hh.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Werner, Sven, Professor emeritusORCID iD iconorcid.org/0000-0001-9069-0807
Alternative names
Publications (10 of 79) Show all publications
Averfalk, H. & Werner, S. (2020). Economic benefits of fourth generation district heating. Energy, 193, Article ID 116727.
Open this publication in new window or tab >>Economic benefits of fourth generation district heating
2020 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 193, article id 116727Article in journal (Refereed) Published
Abstract [en]

The main impetus for lower distribution temperatures in district heating systems is the lower heat supply costs obtained by these lower temperatures. In this paper, the differences in heat supply costs for two different temperature levels have been estimated for various future heat supply options. The estimations were obtained by modelling a district heating system characterised by typical climate conditions for Central Europe. High sensitivity to lower supply costs from lower temperatures was found for geothermal heat, industrial excess heat, and heat pumps, whereas low cost sensitivity was estimated for combined heat and power plants using waste or biomass. Lower heat distribution loss constitutes a minor component of the total cost reductions. The current use of high heat distribution temperatures was identified as an important barrier for the transition to renewable and recycled heat supply in district heating systems. Hence, lower distribution temperatures would facilitate this required transition because lower distribution temperatures provide higher profitability for these renewable and recycled heat sources. © 2019 The Authors. Published by Elsevier Ltd.

Place, publisher, year, edition, pages
London, UK: Elsevier, 2020
Keywords
Low temperature, district heating, cost reduction gradients, 4GDH, economic motivation
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-41287 (URN)10.1016/j.energy.2019.116727 (DOI)2-s2.0-85076847499 (Scopus ID)
Funder
EU, Horizon 2020, 768936
Note

Other funding: International Energy Agency Technology Collaboration Programme on District Heating and Cooling including Combined Heat and Power, IEA-DHC|CHP Annex TS2 Implementation of low-temperature district heating systems.

Available from: 2019-12-20 Created: 2019-12-20 Last updated: 2020-02-18
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
Show others...
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: 2020-01-30Bibliographically 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
Gong, M. & Werner, S. (2019). Enhanced Biomass CHP plants for district heating systems. In: Henrik Lund, Brian Vad Mathiesen & Poul Alberg Østergaard (Ed.), Book of abstracts: 5th International Conference on Smart Energy Systems in Copenhagen, on 10-11 September 2019. Paper presented at 5th International Conference on Smart Energy Systems and 4th Generation District Heating, Copenhagen, Denmark, 10-11 September, 2019 (pp. 239-239). Aalborg: Aalborg Universitetsforlag
Open this publication in new window or tab >>Enhanced Biomass CHP plants for district heating systems
2019 (English)In: Book of abstracts: 5th International Conference on Smart Energy Systems in Copenhagen, on 10-11 September 2019 / [ed] Henrik Lund, Brian Vad Mathiesen & Poul Alberg Østergaard, Aalborg: Aalborg Universitetsforlag, 2019, p. 239-239Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

In Sweden, located in North Europa, more than half of the total heat demand in buildings is met by district heating, but only just above one-third of the heat supply comes from Combined Heat and Power. In this paper, a new enhancement of biomass CHP plant is explored. The modification is that a large absorption heat pump is used for the heat supply to the district heating network. This new solution has so far never been implemented outside China. The benefits will be more electricity from lower condenser pressure and more heat obtained from flue gas condensation. The drawback is that the absorption heat pump will require extracted steam that will decrease electricity generation. In order to estimate the offset between the two benefits and the drawback, a simplified model has been developed to study a typical Swedish biomass CHP plant located in Lund. This enhancement could be part of the transition from third generation district heating (3GDH) to fourth generation district heating system (4GDH) by introducing efficient heat supply plants in current systems with high distribution temperatures. Several cases studied concerning both 3GDH and 4GDH have been compared to reference cases. The results show that the enhancement is a possible way to prepare for future 4GDH. Further investigations are recommended concerning pre-investment in absorption heat pumps as a transition strategy for new CHP plants originally designed for return temperatures of 20-30 ºC.

Place, publisher, year, edition, pages
Aalborg: Aalborg Universitetsforlag, 2019
Keywords
district heating, CHP, absorption heat pump, biomass
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-41065 (URN)
Conference
5th International Conference on Smart Energy Systems and 4th Generation District Heating, Copenhagen, Denmark, 10-11 September, 2019
Available from: 2019-12-03 Created: 2019-12-03 Last updated: 2019-12-20Bibliographically 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)000470939500050 ()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: 2020-01-31Bibliographically approved
Gong, M. & Werner, S. (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 concept concerning Combined Heat and Power (CHP) plants for typical Swedish conditions with biomass as fuel. The new enhancement is to use a large absorption heat pump for the final heat supply instead of the turbine condenser. More heat can then be recovered from the three units that will deliver the heat (the flue gas condenser, the turbine condenser and the absorption heat pump). So far, this new CHP solution has never been implemented outside China. For this pre-study, the simulation model was elaborated on design data from the Örtofta biomass CHP plant outside Lund. The results show that Chinese concept will 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. The payback time of installing absorption heat pump is always over eight years within expected intervals for alternative costs for electricity and heat. The Chinese concept is less suitable for the Swedish context with biomass backpressure CHP plants, since the proportion of lost electricity becomes rather high. The Chinese context with utilization of existing condensation turbines is still interesting, since condenser heat can be recycled without major modification of existing 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: 2020-02-19Bibliographically approved
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)000465561400093 ()2-s2.0-85065515173 (Scopus ID)
Projects
TEMPO
Funder
EU, Horizon 2020, 768936
Available from: 2019-04-04 Created: 2019-04-04 Last updated: 2020-02-18Bibliographically 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)000426413400045 ()2-s2.0-85040108589 (Scopus ID)
Available from: 2018-11-18 Created: 2018-11-18 Last updated: 2020-02-18Bibliographically 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
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

Search in DiVA

Show all publications