Calculation problems for gas main pipelines

Thread Content

Feed pressure for catalytic dry gas desulfurization: 1.1 Mpa, flow rate: 3100； The pipeline has a diameter of DN150, which reduces to DN100 at the pressure control valve of the outlet unit. The parameters specified in the design drawings for this outlet unit are a pressure of 0.5 Mpa and a flow rate of 3000. Using the ideal gas law, when the pressure drops from 1.1 to 0.5 Mpa, the volume should increase; specifically: V2 = P1V1/P2 = 6820. The flow velocity at the pressure control valve is u = Q/S = 240.6 M/s. I then did some research but couldn’t find any data on the flow velocity related to dry gas; only the value of 30 m/s for natural gas was available. I would like to ask everyone about the appropriate flow velocity for dry gas, as well as issues such as noise, erosion, vibrations, and static electricity that can occur at high flow velocities. During my research, I found that when the pressure of natural gas exceeds 2 Mpa and drops to 0.1 Mpa, a Joule-Thomson coefficient comes into play, resulting in the formation of C1 and C2 crystalline hydrates. So, will dry gas experience blockage due to the Joule-Thomson coefficient when the outdoor temperature is -40 degrees Celsius in winter? I seek advice from experts. Dry gas pressure decreased from 1.1 to 0.5 volume units