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Spray drying is a widely used technique for production of milk powder. This is a high level energy consumption process. There are scanty published studies on single-stage spray drying plant for skim milk powder production. In this study, thermodynamic analyses, i.e., energy and exergy analyses and exergoeconomic analysis of single stage spray drying unit has been executed for skim milk powder production. The analyzed parameters are specific exergy destruction ratio, exergy efficiency, relative irreversibility factor, energy improvement potential, exergy improvement potential, specific energy destruction ratio, energy efficiency, and relative energy destruction ratio. The energy and exergy equations were used for computation of these parameters. The energy efficiency and exergy efficiency of plant were computed as 89.63 and 49.19%, respectively. The energy and exergy improvement potential were maximum for drying chamber followed by booster pump, which indicated that there was vast scope in the technical improvement for drying chamber. Highest cost of processing was obtained for drying chamber (percentage relative cost difference: 59.84%) followed by cyclone separator (percentage relative cost difference: 48.98%). Based on these analyses, improvement of high improvement potential components of the spray drying plant may be carried out. [ABSTRACT FROM AUTHOR]

[Display omitted] • TJPN nanofluids with silver color balls have performed by SDESS. • It is used the different water depth and ratios of TJPN studied in SDESS. • In some cases, the average exergy efficiency is 2.4% (Double effect) and 3.5% (single effect). • Thermal maximum exergy efficiencies have improved by 17.5% and 21.3%. • The energy and exergy efficiency of DESS with TJPN is 41%, and 5.63% (20%) at a water depth is 0.8 cm. • The overall result for SDESS production is 7.35 kg m−2 per day with TJPN (30%). The implementation of bioactivation nanofluid in single and double slope solar stills (SDESS) is an important aspect from thermo-economic point of view. Based on efficient thermal modelling, a comparative analysis of nanofluids is also suggested for design optimization of solar stills. To develop SDESS observations, the data is taken for the period from January 2021 to April 2022, at KLEF in India. To create green TiO 2 nanoparticles using eco-friendly bleaching chemicals and jackfruit peel (Bioactivation), a green nanoscale approach is used. The performance of the double-effect solar distiller (DESD) is demonstrated using various TiO 2 /Jackfruit peel nanofluids (TJPN) (5%, 10%, 15%, 20%, 25%, and 30%) with silver colour balls. The SDESS results are presented as energy (41%) and exergy (5.63%), with the TJPN having the highest efficacy (20%) based on water depth of 0.8 cm. With a water depth of 0.8 cm over the course of a 12-hour observation period, the total SDESS efficiency result is 7.35 kg/m2 per day and TJPN for 30%. An economic analysis of SDESS is found with the cost of concentration that portable water (per litre) and appraised around 0.0726$ by reimbursement term of 14 months. The average thermo-enviro-economics analysis of SDESS is 3.35 (exergy) and 4.71% (Energy). For 0.8 cm of water depth and an analysis of the weather for good life cycle units, SDESS concentrates 7.97 tonnes of CO 2 emissions. Additionally, the analysis of TJPN optimization by the SDESS is done for 5%, 10%, 15%, 20%, 25%, and 30% and is based on the theoretical yield at the maximum water temperature and water depths of 0.6, 0.8, 1 and 1.2 cm. [ABSTRACT FROM AUTHOR]

• Prism shaped solar still (PSS) has better heat retaining capacity than conventional solar stills (CSS). • With Lauric acid, PSS yields 2530 ml/m2 compared to CSS yield of 2360 ml/m2 with exergy efficiency of 1.01 % and 0.87 % respectively. • Black phosphorus doped Pyrex glass Quantum dot (QD) material able to absorb the large spectrum of solar radiation. • With QD and PCM, PSS yields up to 3685 ml/m2 compared to CSS yield 3040 ml/m2. • Cost analysis shows per liter of distilled water incurred INR 1.6 and 1.9 with payback period of 2.8 years and 3.2 years. The present article takes the challenge to improve solar still performance by surface coating for better energy conversion. An experimental investigation has been conducted on two solar still (SS), namely conventional solar still (CSS) facing the south direction and prism-shaped solar still (PSS) facing the east–west direction in the metrological condition of Varanasi (25.31° N), India. SS's surface solar absorptance and heat storage capacity has been modified by black phosphorus quantum dot material (BPQD) and Lauric acid. The experiments were conducted in three phases, namely SS without BPQD and PCM; SS with PCM only; and SS with BPQD and PCM on different days in nearly the same climatic conditions that showed prism-shaped solar still coated with BPQD material performed better due to its good heat retention capacity than CSS. The results showed that CSS and PSS without PCM and BPQD yield up to 1660 ml/m2 and 1830 ml/m2 with a heating efficiency of 19.72 % and 0.36 % and exergy efficiency of 25.59 %, and 1.08 %, respectively. While using PCM only, CSS and PSS yield up to 2360 ml/m2 and 2530 ml/m2 with heating efficiency of 27.84 % and 0.87 % and exergy efficiency of 35.12 % and 1.01 %, respectively. Whereas, with PCM and BPQD, SSs can produce 3040 ml/m2 and 3685 ml/m2 with exergy and heating of 1.79 % and 37.23 % for CSS, 2.20 %, and 49.30 % for PSS. Moreover, the economic analysis showed that the monetary and energy cost of distilled water incurs only INR 1.9, and INR 1.6 for each liter and INR 2.84 and 2.48 for each kWh with a payback period of 3.2 yr. and 2.8 yr. for CSS and PSS respectively. [ABSTRACT FROM AUTHOR]

India's annual Khoa (Heat Desiccated Milk Food) production was approximately estimated as 7.58 × 106 MT in the year 2019. The khoa is consumed in huge quantities for preparing Indian sweets and; the magnitudes of steam (2365 kg/MT) and electricity (89.23kWh/MT) consumptions in this activity are quite high. In view of this, the present research is an effort to summarize the main derivatives from thermodynamic as well as enviroeconomic analysis of a khoa production unit along with comprehensive assessment, pertaining to mitigation of harmful emissions post adoption of clean energy solution (PV Panels). The aforementioned approaches provide detailed information about qualitative and quantitative aspects of energy consumptions, destructions and improvement potentials along with clear information about mitigation of CO2 (840 Tonnes) during lifetime operation of unit. The exergy efficiency and specific exergy destruction for khoa production unit were enumerated as 26.80% and 665.90 kJ/kg, respectively. The energy efficiency, exergy efficiency, energy improvement potential and exergy improvement potential of steam generation unit vary in the range of approximately 22–99%, 0.25–94%, 0.06–490 kW and 2–15098 kW, respectively; while on the other hand energy efficiency, exergy efficiency, energy improvement potential and exergy improvement potential of khoa production unit found to be in the range of approximately 40–99%, 25–88%, 0.01–38 kW and 0.001–14 kW, respectively. The investment made (10,737 $) for production of clean energy (electricity) will generate an approximate economic saving of 4500 USD/year with a payback period of 6.8 years in line with revenue attainment of 12,180 $ for the lifetime operation of unit. [ABSTRACT FROM AUTHOR]

The proposed research work presents the performance analysis of the vertically mounted bifacial module (VBFM) with and without tracking during the summer and winter seasons. Also, various parameters like energy efficiency, electrical efficiency, electrical exergy, thermal exergy, exergy efficiency, environmental analysis, economic analysis, exergoeconomic analysis, enviroeconomic analysis, and exergoenviroeconomic analysis of the VBFM were studied and presented. The comparative analysis was carried out between two bifacial solar modules installed in two different orientations (east–west and south-north). The experiments were conducted in the real climatic condition of Minjur, Tamil Nadu, India. Under the summer and winter climatic conditions, when the lifetime period of 10, 15, and 20 years are considered higher energy production factor and higher life cycle conversion efficiency was obtained from the vertically mounted bifacial module—east–west (VBFM-EW) with tracking during summer and vertically mounted bifacial module—north–south (VBFM-SN) module without tracking during the winter season. Exergetic cost was calculated by considering 15, 20, 25, and 30 years of the system with 2%, 5%, and 10% interest rates. The maximum exergetic cost was obtained from 30 years of the system under a 2% interest rate. The enviroeconomic and exergoenviroeconomic analysis provides the carbon credits earned from the E-W module was a maximum of Rs 11,036.18 during the summer season and Rs 12,413.48 from the VBFM-SN module during the winter season, considering the life of the system as 15 years. [ABSTRACT FROM AUTHOR]

Energy, exergy and enviroeconomic are some of the most important aspects of the solar still device that should be taken into account. According to productivity, energy, exergy and enviroeconomic approaches, the behavior of a modified multi-wick basin type inverted absorber solar still (MMWBIASS) is analyzed and assessed by installing ten hanging wicks at varied depths of saline water in the basin. This study suggested a technique for increasing the productivity of a solar still by introducing hanging black cotton and jute wicks to provide a constant supply of water in the wicks' strap layer. Experiments have been conducted on MMWBIASS with a basin area of 1 m2 at Mathura, Uttar Pradesh, India, under different weather conditions. Results showed that the annual prices per kilogram of distilled yield were Rs. 0.91 (0.012 US$) and Rs. 1.03 (0.013 US$), and the development method reduced CO2 emission by 42.99 and 37.08 tons, respectively, for black cotton and jute wicks. [ABSTRACT FROM AUTHOR]

In this research, the thermodynamic (energy and exergy) and economic assessments of heat pump-assisted solar still with paraffin wax was investigated under the climatic conditions of Coimbatore city in India during the year 2020. The observed experimental results in heat pump solar still (HPSS) was compared with conventional solar still (CSS) in the same climatic conditions. This model works on the principle of latent heat observed during condensation which was regenerated by heat pump to preheat the inlet basin saline water of solar still. The observed maximum productivity of HPSS was about 14.5 kg/m2, which was 83.7% higher than CSS. The energy and exergy efficiency improvement in HPSS were about 65% and 82.3%, respectively, higher than CSS. The observed maximum coefficient of performance (COP) of heat pump was about 2.61. The payback period (PBP) of CSS and HPSS was estimated to be about 4.1 months and 3.2 months, respectively. The results observed in HPSS have significantly improved the daily productivity than CSS. [ABSTRACT FROM AUTHOR]

This paper presents the exergy and exergo-environmental analysis of the 660 MW supercritical coal-fired unit situated in western India. The study is based upon the SPECO approach, which is followed in the case of exergoeconomic analysis. The proposed research includes evaluating values of exergy of each stream, using F and P principal to find out exergy of fuel, the product of each component, and its exegetic efficiency. It further includes allocation of Eco-indicator 99 assessment grading values to perform life cycle assessment of each component, solving simultaneous equations by suitable solver formed from the environmental impact of components to calculate the exergo-environmental factor of each stream. The exergy efficiency obtained for the supercritical unit is 35.54%. The effect of variation of exergetic efficiency with an inlet pressure of high-pressure turbine for major components is studied. The major components such as steam generator, high-pressure turbine, intermediate-pressure turbine, low-pressure turbine, condensate extraction pump, and boiler feed pump exhibit higher exergetic efficiency at 247 bar. An increase in environmental impact in the exergy flows has been identified for components with having heat, work or fuel at the inlet. The cooling water used in condenser and flues gases exhausted from the supercritical power plant represent the environmental impact rate per unit electricity generated of 2.89 and 3.689 mPts kWh−1. The electricity generated had an environmental impact rate of 39.71 mPts kWh−1. The environmental impact per unit of electricity generated for 660 MW supercritical power plant is evaluated as 46.29 mPts kWh−1. The result obtained from semi-empirical model for environmental impact per unit of electricity is validated by comparing with subcritical and ultra-critical coal-fired power plant. The supercritical coal-fired power plant is proved to be better technology as compared with subcritical coal-fired power plant. The exergo-environmental variable for the steam generator offers high potential to reduce environmental impact by introducing an exhaust gas treatment unit. [ABSTRACT FROM AUTHOR]

Current study aims in finding the combined effect of using rectangular fins, gravels (G) and phase change material (PCM) on the performance of pyramid solar still. Two solar stills, one of conventional type (CSS) and other of modified solar still (MSS) which uses fins and PCM inside the basin, are fabricated. Experiments are conducted at Greater Noida (28°28′N, 77°30′E) of Uttar Pradesh, India, during May 2023. The influence of solar still design modifications (CSS and MSS) and adding gravels (CSS + G and MSS + G) on the performance of solar stills is investigated in terms of productivity, energy, exergy, economic, and environmental parameters. Experimental results show an enhancement of about 84 %, 38 % and 32 % in daily productivity for MSS + G, CSS + G and MSS, respectively, than CSS. The MSS + G shows the highest improvement in energy (81.1 %) and exergy efficiency (273 %) with significant reduction in costs per liter of yield produced (29.2 %) and payback period (29 %) when compared with CSS. About 76 % rise in carbon credits earned is observed for MSS + G than CSS while mitigating the CO 2 emission of 19.14 tons. Conclusively, the innovative design (MSS + G) not only offers cost-effective yield production but also plays a crucial role in promoting environmental sustainability by reducing CO 2 emissions. • This paper develops and tests a modified solar still that uses PCM and fins. • The combined effect of fins, gravels and PCM is investigated. • The experiments conducted in Greater Noida, India, during May 2023. • MSS + G improved daily productivity by 84 %. • MSS + G reduces costs/l of water by 29 % and mitigates CO 2 emissions by 19.14 tons. [ABSTRACT FROM AUTHOR]

Remote regions and poor communities often suffer the most from the shortage of fresh water. Providing a sustainable supply of fresh water and improving the quality of life for millions of people worldwide is crucial. In the present study, two experimental setups, namely (i) a modified pyramid solar still (MPSS) coupled with pulsating heat pipe and (ii) the conventional pyramid solar still (CPSS), were designed, constructed, and investigated under the same ambient conditions of Surat City, India. The MPSS and CPSS were compared for freshwater yield, energy, exergy, and economic analysis at four different depths. The experimental results demonstrate that the accumulated distillate yield for the MPSS was higher than that of the CPSS. The maximum freshwater yield obtained for MPSS and CPSS was approximately 4.10 L/m2-day and 3.05 L/m2-day at 2 cm depth. During the experiment, improvement in the yield of MPSS due to the attachment of PHP was 34.42%, 37.13%, 31.87%, and 29.62 % as compared to CPSS for 2 cm, 3 cm, 4 cm, and 5 cm, respectively. Moreover, the energy and exergy efficiency of MPSS was higher than CPSS. The maximum enhancement for average energy and average exergy efficiency obtained in MPSS was 25.51% and 29.31% compared to CPSS at 2 cm water depth. The economic analysis exhibits that the cost per liter of fresh water was decreased by up to 13.33% compared with CPSS at 2 cm depth. Based on the environmental assessment, the MPSS's most significant environmental parameter (CO2 mitigation) at 2 cm of water depth was 18.79 tons. The present study's advantage is using a pulsating heat pipe and passively transferring the additional heat energy into the basin. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, the performance of a PVT (photovoltaic thermal) air collector with V-groove absorber in the air channel is theoretically and experimentally examined under different climate conditions of Ghaziabad city, India, in summer, June 2019. A low power brushless DC fan is fixed at the input of the air-channel to ensure the circulation of air through the V-groove. The energy balance equation is developed with the matrix-inversion method to estimate the PV (photovoltaic) cell and air output temperatures. The theoretical results obtained using mathematical modeling has been compared with that of the real-time experimental results. The electrical, thermal, and overall efficiencies for the theoretical and experimental studies are found in the range of 10.39–10.26%, 41.78–41.57%, and 52.17–51.81%, respectively. It has been observed that the theoretical results are coherent with experimental results for the proposed model achieving an accuracy of 98.98%, 99.43%, and 99.31% for electrical, thermal, and overall efficiencies, respectively. [ABSTRACT FROM AUTHOR]

Open drying is practiced for drying Capsicum frutescens in the cottage industries of India. In order to improve drying, an experimental set-up of solar rack dryer is constructed and studied different heat transfer augmentation techniques. A passive heating coil extended from the header of a water-in-glass evacuated tube coupled with parabolic trough is used to augment the heat in the collector section of the dryer. The drying rate in rack dryer is found to be 62% higher than that of open air drying of green chillies. Moreover, the drying rate in augmented rack dryer is found to be 7% higher than that of rack dryer. In addition to this, an effective design for the dryer cabinet with respect to air circulation is arrived through computational fluid dynamics analysis. Through this new design, the drying rate is improved further by 3%. Based on energy analysis, the specific energy consumption during the drying of this particular product using the augmented dryer is found to be 1.27 kWh/kg. The exergy efficiency of the drying chamber is found to be in the range of 4%-45% with an average of 16% for Capsicum frutescens. [ABSTRACT FROM AUTHOR]

In this study, energy and exergy analysis of a 16 MW cogeneration plant of a sugar factory located in India is carried out. Bagasse leaving the mills with 50% moisture is fed directly into the boiler as fuel. Maximum energy loss (23.021%) as well as maximum exergy destruction (68.219%) is found in the boiler furnace. The fuel moisture alone accounts for 11.89% energy loss due to the absorption of huge portion of combustion heat for its vapourization. Therefore, the effect of reducing bagasse moisture content on this analysis is examined through computer simulation. Reducing moisture content of bagasse from 50% to nil would increase the power output, the cogeneration energy efficiency and the cogeneration exergy efficiency by 3597 kW, 3.66% and 3.02% respectively. It is also found that 6.342% of fuel energy is lost through the exhaust gases. To utilize a portion of this waste heat, a vapour absorption refrigeration system is integrated with the considered plant. It is found that the proposed cooling system would produce a refrigerating effect of 594.714 TR with a COP of 0.721 and can, therefore, be used for preserving large quantities of vegetables in a cold storage. • Maximum energy loss as well as maximum exergy destruction occurs in boiler furnace. • Power and efficiencies improve significantly by reducing bagasse moisture to nil. • Reducing bagasse moisture will also reduce exergy destruction in boiler furnace. • Suitable means to dry bagasse before feeding it into the boiler may be adopted. • Utilization of exhaust heat for cooling purpose in cold storage is also examined. [ABSTRACT FROM AUTHOR]

• Comparison of the overall efficiencies of the conventional PV and the water based PVT-PCM panels. • Analysis of the yearly useful thermal energy, useful electrical energy and useful equivalent thermal exergy. • Analysis of embodied energy, energy payback time and lifecycle conversion efficiency. • Investigation of the Uniform end -of -year annual Cost and the Cost of DC electrical energy production. An investigation on PVT-PCM/water system has been carried out under the weather conditions at Kottayam (9.5425 °N, 76.8202 °E), India. In the present paper, experimentations have been done to compare the overall performance of PV and water-based PVT-PCM panels. The PVT-PCM/water system has been analysed under various outdoor environmental conditions and it has been recorded that the integration of PCM contributed to an improved thermal and overall efficiency of 26.87% and 40.59% respectively, along with a rise in electrical efficiency by 17.33% compared with conventional PV panel. It has been found that the payback time for the water-based PVT-PCM system is about 6 years on the overall exergy basis, which is 11.26% shorter compared to conventional PV panels. Also, the water-based PVT-PCM system has long-term lifecycle conversion efficiency compared to conventional PV panel by about 27%. [ABSTRACT FROM AUTHOR]

The dairy processing industry in India, on an average basis, involves an extensive amount of thermal and electrical energy consumption, i.e. 2.51 × 105 kW MT−1 and 1.44 × 105 kW MT−1, respectively, for an installed milk food processing capacity of 1.21 × 105 TPD. However, energy consumption spectrum depends upon the level of automation along with better utilisation of utility resources. The global ultra-high-temperature (UHT) pasteurised milk trade was valued at € 52.29 billion in 2012 and is expected to reach € 114.38 billion by 2019–2020. In the present work energy, exergy and exergoeconomic evaluation of ultra-high-temperature milk pasteurisation plant have been considered. The overall energy efficiency and efficiency pertaining to executable potential of energy in UHT Milk Processing Unit were reported to be 86.36% and 53.02%. The specific exergy destruction and specific exergy improvement potential were estimated to be 219.23 kJ kg−1 and 137.60 kJ kg−1, respectively. The highest possible retrievable exergy potential of the plant was associated with heating coil, i.e. 158.98 kW, followed by homogeniser (54.62 kW), which pinpointed towards the possibility of huge technical improvement. The processing cost was enumerated to be highest for heating coil (rk: 38.35%) followed by regeneration-1 (rk: 23.40%). Further, the total operating cost rate associated with thermodynamic deficiencies of subunits was estimated to be highest for heating coil (4859.82 € H−1) followed by regenerator-2 (1264.88 € H−1) and homogeniser (1187.14 € H−1). The broad survey of thermoeconomic indices of subunits indicated that the level of exergetic destruction was far more on higher side. [ABSTRACT FROM AUTHOR]

The thermodynamic analysis of direct expansion solar-assisted heat pump system working with R290 as a drop-in substitute for R22 was carried out under the metrological conditions of Calicut, India. A prototype of a DXSAHP system consists of a compressor, an air-cooled condenser with evaporator-collector and thermostatic expansion valve. The experiments were carried during the winter months of 2016. The artificial intelligence technique artificial neural network integrated with genetic algorithm model was presented to predict energy and exergy performance of a system. The energy performance ratio of a system was found to be 5.75% higher and reduced heating capacity of about 6.8% when compared to R22. Similarly, the second law analysis (exergy analysis) of a total system working with R290 was found to be better when compared to baseline refrigerant. The selected alternative working fluid is a hydrocarbon and has zero ozone depletion and negligible global warming potential. Hence, R290 can be used as a drop-in substitute for R22 in DXSAHP systems. [ABSTRACT FROM AUTHOR]

The continual need to optimize costs and the recent competitive pressure from renewables have seen renewed focus on improving and optimizing plant components' efficiency. Combined cycle power plants are better from thermal efficiency point of view compared with coal-based power plants. Exergy analysis offers better alternative to energetic analysis based on simpler model of energy balance only. Identifying system energy losses is easier using exergy analysis, making it a better analytical tool. The paper presents a case study of exergy analysis of Gautami combined cycle power plant. Component level theoretical analysis is done first and applied to the operational data from the plant. The results showed that the gas turbine combustion chamber has the highest exergy loss of 33%. Impact factors like ambient temperature, pressure ratio, turbine inlet temperature and heat recovery steam boiler are also considered on the exergy losses of the power plant. [ABSTRACT FROM AUTHOR]

• The various cooling strategies, such as Heat sink, water jacket, air bubble cooling and combination of these techniques are employed. • The percentage drop in maximum panel temperature is found to be highest at 15.36 % and power output increase of 9.31% for the panel attached with water jacket and air bubble with heat sink combination. • Enviro-economic parameters increases with enhancement in the cooling methods and a maximum of 18.75 $/annum is obtained. Solar photo voltaic (PV) panel performance is greatly affected by the rise in temperature of the PV panel. To increase the electrical conversion efficiency of the PV panel, assessments are made under various cooling circumstances. To assess the efficacy of the PV panel using a water-cooling system in the climate of Manipal, India, experimental studies were conducted in this research. The purpose of this research is to evaluate and compare various cooling strategies, such as Heat sink, water jacket, air bubble cooling and combination of these techniques. Air bubbles are introduced inside the cooling jacket, which generates turbulence motion and cools the PV panel. The cooling system is inspected while running at different panel temperatures. The percentage drop in maximum panel temperature is found to be highest at 15.36 % for the panel attached with water jacket and air bubble with heat sink combination. Also, the power output of the panel is found to be the highest for the above combination with the increase of 9.31%. [ABSTRACT FROM AUTHOR]

Abstract The performance of the solar air collector is experimentally investigated at the climate of North Eastern India. Various governing parameters considered for the present investigation are collector tilt angles (30⁰, 45⁰, and 60°), single and double glazing, mass flow rate (0.0039–0.0118 kg/s) and two different absorber plates (plain and corrugated). Results reveal that double glazing absorber plate always gives better performance both energy and exergy point of view, because of reduction of top loses. Increase in mass flow rate of air enhances the energy efficiency. An overall increment of the efficiency with the increase of mass flow rate and number of glazing is as high as 10.35–17.42%. Use of corrugated plate enhances the energy efficiency by 14%, because of improved turbulence effect and increment of the heat transfer area. The maximum enhancement of exergy efficiency for double glazing collector is 6.867% for mass flow rate 0.0118 kg/s compared to single glazing collector. Corrugated absorber plate show 30Pa higher pressure drop than plain absorber plate. Thermo-hydraulic efficiency is found to deviate by almost 6.35% from the corresponding thermal efficiency. Mass flow rate of air in the range of 0.0078–0.0094 kg/s is found to yield qualitative heat transfer. Highlights • Comparison of flat and corrugated plate solar air collector is presented. • Double glazing reduces losses and increase the thermal efficiency by 6.87%. • Increase in mass flow rate by 3 times results in 6%increase of efficiency. • Corrugated plate provides 14% higher efficiency than flat plate collector. • Mass flow rate of air enhances energy efficiency and reduce exergetic efficiency. [ABSTRACT FROM AUTHOR]

The use of non-imaging collectors has a wide scope in process heat applications based on its performance and economics. An experimental investigation of trapezoidal/concave cavity surface receiver (TSR) for non-imaging solar concentrating collector is carried out in this paper. The implementation of surface/coil receiver instead of tubular receiver for non-imaging collector is presented in this paper. A TSR with helical coil is developed for non – imaging concentrating collector, Elliptical Hyperbolic Collector (EHC). Experiments are carried to estimate the thermal performance of the system under various operating conditions such as two operating modes: series and parallel modes of operation of the collector, two circulation modes: passive and active modes. The stagnation temperature of the trapezoidal/concave cavity surface receiver is measured to be 118 °C on a clear sunny day in October and 102 °C on a cloudy day in February. The daily performance tests are performed under different operating conditions. Based on the experimental study, for the flow rate of 0.03 kg/min and 0.5 kg/min, the fluid outlet temperature is estimated to be 87 °C at 768 W/m 2 and 49 °C at 908 W/m 2 respectively. The corresponding instantaneous efficiency was calculated to be 9% and 40% respectively. The numerical model is developed to predict the temperature of the fluid along the receiver. The pressure drop across a receiver is estimated to be 9.3 kPa for a flow rate of 0.5 kg/min. Exergy analysis of the system is carried out and it ranges between 10 and 20%. The costs involved in fabricating the EHC system are compared to that of a non-imaging concentrating collector (CPC) of same aperture area. An economic analysis of the system is also carried out to study the feasibility of the system based on the life cycle savings method by estimating the annual solar savings from the EHC system. The present system can be a suitable option for low and medium temperature process heat applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Green and sustainable DMC is proposed as an additive to Bael biodiesel for enhancing performance and mitigating emissions. • Bael biodiesel has the potential to achieve 30.68% BTE by B15DMC5, with a worthwhile reduction in emissions. • Process optimization and exergy analysis would support process upcycling and energy conservation. • Provide a way to reduce the carbon footprint by carbon–neutral potential Bael biodiesel. Synthesis of biofuel from bioresources represents one of the greatest propitious options for achieving a cleaner production of energy and the global circular bio-economy. The superior cetane rating of biodiesel makes it a fitting fuel for CI diesel engines. The present study aims to valorise Bael seeds for biodiesel production. Bael is a species of tree indigenous to India. The diesel–Bael biodiesel was blended with dimethyl carbonate (DMC) as an ignition enhancer and investigated in a selected diesel engine. This work reports that the Bael biodiesel blend gets a tolerable level of BTE against neat fossil diesel. An utmost BTE of 30.68% was achieved with B15DMC5 which is very close to diesel (31.8%) at peak load. Certainly, BSFC was suppressed and emissions lessened by DMC inclusion. For instance, the CO and HC emissions substantially reduced to a minimum of 0.19% and 179 ppm with the B17.5DMC2.5 blend at peak load. NO x emission is directly proportional to Bael biodiesel concentration, Notably, NO x emission is well controlled at 50% and 75% load even though with the increasing biodiesel concentration in the blend. Though, control of emissions at peak load is still a crucial issue. Nevertheless, the DMC additives controlled the NO x emission at peak load. B15DMC5 blend exhibits progress in combustion through the optimized value of HRR, CGP, and CGT against B20. The presence of NO x and smoke opacity without additives is suppressed up to 7% and 10% with additives. Availability (exergy) and exergy efficiency at different loads of both neat diesel and blended fuels, mainly shaft, cooling water, and exhaust availability were calculated. The results of the study illustrated that the input availability increased at peak loads, as well as gross work output, was maximum at peak load due to higher fuel exergy present in the combustion chamber. A maximum exergy efficiency of 68% was recorded by B15DMC5 at peak load. Finally, the process optimization by RSM has been validated by experimental results and further authenticated with ANN. The results of the RSM model promote it as statistically significant. Generate the regression equation for all output responses. The optimized operating parameters of engine load of 50%, 10% of biodiesel blend, and additive concentration of 3.59% achieved the most optimum output response. The results of the predicted optimized condition of BTE, BSFC, CO, HC, NO x, and Smoke opacity showed 24.051%, 0.441861 kg/kW hr, 0.2028%, 113.607 ppm, 316.099 ppm, and 14.4286% respectively. The R2 values from RSM and ANN DoE models were 0.992834 and 0.99984. This study concludes that a superior precision certainty from both RSM and ANN models is beneficial for engine overall performance estimation. This phenomenon provides a good sign to implement the ANN to forecast engine operational behavior in the future. The novel approach of process optimization by RSM and ANN for Bael biodiesel with DMC blended fuel operate DI CI engine supports the SDGs of the UN such as Good health and Well-being (SDG: 3), Affordable and Clean Energy (SDG: 7), Responsible Consumption and Production (SDG: 12), Climate Action (SDG: 13) and Life on Land (15). [ABSTRACT FROM AUTHOR]

Artificial water bodies like reservoirs are unique in sense that they encompass hybrid characters of both lakes and streams. Detailed study of reservoir ecosystem is necessary in order to understand and evaluate the health of such systems. A universal characteristic of any ecosystem is its ability to counter stress conditions and this ability is termed robustness which signifies the systems sustainability. Exergy or eco-exergy, measuring the amount of stored workable energy in the system is another important descriptor of an ecosystem. Both robustness and eco-exergy are good indicators of ecosystem health and also they are dependent on the magnitude and type of the inflicted stress. Robustness of Bakreswar reservoir system has been studied here following hypothetical perturbation scenarios that represent possible real situations of eutrophication (nutrient loading) and overfishing. Quite a few descriptive ecosystem indices have also been considered for the current study including Total System Throughflow ( TST ), Finn Cycling Index ( FCI ), Redundancy ( R ), Ascendancy ( A ), Developmental capacity ( C ), Total Primary Production to Total Respiration ratio ( TPP/TR ), Total Primary Production to Total Biomass Ratio ( TPP/TB ), detritivory to herbivory ratio and also the Exergy of the system. It is concluded from this study that the Bakreswar reservoir is a moderately stable ecosystem with fair maturity level and is able to withstand stress for a reasonable extent. The network indices revealed that variation in robustness of the system is related more with fish biomass perturbation scenario rather than that for the autotroph biomass perturbations. This is confirmed by the network indices as well as the change in the system exergy values which shows more variation in the fish biomass scenario. [ABSTRACT FROM AUTHOR]

Active solar distillation system integrated with solar pond is the green energy system for desalination without negative environmental impact. This clean technology has potential to contribute a lot to water security, sustainable development, and world stability. In this article, results of the energy as well as exergy analysis performed on this novel system integrated with solar pond are presented. This theoretical analysis is carried out in the climatic conditions of New Delhi (India) during a typical summer day. The model and procedures can be helpful in the design, and performance investigation of the actual system anywhere in the world. The daily productivity, energy, and exergy efficiency of the passive solar still are found to be 5 L/m, 38.63 %, and 2.71 %, respectively, corresponding to a sum total of 24.436 MJ/m day solar energy input in passive mode. With the integration of solar pond in the active solar still, the daily productivity, energy, and exergy efficiency rises to about 9.5 L/m, 46 %, and 14.81 % respectively, for thermal energy input from 100 to 500 W/m during off-sunshine hours. The further improvement in the performance of the same system is observed if the thermal energy is supplied continuously (24 h) to the solar still in addition to incident solar radiation. The proposed system will meet the demand of freshwater in both rural and urban areas and help in reducing the load of CO emission on the environment, saving high grade energy consumed for desalination through conventional devices and technologies. [ABSTRACT FROM AUTHOR]

In this study, energy and exergy analysis of a coal fired steam power plant in India was carried out and the effects of varying the reference ambient temperature, stack gas temperature and the percentage of excess combustion air on this analysis were examined through computer simulation. The combustion process in the boiler was analyzed in detail considering the actual composition and condition of atmospheric air and variation of specific heat of gases with temperature. Maximum energy loss was found in the condenser (62.02%) followed by the boiler (13.03%) while maximum destruction of fuel exergy was found in the boiler system (63.02%) followed by the turbine (9.35%), and then the condenser (3.24%). Significant potential to improve plant efficiency, therefore, exists through reducing irreversibility in the boiler system. The ambient temperature was found to have its highest effect on the changes of the irreversibility rate in the boiler as compared to that in other components. To examine the effects of stack gas temperature and the excess combustion air on the irreversibility rate of the boiler system, the stack gas temperature was varied from the existing 134.3°C to 90°C and the excess air percentage was varied from 25% to 5%. The results showed that decreasing either the percentage of excess combustion air or the exhaust gas temperature or both, causes the irreversibility rate in the boiler to decrease. [ABSTRACT FROM PUBLISHER]

Abstract: In this paper enviroeconomic analysis of two types of hybrid photovoltaic thermal (PVT) array (10.08m×2.16m) has been carried out having two different designs and flow configurations which are explained as, case1: Two integrated columns each having 18 PVT modules in series are connected in parallel and case2: Two integrated columns of 18 modules each having 36 PVT tiles in the module is connected in series. The area of each tile is 0.12m×0.12m. The performance of the two cases has been compared on the basis of annual overall thermal energy and exergy gain for four different climatic conditions of India. As compared with case1, case2 has lower cell temperature (19.0%), higher electrical efficiency (6.5%) and higher average outlet air temperature (18.1%). The annual CO2 mitigation for Bangalore in terms of overall thermal energy gain for case1 and 2 is 90.85tCO2/annum and 99.81tCO2/annum respectively, while in terms overall exergy gain is 41.55tCO2/annum and 45.44tCO2/annum respectively. Also, the environmental cost in terms of overall thermal energy is 1317.37$/annum and 1447.20$/annum respectively while in terms of overall exergy is 602.51$/annum and 658.89$/annum respectively. [Copyright &y& Elsevier]

Abstract: In this paper, comparative analysis of different type of photovoltaic thermal (PVT) air collector namely: (i) unglazed hybrid PVT tiles, (ii) glazed hybrid PVT tiles and (iii) conventional hybrid PVT air collectors have been carried out for the composite climate of Srinagar (India). The comparative study has been carried out in terms of overall thermal energy and exergy gain, exergy efficiency and carbon credit earned by different type of hybrid PVT air collectors. It has been observed that overall annual thermal energy and exergy gain of unglazed hybrid PVT tiles air collector is higher by 27% and 29.3% respectively as compared to glazed hybrid PVT tiles air collector and by 61% and 59.8% respectively as compared to conventional hybrid PVT air collector. It has also been observed that overall annual exergy efficiency of unglazed and glazed hybrid PVT tiles air collector is higher by 9.6% and 53.8% respectively as compared to conventional hybrid PVT air collector. On the basis of comparative study, it has been concluded that CO2 emission reduction per annum on the basis of overall thermal energy gain of unglazed and glazed hybrid PVT tiles air collector is higher by 62.3% and 27.7% respectively as compared to conventional hybrid PVT air collector and on the basis of overall exergy gain it is 59.7% and 22.7%. [Copyright &y& Elsevier]

Abstract: We assess the feasibility of hybrid solar-biomass power plants for use in India in various applications including tri-generation, electricity generation and process heat. To cover this breadth of scenarios we analyse, with the help of simulation models, case studies with peak thermal capacities ranging from 2 to 10 MW. Evaluations are made against technical, financial and environmental criteria. Suitable solar multiples, based on the trade-offs among the various criteria, range from 1 to 2.5. Compared to conventional energy sources, levelised energy costs are high – but competitive in comparison to other renewables such as photovoltaic and wind. Long payback periods for hybrid plants mean that they cannot compete directly with biomass-only systems. However, a 1.2–3.2 times increase in feedstock price will result in hybrid systems becoming cost competitive. Furthermore, in comparison to biomass-only, hybrid operation saves up to 29% biomass and land with an 8.3–24.8 $/GJ/a and 1.8–5.2 ¢/kWh increase in cost per exergy loss and levelised energy cost. Hybrid plants will become an increasingly attractive option as the cost of solar thermal falls and feedstock, fossil fuel and land prices continue to rise. In the foreseeable future, solar will continue to rely on subsidies and it is recommended to subsidise preferentially tri-generation plants. [Copyright &y& Elsevier]

Abstract: Attractive economic performance of energy systems is important for their long term sustainability. In this paper, a cost benefit analysis (CBA), standard thermoeconomic analysis, and a new method that combines the two was applied to seven modelled candidate decentralised energy systems for small Indian rural villages. By including elements of CBA in standard thermoeconomics, economic inefficiencies at the component level and revenue adjusted costs of exergy for each stream were ascertained. The analysed systems all produced household and irrigation electricity as well as a secondary product or service, which in some cases utilised waste heat from the electricity generation process. The system that produced distilled water as a secondary product was the most economically sustainable out of those modelled. While the standard thermoeconomic electricity cost remained around 0.5 USD/kWh for all analysed systems, the benefit to cost ratios varied from 0.29 to 0.97, demonstrating differing appeal to outside investment. By incorporating CBA into standard thermoeconomics the accounted revenue produced a larger spread in exergetic costs than standard thermoeconomics (for example, an electricity cost range of 0.217–0.507 USD/kWh), thus providing a better comparison of systems with different energy end uses. [Copyright &y& Elsevier]

In this paper, an attempt has been made for evaluating the overall thermal energy and exergy provided in the form of heat and electricity from hybrid photovoltaic/thermal (PV/T) solar water heating system considering five different cases with and without withdrawals. The annual heat and electricity are evaluated by considering the four types of weather conditions for five different cities of India (New Delhi, Bangalore, Mumbai, Srinagar, and Jodhpur). It is found that the annual maximum heat and electricity are obtained in case (ii) (energy: 4263.2 kW h and exergy: 529.7 kW h) and minimum in case (v) (energy: 1038.8 kW h and exergy: 196.9 kW h) as compared to all other cases for New Delhi condition. Annual maximum and minimum energy gains and efficiency are obtained for Jodhpur and Srinagar City, respectively. This type of configuration (hybrid PV/T) is very useful in the remote and urban areas, where the electricity and hot water can be obtained simultaneously. [ABSTRACT FROM AUTHOR]

Abstract: Photovoltaic–thermal (PV/T) technology refers to the integration of a PV and a conventional solar thermal collector in a single piece of equipment. In this paper we evaluate the performance of partially covered flat plate water collectors connected in series using theoretical modeling. PV is used to run the DC motor, which circulates the water in a forced mode. Analytical expressions for N collectors connected in series are derived by using basic energy balance equations and computer based thermal models. This paper shows the detailed analysis of thermal energy, exergy and electrical energy yield by varying the number of collectors by considering four weather conditions (a, b, c and d type) for five different cities (New Delhi, Bangalore, Mumbai, Srinagar, and Jodhpur) of India. Annual thermal and electrical energy yield is also evaluated for four different series and parallel combination of collectors for comparison purpose considering New Delhi conditions. This paper also gives the total carbon credit earned by the hybrid PV/T water heater investigated as per norms of Kyoto Protocol for New Delhi climatic conditions. Cost analysis has also been carried out. It is observed that the collectors partially covered by PV module combines the production of hot water and electricity generation and it is beneficial for the users whose primary requirement is hot water production and collectors fully covered by PV is beneficial for the users whose primary requirement is electricity generation. We have also found that if this type of system is installed only in 10% of the total residential houses in Delhi then the total carbon credit earned by PV/T water heaters in terms of thermal energy is USD $144.5 millions per annum and in terms of exergy is USD $14.3 millions per annum, respectively. [Copyright &y& Elsevier]

A solar dryer integrated with photovoltaic powered DC fan has been designed and installed at Solar Energy Park, Indian Institute of Technology Delhi. The dryer has been coupled to a solar air heater having blackened surface of absorber for improved energy collection efficiency and a drying chamber with chimney. An analytical expression for characteristic equation for photovoltaic/thermal mixed mode dryer has been derived as a function of design and climatic parameters. The experiment was carried out for forced mode under no load conditions during April 2008 and validated with theoretical results for New Delhi climatic condition. This paper also shows the detailed analysis of thermal energy, exergy, and electrical energy gain by considering four weather conditions (a, b, c, and d type) for five different cities (New Delhi, Bangalore, Mumbai, Srinagar, and Jodhpur) of India. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, we develop a solar exergy map concept and conduct a comprehensive case study to show how it is utilized and how it is significant for practical solar applications. Based on the exergy content of the solar radiation, the performance of a photovoltaic thermal (PV/T) system is evaluated for different Indian cities, namely Bangalore (latitude 12°58′N, longitude 77°38′E), Jodhpur (latitude 26°18′N, longitude 73°04′E), Mumbai (latitude 18°55′N, longitude 72°54′E), New Delhi (latitude 28°35′N, longitude 77°12′E) and Srinagar (latitude 34°08′N, longitude 74°51′E) for a year and for different cities of U.S.A., namely Chicago (latitude 41°50′N, longitude 87°37′W), Las Vegas (latitude 36°10′N, longitude 115°12′W), Miami (latitude 25°46′N, longitude 80°12′W), New York (latitude 40°47′N, longitude 73°58′E), Portland (latitude 43°40′N, longitude 70°15′W), San Antonio (latitude 29°23′N, longitude 98°33′W), San Francisco (latitude 37°47′N, longitude 122°26′W), Tucson (latitude 32°7′N, longitude 110°56′W) and Tulsa (latitude 36°09′N, longitude 95°59′W) for different months of January, April, June and October. For the first time, the development of exergy maps for the exergy of solar radiation as well as the exergy efficiency of PV/T system is done for the above-mentioned Indian and American climatic conditions. It is found that the predicted exergy efficiency is in good agreement with the experimental results for the climatic conditions of New Delhi, India. It is observed that the average exergy efficiency is highest in Bangalore from January (28%) to April (32.6%) and from September (32.5%) to December (32.4%) and it is highest in Srinagar from May (29.5%) to August (26.8%) for Indian climatic conditions and for American climatic conditions, the PV/T system gives the best performance in terms of exergy efficiency in Las Vegas (32%) and Tucson (32.5–31.5%) in April and June. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In the present work, exergy analysis of a coal-based thermal power plant is done using the design data from a 210 MW thermal power plant under operation in India. The entire plant cycle is split up into three zones for the analysis: (1) only the turbo-generator with its inlets and outlets, (2) turbo-generator, condenser, feed pumps and the regenerative heaters, (3) the entire cycle with boiler, turbo-generator, condenser, feed pumps, regenerative heaters and the plant auxiliaries. It helps to find out the contributions of different parts of the plant towards exergy destruction. The exergy efficiency is calculated using the operating data from the plant at different conditions, viz. at different loads, different condenser pressures, with and without regenerative heaters and with different settings of the turbine governing. The load variation is studied with the data at 100, 75, 60 and 40% of full load. Effects of two different condenser pressures, i.e. 76 and 89 mmHg (abs.), are studied. Effect of regeneration on exergy efficiency is studied by successively removing the high pressure regenerative heaters out of operation. The turbine governing system has been kept at constant pressure and sliding pressure modes to study their effects. It is observed that the major source of irreversibility in the power cycle is the boiler, which contributes to an exergy destruction of the order of 60%. Part load operation increases the irreversibilities in the cycle and the effect is more pronounced with the reduction of the load. Increase in the condenser back pressure decreases the exergy efficiency. Successive withdrawal of the high pressure heaters show a gradual increment in the exergy efficiency for the control volume excluding the boiler, while a decrease in exergy efficiency when the whole plant including the boiler is considered. Keeping the main steam pressure before the turbine control valves in sliding mode improves the exergy efficiencies in case of part load operation. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

[Display omitted] • Development and analysis of BIPVT mathematical thermal model. • Projecting BIPVT as space heating solution for Indian montane climate. • Development of artificial neural network for predicting annual BIPVT yield. • Multi-criteria decision-making method- TOPSIS for selection of BIPVT parameters. • Prediction of annual thermal and exergy outputs with R2 value >97% over unseen data. Indian Himalayan Region (IHR) encompass approximately 16.2% of India's geographical area and characterized as a montane climatic zone. The ambient temperature of this region is extremely low, with a minimum average temperature of 2–18 °C. Major settlements in this region are located at an altitude of more than 1000 m above sea level. Therefore, according to The Energy and Resources Institute (TERI), India , there is excessive thermal and electrical energy consumption in these regions pertaining to space heating. Moreover, the current energy sources utilized are not clean sources and hence contribute towards CO 2 emissions. A building-integrated photovoltaic thermal (BIPVT) system is modelled to provide the necessary thermal energy alongside electricity for space heating intended for the climatic conditions of Srinagar. The study utilized an application-centric approach in modelling and analyzing the BIPVT system and, hence quantifying the annual outputs for Srinagar, India. Furthermore, the developed mathematical model is used for training an artificial neural network to predict the annual thermal and exergy outputs of the system based on six different model parameters. Three designs, one operational and two application-based parameters are considered as inputs to the network. Moreover, a multi-criteria decision-making method is employed to determine the best set of BIPVT parameters giving optimum annual thermal and exergy outputs along with electrical, thermal and exergy efficiencies of the modelled system. The modelled neural network performed reasonably well against the unseen test dataset in predicting the BIPVT yield with an R 2 value > 0.97. An optimum annual thermal and exergy gains of 2,25,459 kWh and 67,132.38 kWh, respectively, are quantified for the best set of BIPVT parameters. The system's optimum average electrical (power conversion), thermal and exergy efficiencies are observed to be 14.87, 56.28, and 17.59%, respectively. [ABSTRACT FROM AUTHOR]

The rapid increase in population and urbanization has led to an enormous increase in the overall vehicular demand. In India, most vehicles run on conventional fuels producing harmful gases and particulate matter, causing an adverse effect on the human health & environment. Most urban cities in India are witnessing a rapid increase in the level of urban air pollution, which can be largely attributed to the continuous surge in the number of on-road vehicles. According to a KPMG report, it is estimated that by 2030 there will be a 100% incremental adoption of electric vehicles which will lead to the minimization of the pollution level generated from the conventional cars. However, in India, 57.3% of electricity is produced through coal thermal power plant. It cannot be denied that coal leaves behind harmful by-products upon combustion. The emissions from the coal power plants in India increased from 901.7 g CO 2 /kWh in 2005 to 926 g CO 2 /kWh in 2012. This is much higher than global averages in the same period, which were 542 g and 533 g CO 2 /kWh, respectively. The increase in the number of electric vehicles is likely to increase the demand for electricity, which may result in a rise in emissions from thermal power plants, thus offsetting the reductions in tailpipe emissions. This study deals with assessing the impact of shifting the fleet from internal combustion engine vehicles (ICEVs) to electric vehicles (EV) on power generation sources, i.e., coal power plants, and its impact on the environment in India. The implication viability of electric vehicle over internal combustion engine vehicle has been assessed with exergy analysis, taking into account the total emissions involved from well to wheel. In the current power generation scenario of India, a comparative analysis of direct and indirect emissions from internal combustion engine vehicles and electric vehicles (powered with coal power generation) shows that electric vehicles emit less CO 2 and CO, whereas SO 2 and Oxides of nitrogen (NO x) emisions (indirectly from the thermal power plant), are higher. • Well to wheel emission comparison of electric vehicle and I.C. engine vehicle. • Degree of implication viability of Electric vehicle is formulated and assessed. • Switching to the electric vehicle is not a panacea for reducing all types of emissions. • Electric vehicle as a viable option in India if power generation shifts to clean mix. [ABSTRACT FROM AUTHOR]

In India, due to the high price of cooking gases, people still cook with noncommercial fuels like kerosene and firewood. These cause a lot of health problems and also harm the environment. A clean solution to this problem is to use a solar cooker. A solar cooker suffers from the problem of low utility and hence takes a longer period of time for cooking. To counter this problem and reduce cooking time, the solar cooker is tested with charcoal coated utensil. In this paper, a parabolic‐type domestic solar cooker is tested for the same utensil with and without cost effective thermal coating. It is observed that the effectiveness and efficiency of cooking is considerably increased by using the charcoal coating on the utensil. Considering the economic condition of the people of the selected area, this method provides a cost effective way to increase the cooking effectiveness of the solar cooker and reduce dependency on noncommercial fuels. [ABSTRACT FROM AUTHOR]

Water quality has emerged as a fast-developing research area. Regular assessment of research activity is necessary for the successful R&D promotion. Water quality research work carried out in different countries increased over the years, and the USA ranked first in productivity while India stands in the seventh position in quantity and occupies the ninth position in quality of the research output. India observes a steady growth in the water quality research. Four thousand six hundred sixteen articles from India assessed from the aspect of citations received distributions of source countries, institutes, journals, impact factor, words in the title, author keywords. The qualitative and quantitative analysis identifies the contributions of the major institutions involved in research. Much of the country’s water quality research is carried out by universities, public research institutions and science councils, whereas the contribution from Ministry of water resources not so significant. A considerable portion of Indian research is communicated through foreign journals, and the most active one is Environmental Monitoring and Assessment journal. Twenty-one percent of work is reported in journals published from India and around 7% ages in open access journals. The study highlights that international collaborative research resulted in high-quality papers. The authors meticulously analyse the published research works to gain a deeper understanding of focus areas through word cluster analyses on title words and keywords. When many papers deal with ‘contamination’, ‘assessment’ and ‘treatment’, enough studies done on ‘water quality index’, ‘toxicity’, considerable work is carried out in environmental, agricultural, industrial and health problems related to water quality. This detailed scientometric study from 1,09,766 research works from SCI-E during 1986-2015 plots the trends and identifies research hotspots for the benefit to scientists in the subject area. This study comprehends the magnitude of water quality research also establishes future research directions using various scientometric indicators. [ABSTRACT FROM AUTHOR]