Energetic, Exergetic, Environmental, and Economic Assessment of a Cascade Refrigeration System Operating with Four Different Ecological Refrigerant Pairs

2021 ◽  
pp. 2150025
Author(s):  
Cleison Henrique de Paula ◽  
Willian Moreira Duarte ◽  
Thiago Torres Martins Rocha ◽  
Raphael Nunes de Oliveira ◽  
Antônio Augusto Torres Maia
Keyword(s):  
Coefficient Of Performance ◽  
Maintenance Cost ◽  
Temperature Cycle ◽  
Refrigeration System ◽  
Cascade System ◽  
Cost Rate ◽  
Total Plant ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration ◽  
System Operating

In this work, a cascade refrigeration system operating with four different ecological refrigerant pairs was modeled. This system uses R744 (Carbon dioxide) in the low-temperature cycle and operates with R290 (propane), R1234yf (2,3,3,3-tetrafluoropropene), R152a (1,1-difluorethane), and R717 (ammonia) in the high-temperature cycle. Energetic, exergetic, environmental, and economic performance of the cascade system was investigated to determine the most appropriate ecological refrigerant couple. The parameters used in each mentioned performance were COP (Coefficient of Performance), [Formula: see text] (Exergy Efficiency), TEWI (Total Equivalent Warming Impact), ECOP (Ecological coefficient of performance), and [Formula: see text] (Total plant cost rate), respectively. The results showed that the cascade refrigeration system operating with R744/R717 provided the best performance for the thermodynamic conditions analyzed, presenting a COP of 2.10, [Formula: see text] of 56.9%, [Formula: see text] of 24 334 USD/year, ECOP of 4.86, and TEWI of 25.67 tons of CO2. Finally, evaluating the total plant cost rate of this cascade system, it was noted that the capital and maintenance cost rate [Formula: see text] corresponds to 89.1% of the [Formula: see text] value, the operational cost rate [Formula: see text] corresponds to 10.27% of the [Formula: see text] value and the environmental cost rate [Formula: see text] corresponds to 0.63% of [Formula: see text].

SIMULATION OF A LOW TEMPERATURE EVAPORATOR IN A CASCADE REFRIGERATION SYSTEM

2011 ◽  
Vol 19 (03) ◽  
pp. 203-212 ◽  
Author(s):  
DUSHYANTHA GUNAWARDANE ◽  
PRADEEP BANSAL
Keyword(s):  
Low Temperature ◽  
Cross Flow ◽  
Finned Tube ◽  
Temperature Cycle ◽  
Refrigeration System ◽  
Mass Flow Rates ◽  
Cascade Refrigeration System ◽  
Refrigeration Capacity ◽  
Cascade Refrigeration ◽  
System Operating

This paper presents a mathematical model for the evaporator of a cascade refrigeration system, operating down to -40°C. The system uses Carbon dioxide (R744) and Propylene (R1270), respectively, as the low temperature and high temperature cycle refrigerant. The model is developed in Engineering Equation Solver software package following the elemental Number of Transfer Units-effectiveness method, where frost has not been considered. The evaporator is a cross-flow finned tube serpentine heat exchanger, which was divided into numerous elements along the flow path of the refrigerant. The inputs to the model include inlet temperatures and mass flow rates of both the streams along with the heat flux, while the main outputs are the outlet temperatures, refrigeration capacity and HX effectiveness. The model is found to underpredict the refrigeration capacity by about 10% when compared with experimental data.

scholarly journals Experimental Analysis of the R744/R404A Cascade Refrigeration System with Internal Heat Exchanger. Part 1: Coefficient of Performance Characteristics

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 6003
Author(s):  
Min-Ju Jeon
Keyword(s):  
High Temperature ◽  
Experimental Studies ◽  
Internal Heat ◽  
Coefficient Of Performance ◽  
Temperature Cycle ◽  
Refrigeration System ◽  
Evaporation Temperature ◽  
Internal Heat Exchanger ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration

This study evaluates the performance of an R744/R404A cascade refrigeration system (CRS) with internal heat exchangers (IHE) in supermarkets. R744 is used as the refrigerant in a low-temperature cycle, and R404A is used as the refrigerant in a high-temperature cycle. In previous studies, there are many studies including theoretical performance analysis of the CRS. However, experimental studies on the CRS are lacking, and experimental research on the R744/R404A system with an IHE is scarce. Therefore, this study provides basic data for optimal refrigeration system design by experimentally evaluating the results of modifying various parameters. The operating parameters considered in this study include subcooling and superheating, condensing and evaporating temperature, cascade evaporation temperature, and IHE efficiency in the R744 low- and R404A high-temperature cycle. The main results are summarized as follows: (1) By applying the results of this study, energy efficiency is achieved by optimizing the overall coefficient of performance (COP) of the CRS, and the refrigerant charge of the R404A cycle is minimized and economic efficiency is also obtained, enabling operation and maintenance as an environment-friendly system. (2) When designing the CRS, finding the cascade evaporation temperature that has the optimum and maximum COP according to the refrigerant combination should be considered with the highest priority.

scholarly journals Heat Exchanger Network Synthesis Integrated with Compression–Absorption Cascade Refrigeration System

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 210 ◽  
Author(s):  
Xiaojing Sun ◽  
Linlin Liu ◽  
Yu Zhuang ◽  
Lei Zhang ◽  
Jian Du
Keyword(s):  
Heat Exchanger ◽  
Waste Heat ◽  
Coefficient Of Performance ◽  
Mixed Integer ◽  
Total Annual Cost ◽  
Network Synthesis ◽  
Refrigeration System ◽  
Operating Condition ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration

Compression–absorption cascade refrigeration system (CACRS) is the extension of absorption refrigeration system, which can be utilized to recover excess heat of heat exchanger networks (HENs) and compensate refrigeration demand. In this work, a stage-wise superstructure is presented to integrate the generation and evaporation processes of CACRS within HEN, where the generator is driven by hot process streams, and the evaporation processes provide cooling energy to HEN. Considering that the operating condition of CACRS has significant effect on the coefficient of performance (COP) of CACRS and so do the structure of HEN, CACRS and HEN are considered as a whole system in this study, where the operating condition and performance of CACRS and the structure of HEN are optimized simultaneously. The quantitative relationship between COP and operating variables of CACRS is determined by process simulation and data fitting. To accomplish the optimal design purpose, a mixed integer non-linear programming (MINLP) model is formulated according to the proposed superstructure, with the objective of minimizing total annual cost (TAC). At last, two case studies are presented to demonstrate that desired HEN can be achieved by applying the proposed method, and the results show that the integrated HEN-CACRS system is capable to utilize energy reasonably and reduce the total annualized cost by 38.6% and 37.9% respectively since it could recover waste heat from hot process stream to produce the cooling energy required by the system.

scholarly journals COP enhancement of vapour compression refrigeration system using dedicated mechanical subcooling cycle

2020 ◽  
Vol 39 (3) ◽  
pp. 776-784
Author(s):  
T.S. Mogaji ◽  
A. Awolala ◽  
O.Z. Ayodeji ◽  
P.B. Mogaji ◽  
D.E. Philip
Keyword(s):  
System Performance ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Condensation Temperature ◽  
Refrigeration System ◽  
Wide Range ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration ◽  
Vapour Compression ◽  
Better Than

This study focused on development of an improved vapour compression refrigeration system (IVCR system). Dedicated mechanical subcooling cycle is employed in attaining the developed IVCR system. The system is composed of two cycles cascade refrigeration system working with R134a. It consists of a rectangular shape with total storage space of 0.582 m3, made of galvanized mild steel and internally insulated with 0.05 m polystyrene foam. Tests under a wide range operating temperature conditions were carried out on the developed IVCR system. Performance evaluation of the system was characterized in terms of cooling capacity and coefficient of performance (COP). Experimental results showed that the COP of the subcooled system improved better than that of the main system from 18.0% to about 33.5% over an evaporating temperature range of -10 to 30oC. It can be concluded that the use of dedicated sub cooling cycle in VCR system is more efficient and suitable for the betterment of thermal system performance. Keywords: Vapour compression Refrigeration system, Coefficient of performance, dedicated subcooled system, Condensation temperature, Evaporation temperature.

scholarly journals CASCADE REFRIGERATION SYSTEM FOR LOW TEMPERATURES USING NATURAL FLUIDS

2021 ◽  
Vol 20 (2) ◽  
pp. 20
Author(s):  
V. B. Rangel ◽  
A. G. S. Almeida
Keyword(s):  
Low Temperatures ◽  
Refrigeration Cycle ◽  
Refrigeration System ◽  
Cascade System ◽  
Energy And Exergy ◽  
Laws Of Thermodynamics ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration ◽  
Natural Refrigerant ◽  
Exergy Analyses

Cascade refrigeration systems work with two or more serial disposed cycles and can obtain internal temperatures below -60°C, which is necessary for several activities in medicine and scientific research. This paper presents a thermodynamic analysis of cascade system refrigeration using natural refrigerant fluids for ultra-low temperatures. These fluids are environmentally friendly refrigerant and are an alternative to hydro chlorofluorocarbons (HCFCs) and to hydrofluorocarbons (HFCs). Energy and exergy analyses were performed using a thermodynamic model based on the law of conservation of mass and also on the first and second laws of thermodynamics. A simulator was developed to assess the technical practicability of this system, considering it running as a real refrigeration cycle. Natural fluids have best performance energetically and environmentally.

APPLICATION OF CASCADE REFRIGERATION SYSTEM WITH MIXING REFRIGERANT IN COLD AIR CUTTING

2005 ◽  
Vol 19 (01n03) ◽  
pp. 521-523
Author(s):  
Y. YANG ◽  
M. W. TONG ◽  
G. YANG ◽  
X. P. WANG
Keyword(s):  
High Efficiency ◽  
Cutting Process ◽  
Refrigeration System ◽  
Cascade System ◽  
Cold Air ◽  
High Efficient ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration ◽  
Mechanical Cutting ◽  
Optimal Mixing

In the mechanical cutting process, the replacement of traditional cutting solution with cold air can avoid the pollution of environment. In order to high efficient the refrigerating device and flexible adjust the temperature of cold air, it is necessary to use cascade refrigeration system to supply cool quantity for the compressed air. The introduction of a two-component non-azeotropic mixing refrigerant into the cryogenic part of the cascade system, can effectively solve the problems of the system working at too high pressure and the volume expanding of refrigerant in case of the cascade refrigeration sets closed down. However, the filling ratio of mixing refrigerants impact on the relationships among the closing down pressure, refrigerating output and refrigerating efficiency. On the basis of computing and experiment, the optimal mixing ratio of refrigerant R22/R13 and a low temperature of -60° were obtained in this study. A cold air injecting device possessing high efficiency in energy saving has also been designed and manufactured. The cold air, generated from this cascade system and employed in a cutting process, takes good comprehensive effects on machining and cutting.

scholarly journals OPTIMIZATION OF CASCADE REFRIGERATION SYSTEM TO ACHIEVE LOWER TEMPERATURES

2020 ◽  
Vol 5 (8) ◽  
Author(s):  
Andrew Raphael Santos Conceição Mendonça ◽  
Francisco Souza Almeida ◽  
Luiz Gustavo Da Cruz Duarte ◽  
Antonio Gabriel Souza Almeida
Keyword(s):  
Thermal Efficiency ◽  
Low Temperatures ◽  
Refrigeration System ◽  
Cascade System ◽  
Theoretical Predictions ◽  
Cascade Refrigeration System ◽  
Mechanical Components ◽  
Cascade Refrigeration ◽  
The Impact ◽  
Made In

Achieve ultra-low temperatures is usually possible due to the use of cascade configurations refrigeration systems. Commonly, the observed results do not match the expected theoretical predictions. Therefore, in order to increase thermal efficiency and reach lower temperatures, adjustments and modifications in mechanical components of refrigeration system, in refrigerant fluids charges, and in general parts arrangement can be done. The system presented herein features a cascade configuration that uses R-404a and R-508b, and was previously able to reach -70°C. This study investigates the impact of optimization changes made in this existing cascade system, regarding the use of a more powerful compressor, in order to achieve -86°C inside the freezer. A series of tests was conducted for each one of the changes, and  this paper presents the complete methodology used, as well as the results found. As we will be able to notice, the results did not match the expected temperature, but contributed to the evolution of the experiment.

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