29th Symposium on Fusion Technology (SOFT 2016)

P3.011 Water Evaporation - Condensation Cooling System Design for Pb-Li17 Cold Trap

7 Sep 2016, 11:00

1h 20m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 11

Poster A. Experimental Fusion Devices and Supporting Facilities P3 Poster session

Speaker

Tomas Romsy (Faculty of Mechanical Engineering)

Description

The liquid metal eutectic Pb-Li17 is considered as one of the possible coolants for the blanket of the fusion reactor DEMO. The main reason for usage of the eutectic Pb-Li17 is the Tritium breeding. The eutectic flow separates alloys of the structural steels and thus be the cause of them corrosion.The cold trap is a device for corrosion products removing from liquid metal. The cold trap was developed by the Research Centre Rez within the Centre for Advanced Nuclear Technologies and consists of three loops. First one is for eutectic flow. The secondary loop contains water-steam mixture which provides cooling of the primary loop by water evaporation. The accumulated thermal energy is subsequently transferred by condensation to the tertiary loop - water cooler (condenser) which performs final heat removal from the trap body. Separation of corrosion products is carried out by gravity when the flow of eutectic with impurities is distributed by technological membranes. The process of separation occurs at lower temperatures than the operating conditions of eutectic in the fusion reactor blankets. For this reason, an efficient cooling of the liquid metal in the cold trap device is necessary. As one of the acceptable variants is the contemplated cooling by water evaporation in the secondary loop and subsequent condensation of the created water–steam mixture at the tertiary loop (condenser). Adding inert gas (Argon) into the mixture is necessary to achieve and control required higher saturation conditions. The presence of this gas in the mixture significantly influences the behaviour of heat and mass transfer. It brings an effect to heat removal from cold trap body. For solving these processes 1D model is developed and applied. Achieved results are analysed and discussed.