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

研究如何提高吸附或化学反应过程中固体颗粒床的热传导率，是实现吸附和化学热泵最主要的问题之一。(1)为了将被动式强化传热技术应用于固体反应物床，采用平板比较法测量了插入不同种类和形状的金属的氧化钙颗粒床的有效导热系数。测量结果表明，含有铜翅片的高密度氧化钙复合材料显示出更大的导热系数。(2)通过在吸附式热泵硅胶柱上增加铜丝网，在化学热泵装置氧化钙床上增加金属翅片和蜂巢状结构，研究了固体床在吸附或化学反应过程中的特性。通过实验验证，采用本文提出的强化传热方法，吸附热泵和化学热泵的传热性能都得到了很大的提高。(3)考虑强化传热作用的固体颗粒床内传热传质同时伴有放热化学反应的数学模型；对含金属翅片的氧化钙床层进行了研究和应用。在理论模型的帮助下，对实验结果进行了较好的解释，并对传热机理和强化传热效果进行了检验。(4)设计制造了加热器/换热管统一结构的高效换热器，便于从固体颗粒床排出/供给反应热。该装置在化工热泵机组上的应用目前正在进行中。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