Analysis of the heat demand in batch kilns
2012 (English)Conference paper, Presentation (Other academic)
During the production of lumber more than half of the entering timber to the sawmill becomes biomass. About 12 %wt of the entering timber is combusted to supply heat for the sawmill. Major part of the heat is supply the kilns. Due to the high evacuation losses the energy efficiency in a traditional drying kiln is only 13 %. This makes the lumber drying to a low and ineffective process in an energy point of view.Forced drying technologies are a compromise between high lumber quality, low lead time and decreased energy use. Often is the quality and lead time prioritised. This paper advises an appropriate method to simulate the energy efficiency when drying lumber in a batch kiln. To ensure real life drying conditions, with sufficient quality and lead time the initial conditions were made from simulated drying schemes, from simulation program called Torksim. By combine thermodynamics and psychrometric relationship, the energy streams and losses during the drying scheme were established. The program can be used to compare several drying conditions and clarify the magnitude of losses. Different types of technologies affecting the kiln energy efficiency and to compare drying conditions to each other. For instance heat exchanger, heat pumps, condense walls, absorption system etc.The used drying conditions are suitable for north European lumber and climate, but the initial conditions can be changed for analyses of other types of drying conditions. The program is a usable tool to analyses different types of technologies effect on the kiln energy efficiency and to compare drying conditions and different drying scheme to each other.
Place, publisher, year, edition, pages
Research subject Energy Engineering
IdentifiersURN: urn:nbn:se:ltu:diva-31903Local ID: 639de65f-e53e-461f-ae48-5b73145f5affOAI: oai:DiVA.org:ltu-31903DiVA: diva2:1005137
International IUFRO Wood Drying Conference : 30/07/2012 - 03/08/2012
Godkänd; 2012; 20130306 (ysko)2016-09-302016-09-30Bibliographically approved