Design and Stress Analysis of a New Distributed Single Tank Molten Salt Heat Storage System with Internal Heat Source

Molten salt energy storage technology shows great potential in a sustainable energy integrated system for its excellent thermal energy storage efficiency and environmental adaptability, and it has received much attention from the academic community. To improve the efficiency of traditional dual-tank heat storage systems, a new distributed single tank thermal storage system with an internal heat source was proposed. The single tank was designed according to API 650 and EN 13445-3:2012 specifications, and the specific data of the storage tank was obtained by combining application examples. The results show the following: (1) the stress of the molten salt storage tank with internal electric heating increases during the heating process, and the peak stress appears at the connection position below the tank body and the electric heater sleeve. (2) The increasing electric heater sleeves lead to the increase in tank stress, and when the number of electric heater sleeves increases from four to eight, the tank stress increases by 24%. (3) The stress of the tank reduces with the increasing axial height of the electric heater sleeve. The stress of the tank is reduced by 8% when the position of the electric heater sleeve is increased from 400 mm to 800 mm. This study can provide some theoretical support for the design and optimization of a single-tank molten salt heat storage system and provide a reference for the design of such storage tanks with a built-in heat source.