This paper presents a novel experimental work to enhance the performance of pyramid solar stills using PCM-encapsulated cylindrical fins with different heights. To optimise the fin's height as well as the water depth, the study was carried out in three phases using three identical pyramid solar stills with a basin area of 1m2. The first phase aimed to investigate the effect of using cylindrical fins of 40 mm height and comparing it with conventional stills at water levels from (10 to 40 mm). The second phase targeted studying the effect of fins heights of 20 mm, 40 mm, and 60 mm on the performance of the solar still. The third phase investigates the effect of paraffin wax embedded inside fin heights of 40 mm and 60 mm on solar still productivity. Results from phase 1 showed that using fins can improve the performance while 10 mm water depth was optimised. Phase two results showed that using a 40 mm fin's height can increase the overall efficiency up to 43.4 % compared with 38.5 % and 35.7 % using the 20 and 60 mm fins due to the shading effect. Based on phase 3 results, when using encapsulated PCM, the overall efficiency of 49.9 % was achieved using 40 mm encapsulated PCM fins compared with 34.6 % when using the conventional still. This increased water productivity by around 44.4 % compared with conventional stills. The cost of one litre produced from conventional, 40 mm finned absorber, and 40 mm finned absorber with PCM pyramid solar stills are 0.047, 0.045, and 0.043 $/l respectively. |
