**4. Conclusions**

In this paper, the heat transfer performance of hydrogen in a decoupled poison hydrogen moderator under supercritical pressure is investigated by numerical method, and the effects of different boundary conditions on flow and heat transfer are compared. The major conclusions are summarized as follows:


Therefore, the concrete influence law of the specific heat of liquid hydrogen on heat transfer is expected for future studies. Meanwhile, it is necessary to establish a 2D model of a moderator for avoiding random errors.

**Author Contributions:** J.T. and L.Z. are the main authors of this manuscript. All the authors contributed to this manuscript. J.T. and L.Z. conceived the novel idea, and Y.L. (Yiping Lu) and S.D. performed the analysis; J.T. and Y.L. (Youlian Lu) analyzed the data and contributed analysis tools; J.T. and L.Z. wrote the entire paper. J.T., T.L. and S.D. checked, reviewed and revised the paper; J.T., C.Y. and S.W. performed final proofreading and supervised this research. All authors have read and agreed to the published version of the manuscript.

**Funding:** This article Supported by the Program for Guangdong Introducing Innovative and Entrepreneurial Teams. (Project number: 2017ZT07S225).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.

### **Nomenclature**


#### **References**

