# Application of Extension Engineering in Safety Evaluation of Chemical Enterprises
## 4 Evaluation and Analysis of Safety and Environmental Data of Each Workshop in Chemical Enterprises
\begin{array}{ll}\text{indoor safety and environment indexes}&\text{hydrogen concentration}&\langle 0.27,0.38\rangle\\ &\text{hydrogen sulfide concentration}&\langle 0.41,0.49\rangle\\ &\text{methane concentration}&\langle 0.38,0.50\rangle\\ &\text{indoor temperature}&\langle 37.28,37.98\rangle\\ &\text{indoor humidity}&\langle 6.21,6.87\rangle\\ &\text{noise}&\langle 99.36,99.42\rangle\\ &\text{voltage}&\langle 229.06,230.96\rangle\\ &\text{thermal comfort index}&\langle 2.08,2.69\rangle\\ &\text{visible light}&\langle 2.72,3.02\rangle\\ &\text{outdoor meteorological indexes}&\text{outdoor temperature}&\langle 34.46,34.96\rangle\\ &\text{outdoor humidity}&\langle 33.59,38.39\rangle\\ &\text{light}&\langle 19980.85,25697.55\rangle\\ &\text{wind}&\langle 19.05,22.97\rangle\\ \end{array} \right)\]  
The fourth workshop:  
\[\left( \begin{array}{ll}\text{indoor safety and environment indexes}&\text{hydrogen concentration}&\langle 0.16,0.22\rangle\\ \text{hydrogen sulfide concentration}&\langle 0.12,0.21\rangle\\ \text{methane concentration}&\langle 0.18,0.26\rangle\\ \text{indoor temperature}&\langle 35.06,35.92\rangle\\ \text{indoor humidity}&\langle 8.22,8.53\rangle\\ \text{noise}&\langle 99.07,99.30\rangle\\ &\langle 220.46,226.90\rangle\\ &\text{thermal comfort index}&\langle 1.62,1.80\rangle\\ &\text{visible light}&\langle 2.18,2.58\rangle\\ &\text{outdoor meteorological indexes}&\text{outdoor temperature}&\langle 32.68,33.46\rangle\\ &\text{outdoor humidity}&\langle 42.40,45.96\rangle\\ &\text{light}&\langle 960.72,11590.26\rangle\\ &\text{wind}&\langle 26.39,28.96\rangle\\ \end{array} \right)\]  
Taking hydrogen concentration in indoor safety and environmental indexes as an example, the correlation degree is calculated as follows:  
Nonrisk:  
First, the interval distance values of hydrogen concentration calculated by Formulas (11) and (12) are:  
\[\rho(X_{11},\Omega_{1})=-0.04,\ \rho(X_{11},\Omega_{2})=-0.12\]  
Second, by using Formula (13), the position value is:  
\[D(X_{11},\Omega_{1},\Omega_{2})=-0.25\]  
Finally, Formula (14) is used to obtain the correlation degree when there is nonrisk:  
\[K(X_{11})=0.16\]  
Similarly, the correlation degree of light risk, medium risk, and heavy risk can be calculated, and the results are \(-0.25\), \(-0.52\), and \(-0.68\), respectively. The correlation degree of each second index in indoor safety and environmental and outdoor meteorological indexes are obtained, as shown in Tables 6 and 7. Therefore, according to Formula (15), the comprehensive correlation degree between indoor safety and environmental indexes and outdoor meteorological indexes is calculated as follows:  
\[K_{1}(X_{2})=(0.28,0.26,0.20,0.26) \begin{pmatrix}0.07&-0.42&-0.65&-0.68\\ 0.05&-0.27&-0.48&-0.63\\ 0.02&-0.49&-0.66&-0.75\\ 0.11&-0.42&-0.62&-0.71\end{pmatrix} =(0.065,-0.395,-0.600,-0.689)\]  
By the above calculation, the weight and correlation degree of the two first-level indexes can be obtained. Therefore, the comprehensive correlation degree of the first workshop of safety and environmental data of chemical enterprises can be calculated according to Formula (15), as shown in the following:  
\[K_{1}(X)=(0.706,0.294) \begin{pmatrix}0.158&-0.265&-0.515&-0.648\\ 0.065&-0.395&-0.600&-0.689\end{pmatrix} =(0.131,-0.303,-0.540,-0.660)\]  
Finally, according to Formula (16), the prerisk level of the first workshop of safety and environmental data of chemical enterprises is determined to be nonrisk. Similarly, the comprehensive correlation degree of the second workshop, third workshop, and fourth workshop can be obtained as follows:  
\[K_{2}(X)=(-0.257,0.187,-0.182,-0.702)\]  
\[K_{3}(X)=(-0.409,0.297,-0.326,-0.289)\]  
\[K_{4}(X)=(-0.305,0.238,-0.203,-0.593)\]  
In the end, the prerisk levels of the four workshops are nonrisk, light-risk, light-risk, and nonrisk.