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Xiaoqiang He

Bio: Xiaoqiang He is an academic researcher from Tsinghua University. The author has contributed to research in topics: Nuclear engineering & Materials science. The author has an hindex of 1, co-authored 1 publications receiving 9 citations.

Papers
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Journal ArticleDOI
TL;DR: The results show that the two-way coupling model, as well as the UDF solving program, performs a more comprehensive approach for the modeling of the gas–liquid two-phase flows in the moisture separators.

18 citations

Journal ArticleDOI
TL;DR: In this article , a coupled irradiation-thermal-mechanical model was developed to simulate the irradiation effects on the heat transfer and stresses of the whole reactor core.

6 citations

Journal ArticleDOI
TL;DR: In this article , a two-dimensional heat pipe model and an open-air Brayton cycle model coupled to the Heat Pipe Reactor TRANsient analysis code, HPRTRAN, were used to analyze a megawatt heat pipe reactor.
Abstract: Heat pipe cooled reactors experience temperature rises of up to 800 K during startup. The in-core heat pipes and the energy conversion system are initially frozen, which leads to a highly coupled heat transfer system that has significant safety challenges. This work modeled the system startup using a two-dimensional heat pipe model and an open-air Brayton cycle model coupled to the Heat Pipe Reactor TRANsient analysis code, HPRTRAN. The heat pipe model was validated with startup experiments showing that the predicted heat pipe wall temperature was within 30 K of the measured temperatures. The Brayton cycle model was validated against experimental data in the literature. The analysis code was then used to analyze a megawatt heat pipe reactor connected to an open-air Brayton cycle, which was used to study the influence of the external reactivity and the inherent feedback on the startup process. The simulations show that the reactor startup process is sensitive to the heat pipe operating state. The startup process can be divided into the subcritical stage, heat pipe startup stage, and increasing power stage. The power peak amplitudes are significantly reduced by slowing the angular speed of the control drum. Reducing the control drum angular speed from 0.1°/min to 0.05°/min reduced the first power peak from 2000 kW to 1000 kW. A modified reactor startup control strategy was then developed that ensures the core safety with the reactivity introduced in steps. Smaller reactivity insertions reduce the power peaks during the initial startup but lead to much longer startup times. A reasonable balance was obtained by repeated insertions of either 30 pcm or 60 pcm for safe startups of the heat pipe cooled reactor.

5 citations

Journal ArticleDOI
TL;DR: In this article , the authors investigate the physical mechanism at the capillary limit for liquid metal wick heat pipes and investigate the special behavior before and after dryout, including dryout oscillations and the recovery process.

3 citations

Proceedings ArticleDOI
08 Aug 2022
TL;DR: In this article , a deep learning model is presented for predicting the automatic scramming assuming no operator intervention, which is based on Long Short-Term Memory (LSTM) model, which are a special type of gated Recurrent Neural Network (RNN) designed to adaptive control the memory length of the learned features and showing good performance in Sequence to Sequence (Seq2Seq) problems.
Abstract: During abnormal conditions of nuclear power plants that do not lead to automatic scram immediately, operators need to monitor the transient condition of nuclear power plant in order to evaluate the development rate of the abnormal conditions. Conventional condition monitoring methods cannot provide operators with an alert or forecast for automatic scram. In this work, a deep-learning model is presented for predicting the automatic scram assuming no operator intervention. The presented prediction model is based on Long Short-Term Memory (LSTM) model, which is a special type of gated Recurrent Neural Network (RNN) designed to adaptive control the memory length of the learned features and showing good performance in Sequence to Sequence (Seq2Seq) problems. The predicting model is trained by transient data of abnormal conditions: the input of model is the nuclear power plant monitoring data; and the output is the remaining time from current time to reactor trip. The predicted remaining time to reactor trip decreases with the development of abnormal condition, thus the output of prediction model will generate a countdown to reactor trip. Prediction experiments were conducted on simulated abnormal condition data generated by a full-scale simulator for a 300MW pressurized water reactor (PWR). The data with artificial noise were also used to test the performance of the presented model. The experiment results shows that the presented prediction model has better prediction performance and is more robust to noisy input than models based on one-hidden-layer feedforward neural networks or simple RNNs (e.g., Elman network). The presented intelligent prediction model can provide nuclear power plant operators with a countdown alert about the upcoming reactor scram, as such the operators can prepare or take countermeasures for it.

Cited by
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Journal ArticleDOI
TL;DR: The simulation result of a separation system is introduced, which proves that numerical methods could be applied to optimize the design of MS for commercial market and the future directions needed to develop both Eulerian-Eulerian and LE methods for MS modeling are reviewed.

24 citations

Journal ArticleDOI
TL;DR: In this article, the authors explored the effect of installing an additional element in the axis of the cyclone separator (in the form of a rod with a circular cross-section) on its performance.

22 citations

Journal ArticleDOI
TL;DR: Four numerical techniques, which covers from numerical discretization schemes, steam properties interpolation, locating a droplet to collision droplet pair search, are introduced for accelerating the implementation of modeling droplet trajectories in MS.

18 citations

Journal ArticleDOI
Li Liu1, Bingbin Ying, Hanyang Gu1, Xu Dehui1, Chao Huang1, Shuo Chen1 
TL;DR: In this paper, a high-pressure flow system is designed to study the performance of a full-scale steam separator package at a rated pressure of 6 MPa and temperature of 275.6 °C.

17 citations

Journal ArticleDOI
TL;DR: In this paper, the geometry-structure optimization, geometry-parameter optimization, and operation-parametrization optimization of cyclone separators have been studied for improving cyclone separation performance.
Abstract: Current studies on improving the separation performance of cyclone separators focus on five aspects: i] geometry-structure optimization, ii] geometry-parameter optimization, iii] operation-paramete...

12 citations