The NOVATEC BioSol technology is based on the principle of Fresnel collector technology. A solar field consists of 16 parallel rows of mirrors. A simple mechanism is used to keep the mirrors adjusted to the position of the sun, while the mirror arrangement is such that it collects the sunlight into a focal line. A receiver is installed in the focal line, in which water evaporates. The vapour is routed to a steam turbine.
A trial facility in Lorca, southern Spain is used to test the technology under practical conditions as well as to quality-test the components of the solar field. The system's efficiency is also tested by measuring the output performance and comparing it to the expected values.
To determine the solar plant's capacity, the generated quantity of heat is measured. Under otherwise constant conditions, this value may be derived from the flow rate of the water heated by solar radiation and the temperature difference between supply and return flows. The temperatures are measured with Pt-100 thermo probes. FLUXUS ® measures the water flow rate using non-invasive clamp-on technology: The ultrasonic transducers are simply clamped to the pipe with no pipework or downtimes required.
The temperature and flow rate values are then digitised and transferred to a central computer. Clamp-on measurement provides maximum flexibility. A single transducer pair fits the whole range of commonly used pipe diameters. Modifications to the system can be made with no regard to the measuring equipment.
The instrumentation used was a FLEXIM FLUXUS®ADM 740 with Q3N7 transducers to measure the flow of water in a pipe diameter of 32mm with a temperature range of 50 to 100 degrees C and pressure up to 55 bar.
The installation offered many advantages including the that the measurement is not affected by pressure, its ease of installation and no changes in the pipework are required.
