| With the emergence of the energy and resource crisis, the significance of energy saving, low carbon and green architecture in national economy, it gets more and more attention. Engineering practice shows that the thermal insulation of wall and window, which is the key to achieve building energy efficiency, and the development of wall materials, which is also the basis for the realization of building energy efficiency. So along with the national wall change policy implementation, different types of new wall materials appeared on the market, among them, the hollow brick have been very widely used. Through setting the air layer and introducing micro-porous in the bricks, that can effectively improve the characteristics of thermal performance. However, hollow bricks'groove design is not very reasonable, and lack of micro-porous research. The following analysis is the view of above questions:First, considering hole pattern, hole diameter ratio, holes rate, hole row number and column number, arrangement, etc, and these holes structure on the characteristics of the thermal performance impact, Simulation results show that rectangular hole has the better thermal insulation performance, and as rectangular hole length-width ratio increases, the heat preservation effect is better; increasing holes row and column number, holes rate and pore rib extension cord coefficient, the thermal conductivity of hollow bricks can be improved. the market energy-saving hollow bricks 190mm×200mm×240mm ,its thermal conductivity of simulation analysis is 0.258 W/(m·K), the actual measurement value is 0.248 W/(m·K), the relative error is about 3.6%; through the optimized design, its thermal conductivity of simulation analysis is 0.236 W/(m·K), compared with the market energy-saving hollow bricks, thethermal conductivity reduce about 8.5%.In chapter 4, based on analyzing sawdust, coal gangue and paper mill sludge basic physical property, chemical composition and pyrolysis characteristics, separately as different dosage mixed with shale, after aging, molding, dry and sintering, get the finished, through mixture plasticity index, the density and compressive strength index of the finished to analyze the reasonable dosage of pore-forming agent in producing micro-porous shale hollow bricks.Test analysis shows as follows: pore-forming agents combustion tend to occur in 200 ~ 600℃, therefore, during the sintering process, too fast heating rate is unfavorable, make pore-forming agents burning full so as to promote firing response; with the sawdust and coal gangue content increased, the plasticity index of mixture appears decreasing trend, while the paper mill sludge can improve the formability of mixture; Secondly, when the admixture proportion of sawdust is 9%, the density is reduced to 1166 Kg/m~3, thermal conductivity reaches 0.48W/(m·K); coal gangue admixture proportion is 60%, the density is reduced to 1457Kg/m~3, thermal conductivity reaches 0.62 W/(m·K); when the admixture proportion of paper mill sludge is 11%, density is reduced to 1284Kg/m~3, thermal conductivity reaches 0.54 W/(m·K). Combined with the requirements of production process and mechanical properties, the appropriate dosage of pore-forming agents in the production as follows: sawdust dosage≤5%, paper mill sludge dosage≤9%, under the premise of ensuring the plasticity and heating value of mixture, the dosage of coal gangue is as maximum as possible, to save coal. Finally, By using X-ray diffraction to analyze the phase composition of fired brick, whose ingredients contain sawdust 3%, coal gangue 60% and paper mill sludge 7%, the result showed that after 950℃firing reaction the main phase composition are quartz, mullite and feldspar, etc.In chapter 5, using optimized brick type, reasonable shale and coal gangue dosage, through the production sintering experiment, we get the energy-saving shale hollow brick, its strength meet GB13545-2003 standards for compressive strength MU2.5 and density is as low as 700Kg/m~3.
|
PDF Full Text Request