Experiment Research On Performance Of Novel Silica Gel/Calcium Chloride Composite Adsorbents

Adsorption refrigeration is a kind of green refrigeration technology which can effectively utilize low grade energy as well as use environmental friendly refrigerant, it conforms to the trends of energy and environment in coordinated development. Employing waste heat of ship cylinder cooling water and exhaust gas to drive solid adsorption refrigeration can improve newly built ship’s ship energy efficiency design index (EEDI) as well as ship energy efficiency operation index (EEOI). However, low specific cooling power (SCP) limits adsorption refrigeration’s extensive application, development of adsorbents which have low generation temperature as well as high heat and mass transfer performance become an important task to solve this problem.Aiming at the present status, experimentally study of this thesis is carried out on silica gel/calcium chloride composite adsorbents in the following aspects:(1) For given conditions, adsorption amount changes within30minutes of A(2-3nm), B(4-7nm), C(8-10nm) type silica gels with different average pore sizes;(2) The influence of calcium chloride mass fraction on A, B, C type silica gel’s impregnating degree;(3) The influence of calcium chloride solution impregnation on A, B, C type silica gel’s adsorption performance;(4) The influence of calcium chloride solution impregnation on silica gel microscopic surface morphology;(5) Decaying cycle change of composite adsorbents which prepared by B type silica gel. Experimental results show that:(1) A, B, C type silica gel’s adsorption amounts all increase with adsorption time, for a give adsorption time, A type silica gel has the largest adsorption amount, C type takes the second place;(2) Within the same impregnation time, calcium chloride carrying rates all increases with calcium chloride solution mass fraction, for the same calcium chloride solution impregnation, A type silica gel’s calcium chloride carrying rate is relatively small, while for B type silica gel and C type silica gel, carrying rate is large;(3) Compared to pure A type silica gel, adsorption amounts of composite adsorbents prepared by A type silica gel dramatically reduce, while for composite adsorbents prepared by B type silica gel and C type silica gel, the adsorption amounts increase obviously, the increase amounts for B type are more significant, which shows that A type silica gel is not fit for modification by impregnation method, while B type silica gel and C type silica gel are suitable;(4) Surface roughness increase for composite adsorbents prepared by B type silica gel, concave-convex structures on the surface increase and become even, which benefit for its adsorption quality;(5) Even though adsorption amounts of composite adsorbents prepared by B type silica gel increase, its reusability performance doesn’t show good effects, after repeated use, composite adsorbent’s adsorption performance worsen greatly.The study of this thesis has reference value for silica gel/calcium chloride composite adsorbent’s application to design of actual adsorption refrigeration system.