3.2.5. Energy Utilization Ratio

Energy utilization ratio as performance indicators of the energy analysis were calculated by the energy that the soil ultimately uses and low calorific value of 1 km of NG:

$$
\eta\_{cm=} \frac{Q\_{s,a}}{Q\_{ar,\text{act}}} \tag{25}
$$

## *3.3. Exergy Analysis Model*

One kilogram of natural gas (NG) is the total exergy source of the system and the study about the exergy flow and the exergy loss is started with the exergy of one kilogram of natural gas (NG). The temperature used in modeling is shown in Table 1 or calculated in Appendix B (c).
