Photovoltaic modules are a crucial component of power plant systems, bearing the heavy responsibility of providing a continuous and reliable output of clean electricity. Due to considerations of module quality, safety, and logistics costs, the industry has traditionally employed mature and efficient side-standing packaging. However, in recent years, with the continuous increase in module size, ultra-large modules exceeding 1.3 meters in width can no longer be accommodated in two rows of side-standing packages within mainstream 40-foot high cube shipping containers. Therefore, ultra-large modules have had to find alternative solutions, attempting to use vertical or horizontal placement methods.
However, has this "novel" placement method, which challenges the common sense of physics, truly solved the problem? Without adequately considering the safety of component transportation, such an operation is somewhat like burying one's head in the sand. What are the risks of vertical packaging of components? We will analyze this for you using basic physics and mechanics.
1. Increased kinetic energy from component tipping increases the risk of workers being injured.
It is well known that the higher an object's center of gravity, the greater the risk of it tipping over. Because the oversized modules are vertically packaged, with a single module reaching a staggering 2.4 meters in height, their physical center of gravity is nearly twice as high as that of traditional side-mounted modules. Furthermore, the weight exceeding 35 kg more than doubles the module's tipping kinetic energy, exponentially increasing the risk of worker injury. In the event of an accident, both the EPC contractor and the owner will face enormous trouble and unpredictable consequences.
II. The use of supporting steel frames is complex and subject to numerous limitations.
Recognizing the significant risks involved in disassembling components on-site, the oversized components had to be fitted with supporting steel frames to maintain system stability. This highlights the fact that inherent design flaws can only be compensated for by "external equipment." However, the use of supporting steel frames is not without its limitations and faces numerous constraints.
As shown in the diagram above, taking an initial tilt angle of 75° as an example, the weight of the super-large component is 38.5 kg. If 31 components are used in a single haul, the total pressure value of the single haul component is:
G = 38.5 X 31 X 9.8 = 11696.3N
The vertical pressure exerted by the single-spindle assembly on the inclined surface of the bracket is:
F = GX cos75° = 3027N
If the coefficient of friction between the support frame and the sand is taken as 0.4, then according to the horizontal force balance relationship:
Fmax = (M_bracket x 9.8 + FX cos75°) x 0.4 ≥ F1
Calculations show that the support needs a counterweight greater than 666 kg to prevent slippage. Similarly, the required counterweight for the support at different tilt angles can be deduced; the smaller the tilt angle of the component, the greater the required counterweight, which may even exceed a staggering 1 ton.
On the other hand, when the back of the module is subjected to wind pressure, the minimum number of modules on the tray must also be considered. According to the torque balance relationship M1=M2, calculations show that if the number of modules is less than 10 and the tilt angle is 85°, the modules will be blown away in a level 5 gale. Therefore, under many constraints, this solution is basically not applicable on the project site.
From a scientific perspective, simplicity often indicates a more optimized and complete methodology, while complexity often reflects design flaws and only adds unnecessary complications. No matter how elaborate the design, if the operational complexity and risk are excessive, this perfectly illustrates the reality of new vertical packaging for oversized components.
Overall, the solution of anti-tipping brackets for ultra-large components is difficult to implement. Under certain wind conditions, the components are at risk of tipping over and may injure operators. Therefore, it cannot be considered a mature solution for unpacking and placing vertically placed components on site.
According to professional EPC personnel, the more convenient the project construction, the better. Overly complex construction plans not only delay project progress but also, when projects are rushed, workers' negligence in operating procedures and inadequate component securing can lead to components being blown away in strong winds, causing serious economic losses. Therefore, new vertical packaging solutions for oversized components carry significant risks, and investors should choose them with caution.
The initial choice of dual-core diodes for ultra-large modules proved to be a mistake (recently, with the development of single-core diodes, the risk of uneven current distribution in dual-core diodes was recognized). Now, the proposed use of an extremely immature vertical packaging solution, disregarding various risks, raises serious questions. (4590 reads)
