Some common alternatives to R11 refrigerant in centrifugal chillers include R123, R134a, and R513A. These refrigerants have similar thermodynamic properties to R11 but are more environmentally friendly. R123, for example, has a lower GWP and is widely used in low-pressure centrifugal chillers. R134a is another popular alternative, but it requires modifications to the chiller design and operation due to its higher pressure ratio. R513A is a newer refrigerant that offers a balance between performance and environmental sustainability.