Session: 30-11 Testing 1

Paper Number: 129244

129244 - The Design, Fabrication, and Installation of the Inconel 740H Piping System for a 10 MW sCO2 Pilot Plant 

The STEP [Supercritical Transformational Electric Power] 10MWe sCO2 [supercritical CO2] pilot plant operates on a recompression cycle (RCBC) cycle up to 715°C and 250bar at the turbine inlet. Initial testing phases for this facility will operate a simple-recuperated cycle with turbine inlet temperatures up to 500 °C as a stepwise risk mitigation. While the uncooled turbine design includes novel thermal management, the surrounding piping must also withstand these conditions. This paper summarizes the design, fabrication, and installation of the high temperature piping throughout the system. These piping sections include pipe materials of the high-nickel alloy, Inconel 740H. Through this experience, supply chain, weld procedures, general handling, and inspection were among key challenges. The supply chain needed to produce extruded pipe, pipe fittings including elbow and tees along with flanges and flange clamps. The high temperature pipe sections that used the Inconel 704H material utilized Grayloc flanges to connect the piping to the equipment. This project involved pipe sizes and schedules that have not been previously produced with Inconel 740H. Inconel 740H requires careful attention when performing welds to ensure that the weld is not contaminated and that the correct temperatures are used with the proper shielding gas mixture. With the proper weld procedure and attention to detail consistent quality welds can be produced. The paper will detail these challenges and the lessons learned that came from them resulting in a successful installation.

Presenting Author: Fernando Karg Bulness Southwest Research Institute

Presenting Author Biography: Mr. Karg Bulnes is a Research Engineer within the Power Cycle Machinery Section of the Machinery Department at Southwest Research Institute. He is interested in thermodynamics, fluid dynamics, energy storage, and rotating machinery. His areas of technical expertise include turbomachinery testing, power cycles, and energy storage, and piping systems.

Authors:

Seth Cunningham Southwest Research Institute
Mitchell Rhodes Southwest Research Institute
Fernando Karg Bulness Southwest Research Institute
Jonathan Wade Southwest Research Institute
George Khawly Southwest Research Institute