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BETA
Werner, Sven, Professor emeritusORCID iD iconorcid.org/0000-0001-9069-0807
Alternative names
Publications (10 of 77) Show all publications
Calikus, E., Nowaczyk, S., Pinheiro Sant'Anna, A., Gadd, H. & Werner, S. (2019). A data-driven approach for discovering heat load patterns in district heating. Applied Energy, 252, Article ID 113409.
Open this publication in new window or tab >>A data-driven approach for discovering heat load patterns in district heating
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2019 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 252, article id 113409Article in journal (Refereed) Published
Abstract [en]

Understanding the heat usage of customers is crucial for effective district heating operations and management. Unfortunately, existing knowledge about customers and their heat load behaviors is quite scarce. Most previous studies are limited to small-scale analyses that are not representative enough to understand the behavior of the overall network. In this work, we propose a data-driven approach that enables large-scale automatic analysis of heat load patterns in district heating networks without requiring prior knowledge. Our method clusters the customer profiles into different groups, extracts their representative patterns, and detects unusual customers whose profiles deviate significantly from the rest of their group. Using our approach, we present the first large-scale, comprehensive analysis of the heat load patterns by conducting a case study on many buildings in six different customer categories connected to two district heating networks in the south of Sweden. The 1222 buildings had a total floor space of 3.4 million square meters and used 1540 TJ heat during 2016. The results show that the proposed method has a high potential to be deployed and used in practice to analyze and understand customers’ heat-use habits. © 2019 Calikus et al. Published by Elsevier Ltd.

Place, publisher, year, edition, pages
Oxford: Elsevier, 2019
Keywords
District heating, Energy efficiency, Heat load patterns, Clustering, Abnormal heat use
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hh:diva-40907 (URN)10.1016/j.apenergy.2019.113409 (DOI)000497968000013 ()2-s2.0-85066961984 (Scopus ID)
Funder
Knowledge Foundation, 20160103
Available from: 2019-11-12 Created: 2019-11-12 Last updated: 2019-12-11Bibliographically approved
Lennermo, G., Lauenburg, P. & Werner, S. (2019). Control of decentralised solar district heating. Solar Energy, 179, 307-315
Open this publication in new window or tab >>Control of decentralised solar district heating
2019 (English)In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 179, p. 307-315Article in journal (Refereed) Published
Abstract [en]

The purpose of decentralised solar district heating plants is to feed solar heat directly into district heatingnetworks. This decentralised heat supply has to consider two major output conditions: a stable required feed-insupply temperature and a feed-in heat power equal to the heat output from the solar collectors. However, manyinstallations cannot achieve the second output condition, since severe oscillations appear in the feed-in heatpower. This problem can be solved by two different control concepts with either temperature- or flow-control.Detailed measurements from two reference plants are provided for these two different control concepts. Onemain conclusion is that a robust control system is characterized by the ability to provide required flows andtemperatures. The major difference between robust and less robust control is that the supply temperatures and/or flows do not fluctuate even if the input conditions are unfavourable. © 2019 Elsevier Ltd. All rights reserved.

Place, publisher, year, edition, pages
Oxford: Elsevier, 2019
Keywords
Solar thermal, Feed-in systems, District heating, Control strategy, Prosumers
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-40906 (URN)10.1016/j.solener.2018.12.080 (DOI)000458942300029 ()2-s2.0-85059474876 (Scopus ID)
Funder
Knowledge Foundation
Note

Other funders: Industrial post-graduate school Reesbe & Fjarrsyn project (3314)

Available from: 2019-11-12 Created: 2019-11-12 Last updated: 2019-11-26Bibliographically approved
Persson, U., Wiechers, E., Möller, B. & Werner, S. (2019). Heat Roadmap Europe: Heat distribution costs. Energy, 176, 604-622
Open this publication in new window or tab >>Heat Roadmap Europe: Heat distribution costs
2019 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 176, p. 604-622Article in journal (Refereed) Published
Abstract [en]

This analysis elaborates further the concept of physical and economic suitability for district heating in EU28 by an aggregation regarding key dimensions such as land areas, populations, heat demands, and investment volumes. This aggregation is based on a resolution on hectare level by slicing the total land area into 437 million pieces. Results show that heat demands in buildings are present in 9% of the land area. Because of high concentrations in towns and cities, 78% of the total heat demand in buildings originate from dense urban areas that constitute 1.4% of the total land area and 70% of the population. Due to these high heat densities above 50 MJ/m2 per year, the paper evaluates a setting where district heating is individually expanded in each member state for reaching a common 50% heat market proportion in EU28 at lowest cost. At this saturation rate, the aggregated EU28 district heat deliveries would increase to 5.4 EJ/a at current heat demands and represents an expansion investment volume, starting from current level of 1.3 EJ, of approximately 270 billion euro for heat distribution pipes. Given the current high heat densities in European urban areas, this study principally confirms earlier expectations by quantitative estimations. © 2019 Elsevier Ltd

Place, publisher, year, edition, pages
London: Elsevier, 2019
Keywords
District heating, Distribution capital cost, Heat density, Land use, Geographical information systems, European union
National Category
Energy Systems Remote Sensing
Identifiers
urn:nbn:se:hh:diva-39226 (URN)10.1016/j.energy.2019.03.189 (DOI)2-s2.0-85064154901 (Scopus ID)
Projects
Heat Roadmap Europe
Funder
EU, Horizon 2020, 695989
Available from: 2019-04-14 Created: 2019-04-14 Last updated: 2019-05-09Bibliographically approved
Gong, M. (2019). New system solution for biomass CHP plant. Eskilstuna: Energimyndigheten
Open this publication in new window or tab >>New system solution for biomass CHP plant
2019 (English)Report (Other academic)
Alternative title[sv]
Ny systemlösning för biokraftvärme
Abstract [en]

The main propose with this pre-study was to assess a new Chinese conceptconcerning Combined Heat and Power (CHP) plants for typical Swedish conditionswith biomass as fuel. The new enhancement is to use a large absorption heat pumpfor the final heat supply instead of the turbine condenser. More heat can then berecovered from the three units that will deliver the heat (the flue gas condenser, theturbine condenser and the absorption heat pump). So far, this new CHP solution hasnever been implemented outside China.For this pre-study, the simulation model was elaborated on design data from theÖrtofta biomass CHP plant outside Lund. The results show that Chinese conceptwill provide the higher conversion efficiency, but with lower power-to-heat ratio.The main benefit is that more heat can be recycled from the flue gas condenser. Thepayback time of installing absorption heat pump is always over eight years withinexpected intervals for alternative costs for electricity and heat.The Chinese concept is less suitable for the Swedish context with biomass backpressureCHP plants, since the proportion of lost electricity becomes rather high.The Chinese context with utilization of existing condensation turbines is stillinteresting, since condenser heat can be recycled without major modification ofexisting turbines.

Place, publisher, year, edition, pages
Eskilstuna: Energimyndigheten, 2019. p. 15
Keywords
Biomass, combined heat and power, absorption heat pump
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-41078 (URN)
Projects
Ny systemlösning för biokraftvärme
Funder
Swedish Energy Agency, 46415-1
Available from: 2019-12-03 Created: 2019-12-03 Last updated: 2019-12-10
Averfalk, H., Ottermo, F. & Werner, S. (2019). Pipe Sizing for Novel Heat Distribution Technology. Energies, 12(7), Article ID 1276.
Open this publication in new window or tab >>Pipe Sizing for Novel Heat Distribution Technology
2019 (English)In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 7, article id 1276Article in journal (Refereed) Published
Abstract [en]

This paper assesses pipe sizing aspects for previously proposed, novel, low heat distribution technology with three pipes. Assessment issues include heat loss, pressure loss, and pipe sizing for different typical pipe configurations. This assessment has been provided by the analysis of a case area with single-family houses. Concerning heat loss, the proposed three-pipe solutions have the same magnitude of heat loss as conventional twin pipes, since lower return temperatures compensate for the larger heat loss area from the third pipe. Regarding pressure loss, the main restriction on the size of the third pipe is limited to the pressure loss in the third pipe. Thermostatic valves to manage the flow rate of the third pipe are advocated, since alternative small pumps have not been found to be commercially available. The pipe sizing recommendation is that the third pipe for recirculation purposes can be two to three standard pipe sizes smaller than the corresponding supply and return pipe, if no prosumer is connected in the heat distribution network.

Place, publisher, year, edition, pages
Basel: MDPI, 2019
Keywords
low temperature, district heating, pressure gradients, three-pipe system, 4GDH-3P
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-39198 (URN)10.3390/en12071276 (DOI)
Projects
TEMPO
Funder
EU, Horizon 2020, 768936
Available from: 2019-04-04 Created: 2019-04-04 Last updated: 2019-04-04Bibliographically approved
Averfalk, H. & Werner, S. (2018). Efficient heat distribution in solar district heating systems. In: SDH Solar District Heating: Proceeding. Paper presented at 5th International Solar District Heating Conference, Graz, Austria, April 11-12, 2018 (pp. 63-66).
Open this publication in new window or tab >>Efficient heat distribution in solar district heating systems
2018 (English)In: SDH Solar District Heating: Proceeding, 2018, p. 63-66Conference paper, Published paper (Refereed)
Abstract [en]

This paper contains a short analysis showing the main benefit for solar district heating when a novel heat distribution concept with low temperatures is applied. The analysis is performed by comparing the annual solar heat output from a solar collector field for current heat distribution temperatures in Sweden with the corresponding output for the novel heat distribution concept. The results show that the new low temperature concept provides 66% more solar heat for a typical solar collector. Hereby, the solar collector field can be reduced with 40%, giving a corresponding cost reduction for solar heat generated. Another result is that the cost gradient for lower costs from lower return temperatures is five times higher for solar district heating compared to current heat supply in Swedish district heating systems. One major conclusion is that high heat distribution temperatures in current European district heating systems are a major barrier for the competitiveness of solar district heating.

National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-36730 (URN)
Conference
5th International Solar District Heating Conference, Graz, Austria, April 11-12, 2018
Available from: 2018-05-07 Created: 2018-05-07 Last updated: 2018-06-12Bibliographically approved
Averfalk, H. & Werner, S. (2018). Novel low temperature heat distribution technology. Energy, 145, 526-539
Open this publication in new window or tab >>Novel low temperature heat distribution technology
2018 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 145, p. 526-539Article in journal (Refereed) Published
Abstract [en]

Lower future heat demands and lower availability of non-fossil high temperature heat supply are expected future market conditions that restrain the long-term viability of contemporary district heating systems. Hence, current district heating technology should be enhanced to increase system performance in new heat distribution areas. This paper aims to outline a proposal for technical improvements required to achieve lower annual average return temperatures in new residential buildings to improve viability in future market conditions. The proposed technical solution consists of three principle changes: three-pipe distribution networks, apartment substations, and longer thermal lengths for heat exchangers. The three technical modifications aims at addressing system embedded temperature errors. Furthermore, a simulation model was developed to assess the proposed technical solution concerning different energy performances of buildings and different thermal lengths in heat exchangers. The results show that implementation of the three technical modifications reaches time-weighted annual average return temperatures of 17–21 °C with supply temperatures of about 50 °C. The results also verify the increased necessity to separate the network return flows into delivery and recirculation flows in residential substations as energy performance in buildings increase.

Place, publisher, year, edition, pages
London: Elsevier, 2018
Keywords
Low temperature, District heating, Three-pipe system, Recirculation, 4GDH-3P
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-38360 (URN)10.1016/j.energy.2017.12.157 (DOI)
Available from: 2018-11-18 Created: 2018-11-18 Last updated: 2019-04-04Bibliographically approved
Lygnerud, K. & Werner, S. (2018). Risk assessment of industrial excess heat recovery in district heating systems. Paper presented at 3rd International Conference on Smart Energy Systems and 4th Generation District Heating (SES4DH), Sep 12-13, 2017, Copenhagen, Denmark. Energy, 151, 430-441
Open this publication in new window or tab >>Risk assessment of industrial excess heat recovery in district heating systems
2018 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 151, p. 430-441Article in journal (Refereed) Published
Abstract [en]

The recovery of industrial excess heat for use in district heating systems can be characterised by great political interest, high potential, low utilisation and often high profitability. These characteristics reveal that barriers are present for its greater utilisation. One identified barrier is the risk that industries with excess heat can terminate their activities, resulting in the loss of heat recovery. Excess heat recovery investments are therefore sometimes rejected, despite them being viable investments. The risk of termination of industrial activities has been assessed by a study of 107 excess heat recoveries in Sweden. The analysis verified that terminated industrial activities are one of two major explanations for terminated heat delivery. The other major reason is substitution by another heat supply. These two explanations correspond to approximately 6% of all annual average heat recoveries. The identified risk factors are small annual heat recovery and the use of heat pumps when low-temperature heat was recovered. The main conclusion is that a small proportion of industrial heat recovery has been lost in Sweden because of terminated industrial activities. The risk premium of losing industrial heat recovery for this specific reason should be considered to be lower than often presumed in feasibility studies. © 2018 Elsevier Ltd

Place, publisher, year, edition, pages
London: Elsevier, 2018
Keywords
District heating, Excess heat recovery, Risk assessment, Sweden
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-38362 (URN)10.1016/j.energy.2018.03.047 (DOI)000432509000038 ()2-s2.0-85046011200 (Scopus ID)
Conference
3rd International Conference on Smart Energy Systems and 4th Generation District Heating (SES4DH), Sep 12-13, 2017, Copenhagen, Denmark
Note

Funding Agency:

Fjarrsyn programme Grant number: 4311

Swedish Energy Agency

Swedish District Heating Association

Available from: 2018-11-18 Created: 2018-11-18 Last updated: 2018-11-20Bibliographically approved
Sernhed, K., Lygnerud, K. & Werner, S. (2018). Synthesis of recent Swedish district heating research. Paper presented at 3rd International Conference on Smart Energy Systems and 4th Generation District Heating (SES4DH), Copenhagen, Denmark, Sept. 12-13, 2017. Energy, 151, 126-132
Open this publication in new window or tab >>Synthesis of recent Swedish district heating research
2018 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 151, p. 126-132Article in journal (Refereed) Published
Abstract [en]

In Sweden, district heating meets currently above half of the heat demands in buildings. District heating research in Sweden has a long tradition dating back to 1975. The latest research program period included 34 projects and was executed between 2013 and 2017. In this paper, a synthesis is performed on the Swedish research frontier by assessing these recent research projects. The three study purposes was to provide an overview over the executed projects, to identify new research questions, and to identify future challenges to the Swedish district heating industry. The assessment was based on six defined key areas, such as demand, resources, system frameworks, technology, cold supply, and international perspective. The subsequent content analysis was performed from three perspectives: the perspective of energy system transition, the customer perspective, and the sustainability perspective. Final conclusions include the three future challenges for the Swedish district heating industry. These are future strategies to communicate the value of district heating, vision for district heating beyond the transition to fossil free supply, and technology development for efficient use of low temperature heat sources. © 2018 Elsevier Ltd

Place, publisher, year, edition, pages
London: Elsevier, 2018
Keywords
District heating, District cooling, Research program, Sustainability, Customer perspective, Energy system transition
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-38363 (URN)10.1016/j.energy.2018.03.028 (DOI)000432509000012 ()2-s2.0-85046035510 (Scopus ID)
Conference
3rd International Conference on Smart Energy Systems and 4th Generation District Heating (SES4DH), Copenhagen, Denmark, Sept. 12-13, 2017
Note

Funding: Swedish Energy Agency

Available from: 2018-11-18 Created: 2018-11-18 Last updated: 2018-11-22Bibliographically approved
Lund, H., Østergaard, P. A., Chang, M., Werner, S., Svendsen, S., Sorknæs, P., . . . Möller, B. (2018). The status of 4th generation district heating: Research and results. Energy, 164, 147-159
Open this publication in new window or tab >>The status of 4th generation district heating: Research and results
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2018 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 164, p. 147-159Article in journal (Refereed) Published
Abstract [en]

This review article presents a description of contemporary developments and findings related to the different elements needed in future 4th generation district heating systems (4GDH). Unlike the first three generations of district heating, the development of 4GDH involves meeting the challenge of more energy efficient buildings as well as the integration of district heating into a future smart energy system based on renewable energy sources. Following a review of recent 4GDH research, the article quantifies the costs and benefits of 4GDH in future sustainable energy systems. Costs involve an upgrade of heating systems and of the operation of the distribution grids, while benefits are lower grid losses, a better utilization of low-temperature heat sources and improved efficiency in the production compared to previous district heating systems. It is quantified how benefits exceed costs by a safe margin with the benefits of systems integration being the most important. © 2018 Elsevier Ltd

Place, publisher, year, edition, pages
London: Elsevier, 2018
Keywords
4 generation district heating, 4GDH, Low-temperature district heating, Smart energy systems, Smart thermal grids, Meta conclusions
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-38361 (URN)10.1016/j.energy.2018.08.206 (DOI)2-s2.0-85053436797 (Scopus ID)
Available from: 2018-11-18 Created: 2018-11-18 Last updated: 2018-11-20Bibliographically approved
Projects
Future heat demands 2 [P37905-1_Energi]; Halmstad UniversityDistrict heating research in China [P37907-1_Energi]; Halmstad UniversityDistrict heating in the energy system 2 [P37906-1_Energi]; Halmstad UniversityFuture district heating technology [P41302-1_Energi]; Halmstad UniversityPre-study - new task sharing annex within the IEA-DHC-programme [P42854-1_Energi]; Halmstad University
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9069-0807

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