DEVELOPMENT OF A FIELD-BASED MATERIALS TEST-RIG

Abstract

Scaling also known as fouling and corrosion is a serious problem in geothermal applications. In a binary plant, the components most affected are the primary heat exchangers which are in direct contact with the geothermal fluid on the one side and the binary fluid on the other side. The build-up of scale leads to a reduction in heat exchanger efficiency while corrosion results in a reduced equipment lifetime. The extent of scaling and corrosion is a function of the chemical composition of the brine, the process conditions and the selected material. In the context of material selection, the guiding question is: ‘What material performs best for any given application in the Above Ground Geothermal and Allied Technologies (AGGAT) environment’. Test results obtained under idealized conditions in laboratory set-ups need to be verified by field based testing. The NZ Heavy Engineering Research Association (HERA) in cooperation with its industry members and Universities has developed a field-based material test rig (MTR). This paper gives an overview of the features of the MTR.