Аuthors

Panin Y. V.^*, Beliakov A. Y.^**

Lavochkin Research and Production Association, NPO Lavochkin, 24, Leningradskay str., Khimki, Moscow region, 141400, Russia

*e-mail: yuriy.panin@gmail.com
**e-mail: BeliakovAIU@laspace.ru

Abstract

Thermal control systems of modern spacecraft (SC) are based on the use of heat pipes of various types. A special place among heat pipes is occupied by loop heat pipes (LHP). LHP is a system consisting of an evaporator with a compensation chamber adjacent to the evaporator, a condenserradiator and small-diameter connecting tubes (condensate and vapor lines). Unlike axial or arterial heat pipes, LHP have a separate evaporator and condenser. This paper considers the application of loop heat pipes (LHP) for heat removal from hard-to-reach isolated modules of the SC using a composite heat conductor based on them. This heat conductor includes two series-connected loop heat pipes. The first loop heat pipe (LHP-1) is used to heat transfer from the heat source and transfer it to the condensation heat exchanger (condenser). The second LHP (LHP-2) is used to create a heat sink in the LHP-1 condenser and heat transfer from the LHP-1 condenser by the LHP-2 to the radiator. The purpose of this work is to estimate the temperature difference at the junction of two LHPs considering the optimization of the design of the LHP-1 condenser. The problem can be solved by thermal calculation of three design options for the LHP-1 condenser and then selecting the optimal one. These variants differ in the number of turns of the LHP -1 channel in the condenser (coil): in the first variant, the channel has one 90-degree turn, in the second – two, and in the third – three. Optimization is performed according to two criteria: the temperature difference at the junction and the simplicity of manufacturing the LHP-1 condenser. The temperature difference must be minimized. Manufacturing the condenser should be as simple as possible. For thermal calculations, the Siemens NX FloEFD computing software package based on the finite element method is used. As a result of the thermal calculation, the temperature fields of three variants of the joint of two LHP with different versions of the capacitor were obtained. Based on these temperature fields, their comparative analysis is carried out. Based on this analysis, the optimal configuration of the capacitor LHP-1 is selected.

Keywords:

loop heat pipes, thermal model, thermal calculation, condenser, evaporator, finite element method

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