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The present paper reviewed the studies of the hybrid solar-biomass power plants. Based on renewable energy, several configurations of hybrid power cycles are discussed and summarized. It includes the technical, economical, and environmental aspects of the hybrid solar-biomass plant, how the hybrid power plant works, and the essential resources required for the setup and running of the hybrid solar biomass plant. The advantages and disadvantages associated with the single renewable resource-based power plants are also discussed. The hybrid power plants help rectify the disadvantages over single resource plants, improve the power production rate of the plant, and help it run over seasonally. The present paper also discussed the solar and biomass potential in the Indian context and compared the progress of the hybrid solar-biomass power generation system with other countries.

The extraordinary amount of solar irradiative energy all around the Earth has one of the motivational factors to work with such systems that utilize these for the services towards the benefits of mankind and its progressive growth, and that makes a powerful society and commendable nation. However, in the current era an unavoidable problem for the scarcity of potable water is going on, as brackish water keeps increasing faster than the approachable fresh water resources. For this, solar still systems for water treatment are one of the best solutions that utilize the solar energy as a prime source of working to the system. Out of those systems, energy matrix is one of the important performing factors that indicate the overall usability, payout characteristics, life cycle performing efficiency, etc. of the system. The current presentation reflects that active parameters undertaken in previous studies especially based on the energy matrix for active solar stills. A comparative result has been shown that results better in favor of nanoparticles and lower embodied energetic systems. Based on the overall performances and influencive parameters, a discussion and focused concluding remarks has been framed that suitably justifies the development towards this technology.

Enhancing the heat transfer rate in a double pipe heat exchanger is imperative for decreasing the overall cost of its operation. A popular way to increase the performance of these heat exchangers is using inserts such as twisted tape, perforated twisted tape, twisted tape with peripheral cuts, helical inserts, etc. In this paper, a novel triangular perforated twisted tape with V cut (TPTTV) has been introduced and numerical investigation has been carried out. The proposed inserts is placed in the inner pipe of the double pipe heat exchanger to create a swirl motion and increase turbulence intensity in the flow of the fluid. The simulation has been performed in the laminar flow region to turbulent flow regimes. It is found the best thermal–hydraulic performance at the lower pitch value of 50 mm. The effect of the pitch of the TPTTV insert has been extensively studied and the effect of overall heat transfer, Nusselt number, friction factor, and thermal–hydraulic factor has been reported. The value of the thermal performance factor for TPTTV insert is 1.49 which is more than the thermal performance factor of plain twist tape insert.

The present study proposed the water generating system through humidification-dehumidification desalination unit and RO powered by organic Rankine cycle to generate both power and drinking water from the waste heat of Naval Ship by using a low-temperature organic Rankine cycle. Waste heat from the naval ship is used in order to run the topping cycle namely the organic Rankine cycle for power generation which operates the RO system for drinking water. A water-heated humidification dehumidification (HDH) desalination unit is also integrated with the organic Rankine cycle system to produce additional freshwater. The mass and energy balance equations are designed to analyze the thermodynamic performance of the cogeneration of the power-water system at the designed conditions. Suitable working fluids for the organic Rankine cycle are chosen on the basis of thermophysical properties i.e. lower boiling point, critical temperature & pressure and global warming potential. Furthermore, the impact of various vital parameters like extraction pressure, vapor extraction ratio, condenser temperature, turbine inlet pressure, etc. on the performance. It was founded that the impact of extraction parameters on the cycle, the net power, total efficiency and water production is 16.74 kW, 42.10% and 75.18 kg h−1 respectively. The extraction ratio variation causes the improvement in the water production and power generation and lower extraction ratio has better results. The RO System used is direct mechanical coupling which uses the power to run the system and produces the water, 2.4L of drinking water is produced using 16.74 kW power, respectively.

Due to the lower productivity of solar still, researchers from all around the world are continually ensuing to improve distillate output. Hence, there are lots of opportunities and scope of research work on the solar still. Solar desalination is the process of purification saline water to get fresh potable water using direct solar energy. Seawater is available in abundance but the process of desalinating the seawater is very expensive due to enormous energy requirements. Over the years direct solar energy is used as one of the cheapest desalination methods to drive the desalination systems which has no environmental impact also. The solar-based desalination system is referred to as solar still. The basin water depth is inversely proportional to the productivity of potable water. The difference between saline water temperature and glass temperature controls the evaporation rate. The water surface area is directly proportional to the distillation rate. The water surface area has been increased by submerging the wicks in the water, the use of porous materials, fins, sponge, etc. Instead of a single flat horizontal collector, the cascade style still gives more useful results in terms of desalination. The use of phase change materials helped further in the overall increase in the distillation rate. In the present short review paper research works done in this decade have been considered and four primary methods like the effect of the finned absorber plate, cotton wick, and phase change material and nanoparticles have been discussed. It will help future research in the area of solar still to provide an economically viable solution for sustainable potable water.

The present era is living with very fast growing pace despite having the usual kind of natural resources available that are always we have in a limited amount with expansible and irreversible in nature. It has to be bothered about saving and sustaining our natural resources for better future along with the development of self sustainable, economic and environment friendly technology such as solar decontamination systems. And, current situation with water stress or even costlier potable water availability motivates us to work with such systems that have easy technology, self sustainable, and eco friendly establishment serving the society. This work shows a comparative performance analysis between single and double solar stills with four combinations as with circular and square fin, jute and black cotton wick for energy matrix and enviroeconomic considerations. Still with square fins found better and having less embodied energy (379.62 kWh) comparative to others. It has yield up to 4.55 l/m2/day with 36.6 tons CO2 lessening for thirty years of the overall systems performing life. Equivalent minatory value for the CO2 lessening scored by the proposed system is noticed as $365.63. Further, still have least time recovery for the equivalent energy payout and superior adaptation efficiency of the system through its working of life cycle i.e. 0.48 years, and 0.44 correspondingly.

The enhancement of the heat transfer rate in the heat exchanger is imperative for decreasing the overall cost of its operation. A popular way to increase the performance of these heat exchangers is by use of plain twisted tape, twisted tape with perforation, twisted tape with peripheral cuts, helical inserts, etc. In this paper, a novel twisted tape with trapezoidal ribs has been introduced and numerical investigation has been carried out. The proposed insert created a swirl motion and increased the turbulence intensity in fluid flow in the tube. The CFD simulation has been performed in the turbulent flow regimes with Reynolds number varying from 4000 to 12000. The inclination of ribs has been varied from 30° to 60° and their effects on heat transfer characteristics have been extensively studied. The highest Nusselt number and friction factor are observed with a slant angle of 60° but the thermal performance factor is found highest with a slant angle of 30°. The results are in good agreement with Promvonge model. It is found that the main cause for augmented heat transfer rate observed in twisted tape with trapezoidal ribs is due to higher turbulence intensity induced by trapezoidal ribs.

Energy demand throughout the world is rapidly increasing and to fulfill that demand, a large amount of fossil fuels is used in majority of the power generation systems. High use of the fossil fuels causes massive environmental pollution and GHG. These issues can be addressed to a great extent by using biomass materials as a substitute to the fossil fuels. The biomass materials require certain systems, to ensure high conversion efficiency into thermal and electrical energy; one of such systems is the biomass gasifier. In this study a downdraft gasifier is coupled with a dual fuel engine. When the producer gas is blended with diesel in a dual fuel engine high amount of nitrogen is present in the producer gas, but the temperature of the combustion chamber is low so nitrogen behaves like an inert gas and because of this 67.8% NOx emission is reduced. A reduction of 60% in GHG emission is observed. The noise level is increased slightly.

Efficient utilization of renewable energy by reducing the dependency on conventional energy sources has become the major concern currently in the field of engineering and scientific research in order to mitigate the environmental issues caused by the conventional sources. There are many researches happening worldwide for reducing building energy consumption by introducing passive concepts. The present work reviews such passive solar concepts and its integration in building envelope design to provide thermal, lighting and acoustic comfort for occupants residing in the building without the help of any conventional space heating and cooling techniques.

There are two major classifications of augmenting heat transfer: passive and active. In the active technique, external energy is supplied to the fluid by mechanical rotation of the surface, the mixture of fluid with mechanical accessories, etc. On the other hand, the passive technique does not use any power. The technique includes twisted tapes, coiled wire, rough surfaces, extended surfaces, surfaces coated devices to generate turbulence. Many inserts induce secondary flow favoring thermal heat exchange. This review article will focus on enhancing the heat transfer and associated pressure drop with the flow boiling using coiled wire as a turbulent promoter. The insert breaks the boundary layer of the fluid at the solid-liquid interface near the inner wall of the pipe. Insert also creates turbulence and rotary motion within the test section, this makes turbulent flow leading to better heat transfer by convection. Helical wire produces a helical flow to the periphery superimposed on the main axial flow. The augmented heat transfer with two-phase flow boiling using coiled wire studied experimentally in recent years by many investigators. Scanty literature is available on analytical work and numerical simulation. However, the reliability and error band does not quantify such work for system design. Most of system design and selection is based upon experimental data and proposed correlations for heat transfer and pressure drop. In this paper, a comprehensively relative study of such work is critically reviewed and presented.

Energy conservation and system cost minimization are important aspects of heat exchanging devices. In industrial and domestic applications, various types of heat exchanging systems are utilized for the exchange of heat. The concerted efforts are made to design and develop the heat exchanger, which requires a lower space requirement, less material and other operational costs. The thermal performance of the system is improved by the insertion of twisted tape in the flow, which promotes turbulence intensity. Researchers have tried active as well as passive techniques for system thermal performance enhancements. These systems usually minimize the thermal resistance by improving turbulence in the fluid domain or by increasing the effective heat transfer surface area. Sometimes, doing this will increase the required pumping power which increases the operating costs, which is surely a demerit. The effectiveness is expressed in the form of thermal-hydraulic performance, a thermal performance factor. It is obtained from the heat transfer rate and the friction factor, with and without using inserts in the tube. Different types of inserts are being attempted to use in heat exchanging devices. Several parameters of the inserts like the length of inserts, the width of inserts, the pitch of inserts, etc., have been used for experimentation. Also, the different effect ratios like twist ratio, clearance ratio, width ratio, etc., have been studied. In the current work, research study of different types of twisted tape and their modifications has been critically reviewed and presented. The experimental and numerical aspect has been presented.

The depletion of fossil fuels and environmental concerns has compelled the research community to explore the utility of solar energy for all societal needs. The parabolic trough collector (PTC) receives the parallel rays of solar energy and converges it on a line where the receiver tube is installed. The receiver tube is a circular pipe of high thermal conductivity through which the heat transport fluid flows to utilize solar heat energy. The fluid used in the receiver is normally water, synthetic oils, etc. The use of such fluid helps us to absorb more thermal energy than that of base fluids. The thermal efficiency of the PTC can be further elevated by using fluids having enhanced thermal property. Researchers used different nanofluids to analyze the thermal collection energy enhancement. A PTC with nanofluids flow has been modeled and solved numerically using available software. The heat flux on the outer surface of the receiver tube is constant in the circumferential direction as well as in the longitudinal direction. In this work, effect of symmetrical heating loading over the PTC by applying over the outer surface has been studied numerically.

The paper contains the experimental investigations on the pressure drop for the two phase flow in the flow boiling of refrigerant with the insertion of twisted tape in the horizontal circular tube. The Pressure drop analysis, based on data using the twisted tape is performed using the refrigerant R-407C in a horizontal tube with the inner diameter 13.4mm and 2m long. Twisted tapes with twist ratio 9, 14 are used for the predictive results. The experimental investigation was carried out with the operating condition: i)Refrigerant mass flux:100-350 kg m−2s−1 ii) heat flux: 0-10 KWm−2 iii) evaporating pressure 3-8 bar iv) evaporating temperature −15 to 15 °C v) vapor quality 0.05-0.9. The available literature was consider for the comparison of experimental and predictive pressure drop. It showed that the Kanizawa and Ribatski proposed pressure drop correlation is suitable to use, present data base 99% of the error band with ±30 %.

Self-healing material are gaining interest of the researchers in the direction where material can mimic biological process of healing, for an example, healing of wound on skin, reunion of broken bone segment, etc such invincible process of healing, is still a fantasy. Several publications are available on polymer based self-healing composite material compared to other materials like metals, ceramics etc. The self-healing of polymers requires less energy because of weak bond strength compared to metallic bond strength. Self-healing enhances the mechanical properties of materials which can significantly increase the service life of structural or mechanical member. In metallic materials, Self-healing at nano-scale level is limited to crack closer at same scale level only. Once crack is reached a level above nano scale, it tends to grow because of crack coalescence. Disintegrated Melt Deposition technique and Semi Solid Metal processing techniques are discussed to develop Nano SMA based self-healing alloy. In this paper, recent works of self-healing metallic materials have been covered.

The present work deals with the thermodynamic analysis of a solar-powered triple combined power cycle to generate emission-free power. The triple combined cycle comprises one topping cycle as Brayt...

A renewable thermal energy collection device was built and metallic oxide nanofluids namely cerium oxide, aluminium oxide and titanium oxide in base fluid water were used. At 3 vol% and a flow of four litres per minute, the renewable energy collector efficiency was computed and compared with the values obtained using water as the working fluid. It was observed that by using Ceria, Alumina and Titania nanofluids, collector efficiencies of 60%, 58% and 56% were achieved respectively. When compared with the values obtained by using water, the efficiency enhancement was 27% for Ceria, 25% for Alumina and 23% for Titania nanofluids.

Conventional fluids used for heat transfer applications in solar thermal devices such as solar thermal collectors limit the performance enhancement and compact size preference of the collectors. This limitation can be overcome by using unconventional class of working fluids called nanofluids. The present work aims to prepare nanofluid and study its various thermal and physical properties for use in the solar thermal collectors. Cobalt oxide nanoparticles are added to de-ionized water along with decyl glucoside surfactant and bath sonicated to homogenize the fluid. Concentration of Cobalt oxide nanoparticles varying from 0.1vol% to 0.4vol% are prepared and at different volume fractions the thermo-physical properties of the nanofluid such as relative viscosity, and thermal conductivity are measured over a temperature range limit of 30oC to 60oC. Results showed that relative viscosity values showed a decreasing trend with temperature and increased with the increase in the volume fraction of nanoparticles. The thermal conductivity ratio of the nanofluid increased and showed a maximum value of enhancement up to 25 %.

The world’s energy demand is growing day by day and with ever expanding urbanization and better set of living standards it is expected to increase more in the coming future. At this increasing rate of fuel consumption, it has become evident that biodiesel is going to make a considerable contribution to the future energy demands of the human population. Biodiesel can be obtained from edible as well as from non-edible oil sources however considering the substantial increase in the population and the expected food and resources requirement in the future, the biodiesel from non-edible oil sources is considered a much safer and optimal solution. Moreover the feedstock for non-edible oil sources are much cheaper than that of edible oil sources hence helping in the much needed cost cutting. Also today’s energy sources are creating much pollution too and hence these alternative fuel sources if cannot completely eradicate, should at least release less amount of harmful gases and cause less damage to the environment. Keeping in mind the alternative fuel needs of the future and the toxicity and harmful gases emission. In this paper the emission characteristics of various biodiesels from non-edible oil sources is analyzed

The electrical conversion efficiency of Solar photovoltaic module strongly depends on the operating temperature. Only up to 20% of the incident solar irradiation is converted to electricity and rest energy either reflected back to atmosphere or converted into heat and thereby increasing the cell temperature. As the cell temperature rises, the electrical efficiency decreases. There is need to cool down temperature of the solar photovoltaic panel to get maximum electrical conversion efficiency. Researchers have implemented many techniques for cooling solar PV by active and passive cooling technique. Active cooling uses air, water, nanofluids etc for cooling where as in passive cooling uses of phase change materials like paraffin wax, eutectics, organic materials, cotton wick etc for the cooling purpose. Nanofluids are used to bring down the temperature of the panel by increasing the thermal conductivity of base fluids. In this paper, emphasis has been given to present the effect of nanofluids as coolant in solar photovoltaic panel.

Phase change materials (PCMs) are utilized effectively for the purpose of storage of thermal energy. It provides certain advantages such as isothermal storage process and high energy storage density. A large number of phase change materials in a wide range of temperatures are being researched upon for making them useful and employable in latent heat storage systems for different purposes. The desirable and undesirable qualities of different types of PCM have been included in the paper to give the readers an insight into what qualities are required in a PCM to be useful for different practical applications. Various applications of PCMs in solar air heater and water heater, solar greenhouse, solar cooker, trombe wall and wallboards are discussed and their uses in refrigeration have also been reported in this paper.

Hydrogen gas is environmental friendly and harmless energy carrier. It will be very crucial and future sustainable energy system due to rapid depletion of fossil fuel and greenhouse gas emission. Application of hydrogen gas is being promoted because the by-product is pure water which is pollution free. One of the major impediments for the transition to a hydrogen based energy system is the lack of satisfactory hydrogen storage alternatives. In recent years, various hydrogen storage materials have been extensively studied. But, still there are challenges to use them in engineering products due to energy consumption in storing and release of hydrogen. Sodium Silicide (NaSi) is a chemical compound that which reacts with tap water at atmospheric conditions and produces hydrogen gas. In this paper possibility of use of NaSi as a source of release of hydrogen gas usage has been reviewed. Storage of hydrogen is not required. Different energy storage materials and their challenges also have been discussed very briefly which can be used in fuel cells. Main focus of this paper is to highlight the application of NaSi as a portable source of energy which can be used in the fuel cells for various power applications.

A renewable solar parabolic trough collector with water flow condition in the laminar flow zone and turbulence flow zone is simulated and analyzed using computational fluid dynamics (CFD) software. CFD modeling is considered for copper absorber pipe with one half surface of the pipe exposed to direct solar radiation and other half exposed to reflected solar radiation. The modes of heat transfer applicable for the model being conduction heat transfer between the tube metal surface to the circulating water and the mixed convection heat transfer in the circulating water inside the tube. An experimental model was built and experiments were performed at 1 LPM (Laminar zone) and 5 LPM (Turbulence zone) flow rates. To correlate the findings with simulation, a CFD model is developed and the 3-D temperature distribution and velocity distribution inside the collector tube was studied at laminar zone and turbulence zone of the water flow. The model predicted the outlet temperature of the water and the outlet velocity from collector tube in different flow conditions and the same is compared with the experimental data at varying solar radiation and there exists good correlation between them.

In present work, an attempt has been made to study the experimental characterization of Iron-ore suspension. Characterization of iron-ore suspension depends on physicochemical, morphological and flow characteristics. In this context, physical, chemical and flow properties of iron ore slurry had been investigated at solid concentration ranging from 20-50% (by weight). Rheological experiments were performed at shear rate ranging from 0-600 s-1. From experiments, it is observed that iron-ore slurry shows the Newtonian flow characteristics up to 30% solid concentration (by weight). Results showed that apparent viscosity of slurry increases with solid concentration. The modelling results obtained from Rosin-Rammler (RR) model found to be in good agreement with experimental data of mass distribution function F(d) as compared to Gates-Gaudin-Schumann (GGS).

For past decades, excessive extraction of fossil fuels to cater the energy demands of ever rising population and industrial growth has resulted in situation to look for alternative resources of energy. In addition, endless use of petroleum based fuels like diesel have caused in environmental degradation. Different alternative fuels like biodiesel, alcohols fuels (ethanol, butanol, pentanol), hydrogen, Liquefied Petroleum Gas (LPG), methane, and Compressed Natural Gas (CNG) have caught the attention of researchers around the world due to similar performance and improved emission characteristics compared to fossil diesel.This work dealsabout investigation of physical and chemical properties of ethanol & diesel blends .The focus is around the properties which impact the infusion properties and motor attributes, ethanol and diesel fuel mixes are measured by prerequisites for the diesel fuel. The result shows that 15% ethanol diesel fuel mixes utilizing ethanol as a transportation fuel could display preferable environment execution over ordinary gas in the terms of an Earth-wide temperature boost and fossil fuel utilization. The result also shows that HC and CO emissions are low in case 15% ethanol/diesel blends as compared to diesel.

In today’s world, as electricity consumption is increasing, people are more dependent on electricity. Solar Photovoltaic system is one method to generate electricity. The conversion efficiency of solar photovoltaic panel depends on atmospheric condition and reflection. The operating temperature of photovoltaic module plays an important role in performance of PV system as efficiency of PV system decreases when temperature module increases. The operating photovoltaic cells at high temperature degrades the material of it in long time. Operating solar photovoltaic at lower temperature will increase its lifespan. This will reduce module surface area by increasing overall output power. Researchers have proposed and tested several cooling techniques for the panel. One of the most common and effective way to cool PV module is used of water as coolant. In this paper, efforts made by various researchers to cool down solar photovoltaic module to increase the efficiency using water application have been discussed. The application of water on front surface, rear surface, both front and rear surface have been reviewed extensively. The performance of module by immersion in water also have been reported.

Energy conservation and cost minimization are important aspects of heat exchanging devices. In the heat exchanger, concerted efforts are going to improve the heat transfer augmentation. Researchers tried active as well as passive techniques for it. In the current work research study of different types of twisted tape, twisted wires have been critically examined in recent years. The experimental and numerical aspect has been presented. This will help the system design for the maximization of heat transfer and minimization of the pumping power of the thermal systems.

With the increasing demand for renewable energy sources and the huge gap between the demand and supply conditions, measures have been implemented to enhance the productivity of the existing renewable energy sources. The sun supplies an ample amount of light and heat, which can be converted into abundant and safer solar energy. Photovoltaic (PV) cells can be employed for the conversion of abundant solar energy to useful electricity. But the issue of heating up of the PV cells drastically reduces the conversion efficiency of the system. Hence, there is a need for some additional arrangement to this system that can arrest the temperature rise of PV. This paper is a review of such systems that employ eutectic for the thermal regulation of the PV panel. It is a passive cooling technique which can be utilized very easily and cheaply .

Recent studies on the potential of the nanofluids on the performance enhancement of the parabolic trough collectors seem to be pointing toward development of the next generation of the solar collectors having great potential to be used for co-generation with integrated solar thermal systems. To achieve it, most researchers are investigating the superior performance of non-conventional heat transfer fluids, such as the nanofluids. The present paper is an effort to review recent research efforts on the performance of parabolic trough collectors using nanofluids. Studies on the various properties of nanofluids seem to be suggesting the positive impact of these fluids in increasing the heat transfer characteristics. The concurrent studies carried out to use nanofluids in coupled solar thermal systems are likely to enhance the process of heat energy collection from the sun in a highly concentrating trough type collector. The objective of the current study is to report recent progress on thermal efficiency enhancement in the parabolic solar trough collector using nanofluids. Experimental and numerical simulation results have been covered by referring to recent research papers. This work will act as a valuable tool to future researchers.

In the present study, the effects on the thermal performance of nanofluid in flat-plate solar collector are studied experimentally. The thermophysical properties (thermal conductivity, viscosity, density, and specific heat) of CeO2–water nanofluid measured with a wide range of volume concentrations (0.25–2.0%) using 30 nm particle size. Maximum enhancement in thermal conductivity is observed up to 41.7% at 1.5% volume fraction of nanofluid at an 80 °C temperature in comparison with the base fluid. Viscosity decreases with increasing the temperature but increases with a particle volume concentration of nanofluid at a particular temperature. The experimental setup fabricated for the study of heat collection using a flat plate. The mass flow rate of nanofluids was adjusted (at a given volume concentration) for experimentation. The collector temperatures, ambient, and tap water temperatures, radiation, and wind speed were measured. Experimental results exhibit that the maximum collector efficiency is obtained up to 57.1% at an optimum concentration with a mass flow rate of 0.03 kg/s. The results show that the CeO2–water nanofluid as working fluid improves the collector efficiency in comparison with water as a working fluid. This also has been observed that the thermal efficiency of collector increases with a decrease in the temperature reduced parameter.

The recessed ceiling light emitting diodes (LED) lights or downlights are installed in a hole (cavity) in the ceiling of a building. The air surrounding LED circulates due to natural convection and carries heat from the LED light to the concrete. LED lights use electronic chips operated by a controlled direct current that is obtained from converting the alternating current to direct current by an electronic circuit. Thus, the heat is generated and the temperature of LED increases which affects LED performance and life adversely. In this paper, the momentum and energy equations are solved using Ansys FLUENT. The procedure for an axisymmetric analysis has been developed. Two cases - the air inside the cavity and an extended air envelop below the LED light in addition to the air in the cavity have been compared. The interaction between air in the cavity and in the room shows significant advantage and maximum temperature reduces to 403 K as compared to the isolated air in the cavity at 438 K. The study shows that the natural convection currents can influence the heavier air away from the heating zone also resulting in increased heat transfer.

Concentrated solar power is one of the ways to convert solar energy into process heat or electricity. Now a day's different types of collectors are available but Parabolic Trough Collector (PTC) is used in the current study. The basic working principle for this type of collector is that it receives the parallel solar rays on the collector after reflection converges linearly on the absorber tube which is a circular pipe through which the fluid flows and thus solar energy is transferred to the fluid. The solar energy is thus utilized in heating the fluid flowing in the absorber tube. The solar radiation effect after the reflection from the collector has been modeled using the Monte Carlo Ray Tracing technique (MCRT). The heat flux is uniform in the longitudinal direction of the tube but it varies in the circumferential direction of any axial location. Most of the authors used constant heat flux on the collection tube. The current study aims to apply the unsymmetrical heating load over the absorber tube of PTC to perfectly simulate the actual condition.

Over the past few decades, the world has started moving towards renewable resources of energy from non-renewable resources for meeting today’s energy demand. The solar energy is available abundant in nature and easy to harvest it, and provides a natural solution to move ahead in fulfilling the energy requirement. The solar photovoltaic cells convert solar energy to electrical energy. In general, the regular PV module cell converts nearly about 5–18% of the incidental solar radiation into electricity, and in order to maintain energy balance nearly 60% of incidental radiations are converted in the form of heat energy and with scientific and experimental analysis; it is already pre-determined that with increase in internal PV cell temperature there is an exponential decrease in electrical efficiency of the solar cell gradually with this alternate cooling and superheating process over a time period thermal stresses are formed in solar cell which eventually degrades the cell. A practical way of marginally increasing the output efficiency of solar PV cell is to decrease the operating and surrounding temperature of solar PV, which can be achieved by maintaining a stipulated temperature when solar photovoltaic cell is in operation. Therefore, in the following work, a novel passive technique of cooling has been introduced by basic principles of evaporation using sand dunes concept of cooling and will be investigated experimentally.

Nanofluids have found their applications in various fields of heat transfer and their demand in various industries in ever growing. Pool boiling of nanofluids has always been a topic of great interest and research. In past years, a lot of experimental works have been done on various nanofluids and base fluid solutions to study about the influence of nanofluids on critical heat flux and heat transfer coefficient. Through these works, various factors such as surface roughness, wettability, contact angle, and particle deposition have also been studied as how these factors influence CHF. This paper also focuses on the past work and studies done on nanofluid pool boiling comprising of the very existing data.

In the present, the parameters responsible for head loss have been optimized by using Taguchi approach. The head loss characteristics in transportation of slurry are function of various parameters like solid concentration, flow velocity and additive proportion. Present investigation is focused to recognize the most influencing parameter for the head loss in 90° pipe bend. Several influencing parameters of head loss are optimized with the help of the Taguchi method. L16 array is used for experimental design of process parameters. The S/N ratio for head loss is characterized by using smaller-is-better rule. The solid concentration of slurry was varied from 30 to 60% (by weight) for flow velocity range of 2–5 m/s. Series of experiments are performed on pilot plant test loop to obtain head loss in pipe bend. Results obtained from experimental design reveal that flow velocity is found as a dominating parameter as compared to solid concentration and proportion of additive. Probability plot reveals that the experimental data follows the 95% level of confidence.

Most of the conventional Solar Photovoltaic module consists of a Silicon cell that converts sunlight into electric energy. The process of conversion into electricity is exothermic and all photons are not able to produce electricity due to insufficient energy. Depending upon efficiency to convert it into electricity only the small amount of radiations are used and rest all are involved in increasing the temperature of the module. Study shows that 80% of incident solar radiation are absorbed by a solar photovoltaic cell. This increases the temperature of the module, reduces its electrical efficiency. This increase in temperature affects the power output and lifespan of the PV module. So to maintain the temperature of the module various cooling methods such as air cooling, hydraulic cooling, heat pipe cooling, cooling with phase change materials and cooling with nanofluids have been reported in the literature. The use of suitable nanofluids is one of the effective methods to increase thermal capacitance and control the temperature rise of the PV module. To increase the performance of the system thermal properties of working fluid must be improved which is achieved by using suitable additives with the base fluid which are referred to as nanofluids. Using Copper oxide/water as a working fluid analysis was performed. It was concluded that performance can be improved significantly if we integrate the system with a good heat exchanger. In this paper, the effect of CuO based nanofluids as a cooling medium for a PV module has been reported.

In a nuclear reactor, loss of coolant accident (LOCA) considers wide range of postulated damage or rupture of pipe in the heat transport piping system. In case of LOCA with/without failure of emergency core cooling system in a Pressurized Heavy Water Reactor, the pressure tube (PT) temperature can rise significantly due to fuel heat up and gross mismatch of heat generation and heat removal in the affected channel. The extent and nature of deformation is important from reactor safety point of view. Experimental set-ups have been designed and fabricated to simulate ballooning (radial deformation) of PT for 220 MWe IPHWRs. Experiments have been conducted using voided PTs at 4 and 6 MPa internal pressure at different heating rates. It is observed that at 4 MPa and 6 MPa internal pressure, the PT sagged at about 500 °C before the ballooning initiation. The ballooning initiates at a temperature around 625 °C and contact between PT and Calandria Tube (CT) occurs at around 680 °C, respectively, for 4 MPa and the same was at 550 °C and 640 °C for 6 MPa. The structural integrity of PT is retained (no breach) for all the experiments. The PT heat up is found to be arrested after the contact between PT and CT, thus establishing the moderator acting as an efficient heat sink for IPHWRs. A thermal creep model ‘PTCREEP’ has been developed to predict creep behaviour of the PT of IPHWR. It is found that the contact time predicted by PTCREEP is very close to the experimental result. Hence, PTCREEP can be used for the prediction of the ballooning behaviour of the PT for IPHWR in case of LOCA for the operating temperature and pressure range.

Pressure tube (zirconium 2.5 wt.% Nb) serves as a pressure boundary for the coolant that removes nuclear heat generated in the reactor core of Indian Pressurised Heavy Water Reactors (IPHWRs). Under postulated low frequency ( −6 per year) accidents like Loss of Coolant Accident (LOCA) along with failure of Emergency Core Cooling System (ECCS) injection, heatup of pressure tube (PT) combined with internal pressure and the weight of the fuel bundle may lead to deformation. The extent and nature of deformation is important from reactor safety point of view. An experimental set-up has been designed and fabricated to simulate sagging (downward deformation) of PT due to its own weight and the weight of fuel bundles for 220 MWe IPHWRs. Experiments are conducted at different heatup rates of voided PTs. It is observed that sagging initiates at a temperature around 450 °C. Contact between PT and calandria tube (CT) occurs at around 585–625 °C, respectively. Once PT–CT contact takes place, PT temperature either decreases or the temperature rise remains controlled whereas CT temperature keeps on increasing for next 20–30 s. The contact location in all the experiments was near the centre of the tube. Structural integrity of PT is retained (no breach) for all the experiments. The PT temperature rise is found to be arrested after the contact between PT and CT, thus establishing that moderator acts as an efficient heat sink for IPHWRs.

Titania nanofluid is procured and six different volumes fractions are prepared and homogenised. The nanofluid is subjected to experimental study in a built sustainable solar thermal energy collector model. Theoretical models for the calculation of pressure drop are used and the values are compared with results obtained using experimental setup. The experimental values obtained are on the higher side. At a volume fraction of 3% of the titania nanofluid, the collector exhibited thermal efficiency of 56% with a pressure drop of 16 mm of water column. This is compared with values using water with 28% thermal efficiency at a pressure drop of 4.5 mm of water column. Finally, a model is developed to predict the pressure drop and thermal efficiency by using TiO2-H2O nanofluid in a solar thermal energy collector.

Co3O4-H2O solution along with surfactant is subjected to magnetic stirring and ultra-sonication at 60°C. The obtained homogenous dispersant was divided into four samples of varying volume fractions 0.1vol% to 0.4vol%.Each sample was filled in a metered tank and recirculated in a closed loop solar thermal collector. The setup was subjected to incident solar flux with an average value of 650 W/m2.At a constant fluid flow of 4LPM, the heat transfer coefficient was evaluated for different volume fractions of nanofluid. The obtained values are compared with the values for water as the working fluid. It was observed that at 0.4vol% of nanofluid and 60°C fluid temperature, the heat transfer coefficient increased by 8% when compared to the values for water.

The economy of a nation depends critically on the availability of the energy resources such as fossil fuels and with rapid industrialistion and growth in population there is rapid increase in the demand of energy and fossil fuels. Non-edible oil derived biodiesels can be have future prospect. These non-edible oil source Jatropha and Pongamia are perceived as most important species for biofuel development in India. The study reveals that fuel consumption per unit brake power for Pongamia biodiesel (PB60) is 30% higher as compare to diesel while for PB30 blend it is 10% higher while BTE of PB100 is lower as comparable to diesel while for PB20 it is similar to that of diesel. The study shows that Pongamia blend PB20 performance characteristics are comparable to that of diesel with lower emission it can be recommended as an alternative to diesel.

In Indian pressurized heavy water reactor (PHWR), loss of coolant accident with simultaneous failure of emergency core cooling system can lead to significant temperature rise in the pressure tube (PT) with the system internal pressure varying from 9 MPa to 0.1 MPa during the event. This high temperature can cause metallurgical and geometrical changes in the PT. PT would deform plastically due to internal pressure and fuel weight. A computer code “PTCREEP” based on physical models was developed to simulate the ballooning deformation expected during the channel heatup condition under internal pressure. This paper presents the assessment of the code PTCREEP against the set of experiments conducted with PT material used in Indian PHWRs.

A study has been carried out by experimental simulation of the loss of coolant accident (LOCA) in an Indian pressurized heavy water reactor (IPHWR). The experiment has been carried out taking a completely voided fuel channel of Indian PHWR at 40 bar inside pressure as test-section. In order to simulate the rate of heat generation during LOCA, the pressure tube (PT) was electrically heated with a 12VDC/3500A rectifier. Initially the set-up was maintained at 300 °C temperature by resistance heating of PT. After attaining nearly steady state a step input of 21 kW electrical heating was given to the test-section which resulted in the temperature rise of PT with a gross rate of 2.8 °C/s. The ballooning deformation of test-section tube i.e. PT initiated at 575 °C temperature. With the progress of ballooning the rate of temperature rise was reduced due to high heat transmission to CT and subsequently to water in the tank surrounding CT. The pressure tube (PT) and calendria tube (CT) contact established at the average PT temperature of 680 °C. The contact was also confirmed from the average temperature profile of CT.Copyright © 2010 by ASME