Numerical investigation of a vertical triplex?tube latent heat storage/exchanger to achieve flexible operation of nuclear power plants

The current numerical investigation is carried out to assess the possibility of integrating a latent heat thermal energy storage (TES) in nuclear power plant (NPP) system. This would allow improving capability such plants operate load-following mode by eliminating gap between supply and demand grid. In contrary previously published TES designs, phase change material (PCM) triplex-tube containers are vertically oriented present study take advantage melting/solidification enhancements induced buoyancy forces. addition, two different fluids simultaneously co-circulating within storage, hence, allowing for this component as system (under extreme charging/discharging conditions) or simple exchanger normal steady-state conditions). computational domain, study, reduced from full geometry single container owing homogeneous triangular positioning annular tubes vessel. results show that time required fully melt solid PCM around 27 hours during charging mode, thus, relatively long-time margin even under an postulated accident scenario consisting inability secondary loop remove opposite discharging needed solidify 100% liquid 17 hours. During simultaneous (SCD) with constant load, fraction nearly fixed time. Hence, said role standard exchanger. Finally, simulations conducted SCD variable demonstrate coupled can follow daily variations grid without having any significant impact on operation reactor. operating changing phases vice versa adapt anticipated.