Research And Development Of The Getter In VIPs For Marine Reefer Containers

Vacuum insulation panels(VIPs) are a kind of super heat insulation materials, which have the advantages of the lower thermal conductivity, thin thickness and light weight. In the marine reefer containers, the application of a new heat insulation material VIPs having good performance is an effective measure to reduce the container’s energy consumption by inserting the getter within the VIPs. In order to develop a suitable getter for marine environment,researches have been carried out in following aspects:(1) Analysis of the releasing gas of VIPs and the performance test of the getter provided by collaborator. Firstly, under the similar condition of the running environment of marine reefer containers, a Gas Chromatography-Mass Spectrometer was used for analyzing the compositions of the gas released from VIPs. Secondly, determination of the composition of the getter sample was realized by employing the INCA spectrometer(EDS) and scanning electron microscopy(SEM). Results show that the main ingredients of gas released from VIPs were1-dimethyl(3-propyl chloride) butyl oxygen silane(41.11%) and 1, 4-dioxane-2, 5-two methanol(21.83%), which were macromolecular alkane. Results also reveal that the getter components are56.21% Ca CO3, 56.21% Ca O and 42.56% Mg O. At 30℃, the equilibrium pressure below0.1MPa, the storage density of hydrogen is less than 0.2 wt%; the adsorption amount of water vapor on the sample is less than 2.21 mmol/g. The modifying the composition and optimizing the structure of getter sample should be carried out to adapt the performance requirements of reefer containers on board ships.(2) Analysis of adsorption equilibrium of water vapor on typical adsorbents. In order to improve the getter’s water vapor adsorption performance, simplified gravimetric method was introduced to measure the adsorption amount of water vapor on typical silica gel, carbon molecular sieve(CMS), and activated carbon under the saturation pressures of saturation water at 25℃. And then to measure the adsorption isotherm of water vapor on activated carbon SAC-02(in BET specific surface area about 1916m2/g), CMS, silica gel which have good water vapor absorption performance under the saturation pressures of ten different kinds of typical salt solutions at 10℃-30℃ respectively, the Clausius-Clapeyron equation and DA equation were selected to calculate the isosteric heat of adsorption of water vapor in the adsorbents. The experimental results show that at 10℃-30℃, the maximum adsorption amount of water vapor on activated carbon SAC-02 is 11.8 mmol/g, the isosteric heat of adsorption of water vapor is37.24-41.31 k J?mol-1, with average value 39.29 k J?mol-1. At 30℃, under the lower pressure(p/p0 is below 0.4), the adsorption amount of water vapor on activated carbon SAC-02 and CMS is lower than that of the silica gel. As the pressure rises to maximum, activated carbon SAC-02 will have the biggest adsorption amount of water vapor. So, activated carbon SAC-02 having higher specific surface area and meso porous volume is a good water vapor absorbent.(3)The composite getter in VIPs was developed experimentally. According to that main ingredients of gas released by the core material may crack into ethylene, propylene under thecondition of the running environment of marine reefer containers, the getter modification solution which uses activated carbon SAC-02 as carrier, modified with Cu(NO3)2 was chosen to develop a getter of adsorbing both water vapor and main ingredients of releasing gas. Test results showed that before modifying, the adsorption amount of ethylene, propylene was 9.8cc/g and10cc/g, and after modifying, the adsorption amount of ethylene, propylene was 46cc/g and48cc/g. But for hydrogen adsorption quantity, it didn’t change significantly. The activated carbon modified with Cu(NO3)2 has a better performance of adsorbing ethylene, propylene. A new type of getter which has a good performance of adsorbing water vapor, ethylene, propylene and hydrogen can be developed by using activated carbon SAC-02 as carrier, modified with Cu(NO3)2.Based on the experimental research, a technical solution is proposed for developing a new type of composite getter in VIPs which uses activated carbon as carrier, modified with Cu(NO3)2,and experimental verification is carried out, the foundation is made for application of VIPs for marine reefer containers.