Modular, Thermal Bus-to-Radiator Integral Heat Exchanger Design for Space Station Freedom

A conceptual design for the interface of the Space Station Freedom (SSF) two-phase thermal bus with the heat rejecting radiator panels has been developed. The concept uses baseline technology for the radiator panels and the thermal bus condenser and replaces the current baseline interface hardware with a direct bus-to-radiator heat pipe integral connection. The concept integrates the radiator panel and condenser units into a single unit and is referred to as the “integral heat exchanger (IHX)” concept. It addresses the substantial weight and assembly complexities and inefficiency of the current contact heat exchanger mechanism.

This paper presents a brief overview of the SSF testing that has led to development of the IHX concept, describes the concept and addresses the savings that could be achieved using the IHX concept to maximize radiator surface temperature and thereby heat rejection capability. It also presents data on the weight, and volume savings that can be achieved using the concept and addresses the logistical implications of a direct bus-to-radiator Orbital Replacement Unit versus the separable condenser and radiator panels in the current baseline and 1990 Preliminary Design Review (PDR) SSF Thermal Control System (TCS). The concept has been proposed for initial SSF implementation but can also be used to enhance SSF heat rejection capabilities