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Renström, R. & Brunzell, L. (2018). En introduktion för att studenter ska utveckla egna strategier för skrivandet. In: Madelaine Johansson, Lena E. Johansson (Ed.), Studentaktiva lärande- och examinationsformer: Bidrag från universitetspedagogisk konferens 2017 (pp. 93-108). Karlstad: Karlstads universitet
Open this publication in new window or tab >>En introduktion för att studenter ska utveckla egna strategier för skrivandet
2018 (Swedish)In: Studentaktiva lärande- och examinationsformer: Bidrag från universitetspedagogisk konferens 2017 / [ed] Madelaine Johansson, Lena E. Johansson, Karlstad: Karlstads universitet, 2018, p. 93-108Chapter in book (Other academic)
Abstract [sv]

I högre utbildning är akademiskt skrivande något som studenter behöver stöd att utveckla genom hela sin utbildning. Handledningen är en central del i denna process men det finns en risk att handledaren i stället för att lyfta halvfärdiga texter i själva verket drar ner studenter eller lämnar otydliga synpunkter. Det finns även en risk att handledaren över skrivarbetet och gör det till sitt.

Vi arbetar med en handledningsmodell som vi kallar ”Direkthandledning”. Modellen ger stor frihet för förändringar och stora delar avutbildningsmiljön arbetar med liknande modeller. Drivkraften är att göra handledningen effektivare, att öka studenternas respons för lärarnas synpunkter samt ge studenterna egna strategier för sitt skrivande. Direkthandledningsmodellen används i hela utbildningen och i denna artikel presenteras introduktionen. I handledningsmodellen separeras innehåll och form. I introduktionen handleds enbart formen, hur rapporten är formaliserad, strukturerad och skriven.I direkthandledningsmodellen får studenten alltid en tydlig process och kravspecifikation på vad som förväntas. I introduktionen genomförs en individuell studie och först när studenten skrivit en inledning, metod och resultat som är i läs- och kommentarbart skick, får studenten handledning. Texten skall då följa en utskickad och kommunicerad mall och struktur. Återkopplingen utgår från kravspecifikationen. När studenten kommer till handledningen har handledare och student en diskussion kring hur arbetet är presenterat, inget annat. Under handledningen får studenten tydlig information om hur denne ligger till i förhållande till kravspecifikationen.

Modellen har lett till betydande förbättringar av responsen på synpunkter. Studenter uppger att de börjat utveckla egna strategier för sitt skrivande.

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2018
Series
Utveckling av undervisning och examination i högre utbildning: utgiven av Universitetspedagogiska enheten vid Karlstads universitet ; 2018:1
National Category
Educational Sciences
Identifiers
urn:nbn:se:kau:diva-72045 (URN)978-91-7063-869-5 (ISBN)978-91-7063-964-7 (ISBN)
Available from: 2019-05-15 Created: 2019-05-15 Last updated: 2019-05-15Bibliographically approved
Renström, R., Johansson-Cider, H. & Brunzell, L. (2018). Energy performance of an industrial superheated steam heat pump flash dryer for drying of bio-fuel. In: Carcel, JA Clemente, G GarciaPerez, JV Mulet, A Rossello, C (Ed.), IDS'2018: 21ST INTERNATIONAL DRYING SYMPOSIUM. Paper presented at 21st International Drying Symposium (IDS); Valencia, SPAIN; Date: SEP 11-14, 2018 (pp. 1495-1502). University Politecnica Valencia
Open this publication in new window or tab >>Energy performance of an industrial superheated steam heat pump flash dryer for drying of bio-fuel
2018 (English)In: IDS'2018: 21ST INTERNATIONAL DRYING SYMPOSIUM / [ed] Carcel, JA Clemente, G GarciaPerez, JV Mulet, A Rossello, C, University Politecnica Valencia , 2018, p. 1495-1502Conference paper, Published paper (Refereed)
Abstract [en]

Drying is an energy demanding industrial process and methods for reducing the energy consumption of drying is of interest to industry as well as society. This article presents the drying system of a biofuel factory. Steam is used as the refrigerant. Superheated steam is used as drying gas in a flash dryer with 28.8 tons/h dewatering capacity. The system includes an energy recovering water heat pump that receives its heat from the excess drying steam and heats the dryer. The SMER of the drying process ranges between 3 and 4 and the COP of the heat pump process ranges between 4 and 5.5 during one production season of peat drying. Variations in performance can be explained by variations in inlet moisture content and production rate. The example of this drying system shows the feasibility of drying in superheated steam, heat pump drying and water as refrigerant in high-temperature heat pumps.

Place, publisher, year, edition, pages
University Politecnica Valencia, 2018
Keywords
steam drying, heat pump process, peat, sawdust, industrial operation
National Category
Energy Systems
Research subject
Energy Technology
Identifiers
urn:nbn:se:kau:diva-74340 (URN)10.4995/ids2018.2018.7379 (DOI)000477977800187 ()978-84-9048-688-7 (ISBN)
Conference
21st International Drying Symposium (IDS); Valencia, SPAIN; Date: SEP 11-14, 2018
Available from: 2019-08-15 Created: 2019-08-15 Last updated: 2019-08-15
Brunzell, L. & Renström, R. (2018). Utformning av aktiva pedagogiska möten i en kurs med flippat lärande. In: Madelaine Johansson, Lena E. Johansson (Ed.), Studentaktiva lärande- och examinationsformer: Bidrag från universitetspedagogisk konferens 2017 (pp. 21-34). Karlstad: Karlstads universitet
Open this publication in new window or tab >>Utformning av aktiva pedagogiska möten i en kurs med flippat lärande
2018 (Swedish)In: Studentaktiva lärande- och examinationsformer: Bidrag från universitetspedagogisk konferens 2017 / [ed] Madelaine Johansson, Lena E. Johansson, Karlstad: Karlstads universitet, 2018, p. 21-34Chapter in book (Other academic)
Abstract [sv]

Att använda flippat lärande i undervisningen har blivit mer och mer vanligt i högre utbildning. Studier pekar på att den formen av undervisning leder till ökad förståelse, ett ökat engagemang och motivation hos studenterna. Dock finns ett uttalat behov av ytterligare forskning inom området. I denna studie ligger fokus på hur de pedagogiska mötena i en typisk teknisk grundkurs kan utformas för att vara aktiva och främja lärandet i de högre kunskapsnivåerna. Den nya utformningen bygger på att traditionella möten med studenter såsom föreläsningar och lektioner har bytts ut mot diskussionstillfällen och laborationer. Räkneövningar finns i båda upplägg men fokus i det nya ligger i att arbeta med koncept och hur problem ställs upp. Den operativa räkningen lämnas alltid till studenterna. Resultaten blir att lärarna idag kan möta studenterna och agera som en coach i deras lärande, studenterna är mer aktiva och vi arbetar med kunskapsmål där vi analyserar, kritiskt utvärderar, utformar system och gör avvägda antaganden. Genomströmningen har ökat från mellan 40-50% till mellan 60-70% trots ett ökat krav på förståelsen i examinationen.

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2018
Series
Utveckling av undervisning och examination i högre utbildning: utgiven av Universitetspedagogiska enheten vid Karlstads universitet ; 2018:1
National Category
Educational Sciences
Identifiers
urn:nbn:se:kau:diva-72044 (URN)978-91-7063-869-5 (ISBN)978-91-7063-964-7 (ISBN)
Available from: 2019-05-15 Created: 2019-05-15 Last updated: 2019-05-15Bibliographically approved
Bengtsson, P., Berghel, J. & Renström, R. (2015). A household dishwasher heated by a heat pump system using an energy storage unit with water as the heat source. International journal of refrigeration, 49, 19-27
Open this publication in new window or tab >>A household dishwasher heated by a heat pump system using an energy storage unit with water as the heat source
2015 (English)In: International journal of refrigeration, ISSN 0140-7007, E-ISSN 1879-2081, Vol. 49, p. 19-27Article in journal (Refereed) Published
Abstract [en]

Electricity usage by a household dishwasher can be reduced by using a heat pump system to heat the dishwasher cabinet, dishware and washing water. The evaporator obtains the energy from an energy storage unit which consists of a container filled with water which freezes to ice. The majority of the heat transfer from the energy storage to the evaporator occurs when ice is created in the energy storage unit. A transient simulation model of a dishwasher with a heat pump system was developed and compared to an experimental setup with good agreement. A simulation study of the compressor cylinder volume and the compressor operating time was performed. The results showed a 24% reduction in total electricity use compared to a dishwasher cycle using a traditional electric element.

Place, publisher, year, edition, pages
Elsevier, 2015
Keywords
Appliances, Energy use, Heat transfer, Freezing, Transient simulation, Appareils domestiques, Utilisation d'énergie, Transfert de chaleur, Congélation, Simulation transitoire
National Category
Energy Engineering
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-39072 (URN)10.1016/j.ijrefrig.2014.10.012 (DOI)000348012500004 ()
Funder
Knowledge Foundation
Available from: 2016-01-19 Created: 2016-01-19 Last updated: 2019-07-12Bibliographically approved
Berghel, J. & Renström, R. (2014). An Experimental Study on the Influence of Using a Draft Tube in a Continuous Spouted Bed Dryer. Drying Technology, 32(5), 519-527
Open this publication in new window or tab >>An Experimental Study on the Influence of Using a Draft Tube in a Continuous Spouted Bed Dryer
2014 (English)In: Drying Technology, ISSN 0737-3937, E-ISSN 1532-2300, Vol. 32, no 5, p. 519-527Article in journal (Refereed) Published
Abstract [en]

Further increasing the production of processed biofuel also increases the demands on drying capacity. With the aim of increasing the heat capacity flow, experimental tests have been performed on the process of drying sawdust in a continuous spouted bed dryer with nine different draft tube designs. The results showed that a draft tube with an increased length and an increased disengagement height decreased the dry substances' flow rate throughout the dryer. The results also showed that the mass of the material in the dryer was approximately the same in all the tests. This means that the draft tubes, no matter their size, do not influence the amount of material in the dryer.

Place, publisher, year, edition, pages
Taylor & Francis, 2014
Keywords
Sawdust, Superheated steam, Spouted bed dryer
National Category
Climate Research
Identifiers
urn:nbn:se:kau:diva-41535 (URN)10.1080/07373937.2013.840648 (DOI)000333995000004 ()
Available from: 2016-04-25 Created: 2016-04-11 Last updated: 2017-11-30Bibliographically approved
Renström, R. & Berghel, J. (2014). Experimental results from drying sawdust below the fiber saturation point using a vertical pneumatic dryer. In: IDS 2014, The 19th International Drying Symposium: . Paper presented at IDS 2014, The 19th International Drying Symposium 24-27 Augusti, Lyon Frankrike. Lyon, France
Open this publication in new window or tab >>Experimental results from drying sawdust below the fiber saturation point using a vertical pneumatic dryer
2014 (English)In: IDS 2014, The 19th International Drying Symposium, Lyon, France, 2014Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Lyon, France: , 2014
National Category
Energy Engineering
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-34914 (URN)
Conference
IDS 2014, The 19th International Drying Symposium 24-27 Augusti, Lyon Frankrike
Available from: 2015-01-15 Created: 2015-01-15 Last updated: 2016-05-25Bibliographically approved
Bengtsson, P., Berghel, J. & Renström, R. (2014). Performance Study of a Closed-Type Heat Pump Tumble Dryer Using A Simulation Model and an Experimental Set-Up. Drying Technology, 32(8), 891-901
Open this publication in new window or tab >>Performance Study of a Closed-Type Heat Pump Tumble Dryer Using A Simulation Model and an Experimental Set-Up
2014 (English)In: Drying Technology, ISSN 0737-3937, E-ISSN 1532-2300, Vol. 32, no 8, p. 891-901Article in journal (Refereed) Published
Abstract [en]

In the interests of competitiveness, manufactures of tumble dryers are seeking to reduce both their electricity use and the drying time. This study examines how the cylinder volume of the compressor and the total heat transfer of the condenser influence the drying time and electricity use in a heat pump tumble dryer. A transient simulation model was developed and compared to an experimental set-up with good similarity. The simulations show that increasing the cylinder volume of the compressor by 50% decreases the drying time by 14% without using more electricity.

Place, publisher, year, edition, pages
Taylor & Francis Group, 2014
Keywords
Energy analysis; Heat and mass transfer; Heat pump drying; Mathematical modeling
National Category
Energy Systems
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-33839 (URN)10.1080/07373937.2013.875035 (DOI)000337247400004 ()
Available from: 2014-09-26 Created: 2014-09-26 Last updated: 2019-07-12Bibliographically approved
Berghel, J. & Renström, R. (2014). Superheated steam drying of sawdust in continuous feed spouted beds: a design perspective. Biomass and Bioenergy, 71(0), 228-234
Open this publication in new window or tab >>Superheated steam drying of sawdust in continuous feed spouted beds: a design perspective
2014 (English)In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 71, no 0, p. 228-234Article in journal (Refereed) Published
Abstract [en]

Spouted bed drying technology shows promising results for the drying of unscreened sawdust in superheated steam. In this paper, the experiences from designing, running and evaluating two spouted bed continuous feed dryers are presented. Stable running conditions and drying results have been achieved. This has been particularly important for sawdust that will be compressed into pellets or briquettes. The spouted bed superheated steam dryer also shows high potential for energy efficient integration into sawmills. Our recommendation is thus, to use the outlet steam temperature as the control parameter for the outlet moisture content. A drying rate above and one below the fibre saturation level, can be identified. Visual observations through the viewing glass in the drying zone in both the dryers clearly showed that not all of the material participated in the spout at all times; there were, however, no indications of dead zones. A heat transfer analysis indicated that only about 70% of the surface area of the material was in thermal contact with the steam. This paper sums up the experiences regarding drying properties, control and system properties obtained when sawdust is dried using superheated steam as the drying medium. Further work on standardised dryers in series or in parallel is necessary to increase the capacity in the spouted bed dryer.

Keywords
Sawdust, Drying, Spouted bed, Sawmills, Superheated steam
National Category
Energy Engineering
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-34915 (URN)10.1016/j.biombioe.2014.10.004 (DOI)000345349500022 ()
Available from: 2015-01-15 Created: 2015-01-15 Last updated: 2017-12-05Bibliographically approved
Gustavsson, C., Nilsson, L. & Renström, R. (2014). Syngas as an Additional Energy Carrier in the Pulp and Paper Industry: A Mill-Wide System Analysis of a Combined Drying Concept, Utilizing On-Site Generated Gas and Steam. Energy & Fuels, 28(9), 5841-5848
Open this publication in new window or tab >>Syngas as an Additional Energy Carrier in the Pulp and Paper Industry: A Mill-Wide System Analysis of a Combined Drying Concept, Utilizing On-Site Generated Gas and Steam
2014 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 28, no 9, p. 5841-5848Article in journal (Refereed) Published
Abstract [en]

Large amounts of thermal energy are required for different unit operations in the pulp and paper industry. Typically, this energy is distributed by means of steam. In this study, introduction of in-situ-generated syngas as an energy carrier in parallel to the predominant steam has been investigated. The examined systems use dual fluidized-bed gasification integrated with a solid fuel boiler of a paper mill together with impingement drying in combination with cylinder drying, a concept enabling higher specific drying rates. The studied systems exhibit reduced overall energy use when compared to the present situation with conventional steam-heated cylinder drying. Cold tar cleaning by condensation/absorption and firing of the syngas in a gas turbine followed by utilization of the exhaust gases for drying are interesting options because this results in reduced biomass consumption with maintained power production.

Place, publisher, year, edition, pages
Washington, DC, USA: American Chemical Society (ACS), 2014
National Category
Energy Systems
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-33956 (URN)10.1021/ef5010144 (DOI)000342118200030 ()
Funder
Knowledge Foundation
Available from: 2014-10-02 Created: 2014-10-02 Last updated: 2017-12-07Bibliographically approved
Ståhl, M., Berghel, J., Frodeson, S. & Renström, R. (2013). Energy reduction in wood-fuel pellet production. Forest bioenergy review, 4(19), 6
Open this publication in new window or tab >>Energy reduction in wood-fuel pellet production
2013 (English)In: Forest bioenergy review, ISSN 2045-8614, Vol. 4, no 19, p. 6-Article in journal (Other academic) Published
Place, publisher, year, edition, pages
UK: K V J Enterprises, 2013
National Category
Energy Engineering
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-34916 (URN)
Available from: 2015-01-15 Created: 2015-01-15 Last updated: 2018-04-16Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-5764-7062

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