Neon pulsating heat pipe with innovative flexible evaporator to facilitate cryocooling of superconducting devices

Abstract

Abstract Cryogenic pulsating heat pipes (PHP), also termed oscillating heat pipes, are passive thermal links that transfer heat by oscillatory motion of two-phase cryogen confined in serpentine-shaped capillary tubes. It is composed of three sections, namely, the condenser (cold sink), the evaporator (heat source) and the adiabatic part that can range from several centimetres to few metres. In spite of longer lengths, PHPs hold an advantage that their weight does not radically increase in comparison to counterparts like metallic thermal straps. The aim is to present cryogenic PHPs as one of the potential thermal links aiding in distant cooling of superconducting devices from active cryocoolers. A 0.4 m long neon PHP with 1 mm capillary tube diameter has been recently developed characterized by one of the highest thermal conductance reported till date both in vertical and horizontal orientation. An innovative modification in the construction of PHP evaporator is showcased in this article. This would considerably enhance the flexibility of PHPs in terms of their employment geometrically within the targeted application. Pilot experimental results for neon PHP coupled with the altered evaporator is presented for heat load up to 18 W.