Thermodynamic Analyses for Optimizing the Design of HTGR's Helium Brayton Cycles

摘要

The paper analyzes the close-circuit Brayton (Joule) cycles for High Temperature Gas (Helium) cooled nuclear Reactors (HTGR). Analyzed cycles are with Regenerative Heat Exchanger (RHE), Fragmented Compression and Inter-Cooling (FC&IC). The HTGR imposes the working agent and hot source's parameters. The cooling conditions give the cycle's minimal temperature. In the 1st paper's section, for ideal processes cycles we show that: A) the boundary parameters and design schemes inflict: A_1) the compression ratios (ε), A_2) the specific net work per 1 kg He (w_(net), and A_3) the thermal efficiencies (η_(th); B) the performances are increasing with the IC's number. In the 2nd section we are taking into consideration the irreversibility's factors (temperature difference at RHE, revolving machines isentropic efficiencies, and pressure drops) doing sensitivity analyses about their influences on real processes cycle's performances. We show that: 1) cycle's performances are not continuous growing with IC's number, and 2) the main influences on design's option are given by: 2_1) the temperature difference at RHE and 2_2) the pressure drops. In the 3rd section we adjusted all the quality factors in a similar manner, reducing the irreversibility's, showing the synergic influences. The 4~(th) section relaxes the hot source's restrictions. It analyses the influence of HTGR output/input temperatures variation on the main thermodynamic data, showing: α) the benefit of maximal temperature increase and β) the need to correlate HTGR's temperature increment output vs. input with the maximal temperature. The final section contains the main conclusions of the paper.