Extension of a Fiberglass Cooling Water System of a Power Plant
The objectives of the surge analses were as followed:
- To define the maximum and minimum pressures during the various upset scenarios.
- To define necessary measures to protect the cooling water network against overpressures or vacuum conditions that exceed the pipe and equimpent allowable values.
- To supply pressure / flow time history plots at important locations in the system.
The various analyses have been performed using the software package BOSfluids.
Based on the steady state condition six critical upset scenarios were identified and analyzed. In all scenarios pressure waves were generated that travel thru the system and cause alternating high and low pressure regions to occur in the piping and most of the equipment. The results of these analyses were as followed:
- The used valve closing time of 30 seconds is sufficiently slow.
- All maximum pressures calculated were well below the allowable 5 barg.
- Minimum pressures at or around all vacuum occurred at several places during several scenarios. All pipes were vacuum resistant.
- Most cavities arised during one pump operation around the surface, condenser and heat exchanger due to column separation. Mainly around and in the upper condenser pass.
- Start-up scenarios provided no problems for the system.
- Unbalanced forces were large due to large diameter and sudden pressure change.
Based on the above it can be concluded that the system is fit for purpose and can withstand all the cases analyzed.