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Lindberg, Carl-FredrikORCID iD iconorcid.org/0000-0003-0274-4719
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Publications (10 of 15) Show all publications
Zimmerman, N., Kyprianidis, K. & Lindberg, C.-F. (2019). Achieving lower district heating network temperatures using feed-forward MPC. Materials, 12(15), Article ID 2465.
Open this publication in new window or tab >>Achieving lower district heating network temperatures using feed-forward MPC
2019 (English)In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, no 15, article id 2465Article in journal (Refereed) Published
Abstract [en]

The focus of this work is to present the feasibility of lowering the supply and return temperatures of district heating networks in order to achieve energy savings through the implementation of feed-forward model predictive control. The current level of district heating technology dictates a need for higher supply temperatures, which is not the case when considering the future outlook. In part, this can be attributed to the fact that current networks are being controlled by operator experience and outdoor temperatures. The prospects of reducing network temperatures can be evaluated by developing a dynamic model of the process which can then be used for control purposes. Two scenarios are presented in this work, to not only evaluate a controller's performance in supplying lower network temperatures, but to also assess the boundaries of the return temperature. In Scenario 1, the historical load is used as a feed-forward signal to the controller, and in Scenario 2, a load prediction model is used as the feed-forward signal. The findings for both scenarios suggest that the new control approach can lead to a load reduction of 12.5% and 13.7% respectively for the heat being supplied to the network. With the inclusion of predictions with increased accuracy on end-user demand and feed-back, the return temperature values can be better sustained, and can lead to a decrease in supply temperatures and an increase in energy savings on the production side.

Place, publisher, year, edition, pages
MDPI AG, 2019
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-45030 (URN)10.3390/ma12152465 (DOI)000482576900126 ()31382435 (PubMedID)2-s2.0-85070601468 (Scopus ID)
Available from: 2019-08-22 Created: 2019-08-22 Last updated: 2019-10-14Bibliographically approved
Hermansson, K., Kos, C., Starfelt, F., Kyprianidis, K., Lindberg, C.-F. & Zimmerman, N. (2018). An Automated Approach to Building and Simulating Dynamic District Heating Networks. IFAC-PapersOnLine, 51(2), 855-860
Open this publication in new window or tab >>An Automated Approach to Building and Simulating Dynamic District Heating Networks
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2018 (English)In: IFAC-PapersOnLine, ISSN 2405-8963, Vol. 51, no 2, p. 855-860Article in journal (Refereed) Published
Abstract [en]

In Nordic countries, district heating accounts for a large share of the consumers’  heat demand. In Sweden, roughly 50% of the total heat demand is attributed to district heating. Which, over the past few years, is equivalent to around 50 TWh, and imposes a difficult balance between supply and demand for the suppliers of district heating. For large networks the propagation of heat from supplier to end-user can vary several hours. Further complexities of large networks, which can consist of multiple overlapping rings, is that during transient conditions the flow can actually change direction. A dynamic modeling library has been developed in Modelica using OpenModelica for district heating networks. Methods for modeling, handling data, simulating and the visualization of results has been developed using Matlab. The model has been validated using data from Mälarenergi  AB, a local provider of district heating in Västerås, Sweden. The model provides to an acceptable degree in predicting the heat propagation and temperature distribution in a localized case study. Adding a higher level of robustness, the model has the capacity to handle bi-directional and reversing flows in complex ring structures. Through this work, the combination of OpenModelica and Matlab, a framework for automating the building and simulation of district heating networks is obtainable. The implications of automating network modeling from computer-aided design drawings allows for a quick robust overview of how the network is working and how prospective additions to the network could impact the end-users. Furthermore, incorporating visual aspects for heat propagation in a network contributes to a higher understanding of complex network structures. 

Place, publisher, year, edition, pages
Elsevier B.V., 2018
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-39303 (URN)10.1016/j.ifacol.2018.04.021 (DOI)000435693000146 ()2-s2.0-85046689930 (Scopus ID)
Available from: 2018-05-24 Created: 2018-05-24 Last updated: 2018-07-12Bibliographically approved
Zimmerman, N., Kyprianidis, K. & Lindberg, C.-F. (2018). Waste fuel combustion: Dynamic modeling and control. Processes, 6(11), Article ID 222.
Open this publication in new window or tab >>Waste fuel combustion: Dynamic modeling and control
2018 (English)In: Processes, ISSN 2227-9717, Vol. 6, no 11, article id 222Article in journal (Refereed) Published
Abstract [en]

The focus of this study is to present the adherent transients that accompany the combustion of waste derived fuels. This is accomplished, in large, by developing a dynamic model of the process, which can then be used for control purposes. Traditional control measures typically applied in the heat and power industry, i.e., PI (proportional-integral) controllers, might not be robust enough to handle the the accompanied transients associated with new fuels. Therefore, model predictive control is introduced as a means to achieve better combustion stability under transient conditions. The transient behavior of refuse derived fuel is addressed by developing a dynamic modeling library. Within the library, there are two models. The first is for assessing the performance of the heat exchangers to provide operational assistance for maintenance scheduling. The second model is of a circulating fluidized bed block, which includes combustion and steam (thermal) networks. The library has been validated using data from a 160 MW industrial installation located in Västerås, Sweden. The model can predict, with satisfactory accuracy, the boiler bed and riser temperatures, live steam temperature, and boiler load. This has been achieved by using process sensors for the feed-in streams. Based on this model three different control schemes are presented: a PI control scheme, model predictive control with feedforward, and model predictive control without feedforward. The model predictive control with feedforward has proven to give the best performance as it can maintain stable temperature profiles throughout the process when a measured disturbance is initiated. Furthermore, the implemented control incorporates the introduction of a soft-sensor for measuring the minimum fluidization velocity to maintain a consistent level of fluidization in the boiler for deterring bed material agglomeration.

Place, publisher, year, edition, pages
MDPI AG, 2018
Keywords
Circulating fluidized bed boiler, Dynamic modeling, Process control, Refuse derived fuel, Waste to energy
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-41774 (URN)10.3390/pr6110222 (DOI)000451530400018 ()2-s2.0-85057842748 (Scopus ID)
Available from: 2018-12-20 Created: 2018-12-20 Last updated: 2019-10-14Bibliographically approved
Anbalagan, A., Schwede, S., Lindberg, C.-F. & Nehrenheim, E. (2017). Continuous microalgae-activated sludge flocs for remediation of municipal wastewater under low temperature. In: Peter Van der Steen (Ed.), : . Paper presented at 1st IWA Conference on Algal Technologies for Wastewater Treatment and Resource Recovery (pp. 1-8).
Open this publication in new window or tab >>Continuous microalgae-activated sludge flocs for remediation of municipal wastewater under low temperature
2017 (English)In: / [ed] Peter Van der Steen, 2017, p. 1-8Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

The operational performance of indigenous microalgae-activated sludge was evaluated regarding the nutrient removal efficiency using raw wastewater collected from Västerås wastewater treatment plant, Sweden at limited artificial surface lighting (290 μmol m-1 sec-1) and Nordic wastewater conditions (13°C). Additionally, the oxygen production and consumption, biomass concentration and its settling was evaluated during the symbiotic algal-bacterial interaction. The results confirmed oxygenic organic compound removal (COD removal of 65-94%) at higher (31-45 d) and lower (13-18 d) sludge retention time (SRT). Also, a complete removal of ammonium throughout the process and partial nitrite-nitrate removal at all SRTs (total nitrogen removal of 41- 62%) were observed. Likewise, a partial phosphorus (P)removal was observed in the effluent which provides an opportunity to capture free P fromthe effluent for recovery as fertiliser. Further, the microalgal growth was slower due to lightor inorganic carbon limitation or ammonium repression caused by higher internal recirculationas observed from ammonium and nitrite-nitrate levels in the PBR. Most importantly, effectivePBR biomass concentration based nutrient removal and relative sludge recirculation have tobe considered in the PBR design to avoid light limitation and activate symbiosis.

Keywords
Indigenous microalgae-activated sludge, Lighting, Nordic wastewater condition; Sludge retention time; Sludge recirculation
National Category
Environmental Engineering
Research subject
Biotechnology/Chemical Engineering
Identifiers
urn:nbn:se:mdh:diva-38020 (URN)
Conference
1st IWA Conference on Algal Technologies for Wastewater Treatment and Resource Recovery
Available from: 2018-01-12 Created: 2018-01-12 Last updated: 2018-05-07Bibliographically approved
Schwede, S., Anbalagan, A., Krustok, I., Lindberg, C.-F. & Nehrenheim, E. (2016). Evaluation of the microalgae-based activated sludge (MAAS) process for municipal wastewater treatment on pilot scale. In: : . Paper presented at IWA World Water Congress.
Open this publication in new window or tab >>Evaluation of the microalgae-based activated sludge (MAAS) process for municipal wastewater treatment on pilot scale
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2016 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The microalgae-based activated sludge (MAAS) process was evaluated regarding the removal efficiency of organic matter and nitrogen from physiochemically pretreated municipal wastewater at different hydraulic retention time (HRT) on pilot scale. Additionally, the interplay between the algal and bacterial consortium was evaluated regarding the ability of the algal consortium to provide oxygen for bacterial oxidation processes. The results showed in general high organic matter (COD removal 75-90%) and total nitrogen (40-50%) removal at all HRTs (6, 4 and 2 days). The dissolved oxygen (DO) concentration was maintained stable at 6 days (6.04±0.47 mg L-1) and 4 days (4.24±0.62 mg L-1) HRT. However, the DO significantly declined at 2 days HRT due to loss of biomass at the high influent flow in the sedimentation unit. Nevertheless, the MAAS process functioned as a symbiotic algal-bacterial system with bacterial organic matter oxidation and nitrification and algal nutrient removal.

National Category
Water Treatment
Identifiers
urn:nbn:se:mdh:diva-34538 (URN)
Conference
IWA World Water Congress
Available from: 2016-12-22 Created: 2016-12-22 Last updated: 2017-02-02Bibliographically approved
Anbalagan, A., Schwede, S., Lindberg, C. F. & Nehrenheim, E. (2016). Influence of hydraulic retention time on indigenous microalgae and activated sludge process. Water Research, 91, 277-284
Open this publication in new window or tab >>Influence of hydraulic retention time on indigenous microalgae and activated sludge process
2016 (English)In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 91, p. 277-284Article in journal (Refereed) Published
Abstract [en]

Integration of the microalgae and activated sludge (MAAS) process in municipal wastewater treatment and biogas production from recovered MAAS was investigated by studying the hydraulic retention time (HRT) of semi-continuous photo-bioreactors. An average total nitrogen (TN) removal efficiency (RE) of maximum 81.5 ± 5.1 and 64.6 ± 16.2% was achieved at 6 and 4 days HRT. RE of total phosphorous (TP) increased slightly at 6 days (80 ± 12%) HRT and stabilized at 4 days (56 ± 5%) and 2 days (55.5 ± 5.5%) HRT due to the fluctuations in COD and N/P mass ratio of the periodic wastewater. COD and organic carbon were removed efficiently and a rapidly settleable MAAS with a sludge volume index (SVI_10) of less than 117 mL g-1 was observed at all HRTs. The anaerobic digestion of the untreated MAAS showed a higher biogas yield of 349 ± 10 mL g VS-1 with 2 days HRT due to a low solids retention time (SRT). Thermal pretreatment of the MAAS (120 °C, 120 min) did not show any improvement with biogas production at 6 days (269 ± 3 (untreated) and 266 ± 16 (treated) mL gVS-1), 4 days (258 ± 11(untreated) and 263 ± 10 (treated) mL gVS-1) and 2 days (308 ± 19 mL (treated) gVS-1) HRT. Hence, the biogas potential tests showed that the untreated MAAS was a feasible substrate for biogas production. Results from this proof of concept support the application of MAAS in wastewater treatment for Swedish conditions to reduce aeration, precipitation chemicals and CO2 emissions. 

Keywords
Activated sludge process, Anaerobic digestion, Hydraulic retention time, Microalgae, Nutrient removal, Thermal pretreatment
National Category
Environmental Biotechnology
Identifiers
urn:nbn:se:mdh:diva-31345 (URN)10.1016/j.watres.2016.01.027 (DOI)000371189100028 ()26803263 (PubMedID)2-s2.0-84960332248 (Scopus ID)
Available from: 2016-03-24 Created: 2016-03-24 Last updated: 2018-10-16Bibliographically approved
Lindberg, C.-F. & Isaksson, A. (2015). Comparison of different sampling schemes for wireless control subject to packet losses. In: First International Conference on Event-Based Control, Communication, and Signal Processing: . Paper presented at First International Conference on Event-Based Control, Communication, and Signal Processing. June 17-19, 2015, Krakow, Poland.
Open this publication in new window or tab >>Comparison of different sampling schemes for wireless control subject to packet losses
2015 (English)In: First International Conference on Event-Based Control, Communication, and Signal Processing, 2015Conference paper, Published paper (Refereed)
Abstract [en]

Three different approaches to reduce the amount of communication in wireless control subject to packet losses have been evaluated in an extensive simulation study. The sampling approaches are: slow periodic, event-based and self-triggered sampling. They are ranked based on their integrated absolute error (IAE) control performance and also compared with fast periodic sampling. The three approaches have surprisingly equal control performance in the nominal case (without packet losses) for a wide range of test scenarios (process models, controller tunings etc.). With packet losses the importance of re-transmissions becomes evident.

Keywords
Wireless control; Sampling schemes; Packet loss; Event-based sampling; Self-triggered sampling; Periodic sampling
National Category
Control Engineering
Research subject
Mathematics/Applied Mathematics
Identifiers
urn:nbn:se:mdh:diva-29445 (URN)10.1109/EBCCSP.2015.7300683 (DOI)978-1-4673-7888-8 (ISBN)
Conference
First International Conference on Event-Based Control, Communication, and Signal Processing. June 17-19, 2015, Krakow, Poland
Projects
WiComPI
Funder
VINNOVA
Available from: 2015-11-09 Created: 2015-11-09 Last updated: 2015-11-19Bibliographically approved
Lindberg, C.-F., Bhutani, N., Starr, K. & Horton, R. (2015). Energy Conservation in Industry: Steam Energy Fingerprint of Paper Machine. In: Jinyue Yan (Ed.), Handbook of Clean Energy Systems: (pp. 2175-2181). Chichester, West Sussex, UK: John Wiley & Sons
Open this publication in new window or tab >>Energy Conservation in Industry: Steam Energy Fingerprint of Paper Machine
2015 (English)In: Handbook of Clean Energy Systems / [ed] Jinyue Yan, Chichester, West Sussex, UK: John Wiley & Sons, 2015, p. 2175-2181Chapter in book (Refereed)
Abstract [en]

There is a large value in making the industry more energy efficient. The benefit is not only energy savings and reduction of CO2 emissions, the industry also becomes more competitive due to lower costs for energy, and often also improved production rate and product quality due to positive side effects when processes are made more efficient. Several factors influence efficiency, the most important ones are presented, as well as advices for an assessment and actions for improvements.

As an example a steam energy fingerprint of a paper machine is given. In the assessment energy flows are quantified, energy users in the paper machine are benchmarked and actions for improving efficiency are suggested.

Place, publisher, year, edition, pages
Chichester, West Sussex, UK: John Wiley & Sons, 2015
Keywords
Energy efficiency, Assessment, Benchmarking, KPI, Paper machine
National Category
Energy Systems
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-29446 (URN)10.1002/9781118991978.hces183 (DOI)978-1-118-38858-7 (ISBN)
Available from: 2015-11-09 Created: 2015-11-09 Last updated: 2015-11-19Bibliographically approved
Lindberg, C.-F., Tan, S., Yan, J. & Starfelt, F. (2015). Key performance indicators improve industrial performance. Paper presented at 7th International Conference on Applied Energy (ICAE), MAR 28-31, 2015, Abu Dhabi, U ARAB EMIRATES. Energy Procedia, 75, 1785-1790
Open this publication in new window or tab >>Key performance indicators improve industrial performance
2015 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, p. 1785-1790Article in journal (Refereed) Published
Abstract [en]

Key Performance Indicators (KPIs) are important for monitoring the performance in the industry. They can be used to identify poor performance and the improvement potential. KPIs can be defined for individual equipment, sub-processes, and whole plants. Different types of performances can be measured by KPIs, for example energy, raw-material, control & operation, maintenance, etc. Benchmarking KPIs with KPIs from similar equipment and plants is one method of identifying poor performing areas and estimating improvement potential. Actions for performance improvements can then be developed, prioritized and implemented based on the KPIs and the benchmarking results. An alternative to benchmarking, which is described in this paper, is to identify the process signals that are strongest correlated with the KPI and then change these process signals in the direction that improves the KPI. This method has been applied to data from a combined heat and power plant and a suggestion are given on how to improve boiler efficiency. 

National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-29328 (URN)10.1016/j.egypro.2015.07.474 (DOI)000361030003006 ()2-s2.0-84947125510 (Scopus ID)
Conference
7th International Conference on Applied Energy (ICAE), MAR 28-31, 2015, Abu Dhabi, U ARAB EMIRATES
Available from: 2015-10-15 Created: 2015-10-15 Last updated: 2017-12-01Bibliographically approved
Lindberg, C.-F., Zahedian, K., Solgi, M. & Lindkvist, R. (2014). Potential and limitations for industrial demand side management. Paper presented at The 6th International Conference on Applied Energy – ICAE2014, Taipei 30 May – 2 June 2014. Energy Procedia, 61, 415-418
Open this publication in new window or tab >>Potential and limitations for industrial demand side management
2014 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 61, p. 415-418Article in journal (Refereed) Published
Abstract [en]

The growing share of variable renewable power such as wind and solar photovoltaic (PV) emphasize the importance of demand side management. In a couple of years consumers have to adapt their consumption more to available generated power in order to maintain grid stability and to reduce their electricity costs. In this study the potential and limitations for demand side management in about 15 different companies in Sweden has been investigated. A brief description of some of the company’s production process is given, with focus on electrical consumption. Suggestions on different demand side management possibilities are presented as well as limitations. The suggestions are given for different time horizons, from load shifting between hours, to weeks and years. Potential savings achieved with demand side management have also been evaluated based on historical electricity prices from different countries.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Demand side management; Demand response; Load scheduling; Smart grid; Renewable energy
National Category
Control Engineering
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-26899 (URN)10.1016/j.egypro.2014.11.1138 (DOI)000375936100098 ()2-s2.0-84922377188 (Scopus ID)
Conference
The 6th International Conference on Applied Energy – ICAE2014, Taipei 30 May – 2 June 2014
Available from: 2014-12-12 Created: 2014-12-12 Last updated: 2017-12-05Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0274-4719

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