http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Yaoli Zhang (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
The optimization for the straight-channel PCHE size for supercritical CO<sub>2</sub> Brayton cycle
Xu, Hong,Duan, Chengjie,Ding, Hao,Li, Wenhuai,Zhang, Yaoli,Hong, Gang,Gong, Houjun Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.6
Printed Circuit Heat Exchanger (PCHE) is a widely used heat exchanger in the supercritical carbon dioxide (sCO<sub>2</sub>) Brayton cycle because it can work under high temperature and pressure, and has been a hot topic in Next Generation Nuclear Plant (NGNP) projects for use as recuperators and condensers. Most previous studies focused on channel structures or shapes. However, no clear advancement has so far been seen in the allover size of the PCHE. In this paper, we proposed an optimal size of the PCHE with a fixed volume. Two boundary conditions of PCHE were simulated, respectively. When the volume of PCHE was fixed, the heat transfer rate and pressure loss were picked as the optimization objectives. The Pareto front was obtained by the Multi-objective optimization procedure. We got the optimized number of PCHE channels under two different boundary conditions from the Pareto front. The comprehensive performance can be increased by 5.3% while holding in the same volume. The numerical results from this study can be used to improve the design of PCHE with straight channels.
-
Pengfei Wang,Peng Ding,Wenhuai Li,Rongshun Xie,Chengjie Duan,Gang Hong,Yaoli Zhang 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.3
An experimental study has been conducted to investigate the heat transfer characteristics of supercriticalcarbon dioxide (sCO2) uniformly heated in the horizontal circular smooth tube. The results illustratedthat there was a significant difference in heat transfer between the top wall and bottom wall due to thebuoyancy. Bulk flow acceleration cannot be negligible in the high heat flux region, which leads to heattransfer deterioration. A new heat transfer correlation is proposed, in which the buoyancy parameter andbulk flow acceleration have been taken into account. The new correlation and six classic correlations forsCO2 are examined in horizontal tubes. The comparison indicates that the new correlation has a betterperformance for sCO2 flowing through a horizontal heating tube under natural circulation conditions. Forexample, 94.9% of the calculated results using the new heat transfer correlation were within ±30% of theexperimental results while only 87.9% of that using the Jackson correlation (the best of the six) werewithin the same error bands.
-
Numerical analysis of Poiseuille-Rayleigh-Bénard convection in supercritical carbon dioxide
Wang Zhipeng,Xu Hong,Chen Chong,Hong Gang,Song Zhenguo,Zhang Yaoli 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.9
The supercritical carbon dioxide (SeCO2) Brayton cycle is an important energy conversion technology for the fourth generation of nuclear energy. Since the printed circuit heat exchanger (PCHE) used in the SeCO2 Brayton cycle has narrow channels, Rayleigh-Benard (RB) convection is likely to exist in the tiny channels. However, there are very few studies on RB convection in supercritical fluids. Current research on RB convection mainly focuses on conventional fluids such as water and air that meet the Boussinesq assumption. It is necessary to study non-Boussinesq fluids. PRB convection refers to RB convection that is affected by horizontal incoming flow. In this paper, the computational fluid dynamics simulation method is used to study the PRB convection phenomenon of non-Boussinesq fluid-supercritical carbon dioxide. The result shows that the inlet Reynolds number (Re) of the horizontal incoming flow significantly affects the PRB convection. When the inlet Re remains unchanged, with the increase of Rayleigh number (Ra), the steady-state convective pattern of the fluid layer is shown in order: horizontal flow, local traveling wave, traveling wave convection. If Ra remains unchanged, as the inlet Re increases, three convection patterns of traveling wave convection, local traveling wave, and horizontal flow will appear in sequence. To characterize the relationship between traveling wave convection and horizontal incoming flow, this paper proposes the relationship between critical Reynolds number and relative Rayleigh number (r).
-
Yao Li,Haiqing Si,Yitong Zong,Xiaojun Wu,Peihong Zhang,Hongyin Jia,Shuqing Xu,Dayong Tang 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.6
The process of obtaining flight data from flight test is complex and costly, which makes it difficult to identify aerodynamic parameters. Therefore, Cessna172 flight simulator was used for flight data extraction, which ensures the convenience, efficiency and economy of the test. To obtain aerodynamic model, based on the idea of machine learning, a recurrent neural network was used to process multi-dimensional nonlinear flight test data, and a real-time recursive learning algorithm was proved to be suitable for dynamic training. Due to the large amount of state parameter data generated by aircraft, which will cause the real-time recursive learning algorithm to train slowly. So, Kalman filter algorithm was introduced for system identification. Considering validity analysis, the comparative verification method was used to verify system identification model. Results show that the aircraft aerodynamic and aerodynamic moment models have good applicability and can be popularized and applied.
ScienceON연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
