Micro heat management

The investigations refer to the general capability of micro reactors to perform short-time processing with highy intensified mass and heat transfer. A special focus of most investigations on the oxidation of ammonia was the heat management. The use of new concepts for heat supply and removal opens the door to operation in new process regimes with very different product spectra. 

Beneficial micro reactor properties mainly refer to improving heat management as a key for obtaining a partial reaction in a consecuhve sequence, when large heats are released by reaction steps other than the partial one (see also Section 3.3.1). 

From this equation, the adiabatic heating rate AT/At can be obtained as 130 K s-1. This is only an estimated value neglecting heat losses to the walls and to the gas but it indicates that fast heat during the start of the engine should be possible. This heating mechanism is certainly also useful in immobile applications and it demonstrates clearly that efficient heat management by internal resistance heating is possible in micro structured devices. 

Different types of membrane reactors for hydrogen production have been proposed in the literature. Most of the previous work has been performed in packed bed membrane reactors (PBMRs) however, there is an increasing interest in novel configurations such as fluidized bed membrane reactors (FBMRs) and membrane micro-reactors (MMRs), especially because better heat management and decreased mass transfer limitations can be obtained in these novel reactor configurations. 

We attempt here to describe the fundamental equations of fluid mechanics and heat transfer. The main emphasis, however, is on understanding the physical principles and on application of the theory to realistic problems. The state of the art in high-heat flux management schemes, pressure and temperature measurement, pressure drop and heat transfer in single-phase and two-phase micro-channels, design and fabrication of micro-channel heat sinks are discussed. 

Calame JP, Myers RE, Binari SC, Wood FN, Garven M (2007) Experimental investigation of micro-channel coolers for the high heat flux thermal management of GaN-on-SiC semiconductor devices. Int J Heat Mass Transfer 50 4767-4779 Celata GP, Cumo M, Zummo G (2004) Thermal-hydraulic characteristics of single- phase flow in capillary pipes. Exp Thermal Fluid Sci 28 87-95 Celata GP (2004). Heat transfer and fluid flow in micro-channels. Begell House, N.Y. 

Morini Gl, Lorenzini M, Salvigini S (2006) Friction characteristics of compressible gas flows in micro-tubes. Exp. Thermal and Fluid Science 30 733-744 Mudawar 1 (2001) Assessment of high-heat-flux thermal management schemes. IEEE CPT Trans 24 122-141... 

Water could additionally be injected via a third micro mixer in the ethanol/cata-lyst solution mixture [51], This served for heat transfer characterization, adjustment of temperature before reaction and most prominently dilution of the reaction mixture. By the last step, runaway situations occurring during the reaction can be managed. 

Utilized micro technology for reactor, heat exchanger, and fuel vaporizer to improve system efficiency through optimized thermal management and fluid dynamics. 

Baird E, Mohseni K (2008) Digitized heat transfer a new paradigm for thermal management of compact micro systems. IEEE Trans Compon Packag Technol 31(1) 143-151... 

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