scholarly journals Use of Magnetocaloric Material for Magnetic Refrigeration System: A Review

2019 ◽  
Vol 16 (3) ◽  
pp. 209-224
Author(s):  
I. A. Abdel-Latif ◽  
Mahrous R. Ahmed
Keyword(s):  
Materials Science ◽  
Cooling System ◽  
Global Climate ◽  
Environmentally Friendly ◽  
Magnetic Refrigeration ◽  
Cooling Efficiency ◽  
Cooling Systems ◽  
Magnetic Refrigerator ◽  
System A ◽  
Alternative Materials

Our daily need to cooling system is grown up. The used cooling systems are the source of the harmful changes in the global climate. And so, we need to search a new alternate cooling systems applying environmentally friendly technology that may help in decreasing the pollutions in our world. The progress in materials science allows to use some materials for cooling purposes. This new class of materials is so called "magnetic refrigerator". The basics of magnetic refrigeration depends on the magneto-caloric properties to reach low temperatures and obtain cooling system. The advantage of magnetic refrigerator (MR); First, the cooling efficiency is higher than conventional vapor refrigerator CVM where its cooling efficiency ~30-60% while the cooling efficiency in CVM ~ 5-10%. Second, MR can be more compactly built. Third, it is safe and an environmentally friendly cooling. In this work, we will highlight on the scientific efforts to find optimum properties to be applied as the magnetic refrigeration. In this review the highlights of the scientific efforts to seek for the best alternative materials to be used as a magnetic refrigeration applications. The low coast and small size of magnetic cooling is one the important advantage. This review consists of five sections; I. Introduction, II.Synthesis of MC materials, III. Crystal structure of MC materials and IV. Characterization and applications of MC materials, and V. Conclusions.

scholarly journals Solar-driven Refrigerator for off-grid Regions

2019 ◽  
Vol 103 ◽  
pp. 01001
Author(s):  
Jakub Kuś ◽  
Kyrylo Rudykh ◽  
Marcin Kobas ◽  
Maciej Żołądek ◽  
Szymon Sendłak ◽  
...  
Keyword(s):  
Cooling System ◽  
Electrical Power ◽  
African Countries ◽  
Cooling Systems ◽  
System A ◽  
Absorption Cooling ◽  
Pv Modules ◽  
Solar Powered ◽  
Conventional Cooling ◽  
Absorption Cooling System

Refrigeration systems are necessary for people living in hot climates. A majority of tropical and subtropical countries uses electrical power as a source of cooling. During the seasons of high ambient temperature there is a significant cooling load due to increased level of energy consumption. Cooling systems are therefore necessary in African countries in order to keep medications and food in safe conditions. Furthermore, there is a power shortage crisis due to the high demand for cooling. TRNSYS software allows to simulate a complete solar-powered absorption cooling system. A model used in an experiment includes PV modules making it advantageous over a conventional cooling system. PV modules of assumed area are sufficient to maintain the temperature inside cooling device below 6°C over the whole year.

A Review of Cooling Systems in Electric/Hybrid Vehicles

2010 ◽  
Author(s):  
Wamei Lin ◽  
Bengt Sunde´n
Keyword(s):  
Power Efficiency ◽  
Cooling System ◽  
High Energy ◽  
Hybrid Vehicles ◽  
Electronic Equipment ◽  
Great Promise ◽  
Cooling Systems ◽  
System A ◽  
Green Power ◽  
Motor Cooling

Due to increasing oil demand and serious global warming, a green power generation system is urgently requested in transportation. Electric/hybrid vehicles (EV/HEV) have been considered as a potential solution with great promise in achieving high energy/power efficiency and a low environmental impact. The important electric and electronic equipment in EV/HEV are the battery, inverter and motor. However, because of the high power density in the inverters or the low working temperature of batteries, the cooling problems affect significantly the working performance or the lifetime of electric and electronic equipment in EV/HEV. This paper views different cooling systems including the battery cooling system, inverter cooling system and motor cooling system. A general introduction to the EV/HEV and the electric and electronic equipment working processes are briefly presented at first. Then different methods for the battery cooling system, the inverter cooling system and the motor cooling system are outlined and discussed in this paper. Among other things, the means of using phase change material, or electro-thermal modules are significant for the battery cooling system. Finally, some conclusions or recommendations are presented for the cooling systems, in order to promote the EV/HEV development.

Long axis heat distribution in a tunnel-ventilated broiler house equipped with an evaporative pad cooling system

2009 ◽  
Vol 49 (12) ◽  
pp. 1125 ◽  
Author(s):  
M. Dağtekin ◽  
C. Karaca ◽  
Y. Yildiz
Keyword(s):  
High Temperatures ◽  
Air Temperature ◽  
Egg Production ◽  
Cooling System ◽  
Heat Distribution ◽  
Exit Point ◽  
Cooling Efficiency ◽  
Cooling Systems ◽  
Southern Turkey ◽  
Broiler House

Chicken meat and egg production in the Çukurova region of Southern Turkey shows enormous potential for growth. However, high temperatures in summer pose serious difficulties for these types of production. Evaporative pad cooling systems have been used to minimise rises in temperature and are commonly used in poultry houses in this region. The change of air temperature from the entry point to the system through the pads, to the exit point of the broiler house was investigated in this study. Experiments were carried out in a tunnel-ventilated broiler house in the Çukurova region. The broiler house has the capacity to house 15 000 chicks with a floor area of 70 by 12 m. In this experiment, the broiler house incorporated 15-cm-thick cellulose-based pads. Results obtained in August–September 2007 revealed a cooling efficiency of 69.35%, a 5.19°C decrease from the outside air temperature after passing through the pads, and a 1.52°C increase in air temperature at the exit point, which was located at the end of the broiler house.

scholarly journals Efficiency of cooling systems in broiler houses during hot days

2021 ◽  
Vol 51 (8) ◽  
Author(s):  
Maurício Portella dos Santos ◽  
Matheus Deniz ◽  
Karolini Tenffen de Sousa ◽  
Daniela Regina Klein ◽  
Tatiane Branco ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Spatial Distribution ◽  
Environmental Variables ◽  
Cooling System ◽  
Ventilation System ◽  
Cooling Efficiency ◽  
Cooling Systems ◽  
Hot Days ◽  
Evaporative Cooling System ◽  
Broiler House

ABSTRACT: This study evaluated: (1) the vulnerability of broiler houses with different cooling systems, and (2) the spatial distribution of environmental variables during hot days. Four potentially vulnerable commercial broiler houses in southern Brazil were selected according to the following parameters: absence or presence of different cooling systems, broilers older than 28 days, and outside air dry-bulb temperature over 30°C. Broiler house vulnerability was classified according to the cooling and mechanical ventilation system: cellulose pad cooling (CPC), sprinkling (SPK), fogging (FOG), and mechanical ventilation without evaporative cooling system (VTL). The air dry-bulb temperature (Tdb, °C) and relative humidity (RH, %) were recorded every 10 min. For each broiler house, we evaluated: (1) relative cooling efficiency (RCE) and (2) inside spatial distribution of microclimate variables using a geostatistical technique. The CPC and SPK did not differ (P<0.05) in RCE (81.6% and 80.7%, respectively), but both differed from FOG (23.8%) and VLT (1.87%) systems. The highest variations in indoor Tdb were recorded in the FOG (7 °C), followed by the SPK (4 °C) and CPC (3 °C). In the CPC, there was an increase in RH from the middle to the end of the broiler house near the exhaust fans. In conclusion, the relative cooling efficiency and the inside spatial distributions of environmental variables in the broiler houses were influenced by the existing cooling system.

scholarly journals Evaporative cooling efficiency of pads consisting of vegetable loofah

2019 ◽  
Vol 10 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Júlio César Ferreira de Melo Júnior ◽  
João Victor Martins Bamberg ◽  
Neiton Silva Machado ◽  
Emanuelly Nadja Gomes Caldas ◽  
Marcos Sales Rodrigues
Keyword(s):  
Cooling System ◽  
Evaporative Cooling ◽  
Cooling Efficiency ◽  
Air Flow Rate ◽  
Direct Evaporative Cooling ◽  
Alternative Materials ◽  
Before And After ◽  
Evaporative Cooling System ◽  
Sources Of Variation ◽  
Adjusted Model

Brazilian agroindustry has presented constant innovations in the use of equipment and materials, among which are those that generate artificial thermal conditioning inside the zootechnical facilities, through a direct evaporative cooling system (DEC). In order to mitigate the effects of high temperatures associated with low air humidity in buildings in the northeastern region of Brazil, the use of DEC systems is evident. Therefore, DEC’s built with evaporative pads constituted of alternative materials, prove to be an interesting and viable alternative. The aim of this work was to evaluate the cooling efficiency of the evaporative pads constituted of vegetable loofah. The experiment was performed at the Campus de Ciências Agrárias, Federal University of the São Francisco Valley (UNIVASF) in Petrolina, Pernambuco state. The experimental design was in randomized blocks, in a 4x4 factorial scheme, with 13 replicates. Air temperature and relative humidity values were collected before and after the passage through the pad for different flow velocities and pad thicknesses, in order to calculate the evaporative efficiency. The variance analysis was significant at 5% probability for the sources of variation of the pad thickness (0.05, 0.075, 0.1 and 0.125 m) and the air flow rate (0.076, 0.264, 0.459 and 0.773 m s-1), and the interactions. The highest efficiency, 57.0% was observed for the interaction between the thickness of 0.125 m and the speed of 0.773 ms-1 as adjusted model.

Assessment of thermal behavior of a cooling system to reduce thermal fatigue cracks in aluminum injection molds

2020 ◽  
pp. 75-86
Author(s):  
Sergio Antonio Camargo ◽  
Lauro Correa Romeiro ◽  
Carlos Alberto Mendes Moraes
Keyword(s):  
Thermal Fatigue ◽  
Cooling System ◽  
Fatigue Cracks ◽  
Cooling Water ◽  
Thermal Conditions ◽  
Thermal Gradients ◽  
Ansys Software ◽  
Cooling Systems ◽  
Thermal Fatigue Cracks ◽  
Number Of Cycles

The present article aimed to test changes in cooling water temperatures of males, present in aluminum injection molds, to reduce failures due to thermal fatigue. In order to carry out this work, cooling systems were studied, including their geometries, thermal gradients and the expected theoretical durability in relation to fatigue failure. The cooling system tests were developed with the aid of simulations in the ANSYS software and with fatigue calculations, using the method of Goodman. The study of the cooling system included its geometries, flow and temperature of this fluid. The results pointed to a significant increase in fatigue life of the mold component for the thermal conditions that were proposed, with a significant increase in the number of cycles, to happen failures due to thermal fatigue.

Characterization of an Isolated Hybrid Cooled Server With Failure Scenarios Using Warm Water Cooling

2017 ◽  
Author(s):  
Uschas Chowdhury ◽  
Manasa Sahini ◽  
Ashwin Siddarth ◽  
Dereje Agonafer ◽  
Steve Branton
Keyword(s):  
Energy Consumption ◽  
Data Centers ◽  
Cooling System ◽  
Warm Water ◽  
Alternative Methods ◽  
Inlet Temperature ◽  
Cooling Efficiency ◽  
Water Cooling ◽  
Liquid Cooling ◽  
Total Energy Consumption

Modern day data centers are operated at high power for increased power density, maintenance, and cooling which covers almost 2 percent (70 billion kilowatt-hours) of the total energy consumption in the US. IT components and cooling system occupy the major portion of this energy consumption. Although data centers are designed to perform efficiently, cooling the high-density components is still a challenge. So, alternative methods to improve the cooling efficiency has become the drive to reduce the cooling cost. As liquid cooling is more efficient for high specific heat capacity, density, and thermal conductivity, hybrid cooling can offer the advantage of liquid cooling of high heat generating components in the traditional air-cooled servers. In this experiment, a 1U server is equipped with cold plate to cool the CPUs while the rest of the components are cooled by fans. In this study, predictive fan and pump failure analysis are performed which also helps to explore the options for redundancy and to reduce the cooling cost by improving cooling efficiency. Redundancy requires the knowledge of planned and unplanned system failures. As the main heat generating components are cooled by liquid, warm water cooling can be employed to observe the effects of raised inlet conditions in a hybrid cooled server with failure scenarios. The ASHRAE guidance class W4 for liquid cooling is chosen for our experiment to operate in a range from 25°C – 45°C. The experiments are conducted separately for the pump and fan failure scenarios. Computational load of idle, 10%, 30%, 50%, 70% and 98% are applied while powering only one pump and the miniature dry cooler fans are controlled externally to maintain constant inlet temperature of the coolant. As the rest of components such as DIMMs & PCH are cooled by air, maximum utilization for memory is applied while reducing the number fans in each case for fan failure scenario. The components temperatures and power consumption are recorded in each case for performance analysis.

Remote Heat Pipe Based Heat Exchanger Performance in Notebook Cooling

2005 ◽  
Author(s):  
Seyyed Khandani ◽  
Himanshu Pokharna ◽  
Sridhar Machiroutu ◽  
Eric DiStefano
Keyword(s):  
Heat Exchanger ◽  
Thermal Resistance ◽  
Heat Pipe ◽  
Cooling System ◽  
Temperature Drop ◽  
Operating Conditions ◽  
Cooling Systems ◽  
Temperature Variations ◽  
Non Linear ◽  
Condenser Temperature

Remote heat pipe based heat exchanger cooling systems are becoming increasingly popular in cooling of notebook computers. In such cooling systems, one or more heat pipes transfer the heat from the more populated area to a location with sufficient space allowing the use of a heat exchanger for removal of the heat from the system. In analsysis of such systems, the temperature drop in the condenser section of the heat pipe is assumed negligible due to the nature of the condensation process. However, in testing of various systems, non linear longitudinal temperature drops in the heat pipe in the range of 2 to 15 °C, for different processor power and heat exchanger airflow, have been measured. Such temperature drops could cause higher condenser thermal resistance and result in lower overall heat exchanger performance. In fact the application of the conventional method of estimating the thermal performance, which does not consider such a nonlinear temperature variations, results in inaccurate design of the cooling system and requires unnecessarily higher safety factors to compensate for this inaccuracy. To address the problem, this paper offers a new analytical approach for modeling the heat pipe based heat exchanger performance under various operating conditions. The method can be used with any arbitrary condenser temperature variations. The results of the model show significant increase in heat exchanger thermal resistance when considering a non linear condenser temperature drop. The experimental data also verifies the result of the model with sufficient accuracy and therefore validates the application of this model in estimating the performance of these systems.   This paper was also originally published as part of the Proceedings of the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems.

Numerical Simulation on the Temperature Characteristics of Indirect Air Cooling System

2015 ◽  
Vol 741 ◽  
pp. 536-540
Author(s):  
Xiao Zhi Qiu ◽  
Yan Ming Zhao ◽  
Bao Hua Huang ◽  
Wei Xu
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Cooling System ◽  
System Change ◽  
Temperature Characteristic ◽  
Air Cooling ◽  
Ansys Software ◽  
System A ◽  
Air Cooling System ◽  
Simulation Results

Based on the analysis of indirect air cooling system, a numerical simulation model of indirect air cooling system was constructed by ANSYS software. According to the different wind speed condition, the temperature characteristic of indirect air cooling system was analyzed. The simulation results show that with the increase of wind speed, the ventilation and heat release of the indirect air cooling system change greatly. It provides a theoretical basis for the design of the wind-proof device of indirect air cooling system.

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