Session: 20-01: Compressor Operation and Process Design

Paper Number: 151202

Integrally Geared Centrifugal Compressors: Control Methods, Applications and Process Control 

Integrally geared centrifugal compressors (IGC) are used in many gas compression processes, including air separation, LNG,  sCO2 bottoming cycles, fuel gas compression and plant air compression. They allow to mechanically couple several compressor or expander stages via a central, single or multistage helical gear. The basic design involves a centrally arranged gear (‘Bullgear’) driving multiple pinions. The pinions are connected to individual compressor or expander stages, with a stage on each end of a pinion. The layout allows for the pinions to have different gear ratios, so they will be able to run at different speeds, allowing for optimal aerodynamic speeds of the impellers. All stages usually have an axial inlet and a radial outlet. Intercooling after every stage is feasible, and often used. The pinions can either support compressor or expander stages.  Because integrally geared compressors allow the use of variable inlet and diffuser vanes for every stage if needed, in many instances variable speed drivers are not necessary. On the other hand, where variable speed drives either as main or supporting drivers are used, the control methods have to be coordinated.  Of particular interest is the substantially different behavior of different control methods, and their impact on the compressor map, the interaction with the process,  as well as the design of surge avoidance systems.

Presenting Author: Karl Wygant Ebara Elliott Energy

Presenting Author Biography: Dr. Wygant is Sr. Manager of Advanced Technology Programs at Elliott Group. Dr. Wygant holds an M.S. and Ph.D. in Mechanical Engineering from the University of Virginia and an M.B.A. from Norwich University. His engineering experience over the last 25 years is related to a development of new turbomachinery products, including: rocket turbopumps, automotive turbochargers, industrial compressors, steam turbines, gas turbines, and novel turbomachinery applications. His management background includes: project management, multi-group management, business management, and leading new product development from inception to market delivery

Authors:

Rainer Kurz RKSBenergy
Karl Wygant Ebara Elliott Energy
Klaus Brun Ebarra Elliott Energy