Experimental Investigation of Performance Effect of Working Parameters on Bi-Evaporator Compression/Ejection Refrigeration System

2017 ◽  
Author(s):  
Huadong Liu ◽  
Xinli Wei ◽  
Zhenzhen Wang ◽  
Lihong Geng ◽  
Chunhe Li
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Water Temperature ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Entrainment Ratio ◽  
Performance Effect ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration ◽  
Working Parameters

In this paper, a bi-evaporator compression/ejection refrigeration is experimental investigated to recycle the throttling loss in traditional vapor compression refrigeration cycle by using an ejector. The effects of working parameters on the system performance are mainly analyzed. The results are as follows: the ejector entrainment ratio decreases as the condenser and the high-temperature inlet water temperature increases, but rises with the increasing of low-temperature evaporator inlet water temperature; the system COP rises with the decreasing of inlet water temperature of condenser, and increases with the rise of inlet water temperature of high-temperature evaporator; the inlet water temperature of the condenser and the high-temperature has greater influences on the performance of BCERC system. The system COP increases about 0.25 when the condenser inlet water temperature decreases per 5°C; while the system COP rise about 0.114 as the high-temperature evaporator inlet water temperature increases per 5°C. The low-temperature evaporator inlet water temperature has little effects on the performance of the BCERC system. The results can be references for the design and operation of the BCERC system.

scholarly journals Parametric analysis of a combined ejector-vapor compression refrigeration cycle

2020 ◽  
Vol 15 (3) ◽  
pp. 398-408
Author(s):  
I Ouelhazi ◽  
Y Ezzaalouni ◽  
L Kairouani
Keyword(s):  
Current Model ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Entrainment Ratio ◽  
Constant Area ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration

Abstract From the last few years, the use of efficient ejector in refrigeration systems has been paid a lot of attention. In this article a description of a refrigeration system that combines a basic vapor compression refrigeration cycle with an ejector cooling cycle is presented. A one-dimensional mathematical model is developed using the flow governing thermodynamic equations based on a constant area ejector flow model. The model includes effects of friction at the constant-area mixing chamber. The current model is based on the NIST-REFPROP database for refrigerant property calculations. The model has basically been used to determine the effect of the ejector geometry and operating conditions on the performance of the whole refrigeration system. The results show that the proposed model predicts ejector performance, entrainment ratio and the coefficient of performance of the system and their sensitivity to evaporating and generating temperature of the cascade refrigeration cycle. The simulated performance has been then compared with the available experimental data from the literature for validation.

Improved performance of a nanorefrigerant-based vapor compression refrigeration system: A new alternative

2020 ◽  
pp. 095765092090455
Author(s):  
Lal Kundan ◽  
Kuljeet Singh
Keyword(s):  
Temperature Drop ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Flow Rates ◽  
System A ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration ◽  
Improved Performance

An attempt has been made to improve the heat transfer characteristics of the vapor compression refrigeration cycle using nanorefrigerant (R134a and Al2O3, size 20 nm). The performance parameters such as, coefficient of performance, cooling capacity, energy consumption, and temperature drop across condenser and evaporator have been investigated and analyzed. This has been done by varying the mass fraction of nanoparticles of Al2O3 (0.5–1 wt%) and the flow rate of nanorefrigerant. The investigation has been carried out using three types of nanorefrigerants, i.e. pure R134a, R134a+Al2O3 (0.5 wt%), and R134a+Al2O3 (1 wt%) at flow rates of 6.5 L/h and 11 L/h, respectively. The coefficient of performance of the refrigeration system using 0.5% of Al2O3 (wt%) is found to be improving with volume flow rates of nanorefrigerant, i.e. 7.20% for 6.5 L/h and 16.34% for 11 L/h. The use of nanorefrigerant (R134a+Al2O3) has also resulted in a significant increase in the cooling capacity of the refrigeration system. A substantial drop in the temperature across the condenser (3.0–23.77%), and gain in temperature across the evaporator (4.69–39.30%) is also observed for the refrigeration system under investigation.

Performance Analysis of Refrigerants R1234yf, R1234ze and R134a in Ejector-Based Refrigeration Cycle

2018 ◽  
Vol 26 (03) ◽  
pp. 1850026 ◽  
Author(s):  
Ajay Kumar Yadav ◽  
Neeraj
Keyword(s):  
Heat Pump ◽  
Power Plants ◽  
Operating Conditions ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Entrainment Ratio ◽  
Evaporator Temperature ◽  
Wide Range ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration

Performance enhancement of refrigeration and heat pump systems by cycle modification is an emerging research topic now-a-days to reduce the electricity consumption leading to mitigate the problems related to the environmental pollution by utility power plants. Due to no moving parts, low cost, simple structure and low maintenance requirements, the use of two-phase ejector has become a promising cycle modification recently. Use of ejector as an expansion device by replacing the throttle valve in the vapor compression refrigeration cycle seems to be one of the efficient ways to reduce the throttling losses or the expansion irreversibility in the refrigeration/heat pump cycle. Ejector also reduces the compressor work by raising the suction pressure to a level higher than that in the evaporator leading to the improvement of COP. The present work aims to evaluate the performance of an ejector based vapor compression refrigeration cycle under a wide range of operating conditions. Two newly proposed refrigerants i.e., R1234yf and R1234ze, and commonly used refrigerant R134a are considered for simulation and a comparative study has been carried out. A numerical model is developed and a parametric study of important parameters such as entrainment ratio, high side pressure (condenser pressure) and evaporator temperature are analyzed for the improvement of COP of the system. Results show that the COP of the R1234ze is highest compared to R1234yf and R134a for the given evaporating and condensing temperature.

scholarly journals New HFC/HFO Blends as Refrigerants for the Vapor-Compression Refrigeration System (VCRS)

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 946
Author(s):  
Bartosz Gil ◽  
Anna Szczepanowska ◽  
Sabina Rosiek
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Mass Fraction ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Operational Parameters ◽  
Vapor Compression Refrigeration ◽  
Low Global Warming Potential ◽  
Triangular Design

In this work, which is related to the current European Parliament Regulation on restrictions affecting refrigeration, four new three-component refrigerants have been proposed; all were created using low Global Warming Potential(GWP) synthetic and natural refrigerants. The considered mixtures consisted of R32, R41, R161, R152a, R1234ze (E), R1234yf, R1243zf, and RE170. These mixtures were theoretically tested with a 10% step in mass fraction using a triangular design. The analysis covered two theoretical cooling cycles at evaporating temperatures of 0 and −30 °C, and a 30 °C constant condensing temperature. The final stage of the work was the determination of the best mixture compositions by thermodynamic and operational parameters. R1234yf–R152a–RE170 with a weight share of 0.1/0.5/0.4 was determined to be the optimal mixture for potentially replacing the existing refrigerants.

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