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Vibration analysis of the refrigeration circuit in a chilled water station
No full textTässä diplomityössä tutkitaan sitä, millaista värähtelyä kylmävesiaseman kylmäpiirissä esiintyy. Työn tavoitteena on antaa lukijalle yleiskuva siitä, miten värähtely syntyy kylmäaineputkissa, sekä koota yhteen muutamia hyväksi todettuja suunnittelukäytäntöjä. Lisäksi työssä kerrotaan, kuinka ominaistaajuuksia voidaan arvioida numeerisesti simulaation avulla.
Kylmäpiirin ominaistaajuuksia simuloitiin SolidWorksissa muutamilla erilaisilla tuennoilla, sekä simuloitiin sitä, miten putkistoissa oleva kylmäaine vaikuttaa ominaistaajuuksiin. Simulaation tuloksena saatiin laskettua värähtelymoodeja kylmäaineputkistolle ilman putkikannaketta ja putkikannakkeen kanssa. Lisäksi tuloksista voidaan päätellä, että jäykempi putkituenta nosti kylmäaineputkiston ominaistaajuuksia. Kylmäaineen vaikutus tuloksiin oli taas päinvastainen, sillä kylmäaineen tiheys lisättynä putkiston tiheyteen laski hieman saatujen värähtelymoodien ominaistaajuuksia.
Mahdollisessa jatkotutkimuksessa voitaisiin selvittää myös muiden kylmävesiasemien ominaistaajuuksia, sekä tarkentaa nykyisen simulaation tuloksia mittaamalla käytetyistä komponenteista tarkemmat alkuarvot. Jatkotutkimuksessa voitaisiin myös tehdä simulaatiota tukeva mittaustyö, jolla voitaisiin varmentaa simulaation tuloksia. Asentamalla kylmäpiiriin kiihtyvyysantureita voitaisiin tutkia, onko mahdollista havaita vikatilanteita kylmäpiirissä, kuten kompressorin epätyypillistä värähtelyä. Näin voisi olla mahdollista toteuttaa esimerkiksi ennakoivaa huoltoa.In this master’s thesis it is researched what kinds of vibrations occur in the refrigeration circuit of a cold-water station. The aim of this research is to help the reader understand what causes vibrations while also providing useful information about designing refrigerant circuits.
The vibrations of refrigeration circuits with different supports were simulated using SolidWorks. Also, it was simulated how refrigerant in refrigerant lines affect the natural frequencies. As a result, the different vibration modes of a refrigerant circuit were calculated without and with support. The results showed that stiffer refrigerant line supports increased the natural frequencies. Refrigerant in refrigerant lines on the other hand slightly lowered the natural frequencies.
In the possible future research, the natural frequencies of other cold-water circuits should be simulated. Also, the simulation performed in this thesis could be improved by measuring the real material values for the used components. The results of this thesis could also be validated by installing accelerometers into a cold-water station and measuring the real vibrations. These accelerometers could be possibly used to find abnormal vibrations to anticipate the possible need for maintenance
Teleskooppisen hitsaustornin konseptisuunnittelu
No full textThis thesis deals with the conceptual design of a telescopic welding tower. While modern day manufacturing industry is growing and developing, manufacturing machines must develop alongside to enable more efficient working. The aim was to develop a machine that has an excellent horizontal reach to workpiece and while the boom is packed it would require less machine footprint than conventional fixed boom. This thesis is focusing on column and boom structural design as well as cable and welding consumables handling.
Based on the technical specification agreed on beginning there is calculated optimal cross sections for the booms. For the optimal boom there is done FE-study, which confirms the calculations. Based on calculation there is done two different options for boom with different style of movement. One with linear guideways and one with sliding rollers. For the column and handling cables is shown options that are based on existing structures. Calculations are based on using steel but also using lighter material is studied.
Options and designs for structures that are shown in this thesis are evaluated in the end and also needs for follow-up actions and final design are gone through. Based on the figures in the end there are achieved space saving and reach.Tämä tutkielma käsittelee teleskooppisen hitsaustornin konseptisuunnittelua. Nykyajan valmistava teollisuus kehittyy ja valmistuslaitteiden pitää kehittyä mukana, jotta valmistus olisi mahdollisimman tehokasta. Tässä työssä konseptoidaan tähän tarkoitukseen tehokasta hitsauslaitetta. Tavoitteena oli saavuttaa laite, jolla on erinomainen ulottuvuus työkappaleelle vaakasuunnassa sekä puomi sisään ajettuna se veisi vähemmän tilaa kuin perinteinen kiinteäpuominen hitsaustorni. Työssä keskitytään vaakapuomiin, pystypuomiin sekä kaapeleiden ja hitsauslisäaineiden hallintaan.
Lähtötietojen pohjalta lasketaan optimaaliset koot eri vaiheiden puomien poikkileikkauksille. Optimaalisesta puomista tehdään myös FE-tutkimus, joka vahvistaa laskujen oikeellisuuden. Laskennan perusteella tehdään kaksi eri variaatiota puomeista johteilla ja liukurullilla toimivana. Pystypuomin ja kaapelien hallintaan esitetään vaihtoehdot, jotka pohjautuvat olemassa oleviin toteutuksiin. Laskennat pohjautuvat teräksen käyttöön vaakapuomissa, mutta myös kevyemmän materiaalin käyttöä on tarkasteltu.
Työssä esitetyt vaihtoehdot ja suunnitelmat rakenteille ovat lopuksi arvioitu sekä tarpeet jatkotoimenpiteisiin ja lopullisen tuotteen suunnittelemiseen ovat käyty läpi. Lopussa esitettyjen kuvien perusteella tilasäästöä ja ulottuvuutta on saavutettu
Design and development of a self-learning course on battery material recycling
Get PDFWith the rapid development of the electric vehicle industry and the approaching peak of power battery retirement, battery material recycling has become a critical issue for resource circulation and environmental protection. The focus of the work is systematically exploring the current status and development trends of battery material recycling technologies.
By integrating the design principles and development methods of self-learning courses, this research developed a self-learning course on battery material recycling, focusing on sustainable practices in the electric vehicle industry. The course covers key topics such as material classification, recycling processes, and emerging technologies, using text, videos, and animations. Implemented on an online platform with interactive features, it was evaluated positively for enhancing students' knowledge and practical skills. This study offers a structured model for online education in technical fields and emphasizes the importance of resource recovery. Future work will focus on optimizing content and expanding the course's reach
Techno-economic analysis of heavy-duty electric vehicles : assessing the financial viability of BE-HDEVs through TCO modelling
Get PDFThis thesis explores the transition towards Zero-Emission Heavy Duty transportation by doing a thorough techno-economic analysis of heavy-duty electric vehicles (HDEVs). Key principles explored in the research are the impact of batteries and total cost of ownership (TCO) on the adoption of electric vehicles on a large scale. This analysis covers in-depth evaluations of Nickel Manganese Cobalt (NMC), Nickel Cobalt Aluminium (NCA) and Lithium Iron Phosphate (LFP), along with their functions, costs and advantages in HDEVs. The analysis reveals that NMC and NCA batteries are generally preferred for long-distance applications due to their higher energy density, while LFP batteries are more suited to short-haul and urban operations because of their superior thermal stability and longer life cycle. The TCO assessment incorporates acquisition costs, operational expenses, maintenance requirements, and charging infrastructure considerations, while accounting for evolving battery prices and regulatory developments across European markets. The study reveals that although HDEVs currently require higher upfront investment compared to conventional diesel vehicles, their long-term economic prospects are strengthening through technological improvements, decreasing battery costs, and supportive policy measures. The results testify that even though diesel trucks are cheaper to acquire, electric trucks offer lower running costs over time, and this applies much more to regional routes. In addition, the study focuses on megawatt-level charging systems important for long-haul electric freight transport by looking at tech needs and barriers to use. By exploring the key elements that influence the use of electric heavy-duty trucks, this thesis gives useful information to industry players, transport operators and those shaping transportation policy as they switch to environmental transportation
Post-800 V electric vehicles
Get PDFThis thesis concentrates on the requirements and implications of post-800 V electric-vehicle (EV) architectures by providing first an independent analysis of the transition from 400 V to 800 V systems. Beginning with an overview of high-voltage powertrain fundamentals, the work systematically reviews the roles and interactions of the battery, inverter, motor, and on-board charger subsystems. A structured literature survey of academic and industry sources identifies the principal benefits of 800 V systems, such as, reduced current requirements, lighter cabling, higher charging power densities, and improved overall efficiency, and contrasts these with the increased insulation demands, component costs, and safety considerations inherent to higher voltages. Quantitative comparisons between representative 400 V and 800 V EV models are conducted, examining metrics such as peak charging rate, energy losses, thermal performance, and system-level mass. The results indicate that 800 V architectures can deliver up to 50 % faster charging and reduce electrical losses by approximately 15 %, while incurring an estimated 15–20 % increase in power-electronics cost and complexity. Based on these findings, the thesis discusses design strategies and technological pathways to mitigate technical and economic barriers and offers guidance for manufacturers and policymakers considering the adoption of post 800 V EV platforms. The conclusions underscore the potential of high-voltage architectures to accelerate EV performance and charging infrastructure development, while highlighting areas for further research in materials, safety standards, and cost optimization
Ultrakevyen lentokoneen putkiklusteriyhdyskappaleen suunnittelu ainetta lisäävää valmistusta varten
No full textThis thesis is about the tubular joint of an airplane, i.e. a cluster that is intended to be printed from metal. The part has straight-cut ends that enable orbital welding using the TIG welding method. The cluster part reduces the manual work of the tube ends and manual welding. Another perspective is how modern additive manufacturing changes the design method and the size of the printed object. This thesis looks to the future possibilities of trike design. Ultralight aircraft trike is lightweight and must be optimised structure. A common design feature among trikes is the use of single-tube frame, this is often enclosed by composite fairing for aerodynamic shaping rather than structural integrity. With a single tube structure protecting the occupants rather poorly. The diagonal tubular-frame, being wider than the passengers, offers improved protection by absorbing part of impact forces during collision. The aim is to design and optimise the cluster joints of a tubular aircraft, by removing stress peaks from the joint and nearby area. In this work, various printable joint areas are designed at the junctions of tubes. The initial analysis has determined the tube dimensions to the frame. Subsequently more detail static cluster analysis is carried out on specific sections in this thesis. The cluster structure is thickened based on von-Mises stress obtained from the analysis. The shape of the tube part changes more suitable for 3D printing than for machining. From the re-analysis, it can be concluded that stress peaks have decreased in the cluster joint and in the nearby area. Alternatively, cluster have been designed using shape optimisation tool, which reduces material from original design and analysed based on the applied loads. In the thesis, parts and brackets related to the tube structure are designed on ultralight trike.Tämä diplomityö käsittelee lentokoneen putkirakenteista liitosta eli klusteria, joka on tarkoitettu metallista tulostettavaksi. Klusteriosassa suoraksi leikatut putkimaiset liitospäät mahdollistavat automaattisen orbitaalihitsaamisen TIG-hitsausmenetelmällä. Klusteriosa vähentää putkien päiden manuaalista valmistamista sekä käsin hitsaamista. Toinen näkökulma on miten moderni 3D tulostaminen muuttaa suunnittelutapaa ja tulostettavan kappaleen kokoa. Ultrakevyt trike on kevytrakenteinen ja sen on oltava rakenteeltaan optimoitu. Yksiputkinen runkorakenne suojaa matkustajia varsin heikosti. Putkirunkoinen diagonaalirakenteinen runko, joka on leveämpi kuin matkustajat suojaavat törmäystilanteessa paremmin ja ottaa osan voimista törmäystilanteessa vastaan. Työn tavoitteena suunnitella putkirunkoisen lentokoneen klusteriosia siten että jännityshuiput liitoksessa ja sen lähialueella saadaan pienennettyä. Alkuanalyysin perusteella on määritelty putkien halkaisijat runkoon. Putkien yhtymäkohtaan eli klusteriin tehdään staattinen analyysi. Analyysin von-Mises jännityksen suhteen lisätään klusteriosaan materiaalia. Uudelleenanalysoinnista voidaan havaita jännityshuippujen pienentyneen korvakkeessa, putkissa ja lähialueella. Vaihtoehtoisesti klusteri on suunniteltu muodonoptimointityökalulla, joka poistaa materiaalia alkuperäisestä rakenteesta annettujen määritelmien mukaan kuormitukseen perustuen. Työssä suunnitellaan runkorakenteeseen liittyviä osia, sekä korvakkeita ultrakevyeen trikeen
Creating programming tasks in Java to support learning in Object-oriented programming course
No full textTyössä luotiin uudet viikkotehtävät LUT-yliopiston Olio-ohjelmoinnin kurssille. Työssä tunnistettiin kurssin nykyisten tehtävien suurimmat ongelmakohdat, ja uudet tehtävät luotiin hyödyntämällä kurssin opetusmateriaalia sekä ohjelmointitehtäviin liittyvää kirjallisuutta.
Työn onnistuneisuutta arvioitiin vertaamalla uusia tehtäviä vanhoihin, jonka pohjalta uudet tehtävät osoittautuivat vastaavan paremmin kurssin sisältöä. Työssä myös verrattiin Olio-ohjelmoinnin kurssin 2025 toteutusta, jossa uudet tehtävät olivat ensimmäistä kertaa käytössä, vuoden 2024 toteutukseen, jossa oli vanhat tehtävät. Kurssipalautteiden vertauksesta selvisi, että opiskelijoiden kurssin aiheiden ymmärryksen keskiarvo oli noussut uudella toteutuksella.
Jatkotutkimusta olisi hyvä tehdä esimerkiksi keräämällä tarkemmin palautetta yksittäisistä viikkotehtävistä, jotta uusien tehtävien hyötyä voitaisiin mitata tarkemmin, ja myös mahdollisesti parantaa.New weekly assignments were created for the Object-Oriented Programming course at LUT University. In this study, the main problems of the course’s current assignments were identified, and the new assignments were created by utilizing the course’s learning material and literature related to programming assignments.
The success of the study was measured by comparing the new assignments with the old assignments, from which it was determined that the new assignments aligned with the syllabus better. The 2025 implementation of the Object-Oriented Programming course, where the new assignments were in use for the first time, was also compared to the 2024 implementation, which had the old assignments. A comparison of both of the courses’ feedback revealed that the average student understanding of the course topics had increased with the new implementation.
Further research should be conducted, by collecting more detailed feedback on individual weekly assignments, so that the usefulness of the new assignments can be measured more accurately and also potentially improved
Digital transformation in SMEs : drivers, challenges, and the impact of emerging technologies on decision-making and management control
Get PDFThis study contributes to the fields of performance and strategic management by addressing the implications of digital transformation (DT) in small and medium-sized enterprises (SMEs). Drawing on theories of management control systems (MCS), organizational control (OC), organizational dynamics, workforce development, and decision-making, it delves into the drivers, challenges, and impacts of emerging technologies on management operations.
The study presents a comprehensive theoretical framework for facilitating DT in SMEs, integrating MCS, OC, decision-making processes, organizational dynamics, and employee capabilities with digital expertise. This framework provides a structured approach to understanding the factors influencing DT and its organizational implications.
Through a combination of empirical research and literature analysis, the study sheds light on the workforce and organizational implications of DT in SMEs. It underscores the role of digital transformation in reshaping management control systems and decision-making processes, providing insights into the challenges and opportunities that SMEs encounter during this transition.
The research introduces four key propositions aimed at facilitating the implementation of DT in management operations in SMEs. First, it suggests that managers are evolving toward collaborative leadership, emphasizing human-centric approaches and interpersonal interactions to drive organizational success. Second, decision-making processes are becoming more decentralized, enabling prompt and accurate decisions and fostering greater engagement with MCS and OC. Third, while automation enhances efficiency by streamlining routine tasks, it also creates role polarization and intensifies the demand for digital skills, raising concerns about agility and adaptability in existing workforce development paradigms. Finally, the study underscores the enduring relevance of human intuition and contextual judgment, suggesting that digital tools and AI should augment rather than replace human decision-making—thereby offering a more balanced view than current efficiency focused narratives.ei tietoa saavutettavuudest
The environmental impacts of vegetarian diets in public discussion
No full textTässä kandidaatintyössä tarkastellaan sosiaalisessa mediassa tapahtuvaa julkista keskustelua kasvisruokavalion ympäristövaikutuksista. Työhön on valittu ajankohtaisia suomalaisia medialähteitä kolmesta eri median kanavasta: Facebookista, Instagramista ja TikTokista. Työn tavoitteena on selvittää, puhuuko enemmistö kasvisruokaa vastaan vai puolesta, ja mitkä ovat yleisimmät argumentit kannattamaan näitä mielipiteitä. Tutkitaan mitkä ovat yleisimmät väittämät ja minkälainen luonne keskusteluissa on. Näiden jälkeen selvitetään, kuinka moni keskustelun argumenteista piti paikkaansa ja mitä se kertoo eri medialähteistä.
Mediakanavista valittiin jokaisesta kaksi julkaisua, joiden viisi tykätyintä kommenttia otettiin tarkempaan tarkasteluun. Facebookin sisältö oli kaikista monipuolisinta ympäristövaikutuksien ympärillä ja moni väite osoittautui taruksi. Instagramissa keskustelu kasvisruokavalion ympärillä oli myönteisintä ja julkaisun kommenttien sisältö oli usein totta. TikTokissa taas oli vähiten keskustelua kasviruokavalioiden ympäristövaikutuksista. TikTokissa oli myös havaittavissa paljon negatiivista näkökulmaa kasvisruokavalioon liittyen.
Tuloksista voidaan todeta, että median kommenttiosioissa liikkuu paljon misinformaatiota ja lisätiedottamiselle olisi tarvetta. Tässä tutkielmassa tarkastelluissa julkaisuissa virheellisiä väittämiä esiintyi useammin sekaruokavaliota kannattavien kuin kasvisruokavaliota kannattavien kommenteissa. Yksi syy suurelle lihan kulutukselle voikin olla tämä ihmisten tiedon puute, vaikka kasvisruokavalio olisikin ympäristöystävällisempi vaihtoehto. Yleisimmät kommentit ja argumentit käsittelivät kasvisten pitkiä tuontimatkoja, soijan viljelyä sekä vedenkulutusta. Etenkin avokado mainittiin monessa vedenkäyttöä koskevassa keskustelussa ja sai runsaasti huomiota.This Bachelor's thesis examines the public debate on the environmental impacts of vegetarian diets on social media. The study focuses on contemporary media, specifically analysing three Finnish social media platforms: Facebook, Instagram and TikTok. The aim of this thesis is to find out whether there are more people that speaks for vegetarian food or against it and what are the most common arguments supporting each stance. In addition, the nature of these comments is estimated and the accuracy of arguments evaluated.
Two posts were selected from each platform and the five most liked comments per post taken into closer analysis. Facebook's content varied the most around environmental impacts and many claims turned out to be untrue. On Instagram, discussions were generally positive towards vegetarian diets and the comments often contained factually correct information. TikTok had the least discussion about environmental impacts of vegetarian diets. There was also a lot of negative perspective in TikTok about vegetarian diets.
The results indicate that there is a lot of misinformation in the media’s comment sections and there is a need for spreading awareness. In the posts analysed for this thesis, incorrect claims appeared more frequently in the comments of those supporting an omnivorous diet than in those supporting a vegetarian diet. One reason for the large consumption of meat may be this people’s lack of information, even though vegetarian diet would be more environmentally friendly option. The most common comments and arguments included concerns about the long transport distances of vegetables, soybean cultivation, and water usage. Especially avocado was frequently mentioned in discussions about water use and received a lot of attention
Bio-composite materials in door manufacturing : a design and sustainability assessment based on literature and engineering practice
Get PDFInterior doors are typically made of steel, PVC, or hardwood materials that carry high carbon footprints and depend on non-renewable resources. To respond to this sustainability issue, the study investigates bio-composite materials as alternatives for door manufacturing in a design and sustainability context. Methodologically, the work integrates a literature review with practical design engineering, including developing a 3D model in SolidWorks and conducting a simplified Life Cycle Assessment (LCA) to evaluate the design’s environmental impacts. The proposed door design utilizes Wood Plastic Composite (WPC) for the leaf and handle, Cellular WPC (CWPC) for the frame, and a hybrid hinge combining hardwood with AISI 304 stainless steel. This hybrid combination is intended to ensure durability in high-stress points like the hinge while still keeping metal usage minimal. Selected for their performance and eco-friendly attributes, the bio-composites offer adequate mechanical strength and improved moisture resistance while significantly reducing weight owing to CWPC’s lightweight cellular structure. A cradle-to-grave LCA indicates that the bio-composite design yields roughly a 41% lower greenhouse gas footprint than a conventional steel-core door. Additionally, all components are recyclable or recoverable at end-of-life (thermoplastic WPC/CWPC can be reprocessed, wood can be energy-recovered, and steel is fully recyclable). Overall, the findings demonstrate the feasibility of replacing traditional door materials with these bio-composites, achieving substantial reductions in environmental impact without compromising functional performance