Influence of Debris on Water Intake Gratings in Small Hydroelectric Plants: An Experimental Study on Hydraulic Parameters

Abstract

Deposition of debris on the screens of hydroelectric power plants translates into measurable economic losses. Occurring plant debris, although it is an organic material, is characterised by different forms and structure. It is often leaves, branches, and grasses in lowland areas, while in mountainous regions, broken boughs and trees can be expected. On the trash racks of power plants, debris may be deposited in different forms, shapes, and places. This work aims to determine the impact of the degree of submergence of debris on the values of the force acting on the racks. This paper analyzes the influence of the rectangular shape of the debris deposited on the trash racks and its degree of submergence and weight on the obtained values of the force acting on the racks as a result of water pressure, which directly affects the hydraulic losses and productivity of hydroelectric power plants. Our research confirms the negative influence of the deposited plant debris on the value of forces recorded on the gratings. The increase in the recorded force, and thus the resistance on the grating, is obviously dependent on the degree of obstruction of the debris by the grating obtained by changing the degree of debris immersion and its weight. In the case of changing the degree of submergence, the increase in force recorded on the gratings varied during the experiment from about 25% recorded for the fully submerged debris compared to that of the partially submerged debris for the mass of 100 g; in comparison, an increase of about 31% was recorded for that of the mass of 200 g. However, comparing the values of the forces recorded on the obstructed grids to that of the forces recorded on the clean grids, the increase ranged from about 15–53%.

Non-perennial segments in river networks

“…However, the network-scale effects of non-perenniality largely depend on the spatial arrangement of NPRs within the river network (Figure 3). Where NPRs are concentrated in the headwaters, particularly in deciduous forested areas 36 , the downstream effects of non-perenniality will be high seasonal inputs of unprocessed litter (Figure 3) that can reduce downstream water quality 80 or cause technical problems for dam intakes 81 . In contrast, where NPRs are in downstream segments of river networks, which are typically less dependent on terrestrial litter inputs from riparian zones, lower fluxes of unprocessed litter are expected in downstream river network segments.…”

An integral assessment of landslide dams generated by the occurrence of rainfall-induced landslide and debris flow hazard chain

“…It is fundamental to investigate and complement those studies of disaster chains up to the evaluation of the generation of the obstruction and its possible impacts. Uncontrolled transport of debris flow can be a major problem in maintaining the proper operation of hydroelectric facilities in the future (Walczak et al, 2021). Enhanced resilience to future obstructions on the river generated by debris flow landslide dam chain triggered by rain will be essential for reliable electricity supply and ensuring greater long-term opportunities (Chen et al, 2023).…”

Analysis of the Influence of Hydraulic and Hydrological Factors on the Operating Conditions of a Small Hydropower Station on the Example of the Stary Młyn Barrage on the Głomia River in Poland

“…The largest increase in the installed capacity is reported for Europe at 734 MW, the Americas with 698 MW and Africa with 134 MW. However, it must be remembered that SHPPs are characterized by specific problems related to operating conditions [18][19][20]. The problems of operating SHPPs are related to both the material carried by the water, overgrowth of riverbeds with vegetation, water quality, range of operation of the hydropower turbines and water level at the downstream position of the SHPPs, as well as the technical condition of the structures [8,21].…”