1、standard of execution

AAMA 501.5-2007 Test Method For Thermal Cycling Of Exterior Walls

JG/T 397-2012  Test method for thermal cycling of curtain walls

2、Main technical index

Thermal cycle testing equipment:

outdoor temperature control accuracy: +82±3℃ -18±3℃;

Rising and cooling speed: 50℃/h;

Indoor temperature control accuracy: +24±3℃;

Temperature measurement system：

Pt100/ Pt1000 platinum resistance temperature; XSLE/ -64s2 multi-point circuit detector;

Polyurethane double-sided color steel insulation box：

Box volume: 6000×8000×1500mm；Thickness of insulation board: 150m; Bulk density: 40kg/m3;

Thermal conductivity: 0.033w /(m·k);Insulation area outside the box: 6×8+28×2=104m2;

Experimental area: 6×8=48m2; The heat transfer coefficient of curtain wall glass is 1.5w /(m2·k);

3、Testing process

In order to accurately reproduce the specified figure in the standard in the thermal cycle detection, a complete thermal cycle process is decomposed into 2 stages and 7 steps, which are defined as high temperature program and low temperature program respectively.

1）Preparation stage: the indoor equipment starts to work normally, and the outdoor equipment enters the preheating state (preheating to 24℃), when the indoor control temperature reaches 24℃±3℃ and is kept for one hour. Outdoor began to warm, theoretically speaking, the outdoor incubator should also start from 24℃.

2）High temperature heating stage: the indoor equipment works normally and is kept at 24℃±3℃. When the outdoor heating system starts to work, the heating in this section should also be required in the control procedure, otherwise the temperature fluctuates violently in the heating process and cannot be controlled.

3）High temperature maintenance stage: the indoor equipment works normally and is kept at 24℃±3℃. The temperature of the outdoor incubator is kept at 82℃±3℃.

4）High temperature cooling stage: the indoor equipment works normally and is kept at 24℃±3℃. The outdoor incubator began to cool from the high temperature. Drop temperature from 82℃ to 24℃ within 1 hour as required by the standard.

5）Low temperature cooling stage: the indoor equipment works normally and is kept at 24℃±3℃. The outdoor incubator began to cool from a low temperature. Reduce temperature from 24℃ to -18℃ within 1 hour as required by the standard.

6）Low temperature maintenance stage: the indoor equipment works normally and is kept at 24℃±3℃. The outdoor incubator starts to keep low temperature. Keep the temperature at -18℃±3℃ for 2 hours.

7）Low temperature heating stage: the indoor equipment works normally and is kept at 24℃±3℃. The outdoor insulated box starts from low temperature heating and reaches 24℃ within 1 hour.

AAMA501.5-98 the thermal cycle testing technology to provide the thermal cycle of cool up the whole process of 3, 6 need to have auxiliary adjustment of freezing and thawing, and the slight adjustment, do not need to use energy, and test the scene of the air temperature is below/above control temperature in the incubator, using the natural wind can be qualified for this job. 4, 7. In the stage of high temperature cooling (low temperature heating), it can also be solved by using the natural forced ventilation in the test site. Under the control of the control system, the natural air ventilation system is firstly started to directly replace the heat/cold air in the box to the outside of the box. When the temperature drops to close to or equal to the ambient temperature, start the cooling/electric heater power system to work to meet the requirements of relay cooling and heating, which is designed to meet our original intention. The design principles of practicality and economy are realized at the same time.
The two fans are installed on the top and bottom of the box respectively, and it is stipulated that the two fans work in the opposite way, one is for air supply, the other is for air exhaust, and the other is for air exhaust when the temperature is down, and the other is for air exhaust when the temperature is up.Site and power requirements are designed according to the size of the test piece。