With the advent of the 5G era,the design of electronic equipment is developing towards thinness,intelligence and multi-function,which requires higher cooling performance of the equipment.Micro-channel heat sink is pro...With the advent of the 5G era,the design of electronic equipment is developing towards thinness,intelligence and multi-function,which requires higher cooling performance of the equipment.Micro-channel heat sink is promising for the heat dissipation of super-thin electronic equipment.In this study,thermal resistance theoretical model of the micro-channel heat sink was first established.Then,fabrication process of the micro-channel heat sink was introduced.Subsequently,heat transfer performance of the fabricated micro-channel heat sink was tested through the developed testing platform.Results show that the developed micro-channel heat sink has more superior heat dissipation performance over conventional metal solid heat sink and it is well suited for high power LEDs application.Moreover,the micro-channel structures in the heat sink were optimized by orthogonal test.Based on the orthogonal optimization,heat dissipation performance of the micro-channel radiator was further improved.展开更多
With the progressive increase in the number of transistors that can be accommodated on a single integrated circuit,new strategies are needed to extract heat from these devices in an efficient way.In this regard method...With the progressive increase in the number of transistors that can be accommodated on a single integrated circuit,new strategies are needed to extract heat from these devices in an efficient way.In this regard methods based on the combination of the so-called“jet impingement”and“micro-channel”approaches seem extremely promising for possible improvement and future applications in electronics as well as the aerospace and biomedical fields.In this paper,a hybrid heat sink based on these two technologies is analysed in the frame of an integrated model.Dedicated CFD simulation of the coupled flow/temperature fields and orthogonal tests are performed in order to optimize the overall design.The influence of different sets of structural parameters on the cooling performance is examined.It is shown that an optimal scheme exists for which favourable performance can be obtained in terms of hot spot temperature decrease and thermal uniformity improvement.展开更多
The hybrid manifold micro-pin-fin(MMPF)heat sink combined nozzle jets is an option for large-scale integrated circuits(LSI).The demond for uniform and ultra-high heat flux removal by MMPF heat sink has not been adequa...The hybrid manifold micro-pin-fin(MMPF)heat sink combined nozzle jets is an option for large-scale integrated circuits(LSI).The demond for uniform and ultra-high heat flux removal by MMPF heat sink has not been adequately investigated.This work aims to solve the problem of fluid organization.The proposed basic tiling topologies,including square,regular hexagon,30°rhombus,and 60°rhombus topologies,provide different organized fluid flows and heat transfer patterns.The present study focuses on comparing these topologies according to independent porous medium parameters,such as nozzle pore size D_(Z),flow pore size D_(X,Y),and porosityε.The results show that the square topology achieves the smallest total thermal resistance R_(tot)value of0.0975×10^(-4)K m^2/W,while the hexagon topology achieved the highest value of COP/?T,which was 2033.9 K^(-1).According to the sensitivity analysis results,the optimal total thermal resistance can be obtained by balancing the influences of nozzle pore size,flow pore size,and porosity.The optimal pressure drop can be obtained by maximizing the porosity.展开更多
Microstructure heat sinks have great potential for high heat flux cooling.In this paper,we compared microchannel(MC),micro-pin-fin(MPF),manifold microchannel(MMC),and manifold micro-pin-fin(MMPF)heat sinks to figure o...Microstructure heat sinks have great potential for high heat flux cooling.In this paper,we compared microchannel(MC),micro-pin-fin(MPF),manifold microchannel(MMC),and manifold micro-pin-fin(MMPF)heat sinks to figure out the pros and cons.Fluid flow and manifold unit models are used to study thermal and hydrodynamic performance.The heat sinks with different channel/fin sizes,manifold numbers,and porosities are discussed according to the pressure drop,temperature,thermal resistance,and coefficient of performance.Results show that MMC and MMPF heat sinks are superior to MC and MPF heat sinks,and there are also differences between MMC and MMPF heat sinks.Typically,the MMPF heat sink has lower maximum temperature,temperature non-uniformity,and total thermal resistance R_(tot).In contrast,the MMC heat sink has a lower pressure drop and higher COP.For the MMPF heat sink,at the nozzle width of 6.75μm and the MPF width of 70.71μm(porosity=0.167),it achieves the lowest total thermal resistance of R_(tot)=2.97×10^(-6)K m^(2)/W.Under 10^(3)W/cm^(2)heat flux,the maximum surface temperature rise is 29.74 K,and the maximum temperature difference of the heating surface is 3.15 K.This research initially provides a clear reference on the selection of single-phase cooling microstructures for ultra-high heat flux dissipation.展开更多
Double layer micro-channel heat sink(DLMCHS) has been widely used in various electronic devices; however, the existence of the nonuniform thermal strain distribution in actual operation has adverse effect on the overa...Double layer micro-channel heat sink(DLMCHS) has been widely used in various electronic devices; however, the existence of the nonuniform thermal strain distribution in actual operation has adverse effect on the overall stability. In this paper, two optimized designs of DLMCHS with cutting baffles on top and bottom layers are presented based on the traditional DLMCHS. The heat transfer and thermal stress performance are numerically analyzed and compared with the traditional DLMCHS. The results indicate that cutting baffles of micro-channels remarkably improves heat transfer and thermal stress performance. The optimized design with cutting baffles on the bottom layer decreases thermal strain but deteriorates heat transfer performance. The model with cutting baffles on the top layer has better combined thermal strain and heat transfer performance, which reduces thermal strain by about 1.5 times and enhances heat transfer by about 26.5%. For the design with cutting baffles on the top board, adding metal foam in the inlet collector can decrease the total minimum thermal strain by 51.4% and maximum temperature by 1.4 K, and increase the Nusselt number by 15%. These results indicate that DLMCHS with cutting baffles on the top layer has great potential for thermal managements on electronic devices with high power density.展开更多
The increasing power density of IT electronics and the enormous energy consumption of data centers lead to the urgent demand for efficient cooling technology.Due to its efficiency and safety,liquid-cooled heat sink te...The increasing power density of IT electronics and the enormous energy consumption of data centers lead to the urgent demand for efficient cooling technology.Due to its efficiency and safety,liquid-cooled heat sink technology may gradually replace air-cooled technology over time.With the ambient or higher water supply temperature,the liquid-cooled technology shortens the operating time of the chiller and improves its coefficient of performance,while the pump power consumption may increase for satisfying the constant cooling capacity.Therefore,it is significant to study the optimal water supply temperature to achieve energy-efficient operation of data centers.A virtual 30.1 kW data center is considered as the case,the liquid-cooled system is constructed with a combination of innovative manifold microchannel heat sink with oblique fins and indirect evaporative cooling technology to minimize energy consumption.A hybrid thermal management model integrating the heat dissipation model and the power consumption model is established by TRNSYS and FLUENT software.To the highest chip-safe operating temperature premise,the energy performance is analyzed under various water supply temperatures in Guangzhou.The result shows that only 21.5-hour mechanical cooling is needed with the 30℃server inlet temperature throughout the year.And the minimized power consumption occurs with the constant 29℃server inlet temperature.Moreover,the temperature adaptive control strategy(TACS)is adopted to test the cooling system power consumption under different regulation frequencies,and the by-week TACS can achieve another 11.5%energy saving than the minimum power consumption of the constant temperature control strategy.展开更多
基金Supported by the National Natural Science Foundation of China(Grant Nos.51975135 and 52005422)Guangzhou Science and Technology Project(Grant No.201707010429)Special Innovation Projects of Universities in Guangdong Province(Grant No.2018GKTSCX085).
文摘With the advent of the 5G era,the design of electronic equipment is developing towards thinness,intelligence and multi-function,which requires higher cooling performance of the equipment.Micro-channel heat sink is promising for the heat dissipation of super-thin electronic equipment.In this study,thermal resistance theoretical model of the micro-channel heat sink was first established.Then,fabrication process of the micro-channel heat sink was introduced.Subsequently,heat transfer performance of the fabricated micro-channel heat sink was tested through the developed testing platform.Results show that the developed micro-channel heat sink has more superior heat dissipation performance over conventional metal solid heat sink and it is well suited for high power LEDs application.Moreover,the micro-channel structures in the heat sink were optimized by orthogonal test.Based on the orthogonal optimization,heat dissipation performance of the micro-channel radiator was further improved.
基金National Natural Science Foundation of China(No.51676030,Zhou,X.M.,http://www.nsfc.gov.cn/)Sichuan Science and Technology Program(No.2019JDRC0026,Zhou,X.M.,http://scst.tccxfw.com/)。
文摘With the progressive increase in the number of transistors that can be accommodated on a single integrated circuit,new strategies are needed to extract heat from these devices in an efficient way.In this regard methods based on the combination of the so-called“jet impingement”and“micro-channel”approaches seem extremely promising for possible improvement and future applications in electronics as well as the aerospace and biomedical fields.In this paper,a hybrid heat sink based on these two technologies is analysed in the frame of an integrated model.Dedicated CFD simulation of the coupled flow/temperature fields and orthogonal tests are performed in order to optimize the overall design.The influence of different sets of structural parameters on the cooling performance is examined.It is shown that an optimal scheme exists for which favourable performance can be obtained in terms of hot spot temperature decrease and thermal uniformity improvement.
基金supported by the National Natural Science Foundation of China(Grant No.51876062)the Interdisciplinary Innovation Program of North China Electric Power University。
文摘The hybrid manifold micro-pin-fin(MMPF)heat sink combined nozzle jets is an option for large-scale integrated circuits(LSI).The demond for uniform and ultra-high heat flux removal by MMPF heat sink has not been adequately investigated.This work aims to solve the problem of fluid organization.The proposed basic tiling topologies,including square,regular hexagon,30°rhombus,and 60°rhombus topologies,provide different organized fluid flows and heat transfer patterns.The present study focuses on comparing these topologies according to independent porous medium parameters,such as nozzle pore size D_(Z),flow pore size D_(X,Y),and porosityε.The results show that the square topology achieves the smallest total thermal resistance R_(tot)value of0.0975×10^(-4)K m^2/W,while the hexagon topology achieved the highest value of COP/?T,which was 2033.9 K^(-1).According to the sensitivity analysis results,the optimal total thermal resistance can be obtained by balancing the influences of nozzle pore size,flow pore size,and porosity.The optimal pressure drop can be obtained by maximizing the porosity.
基金supported by the National Natural Science Foundation of China(Grant No.51876062)the Interdisciplinary Innovation Program of North China Electric Power University。
文摘Microstructure heat sinks have great potential for high heat flux cooling.In this paper,we compared microchannel(MC),micro-pin-fin(MPF),manifold microchannel(MMC),and manifold micro-pin-fin(MMPF)heat sinks to figure out the pros and cons.Fluid flow and manifold unit models are used to study thermal and hydrodynamic performance.The heat sinks with different channel/fin sizes,manifold numbers,and porosities are discussed according to the pressure drop,temperature,thermal resistance,and coefficient of performance.Results show that MMC and MMPF heat sinks are superior to MC and MPF heat sinks,and there are also differences between MMC and MMPF heat sinks.Typically,the MMPF heat sink has lower maximum temperature,temperature non-uniformity,and total thermal resistance R_(tot).In contrast,the MMC heat sink has a lower pressure drop and higher COP.For the MMPF heat sink,at the nozzle width of 6.75μm and the MPF width of 70.71μm(porosity=0.167),it achieves the lowest total thermal resistance of R_(tot)=2.97×10^(-6)K m^(2)/W.Under 10^(3)W/cm^(2)heat flux,the maximum surface temperature rise is 29.74 K,and the maximum temperature difference of the heating surface is 3.15 K.This research initially provides a clear reference on the selection of single-phase cooling microstructures for ultra-high heat flux dissipation.
基金supported in part by the National Natural Science Foundation of China (No. 51676208)the Fundamental Research Funds for the Central Universities (No. 18CX07012A)
文摘Double layer micro-channel heat sink(DLMCHS) has been widely used in various electronic devices; however, the existence of the nonuniform thermal strain distribution in actual operation has adverse effect on the overall stability. In this paper, two optimized designs of DLMCHS with cutting baffles on top and bottom layers are presented based on the traditional DLMCHS. The heat transfer and thermal stress performance are numerically analyzed and compared with the traditional DLMCHS. The results indicate that cutting baffles of micro-channels remarkably improves heat transfer and thermal stress performance. The optimized design with cutting baffles on the bottom layer decreases thermal strain but deteriorates heat transfer performance. The model with cutting baffles on the top layer has better combined thermal strain and heat transfer performance, which reduces thermal strain by about 1.5 times and enhances heat transfer by about 26.5%. For the design with cutting baffles on the top board, adding metal foam in the inlet collector can decrease the total minimum thermal strain by 51.4% and maximum temperature by 1.4 K, and increase the Nusselt number by 15%. These results indicate that DLMCHS with cutting baffles on the top layer has great potential for thermal managements on electronic devices with high power density.
基金financially supported under Guangzhou Science and Technology Plan Project (No.202201010108)CAS Science and Technology Service Network Program Project (No.20211600200082)Guangzhou Development Zone International Science and Technology Cooperation Project Funding (No.2021GH07).
文摘The increasing power density of IT electronics and the enormous energy consumption of data centers lead to the urgent demand for efficient cooling technology.Due to its efficiency and safety,liquid-cooled heat sink technology may gradually replace air-cooled technology over time.With the ambient or higher water supply temperature,the liquid-cooled technology shortens the operating time of the chiller and improves its coefficient of performance,while the pump power consumption may increase for satisfying the constant cooling capacity.Therefore,it is significant to study the optimal water supply temperature to achieve energy-efficient operation of data centers.A virtual 30.1 kW data center is considered as the case,the liquid-cooled system is constructed with a combination of innovative manifold microchannel heat sink with oblique fins and indirect evaporative cooling technology to minimize energy consumption.A hybrid thermal management model integrating the heat dissipation model and the power consumption model is established by TRNSYS and FLUENT software.To the highest chip-safe operating temperature premise,the energy performance is analyzed under various water supply temperatures in Guangzhou.The result shows that only 21.5-hour mechanical cooling is needed with the 30℃server inlet temperature throughout the year.And the minimized power consumption occurs with the constant 29℃server inlet temperature.Moreover,the temperature adaptive control strategy(TACS)is adopted to test the cooling system power consumption under different regulation frequencies,and the by-week TACS can achieve another 11.5%energy saving than the minimum power consumption of the constant temperature control strategy.
