Design and development of instrumentation and data acquisition for a photovoltaic driven community scale RO desalination system and its performance studies

This work is related to the design and development of instrumentation, data acquisition and graphical user interface of Photovoltaic driven Reverse Osmosis system for monitoring and performance evaluation purposes. Installed PV system comprises of 12 PV panels, trackers, batteries and inverter whereas RO system is equipped with pre filters, pumps, energy recovery devices and filtration membranes. Proper instrumentation is carried out in PV system to measure the irradiation, temperatures, voltage and current at various points. Moreover various sensors are used to measure the pressures, flows, salinities at RO unit. Signal conditioning circuits are designed to adjust sensor output signals for computer interface. A simple moving average filter is used to suppress the measurement noise. The experimental investigation of PVRO system is carried out by using LabVIEW interface capabilities. The developed system reveals and stores the pronounced impact of measured variables on the PV output power and specific energy consumption of the RO filtration system. The online data display in multi-scale window frame is very informative for system operation and analysis. During the experimental run of PVRO system using the developed DAQ system, the PV system generated 7.5kWh of energy during the whole day operation. Feed water having 7100ppm salinity and its flow rate was set to 850 lit/hour by adjusting the RPM of the high pressure pump. Clean water flow rate is recorded to be at 465 lit/hour having salinity of 115 ppm during the RO operation. Specific energy consumption of RO system comes out to be 2.083kWh/m³ for 7100ppm salinity of feed water.