抄録
The SuperCritical Water-cooled Reactor (SCWR) concept is one of six Generation-IV nuclear-reactor systems currently under development worldwide. One of the benefits of such a reactor is the increase in thermal efficiency due to the reactor coolant operating above the critical point of water (22.064 MPa and 373.95℃). Pressure-Tube (PT) SCWRs are being designed to work at pressures of 25 MPa with reactor outlet temperatures up to 625℃. These operating conditions make them a suitable candidate for thermochemical hydrogen cogeneration. This work investigates the use of SCWR process heat for the thermochemical production of hydrogen. A thermochemical cycle currently being studied for this purpose is the 4-stage Copper-Chlorine (Cu-Cl) cycle, due to its relatively low temperature requirements when compared to other existing thermochemical cycles. To achieve this, an intermediate Heat eXchanger (HX) linking an SCWR Nuclear Power Plant (NPP) and a hydrogen production facility is considered. The objective of this work is to complete a heat-transfer analysis on an intermediate counter-flow double-pipe HX to be used for the cogeneration of hydrogen. The HX is located downstream of an SCWR using the reactor coolant, SuperCritical Water (SCW), through the inner tube and a separate supercritical working fluid in the outer tube. In this work the thermal energy requirements for the 4-stage Cu-Cl cycle are identified. A numerical model is developed in MATLAB and a sensitivity analysis is conducted. The sensitivity analysis determines the effect that various parameters, such as pressure, mass flux, percentage of power diverted and pipe thickness will have on the overall system. Based on the results obtained from the numerical model, the design of the counter-flow double-pipe HX can be optimized to improve its efficiency. Ultimately, this will give an indication to a size of the HX depending on input parameters that are selected.
