Study On Heat Transfer Performance Of New Type Of Concrete Block Wall Filling With Compressed Blocks Of Wheat Straw

Today,the energy sources in the world is rigorous,and the building energy conservation is still the focus around the world.Among many kinds of energy conservation technologies,the system of self-insulation wall is focused on and used widely,because of its many advantages.Especially in our country,it’s developed quickly,and lots of scholars and research institutions have got an abundance of theoretical research achievements and practical applications.The heat transfer performance of the walls which is built of the four new types of concrete hollow blocks(the basic type concrete block,the half-angle type concrete block,the template concrete block of horizontal structure zone and the angle concrete block),the compressed blocks of wheat straw and the glazed hollow beads-wheat straw insulation mortar were tesed by experiments and also they were researched by numerical simulation.According to the result of the research,some points were got.The variation of heat transfer coefficient curves with time and the average heat transfer coefficients of the experimental walls were got by the cold&hot box-heat flow meter method in experiment.And the variation of temperature curves of the walls’ typical positions were got by distributing a quantity of temperature sensors in the walls.The result shows that the thermal resistance of the concrete hollow block can be improved by decreasing the quantity of the thermal bridges and at the same extending the length of each one.The heat-preservation property of the wall can be cut down by the inner core column.It’s of great use for the improvement of the concrete block and the wall to fill the the compressed block of wheat straw or the EPS board into it.But the compressed block of wheat straw can improve the stability of the thermal resistance much better than the EPS board.So according to the result,the conclusion was got that within a certain range, the thermal insulation material filled ioto the concrete hollow block which has much less porosity can improve the stability of the thermal resistance of the wall much better.The use of the insulation mortar can improve the wall’s heat-preservation property obviously,but it’s of some disadvantageous effect on the stability of the thermal resistance,because it has amount of pores.The one-dimensional steady-state thermal transmission courses of the walls which were filled with the compressed blocks of wheat straw were simulated by ANSYS software, then got and analyzed the nodal temperature and the thermal flux vector of these walls.The result shows that filling the compressed blocks of wheat straw into the concrete hollow block can prevent the heat-transfer,but also increase the heat in some rib-walls of the concrete block and strengthen the thermal bridge effect. The insulation mortar can not only reduce the heat in the compressed blocks of wheat straw,but also can decrease the heat in the rib-walls,so the use of it can weaken the concrete block’s thermal bridge effect.The template concrete block of horizontal structure zone and the angle concrete block can weaken the thermal bridge effect of the ring beam and the core column through the advantage of their structure,and also can provide templates for pouring.They can improve the heat-preservation property of the wall,and at the same time improve the efficiency of the wall’s building.As to the wall of common masonry structure,the Self-insulation structural wall with inner frame has much better heat-preservation property and mechanical behavior,and also it has simple construction technique and quick building.So it can reduce lots of the construction cost.The development of the compressed block of wheat straw and the insulation mortar expand the use range of the crop straw to the construction materials area better,therefore provide an economic and environmentally protective way for its rational use.