Strip-and-Zone Micro-Channel Liquid Cooling of Integrated Circuits Chips With Non-Uniform Power Distributions

2013 ◽  
Author(s):  
Yu Zhang ◽  
Yubai Li ◽  
Xin Li ◽  
Shi-Chune Yao
Keyword(s):  
Integrated Circuit ◽  
Power Distribution ◽  
Channel Width ◽  
Total Power ◽  
Maximum Temperature ◽  
Air Cooling ◽  
Micro Channel ◽  
Liquid Cooling ◽  
Micro Channels ◽  
Parallel Strips

For a high-power integrated circuit (IC), it is desirable to cool with the liquid micro-channels. However, the non-uniform power distribution of the IC is a great challenge. In this paper, the strip-and-zone strategy is presented. First, the optimal channel-width assuming a uniform power distribution of the total chip power is considered as a nominal situation. Then, according to the distribution of the power density of the power blocks on chip, the micro-channels are divided into several parallel strips with various zones in these strips. A further optimization of the channel-width of each zone in the strips shall be made that a higher heat transfer coefficient will occur in the zones of higher heat flux, while the strips of higher total power will have same or less flow resistances. As a result, under the same pressure drop among all the strips, same or more flow will occur at the strips of higher total power and the maximum temperature on the chip is reduced. Illustration of this strip-and-zone micro-channel liquid cooling design is provided through a design case of an IC chip with realistic power distribution. Comparing with the same chip at the air cooling and at the micro-channel cooling with the nominal channel-width, the chip at strip-and-zone micro-channel liquid cooling yields the lowest surface temperature as expected.

Design and Study of a Phase Change Micro-Channel Heat Sink

2012 ◽  
Vol 472-475 ◽  
pp. 1686-1692
Author(s):  
Dong Fang Wang ◽  
Yu Ting Wu ◽  
Bin Liu ◽  
Chong Fang Ma
Keyword(s):  
Heat Sink ◽  
Thermal Flux ◽  
Air Cooling ◽  
Micro Channel ◽  
Vapor Compression ◽  
Heat Transfer Area ◽  
Refrigeration System ◽  
Liquid Cooling ◽  
Vapor Compression System ◽  
Set Up

It is difficult to cool high thermal flux electronics by traditional methods such as air cooling, common liquid cooling and so on. However, vapor compressor refrigeration system is an efficient approach to solve this problem. Heat sink is important equipment in system, so the goal of this paper is to design a heat sink which is similar to an evaporator in vapor compression system with head load 100W. Mathematical model of heat sink is set up. Different heat flux, pressure drop, heat transfer area and weight with different micro-channel width are obtained finally.

Development of a Numerical Model for Non-Uniformly Powered Die to Improve Both Thermal and Device Clock Performance

2009 ◽  
Author(s):  
Saket Karajgikar ◽  
Dereje Agonafer ◽  
Kanad Ghose ◽  
Bahgat Sammakia ◽  
Cristina Amon ◽  
...  
Keyword(s):  
Power Distribution ◽  
High Speed ◽  
Junction Temperature ◽  
Total Power ◽  
Maximum Temperature ◽  
Large Temperature ◽  
Computer Performance ◽  
Performance Loss ◽  
Functional Blocks ◽  
Functional Components

Integration of different functional components such as level two (L2) cache memory, high-speed I/O interfaces, memory controller, etc. has enhanced microprocessor performance. In this architecture, certain functional units on the microprocessor dissipate a significant fraction of the total power while other functional blocks dissipate little or no power. This highly non-uniform power distribution results in a large temperature gradient with localized hot spots that may have detrimental effect on computer performance and product reliability as well as yield. Moving the functional blocks may reduce the junction temperature but can also affect the performance by a factor as high as 35%. In this paper, multi-objective optimization is performed to minimize the junction temperature without significantly altering the computer performance. From the results, the minimum and the maximum temperature was 82.4°C and 94.5°C with a corresponding penalty on the performance of 35% and 0% respectively. The optimized location of the functional blocks resulted in a temperature of 83.2°C for a performance loss of 5%.

Effect of Flow Arrangements on Thermohydraulic Performance of a Microchannel Heat Sink

2009 ◽  
Author(s):  
Satbir S. Sehgal ◽  
Krishnan Murugesan ◽  
S. K. Mohapatra
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Experimental Studies ◽  
Heat Sinks ◽  
Heat Transfer Analysis ◽  
Maximum Temperature ◽  
Micro Channel ◽  
Flow Conditions ◽  
Micro Channels ◽  
Microchannel Heat Sinks

The advancements in fabricating and utilizing microchannel heat sinks (MCHS) for cooling of electronic devices during the last decade has not been matched by corresponding advances in our fundamental understanding of the unconventional micro fluidics. Many theoretical and experimental studies have been reported for the heat transfer analysis along the direction of flow within the microchannels, but to the best knowledge of the authors, the effect of the size of the inlet and outlet plenum and direction of the flow to the plenums was not studied exhaustively till date. The liquid is supplied to the microchannels via the inlet and outlet plenums and this can be achieved by many flow arrangements. Due to the small size of the channel dimensions, the entrance and exit conditions will significantly affect the heat transfer characteristics of the flow field in the channel. Instability effects at the entrance and exit regions of the micro-channel also need to be fully understood for efficient design of microchannel heat sinks. This paper presents an experimental study that has been conducted to explore the effect of entrance & exit conditions of the liquid flow within a copper micro-channel heat sink (MCHS). Three test pieces having inlet & outlet plenum dimensions of 8mm × 30mm, 10mm × 30 mm and 12 mm × 30 mm each with constant depth of 2.5 mm have been selected. Three different flow arrangements (U-Type, S-type and P-type) are studied for each test piece resulting in total nine flow arrangements. Each micro-channel heat sink contains an array of micro-channels in parallel having individual width of 330μm and channel depth of 2.5 mm. A comparison is made based on thermohydraulic performance of MCHS for different flow conditions at inlet and outlet plenums maintaining constant heat flux. Deionised water has been used in the experiments for the Reynolds number ranging from approximately 220 to 1100. The results are interpreted based on pressure drops and maximum temperature variations for these nine flow arrangements. Tests has been conducted to look for optimized dimensions and flow conditions at inlet and outlet plenums for the given fixed length of microchannels under same conjugate heat transfer conditions. Evaluations of experimental uncertainties have been meticulously made while selecting the instruments used in the experimental facility.

Evaluation of Cooling Technologies for Xeon Phi™ Based High Performance Computing Clusters

2015 ◽  
Author(s):  
Suchismita Sarangi ◽  
Will A. Kuhn ◽  
Scott Rider ◽  
Claude Wright ◽  
Shankar Krishnan
Keyword(s):  
High Performance Computing ◽  
High Performance ◽  
Total Power ◽  
Air Cooling ◽  
Xeon Phi ◽  
Liquid Cooling ◽  
Immersion Cooling ◽  
Performance Per Watt ◽  
Cpu Temperature ◽  
Performance Computing

Efficient and compact cooling technologies play a pivotal role in determining the performance of high performance computing devices when used with highly parallel workloads in supercomputers. The present work deals with evaluation of different cooling technologies and elucidating their impact on the power, performance, and thermal management of Intel® Xeon Phi™ coprocessors. The scope of the study is to demonstrate enhanced cooling capabilities beyond today’s fan-driven air-cooling for use in high performance computing (HPC) technology, thereby improving the overall Performance per Watt in datacenters. The various cooling technologies evaluated for the present study include air-cooling, liquid-cooling and two-phase immersion-cooling. Air-cooling is evaluated by providing controlled airflow to a cluster of eight 300 W Xeon Phi coprocessors (7120P). For liquid-cooling, two different cold plate technologies are evaluated, viz, Formed tube cold pates and Microchannel based cold plates. Liquidcooling with water as working fluid, is evaluated on single Xeon Phi coprocessors, using inlet conditions in accordance with ASHRAE W2 and W3 class liquid cooled datacenter baselines. For immersion-cooling, a cluster of multiple Xeon Phi coprocessors is evaluated, with three different types of Integrated Heat Spreaders (IHS), viz., bare IHS, IHS with a Boiling Enhancement Coating (BEC) and IHS with BEC coated pin-fins. The entire cluster is immersed in a pool of Novec 649 (3M fluid, boiling point 49 °C at 1 atm), with polycarbonate spacers used to reduce the volume of fluid required, to achieve target fluid/power density of ∼ 3 L/kW. Flow visualization is performed to provide further insight into the boiling behavior during the immersion-cooling process. Performance per Watt of the Xeon Phi coprocessors is characterized as a function of the cooling technologies using several HPC workloads benchmark run at constant frequency, such as the Intel proprietary Power Thermal Utility (PTU), and industry standard HPC benchmarks LINPACK, DGEMM, SGEMM and STREAM. The major parameters measured by sensors on the coprocessor include total power to the coprocessor, CPU temperature, and memory temperature, while the calculated outputs of interest also include the performance per watt and equivalent thermal resistance. As expected, it is observed that both liquid and immersion cooling show improved performance per Watt and lower CPU temperature compared to air-cooling. In addition to elucidating the performance/watt improvement, this work reports on the relationship of cooling technologies on total power consumed by the Xeon-Phi card as a function of coolant inlet temperatures. Further, the paper discusses form-factor advantages to liquid and immersion cooling and compares technologies on a common platform. Finally, the paper concludes by discussing datacenter optimization for cooling in the context of leakage power control for Xeon-Phi coprocessors.

Effect of Relocation of Functional Units of a Non-Uniformly Powered Microprocessor on Thermal and Device Clock Performance

2009 ◽  
Author(s):  
Saket Karajgikar ◽  
Dereje Agonafer ◽  
Kanad Ghose ◽  
Bahgat Sammakia ◽  
Cristina Amon ◽  
...  
Keyword(s):  
Power Distribution ◽  
High Speed ◽  
Junction Temperature ◽  
Total Power ◽  
Maximum Temperature ◽  
Large Temperature ◽  
Computer Performance ◽  
L2 Cache ◽  
Functional Units ◽  
Functional Components

Integration of different functional components such as level two (L2) cache memory, high-speed I/O interfaces, memory controller, etc. has enhanced microprocessor performance. In this architecture, certain functional units on the microprocessor dissipate a significant fraction of the total power while other functional units dissipate little or no power. This highly non-uniform power distribution results in a large temperature gradient with localized hot spots that may have detrimental effects on computer performance, product reliability, and yield. Moving the functional units may reduce the junction temperature but can also affect performance by as much as 30%. In this paper, multi-objective optimization is performed to minimize the junction temperature without significantly altering the computer performance. From the results, the minimum and the maximum temperature was 56.6°C and 62.2°C with a corresponding penalty on the performance of 14% and 0% respectively. The numerical analysis was performed for 90 nm Pentium® IV Northwood architecture at 3 GHz clock speed.

Porous Media Modeling of Two-Phase Micro-Channel Cooling of Electronic Chips With Non-Uniform Power Distribution

2013 ◽  
Author(s):  
Hua Zhang ◽  
Jun Jie Liu ◽  
Yubai Li ◽  
S. C. Yao
Keyword(s):  
Porous Media ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Distribution ◽  
Heat Load ◽  
Computation Time ◽  
Micro Channel ◽  
Two Phase ◽  
Flow Rates ◽  
Micro Channels

Compared to single phase heat transfer, two-phase micro-channel heat sinks utilize latent heat to reduce the needed flow rate and maintaining a rather uniform temperature close to the boiling temperature. The challenge in the application of cooling for electronic chips is the necessity of modeling a large number of micro channels using large number of meshes and extensive computation time. In the present study, a modified porous media method modeling of two phase flow in micro-channels is performed. Compared with conjugate CFD method, it saves computation effort and provides a more convenient means to perform optimization of channel geometry. The porous media simulation is applied to a real chip. The channels of high heat load will have higher qualities, larger flow resistances and lower flow rates. At a constant available pressure drop over the channels, the low heat load channels show much higher mass flow rates than needed. To avoid this flow mal-distribution, the channel widths on a chip are adjusted to ensure the exit qualities and mass flow rate of channels are more uniform. As a result, the total flow rate on the chip is drastically reduced, and the temperature gradient is also minimized. However, it only gives a relatively small reduction on the maximum surface temperature of chip.

Porous Media Thermal Modeling of an Electronic Chip With Non-Uniform Power Distribution and Cooled by Micro-Channels

2013 ◽  
Author(s):  
Yubai Li ◽  
Yu Zhang ◽  
Shi-Chune Yao
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Porous Media ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Power Distribution ◽  
Micro Channel ◽  
Entrance Effect ◽  
Micro Channels ◽  
The Heat Transfer Coefficient

Micro-channels are used for the cooling of electronic chips. However, the 3D-CFD modeling of the large number of channels in a full chip requires huge number of meshes and computation time. Although porous media modeling of micro-channels can significantly reduce the effort of simulation, most porous media models are based upon the assumption that the surface heat flux or temperature is uniform on the chip. In reality, the heat flux on the chip is usually highly non-uniform. As a result, the heat transfer coefficient along the micro-channel is not uniform. In the present study, the porous media model considers the simultaneously developing entrance effect at the micro-channel inlet, and the thermally developing entrance effect due to the severe heat flux variation along the channel. Duhamel integral is used to determine the heat transfer coefficient variation corresponding to the heat flux distribution along the channels, and comparisons are made with the rigorous conjugate conduction-convection modeling. The computing cost of this modeling method is only about 1% (including one time of iteration) of 3D-CFD simulation. To demonstrate this approach, a full scale electronic chip with realistic power distribution on the surface is modeled, and the temperature map on the chip’s heating surface is provided.

Improving the efficiency of oilfield electric power distribution

2019 ◽  
pp. 79-87
Author(s):  
Yu. F. Yu. F. Romaniuk ◽  
О. V. Solomchak ◽  
М. V. Hlozhyk
Keyword(s):  
Power Distribution ◽  
Reactive Power ◽  
Power Transmission ◽  
Transmission Efficiency ◽  
Active Power ◽  
Oil Field ◽  
Total Power ◽  
Simultaneous Increase ◽  
Active Load ◽  
Step Down

The issues of increasing the efficiency of electricity transmission to consumers with different nature of their load are considered. The dependence of the efficiency of the electric network of the oil field, consisting of a power line and a step-down transformer, on the total load power at various ratios between the active and reactive components of the power is analyzed, and the conditions under which the maximum transmission efficiency can be ensured are determined. It is shown by examples that the power transmission efficiency depends not only on the active load, but also largely on its reactive load. In the presence of a constant reactive load and an increase in active load, the total power increases and the power transmission efficiency decreases. In the low-load mode, the schedule for changing the power transmission efficiency approaches a parabolic form, since the influence of the active load on the amount of active power loss decreases, and their value will mainly depend on reactive load, which remains unchanged. The efficiency reaches its maximum value provided that the active and reactive components of the power are equal. In the case of a different ratio between them, the efficiency decreases. With a simultaneous increase in active and reactive loads and a constant value of the power factor, the power transmission efficiency is significantly reduced due to an increase in losses. With a constant active load and an increase in reactive load, efficiency of power transmission decreases, since with an increase in reactive load, losses of active power increase, while the active power remains unchanged. The second condition, under which the line efficiency will be maximum, is full compensation of reactive power.  Therefore, in order to increase the efficiency of power transmission, it is necessary to compensate for the reactive load, which can reduce the loss of electricity and the cost of its payment and improve the quality of electricity. Other methods are also proposed to increase the efficiency of power transmission by regulating the voltage level in the power center, reducing the equivalent resistance of the line wires, optimizing the loading of the transformers of the step-down substations and ensuring the economic modes of their operation.

scholarly journals Reducing the Cooling Energy Consumption of Telecom Sites by Liquid Cooling

Proceedings ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 19
Author(s):  
Jari Huttunen ◽  
Olli Salmela ◽  
Topi Volkov ◽  
Eva Pongrácz
Keyword(s):  
Energy Savings ◽  
Reduction Potential ◽  
Dissipated Energy ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Mobile Data ◽  
Commercial Use ◽  
The Future ◽  
Base Transceiver Station ◽  
Ventilation Duct

The use of mobile data has increased and will continue to increase in the future, because more data is moving to wireless networks such as 5G. Cooling energy need is also expected to increase in indoor telecom rooms, and can be as high as the equipment’s own power consumption. The world’s first liquid Base Transceiver Station (BTS) was adopted into commercial use in 2018, in Helsinki, Finland. Conventional air-cooled BTS hardware was converted into liquid-cooled BTS equipment. Heat from the BTS was pumped out of the site room, and thus ventilation or air conditioning was not needed for the heat load from the BTS. Heat stored in the liquid was released into the ventilation duct of the building, still providing annual cooling energy savings of 70%, when compared to air cooling. In the future, 80% of the total dissipated energy, 13450 kWh/a in total, can potentially be used for heating purposes. In terms of CO2 emissions, adapting liquid cooling showed an 80% reduction potential when compared to air cooling.

scholarly journals Towards bio-inspired artificial muscle: a mechanism based on electro-osmotic flow simulated using dissipative particle dynamics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ramin Zakeri
Keyword(s):  
Zeta Potential ◽  
Electric Field ◽  
Dissipative Particle Dynamics ◽  
Artificial Muscle ◽  
Particle Dynamics ◽  
Polymer Membrane ◽  
Channel Width ◽  
Micro Channel ◽  
Osmotic Flow ◽  
Electro Osmotic Flow

AbstractOne of the unresolved issues in physiology is how exactly myosin moves in a filament as the smallest responsible organ for contracting of a natural muscle. In this research, inspired by nature, a model is presented consisting of DPD (dissipative particle dynamics) particles driven by electro-osmotic flow (EOF) in micro channel that a thin movable impermeable polymer membrane has been attached across channel width, thus momentum of fluid can directly transfer to myosin stem. At the first, by validation of electro-osmotic flow in micro channel in different conditions with accuracy of less than 10 percentage error compared to analytical results, the DPD results have been developed to displacement of an impermeable polymer membrane in EOF. It has been shown that by the presence of electric field of 250 V/m and Zeta potential − 25 mV and the dimensionless ratio of the channel width to the thickness of the electric double layer or kH = 8, about 15% displacement in 8 s time will be obtained compared to channel width. The influential parameters on the displacement of the polymer membrane from DPD particles in EOF such as changes in electric field, ion concentration, zeta potential effect, polymer material and the amount of membrane elasticity have been investigated which in each cases, the radius of gyration and auto correlation velocity of different polymer membrane cases have been compared together. This simulation method in addition of probably helping understand natural myosin displacement mechanism, can be extended to design the contraction of an artificial muscle tissue close to nature.

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