| 1. |
- Bengtsson, Peder, 1968-, et al.
(författare)
-
A household dishwasher heated by a heat pump system using an energy storage unit with water as the heat source
- 2015
-
Ingår i: International journal of refrigeration. - : Elsevier. - 0140-7007 .- 1879-2081. ; 49, s. 19-27
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Berghel, Jonas, 1966-, et al.
(författare)
-
From sawdust to pellets. Still a challenge...
- 2012
-
Ingår i: Public Service Review European Union. - : European union. ; :33, s. 398-399
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 5. |
|
|
| 6. |
- Berghel, Jonas, 1966-, et al.
(författare)
-
Lösningarna finns! Är pelletsproducenterna medvetna om problemen?
- 2011
-
Ingår i: Bioenergi. - Gävle : Region Gävleborg. - 9789163391262 ; , s. 25-29
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Sverige är inte längre världsledande som pelletsproducent. USA producerar allra mest pellets i världen. Kanada och Ryssland producerar också allt mer pellets. Ingen av dessa länder har någon omfattande inhemsk konsumtion. I stort sett all pellets exporteras och det sker huvudsakligen till Europa. Sannolikt kommer det att leda till att priset på pellets i Europa sjunker, med följd att lönsamheten för svenska pelletsproducenter minskar.
|
|
| 7. |
- Berghel, Jonas, 1966-, et al.
(författare)
-
The effects of kraft lignin additives on wood fuel pellet quality, energy use and shelf life
- 2013
-
Ingår i: Fuel processing technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 112:0, s. 64-69
-
Tidskriftsartikel (refereegranskat)abstract
- In 2011, the total consumption of pellets in Sweden amounted to 1.9 million tons, which represents an energy value of 9 TWh. The pellets are used in large-scale as well as in small-scale applications, and increased demands on pellet quality are likely to force pellet producers to improve on the pellet properties. One way of increasing pellet quality is by using additives. The purpose of this article, therefore, is to examine kraft lignin as an additive. Pelletswere produced in a small industrial pellet press located at KarlstadUniversity, Karlstad, Sweden, and 1–4% of kraft lignin was added to the pellets. The results indicate that the addition of an increased amount of kraft lignin to the pellets increases their mechanical durability and their lengths. The results also indicate that dry kraft lignin yields pellets with higher durability as compared to wet kraft lignin. The energy demand was unaffected by the increased use of kraft lignin. The general results presented in this paper are useful for producers of lignin, pellet producers and end-users of pellets, who are interested in developing their products and/or improving the production processes.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Brunzell, Lena, 1979-, et al.
(författare)
-
Recommendations for revising the energy label system for dishwashers : Supporting sustainable development and usage through the interaction of energy labels, technical improvements and consumer behaviour
- 2019
-
Ingår i: Energy Efficiency. - : Springer. - 1570-646X .- 1570-6478. ; 13:1, s. 145-155
-
Tidskriftsartikel (refereegranskat)abstract
- Historically, domestic chores such as washing dishes were all done by hand. Today it is estimated that 44% of the households in the EU are equipped with a dishwasher. In this article, we discuss the connections between technical developments, consumer behaviour and the test standard for energy labels. The aim of this study is to provide recommendations for future work that would strengthen the role of the energy label in order to promote the more sustainable technical development of household appliances. Technical developments are compared with the consequences of different consumer behaviour. It was found that technical developments could reduce annual energy use, but depending on the implemented technology, this is often complex and requires additional components. On the other hand, a consumer can easily increase energy usage by 50% without being aware of doing so, when goods are pre-treated, appliances incorrectly loaded, or inappropriate programs selected. Our recommendation is first of all to encourage the use of dishwashers as they consume less energy and water compared with washing up manually. A holistic approach should be taken to updating the energy labelling system. Actual consumer behaviour must be taken into account and, perhaps most importantly, as dishwashers are becoming ever more energy efficient, consumers must be educated in using the machines in an environmentally friendly way. We conclude that the energy labelling system is outdated; it must be fundamentally revised and must take into account consumer behaviour.
|
|
| 11. |
- Brunzell, Lena, 1979-, et al.
(författare)
-
Utformning av aktiva pedagogiska möten i en kurs med flippat lärande
- 2018
-
Ingår i: Studentaktiva lärande- och examinationsformer. - Karlstad : Karlstads universitet. - 9789170638695 - 9789170639647 ; , s. 21-34
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- 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.
|
|
| 12. |
- Frodeson, Stefan, 1968-, et al.
(författare)
-
Drying of Grain
- 2011
-
Ingår i: 5th Nordic Drying Conference. - Trondheim : SINTEF. - 9788292739846
-
Konferensbidrag (refereegranskat)
|
|
| 13. |
|
|
| 14. |
- Frodeson, Stefan, 1968-, et al.
(författare)
-
The Potential of Using Two-Step Drying Techniques for Improving Energy Efficiency and Increasing Drying Capacity in Fuel Pellet Industries
- 2013
-
Ingår i: Drying Technology. - : Taylor & Francis. - 0737-3937 .- 1532-2300. ; 31:15, s. 1863-1870
-
Tidskriftsartikel (refereegranskat)abstract
- The use of wood fuel pellets has increased worldwide in recent years, and pellet producers conclude that the lack of drying capacity is a barrier to increased production. In this study, we develop a concept of two different dryers called the two-step drying technique. The aim is to show the potential for increasing the drying capacity and improving energy efficiency when introducing a second dryer into the pellet plant. The study is theoretical and based on an industrial packed moving bed dryer. It shows that the drying capacity increased by 22% when a pneumatic second dryer was used.
|
|
| 15. |
|
|
| 16. |
- Gustavsson, Christer, 1968-, et al.
(författare)
-
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
-
Ingår i: Energy & Fuels. - Washington, DC, USA : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 28:9, s. 5841-5848
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 17. |
|
|
| 18. |
- Renström, Roger, 1960-, et al.
(författare)
-
En introduktion för att studenter ska utveckla egna strategier för skrivandet
- 2018
-
Ingår i: Studentaktiva lärande- och examinationsformer. - Karlstad : Karlstads universitet. - 9789170638695 - 9789170639647 ; , s. 93-108
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- 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.
|
|
| 19. |
- Renström, Roger, 1960-, et al.
(författare)
-
Energy performance of an industrial superheated steam heat pump flash dryer for drying of bio-fuel
- 2018
-
Ingår i: IDS'2018. - Valencia : University Politecnica Valencia. - 9788490486887 ; , s. 1495-1502
-
Konferensbidrag (refereegranskat)abstract
- 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.
|
|
| 20. |
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
- Stawreberg, Lena, 1979-, et al.
(författare)
-
Energy Losses by Air Leakage in Condensing Tumble Dryers
- 2012
-
Ingår i: Applied Thermal Engineering. - : Elsevier. - 1359-4311 .- 1873-5606. ; 37:May, s. 373-379
-
Tidskriftsartikel (refereegranskat)abstract
- Tumble dryers, used for the drying of textiles, consume a considerable amount of electricity due to the large number of dryers in use. A large amount of this electricity is produced from coal, making it important to reduce the electricity use and, hence, the carbon dioxide emissions. Earlier studies made on the condensing tumble dryer have pointed out that leakage is one of the parameters affecting the electricity use for the drying process. With a view to reducing the energy use, leakage was estimated through measurements and modelling. Energy balances were used in order to verify the leakage. The energy balance showed good agreement with the results from the model and confirms that the leakage out from the dryer arises mainly between the heater and the drum where the air is hot and has low relative humidity. Large leakage at this location is detrimental for the energy efficiency of the dryer, meaning that the leakage must be reduced in order to obtain a reduced energy use. Results from the model also point out that even small changes in the size of gaps, or changes to the pressure in the internal system, result in a significant change in leakage from the dryer
|
|
| 24. |
- Ståhl, Magnus, 1973-, et al.
(författare)
-
Effects on Pellet Properties and Energy Use When Starch Is Added in the Wood-Fuel Pelletizing Process
- 2012
-
Ingår i: Energy & Fuels. - Washington DC, Oxford UK : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 26:3, s. 1937-1945
-
Tidskriftsartikel (refereegranskat)abstract
- The production and use of wood-fuel pellets have increased significantly worldwide in recent years. The increased use of biomaterials has resulted in higher raw material prices, and there are no signs that indicate a decrease in raw material competition. Additives can be used for different purposes. Partly, they are used to facilitate the use of new raw materials to increase the raw material base, and partly, they are used to decrease the energy use in the pelletizing process. They are also used to increase durability or shelf life. Consequently, it is necessary to do research that systematically investigates the consequences of using additives. In this work, it is investigated how various percentages of different kinds of starch influence pellet properties, including shelf life and energy use in the pelletizing process. Four different starch grades were used: native wheat starch, oxidized corn starch, native potato starch, and oxidized potato starch. The pellets were produced in a small industrial pellet press located at Karlstad University, Karlstad, Sweden. The result shows that starch increases the durability of the pellets. Oxidized starches increase the durability more than native starches, and the best results were obtained by adding oxidized corn starch. The durability did not decrease with storage time when the pellets were stored indoors during 7 months. The oxidation process was not consistently altered by the addition of starch. The energy consumption of the pellet press decreases when starch is added. Again, the oxidized corn starch showed the best result; when 2.8% of corn starch was added, the average energy consumption was reduced by 14%
|
|
| 25. |
- Ståhl, Magnus, 1973-, et al.
(författare)
-
Energy reduction in wood-fuel pellet production
- 2013
-
Ingår i: Forest bioenergy review. - UK : K V J Enterprises. - 2045-8614. ; 4:19, s. 6-
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
