Numerical Heat Transfer Model Research Articles

Numerical Modelling of Coupled Heat and Mass Transfer in Porous Materials: Application to Cinder Block Bricks

Numerical Modelling of Coupled Heat and Mass Transfer in Porous Materials: Application to Cinder Block Bricks

Thermal and electrical evaluation of insulated gate bipolar transistor (IGBT) power modules

The thermal reliability of two different high-power insulated gate bipolar transistor (IGBT) modules was studied under both conduction and switching regimes by experimental and numerical approaches. Indeed, the reliability of semiconductor devices is tightly linked to the junction temperatures reached in the IGBT, which is a function of the diode chips present in such devices and its operating condition. However, measurements of the semiconductor temperatures are often difficult to be done, thus requiring modeling and simulation tools to accurately evaluate the instantaneous temperature under different thermal loads. For this reason, a transient 3D heat transfer numerical model of two different IGBT power devices was proposed using the Finite Element Method, assuming that heat is dissipated on the IGBT by natural convection and radiation. These simulations were validated with experimental measurements, obtained through infrared thermography, performed for the IGBT modules either opened or enclosed, varying the heat source, the module orientation and under conduction or switching regime. For the switching regime, power losses due to the gate-closing and gate-opening transitions between conducting and non-conducting states were taken into consideration. The heat losses were modeled assuming the time-dependent heat dissipation obtained by previous electrical simulations, and it was compared with time-averaged heat source solutions. Results showed that averaging the heat source can significantly reduce the computational time, allowing quick design explorations. Overall, the numerical model led to deviations of less than 16% over the transient heating and at steady-state. Finally, the impact of a heat sink attached to the IGBT was studied, demonstrating that the proposed model can be used for accurate and quick investigations of potential failures and for the development of more efficient IGBT devices.

The design and operation optimization for conductive rubber heated snow melting bridge deck pavement

In order to solve the problem of ice and snow disasters on roads, this study proposed a new technology for active deicing of bridge decks using conductive rubber heating system (CRHS) as the heat source. The existing measures to improve the operation efficiency of snowmelt pavement often only optimize 1–2 influencing factors, and lack of optimization of multiple factors such as paving design, operation and environment. Therefore, in order to improve the operation efficiency, this study carried out multi-objective optimization on the design and operation of conductive rubber heated snow melting bridge deck pavement. The bridge deck pavement scheme of conductive rubber heating system was proposed, and its two-dimensional numerical model of heat transfer was established. The laying spacing of conductive rubber (s), heating power (p), ambient temperature (t) and wind speed (v) were used as input parameters for system operation optimization. Predictive models for total heating time (THT) and the loss of energy rate (LER) were developed using response surface methodology (RSM). The specific effects of input parameters on THT and LER and their interactions were analyzed by thermal simulation. Aiming at less THT and lost energy (LE), the optimal input parameters of conductive rubber heating system were obtained by the multi-objective particle swarm algorithm. The results indicated that shorter THT and lower LE could be achieved when the laying spacing (s) was 0.25 m, the ambient temperature (t) was −3 °C, the wind speed (v) was 2 m/s, and the input power was 550 W/m2. And adjusting s was more effective than adjusting p to obtain low THT and LER. The results and recommendations can effectively guide the operation of conductive rubber heating system. The multi-objective optimization research idea of improving the operation efficiency of snowmelt pavement in this paper can provide reference for similar deicing pavement applications.

Analysis of heat charging and release processes in cascade phase change materials energy storage floor heating systems: Performance evaluation

To address the issues of high energy consumption, significant temperature fluctuation and low heat release efficiency in conventional energy storage floor heating systems, this study proposes a novel solution known as the cascade energy storage floor heating system. This system incorporates two layers of phase change materials (PCMs) with distinct phase change temperatures as the thermal energy storage medium. A coupled heat transfer numerical model is developed to analyze the heat charging and release processes within the floor heating system. The evolutions of liquid fraction of PCMs, flow field and floor surface temperature are investigated during the heat charging and release processes. The findings demonstrate that the cascade PCM energy storage floor heating system avoids overheating and saves >19 % of energy consumption during the heat charging process, elevates the floor surface temperature by about 2 K during the late stage of heat release and thus reduces floor surface temperature fluctuation in comparison with the single-stage PCM system. These improvements are conducive to enhancing the energy utilization rate. Due to better synergistic solidification of the two PCM layers, the system with a PCM proportion of 1:1 exhibits superior overall heat release performance when compared to systems with PCM proportions of 1:2 or 2:1. The research outcomes provide a theoretical foundation and technical guidance for the practical implementation of cascade PCM energy storage technology in the field of building energy conservation.

Investigation of the performance enhancement of building-integrated photovoltaic system using evaporative porous clay applied in different building's directions

The integration of photovoltaic (PV) modules with building's facades and roofs results in significant reduction in the PV module's efficiency owing to its temperature rising, as well as increasing in the building's indoor thermal gain. Thus, this study proposed cost-effective and eco-friendly passive cooling technique utilizing evaporative porous clay material to minimize the integrated PV module's temperature. An experimentally validated numerical study is being performed using different clay thickness and porosity to estimate the expected enhancement in the thermal and electrical performance of the building-integrated photovoltaic (BIPV) system. The experimental tests were carried out using prototype of small rooms integrated with PV panels installed with a water-saturated porous clay material to validate the presented transient numerical heat and mass transfer model. After that, the proposed system is being compared with another passive cooling mechanism using phase change material (PCM), and the results are then analyzed and compared. The findings showed a maximum reduction of 19.1 °C and 12.8 °C of peak PV temperature when the porous clay and PCM are utilized, while the building's side temperature reduced by around 11.2 °C and 10.9 °C, respectively. Further, porous clay achieved up to 9.8 % improvement in PV system's efficiency, with a maximum water consumption rate reached around 3.35 L/h.m2. Moreover, applying such a porous clay cooling approach resulted in a maximum reduction of 53.8 % in the building's annual thermal load. In the outcomes reported here, porous clay with the least thickness and highest porosity achieved more feasible cooling effects compared with PCM.

Numerical modeling and experimental validation of heat transfer in a research nuclear reactor evaporator by considering the precipitate formation

One of the wastewater treatment units in the Tehran Research Nuclear Reactor (TRNR) is an evaporator unit, which consists of a semi-batch single-stage kettle-type evaporator with heating coils and auxiliary equipment. The concentrate of this unit is immobilized in cement. So, the precipitate specie, concentrate composition, and its amount are important parameters for further waste treatment steps. In this research, a new bulk mathematical model is developed based on the total mass balance, the partial mass balance of ions in the concentrate and precipitates, as well as the energy balance to investigate the performance of the Tehran Research Nuclear Reactor evaporator. The resulting ordinary differential equations are solved numerically with a proposed algorithm. In this simulation, Pitzer equations are used to calculate the activity coefficient of water and ions, density, and solubility of salts. The temperature and pressure dependence of the developed model parameters are also considered. Moreover, the effect of precipitate formation on the overall heat transfer coefficient with time dependence correlation is also taken into account. Results show a good agreement between the experimental data and the developed model, and the relative error of different parameters is reported between 2% and 13%.

The Mathematical Modeling and Performance of Sky Radiative Coolers

Sky radiative cooling is a kind of passive cooling technology that uses the “atmospheric window” to emit the object’s own heat to the low temperature of outer space; this technology has low energy consumption, no pollution, and other useful characteristics, so in recent years it has attracted widespread attention. The cooling effect of the sky radiative cooler is mainly affected by the constantly changing outdoor ambient temperature. In addition, the structure of the radiative cooler itself also means that its radiative cooling power undergoes obvious changes. Here, we utilized COMSOL simulation software to establish a numerical heat transfer model for radiative cooling, aimed at investigating the influencing factors on the sky radiative cooler and methods to enhance the structure of the radiative cooling. This study discusses outdoor ambient wind speed, the inlet flow rate of the cooler, installation angle of the cooler, and different cooler structures. Based on simulation results, it is observed that, for varying wind speeds, when the ambient radiation temperature is higher than the surface temperature of the cooler, a larger ambient wind speed leads to a poorer refrigeration effect. The maximum temperature difference in surface temperature at wind speeds of 0 m/s and 4 m/s is 0.59 °C. When the ambient temperature is lower than the surface temperature of the cooler, a smaller wind speed results in a greater net refrigeration power. The maximum temperature difference in this scenario is 0.32 °C. The net refrigeration power of the radiative cooler increases with an increase in water flow rate. As the water flow rate increases from 0 L/min to 5 L/min, the net refrigeration power increases from 25 W/m2 to 200 W/m2 and gradually stabilizes. Considering the radiative impact of the cooler on the surrounding environment, as the installation angle increases from 0° to 90°, the surface temperature of the cooler first increases and then decreases, reaching its highest temperature of 29.26 °C at 45°. The surface temperature of the cooler varies with the thickness of the air sandwich, increasing from 1 cm to 12 cm, and then decreasing. The lowest temperature of 23.4 °C is achieved at a thickness of 8 cm. The increase in the fin structure on the surface of the radiative cooler leads to a decrease in its refrigeration performance, and the difference between the inlet and outlet temperatures of the radiative cooler with a flat plate structure is always greater than that of the finned plate, and the difference in the average radiance is 23.52 W/m2. Finally, the energy-saving effect of the sky radiative cooling composite system is analyzed. Taking a typical small office building as an example, an energy consumption analysis model is set up, and the energy consumption of the composite system is simulated in four cities with different climates, using EnergyPlus software (version 8.6); the system’s power consumption is the largest in hot and humid climates. Compared with the traditional vapor-compression refrigeration system, the composite system reduces air conditioning power consumption by 25.7%, 32.5%, 37.1%, and 44.8% in Guangzhou, Shanghai, Jinan, and Shenyang, respectively. The main innovations of this paper include analyzing and studying the influence of the tilt angle change of the radiative plate on the refrigeration performance of the cooler and the relationship between the surrounding buildings, adding air sandwiches and ribs to the radiative cooler to analyze the influence of convective heat transfer on the refrigeration effect, which plays a guiding role in the design and research of the sky radiative cooler.

Double-sided numerical thermal modeling of fan-out panel-level MOSFET power modules

Double-sided packages for heat dissipation are an efficient thermal management mechanism for power semiconductor devices. A fan-out panel-level packaging (FOPLP), as one of the double-sided forms, exhibits excellent electro–thermal characteristics and provides low stray inductance and thermal resistance. Besides, the temperature at each point within the structure is closely related to its thermo–mechanical properties and device reliability. However, thermal resistance is limited in describing the temperature distribution. Finite element analysis (FEA) requires time-consuming construction of 3D models. Therefore, to depict the temperature distribution of FOPLP rapidly and accurately, a numerical heat transfer model was proposed for the double-sided package structure. The solution was obtained from the steady-state thermal balance Laplace equation using the separation of variables method. Several boundaries were analyzed to determine the specific parameters in the model. Finally, the temperature field predicted by the derived numerical model was compared with finite element simulation results. The proposed model was consistent with both Silicon (Si) and Silicon Carbide (SiC) FOPLP structures within the error of 15 % at the center of the device, which verified the validity and accuracy of the numerical model for double-sided heat dissipation. The proposed models and results could contribute to the development of effective thermal design tools for double-sided thermal power modules.

Numerical modeling of heat transfer in Al2O3/H2O nanofluid flowing through a Bessel-like converging pipe

Numerical modeling of heat transfer in Al2O3/H2O nanofluid flowing through a Bessel-like converging pipe

Numerical Simulation and Analysis of the Heat and Mass Transfer of Oil-Based Drill Cuttings in a Thermal Desorption Chamber

To reveal the coupled heat and mass transfer process during thermal desorption of oil-based drill cuttings, a numerical model of heat and mass transfer was established, which is divided into four components = evaporation. The C language programming catch-up method was used to solve the discrete equation, and the interactive effects of the oil-based drill cuttings’ particle size, water content, oil content, content of light and heavy components in oil, heating temperature, heating time, and other operating parameters on the mass and heat transfer of the oil-based cutting particles were investigated. Results showed that the time at which the center point temperature of oil-based drill cuttings with radius of 1 mm and 5 mm reached 600 °C was 441 s and 63 s, respectively, and the temperature difference between the center and the surface increased with particle size. The desorption process of water, light components, and heavy components was not completed individually but mixed alternately. The duration of each desorption component was closely related to the temperature at the center of the oil-based drill cuttings. The smaller the particle size was, the lower the water and oil contents were, and the higher the heating temperature and time were. These conditions were beneficial to thermal desorption, mass transfer, and heat transfer.

Numerical modeling and experimental verification for anisotropic heat conduction process in velocity probe of the thermal mass flowmeter

Traditional models ignore the temperature gradients caused by anisotropic heat conduction process in the axial and radial directions of the velocity probe of a thermal mass flowmeter (TMF), essentially assuming constant wall temperature. Recently, a novel TMF with a large length–diameter ratio of the velocity probe and more evident temperature gradient was proposed; although this novel TMF is insensitive to the radial velocity profile, it leads to significant calculation errors. To reduce the error of this TMF, this study proposes a numerical model of pipeline flow heat transfer that considers the axial and radial heat conduction of the velocity probe. The velocity probe axial heat conduction numerical model is proposed, and the results of apparent thermal conductivity are verified using empirical formulas. A feedback adjustment convergence program is performed to maintain the average temperature of the velocity probe at 10 K above the temperature of the observed fluid. The simulation results showed that a temperature gradient forms in both the axial and radial directions of the velocity probe of the improved model. Moreover, the higher the flow velocity and the farther it is from its central axis, the lower the temperature. Experimental results revealed that, at a velocity rang of 1.0–7.0 m/s, the average relative error between the improved simulated results and current experimental data is 2.92 % and the maximum relative error is 10.91 %, whereas the average relative error between the traditional simulated results and original experimental data is 7.44 % and the maximum relative error is 19.45 %. Thus, the improved model better simulates the real process.

Effect of CMAS penetration behavior on stress evolution in TBCs under three-dimensional temperature gradients

CaO–MgO–Al2O3–SiO2 (CMAS) penetration is the primary failure mode of thermal barrier coating (TBC) film cooling systems, and therefore, understanding the CMAS penetration behavior and its effect on the internal stress evolution of TBCs is necessary. In this study, the effect of nonuniform CMAS penetration on the stress profile of a top ceramic (TC) coating layer was investigated under a nonuniform temperature field with three different mainstream temperatures (1561, 1623, and 1673 K). Further, a conjugate heat transfer numerical model was established to determine the temperature distribution in the TBCs with a gas-film cooling system. A phase-field model was adopted to study the CMAS penetration behavior. Moreover, the effects of CMAS penetration on the temperature distribution, growth rate of the thermal growth oxide (TGO), and residual stress are discussed. The CMAS penetration continuously eroded the TC layer, following the temperature distribution trend. CMAS penetration achieved temperature increments of 26.1, 35.1, and 40.3 K at the TC/TGO interface and TGO thickness differences up to 0.12, 0.26, and 0.37 μm after 500 h oxidation at the three mainstream temperatures. A significant increase in the residual stresses of the TBCs caused by CMAS penetration was observed. The von Mises stress increased from 243.7, 295.7, and 339.9 MPa to 367.0, 391.5, and 414.9 MPa, respectively. Driving forces for Mode I and Mode II interfacial cracks at the trailing edge of the cooling hole increased with CMAS penetration, and the increase in the mainstream temperature enhanced the driving forces.

Numerical Investigation on the Performance of Horizontal Helical-Coil-Type Backfill Heat Exchangers with Different Configurations in Mine Stopes

The application of ground heat exchanger technology in backfill mines can actualize subterranean heat storage, which is one of the most effective solutions for addressing solar energy faults such as intermittence and fluctuation. This paper provides a 3D unsteady heat transfer numerical model for full-size horizontal backfill heat exchangers (BFHEs) with five configurations in a mining layer of a metal mine by using a COMSOL environment. In order to ensure the fairness of the comparative analysis, the pipes of BFHEs studied have the same heat exchange surface area. By comparing and evaluating the heat storage/release characteristics of BFHEs in continuous operation for three years, it was discovered that the helical pipe with serpentine layout may effectively enhance the performance of BFHEs. Compared with the traditional SS BFHEs, the heat storage capacity of the S-FH type is significantly increased by 21.7%, followed by the SA-FH type, which is increased by 11.1%, while the performances of U-DH and SH type are considerably lowered. Also, the impact of the critical structural factors (pitch length and pitch diameter) was further studied using the normalized parameters C1 and C2 based on the inner diameter of the pipe. It is discovered that BFHEs should be distributed in a pipe with a lower C1, and increasing C2 encourages BFHEs to increase the storaged/released heat of BFHEs. By comparatively analysing the effect of thermal conductivity, it is found that the positive effects of thermal conductivity on the performance of SH, U-DH, SA-FH, and S-FH type BFHEs are found to decrease successively. This work proposes a strategy for improving the heat storage and release potential of BFHEs in terms of optimal pipe arrangement.

Data-driven and physics-based modelling of process behaviour and deposit geometry for friction surfacing

In the last decades, there has been an increase in the number of successful machine learning models that have served as a key to identifying and using linkages within the process-structure–property-performance chain for vastly different problems in the domains of materials mechanics. The consideration of physical laws in data-driven modelling has recently been shown to enable enhanced prediction performance and generalization while requiring less data than either physics-based or data-driven modelling approaches independently. In this contribution, we introduce a simulation-assisted machine learning framework applied to the solid-state layer deposition technique friction surfacing, suitable for solid-state additive manufacturing as well as repair or coating applications. The objective of the present study is to use machine learning algorithms to predict and analyse the influence of process parameters and environmental variables, i.e. substrate and backing material properties, on process behaviour and deposit geometry. The effects of maximum process temperatures supplied by a numerical heat transfer model on the predictions of the targets are given special attention. Numerous different machine learning algorithms are implemented, optimized and evaluated to take advantage of their varied capabilities and to choose the optimal one for each target and the provided data. Furthermore, the input feature dependence for each prediction target is evaluated using game-theory related Shapley Additive Explanation values. The experimental data set consists of two separate experimental design spaces, one for varying process parameters and the other for varying substrate and backing material properties, which allowed to keep the experimental effort to a minimum. The aim was to also represent the cross parameter space between the two independent spaces in the predictive model, which was accomplished and resulted in an approximately 44 % reduction in the number of experiments when compared to carrying out an experimental design that included both spaces.

REDUCED HEAT LOSS THROUGH WINDOW STRUCTURES

The results of theoretical and experimental studies of heat transfer through the window structures of the building are presented, the thermal characteristics of the windows are established and the level of heat loss realized through them is estimated. To determine the heat transfer resistance of two-chamber double-glazed units, numerical modeling of radiative-convective heat transfer is performed, taking into account the thermal conductivity of the gas layer between the glasses. Natural free convection of the gaseous medium in the double-glazed chambers occurs as a result of the temperature difference between the side glass surfaces of the chamber. Modeling is performed by numerically solving the system of fluid dynamics and energy equations for the air layer and glass. On the inner surfaces of the chambers, conditions of the fourth kind are set, which take into account the radiation and conductive components of the total heat flow coming from the glass surface. The results of simulation of heat transfer through double-glazed windows with ordinary glass indicate that about 60 % of heat is transferred by radiation. Therefore, an effective measure to reduce heat loss through windows is to reduce the radiation component of the total heat flow by applying a low-emissivity coating to the inner surfaces of the glass unit. This makes it possible to reduce the total heat flow (and, accordingly, heat loss to the environment) by 20–34 %, depending on the number of glass surfaces with this coating. Conducted independent experimental studies confirm the modeling results. In order to comply with the current requirements of state building regulations and to achieve the energy efficiency class of type C buildings (specific heat consumption for heating 1 sq. m of usable area is less than 75 kWh), for the climatic conditions of Kyiv, it is recommended to use double-chamber windows with two low-emission coatings with the formula of the glass unit: 4M1-10-i4M1-10-i4M1. Bibl. 22, Fig. 8.

Investigation on the thermal hydraulic characteristics of sodium-supercritical CO2 in compact heat exchange channel

Sodium-cooled fast reactor coupled with supercritical CO2 Brayton cycle has broad development prospects owing to the high thermal efficiency, smaller components and compact footprint. As one of the key components, sodium-supercritical CO2 compact heat exchanger plays a vital role in improving the operation performance of coupled power systems. In this paper, a numerical model for coupling heat transfer of sodium-supercritical CO2 in a straight-channel compact heat exchange channel is established and the prediction accuracy of the model is verified with experimental results. The influence of structural parameters and flow parameters on the resistance characteristics and heat transfer performance of cold and hot channels is systematically analyzed. The results show that the structure of semi-circular cross-section with an ABAB layout performs best in heat transfer performance. For the sodium channel, performance evaluation criteria gradually grow with the increase of sodium inlet velocity and slowly decline with the supercritical CO2 inlet velocity. For the supercritical CO2 channel, performance evaluation criteria decrease with the increase of sodium inlet velocity and increase with the supercritical CO2 inlet velocity. Reducing the supercritical CO2 inlet temperature could effectively improve the thermal hydraulic performance of the sodium-supercritical CO2 compact heat exchange channel.

Optimization design of solid-state hydrogen storage device for fuel cell forklift

Solid-state hydrogen storage device using metal hydride have enormous advantages for fuel cell forklifts. In addition to high volume hydrogen storage density, the solid-state hydrogen storage device can also be used as a counterweight for the forklift. At the same time, the solid-state storage device has low hydrogen storage pressure and safety, and the fuel (H2) refueling is convenient and low-cost. In this paper, a two-dimensional heat and mass transfer numerical model has been developed to predicting the performance of the metal hydride tank filled with Ti0.9Zr0.1Cr0.35Mn1.4V0.2Fe0.05 alloy. The validity of this numerical model was tested by comparison with the experimental data of the metal hydride hydrogen storage tank with a hydrogen capacity of 1 kg, achieving a good agreement between all the data. And a solid-state hydrogen storage device with an effective hydrogen capacity of 1.5 kg is optimally designed for 3.5 T fuel cell forklift. The completion rate of hydrogen refueling in the solid-state hydrogen storage device will reach 97.6 % within 30 min, and continuously discharging over 1.5 kg H2 under flow rates of 150 SL/min and 250 SL/min. The optimized solid-state hydrogen storage device was integrated in a power module for 3.5 T fuel cell forklift which allows uninterrupted operation for at least 6 h 8 min under rated operation.

Heat transfer characteristics of phase change materials in double-layer packed bed under dynamic thermal boundary

Dynamic thermal boundary conditions have a significant impact on the thermal storage performance of phase change materials (PCMs) in packed beds. In this paper, an unsteady numerical heat transfer model of a double-layer packed bed is established and verified. The heat storage characteristics of the four PCM combination schemes are calculated and compared, and the sinusoidal wave heat source is used as an input parameter to study the influence of wave amplitude and period changes on the thermal performance of the system. The study shows that when the volume ratio of PCM 1 to PCM 2 is 1/3:2/3, the melting time is shorter and the heat storage rate is faster. The long-period fluctuation can significantly shorten the melting time and improve thermal performance. When the period is 120 min, the melting time is shortened by about 15.2 % compared with the steady state, and the heat storage rate is increased by 19.6 %. The larger the amplitude of the heat source, the stronger the promotion effect on melting. When the amplitude is 16 °C, the melting time is shortened by about 17.7 % compared with the steady state, and the heat storage rate is increased by 16.7 %. The research results can provide some reference for the design of a double-layer packed bed under the dynamic heat source.

A numerical model for convective-condensation heat transfer of flue gas and its application on fin efficiency calculation

Condensing heat exchangers have been widely employed because they can recover heat and water from the exhaust flue gas efficiently. In this study, the effects of heat transfer condition, water vapor volume fraction and fin geometry parameter on the convective-condensation heat transfer process of the annular finned tube are evaluated through applying a new numerical model for simulation. The outer wall temperature of the base tube promotes the improvement of fin efficiency. But due to the increasing condensation of water vapor, the driving force of the fin temperature rise reduces. Thus, the sensible heat transfer efficiency of the fin drops. Under the working conditions in this study, when the outer wall temperature of the base tube ascends from 320.8 to 330.3 K, the sensible heat transfer efficiency of the fin increases by 9.6%. The effects of water vapor volume fraction on the sensible and latent heat transfer efficiencies of fin show the opposite trends. As the water vapor volume fraction increases from 0.05 to 0.20, the latent heat transfer efficiency of the fin rises from 0 to 0.102, while the sensible heat transfer efficiency reduces from 0.441 to 0.396. Among the fin geometrical parameters, the fin height has the greatest influence on the fin efficiency. When the fin height increases from 7 to 16 mm, the fin sensible and latent transfer efficiencies drop by 33.8 and 76.7%, respectively.

Topology optimization of laminated-sheet microchannel heat sinks based on a pseudo-three-dimensional method

Laminated-sheet microchannel heat sinks (LS-MHSs) have shown enormous potential in the thermal management of integrated chips due to their advantages of easy integration, high surface-to-volume ratio and high heat transfer efficiency. In this paper, a five-layer pseudo-3D (P3D) conjugated heat transfer model of the double-layer microchannel heat sink (DL-MHS) was established, and topology optimization (TO) was applied for optimal design of the DL-MHS. The effects of different inlet pressures and lamination methods on the optimal design were discussed, and then, the optimization results were compared with those obtained for a single-layer microchannel heat sink (SL-MHS) and conventional parallel microchannel heat sink (CP-MHS). A full-scale 3D conjugate heat transfer numerical model was also built to investigate the heat transfer and fluid flow performance of the topology optimized microchannel heat sink. The results showed that the topology optimized microchannel heat sink can enhance heat transfer and show a higher heat transfer and comprehensive performance compared to the conventional parallel microchannel heat sink. Under the same pumping power consumption, the topology optimization of the DL-MHS with parallel flow obtains the best heat transfer performance, which is 2.04 times that of the CP-MHSs and 1.09 times that of the SL-MHS. Under the same pumping power consumption, the topology optimization of the DL-MHS with counter flow achieves the best temperature uniformity and its maximum temperature difference is 5.0–16.9 K lower than that of the CP-MHSs and 1.6–3.4 K lower than that of the SL-MHS.