A Systems Approach to Optimize the Operation of a Refrigeration Unit at a Chemical Plant

摘要

This paper focuses on the ongoing system levelrnanalysis and the optimization results of two steamturbinerndriven refrigeration units at the DowrnChemical company Peroxymerics (PXC) plantrnlocated at St. Charles Operations in Hahnville, LA.rnSix-sigma has been accepted as a corporate-widernphilosophy at the Dow Chemical Company, and thisrnmethodology was applied to this refrigeration systemrnoptimization at the plant. Process refrigeration at thernplant comprises of two individual systems thatrnoperate at different temperature levels and serve arnmyriad of process loads as well as provide chilledrnwater for the plant. The total plant capacity is ~6,500rnrefrigeration tons and has a total charge of 225,000rnlbs of refrigerant - R134a. Two steam turbines drivernthe refrigerant compressors. The utility cost structurernis interlaced with costs and credits for the supply andrnreturn steam to the plant headers. As a first steprntowards a systems approach for optimization of thernrefrigeration unit operation, Dow Chemical Companyrncontracted with Hudson Technologies to undertake arnfeasibility study. After the projects were completed,rnoperational data was then collected and analyzed tornquantify the cost savings and level of optimization.rnTrending certain key parameters indicated ongoingrnperformance and closely monitored systemrndegradation.