The use of active magnetic bearings has been on the rise, owing to this system’s increased efficiency, its high-speed capabilities and low maintenance needs.
The applications of active magnetic bearings are wide, and have opened many doors in different areas. In the field of thermal engineering, their use has translated into the development of highly-efficient, large-capacity heat pumps and dry condenser chillers, thus facilitating the development of increasingly sophisticated equipment.
In the current context, enhancing efficiency and reducing maintenance needs remain two key interests when developing any piece of equipment. It’s precisely in this context where active magnetic bearings stand out as an alternative to conventional mechanical bearings. Let’s see what they are exactly and how they’re improving efficiency across a wide range of equipment.
What are active magnetic bearings
Active magnetic bearings are a type of bearing that employs magnetism to support and stabilize rotation of moving parts, such as shafts. As such, it’s able to perform this operation without the need for physical contact.
The working principle behind active magnetic bearings is as follows: it presents a rotating part and a stationary part, both of them incorporating electromagnets that act in combination. Through the generation of magnetic fields, these forces are capable of maintaining stability during rotation.
The benefits of an active magnetic bearing system
Active magnetic bearings present a series of advantages which have led professional and regulatory bodies (such as the U.S. Department of the Navy) to recommend their implementation. In this particular case study, the organization corroborated that magnetic bearing control can perform more efficiently than conventional mechanical bearings, particularly during partial load conditions. Research detected an average of 49% in power savings and a 6.4 years average ROI.
The reason behind the benefits of active magnetic bearings is their no-contact working principle between rotating and stationary parts, as opposed to conventional bearings. In fact, the latter rely on mechanical contact to support the load and reduce friction and must use oil as a lubricant, becoming the cause of wear in the equipment.
As such, the magnetic bearing provides several advantages for the high lift oil free compressor compared with the traditional oil lubed compressor with gear box:
- Frictionless performance: there’s a lack of physical contact between the moving parts and thus, virtually no friction. This working principle allows for a higher heat transfer efficiency of the chiller, reducing energy losses due to friction.
- Direct drive motor compressor, no gearbox and less moving parts.
- No oil pump required, no oil pump nor oil heater power consumption.
- No oil injection piping, no oil cooler, no oil filters, less possible leaking points (joints).
- Low maintenance: because of this lack of mechanical contact and an oil free functioning, wear of parts also diminishes, resulting in reduced maintenance requirements and a longer service life.
- Minimum noise and vibration: the lack of physical contact between the parts results in less noise and vibrations
All in all, the implementation of active magnetic bearings in centrifugal chillers results in higher efficiencies and less maintenance needs, two crucial aspects that define priorities in the current context.
This is particularly true for partial-load scenarios. For instance, in the field of district cooling and district heating, the implementation of active magnetic bearings can be fundamental for increasing efficiency in handling varying cooling and heating loads from different buildings in the same district. It can also play an essential role in optimizing vapor compression systems. As such, it’s a step forward in guaranteeing resources are optimally allocated optimally and waste is minimized.
h2. Applying active magnetic bearings
When aiming at increasing efficiency, the design phase is everything, a blanket statement which also applies to incorporating active magnetic bearings to their numerous applications.
At Araner, our perspective and expertise in thermal engineering have led us to apply active magnetic bearings as part of our equipment. This has meant we’re now able to implement them in our large-capacity heat pumps.When considering the implications of active magnetic bearings and overall equipment efficiency, design optimization is key. This is particularly true in the case of heat pumps, as they remain crucial throughout all stages of the refrigeration cycle.
Finally, the hallmarks of this latest technology could be summarized as long-lasting dependability, highly energy efficient performance for low cost of ownership, smaller area footprint and quiet operation. Through a step-by-step process, at Araner we ensure this application is project-specific and results in the system’s greater optimization. This takes us to the forefront of developing successful district heating systems, leading the way for helping our clients access more efficient equipment.
Get in touch with us and speak to our team about how we can help you achieve an efficient, sustainable project through state-of-the-art equipment.