Fundamental Studies on Passive-Type Heat Transfer Enhancement of Solid Reaction Bed

本研究致力于开发有效的方法来提高吸附或化学反应过程中固体颗粒床内的导热速率，这被认为是实现吸附和化学热泵的最主要问题之一。(1)为了将被动式强化换热技术应用于固体反应物床，采用平板比较法测量了不同金属种类和形状的氧化钙颗粒床的有效导热系数。实验结果表明，含铜翅片的高密度氧化钙复合材料具有较大的导热系数。(2)在…的硅胶柱中加入铜丝网，研究了热泵装置中固相床在吸附或化学反应过程中的特性更多的是一种吸附热泵，并将金属翅片和蜂窝材料置于氧化钙床中的一种化学热泵装置中。验证了采用本文提出的强化传热方法后，吸附热泵和化学热泵的换热性能均有较大的改善。(3)建立了考虑强化传热的固体颗粒床内伴随放热化学反应的传热传质数学模型，并将其应用于含金属翅片的氧化钙床中。利用理论模型对实验结果进行了较好的解释，并对其传热机理和强化换热效果进行了探讨。(4)设计制造了加热器/换热管一体化结构的高效换热器，以便于反应热从固体颗粒床中排出/提供给固体颗粒床。该装置在化学热泵机组上的应用正在进行中。较少

The Present research is concerned with the study on the development of efficient methods in enhancing the heat conduction rate in the solid particle bed in the process of adsorption or chemical reaction, which is deemed one of the most principal problem in realizing adsorption and chemical heat pumps. The results obtained in the last fiscal years of 1988 and 1989 are summarized below:(1)In order to apply the passive-type heat transfer enhancement technique to the solid reactant bed, effective thermal conductivities of calcium oxide particle beds into which various kinds and shapes of metals were inserted, were measured by a plate comparative method. As a result of the measurements, it was recognized that a high-density composite of calcium oxide involving copper fins shows a larger thermal conductivity value.(2)The characteristics of the solid bed in the process of adsorption or chemical reaction in the heat pump unit were investigated by adding copper wire mesh to silica gel column in … More an adsorption heat pump, and metal fins and honeycombs to calcium oxide bed in a chemical heat pump apparatus. Then, it was verified that the heat transfer performance of both the adsorption and the chemical heat pumps were greatly improved by adopting the present heat transfer enhancement method.(3)Mathematical model representing both heat and mass transfer accompanied by exothemic chemical reaction in the solid particle bed which the heat transfer enhancement is taken into; consideration was developed and was applied to calcium oxide bed involving metal fins. With the aid of the theoretical model, the experimental results were explained well, and the heat transfer mechanism as well as the heat transfer enhancement effect were examined.(4)High-efficiency heat exchanger having an unified structure of heater/heat exchanging tube was designed and manufactured, so as to facilitate the removal/supply of reaction heat from/to the solid particle bed. The application of this device to the chemical heat pump unit is now in progress. Less