Bijan Kumar Mandal - Academia.edu (original) (raw)

Papers by Bijan Kumar Mandal

International Journal of Ambient Energy, 2020

This paper investigates the effect of using expander instead of throttle valves on the thermodyna... more This paper investigates the effect of using expander instead of throttle valves on the thermodynamic and economic performances of a cascade refrigeration system with refrigerant pairs R170-R161 and R41-R161. The influences of different design parameters on the thermo-economic performance parameters of the cascade refrigeration system with expander have been studied and compared with the results obtained from a conventional cascade refrigeration system. Results from the conventional cascade refrigeration system have been taken from the authors' previous work. The predicted results show that the cascade refrigeration system using expanders provides better thermo-economic performances compared to the conventional system. Results also show that refrigerant R170 in the LTC can provide higher performance compared to R41 due to its higher liquid specific volume. The present system with expanders can achieve 16-23% higher COP, upto 3.6% higher exergetic efficiency and 0.5-4% less plant cost rate compared to the conventional cascade refrigeration system.

Microgravity Science and Technology, 2018

The transient behavior of flame in terms of temperature development and soot formation has been i... more The transient behavior of flame in terms of temperature development and soot formation has been investigated numerically with an in-house developed code at normal gravity, reduced gravity of 0.5 G, and 0.0001 G (microgravity) in a methane air co flow laminar diffusion flame. The intermediate data of the field variables have been recorded at suitable intervals of time from ignition to convergence. Enhanced soot volume due to more residence time at lower gravity increases the radiative heat loss causing shrinkage of high temperature borne zone. Both soot volume and soot number register a build up and then a decay till steady state. The corresponding periods increase with the reduction of gravity. At microgravity, both the soot volume and soot particle number reach the peak at the same time and also almost stabilize concomitantly, unlike in other two gravity levels. The peak value of soot volume fraction, under 0.5 G and microgravity at steady state, become as high as 3.5 and 7 times respectively of the values at normal gravity due to surface growth. The soot number density, however, increases only 1.2 and 1.35 times respectively. The relatively lower factor of increase of soot number density is due to coagulation.

Journal of Thermal Science and Engineering Applications, 2020

An attempt has been made to investigate numerically a two-stage refrigeration system with flash i... more An attempt has been made to investigate numerically a two-stage refrigeration system with flash intercooler of 50 kW cooling capacity using refrigerant R410A and its possible alternative R32. Development of the simulation model for the analysis of the system has been carried out in engineering equation solver considering the energetic, exergetic, economic, and environmental aspects. Evaporator and condenser temperatures have been varied from −50 °C to −25 °C and 40 °C to 55 °C, respectively, to carry out the simulation work. Co-efficient of performance (COP), exergetic efficiency, and plant cost rate are the three performance parameters computed in this present work. Results show that the performances of the system using R32 are comparable with those of the system using R410A. It is also observed that R32 shows slightly better thermo-economic performances at higher condenser temperature. Multi-objective optimization has also been carried out using the toolbox available for optimizat...

A numerical simulation of vapour compression refrigeration system has been carried out using diff... more A numerical simulation of vapour compression refrigeration system has been carried out using different refrigerants such as R152a, R404A and R600a. A computational simulation model is developed and simulation is carried out using CoolPack software for analyzing the vapour compression refrigeration system performances. Simulation is done within the condenser temperature range of 25°C to 45°C and evaporator temperature range of 0°C to-20°C. Effect of compressor isentropic efficiency and degree of subcooling is also taken into consideration for the simulation model. The parameters that are computed in this study are required compressor power, coefficient of performance (COP) and required mass flow rate of refrigerants. Effect of degree of subcooling on these computed parameters are also computed in this present work. The performances of the different refrigerants mentioned have been compared and R-152a is found to be the most efficient one.

Energy Procedia, 2014

ABSTRACT The effect of addition of jatropha biodiesel to mineral diesel on the performance and em... more ABSTRACT The effect of addition of jatropha biodiesel to mineral diesel on the performance and emission characteristics of a conventional compression ignition engine have been experimentally investigated and compared with simulated data using Diesel-RK software. The experiments were carried out using pure diesel (B0) and pure jatropha biodiesel (JB100) as fuels. The performance characteristics shows that brake specific fuel consumption (BSFC) increases and brake thermal efficiency decreases with the use of jatropha biodiesel. Experimentally, pure diesel has maximum efficiency 29.6%, where as pure biodiesel has maximum efficiency of 21.2%. In the simulation, the pure diesel has maximum efficiency 30.3% where as pure jatropha biodiesel has the maximum efficiency of 27.5%. In respect of emission characteristics, NOx emission is found to increase with load as well as use of biodiesel in both experimental and simulation study. After the successful validation of the numerical study with the experimental, another simulation was done, where the performance, combustion and emission characteristics of the same engine fueled with pure diesel (B0), pure jatropha biodiesel (JB100) and 50% jatropha blend (JB50) were derived. In the numerical study it is found that, with the use of jatropha biodiesel the BSFC increases whereas brake thermal efficiency decreases. Combustion characteristics show an increase in peak cylinder pressure and a decrease in ignition delay period with the increase in biodiesel share in the blends; whereas the emission of NOx and CO2 increases; smoke and PM emission decreases for the same.

Advances in Mechanical Engineering, 2020

Thermodynamic properties of steam are very often required to evaluate the performance of power pl... more Thermodynamic properties of steam are very often required to evaluate the performance of power plant and other industries where process steam is used. Simplified equations and correlations have been identified from the literature for different properties of steam and used to develop a code in C language. The present code can predict properties of saturated water and steam in the temperature range of 0 to 370°C. The only input required to run this code is temperature and the output is the corresponding saturated thermodynamic properties such as specific enthalpy, entropy, and specific volume. The data generated from this code is then compared with the data available in standard steam table. It is observed that the average error for all properties is less than 0.2% which is good enough for most applications. This code can also be used as a subroutine for the performance optimization of any power plant.

2017 International Conference on Advances in Mechanical, Industrial, Automation and Management Systems (AMIAMS), 2017

A mathematical simulation has been performed to investigate the energetic, combustion and environ... more A mathematical simulation has been performed to investigate the energetic, combustion and environmental behavior of a mono cylinder, water cooled, four stroke DI diesel engine fuelled with diesel, diesel-ethanol (15% by volume) and diesel-methanol (15% by volume) blends. The results show that alcohol blending to diesel reduces the emissions of NOx, smoke opacity, specific PM and specific CO2. From the performance aspect, brake thermal efficiency is found to be higher with both the alcohol-diesel blends compared to neat diesel. However, brake specific fuel consumption is also slightly higher than conventional diesel. The maximum pressure and temperature rise during combustion are less than diesel which is reflected in the results of emissions also. The higher ignition delay of alcohol-diesel blends results a higher heat release rate compared to neat diesel as the premixed phase of combustion is more predominant with alcohol-diesel blends.

A certain percentage of the vapor compression based refrigeration, air conditioning and heat pump... more A certain percentage of the vapor compression based refrigeration, air conditioning and heat pump systems continue to run on halogenated refrigerants due to its excellent thermodynamic and thermo-physical properties along with the low cost. However, the halogenated refrigerants have adverse environmental impacts such as ozone layer depletion potential and global warming. Hence, it is necessary to look for alternative refrigerants to full fill the objectives of the international protocols (Montreal and Kyoto) and to satisfy the growing worldwide demand. In this context, the use of "natural" refrigerants (air, CO2 or ammonia) becomes a possible solution. We introduce in this study the merit of redeploying these natural refrigerants as an alternative solution to replace halogenated refrigerants. This paper reviews the various experimental and theoretical studies carried out around the globe with environment friendly alternatives such as hydrocarbons (HC), hydroflurocarbons (H...

The techniques of dilution of fuel or air with inert gases such as nitrogen and argon are used to... more The techniques of dilution of fuel or air with inert gases such as nitrogen and argon are used to reduce pollutants in diffusion flame. The flame structure and the temperature distribution change significantly due to inert gas addition to fuel stream. In this work, a CFD code has been developed to predict the flame height and temperature distribution in an axisymmetric laminar confined methane-air diffusion flame after diluting the fuel with different percentages of nitrogen. The code is validated with the experimental results and the results obtained by running the CFD code are in well agreement with that of experimental results. The temperature of the air and fuel are initially taken as 300K. Mass flow rate of the fuel is taken as 3.71×10 kg/s and mass flow rate of the air is taken as 2.7103×10 kg/s. The total mass flow rate through the central jet (fuel jet) is, however, kept constant. The radiation effect is also included through an optically thin radiation model. An explicit fi...

This paper presents a review of the use of ethanol in SI engine, its performance and emission cha... more This paper presents a review of the use of ethanol in SI engine, its performance and emission characteristics based on the works of different researchers and scientist available in the literature. The advantages of using ethanol as SI engine fuel include its greenness, renewability, higher availability and usability in near future, higher octane number, higher volumetric efficiency, higher compression ratio and biodegradability. Ethanol can be produced biologically from sugarcane, crop residues, cellulose, agricultural biomass, municipal waste etc. The experiment conducted by different researchers and their experimental results shows that brake specific fuel consumption, brake torque, indicated power, thermal efficiency increases or decreases depending upon the operating condition of the engine and ethanol percentage in the ethanol-gasoline blends. However, the compression ratio always increases due to enhancement of the octane number of the blend. On the other hand volumetric effic...

A global concern that has arisen in the present time due to the constant depletion of the fossil ... more A global concern that has arisen in the present time due to the constant depletion of the fossil fuels reservoirs and also due to the greenhouse gases emitted by use these fuels has led many researchers to find alternate sources of energy, out of which biodiesels have found a suitable place. Thus, in this effort of finding the compatibility of bio-fuels in present diesel engines, many experimental works have been carried out. However, these experimental works consume much cost and time when compared to numerical simulations. Under this context, an effort has been made in this paper to numerically simulate the performance and emission characteristics of a CI engine fueled with diesel, diesel and ethanol 20% blend (E20), diesel and jatropha 20% blend (JB20) and diese, ethanol 20% and jatropha 20% blend (JBE20) and make a comparison between the same. It was found that the use of JB20 decreased the thermal efficiency compared to pure diesel. However, ethanol blends increased the efficie...

This paper presents a brief review on the use of methanol and di-methyl ether (DME) in spark igni... more This paper presents a brief review on the use of methanol and di-methyl ether (DME) in spark ignition engine, their performance and emission characteristics based on the reports of different researchers available in the literature. Methanol can be produced from avail-able fossil raw materials and also from biomass. A very few literature is available on the study of DME as a supplementary fuel to gasoline. Therefore the authors have made an attempt to compile those findings in this paper for further progress. Also the usability of methanol as a supplementary fuel have been complied and represented in graphical man-ner. DME is primarily produced by converting natural gas, organic waste or biomass to synthetic gas in a twostep synthesis process. The review shows that engine power, brake specific fuel consumption, brake thermal efficiency increases or decreases depending upon the operating conditions of the engine and methanol percentage in the methanol-gasoline blends. Similar trend is...

Conventional vapor compression refrigeration system consumes a large quantity of high grade energ... more Conventional vapor compression refrigeration system consumes a large quantity of high grade energy. This energy can be generated by the combustion of fossil fuels which produces air pollutants such as oxides of nitrogen and sulphur. To overcome this problem, ejector refrigeration system (ERS) which is powered by low grade thermal energy such as waste heat from industrial processes, exhaust emissions from internal combustion engines and solar energy, is believed to be most effective one. This paper presents a brief review of the working principle of the ejector refrigeration system and the performance of this system based on the works of different researchers available in the literature. The effects of different controlling parameters of the ejector refrigeration system such as generator temperature, evaporator temperature, and condenser temperature on the performance have been discussed.

Environmental degradation and depletion of fossil fuel reserves are matters of great concern arou... more Environmental degradation and depletion of fossil fuel reserves are matters of great concern around the world. Diesel is one of the main transport fuel used in sector and India depends heavily on oil import. Recent concerns over the environment, increasing fuel prices and shortage of its supply have promoted the interest in development of the alternative sources for petroleum fuels. It is observed by several researchers that with biodiesel fuelled compression ignition (CI) engine; the exhaust emission is lower than that of diesel, whereas the NOx emission increases due to the excess oxygen content and high in-cylinder temperature of biodiesel. So, the exhaust gas recirculation (EGR) technique may be employed to lower the NOx emissions form CI engines. Although, EGR in CI engine has a number of benefits on the combustion process and emissions, its effect on the performance of the engine should be critically evaluated. Keeping this in mind, only the performance characteristics of a do...

The present study converses the usability of ethanol as a clean and green renewable alternative f... more The present study converses the usability of ethanol as a clean and green renewable alternative fuel for spark ignition engine. The study emphasizes not only on the inherent properties of ethanol as a fuel but also elaborately reviews about the performance characteristics of the engine considering the effects of different important parameters like cyclic variability, ignition timing, internal cylinder pressure. The study reveals the physical understanding of the engine performance characteristics under different operating conditions. In this paper, the performance analysis carried out by different researchers from their experimental and theoretical results has been presented in brief. The review of the investigation reports found in the literature reveals that the cyclic variability, ignition timing, internal cylinder pressure have a great role on engine performance with ethanol as a blended fuel with gasoline.

International Journal of Air-Conditioning and Refrigeration, 2019

This paper presents a review on energy and exergy analysis of two-stage vapour compression refrig... more This paper presents a review on energy and exergy analysis of two-stage vapour compression refrigeration (VCR) system. The use of alternative refrigerants instead of conventional refrigerants has also been addressed. The governing equations for the energetic and exergetic analysis of two-stage VCR system have been identified and presented. Several experimental and numerical investigations and their findings on the performance of the two-stage VCR system available in the literature have been discussed in brief. Some of the results have also been reproduced as case studies.

Energy Conversion and Management, 2018

In this paper, the energy and exergy performance of several polygeneration arrangements driven by... more In this paper, the energy and exergy performance of several polygeneration arrangements driven by low and medium temperature geothermal resource is investigated. The aim is to assess and compare different coupling schemes, identifying suitable thermally driven technologies for each type of arrangement. The polygeneration system is intended to produce power, cooling and heat for direct uses by considering variations of series and parallel coupling schemes along with different alternatives of ORC and absorption cooling machines. The study was conducted considering a temperature range of low-to-medium geothermal resource from 80°C to 150°C. Mathematical models are developed based on first and second law of thermodynamics and solved by means of an equation solver. The results show a threshold temperature that makes a shift between feasible polygeneration arrangements and the type of thermally driven technologies adopted, resulting in two different polygeneration arrangements with highest energetic and exergetic performance. The first arrangement correspond to a temperature range that lies between 80°C and 110°C, and the second one between 110°C and 150°C. The polygeneration arrangement with highest exergetic performance for the first range of temperatures was the hybrid parallel-series cascade arrangement (HPS2) having exergy efficiencies between 42.82% and 50.11%, while the one corresponding to the second temperature range was the series cascade arrangement (SC1) presenting exergy efficiencies from 51.44% to 52.9%. This effect is a consequence of the available temperature of the geothermal resource and the intrinsic energy performance of the different technologies considered. In regard to thermally driven technologies, arrangements where ORC and TDC subsystems are placed at the first thermal level, are the ones with the highest energetic and exergetic performance. Arrangements that have those components at the last level, present lowest performances.

Energy, 2017

Investigates the effect of alcohol addition to biodiesel on CI engine characteristics.  Ethanol ... more Investigates the effect of alcohol addition to biodiesel on CI engine characteristics.  Ethanol and methanol addition to biodiesel increases thermal efficiency marginally.  Ignition delay for blended fuels is increased resulting higher heat release.  Peak pressure rise is lower for alcohol blended biodiesels.

Clean Technologies and Environmental Policy, 2017

The objective of the present study refers to the examination of a diesel engine characteristics f... more The objective of the present study refers to the examination of a diesel engine characteristics for various fractions of diethyl ether (DEE) as an oxygenated fuel additive in cottonseed oil biodiesel-diesel fuel blends. Firstly, several tests performed for diesel and B20 blend. Then, 2.5%, 5%, 7.5%, and 10% of DEE by volume was mixed with biodiesel-diesel fuel to prepare the ternary blends. All the fuel samples were run on in a single-cylinder, four-stroke, and direct-injection diesel engine at five different engine loads and fixed engine speed conditions. The experimental results showed that BTE was decreased by 17.39% while increasing in BSFC by 29.15% for 10% addition of DEE in the blend as compared to diesel fuel. Besides, the engine fueled with ternary blends revealed mitigation up to 12.89%, 4.12%, and 8.84% in the HC, smoke, and NO X emissions, on an average, respectively than those of diesel fuel. CO emission exhibited increasing trends with the diesel fuel at higher proportions of DEE despite up to 40.09% dropdown remarked for lower concentration at the maximum load. By the way, the CO 2 also dropped under high loads. However, the combustion behaviors vaguely deteriorated when the CI engine run on all ternary blends. As a consequence, DEE can be evaluated as an auspicious aspect to remove the main issues with the usage of cottonseed oil biodiesel. It can be further highlighted that the addition of DEE up to 10% (by vol.) could be considered as a promising technique for the utilization of biodiesel/diesel blend efficiently in the CI engines without any major modifications.

Journal of Mechanical Science and Technology, 2016

A numerical simulation has been conducted in this study to evaluate the effect of methanol additi... more A numerical simulation has been conducted in this study to evaluate the effect of methanol addition to the blend of diesel and palm streain biodiesel. Also the effect of diesel-palm streain biodiesel blend has been considered and compared to that of baseline fuel, diesel and palm biodiesel. A commercial software Diesel-RK has been used in this study to simulate a single cylinder, naturally aspirated, direct injection, four stroke diesel engine. The results indicate that except a minor increase in the brake specific fuel consumption, the entire performance and emission characteristics with methanol blended diesel-biodiesel blends are much better than that of diesel. The dieselbiodiesel blend also shows better emission characteristics than that of diesel except NOx emission.