Apparatus and method for estimating thickness of sediment, and non-transitory computer-readable recording medium

The present disclosure provides an estimation apparatus including a controller that: acquires a first pipe surface temperature, which is an outer surface temperature at a sediment generation location of a pipe through which a fluid flows, and a second pipe surface temperature, which is an outer surface temperature at a sediment generation location of the pipe through which the fluid flows; the second pipeline surface temperature is a second pipeline surface temperature at a sediment generation position at which the sediment adheres to an inner surface of the pipeline, and the second pipeline surface temperature is an outer surface temperature of the pipeline at a reference position different from the sediment generation position; calculating an in-pipe fluid temperature based on the second pipe surface temperature, the in-pipe fluid temperature being a temperature of the fluid at the sediment generation location; and estimating the thickness of the sediment based on the in-pipe fluid temperature and the first