Energetic and exergetic investigation of a novel solar assisted mechanical compression refrigeration system

2017 ◽  
Vol 147 ◽  
pp. 1-18 ◽  
Author(s):  
Evangelos Bellos ◽  
Michalis Gr. Vrachopoulos ◽  
Christos Tzivanidis
Keyword(s):  
Mechanical Compression ◽  
Refrigeration System

scholarly journals FREON COOLING MINISYSTEM USING CIRCULAR MICRO-CHANNELS

2017 ◽  
Vol 20 (2) ◽  
Author(s):  
LILIANA PĂTULEANU ◽  
IOAN-COZMIN MANOLACHE-RUSU ◽  
TIBERIU BURDAN ◽  
FLORIN ANDRONIC ◽  
IVAN RADION
Keyword(s):  
Processing Speed ◽  
Heat Exchangers ◽  
Mechanical Compression ◽  
Refrigeration System ◽  
Electronic Components ◽  
Local Cooling ◽  
New Methods ◽  
Micro Channels ◽  
Nano Channel ◽  
Set Up

<p>The necessity of a higher data processing speed was crucial for the advances in computer science. There were created processors that needed increasingly more power, so that new methods were discovered and more complex systems were created in order to solve the cooling issue. In this paper, there are presented the trials performed on a mini refrigeration plant that used mechanical compression of Freon’s, designed to cool electronic components like microprocessors, microcontrollers, graphic stations, or in the case of local cooling in diverse areas such as bioengineering, optics and nanotechnologies. The refrigeration system was constructed as an experimental set-up and consists of the following: two mini heat exchangers, working both as a condenser and a vaporizer, which are made of circular micro channels, a refrigeration compressor, lamination valve which contains a circular nano channel and a micro filter. The experimental determinations have proven that, although such a system contains a small quantity of Freon, of the order of milligrams, it reaches temperatures of -44 °C.</p>

Advanced Solar-Assisted Cascade Ejector Cooling / CO2 Sub-Critical Mechanical Compression Refrigeration System

2011 ◽  
Author(s):  
V.O. Petrenko ◽  
Chien Te Liu ◽  
Kostyantyn Shestopalov ◽  
Volodymyr Ierin ◽  
Oleksiy Volovyk ◽  
...  
Keyword(s):  
Mechanical Compression ◽  
Refrigeration System

Miniaturized Refrigeration System With Absorption: Application to Microelectronics Cooling

2007 ◽  
Author(s):  
Victor Chiriac ◽  
Florea Chiriac
Keyword(s):  
Printed Circuit Board ◽  
Real Life ◽  
Thermodynamic Cycle ◽  
Ammonia Solution ◽  
Circuit Board ◽  
Small Scale ◽  
Mechanical Compression ◽  
Refrigeration System ◽  
Compact Heat Exchangers ◽  
Component Design

The study develops an analytical model of an optimized small scale refrigeration system using a thermo-chemical compressor, with application to the cooling of the electronic components populating a Printed Circuit Board (PCB) in a High-Power Microelectronics System. This work continues the authors’ previous study of a refrigeration system with mechanical compression and ejector compression [1–3]. However, the present study introduces the thermo-chemical compressor, comprised of an absorber-desorber unit, also known as refrigeration with absorption. This is a viable alternative to the mechanical compression systems, providing an improved feasibility and reliability at smaller scales. The proposed system includes miniaturized refrigeration components, designed to fit smaller scale power electronics, and uses a binary water-ammonia solution, compact heat exchangers with meso-channels and hydrogen as compensation gas in order to eliminate the circulation pump. The efficiency of the system is evaluated and further compared to mechanical compression designs at similar cooling powers. The study also discusses the thermodynamic cycle specifics and provides an extensive analytical evaluation and calculation of each miniaturized component design. The COP of the system is ∼ 0.4 – 0.5. The study is concluded by identifying the pros and cons of implementing such an absorption system to real-life microelectronics applications. The advantages of the optimized refrigeration design are highlighted, establishing a performance vs. size comparison to vapor-compression refrigerators, to serve as the basis for the enhanced cooling of future miniaturized refrigeration applications.

scholarly journals Design of eco-friendly refrigeration system

2019 ◽  
Vol 3 (2) ◽  
pp. 1-11
Author(s):  
Ricardo Fabricio Muñoz Farfán ◽  
Telly Yarita Macías Zambrano ◽  
Víctor Manuel Delgado Sosa ◽  
Vicente Zambrano
Keyword(s):  
Freezing Temperature ◽  
Food Storage ◽  
Freezing Process ◽  
Mechanical Compression ◽  
Refrigeration System ◽  
Air Conditioning System ◽  
Specific Product ◽  
Technological Transfer ◽  
Installed Capacity ◽  
Temperature Interactions

The present study of a freezing system has developed based on an air conditioning system, whose purpose is to take advantage of the technological transfer of cold producing equipment for food storage and conservation uses. The installed capacity of 9000 BTU/Hr was considered for the choice of equipment. We studied the freezing process of fish, water, and the preservation of legumes with a volume of 1 kg per product individually. The freezing temperature has evaluated with a mechanical compression refrigeration system of Gas R22 with temperature interactions of 29.6 ° C to -12 ° C. and monitored with a Proportional Integrative Derivative (PID) controller. For production cost, the equipment was mostly made of its parts and pieces with recycling material. A descriptive experimental design has carried out, for the verification of results. The equipment managed to reach chamber temperatures of -13 ° C from 20 minutes once the equipment (compressor) has turned on under specific product descriptions.

scholarly journals CO2 Transcritical Refrigeration Cycle with Dedicated Subcooling: Mechanical Compression vs. Absorption Chiller

2019 ◽  
Vol 9 (8) ◽  
pp. 1605 ◽  
Author(s):  
Evangelos Bellos ◽  
Christos Tzivanidis
Keyword(s):  
Small Difference ◽  
Electricity Consumption ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Mechanical Compression ◽  
Refrigeration System ◽  
Absorption Chiller ◽  
Vapor Compression Refrigeration ◽  
Temperature And Pressure ◽  
Exergy Performance

The objective of this paper is the comparison of two dedicated subcooling methods, after the gas cooler, in a CO2 transcritical refrigeration system. The use of vapor compression refrigeration with R134a for subcooling is the first method, and the second is the use of an absorption chiller that operates with a LiBr-H2O working pair. The examined systems are compared energetically and exegetically with the reference transcritical CO2 refrigeration cycle without subcooling. The analysis is conducted for different operating scenarios and in every case, the system is optimized by selecting the proper temperature and pressure levels. The analysis is performed with a developed and validated model in Engineering Equation Solver. According to the final results, the use of the absorption chiller is able to decrease the system electricity consumption by about 54% compared to the simple transcritical cycle, while the decrease with the mechanical subcooling is 41%. Both systems with dedicated subcooling are found to have an important increase in the system exergy performance compared to the simple transcritical cycle. However, the system with the mechanical subcooling is found to be the best choice exegetically, with a small difference from the system with the absorption chiller.

scholarly journals Investigation on the Performance of a Solar Hybrid Refrigeration System Using Environmentally Friendly Fluids

2020 ◽  
Vol 38 (4) ◽  
pp. 960-966
Author(s):  
Latra Boumaraf ◽  
Rachedi Khadraoui
Keyword(s):  
Cooling Capacity ◽  
Operating Conditions ◽  
Mechanical Compression ◽  
Refrigeration System ◽  
Perfect Gas ◽  
Entrainment Ratio ◽  
Medium Temperature ◽  
D Model ◽  
Constant Section ◽  
Solar Refrigeration

In order to evaluate the performance of a hybrid compression / ejection refrigeration system using solar energy at low or medium temperature, a simulation model of its behavior based on those of its various components has been developed. It includes in particular for the ejector, a 1-D model of the "constant section mixing" type developed in optimal transition regime. The refrigerants tested are steam for the ejector loop and the R1234yf (replacing the R134a) for the mechanical compression loop. The behavior of the H2O vapor flowing in the ejector is considered that of the perfect gas. The properties of refrigerants are calculated using REFPROP® software, everywhere else. For a cooling capacity of 10 kW and air conditioning operating conditions, the model allows to determine the main parameters of the ejector and its entrainment ratio, the thermal and mechanical COP of the whole refrigeration system as well as the necessary surface of the solar collector. Furthermore, the influence of the temperature of the boiler, the condenser, the intercooler as well as that of the evaporator on the mechanical COP of the hybrid system and the solar collection surface in particular, were examined. The results highlight that the solar refrigeration system with hybrid cycle compression/ejection using the refrigerants H2O/R1234yf allows an increase of the mechanical COP higher than 50% compared to that of the conventional refrigeration system and thus constitutes an acceptable ecologically system that can compete with the latter.

scholarly journals Análisis de las irreversibilidades en un proceso de paro y arranque en un sistema de refrigeración con R-134a

2020 ◽  
pp. 1-6
Author(s):  
Carlos Rangel-Romero ◽  
Juan Carlos Rojas-Garnica ◽  
Guillermo Flores-Martíne ◽  
Antonio Barcelata-Pinzón
Keyword(s):  
Energy Consumption ◽  
Process Evaluation ◽  
Vapor Compression ◽  
Mechanical Compression ◽  
Refrigeration System ◽  
Laws Of Thermodynamics ◽  
Expansion Valve ◽  
R 134A

In this work, an evaluation of the energy in a start-stop process is made by analyzing the generated irreversibilities in a refrigeration system by mechanical vapor compression with R-134a refrigerant at a flow of 1.0 L / s. This system is installed in the LABINTHAP of the SEPI-ESIME-IPN. For this analysis, there is software that captures data on the pressures and temperatures from the refrigerant at the inlet and outlet of the evaporator, compressor, condenser, and expansion valve at oneminute intervals. For the analysis of the generated irreversibilities, the first and second laws of thermodynamics were used. And, in the process evaluation of stopping and starting, it was shown that the compressor sets a trend of higher energy consumption, so a process of regulation of the refrigeration system by mechanical compression of steam is proposed.

The Miniaturization of a Refrigeration Vapor Compression System and Application to the Cooling of High Power Microelectronics

2006 ◽  
Author(s):  
Victor Chiriac ◽  
Florin Chiriac
Keyword(s):  
High Power ◽  
Cooling System ◽  
Real Life ◽  
System Level ◽  
Small Scale ◽  
Vapor Compression ◽  
Mechanical Compression ◽  
Refrigeration System ◽  
Compression System ◽  
Vapor Compression System

The study develops an analytical model of an optimized small scale refrigeration system using ejector vapor compression, with application to the cooling of the electronic components populating a Printed Circuit Board (PCB) in a High-Power Microelectronics System. The authors' previous studies [1 - 3] evaluated a vapor compression system using an off-the-shelf mechanical compressor and associated components, focusing mainly on the thermal feasibility of the mechanical refrigeration system and on-chip system-level incorporation. Present investigation focuses on the miniaturization of the various components of the vapor compression system (targeting the alternative ejector vapor compressor), with the intent to establish a cooling system for high power microelectronics, designed to fit smaller packages populating PCB, yet using a different approach for the vapor compression process. The previous study [1] evaluated several optimized evaporator designs for the mechanical compression system. The current design with miniaturized ejector is evaluated to address similar power dissipation ranges as before. In the final section of the study, the efficiency of the proposed ejector vapor compression system is compared to mechanical compression designs at same cooling powers. It is the intent of the authors to present an alternative vapor compression system and identify the pros and cons of implementing such a system to real-life microelectronics applications.

Optimum Choice of Refrigerant for Miniature Vapour Compression Refrigeration System

2011 ◽  
Vol 3 (3) ◽  
pp. 134-136
Author(s):  
M. M. Tayde M. M. Tayde ◽  
◽  
Pranav Datar ◽  
Pankaj kumar ◽  
Dr. L. B. Bhuyar Dr. L. B. Bhuyar
Keyword(s):  
Refrigeration System ◽  
Optimum Choice ◽  
Vapour Compression
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