Världens energiförbrukning ökar ständigt. Detta ger upphov till stora miljöproblem där klimatförändringen är ett av de största problemen. Hushållens energiförbrukning står idag för en betydande del av den totala energianvändningen. Det är därför viktigt att effektivisera hushållens energianvändning för att reducera deras påverkan på miljön. Vitvaror, som står för en stor del av hushållens energianvändning, har en stor potential att energieffektiviseras. Ett exempel på en vitvara där mycket energi kan sparas är diskmaskiner. Diskmaskiner tvättar, sköljer och torkar smutsig disk. Med dagens diskmaskiner går det åt mindre energi och vatten än vad det gjorde förr, då detta arbete gjordes för hand. Det finns dock fler åtgärder som kan utföras för att minska diskmaskinernas energiförbrukning. Det läggs bl.a. ned mycket arbete på att minska energiförbrukningen vid uppvärmningen av vattnet i diskmaskinerna och för att minska den energi som går åt i torkfasen. En diskmaskin där uppvärmningen sker via en värmepump utvecklas av Asko Appliances AB. Värmen som behövs i diskmaskinen tar värmepumpen från en vattenbehållare, vilket får vattnet att frysa till is. Torkningen av disken i denna diskmaskin kommer att ske genom att den fuktiga luften inuti diskmaskinen förs ut med hjälp av en fläkt. Den drivs sedan, genom en luftspalt, förbi islagret där fukten i luften kondenseras mot den kalla yta som skapas av islagret. Luften förs sedan tillbaka till diskmaskinen. I detta examensarbete utvärderas denna torkmetod. Den jämförs även med den teknik som används av Asko Appliances AB idag, där den fuktiga luften förs ut ur diskmaskinen till det rum där diskmaskinen står samtidigt som rumsluft förs in. Försök kommer att utföras på en diskmaskin med ett externt islager. Utvärderingen av torkningen i försöken gjordes med hjälp av torksyning. En matematisk modell med en energibalans över torkfasen har också byggts. Simuleringar utfördes på modellen och resultaten verifierades med försöken. Från modellen beräknades mängden vatten som torkas inuti diskmaskinen under torkfasen. Resultaten från torksyningen visade att torkmetoden med islager fungerar bättre än torkmetoden som används av Asko Appliances AB idag. Höga temperaturer och luftflöden visade sig ge det bästa torkresultatet enligt både försöken och modellen. Enligt modellen är torkningen mest energieffektiv då starttemperaturen är 70 °C, men eftersom så mycket vatten som sitter på diskmaskinens väggar då torkas är den starttemperaturen inte den mest effektiva i verkligheten. Den starttemperatur som är mest energieffektiv är 60 °C. Då torkas disken lika bra och det används 0,5 MJ mindre energi än då starttemperaturen är 70 °C. / The energy consumption is constantly increasing. The results are major environmental issues in which climate change is one of the biggest problems. Household energy consumption currently account for a significant share of the total energy consumption. Therefore it is important to improve household energy consumption to reduce household environmental impact. Appliances, which accounts for a large portion of household energy use, have a great potential for energy improvement. One example of an appliance where much energy can be saved is dishwashers. Dishwashers wash, rinse and dry dirty dishes. The dishwashers produced today uses less energy and water than before, when this work was done by hand. There are still more actions that can be taken to reduce the dishwasher's energy consumption. A lot of efforts are made among other things to reduce the energy consumption during the heating of the water inside the dishwasher and to reduce the energy consumed during the drying phase. A dishwasher where the heating occurs by a heat pump is developed by Asko Appliances AB. The heat pump takes the heat that is needed for the dishwasher from a water tank, causing the water to freeze. The drying of the dishes in this dishwasher will be done by letting the humid air inside the dishwasher out, using a fan. The air is then driven past the ice stock by making it go through an air gap, where the moisture condenses from the air on the cold surface created by the ice. The air then returns back into the dishwasher. In this thesis, this drying method is evaluated and compared with the technology used by Asko Appliances AB today, where the humid air is leaving the dishwasher and is brought into the room where dishwasher stands while air from the room is entering. Experiments will be performed on a dishwasher with an external ice stock. The evaluation of the drying process experiment was done using inspection. A mathematical model with an energy balance over the drying phase was built. Simulations were performed on the model and the results were verified by the experiments. With the model, the amount of water that evaporates inside the dishwasher during the drying phase was calculated. Results from the inspection showed that the drying method using the ice stock better performs than the drying method used by Asko Appliances AB today. High temperatures and air flow rates were found to provide a better result according to the experiments and the model. The drying is according to the model most energy efficient when the starting temperature is 70 °C, but since so much water located on the dishwasher walls is dried at that starting temperature, the in reality most efficient starting temperature is 60 °C. Then the dish is dried just as well and the energy consumption is 0.5 MJ less than when the starting temperature is 70 °C.

An ambitious and novel approach to engineering design and sustainability has been taken to explore the potential of drawing parallels between mechanical and biological systems for the possible development of sustainable engineering design metrics using a thermodynamic model. This approach looks to biology. Natural selection has given biological beings and processes high exergetic efficiencies, even while being only 30-40% energy efficient on the cell level. This energy inefficiency, resulting in a release of heat, can then be used to aid in driving other biochemical processes. The Gibbs free energy becomes more negative proportionally with an increase in temperature, resulting in a more favorable reaction. This effective use of waste heat from cell processes actually results in an increase in overall efficiency of an organism, around 50-60%. As in all systems the boundary defines the analysis. An exergy analysis was conducted on a residential dishwashing machine in several boundary configurations in order to develop an appropriate model. Exergy serves as a tool for identifying and quantifying losses in the system so that future works can be aimed at reducing irreversibilities. This model was then compared to data previously available regarding exergy within various processes of a biological cell. In future work, it is this comparison, which can be used to develop metrics for use early in the design stage to more efficiently use available and sustainable resources. There is a large difference between the two systems, with the dishwasher only having an effectiveness of 1.3%.

This thesis project concerns the creation of a simulation model for the hydraulic system of a commercial dishwasher machine. A 1D model was created using the Simscape physical network modeling tool integrated into the widely used MATLAB software environment. The resultant model can predict the hydraulic performance of the dishwasher for various cases of input parameters. It can also simulate certain state varying aspects of the dishwasher such as its flow controller which opens and shuts off flow to different parts of the system. The model can achieve sufficiently low runtimes where it can be faster than the real-time operation of the target system. The modularity of the physical network approach allows for the quick testing of changes to the overall design of the hydraulic system, a useful attribute when it comes to investigating performance requirements. The results of this work show promise in Simscape as a modeling tool for multi-physics systems. The model developed can serve as a foundation for further development to be carried out and more aspects of the dishwasher machine, such as its heating, be added to the model so it can cover a broader range of the dishwasher’s behavior.

The standard for standing household dishwashers to date includes some means of adjusting the height of the upper basket in order to facilitate a more efficient loading of dishware. Ordinarily this is done by lifting the basket and locking it in a few positions. A more efficient and satisfactory method of handling the elevation that instils a premium sensation was to be developed. A design process was initiated and using CAD, a 3D model with associated drawings was created. A FEM analysis was conducted on the most vital components and a subsequent prototype was built. Preliminary results indicated flaws in the construction, however developing solutions appeared promising. The FEA concluded that the key components were sufficiently dimensioned for the tasks given. In the end, the project requirements were fulfilled although with set conditions modified, and without an end user trial.

As the energy efficiency of dishwashers continuously improves, differentmanufacturers need to find new innovative solutions to further improve thedishwashers. To do so one can divide the areas of improvement into 4 parameters,water temperature, washing time, chemical treatment and mechanical processing.In this thesis the focus lies on the mechanical processing and the washing time. The conventional spray arm of today's dishwashers sets its rotational velocitythrough the water pressure. To step away from this ASKO Appliances AB hasdeveloped a prototype with a motorized lower spray arm. The purpose of this studyis therefore to investigate how the motorized spray arm performs in terms of energyusage, wash results and sound. This when altering the factors water pressure,rotational velocity and washing time. To get reliable results with the least amount of tests, the methodology of Design ofExperiments was used through the software MODDE 7. A 3-level full factorialdesign was chosen. The three factors were varied in three levels -1, 0, 1 and fiveextra centerpoints were added resulting in a test schedule of 32 tests. To measurethe wash result a soiling method and an evaluation method was developed. Theresults of the executed test schedule was analysed through MODDEs in-builtregression model Multiple Linear Regression. The analysed test results showed that the wash time was the dominant factor forboth energy usage and wash result and the second most dominant factor was waterpressure. The rotational velocity had little to no effect on the energy usage and asmall effect on the wash result at a low water pressure but increasing effect for ahigher water pressure. The measured sound values were constant over time andincreased with both increased water pressure and rotational velocity. The optimalrunning conditions regarding wash result was investigated using MODDE and thentested. The optimal rotational velocity was the setting 1, the highest level, for allthree time settings. The optimal water pressure was in the mid to high region, andincreased with increasing wash time. The results from the three optimum tests for the prototype were then compared totests with a conventional dishwasher with a pressure driven spray arm. Theconventional dishwasher was runned with its normal running conditions for thethree different time settings. The prototype achieved a similar wash result as theconventional machine for the time setting -1 but slightly better for the time setting0 and 1. The energy usage for the prototype was a doubling of the conventionalmachines energy usage. The sound measurements were excluded due to muffelingdifferences between the machines

White goods companies strive continuously to upgrade their dishwashers. Lately a technique with pulsating spray pressure has appeared on the market. According to previous studies there is a direct correlation between the spray pressure and the cleaning performance. The same study also shows an opposite correlation between rotational speed of the washing arms and cleaning performance.  The purpose of this study is to investigate how pulsating spray pressure impacts the dishwasher’s performance. This is done by answering the questions how pulsating spray pressure impacts cleaning performance, the circulation pump’s electricity consumption, the water consumption and noise level. One more part of the goal is to give advice for further studies of pulsating spray pressure in dishwashers.  This is an experimental study where 6 different variants of pulsating spray pressure where compared against a reference case with constant spray pressure. The pulsation variants examined in the study differed in in the range of the rpm, the time for one pulsation cycle, and how long the rpm where kept constant at the outer position. All tests where done with a prototype of model Asko DB12441B. The cleaning performance where evaluated by photographing the dishes before and after the washing program and analyzing the pictures in computer programs. The electricity consumption was measured by logging the effect use of the pump every second. The water consumption was measured by adding or subtracting 1 dl water to the dishwasher manually. Both the maximum and average generation of noise was detected when the noise level was measured.  The result shows that pulsating spray pressure increased the cleaning performance for the lower basket, but not in the upper basket. With pulsating spray pressure, the electricity consumption could be lowered in all operating cases except one. No further addition of dish water was needed for pulsating spray pressure, with the measurement accuracy used in the experiments. The noise level was higher in all investigated operating cases with pulsating spray pressure.

<p>För ett genomsnittligt småhus i Sverige idag går ca 5000 kWh till hushållsel. Av dessa 5000 kWh går 7% till att driva diskmaskiner. Effektiviseringen av diskmaskiner har framförallt strävat efter en låg vatten- och energianvändning, en kort processtid samt en effektiv rening av disken.</p><p>Det finns dock gränser för hur effektiva diskmaskinerna kan göras med traditionell teknik. Därför har producenter under de senaste åren börjat se sig om efter mindre traditionella metoder som till exempel bruket av en värmepump för att få ned energiförbrukningen.</p><p>Syftet med det här examensarbetet har varit att ta fram systemlösningar för värmepump i diskmaskin samt att utvärdera energibesparingspotentialen i denna tillämpning.</p><p>Målet har varit att ta fram och beskriva de möjliga systemlösningar som uppstår vid en idégenerering. Att välja ut två lösningar för närmare undersökning, att bestämma en lämplig kompressoreffekt samt att beräkna energibesparingen dessa lösningar ger.</p><p>En litteraturstudie har gjorts av teknik och tillämpningar inom området, som till exempel värmeväxlaranvändning i diskmaskiner samt användandet av värmepumpar i andra vitvaror. Denna litteraturstudie följdes upp av en idégenerering, som tar hänsyn till möjliga värmekällor och –sänkor. Idégenereringen gav upphov till två systemlösningar som modellerades i MATLABs Simulink för att en lämplig kompressoreffekt och storleken på energibesparingen skulle bestämmas.</p><p>De två utvalda lösningarna ifrån idégenereringen var utomhusluftlösningen, där värme hämtas från uteluften och energilagerlösningen, där värme hämtas ur ett energilager. I båda lösningarna överförs värmen till det kalla ingående vattnet.</p><p>Energiåtgången för utomhusluftlösningen var beroende av köldmediets förångningstemperatur och modellering av lösningen visade att energiåtgången var 0,25 kWh vid en förångningstemperatur på -10°C, och 0,18 kWh vid 5°C. Vid modellering av energilagerlösningen påvisades en energiåtgång på 0,23 kWh. Slutsatsen som drogs var att kompressorn vid energilagerlösningen skall leverera en effekt på 240 W till köldmediet.</p> / <p>For an average detached house in Sweden today about 5000 kWh are used for household electricity. Of these 5000 kWh 7% are used to run dishwashers. The streamlining of dishwashers has above all strived for a lower water and energy use, a short process time along with a more efficient cleaning of the dishes.</p><p>There are however limits for how efficient the dishwashers can be made with traditional technology and acceptable costs. Therefore producers have, during recent years, started looking for less traditional methods, for example the use of a heat pump to reduce the energy use.</p><p>The purpose of this examination work has been to find system solutions for an application of a heat pump in a dishwasher and to evaluate the possible energy saving for each solution.</p><p>The goal has been to find and describe possible system solutions, which came up during the idea generation. To choose some of these for a closer investigation, to decide a fitting mechanical power for the compressor and to calculate the energy saving these solutions give rise to.</p><p>The method has consisted of a literature study, an idea generation, which takes the heat sources and sinks in consideration and a modelling in MATLAB’s Simulink of the selected solutions from the idea generation, which has been used to fit a mechanical power for the compressor.</p><p>The result of the idea generation was two solutions, an outdoor air solution, which collects heat from the outdoor air and gives it to the cold water which enters the machine and a energy storage solution, which collect heat from a heat stock to give to the cold entering water. A modelling of these show an energy usage of 0,24 respectively 0,17 kWh for the outdoor air solution, with a heat source temperature at 10 °C respectively 5°C and a energy usage of 0,22 kWh for the energy storage solution for one round.</p><p>The conclusion that was drawn was that the compressor of the energy storage solution should deliver a mechanical power of 240 W to the refrigerant.</p>

För ett genomsnittligt småhus i Sverige idag går ca 5000 kWh till hushållsel. Av dessa 5000 kWh går 7% till att driva diskmaskiner. Effektiviseringen av diskmaskiner har framförallt strävat efter en låg vatten- och energianvändning, en kort processtid samt en effektiv rening av disken. Det finns dock gränser för hur effektiva diskmaskinerna kan göras med traditionell teknik. Därför har producenter under de senaste åren börjat se sig om efter mindre traditionella metoder som till exempel bruket av en värmepump för att få ned energiförbrukningen. Syftet med det här examensarbetet har varit att ta fram systemlösningar för värmepump i diskmaskin samt att utvärdera energibesparingspotentialen i denna tillämpning. Målet har varit att ta fram och beskriva de möjliga systemlösningar som uppstår vid en idégenerering. Att välja ut två lösningar för närmare undersökning, att bestämma en lämplig kompressoreffekt samt att beräkna energibesparingen dessa lösningar ger. En litteraturstudie har gjorts av teknik och tillämpningar inom området, som till exempel värmeväxlaranvändning i diskmaskiner samt användandet av värmepumpar i andra vitvaror. Denna litteraturstudie följdes upp av en idégenerering, som tar hänsyn till möjliga värmekällor och –sänkor. Idégenereringen gav upphov till två systemlösningar som modellerades i MATLABs Simulink för att en lämplig kompressoreffekt och storleken på energibesparingen skulle bestämmas. De två utvalda lösningarna ifrån idégenereringen var utomhusluftlösningen, där värme hämtas från uteluften och energilagerlösningen, där värme hämtas ur ett energilager. I båda lösningarna överförs värmen till det kalla ingående vattnet. Energiåtgången för utomhusluftlösningen var beroende av köldmediets förångningstemperatur och modellering av lösningen visade att energiåtgången var 0,25 kWh vid en förångningstemperatur på -10°C, och 0,18 kWh vid 5°C. Vid modellering av energilagerlösningen påvisades en energiåtgång på 0,23 kWh. Slutsatsen som drogs var att kompressorn vid energilagerlösningen skall leverera en effekt på 240 W till köldmediet. / For an average detached house in Sweden today about 5000 kWh are used for household electricity. Of these 5000 kWh 7% are used to run dishwashers. The streamlining of dishwashers has above all strived for a lower water and energy use, a short process time along with a more efficient cleaning of the dishes. There are however limits for how efficient the dishwashers can be made with traditional technology and acceptable costs. Therefore producers have, during recent years, started looking for less traditional methods, for example the use of a heat pump to reduce the energy use. The purpose of this examination work has been to find system solutions for an application of a heat pump in a dishwasher and to evaluate the possible energy saving for each solution. The goal has been to find and describe possible system solutions, which came up during the idea generation. To choose some of these for a closer investigation, to decide a fitting mechanical power for the compressor and to calculate the energy saving these solutions give rise to. The method has consisted of a literature study, an idea generation, which takes the heat sources and sinks in consideration and a modelling in MATLAB’s Simulink of the selected solutions from the idea generation, which has been used to fit a mechanical power for the compressor. The result of the idea generation was two solutions, an outdoor air solution, which collects heat from the outdoor air and gives it to the cold water which enters the machine and a energy storage solution, which collect heat from a heat stock to give to the cold entering water. A modelling of these show an energy usage of 0,24 respectively 0,17 kWh for the outdoor air solution, with a heat source temperature at 10 °C respectively 5°C and a energy usage of 0,22 kWh for the energy storage solution for one round. The conclusion that was drawn was that the compressor of the energy storage solution should deliver a mechanical power of 240 W to the refrigerant.

Detta examensarbete omfattar akustiska undersökningar utav en desinficerande diskmaskin av typ Getinge 8666/8668 och har utförts på Getinge Desinfection AB i Växjö. Vi har undersökt hur man med enkla medel kan sänka ljudtrycksnivån i maskinens närhet. Mätningar har utförts på diskmaskinens torkprogram, där torkfläktarna är de mest dominerande ljudkällorna och ljudet främst är luftburet. En systematisk analysmetod bestående av införandet av successiva dämpningsåtgärder visade att de dominerande ljudvägarna går via taket, golvet samt till viss del spalter i maskinens väggar. Genom att isolera både tak, golv och spalter kunde ljudtrycksnivån sänkas med totalt hela 5,9 dB. Med enkla produktionsanpassade lösningar, i form utav en isolerad golvsockel och en bättre kåpa runt fläktarna, kan man sänka nivån med så mycket som 3,6 dB. Rapporten ska även kunna användas som ett underlag för vidare akustiska undersökningar på Getinge Desinfection AB. / This dissertation examines acoustic research of a disinfecting dishwasher type Getinge 8666/8668. The research has been performed in collaboration with Getinge Desinfection AB, a world wide known manufacturer of disinfecting equipment for healthcare, located in Växjö, Sweden. We have examined how to reduce noise from the dishwasher with simple measures. Measurements have been performed during the drying program of the machine. The drying fans are the dominating sources of sound, and the sound is air bourn. A systematic method by reducing the sound step by step shows that the major ways of sound is through the ceiling and through the floor. There is also a minor noise leakage through the gaps in the walls of the dishwasher. By isolating the ceiling, the floor and the gaps in the walls, it is possible to reduce the noise with totally 5.9 dB. With more production adapted solutions, in shape of an isolated floor base and a more efficient fan cover, it is possible to reduce the noise with as much as 3.6 dB. This dissertation is thought to be used as a basis for further acoustic research at Getinge Desinfection AB.

<p>Detta examensarbete omfattar akustiska undersökningar utav en desinficerande diskmaskin av typ Getinge 8666/8668 och har utförts på Getinge Desinfection AB i Växjö. Vi har undersökt hur man med enkla medel kan sänka ljudtrycksnivån i maskinens närhet. Mätningar har utförts på diskmaskinens torkprogram, där torkfläktarna är de mest dominerande ljudkällorna och ljudet främst är luftburet. En systematisk analysmetod bestående av införandet av successiva dämpningsåtgärder visade att de dominerande ljudvägarna går via taket, golvet samt till viss del spalter i maskinens väggar. Genom att isolera både tak, golv och spalter kunde ljudtrycksnivån sänkas med totalt hela 5,9 dB. Med enkla produktionsanpassade lösningar, i form utav en isolerad golvsockel och en bättre kåpa runt fläktarna, kan man sänka nivån med så mycket som 3,6 dB. Rapporten ska även kunna användas som ett underlag för vidare akustiska undersökningar på Getinge Desinfection AB.</p> / <p>This dissertation examines acoustic research of a disinfecting dishwasher type Getinge 8666/8668. The research has been performed in collaboration with Getinge Desinfection AB, a world wide known manufacturer of disinfecting equipment for healthcare, located in Växjö, Sweden. We have examined how to reduce noise from the dishwasher with simple measures. Measurements have been performed during the drying program of the machine. The drying fans are the dominating sources of sound, and the sound is air bourn. A systematic method by reducing the sound step by step shows that the major ways of sound is through the ceiling and through the floor. There is also a minor noise leakage through the gaps in the walls of the dishwasher. By isolating the ceiling, the floor and the gaps in the walls, it is possible to reduce the noise with totally 5.9 dB. With more production adapted solutions, in shape of an isolated floor base and a more efficient fan cover, it is possible to reduce the noise with as much as 3.6 dB. This dissertation is thought to be used as a basis for further acoustic research at Getinge Desinfection AB.</p>