On-line life prediction of crude heater tubes using infrared technology

On the consideration of safety and economy, the work presented in this paper focuses on the life prediction of crude oil heater tubes. Temperature measurement becomes key process in the evaluation because the life of heater tube is sensitive to it. Temperature information of tubes has been acquired by infrared inspection method, which can do the on-line measurement with speediness and accuracy. The infrared images of the third pair of tubes, which are tested three times, are showed as an example in the paper. We get the temperature values from these images by using software of infrared image, which is programmed by our research group. Combined with the temperature and other operation data of three times testing, the state and remaining life of the tubes were assessed and analyzed by accumulated tube damage method using Larson-miller creep model. From calculation results, the conclusion can be made that the remaining life of the third pair of tubes are 7 years in current operating condition. The research we have done contributes to providing scientific reference for deciding repair or replacement of tubes. This kind of life prediction technique has a bright future in the industry practice.