The effect of surface roughness of the impeller to the performance of pump as turbine pico power plant

Abstract

Pump as Turbine (PAT) is one of a hydropower plant that applies a pump with a reversed flow, working as a turbine to generate electrical power. It has the advantages of low-cost, widely available in the market and user-friendly. However, like other hydropower plants, PAT technology has low performance in term of power output. The impeller surface roughness is one of critical aspect, which influences PAT performance because poor surface roughness causes losses and cavitation. The objective of the research is to increase the PAT performance by improving the quality of the surface roughness and validate by the experimental tests. A low-cost and customize hand grinding process was applied to produce five impellers with three different levels of surface roughness (average surface roughness of 0.16 mm, 0.24 mm, and 0.40 mm), an edge rounded impeller, and a varnish lacquer coated impeller. All of the impellers undergo performance testing. The performance of the original impeller (without modification) used as a comparison. The experiment result shows that an impeller with a lower surface roughness (lower Ra number) has a higher performance. An impeller with an average surface roughness of 0.16 mm improved 10.9% of its initial performance. Additional edge rounding for a 0.16 mm surface roughness impeller would improve its performance by 13.1%. The optimum turbine efficiency of 15.45% was achieve-able by implementing an impeller with the lowest surface roughness.

Experimental Investigation on Improving Lifetime of Peripheral Pump Impeller under Cavitation Using Different Techniques

“…The specifications of the eight impellers, including the original impeller, are presented in Table 1. The surface roughness of the radial flow pump impeller is the most important factor in determining the amount of hydraulic flow and friction losses [20]. As shown in the table three impellers with three different levels of arithmetic surface roughness (Ra) of 0.35µm, 1.38µm, and 3µm, in addition to the original one with an arithmetic surface roughness (Ra) of 3µm were produced using a low-cost and customizable hand grinding procedure.…”

“…Statistical measures, such as arithmetic surface roughness (Ra), are commonly used to assess surface roughness. The control of erosion and material removal is known to be influenced by surface roughness [20]. For optimizing the impeller lifetime, three impellers with different surface roughness (Ra) (0.35, 1.38, and 3) µm and the original one with (3µm), were operated under cavitation conditions for (300) minutes at a pump rated speed of 2900 rpm.…”

Modern Monitoring Instrument to Support Fishing Vessel Operation and Maintenance: A Review

“…Temperature sensors with code DS18B20 can use Arduino as the processor [77], [78]. Likewise, in his article Zariatin [79] measured water pressure using the HK1100c sensor with an Arduinoboard processor for measuring pressure. Similarly, to get the rotational speed and time of Arduino, Putu [80] used Arduino as the processor.…”

Numerical and experimental study of mixed flow pump as turbine for remote rural micro hydro power plant application

“…It has also introduced a method for predicting PAT performance based on theory and numerically in a single stage centrifugal pump operated as a turbine. The surface roughness effect of the impeller/pump blade used as a turbine has been studied by [17]. Another study introducing a new theoretical method for predicting the best efficiency points of PAT has been worked out by [18], where the theory is based on the principle of matching impeller-volute, which is then validated using three centrifugal pumps with specific speeds.…”