scholarly journals Performance Analysis of Vapour Compression Refrigeration System with Serpentine and Spiral Condensers by Using R600a

2019 ◽  
pp. 21-25
Author(s):  
P. Kesavulu ◽  
K. Prahlada Rao
Keyword(s):  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Economic Output ◽  
Refrigeration Unit ◽  
Load Increase ◽  
Heating Load ◽  
Compressor Work ◽  
Cooling Loads ◽  
Vapour Compression ◽  
Ozone Depletion Potential

The present work is to analyse the performance of VCRS system with two condensers i.e., Serpentine and Spiral tube using Isobutane (R600a) refrigerant. These two condensers are kept in parallel with other components of refrigerating unit while construction. The performance of refrigeration system is checked for each condenser at various cooling loads. The performance of the condenser is measured for whole refrigeration unit in terms of C.O.P, compressor work, Efficiency of the system, Heat Rejection Ratio, and Heat Rejected from Condenser. The result will show that for both condensers for refrigerant R600a, coefficient of performance increases with increase in heating load, increase in refrigerating effect and decrease in compressor work. From the analysis of two condensers, coefficient of performance of refrigeration system using serpentine and spiral condenser VCRS is more compared to conventional VCRS. Also, R600a gives better cooling effect than tetrafluroethane (R134a). The substitution of R134a by R600a is useful in order to generate a good thermo-economic output, zero ODP (Ozone Depletion Potential) and very low GWP (Global Warming Potential).

scholarly journals Cop Enhancement of Vapour Compression Refrigeration System

2021 ◽  
pp. 1-6
Author(s):  
B Sairamakrishna ◽  
◽  
T Gopala Rao ◽  
N Rama Krishna ◽  
◽  
...  
Keyword(s):  
Tube Diameter ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Expansion Valve ◽  
Compressor Inlet ◽  
Work Input ◽  
Compressor Work ◽  
Vapour Compression ◽  
Design And Testing ◽  
Nozzle Inlet

This experimental investigation exemplifies the design and testing of diffuser at compressor inlet and nozzle at condenser outlet in vapour compression refrigeration system with the help of R134a refrigerant. The diffuser with divergence angle of 12°,14° and the nozzle with convergent angle 12°,14° are designed for same inlet and outlet diameters. Initially diffusers are tested at compressor inlet diffuser is used with inlet diameter equal to exit tube diameter of evaporator and outlet tube diameter is equal to suction tube diameter of the compressor. Diffuser helps to increases the pressure of the refrigerant before entering the compressor it will be helps to reduces the compression work and achieve higher performance of the vapour compression refrigeration system. Then nozzles are testing at condenser outlet, whereas nozzle inlet diameter equal to discharging tube diameter of condenser and outlet diameter equal to inlet diameter of expansion valve. Additional pressure drop in the nozzle helped to achieve higher performance of the vapour compression refrigeration system. The system is analyzes using the first and second laws of thermodynamics, to determine the refrigerating effect, the compressor work input, coefficient of performance (COP).

SIMULATION OF A SIMPLE VAPOUR-COMPRESSION REFRIGERATION SYSTEM USING R134a

2016 ◽  
Vol 78 (9-2) ◽  
Author(s):  
Mohd Yusoff Senawi ◽  
Farah Wahidah Mahmod
Keyword(s):  
Steady State ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Input Coefficient ◽  
Work Input ◽  
Compressor Work ◽  
Computerized Simulation ◽  
Steady State Simulation ◽  
Vapour Compression ◽  
Isentropic Efficiency

A computerized simulation of a simple single-stage vapour-compression refrigeration system has been made. The steady-state simulation uses the accurate property correlations developed by Cleland for refrigerant R134a. The inputs to the program are: evaporator pressure, condenser pressure, superheating at evaporator outlet, subcooling at condenser outlet and compressor isentropic efficiency. The program outputs are: refrigerating effect, compressor work input, coefficient of performance (COP) and suction vapour flow rate per kW of refrigeration. An increase in the evaporator pressure from 150 to 250 kPa improves the COP by 40%. The COP is decreased by 35% when the condenser pressure is increased from 1000 to 1500 kPa. Increasing the superheat at the evaporator outlet from 0 to 160C improves the COP by 2.6%. An increase in subcooling at the condenser outlet from 0 to 160C increases the COP by 20%. The COP is improved by 150% when the compressor isentropic efficiency is increased from 0.4 to 1.

scholarly journals Enhancement of Cop of Vapour Compression Refrigeration System by using Diffusers

2019 ◽  
Vol 8 (2) ◽  
pp. 6123-6129
Keyword(s):  
Tube Diameter ◽  
Coefficient Of Performance ◽  
Divergence Angle ◽  
Refrigeration System ◽  
Suction Tube ◽  
Compressor Inlet ◽  
Work Input ◽  
Compressor Work ◽  
Vapour Compression ◽  
Design And Testing

This experimental investigation exemplifies the design and testing of four diffusers at compressor inlet and condenser inlet in the vapour compression refrigeration system with the help of R134a refrigerant .The Four diffusers with divergence angle of 10°,12°, 14° and 16° are designed for same inlet and outlet diameters. Diffusers are testing at compressor inlet first. The diffusers are used with inlet diameter equal to discharging tube diameter of evaporator and outlet diameter is equal to suction tube diameter of the compressor. One of the diffuser gives the better performance, it will fixed at compressor inlet. Then diffusers are testing at condenser inlet, diffuser inlet diameter equal to discharging tube diameter of compressor and outlet diameter equal to condenser inlet diameter The system is analyzes using the first and second laws of thermodynamics, to determine the refrigerating effect, the compressor work input, coefficient of performance(COP). During the experimental test,the coefficient of performance (COP) of the system without diffuser and with diffuser optimized at compressor inlet and condenser inlet are find out. At compressor inlet 14° divergence angle of diffuser given the maximum cop (2.46). Percentage of increase in cop is approximately 6%. At condenser inlet 12° divergence angle of diffuser given the maximum cop (2.59).Percentage of increase in cop is approximately 3%.

scholarly journals Cop Enhancement of Vapour Compression Refrigeration System

2021 ◽  
Vol 1 (2) ◽  
pp. 1-6
Author(s):  
Sairamakrishna B ◽  
T Gopala Rao ◽  
Rama Krishna, N
Keyword(s):  
Tube Diameter ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Expansion Valve ◽  
Compressor Inlet ◽  
Work Input ◽  
Compressor Work ◽  
Vapour Compression ◽  
Design And Testing ◽  
Nozzle Inlet

This experimental investigation exemplifies the design and testing of diffuser at compressor inlet and nozzle at condenser outlet in vapour compression refrigeration system with the help of R134a refrigerant. The diffuser with divergence angle of 12°,14° and the nozzle with convergent angle 12°,14° are designed for same inlet and outlet diameters. Initially diffusers are tested at compressor inlet diffuser is used with inlet diameter equal to exit tube diameter of evaporator and outlet tube diameter is equal to suction tube diameter of the compressor. Diffuser helps to increases the pressure of the refrigerant before entering the compressor it will be helps to reduces the compression work and achieve higher performance of the vapour compression refrigeration system. Then nozzles are testing at condenser outlet, whereas nozzle inlet diameter equal to discharging tube diameter of condenser and outlet diameter equal to inlet diameter of expansion valve. Additional pressure drop in the nozzle helped to achieve higher performance of the vapour compression refrigeration system. The system is analyzes using the first and second laws of thermodynamics, to determine the refrigerating effect, the compressor work input, coefficient of performance (COP).

scholarly journals Cop Enhancement of Vapour Compression Refrigeration System

2021 ◽  
Vol 1 (2) ◽  
pp. 1-6
Author(s):  
Sairamakrishna B ◽  
T Gopala Rao ◽  
Rama Krishna N
Keyword(s):  
Tube Diameter ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Expansion Valve ◽  
Compressor Inlet ◽  
Work Input ◽  
Compressor Work ◽  
Vapour Compression ◽  
Design And Testing ◽  
Nozzle Inlet

This experimental investigation exemplifies the design and testing of diffuser at compressor inlet and nozzle at condenser outlet in vapour compression refrigeration system with the help of R134a refrigerant. The diffuser with divergence angle of 12°,14° and the nozzle with convergent angle 12°,14° are designed for same inlet and outlet diameters. Initially diffusers are tested at compressor inlet diffuser is used with inlet diameter equal to exit tube diameter of evaporator and outlet tube diameter is equal to suction tube diameter of the compressor. Diffuser helps to increases the pressure of the refrigerant before entering the compressor it will be helps to reduces the compression work and achieve higher performance of the vapour compression refrigeration system. Then nozzles are testing at condenser outlet, whereas nozzle inlet diameter equal to discharging tube diameter of condenser and outlet diameter equal to inlet diameter of expansion valve. Additional pressure drop in the nozzle helped to achieve higher performance of the vapour compression refrigeration system. The system is analyzes using the first and second laws of thermodynamics, to determine the refrigerating effect, the compressor work input, coefficient of performance (COP).

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).

Environment Friendly Mixed Refrigerant to Replace R-134a in a VCR System with Exergy Analysis

2014 ◽  
Vol 984-985 ◽  
pp. 1174-1179
Author(s):  
N. Austin ◽  
P.M. Diaz ◽  
D.S. Manoj Abraham ◽  
N. Kanthavelkumaran
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Ozone Depletion ◽  
Exergy Analysis ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Evaporator Temperature ◽  
Environment Friendly ◽  
A Charge ◽  
Vapour Compression

Study on environment friendly mixed refrigerant to replace R134a in vapour compression refrigeration (VCR) System. The mixed refrigerants investigated are propane (R290), butane (R600), isobutene (R600a) and R134a. Even though the ozone depletion potentials of R134a relative to CFC-11 are very low; the global warming potentials are extremely high and also expensive. For this reason, the production and use of R134a will be terminated in the near future. Hydrocarbons are free from ozone depletion potential and have negligible global warming potential. The results showed that, mixed refrigerant with charge of 80 g satisfy the required freezer air temperature when R134a with a charge of 110 g is used as refrigerant. The actual COP of refrigerator using mixed refrigerant was almost nearer that of the system using R134a as refrigerant. The coefficient of performance of the vapour compression refrigeration system using mixed refrigerant MR-3 [R134a/R290/ R600a/ R600 (20/35/40/5)] is having very close value with R134a and the Global warming potential of MR-3 is negligible when compared with R134a. Hence the mixed refrigerant MR-3 is chosen as an environmental friendly alternate refrigerant to R134a. The exergy analysis of the vapour compression refrigeration system using R134a and all the above mixtures are investigated. The effect of evaporator temperature on exergy efficiency and exergy destruction ratio of the system are experimentally studied. The exergy defect in the compressor, condenser, expansion device and evaporator are also obtained. Key words: R134a, Mixed refrigerant, Chlorofluorocarbons, Propane, Butane, Isobutene, REFPROP, COP, ODP, GWP, Exergy, VCR System.

scholarly journals Analytical computation of thermodynamic performance parameters of actual vapour compression refrigeration system with R22, R32, R134a, R152a, R290 and R1270

2018 ◽  
Vol 144 ◽  
pp. 04009 ◽  
Author(s):  
Shaik Sharmas Vali ◽  
Talanki Puttaranga Setty ◽  
Ashok Babu
Keyword(s):  
Mineral Oil ◽  
Performance Parameters ◽  
Refrigeration System ◽  
Analytical Computation ◽  
Volumetric Capacity ◽  
Discharge Temperature ◽  
Thermodynamic Performance ◽  
Compressor Work ◽  
Refrigeration Capacity ◽  
Vapour Compression

The present work focuses on analytical computation of thermodynamic performance of actual vapour compression refrigeration system by using six pure refrigerants. The refrigerants are namely R22, R32, R134a, R152a, R290 and R1270 respectively. A MATLAB code is developed to compute the thermodynamic performance parameters of actual vapour compression system such as refrigeration effect, compressor work, COP, power per ton of refrigeration, compressor discharge temperature and volumetric refrigeration capacity at condensing and evaporating temperatures of 54.4oC and 7.2oC respectively. Analytical results exhibited that COP of both R32 and R134a are 15.95% and 11.71% higher among the six investigated refrigerants. However R32 and R134a cannot be replaced directly into R22 system. This is due to their higher compressor discharge temperature and poor volumetric capacity respectively. The discharge temperature of both R1270 and R290 are lower than R22 by 20-26oC. Volumetric refrigeration capacity of R1270 (3197 kJ/m3) is very close to that of volumetric capacity of R22 (3251 kJ/m3). Both R1270 and R290 shows good miscibility with R22 mineral oil. Overall R1270 would be a suitable ecofriendly refrigerant to replace R22 from the stand point of ODP, GWP, volumetric capacity, discharge temperature and miscibility with mineral oil although its COP is lower.

scholarly journals Effect of Titanium Oxide Nano Lubricants Applied to R134a Refrigeration System

2020 ◽  
Vol 8 (5) ◽  
pp. 5557-5559
Keyword(s):  
Steady State ◽  
Tio2 Nanoparticles ◽  
Titanium Oxide ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Compressor Work

In this work experiment is performed by using titanium oxide (Tio2) nanoparticles at three different nanoaparticles containing lubricants 0.2g/l,0.4g/l as well as 0.6g/l . An experiment was performed by dispersing titanium oxide (Tio2) nanoparticles and the variables such as compressor work, Coefficient of performance (C.O.P) and refrigeration has been analysed.The experiment was conducted with R134a refrigerant under steady state conditions.Inclusion of Tio2 nanoparticles improved the coefficient as well as cooling capacity of presentation and the compressor work is get reduced.

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.

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