Application of UVAS and TDLAS-based multi-combustion-parameter diagnosis using computerized tomography

•A custom CT cell that is suitable for space limitation requirements was designed to develop a multi-parameter-combustion diagnosis.•The corrected CO and NO absorption databases were established for CT reconstruction.•The accuracy of the CT algorithm and the rationality of the custom CT cell structure design were verified by optical path evaluation simultaneously through CFD simulation results reconstruction.•The multi-combustion-parameter diagnosis system was tested by methane-premixed flame and standard NO gas, and the results showed high accuracy. Fossil fuel combustion is the main source of mechanical power and will be accompanied by the production of a large number of toxic and harmful substances, such as NO and CO. In this study, Computed Tomography-Tunable Diode Laser Absorption Spectroscopy (CT-TDLAS) and Computed Tomography-Ultraviolet Absorption Spectroscopy (CT-UVAS) were used to establish a multi-combustion-parameter diagnosis system. A corrected H2O absorption database was applied by the wavelength at 1388 nm and 1343 nm. The spectra at 2325 nm were used to establish the CO absorption database. NO absorption database at 214 nm/226 nm was established by UVAS. The nonlinear least squares with the polynomial fitting method was applied to CT reconstruction. A custom CT cell was designed to fix the fiber and probes of the CT-TDLAS and CT-UVAS, and its rationality was evaluated by the Sum of squared difference (SSD) and Zero-mean normalization cross-correlation (ZNCC) through the comparison between CFD simulation and CT reconstruction. In the experiment, the CT reconstruction of the temperature, H2O, and CO showed significant distribution profile differences between two premixed flames. The NO detection function was demonstrated by standard NO gas, and the maximum average relative error was 4.99 %. The results show that the multi-combustion-parameter diagnosis system can measure the temperature, H2O, CO, and NO distribution of the combustion flow field at high frequency. The multi-combustion-parameter diagnosis system will assist with research and diagnosis on controlling NO generation and promoting combustion efficiency.