scholarly journals Illustrating the relationship between the coefficient of performance and the coefficient of system performance by means of an R404 supermarket refrigeration system

2016 ◽  
Vol 70 ◽  
pp. 225-234 ◽  
Author(s):  
M.R. Braun ◽  
P. Walton ◽  
S.B.M. Beck
Keyword(s):  
System Performance ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
The Relationship

Experimental Analysis on Vapour Compression Refrigeration System Using Nanolubricant with HFC-134a Refrigerant

Nano Hybrids ◽  
2015 ◽  
Vol 9 ◽  
pp. 33-43 ◽  
Author(s):  
A. Manoj Babu ◽  
S. Nallusamy ◽  
K. Rajan
Keyword(s):  
Energy Consumption ◽  
System Performance ◽  
Mineral Oil ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Hfc 134A ◽  
Reduce Energy Consumption ◽  
And Performance ◽  
Vapour Compression ◽  
Better Than

This paper investigates the reliability and performance of a refrigeration system using nanolubricant with 1, 1, 1, 2-Tetrafluoroethane (HFC-134a) refrigerant. Mineral Oil (MO) is mixed with nanoparticles such as Titanium Dioxide (TiO2) and Aluminium Oxide (Al2O3). These mixtures were used as the lubricant instead of Polyolester (POE) oil in the HFC-134a refrigeration system as HFC-134a does not compatible with raw mineral oil. An investigation was done on compatibility of mineral oil and nanoparticles mixture at 0.1 and 0.2 grams / litre with HFC-134a refrigerant. To carry out this investigation, an experimental setup was designed and fabricated in the lab. The refrigeration system performance with the nanolubricant was investigated by using energy consumption test. The results indicate that HFC-134a and mineral oil with above mentioned nanoparticles works normally and safely in the refrigeration system. The refrigeration system performance was better than the HFC-134a and POE oil system. Thus nanolubricant (Mixture of Mineral Oil (MO) and nanoParticles) can be used in refrigeration system to considerably reduce energy consumption and better Coefficient of Performance (COP).

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.

Investigation on Influence of Solar Radiation on Performance of Solar Adsorption Refrigeration System

2014 ◽  
Vol 953-954 ◽  
pp. 57-60
Author(s):  
Xiang Bo Song ◽  
Xu Ji ◽  
Ming Li ◽  
Jie Qing Fan ◽  
Bin Luo ◽  
...  
Keyword(s):  
Solar Radiation ◽  
System Performance ◽  
Refrigeration System ◽  
Adsorption Refrigeration ◽  
Bed Temperature ◽  
The Relationship

This article conducts the research on the relationship between the solar radiation and the adsorption bed temperature, the adsorption bed pressure and the system performance, and obtains that the solar radiation indirectly influences the system refrigeration performance through influencing the adsorption bed temperature and adsorption bed pressure. And in a certain range, the bigger solar radiation is, the higher adsorption bed temperature is, the system refrigeration efficiency is higher, the maximum refrigeration efficiency is 0.122.

Performance Comparison of a Truck Refrigeration System with R404A, R134a, R1234yf, and R744 Refrigerants under Frosting Conditions

2016 ◽  
Vol 24 (01) ◽  
pp. 1650005 ◽  
Author(s):  
Yunchan Shin ◽  
Honghyun Cho
Keyword(s):  
Analytical Model ◽  
Indoor Air ◽  
System Performance ◽  
Operating Time ◽  
Performance Comparison ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Average Error ◽  
Refrigeration System ◽  
Air Conditioners

A new refrigerant is needed because the GWP of the R404A and R134a that are used in existing refrigerated trucks and automotive air conditioners is so high. This study predicts cooling performance by using an analytical model, for refrigeration systems using R404A and R134a. Furthermore, the performances of those systems were compared with those of alternative refrigeration systems using R1234yf and R744. The performance data of the analytical model had a trend similar to that of the experimental data: the average error between the analytical and experimental results was within 5.4%. The frost thickness of the R404A system for all operating conditions was about 2.4–3.7% larger than that of other systems because the evaporating temperature of the R404A system was lower than that for other refrigerants. For various operating conditions, the coefficient of performance (COP) of the R134a system was higher than that of other systems, while the R744 system showed the lowest performance. However, the COP reduction of the R744 system with operating time was the smallest because the thermodynamic properties of R744 were very superior. In addition, the frost thickness was seriously affected by the variations of indoor air temperature and compressor rotation speeds, and the system performance decreased significantly for severe operating conditions.

Performance Analysis of a Novel Compression Refrigeration System

2014 ◽  
Vol 721 ◽  
pp. 170-173
Author(s):  
Zhi Wen Cheng
Keyword(s):  
Performance Analysis ◽  
Theoretical Analysis ◽  
System Performance ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
The Novel ◽  
Refrigeration System ◽  
Jet Pump ◽  
Evaporation Temperature ◽  
Compressor Inlet

In this paper, the theoretical analysis and calculation were put forward for the novel compression refrigeration cycle, new cycle compared with conventional compression refrigeration cycle adding a jet pump and evaporator to reduce throttling losses and improve the compressor inlet pressure. The results show that COP decreases with the increase of condensing temperature, with the increase of evaporation temperature increased, and decreased with the increase of the ejector coefficient. Novel compression refrigeration cycle coefficient of performance than the conventional compression refrigeration system performance coefficient increased by 8-15%.

scholarly journals Case study of liquid suction heat exchanger in a mechanical refrigeration system using alternative refrigerants

2020 ◽  
Vol 9 (3) ◽  
pp. 644
Author(s):  
Raid Ahmed Mahmood
Keyword(s):  
Heat Exchanger ◽  
System Performance ◽  
Good Alternative ◽  
High Response ◽  
Coefficient Of Performance ◽  
Alternative Refrigerant ◽  
Refrigeration System ◽  
Alternative Refrigerants

This paper investigates the effect of adding a liquid-suction heat exchanger on the performance of a mechanical refrigeration system using alternative refrigerants. Engineering Equation Solver (EES) was used to simulate a mechanical refrigeration system in two configurations: modified system with liquid-suction heat exchanger and system without liquid-suction heat exchanger. The results revealed that the liquid-suction heat exchanger has a significant effect on the system performance as it influences the subcooling and superheating temperatures. The results also showed that the highest value of the coefficient of performance (COP) was achieved by the modified system with refrigerant type R134a, COP was about 7% and 12% higher than that of refrigerants R600a and R22 respectively. It also presented that R600a has high response to increase the refrigerant effect when the liquid-suction heat exchanger is used. R600a is good alternative refrigerant and it can be used in the mechanical refrigeration system, but its COP is lower than that of R134a.  

The relationship of a retinal-gain index to system performance.

1960 ◽  
Author(s):  
S. Seidenstein ◽  
R. Chernikoff ◽  
F. V. Taylor
Keyword(s):  
System Performance ◽  
Relationship Of ◽  
The Relationship

Thermodynamic Performance of an Actual Thermo-Acoustic Refrigeration Micro-Cycle

2012 ◽  
Vol 614-615 ◽  
pp. 64-68
Author(s):  
Tuo Wang ◽  
Feng Wu ◽  
Jin Hua Fei ◽  
Ming Fang Liu
Keyword(s):  
Coefficient Of Performance ◽  
Pressure Amplitude ◽  
Cooling Load ◽  
Acoustic Effect ◽  
Thermodynamic Performance ◽  
Monotonically Increasing Function ◽  
Analytic Expressions ◽  
New Type ◽  
The Relationship ◽  
Increasing Function

Thermo-acoustic refrigerator is a new type of engine, which is based on the thermo-acoustic effect. A new model which expresses as an ellipse in pressure-volume diagram is established to investigate the thermodynamic performance of an actual thermo-acoustic refrigeration micro-cycle. The demarcation points of endothermic processes and exothermic processes in the actual micro-cycle are found. The analytic expressions of the dimensionless cooling load and the coefficient of performance (COP) are deduced. The relationship between the dimensionless cooling load and the COP are investigated by numerical examples. The results show that the dimensionless cooling load is a monotonically increasing function of the COP and the pressure amplitude.

scholarly journals Using Higher-Order Constructs to Estimate Health-Disease Status: The Effect of Health System Performance and Sustainability

Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1228
Author(s):  
Alicia Ramírez-Orellana ◽  
María del Carmen Valls Martínez ◽  
Mayra Soledad Grasso
Keyword(s):  
Health System ◽  
Social Services ◽  
System Performance ◽  
Structural Equation ◽  
Disease Incidence ◽  
Disease Status ◽  
Well Being ◽  
Equation Modeling ◽  
Health System Performance ◽  
The Relationship

This article aims to provide information to public agencies and policymakers on the determinants of health systems and their relationships that influence citizens’ health–disease status. A total of 61 indicators for each of 17 Spanish autonomous communities were collected from the Spanish Ministry of Health, Social Services, and Equality between 2008 and 2017. The applied technique was partial least squares structural equation modeling (PLS-SEM). Concerning health–disease status, an influence of sustainability and performance on the health system was hypothesized. The findings revealed that health system sustainability had a negative effect on health–disease status, measured in terms of disease incidence. However, the relationship between health system performance and health–disease status is positive. Furthermore, health system performance mediates the relationship between sustainability and health–disease status. According to our study, if we consider the opposite poles that make up the definition of health–disease status (well-being and disease), this concept is defined more by the incidence of the negative aspect.

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