The Comparative Analysis of R22 and R134a Applied in a Five-Stage Auto-Cascade Refrigeration System

2013 ◽  
Vol 291-294 ◽  
pp. 1740-1745
Author(s):  
Wei Zhao ◽  
Rui Xi Liu ◽  
Hai Dong Zhang ◽  
Hua Zhang ◽  
Shu Chun Zhang
Keyword(s):  
Comparative Analysis ◽  
High Temperature ◽  
Refrigeration System ◽  
Discharge Temperature ◽  
Cascade Refrigeration System ◽  
High Temperature Stage ◽  
Cascade Refrigeration

The mixed refrigerants R22/R23/R14/R740/R728 and R134a/R23/R14/R740/R728 are used in a five-stage auto-cascade refrigeration system for study in this paper. Through theoretic comparison of high temperature stage refrigerant R22 and R134a and repeated experiments we can get the results that the discharge temperature of the refrigerant R134a can be effectively controlled and a lower refrigeration temperature can be got than the refrigerant R22.

Energy and exergy analysis of a subcritical cascade refrigeration system with internal heat exchangers using environmentally-friendly refrigerants

2020 ◽  
pp. 1-33
Author(s):  
Cenker Aktemur ◽  
Ilhan Tekin Öztürk
Keyword(s):  
Heat Exchangers ◽  
Internal Heat ◽  
Exergy Efficiency ◽  
Refrigeration System ◽  
Evaporator Temperature ◽  
Discharge Temperature ◽  
Thermodynamic Performance ◽  
Condenser Temperature ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration

Abstract This study focuses on a thermodynamic performance analysis of a subcritical cascade refrigeration system (CRS) with internal heat exchangers (IHXs) using R41/R601, R41/R602A, and R41/cyclopentane as refrigerant pairs. The effect of evaporator temperature (Tev), condenser temperature (Tcond) and temperature difference in cascade heat exchanger (ΔTCHX) on examined performance parameters are investigated. Each performance parameter is scrutinized by an optimum LTC condenser temperature. The operating parameters have some implications on the overall thermodynamic performance of the system. A change of 10°C in the Tev and Tcond affects the performance of the system by approximately +26% and −8%, respectively. Moreover, a variation of 1°C in the ΔTCHX reduces the performance of the system by about 2%. The effect of IHXs on the system has some interesting results. The COP and exergy efficiency values of the system using R41/cyclopentane tend to constantly decrease by nearly 4.05%. Although not as much as R41/cyclopentane, there is also a slight drop in the performance of other refrigerant pairs. The discharge temperature in LTC and HTC compressors exceeds 120°C for low-temperature refrigeration requirements, which is highly undesirable. Furthermore, the top priority components for the system improvement are HTC condenser, HTC compressor, and CHX. The refrigerant pairs with the thermodynamic performance from best to worst are R41/R601, R41/cyclopentane, and R41/R602A, respectively. Finally, the COP and exergy efficiency values of the modeled system are 10.40% higher and 3.06% lower, respectively, compared to current models in the literature.

PERFORMANCE EVALUATION OF CASCADE REFRIGERATION SYSTEMS USING DIFFERENT REFRIGERANTS

2012 ◽  
Vol 20 (03) ◽  
pp. 1250010 ◽  
Author(s):  
ANTONIO MESSINEO ◽  
DOMENICO PANNO
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Low Temperature ◽  
Operating Parameters ◽  
Refrigeration System ◽  
Alternative Refrigerants ◽  
Negative Effects ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration ◽  
Interesting Alternative

Due to the negative effects of synthetic refrigerants on the environment, natural refrigerants have obtained again interest as alternative refrigerants for different applications because of their zero ODP and negligible GWP. This paper presents a thermodynamic analysis of different two-stage cascade refrigeration systems using as refrigerant carbon dioxide (R744) in low-temperature circuit, and, respectively, ammonia (R717), propane (R290), butane (R600), R404A, R410A and R134a in high-temperature circuit. The operating parameters considered in this study include condensing and evaporating temperatures in high-temperature circuit, temperature difference in the cascade heat exchanger, and evaporating and condensing temperatures in the low-temperature circuit. The results obtained show that a cascade refrigeration system using natural refrigerants is an interesting alternative to systems using synthetic refrigerants for energetic, security and environmental reasons.

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 Comparative analysis of a cooling systems working on an environmentally friendly refrigerants

2021 ◽  
pp. 32-40
Author(s):  
Adam RUCIŃSKI ◽  
Mateusz DALBA ◽  
Rafał LASKOWSKI
Keyword(s):  
Carbon Dioxide ◽  
Adverse Effect ◽  
Comparative Analysis ◽  
Operating Parameters ◽  
Meat Processing ◽  
Refrigeration System ◽  
Cooling Systems ◽  
Cascade Refrigeration System ◽  
Polish Law ◽  
Cascade Refrigeration

The paper treats with refrigerants which affect on excessive heating of atmosphere. They are in group offluorinated greenhouse gases which are regulated by European and polish law. The main aim is to lower their amount in industry leading to overall removal from use. We present possible way to design refrigeration system lowering their adverse effect on natural environment. So three options of cooling systems are analyzed: one-stage refrigeration system working with R449A, cascade refrigeration system with R744 (carbon dioxide)/ R134a and R717 (ammonia) refrigeration plant. Due to the nowadays raising use of the cascade systems, an analysis of the operating parameters of such installation was carried out with considering the cascade heat exchanger as a condenser/evaporator. The installations concerned are three alternative offers for meat processing manufactory. A thermal balance was prepared for chambers located in building and the operating parameters of the installation were assumed. The equipment corresponding to the required cooling capacities were selected.

Sign in / Sign up

Export Citation Format

Share Document