Heat Pipe Cooling Research Articles

Analytical Modeling of Temperature Field of SPMSM Based on Heat Pipe Cooling Technology

Analytical Modeling of Temperature Field of SPMSM Based on Heat Pipe Cooling Technology

Numerical method research and characteristics analysis on frozen start-up process of high-temperature heat pipe

Future space exploration technology requires a long-life and reliable power source that is not reliant on solar energy. Space micro-reactors are able to meet this need, with Heat Pipe Cooled Reactors (HPR) emerging as a notable type of space micro-reactor that has attracted widespread attention in recent years. The HPR utilizes high-temperature alkali metal heat pipes for heat transfer, which presents certain complexities due to the solid state of the alkali metals working medium at room temperature. This results in a three-phase transition during the high-temperature heat pipes start-up process, which significantly impacts the heat transfer characteristics and dynamic behavior of the HPR start-up process. Consequently, thorough research is necessary in this area. Numerical simulation is a crucial tool that can effectively analyze, predict, and guide experiments. This article utilizes the Finite Volume Method (FVM) to develop a simulation code for high-temperature heat pipe frozen start-up. Various physical models are integrated to describe different components of the heat pipe: the container is represented by a two-dimensional axisymmetric heat conduction equation, the wick region utilizes a Fixed Grid Method (FGM) to depict the melting process of the medium, and the vapor channel is described through a two-dimensional axisymmetric compressible laminar flow. The wick region and vapor channel are coupled through the evaporation and condensation of the medium. For the vapor channel, numerical methods such as SIMPLE and PISO are used for solving. Adaptive time step and OpenMP acceleration are employed in the code to enhance computational efficiency. Finally, by comparing the calculated results with experimental data, the feasibility and accuracy of the code are assessed, highlighting special phenomena during the start-up process. The findings confirm that the developed code accurately predicts parameter changes during start-up, and can serve as a heat pipe analysis module for multi-physics coupling analysis of HPR.

Study on the Hydration Heat Effect and Pipe Cooling System of a Mass Concrete Pile Cap

Under the action of cement hydration heat, the construction environment, thermal insulation measures, and pipe cooling systems, a mass concrete pile cap is subject to a complex internal temperature field, which makes it difficult to control its internal surface temperature difference (TISTD), the internal adiabatic temperature rise (TIATR), and the surface temperature (TST). In this study, a mass concrete pile cap of a very large bridge (the length, width, and height were 26.40 m, 20.90 m, and 5.00 m, respectively, and the central-pier pile cap was constructed with C40 concrete) was taken as the research object. The control factors affecting the temperature field of the pile cap were determined by comparing the field temperature measurements with the values calculated with finite element software simulation analysis. By using Midas Civil (2022 v1.2) and Midas FEA (NX 2022) finite element software, these factors (the concrete mold temperature, the concrete surface convection coefficient, the ambient temperature, the pipe cooling system parameters, etc.) were numerically analyzed, and their influence laws and degrees were determined.

BATTERY COOLING SYSTEMS OF ELECTRIC VECHILES

To enhance electric vehicle battery performance, the Battery Thermal Management System (BTMs) plays a crucial role by regulating internal battery temperature within optimal limits. Among the key components, the cooling system is paramount in maintaining this temperature range. Various cooling techniques such as Air Cooling (AC), Liquid Cooling (LC), Refrigerant Direct Cooling (RDC), Phase Change Material (PCM) based systems, Thermoelectric Cooling (TC), Heat Pipe Cooling (HPC), and Hybrid Cooling (HC) have been employed in electric vehicles. This paper provides an exhaustive review of these cooling systems, delineating their respective merits and demerits. The findings offer valuable insights for researchers delving into electric vehicle battery cooling technology. Keywords: Electric vehicle, battery, cooling system, thermal management system.

Li-Ion Battery Immersed Heat Pipe Cooling Technology for Electric Vehicles

Lithium-ion batteries, crucial in powering Battery Electric Vehicles (BEVs), face critical challenges in maintaining safety and efficiency. The quest for an effective Battery Thermal Management System (BTMS) arises from critical concerns over the safety and efficiency of lithium-ion batteries, particularly in Battery Electric Vehicles (BEVs). This study introduces a pioneering BTMS solution merging a two-phase immersion cooling system with heat pipes. Notably, the integration of NovecTM 649 as the dielectric fluid substantially mitigates thermal runaway-induced fire risks without requiring an additional power source. Comprehensive 1-D modeling, validated against AMESim (Advanced Modeling Environment for Simulation of Engineering Systems) simulations and experiments, investigates diverse design variable impacts on thermal resistance and evaporator temperature. At 10 W, 15 W, and 20 W heat inputs, the BTMS consistently maintained lithium-ion battery temperatures within the optimal range (approximately 27–34 °C). Optimized porosity (60%) and filling ratios (30–40%) minimized thermal resistance to 0.3848–0.4549 °C/W. This innovative system not only enhances safety but also improves energy efficiency by reducing weight, affirming its potential to revolutionize lithium-ion battery performance and address critical challenges in the field.

Experimental Investigation on Affecting Air Flow against the Maximum Temperature Difference of a Lithium-Ion Battery with Heat Pipe Cooling

Research on battery thermal management systems (BTMSs) is particularly significant since the electric vehicle sector is growing in importance and because the batteries that power them have high operating temperature requirements. Among them, heat pipe (HP)-based battery thermal management systems have very high heat transfer performance but fall short in maintaining uniform temperature distribution. This study presented forced air cooling by an axial fan as a method of improving the cooling performance of flat heat pipes coupled with aluminum fins (FHPAFs) and investigated the impact of air velocity on the battery pack’s maximum temperature differential (ΔTmax). All experiments were conducted on lithium nickel manganese cobalt oxide (NMC) pouch battery cells with a 20 Ah capacity in seven series connections at room temperature, under forced and natural convection, at various air velocity values (12.7 m/s, 9.5 m/s, and 6.3 m/s), and with 1C, 2C, 3C, and 4C discharge rates. The results indicated that at the same air velocity, increasing the discharge rate increases the ΔTmax significantly. Forced convection has a higher ΔTmax than natural convection. The ΔTmax was reduced when the air velocity was increased during forced convection.

Temperature Field Calculation of the Hybrid Heat Pipe Cooled Permanent Magnet Synchronous Motor for Electric Vehicles Based on Equivalent Thermal Network Method

A hybrid heat-pipe cooling structure for the permanent magnet synchronous motor for electric vehicles was analyzed in this paper to effectively equalize the axial temperature rise and reduce the average temperature of each heat-generating component in the motor. A temperature field calculation method for the hybrid heat-pipe cooling permanent magnet synchronous motor based on an equivalent thermal network method was proposed in this paper to save computing resources in temperature field analyses for hybrid heat-pipe cooling motors. The results were verified against the simulation results of the computational fluid dynamics method under three common operating conditions for electric vehicles. The error was proven to be within 5%. The calculation time of the proposed method was compared with the computational fluid dynamics method, which demonstrated that the calculation time of the proposed method was within 194 s.

Improved Thermal Management and Analysis for High-Power Heat Pipe Cooled FSCW PMSM for HEV Auxiliary Power Unit Application

Improved Thermal Management and Analysis for High-Power Heat Pipe Cooled FSCW PMSM for HEV Auxiliary Power Unit Application

LOAD DYNAMIC MATCHING METHOD STUDY ON A HEAT PIPE COOLED REACTOR

LOAD DYNAMIC MATCHING METHOD STUDY ON A HEAT PIPE COOLED REACTOR

Effect of Local Heat Pipe Cooling on Throughput Distribution and Thermal Homogeneity in a Binary Melt Pre-Distributor for Polyolefin Extrusion

In polymer blown film extrusion, inhomogeneous die temperature distributions lead to an inhomogeneous temperature and cause film thickness variations. To avoid an inhomogeneous film thickness and to achieve good film qualities, thermal homogenisation of the melt is necessary. Therefore, a new approach for cooling hot spots with heat pipes is investigated. CFD Simulations in OpenFOAM show that heat pipes can be used to influence melt temperatures locally in the places in which a temperature reduction is required. Since the outlets interact in a pre-distribution die, one heat pipe is not sufficient to homogenise the temperature at every outlet to similar temperatures. Two heat pipes show much better results with lower average temperature deviations between the distributor outlets. In order to equalise the temperature at all outlets, at least one heat pipe per outlet will be required.

Study on Thermal-hydraulic Characteristics of Ocean Silent Heat Pipe Cooled Reactor

Study on Thermal-hydraulic Characteristics of Ocean Silent Heat Pipe Cooled Reactor

An Improved Model of the Heat Pipe Based on the Network Method Applied on a Heat Pipe Cooled Reactor

As the unique piece of heat transport equipment in a heat pipe cooled reactor, an accurate simulation of the heat pipe is helpful for understanding the real behavior of the reactor core and the reactor system. Based on the network method, an improved model for the heat pipe which considers the heat conductance in the wall, the vapor flow in the vapor space, and the liquid flow in the wick is proposed. Meanwhile, the gravity term is also added to the flow equation. Compared with the experimental results of a copper-water heat pipe, the validity of this model is verified. Then, a high-temperature sodium heat pipe of 1.0 m length is selected as the study object. Based on the analysis, it can be found that the total temperature difference of the heat pipe is 31.7 K, and the temperature drop caused by the vapor flow is only 2.6 K. As for the flow pressure drop in the heat pipe, the pressure drop is mainly concentrated in the wick region, which is 8,422.47 Pa, and the pressure drop in the vapor space is only 896.68 Pa. In cases of non-uniform heating and cooling, high heat leakage, and inclined operation, results indicate that the greater the non-uniformity of heating or cooling, the greater will be the temperature drop of the heat pipe. With the increase of heat leakage, the operating temperature of the heat pipe decreases significantly, and the total temperature drop increases. The heat pipe can operate at all positive inclination angles, but when the inclination angle exceeds−30°, the heat pipe will reach the capillary limit, and it may be damaged. All of these results can provide support for the design and simulation of a heat pipe cooled reactor.

The Low-Enriched Uranium Core Design of a Mw Heat Pipe Cooled Reactor

The Low-Enriched Uranium Core Design of a Mw Heat Pipe Cooled Reactor

Thermal Management of Electric Bike Battery Module Based on Heat Pipe Cooling System

Thermal Management of Electric Bike Battery Module Based on Heat Pipe Cooling System

Conceptual Design of a 3 Mwth Yttrium Hydride Moderated Heat Pipe Cooled Micro Reactor

Conceptual Design of a 3 Mwth Yttrium Hydride Moderated Heat Pipe Cooled Micro Reactor

Control Strategy Study for a Heat Pipe Cooled Nuclear Reactor

Control Strategy Study for a Heat Pipe Cooled Nuclear Reactor

Thermal Management of Electric Vehicle Battery Module Based on Heat Pipe Cooling System

Thermal Management of Electric Vehicle Battery Module Based on Heat Pipe Cooling System

Electro-Thermal Modeling of Power IGBT Module Cooled by A Heat Pipe Cooling System

This paper deals with the development of an electro-thermal model of an Insulated Gate Bipolar Transistor (IGBT) with a water-cooled heat pipe cooling system. Firstly, a thermal model of the heat pipe cooling system is proposed. Then, an electro-thermal model of the IGBT is developed to predict the junction temperature variations in transient operation. The thermal model of the IGBT is determined on the base of the thermal-capacitance lumped method. The electrical model of the IGBT is developed by considering the effect of the junction temperature on its static electrical parameters. Finally, the electro-thermal model is considered in a boost converter application. The model predictions show the effectiveness of the heat pipe cooling system for different commutation frequencies. It is proved that the heat pipe cooling system can keep the junction temperature of the IGBT at values allowing safe operation.

Investigation on the Use Solar Thermoelectric Generator for Open Pond Cultivation with Heat Pipe Cooling

Investigation on the Use Solar Thermoelectric Generator for Open Pond Cultivation with Heat Pipe Cooling

Comparison of Heat-Pipe Cooling System Design Processes in Railway Propulsion Inverter Considering Power Module Reliability

In this paper, the effect of the heat-pipe cooling system design processes on the reliability of the power module in a railway propulsion inverter was investigated. The existing design processes for the heat-pipe cooling system guarantee that the junction temperature of power devices does not exceed the maximum allowable junction temperature when the railway propulsion inverter operates under its mission profile; therefore, each step of the design process was reviewed to analyze the effect of the heat-pipe cooling system. Based on the processes, in the calculation for the required thermal resistance of the heat-pipe cooling system, two difference losses were considered with the thermal resistances of the insulated gate bipolar mode transistor (IGBT) module and the thermal grease at an interface between the baseplate of IGBT module and heat-pipe cooling system. The control scheme and mission profile of the train were taken into account to calculate the power losses. Then, the designed heat-pipe cooling systems were compared in terms of the size and weight. In addition, the junction temperatures and lifetimes of the power module with heat-pipe cooling systems designed by different power losses were estimated and compared. Finally, guidelines for a heat-pipe system cooling design are proposed.