# Model Experimental Study on De-Icing Method of Bridge Pylon Beam Based on Electric Heating
## 2 Model Test Design
### Test System and Working Relationships  
The model profiles for the icing and de-icing tests in this study are shown in Figure 3a; the working relationship between the test systems and the equipment is shown in Figure 3b. Figure 3: \(Cont.\)  
Figure 2: Technical route. The beam model for the experiment was a rectangular beam with a 0.5 m high support placed at the bottom to support the beam. Three nozzles were arranged above the beam at a 1.7 m distance as rainfall outlets and were connected to the external chiller through a water pipe. The chiller could reduce the water temperature to 0.5-1.5 \({}^{\circ}\)C. The above model and equipment were placed in the cold chamber, which was used to simulate the low temperature environment. Five systems were used in the experiment: a spray system was used to simulate rainfall; a wind delivery system was used to provide wind; a heating system was used for the de-icing; a monitoring system was used to observe and record the test situations; and a data acquisition system was used to monitor and record the temperature changes. The details of each test system and the equipment are as follows:  
1. The spray system
2. The spray system is composed of a chiller and nozzles. The chiller is an air-cooled low-temperature chiller. The main function is to lower the temperature of the water to 0.5-1.5 \({}^{\circ}\)C and to speed up the icing process in a manner as close as possible to that of the practical situation. The nozzles are air atomization nozzles with an outlet diameter of 0.5 mm; the main function is to reduce the particle size of the raindrops to a certain extent, thus speeding up the condensation rate of the raindrops and making the icing easier. The number of nozzles is 3, each with a spacing of 0.5 m and a height of 1.7 m above the beam. 3. The wind delivery system
4. The wind delivery system is composed of a fan and a regulator. The fan is an axial fan with a power of 2 kW, a rated voltage of 380 V, an air volume of 18,700 m\({}^{3}\)/h, an air supply diameter of 610 mm, and a maximum wind velocity of 8 m/s. The main function is to simulate the wind condition. The regulator is a three-phase regulator, model TSGC2-3 KVA, and by connecting in a series with the axial fan, the voltage of the fan can be changed, thus changing the wind velocity. The icicles tilted inward after the wind was applied; thus, it was difficult to obtain good observations and photographs as the line of sight was blocked by the supports of the beam. Therefore, in order to better observe the tilt of the icicles after the wind was applied, the icing surface of the beam and the wind direction in the icing test were set as shown in Figure 4. An anemometer was used to measure the wind velocity in the range of 0.6-60 m/s, with an accuracy of \(\pm\)3%. 3. The heating system
4. The heating system is composed of a stainless steel module, heat-insulated film, a carbon fiber heating cable (CFHC), and an external power supply. The main function is to generate heat to prevent the beam from icing. 35. (4) The monitor system  
The monitoring system is composed of cameras and video recorders. The main function is to monitor and record the test situation in real time for better analysis of the test process. (5) The data acquisition system  
The data acquisition system is composed of thermocouples and a data collector. The thermocouple is a K-type, and the temperature measurement range is from \(-\)50 \({}^{\circ}\)C to \(+\)160 \({}^{\circ}\)C. The data collector can detect and record the temperature change in real time by connecting with the thermocouple.