## 5 Conclusions  
In this paper, a model test bench designed for submersible high-pressure gas proportional short-circuit blowing was employed to perform L\({}_{\text{18}}\) (\(3^{7}\)) orthogonal experiments encompassing multiple factors at various levels. Furthermore, the training and prediction results derived from the 18 orthogonal experiments were subjected to analysis using a BPNN and Pearson correlation. The key conclusions are summarized below:  
* First, an extreme variance method was utilized to analyze the data from the orthogonal experiments, identifying the optimal combination of several factors: blowing duration (accounting for 39.16%), back pressure (accounting for 33.35%), gas blowing group pressure (accounting for 10.94%), and sea valve flow area (9.02%). Among these variables, blowing duration proved to be the most sensitive factor, with an F-ratio of 3.27;
* Second, a BPNN was implemented for both training and prediction based on the orthogonal experimental data. The findings indicate that the BPNN's robust nonlinear fitting capability effectively predicted high-pressure gas short-circuit blowing. The statistical evaluation metrics ranged from \(10^{-1}\) to \(10^{-12}\), the relative errors remained within a threshold of 3%, and the prediction accuracy achieved up to 100%. This validates the BPNN as a credible AI-based predictive approach for submersible short-circuit blowing;
* Third, Pearson correlation analysis was conducted on the BPNN's training set data to explore the relationship between the individual factors and outcomes. The results reveal positive correlations among the following: blowing duration (with a correlation coefficient of 0.6535), sea tank back pressure (0.8105), gas cylinder group pressure (with a correlation coefficient of 0.5569), and internal diameter of the sea valve (0.5373). In contrast, a negative correlation (-0.3741) with the gas supply pipeline length indicates the better efficiency of short-circuit blowing compared to conventional methods. Building on the previously discussed conclusions, a series of recommendations for engineering design and operational practices related to submersible high-pressure gas short-circuit blowing are presented below:  
* First, concerning blowing techniques, short-circuit blowing exhibits superior efficiency compared to conventional methods due to its reduced length of gas supply pipelines;
* Second, in terms of engineering design, several manipulation factors, including the increased volume and pressure of the cylinder group, as well as the enlarged flow area of the sea valve, have a positive impact on blowing performance. Additionally, it is crucial to establish appropriate specifications for the gas supply pipeline, including its inner diameter and length;
* Third, concerning operations, it is of vital importance to ensure that the optimal duration of blowing corresponds to the variations in the outboard back pressure during the operation process. In summary, this study introduces a robust predictive methodology for submersible short-circuit blowing, providing valuable recommendations for engineering design and operational protocols. This encompasses the advantages of the short-circuit blowing \begin{table}
\begin{tabular}{c c c} \hline \hline
**Index of Literature** & **Relative Error** & **Research Objects** \\ \hline Ref. [2] & 0.53–39.17\% & Peak pressure of ballast tank, which was directly related to drainage percentage \\ Refs. [10,11] & 8\% & The flowing rate of the high-pressure gas cylinder group, which was closely related to the drainage percentage \\ Ref. [8] & \textless{}5\% & Drainage percentage by gas jet blowing-off, which is a similar method to short-circuit blowing \\ Ref. [9] & \textless{}10\% & Drainage percentage by gas jet blowing-off, which is a similar method to short-circuit blowing \\ This study & 0.00–1.57\% & Drainage percentage of ballast tank during short-circuit blowing \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Comparison of existing results and this study.