Simulation and optimisation of gas storage tanks filled with heat sink

One of the unique features of the pebble bed modular reactor (PBMR) is its load following capability, enabled by extracting or injecting of helium from or to the system during operation. Filling the tanks with a heat sink would reduce the necessary gas storage area dramatically. The heat sink would absorb the energy that the hot gas contains and consequently the gas would experience a decrease in temperature. This implies that the density of the gas will increase and allow more helium to be stored in the same tank before the tank's maximum operating pressure is reached. A computational fluid dynamics (CFD) study indicated that the heat sink in fact reduced the total pressure in the tank significantly. The large heat transfer area that the heat sink provides ensures that this kind of system has a quick thermal response. In order to make optimal use of this advantage, the gas must be distributed evenly throughout the tank and no local high-temperature regions must occur. A few injection concepts were investigated to optimise for this requirement