Geothermal utilization is attracting attention as an alternative energy to fossil fuels.A research group led by Dr. Takuya Okazaki and Professor Hideki Kuramitsu of the Graduate School of Science and Engineering, University of Toyama has developed a sensor that plays a major role in promoting this.
Japan is a geothermal powerhouse with the world's third largest amount of geothermal resources.Geothermal energy is attracting attention as a renewable energy source, but scale (scale) is a major obstacle to promoting its use.This is a deposit due to inorganic salts such as calcium carbonate and amorphous silica, which causes a decrease in heat exchange efficiency and flow rate.
Therefore, the research group has developed a new sensor that can evaluate the scale generated from geothermal water in real time.The sensor used is an exposed optical waveguide called the core of an optical fiber.The adhesion of a scale with a higher refractive index than the material forming the core to the sensing site inhibits total internal reflection in the optical fiber and reduces the intensity of the propagating light.The resulting attenuation of light allows remote real-time evaluation of scale generation from geothermal water.
The features of this sensor are that it has a simple structure, excellent heat resistance, and low cost.It has become possible to quickly evaluate scales, which used to rely on visual inspection and measurement from weight and flow rate.
In addition, in the measurement of adding a general scale inhibitor on the market to geothermal water, it was found that a slight difference in the concentration of addition had a great effect on scale generation.It has also become possible to accelerate research for scale suppression.
It is expected to be a significant stepping stone to the solution of the scale problem, which is a major obstacle in geothermal development.
Paper information:[Scientific Reports] Fiber Optic Sensor for Real-Time Sensing of Silica Scale Formation in Geothermal Water (English)
