Project Background: Rigid Demand for Temperature Control in Jiangsu's Photovoltaic Industry Base

As the global photovoltaic (PV) industry develops towards higher efficiency and scale, Jiangsu, as a core domestic hub for PV manufacturing, brings together numerous manufacturers of silicon wafers, solar cells, and modules. The PV panel manufacturing process (including silicon wafer cutting, cleaning and texturing, PECVD coating, screen printing, and module encapsulation) has stringent requirements for environmental temperature, humidity, and process equipment temperature control. A temperature fluctuation exceeding ±1°C will directly affect solar cell conversion efficiency, module lifespan, and product consistency. Localized overheating is even more likely to cause production hazards such as silicon wafer fragmentation and coating delamination.

To meet the core needs of a large-scale solar PV panel factory for 24-hour continuous production, high-precision temperature control, and energy-saving, stable operation, OYRR customized a comprehensive solution featuring multi-specification falling film water-cooled screw chillers (100RT/200RT/300RT) alongside a fully integrated chiller plant room. With a total cooling capacity of 3000kW, this solution covers full-scenario temperature control for production workshops, core process equipment, and testing laboratories, facilitating the efficient implementation of the Jiangsu project.

II. Core Cooling Requirements of Solar PV Panel Manufacturing Processes

1.  High-Precision Temperature Control

•        Silicon Wafer Cutting / Cleaning: 23±1°C, preventing wafer fragmentation caused by thermal expansion and contraction, thus ensuring cutting precision.

•        PECVD Coating: 20±0.5°C in a low-humidity environment (Relative Humidity ≤45%), ensuring the uniformity and adhesion of the coating layer.

•        Module Encapsulation: 25±2°C, stabilizing the cross-linking reaction of the EVA film to enhance the sealing performance of the module.

2. Customized Cooling Capacity Output

The total cooling capacity requirement of the project is precisely matched at 3000kW. A combination of multi-specification chillers is required to adapt to the differentiated heat loads across various production stages (such as high-load heat dissipation for coating equipment and low-load constant temperature for testing labs). It also ensures continuous, uninterrupted cooling to accommodate the factory's three-shift production model.

3. Energy Efficiency, Safety, and Reliability

•        Jiangsu features high temperatures and high humidity in summer, and mild winters. The system must adapt to environmental conditions ranging from -10°C to 40°C.

•        The System Coefficient of Performance (COP) must be ≥5.6, reducing the factory's air conditioning energy consumption by 30%-40%.

•        Anti-condensation, anti-corrosion, and electrical insulation protections are required to completely eliminate the risks of short circuits in production equipment and process contamination.

III. OYRR's Multi-Specification Falling Film Water-Cooled Screw Chiller Solution

Core Advantages (Exclusive to Falling Film Technology)

•        High Efficiency & Energy Saving: Utilizing falling film evaporators, the heat exchange efficiency increases by 30% compared to traditional dry-type evaporators. The entire system's COP reaches 6.0, saving over 25% energy compared to standard screw chillers.

•        Precise Temperature Control: Temperature control accuracy is within ±0.3°C, with a load adjustment range of 8%-100%, adapting to dynamic heat load fluctuations across different process stages (e.g., sudden heat load changes caused by the starting and stopping of coating equipment).

•        Environmental Adaptability: Heat exchangers are designed with stainless steel and anti-corrosion coatings, withstanding Jiangsu's humid and high-salt-spray environments to extend the equipment's service life to over 15 years.

4. Integrated Chiller Plant Room Design (Exclusive to Jiangsu Project)

（1）Plant Room Layout and Structure

•        Area: An approximately 600m² dedicated refrigeration plant room accommodating the installation of 4 multi-specification chillers, cooling towers, water pumps, water tanks, power distribution cabinets, and control systems.

•        Load-bearing Capacity: Floor load-bearing capacity ≥2.0t/m². Independent reinforced foundations are established for the 300RT large chillers to accommodate equipment loads.

•        Ventilation and Noise Reduction: Utilizing soundproof panel enclosures combined with silencing devices (operating noise ≤65dB), alongside a combination of mechanical exhaust and natural ventilation, to ensure plant room heat dissipation efficiency and prevent noise from affecting production workshops.

（2）System Architecture: Zoned Control and Intelligent Linkage

•        Main Refrigeration System: 4 chillers provide cooling to specific zones. The core process area (PECVD coating / encapsulation) is equipped with a 300RT primary chiller, while auxiliary areas are paired with 100RT smaller chillers. Featuring an N+1 redundancy design (reserving an emergency switch interface for 1 chiller), a single unit failure will not disrupt the cooling supply to its respective zone.

•        Circulating Water System: 12 variable-frequency water pumps (6 duty, 6 standby), constant pressure make-up water devices, and fully automatic water softeners ensure circulating water quality meets standards (conductivity ≤500μS/cm) and water pressure remains stable, preventing scale from affecting heat exchanger efficiency.

•        Cooling Tower System: 3 cross-flow, low-noise cooling towers (one for each 300RT/200RT chiller, and one shared by the two 100RT chillers) provide full-load forced heat dissipation in summer and switch to a natural cooling mode in winter, improving the energy saving rate by 40%.

•        Thermal Storage System: Equipped with chilled water storage tanks, leveraging Jiangsu's peak-to-valley electricity price differences (valley period rate is 0.35 RMB/kWh). Cooling is stored during off-peak night hours and released during peak daytime hours, generating significant annual electricity cost savings.

3）Intelligent Control System

•        Central PLC + industrial touch screen monitors real-time operating parameters of each chiller (temperature, pressure, flow rate, energy consumption) and environmental data of the process areas.

•        Seamlessly integrates with the factory's MES (Manufacturing Execution System), enabling AI-powered intelligent cooling distribution. Chiller operating statuses are dynamically adjusted based on the production load of each workshop (e.g., the number of operating coating machines).

•        Supports remote monitoring (mobile/PC), early fault warnings (SMS/APP push notifications), and automatic switching to standby equipment, achieving unattended operation and maintenance, thereby reducing O&M costs by 50%.

IV. Implementation Value of the Solution in the Jiangsu Project

1.  Energy Saving and Cost Reduction:

•        The system's comprehensive COP reaches 6.0. Compared to traditional cooling solutions, it saves 1.3 million kWh of electricity annually and reduces carbon emissions by 1,040 tons, meeting the green production requirements of the PV industry.

•        The combination of thermal storage and winter natural cooling achieves an annual comprehensive energy saving rate of 35%, shortening the ROI (Return on Investment) cycle to 3.5 years.

•        Falling film technology paired with maintenance-free heat exchangers brings annual maintenance costs down to just 80,000 RMB, which is 45% lower than the industry average.

2. Safety and Reliability: Forging a Solid Defense for PV Production Safety

•        Triple protections—a closed-loop circulation system, leak detection, and insulating coolant—eliminate electrical safety risks and silicon wafer contamination.

•        Multi-level temperature protection (automatic shutdown upon over-temperature), anti-condensation design, and emergency pressure relief devices provide an all-around defense against production equipment damage and process defects.

•        The continuous trouble-free running time of the chillers is ≥9,000 hours, ensuring the factory's 24-hour uninterrupted production and reducing production interruption losses by 90%.