Runaway Conditions Research Articles

Local and nonlocal conditions for electron runaway in a gas gap with a conical cathode with a variable opening angle

The conditions for the generation of runaway electrons in an air gap are compared at different degrees of inhomogeneity of the electric field distribution provided by varying the opening angle of the conical cathode: in the range 40°–120° in experiments and 0°–180° in calculations. It is demonstrated that, in a weakly inhomogeneous electric field (according to the proposed classification, this corresponds to cones with angles greater than the Taylor angle of 98.6°), the runaway condition has a local character. The transition of free electrons into the runaway mode is determined by the local distribution of the electric field near their starting point—the tip of the cone. The local electric field strength must exceed a threshold value comparable to the strength critical for the runaway of electrons in a uniform field. In a strongly inhomogeneous field (cones with angles less than 98.6°), this condition is not sufficient for electrons to run away throughout the gap. Electrons accelerating in the near-cathode region may begin to slow down in a weak field at a distance from the cathode. In this case, the runaway condition becomes nonlocal. It is determined by the dynamics of electrons in the entire gap, primarily in the near-anode region, and reduces to the requirement that the potential difference applied to the gap exceeds a certain threshold value.

Research on the influence of labyrinth ring configuration on runaway characteristics of pump-turbines

The labyrinth ring can reduce the volume loss, mitigate the influence of force characteristics when the unit is operating, and ensure the efficient, safe, and stable operation of the unit. It is usually installed in the upper crown and lower ring of the pump-turbines runner. When the pump-turbines unit is running in runaway condition, the internal flow field structure is more complicated due to the different forms of labyrinth ring, so a new method needs to be adopted to analyze it from a new perspective. In this paper, a high head pump-turbines was selected as the research object. Combined with the experimental and numerical simulation results, the flow field structure corresponding to different upper labyrinth ring forms under runaway condition was analyzed and visualized in many aspects. The results show that the mixed type labyrinth ring can improve the undesirable flow regime in the runner and draft tube. The guide vanes under the serrated type labyrinth ring are more likely to be damaged due to greater force. The influence of the mixed type labyrinth ring on the radial force of the runner is only half that of the ladder type, which has a great advantage in maintaining the radial stability of the runner. The ladder and serrated type labyrinth ring can make the unit obtain less axial water thrust. In addition, based on the Finite-Time Lyapunov Exponent (FTLE) method, the flow field structure in the vaneless region was analyzed, and it was found that the labyrinth ring may affect the flow in the flow path of the guide vane and the vaneless region, thus causing the change of axial water thrust. This study reveals the internal flow and force characteristics of pump-turbines with different types of labyrinth rings under runaway condition and provides a technical reference for further understanding and studying the influence of labyrinth ring forms on pump-turbines performance and force characteristics.

Analysis of the behavior of a gas-generating system under runaway conditions in a closed vessel

In the event of a runaway reaction, emergency relief systems (ERS) act as the last line of defense against the vessel explosion. To date, ERS design for scenarios involving the runaway of chemical mixtures that generate gaseous reaction products remains very challenging as it requires the prediction of the gas generation rate under runaway conditions at large scale. Current methodologies for the assessment of the gas generation rate are based on pseudo-adiabatic calorimetric experiments at laboratory scale in which the temperature and pressure profiles resulting from the runaway are used to assess the gas generation rate using the ideal gas law. The gas generation rate needs to be further corrected for the thermal inertia (φ-factor), of the calorimetric cell used (φ>1) to predict large scale behavior (φ≈1). The work described in this paper focuses on evaluating the capability of this approach to accurately assess the gas generation rate. It uses a dynamic simulator tool based on rigorous thermodynamics to calculate the temperature, pressure, and the composition of each component in a closed vessel containing a gas generating reactive mixture (decomposition of 20 % w/w di-tert butyl peroxide in toluene) under runaway conditions over a range of initial vessel fill levels. The results were analyzed to develop a better understanding of the phenomena that govern the thermal behavior of the mixture, the overall pressurization of the vessel, rate of generation of the gaseous products and its distribution in the liquid and vapor phase of the vessel as the runaway reaction occurs. The simulated pressure, temperature and phase composition data rigorously calculated by the simulator were used to assess and highlight the limitations of using the temperature and pressure in a closed vessel and the ideal gas law to evaluate the gas generation rate. The simulations were also used to evaluate the validity of φ-factor correction methods currently available in the literature.

Numerical investigation of energy dissipation and vortex characteristics on the S-shaped region of a reversible pump-turbine

In order to meet the regulation needs of power system, the pump-turbine is prone to operate in the S-shaped region during frequent start-up, leading to unit vibration and grid connection failure. In this paper, the S characteristic experiment was carried out, and the entropy production, unstable flow and vortex structure under turbine, runaway, turbine breaking, reverse pump conditions with optimum guide vane opening are detailed analyzed. The relationship between the energy dissipation and flow field characteristics is clarified. The results show that the runner entropy production is the largest in all components, and the wall entropy production is greater than the fluctuating entropy production under turbine condition. With the decrease in discharge, the fluctuating entropy production and wall entropy production first increase and then decrease, reaching the maximum values in the runaway condition. The circumferential movement trend of water enhances, and forms circumferential flow in the vaneless region. The separation vortex formed on the blade suction surface extends from the blade inlet to the middle of the flow channel, inducing a high entropy production. Under the turbine braking condition, the tangential velocity increases rapidly in the vaneless region. The circumferential flow develops into water ring, blocking the water flows into the runner. Under the reverse pump condition, the water flows in the opposite direction, with negative tangential and streamwise velocities. The absolute flow angle becomes obtuse, and a large-scale reverse vortex is formed. The runner inlet is blocked by the water ring, and the flow channel is almost completely filled with the low-speed region. The proportion of the guide vanes entropy production reaches maximum. Unstable flow leads to the increase in vorticity. Separation vortex, bypassed vortex, and reverse flow vortex leads to an increase in VST, forming a high VST region at corresponding positions. Due to the rotational motion accompanying the development of separated vortex, it leads to the increase in CFT. In addition, the circumferential flow and water ring have higher tangential velocities, which can lead to high CFT regions.

Clarifying the Impact of Electrode Material Heterogeneity on the Thermal Runaway Characteristics of Lithium‐Ion Batteries

The safety and efficiency of lithium‐ion batteries (LIBs) suggest a promising future for this technology, particularly in the automobile industry. However, thermal runaway—wherein a LIB undergoes an uncontrollable increase in temperature that may result in smoke, fire, or explosion—represents an important and widely studied failure type. Since the electrodes of LIBs are manufactured from porous composite materials, their heterogeneity can significantly influence the effective material characteristics and microscale behaviors of LIBs during operation. Microstructure geometric and electrochemical–thermal models are typically used to investigate these impacts. Herein, a microstructure geometric model is constructed of LIB's electrodes. A virtual multiphysics model is used to simulate the overcharging thermal runaway condition. The model's accuracy is validated through real‐world experiments. The model shows greater accuracy compared to the result from a conventional homogeneous geometric model and better reflects the heterogeneous internal phenomenon. The model is applied to a variable analysis in order to investigate how the varying heterogeneity of the cathode's porosity impacts the cell during overcharging thermal runaway behavior. Our results indicate that decreasing porosity heterogeneity at the cathode may delay thermal runaway, owing to the heterogeneous impact on particle diffusion behaviors and the side reaction rate.

Experimental study of dual nano-network, high-temperature resistant aerogel material as an integration of thermal management functions

Thermal management system is highly desirable to guarantee the performance and thermal safety of lithium-ion batteries, but it reduces the energy density of battery modules and even is unable to provide highly effective protection. Here, a thermal management function integrated material is presented based on high-temperature resistant aerogel and phase change material and is applied at both charge–discharge process and thermal runaway condition. In this sandwich structure Paraffin@SiC nanowire/Aerogel sheet (denoted as PA@SAS) system, SiC nanowires endow the middle aerogel sheet (SAS) a dual nano-network structure. The enhanced mechanical properties of SAS were studied by compressive tests and dynamic mechanical analysis. Besides, the thermal conductivity of SAS at 600 °C is only 0.042 W/(m K). The surface phase change material layers facilitate temperature uniformity of batteries (surface temperature difference less than 1.82 °C) through latent heat. Moreover, a large-format battery module with four 58 Ah LiNi0.5Co0.2Mn0.3O2 LIBs was assembled. PA@SAS successfully prevents thermal runaway propagation, yielding a temperature gap of 602 °C through the 2 mm-thick cross section. PA@SAS also exhibits excellent performance in other safety issues such as temperature rise rate, flame heat flux, etc. The lightweight property and effective insulation performance achieves significant safety enhancement with mass and volume energy density reduction of only 0.79% and 5.4%, respectively. The originality of the present research stems from the micro and macro structure design of the proposed thermal management material and the combination of intrinsic advantages of every component. This work provides a reliable design of achieving the integration of thermal management functions into an aerogel composite and improves the thermal safety of lithium-ion batteries.

Study on the Transition Process of Normal Shutdown of Large Vertical Submersible Mixed Flow Pump Unit

_ Water pump units are essential in water conservation projects. Axial flow pumps, crossflow pumps, and mixed-flow pump units are commonly implemented in new pumping station projects. The technology related to water pump units has been substantially developed in recent years. Nonetheless, the large vertical submersible mixed-flow pump unit is still considered a relatively novel pumping station unit. The operational status of a submersible pump unit can be influenced by the gate or flapper door of the outlet during its startup and shutdown process. During this process, the pump speed, flow rate, and other external characteristic parameters of the unit undergo significant changes in a short time period. The appearance of unstable flow phenomena, such as flow separation and vortex, inside the unit has a significant impact on its safety and stability. Hence, studying the normal shutdown process of the pump unit is essential to investigate factors influencing the unit’s stability. This paper presents a numerical simulation and analysis of the normal shutdown process of a large vertical submersible mixed-flow pump unit. Analysis of the results revealed that the “backflow” phenomenon of water flow occurs during all four cases of the normal shutdown transition process. The unit’s operating conditions are largely determined by the closing time of the flapper door. The unit will experience runaway conditions when the flapper door’s closing time is longer (4 seconds). Keywords vertical submersible mixed flow pump; normal shutdown process; numerical simulation

Simulations on hybrid thermal management of mini-channel cold plate and PCM for lithium-ion batteries under discharging and thermal runaway conditions

In this study, we compared the performance of different structures of mini-channel cold plate (MCP) - phase change material (PCM) hybrid thermal management on discharge and thermal runaway. The heat transfer structures for them can be categorized into three types: (a) uncoupled, (b) semi-coupled, and (c) fully coupled. Among these, the semi-coupled design B exhibits the best performance. Specifically, in the high rate discharge condition, the structure can control the battery temperature at 44.37 °C at low coolant mass flow rate, and the temperature at 36.47 °C at high mass flow rate, while the temperature difference (TD) of a single cell does not exceed 2.01 °C. In a low-multiplier discharge zero-energy system, the pack temperature rise can be limited to no more than 10 °C in 35 °C environment. Under external short-circuit conditions, a lower coolant mass flow rate is sufficient to keep the pack temperature at 43.22 °C. Under internal short-circuit thermal runaway (TR), lower coolant mass flow rate can prolong the TR of the adjacent cell up to 521 s, and higher mass flow rate can completely inhibit the occurrence of TR. The objective of this study is to offer valuable references for the design and implementation of hybrid MCP-PCM cooling systems.

Reduced Water Loss due to Photochemistry on Terrestrial Planets in the Runaway Greenhouse Phase around Pre-main-sequence M Dwarfs

Terrestrial planets currently in the habitable zone around M dwarfs are estimated to have been in runaway greenhouse conditions for up to ∼1 Gyr due to the long-term pre-main-sequence phase of M dwarfs. These planets likely lose a significant portion of water during the pre-main-sequence phase owing to H2O photolysis followed by hydrogen and oxygen loss to space. However, the effects of H2O reproduction reactions and UV shielding by chemical products that reduce photolysis-induced water loss have yet to be estimated. Here, we apply a 1D photochemical model to a H2O-dominated atmosphere of an Earth-like planet around a pre-main-sequence M dwarf to estimate these effects. We find that water loss is suppressed by efficient H2O reproduction reactions and by UV shielding due to O2. The water loss rate decreases by several to several hundred times compared to that in previous studies, with the assumption that the water loss rate is limited by stellar X-ray and extreme-ultraviolet flux or hydrogen diffusion through the atmosphere. Our results imply that terrestrial planets currently in the habitable zone around M dwarfs are more likely to retain surface water than previously estimated.

Multiphysics integrated model of NMC111 battery module for micro-mobility applications using PCM as intercell material

The widespread use of e-bikes and e-scooters powered by lithium-ion batteries in urban settings has heightened safety concerns, particularly the risk of thermal runaway, which can result in dangerous incidents. The surge in battery-related fire incidents highlights the critical need for a deep understanding of thermal runaway phenomena. This study addresses this imperative by introducing a Multiphysics model combining pseudo-bidimensional electrochemical for simulating electrical performance, lumped thermal model for simulating the heat transfer behavior inside the module, and a thermal runaway kinetic model for propagation evaluation. This approach facilitates precise predictions of battery performance and proactively addresses safety concerns by incorporating thermal behavior simulations and predicting potential thermal runaway events. The model proposed allows the evaluation of different strategies for improving battery safety and performance, such as phase change materials and thermal insulators. Simulations reveal that implementing sodium hydrogen phosphate dodecahydrate (Na2HPO4··12H2O) as an intercell material substantially enhances thermal management. This material reduced the maximum temperature of the battery module by up to 30% during critical thermal runaway events. Additionally, it slowed the rate of temperature increase by 50%, significantly decreasing the possibility of adjacent cells reaching thermal runaway conditions. The research findings demonstrate the effectiveness of advanced thermal management strategies using PCMs to prevent potentially catastrophic thermal events in battery modules typical of micro-mobility devices.

Effects of Trigger Method on Fire Propagation during the Thermal Runaway Process in Li-ion Batteries

Abstract Lithium-ion batteries are prone to fire hazards due to the possibility of thermal runaway propagation. During battery product development and subsequent safety tests for design validation and safety certification, the thermal runaway onset is triggered by various test methods such as nail penetration, thermal ramp, or external short circuit. This failure initiation method affects the amount of heat contributions and the composition of gas generations. This study compares two such trigger methods, external heating and using a thermally-activated internal short circuit device (ISCD). The effects of the trigger method on total heat generation are experimentally investigated within 18650 cylindrical cells at single cell level as well as at multiple cell configuration level. The severity of failure was observed to be worse for cells with ISCDs at single cell level, whereas quite the opposite results were observed at multiple cell configuration level. A preliminary numerical analysis was performed to better understand the battery safety performance with respect to thermal runaway trigger methods and heat transfer conditions.

Assessing thermal hazards in bio-oil-glyoxal polymerization and curing with DGEBA and bio-char

Traditional novolac resin uses formaldehyde and an excess of phenol under an acid catalyst which has a remarkable production and wide applications, however, the polymerization and its curing reaction are highly exothermic and heat generation with the release of harmful gases (formaldehyde and phenol) link to a high potential of thermal runaway hazard and the possibility of explosions in resin factories. To make a sustainable novolac-type resin, the water-insoluble fraction of bio-oil glyoxal (BOG) resin was utilized as an ideal phenol bioresource. The safety criteria of renewable resins polymerization and its curing reaction were investigated using the Differential Scanning Calorimeter (DSC) and evaluated by comparing the critical runaway conditions with those of traditional non-renewable resins. The reaction mechanism of the novolac resin synthesis and curing reaction were discussed as well. The results indicate that the use of bio-oil can reduce the heat risk of polymerization reactions. The introduction of biochar for the first time in curing reactions has shown a potential beyond anticipation in reducing the heat risk of curing reactions.

A comparative DFT study on the adsorption properties of lithium batteries thermal runaway gases CO, CO2, CH4 and C2H4 on pristine and Au doped CdS monolayer

The thermal runaway gases, such as CO, CO2, CH4, and C2H4, will leak from the battery electrolyte when lithium batteries in extreme discharge or thermal runaway conditions. The structural properties, differential charge density (DCD), density of state (DOS), gas adsorption properties, desorption time, work function and front-orbit theory calculation of pristine and Au doped CdS monolayer are explored and compared by first-principle calculation. The adsorption energy of CO, CO2, CH4 and C2H4 on the surface of Au–CdS are –0.89 eV, –0.40 eV, –0.14 eV and –0.77 eV, respectively. After doping, the adsorption type of CO and C2H4 are chemical type. Partial density of states shows that the gas molecules react with doped precious metal atoms. The adsorption ability of Au–CdS can be ranged as CO>C2H4>CO2>CH4. C2H4 on the surface of Au–CdS can desorb within 10 s at room temperature. As a result, Au–CdS exhibits tremendous prospective application as CO or C2H4 gas sensor. This study demonstrates that the adsorption and sensing properties of CdS monolayer can be improved effectively by the introduction of precious metal.

Thermal runaway criterion as a basis for the protection of high-temperature superconductor magnets

High-temperature superconductor (HTS) based high-field magnet systems are essential for particle accelerators and fusion energy applications. Quench protection of such magnets is difficult owing to a slow quench propagation velocity in HTS. While in conventional NbTi and Nb3Sn-based magnets, a normal zone expands typically quickly, and the stored energy is dissipated across a large volume of the windings, a normal zone in an HTS magnet propagates slowly and, thus, can heat up quickly to high temperatures destroying the conductor. At the same time, growing experimental evidence suggests that HTS conductors can operate in a stable dissipative flux flow regime for a substantial range of operational currents before entering an irreversible thermal runaway. Therefore, a new protection paradigm for HTS magnets has emerged, aiming to prevent quenching, using advanced diagnostics to detect the dissipative regime onset. In the present paper, we propose a simple criterion for the thermal runaway in HTS conductors and calculate allowable temperature margins within which an HTS magnet can be operated safely. Outside of those temperature margins, a common quench integral approach may be used to estimate the upper boundary of the time margin for activating the protection system. We verify the applicability of our approach by comparing the calculated runaway conditions for a Bi-2223 conductor with the experimentally measured values. The thermal and time margins can define the quench protection system’s requirements for implementing the quench-avoiding protection paradigm.

Pressure pulsation of pump turbine at runaway condition based on Hilbert Huang transform

Pumped storage is an important component of electrified wire netting. The safe and stable operation of pump turbines is extremely important. Among them, pressure pulsation is one of the main causes of pump turbine vibration. The characteristics of pressure pulsation are relatively complex, and it is difficult to directly observe their temporal changes using commonly used FFT methods. The division of frequency characteristics is often vague. Meanwhile, it is difficult to explain some phenomena such as frequency doubling. This article focuses on a certain model of pump turbine and uses SST model to numerically simulate the runaway condition of the pump turbine. And the Hilbert Huang transform method is used to analyze the pressure pulsation in the vaneless region and draft tube. The results show that the main characteristic frequencies of the vaneless region are blade passing frequency 112.5 Hz and rotational frequency 12.5 Hz. The main characteristic frequencies of the draft tube are vortex rope frequency near 3 Hz which energy ratio is up to 50%, rotational frequency, and blade passing frequency. The pressure pulsation characteristics in the vaneless region have changed from a complex composition of double blade passing frequency and rotational frequency to a distribution dominated by blade passing frequency. In the passage of the guide vane, the pressure pulsation is almost only characterized by blade passing frequency. The frequency characteristics of the vaneless region between the runner and the guide vane become complex again. Meanwhile, the results show that the characteristic frequencies of the vaneless region and the draft tube propagate upstream and downstream.

Numerical Investigation of the Influence of Cavitation on the Runner Speed at Speed-No-Load and Runaway for a Francis Turbine of Low Specific Speed

Abstract Studies have shown that the runner speed of hydraulic turbines at no-load conditions is affected by cavitation. However, those studies did not provide explanations relating the variation of the no-load runner speed to cavitation. Understanding why cavitation affects the runner speed is crucial because the maximum runner speed is reached in no-load condition, and this speed must remain below a limit to ensure the generator's safety. This paper uses numerical simulations to investigate the effect of cavitation on two no-load conditions, the runaway and the speed-no-load, for a low specific speed Francis turbine at model scale. The study is based on unsteady Reynolds-averaged Navier–Stokes simulations with and without cavitation and focuses on averaged quantities. At no-load, the regions over the blades producing a motor torque, i.e., oriented with the turbine rotating direction, must be balanced by regions producing a braking torque, opposed to the turbine rotation, to achieve a zero-torque condition. At runaway, cavitation mainly affects regions where a motor torque is produced. However, the zones affected by cavitation have a small contribution to the total motor torque. Therefore, for the runaway condition studied, the torque balance over the blade is hardly affected by cavitation, and the impact of cavitation on the runaway speed is negligible. At speed-no-load, comparisons between cavitating and noncavitating simulations indicated that cavitation affects mainly the braking torque regions. Those regions result from an interaction between the runner blades and a backflow extending from the draft tube cone to the runner outlet. In that case, cavitation strongly affects the torque balance over the blades, and consequently, the runner speed will adapt to find another zero torque condition.

Lithium-ion battery thermal management system using MWCNT-based nanofluid flowing through parallel distributed channels: An experimental investigation

In the present research, a newly designed liquid-based battery thermal management system (BTMS) for lithium-ion batteries (LIBs) is developed and its thermal performance at different discharge rates (C-rates) is experimentally examined. The influence of various performance parameters such as the number of channels, flow configurations, working fluids, and C-rates on the cooling performance of the proposed BTMS is evaluated. Pure water, binary fluid (70 % water + 30 % ethylene glycol (EG)), and multi-walled carbon nanotubes (MWCNTs)-based nanofluids at different volume fractions (ϕv) (0.15 %, 0.30 %, and 0.45 %) in the binary fluid are used in this study and their cooling effectiveness to keep battery temperature within ideal ranges is compared. The experiments are performed at 0.5C, 1.2C, and 2.1C rates and it is discovered that nanofluids provide superior cooling performance compared to water and binary fluid mixture. Results demonstrate that the cooling performance is enhanced with the number of channels, nanoparticle concentration, and flow configurations. Nanofluid with 0.45 % ϕv of MWCNTs shows the maximum drop in battery temperature which is about 8.7 °C for configuration I, 11.8 °C for configuration II, and 17.1 °C for configuration III, respectively. Among all the flow configurations, configuration III gives the best cooling effectiveness and lowers the average temperature of cells by 10–17.01 °C using different working fluids. Configuration III also enhances the battery temperature uniformity and maintains the maximum temperature deviation within the battery module (∆Tmax) inside 1.5–2.4 °C for different working fluids at a 2.1C rate, which is well below 5 °C, and hence it helps to prevent the thermal runaway (TR) condition. Additionally, nanofluid with 0.45 % ϕv increases pressure drop (Δp) by 23.98 % and 17.91 % compared to water for single and dual channel arrangements, respectively.

Electron Runaway Conditions for a Gas Diode with a Cathode in the Form of the Taylor Cone

Electron Runaway Conditions for a Gas Diode with a Cathode in the Form of the Taylor Cone

Tuning the pin configuration on cold plate for better thermal management of lithium-ion battery

Enhancing cooling performance with the lowest pressure drop characteristics is a persistent problem in battery thermal management systems. The present investigation discusses the design of cooling plate pin configuration, especially for the fast charging–discharging operation of lithium-ion batteries. At first, the effect of pin geometrical configurations, viz. triangular, square, circular and elliptical, are studied for thermohydraulic characteristics. Further, orientation of the pin is investigated for normal and thermal runaway conditions. Furthermore, the effect of discharge rate and flow direction on thermal runaway behavior is also analyzed. Our results reveal that introducing pin on the cooling plate is desirable for better battery thermal management and keeping the battery surface temperature within safety guidelines. Further, the elliptical pin on the cooling plate is found to result in the least pressure drop (+80.46%) among pin configurations considered. The temperature of battery surface is found to be minimum when the pins are oriented at an angle of 90° to a flow direction of 180°, which is recommended particularly for the operation of the battery under thermal runaway. Furthermore, the pin configuration maintained cell surface temperature below 22°C and 75°C during normal and thermal runaway conditions, respectively. Moreover, the maximum pressure drop is found to be 225 and 136 kPa during normal and thermal runaway conditions, respectively.

Analysis of Vortex Evolution in the Runner Area of Water Pump Turbine under Runaway Conditions

In order to study the evolution principle of the coherent structure in the low flow rate runaway condition, the pump turbine of a certain pumped storage power plant was employed. The transient dynamic stress of the runner was numerically simulated and examined in this study in order to analyze the coherent structure of the vortex and the stability of the grid connection during the transition process. Based on the realizable k-ε turbulent model, the unsteady flow of the whole pump turbine channels was calculated. The results show that the flow in the runner channels presents with a turbulence state, and with many different scales vortices. These vortex structures are mainly distributed in the inlet region of the blade, the area of the blade trailing edge and the middle section of the runner channels. These vortex structures affect the distribution of the blade pressure load. Moreover, the vortex structure at the inlet of the runner depends on the change in the attack angle. In the flow region formed at the outlet of the blade near the suction surface and the runner cone, the blade has a limited effect on the fluid; thus, the vortex structure depends on the Coriolis force and the centrifugal force joint action. The evolution of these vortex structures will have a greater impact on the grid connection of the power station. During the operation of the power station, it is necessary to reduce the time of transitional conditions so that the power station can operate efficiently.