Model-Based Heater Control Design for Loop Heat Pipes

Loop Heat Pipes (LHPs) are passive two-phase heat transfer devices which are often used for the thermal control in satellites. The working principle of a LHP is based on the evaporation of a working fluid and its subsequent condensation at a remotely located heat sink. A common task in aerospace technology is to maintain a desired operating temperature to ensure an optimal operation of the satellite's electronic devices. To this end, an additional heater may be placed on the compensation chamber. This work presents the very first model-based heater control design approach. Using energy equations, the complex dynamics of the LHP are modeled analytically. As an example, a PI controller commonly used for the LHP heater control is parametrized by this model and implemented on a LHP test bench for experimental validation.