Application method of rigid foam insulation board
1. Determine the basic insulation structure type and protection measures
The sandwich and hollow type are suitable for the plate base with large upper load, and the laminated type is suitable for the plate base with smaller upper load. Multilayer applications are widely used.
There are currently two methods of protection: 1 vertical closed section; 2 horizontal protective section
Through practice test, it is considered that the horizontal protection section has a simple structure and convenient construction, so the horizontal protection section is generally selected.
2, determine the thickness of the insulation layer
At present, there are three methods for calculating the thickness of the insulation layer: the correlation analog method, the equivalent method, and the analytical method. These three methods, we believe that the thickness of the insulation layer calculated by the relevant comparison method is closer to the actual, so this method is used to calculate the thickness of the insulation layer. The calculation method of the correlation analogy method is introduced as follows:
Calculation formula:
RH=RiK=KR0FiF
Where: RH is the design thermal resistance value; R0 is the thermal insulation thermal resistance of the project to be built; Fi is the freezing index of the site to be built, °C·d, can be detected from the local weather station, the method is: from the first time When the negative temperature occurs, the substitution number is started and the negative temperature is added until the negative temperature is not present. The substitution number and the maximum value are both the freezing index; F is the typical freezing index, and the test field F0=18100 ° C·d.
R0=1α+δλ+sλs
Where: R is the thermal resistance; δ is the thickness of the concrete; s is the thickness of the thermal insulation material; λs is the thermal conductivity of the thermal insulation material, taking 0·034; λ is the thermal conductivity of the concrete, taking 1·3; α is the influence coefficient, Take 21.36.
Test field: R=121·36+0·051·3+0·10·034=3·026 m2/h·C/kW
The above value can be regarded as a constant, to calculate other unknowns, and R and F and the local Fi value are substituted into the formula to obtain the RH value, and then the S value of the insulation layer thickness is reversed according to the formula.
S=[RH-1α+δλ)]λs
Raohe County has a freezing index of 2 217 ° C·d. If the foundation is 50 cm deep, the insulation layer is 10 cm thick, which is equivalent to 1 cm. The thickness of the insulation layer can protect 15 cm. The soil layer is not frozen. According to the economic comparison, the basic foundation is 50 cm. ~1 m is more suitable.
3. Determination of the width of the insulation board
In order to prevent the freezing damage of the foundation cold bridge, the insulation board laying width must be greater than the foundation width. The width greater than the base is actually the length of the horizontal protection segment, and its value is:
L=(0·6-0·8)Hd
Where: Hd is the local maximum freezing depth.
Screw and Barrel for injection machine
Screw And Barrel For Injection Machine,Screw Barrel,Screw And Barrel,Barrel Screw
Zhoushan Jinsheng Bimetallic Plastic Machinery Factory , https://www.jinshenggalloy.com