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Title: Central Receiver Solar Thermal Power System, Phase 1: preliminary design report. Volume V. Thermal storage subsystem. [150 MW commercial tower focus plant and 10 MW pilot plant]

Technical Report ·
OSTI ID:5252962

The design, construction, and testing of a two stage thermal storage system for the 150 MW commercial tower focus plant and the 10 MW pilot plant are described. The higher temperature stage stores steam superheat energy as sensible heat in a heat transfer salt medium and the lower temperature stage stores steam latent heat energy and condensate sensible heat in a hydrocarbon oil storage medium. The system is designed to accept thermal energy in the form of a superheated steam from the Receiver Subsystem, store the energy for a period of time up to 20 hours, then supply the stored energy to the Electric Power Generation Subsystem in the form of superheated steam for operation of a turbine. The higher temperature stage uses heat transfer salt for its storage medium; this material is a eutectic mixture of 40 percent NaNO/sub 2/, 7 percent NaNO/sub 3/, and 53 percent KNO/sub 3/. During charging of the system the salt is pumped from a cooler reservoir, through a heat exchanger in which superheat energy is removed from the incoming steam, then to the warmer reservoir where it is stored at a temperature of 755 K (900/sup 0/F). The lower temperature stage uses a hydrocarbon oil for its storage medium; this material is an aliphatic petroleum heat transfer oil, Exxon Caloria HT-43. Operation of the oil stage is completely analogous to operation of the salt stage; during charging of the system oil is pumped from a cooler reservoir, through two heat exchangers in which latent heat is removed from the incoming steam and sensible heat is removed from the condensate, then to a warmer reservoir where it is stored at a temperature of 568 K (563/sup 0/F). The storage system output is superheated steam at 3030 kPa (440 psia) and 700 K (802/sup 0/F) which is transported to the turbine. Specifications are included. (WHK)

Research Organization:
Martin Marietta Corp., Denver, Colo. (USA). Aerospace Div.
DOE Contract Number:
EY-77-C-03-1110
OSTI ID:
5252962
Report Number(s):
SAN/1110-77-2(Vol.5)
Country of Publication:
United States
Language:
English