pankaj kalita - Academia.edu (original) (raw)
Papers by pankaj kalita
Materials Today: Proceedings
International Energy Journal, 2012
In the present investigation, the effects of blending of biomass in sand, superficial velocity an... more In the present investigation, the effects of blending of biomass in sand, superficial velocity and operating pressure on bed hydrodynamics and heat transfer in a pressurized circulating fluidized bed have been studied. Experiments have been conducted at four different percentage blending of biomass such as 2.5%, 7.5%, 15% and 20% in sand and with two different weight composition ratios. All the above studies have been made at two different superficial velocities of 5 and 7 m/s and at three different operating pressures such as 1, 3 and 5 bar. The sand and biomass particle sizes used for the study are 309 µm and 407 µm, respectively. Results show that, with the increase in operating pressure , t he bed voidage decreases . The axial heat transfer coefficient increases from the bottom to the top of heat transfer probe with the increase in operating pressure. The radial variation of heat transfer coefficient decreases from the wall to the core of the heat transfer probe. The heat transf...
INTERNATIONAL CONFERENCE ON ENERGY AND ENVIRONMENT (ICEE 2021), 2021
Gas solid fluidized bed application has gained popularity as an excellent contacting device that ... more Gas solid fluidized bed application has gained popularity as an excellent contacting device that is been widely used in thermo-chemical processes, drying application in food processing industries etc. due to its favorable heat transfer characteristics. Most of the outmoded fluidization activities reported is confined with columnar/cylindrical shaped bed reactors. Conventionally, tapered/conical reactors are used for energy conversion which has substantial dynamic characteristics over the columnar reactors in terms of smooth, steady operation with marginal pressure variation. This work focuses on the computational modelling and simulation on the effect of various parameters like par, Stagnant bed height, Superficial velocity, Minimum fluidization velocity and Heat transfer characteristics upon variation in the taper angle of Tapered Fluidized Bed Reactor (TFBR) using Computational Fluid Dynamics (CFD) solver FLUENT. Two Fluid Model (TFM) is adopted for the simulation studies where both the phases (Solid, Gas) are treated as fluids. The results obtained are compared with simulation conducted for columnar reactor having same axial length. 2D domain has the axial length of 1.2 m and bottom diameter of 0.15 m. Simulation results shows that the finer the particle size becomes, greater is the heat transfer by conduction from bed to wall compared to larger particles. The interphase heat transfer from Solid-Air is maximum in the reactor core section. Although the particle volume fraction is observed to be more in columnar reactor, better fluidization characteristics is observed in reactor with taper angle 4.52°.
International Journal of Energy Research, 2020
This study has dealt with the synthesis and characterization of biochars produced from three biom... more This study has dealt with the synthesis and characterization of biochars produced from three biomasses, viz. water hyacinth (whole plant and its components), yellow oleander, and sugarcane bagasse, and their comparative assessment for potential application in agronomy and energy production. The pyrolysis was carried out in a fixed batch reactor at 350 C and 550 C with a heating rate of 20 Cmin −1. Biochars were characterized for proximate and ultimate (elemental) analysis, and also using standard techniques (SEM, EDX, TGA, BET, XRD, and FTIR). Biochars produced at 550 C from all the feedstock had good properties (carbon content: 39.09-80.74%, pH: 7.36-10.42, calorific value: 16.98-30.18 MJ kg −1 , and ash content: 0.89%-21.78%). Moreover, relatively low atomic ratios (H/C 0.25-0.47 and O/C 0.15-1.11) of all biochars indicated their potential as solid fuel. XRD results showed the presence of amorphous and crystalline structures, and minerals like sylivite, quartz, kalsilite, and tridymite in the biochar. Biochar produced from sugarcane bagasse at 550 C possessed the best properties: fixed carbon (77.42%), bulk density (0.13 kg/m 3), brunauer-emmett-teller (BET) surface area (17.78 m 2 /g), pore size (12.86 nm), total pore volume (0.025 cm 3 /g), calorific value (30.18 MJ kg −1), ash content (1.16%), and moisture content (2.03%).
Sādhanā, 2019
Solar energy is one of the most suitable renewable energy options in India. In the last decade, s... more Solar energy is one of the most suitable renewable energy options in India. In the last decade, solar energy installations have received an ample impetus in India due to active initiatives taken by the Indian government. However, the solar energy potential of country's NorthEastern (NE) part is not utilized effectively so far. In the present study, a comprehensive analysis of the feasibility of installation of a megawatt-level gridconnected solar photovoltaic (SPV) power plant in all the state capitals of NE India is carried out. The climatic data collected from various online sources and NASA climatic database were utilized in designing a 2 MW SPV plant. The theoretical procedure involved in designing the SPV plant is also presented in this study. PVsyst simulation software is used to predict the performance of 2 MW power plants for these eight states of India. From the analysis, it is observed that NE India has an immense potential for installation of solar energy conversion devices and thus it can be harvested economically. It has been observed that locations of Guwahati and Gangtok provide a high performance ratio of 0.855. Aizawl provides the minimum unit cost of electricity generated at a value of 3.88 INR/unit. The analysis also reveals that the Aizawl and Guwahati are the most suitable locations for installation of SPV power plant amongst the NE capitals.
Coal and Biomass Gasification, 2017
Over the years, gasification technology has been established as one of the efficient thermochemic... more Over the years, gasification technology has been established as one of the efficient thermochemical conversion processes catering to a wide variety of applications like thermal, power generation and liquid fuel production through Fischer–Tropsch route. However, there are issues with the conversion devices when the biomass feed material changes and hence understanding of product gas behaviour and its variability is important in order to utilize the biomass gasification technology effectively in the long run. The current chapter addresses these issues relating to biomass characterization, product gas estimation and utilization, and advances in this technology. Furthermore, an example of an equilibrium model formulation for prediction of product gas generated from rice husk has been presented, and a brief about reaction kinetics has been discussed. A comparison of model result and experimental data has also been briefly presented. The recent trends in biomass gasification research show a promising future for this technology. Moreover, techno-economic evaluations prove that biomass gasification is not only technically viable but also a sound economic option. It is expected that biomass gasification will contribute more to the global energy requirements and thus to the economy in the coming future.
Renewable Energy, 2008
Fluoride contaminated drinking water is a severe problem in many parts of the world because of fl... more Fluoride contaminated drinking water is a severe problem in many parts of the world because of fluoride-related health hazards, which are considered to be a major environmental problem today. The present work is aimed at utilizing solar energy for removal of fluoride from drinking water by using a “solar still”. Also tests have been conducted with the “solar still” to
Procedia Engineering, 2013
In the present work, a pressurized circulating fluidized bed (PCFB) unit of 54 mm inner diameter ... more In the present work, a pressurized circulating fluidized bed (PCFB) unit of 54 mm inner diameter and riser height of 2000 mm has been fabricated to investigate the effect of pressure on suspension density and heat transfer. The effects of blending of biomass in sand, and superficial velocity on bed hydrodynamics and heat transfer has also been studied. Experiments have been conducted at four different percentage blending of biomass such as 2.5 %, 7.5 %, 15 % and 20 % in sand with two different weight composition ratios and at a superficial velocity of 5 m/s. Operating pressure is varied from 1 to 5 bar in a step of 2 bar. Results show that, the axial heat transfer coefficient increases from the bottom to the top of heat transfer probe with the increase in operating pressure. The radial variation of heat transfer coefficient decreases from the wall to the core of the heat transfer probe. The heat transfer coefficient is also found to be higher in between the 7.5 to 15 % biomass blending in sand. The overall uncertainty in calculating heat transfer coefficient is found to be 3.90 %.
Journal of Electrochemical Energy Conversion and Storage, 2019
Lithium-ion (Li-ion) battery pack is vital for storage of energy produced from different sources ... more Lithium-ion (Li-ion) battery pack is vital for storage of energy produced from different sources and has been extensively used for various applications such as electric vehicles (EVs), watches, cookers, etc. For an efficient real-time monitoring and fault diagnosis of battery operated systems, it is important to have a quantified information on the state-of-health (SoH) of batteries. This paper conducts comprehensive literature studies on advancement, challenges, concerns, and futuristic aspects of models and methods for SoH estimation of batteries. Based on the studies, the methods and models for SoH estimation have been summarized systematically with their advantages and disadvantages in tabular format. The prime emphasis of this review was attributed toward the development of a hybridized method which computes SoH of batteries accurately in real-time and takes self-discharge into its account. At the end, the summary of research findings and the future directions of research such ...
Related Article: Debabrata Dhara, Debdeep Mandal, Avijit Maiti, Cem B. Yildiz, Pankaj Kalita, Nic... more Related Article: Debabrata Dhara, Debdeep Mandal, Avijit Maiti, Cem B. Yildiz, Pankaj Kalita, Nicolas Chrysochos, Carola Schulzke, Vadapalli Chandrasekhar, Anukul Jana||Dalton Trans.|||doi:10.1039/C6DT04321F
Related Article: Sourav Biswas, Kochan S. Bejoymohandas, Sourav Das, Pankaj Kalita, Mundalapudi L... more Related Article: Sourav Biswas, Kochan S. Bejoymohandas, Sourav Das, Pankaj Kalita, Mundalapudi L. P. Reddy, Itziar Oyarzabal, Enrique Colacio, Vadapalli Chandrasekhar|2017|Inorg.Chem.|56|7985|doi:10.1021/acs.inorgchem.7b00689
Emerging Pollutants - Some Strategies for the Quality Preservation of Our Environment, 2018
Water is a primary element for all living things, and we need water for each and every dayto-day ... more Water is a primary element for all living things, and we need water for each and every dayto-day activity related to agricultural, industrial, and domestic cares and, thus, its quality influences all aspects of human life including energy, food, health, and economy. Safe drinking water is our primary need to protect our life and thus developing efficient and affordable techniques for water treatment to access potable water to the humanity. Water pollution is one of the severe environmental and health problems worldwide. Pollutants in water can be of organic, inorganic, heavy metals, microbial, and radioactive species, which may be in different forms viz. suspended, dissolved, or dispersed materials. The water quality is mainly affected by industrial discharges, agricultural activities, mismanagement of hazardous materials, etc. Nowadays, nanotechnology offers the possibility of an efficient removal of water pollutants including metals, organic dyes, bacteria, parasites, etc. Magnetic nanomaterials like iron oxide (Fe 3 O 4) are very promising materials used in water decontamination particularly for heavy metals and dyestuffs because of their ease of separation through external magnet, high surface area, unique morphology as well as their high stability. These materials can be used as adsorbent, photocatalyst, and coagulating agents for water remediation based on their composite materials or surface functionalities.
Advances in Sustainable Energy, 2021
Coordination Chemistry Reviews, 2021
Abstract Molecular nanomagnets containing heterometallic 3d-4f complexes have been investigated e... more Abstract Molecular nanomagnets containing heterometallic 3d-4f complexes have been investigated extensively for the past few years realizing the role of exchange interaction to minimize the QTM effect. In this context, heterometallic complexes particularly containing CuII-LnIII have encompassed a pivotal role due to the ferromagnetic exchange interaction. Herein we review the Cu/Ln complexes that exhibit single molecule magnet (SMM)/magnetocaloric effect (MCE) in a comprehensive way.
International Journal of Green Energy, 2020
ABSTRACT Electric vehicles that run on batteries have a major disadvantage of temperature abnorma... more ABSTRACT Electric vehicles that run on batteries have a major disadvantage of temperature abnormalities when operated at extreme working conditions. Therefore, thermal management of battery pack is essential to ensure its safety and performance. There are three operation strategies of thermal management air-based, liquid-based, and phase change material-based battery thermal management systems (BTMSs). Optimization studies on BTMSs have been focused mainly on the structural parameters as compared to the operating parameters. In liquid cooled multichannel flow-type BTMSs, equal flow rates are employed in all the channels. However, only a few studies have focused on variable coolant flow rates in channel-type liquid BTMS and its optimization. In this paper, a multichannel cold plate-based liquid BTMS is proposed for Lithium-ion battery pack comprising of two prismatic cells operating at 1 C discharge rate. Multi-objective optimization (MOO) technique coupled with computational fluid dynamics (CFD) simulations is used for obtaining optimal mass flow rate combination of coolant in the channels for reducing the power consumption of the BTMS without compromising on its thermal performance. Response surface methodology is adopted for the sensitivity analysis of the operating parameters and Multi Objective Genetic Algorithm (MOGA) approach is used to obtain the optimal solution set. The results showed a maximum reduction of 66.33%, 38.10%, and 43.56% for mass flow rate, maximum pressure and power consumption respectively in comparison to equal mass flow rate case whereas the temperature rise and temperature distribution of the battery system remain within the nominal range.
Applied Thermal Engineering, 2021
Abstract The electrical output of the Photovoltaic (PV) cells decreases with the increase in the ... more Abstract The electrical output of the Photovoltaic (PV) cells decreases with the increase in the operating temperature. To address the issue of electrical power drop in PV, a new hybrid collector called photovoltaic-thermal (PV/T) module has been proposed by the researchers. PV/T combines a PV and thermal absorber; it helps in cooling of PV and to harness the waste heat from PV for utilizing in low-temperature applications. However, the cooling uniformity and thermal efficiency remain to be major challenges for the broader applicability of PV/T. In this work, a novel rectangular spiral tube only absorber is developed with a transparent multi-crystalline PV module with absorber tubes directly glued to the PV backside. A novel form-stable composite developed by simple impregnation method using PCM (OM35) and biochar derived from water hyacinth. This novel composite is embedded in the enclosure formed by the PV and back cover to improve cooling uniformity and better absorption of incoming radiation due to the blackish appearance of the composite. In the composite, 5% by wt aluminium metal powder is added. The thermal conductivity of the composite is found to improve by 1.66 times than that of pure PCM, while aluminium metal powder is added. The heat of fusion is calculated to be 78 J/g. The developed PV/T system has been experimentally evaluated under outdoor conditions. The average electrical, thermal, energy and exergy efficiency of the PV/T system with novel form-stable thermal energy storage material is reported to be 13 ± 5.04%, 66.6 ± 5.48%, 79.6 ± 5.53%, and 15 ± 5.58% respectively, whereas the average electrical efficiency PV during the experiment found to be 10.7 ± 5.04%. The electrical efficiency of the PV module used is 14.64% under Standard Test Conditions. There is an improvement of 18.4% in electrical output as compared to PV with this novel arrangement.
Materials Today: Proceedings
International Energy Journal, 2012
In the present investigation, the effects of blending of biomass in sand, superficial velocity an... more In the present investigation, the effects of blending of biomass in sand, superficial velocity and operating pressure on bed hydrodynamics and heat transfer in a pressurized circulating fluidized bed have been studied. Experiments have been conducted at four different percentage blending of biomass such as 2.5%, 7.5%, 15% and 20% in sand and with two different weight composition ratios. All the above studies have been made at two different superficial velocities of 5 and 7 m/s and at three different operating pressures such as 1, 3 and 5 bar. The sand and biomass particle sizes used for the study are 309 µm and 407 µm, respectively. Results show that, with the increase in operating pressure , t he bed voidage decreases . The axial heat transfer coefficient increases from the bottom to the top of heat transfer probe with the increase in operating pressure. The radial variation of heat transfer coefficient decreases from the wall to the core of the heat transfer probe. The heat transf...
INTERNATIONAL CONFERENCE ON ENERGY AND ENVIRONMENT (ICEE 2021), 2021
Gas solid fluidized bed application has gained popularity as an excellent contacting device that ... more Gas solid fluidized bed application has gained popularity as an excellent contacting device that is been widely used in thermo-chemical processes, drying application in food processing industries etc. due to its favorable heat transfer characteristics. Most of the outmoded fluidization activities reported is confined with columnar/cylindrical shaped bed reactors. Conventionally, tapered/conical reactors are used for energy conversion which has substantial dynamic characteristics over the columnar reactors in terms of smooth, steady operation with marginal pressure variation. This work focuses on the computational modelling and simulation on the effect of various parameters like par, Stagnant bed height, Superficial velocity, Minimum fluidization velocity and Heat transfer characteristics upon variation in the taper angle of Tapered Fluidized Bed Reactor (TFBR) using Computational Fluid Dynamics (CFD) solver FLUENT. Two Fluid Model (TFM) is adopted for the simulation studies where both the phases (Solid, Gas) are treated as fluids. The results obtained are compared with simulation conducted for columnar reactor having same axial length. 2D domain has the axial length of 1.2 m and bottom diameter of 0.15 m. Simulation results shows that the finer the particle size becomes, greater is the heat transfer by conduction from bed to wall compared to larger particles. The interphase heat transfer from Solid-Air is maximum in the reactor core section. Although the particle volume fraction is observed to be more in columnar reactor, better fluidization characteristics is observed in reactor with taper angle 4.52°.
International Journal of Energy Research, 2020
This study has dealt with the synthesis and characterization of biochars produced from three biom... more This study has dealt with the synthesis and characterization of biochars produced from three biomasses, viz. water hyacinth (whole plant and its components), yellow oleander, and sugarcane bagasse, and their comparative assessment for potential application in agronomy and energy production. The pyrolysis was carried out in a fixed batch reactor at 350 C and 550 C with a heating rate of 20 Cmin −1. Biochars were characterized for proximate and ultimate (elemental) analysis, and also using standard techniques (SEM, EDX, TGA, BET, XRD, and FTIR). Biochars produced at 550 C from all the feedstock had good properties (carbon content: 39.09-80.74%, pH: 7.36-10.42, calorific value: 16.98-30.18 MJ kg −1 , and ash content: 0.89%-21.78%). Moreover, relatively low atomic ratios (H/C 0.25-0.47 and O/C 0.15-1.11) of all biochars indicated their potential as solid fuel. XRD results showed the presence of amorphous and crystalline structures, and minerals like sylivite, quartz, kalsilite, and tridymite in the biochar. Biochar produced from sugarcane bagasse at 550 C possessed the best properties: fixed carbon (77.42%), bulk density (0.13 kg/m 3), brunauer-emmett-teller (BET) surface area (17.78 m 2 /g), pore size (12.86 nm), total pore volume (0.025 cm 3 /g), calorific value (30.18 MJ kg −1), ash content (1.16%), and moisture content (2.03%).
Sādhanā, 2019
Solar energy is one of the most suitable renewable energy options in India. In the last decade, s... more Solar energy is one of the most suitable renewable energy options in India. In the last decade, solar energy installations have received an ample impetus in India due to active initiatives taken by the Indian government. However, the solar energy potential of country's NorthEastern (NE) part is not utilized effectively so far. In the present study, a comprehensive analysis of the feasibility of installation of a megawatt-level gridconnected solar photovoltaic (SPV) power plant in all the state capitals of NE India is carried out. The climatic data collected from various online sources and NASA climatic database were utilized in designing a 2 MW SPV plant. The theoretical procedure involved in designing the SPV plant is also presented in this study. PVsyst simulation software is used to predict the performance of 2 MW power plants for these eight states of India. From the analysis, it is observed that NE India has an immense potential for installation of solar energy conversion devices and thus it can be harvested economically. It has been observed that locations of Guwahati and Gangtok provide a high performance ratio of 0.855. Aizawl provides the minimum unit cost of electricity generated at a value of 3.88 INR/unit. The analysis also reveals that the Aizawl and Guwahati are the most suitable locations for installation of SPV power plant amongst the NE capitals.
Coal and Biomass Gasification, 2017
Over the years, gasification technology has been established as one of the efficient thermochemic... more Over the years, gasification technology has been established as one of the efficient thermochemical conversion processes catering to a wide variety of applications like thermal, power generation and liquid fuel production through Fischer–Tropsch route. However, there are issues with the conversion devices when the biomass feed material changes and hence understanding of product gas behaviour and its variability is important in order to utilize the biomass gasification technology effectively in the long run. The current chapter addresses these issues relating to biomass characterization, product gas estimation and utilization, and advances in this technology. Furthermore, an example of an equilibrium model formulation for prediction of product gas generated from rice husk has been presented, and a brief about reaction kinetics has been discussed. A comparison of model result and experimental data has also been briefly presented. The recent trends in biomass gasification research show a promising future for this technology. Moreover, techno-economic evaluations prove that biomass gasification is not only technically viable but also a sound economic option. It is expected that biomass gasification will contribute more to the global energy requirements and thus to the economy in the coming future.
Renewable Energy, 2008
Fluoride contaminated drinking water is a severe problem in many parts of the world because of fl... more Fluoride contaminated drinking water is a severe problem in many parts of the world because of fluoride-related health hazards, which are considered to be a major environmental problem today. The present work is aimed at utilizing solar energy for removal of fluoride from drinking water by using a “solar still”. Also tests have been conducted with the “solar still” to
Procedia Engineering, 2013
In the present work, a pressurized circulating fluidized bed (PCFB) unit of 54 mm inner diameter ... more In the present work, a pressurized circulating fluidized bed (PCFB) unit of 54 mm inner diameter and riser height of 2000 mm has been fabricated to investigate the effect of pressure on suspension density and heat transfer. The effects of blending of biomass in sand, and superficial velocity on bed hydrodynamics and heat transfer has also been studied. Experiments have been conducted at four different percentage blending of biomass such as 2.5 %, 7.5 %, 15 % and 20 % in sand with two different weight composition ratios and at a superficial velocity of 5 m/s. Operating pressure is varied from 1 to 5 bar in a step of 2 bar. Results show that, the axial heat transfer coefficient increases from the bottom to the top of heat transfer probe with the increase in operating pressure. The radial variation of heat transfer coefficient decreases from the wall to the core of the heat transfer probe. The heat transfer coefficient is also found to be higher in between the 7.5 to 15 % biomass blending in sand. The overall uncertainty in calculating heat transfer coefficient is found to be 3.90 %.
Journal of Electrochemical Energy Conversion and Storage, 2019
Lithium-ion (Li-ion) battery pack is vital for storage of energy produced from different sources ... more Lithium-ion (Li-ion) battery pack is vital for storage of energy produced from different sources and has been extensively used for various applications such as electric vehicles (EVs), watches, cookers, etc. For an efficient real-time monitoring and fault diagnosis of battery operated systems, it is important to have a quantified information on the state-of-health (SoH) of batteries. This paper conducts comprehensive literature studies on advancement, challenges, concerns, and futuristic aspects of models and methods for SoH estimation of batteries. Based on the studies, the methods and models for SoH estimation have been summarized systematically with their advantages and disadvantages in tabular format. The prime emphasis of this review was attributed toward the development of a hybridized method which computes SoH of batteries accurately in real-time and takes self-discharge into its account. At the end, the summary of research findings and the future directions of research such ...
Related Article: Debabrata Dhara, Debdeep Mandal, Avijit Maiti, Cem B. Yildiz, Pankaj Kalita, Nic... more Related Article: Debabrata Dhara, Debdeep Mandal, Avijit Maiti, Cem B. Yildiz, Pankaj Kalita, Nicolas Chrysochos, Carola Schulzke, Vadapalli Chandrasekhar, Anukul Jana||Dalton Trans.|||doi:10.1039/C6DT04321F
Related Article: Sourav Biswas, Kochan S. Bejoymohandas, Sourav Das, Pankaj Kalita, Mundalapudi L... more Related Article: Sourav Biswas, Kochan S. Bejoymohandas, Sourav Das, Pankaj Kalita, Mundalapudi L. P. Reddy, Itziar Oyarzabal, Enrique Colacio, Vadapalli Chandrasekhar|2017|Inorg.Chem.|56|7985|doi:10.1021/acs.inorgchem.7b00689
Emerging Pollutants - Some Strategies for the Quality Preservation of Our Environment, 2018
Water is a primary element for all living things, and we need water for each and every dayto-day ... more Water is a primary element for all living things, and we need water for each and every dayto-day activity related to agricultural, industrial, and domestic cares and, thus, its quality influences all aspects of human life including energy, food, health, and economy. Safe drinking water is our primary need to protect our life and thus developing efficient and affordable techniques for water treatment to access potable water to the humanity. Water pollution is one of the severe environmental and health problems worldwide. Pollutants in water can be of organic, inorganic, heavy metals, microbial, and radioactive species, which may be in different forms viz. suspended, dissolved, or dispersed materials. The water quality is mainly affected by industrial discharges, agricultural activities, mismanagement of hazardous materials, etc. Nowadays, nanotechnology offers the possibility of an efficient removal of water pollutants including metals, organic dyes, bacteria, parasites, etc. Magnetic nanomaterials like iron oxide (Fe 3 O 4) are very promising materials used in water decontamination particularly for heavy metals and dyestuffs because of their ease of separation through external magnet, high surface area, unique morphology as well as their high stability. These materials can be used as adsorbent, photocatalyst, and coagulating agents for water remediation based on their composite materials or surface functionalities.
Advances in Sustainable Energy, 2021
Coordination Chemistry Reviews, 2021
Abstract Molecular nanomagnets containing heterometallic 3d-4f complexes have been investigated e... more Abstract Molecular nanomagnets containing heterometallic 3d-4f complexes have been investigated extensively for the past few years realizing the role of exchange interaction to minimize the QTM effect. In this context, heterometallic complexes particularly containing CuII-LnIII have encompassed a pivotal role due to the ferromagnetic exchange interaction. Herein we review the Cu/Ln complexes that exhibit single molecule magnet (SMM)/magnetocaloric effect (MCE) in a comprehensive way.
International Journal of Green Energy, 2020
ABSTRACT Electric vehicles that run on batteries have a major disadvantage of temperature abnorma... more ABSTRACT Electric vehicles that run on batteries have a major disadvantage of temperature abnormalities when operated at extreme working conditions. Therefore, thermal management of battery pack is essential to ensure its safety and performance. There are three operation strategies of thermal management air-based, liquid-based, and phase change material-based battery thermal management systems (BTMSs). Optimization studies on BTMSs have been focused mainly on the structural parameters as compared to the operating parameters. In liquid cooled multichannel flow-type BTMSs, equal flow rates are employed in all the channels. However, only a few studies have focused on variable coolant flow rates in channel-type liquid BTMS and its optimization. In this paper, a multichannel cold plate-based liquid BTMS is proposed for Lithium-ion battery pack comprising of two prismatic cells operating at 1 C discharge rate. Multi-objective optimization (MOO) technique coupled with computational fluid dynamics (CFD) simulations is used for obtaining optimal mass flow rate combination of coolant in the channels for reducing the power consumption of the BTMS without compromising on its thermal performance. Response surface methodology is adopted for the sensitivity analysis of the operating parameters and Multi Objective Genetic Algorithm (MOGA) approach is used to obtain the optimal solution set. The results showed a maximum reduction of 66.33%, 38.10%, and 43.56% for mass flow rate, maximum pressure and power consumption respectively in comparison to equal mass flow rate case whereas the temperature rise and temperature distribution of the battery system remain within the nominal range.
Applied Thermal Engineering, 2021
Abstract The electrical output of the Photovoltaic (PV) cells decreases with the increase in the ... more Abstract The electrical output of the Photovoltaic (PV) cells decreases with the increase in the operating temperature. To address the issue of electrical power drop in PV, a new hybrid collector called photovoltaic-thermal (PV/T) module has been proposed by the researchers. PV/T combines a PV and thermal absorber; it helps in cooling of PV and to harness the waste heat from PV for utilizing in low-temperature applications. However, the cooling uniformity and thermal efficiency remain to be major challenges for the broader applicability of PV/T. In this work, a novel rectangular spiral tube only absorber is developed with a transparent multi-crystalline PV module with absorber tubes directly glued to the PV backside. A novel form-stable composite developed by simple impregnation method using PCM (OM35) and biochar derived from water hyacinth. This novel composite is embedded in the enclosure formed by the PV and back cover to improve cooling uniformity and better absorption of incoming radiation due to the blackish appearance of the composite. In the composite, 5% by wt aluminium metal powder is added. The thermal conductivity of the composite is found to improve by 1.66 times than that of pure PCM, while aluminium metal powder is added. The heat of fusion is calculated to be 78 J/g. The developed PV/T system has been experimentally evaluated under outdoor conditions. The average electrical, thermal, energy and exergy efficiency of the PV/T system with novel form-stable thermal energy storage material is reported to be 13 ± 5.04%, 66.6 ± 5.48%, 79.6 ± 5.53%, and 15 ± 5.58% respectively, whereas the average electrical efficiency PV during the experiment found to be 10.7 ± 5.04%. The electrical efficiency of the PV module used is 14.64% under Standard Test Conditions. There is an improvement of 18.4% in electrical output as compared to PV with this novel arrangement.