Development of Axial-Flow Hydrokinetic Turbine Systems for Shallow Tropical Rivers

• Main Author: Kheng Wee, Tan
• Format: Thesis
• Language: English; English; English
• Published: UNIMAS 2023
• Subjects: TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://ir.unimas.my/id/eprint/43045/3/Tan%20Kheng%20Wee_dsva.pdf; http://ir.unimas.my/id/eprint/43045/4/Thesis%20PhD_%20Tan%20Kheng%20Wee%20-%2024%20pages.pdf; http://ir.unimas.my/id/eprint/43045/7/Thesis%20PhD_%20Tan%20Kheng%20Wee.ftext.pdf; http://ir.unimas.my/id/eprint/43045/

Currently, the majority population of the world without access to electricity are countries in the tropics. Although Malaysia was among the tropical country listed to achieve 100 % accessibility in 2015, the state of Sarawak still has about 5 % of its population that does not. Due to the uneconomical grid connection, the state government has implemented small-scale conventional Micro-Hydropower (MHP) and Solar Energy Systems (SES) because of their abundant resources. However, despite being the preferred choice, small-scale MHP is inapplicable in the area where the topography does not favour it. In the meantime, the off�grid rural communities rarely have the purchasing power to acquire expensive equipment manufactured in high-cost countries. Besides, few commercially available small-scale Hydrokinetic Turbines (HKT) were developed specifically for shallow rivers (less than 1 m), and their design might not be entirely suitable for tropical rivers. Subsequently, this research aimed to construct a low-cost axial-flow HKT acceptable for shallow rivers in the tropics and would produce 2 kWh of energy per day. Two prototypes are designed and built in this research. The first was to evaluate the concept of building an HKT solely with off-the-shelf materials while the second was to overcome the issues faced by the first. The second improved prototype, with a 0.585 m reprofiled fan rotor with swept-back blades as the turbine rotor, produced 92.29 W of power from a flow velocity of 1.26 m/s, and its estimated efficiency is 0.34. Therefore, it can generate more than 2 kWh per day and is considered sufficient for a typical rural household. Besides, the improved prototype only costs USD 750 and is a fraction of the cost of commercial HKT for shallow rivers. Nevertheless, the study also revealed the Smart Drive motor as a promising and versatile candidate to be used as a generator for small-scale HKT construction. It produces less noise and has lower cogging torque than the DC brushed motor used in the improved prototype. A basic guide is also presented for small-scale HKT construction with the modified Smart Drive motor – with the 60 SP and 60P configuration – as an alternative generator.