Development of Ultra Z-Blade turbine for pico-hydro system for low head low flow water resources

• Main Author: Mohd Rais, Nurul Ashikin
• Format: Thesis
• Language: English; English
• Published: 2022
• Subjects: T Technology (General); TJ Mechanical engineering and machinery
• Online Access: http://eprints.utem.edu.my/id/eprint/26902/3/Development%20of%20Ultra%20Z-Blade%20turbine%20for%20pico-hydro%20system%20for%20low%20head%20low%20flow%20water%20resources.pdf; http://eprints.utem.edu.my/id/eprint/26902/4/Development%20of%20Ultra%20Z-Blade%20turbine%20for%20pico-hydro%20system%20for%20low%20head%20low%20flow%20water%20resources.pdf; http://eprints.utem.edu.my/id/eprint/26902/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=122161

Hydropower is an attractive alternative to conservative fossil-based electricity generation source such as coal and gas. This is because it does not pollute the air from the release of toxic gasses such as the carbon monoxide. However, development of a hydropower electricity generation will cause for detrimental ecological impacts at its surrounding area. A much safer option to hydropower is the pico-hydro system since that it only requires a stream of water to harvest electrical energy through turbine rotation. There are two types of water turbine; namely impulse and reaction turbine. This research will only focus on the reaction type because it only requires a small amount of water to rotate a turbine. Cross Pipe Turbine (CPT) is suitable for high head and high water flow, Split Reaction Turbine (SRT) is fit for high head and low water flow and Z-Blade Turbine (ZBT) is applicable for low head and low water flow. Currently, there is still no work done to cover for the low head and ultra-low water flow section. Therefore, this work tries to cater for this by developing an ultra z-blade turbine for pico-hydro generation system for low head and ultra-low flow water resources. With an experimental approach, design improvement on the available ZBT was done. The important parameters of the design are illustrated with an exploratory approach in this study that can produce the most optimum design. The newly designed U-ZBT field data is then used to compare its performance against the already established CPT, SRT and ZBT. The numerical simulations for ideal and actual settings are presented to define characteristics of twelve mechanical and electrical parameters in this system. As a result, the operational parameters of the turbines in terms of power loss, power output, and efficiency may be established by using a loss factor (k-factor) and conducting a parametric analysis and field test under various conditions. The performance of Ø0.019m: 0.75-inch blade was superior to that of Ø0.05m: 2-inch blade when compared to the latter. In low head water conditions, it has the capability of achieving rotational speeds (up to 130 rpm) at minimal mass flow rates (around 1.77 L/sec), with mechanical power (approximately 60W), low energy loss (average 20%), and the efficiency (up to 66%). Even though the efficiency that it produced is 66% as opposed to 78% yielded by ZBT, U-ZBT is superior because the power that it produced is generated at a much lower water flow rate of 1.77L/s. This is 11.5% lower than required by the latter. It is hoped that the findings by this research work can benefit the community at the rural area in terms of generation of electricity by pico-hydro which can be achieved even at a very low flow rate water resources.