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This study examines a cross-flow turbomachine designed for power generation in areas with limited discharge and head availability, focusing on sustainability, affordability, and ease of operation. It investigates how varying the number of blades in the runner affects turbine performance while keeping other design factors constant. Testing runners with 8, 12, 16, 20, and 24 blades under identical conditions reveal consistent RPM variations across different blade numbers for various parameter combinations. The study identifies a 12-blade configuration as optimal for electrification projects at selected sites. Experimental validation using the Taguchi technique confirms the reliability of the findings. Additionally, the research explores the turbine's performance under different nozzle tip elevations (18 cm, 16 cm, and 14 cm). The highest observed runner speed is 345 RPM for the 12-blade runner at an 8° angle of attack, with similar speeds recorded for the 24-blade runner under similar conditions. [ABSTRACT FROM AUTHOR]

The aim of the present work is to analyse a novel solar air heater configured with U-shaped longitudinal fins. The application of the proposed air heater for freshwater production and agriculture drying has also been analysed for the coastal area of India. The results are motivating for use of the proposed air heater for household requirements and smallscale industrial purposes to improve the earning in coastal regions. The mathematical model for time-dependent behaviour of the proposed air heater has been prepared by considering the energy balance of air heater components and solved to get the outlet temperature of the air from air heater. The results proved that the heater is suitable for the desalination and drying of many agricultural products. The effect of operating parameters has also been analysed to find suitable values for freshwater production. Optimum air mass flow rate of 160 kg/hr in air heater has been found whereas higher water temperature in the storage tank and lower temperature of cooling water in dehumidifier found suitable for higher yield of freshwater. In the drying process, significant improvement has been observed compared to direct solar drying and conventional air heater with 12 hours drying time for banana slices and 10 hours for garlic was found. [ABSTRACT FROM AUTHOR]

An adsorption refrigeration system (ARS) working on silica-gel/methanol pair has been investigated analytically and experimentally. By applying the mass balance in the adsorber bed the mechanism of adsorption in the thermal compressor with respect to time and bed length was determined. An experimental analysis was performed using a thermal gravimetric analyzer (TGA) to evaluate the mass transfer coefficient and optimum cycle time for silica-gel/methanol pair at different working temperatures. The Diffusion coefficient Ds and Activation energy Ea for silica-gel/methanol pair were found 2.55 × 10-4 m2/s and 83.08 KJ/mol. Further, the results of variation of regeneration temperature on the performance of the system in terms of COP (Coefficient of Performance) and SCP (Specific Cooling Power) was evaluated; the maximum average theoretical COP and SCP achieved by the system was 0.5 and 102 W/kg near about 127°C regeneration temperature. [ABSTRACT FROM AUTHOR]

In this work, a solar desalination system working through cyclic humidification and dehumidification and also utilizing waste hot air of air conditioner is analyzed numerically for the production of potable water during day and night both operations. The productivity of the proposed system is investigated for different operating and design variables and compared with a conventional system by simulation of a mathematical model based on energy and mass conservation of considered components in transient behavior using MATLAB. During simulations, climatic and geographic condition of Mumbai (India) is used due to the availability of saline water, humid air and the high annual operation of air conditioners. In proposed system air is heated by a double pass solar air heater whereas the saline water is heated by the hot air coming out from the air-cooled condenser of air conditioning unit particularly during day hour operation. The same arrangement is used to heat both air and water during night hours. The use of hot air from the condenser of air conditioner proved beneficial by increasing the yield by 21%-31% per day that depends under different operating and design conditions. Air mass flow rate of 0.032-0.035 kg/s in air heater found suitable and resulted in maximum productivity of 6 kg/d. The mass flow rate of cooling water at 0.038 kg/s has been found suitable with a maximum productivity of 7 kg/d. Need for higher Initial water temperature in a storage tank with a productivity of 8.2 kg/d at water temperature 46°C and low temperature of cooling water in a dehumidifier with a maximum productivity of 10 kg/d found by the analysis. Productivity variation in the range 4-10.2 kg/d has been found as the heater area varied from 0.5 to 2.5 m2. The proposed system found suitable to work in a region with higher wind speed and ensured better utilization of thermal energy with gained output ratio close to 1. [ABSTRACT FROM AUTHOR]