loadings was dispersed in erythritol to make composites for the proof-of-concept tests. It was shown that the degree of supercooling of erythritol can be reduced significantly from over 64 ? to about 21 ? in the presence of only 1.0 wt.% PVP. Along with the mitigated supercooling effect, the addition of PVP also leads to an increase of the retrievable latent heat during crystallization, from ~187 J/g to ~224 J/g at the same minute PVP loading of 1.0 wt.%, by increasing the crystallinity of erythritol. The PVP-loaded erythritol composites exhibit little sacrifice in latent heat of fusion, i.e., only ~15% loss when the PVP loading reaches 6.0 wt.%. In addition, multiple tests confirmed that PVP can be dissolved in erythritol, thus desirable compatibility was obtained and the composites would have long-term reliability. This proposed additive enables an efficient and cost-effective way for improving the crystallization behaviors of erythritol (and other polyol PCMs) towards real-world applications.

Place, publisher, year, edition, pages
Elsevier BV, 2022
Keywords
Crystallization, Erythritol, Latent heat storage, Phase change material, Polyvinylpyrrolidone, Supercooling
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-311515 (URN)10.1016/j.est.2021.103915 (DOI)000780239200005 ()2-s2.0-85122099300 (Scopus ID)
Note

QC 20220503

Available from: 2022-05-03 Created: 2022-05-03 Last updated: 2023-08-28Bibliographically approved
Gunasekara, S. N., Martin, V. & Edén, T. (2021). Distributed Cold Storage in District Cooling. Stockholm
Open this publication in new window or tab >>Distributed Cold Storage in District Cooling
2021 (English)Report (Other academic)
Alternative title[sv]
Distribuerade kyllager i Fjärrkylanät : Workpackage 2.3 i projekt Termiskaenergilager
Abstract [en]

District cooling (DC) is an important sector within today’s energy systems, with a renewed interest in cooling as an energy service, owing to global warming. Cold storages (CSs) are an important element in DC systems, to alleviate unnecessary capacity investment costs while accommodating peak shaving and load shifting, and to lower the cold production costs as well. Through a current status mapping of DC and CS in Sweden, it is found that the DC supply is about 1 TWh/year as opposed to the estimated 2-5 TWh annual cooling demand. This also revealed that the existing CSs are almost exclusively cold water storages, and which are most likely centralized units located adjacent to cold production plants. This brings us to the question: how can expanded integration of CS allow for DC to meet an even larger share of the cooling demand, in a robust, cost effective and environmentally sound way?

To answer this, it is important to first recognize the available CS alternatives and their potential. Sundsvall seasonal snow storage system is an attractive Swedish exception to cold water CS. Cold water thermal energy storage (TES), in tanks and natural rock caverns (CTES) operate more for short-term CS whereas e.g. aquifer TES (ATES) and borehole TES (BTES) are utilized for seasonal storage (yet in building-scale). Hornsberg CTES and Arlanda ATES are Swedish UTES CS examples. Their relatively high technology readiness levels (TRLs) encourage their exploitation. CSs with snow and ice as phase change materials (PCMs) are gaining interest for being compact storages (up to 60 kWh/m3 unlike 7 kWh/m3~with water) with rather competitive costs for daily storage in buildings or small districts. Examples are Chitose airport, Hokkaido, and Nagoya JR station in Japan and Paris La Défense in France. CS with other PCMs or thermochemical heat storage materials (TCMs) are scarce in DC. Two PCM examples on building cooling systems are e.g. in Gothenburg, Sweden, and in Bergen, Norway, using salt-hydrates. CS with PCMs and TCS has lower TRLs and hence requires further research before reaching district level applications. 

Within this background, the true benefits of CSs are evaluated herein with a special focus on distributed CS solutions. For that, the existing DC system of Norrenergi AB (catering to Solna and Sundbyberg) was chosen as a case study for a techno-economic performance evaluation and cost benefit analysis. Norrenergi AB’s DC system comprises three production plants in Frösunda, Sundbyberg and Solna Strand, with one CS of 10 MW (75.7 MWh, 6500 m3), altogether allowing a 73.1 MW peak installed capacity. Here, the expanded integration of CS capacity has been explored through the DC system (i.e., production versus demand) optimization as well as DC distribution grid dynamics optimization. Centralized and distributed CSs, considering cold water CSs (due to data limitations on other alternatives) were employed. The DC system analysis was performed as the first step using the software tool BoFit, whereas, the DC distribution grid dynamics were then evaluated using the software tool Netsim. 

With BoFit, three scenarios were analyzed besides today’s system- the base case (BC). In these scenarios, one additional CS of 15 MW or two CSs of 3 MW were considered at different production locations and supply combinations. Hereby, the most cost effective solution was to install one additional central CS of 15 MW in Sundbyberg. As this BoFit analysis was inconclusive on the impacts of these CSs on the distribution grid, the investigations were continued to distribution grid dynamics assessment with Netsim. In Netsim, three corresponding scenarios were analyzed using additionally: a 15 MW CS in Sundbyberg (centralized), a 15 MW CS in Frösunda (at a distributed location) and two 3 MW CSs at both Sundbyberg and Frösunda. The distributed location in Frösunda was chosen for displaying low differential pressure bottlenecks as found using Netsim. The results revealed that the optimal CS choice lies in two CSs, one located centrally in Sundbyberg and one at the distributed location in Frösunda, with a total capacity of 6-15 MW. Therein, six more scenarios (A-F) were analyzed in Netsim with two equisized CSs of 3, 4, 5, 6, 7 and 7.5 MW capacity. Here, scenario F with two CSs of 7.5 MW capacity each is found as the most optimal solution, with the lowest costs (99 SEK/MWh,cold and 589 SEK/MWh,electricicty) than the other scenarios and the BC (105 SEK/MWh,cold and 608 SEK/MWh,electricity). Although the relative difference between the operational costs savings of each consecutive scenario (A-F) is low, scenario F allows the best savings (for cold production cost per used electricity). 

For a 10% demand increase, scenario F and the BC were then compared in Netsim against two other alternatives: a pipe extension (~420 m) at Frösunda low-pressure loop and a new chiller (6 MW) in Sundbyberg. Therein, scenario F followed by the new chiller had the lowest operational costs, while the new pipe extension had the lowest investment cost. Once the annual operating costs and apportioned investment costs were combined, scenario F exhibited the best cost savings, overall. It allows 3% annual cost savings than the BC, while avoids 16% and 4.5% of the costs if instead a new chiller or a new pipe extension was used. Scenario F also facilitates the largest reductions in peak electricity use (4 MW,electricity/peak hour and 35 MWh,electricity/day) and peak cold production (115 MWh,cold/day), successfully adopting power-to-cold. Sensitivity analyses on ground temperature increases and electricity price fluctuations also confirmed that scenario F outperforms the BC. Therefore, scenario F is the most optimal solution for competitively expanding DC.

In summary, this work exemplifies the benefits in implementing CSs in DC, in peak shaving, load shifting, and power-to-cold adaptations, overall leading to cost savings. Also, this work highlights the particular benefits of distributed CSs in better managing the DC distribution grid dynamics. As a whole, the work conveys the importance of DC system-level as well as distribution grid-level optimizations, which are more effective in combination to truly decide the suitability, sizing and positioning of CSs in DC. Important KPIs are also proposed herein for their general utility, i.e., the unit operating cost of cold (e.g. in SEK/MWh,cold) and unit operating cost of electricity to produce that cold (SEK/MWh,electricity), for cost as well as power-to-cold implications. Moving beyond cold water CSs is a potential future work with benefits. In future studies, CS in DC will be developed with a detailed focus on power-to-cold synergies, which emerges as a promising business area in a future electricity system with a large proportion of solar and wind.

Place, publisher, year, edition, pages
Stockholm: , 2021. p. 110
Keywords
Thermal Energy Storage (TES), Cold Storage (CS), Distributed Cold Storage, District Cooling (DC), Power-to-Cold, System and Grid optimization
National Category
Energy Systems
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-323598 (URN)978-91-7673-751-4 (ISBN)
Projects
Work package 2.3 of Project Thermal Energy Storage (Termiskaenergilager) of Energiforsk together with KTH Royal Institute of Technology and Norrenergi AB
Funder
Swedish Energy Agency, 45976-1
Note

I det här arbetspaketet (WP 2.3 inom Termiska energilager – lösningen för ett flexibelt energisystem projekt) har distribuerade kyllager i fjärrkylanät undersökts. Detta är gjort främst genom en litteraturstudie där olika tekniker för kylproduktion och kyllager har kartlagts och en fallstudie där implementering av kyllager i Norrenergi AB:s fjärrkylanät har analyserats genom simuleringar och  utvärderingar av tekno-ekonomisk prestanda.QC 20230208

I det här arbetspaketet (WP 2.3 inom Termiska energilager – lösningen för ett flexibelt energisystem projekt) har distribuerade kyllager i fjärrkylanät undersökts. Detta är gjort främst genom en litteraturstudie där olika tekniker för kylproduktion och kyllager har kartlagts och en fallstudie där implementering av kyllager i Norrenergi AB:s fjärrkylanät har analyserats genom simuleringar och  utvärderingar av tekno-ekonomisk prestanda.QC 20230208

I det här arbetspaketet (WP 2.3 inom Termiska energilager – lösningen för ett flexibelt energisystem projekt) har distribuerade kyllager i fjärrkylanät undersökts. Detta är gjort främst genom en litteraturstudie där olika tekniker för kylproduktion och kyllager har kartlagts och en fallstudie där implementering av kyllager i Norrenergi AB:s fjärrkylanät har analyserats genom simuleringar och  utvärderingar av tekno-ekonomisk prestanda.QC 20230208

I det här arbetspaketet (WP 2.3 inom Termiska energilager – lösningen för ett flexibelt energisystem projekt) har distribuerade kyllager i fjärrkylanät undersökts. Detta är gjort främst genom en litteraturstudie där olika tekniker för kylproduktion och kyllager har kartlagts och en fallstudie där implementering av kyllager i Norrenergi AB:s fjärrkylanät har analyserats genom simuleringar och  utvärderingar av tekno-ekonomisk prestanda.

QC 20230208

Available from: 2023-02-06 Created: 2023-02-06 Last updated: 2023-02-08Bibliographically approved
Gunasekara, S. N., Bilek, Z., Eden, T. & Martin, V. (2021). Distributed cold storage in district cooling-Grid dynamics and optimal integration for a Swedish case study. Paper presented at 17th International Symposium on District Heating and Cooling (DHC), SEP 06-09, 2021, Nottingham Trent Univ, Nottingham, England. Energy Reports, 7, 419-429
Open this publication in new window or tab >>Distributed cold storage in district cooling-Grid dynamics and optimal integration for a Swedish case study
2021 (English)In: Energy Reports, E-ISSN 2352-4847, Vol. 7, p. 419-429Article in journal (Refereed) Published
Abstract [en]

District cooling (DC) is gaining interest with global warming and rising demands on indoor comfort. As DC grid expansions are capital intensive, cost effective alternatives to meet these rising cooling demands are desired. Integrating cold storage (CS) into the grids is one attractive choice, allowing peak shaving, load shifting, and renewable electricity recovery via power-to cold. To analyze the impact of new CSs, the DC distribution grid dynamics must be investigated. This work evaluates the implementation of several new CSs into an existing DC system (called the base case-BC), to find the optimal solution. This is performed considering the case study DC system of Norrenergi AB, Sweden, catering to Solna and Sundbyberg via three production plants Solnaverket, Sundbybergsverket and Frosundaverket, and a 10 MW CS (in Solnaverket). The software tool Netsim is used for distribution grid dynamics analysis of the BC and three scenarios with additional cold storages, for the optimization of differential pressure (dP) of the grids to be within 100-800 kPa. These scenarios include: one additional 15 MW CS in Sundbybergsverket (Scenario 1), one additional 15 MW CS in Frosunda (Scenario 2) and two additional 3 MW CSs in Sundbybergsverket and Frosunda (Scenario 3). The CSs in Sundbybergsverket are centrally placed, whereas, those in Frosunda were positioned in a grid loop experiencing low differential pressure, identified in Netsim simulations of BC. The simulations were done for 24 h at 1-hour resolution, on a chosen historically highest demand day (02 August 2018). The results indicate that the optimal solution is implementing two additional CSs in Sundbybergsverket (centralized) and Frosunda (distributed), each with a capacity between 3-7.5 MW (6-15 MW total capacities). Further evaluations to determine the optimal sizing of these CSs is the next step in this study.

Place, publisher, year, edition, pages
Elsevier BV, 2021
Keywords
District cooling (DC), Cold storage (CS), Distributed cold storage, Distribution grid dynamics, Base case (BC), Scenarios (Sc.s), Netsim
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-306527 (URN)10.1016/j.egyr.2021.08.086 (DOI)000727767400007 ()2-s2.0-85130333735 (Scopus ID)
Conference
17th International Symposium on District Heating and Cooling (DHC), SEP 06-09, 2021, Nottingham Trent Univ, Nottingham, England
Note

QC 20211217

Available from: 2021-12-17 Created: 2021-12-17 Last updated: 2023-06-08Bibliographically approved
Abdi, A., Shahrooz, M., Chiu, J. N. & Martin, V. (2021). Experimental investigation of solidification and melting in a vertically finned cavity. Applied Thermal Engineering, 198, Article ID 117459.
Open this publication in new window or tab >>Experimental investigation of solidification and melting in a vertically finned cavity
2021 (English)In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 198, article id 117459Article in journal (Refereed) Published
Abstract [en]

Extending the heat transfer area is a simple technique to improve the thermal performance of phase change materials with low thermal conductivity. However, as the governing mechanisms differ in solidification and melting, fins can affect the processes in different ways. This demands assessment of fin enhancement in a combined analysis on both solidification and melting, often neglected in literature. This paper presents visual-izations of solidification and melting of n-eicosane in a rectangular cavity and experimentally investigates the enhancing effect of vertical fins with varying number and length. Experiments were conducted at water inlet temperature ranges of 15-25 degrees C and 50-60 degrees C for the solidification and melting processes, respectively. The results show that the vertical fins can be more influential in solidification rather than in melting with similar losses in the storage capacity. In the solidification process, as natural convection is absent, the mean power is enhanced by a maximum of 395% with a 10% loss in the storage capacity, as compared to the benchmark. In the melting case, the mean power is increased by a maximum of 90% with a 9% loss in the storage capacity. Although increasing the surface area with vertical fins contributes to development of convective structures, it makes a modest enhancement. In overall, increasing the fin volume fraction, in exchange for the loss in the storage capacity, enhances the solidification significantly while it has relatively low enhancement effect in melting. At the end, the performed experiments could be helpful for validation of future simulation tools with complex features, particularly solidification models lacking in literature.

Place, publisher, year, edition, pages
Elsevier BV, 2021
Keywords
PCM, Cavity, Vertical fin, Solidification, Melting
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-303757 (URN)10.1016/j.applthermaleng.2021.117459 (DOI)000701603600001 ()2-s2.0-85113634102 (Scopus ID)
Note

QC 20211028

Available from: 2021-10-28 Created: 2021-10-28 Last updated: 2022-06-25Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9556-552X

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