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ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
NUMERIC EVALUATION OF A HEAT PIPE-RADIATOR ASSEMBLY FOR SPACE POWER SYSTEMS
Submission Author:
Luis Felipe Ribeiro Romano , SP , Brazil
Co-Authors:
Luis Felipe Ribeiro Romano, Guilherme Borges Ribeiro
Presenter: Guilherme Borges Ribeiro
doi://10.26678/ABCM.ENCIT2018.CIT18-0046
Abstract
The research and technological development towards compact energy conversion systems for space applications allows the emergence of new mission possibilities, especially those directed for deep space explorations. Considering the Closed Brayton Cycle of as the energy conversion system for nuclear power, an analysis was conducted regarding the conversion cycle’s Cold Side mass. The complete radiator assembly was separated in control volumes, considering variable geometry parameters for each of them, presenting a variable sized trapezoidal space radiator assembly as output. Each control volume is physically and thermally coupled with water heat pipe (HP). The heat flux was limited by the geometry of each panel section, being its heat pipe modeled to fit given geometry and verified against its operational limits. The model considered a geometric and thermal coupling with temperature drops along the heat pipe axial direction, the radiator panel surface – modeled as a radiative fin – and the heat exchanger duct, providing reasonable global parameters to aid the decision making of the radiator designer. The model showed feasible results within a range of 507K and 525K for the duct inlet temperature, with the first law cycle efficiency ranging between 20% and 25%. Considering the fixed wick and initial heat pipe geometry input provided, a heat pipe spacing of 0.05 ~ 0.15m and a radiation shield shadow’s angle of 0 ~ 5° provided the lowest feasible heat piperadiator mass. Cold Side total masses of 600 to 800kg were observed, along with HP quantities ranging from 175 to 375 and a total radiator length of roughly 25m.
Keywords
Radiator, Heat Pipes, Space, Brayton Cycle
