Mechanical Design of Steel Tubing for Use in Black Liquor Recovery Boilers
- ORNL
Finite element models were developed for thermal-mechanical analysis of black liquor recovery boiler floor tubes. Residual stresses in boiler floors due to various manufacturing processes were analyzed. The modeling results were verified by X-ray and neutron diffraction measurements at room temperature on as-manufactured tubes as well as tubes after service. The established finite element models were then used to evaluate stress conditions during boiler operation. Using these finite element models, a parametric response surface study was performed to investigate the influence of material properties of the clad layer on stresses in the floor tubes during various boiler operating conditions, which yielded a generalized solution of stresses in the composite tube floors. The results of the study are useful for identifying the mechanisms of cracking experienced by recovery boilers. Based on the results of the response surface study, a recommendation was made for more suitable materials in terms of the analyzed mechanical properties. Alternative materials and manufacturing processes are being considered to improve the resistance to cracking and the in-service life of composite tubes. To avoid numerous FE stress-strain analyses of composite tubes made of different material combinations, a response surface study was performed that considered two essential mechanical properties of the clad material - coefficient of thermal expansion and yield stress - as independent variables. The response surface study provided a generalized solution of stresses in the floor in terms of the two selected parameters.
- Research Organization:
- Oak Ridge National Lab., TN (US)
- Sponsoring Organization:
- USDOE Office of Science (US)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 754817
- Report Number(s):
- ORNL/P99-104688
- Country of Publication:
- United States
- Language:
- English
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