Littérature scientifique sur le sujet « Refrigeratori domestici »
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Articles de revues sur le sujet "Refrigeratori domestici"
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EVANS, ELLEN W., et ELIZABETH C. REDMOND. « Time-Temperature Profiling of United Kingdom Consumers' Domestic Refrigerators ». Journal of Food Protection 79, no 12 (1 décembre 2016) : 2119–27. http://dx.doi.org/10.4315/0362-028x.jfp-16-270.
Texte intégralRésumé :
ABSTRACT Increased consumer demand for convenience and ready-to-eat food, along with changes to consumer food purchase and storage practices, have resulted in an increased reliance on refrigeration to maximize food safety. Previous research suggests that many domestic refrigerators operate at temperatures exceeding recommendations; however, the results of several studies were determined by means of one temperature data point, which, given temperature fluctuation, may not be a true indicator of actual continual operating temperatures. Data detailing actual operating temperatures and the effects of consumer practices on temperatures are limited. This study has collated the time-temperature profiles of domestic refrigerators in consumer kitchens (n = 43) over 6.5 days with concurrent self-reported refrigerator usage. Overall, the findings established a significant difference (P < 0.05) between one-off temperature (the recording of one temperature data point) and mean operating temperature. No refrigerator operated at ≤5.0°C for the entire duration of the study. Mean temperatures exceeding 5.0°C were recorded in the majority (91%) of refrigerators. No significant associations or differences were determined for temperature profiles and demographics, including household size, or refrigerator characteristics (age, type, loading, and location). A positive correlation (P < 0.05) between room temperature and refrigerator temperature was determined. Reported door opening frequency correlated with temperature fluctuation (P < 0.05). Thermometer usage was determined to be infrequent. Cumulatively, research findings have established that the majority of domestic refrigerators in consumer homes operate at potentially unsafe temperatures and that this is influenced by consumer usage. The findings from this study may be utilized to inform the development of shelf-life testing based on realistic domestic storage conditions. Furthermore, the data can inform the development of future educational interventions to increase safe domestic refrigeration practices.
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Agi, V. N., C. P. Aleru et E. J. Uweh. « Bacterial Contamination of Some Domestic and Laboratory Refrigerators in Port Harcourt Metropolis ». European Journal of Health Sciences 6, no 1 (28 février 2021) : 16–34. http://dx.doi.org/10.47672/ejhs.662.
Texte intégralRésumé :
Background: A refrigerator is a potential source of pathogen contamination leading to food spoilage and food borne diseases. It forms an essential connection in broad chain of cross contamination which might possibly lead to the outbreaks of food borne diseases.
Purpose: The aim of the study was to evaluate bacterial Contamination of Some Domestic and Laboratory Refrigerators in Port Harcourt Metropolis.
Methodology: This study was done in Port Harcourt metropolis in Rivers state, Nigeria. Sterile swab sticks moistened with peptone water were used to swab the handles, bases, sides and shelves of domestic (90) and laboratory (60) refrigerators. One hundred and fifty (150) samples obtained in total were inoculated and identified using standard conventional methods of bacteria identification.
Results: The results showed 100% bacterial contamination. With prevalence rates of Staphylococcus aureus(30.6%), Klebsiella pneumonia (5.3%), Vibro cholera (4.7%), Escherichia coli (4%), Salmonella typhi (3.3%), Pseudomonas aeruginosa (2%), Bacillus cereus (1.3%), Clostridium botulinium (1.3%), Shigellaspecies (1.3%), Listeria monocytogenes (1.3%), Proteus mirabilis (1.3%), Vibroparahaemolyticus (1.3%), Yersinia enterocolitica (1.3%) and Clostridium perfringens(0.7%). Chi square confirms that relationships exist between bacteria isolate with the batch sampled (chi square =139.239; df=54; p=0.00), Gram reaction (chi square =150.000; df=18; p=0.00) and the refrigerator type (chi square =35.325; df=18; p=0.00). However, no statistically significant association exists between isolates and positions on Refrigerator (chi square = 68.080; df=72; p=0.61).
Conclusion: The outcome of this study confirms the presence of mesophilics and psychrotrophic bacteria in refrigerators, including potential foodborne pathogens which can cause serious health challenges. Hence, refrigerators are potential pathogen contamination sources. Therefore, proper hand hygiene, awareness and sensitization on maintenance of appropriate, good storage and refrigerator management is recommended for all.
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MORI, MIHO, YOSHIKAZU SAKAGAMI, MEGUMI TANAKA, RYO INOUE et TORU JOJIMA. « Analysis of the Relationship of Microbial Contamination with Temperature and Cleaning Frequency and Method of Domestic Refrigerators in Japan ». Journal of Food Protection 83, no 7 (23 juin 2020) : 1234–40. http://dx.doi.org/10.4315/0362-028x.jfp-19-322.
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ABSTRACT Hygiene management of domestic refrigerators is an important aspect of food poisoning prevention. The aim of the present study was to confirm the relationship between microbial contamination and hygiene management by measuring microbial levels and investigating temperature and cleaning frequency and method of domestic refrigerators in Japan. We analyzed three internal sections (the egg compartment, bottom shelf, and vegetable drawer) of 100 domestic refrigerators in Japan. Salmonella, Listeria monocytogenes, and Yersinia enterocolitica were not found in any of the refrigerators, but coliforms and Escherichia coli were detected in more than one household, and Staphylococcus aureus was the most frequently isolated pathogen. The prevalences of these microorganisms had similar tendencies in all three sections sampled and were highest in the vegetable drawer. The temperature distribution in the refrigerators was also investigated, and a temperature >6.1°C (improper temperature) was found in 46.2% of the areas surveyed. Only 17% of the respondents cleaned their refrigerators monthly or more often, and this frequency was lower than that reported in other countries. Fifty percent of the respondents used only water to clean the refrigerator, 10% used only an alcohol or disinfecting wipe, and 8% used only a dry cloth. Although no significant correlations were found between microbial contamination and temperatures in refrigerators, correlations were found between microbial contamination and refrigerator cleaning frequency and/or method. To our knowledge, this is the first detailed survey concerning relationships between microbial contamination and hygiene management in domestic refrigerators in Japan. The data obtained can be used to promote food poisoning management in Japanese households. HIGHLIGHTS
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Khalsa, Kawal Preet Singh, et Sayan Sadhu. « Experimental Study of Domestic Refrigerator Performance Improvement with Evaporative Condenser ». International Journal of Air-Conditioning and Refrigeration 29, no 02 (28 avril 2021) : 2150015. http://dx.doi.org/10.1142/s2010132521500152.
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Evaporation of defrosted water in household refrigerators and condenser waste heat utilization has been reported by many researchers but limited literature is available on the study of evaporative cooling in domestic refrigerators (condenser waste heat utilization for defrost water evaporation) with helical coil heat exchangers. This paper is concerned with evaluating domestic refrigerator performance by employing an evaporative helical coil heat exchanger before hot wall condenser which is utilized for evaporation of defrost water and reducing the superheated refrigerant temperature to condensing temperature to reduce the condenser load and improve the overall performance of a domestic refrigerator. Results show that evaporative cooling increases COP of the system by 25.3%, reduces the energy consumption of the refrigerator by 7.3% and the compressor run time by 10.6%. These experimental results also revealed that using two different thermal conductivity tube materials for evaporative helical coil condenser (Copper tube and Zinc coated steel tube) provided with less wall thickness (0.2[Formula: see text]mm) PVC coating results in good agreement for the same evaporation rate of defrosted water.
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Zavvar Sabegh, Mohammad Reza, et Chris Bingham. « Model Predictive Control with Binary Quadratic Programming for the Scheduled Operation of Domestic Refrigerators ». Energies 12, no 24 (7 décembre 2019) : 4649. http://dx.doi.org/10.3390/en12244649.
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The rapid proliferation of the ‘Internet of Things’ (IoT) now affords the opportunity to schedule the operation of widely distributed domestic refrigerator and freezers to collectively improve energy efficiency and reduce peak power consumption on the electrical grid. To accomplish this, the paper proposes the real-time estimation of the thermal mass of each refrigerator in a network using on-line parameter identification, and the co-ordinated (ON-OFF) scheduling of the refrigerator compressors to maintain their respective temperatures within specified hysteresis bands commensurate with accommodating food safety standards. A custom model predictive control (MPC) scheme is devised using binary quadratic programming to realize the scheduling methodology which is implemented through IoT hardware (based on a NodeMCU). Benefits afforded by the proposed scheme are investigated through experimental trials which show that the co-ordinated operation of domestic refrigerators can i) reduce the peak power consumption as seen from the perspective of the electrical power grid (i.e., peak load levelling), ii) can adaptively control the temperature hysteresis band of individual refrigerators to increase operational efficiency, and iii) contribute to a widely distributed aggregated load shed for demand side response purposes in order to aid grid stability. Importantly, the number of compressor starts per hour for each refrigerator is also bounded as an inherent design feature of the algorithm so as not to operationally overstress the compressors and reduce their lifetime. Experimental trials show that such co-ordinated operation of refrigerators can reduce energy consumption by ~30% whilst also providing peak load levelling, thereby affording benefits to both individual consumers as well as electrical network suppliers.
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Vegara, Alberto, Pierluigi Di Ciccio, Anna Rita Festino, Claudia Costanzo, Luca Pennisi et Adriana Ianieri. « The management of the domestic refrigeration : microbiological status and temperature ». British Food Journal 116, no 6 (27 mai 2014) : 1047–57. http://dx.doi.org/10.1108/bfj-05-2012-0103.
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Purpose – The purpose of this paper is to provide information on the consumer management of refrigerated food, establish the level and the incidence of bacterial contamination and operating temperatures in domestic refrigerators from north and centre Italy. Design/methodology/approach – A questionnaire was designed involving 24 questions which covered three topics: the socio-demographic data, the domestic management of refrigerated food and general information about the refrigerator. The questionnaire responses were subjected to descriptive statistical analysis and further processed with the multiple correspondence analysis (MCA) and cluster analysis (CA). Based on MCA and CA, 84 refrigerators were selected to assess the temperature and the microbiological status (total viable counts (TVC); Enterobacteriaceae total counts (ETC); Salmonella spp. and Listeria spp.). Findings – Totally, 660 interviews were carried out. The majority of respondents were female (81.4 per cent) and were married (71.4 per cent). Almost an half of them were between 31 and 50 years old (48.2 per cent) and had a secondary school degree (47 per cent). Regarding domestic management of refrigerated food, the majority of respondents (87.2 per cent) were aware of the correct temperature range (1-5°C) for retail refrigerator units, but only 18 per cent of them check the temperature. Listeria monocytogenes and Salmonella spp. were not recovered; Listeria innocua was recovered (2.4 per cent). Regarding the TVC values, the 21.5 per cent of the tested refrigerators were classified as insufficient (from 100 to 104 cfu/cm2) or inadequate (>104 cfu/cm2). Consumer education should be focused in order to reduce foodborne disease. Only safety-conscious consumers can become active partners within the food safety chain. Originality/value – Result obtained from the present survey revealed that consumers are not familiar with their role in the food safety chain and that they allow numerous opportunities for microbiological contamination of food. The study clearly indicates the need for greater consumer education regarding proper domestic refrigerator management. Indeed, appropriate behaviours could make the refrigerator less likely to act as a significant niche for persistence and dissemination of food pathogens.
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KILONZO-NTHENGE, AGNES, FUR-CHI CHEN et SANDRIA L. GODWIN. « Occurrence of Listeria and Enterobacteriaceae in Domestic Refrigerators ». Journal of Food Protection 71, no 3 (1 mars 2008) : 608–12. http://dx.doi.org/10.4315/0362-028x-71.3.608.
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Consumers' refrigeration practices have a significant impact on the safety and quality of foods. To determine the prevalence and the identity of microorganisms in domestic refrigerators, swab samples were taken from various locations in the refrigerators from 137 households in middle Tennessee. The swabs were inoculated into different media, and standard procedures were used to characterize the isolates. API 20E and API Listeria were used for identification of Enterobacteriaceae and Listeria spp., respectively. The Kirby-Bauer technique was used to test resistance of the isolates. Actual counts for aerobic and Enterobacteriaceae ranged from not detected to 8.53 and 8.39 log CFU per sample, respectively. Klebsiella pneumoniae (23.4%), Klebsiella oxytoca (6.8%), Klebsiella terrigena (4.0%), Enterobacter sakazakii (2.2%), and Yersinia enterocolitica (0.7%) were some of the bacteria of concern that were isolated from domestic refrigerators. Resistance to antibiotics was most common in erythromycin (39.9%), followed by ampicillin (33.8%), cefoxitin (12.8%), tetracycline (5%), streptomycin (4.0%), nalidixic acid (2.1%), kanamycin (1.4%), and colistin (0.7%). None of the isolates tested was resistant to ciprofloxacin or gentamycin. Listeria spp. were also detected in six refrigerators. These findings underline the need for greater consumer education regarding proper refrigerator cleaning and safe food handling practices.
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Baltrėnas, Pranas, Kęstutis Mačaitis et Vytautas Mačaitis. « REASEARCH AND EVALUATION OF ELECTROMAGNETIC FIELDS OF REFRIGERATORS / ŠALDYTUVŲ ELEKTROMAGNETINIŲ LAUKŲ TYRIMAI IR VERTINIMAS ». Mokslas - Lietuvos ateitis 5, no 4 (25 novembre 2013) : 369–75. http://dx.doi.org/10.3846/mla.2013.59.
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The use of refrigerators causes the occurence of electromagnetic fields that are invisible and intangible, which therefore makes difficulties in protecting ourselves from them. A refrigerator is an irreplaceable item in domestic household and thus can be hardly ignored by a modern way of human life. In order to preserve the characteristics of products, the refrigerator must operate continuously (24 hrs a day), regardless of the time of the year. This results in a huge increase in electricity consumption, which leads to energy consumption related pollution of the environment emitting CO2 gas. On these grounds, it is necessary to assess electromagnetic fields created by the refrigerator. Studies on electromagnetic fields produced by refrigerators were conducted in domestic premises where people spent a significant part of the day. For comparison purposes, five different power refrigerators were chosen (1 – 0.20 kW; 2 – 0.25 kW; 3 – 0.30 kW; 4 – 0.35 kW; 5 – 0.40 kW). The obtained results, according to the parameters of their electromagnetic fields, were presented in graphs and charts and showed that the values of electric and magnetic intensity of refrigerators depended on the distance and the power of the refrigerator. The conducted research also disclosed that none of tested refrigerators exceeded the permissible limits of electromagnetic fields. Article in Lithuanian. Santrauka Naudojant buitinę techniką susidaro elektromagnetiniai laukai. Elektromagnetiniai laukai yra nematomi ir nejuntami, tad nuo jų sunku apsisaugoti. Šaldytuvas – nepamainomas daiktas namų ūkyje, be kurio neįsivaizduojama šiuolaikinio žmogaus buitis. Kad būtų išsaugotos šaldytuve laikomų produktų savybės, šaldytuvas privalo veikti nuolatos (24 val./parą) nepriklausomai nuo metų laiko. Dėl to esti gana didelis elektros energijos suvartojimas, ir tai lemia su energijos vartojimu susijusią aplinkos taršą CO2 dujomis. Taip pat šie buitiniai prietaisai skleidžia elektromagnetinius laukus. Juos svarbu įvertinti ir palyginti su leidžiamomis higienos normų. Šaldytuvų elektromagnetinių laukų tyrimai atlikti buitinėse patalpose, kur nemažą dienos dalį praleidžia žmonės. Matavimams pasirinkti 5 skirtingo galingumo šaldytuvai (1 – 0,20 kW; 2 – 0,25 kW; 3 – 0,30 kW; 4 – 0,35 kW; 5 – 0,40 kW). Siekiant palyginti, elektromagnetinių laukų, susidarančių veikiant šaldytuvams, parametrai pateikiami diagramomis bei grafikais. Tyrimo metu nustatytos šaldytuvų elektrinio ir magnetinio stiprio reikšmės įvairiais atstumais bei jų priklausomybė nuo šaldytuvo galingumo.
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Belman-Flores, Juan, Diana Pardo-Cely, Francisco Elizalde-Blancas, Armando Gallegos-Muñoz, Vicente Pérez-García et Miguel Gómez-Martínez. « Perspectives on Consumer Habits with Domestic Refrigerators and Its Consequences for Energy Consumption : Case of Study in Guanajuato, Mexico ». Energies 12, no 5 (5 mars 2019) : 860. http://dx.doi.org/10.3390/en12050860.
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This work presents the main behaviors shown in the habits of consumers of domestic refrigerators, which influences the energy consumption of this appliance. This study is based on a series of surveys answered by 200 consumers from four cities in the State of Guanajuato, Mexico. The questions were arranged with the aim of evaluating the general characteristics and usage habits such as refrigerator age, door opening frequency, damper position, load of food supplies, external and internal cleaning habits, and nearby heat sources, among other things. The randomly interviewed consumers were individuals between 20 and 60 years of age, who were interviewed using handmade surveys by experts in the field of refrigeration. In some cases, photographic evidence was gathered from the consumers’ refrigerators to represent the typical usage habits. In general, the results show that better usage habits are necessary from an energy point of view. Most consumers agree with adopting best practices for using their refrigerator.
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Yella, Ramya, R. Naveen Kumar, Sudershan R. Vemula, Balakrishna Nagalla et SubbaRao M. Gavaravarapu. « Food Safety in Domestic Refrigerators - A Mixed Methods Study to Identify Key Messages for Promoting Safe Storage Practices among Households ». Indian Journal of Nutrition and Dietetics 53, no 1 (1 mars 2016) : 1. http://dx.doi.org/10.21048/ijnd.2016.53.1.3871.
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A significant proportion of foodborne diseases arise from practices in home kitchens. Not only how food is handled but also how it is stored determines its safety. The current study aimed to assess knowledge and practices of households related to storage of foods in refrigerator and identify key messages to promote safe storage practices. A cross-sectional study employing mixed methods (combination of quantitative and qualitative methods) was carried out among households who owned refrigerators. Quantitative data on knowledge and practices were collected from women (n=120) who were responsible for cooking and storing foods at household level using a pretested questionnaire and qualitative data on status of the refrigerators was collected using non-participant observation technique. Leftover foods stored in refrigerators for > 24h were collected from a sub-sample (n=18) to assess the presence of food pathogens. Over 34.2% preserved leftover non-vegetarian foods at room temperature. About 65% stored leftover foods in refrigerators for >24h. Only 10% cleaned the refrigerator every week and about 20% had knowledge of the working temperature of the refrigerators. There was a significant association (P<0.05) between education and knowledge as well as practices among households. Salmonella spp. (44.4%), E. coli (27.7%), fecal coliforms (11.1%) and S. aureus (5.5%) were detected in refrigerated leftover foods. Observational studies revealed some risky storage behaviors. Most of the households are not aware of the safe storage and refrigeration practices. The detected foodborne pathogens in refrigerated leftover food samples indicate a potential hazard in refrigerated foods. The study identified five key messages for food safety communication.
Thèses sur le sujet "Refrigeratori domestici"
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Metallo, Antonio. « Analisi sperimentale delle prestazioni energetiche dei fluidi frigoriferi tipo “HFO” candidati alla sostituzione dell’R134a ». Doctoral thesis, Universita degli studi di Salerno, 2016. http://hdl.handle.net/10556/2218.
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2014 - 2015The present experimental work was born from the need to expand the knowledge on the new type of refrigerant fluids, the HFO, representing the fourth generation of fluorinated refrigerants, born in response to the directives before the Kyoto Protocol and subsequently with the entry into force of the new Regulation in the European field (F-gas Regulation) requiring the reduction of greenhouse gases, including HFCs are also included. The on HFO-based technology offers interesting promises as regards energy efficiency and environmental impact. The primary characteristic of the HFO is the global warming potential (GWP) extremely low. In spite of other fluids, comparable yields of 'R134a are obtainable without significant modifications of' hardware plant, as some of the main thermodynamic properties (boiling point, critical point, the vapor density of the liquid and density) of HFO are very similar to those of R134a. In fact, the knowledge of the chemical-physical properties of a fluid refrigerant is of fundamental importance to be able to properly size the mechanical components used in the reverse cycle of the vapor compression. This allows you to assess whether or not to introduce new fluids on existing plants, and how they might be amended if necessary to make the drop-in. For both fluids and even after the two mixtures were made tests according to UNI ISO 15502 using an experimental system a refrigerating machine samsung RT 59QBPN, energy class A + two compartments, one from 342 liters for fresh food, and that for frozen from 131 l. Three types of tests are identified: pull-down, the endurance tests twenty-four hours at -18 ° C and -26 ° C. At first we have to check the performance of the 'system with R134a .All data were acquired using LabView and analyzed using a MatLab program. Once extracted the main thermodynamic properties of the cycle and performances relating to 'R134a, it was made the drop-in with the then R1234ze with R1234yf, and finally were tested mixtures. Though . performance of 'R1234yf are very similar to those of R134a performance parameters of' HFO1234ze slightly exceed those the traditional R134a, also diminish both the TEWI that 'LCCP, which is why you might think as a valid candidate for a next use in domestic refrigeration systems. Even better the performance following the drop-in first goes to a R134a HFOyf-mixture and subsequently with the R134a-HFOze. In summary, they have obtained for the first mixture a decrease in consumption (≈16%) of TEWI (≈16.5%) and LCCP (≈16%). It remains to evaluate the performance in other types of applications. [edited by author]
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Watkins, Helen. « Fridge space : journeys of the domestic refrigerator ». Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/969.
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My dissertation emerges from a curiosity about the mundane objects and machines with which we live and it pauses in Britain’s kitchens to ask what we might learn from looking in the fridge. Considered by many to be a rather ordinary and unremarkable appliance, the refrigerator forms a virtually ubiquitous backdrop to routine activities of feeding, provisioning and storing, but rarely is it brought into explicit focus.
This study traces the ‘career’ of the mechanical refrigerator and is based upon interviews and archival work in Britain. I unravel intersecting histories and geographies of cooling, discuss a global trade in ice, explore changing understanding of the nature of heat and cold and show how varied ideas and technologies contributed to achieving the creation of artificial cold. The means by which these techniques were translated into the home is central to my discussion and I show how the domestication of refrigeration also played a role in the reconfiguration of associated practices, such as freezing, shopping and eating. I consider the process of normalisation through which refrigerators shifted category from novel products to essential appliances and argue that in many ways the refrigerator has now become integral to the constitution of domestic space.
My research follows the lifecourse of the refrigerator and its journeys through multiple sites and spaces, enabling me to analyse diverse refrigerator knowledges and practices from repair shops and recycling facilities to scrap yards and museums, in addition to the home. Although using a refrigerator is frequently dismissed as something ‘self-evident’ or ‘obvious,’ I argue that fridge practices are not innate but learned. I explore ways in which these knowledges travel and pay particular attention to the translation of scientific and technical knowledges into domestic contexts. The ‘reach’ of the domestic refrigerator is considerable and I use one of the more notorious moments in its career, when refrigerators were implicated in global climate change, as a way to show how day to day activities like chilling milk and lettuce can have far-reaching effects at a range of scales.
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kingston, Paul Michael Jude. « Experimental and computational studies in a domestic refrigerator ». Thesis, Liverpool John Moores University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.528457.
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Marques, Ana Catarina Almeida. « Novel design and performance enhancement of domestic refrigerators with thermal storage ». Thesis, London South Bank University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.631725.
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A growing global environmental awareness and the rising costs of energy are driving demand for the development of sustainable cooling technologies. Most governments worldwide have implemented minimum energy performance standards for household refrigerators and innovative new solutions are required to improve the efficiency of these appliances. This thesis investigated the design and operation of a thermal storage refrigerator. The aim was to improve the refrigerator energetic efficiency, temperature stability and extend its offcycle. The research demonstrated that larger displacement compressors are more efficient. The proposed method to exploit the superior performance of large compressors is to accumulate their high cooling capacity in a phase change material (PCM). The combination of thin phase change material with a large displacement compressor is a novel design approach with the potential to enhance the refrigerator efficiency. Theoretical modelling and experimental validation were undertaken to determine the phase change material charge and discharge rate and the corresponding refrigerator on and off cycle durations. The integration of a 5 mm PCM slab into the refrigerator allowed 3 to 5 hours of continuous operation without power supply (compared to 9 minutes without PCM) depending on the ambient temperature. A computational fluid dynamics (CFD) model was used to predict the airflow and temperature distribution within the thermal storage refrigerator. Several design options were investigated by simulation to identify the most effective PCM configuration (horizontal or vertical), the phase change temperature and the design for the refrigerator i.e. conventional door type or top opening drawer appliance. The CFD was used to select the best design options for developing a novel thermal storage refrigerator. A horizontal PCM configuration was found to be more efficient than a vertical PCM. The temperature distribution with a horizontal PCM was tested experimentally and the results were shown to be in close agreement with the CFD predictions. Both the simulation and the experimental results suggested that a eutectic with a phase change temperature below 0°C needs to be employed to maintain the compartment temperature within acceptable limits.
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Mango, Omar I. K. « The effect of design parameters of compressors on the performance of domestic refrigerators ». Thesis, University of Hertfordshire, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259540.
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Geppert, Jasmin [Verfasser]. « Modelling of domestic refrigerators’ energy consumption under real life conditions in Europe / Jasmin Geppert ». Aachen : Shaker, 2011. http://d-nb.info/1070151297/34.
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Chávez, Gutiérrez Mirko Salomon 1978. « Estudo experimental de um dispositivo de condensação evaporativa, aplicado a refrigeradores domesticos ». [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255749.
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Orientador: Vivaldo Silveira JuniorDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Os equipamentos utilizados para refrigeração e condicionamento ambiental têm um potencial significativo de redução de consumo energético, principalmente porque esta pratica utilizam quantidades significativas de energia e são encontrados em todas as residências e indústrias. Neste contexto existem numerosos estudos dirigidos para aumentar a eficiência energética dos sistemas de refrigeração domésticos, utilizando diferentes estratégias tecnológicas. O dispositivo proposto neste trabalho atua como um condensador evaporativo, substituindo o ar,, como meio de troca térmica convencional dos sistemas de refrigeração domésticos, por uma corrente vertical de água em contato com a superfície do condensador, aproveitando desta maneira o calor absorvido pela água na mudança de fase (efeito evaporativo) e diminuindo a temperatura de condensação. O protótipo foi desenvolvido, considerando o principio de funcionamento dos condensadores evaporativos industriais e adaptado numa escala menor, para que possa ser facilmente montado na estrutura de um refrigerador doméstico convencional. Com as mudanças nas condições de condensação, especificamente a temperatura, procura-se aumentar o COP (coeficiente de desempenho) que é um indicador da eficiência do sistema, dado que nessas condições de funcionamento, o efeito frigorífico torna-se maior e o trabalho do compressor torna-se menor durante o ciclo. Estas condições de funcionamento, assim como o consumo de energia elétrica, foram monitorados e comparados com os sistemas de refrigeração convencional, utilizando uma câmara especialmente condicionada para esse propósito. Assim, o desempenho do sistema com as novas condições de condensação, promovidas pelo dispositivo, teve uma maior eficiência global com um COP maior em 24% e, em consequência, um aumento da eficiência energética do sistema, com uma redução de 17% de energia em ensaios padronizados conforme norma ABNT 12888
Abstract: Los equipos utilizados para refrigeración y condicionamiento ambiental tienen gran potencial de reducción de consumo energético, principalmente porque estos aparatos utilizan cantidades significativas de energía y son encontrados en la mayoría de residencias y en las industrias. Existen numerosos estudios dedicados a aumentar la eficiencia energética de los sistemas de refrigeración domésticos utilizando diferentes estrategias tecnológicas. El dispositivo propuesto en este trabajo actuara como un condensador evaporativo, substituyendo el aire, como medio de intercambio de calor convencional de los sistemas de refrigeración domésticos, por una corriente vertical de agua en contacto con la superficie del condensador, aprovechando de esta forma el calor absorbido por el agua durante el cambio de estado (efecto evaporativo) y disminuyendo la temperatura de condensación. Este prototipo fue desarrollado considerando el principio de funcionamiento de los condensadores evaporativos industriales y fue adaptado a una escala menor, para que pueda ser fácilmente instalado en la estructura de un refrigerador domestico convencional. Con las modificaciones en las condiciones de condensación específicamente, la temperatura, se procura aumentar el COP (coeficiente de desempeño), que es un indicador de la eficiencia del sistema, en vista que en estas condiciones de funcionamiento, el efecto frigorífico se torna mayor y el compresor trabaja menos durante el ciclo. Estas condiciones de funcionamiento, así como el consumo de energía eléctrica son monitoreados e comparados con los sistemas de refrigeración convencional, utilizando una cámara especialmente condicionada para este propósito. De esta manera el desempeño del sistema con las nuevas condiciones de condensación, promovidas por el dispositivo en estudio, tuvo una mayor eficiencia global con un COP superior en 24%, y como consecuencia un aumento de la eficiencia energética del sistema, con una reducción del consumo de energía en 17% durante ensayos homogenizados según la norma Brasileña ABNT 12888
Mestrado
Mestre em Engenharia de Alimentos
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Mancini, Ferdinando. « ENERGY EFFICIENCY IMPROVEMENTS OF HOUSEHOLD HEAT PUMP SYSTEMS ». Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3423220.
Texte intégralRésumé :
Sustainable development is one of the major challenges that humanity faces today. The rational use of energy resources and the increase of systems efficiency seems to be an important task for all contexts of modern life, from industry to transport and household appliances. The interest on this subject is justified not only by the price of energy, which can potentially increase, but also by the need to reduce emissions of gases, which are thought to be responsible for global warming.
This work wants to present innovative solutions for the energy efficiency improvement of household heat pump systems, with particular reference to heat pump dryers, domestic refrigerators and tap water heat pumps.
Since clothes drying is a very energy-intensive process, in recent years much attention has been paid to the development of energy efficient dryers. The heat pump has been recognised as a very attractive technology for this application. Actual interest is focused on finding good alternatives to halocarbon refrigerants. Because it’s safe for domestic rooms, carbon dioxide is regarded as a possible substitute for the traditional synthetic compounds. In this research work, the CO2 transcritical cycle is compared with the traditional R134a subcritical cycle. The comparison is carried out with a theoretical analysis and experimental tests, returning a positive assessment for CO2 as working fluid.
Tap water heat pumps are considered a privileged application for the employment of CO2 as refrigerant. This work presents an innovative upper cycle pressure control logic to face the optimisation problem, and also reports an experimental investigation of CO2 heat pump prototype, using a double wall plate heat exchanger gas cooler. This solution was studied as a possibility to reduce the risk of tap water contamination with lubricant oil.
Here some innovative solutions for the energy efficiency improvements of household refrigerators are presented. An experimental study was carried out on a under-counter refrigerator to analyse the effect of the operating cycling frequency on the electric consumptions. The experimental results show a reduction in energy consumption when the frequency of the compressor start-up increases.
To better understand these issues it was developed a dynamic simulation model for evaporators, based on the “moving boundary” scheme. Temporal integration of core variables makes the mean void fraction to be time-variant. The use of this kind of variables improves the model accuracy and speed, with respect to boundary variables, when the compressor start-up is simulated. This choice was considered suitable to simulate household refrigerators, which typically work with continuous on/off cycles.
Finally it’s presented an innovative solution for the energy efficiency improvement of total no-frost combi refrigerators. In these systems the fresh food compartment is cooled by air streams coming from the freezer. Therefore, the refrigeration unit produces the cooling effect at a temperature which is suitable for the freezer, but considerably colder than what is needed for the fridge. Consequently the system works with the thermodynamic disadvantage of supplying the cooling power at the lowest level of temperature. It was studied a combined household refrigerator (fridge/freezer), which works with a single refrigeration unit, but with two different air-loops. The unit consists of a single evaporator, which is employed to cool both the compartments. The air flow, involving the heat exchanger, comes alternately from the fridge or from the freezer. In this way the system works at two different evaporating temperatures, improving the thermodynamic efficiency when the fresh food compartment requires the cooling supply.Lo sviluppo sostenibile rappresenta una delle più importanti sfide che oggi l’umanità deve affrontare. L’uso razionale delle risorse energetiche e l’aumento dell’efficienza dei sistemi che le utilizzano, è un importante obiettivo per tutti i contesti della vita moderna, dal settore industriale, ai trasporti, agli elettrodomestici di uso quotidiano. L’interesse verso questo tema è giustificato, non solo dal prezzo dell’energia in potenziale aumento, ma anche dalla necessità di ridurre le emissioni dei gas che sono ritenuti responsabili del riscaldamento globale. Questo lavoro si inquadra nello studio di soluzioni tecnologiche innovative volte al miglioramento dell’efficienza energetica di apparecchiature domestiche, più precisamente macchine che operano con un ciclo inverso a compressione di vapore. In particolare verrà fatto riferimento ad asciugabiancheria a pompa di calore, refrigeratori domestici e pompe di calore per il riscaldamento di acqua calda sanitaria. Come è noto, le asciugatrici domestiche realizzano un processo termodinamico che richiede un elevato dispendio energetico. Per questo motivo negli ultimi anni si è dato molto spazio alla ricerca di soluzioni che ne possano ridurre i consumi elettrici, trovando nella tecnologia della pompa di calore una significativa possibilità di miglioramento. Oggi l’attenzione è rivolta a incrementarne ulteriormente l’efficienza energetica e a trovare dei sostituiti ai tradizionali fluidi refrigeranti alogenati per ridurne l’impatto sull’ambiente. Poiché non è né tossica né infiammabile, l’anidride carbonica è perfettamente compatibile con gli ambienti domestici, ed è vista come un possibile sostituto dei composti sintetici. In questo lavoro il ciclo transcritico ad anidride carbonica viene messo a confronto, sia su base teorica che sperimentale, con il ciclo subcritico a R134a. I risultati di questa indagine mostrano buone prospettive per l’impiego della CO2 in questa applicazione. Nella sezione successiva verranno approfonditi aspetti teorici e tecnologici delle pompe di calore dedicate al riscaldamento di acqua calda sanitaria, applicazione in cui il ciclo transcritico ad anidride carbonica risulta essere molto efficace. L’analisi prevede lo studio di logiche di controllo di tipo adattativo per l’ottimizzazione della pressione superiore di ciclo. Sarà inoltre presentato uno studio sperimentale di macchine operanti con gas-cooler a piastre a doppia parete, impiegato per ridurre il rischio di contaminazione del circuito idraulico. Verranno poi approfondite alcune tematiche legate al miglioramento dell’efficienza energetica dei refrigeratori domestici. Si riportano i risultati di un’indagine sperimentale condotta su un frigorifero domestico di tipo “sottotavolo”, i cui consumi elettrici sono stati monitorati al variare della frequenza ciclica di accensione del compressore. Per questa apparecchiatura è stata registrata una significativa riduzione dei consumi ad elevati frequenze. Per approfondire ulteriormente questi temi, mediante simulazione numerica, è stato sviluppato un modello per evaporatori in regime di funzionamento dinamico, seguendo uno schema di tipo “moving boundary”. Un’opportuna scelta delle variabili di stato (nello specifico, variabili corrispondenti a proprietà medie e non a grandezze di confine del modello) ha permesso di tenere conto delle variazioni nel tempo del grado di vuoto medio della zona bifase e di conseguire una maggiore velocità di simulazione dei transitori di avviamento del compressore. Questo modello è stato quindi sviluppato appositamente per la simulazione di refrigeratori domestici che operano in regime ciclico di funzionamento. Infine, nell’ottica del miglioramento dell’efficienza dei refrigeratori domestici combinati di tipo total-no-frost, viene presentata una soluzione innovativa per il ciclo termodinamico. In queste apparecchiature il vano dei prodotti freschi viene di solito raffreddato facendo circolare una piccola portata d’aria proveniente dal vano dei prodotti surgelati. Questo tipo di funzionamento è inefficiente, in quanto la potenza frigorifera viene erogata al più basso livello di temperatura. La soluzione studiata prevede, invece, di convogliare alternativamente verso l’evaporatore due flussi d’aria che raffreddano distintamente i due vani refrigerati. Così facendo è possibile differenziare due livelli di temperatura per la produzione della potenza frigorifera, conseguendo un aumento dell’efficienza energetica quando l’unità opera al raffreddamento del vano a temperatura positiva.
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Kinoshita, Denise [UNESP]. « Simulação numérica da convecção natural no interior de um refrigerador doméstico ». Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/88860.
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kinoshita_d_me_ilha.pdf: 2189895 bytes, checksum: 18c800e5f3dc7c91ac3187a97f2410b9 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Neste trabalho realizou-se um estudo numérico do escoamento em gabinetes de refrigeradores domésticos operando em regime de convecção natural, usando-se o Método de Volumes Finitos. No procedmento numérico, o problema do acoplamento pressão-velocidade foi resolvido pelo algoritmo SIMPLE - Semi Implicit Method for Pressure Linked Equations para malha desencontrada. O esquema Power-Law foi utilizado como função de interpolação para os termos convectivo-difusivos e o TDMA-Tri Diagonal Matrix Algorithm foi usado para resolver os sistemas de equações algébricas. O gabinete do refrigerador foi modelado como uma cavidade tridimensional vazia sem prateleiras e o evaporador foi modelado como uma placa plana vertical com temperatura uniforme prescrita. O código numérico foi verificado parcialmente para problemas clássicos de convecção natural encontrados na literatura. Resultados experimentais preliminares para um refrigerador doméstico comercial de 350 l também foram levantados para a validação do código numérico. Após a validação do código numérico, as influências do posicionamento e temperatura do evaporador nos campos de temperatura e velocidade foram analisadas para três configurações do gabinete: gabinete sem gaveta de verdura, gabinete com gaveta de verdura e gabinete com gaveta de verdura com aberturas laterais. O modelo de gabinete com gaveta de verdura com aberturas laterais mostrou-se o mais adequado para estudar o problema. Nove posições do evaporador foram avaliadas, mostrando que o posicionamento na direção horizontal praticamente não influencia o campo de temperatura e velocidade do escoamento, enquanto que o posicionamento na direção vertical tem uma influencia significativa. Os campos de velocidade e temperatura e a carga térmica do evaporador...
A numerical study of the flow inside cabinets of domestic refrigerators working on natural convection regime is performed in this work using the Finite Volume Method as numerical procedure for solving the governing equations. The pressure-velocity coupling was solved using the algorithm SIMPLE–Semi Implicit Method for Pressure Linked Equations applied to a staggered mesh. The Power-Law scheme was used as interpolation function for the convective-diffusive terms, and the algorithm TDMA-Tri Diagonal Matrix Algorithm was used to solve the systems of algebraic equations. The model was applied to static refrigerator working in steady state with constant and uniform evaporator temperature. The cabinet was considered as an empty three-dimensional cavity without shelves and the evaporator was modeled as a vertical flat plate with prescribed uniform temperature. The numerical code was partially verified for classical natural convection problems usually found in the literature. Preliminary experimental results for a 350 l commercial domestic refrigerator were also obtained for validating the numerical code. After validating the numerical code, the influence of the positioning and temperature of the evaporator on the temperature and velocity fields were analyzed for three cabinet configurations: cabinet without vegetable drawer, cabinet with vegetable drawer, and cabinet with vegetable drawer presenting lateral openings. The model including the vegetable drawer with lateral openings showed to be the best model to study the problem. Nine evaporator positions were evaluated, showing that the positioning in the horizontal direction practically does not affect the temperature and velocity fields of the flow, while the vertical positioning has a significant effect on the results. The temperature and velocity... (Complete abstract click electronic access below)
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Björk, Erik. « Energy Efficiency Improvements in Household Refrigeration Cooling Systems ». Doctoral thesis, KTH, Tillämpad termodynamik och kylteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-93061.
Texte intégralRésumé :
This thesis is based on eight articles all related to the characteristics of the cooling system and plate evaporator of a household refrigerator. Through these articles, knowledge is provided that can be used to increase the operational efficiency in household refrigeration. Papers A, B and C focus on heat transfer and pressure drop in a commonly used free convection evaporator – the plate evaporator. Applicable correlations are suggested on how to estimate the air side heat transfer, the refrigerant side pressure drop and the refrigerant side heat transfer. Papers D, E and F hold a unique experimental study of the refrigerant charge distribution in the cooling system at transient and steady state conditions. From this cyclic losses are identified and estimated and ways to overcome them are suggested. In paper G the topic “charging and throttling” is investigated in an unparalleled experimental study based on more than 600 data points at different quantities of charge and expansions device capacities. It results in recommendations on how to optimize the capillary tube length and the quantity of refrigerant charge. Finally, Paper H holds a thermographic study of the overall cooling system operating at transient conditions. Overall, a potential to lower the energy use by as much as 25 % was identified in the refrigerator studied. About 10 % was found on the evaporator’s air side. 1-2 % was identified as losses related to the edge effect of the evaporator plate. About 8 % was estimated to be cyclic losses. About 5 % was found in cycle length optimization. It is believed that most of these findings are of general interest for the whole field of household refrigeration even though the results come from one type of refrigerator. Suggestions of simple means to reduce the losses without increasing the unit price are provided within the thesisQC 20120411
Livres sur le sujet "Refrigeratori domestici"
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Marchant, David R. A manual on domestic refrigerator service and repair. Shotton : Marchant, 1987.
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Meier, Alan. Energy use of ice making in domestic refrigerators : Project summary. Research Triangle Park, NC : U.S. Environmental Protection Agency, Air and Energy Engineering Research Laboratory, 1992.
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S, Muthuraman. Eco-Friendly Refrigerants in Domestic Refrigerators : COMPUTER SIMULATION AND ANALYSIS OF AN EVAPORATOR IN DOMESTIC REFRIGERATOR WITH HFC134a AND HC290 MIXTURES. VDM Verlag Dr. Müller, 2010.
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Geller, Howard S. Analysis of Minimum Efficiency Standards and Rebate Incentive Programs for Domestic Refrigerators in the Pacific Northwe. Bonneville Power Administration, 1986.
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Analysis of Minimum Efficiency Standards and Rebate Incentive Programs for Domestic Refrigerators in the Pacific Northwest : Executive Summary. Bonneville Power Administration, 1986.
Trouver le texte intégralChapitres de livres sur le sujet "Refrigeratori domestici"
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Hill, Malcolm R., et Richard McKay. « Domestic Refrigerators ». Dans Soviet Product Quality, 92–110. London : Palgrave Macmillan UK, 1988. http://dx.doi.org/10.1007/978-1-349-09290-1_6.
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Min’an, Wang. « Refrigerator ». Dans Domestic Spaces in Post-Mao China, 13–24. Abingdon, Oxon ; New York, NY : Routledge, 2018. | Series : Postcolonial politics | “Published in Chinese by Henan University Press 2015.” : Routledge, 2017. http://dx.doi.org/10.4324/9781315228372-2.
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Clodic, D., et M. Ben Yahia. « Last Progresses for Energy Savings for Domestic Refrigerators ». Dans Energy Efficiency in Household Appliances, 539–46. Berlin, Heidelberg : Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-642-60020-3_61.
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Toapanta-Ramos, Fernando, César Nieto-Londoño, Elizabeth Suquillo-Goméz et William Quitiaquez. « Flow Maps in the Boiling Process in Domestic Refrigerators ». Dans Communication, Smart Technologies and Innovation for Society, 419–32. Singapore : Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-4126-8_38.
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Pavithran, Anand, Meeta Sharma et Anoop Kumar Shukla. « Energy Utilization Reduction of Domestic Refrigerator Using Phase Change Materials ». Dans Lecture Notes in Mechanical Engineering, 695–706. Singapore : Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-0159-0_61.
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Babarinde, T. O., S. A. Akinlabi et D. M. Madyira. « Experimental Study of Performance of R600a/CNT-Lubricant in Domestic Refrigerator System ». Dans Lecture Notes in Mechanical Engineering, 741–51. Singapore : Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-4488-0_62.
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Vasu, Vemuloori, Donthu Rakesh, K. Bintu Sumanth et V. Uma Sai Vara Prasad. « Experimental Investigation on Low-Pressure Receiver Incorporated Domestic Refrigerator with Al2O3 Nanoparticles ». Dans Lecture Notes in Mechanical Engineering, 319–27. Singapore : Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-1307-7_35.
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Shikalgar, N. D., S. N. Sapali et A. B. Shinde. « Mathematical Modeling of a Skin Condenser with Angular Contact for Domestic Refrigerator ». Dans Applications of Computation in Mechanical Engineering, 327–35. Singapore : Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6032-1_26.
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Pegallapati, A. Saikiran, et Maddali Ramgopal. « Modeling of Frosting on Fin-and-Tube Heat Exchanger of a Domestic Refrigerator ». Dans Advances in Air Conditioning and Refrigeration, 235–42. Singapore : Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-6360-7_21.
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Saji Raveendran, P., P. C. Murugan, T. Darwin, Godwin Glivin et Gaurav Dwivedi. « Energy Analysis of R1234yf/R134a as Replacement of R134a in a Domestic Refrigerator ». Dans Lecture Notes in Mechanical Engineering, 495–502. Singapore : Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-8341-1_41.
Texte intégralActes de conférences sur le sujet "Refrigeratori domestici"
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Huan, Zhongjie, et Chaohong Guo. « Optimization of the Capillary Tube for Domestic Refrigerator With Mixture of Propane and Isobutene as Refrigerant ». Dans 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22574.
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The hydrocarbon mixture of R290/R600a with mass ratio of 50/50 is regarded as a promising long-term refrigerant to replace R12 in domestic refrigerators since it can potentially provide higher COP than R12 system under the same operating conditions. In practical application, the length of the capillary tube should be matched with this alternative mixture; otherwise, the refrigerator system can probably consume more energy than the R12 system. In this paper, a simulation model of adiabatic capillary tube, in which some empirical coefficients are modified due to their inapplicability for R290/R600a, is established to illustrate the influences of the length of the capillary tube on the performance of the refrigerator. During the investigation a domestic refrigerator of 150L is used to test the thermodynamic cycle performances of R290/R600a (50/50) under conditions with different lengths of the capillary tube. The experimental results indicate that the R290/R600a (50/50) mixture with the optimized capillary length, which was obtained from simulation, has the higher energy efficiency and a lower discharge temperature than the original R12 system. The proposed mixture is proven to be a suitable long-term alternative in terms of its excellent thermodynamic cycle performances.
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Todd, Jessica. « Analytical and Experimental Study of Potential Heat Recovery From Household Refrigerators ». Dans ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60166.
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Opportunities for waste recovery exist in many types of industrial devices as summarized by Kreith and West [1]. However, no experimental data regarding the potential of heat recovery from household refrigerators have been published in open literature. The decision to implement a heat recovery option depends mostly on convenience and cost. In some cases, however, the decision is difficult because there is a lack of reliable information of the payback for a potential application. This article provides useful information for the design and payback of a waste heat recovery system on a household refrigerator. This paper presents experimental and analytical results of energy recovery potential from the heat rejected by the condenser coils of a household refrigerator. Using a small heat exchanger affixed to the condenser coils, the heat thus recovered can preheat domestic tap water. The analytical study considered three designs: A heat exchanger with the refrigerant condensing on the outside of water pipes, refrigerant on the inside of a counter-flow heat exchanger, and the refrigerant condensing inside a serpentine coil enclosed by a container filled with household tap water. Considering economic feasibility and manufacturing ease, the serpentine coil design was chosen. Experimental data confirmed the heat recovery possibility from the condenser coils. The serpentine coil design can achieve a payback time of 2 to 10 years dependent on whether the domestic hot water uses electric or gas heating.
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Hessami, Mir-Akbar, et Arnd Hilligweg. « Energy Efficient Refrigerators : The Effect of Door Gasket and Wall Insulation on Heat Transfer ». Dans ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-55147.
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The energy efficiency of refrigerators not only depends on the efficiency of the various components used in the cycle but also on their thermodynamics cycle efficiency as well the thermal efficiency of the cabinet housing the components. Efficiency improvements to the thermodynamics cycle and refrigerator components have been the subject of various papers published in the open literature. Not many researchers have looked at reducing the heat leakage into the refrigerator cabinet with the explicit objective of reducing the power consumption of the unit and hence improving its thermal efficiency. This paper is based on an experimental study of this topic, and includes information on the experimental rig used and the results obtained. This research was performed in two stages: The first stage was focused on improving the energy efficiency by changing wall insulation while the second stage was to study the heat transfer through the doors’ gaskets. For the first part, a domestic refrigerator was instrumented with many thermocouples and heat flux meters to measure the inside and outside air temperatures and the heat transfer through the wall of the unit, respectively. These measurements were taken under different environmental conditions as well as different insulation thickness in the walls of the cabinet. For the second part, using a specially designed and manufactured experimental rig, various door gaskets were placed between a warm and a cold chamber and heat transfer through the gasket was measured. The results showed that by adding 30 mm polystyrene insulation to the walls of the refrigerator, the heat transfer through the walls reduced by around 35%. The power consumption data agreed very well with the measured heat flux through the walls. The percentage heat transfer through the doors’ gaskets was confirmed to be about 13% of the total heat transferred into the unit.
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Zhang, Chaolei, Yongsheng Lian, Michael Kempiak, Erik Hitzelberger et Scott Crane. « Experimental and Numerical Investigation of a Domestic Refrigerator ». Dans ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21156.
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An integrated experimental and numerical investigation was carried out to gain insight into the heat transfer phenomena and flow characteristics inside a domestic refrigerator. A refrigerator model was constructed using insulation foam sheets according to the inner dimensions of a household refrigerator. A reversal heat leak analysis was conducted on the constructed model in a temperature-controlled chamber, where the chamber temperature was lower than the inner temperature of the refrigerator. A temperature-controlled heater was mounted where the evaporator was. The heater was enclosed in a heater box to heat the air and to maintain a high temperature in the refrigerator. A variable speed fan was used to force air circulation. Thermocouples were used to measure the temperature at specified positions and to measure the average temperature difference across the refrigerator side walls. The correlation between the status of the heater and the control temperature variation pattern was analyzed. Heat loss rate was calculated using the data from the thermocouples too. The calculated heat loss rate closely matched the generated heat by the heater and the fan. Moreover, according to the results with different input voltages, the variation trend of the heat flux density was analyzed. A conjugate heat transfer analysis was conducted based on the constructed model using Fluent. The heater was modeled as a heat volume source and the fan was modeled using a pressure jump condition based on the experiment result. Comparisons were made between the experimental and numerical results. The predicted heat loss rate and the heat flux density through the walls matched very well with the experimental results. And the variation trend of the heat flux density with different input voltages also showed the same trend as the experimental result. And the airflow pattern and the temperature distribution were also analyzed in detail.
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Zhang, Chaolei, et Yongsheng Lian. « Numerical Investigation of Heat Transfer and Flow Field in Domestic Refrigerators ». Dans ASME 2013 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fedsm2013-16039.
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Air circulation and temperature distribution inside a domestic refrigerator chamber are two important factors in refrigerator design. They are critical for food quality control and energy saving and are affected by natural/forced convection, radiation and layout of the stored food. Knowledge about the actual air flow and temperature distributions inside a refrigerator is required to improve temperature homogeneity and reduce energy consumption. In present work we numerically study the air circulation and the heat transfer phenomena in a domestic frost-free refrigerator. The inner compartment, the evaporator and the outside thermal insulation foam are considered. The conjugate heat transfer problem is studied by solving the unsteady laminar Navier-Stokes equations using a finite volume method. The Boussinesq approximation is used to model the natural convection. The discrete ordinate method is adopted to take into account the radiation heat transfer between the cold back evaporator and warm surfaces to further understand the impact of radiation. The accuracy of the numerical methods is verified through grid sensitivity analysis and comparison with available numerical and experimental data. Comparisons are made with and without radiation. Our simulations show that radiation significantly changes the temperature distribution and air circulation pattern. The effects of shelf and food stored on the temperature distribution and air circulation are also studied by comparing three configurations: empty refrigerator, empty refrigerator with shelves and loaded refrigerator with food.
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Phuchamniphatthananun, Athiwat, et Wanchalerm Pora. « A smart domestic refrigerator with energy efficiency improvement ». Dans 2019 IEEE Asia Pacific Conference on Circuits and Systems (APCCAS). IEEE, 2019. http://dx.doi.org/10.1109/apccas47518.2019.8953072.
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Belozerov, V. V., Y. V. Sukhova et M. V. Belozerov. « MODEL MULTI-SPLIT SYSTEMS WITH NANOTECHNOLOGIES FOR SUPPRESSING FIRES AND PREVENTING EXPLOSIONS FROM GAS IN THE RESIDENTIAL SECTOR ». Dans INNOVATIVE TECHNOLOGIES IN SCIENCE AND EDUCATION. DSTU-Print, 2020. http://dx.doi.org/10.23947/itno.2020.352-356.
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The article, based on a statistical analysis of fires in the residential sector in southern Russia, presents the results of long-term studies of the "intellectualization" of household electrical appliances (televisions, refrigerators, electricity meters, etc.), which can reduce the number of fires and the consequences of them. It is shown that split systems that “pump through” the air of the rooms where they are installed, as the most “fast” aspiration fire alarm systems do, are the most “suitable” electrical appliances, the intellectualization of which will allow not only early detection of dangerous fire factors and explosion from leakage of domestic gas, but suppress ignition and prevent an explosion if instead of a fan of the indoor unit, a thermomagnetic air separator is installed, which releases oxygen from the air and leads it out through the drainage pipe, and returns the remaining inert atmospheric gases to the room. A model of such a multi-split system was investigated and the modernization of the proposed method with the help of a "magnetic refrigerator" was developed, which will not only double the efficiency of creating comfortable living conditions and reduce energy consumption, but also eliminate fire hazardous external blocks that "spoil the facades" of multi-storey residential buildings
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Ponmurugan, M., M. Ravikumar et A. Sundaramahalingam. « A review on utilization of waste heat from domestic refrigerator ». Dans INTERNATIONAL CONFERENCE ON MATERIALS, MANUFACTURING AND MACHINING 2019. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5117987.
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Borikar, Sanjaykumar A., et Mahendra M. Gupta. « Review on performance and energy efficiency improvement in domestic refrigerator ». Dans INTERNATIONAL CONFERENCE ON SUSTAINABLE ENGINEERING AND TECHNOLOGY (ICONSET 2018). Author(s), 2018. http://dx.doi.org/10.1063/1.5079010.
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Harun-Or-Rashid, Mohammad, K. M. Rashid Shahrier et Farzana Alam Shakila. « Performance Analysis of a Domestic Refrigerator Using R134a and R600a Refrigerant ». Dans 2021 International Conference on Automation, Control and Mechatronics for Industry 4.0 (ACMI). IEEE, 2021. http://dx.doi.org/10.1109/acmi53878.2021.9528273.
Texte intégralRapports d'organisations sur le sujet "Refrigeratori domestici"
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Sand, J. R., C. L. Rice et E. A. Vineyard. Alternative refrigerants and refrigeration cycles for domestic refrigerators. Office of Scientific and Technical Information (OSTI), décembre 1992. http://dx.doi.org/10.2172/10184084.
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Yashar, David A. Development of a Method to Measure the Energy Consumption of Automatic Icemakers in Domestic Refrigerators with Single Speed Compressors. Gaithersburg, MD : National Institute of Standards and Technology, septembre 2012. http://dx.doi.org/10.6028/nist.tn.1759.
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Sand, J. R., et E. A. Vineyard. (Discussion of domestic refrigerator/freezer (R/F) design for nonazeotropic refrigerant mixtures (NARMs), Hannover, W. Germany, and visit to Kassel, W. Germany, May 2--5, 1989) : Foreign trip report. Office of Scientific and Technical Information (OSTI), mai 1989. http://dx.doi.org/10.2172/6059766.
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