Field testing and numerical analysis of pavement-integrated photovoltaic/thermal system (PIPVT)

Heat transfer and thermoregulation within single cells revealed by transient plasmonic imaging

Experimental investigation of a solar thermal storage heater assembled with finned heat pipe and collective vacuum tubes

Overheating failure is one of the common causes of motor converter failure, so it is very important to improve the heat dissipation of the converter. In response to the inefficiency of traditional converter heat dissipation devices, we propose a novel heat dissipation device. The device combines micro-heat pipe arrays (MHPAs) and interleaved fins, and the MHPAs were initially applied in the converter. The device leverages the exceptional thermal conductivity of the MHPA to rapidly transfer heat from the heat source to various parts of the fins, ultimately achieving efficient heat dissipation and lowering the temperature. This study investigates the thermal resistance, heat dissipation performance, and overall temperature distribution of both the new and traditional heat dissipation devices using theoretical modeling, multi-condition experimental comparisons, and numerical simulation analysis. The experimental results demonstrate that the new heat dissipation device exhibits lower thermal resistance, higher heat dissipation, and greater convective heat transfer intensity compared to the conventional device. In a scenario with 6.3 kW power and 4.3 m/s wind speed, the new heat dissipation device decreases thermal resistance by 15 times, boosts heat dissipation by 30%, enhances convective heat transfer by 12.5%, and lowers the heatsink object temperature by 30%. As power and wind speed increase, the heat dissipation performance of the new heat dissipation device can be further improved. Additionally, the new heat dissipation device exhibits a characteristic where the temperature of the fins is higher on the outside and lower on the inside. Increasing the length of the fins helps improve the device’s heat dissipation performance. The feasibility of the MHPA being applied in converter heat dissipation systems is validated in this study. This device significantly enhances converter heat dissipation efficiency and is crucial for advancing the high-power capabilities of motors.

   The heat dissipation structure used in modern airborne radar chassis not only requires lightweight, but also pursues better mechanical properties and heat dissipation performance. In this study, a stochastically porous pomelo peel-inspired gradient structure was fabricated by laser powder bed fusion using Al-Mg-Sc-Zr powder. This study focused on the formability, microstructure, mechanical properties, and heat dissipation performance of the biomimetic structure through experimental and finite element analysis approaches. The influence of volume fraction (VF) on structural mechanical properties, deformation modes, stress distribution, and heat dissipation performance was investigated. The results showed that the mechanical properties of the structure declined as the VFs decreased. The optimal mechanical performance was obtained at the VF of 45%, where the compressive strength, specific energy absorption (Ws), and specific compressive strength values were measured to be 63.47 MPa, 34.84 J/g, and 142.16 MPa/(g·cm-3), respectively. Moreover, the Ws of the structures was higher than that of the reported aluminum alloy structures at the same VF. The biomimetic structure exhibited improved heat dissipation performance as the VFs decreased, with Reynolds number ranging from 2700 to 13,400. The structure of 30% VF with a remarkable heat transfer efficiency index of 1.86 displayed the best heat dissipation performance. In addition, compared with the traditional fin structures, the bionic structure possessed better thermal resistance, heat transfer efficiency index, and temperature uniformity at the same VF. This study demonstrated notable potential of pomelo peel-inspired design for lightweight load-bearing applications capable of heat-dissipating performance, providing a novel perspective for design and fabrication of versatile structures in the aviation field.

Thermo–mechanical coupled analysis for tunnel lining with circular openings

To explore the distribution law of the temperature field in the motor pump and the influence of the fan-shaped DC channel with spoiler in the pump housing on its heat dissipation performance. This study takes the arc-gear type hydraulic motor pump as the research object. In COMSOL, a coupled heat transfer simulation model of the motor pump’s fluid-solid coupling is established, and the internal temperature field characteristics are analyzed. To improve the heat dissipation effect of the motor pump, it is proposed to arrange spoiler in the fan-shaped DC channel of the pump housing to enhance heat dissipation. Three types of spoilers, namely, wing-shaped, inclined rectangle-shaped, and wave-shaped, are designed. The simulation results show that when the motor pump operates under rated conditions, due to the poor heat dissipation environment inside the motor pump, the high-temperature areas of the motor pump are concentrated in the rotor and permanent magnet parts. After arranging the spoiler, the turbulent kinetic energy and vorticity in the fan-shaped DC channel of the pump housing are significantly enhanced. All three spoiler structures can reduce the maximum temperature of each component of the motor. According to the comprehensive performance evaluation criterion (PEC), the inclined rectangle-shaped structure has the best comprehensive heat transfer performance (PEC = 1.114), while the wave-shaped structure has higher heat transfer efficiency but greater pressure loss. The wing-shaped structure has relatively limited enhancement effect on heat dissipation. This study systematically quantifies the influence of different spoiler structures on heat dissipation performance and flow resistance characteristics, providing a solution for enhancing the heat dissipation of the motor pump.

In order to increase heat dissipation efficiency of the heat sink, heat dissipating paint using hexagonal boron nitride (hBN) as a thermal conductive additive is designed and evaluated. The adhesion strength of the heat dissipating paint onto the aluminum (Al) plate is confirmed by the cross‐cut adhesion test method (ISO 2409). The ratio of detachment of the coating film from the Al plate is observed to be 5% or less and, from the resultants, it is found that the adhesion strength of the hBN‐based heat dissipation paint is excellent. The heat dissipation performance of the heat dissipating paint is determined by the temperature difference between the paint coated Al plate and the unpainted Al plate when the heat generated from the heat source is transferred to the around through the Al plate. The hBN‐based heat dissipating paint has the effect of lowering the temperature of the Al plate by 6 °C or more, and the heat dissipation performance of the paint tends to gradually increase with time. When the thickness of the coating film is reduced by about 20%, the heat dissipation performance is improved by more than 50%. As a result, the hBN‐based heat dissipating paint is able to achieve heat dissipation performance of more than 10 °C.

This article introduces the importance of optimizing the cold plate of phased array radar T/R modules to improve their heat dissipation performance. Based on the heat dissipation design input of a certain type of phased array T/R module, the design ideas of the cold plate are analyzed. In order to improve the heat dissipation performance of the cold plate and optimize the temperature uniformity of the power amplifier module, two heat transfer enhancement schemes, bending channel and flat channel, are adopted in the structural design of the module cold plate. After simulation calculations, the heat dissipation performance and flow resistance indicators of two schemes were obtained, showing that a straight channel has better heat dissipation and flow characteristics. After conducting heat dissipation performance tests on the flat and DC channel cold plates, the maximum temperature of the power amplifier module was 48 ° C, and the maximum temperature difference on the surface of each channel was 5.75 ° C, fully meeting the heat dissipation requirements.

Enhanced heat dissipation of V-trough PV modules for better performance

Microchannel has been widely used in the cooling, heat exchange, and thermal control modules of automation devices due to its many merits such as high efficiency of heat exchange, energy-saving, and can make full use of the sensible and latent heat. However, the integrity of the overall-optimized heat dissipation enhancement design of automation systems based on microchannel units is very limited, and few existing studies have concerned about the simulation of the heat flow and transfer features of microchannel heat sinks. For this reason, this paper aims to study a design scheme of the heat dissipation enhancement of automation systems from an overall optimization scale based on the microchannel heat exchange units and evaluate its heat dissipation performance. At first, this paper built a Microchannel Heat Sink (MHS) model and gave the steps of the proposed design scheme. Then, the temperature field of heat dissipation process of the internal components of automation equipment was simulated and analyzed, and the scientificity and effectiveness of the proposed design scheme were verified via experiment. At last, the relationship between the pressure drop of microchannel units and the temperature of fluid was discussed, the heat dissipation performance was compared, and the evaluation results were given.

The aim of this project is to investigate the performance of photovoltaic (PV) panel influence by wind speed in Kangar, Perlis, Malaysia. A low conversion energy efficiency of the PV panel is the major problem of a PV application system. The PV panel is absorbed solar irradiance minor converted into electrical energy, and the rest is converted into heat energy. Therefore, the heat energy generated by the PV panel is increased in its operating temperature. However, PV panel is necessary to operate them at the low operating temperatures to keep the PV panel electrical efficiency at an acceptable level. In this experiment, one unit of the PV panel was limited wind flow over its surface and the other one PV panel was operated in the normal condition. The operating temperature of the PV panel with wind speed is less than the PV panel without wind speed. This is due to wind flow over the surface of the PV panel can enhance heat extraction from the PV panel. Hence, PV panel with wind speed can generate a higher output power than that without wind speed. This improvement output performance of PV panel will have an important contribution to PV application systems.

The performance of a photovoltaic (PV) module is largely dependent on the temperature of the PV cell. Hence, heat management in a PV module is crucial to improving the performance and predicting the generated energy. The thermal conductivity of the backsheet affects the direction of the heat dissipation inside the module, with the heat generated by the cell and transferred through the backsheet increasing with increasing thermal conductivity of the backsheet, resulting in improved heat conduction in the in-plane direction. In this article, the temperature of the PV cell in two modules with different types of backsheet was predicted through numerical simulation and the results were compared with experimental results. The factors that affect the heat dissipation in the PV module and the heat dissipation mechanism were investigated, and a thermally efficient structure for improving the PV module performance was developed.

Photovoltaic (PV) inverter plays a crucial role in PV power generation. For high-power PV inverter, its heat loss accounts for about 2% of the total power. If the large amount of heat generated during the operation of the inverter is not dissipated in time, excessive temperature rise will reduce the safety of the devices. This paper proposes a closed PV inverter structure based on heat pipe and liquid cooling which overcomes the noise, dust and other problems caused by traditional air-cooling heat dissipation method and reduces cost of the volume occupied inside the body. Heat is dissipated through heat pipes, which are efficient heat transfer units. A simulation model of the actual cabinet was established using computational fluid dynamics (CFD), and the maximum junction temperature in the inverter was investigated under different coolant temperatures, flow rates, cooling liquid and heat loads. The results showed that the liquid cooling heat dissipation structure can effectively dissipate the heat inside the cabinet. The impact of two different types of heat sink used for power modules on temperature uniformity was studied. The results indicated that the 9-heat pipe type heat sink has better heat dissipation and uniform hot spots performance, the maximum heat source temperatures in the chip and capacitor were reduced by 9.91?C and 7.49?C respectively. Finally, the performance of the two types of radiators under different heat loads was studied.

<div class="section abstract"><div class="htmlview paragraph">A liquid-cooled plate is an important component for cooling batteries inside a battery package system. The structure of the liquid-cooling plate significantly affects the temperature conditions of power batteries and the energy consumption of the liquid-cooling system. However, there is a lack of precise knowledge regarding the specific factors that contribute to these impacts. In this study, the influence of structural parameters of flow channel on the heat dissipation performance is studied to solve above problems. A test bench for measuring battery pack cooling performances was built, and pressure drop of liquid-cooled plate and maximum temperature of battery were measured. A CFD model for liquid-cooled plate performance calculations was developed. Using the established model, pressure drop, and maximum temperature were calculated. The measured data are compared with the calculated date, which validate the proposed model. Using DOE with 3-factors 3-levels and using Analysis of Variance, the factors for influencing ‘S’-shaped liquid-cooled plate heat dissipation performance were analyzed. Prioritize the temperature characteristics of the liquid-cooled plate to get the best parameter combinations. Using the best parameter combinations of A<sub>3</sub>B<sub>1</sub>C<sub>3</sub>, a new liquid-cooled plate is designed. Under different discharge rates and inlet flow rates, the heat dissipation performance of initial liquid-cooled plate and the new designed liquid-cooled plate is compared. The calculation results show that the volume of channel and the length of channel have a great influence on the flow resistance. The length of the channel has a great influence on temperature uniformity. The length and the aspect ratio of channel have a great influence on the heat dissipation capacity. Compared with the initial liquid-cooled plate, although the flow resistance of the new liquid-cooled plate is greater resulting in more energy consumption, the temperature uniformity and heat dissipation capacity are improved, under different discharge rates and inlet flow rates. This study serves as a valuable reference for designing liquid-cooled plates.</div></div>

COMSOL Multiphysics software was used to construct a numerical opto-electro-thermal coupling model to investigate the mechanisms of internal heat generation, conduction, and dissipation in inverted (p-i-n architecture) perovskite solar cells (PSCs). The research results indicate that Joule heating and Shockley-Read-Hall (SRH) recombination are the primary sources of heat, leading to significant accumulation of heat at the interfaces between the perovskite and the electron transport layer (ETL), as well as between the ETL and the electrode. This concentration of heat not only affects the performance of the device but also poses challenges for overall thermal management. Therefore, we compared four different top electrode materials (Ag, Cu, Al, and reduced graphene oxide) to assess their performance in terms of heat dissipation efficiency. The results showed that reduced graphene oxide (RGO) performed exceptionally well in heat dissipation efficiency, primarily due to its high thermal conductivity, which enables it to effectively reduce heat accumulation at the interfaces, thereby improving performance of PSCs. This finding provides important material selection criteria for optimizing the thermal management of PSCs.