Apparatus and method for measuring stress distribution on membrane surface based on fiber grating sensing

Abstract

The invention discloses a film surface stress distribution measurement device and method based on fiber grating sensing. The method comprises steps that multiple fiber grating sensors are selected, difference of center wavelengths of any two fiber grating sensors is not smaller than 2nm, the multiple fiber grating sensors are connected in series through utilizing single-mode fiber, pre-stress is applied to the series fiber grating sensors, the fiber grating sensors after pre-stress application are fixed on a film assembly through UV glue, and the distance between each fiber grating sensor andthe film surface is in a range of 0-1mm; the film assembly is packaged and is connected with a fiber grating demodulator, a static value of the center wavelength of each fiber grating sensor and a measurement value and a change value after water injection are detected through utilizing self-contained software of the fiber grating demodulator, the film surface stress distribution condition under different flow velocities can be acquired according to the light grating sensing principle, and the foundation for scientific judgment of the film surface hydraulic state is further laid.

Description

technical field [0001] The invention relates to the field of fiber grating sensing technology and membrane water treatment technology, in particular to a membrane surface stress distribution measurement system based on fiber grating sensing. Background technique [0002] Membrane technology has been widely used in water treatment for brackish water desalination, seawater desalination, industrial water supply treatment, pure water and ultrapure water because of its advantages of energy saving, high efficiency, economy, simplicity and convenience, and no secondary pollution. Preparation, wastewater treatment, wastewater reuse, etc. However, in the process of membrane water treatment such as forward osmosis, there are problems of concentration polarization and membrane fouling, which reduce the flux. By changing the operating conditions (water velocity and pressure, etc.), concentration polarization and membrane fouling can be slowed down. If the stress on the membrane interf...

AI Technical Summary

Problems solved by technology

[0004] At present, there is no measurement system for the stress distribution of the membrane surface based on fiber grating sensing technology

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