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Publications (10 of 15) Show all publications
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
Norrström, H. & Gong, M. (2019). InterSolar 2019: 14–17 maj, München, Tyskland: Trendrapport från konferens och mässa. Halmstad
Open this publication in new window or tab >>InterSolar 2019: 14–17 maj, München, Tyskland: Trendrapport från konferens och mässa
2019 (Swedish)Report (Other (popular science, discussion, etc.))
Abstract [sv]

Denna rapport är en summering av ett besök vid InterSolar-eventet som ägde rum 14-17 maj 2019 i München. Besöket genomfördes på uppdrag av Alexanderssoninstitutet inom deras projekt SolReg Halland med Julia Englund som projektkoordinator. Syftet med att besöka InterSolar var att göra en trendspaning i solenergibranschen. Uppdraget var att samla information för att analysera mönster. Frågorna som skulle besvaras var:

☼   Vilka trender kan vi lära av för att öka användningen av solenergi i Halland?

☼   Vad kan vi göra för att stärka solenergibranschen i Hallandsregion?

Konferensen och mässan InterSolar Europe ingår i the Smarter E Europe the Innovation Hub for New Energy Solutions. Deras syfte är dels att uppmärksamma de innovatörer som driver omställningen av energisystemen och dels att fungera som mötesplats för solenergibranschen. Bokningsbara konferensrum fanns tillgängliga över hela konferens- och mässområdet.

Konferensen InterSolar marknadsfördes tillsammans med tre andra konferenser 14-15 maj;

  • ees Europe —för lagring av elektrisk energi
  • Power2drive Europe — för infrastruktur, laddning och e-mobilitet
  • Smart renewable systems — för interaktiva byggnader, smarta hem och lokala mikronät.

Nästan samtidigt, 15-17 maj, genomfördes mässan InterSolar Europe tillsammans med tre andra mässor;

  • ees Europe —för lagring av elektrisk energi
  • Power 2 drive Europe — för infrastruktur, laddning och e-mobilitet
  • EM-power — för intelligent energianvändning inom industrin och bebyggelse.

Hela konceptet genomförs såväl i Europa som i Asien, Sydamerika och Nordamerika men vid olika tidpunkter på året.

Place, publisher, year, edition, pages
Halmstad: , 2019. p. 26
Keywords
solenergi, mässa, trendanalys
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-41194 (URN)
Projects
SolReg Halland
Available from: 2019-12-09 Created: 2019-12-09 Last updated: 2020-02-19Bibliographically 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
Gong, M. (2017). Exergy and cost analysis of heating systems with energy storage. In: : . Paper presented at The 3rd International Conference on Smart Energy Systems and 4th Generation District Heating, 12-13 September 2017, Copenhagen, Denmark.
Open this publication in new window or tab >>Exergy and cost analysis of heating systems with energy storage
2017 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

About three quarters of the total final energy consumption is in the form of electricity and district heat and 49 TWh of district heat was used in Sweden in 2015. The energy supply and user demands vary and do not always match. The electricity production depends on the available energy resource that often is renewable, such as wind, solar and hydro power. The heat demand strongly depends on outdoor temperature and the weather conditions. Electricity and thermal storages are needed in order to reduce the losses from the lack of match between production and consumption. The cost of energy examined by others shows that electricity storage is about 100 times more expensive than thermal storage. However, in this study cost of exergy is only 20 times more for electricity than thermal. This study views electricity and district heat from source to end use and analyze the cost of exergy with storage. With a surplus of electricity the most efficient and cheapest way is to use electricity storage, such as battery or hydro storage on the purpose of electricity usage. The advantage of thermal storage depends strongly on the purpose of use, e.g. if it is for heating purposes. Heat pump is a method to convert electricity to district heat with 56% exergy efficiency. This paper will analyze different cases in order to give a more detailed discussion. Further studies of more cases are needed in the future.

Keywords
energy storage, exergy, renewable energy
National Category
Energy Systems
Identifiers
urn:nbn:se:hh:diva-35152 (URN)
Conference
The 3rd International Conference on Smart Energy Systems and 4th Generation District Heating, 12-13 September 2017, Copenhagen, Denmark
Available from: 2017-10-05 Created: 2017-10-05 Last updated: 2017-10-10Bibliographically approved
Averfalk, H., Ingvarsson, P., Persson, U., Gong, M. & Werner, S. (2017). Large heat pumps in Swedish district heating systems. Renewable & sustainable energy reviews, 79, 1275-1284
Open this publication in new window or tab >>Large heat pumps in Swedish district heating systems
Show others...
2017 (English)In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 79, p. 1275-1284Article in journal (Refereed) Published
Abstract [en]

Power-to-heat solutions like heat pumps and electric boilers are foreseen to be possible future tools to stabilise international power markets with high proportions of variable power supply. Temporary low cost electricity can be used for heat generation at times with high availability of wind and solar power through substitution of ordinary heat supply, hence contributing to increased energy system sustainability. Power-to-heat installations in district heating systems are competitive due to low specific investment and installation costs for large electric boilers, heat pumps, and heat storages. Several large-scale heat pumps were installed in Swedish district heating systems during the 1980s, since a national electricity surplus from new nuclear power existed for some years. The aim of this paper is to summarise the accumulated operation experiences from these large Swedish heat pumps to support and facilitate planning of future power-to-heat solutions with heat pumps in district heating systems. Gained experiences consider; installed capacities, capacity utilisation, heat sources used, refrigerant replacements, refrigerant leakages, and wear of mechanical components. The major conclusion is that many of the large thirty-year-old heat pumps are still in operation, but with reduced capacity utilisation due to internal competition from waste and biomass cogeneration plants in the district heating systems.

Place, publisher, year, edition, pages
Kidlington: Pergamon Press, 2017
Keywords
Power-to-heat, Heat pumps, District heating, District cooling, Integrated energy systems
National Category
Energy Systems
Identifiers
urn:nbn:se:hh:diva-34097 (URN)10.1016/j.rser.2017.05.135 (DOI)000410011500091 ()2-s2.0-85019691543 (Scopus ID)
Available from: 2017-06-13 Created: 2017-06-13 Last updated: 2020-02-18Bibliographically approved
Gong, M. & Werner, S. (2017). Mapping energy and exergy flows of district heating in Sweden. Energy Procedia, 116, 119-127
Open this publication in new window or tab >>Mapping energy and exergy flows of district heating in Sweden
2017 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 116, p. 119-127Article in journal (Refereed) Published
Abstract [en]

District heating has been available in Sweden since the 1950s and used more than half of the total energy use in dwelling and no-residential premises in 2013. Energy and exergy efficient conversion and energy resources are key factors to reduce the environmental impact. It is important to understand energy and exergy flows from both the supply and demand sides. The exergy method is also a useful tool for exploring the goal of more efficient energy-resource use. Sankey diagrams together with energy and exergy analyses are presented to help policy/decision makers and others to better understand energy and exergy flows from primary energy resource to end use. The results show the most efficient heating method in current district heating systems, and the use of renewable energy resources in Sweden. It is exergy inefficient to use fossil fuels to generate low quality heat. However, renewable energies, such as geothermal and solar heating with relative low quality, make it more exergy efficient. Currently, about 90% of the energy sources in the Swedish district heating sector have an origin from non-fossil fuels. Combined heat and power is an efficient simultaneous generator of electricity and heat as well as heat pump with considering electricity production. Higher temperature distribution networks give more distribution losses, especially in exergy content. An outlook for future efficient district heating systems is also presented.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2017
Keywords
District heating, exergy, Sankey diagram, Grassmann diagram, Sweden
National Category
Energy Systems
Identifiers
urn:nbn:se:hh:diva-35151 (URN)10.1016/j.egypro.2017.05.060 (DOI)000406743000011 ()2-s2.0-85028600044 (Scopus ID)
Available from: 2017-10-05 Created: 2017-10-05 Last updated: 2017-10-05Bibliographically approved
Gong, M. & Wall, G. (2016). Exergy Analysis of the Supply of Energy and Material Resources in the Swedish Society. Energies, 9(9), Article ID 707.
Open this publication in new window or tab >>Exergy Analysis of the Supply of Energy and Material Resources in the Swedish Society
2016 (English)In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 9, no 9, article id 707Article in journal (Refereed) Published
Abstract [en]

Exergy is applied to the Swedish energy supply system for the period 1970–2013. Exergy flow diagrams for the systems of electricity and district heating as well as for the total supply system of energy and material resources for 2012 are presented. The share of renewable use has increased in both electricity and district heat production. The resource use is discussed in four sectors: residential and service, transportation, industry and agriculture. The resource use is also analyzed with respect to exergy efficiency and renewable share. The total exergy input of energy and material resources amounts to about 2700 PJ of which about 530 PJ was used for final consumption in 2012. The results are also compared with similar studies. Even though the share of renewable resource use has increased from 42% in 1980 to 47% in 2012, poor efficiency is still occurring in transportation, space heating, and food production. A strong dependence on fossil and nuclear fuels also implies a serious lack of sustainability. A more exergy efficient technology and a higher renewable energy share are needed in order to become a more sustainable society.

Place, publisher, year, edition, pages
Basel: M D P I AG, 2016
Keywords
energy, renewable, exergy flow diagram, electricity, district heating, Sweden
National Category
Energy Engineering
Identifiers
urn:nbn:se:hh:diva-31926 (URN)10.3390/en9090707 (DOI)000383547900044 ()2-s2.0-84988023651 (Scopus ID)
Available from: 2016-09-05 Created: 2016-09-05 Last updated: 2018-10-22Bibliographically approved
Gong, M. & Werner, S. (2016). Mapping Energy and Exergy Flows of District Heating in Sweden. In: Rolf Ulseth & Kyung Min Kim (Ed.), Proceedings the 15th International Symposium on District Heating and Cooling: September 4th - 7th, 2016, Seoul, South Korea. Paper presented at The 15th International Symposium on District Heating and Cooling September 4-7, 2016, Seoul, Republic of Korea (South Korea) (pp. 96-102).
Open this publication in new window or tab >>Mapping Energy and Exergy Flows of District Heating in Sweden
2016 (English)In: Proceedings the 15th International Symposium on District Heating and Cooling: September 4th - 7th, 2016, Seoul, South Korea / [ed] Rolf Ulseth & Kyung Min Kim, 2016, p. 96-102Conference paper, Published paper (Refereed)
Abstract [en]

District heating has been available in Sweden since the 1950s and used more than half of the total energy use in dwelling and no-residential premises in 2013. Energy and exergy efficient conversion and energy resources are key factors to reduce the environmental impact. It is important to understand energy and exergy flows from both the supply and demand sides. The exergy method is also a useful tool for exploring the goal of more efficient energy-resource use. Sankey diagrams together with energy and exergy analyses are presented to help policy/decision makers and others to better understand energy and exergy flows from primary energy resource to end use. The results show the most efficient heating method in current district heating systems, and the use of renewable energy resources in Sweden. It is exergy inefficient to use fossil fuels to generate low quality heat. However, renewable energies, such as geothermal and solar heating with relative low quality, make it more exergy efficient. Currently, about 90% of the energy sources in the Swedish district heating sector have an origin from non-fossil fuels. Combined heat and power is an efficient simultaneous generator of electricity and heat as well as heat pump with considering electricity production. Higher temperature distribution networks give more distribution losses, especially in exergy content. An outlook for future efficient district heating systems is also presented.

Keywords
District heating, exergy, Sankey diagram, Sweden
National Category
Energy Systems
Identifiers
urn:nbn:se:hh:diva-31984 (URN)
Conference
The 15th International Symposium on District Heating and Cooling September 4-7, 2016, Seoul, Republic of Korea (South Korea)
Available from: 2016-09-13 Created: 2016-09-12 Last updated: 2017-01-13Bibliographically approved
Gong, M. & Werner, S. (2015). An assessment of district heating research in China. Renewable energy, 84, 97-105
Open this publication in new window or tab >>An assessment of district heating research in China
2015 (English)In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 84, p. 97-105Article in journal (Refereed) Published
Abstract [en]

The recent growth of the Chinese district heating sector has been very high. No other country in the world can show the same growth rate during the last decades. The heated building area increased six times between 1995 and 2008. China has also enjoyed strong growth of scientific articles and papers about district heating in recent years. One third of all international scientific journal articles and conference papers about district heating came from Chinese scientists during 2010–2012, while Swedish scientists accounted for one quarter according to the Scopus scientific search engine. It is important to identify the Chinese district heating research to judge the potential for future collaborative research on district heating systems between Sweden/Europe and China. The 205 international publications on district heating by Chinese scientists published until 2013 have been mapped and summarised with respect to demand, supply, technology, market and environment. More diversified heat supply with renewable source was grasping the Chinese interest, since many new systems have been established, having more degrees of freedom when choosing various heat supply and technology options. The Chinese district heating systems were compared with sustainable district heating solutions in Sweden. Both countries would benefit from future research cooperation. © 2015 Elsevier Ltd.

Place, publisher, year, edition, pages
Kidlington: Pergamon Press, 2015
Keywords
China, Sweden, District heating, Heat supply
National Category
Energy Systems
Identifiers
urn:nbn:se:hh:diva-29504 (URN)10.1016/j.renene.2015.05.061 (DOI)000362618900011 ()2-s2.0-84936972135 (Scopus ID)
Funder
Swedish Energy Agency, 2013-005290
Note

This work has been financially supported by Fjärrsyn, the Swedish district heating and cooling research program funded by the Swedish Energy Agency and the Swedish District Heating Association.

Available from: 2015-09-23 Created: 2015-09-23 Last updated: 2018-03-22Bibliographically approved
Gong, M. & Werner, S. (2015). Exergy analysis of network temperature levels in Swedish and Danish district heating systems. Renewable energy, 84, 106-113
Open this publication in new window or tab >>Exergy analysis of network temperature levels in Swedish and Danish district heating systems
2015 (English)In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 84, p. 106-113Article in journal (Refereed) Published
Abstract [en]

Exergy concept is applied on district heating systems with different network temperature levels in their distribution networks. These district heating systems use a combination of renewables and heat recovery from other primary processes. The aim is to show simplicity and value of using exergy concept when comparing current and future temperature levels. Both the traditional exergy factor and the novel exergy utilisation rate are used in these analyses. Exergy utilisation rate expresses the ratio between the exergy delivered to customer heating systems and the exergy content in heat supply input to the distribution network. The analyses are performed on four different generations of district heating technologies, two national groups of district heating systems in Denmark and Sweden for revealing variations among systems, and two municipal systems for revealing variations within systems. The main conclusions are simplifications can be introduced in order to analyse the network temperature levels, current exergy factors reveal that current temperature levels can be reduced, and that almost two thirds of the exergy content in heat supply input are lost in the heat distribution chain. These conclusion will be vital input in developing the future fourth generation of district heating systems using both renewables and heat recovery. © 2015 Elsevier Ltd.

Place, publisher, year, edition, pages
Kidlington: Pergamon Press, 2015
Keywords
Exergy factor, Exergy utilisation rate, District heating, 4GDH
National Category
Energy Systems
Identifiers
urn:nbn:se:hh:diva-29505 (URN)10.1016/j.renene.2015.06.001 (DOI)000362618900012 ()2-s2.0-84946473498 (Scopus ID)
Available from: 2015-09-23 Created: 2015-09-23 Last updated: 2018-03-22Bibliographically approved
Projects
District heating research in China [P37907-1_Energi]; Halmstad UniversityIntegration of electricity and heat using high temperature thermal storage [48190-1]; Halmstad University
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-8307-124X

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