热管理器的优化分析与设计

本文建立了热管理器设计计算模型,分析了换热系数、气流通道截面积、换热面积密度、管束排列形式等结构参数对热管理器控温性能的影响,并由此指出了优化热管理器体积的途径。运用上述设计计算模型并根据优化途径的指导,设计了应用于16 kW发电量的微型CCHP系统的热管理器,优化设计后的热管理器体积不到原有样机的一半。本文提出的设计计算模型和热管理器体积优化途径可作为今后热管理器研究和设计的有效工具。

Dynamic thermal management by greedy scheduling algorithm

Chip multiprocessors(CMPs) allow thread level parallelism,thus increasing performance.However,this comes with the cost of temperature problem.CMPs require more power,creating non uniform power map and hotspots.Aiming at this problem,a thread scheduling algorithm,the greedy scheduling algorithm,was proposed to reduce the thermal emergencies and to improve the throughput.The greedy scheduling algorithm was implemented in the Linux kernel on Intel's Quad-Core system.The experimental results show that the greedy scheduling algorithm can reduce 9.6%-78.5% of the hardware dynamic thermal management(DTM) in various combinations of workloads,and has an average of 5.2% and up to 9.7% throughput higher than the Linux standard scheduler.

Rigid Sensor Allocation and Placement Technique for Reducing the Number of Sensors in Thermal Monitoring

Using embedded thermal sensors, dynamic thermal management(DTM) techniques measure runtime thermal behavior of high-performance microprocessors so as to prevent thermal runaway situations. The number of placed sensors should be minimized, while guaranteeing accurate tracking of hot spots and full thermal characterization. In this paper, we propose a rigid sensor allocation and placement technique for determining the minimal number of thermal sensors and the optimal locations while satisfying an expected accuracy of hot spot temperature error based on dual clustering. We analyze the false alarm rates of hot spots using the proposed methods in noise-free, with noise and sensor calibration scenarios, respectively. Experimental results confirm that our proposed methods are capable of accurately characterizing the temperatures of microprocessors.

A preliminary experimental validation of superposition strategy in thermal management of integrated circuit with multiple hot-spots

Thermal management is a key issue in the integrated circuit(IC)design.In this paper,the superposition strategy was experimentally validated using a modeling IC device,which was fabricated by laboratory-level microfabrication technique.Metal thin film resistors on the top of dielectric layer were used to analogize the multiple hot-spots in the modeling IC device.The measured temperature rise with multiple hot-spots agrees well with the predictions given by the superposition calculations.With the help of the superposition strategy,thermal management of IC device can be significantly simplified by decomposing the system into sub-systems and optimizing each part individually.The influence coefficients in the superposition strategy extracted from the experimental measurement offer the IC designers a useful engineering tool to facility the thermal optimization and evaluate the thermal performance of IC devices.

Thermal Management Controller for Heat Source Temperature Control and Thermal Management

In many heat recovery processes,temperature control of heat source is often required to ensure safety and high efficiency of the heat source equipment.In addition,the management of recovered heat is important for the proper use of waste heat.To this aim,the concept of thermal management controller(TMC),which can vary heat transfer rate via the volume variation of non-condensable gas,was presented.Theoretical model and experimental prototype were established.Investigation shows that the prototype is effective in temperature control With water as the working fluid,the vapor temperature variation is only 1.3℃when the heating power varies from 2.5 to 10.0 kW.In variable working conditions,this TMC can automatically adjust thermal allocation to the heat consumer.