Abstract: Heat load, feed water pressure and other factors influence the vapor-solid-liquid phase change interfaces during the start-up and work processes, and this will affect sublimator's work stability and operation strategy. Experiments on sublimator start-up with both low thermal load and low feed water pressure, and start-up with both high thermal load and high feed water pressure conditions were carried out to study the Influences of heat load and feed water pressure on the start-up and steady-state work performance of sublimator. At the same time, a two-step experiment on sublimator was also carried out and the temperature responses of sublimator were tested. Start-up sublimator with low heat load and low feed water pressure achieved a steady state at first, and then both the thermal load and feed water pressure were increased to a large value. The experimental results revealed that: 1) Sublimator start-up with high thermal load and high feed water pressure reaches the steady-state in a shorter time, but this will increase the risk of breakthrough in start-up process. 2) Due to the advanced self-adjust capability of the liquid-solid-gas interface location in sublimator, a new balance will be established quickly. This indicates that the risk of breakthrough can be decreased through starting the sublimator in low thermal load and low feed water pressure. Increasing the thermal load and feed water pressure after it reaches the steady state to decrease the risk of "breakthrough", it will not influence the heat rejection performance.

Key words: sublimator, heat load, feed water pressure, breakthrough, operation strategy