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Digesters at a biogas plant have high temperatures and poor insulation. There is great potential to save energy by improving the construction. This study has two aims. One is to compare the difference between a simple steady-state calculation and a calculation that uses simulated values from Heat2. The second is to develop an improved insulation method at the concrete digester that can be used in future projects. Ten different insulation scenarios have been simulated to understand how to improve the insulation method to develop an idea of where the insulation has the most impact. Then a combined insulation method was created from the scenarios. That combined method was then simulated with 5 different insulation thickness to find the most profitable design. The conclusion was that there is great value in making more advanced calculations for the walls and floor because the energy losses are very excessive using the simplified calculation, especially on surfaces covered in soil. It was proved difficult to calculate the losses for the roof, this was because the assumption that was needed to perform the calculation does not mirror the reality. Due to this, the roof has been neglected in the suggested insulation method. The insulation method proposed provides an energy saving of 58 MW h/year and a discounted payback time of 4, 3 years if the saved energy can be delivered as 90◦C degree hot water into the district heating network.

Production of muesli is an energy intensive process which consumes enormous amount of energy invarious forms. In this study, energy flow accounting tool has been employed which is a valuable tool for mapping and quantifying the energy flows within a specific system such as a nation, city or factory. Thistool aids in highlighting the pathways of energy throughout the system and identifies the sources ofenergy loss. Furthermore, to support identification and assessment of CP measures the energy flowaccounting method was integrated within the CP assessment methodology framework. Energy balance established with the help of energy flow accounting method, also highlights different energy inflows andoutflows in the process such as steam, oil, gas and raw material. The utmost energy consuming subprocesses in muesli production are cleaning, rolling, air blowers, husk removal, extruder and mothermachine. Since Läntmannen Cerealia at Järna generates steam, hot water and district heating from removed husk, along with recovering the steam loss in form of condensate, the overall efficiency of their system is approximately 90%. Moreover, an attempt to establish extensive energy balance at the plant has not been undertaken. This factor serves as the stimulus for the study project as it promises futurework in this domain. This comprehensive report demonstrates a nearly accurate picture of the energybalance of muesli production at Läntmannen Cerealia. The energy losses in different manifestation ofenergy during various sub processes have also been presented in the report. Additionally, suggestions for improvement have been furnished to reduce the energy losses during the process of production. However, feasibility analysis is recommended before the implementations of these measures. Implementation of the aforementioned measures could potentially decrease the energy losses in production of muesli and can boost the environmental performance of the entire process.

In spite of their high technical maturity, load sensing systems (LS) have system-inherent energy losses that are largely due to the operation of parallel actuators with different loads at the same pressure level. Hereby, the pressure compensators of the system are crucial. So far, excessive hydraulic energy has been throttled at these compensators and been discharged as heat via the oil. The research project “Reduction of System Inherent Pressure Losses at Pressure Compensators of Hydraulic Load Sensing Systems” aims to investigate a novel solution of reducing such energy losses. The pressure of particular sections can be increased by means of a novel hydraulic circuit. Therefore, a recovery unit is connected in series with a hydraulic accumulator via a special valve in the reflux of the actuators. The artificially increased pressure level of the section reduces the amount of hydraulic power to be throttled at the pressure compensators. As long as a section fulfills the switching condition of the valve, pressure losses at the respectiv pressure compensator can be reduced. Thus, via a suitable recovery unit excessive energy can be regenerated and can be directed to other process steps eventually.

<p>Bioenergi är en stor industri i Sverige och står för en betydande del av energiomsättningen. Bioenergi i form av flis förvaras runt om i landet på hög i väntan på förbränning. Då högarna läggs upp startar olika processer som värmer upp stacken, ofta till temperaturer på 50°C under det första dygnet. En vanlig ansats i litteraturen är att denna temperaturstegring beror på aerob nedbrytning. Arbetet ämnar undersöka om denna uppvärmning endast beror av mikrobiella aktiviteter. Hypotesen prövas genom kalorimetriska mätningar av effekt från prover av flis och simulering av första dygnets temperaturutveckling i ett program som programmeras under arbetes gång.</p><p>I modellen så betraktas för enkelhets skulle flisstacken som en avlång figur med rektangulärt tvärsnitt. Figuren delas sedan in i lämpligt stora beräkningsceller. Problemet löses genom att iterativt räkna fram ett strömningsfält. Strömningsfältet och effekterna som räknas ut hålls sedan konstanta under ett tidssteg, 5-15min. Den magasinerade värmeenergin används sedan för att räkna fram en ny temperatur som så ger ett nytt strömningsfält och nya effekter. I modellen användes enbart explicita metoder eftersom de är snabbare och mycket enklare att programmera.</p><p>Ett flertal experiment i kalorimeter genomfördes med olika prover av flis och torv. Prover med barkflis gav högst utslag. Den högsta effekten som uppmättes var 2,16W/kg TS. Då effekter av denna storleksordning användes som inre effektgenerering i programmet gav detta inte en temperatur ökning motsvarande sådana som uppmätts i verkligheten. Detta tyder på att mer än aerob nedbrytning krävs för att ge en temperatur på över 50°C.</p> / <p>Bioenergy is a major industry in Sweden and accounts for a significant part of the energy production. Bioenergy in the form of wood chips is stored in piles across the country awaiting combustion. When the piles are acumulated, various processes that heat the stack begin, often to temperatures of 50 °C during the first day. A common approach in the literature is that this temperature rise is due to the aerobic decomposition. This paper will investigate whether the microbial activity is the fundamental cause for warming. The hypothesis is tested by calorimetric measurements of power from the samples of wood chips and simulation of the first day's temperature development in a programme that was desinated.</p><p>For simplicity the model considers an oblong wood chip pile with rectangular cross-section. The pile is then subdivided into appropriately sized calculation cells. The problem is solved by calculating a flow field iteratively. The flow field and the effects that are calculated is then static during one time step for approximately 5-15 minutes. The produced heat energy is then used to calculate a new temperature, which renders a new flow field and new powers. The model uses only explicit methods because they are faster and much easier to programme.</p><p>Several calorimetric experiments were carried out with various samples of wood chips and peat. Samples of bark chips achieved the highest result. The highest power measured was 2.16 W / kg DM. When the effects of this magnitude were used as internal power source in the programme the temperature did not increase corresponding to those measured in reality. This suggests that more than aerobic decomposition is needed to reach a temperature above 50°C.</p>

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Bioenergi är en stor industri i Sverige och står för en betydande del av energiomsättningen. Bioenergi i form av flis förvaras runt om i landet på hög i väntan på förbränning. Då högarna läggs upp startar olika processer som värmer upp stacken, ofta till temperaturer på 50°C under det första dygnet. En vanlig ansats i litteraturen är att denna temperaturstegring beror på aerob nedbrytning. Arbetet ämnar undersöka om denna uppvärmning endast beror av mikrobiella aktiviteter. Hypotesen prövas genom kalorimetriska mätningar av effekt från prover av flis och simulering av första dygnets temperaturutveckling i ett program som programmeras under arbetes gång. I modellen så betraktas för enkelhets skulle flisstacken som en avlång figur med rektangulärt tvärsnitt. Figuren delas sedan in i lämpligt stora beräkningsceller. Problemet löses genom att iterativt räkna fram ett strömningsfält. Strömningsfältet och effekterna som räknas ut hålls sedan konstanta under ett tidssteg, 5-15min. Den magasinerade värmeenergin används sedan för att räkna fram en ny temperatur som så ger ett nytt strömningsfält och nya effekter. I modellen användes enbart explicita metoder eftersom de är snabbare och mycket enklare att programmera. Ett flertal experiment i kalorimeter genomfördes med olika prover av flis och torv. Prover med barkflis gav högst utslag. Den högsta effekten som uppmättes var 2,16W/kg TS. Då effekter av denna storleksordning användes som inre effektgenerering i programmet gav detta inte en temperatur ökning motsvarande sådana som uppmätts i verkligheten. Detta tyder på att mer än aerob nedbrytning krävs för att ge en temperatur på över 50°C. / Bioenergy is a major industry in Sweden and accounts for a significant part of the energy production. Bioenergy in the form of wood chips is stored in piles across the country awaiting combustion. When the piles are acumulated, various processes that heat the stack begin, often to temperatures of 50 °C during the first day. A common approach in the literature is that this temperature rise is due to the aerobic decomposition. This paper will investigate whether the microbial activity is the fundamental cause for warming. The hypothesis is tested by calorimetric measurements of power from the samples of wood chips and simulation of the first day's temperature development in a programme that was desinated. For simplicity the model considers an oblong wood chip pile with rectangular cross-section. The pile is then subdivided into appropriately sized calculation cells. The problem is solved by calculating a flow field iteratively. The flow field and the effects that are calculated is then static during one time step for approximately 5-15 minutes. The produced heat energy is then used to calculate a new temperature, which renders a new flow field and new powers. The model uses only explicit methods because they are faster and much easier to programme. Several calorimetric experiments were carried out with various samples of wood chips and peat. Samples of bark chips achieved the highest result. The highest power measured was 2.16 W / kg DM. When the effects of this magnitude were used as internal power source in the programme the temperature did not increase corresponding to those measured in reality. This suggests that more than aerobic decomposition is needed to reach a temperature above 50°C.

No description available.

No description available.

Made available in DSpace on 2015-05-08T14:53:28Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1762592 bytes, checksum: cca27833e8f0fa6da04864abd685e1df (MD5) Previous issue date: 2013-09-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work aimed to analyze the energy efficiency (EE) in a textile company in the state of Paraíba energy losses relating to productivity, therefore we performed a literature search about the concepts of productivity, EE, and losses on the textile sector with emphasis spinning sector. The objective of the research was to analyze the relationship between EE and productivity from the point of view of the losses, with the specific objectives to raise productivity if current industry, identifying energy losses exist, raising the potential for improvement and simulate new level compared to improvements in productivity caused by EE. The research was conducted through a case study of an industry in the textile industry, and an applied research focus using quantitative and qualitative document analysis, structured interviews and direct observation as instruments. Variables of productivity (production, consumption and productivity) and energy efficiency (energy management, motor systems and lighting systems), being raised production data; electricity consumption and calculated productivity. Through research we obtained the following results: With respect to the energy profile were observed: a) The energy has the potential reduction in the order of 2% through improved energy management b) The driving system corresponds to 80% of total consumption of electricity and has a potential reduction of 2% and b) The lighting system corresponds to 5% of total consumption and found a potential improvement of 22.86% c) The remaining 15% are for to other energy uses (compressors, air conditioning, etc..) that are not addressed in this study. On the relationship between productivity and EE was found that the variables have a direct relationship, it was observed that the reduction of electricity losses corresponds to 4.74% of total consumption and the increase of 4.96% in terms of productivity, thereby proved the relationship between EE and productivity, and that this is directly proportional. / Esta dissertação visou analisar a Eficiência Energética (EE) em uma empresa têxtil do estado da Paraíba relacionando as perdas energéticas com a produtividade, para tanto foi realizada uma pesquisa bibliográfica a cerca dos conceitos de produtividade, EE, perdas e sobre o setor têxtil com ênfase no setor de fiação. O objetivo geral da pesquisa foi analisar a relação entre a EE e a produtividade sob o ponto de vista das perdas, tendo como objetivos específicos levantar a produtividade atual da indústria caso; identificar as perdas energéticas existentes; levantar as potencialidades de melhorias e simular o novo nível de produtividade face às melhorias causadas pela EE. A pesquisa foi realizada através de um estudo de caso numa indústria do segmento têxtil, sendo uma pesquisa aplicada de enfoque quanti-qualitativo utilizando a análise documental; entrevista estruturada e observação direta como instrumentos. Foram analisadas variáveis de produtividade (Produção, consumo de energia e produtividade) e de eficiência energética (Gestão energética, sistemas motrizes e sistemas de iluminação), sendo levantados os dados de produção; consumo de energia elétrica e calculada a produtividade. Através da pesquisa foram obtidos os seguintes resultados: Com relação ao perfil energético observaram-se: a) O consumo de energia tem potencial de redução na ordem de 2% através do melhoramento da gestão energética; b) O sistema motriz corresponde a 80% do consumo total de energia elétrica e tem um potencial de redução de 2% e; b) O sistema de iluminação corresponde a 5% do consumo total e foi encontrado um potencial de melhoria de 22,86%; c) Os 15% restantes são referentes aos demais usos de energia (Compressores, ar condicionado e etc.) que não são abordados neste estudo. Sobre a relação entre produtividade e EE foi encontrado que as variáveis possuem relação direta, sendo observado que a redução das perdas de energia elétrica corresponde a 4,74 % no consumo total e no aumento de 4,96% em termos de produtividade, desse modo comprovou-se a relação entre EE e produtividade e que esta é diretamente proporcional.