## 5 Results and Discussion
### Data Reconciliation Without Gross Errors  
This section is an overview of two calculation conditions that do not include gross errors. The reconciliation results of some parameters under Conditions 1 and 2 are shown in Tables 7 and 8, where Val. represents value, De. represents deviation, and Un. represents uncertainty. As can be seen from the tables, since Conditions 1 and 2 do not have gross error sensors, the overall reconciliation effect of the system is relatively good, and the overall reconciliation trend of the two is consistent. The level of reconciliated deviation is small. It can be seen deviations of most parameters under two working conditions are less than 1,  
Figure 3: Iterative calculation of equation residual under different working conditions. Figure 2: Quality factor of parameters under different working conditions. and the deviations of very few parameters are also fluctuating around 1%. Measured values of known variables or calculated values of unknown variables still have large deviations from the design values within the allowable deviation range even if they do not contain gross errors. Most of them are mass flow sensors such as mass flow of gas and mass flow of CO\({}_{2}\) in ST1, etc. The deviations of these sensors have been significantly reduced after reconciliation. However, in fact, the deviations of a very small number of parameters are increased, such as SC output pressure under Condition 1 and AC power under Condition 2. This is because data reconciliation is a reconciliation process for parameters of the whole thermal system, and its essence is to disperse the large deviations of some parameters into other parameters to improve the quality of all parameters. In addition, compared with the change of uncertainty before and after reconciliation, the uncertainties of parameters also have a very obvious decline, and those after reconciliation are below 3%. It can be shown that the data reconciliation greatly reduces the uncertainty of the parameter whether known variables or unknown variables, and effectively improve the accuracy of measurement data. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & **Design** & \multicolumn{3}{c}{**Measured**} & \multicolumn{3}{c}{**Reconciliated**} & \multirow{2}{*}{**Unit**} \\  & **Val.** & **Val.** & **De.** & **Un.** & **Val.** & **De.** & **Un.** & \\ \hline Mass flow of gas & 92.900 & 91.140 & 1.89\% & 5.00\% & 92.476 & 0.46\% & 2.54\% & kg/s \\ H hot side output temperature & 72.690 & 72.459 & 0.32\% & 0.58\% & 72.689 & 0.001\% & 0.45\% & \({}^{\circ}\)C \\ H cold side output temperature & 517.600 & 516.618 & 0.19\% & 0.25\% & 517.585 & 0.003\% & 0.12\% & \({}^{\circ}\)C \\ Mass flow of CO\({}_{2}\) in ST1 & 69.890 & 71.942 & 2.94\% & 10.00\% & 70.085 & 0.28\% & 2.55\% & kg/s \\ SC inlet pressure & 8.000 & 7.928 & 0.90\% & 2.00\% & 7.971 & 0.36\% & 1.37\% & MPa \\ SC output pressure & 24.000 & 23.981 & 0.08\% & 2.00\% & 23.976 & 0.10\% & 1.39\% & MPa \\ SC inlet temperature & 32.000 & 31.288 & 2.22\% & 0.66\% & 31.955 & 0.14\% & 0.20\% & \({}^{\circ}\)C \\ HTR cold side & 380.330 & 379.476 & 0.22\% & 0.31\% & 380.278 & 0.01\% & 0.13\% & \({}^{\circ}\)C \\ output temperature & 32.530 & 132.529 & 0.001\% & 10.00\% & 132.950 & 0.32\% & 2.58\% & kg/s \\ Mass flow of CO\({}_{2}\) in ST2 & 62.640 & 65.759 & 4.98\% & 10.00\% & 62.865 & 0.36\% & 2.74\% & kg/s \\ AC power & 40,014 & 39,817 & 0.49\% & 12.38\% & 39,868 & 0.36\% & 2.86\% & kW \\ GT power & 70,997 & 70,949 & 0.07\% & 11.21\% & 71,332 & 0.47\% & 2.64\% & kW \\ ST1 power & 9490 & 9480 & 0.10\% & 11.73\% & 9511 & 0.23\% & 2.88\% & kW \\ ST2 power & 6733 & 6713 & 0.29\% & 15.92\% & 6752 & 0.29\% & 2.85\% & kW \\ SC power & 3457 & 3433 & 0.69\% & 11.93\% & 3456 & 0.01\% & 9.37\% & kW \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Reconciliation results of some parameters in Condition 1.