Solar laminators are essential equipment for every solar cell module manufacturer. With the development of the solar photovoltaic industry, reducing equipment investment and operating costs has become a crucial issue that every manufacturer must address. The cost of using the laminator accounts for a significant portion of the module cost, and research into reducing the input costs of the lamination process has been put on the agenda. Thermal storage laminators represent a future trend in cost reduction.
I. Introduction to the Principle of Solar Photovoltaic Laminators
The principle of a solar photovoltaic laminator is to apply pressure to the surface of each layer of material in the module, and then press these materials together tightly while heated. It typically consists of four main systems: a heating system, a vacuum system, a pneumatic system, and a control system.
II. Analysis of the Use of Solar Photovoltaic Modules
The costs in the laminator production process mainly include equipment purchase costs, water, electricity, gas, labor, daily maintenance costs, and daily consumables (silicone sheets and heat transfer oil, vacuum pump components).
Equipment procurement costs are a one-time investment, which are then gradually transferred to the finished components, also known as equipment depreciation cost transfer.
Water, electricity, and gas costs: Currently, the mainstream laminators in China use hot oil heating. Taking a single-layer, single-cavity laminator as an example, the basic rated power of the laminator is 70KW. Combined with the power of the vacuum pump, the overall power of a laminator is 80KW, but the actual operating power averages 45KW. Due to varying electricity prices in different regions, we calculate at 0.8 yuan/kWh, 45*0.8=36 yuan. The laminator consumes approximately 100L/minute of air, and the cost of compressed air per cubic meter is approximately 0.2 yuan. Thus, the hourly air consumption is 6000L, approximately 6 cubic meters, totaling 6*0.2=1.2 yuan. The total water, electricity, and gas costs are 36+1.2=37.2 yuan/hour. Calculated at 3.3 cycles per hour, 37.2/(4*3.3)=2.82 yuan/unit, 2.82/300w=0.094 yuan/W, and the water and electricity cost per watt of component is 0.9 fen.
Equipment maintenance costs. Based on our actual usage experience, taking an oil-heated laminator as an example, the spare parts that are prone to failure on laminators mainly include the 24V power supply, three-phase solid-state relays, photoelectric sensors, chains, and valves. Due to the frequent on/off cycles of heating, solid-state relays are most prone to failure, and spare parts must be kept on hand. Various valves, especially pneumatic valves, are present on the laminator and are crucial to its quality. These parts must be safe and reliable. Domestically produced valves are prone to failure, so imported pneumatic valves are often used. Due to the limited manufacturing capabilities of domestic laminators and insufficient process precision, chains frequently experience wear during actual use, leading to equipment downtime. The exact reasons why photoelectric sensors and 24V power supplies are considered easily damaged spare parts are not yet clear, but they are likely related to the installation environment. Failures of these spare parts are somewhat random; having a few spare parts on hand is sufficient.
III. Proposed Development Direction of Laminators
In response to the needs of component manufacturers, the current development trend of laminator equipment manufacturers is mainly towards double-layer, multi-layer, dual-cavity double-layer laminators, and regenerative laminators.
Comparison between single-layer and multi-layer laminators.
Currently, the most mature laminators on the market are double-layer laminators and ten-layer laminators. The power consumption of double-layer laminators and ten-layer laminators is similar, but the output of ten-layer laminators is much higher. However, the control system of ten-layer laminators is very complex, and the failure rate is correspondingly dozens of times higher. Therefore, the overall evaluation result is that ten-layer laminators are not as practical as double-layer laminators, but multi-layer laminators are a trend.
Comparison between single-chamber laminators and multi-chamber laminators.
The dual-chamber laminator halved the original process. The two chambers are connected in series, simplifying functionality and reducing the failure rate compared to a single-chamber laminator. Although the equipment investment increased somewhat, the 50% increase in production capacity made it worthwhile.
Comparison of oil-heated and electric-heated laminators.
The biggest advantage of oil-heated laminators over electric-heated laminators is their stable and uniform heating, while electric-heated laminators offer faster temperature response and are more environmentally friendly and safer. However, with advancements in temperature control and heating technology, electric laminators are likely to be reintroduced.
Comparison of regenerative laminators and conventional laminators.
Electricity costs are a major expense in the lamination process, so reducing electricity consumption or saving on electricity bills is the primary goal for cost reduction. Conventional laminators consume electricity directly, meaning that electricity and heat are consumed immediately, with heat consumption and electricity usage corresponding instantly.
A thermal regenerative laminator is a type of laminator whose heat consumption and electricity usage can be controlled and managed in a staggered manner. It is a type of laminator that can actively manage the timing of electricity consumption.
Here, we first need to understand some of our country's power regulation policies. Peak-valley pricing is a power price reform measure in my country. By significantly reducing nighttime electricity prices, it encourages residents to use electricity at different times of the day, thereby alleviating peak electricity demand and ensuring the safety of the urban power grid. Implementing peak-valley pricing divides daily electricity consumption into two periods: 10 PM to 7 AM (or 9 PM to 6 AM) is the "valley" period, and daytime is the "peak" period. By significantly reducing nighttime electricity prices and appropriately increasing daytime prices, it encourages residents to use electricity at night. In November 2010, six ministries, including the National Development and Reform Commission and the State Electricity Regulatory Commission, jointly issued the "Measures for Electricity Demand-Side Management," which proposed sixteen qualitative or quantitative management and incentive measures for the electricity demand side, including "promoting and improving the peak-valley pricing system and encouraging off-peak energy storage," etc. The "Measures" came into effect on January 1, 2011.
Taking full advantage of off-peak electricity prices at night to store heat for use during peak or off-peak hours is an effective way to save on electricity bills. Using the peak-valley electricity price difference in Jiangsu Province as a reference, savings of over 0.5 yuan per kilowatt-hour can be achieved.
Hebei Chuangshi New Material Technology Co., Ltd. produces phase change heat storage devices, which are application devices of phase change composite new materials. They can be directly applied to existing laminators or integrated to replace the original laminator heating system. This allows for heat storage during off-peak hours and utilization during peak hours, helping owners proactively save on electricity bills. Although heat storage laminators increase initial investment, the overall savings are substantial.
Conclusion: Under the societal requirement for enterprises to conserve energy and reduce consumption, appropriately increasing the use of multi-layer laminators can improve energy efficiency and reduce component costs. Multi-layer laminators and dual-cavity dual-layer laminators represent future development directions, and the heating method for laminators will gradually shift from oil heating to electric heating. With the development of thermal energy storage technology, thermal storage multi-layer multi-cavity laminators will become the future trend.
