Fraunhofer Water Systems Alliance (SysWasser)In the phase change slurry process, part of the thermal energy found in wastewater is transferred into a long-term stable mechanical-thermal resilient emulsion with drops of paraffin in water in order to make use of the high energy densities which result from the paraffin’s phase transition from solid to fluid (200 kJ/kg melting enthalpy).
As the paraffin is blended into a suspension (phase change slurry, PCS), the material has the same advantages as fluid mediums, e.g. pumpability and high heat performance.
Various paraffins (with different chain lengths) can be used to find customized cooling mediums and/or appropriate cold storage applications for defined temperature ranges. The heat stored in the PCS can be released on demand through the heat pump and recycled into heating or warm water systems.