All products will eventually end up as waste, which in a sustainable society has to be handled in an efficient and environment friendly way. This report focuses on waste fractions meant for combustion, often difficult to characterize. However, more homogeneous fractions that are treated biologically are also discussed. The study concerns the region of Borås, Sweden, where the waste plant Sobacken has provided a good starting point. On this site, fuel to the Energy-from-Waste plant of Borås Energi is prepared and the biological waste is treated through anaerobic digestion. One important part of the study has been to collect experience-based knowledge from the technical staff at Sobacken and Borås Energi. This information was compiled into an overview of wanted and unwanted fractions to the preparation plant and the boilers respectively. The purpose of this overview is to complement existing delivery terms and thereby facilitate an increased quality of the fuel from the suppliers. A significant element of the analysis has been to characterize the content of the industrial waste sent to Sobacken for combustion. Chemical analyses of the prepared fuel as well as the conducted waste component analysis indicate a heterogeneous composition of the waste. A heterogeneous fuel often results in an uneven combustion, leading to higher emissions and an unwanted variation in the energy production. Through the waste component analysis, a comprehensive picture of the waste composition was attained. Materials non-valid for delivery mostly consisted of wet domestic waste (biodegradable materials), but some hazardous waste was also found. The results of the waste component analysis were communicated to the involved suppliers and this has already resulted in a considerable reduction of the amount of biodegradable waste in the deliveries of industrial waste. / Förr eller senare blir alla produkter avfall, som i ett uthålligt samhälle måste hanteras på ett resurssnålt och miljövänligt sätt. Det här arbetet är främst inriktat mot de svåridentifierade fraktionerna som är ämnade för förbränning, men berör även de mer homogena fraktionerna som behandlas biologiskt genom rötning. Arbetet har utförts i Boråsregionen där Sobackens avfallsanläggning, med beredning av avfallsbränsle till Borås Energis två FB-pannor och rötkammare, har utgjort en naturlig utgångspunkt. Ett stort inslag i arbetet var sammanställning av erfarenhetsbaserade kunskaper hos driftteknikerna på beredningsanläggningen, liksom hos Anders Johnsson på Borås Energi. På detta sätt erhölls viktig information om både bra och dåliga fraktioner, för såväl avfallskross som för pannor. Dessa fakta har bland annat använts för att sätta samman en översikt över önskade respektive oönskade fraktioner. Översikten är tänkt som komplement till befintliga leveransregler, i syfte att förenkla för avfallsleverantörerna. Stor vikt har lagts vid att försöka kartlägga sammansättningen av det verksamhetsavfall som kommer in till Sobackens beredningsanläggning. Både kemiska analyser av bränsleprov och utförd plockanalys visar på en heterogen sammansättning i avfallet. Ett heterogent bränsle brinner i många fall ojämt, vilket resulterar i högre emissionsnivåer samt en icke-önskvärd variation i energiproduktion. I och med plockanalysen erhölls en övergripande bild av förbränningsavfallets sammansättning. Det icke leveransgilla materialet som påträffades utgjordes främst av blött hushållsavfall (biologiskt nedbrytbart material), men även av en del elektronik påträffades. Efter avslutad analys kommunicerades erhållna resultat med aktuella leverantörer, vilket hittills har resulterat i en betydande minskning av biologiskt nedbrytbart material i verksamhetsavfallet.

In this thesis an apparatus is designed which enables the testing of thermal power plant boiler tubes against erosion. The apparatus makes use of a tube sample directly cut from the boiler tubes and simulates conditions similar to those prevailing in boilers in lignite fired power plants. The apparatus is composed of three components / a furnace for heating the sample, a loading system which allows application of tensile stresses while allowing the rotation of the sample, and a particle blower that delivers abrasive particles to the surface of the sample. The abrasive material used in the test is mixture of oxides, 90% of which is Al2O3 and the average particle size is approximately 300 &micro / m. The unit as designed would allow testing of boiler tubes up to a temperature of 650 C, and particle velocity of up to 50 m/s. The apparatus as tested at room temperatures for four identical samples have yielded very similar erosion values based on measurement of weight loss. At elevated temperature, erosion could be measured by a thickness loss since the oxidation that occurs complicates the erosion measurement. Two economizer material / P235GH and 16Mo3 were tested at 500oC with particle velocity of 10 m/s. The testing has shown that 16Mo3 has better performance than P235GH, the erosion rate differing by 20 percent.

How to exploit and make use of natural gas hydrates in oceans will weigh much in the future researches. Unlike the oil or gas reservoirs, the distributions of natural gas hydrate are very complicated and don’t congregate massively in oceanic sediments. Besides, factors such as seafloor geohazards and climate must be taken into account, which makes it much more difficult and complicated to exploit oceanic gas hydrates than conventional oil or gas. Nowadays neither of such methods as thermal stimulation, depressurization, inhibitor injection, carbon dioxide replacement and mixing exploitation etc. is applied to exploit gas hydrates in marine sediments because of their disadvantages. This paper introduces a conception of combining solar and geothermal energy for gas hydrates exploitation. The model mainly includes five parts: solar energy transferring module, sea water circulating module, underground boiler module, platform and gas-liquid separating module. Solar cells and electric heaters are used to heat the formations containing hydrates. Because they become relatively more mature and cheaper, it’s the key of how to utilize the geothermy to exchange heat in developing this conception, which needs solution of fluid leakage, circulating passages and heat-exchange interface problems in building underground boiler. Probably it’s a feasible measure to use an effective hydraulic control system and hydraulic fracturing. The idea should be a good choice to exploit marine gas hydrates by combining solar and geothermal energy since this method has a great advantage either in terms of efficiency or cost.

Pateikto magistrantūros baigiamojo darbo tikslas – išmatuoti degimo proceso kokybę, atlikti reguliavimus. Išnagrinėti galimybę automatiškai ir optimaliai valdyti kieto kuro katilo degimo procesą. Palyginti gautus eksperimento rezultatus, vykdant degimo proceso reguliavimus. Darbe išanalizuotas medienos biomasės panaudojimo Lietuvoje potencialas. Pateiktos technologijos šiluminės energijos gamybai decentralizuotam šildyme. Pristatyti automatinio reguliavimo sistemos principai. Pateikta tyrimo metodika, rezultatai. / The aim of master thesis is – measure results burning process quality and curry out regulation. The research possibility control solid fuel boilers burning process. There is made an analysis of biomass utilizing potential in Lithuania. There is listed technology’s in heating production. Also in this work are given the rules of system automatic control. There is a listed research methodic, results.

Darbe nagrinėta biokuro kūryklų įvairovė, išmetamų teršalų poveikis aplinkai bei žmogui. Pagrindinis darbo tikslas - ištirti biokuro kūryklų (katilo ir krosnies) išmetamų dūmų sudėtį ir teršalų koncentracijas bei įvertinti jų atitikimą normatyviniams dokumentams. Magistriniame darbe apžvelgta biokuro sąvoka, sudėtis ir savybės. Apžvelgta oro ir deguonies kiekio įtaka degimo procesui. Taip pat darbe apžvelgti katilų ir krosnių pagrindiniai elementai bei jų veikimo principai. Nagrinėjama oro taršos problema bei emisijos, deginant biokurą. Darbe pateikiama biokuro degimo tyrimo metodika, veiksniai nuo kurių priklauso biokuro sudegimo pilnumas. Tyrimai atlikti naudojantis dviejų skirtingų namų 2011 m. šildymo sezono duomenimis. Pamatuoti katilo bei krosnies emisijų kiekiai ir palyginta, kuris įrenginys mažiausiai teršia aplinką, remiantis normatyviniais dokumentais. Taip pat matuoti deguonies kiekio dūmuose svyravimai visame degimo procese. Remiantis informacijos šaltiniuose pateiktomis formulėmis apskaičiuotas optimalus oro pertekliaus koeficientas skirtingiems degimo įrenginiams. / This paper analyzes a variety of biofuel furnaces, emissions and the impact on humans. The main aim - to investigate bio flue (boiler and furnace), the composition of the smoke emissions and concentrations of pollutants and to assess their compliance with the normative documents. This thesis covers an overview of the concept of bio-fuels, composition and properties. The theoretical aspects of air and oxygen influence the combustion process. Also look at the boilers and heating elements and their operating principles. The present problem of air pollution and emissions from combustion of biofuels. The paper presents the combustion of biofuels research methodology, the factors which determine the completeness of combustion of biofuels. Investigations were carried out using two different houses in 2011. heating season. Measure the boiler or furnace emissions and compared to plant environmentally friendly, according to legal documents. Also measure the oxygen content of flue variations throughout the combustion process. Based on information provided by sources in the equations estimated optimum excess air ratio for different combustion device.

No description available.

Umeå Energi AB har bestämt att en kontroll av pannverkningsgraden för kraftvärmepannan Dåva 2 skall genomföras. I dagsläget genomförs en beräkning av verkningsgraden månadsvis med den direkta beräkningsmetoden. Resultatet varierar dock kraftigt månad till månad varav en undersökning med indirekt beräkningsmetod är av intresse. Arbetet genomförs för att ge en mer noggrant beräknad verkningsgrad samt utreda förlustfaktorer kopplad till pannan. Då pannverkningsgraden i vanliga fall inte inkluderar rökgaskondensering beräknades också totalverkningsgraden för att ge en mer rättvis bild av pannan samt för att illustrera dess relevans. Arbetet genomfördes för två olika driftsfall, hög och låg last, för att undersöka hur verkningsgraden varierar beroende på driftsfall. Arbetet inleddes genom att studera de standarder som finns inom området för att utreda vilka faktorer som skulle beräknas samt vilka kriterier som skulle följas. Det framgick att en hel del provtagningar och analyser skulle genomföras på bland annat bränsle, aska och rökgaser. Detta krävde i sin tur en noggrann planering varav ett provtagningsschema skapades. Samtliga provtagningar genomfördes vid bägge driftsfallen och proverna skickades på analys, därefter kunde verkningsgraden beräknas. Resultatet tyder på hög totalverkningsgrad med något lägre pannverkningsgrad. Beroende på driftsfall varierar pannverkningsgraden mellan 74% vid hög last och 72% vid låg last. Totalverkningsgraden ligger på 92% vid hög last och 91% vid låg last. Den förlustfaktor som är av störst magnitud är rökgasförluster som beror av rökgasernas fukthalt och temperatur. Rökgasförlusterna varierar mellan 24% till 26% för pannverkningsgraden och 6.6% till 7.2% för totalverkningsgraden. Utöver rökgasförlusterna ligger strålningsförlusterna på runt 0.7% vid bägge driftsfallen. Förbränningsförlusterna är mycket låga och varierar mellan 0.52% och 0.53% vilket i kombination med de låga askförlusterna (0.006%-0.04%) tyder på mycket bra förbränning. På grund av de höga verkningsgraderna framkom inga självklara effektiviseringsåtgärder. Då rökgasförlusterna är de största förlustfaktorerna är därför åtgärder mot dessa av störst betydelse för verkningsgraden. Ett alternativ för att öka verkningsgraden ytterligare är att minska fukthalten på de utgående rökgaserna. De är i dagsläget runt 9% och står för majoriteten av rökgasförlusterna. En sänkning av denna fukthalt kan erhållas genom att sänka temperaturen på rökgaserna och på så vis kondensera mer fukt ur rökgaserna. Detta innebär att temperaturen på kondensatet i rökgaskondenseringsanläggningen måste sänkas, vilket i sin tur innebära att antingen sänka fjärrvärmereturen som kyler kondensatet, alternativt installera en värmepump mellan kondensatet och fjärrvärmereturen. Detta kräver dock en djupare utredning för att fastställa om dessa effektiviseringsåtgärder är genomförbara rent tekniskt samt om de är ekonomiskt försvarbara. / Umeå Energi AB has decided that an evaluation of boiler efficiency should be performed on their CHP-plant Dåva 2. Calculation of the efficiency using the input-output method is currently carried out monthly but the results vary greatly over time whereby an evaluation of the efficiency using the energy balance method was of interest. This was done to give a more accurate efficiency and to evaluate boiler losses. Due to the fact that the boiler efficiency doesn’t usually include flue gas condensation two different efficiency were calculated, boiler efficiency and total efficiency.  The boiler and total efficiency was determined for the CHP during two different loads, high and low. This was done to investigate how the efficiency varies with different loads. The work was initiated by studying the standards in the field of efficiency calculations to evaluate which factors and criteria to be calculated and followed.  It was shown that a lot of samplings and analysis was to be performed which demanded accurate sampling interval. A sampling schedule was therefore constructed to be followed. All sampling was then performed at both loads and the efficiency calculations could begin. The results indicate a high total efficiency with somewhat lower boiler efficiency. The boiler efficiency varied depending on the load by 74% on high load and 72% on low load. The total efficiency was 92% on high load and 91% on low load. The greatest losses were all connected to flue gas losses. Losses like moisture in flue gas or hot dry flue gas. The flue gas losses varied between 24% to 26% for the boiler efficiency and 6.6% to 7.2% for the total efficiency on high and low loads. Besides flue gas losses the next greatest loss is radiation losses, about 0.7% for both high and low loads. Losses due to incomplete combustion were very low and varied between 0.52% and 0.53% for high and low load which in combination with the low ash loses (0.006%-0.04%) indicates very good combustion. Due to the relatively high efficiencies, no obvious solutions for decreased energy losses were found. The greatest energy losses are flue gas losses and a solution to this will influence the efficiency the most. One solution to increase the efficiency is to reduce the moisture content of the flue gas. At this time the moisture content is at 9% and contributes the most to the flue gas losses. Reducing the moisture content can be done by lowering the flue gas temperature. This will increase the amount of moisture that is condensed in the flue gas condenser. To achieve this, the flue gas condensate temperature needs to be decreased. This can be done by either lowering the temperature on the district heating return which is cooling the flue gas condensate or install a heat pump between the flue gas condensate and the district heating return. These solutions require a more in depth analysis to evaluate if this is technically possible and if it is economically viable.

Electrostatic precipitators (ESPs) are commonly used to control particulate emissions from recovery boilers in the kraft pulping process. The electrical resistivity of entrained particulates is known to affect the performance of ESPs. There are many factors which influence resistivity of particulate matter, such as field strength, time of exposure, particle size, particle composition, temperature, and flue gas composition. The objective of this study was to identify the ideal operating conditions and dust particle characteristics which lead to an optimum dust resistivity and maximized ESP efficiency. The effect of these factors was examined through a variety of experimental and analytical techniques on kraft recovery boiler ash samples and synthetically prepared samples. It was concluded that particle composition, gas composition, and ambient temperature had the most pronounced effects, while the other factors, such as field strength and exposure time, had a smaller impact on particle resistivity.

Electrostatic precipitators (ESPs) are commonly used to control particulate emissions from recovery boilers in the kraft pulping process. The electrical resistivity of entrained particulates is known to affect the performance of ESPs. There are many factors which influence resistivity of particulate matter, such as field strength, time of exposure, particle size, particle composition, temperature, and flue gas composition. The objective of this study was to identify the ideal operating conditions and dust particle characteristics which lead to an optimum dust resistivity and maximized ESP efficiency. The effect of these factors was examined through a variety of experimental and analytical techniques on kraft recovery boiler ash samples and synthetically prepared samples. It was concluded that particle composition, gas composition, and ambient temperature had the most pronounced effects, while the other factors, such as field strength and exposure time, had a smaller impact on particle resistivity.

Apresenta-se uma avaliação técnico-econômica para o préaquecimento solar da água de reposição em caldeiras de sistemas de vapor abertos. São empregados, para compor um estudo de caso, os dados de uma indústria de laticínios de médio porte situada próximo da cidade do Rio de Janeiro. Quarenta e oito simulações computacionais do sistema de aquecimento solar (SAS) foram realizadas em TRNSYS, correspondendo aos 5% melhores resultados econômicos de uma série de 2.700 simulações mais simples (método φ-f-chart), programados em MATLAB. Foram empregados dados horários de ano típico meteorológico (TMY) para a cidade do Rio de Janeiro. O ganho econômico foi baseado no consumo evitado dos três combustíveis mais comuns na indústria de laticínios, enquanto o custo de investimento foi composto a partir de valores comerciais e da literatura. Os resultados da avaliação econômica mostraram-se desfavoráveis para a substituição de óleo combustível, favoráveis no caso de caldeiras a gás natural, condicionado a existência de subsídios, e bem competitivos para a substituição de GLP. A eficiência térmica do sistema mostrou ser o parâmetro técnico chave para o desempenho econômico, consequentemente, uma vez que a eficiência se mostrou inversamente proporcional tanto ao volume do reservatório quanto à área de coletores, não há uma configuração ótima para o sistema. Não obstante, os resultados permitiram a proposição de políticas públicas para incentivar o uso da energia solar na indústria leiteira e, consequentemente, contribuir para a preservação ambiental. / It is presented a technical and economical feasibility assessment of solar preheating of steam boiler feed water for opened vapor systems. Data from a medium sized dairy industry near Rio de Janeiro city, in Brazil, is used to compose a case study. Forty eight solar heating system (SAS) computer simulations were carried out in TRNSYS, for a range of design parameters corresponding to the 5% best economical results of a series of 2700 simpler simulations (φ,f-chart method), programmed on MATLAB. Rio de Janeiro typical meteorological year (TMY) hourly weather data was used. Revenue was based on the avoided consumption of the three most used fuels on dairy industries, while investment cost was composed from both commercial and literature values. Economical assessment results showed unfavorable for the displacement of fuel oil, favorable for substituting natural gas, provided subsidizing, and well competitive against LPG. Systems thermal efficiency showed to be the key technical factor for economical performance, thus, as efficiency was found to be inversely proportional for both storage volume and collector area, there isnt an optimal system configuration. The results, though, made it possible to address environmentally sound public policies to encourage solar energy use on dairy industries.