Fab Purification Workshop Renovation Project of a Large Semiconductor Chip Manufacturing Plant.
1. Original equipment: There are a total of 2000 AC FFUs (AC-FFUs) in the workshop, with a rated power of 350W per unit, using tap speed regulation, and operating at high speed all year round (actual power consumption is close to the rated power).
2. Facing problems:
2.1 Huge energy consumption: 2000 AC-FFUs operate 24 hours a day without interruption, with extremely high annual electricity consumption, making electricity costs a heavy burden.
2.2 Extensive control: unable to accurately adjust the air volume according to actual environmental needs, can only be fixed at high wind speeds, resulting in huge energy waste.
2.3 Fluctuations in Cleanliness: Fluctuations in grid voltage and increased filter resistance can lead to unstable wind speeds, affecting the uniformity and stability of the clean area.
3. Renovation plan: Replace all 2000 AC FFUs with DC FFUs (EC-FFU) and deploy an intelligent group control system.
Detailed explanation of energy-saving technology application: The energy-saving of DC FFU is not caused by a single technology, but by a combination of techniques. The following are the applications of its core energy-saving technology:
3.1 High efficiency DC brushless motor (core foundation)
3.1.1 Technical application: DC FFU uses permanent magnet synchronous motor (EC Motor), whose motor efficiency can reach 80% -90%. The efficiency of AC induction motors is generally lower than 50%.
3.1.2 Case Study: This means that even at the same speed, EC motors have a much higher efficiency in converting electrical energy into mechanical energy than AC motors, reducing energy loss from the source.
3.2 Stepless speed regulation and intelligent feedback control (energy-saving key)
3.2.1 Technical application: DC FFU supports 0-100% stepless speed regulation. The intelligent group control system monitors the total supply air static pressure in real-time through static pressure sensors distributed throughout the workshop.
3.2.2 Case Study:
3.2.2.1 Traditional AC-FFU: All fans run at full speed regardless of production process requirements. Even if the tap is adjusted to medium speed, the motor efficiency will sharply decrease, and the energy-saving effect is limited.
3.2.2.2 Intelligent EC-FFU group control: The system sets a target static pressure value (such as 45Pa). When the exhaust volume of the production line equipment decreases or the filter resistance has not increased, the system will automatically reduce the speed of all FFUs to maintain a constant static pressure. The relationship between rotational speed and power consumption is cubic, meaning that a 10% decrease in rotational speed can reduce power consumption by approximately 27%!
3.3 Soft start and power factor correction (hidden energy-saving)
3.3.1 Technical application: The DC FFU is equipped with an intelligent driver, which has soft start function (starting current<1.5A) and high power factor correction (PF>0.98).
3.3.2 Case Study:
3.3.2.1 AC-FFU: The startup surge current can reach up to 10-20A, which has a significant impact on the power grid and a low power factor (about 0.7). Additional capacitor compensation is required, otherwise the power company will charge a penalty (power adjustment fee).
3.3.2.2 EC-FFU: Almost no start-up shock, power factor close to 1.0, reducing line losses and transformer loads, achieving energy savings from the perspective of the entire power supply system.
3.4 Low heat generation reduces air conditioning load (secondary energy saving)
3.4.1 Technical application: EC motors operate efficiently with much lower heat generation than AC motors.
3.4.2 Case Study: The semiconductor workshop has extremely high requirements for temperature control. When 2000 AC-FFUs are in operation, it is equivalent to a huge heat source of 700kW (2000 x 0.35kW), which requires additional air conditioning cooling to offset this heat. After replacing with EC-FFU, the total heat generation was significantly reduced, bringing considerable secondary energy savings to the workshop air conditioning refrigeration system.