This thesis describes the design of hot air boilers for burning wood chips for the production of process air at 500 ° C and a given flow rate 2 Nm3 / s. The work deals with general combustion and fuel economy of biomass boilers.

<div> <p>Thermal processing is a critical step in shelf-stable food manufacturing to the ensure safety of the food products. To accurately model and establish the thermal processes, temperature-dependent thermal properties are needed. Existing methods for measuring the temperature-dependent thermal diffusivity (α), thermal conductivity (k) and volumetric heat capacity (C) are time consuming, tend to have high errors, and cannot provide results in a single experiment, especially at temperatures above 100°C. A novel bench scale device, named Thermal Properties Cell (TPCell), was custom made to rapidly estimate the temperature-dependent thermal parameters of food products. </p> <p> </p> <p>The TPCell used thin film heaters as the heating elements. The first study focused on estimating the thermal properties of a thin film heater. Using mathematical modeling and sequential parameter estimation, the effective thermal diffusivity of the thin film heater was found at different temperatures. The estimated thermal properties of the thin film heater were used for the second study.</p> <p> </p> <p>The objective of the second study was to design optimal complementary experiments using TPCell. Complementary experiments are a combination of experiments that enable estimation of multiple thermal parameters from the experimental temperature data, based on sensitivity analysis. Sensitivity coefficients indicate the extent of change in a measured variable due to a change in value of an input parameter. Designs of experiments were simulated and their impact on sensitivity and optimality criteria was analyzed. Results from the simulated profiles were validated using sweet potato puree. </p> <p> </p> <p>Learnings from this work can be directly applied for the optimization of all types of food thermal processes, including retort and aseptic processing. Optimally designed processes increase preservation of the heat labile nutrients, color, flavor, and taste compounds, thereby enhancing the quality of food products.</p> </div> <br>

A heater designed to monitor surface temperature fluctuations during pool boiling experiments while the bubbles were simultaneously being observed has been fabricated and tested. The heat source was a transparent indium tin oxide (ITO) layer commercially deposited on a fused quartz substrate. Four copper-nickel thin film thermocouples (TFTCs) on the heater surface measured the surface temperature, while a thin layer of sapphire or fused silica provided electrical insulation between the TFTCs and the ITO. The TFTCs were micro-fabricated using the liftoff process to deposit the nickel and copper metal films. The TFTC elements were 50 microns wide and overlapped to form a 25 micron by 25 micron junction. TFTC voltages were recorded by a DAQ at a sampling rate of 50 kHz. A high-speed CCD camera recorded bubble images from below the heater at 2000 frames/second. A trigger sent to the camera by the DAQ synchronized the bubble images and the surface temperature data. As the bubbles and their contact rings grew over the TFTC junction, correlations between bubble behavior and surface temperature changes were demonstrated. On the heaters with fused silica insulation layers, 1-2 C temperature drops on the order of 1 ms occurred as the contact ring moved over the TFTC junction during bubble growth and as the contact ring moved back over the TFTC junction during bubble departure. These temperature drops during bubble growth and departure were due to microlayer evaporation and liquid rewetting the heated surface, respectively. Microlayer evaporation was not distinguished as the primary method of heat removal from the surface. Heaters with sapphire insulation layers did not display the measurable temperature drops observed with the fused silica heaters. The large thermal diffusivity of the sapphire compared to the fused silica was determined as the reason for the absence of these temperature drops. These findings were confirmed by a comparison of temperature drops in a 2-D simulation of a bubble growing over the TFTC junction on both the sapphire and fused silica heater surfaces. When the fused silica heater produced a temperature drop of 1.4 C, the sapphire heater produced a drop of only 0.04 C under the same conditions. These results verified that the lack of temperature drops present in the sapphire data was due to the thermal properties of the sapphire layer. By observing the bubble departure frequency and site density on the heater, as well as the bubble departure diameter, the contribution of nucleate boiling to the overall heat removal from the surface could be calculated. These results showed that bubble vapor generation contributed to approximately 10% at 1 W/cm^2, 23% at 1.75 W/cm^2, and 35% at 2.9 W/cm^2 of the heat removed from a fused silica heater. Bubble growth and contact ring growth were observed and measured from images obtained with the high-speed camera. Bubble data recorded on a fused silica heater at 3 W/cm^2, 4 W/cm^2, and 5 W/cm^2 showed that bubble departure diameter and lifetime were negligibly affected by the increase in heat flux. Bubble and contact ring growth rates demonstrated significant differences when compared on the fused silica and sapphire heaters at 3 W/cm^2. The bubble departure diameters were smaller, the bubble lifetimes were longer, and the bubble departure frequency was larger on the sapphire heater, while microlayer evaporation was faster on the fused silica heater. Additional considerations revealed that these differences may be due to surface conditions as well as differing thermal properties. Nucleate boiling curves were recorded on the fused silica and sapphire heaters by adjusting the heat flux input and monitoring the local surface temperature with the TFTCs. The resulting curves showed a temperature drop at the onset of nucleate boiling due to the increase in heat transfer coefficient associated with bubble nucleation. One of the TFTC locations on the sapphire heater frequently experienced a second temperature drop at a higher heat flux. When the heat flux was started from 1 W/cm^2 instead of zero or returned to zero only momentarily, the temperature overshoot did not occur. In these cases sufficient vapor remained in the cavities to initiate boiling at a lower superheat.

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Yes / In all industrial petrochemical plants and refineries, the furnace is the source of heat resulting from fuel combustion with air. The model-based furnace simulation is considered one of the efficient methods help to reduce the energy loss and maintain fixed refinery revenues, conserving energy, and finally reducing external fuel consumption and total fuel cost. In this paper, a model-based simulation is carried out for a natural air draught industrial scale furnace related to Liquified Petroleum Gas (LPG) production plant in Libya to thoroughly investigate the most responsible factors in lowering the furnace butane exit temperature, which is supposed to be two degrees Fahrenheit higher than inlet temperature. Therefore, to resolve this industrial problem, Aspen Hysys V10, coupling with EDR (exchanger design and rating) is used to carry out rigorous model-based simulation. This is specifically used to assess the impact of heat loss from inside the firebox to the surrounding medium and heat loss from the furnace stack and walls, besides the effect of excess air on the furnace efficiency. Furthermore, this research intends to verify whether the operating conditions, such as furnace tubes inlet flow rate, temperature and pumping pressure, are conforming to the upstream process design specifications or need to be adjusted. The results confirm that increasing furnace outlet temperature two degrees Fahrenheit from off specification 190 °F instead of 184 °F is successfully achieved by decreasing upstream stream flowrate 25% below the operating value and cutback excess air gradually until 20%. Also, the results clarify the necessity of increasing the flue gas temperature by 7% over design condition, to gain a significant reduction of heat loss of 31.6% and reach as low as 35.5 MBtu/hr. This improvement is achieved using optimum operating conditions of an excess air of 20%, and flue gas oxygen content of 3.3% delivered to stack. Accordingly, the furnace efficiency has been increased by 18% to hit 58.9%. Furthermore, the heat loss from the furnace walls can be also reduced by 68% from 5.41 MBtu/hr to 1.7 MBtu/hr by increasing the refractory wall thickness to 6 in., which entails an increase in the furnace efficiency by 3.66% to reach 58.96%. Decreasing the heat loss fraction through the refractory wall, pip doors, expansion windows and refractory hair cracks would also increase the efficiency by 21% to reach a high of 59.7%. Accordingly, a significant reduction in daily fuel consumption is observed, which costs 1.7 M$ per year. The outcomes of this research clearly show the potential of reducing the operation and maintenance costs significantly.

Master’s thesis, „Optimization of hanger design in petrochemical industry heaters”, describes a procedure and means, leading to better hanger design in various cases. The thesis describes several problems which are necessary to be solved in hanger design. Technical expertise is executed on hangers of various designs. The procedure of optimization is shown on one chosen hanger design.

In this research a state-of-the-art micro-thermal conductivity detector is developed based on MEMS technology. Its efficient design include a miniaturized 100×2 µm bridge from doped polysilicon, suspended 10 µm away from the single crystalline silicon substrate through a thermally grown silicon dioxide sacrificial layer. The microbridge is covered by 200 nm silicon nitride layer to provide more life time. Analytical models were developed that describe the relationship between the sensor response and ambient gas material properties. To obtain local temperature distribution and accurate predictions of the sensor response, a computational three dimensional simulation based on real geometry and minimal simplifications was prepared. It was able to handle steady-state and transient state, include multiple physics such as flow, heat transfer, electrical current and thermal stresses. Two new methods of measurement for micro TCD were developed; a time resolved method based on transient response of the detector to a step current pulse was introduced that correlates time constant of the response to the concentration of gas mixture. The other method is based on AC excitation of the micro detector; the amplitude and phase of the third harmonic of the resulting output signal is related to gas composition. Finally, the developed micro-sensor was packaged and tested in a GC system and was compared against conventional and complex FID for the detection of a mixture of VOCs. Moreover compact electronics and telemetry modules were developed that allow for highly portable applications including microGC utilization in the field.

An engine heater is used to warm engine cooling fluid in an engine. This specific case pertains to the engine warmers found in the V8 engines of Scania trucks. The purpose of this study is to make the product development more effective by optimizing the cooperation with suppliers. This is achieved by lowering the costs and development time of the product development. The form and extent to which the supplier is involved can vary, depending on whether or not they are to be fully, partially, or not at all involved in the project. The problem is how a recommendation for collaboration should look like. In order to understand how these recommendations should look, one needs to know which variables affect the cooperation between the company and the supplier. This is done to give a recommendation for how the cooperation with the supplier should be, in order to achieve an effective product development (PD) and high product performance. Through research in the form of written literature, a comparison could be made between the different theories of the PD-process and the cooperation and involvement of the supplier in a company’s PD process, with the company’s actual PD process, but also the cooperation levels with the suppliers in the NPD (New Product Development). This was done to identify which variables influence the cooperation between the company and the supplier, and to find out in what phase of a company’s NPD a supplier should be involved. The results showed that the company had not applied a common development relationship. This meant that it had not made use of organizational enablers (Garengo &amp; Panizzolo, 2013), only technological and methodological enablers. The company's communication channels had not included face-to-face meetings, with communication primarily taking place through email or phone calls. This low level of communication has resulted in a low exchange of knowledge (Thomas, 2013), which affected the NPD efficiency in the form of delays to the project plan. The company had not applied the theory of not trusting “the trust” towards the supplier (Garengo &amp; Panizzolo, 2013) nor kept a constant level of formal control. A case study about the development of engine heaters has also been made. This study has had certain specifications put up as boundaries for the work, such as that the engine heater should be designed in a way that it meets certain demands from the company and the customers. In this case our customers are the assemblers from the production and aftermarket. It should be designed as simply as possible, and be able to function in the most unclean environments, with dust, water, mud and oil. The main principle is to replace the current engine heater that is included in the V8 engines of today, with one that has a new design and takes mount ability, demount ability, quality, and production costs into account, and is backward compatible. The thesis has taken the production development method, from the book "Product Design and development" (Garengo &amp; Panizzolo, 2013) into account in the development of engine heaters. Although it does differ on certain points, such as having the project leader in charge of the time management for the development of entire v8 engines. 3 (80) According to the conclusion, when involved in NPD, the company should apply a constant level of formal control for the supplier during the cooperation - and not just during the serial production (Garengo &amp; Panizzolo, 2013) - and also not trust “trust” towards the supplier and informal controls. The company should use face to face meetings as a preferred communication channel (Garengo &amp; Panizzolo, 2013) in order to achieve NPD (New Product Development) high media richness (high knowledge exchange). When NPD is used for complex products, or has a short project period, the company should involve the supplier at an early phase of the NPD process (Zhao, Cavugsil, &amp; Cavusgil, 2014, for an effective project quality regarding the production speed to the market. An organisational enabler, with the help of a guest engineer or a site engineer (Garengo &amp; Panizzolo, 2013, should also be applied. However, when it comes to new products of great importance the company should avoid involving the supplier for the NPD process (Zhao, Cavugsil, &amp; Cavusgil, 2014) and instead only use technological based integration in a late phase of the process, such as the phase where only technological enablers are used (Garengo &amp; Panizzolo, 2013). / En motorvärmare är en värmare för kylvätska till motorer. Dessa finns i fordon och i detta fall riktas det till motorvärmare i v8 motorer som finns i Företagets lastbilar. Syftet med detta examensarbete är att effektivisera produktutvecklingen genom att optimera samarbetsformerna med leverantörer. Detta sker genom att sänka produktutvecklingens kostnader och utvecklingstid. Samarbetsformen av leverantör kan variera under produktutvecklingen. Beroende på om de skall vara delaktiga i projektet helt och hållet, delvis eller inget. Problemet är hur en rekommendation för samverkan ska se ut. För att kunna ta reda på detta så behöver man veta vilka variabler som påverkar samarbetet mellan företag och leverantör. Detta görs för att kunna ge en rekommendation om det bästa möjliga sättet för vilket ett samarbete med en leverantör bör ske för att uppnå en effektiv produktutveckling (PU) och hög produktprestanda. Via forskning i form av läsning av böcker och artiklar kunde en jämförelse göras mellan de olika teorierna om PU-processen och samarbete &amp; involvering av leverantör i ett företags PUprocess, med företagets verkliga PU-process och dess samarbete &amp; involvering av leverantören i ny produktutveckling (NPU). Detta har gjorts för att ta reda på vilka variabler som har påverkat och påverkar samarbetet mellan företag och leverantör, och för att ta reda på under vilken fas i företagets NPU en leverantör bör bli involverad. Resultatet visade att företaget inte har tillämpat en gemensam utvecklingsrelation, detta innebär att man inte använt sig utav organisatoriska möjliggörare (Garengo &amp; Panizzolo, 2013) utan endast teknologiska och metodologiska möjliggörare. Företagets kommunikationskanal har inte tillämpats genom face to face möten, utan kommunikationen har främst skett genom email eller telefonsamtal. Denna låga kommunikationskanal har resulterat i ett lågt kunskapsutbyte (Thomas, 2013) vilket har påverkat NPU-effektiviteten i form av förseningar av projektplan. Man har inte heller tillämpat att inte lita på tillit gentemot leverantören (Smets, Oorschot, &amp; Langerak, 2013) och inte hållit en konstant nivå av formell kontroll. Det har även gjorts en fallstudie om utvecklingen av motorvärmare. Denna fallstudie gjordes och tillämpades för att kunna gå igenom hela företagets verkliga NPU-process steg för steg, och därefter studera hur samarbetet har varit mellan förtaget och leverantören. Denna studie har haft vissa specifikationer som har satt gränser för arbetet, bl.a. ska motorvärmaren designas så att den uppfyller vissa krav och kundernas krav. Huvudprincipen är att ersätta den nuvarande motorvärmaren som ingår i dagens V8 motorer med en som har en ny design som tar hänsyn till monterbarhet, demonterbarhet, kvalitet, tillverkningskostnad och är bakåtkompatibel. Examensarbetet har tagit hänsyn till produktutvecklingsmetoden från boken ”Product Design and Development” (Ulrich &amp; Eppinger, 2012) vid utvecklingen av motorvärmare. Detta har skett med undantag för vissa punkter som t.ex. hur tidsplaneringen för projektet tagits fram, vilket bestäms av projektledaren som lägger fram tidsplaneringen för utvecklingen av hela v8 motor. Enligt slutsatsen så bör företaget vid NPU tillämpa en konstant nivå av formell kontroll vid samarbete med leverantören vid utvecklingsfasen och inte enbart vid serieproduktion (Smets, Oorschot, &amp; Langerak, 2013), samt att inte lita på tillit gentemot leverantören. Företaget bör 5 (80) även använda face to face möten som kommunikationskanal för att åstadkomma hög informationsutbyte (Thomas, 2013). Vid NPU med en komplex produkt eller vid kort projekttid så bör företaget involvera leverantörer vid tidig fas av NPU-process (Zhao, Cavugsil, &amp; Cavusgil, 2014), för en effektiv projektkvalitet gällande produktsnabbhet till marknad. Samt att tillämpa organisatorisk möjliggörare med hjälp av gästingenjör eller platsingenjör (Garengo &amp; Panizzolo, 2013). Däremot vid en ny produktnyhet som är väldigt viktig för företaget så bör företaget undvika att involvera leverantörer vid NPU-process (Zhao, Cavugsil, &amp; Cavusgil, 2014) genom att använda sig av istället enbart teknologisk utvecklingsrelation i en sen fas av processen (Garengo &amp; Panizzolo, 2013). / NCG projekt