Development of a Prototype Thermoelectric Space Cooling System Using Phase Change Material to Improve the Performance
Development of a Prototype Thermoelectric Space Cooling System Using Phase Change Material to Improve the Performance

Author: Dongliang Zhao

Publisher:

Published: 2014

Total Pages: 152

ISBN-13: 9781321175059

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The thermoelectric cooling system has advantages over conventional vapor compression cooling devices, including compact in size, light in weight, high reliability, no mechanical moving parts, no refrigerant, being powered by direct current, and easily switching between cooling and heating modes. However, it has been long suffering from its relatively high cost and low energy efficiency, which has restricted its usage to niche applications, such as space missions, portable cooling devices, scientific and medical equipment, where coefficient of performance (COP) is not as important as reliability, energy availability, and quiet operation environment. Enhancement of thermoelectric cooling system performance generally relies on two methods: improving thermoelectric material efficiency and through thermoelectric cooling system thermal design. This research has been focused on the latter one. A prototype thermoelectric cooling system integrated with phase change material (PCM) thermal energy storage unit for space cooling has been developed. The PCM thermal storage unit used for cold storage at night, functions as the thermoelectric cooling system's heat sink during daytime's cooling period and provides relatively lower hot side temperature for the thermoelectric cooling system. The experimental test of the prototype system in a reduced-scale chamber has realized an average cooling COP of 0.87, with the maximum value of 1.22. Another comparison test for efficacy of PCM thermal storage unit shows that 35.3% electrical energy has been saved from using PCM for the thermoelectric cooling system. In general, PCM faces difficulty of poor thermal conductivity at both solid and liquid phases. This system implemented a finned inner tube to increase heat transfer during PCM charging (melting) process that directly impacts thermoelectric system's performance. A simulation tool for the entire system has been developed including mathematical models for a single thermoelectric module, for the thermoelectric cooling unit, for the PCM thermal storage unit, and for the outdoor air-water heat exchanger. When modeling PCM thermal storage unit, the enthalpy method has been adopted. Since natural convection has been observed in experiments playing a key effect on heat transfer in PCM, a staged effective thermal conductivity ( k[subscript] e ) concept and modified Rayleigh (Ra ) number formula have been developed to better capture natural convection's variable effects during the PCM charging process. Therefore, a modeling-based design procedure for thermoelectric cooling system integrating with PCM has been proposed. A case study has been completed for a model office room to demonstrate the qualitative and quantitative evaluations to the major system components. Results of this research can be extended to other applications in relevant areas. For instance, the proposed PCM thermal storage unit can be applied to integration with water-cooled conventional air-conditioning devices. Instead of using water cooling, a case study of using the proposed PCM unit for a water-cooled air-conditioner shows a COP increase of more than 25.6%.

Energy Solutions to Combat Global Warming
Energy Solutions to Combat Global Warming

Author: XinRong Zhang

Publisher: Springer

Published: 2016-10-17

Total Pages: 852

ISBN-13: 331926950X

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This book gathers an in-depth collection of 45 selected papers presented at the Global Conference on Global Warming 2014 in Beijing, China, covering a broad variety of topics from the main principles of thermodynamics and their role in design, analysis, and the improvements in performance of energy systems to the potential impact of global warming on human health and wellbeing. Given energy production’s role in contributing to global warming and climate change, this work provides solutions to global warming from the point of view of energy. Incorporating multi-disciplinary expertise and approaches, it provides a platform for the analysis of new developments in the area of global warming and climate change, as well as potential energy solutions including renewable energy, energy efficiency, energy storage, hydrogen production, CO2 capture and environmental impact assessment. The research and analysis presented herein will benefit international scientists, researchers, engineers, policymakers and all others with an interest in global warming and its potential solutions.

Development of an Experimental and Analytical Model of an Active Cooling Method for High-power Three- Dimensional Integrated Circuit (3D-IC) Utilizing Multidimensional Configured Thermoelectric Modules
Development of an Experimental and Analytical Model of an Active Cooling Method for High-power Three- Dimensional Integrated Circuit (3D-IC) Utilizing Multidimensional Configured Thermoelectric Modules

Author: Huy Phan

Publisher:

Published: 2011

Total Pages:

ISBN-13:

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An increase in demand for more functionality and capacity of microelectronic components within the same logistic footprint drives the growth of three-dimensional integrated circuit (3D-IC) packaging technologies in recent years. However, the reduction in size and an increase in transistors density also intensify the heat flux of stacked-dice, which introduces many thermal challenges at both the package and cooling levels. Traditional passive cooling systems such as forced air convection cooling, phase change materials cooling and passive or active heat sinks will become inadequate to cool future processors and cannot accommodate the demand of future sub-ambient cooling of 3D-ICs. Within the past 10 years, major microprocessor manufactures have shifted their focuses toward higher bandwidth rather than frequency; however, the heat flux of current high-end CPU and GPU on the same die with parallel sequential computation is still in the order of 70 to 75 W/cm2 with local heat flux exceeding 1.5W/mm2 and growing. Today, stack-dice are used widely as low-powered memory applications because thermal management of such 3D architectures as high-powered processors inherits many thermal challenges and is very costly. Heat dissipation of 3D-IC is highly non-uniform and non-unidirectional due to many factors such as material properties, power architectures, power leakage, transistor packing density, and real estate available on the processor. Inadequate thermal management of these systems leads to reduction in reliability, performance and ultimately a system's catastrophic failure. In this study, an experimental, an analytical, and a thermal cycling of an active cooling method for three-dimensional integrated circuits utilizing a multidimensional configured thermoelectric cooler were investigated. In addition, an alternative method to analyze thermoelectric cooling system employing a Modified-Graphical-Method (MGM) to eliminate the need of using proprietary fabrication information was also studied.

Data Center Cooling Augmentation Using Micro-encapsulated Phase Change Material
Data Center Cooling Augmentation Using Micro-encapsulated Phase Change Material

Author: Ruddhi Deshmukh

Publisher:

Published: 2014

Total Pages: 44

ISBN-13:

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The ever increasing information technology heat load and data center cooling energy are the main reasons to investigate the performance of microencapsulated phase change slurry over other heat transfer fluids. In recent years, more effort is being made on the development of a new technique to use the phase change materials as pump-able heat transfer fluid and as heat storage system. Thermal Energy Storage (TES) using Phase Change Materials for data centers offers a very effective method of cutting electric power costs for owners and easing demand on the power grid. Thermal storage systems have been around for decades and include various components and methods to store and retrieve pre-cooled medium. PCM storage has been popular in large commercial applications located in regions with high peak (day time) utility energy costs and a much lower off-peak (night time) cost. Microencapsulated phase change slurry is dispersion where the phase change material, microencapsulated by a polymeric capsule, is dispersed in water. Compared to water, these new fluids have a higher heat capacity during phase change and a possible enhancement, as a result of this phase change, in the heat transfer phenomenon. The composition of phase change material used in slurry greatly affects its efficiency, If not selected properly it can cause serious damage, e.g. agglomeration and clogging of pipes. Current available systems use microencapsulated phase change slurry with heat exchangers. The objective of this project is to design and fabricate a shell- tube, phase change material (PCM) based heat exchanger, which can act as a thermal energy storage device, to increase the energy efficiency and hence can be incorporated in data center cooling.

Handbook of Research on Food Processing and Preservation Technologies
Handbook of Research on Food Processing and Preservation Technologies

Author: Preeti Birwal

Publisher: CRC Press

Published: 2021-11-25

Total Pages: 324

ISBN-13: 1000369625

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In this volume, several new food processing and preservation technologies have been investigated by researchers that have the potential to increase shelf life and preserve the quality of foods. This handbook introduces some emerging techniques in the food processing sector, focusing on nonthermal techniques such as high-pressure processing, ultrasonication of foods, microwave vacuum dehydration, thermoelectric refrigeration technology, advanced methods of encapsulation, ozonation, electrospinning, and mechanical expellers for dairy, food, and agricultural processing. These all have a wide range of application. The volume includes studies that show the successful application of these new technologies on a large number of juices, cheeses, yogurts, soups, egg whites and eggs, vegetable slices, purees, and milk, and the extraction, drying enhancement, and modification of enzymes are reported. This volume, part of the multi-volume Handbook of Research on Food Processing and Preservation Technologies will have tremendous application in different areas of the food industry, including food processing, preservation, safety, and quality evaluation. Other volumes of this handbook cover a wide of other emerging technologies. Handbook of Research on Food Processing and Preservation Technologies: Volume 2: Nonthermal Food Preservation and Novel Processing Strategies is an excellent reference resource for researchers, scientists, faculty and students, growers, traders, processors, industries, and others for looking for new nonthermal approaches for food processing and preservation.

Handbook of Research on Food Processing and Preservation Technologies
Handbook of Research on Food Processing and Preservation Technologies

Author: Megh R. Goyal

Publisher: CRC Press

Published: 2022-02-28

Total Pages: 1702

ISBN-13: 1000405117

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The Handbook of Research on Food Processing and Preservation Technologies is a 5-volume collection that highlights various design, development, and applications of novel and innovative strategies for food processing and preservation. Together, the 5 volumes will prove to be valuable resource for researchers, scientists, students, growers, traders, processors, and others in the food processing industry.

An Investigation Into Thermoelectric Coolers
An Investigation Into Thermoelectric Coolers

Author: Eli David Franklin

Publisher:

Published: 2018

Total Pages: 45

ISBN-13:

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A thermoelectric cooler (TEC) is a type of cooler that uses the electricity between the junction of two materials to cause a temperature drop. These coolers operate using the Peltier effect. Effectively, a TEC uses electrical energy to pump heat from one area to another. An understanding of the science of how TECs operate as well as their design will be investigated and finally, a unique design for a TEC with a high efficiency is presented. Current TECs do not operate at high efficiency and cannot generate as much cooling as desired. This report creates a design of a high efficiency cooler that operates at a high coefficient of performance. The design will also include phase change material that will differentiate it from its competition and allow for superior cooling and efficiency. The design will also feature vacuum-sealed chambers that will provide very good insulation and allow for optimal cooling for long periods. This report presents a thermal model of a TEC that will investigate the different thermal systems acting on the cooler and provide a better understanding of the cooler at equilibrium once it reaches its coolest position. A unique heat sink is designed to optimally dissipate the heat that is removed by the TECs. The model can also examine the variables that affect the thermal system that are controllable in the design of the cooler. Given the new design, the cooler in this report was able to cool up 14 cans of soda from 25°C to 12°C in approximately 86 minutes given a constant 12 V power supply. The theoretical analysis concludes that this design is sufficient at creating a cooler with a high efficiency that can cool to the desired low temperature.