<p>Detta arbete beskriver hur Herons ångkula fungerar och hur den har byggts.</p><p>Ånkulan konstruerades för ca 2000 år av Heron.</p><p>Meningen var att få fram en verkningsgrad eftersom denna var okänd. Verkningsgraden blev aldrig konstaterad. Endast en teoretisk beräkning för verkningsgraden gjordes. Kulan sattes inte i rotation av ångtrycket som byggdes upp när det eldades under denna.</p><p>Anledningen var troligen att det var för mycket friktion i tätningen som skulle tillföra matarvatten in i kulan. Värmeöverföringen mellan gaslågan och kulkroppen var inte heller den mest optimala.</p><p>Kulan med tillhörande kringutrustning byggdes under dec-07/jan-08 efter eget tycke och utan någon existerande ritning. Den byggdes för att efterlikna originalet så mycket som möjligt. Dessutom hade en mindre ångkula byggts några år tidigare och denna hade visat sig fungera. Denna något större ångkula fick därför samma utseende.</p><p>Eftersom ångkulan inte orkade rotera råder det inga tvivel om hur ineffektiv denna tidiga reaktionsmotorn är.</p><p>Den fick ingen praktisk betydelse för 2000 år sedan, och det har den inte idag heller.</p><p>En framräknad verkningsgrad finns redovisad och denna blev mycket låg.</p><p>Det var stimulerandel att bygga Herons ångkula men konstruktionen i sig tillhör inte de mest lyckade.</p> / <p>This work describes how the Herons steam ball was built and how it works. It was constructed by Heron 2000 years ago. The purpose was to determine the efficiency of the steam ball because it was unknown. The efficiency was never determined. It was only theoretically determined by calculations. The steam pressure never gave the steam ball rotation when heat was added underneath the construction. A possible reason was that friction in the sealing for supplying feed water into the steam ball was too high.</p><p>The heat transfer was also a reason that the construction did not rotate.</p><p>The steam ball and necessary equipment was fabricated in dec-07/jan-08. It was built without any drawings. The goal was to make it look like the original as much as possible. A smaller steam ball was built some years before. This one did rotate and therefore was the same design given to the bigger one.</p><p>Because of the lack of rotation there was no doubt if the steam ball was a sucsess or not.</p><p>It was not used for any real purpose 2000 years ago and this has not changed.</p><p>A calculated figure of the efficiency was documented in this rapport, and it was very low.</p><p>It was amusing to design and build the steam ball but the construction was clearly no success.</p>

Detta arbete beskriver hur Herons ångkula fungerar och hur den har byggts. Ånkulan konstruerades för ca 2000 år av Heron. Meningen var att få fram en verkningsgrad eftersom denna var okänd. Verkningsgraden blev aldrig konstaterad. Endast en teoretisk beräkning för verkningsgraden gjordes. Kulan sattes inte i rotation av ångtrycket som byggdes upp när det eldades under denna. Anledningen var troligen att det var för mycket friktion i tätningen som skulle tillföra matarvatten in i kulan. Värmeöverföringen mellan gaslågan och kulkroppen var inte heller den mest optimala. Kulan med tillhörande kringutrustning byggdes under dec-07/jan-08 efter eget tycke och utan någon existerande ritning. Den byggdes för att efterlikna originalet så mycket som möjligt. Dessutom hade en mindre ångkula byggts några år tidigare och denna hade visat sig fungera. Denna något större ångkula fick därför samma utseende. Eftersom ångkulan inte orkade rotera råder det inga tvivel om hur ineffektiv denna tidiga reaktionsmotorn är. Den fick ingen praktisk betydelse för 2000 år sedan, och det har den inte idag heller. En framräknad verkningsgrad finns redovisad och denna blev mycket låg. Det var stimulerandel att bygga Herons ångkula men konstruktionen i sig tillhör inte de mest lyckade. / This work describes how the Herons steam ball was built and how it works. It was constructed by Heron 2000 years ago. The purpose was to determine the efficiency of the steam ball because it was unknown. The efficiency was never determined. It was only theoretically determined by calculations. The steam pressure never gave the steam ball rotation when heat was added underneath the construction. A possible reason was that friction in the sealing for supplying feed water into the steam ball was too high. The heat transfer was also a reason that the construction did not rotate. The steam ball and necessary equipment was fabricated in dec-07/jan-08. It was built without any drawings. The goal was to make it look like the original as much as possible. A smaller steam ball was built some years before. This one did rotate and therefore was the same design given to the bigger one. Because of the lack of rotation there was no doubt if the steam ball was a sucsess or not. It was not used for any real purpose 2000 years ago and this has not changed. A calculated figure of the efficiency was documented in this rapport, and it was very low. It was amusing to design and build the steam ball but the construction was clearly no success.

<p> </p><p>Due to its impact on human health and the nature surrounding us, diesel engine emissions have been significantly reduced over the last two decades. This reduction has been enforced by the legislating organs around the world that gradually have made the manufacturers transform their engines to today’s complex high-tech products. One of the most challenging areas to meet the legislations is transient operation where the inertia in gas-exchange system makes transition from one load to another problematic.</p><p> </p><p>Modern engines have great potential to minimize the problems associated with transient operation. However, their complexity also imposes a great challenge regarding optimization and systematical testing of transient control strategies in an engine test bed could be both expensive and time consuming.</p><p> </p><p>The objective of this project is to facilitate optimization of transient control strategies. This should be done by identifying appropriate measurement methods for evaluation of transients and by providing models that can be used to optimize strategies off-line.</p><p> </p><p>Measurement methods for evaluation of transients have been tested in several experiments, mainly focusing on emission but also regarding e.g. EGR flow. Applicable instruments for transient emission measurements have been identified and used. However, no method to measure soot emissions cycle resolved has yet been found. Other measurements such as EGR flow and temperatures are believed to have significantly decreased accuracy during transients.</p><p> </p><p>A model for prediction of NOx emissions have been used and complemented with a new approach for soot emission predictions that has been developed in this project. The emission models have been shown to be applicable over a wide range of operating conditions with exception for highly premixed combustion. It has also been shown that models developed for steady state conditions can be used for transients operation.</p>

<p>This diploma work covers an investigation over the heat - and hot water systems of the</p><p>tenant-owner's association, Bogården. The heat - and hot water needs of Bogården are</p><p>satisfied by both district heating as well as three heat pumps. Implemented investigation</p><p>shows that the heat pumps are not used in a profitable way. Apart from that, the reserve</p><p>possibilities are small. There is also a risk of the growth of Legionella bacterium in the</p><p>hot water system.</p><p>Since the heat pumps are already installed, HSB-Gävleborg (responsible for Bogården)</p><p>has a wish to investigate possible proposed actions for optimization of existing plant.</p><p>After completed investigation, a new proposed action is presented. The new proposed</p><p>action goes on intercepting the hot water production and using the heat pumps to only</p><p>heat production during the heating season. Why the hot water production should be</p><p>intercepted, is just in order to eliminate the risk of Legionella. Besides, the new proposal</p><p>is going to bring about a reserve of 1,534,000 SEK during a twenty-year period. This is</p><p>approximately twice as much as what the existing plant may bring during the same</p><p>period.</p><p>During the work's review, it also has been established that heat - and hot water systems</p><p>are error regulated. Since the diploma work does not cover that piece it is instead</p><p>informed as proposals subject to further investigation.</p>

While biomass utilization for energy conversion in the industrialized nations is being largely developed, highly efficient and environmentally friendly, many tropical countries still use biomass at low efficiencies and high emission levels. The main reasons for these gaps are both political and technological: the energy markets are different, the Gross National Product (GDP) differs widely, and the feedstock differs in form and conversion behaviour. By implementing newer technologies adapted for tropical biomass feedstock, there would be a large potential in these countries for increased energy services since access to modern energy still is an essential step for improving the GDP for a country. Two dominant and tropically placed industries available for energy improvements are the cane sugar and palm-oil industries, which both produce an abundant amount of biomass residues. One step towards enhanced utilization of the residues, which would not require large investment costs in the power plant section nor in the processes of these industries, would be to install a pelletizing unit in the industry area to make fuel out of the excess residues for sale to the nearby villages. The pellets could be used both for cooking/heating and for small-scale power generation in a gasification-IC engine plant. The overall objective of this study is to experimentally evaluate the biomass residues in pellet form from the cane sugar and palm oil industries during conversion to useful energy in small-scale systems. The thesis is built upon five publications which include experimental analysis on flaming pyrolysis and rapid heating of pellets (paper I), pyrolysis in oxygen-free atmosphere and slow heating with subsequent steam gasification (paper II), global pelletizing data such as relative energy consumption, temperature levels, particle size and moisture content for successful pelletizing process (paper III), downdraft gasification evaluation including reactor temperature distribution, gas composition, cold-gas efficiency and packed-bed mechanics (paper IV) and a numerical model including the overall system efficiency for residue-to-electric power based in a small-scale gasifier system (paper V).The single-pellet studies revealed that pyrolysis in reducing atmosphere is to prefer compared to flaming pyrolysis in oxidizing environment with regards to the char quality. The studies also showed favourable thermochemical and mechanical behaviour for smaller size pellets (Ø6- Ø8mm) compared to larger size ones (Ø12 mm). Therefore, a downdraft gasifier of closed constricted type was designed for real gasification tests of the residue pellets of sizes Ø6- Ø8mm. These tests showed that all the studied pellet sorts could be used in one and the same gasifier, resulting in different reactor temperature distributions and gas compositions with lower heating values in the range of 4.1-5.4 MJ/m3n dry gas. The reactor bed dynamics showed to be dependent both on the fuel reactivity and the size, with less pressure drop for larger size pellets with lower reactivity. The pelletizing process itself revealed that the selected residues all needed higher moisture content and smaller particle size than recommended for wood for successful pelletizing. The relative electric energy consumption was lower when producing larger size pellets Ø8 mm than smaller ones (Ø6 mm) of same material. For untreated wet empty-fruit bunch (EFB) a stand-alone power plant with integrated EFB pre-treatment and gasification could generate 380 kWh of net electricity per ton of EFB at a “well-to-wheel” efficiency of 15%. / QC 20100712

This diploma work covers an investigation over the heat - and hot water systems of the tenant-owner's association, Bogården. The heat - and hot water needs of Bogården are satisfied by both district heating as well as three heat pumps. Implemented investigation shows that the heat pumps are not used in a profitable way. Apart from that, the reserve possibilities are small. There is also a risk of the growth of Legionella bacterium in the hot water system. Since the heat pumps are already installed, HSB-Gävleborg (responsible for Bogården) has a wish to investigate possible proposed actions for optimization of existing plant. After completed investigation, a new proposed action is presented. The new proposed action goes on intercepting the hot water production and using the heat pumps to only heat production during the heating season. Why the hot water production should be intercepted, is just in order to eliminate the risk of Legionella. Besides, the new proposal is going to bring about a reserve of 1,534,000 SEK during a twenty-year period. This is approximately twice as much as what the existing plant may bring during the same period. During the work's review, it also has been established that heat - and hot water systems are error regulated. Since the diploma work does not cover that piece it is instead informed as proposals subject to further investigation.

Det här examensarbetet har utförts hos och med stöd av SKF Mekan i Katrineholm. Grundfrågeställningen som innebar upphovet till examensarbetet är om värme påverkar lagerlägets cylindricitet hos ett lagerhus. Detta avgränsas senare till att gälla enbart värmepåverkan under produktion för en typ av lagerhus i en storlek men tre olika materialval. Därmed koncentreras arbetet på gjuterilinan för de mindre lagerhusen samt den bearbetningslina som kallas ”Robot line”. Inledningsvis ges en presentation vad lager och lagerhus är samt vilken funktion de fyller. Därefter ges en överblick av gjuteriet samt bearbetningen. Berörda linor betraktas mer ingående men även övriga linor ges en övergripande bild av. Övriga resurser såsom mätrum samt testlabb presenteras också. De tre olika materialen granskas för att se vilka avgörande skillnader som finns dem emellan. Detta med hjälp av litteratur samt intervjuer med medarbetare hos SKF Mekan, personal vid Linköpings universitet samt SWEREA. Två test som genomförts under arbetets gång beskrivs, varav det ena lyckat men det andra misslyckat. Dock fick det andra testet ett överraskande resultat. Befintliga kontroller längs med produktionskedjan omtalas. Slutligen sammanfattas vilka moment inom gjuteri- samt bearbetningsprocessen där toleransen för cylindriciteten hos lagerläget riskerar att under-/överskridas samt vad som då är orsaken.

In this paper is present information about dry power transformers mechanical design, common electrical characteristics, and electrical characteristics. There compare oil transformers and dry power transformers. There are given conclusions about possible in practice use dry transformers and some to offer a suggestion how to pick and choose transformers.

Summary Efficiency of the model reference based adaptive control systems is investigated and discussed in this master degree work. The main goal of this work was to evaluate and compare the performance characteristics of two widely used in mechatronics adaptive control approach – adaptive control approach based on controller parameters automatic adjustment (parameter adaptive approach) and adaptive control approach based on compensating control signal generation (signal adaptive control). Investigations were carried out on the model of the second order electromechanical velocity control system, realized with help of matlab/simulink software. Transmittance of the reference model is coincident with transmittance of conventional hierarchically arranged velocity control system, adjusted in respect of quantitative optimum conditions. The rapidity of adaptation process in the case of velocity controller detune or control object parameters change, the limits and velocity of system parameters drift and influence of external load on adaptation process were investigated for both – parameter adaptive and signal adaptive control systems cases. For obtaining of continue adaptation process, the harmonious reference and loading signals were applied on the system. The system parameters change was also modeled in harmonious mode. The modeling results allow comparing the performance characteristics of these both adaptive control methods. It was demonstrated in this work that signal... [to full text]

The theme of the filter of compensating devices current harmonics analyzed at present on work is actual, because concrete requirements on quality of electric energy are established. One of such requirements – size of harmonics in a feeding electric network. In industrial electric networks to which converters are connected, high harmonics on size reach 20-25 %. Special devices for eliminating harmonics are used. Condensers which are used for indemnification of reactive electric energy, do not extinguish them, therefore are projected the filter – compensatory installations, using capacity of the battery of condensers as base of the power filter. Bases of designing of the filter – compensatory devices of the parameters of semi-conductor converters of the electric power intended for normalization with a power line are considered. The purpose work of the master – the analysis of a factory electric network on the maximum harmonics and to design the filter for eliminating harmonics. The electric network has been checked up by device PQ ANALYSER. Such harmonics 3, 5, 7, 9, 11, 13 are found. The greatest on a current is third harmonic. Condensers of reactive capacity connected, network does not act on a harmonic. Compensatory installation which is made of separate filters of clearing of harmonics is designed, will strongly reduce the specified harmonics in a factory network.