Development of Arduino-based digital data acquisition on the Pelton turbine trainer

Abstract

The Pelton turbine works in a non-pressure system and is suitable for use as a micro hydro turbine generator in Indonesia. The Pelton turbine is a type of water turbine that does not require a large discharge, relatively high efficiency, and has a simple construction. When passing through the runner blade, the kinetic energy is converted into shaft work and a small part of the energy is released and some is used to fight friction with the turbine bucket surface. The Pelton turbine trainer is designed to obtain data such as turbine power, rotational speed, turbine efficiency, and the effect of turbine bucket modifications. Data on the trainer can be taken using analog measuring instruments or using digital sensors. The disadvantage of using analog measuring instruments is the high error rate in the reading process, in contrast to digital sensors because the reading data can be directly processed and displayed directly. Arduino Mega 2560 microcontroller is used as the brain in processing sensor readings. The water flow meter is used to measure the value of the water flow that flows into the nozzle. The Pressure Sensor is used to measure the pressure of the water flowing through the pipe. The Inductive Proximity Sensor is used to measure the rotational speed of the turbine shaft, and the load cell is used to calculate the torque. When the trainer is activated, the Arduino will immediately read the condition of the sensor sequentially starting from the Pressure Sensor, Water Flow Meter, Inductive Proximity Sensor, then the load cell connected via the HX711 Module. After all the data from the sensor is obtained, the Arduino will calculate the value of the water discharge, the turbine rotation speed, and the turbine torque. The calculated data is then displayed on the LCD and stored on the SD Memory Card. The process will be repeated and only stopped when the trainer is turned off. To regulate the flow of water flowing to the nozzle, a water bypass pipe is added which is controlled by a Globe Valve to regulate the flow rate of water in the bypass pipe. A ball valve is also added to the pipe between the tube and the nozzle, the function of the ball valve is to regulate the amount of water pressure that will flow through the nozzle. From the experimental results obtained constant sensor reading data according to valve conditions, changes in water flow and pressure are directly proportional to turbine torque. By using a digital sensor that is connected to a microcontroller, the reading data can be automatically stored and make it easier for Pelton turbine trainer users.