Preparation Of KAPs-CF-PCM And Study Of Their Thermal Properties

With the increasing depletion of fossil energy sources worldwide,the importance of new energy vehicles is becoming increasingly prominent.The phase-change cooling passive thermal management system has been widely studied by scholars due to its simple structure,excellent temperature control performance and stable operation.In this paper,three super-crosslinked polymer materials were prepared using triphenylphosphine,triphenylbenzene and benzene as crosslinking units,and their microstructure,thermal stability and other thermal properties were tested and analysed.The super-cross-linked polymer/foam copper definite phase change materials were prepared using triphenylphosphine as the cross-linking unit,and their thermal stability,phase change properties and thermal storage and discharge properties were investigated.Using the high thermal conductivity and heat storage/exhaust capability of the composite material,it was prepared as a temperature control module for application in the field of passive battery thermal management,and the heat transfer characteristics of the composite phase change material were investigated.The conclusions of this paper are as follows.(1)Three different types of super-crosslinked polymeric materials,KAPs(1),KAPs(2)and KAPs(3),were explored and prepared using triphenylphosphine,triphenylbenzene and benzene as crosslinking monomers,dimethoxymethane as crosslinking agent and anhydrous ferric chloride as catalyst,respectively.The supercross-linked polymer composite phase change materials(KAPs-PCM)were also prepared by vacuum impregnation with paraffin wax.The results show that KAPs(1)exhibit a distinct porous structure and KAPs(1)has a specific surface area of 1079.1m2/g.KAPs(1),KAPs(2)and KAPs(3)have good chemical compatibility with paraffin wax.KAPs(1)has excellent thermal stability.(2)The super-crosslinked polymer/copper foam carrier(KAPs-CF)was prepared by liquid-phase deposition within the pores of copper foam using triphenylphosphine as the crosslinking unit,and the paraffin wax was compounded with the carrier by vacuum impregnation to finally prepare the super-crosslinked polymer/copper foam shaped phase change material(KAPs-CF-PCM).By investigating the effects of different pore densities and different reaction fluid concentrations on the final supercrosslinked polymer/copper foam carriers,the results showed that a 30 PPI copper foam and normal reaction concentration were the optimal solutions for the preparation of the carriers.Moreover,the phase change properties,encapsulation and thermal stability of the super-crosslinked polymer/copper foam shaped phase change material were tested.The results show that there is good chemical compatibility between the supercrosslinked polymer/copper foam carrier and paraffin wax,and the material has excellent mechanical properties.The material has a maximum enthalpy of 105.98 J/g,a cladding ratio of 62.1% and a thermal conductivity of 55.37 W/(m K),and is able to maintain good thermal cycling stability without significant leakage after 300 thermal cycles.Using the high thermal conductivity and thermal storage and discharge properties of the super-cross-linked polymer/copper foam composite,a photothermal conversion test rig and a photovoltaic conversion test rig of the super-cross-linked polymer/copper foam composite were designed and constructed.The results show that the photothermal conversion efficiency of the material reaches 93.8% and has excellent thermal response capability because of the copper foam thermal conductivity skeleton.A portable LED light source was prepared using the thermal storage properties of the material.(3)A temperature control module for power batteries was prepared using supercross-linked polymer/copper foam shaped phase change material as the base material,and the effect of the super-cross-linked polymer/copper foam shaped phase change material on the temperature control of power batteries at 1C,2C,2.5C and 3C discharge multipliers was explored on this basis,and the heat transfer characteristics of the composite material were further investigated.The results show that the composite phase change material can effectively control the average temperature of the battery.At 1C discharge multiplier,2C discharge multiplier,2.5C discharge multiplier and 3C discharge multiplier,the average temperature of the single cell decreased by 1.9°C,6.5°C,9.5°C and 13.4°C,i.e.by 5.74%,14.41%,18.30% and 22.64% respectively.And it can be seen that as the discharge rate increases,the average surface temperature of the battery gradually increases.The composite phase change material can effectively control the temperature uniformity of the battery,as can be seen from the test results,the maximum temperature difference of the single cell is reduced by 57.14% and the maximum standard deviation is reduced by 60% due to the use of the composite phase change material.This proves that the composite material has a certain influence on the improvement of the temperature uniformity of the battery.This thesis has 44 figures,12 tables and 82 references.