Numerical investigation to optimize the inlet flow distributor of the intermediate heat exchanger in an HTGR

• Published in: Nuclear engineering and design Vol. 356; p. 110363
• Main Authors: Hu, Qingxiang, Yuan, Kun, Peng, Wei, Cui, Jingdan, Peng, Fulei
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2020; Elsevier BV
• Subjects: Distributors; Flow distributor; Flow uniformity; Heat exchangers; Heat transfer; High temperature gas cooled reactors; High-temperature gas-cooled reactor (HTGR); Inlet flow; Installation; Intermediate heat exchanger (IHX); Optimization; Structural optimization; Swirling; Velocity; Flow distributor; Flow uniformity; Intermediate heat exchanger (IHX); High-temperature gas-cooled reactor (HTGR); Structural optimization
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2019.110363

•This study numerical optimized the structure of inlet flow distributor in IHX.•The uniformity index is introduced to quantitatively evaluate the flow uniformity.•The swirling strength is used to quantify the strength of the vortex.•The narrow structure installed at 350 mm height has the best optimization performance. The intermediate heat exchanger (IHX) is a key part of the high-temperature gas-cooled reactor (HTGR). The inlet flow uniformity then strongly impacts the heat transfer in the IHX. The inlet passage design is the main cause of flow nonuniformities and an inlet flow distributor has been shown to effectively reduce these nonuniformities. This study numerically optimized the flow distributor structure by improving the flow uniformity. The structural optimization varied the installation height, distributor length and distributor area. The results show that the distributor length has an optimal value and the distributor area has two opposing effects on the velocity uniformity with both coupled to the installation height. The flow field analysis indicates that the ratio of the flow directly into the distributor and that guided into the distributor that had opposing transverse velocities is the key factor determining the velocity uniformity and the optimization effect can be intuitively reflected by the magnitude of the swirling strength. The optimization shows that the narrow structure at the 350 mm installation height gives the best velocity uniformity of 0.974.