Numerical and experimental investigation on the diffuser optimization of a reactor coolant pump with orthogonal test approach

Long Yun,Zhu Rongsheng,Wang Dezhong,Yin Junlian,Li Tianbin 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.11

The diffuser of a reactor coolant pump was optimized using an orthogonal approach with numerical simulation to improve the pump hydraulic performance. Steady simulation was conducted by solving Reynolds-averaged Naiver-Stokes equations with the SST k-ω turbulence model using CFX code. The influence of the diffuser geometric parameters, namely, S, φ, α 4 , b 4 , δ 2 , R t and R 4 , on the pump performance were determined. L 18 (3 7 ) orthogonal table was chosen for the optimization process. Best indicators were determined, and range analysis of energy losses, head, and efficiency at the rated condition was performed. Optimal parameters of the diffuser were S = 490 mm, φ = 36°, α 4 = 30°, b 4 = 200 mm, δ 2 = 20 mm, R t = 5 mm and R 4 = 565 mm. The final design was experimentally tested. Simulation results showed more remarkable performance than the experimental result. However, the numerical predictions and experimental results were consistent, validating the design procedure. Loading of the impeller and diffuser blades was analyzed to investigate the direct impact on the hydrodynamic flow field. The head was 14.74 m, efficiency was 79.6 %, and efficiency of the prototype pump was 83.3 % when the model pump functioned at the rated conditions. Optimization results showed that efficiency and head were improved at the design condition.

Investigation of Surface Integrity Up-Milling Magnesium Oxide Particle Reinforced Wood-Based Composite

Jinxin Wang,Rongsheng Jiang,Zhanwen Wu,Zhaolong Zhu,Longzhi Yang,Pingxiang Cao 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.3

Metal oxide reinforced composite, as a new kind of engineering material, was an essential research topic to industry. Magnesium oxide as particle-reinforced phase, were mixed with wood fiber-matrix to enhance the mechanical properties of composite. However, the research on the surface quality of this composite is still desirable for expanding its application. In order to investigate the surface integrity of this kind particle-reinforced wood-based composite, spiral up-milling experiments were performed with different cutting depth and cutting speed. The effect of cutting speed and cutting depth on surface integrity was investigated. According to the calculation results of black pixels proportion of binary image of machined surface, surface defects were greatly affected by cutting depth rather than cutting speed. Defects, such as pile-up and debonding of particles, were usually observed under 0.5 mm cutting depth, meanwhile, extensive damage of flacking and fracture of wood fiber-matrix were usually observed under 1.5 mm cutting depth. In all, the machined surface formation mechanism of this composite can be different by changing cutting depth.

A cavitation performance prediction method for pumps PART1-Proposal and feasibility

Yun, Long,Rongsheng, Zhu,Dezhong, Wang Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.11

Pumps are essential machinery in the various industries. With the development of high-speed and large-scale pumps, especially high energy density, high requirements have been imposed on the vibration and noise performance of pumps, and cavitation is an important source of vibration and noise excitation in pumps, so it is necessary to improve pumps cavitation performance. The modern pump optimization design method mainly adopts parameterization and artificial intelligence coupling optimization, which requires direct correlation between geometric parameters and pump performance. The existing cavitation performance calculation method is difficult to be integrated into multi-objective automatic coupling optimization. Therefore, a fast prediction method for pump cavitation performance is urgently needed. This paper proposes a novel cavitation prediction method based on impeller pressure isosurface at single-phase media. When the cavitation occurs, the area of pressure isosurface S_iso increases linearly with the NPSH_a decrease. This demonstrates that with the development of cavitation, the variation law of the head with the NPSH_a and the variation law of the head with the area of pressure isosurface are consistent. Therefore, the area of pressure isosurface S_iso can be used to predict cavitation performance. For a certain impeller blade, since the area ratio R_s is proportional to the area of pressure isosurface S_iso, the cavitation performance can be predicted by the R_s. In this paper, a new cavitation performance prediction method is proposed, and the feasibility of this method is demonstrated in combination with experiments, which will greatly accelerate the pump hydraulic optimization design.

Research on the structure design of the LBE reactor coolant pump in the lead base heap

Yonggang Lu,Rongsheng Zhu,Qiang Fu,Xiuli Wang,Ce An,Jing Chen 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.2

Since the first nuclear reactor first critical, nuclear systems has gone through four generations of history,and the fourth generation nuclear system will be truly realized in the near future. The notions of SVBRand lead-bismuth eutectic alloy coolant put forward by Russia were well received by the internationalnuclear science community. Lead-bismuth eutectic alloy with the ability of the better neutron economy,the low melting point, the high boiling point, the chemical inertness to water and air and other features,which was considered the most promising coolant for the 4th generation nuclear reactors. This studymainly focuses on the structural design optimization of the 4th-generation reactor coolant pump,including analysis of external characteristics, inner flow, and transient characteristic. It was found that:the reactor coolant pump with a central symmetrical dual-outlet volute structure has better radialdirectionbalance, the pump without guide vane has better hydraulic performance, and the pumpwith guide vanes has worse torsional vibration and pressure pulsation. This study serves as experienceaccumulation and technical support for the development of the 4th generation nuclear energy system.

Study on flow characteristics in LBE-cooled main coolant pump under positive rotating condition

Lu Yonggang,Wang Zhengwei,Zhu Rongsheng,Wang Xiuli,Long Yun 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.7

The Generation IV Lead-cooled fast reactor (LFR) take the liquid lead or lead-bismuth eutectic alloy (LBE) as the coolant of the primary cooling circuit. Combined with the natural characteristics of lead alloy and the design features of LFR, the system is the simplest and the number of equipment is the least, which reflects the inherent safety characteristics of LFR. The nuclear main coolant pump (MCP) is the only power component and the only rotating component in the primary circuit of the reactor, so the various operating characteristics of the MCP are directly related to the safety of the nuclear reactor. In this paper, various working conditions that may occur in the normal rotation (positive rotating) of the MCP and the corresponding internal flow characteristics are analyzed and studied, including the normal pump condition, the positive-flow braking condition and the negative-flow braking condition. Since the corrosiveness of LBE is proportional to the fluid velocity, the distribution of flow velocity in the pump channel will be the focus of this study. It is found that under the normal pump condition and positive-flow braking conditions, the high velocity region of the impeller domain appears at the inlet and outlet of the blade. At the same radius, the pressure surface is lower than the back surface, and with the increase of flow rate, the flow separation phenomenon is obvious, and the turbulent kinetic energy distribution in impeller and diffuser domain shows obvious near-wall property. Under the negative-flow braking condition, there is obvious flow separation in the impeller channel.

Study on bidirectional fluid-solid coupling characteristics of reactor coolant pump under steady-state condition

Xiuli Wang,Yonggang Lu,Rongsheng Zhu,Qiang Fu,Haoqian Yu,Yiming Chen 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.7

The AP1000 reactor coolant pump is a vertical shielded-mixed flow pump, is the most important coolant power supply and energy exchange equipment in nuclear reactor primary circuit system, whose steady-state and transient performance affect the safety of the whole nuclear island. Moreover, safety demonstration of reactor coolant pump is the most important step to judge whether it can be practiced, among which software simulation is the first step of theoretical verification. This paper mainly introduces the fluid-solid coupling simulation method applied to reactor coolant pump, studying the feasibility of simulation results based on workbench fluid-solid coupling technology. The study found that: for the unsteady calculations of the pure liquid media, the average head of the reactor coolant pump with bidirectional fluid-solid coupling decreases to a certain extent. And the coupling result is closer to the real experimental value. The large stress and deformation of rotor under different flow conditions are mainly distributed on impeller and idler, and the stress concentration mainly occurs at the junction of front cover plate and blade outlet. Among the factors that affect the dynamic stress change of rotor, the pressure load takes a dominant position.

A cavitation performance prediction method for pumps: Part2-sensitivity and accuracy

Long, Yun,Zhang, Yan,Chen, Jianping,Zhu, Rongsheng,Wang, Dezhong Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.11

At present, in the case of pump fast optimization, there is a problem of rapid, accurate and effective prediction of cavitation performance. In "A Cavitation Performance Prediction Method for Pumps PART1-Proposal and Feasibility" [1], a new cavitation performance prediction method is proposed, and the feasibility of this method is demonstrated in combination with experiments of a mixed flow pump. However, whether this method is applicable to vane pumps with different specific speeds and whether the prediction results of this method are accurate is still worthy of further study. Combined with the experimental results, the research evaluates the sensitivity and accuracy at different flow rates. For a certain operating condition, the method has better sensitivity to different flow rates. This is suitable for multi-parameter multi-objective optimization of pump impeller. For the test mixed flow pump, the method is more accurate when the area ratios are 13.718% and 13.826%. The cavitation vortex flow is obtained through high-speed camera, and the correlation between cavitation flow structure and cavitation performance is established to provide more scientific support for cavitation performance prediction. The method is not only suitable for cavitation performance prediction of the mixed flow pump, but also can be expanded to cavitation performance prediction of blade type hydraulic machinery, which will solve the problem of rapid prediction of hydraulic machinery cavitation performance.

Comparative analysis of internal flow characteristics of LBE-cooled fast reactor main coolant pump with different structures under reverse rotation accident conditions

Lu, Yonggang,Wang, Xiuli,Fu, Qiang,Zhao, Yuanyuan,Zhu, Rongsheng Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.7

Lead alloy is used as coolant in Lead-based cooled Fast Reactor (LFR). The natural characteristics of lead alloy are combined with the simple structural design of LFR. This constitutes the inherent safety characteristics of LFR. The main work of this paper is to take the main coolant pump (MCP) in the lead-cooled fast reactor (LFR) as the research object, and to study the flow pattern distribution of the internal flow field under the reverse rotation pump condition, the reverse rotation positive-flow braking condition and the reverse rotation negative-flow braking condition. In this paper, the double-outlet volute type and the space guide vane are selected as the potential designs of the CLEAR-I MCP. In this paper, the CFD method is used to study the potential reverse accident of the MCP. It is found that the highest flow velocity in the impeller appears at the impeller outlet, and the Q-H curves of the two design programs basically coincide. The space guide vane type MCP has better hydraulic performance under the reverse rotation positive-flow condition, the Q-H curves of the two designs gradually separate with increasing flow rate, and the maximum flow velocity inside the space guide vane type MCP is obviously lower than that of the double-outlet volute type. For the reverse rotation test of MCP, only the condition of the forward rotating pump of the main coolant pump is tested and verified. For the simulation of the MCP in LBE medium, it proved that the turbulence model and basic settings selected in the simulation are reliable.

Multiomics analyses of Jining Grey goat and Boer goat reveal genomic regions associated with fatty acid and amino acid metabolism and muscle development

Zhaohua Liu,Xiuwen Tan,Qing Jin,Wangtao Zhan,Gang Liu,Xukui Cui,Jianying Wang,Xianfeng Meng,Rongsheng Zhu,Ke Wang Asian Australasian Association of Animal Productio 2024 Animal Bioscience Vol.37 No.6

Objective: Jining Grey goat is a local Chinese goat breed that is well known for its high fertility and excellent meat quality but shows low meat production performance. Numerous studies have focused on revealing the genetic mechanism of its high fertility, but its highlighting meat quality and muscle growth mechanism still need to be studied. Methods: In this research, an integrative analysis of the genomics and transcriptomics of Jining Grey goats compared with Boer goats was performed to identify candidate genes and pathways related to the mechanisms of meat quality and muscle development. Results: Our results overlap among five genes (ABHD2, FN1, PGM2L1, PRKAG3, RAVER2) and detected a set of candidate genes associated with fatty acid metabolism (PRKAG3, HADHB, FASN, ACADM), amino acid metabolism (KMT2C, PLOD3, NSD2, SETDB1, STT3B, MAN1A2, BCKDHB, NAT8L, P4HA3) and muscle development (MSTN, PPARGC1A, ANKRD2). Several pathways have also been detected, such as the FoxO signaling pathway and Apelin signaling pathway that play roles in lipid metabolism, lysine degradation, N-glycan biosynthesis, valine, leucine and isoleucine degradation that involving with amino acid metabolism. Conclusion: The comparative genomic and transcriptomic analysis of Jining Grey goat and Boer goat revealed the mechanisms underlying the meat quality and meat productive performance of goats. These results provide valuable information for future breeding of goats.