Method and apparatus for monitoring polyurethane diffusion in a porous medium, device, and medium

A computer device, comprising a processor and a memory, wherein the processor is connected to the memory, the memory is configured to store a computer program, and the processor is configured to execute the computer program to cause the computer device to perform the following steps:

• selecting a diffusion model according to a diffusion characteristic of polyurethane in the porous medium and winding a distributed optical fiber around at least one sensing cage according to a predetermined helical parameter to form a helical structure;
• establishing a spatial Cartesian coordinate system for the porous medium with a polyurethane infiltration point as an origin and mapping coordinates of each temperature measurement point on the helical structure to the spatial Cartesian coordinate system of the porous medium;
• connecting the optical fiber to a distributed temperature sensing system, calibrating an initial value of the distributed temperature sensing system, and measuring an initial moisture field of the porous medium before polyurethane infiltration;
• during the polyurethane diffusion that occurs in the polyurethane infiltration in the porous medium, monitoring temperature transmission fluctuations along the optical fiber by using the distributed temperature sensing system and acquiring a post-infiltration moisture field in a stabilized state of the temperature transmission fluctuations;
• and
• analyzing a change in water content based on the initial moisture field and the post-infiltration moisture field and identifying a polyurethane diffusion distribution field in the porous medium in conjunction with the diffusion model.

A non-transitory computer-readable storage medium storing a computer program, wherein when executed, the computer program causes a processor to perform the following steps:

• selecting a diffusion model according to a diffusion characteristic of polyurethane in the porous medium and winding a distributed optical fiber around at least one sensing cage according to a predetermined helical parameter to form a helical structure;
• establishing a spatial Cartesian coordinate system for the porous medium with a polyurethane infiltration point as an origin and mapping coordinates of each temperature measurement point on the helical structure to the spatial Cartesian coordinate system of the porous medium;
• connecting the optical fiber to a distributed temperature sensing system, calibrating an initial value of the distributed temperature sensing system, and measuring an initial moisture field of the porous medium before polyurethane infiltration;
• during the polyurethane diffusion that occurs in the polyurethane infiltration in the porous medium, monitoring temperature transmission fluctuations along the optical fiber by using the distributed temperature sensing system and acquiring a post-infiltration moisture field in a stabilized state of the temperature transmission fluctuations;
• and
• analyzing a change in water content based on the initial moisture field and the post-infiltration moisture field and identifying a polyurethane diffusion distribution field in the porous medium in conjunction with the diffusion model.