Browsing by Author "Ashok Babu, T.P.A."

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An analysis of cycle-by-cycle fluctuation in combustion parameter in CI engine operation for various bio-fuels
(2011) Bekal, S.; Ashok Babu, T.P.A.
The cycle-by-cycle fluctuations in peak pressure of combustion in a CI engine were studied for lower and higher blends of diesel and ester, and water-in-ester emulsions, at four injection timings and three injection pressures using coefficient of variation. The sunflower ester-diesel blends are found to have lower cycle-by-cycle fluctuations than pongemia ester-diesel blends. The fluctuations are found to be higher than that of diesel for higher blend proportions of ester. The water-in-ester emulsion show higher cycle-by-cycle fluctuations than that of ester-diesel blends. In most cases, the Brake specific energy consumption is also found to be higher where the coefficient of variation has higher values. Copyright © Taylor & Francis Group, LLC.
Automotive air-conditioning system technology: A review
(Inderscience Publishers editor@inderscience.com 29, route de Pre-Bois Case Postale 856, CH-1215 Geneva 15 CH-1215, 2020) Vali, S.S.; Saboor, S.; Prithivi Rajan, S.; Ashok Babu, T.P.A.
Air conditioning in the automobile has become an important area of research. The performance of an air conditioning system in an automobile depends upon three basic important factors such as compressor speed, evaporator load, and condensing temperature. How these factors when varied affects the COP of the system have been detailed in this review paper. Several performance studies on various refrigerants (R134a, R152a, CO2 and R1234yf) used in the automotive air conditioning system operating with various conditions revealed the better COP for R152a in comparison with R134a, whereas COP of R1234yf and CO2 was observed to be slightly lower than R134a. However, safety measures must be followed while using R152a due to its slightly flammable nature (ASHRAE A2 group). In this work, various alternative air conditioning systems used for automobiles have been presented in detail. Â© Â© 2020 Inderscience Enterprises Ltd.
Bio-fuel variants for use in CI engine at design and off-design regimes: An experimental analysis
(2008) Bekal, S.; Ashok Babu, T.P.A.
In this work an attempt has been made to study the ester based fuel variants derived from edible and inedible oil sources for identifying the most appropriate fuel variant and operating mode for running a CI engine based on performance and emission parameters. The twenty four fuel variants tested included esters obtained from the edible sunflower oil, inedible pongamia oil, and their higher and lower proportional blends with diesel. Besides, several other fuel variants obtained from the emulsification of water-in-ester (W/E) with different water proportions have been tested. Basing upon three operational variables, namely, injection timing, injection pressure, and load, comparisons are made in aspects of smoke emissions, NOX emissions, BSEC, and exhaust gas temperatures at the best injection timing. 21.5°, 23°, 24.5° and 27.5° bTDC as the four injection timings and 190, 220 and 250 bar as three injection pressures are considered for the overall study. The 264 sets of experiments conducted with these combinations, focussing on the full and partial load characteristics of the engine, show that both sunflower and pongamia oil esters exhibited similar characteristics in their engine performance, and in both the cases the best BSEC occurred with 220 bar injection pressure for most of the fuel variants, and for straight fuels the ideal injection timing found to be slightly retarded (1.5° crank angle) compared to diesel. However, 24.5° bTDC, normal for the engine, was found to be the most appropriate for the lower blends like B2 (2% ester by volume), B5 and emulsion with 10% water proportion. © 2008 Elsevier Ltd. All rights reserved.
Characterization of sealing ring cavitation in centrifugal pumps with water and viscous oil
(Begell House Inc., 2010) Nair, K.G.; Ashok Babu, T.P.A.
This research paper presents characterization of sealing ring cavitation in centrifugal pumps with water and viscous oil. The paper discusses development of theoretical formulation for sealing ring cavitation and simulation using software model along with experimental validation. The pump performance test results and its standard clearance for the sealing ring are used to simulate the theoretical model. The study is extended for pumps with SAE-30 lubricating oil. The simulation results present the variation of downstream pressure with different sealing ring dimensions in pumps. The value of downstream pressure determines the possibility of occurrence of cavitation at the clearance. The theoretical formulation developed is validated by using a venturi cavitation test set up. Clearances equivalent to various sealing ring dimensions are made at the test section using different hemispherical models. Theoretical formulation for downstream pressure at the clearance of venturi test section is derived using the test set up details and pump specification. The clearance cavitation coefficients as per K. K. Shelneves equation are obtained from theory as well as from experimentation and compared. The phenomena of cavitation damages the sealing ring which results a fall in performance of the pump. However this research work lead to the prediction of sealing ring cavitation in centrifugal pumps handling water and oil enabling the replacement of sealing ring before affecting cavitation damage. © 2010 Begell House, Inc.
Determination of Lockhart-Martinelli parameter using CFD in 2D vertical rectangular and offset mini-channels with R717
(Research India Publications subscription@ripublication.com, 2017) Kutty, S.S.; Ashok Babu, T.P.A.
Study of mini-channels has become more popular in the current scenario due to the increasing developments in the field of compact heat exchangers due to the inherent property of increased heat transfer coefficients. Two types of vertical mini-channels, rectangular and offset channels are studied at six different configurations. The flow properties are analyzed using commercial CFD code by varying hydraulic diameters from 1 – 3 mm and mass flux from 5 – 75 kg/m2s. The friction factor is determined using CFD in two dimensional steady state conditions. The results are compared with available empirical correlations. Modified correlations are proposed for friction factor to determine Lockhart-Martinelli parameter based on CFD results. The Lockhart-Martinelli parameters are determined from modified friction factor correlations. © Research India Publications.
Effect of denatured spirit-water blends on engine performance and exhaust emissions
(Combustion Institute, 2009) Ashok Babu, T.P.A.; Hubballi, P.A.
The obj ective of this study was to investigate the effect of using Denatured spirit (DNS = [Ethanol 93.3% + water 6.7%]) and DNS-Water blends as fuels in a four cylinder four stroke SI engine. In the process of investigation, the performance tests were conducted on the engine to analyze brake thermal efficiency (BThE), brake power (BP), engine torque and brake specific fuel consumption (BSFC). Exhaust emissions were also investigated for carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen (NOx) and carbon dioxide (CO2). The results of the experiments revealed that, both DNS and DNS95W5 (DNS 95% + water 5%) as fuels increase BThe, BP, engine torque and BSFC. The CO, HC, NOx and CO2 emissions in the exhaust decreased. The DNS and DNS95W5 as fuels produced the encouraging results in engine performance and reduced exhaust emissions for all the tested speeds and measured performance parameters. Â© 2009 Combustion Institute. All rights reserved.
Effect of Solar Optical Properties of Building Envelope on Time Lag, Decrement Factor and Energy Saving of Buildings
(Springer Nature, 2020) Mahapatra, D.; Ashok Babu, T.P.A.
World has been suffering from energy crisis since 1970. This is because of the increased population and industrialization. Buildings have a significant contribution to total energy consumption across the globe. The increased urbanization leads to boom in construction of buildings. The materials used for the construction of buildings affect the climate of the city up to a great extent and affect the energy consumption as well. So, construction materials should be chosen wisely. The surface temperature of the building envelope is affected by the coatings used. Cool coatings help in reducing the surface temperature of the building envelope. Time lag and decrement factor are the indicators of energy saving in building. In this paper, the effect of cool coating on time lag and decrement factor was studied. Values of time lag and decrement factor were evaluated in different climatic zones of India. It has been found that as the absorptivity of the building envelope increases, the decrement factor increases. By changing the absorptivity from 0.2 to 0.73, a minimum change of 16% (New Delhi) in decrement factor and 11.75% (Jodhpur) in surface temperature was observed. The maximum change in decrement factor was 56.44% (Jodhpur). The maximum change in surface temperature was 39.02% (Bangalore). So, it should always be practised to keep the absorptivity of the building envelope as low as possible. © 2020, Springer Nature Singapore Pte Ltd.
Effect of using Mahua as an alternative fuel in diesel engine
(2009) Kapilan, N.; Ashok Babu, T.P.A.; Reddy, R.P.
There is an increasing interest in India, to search for suitable alternative fuels that are environment friendly. This led to the choice of non-edible Mahua Oil (MO) as one of the main alternative fuels to diesel oil in India. The objective of the present work is to use MO as a partial renewable alternative substitute for diesel in the agricultural diesel engine. Since the viscosity of the MO is high, it was blended with conventional diesel oil in various proportions (M5, M10, M15 and M20 on volume basis) and fuel properties of the blends were determined and compared with the diesel. Engine tests were carried out on a single cylinder diesel engine at varying loads (0%, 25%, 50%, 75% and 100%), without making any modification in the fuel injection system and the results were compared with the diesel. The M5 and M10 blends resulted in performance and emission characteristics comparable to diesel operation and also emits lower carbon monoxide, hydrocarbon and smoke emissions as compared to other blends. From the analysis, it is concluded that the MO can be partially substituted for diesel oil in the diesel engine, without making any modification in the hardware of the engine.
Experimental and Theoretical Studies of Window Glazing Materials of Green Energy Building in Indian Climatic Zones
(Elsevier Ltd, 2017) Gorantla, G.K.; Saboor, S.; Ashok Babu, T.P.A.
Buildings consume plenty of power for providing thermal and visual comfort inside the buildings. This paper aims at presenting the experimental results of spectral optical properties of the most widely used window glazing materials. The window glazing materials studied include clear glazing, bronze glazing, green glazing and grey coloured glazing materials. A Matlab code employing the British standard method was developed to compute transmittance and reflectance of window glasses at normal incidence angle. This code uses experimentally obtained spectral optical property data from Perkin Elmer lambda 950 spectrophotometer for the computation of transmission and reflection of window glasses. A computer program was developed for computing the total solar radiation passing through glass materials. The heat gain through different glass windows of eight coordinal orientations such as east, west, north, south, northeast, northwest, southeast and southwest in four climatic zones of India was investigated. The solar radiation through south oriented glass was found to be the least among all other orientations studied in four Indian climatic zones. The cooling load through south oriented bronze, glass, green glass and grey glass window were reduced by 23%, 31% and 37%, respectively, as compared to the south oriented clear glass window in four climatic zones of India. The grey glass window is observed to be the most energy efficient as it reduces maximum cooling loads within the building as compared to the other considered glazing materials. The results of this paper are helpful in designing energy efficient commercial buildings for reduced cooling loads. Â© 2017 The Authors.
Experimental investigation in pool boiling heat transfer of ammonia/water mixture and heat transfer correlations
(2011) Sathyabhama, A.; Ashok Babu, T.P.A.
The nucleate pool boiling heat transfer coefficient of ammonia/water mixture was investigated on a cylindrical heated surface at low pressure of 4-8bar and at low mass fraction of 0NH3<0.3 and at different heat flux. The effect of mass fraction, heat flux and pressure on boiling heat transfer coefficient was studied. The results indicate that the heat transfer coefficient in the mixture decreases with increase in ammonia mass fraction, increases with increase in heat flux and pressure in the investigated range. The measured heat transfer coefficient was compared with existing correlations. The experimental data were predicted with an accuracy of ±20% by the correlation of Calus&Rice, correlation of Stephan-Koorner and Inoue-Monde correlation for ammonia/water mixture in the investigated range of low ammonia mass fraction. The empirical constant of the first two correlations is modified by fitting the correlation to the present experimental data. The modified Calus&Rice correlation predicts the present experimental data with an accuracy of ±18% and the modified Stephan-Koorner correlation with an accuracy of ±16%. © 2011 Elsevier Inc.
Improvement of performance of vegetable oil fuelled agricultural diesel engine
(2009) Kapilan, N.; Ashok Babu, T.P.A.; Reddy, R.P.
In recent years, there has been a considerable effort to develop and introduce alternative renewable fuels to replace conventional petroleum based fuels. This led to the choice of non edible Mahua Oil (MO) as one of the main alternative fuels to diesel oil in India. When MO was used as fuel in the diesel engine, it results in lower thermal efficiency and higher smoke emission due to its higher viscosity and lower volatility. Hence in the present work, Liquefied Petroleum Gas (LPG) was inducted along with the air and the LPG supply was varied from zero to the maximum value that the engine could tolerate. The engine tests were conducted on a single cylinder diesel engine, which is used in the agricultural machinery. The engine test with MO+LPG was compared with the LPG+MO biodiesel (MEMO) and Diesel+LPG. From the engine results it is observed that the MO+LPG dual fuel mode operation results in performance close to the MEMO+LPG. The MO+LPG operation results in higher brake thermal efficiency and lower smoke emission as compared to the MO operation. From the present work, it is concluded that the underutilized and non edible MO can be used as a renewable alternative fuel for the diesel engine, for the development of rural economy and for the energy security of India.
Investigation of Various Low Emissivity Glass Materials for Green Energy Building Construction in Indian Climatic Zones
(Elsevier Ltd, 2017) Gorantla, G.K.; Saboor, S.; Ashok Babu, T.P.A.
The buildings are responsible for more than one-third of power consumption in India. Glass is one of the significant building enclosures to control cooling loads in buildings. This paper describes how various low emissivity glasses used for building windows affect thermal performance of green energy buildings. This paper presents the thermal performance of five double glazed low reflective window glass materials such as clear low reflective glass, bronze low reflective glass, green low reflective glass, grey low reflective glass and blue-green low reflective glasses. In this paper, mud brick buildings with five low emissivity glass material windows were designed in three different climatic zones of India such as warm and humid (Mangalore), hot and dry (Jodhpur) and composite (Hyderabad). The results showed that buildings with double glazed low emissivity grey glass window are found to be energy efficient from the least heat gain point of view among all buildings studied in three climatic zones of India. Â© 2017 Elsevier Ltd. All rights reserved.
Performance characteristics of a dual fuel engine operatedwith mahua biodiesel and liquefied petroleum gas
(2011) Kapilan, N.; Ashok Babu, T.P.A.; Reddy, R.P.
Fuel crisis because of dramatic increase in vehicular population and environmental concerns have renewed the interest of the scientific community to look for alternative fuels of bio-origin such as vegetable oils and ethanol. India is looking at biodiesel derived from Mahua oil (MO), as one of the renewable alternative fuels for compression ignition (CI) engine. Although MO biodiesel (MOB) has several advantages over fossil diesel, in the present scenario, the use of biodiesel is restricted due to its high cost. In India, liquefied petroleum gas (LPG) is easily available and is one of the cheapest gaseous fuels. Hence, use of LPG to fuel a CI engine along with MOB seems to be an option for substitution of fossil diesel. In the present work, LPG, which was fumigated along with the air and biodiesel was admitted into the engine cylinder through conventional fueling device as an igniter. A single cylinder CI engine was modified to work in dual fuel mode and engine tests were carried out at rated speed under variable load conditions. The performance of the engine in dual fuel mode was compared with the diesel. The dual fuel operation results in thermal efficiency close to the diesel and also reduces the NOx and smoke emissions significantly. From the experimental results, we concluded that biodiesel in dual fuel mode with cheaper gaseous fuel induction is an option for reducing the operating cost of the biodiesel fuelled CI engine. Copyright © 2011 by ASTM International.
Some studies on chemical composition, and properties of ester of edible and inedible vegetable oils, and their use in CI engine
(Combustion Institute, 2009) Bekal, S.; Ashok Babu, T.P.A.
In this work, the esters produced from two types of vegetable oils â€“ edible and inedible, with pongamia oil representing the inedible oil, and sunflower oil, the edible, are compared on the basis of various physical and chemical properties, NMR and GC analysis, and performance and emission characteristics of the engine on being fuelled by these esters. The results indicate that there is a difference in chemical composition of certain fatty acids which have bearing on the cetane number and shelf life; additionally, there is substantial difference in chemical properties, though the physical properties have similar values; on the performance and emissions front, the edible oil ester is found to be better than inedible oil ester. Â© 2009 Combustion Institute. All rights reserved.
Study of variables affecting the synthesis of biodiesel from Madhuca Indica oil
(2010) Kapilan, N.; Ashok Babu, T.P.A.; Reddy, R.P.
Biodiesel derived from non-edible Madhuca Indica oil (MIO) seems to be a better alternative to diesel oil in India. In the present work, effects of reaction variables such as mass ratio of methanol to oil, catalyst concentration, reaction time and reaction temperature on biodiesel yield were studied. The acid value of the commercially available MIO is high, and hence a two-step process was used to produce biodiesel from MIO. In the first step, the acid value of the MIO was reduced to less than 1 mg KOH/g, using acid-catalyzed transesterification. In the second step, the pretreated MIO was converted to biodiesel using alkalinecatalyzed transesterification. From the experimental results, it is observed that the optimized conditions for biodiesel production are a 1: 4 mass ratio of methanol to oil, 55 °C reaction temperature, 120 min of reaction time, and 1% sodium hydroxide catalyst. The properties of the MIO biodiesel were found to be within the biodiesel limits of the European Union. Hence, the MIO biodiesel can be used as a substitute for diesel for the sustainable development of rural areas and as a renewable fuel. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Study of Various Glass Materials to Provide Adequate Day Lighting in Office Buildings of Warm and Humid Climatic Zone in India
(Elsevier Ltd, 2017) Gorantla, G.K.; Ashok Babu, T.P.A.
A huge amount of energy is attributed to cooling, heating and day lighting in buildings. In the air conditioned space the windows have been closed and the sun control is used to reduce the radiation load. This results in low lumens of light in air conditioned space and demands the artificial lighting and increases the energy consumption for lighting and also the air conditioning load. The objective of this work is to allow the natural sun light through the glass window of same area, and thus less lighting load in the air conditioned space for different climatic conditions. To achieve the objective of the work an investigation of spectral properties of different glass materials such as bronze, green, grey, bronze-reflective, green-reflective and grey-reflective glasses is carried out experimentally using Perkin Elmer lambda 950 Spectrophotometer in the visible solar spectrum region of wavelength range from 380nm-780 nm, to provide optimum daylight factor as per SP: 41 1987 Indian standards to office buildings. The measured spectral properties were used to compute the visible solar properties in the visible region by using British standard method with a MATLAB code. The computed properties transmittance, reflectance and absorbance are used in the simulation tool for daylight calculations. The laterite building models with various window glazing materials were designed in Design builder 4.3.0.039 version tool and day lighting simulation was carried out in Energy plus 8.1.0.009 simulation tool for warm and humid climatic region of India. In this work, total twenty four building models with six window glass materials were investigated in four orientations of window such as East, West, North and South. The simulations were carried out in both summer and winter climates of warm and humid climatic zone for an office building. As far as the daylight factor is concerned, the green-reflective glass placed in south orientation is the best due to its adequate daylight factor (2.05% to 2.06%) in summer season and bronze glass window placed in north orientation is observed to be the best due to its sufficient daylight factor (2.2% to 2.8%) in winter among six studied window glass materials to Mangalore location (Latitude 12.87 N). The results of the study help in designing natural daylight buildings which in turn reduce energy consumption. Â© 2017 The Authors.
Study of Various Glass Window and Building Wall Materials in Different Climatic Zones of India for Energy Efficient Building Construction
(Elsevier Ltd, 2017) Kumar, G.K.; Saboor, S.; Ashok Babu, T.P.A.
The commercial and residential buildings consume about 33% of energy for cooling and day lighting in India. This paper aims to present thermal performance of buildings constructed with various building and window glass materials in five different climatic zones of India. The climates considered include: hot and dry (Ahmedabad), moderate (Bangalore), cold (Guwahati), warm and humid (Madras), and composite (New Delhi). In this study, four building materials such as laterite stone, dense concrete, burnt brick, and mud brick were selected and four glasses such as clear, bronze, green, and bronze-reflective glasses were used for windows. Spectral characteristics of four glasses were measured experimentally by using Perkin-Elmer lambda 950spectrophotometer in the wavelength range of 300 -2500 nm as per ASTM standards. A mat lab code was developed to compute the solar optical properties such as transmittance and reflectance of glasses as per European standards in entire solar spectrum region. The building models were designed in Design builder 4.3.0.039 and thermal analysis was carried out in Energy plus 8.1.0.009. The solar heat gain in buildings was investigated. The results revealed that the mud brick wall building with south bronze-reflective glass window as energy saving from the least heat gain point of view among eighty building models studied. The results also showed that the mud brick wall building with bronze, green and bronze reflective window glasses reduces heat gain through wall by 2.52%, 3.83%, and 6.46% as compared to the mud brick wall building with clear glass window. The results helps in selecting energy saving combination of wall envelope and window glass materials for reducing air-conditioning loads in residential and commercial buildings of five different climatic zones of India. Â© 2017 The Authors. Published by Elsevier Ltd.
Synthesis of biodiesel from edible and non-edible oils and characterisation
(2009) Kapilan, N.; Ashok Babu, T.P.A.; Varun, J.D.
In recent years, biodiesel has been receiving increasing attention because of scarcity and increasing cost of fossil fuels and growing emissions of combustion related pollutants. In the present work, biodiesel was synthesised via the transesterification of edible and non-edible oils such as gingili and mahua, with methanol as alcohol and sodium hydroxide as catalyst. The yield percentage obtained from non-edible mahua oil was comparable to that obtained from edible gingili oil, under optimum conditions. According to American Society of Testing and Methods (ASTM), several tests were conducted to characterise the biodiesel in relation to diesel oil, in order to evaluate various physical, chemical and thermal properties such as viscosity, acid value, iodine value, flash point, fire point and calorific value. From the results, it was observed that the fuel properties of biodiesel produced from mahua oil and gingili oil were within the recommended standards of biodiesel fuel of various countries. Hence the biodiesel produced from gingili oil and mahua oil can be used as a renewable alternative fuel for the diesel engine. © 2009 Energy Institute.
Theoretical Computation of Performance of Sustainable Energy Efficient R22 Alternatives for Residential Air Conditioners
(Elsevier Ltd, 2017) Vali, S.V.; Ashok Babu, T.P.A.
The present paper focuses on theoretical investigation of various new R22 alternatives. In this study R407C and four new R22 alternative refrigerant mixtures composed of R1270, R290, RE170, R134a and R32 at different compositions are considered. All the four new refrigerants possess zero ODP and low GWP compared to R22.The chief objective of the present work is to compute the thermodynamic performance of a standard vapour compression refrigeration cycle with R22 and its alternative refrigerants. A MATLAB code is developed to compute the thermodynamic performance of all the considered refrigerants. Thermodynamic analysis of all the refrigerants are evaluated at the condensing and evaporating temperatures of 54.4Â°C and 7.2Â°C respectively. The results showed that COP for the refrigerant mixture R134a/R1270/RE170 (55/37.5/7.5 by mass percentage) is 5.35% higher among the R22, R407C and four studied refrigerants. The compressor discharge temperature for R134a/R1270/RE170 (55/37.5/7.5 by mass percentage) is 11.9Â°C lower when compared to R22 and hence this mixture indicates the durability of the compressor life. The energy spent by the compressor per ton of refrigeration for the mixture R134a/R1270/RE170 (55/37.5/7.5 by mass percentage) is 5.12% lower among R22, R407C and four investigated refrigerants. The GWP of R134a/ R1270/ RE170 (55/37.5/7.5 by mass percentage) is 716 which is low compared to GWP of R22 (1760). Therefore R134a/R1270/RE170 (55/37.5/7.5 by mass percentage) is a sustainable energy efficient refrigerant to replace R22 used in residential air conditioners from the stand point of COP, compressor discharge temperature, energy savings, GWP and ODP. And also in this study thermodynamic performance of refrigerants are computed at various evaporating temperatures by keeping condenser temperature as constant. Â© 2017 The Authors. Published by Elsevier Ltd.
Theoretical Performance Investigation of Vapour Compression Refrigeration System Using HFC and HC Refrigerant Mixtures as Alternatives to Replace R22
(Elsevier Ltd, 2017) Vali, S.V.; Ashok Babu, T.P.A.
The present paper describes the theoretical thermodynamic performance of vapour compression refrigeration system using HFC and HC blends as an alternatives to replace the refrigerant R22. In this study thermodynamic analysis of window air conditioner with R431A, R410A, R419A, R134a, R1270, R290 and fifteen refrigerant mixtures consists of R134a, R1270 and R290 was carried out based on actual vapour compression cycle. All the investigated refrigerant mixtures are ozone friendly in nature and they possess GWP in the range of 0.0244 to 1.685 times the GWP of R22. Thermodynamic performance analysis of all the investigated refrigerant mixtures were evaluated at the condensing and evaporating temperatures of 54.4oC and 7.2oC respectively. The results show that COP for the refrigerant mixture R134a/R1270/R290 (50/5/45 by mass percentage) is 2.10% higher among the R22, R431A, R410A, R419A, R134a, R1270, R290, and fifteen studied refrigerant mixtures. The compressor discharge temperature of all the studied refrigerants were lower than that of R22 by 4.8oC-22.2oC. The power consumption per ton of refrigeration for the refrigerant mixture R134a/R1270/R290 (50/5/45 by mass percentage) is 2.01% lower among R22, R431A, R410A, R419A, R134a, R1270, R290, and fifteen studied refrigerant mixtures. Overall the thermodynamic performance of refrigerant mixture R134a/R1270/R290 (50/5/45 by mass percentage) is better than that of R22 with reasonable savings in the energy and hence it is an appropriate ecologically energy efficient alternative refrigerant to substitute R22 used in air conditioning applications. Â© 2017 The Authors.