Getting the right woodfuel, the Danish way
- Thursday, 24 March 2016 16:29
Julian Morgan-Jones Visiting the 2.7MW District Heating Plant at Brande
South East Wood Fuels visited Denmark in early March to learn more about fuel types and biomass boiler manufacturing for large scale biomass heating projects. The trip was organised by Justsen Energiteknik and Core Biomass, specialist biomass boiler manufacturers and their UK distributor, both with a fast growing reputation in the UK biomass sector. We visited a 2.75MW district heating plant providing heat for 1700 homes and burning fuel at 46% moisture content, toured the Justsen factory and met biomass expert Pieter Kofman.
On arrival at Billund, the home of Legoland, we met our guide Jeppe Mikkelsen (Project Manager for Justsen) and Pieter Kofman (Senior Consultant Danish Forestry Service) to discuss tailoring fuel specifications and boiler parameters to maximise running efficiency from a range of fuel types. Pieter was able to share some of his 30 years’ experience producing wood fuels and researching energy generation from wood. Interestingly woodchips are always traded by energy content in Denmark using simple formulas for coniferous or deciduous wood based on moisture content and weight. An important point to emerge is that it is critical to run the correct fuel with the right type of boiler. Mike Chapman of SEWF noted that “although this seems obvious, putting wet fuel into a boiler designed for drier fuel below 30% moisture content (MC) will drag efficiencies way down, while doing the converse means that the ceramic linings in wet fuel boilers designed to push up burn temperatures will lead to over-heating when dry fuel is used”. Matching up fuel and boiler is a growing part of what SEWF offer clients to reduce efficiency losses and running costs.
Following an excellent Danish style buffet, which including a delicious chicken stew topped with pastry, we traveled to Brande to see a 2.75MW district heating plant using wet fuel to power a Justsen boiler with air preheating. We arrived just in time to see the daily delivery of 20 tons of wet chips being tipped into the silo before embarking on tour of the plant. From the spotless control room we were able to view all aspects of the district heating arrangements for the 1700 homes connected in the town, our guide proudly explained that the plant was operating at 114% efficiency (achieved through a condenser recovering energy from flue gases). The plant was considered quite small by local standards and was chosen because it was most comparable with the largest systems currently being installed in the UK, we thought it was huge.
From Brande we traveled through the wintry Danish countryside to Aarhus spotting the now characteristic flue in each town associated with biomass heating plants and funny looking stacks of tree tops and chip wood on the edge of fields ready for chipping.
At 8am next morning we were met by Claus and Lars Justsen at their factory. Justsen are a family owned and run business, in operation since 1960, they produce specialized, bespoke systems ranging in size from 1MW -15MW. A tour of the factory was followed by a seminar on the properties of varying fuel types and the design specifics of Justsens Argus Flex boiler range. We were hugely impressed by the level of expertise and innovation, and ability to translate this through the factory floor into bespoke plants matching the specific requirements of particular circumstances. Our visit ended with a discussion about future prospects for biomass heating in the UK and the Renewable Heating Incentive. With proposed tariffs appearing to favour larger more robust systems, and the ability of the Justsen Range to burn a wide range of fuel types we expect to see more of the Justsen brand in the UK in the future.