【作者】 刘涛；

【导师】 杨璐； 邢玉东；

【作者基本信息】 沈阳工业大学 ， 土木水利， 2023， 硕士

【摘要】 聚氨酯材料有良好的稳定性、抗腐蚀性和较低的导热系数,广泛应用于建筑、汽车、家电、航空等领域。随着聚氨酯的生产与消费,产生了大量的聚氨酯废弃物,目前主要通过焚烧掩埋处理,但会造成环境污染和资源浪费。因此,如何有效的处理固废聚氨酯已成为我国实现环境保护和可持续发展的重要问题。本文将固废聚氨酯经发泡处理得到一种新型保温材料:聚氨酯发泡颗粒,具有优良的保温隔热和防火性能。因此本文运用理论计算与数值模拟的方法对聚氨酯发泡颗粒保温板及其外墙外保温系统进行多方面研究,并对工程实际应用有指导意义。主要研究内容如下:(1)基于蒙特卡罗法,实现了保温板发泡颗粒的随机投放,运用Python语言进行自主编程,对聚氨酯发泡颗粒保温板进行二维细观模型建立,并验证了该模型的正确性。采用分步干涉判断算法,在已成功投放发泡颗粒区域中生成并投放圆形孔隙,建立了含圆形孔隙保温板的二维细观模型。(2)探究了聚氨酯发泡颗粒保温板的颗粒掺量、颗粒最大粒径、颗粒形状及颗粒级配对保温板导热系数及弹性模量的影响规律,并得出颗粒最优掺量、颗粒最优最大粒径及颗粒最优级配组合比。(3)将聚氨酯发泡颗粒保温板视为由发泡颗粒、胶凝料及孔隙组成的三相复合材料,基于最小热阻理论,根据保温板组成进行热流途径划分,建立聚氨酯发泡颗粒保温板等效导热系数计算模型。通过简化保温板等效弹性模量计算模型,引入影响因子J,建立保温板二阶等效弹性模量计算模型。(4)对聚氨酯发泡颗粒外墙外保温墙体进行热雨循环及热冷循环,得到其各结构层材料温度场,将温度场结果作为荷载导入到墙体模型中进行温度应力及变形的求解,得到该保温系统的薄弱部位。考虑结露危害,对有无外保温系统的T型节点热桥进行温度效应的有限元模拟,得出热桥节点在基层墙体与混凝土柱交接处易破坏,实际工程中应予以加强。更多还原

【Abstract】 Polyurethane materials have good stability,corrosion resistance and low thermal conductivity,and are widely used in construction,automobile,home appliances,aviation and other fields.With the production and consumption of polyurethane,a large amount of polyurethane waste is produced,which is currently mainly disposed of by incineration and burial,but it will cause environmental pollution and waste of resources.Therefore,how to effectively treat solid waste polyurethane has become an important issue to achieve environmental protection and sustainable development in China.In this thesis,the solid waste polyurethane is foamed to obtain a new type of thermal insulation material:polyurethane foam particles,which has excellent thermal insulation and fireproof performance.Therefore,this thesis uses theoretical calculations and numerical simulations to study various aspects of polyurethane foam particle insulation board and its exterior wall insulation system,and it is of guidance to the practical application of engineering.The main research contents are as follows:(1)Based on the Monte Carlo method,the random placement of insulation board foam particles was realized,and the two-dimensional mesoscopic model of polyurethane foam particle insulation board was established by using Python language for autonomous programming,and the correctness of the model was verified.Step-by-step interference judgment algorithm to generate and drop circular pores in the area where foamed particles have been successfully placed,and a two-dimensional mesoscopic model of the insulation board containing circular pores was established.(2)The influence law of particle content,particle maximum particle size,particle shape and particle grade on the thermal conductivity and elastic modulus of polyurethane foam particle insulation board was investigated,and the optimal particle dosing,optimal particle maximum particle size and optimal particle grade combination ratio were derived.(3)Considering the polyurethane foam particle insulation board as a three-phase composite material composed of foam particles,gelling material and pores,the equivalent thermal conductivity calculation model of polyurethane foam particle insulation board is established based on the minimum thermal resistance theory and heat flow path division according to the composition of the insulation board.By simplifying the calculation model of equivalent elastic modulus of insulation board and introducing the influence factor J,the second-order equivalent elastic modulus calculation model of insulation board is established.(4)Heat and rain cycle and heat and cold cycle are performed on the polyurethane foam particle external wall thermal insulation to obtain the temperature field of its materials of each structural layer,and the temperature field results are imported into the wall model as loads for the solution of temperature stress and deformation to obtain the weak parts of this insulation system.Considering the condensation hazard,finite element simulation of temperature effects on T-node thermal bridges with and without external insulation systems is conducted.It was found that the thermal bridge node is prone to damage at the junction of the base wall and the concrete column,and should be strengthened in practical engineering.更多还原