Cooling Water Injection and Monitoring System to Efficiently Prevent Fouling in Centrifugal Compressors

The potential impact of fouling on ethylene plant equipment is huge. Gas polymerization frequently occurs in the cracked gas compressor, leading to efficiency losses and lower production due to unplanned outages. Injecting cooling water in the process gas compressor can help producers reduce fouling by lowering the temperature. Cooling water effectiveness is strongly dependent on water atomization and gas stream interaction. A series of numerical simulations was performed to validate the modeling approach by comparing the simulation results with available experimental data and a test case. The outcome depends on the selection of the appropriate models for heat transfer, particle coupling and injection definition. The goal is to develop an enhanced cooling system analysis, design and monitoring. The results of this investigation allow for an accurate prediction of actual temperature values inside the compressor, through the flow path, with consequent optimal dimensioning of the water injection system ─ more specifically, liquid flow rate, pressure drop and droplet sizes. An advanced stage-by-stage water injection system coupled with fully removable nozzles during compressor operation and a monitor efficiency control can decrease operational costs and the risk of production loss by providing operators with continuously updated equipment performance.