Development of a Ceramic Tube Heat Exchanger with Relaxing Joint. Final Report, January 1977-June 1980

摘要

Advances in ceramic heat exchanger technology have been aided by work completed under the area investigated by this project. For four tubular ceramic materials, all silicon carbide, statistical strengths have been measured and documented from ambient temperature up to 1370 exp 0 C 950Advances in ceramic heat exchanger technology have been aided by work completed under the area investigated by this project. For four tubular ceramic materials, all silicon carbide, statistical strengths have been measured and documented from ambient temperature up to 1370 exp 0 C (2500 exp 0 F). Of the four materials tested, none were found to possess exceptional strength or probability of failure properties when compared to others in the test group. All material had Weibull modulus's of four to nine with mean material strength ranging from 58.9 to 117 MPa (8.5 to 17 ksi). Three of the ceramic materials were tested for 1000 hours in a simulated high sodium, coal-fired environment. Tests were conducted at gas temperatures of 1370 exp 0 C (2500 exp 0 F). Two of the materials tested were not significantly affected. The other, alpha-sintered SiC, had a reduction in tube wall thickness at the leading edge. Joining of ceramics has significantly been improved as a result of this project. Glass bonded ceramic joints have been manufactured and successfully tested at operating temperature and pressure. Brazed ceramic joints in which a metal was used to bond ceramic components has been successfully tested and used as part of the full size heat exchanger module. The successful operation for seven hours of the full size ceramic heat exchanger test module above 1150 exp 0 C (2100 exp 0 F) outlet temperatures at 689 kPa (100 psi) with firing temperatures at 1370 exp 0 C (2500 exp 0 F) demonstrates the potential of pressurized ceramic heat exchangers. The design operated without major problems and demonstrated the viability of the design's thermal shock capabilities and the design repairability. (ERA citation 05:030907)