DESIGN OF AN ABSORPTION BASED MINIATURE HEAT PUMP SYSTEM FOR COOLING OF HIGH POWER MICROPROCESSORS

摘要

An absorption based miniature heat pump system, which can be driven by the low quality waste heat, is designed for chip cooling applications. Miniaturization is achieved, as the chemically-driven absorption/desorption process permits pressurization of the working fluid in liquid phase, requiring much smaller displacement volume than in vapor compression systems. The goal of this work is to design a system that keeps the chip junction temperature near room temperature, while removing 100 W of heat load. Water/LiBr pair is used as a working fluid. A dual micro-channel array evaporator is used to reduce both the mass flux through each micro-channel and the channel length, thus minimizing the pressure drop. Micro-channel arrays for the desorber and condenser are placed in intimate communication with each other using a hydrophobic membrane, which provides a common chemically-selective interface between the desorber and condenser to separate the water vapor from LiBr solution. The separated water vapor is immediately cooled and converted into a liquid phase at the condenser side. For direct air cooling of the condenser and absorber, offset strip fin arrays are used. The performance of the components and the entire system is numerically evaluated and discussed.