Abstract: As an important and accident-prone subsystem in CSP plants，heat storage system plays a key role in continuous and steady operation of plants. Thus，a delicate design for the storage system is essential for the cost control and safety operation of CSP plants. A delicate design for molten salt volume and wall thickness of tanks in the thermal storage system of CSP plants has been presented.The preheating strategy with the maximum wall temperature difference allowed by storage tanks was obtained after testing the real-time wall temperature of the storage tank and numerically simulating the air flow process of flue gas and molten salt in the tank. The strategy can relieve the thermal stress during storage tank preheating and reduce its risk and failure rate. The strategy has achieved positive effect in practical cases.

Key words: CSP plants, heat storage system, storage tank, molten salt volume, thickness of the wall, preheating, thermal stress