Papers by Vipin Shrivastava
Rajesh Maurya*, Dr. Nitin Shrivastava, Vipin Shrivastava Dept. of Mechanical Engg. University Ins... more Rajesh Maurya*, Dr. Nitin Shrivastava, Vipin Shrivastava Dept. of Mechanical Engg. University Institute of TechnologyR.G.P.V., Bhopal, India. *Corresponding Author: [email protected], Abstract : In this paper different cooling pads have been studied. Three types of cooling pad made of a cellulose, aspen fiber, and coconut coir were comparatively studied. This study is performed in summer and based on weather conditions of Bhopal, India; maximum dry bulb temperature of air 41.2 ̊C and 26.1 ̊C wet bulb temperature. The relative humidity of 31.1 % is carried out from online psychrometric calculator. The primary air velocity considered varies between 0.5 m/s to 3.0 m/s and the performance of the cooling pads are analyzed based on the saturation efficiency, leaving air temperature, specific humidity, relative humidity, cooling capacity and water consumption. Graphs are plotted for variation in Saturation efficiency and cooling capacity for different materials of pad with air mass flow...
Vaccine, 2021
Expansion of immunization coverage is dependent in part on delivering potent vaccines in an equit... more Expansion of immunization coverage is dependent in part on delivering potent vaccines in an equitable and timely manner to immunization outreach session sites from Cold Chain Points (CCPs). When duration of travel between the last CCP and the session site (Time-to-Supply) is too long, three consequences may arise: decreased potency due to exposure to heat and freezing, beneficiary dropouts due to delayed session starts, and, increased operational costs for the Health Facility (HF) conducting the outreach sessions. Guided by the Government of India's recommendation on cold chain point expansion to ensure that all session sites are within a maximum of 60 min from the last CCP, CHAI and the State Routine Immunization Cell in the state of Madhya Pradesh collaborated to pilot a novel approach to cold chain network optimization and expansion in eight districts of Madhya Pradesh. Opportunities for realignment of remote sub-health centers (SHCs) and corresponding session sites to alternative existing CCPs or to HFs which could be converted to new CCPs were identified, and proposed using a greedy adding algorithm-based optimization which relied on health facility level geo-location data. Health facility geo-coordinates were collected through tele-calling and site visits, and a Microsoft Excel based optimization tool was developed. This exercise led to an estimated reduction in the number of remote SHCs falling beyond the permissible travel time from CCPs by 56.89 percent (132 remote sites), from 232 to 100. The 132 resolved sites include 73 sites realigned to existing CCPs, and 59 sites to be attached to 22 newly proposed CCPs. Both the network optimization approach and the institutional capacity built during this project will continue to be useful to India's immunization program. The approach is replicable and may be leveraged by developing countries facing similar challenges due to geographical, institutional, and financial constraints.
International Journal of Green Energy, 2021
This research paper is concerned with a detailed theoretical parametric analysis to optimize the ... more This research paper is concerned with a detailed theoretical parametric analysis to optimize the depth of duct (bed) of blackened wire-screen matrices packed bed solar collector (PBSC) and obtained...
Materials Today: Proceedings, 2021
Abstract The current paper represents CFD simulation on thermo-hydraulic characteristics of a rou... more Abstract The current paper represents CFD simulation on thermo-hydraulic characteristics of a round tube having twisted tape inserts. Friction factor, Nusselt number and enhancement efficiency are evaluated numerically for a tube having twisted tape inserts with various tape length ratios. The variations of pressure loss and heat transfer in the form of fr as well as Nur have been determined numerically and presented in form of graphs. The numerical results show that the tube having twisted tape with different tape length ratios is more effective than the smooth tube in terms of thermo-hydraulic performance. It is found that the tube with full-length tape insert has greater enhancement efficiencythan the short-length one. The average deviation between present predicted CFD results and pervious available experimental results of Nur and fr is
Lecture Notes in Mechanical Engineering, 2021
In this paper, thermal performance assessment of greenhouse solar dryer is being carried out in a... more In this paper, thermal performance assessment of greenhouse solar dryer is being carried out in a noloadcondition. The greenhouse solar dryer was operated under passive mode. The performance of greenhouse is evaluated in different conditions first uncovered floor, second when floor is covered with blue tarpaulin to prevent the heat loss to the ground, and the third when concrete floor is used. The data obtained during the experiment is used to evaluate the thermal performance of the greenhouse solar dryer by calculating various thermal parameters. The average room temperature inside the greenhouse solar dryer was 52% higher than the average ambient temperature in the case of concrete floor while it was 45% higher in tarpaulin covered floor as compared to 23% higher in without covered floor condition. Nomenclature A gd Area of ground (m 2) A vt Area of vent (m 2) B d Breadth of dryer (m) C p Specific heat at constant pressure (J/kg°C) C d Coefficient of diffusivity Gr Grashoff Number g Acceleration due to gravity (m/s 2) h conv Convective heat transfer coefficient (W/m 2°C) h grm Convective heat transfer coefficient for ground to room (W/m 2°C)
Materials Today: Proceedings, 2021
Lecture Notes in Mechanical Engineering, 2021
Lecture Notes in Mechanical Engineering, 2021
Materials Today: Proceedings, 2021
Abstract This paper introduces new CFD-based correlations for ribbed roughened solar air heater. ... more Abstract This paper introduces new CFD-based correlations for ribbed roughened solar air heater. An absorber plate of SAH (solar air heater) attached with circular ribs is analyzed in this article. ANSYS Fluent v16 is utilized to analyze the turbulent airflow for different arrangements of rib. All results are based on CFD (computational fluid dynamics) simulations. The analysis is carried out within the limits of Re from 3800 to 18,000 and P from 10 to 25. The resulting data is reduced into correlations using a linear stepwise regression algorithm. The developed equations for artificially roughened heater of solar air predict all the data for friction factor and Nusselt number within ±5% relative absolute deviation.
Indian Journal of Science and Technology, 2009
Many milk coolers are presently using refrigerant R22 which has substantial ozone depleting poten... more Many milk coolers are presently using refrigerant R22 which has substantial ozone depleting potential along with high global warming potential. As per the commitment of Montreal and Kyoto protocol, R22 is required to be replaced by a suitable eco-friendly refrigerant and this paper explores the various options available. First the performance of 13 eco-friendly refrigerants was compared by simulating their performance with the help of CYCLE D. Then detailed study of binary and ternary mixture refrigerants has been done for selecting a Retrofit mixture for use in place of R22 in the existing milk cooler. Elucidating the performance,ODP and GWP values of refrigerants, it is clear that R1270 is best choice for replacing R22 with zero ODP and negligible GWP. Out of four mixtures, R32/R152 is best with zero ODP and low GWP.
Indian Journal of Science and Technology, 2010
... Alka & Vipin ... Objective The vapour compression refrigeration trainer is an importa... more ... Alka & Vipin ... Objective The vapour compression refrigeration trainer is an important refrigeration unit of the thermal lab of the department of mechanical engineering of University institute of technology, the constituent college of the Rajiv Gandhi technical university, which ...
Material Science Research India, Dec 25, 2012
Renewable and Sustainable Energy Reviews, 2018
Solar energy is the useful energy resource available in plenty in the country like India. Harvest... more Solar energy is the useful energy resource available in plenty in the country like India. Harvesting this energy for maximum power generation is the area of interest to the researchers. Solar power is the conversion of sunlight into electricity, either directly using photovoltaic (PV), or indirectly using concentrated solar power (CSP).In CSP plants at locations with large amounts of direct normal irradiance, TES system is where solar thermal energy is stored during the day time and is used for electricity production during the night. Thermal Energy Storage (TES) systems when integrated into the solar cycle can address such issues related to energy efficiency, process flexibility, reducing intermittency during non-solar hours. This review work focuses and discusses upon the developments in Hybrid Solar Power Generation. The main focus is on CSP technologies, PV-CSP hybrid technology, Heat Transfer Fluid (HTF), and Phase Change Material (PCM) used for thermal energy storage. The research status and the hybrid system performance are summarized from the literature to provide a global point of view on the PV-CSP hybrid technology.
Indian Journal of Science and Technology, 2017
At present, the rapidly growing population throughout the world has imposed a huge gap between de... more At present, the rapidly growing population throughout the world has imposed a huge gap between demand and supply of food. This problem though serious, can be solved either by increasing food supply or by controlling population growth or by both. Apart from these, the most suitable and practical solution may be the reduction in the food losses 1. Agricultural products have the tendency to get spoiled during the post-harvest process 2,3. The annual financial loss has been estimated to be approximately 104 million US dollar due to deficient handling and poor storage facility 4. This loss mainly occurs due to the presence of moisture content which enhances the growth of bacteria and yeasts in them. These biological microorganisms support for spoilage attacks 5,6. Drying is the process that plays an important role in restricting the microorganism growth by reducing the moisture content up to an optimum level 7. Thus, it is essentially the best way to preserve the agricultural products from spoilage 8. Solar drying process not only saves the crops but also maintain the original color, taste etc so that increase the market value of it. Due to abovementioned advantages and need of drying process, small scaled dried food industries have grown up at a very fast rate all over the world to meet the domestic as well as international demands. Various drying techniques can be categorized as solar drying, industrial drying and open sun drying. A device used for the purpose of solar drying is known as the solar dryer. Solar dryers can be classified as passive solar dryers and active solar dryers. Three subgroups of active and passive solar dryers can also be identified: viz., direct mode, indirect mode, and the mixed-mode type as shown in Figure 1.
Indian Journal of Science and Technology, 2017
Objective: Improvement of the thermal efficiency of solar air collector is a major issue in resea... more Objective: Improvement of the thermal efficiency of solar air collector is a major issue in researcher's community. Therefore novel design of solar air collector is constructed. The objectives of this research paper are to obtained the results of novel solar air collector and compare it with conventional type solar air collector. Methods/Statistical Analysis: The experiments are carried out at the different mass flow rate of air on novel design of one glass cover and three absorber plates two-pass solar air collector (OGT h A p TPSAC) and one glass cover and two absorber plates single-pass solar air collector (OGT w A p SPSAC) operating on the same atmospheric conditions. The various thermal parameters such as heat gain, heat loss and thermal efficiency are determined with respect to time of the day. Findings: Major heat loss in any type of solar air collector is due to convection. To minimise this convection loss, vacuum is formed on top portion of novel designed solar air collector. Both solar air collectors taken for the comparison also has a unique feature of thermal storage. Comparative results show that the novel designed two-pass solar air collector is more thermally efficient than conventional single pass solar air collector. Application/improvements: Such type of solar air collector can be used in drying of fruits, crops; space heating for greenhouse, residential building etc.
Heat Transfer Research, 2016
Heat and Mass Transfer, 2015
The convective heat transfer coefficient is an essential parameter for designing of any solar dry... more The convective heat transfer coefficient is an essential parameter for designing of any solar drying system. In this paper heat transfer modeling in term of convective heat transfer coefficient is performed and compared with open sun drying. The data obtained from experimentation under open sun and indirect solar drying conditions have been used to find values of the experimental constant ‘C’ and exponent ‘n’ by regression analysis and, consequently, convective heat transfer coefficient. From this study it is concluded that the convective heat transfer coefficient is decreasing with drying time it is due to decrease in moisture content. Results also showed that convective heat transfer coefficients are more in indirect solar dryer system than under open sun drying.
International Journal of Ambient Energy, 2015
ABSTRACT The increase in cost of fossil fuel and unavailability of electricity are the barrier fo... more ABSTRACT The increase in cost of fossil fuel and unavailability of electricity are the barrier for farmers to run their farm machineries and their development. Solar drying is a technique that not only helps in reducing fossil fuels and greenhouse gas emission by avoiding the use of machines in this sector, but also reduces the post-harvest food losses too. In present study, embodied energy analysis has been done for indirect solar dryer unit. Fenugreek leaves of 02 kg were put in each tray inside indirect solar dryer unit for drying purposes. Various environmental and economic parameters have been evaluated, which includes the payback period by cost, the energy payback time (EPBT), embodied energy, CO2 emission and the earned carbon credit. The total embodied energy of the system is 1081.83 kWh. The EPBT and CO2 emission are found to be 4.36 years and 391.52 kg per year, respectively.
Uploads
Papers by Vipin Shrivastava