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

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).

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

Nigerian Journal of Technology ◽

10.4314/njt.v39i3.17 ◽

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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Comparison of Heat Transfer Performance In Domestic Refrigerator Using Nanorefrigerant And Double Pipe Heat Exchanger

International Journal of Mechanical and Industrial Engineering ◽

10.47893/ijmie.2014.1195 ◽

2014 ◽

pp. 110-116

Author(s):

Teshome Bekele Kotu ◽

R. Reji Kumar

Keyword(s):

Heat Transfer ◽

Energy Consumption ◽

Heat Exchanger ◽

Mineral Oil ◽

Coefficient Of Performance ◽

Normal System ◽

Refrigeration System ◽

Air Conditioners ◽

Double Pipe ◽

Pipe Heat

Convective heat transfer is very important in the HVAC, refrigeration and microelectronics cooling applications. R134a is most widely adopted alternate refrigerant in refrigeration equipment, such as domestic refrigerators and air conditioners. Though the global warming up potential of R134a is relatively high, it is affirmed that it is a long term alternate refrigerants in lots of countries. The addition of nanoparticles to the refrigerant results in improvements in the thermophysical properties and heat transfer characteristics of the refrigerant, there by improving the performance of the refrigeration system. The performance of the domestic refrigeration system with HFC134a/mineral oil system was compared with mineral oil/nanorefrigerant and HFC134a/mineral oil/double pipe heat exchanger. The result indicates that the system performance has improved when HFC134a/mineral oil/DPHE system was used instead of HFC134a/mineral oil and mineral oil/nano refrigerant system. The mineral oil/nano refrigerant and HFC134a/mineral oil/DPHE works normally and safely in the refrigeration system. The HFC 134a/mineral oil/DPHE system reduced the energy consumption by 30% and mineral oil/nano refrigerant system reduced the energy consumption by 26 % when compared with the HFC134a/mineral oil system. There was also an enhancement in coefficient of performance (COP) when DPHE was introduced in the normal system.

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Cop Enhancement of Vapour Compression Refrigeration System

Indian Journal of Production and Thermal Engineering - regular ◽

10.54105/ijpte.b2004.061221 ◽

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).

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Robust design of Passive Assist Devices for multi-DOF robotic manipulator arms

Robotica ◽

10.1017/s0263574716000850 ◽

2017 ◽

Vol 35 (11) ◽

pp. 2238-2255 ◽

Cited By ~ 2

Author(s):

W. Robert Brown ◽

A. Galip Ulsoy

Keyword(s):

Energy Consumption ◽

Robust Design ◽

Energy Minimization ◽

System Performance ◽

Displacement Curve ◽

Assist Devices ◽

Curve Fit ◽

Manipulator Arm ◽

Reduce Energy Consumption ◽

Force Displacement

SUMMARYA comparison of series, parallel, and dual Passive Assist Devices(PADs) designed using energy minimization based on a known maneuver is presented. Implementation of a PAD can result in an improvement in system performance with respect to efficiency, reliability, and/or utility. We introduce a new initial design using a weighted force displacement curve fit. A robust design approach for a family of maneuvers is developed and presented. Applications to a 3-link manipulator arm show that PADs could reduce energy consumption between 60% and 80%.

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Numerical and Experimental Study on the Performance of Thermoelectric Radiant Panel for Space Heating

Materials ◽

10.3390/ma13030550 ◽

2020 ◽

Vol 13 (3) ◽

pp. 550 ◽

Cited By ~ 3

Author(s):

Hansol Lim ◽

Jae-Weon Jeong

Keyword(s):

Energy Consumption ◽

Prediction Models ◽

Thermoelectric Module ◽

Coefficient Of Performance ◽

Joule Effect ◽

Heating Capacity ◽

Simulation Based ◽

Radiant Panel ◽

And Performance ◽

Heating Mode

The purpose of this study is to investigate the suitable operation and performance of a thermoelectric radiant panel (TERP) in the heating operation. First, the hypothesis was suggested that the heating operation of TERP can operate without a heat source at the cold side according to theoretical considerations. To prove this hypothesis, the thermal behavior of the TERP was investigated during the heating operation using a numerical simulation based on the finite difference method. The results indicated that it is possible to heat the radiant panel using a thermoelectric module without fan operation via the Joule effect. A mockup model of the TERP was constructed, and the numerical model and hypothesis were validated in experiment 1. Moreover, experiment 2 was performed to evaluate the necessity of fan operation in the heating operation of TERP regarding energy consumption. The results revealed that the TERP without fan operation showed the higher coefficient of performance (COP) in the heating season. After determining the suitable heating operation of the TERP, prediction models for the heating capacity and power consumption of the TERP were developed using the response surface methodology. Both models exhibited good R2 values of >0.94 and were validated within 10% error bounds in experimental cases. These prediction models are expected to be utilized in whole-building simulation programs for estimating the energy consumption of TERPs in the heating mode.

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Design and Performance Analysis on CO2 Combined System in Supermarket

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.433-440.1219 ◽

2012 ◽

Vol 433-440 ◽

pp. 1219-1225

Author(s):

Jing Hong Ning ◽

Sheng Chun Liu

Keyword(s):

Energy Consumption ◽

Waste Heat ◽

Hot Water ◽

Coefficient Of Performance ◽

Working Fluid ◽

Space Heating ◽

Combined System ◽

Space Cooling ◽

Gas Cooling ◽

And Performance

This paper reports a combined space cooling, space heating, water heating and food refrigeration system (named CO2 combined system) in supermarket. This system using CO2 as the working fluid consists of a two-stage CO2 transcritical cycle used for food refrigeration, a single-stage CO2 transcritical cycle for space cooling in summer and space heating in winter. The waste heat emitted from the CO2 gas cooling in food refrigeration cycle and space cooling and space heating cycles is recovered by heat recover exchanger and is used to provide hot water for space heating and for general usage, such as the catering, the washing and the toilet facilities in the supermarket. So this CO2 combined system improves the coefficient of performance, decreases the energy consumption as well as reduces the heat pollution. Moreover, this CO2 combined system is compared with typical conventional supermarket technology, the results show that the energy consumption of CO2 combined system is reduced largely and energy efficiency is increased obviously. It can be concluded that the CO2 combined system has a good future for protecting environment and saving energy.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.984-985.1174 ◽

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.

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

MATEC Web of Conferences ◽

10.1051/matecconf/201814404009 ◽

2018 ◽

Vol 144 ◽

pp. 04009 ◽

Cited By ~ 2

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.

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Thermal Prospective Estimations of COP and TR for R12 and HR12 Vapour Compression Refrigeration Systems

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.b7136.129219 ◽

2019 ◽

Vol 9 (2) ◽

pp. 897-902

Keyword(s):

Performance Evaluation ◽

Power Consumption ◽

Linear Relationship ◽

System Performance ◽

Graphical Representation ◽

Refrigeration System ◽

Energy Meter ◽

Temperature And Pressure ◽

Vapour Compression ◽

System Performance Evaluation

Experimentations got executed for investigating influence of R12 and HR12 refrigerants on system performance evaluation in terms of COP and TR. Temperature and pressure got measured by different temperature and pressure gauges mounted at several predetermined locations. Additionally, power consumption by refrigeration system also got measured from the installed energy meter readings. Altogether, it summarizes the tabular inscriptions of the variations of COPth, COPact and COPrel with TR for R12 and HR12 refrigerants. Besides, it also demonstrates the graphical representation of the corresponding variations of COPth, COPact and COPrel with TR for R12 and HR12 refrigerants. As expected, it stands observed (from both the stated table and figure) that both COPth and COPact increase with TR, however, the COPrel decreases with the same for said R12 and HR12 refrigerants. Furthermore, the stated variations of COPth, COPact and COPrel with TR remain observed as approximately linear, independently. That’s why, both COPth and COPact stay directly proportional to TR, however, the COPrel stays inversely proportional to the same because of approximately linear relationship between the COPth, COPact and COPrel with TR, individually. Additionally, COPact decreases with the increase of Wi/p for both R12 and HR12 refrigerants. However, Qext increases with Wi/p for both R12 and HR12 refrigerants.

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