Performance investigation of a modified single-basin solar distiller by augmenting thermoelectric cooler as an external condenser.

Harvesting freshwater from saline and seawater using solar energy has proven a significant impact in recent times. The present study aims to investigate the performance of the solar desalination system by incorporating glass reflectors, heat storage media, and a thermoelectric cooling system with a single-basin-type distiller. Accordingly, the objective of the study is to improve the performance of the solar distiller in terms of freshwater production and efficiency compared to a conventional setup. Moreover, the designed unit was tested under the environment of the Western part of India (Mehsana-23.5880° N, 72.3693° E) for 19 days in the months of May and June 2022. The maximum daily productivity observed during the day was 2.5 l at an average solar radiation of 1200 W/m2, which was 1.23 times higher than its conventional counterpart. Similarly, the energy efficiency showed a maximum improvement of 23.73%. At the middle of the day, i.e., maximum performance condition, the exergy efficiency was doubled with current modifications. Solar radiation and ambient temperature were found to be the most critical parameters that influence performance. Modifications also increase the % off sunshine hour productivity compared to sunshine hour from ~ 10 to 11% to ~ 20.8 to 24%, respectively. The cost of water distillation for the proposed solar still was found as 0.037 $/l/m2,s and the payback period was estimated as 2.27 years. The overall results indicate the positive influence of the modifications; hence, this type of setup is feasible for implementation on the field in harsh and coastal line areas. However, modified single-basin solar still needs extended field study to realize the full potential of the modifications.

Performance analysis of a biogas operated porous radiant burner for domestic cooking application.

In this paper, the combustion characteristics of biogas in a Porous Radiant Burner (PRBBG) designed for domestic cooking appliances are presented. Developed PRBBG consists of two layers of porous matrices viz., Silicon Carbide (SiC) and Alumina (Al2O3) and operates in the biogas flow range of 177 to 530 l/h with stable equivalence ratio (ϕ) range of 0.75 to 0.95. The effects of biogas flow rate and equivalence ratio on thermal efficiency (ηth) and emission characteristics of the burner are investigated and also compared with its conventional counterpart. Overall performance assessment shows that PRBBG operating at lower equivalence ratio and lower firing power has better thermal efficiency with lower CO and NOx emissions. The performance of the burner in terms of temperature mapping suggests that firing power variation is of higher importance than that of equivalence ratio. The maximum temperature difference between the center and the periphery of the burner surface is found to be ~ 83 °C at an equivalence ratio of 0.95. The thermal efficiency varies in the range of 51-62% and its maximum is at 0.75 equivalence ratio and 177 l/h flow rate of biogas. Within the range of studied biogas flow rate range, CO emission is in the range of 29-80 ppm and NOx concentration was lower than 4 ppm. Whereas, for Conventional Burner (CB), thermal efficiency, CO, and NOx emission are found in the range of 43-52%, 211-276 ppm, and 9-15 ppm, respectively. The overall performance showed that PRBBG is capable of burning a lean biogas-air mixture with better thermal efficiency and lower emissions.