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.

scholarly journals Análisis de la generación de las irreversibilidades a partir del Coeficiente de Operación en un sistema de refrigeración por compresión mecánica de vapor con R-134a

2019 ◽  
pp. 10-15
Author(s):  
Carlos Rangel-Romero ◽  
Juan Carlos Rojas-Garnica ◽  
Guillermo Flores-Martínez ◽  
Antonio Barcelata-Pinzón
Keyword(s):  
Vapor Compression ◽  
Refrigeration System ◽  
Pressure Drops ◽  
Liquid Line ◽  
Expansion Valve ◽  
Individual Contributions ◽  
Suction Line ◽  
Vapor Compression Refrigeration ◽  
R 134A ◽  
Mathematical Process

This paper presents the development of individual contributions, in the generation of irreversibilities, of a refrigeration system based on the Coefficient of Operation (COP). The generation of irreversibilities has been widely analyzed using the principles of the first and second laws of thermodynamics. This analysis uses the parameters of enthalpy, entropy as well as the temperature and heat generated in each component. The method proposed in this work improves the accuracy of the calculations due to the use of the COP in the mathematical process, which includes the processes of heat transfer and pressure drops developed in the evaporator, suction line, compressor, discharge line, condenser, liquid line and expansion valve of the mechanical vapor compression refrigeration system. The mathematical analyzes and the experimental results are shown, with these it is concluded that the exposed procedure is closer to the real conditions than those traditional procedures found in the text books.

Influence of Cryogenic Treatment on TiC Nanopowder in R600a and R290 Refrigerant Used in Vapor Compression Refrigeration System

2019 ◽  
Vol 27 (04) ◽  
pp. 1950040
Author(s):  
D. Senthilkumar
Keyword(s):  
Energy Consumption ◽  
Cryogenic Treatment ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Vapor Compression Refrigeration

This paper studies the performance of vapor compression refrigeration system using hydrocarbon refrigerant (HCR) mixture (R600a and R290), hydrocarbon nanorefrigerant mixture (R600a and R290/TiC) and cryogenically treated hydrocarbon nanorefrigerant mixture (R600a and R290/Cryo TiC). The COP of HCR (R600a and R290) system is 1.2960, whereas, COP of R600a and R290/TiC nanorefrigerant system is 1.5223. The TiC nanopowder is cryogenically treated at [Formula: see text]C for 24[Formula: see text]h. The treated TiC is dispersed in HCR mixture. Hence, the COP of R600a and R290- Cryo TiC system is further increased to 1.5801. The energy consumption of R600a and R290-TiC is reduced by 10.3% when compared with HCR. Further, it is reduced by 12.69% with respect to cryogenically treated refrigerant (R600a and R290/Cryo TiC) system. The COP is enhanced due to deep cryogenic of TiC nanopowder.

Optimization of Refrigeration Systems for High-Heat-Flux Microelectronics

2008 ◽  
Author(s):  
P. E. Phelan ◽  
Y. Gupta ◽  
H. Tyagi ◽  
R. Prasher ◽  
J. Cattano ◽  
...  
Keyword(s):  
Heat Flux ◽  
Energy Consumption ◽  
System Design ◽  
High Heat ◽  
Heat Fluxes ◽  
Operating Conditions ◽  
High Heat Flux ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Compressor Inlet

Increasingly, military and civilian applications of electronics require extremely high heat fluxes, on the order of 1000 W/cm2. Thermal management solutions for these severe operating conditions are subject to a number of constraints, including energy consumption, controllability, and the volume or size of the package. Calculations indicate that the only possible approach to meeting this heat flux condition, while maintaining the chip temperature below 50 °C, is to utilize refrigeration. Here we report an initial optimization of the refrigeration system design. Because the outlet quality of the fluid leaving the evaporator must be held to approximately less than 20%, in order to avoid reaching critical heat flux, the refrigeration system design is dramatically different from typical configurations for household applications. In short, a simple vapor-compression cycle will require excessive energy consumption, largely because of the superheat required to return the refrigerant to its vapor state before the compressor inlet. A better design is determined to be a “two-loop” cycle, in which the vapor-compression loop is coupled thermally to a primary loop that directly cools the high-heat-flux chip.

Influence of Silicon Carbide Nanopowder in R134a Refrigerant Used in Vapor Compression Refrigeration System

2017 ◽  
Vol 25 (01) ◽  
pp. 1750007 ◽  
Author(s):  
D. Senthilkumar
Keyword(s):  
Silicon Carbide ◽  
Energy Consumption ◽  
Mass Fraction ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Performance Study ◽  
Sic Nanoparticles ◽  
Vapor Compression Refrigeration

This paper deals with the influence of silicon carbide (SiC) nanopowder in R134 a refrigerant used in a vapor compression refrigeration system. The performance study was done by mixing a SiC nanopowder in R134a refrigerant. The energy consumption of the R134a refrigerant with SiC nanoparticles mixture saves 20% energy with 0.25% mass fraction of SiC nanoparticles when compared to the R134a system. The COP of the refrigerant R134a system is 1.24 whereas COP for R134a-SiC nanopowder is 1.81. The SiC nanopowder is cryogenically treated at [Formula: see text]C for 24 h and the COP is found out. The results show that the COP of R134a-SiC nanopowder and R134a-cryo SiC (cryogenically treated silicon carbide nanopowder) is increased when compared to the R134a conventional refrigeration system.

Dynamic Model of Compression Refrigeration System with a High Pressure Receiver

2011 ◽  
Vol 130-134 ◽  
pp. 575-579
Author(s):  
Wen Peng Zhai ◽  
Ai Guo Wu ◽  
Yu Wen You
Keyword(s):  
Optimal Control ◽  
Energy Efficiency ◽  
High Pressure ◽  
Energy Consumption ◽  
Dynamic Model ◽  
Control Design ◽  
Building Energy ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Part Load

Vapor compression chiller, the largest proportion of building energy consumption as the design and running characteristics, work at part load for most of the time. To improve the energy efficiency at part load, this thesis details some efforts to develop a dynamic model of a vapor compressor system suitable for optimal control design purpose. It present the model of high pressure liquid receiver which is important for the mass balance of the whole system and make sure it operated in a set-point designed. Additional experiments were also performed to verify the precision of the model.

scholarly journals Methodology for determining of the main characteristics of a refrigeration system with condensation heat removal by radiative cooling

2021 ◽  
pp. 34-41
Author(s):  
A. P. Tsoy ◽  
A. S. Granovskiy ◽  
R. A. Jamasheva
Keyword(s):  
Energy Consumption ◽  
Heat Removal ◽  
Radiative Cooling ◽  
Condensation Temperature ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Daily Energy ◽  
Vapor Compression Refrigeration ◽  
The City ◽  
Refrigeration Machine

To reduce the condensation pressure of the refrigerant in the summer, refrigeration system has been developed, in which, during periods of high air temperature, the heat of condensation is removed to the coolant, which was pre-cooled at night due to radiative cooling. A methodology has been developed for determining the main characteristics of the elements of the proposed system and calculating its daily energy consumption. The calculation shows that the proposed system with a nominal refrigerating capacity of 10 kW, using the R404a refrigerant, allows in the climate of the city of Shymkent to reduce the condensation temperature to +32.9°C, and daily energy consumption by 6.5% compared to an ordinary vapor compression refrigeration machine.

scholarly journals Parametric Optimization of a Two Stage Vapor Compression Refrigeration System by Comparative Evolutionary Techniques

2021 ◽  
Vol 287 ◽  
pp. 03002
Author(s):  
Shuhaimi Mahadzir ◽  
Rasel Ahmed
Keyword(s):  
Energy Consumption ◽  
Computation Time ◽  
Vital Role ◽  
Computational Effort ◽  
Coefficient Of Performance ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Total Energy Consumption ◽  
Two Stage ◽  
Vapor Compression Refrigeration

Multistage refrigeration system plays a vital role in industrial refrigeration for the chemical, petrochemical, pharmaceuticals and food industries. Modern chemical industries are complex, and the problems are commonly multi-dimensional, non-linear and time-consuming. This study presents the application of evolutionary computation techniques, namely PSO (particle swarm optimization), GA (Genetic Algorithm) and SA (Simulated Annealing) to solve a design problem of a two-stage vapor compression refrigeration system. Two objectives are evaluated, namely the minimization of total energy consumption and maximization of the coefficient of performance (COP) of the system. The basis of design for the two-stage refrigeration system is built from and validated against data from published literature. The mass flow ratio, evaporator and condenser temperature, parameters for subcooling and desuperheating, and the coefficient of performance for the basis of design show acceptable results. The errors are below 5% against the data from published literature, which are within errors of significant figures in the calculations. In this work, the optimum solutions show a reduction of the required amount of energy consumption by 30.8% and an increase of the COP by nearly 77% with respect to the basis of design. Further improvements are made to the optimization procedures to prevent early convergence and to increase the search efficiency for finding the global optima. The findings by PSO, GA and SA are in agreement, and all evolutionary techniques achieved proper convergence of the two objective functions. It is also found that PSO requires lower computational effort, less computation time and is also easier to implement compared to GA and SA.

A DROP-IN ANALYSIS OF THE PERFORMANCE OF R-22 WITH R-134A FOR A DOSMETIC VAPOR COMPRESSION REFRIGERATION SYSTEM

2019 ◽  
Author(s):  
Lucas Silva ◽  
JOÃO PEDRO ◽  
Ewerton Augusto Sousa Nogueira ◽  
José Felipe Dias ◽  
Sabrina Nogueira Rabelo
Keyword(s):  
Vapor Compression ◽  
Refrigeration System ◽  
Vapor Compression Refrigeration ◽  
R 134A

Experimental Investigation of Vapor Compression Refrigeration System Performance Using Nano-Refrigerant

2014 ◽  
Vol 2 (2) ◽  
pp. 12-27
Author(s):  
Ahmed J. Hamad
Keyword(s):  
Experimental Investigation ◽  
System Performance ◽  
Cuo Nanoparticles ◽  
Working Fluid ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Test Rig ◽  
Vapor Compression Refrigeration ◽  
R 134A ◽  
Thermo Physical Properties

     Experimental investigation of vapor compression refrigeration system performance using Nano-refrigerant is presented in this work. Nano-refrigerant was prepared in current work by mixing 50 nanometers diameter of copper oxide CuO nanoparticles with Polyolester lubrication oil and added to the compressor of the refrigeration system to be mixed with pure refrigerant R-134a during its circulation through refrigeration system. Three concentrations (0.1%, 0.25%, and 0.4%) of CuO-R134 a Nano-refrigerant are used to study the performance of the refrigeration system test rig and to investigate the effect of using Nano-refrigerant as a working fluid compared with pure refrigerant R-134a. The results showed that, the increasing in concentration of CuO nanoparticles in the Nano-refrigerant will significantly enhance the performance of the refrigeration system, as adding nanoparticles will increase the thermal conductivity, heat transfer and improve the thermo-physical properties of Nano-refrigerant. Investigation of performance parameters for refrigeration system using Nano-refrigerant with 0.4% concentration compared with that for pure refrigerant R-134a shows that, Nano-refrigerant has reflect higher performance in range of 10% and 1.5% increase in COP and refrigeration effect respectively and 7% reduction in power consumption for refrigeration system. It can be concluded that, Nano-refrigerants can be efficiently and economically feasible to be used in the vapor compression refrigeration systems.

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