Vacuum Chamber Fabrication and Machining for Flywheel Energy Storage

To storage high speed rotating flywheel, the steel chamber need to be vacuum no more than 4pa. We undertook the fabrication and machining of the steel shells and top plates. It require high precision on cutting, roll forming, beveling, welding and machining. Welding quality on the wall of the shell is important in order to achieve high vacuum level. We used helium to test the leakage to meet the requirement--- ≤1.4*10-10*Pa*m3/s . The sealing surface roughness is up to Ra 0.8.

The dimension tolerance are measured by CMMs.

What is Flywheel Energy Storage(FES)?

Energy storage systems (ESS) can be used to balance electrical energy supply and demand. The process involves converting and storing electrical energy from an available source into another form of energy, which can be converted back into electrical energy when needed. The forms of energy storage conversion can be chemical, mechanical, thermal, or magnetic. ESS enable electricity to be produced when it is needed and stored when the generation exceeds the demand. Storage is beneficial when there is a low demand, low generation cost, or when the available energy sources are intermittent. At the same time, stored energy can be consumed at times of high demand, high generation cost, or when no alternative generation is available.

Flywheel Energy Storage (FES) is a relatively new concept that is being used to overcome the limitations of intermittent energy supplies, such as Solar PV or Wind Turbines that do not produce electricity 24/7.

A flywheel energy storage system can be described as a mechanical battery, in that it does not create electricity, it simply converts and stores the energy as kinetic energy until it is needed. In a matter of seconds, the electricity can be created from the spinning flywheel making it the ideal solution to help regulate supply in the electrical grid.

It is based on a really old concept and is very similar to an old-fashioned pottery wheel where the potter moves his feet to make the wheel spin. As the potter works, he removes energy from the system, so to keep the wheel spinning; he needs to keep moving his feet.

Structure and Components of Flywheel Energy Storage System

FESS consist of a spinning rotor, MG, bearings, a power electronics interface, and containment or housing.

• Flywheel Rotor
  The stored energy in a flywheel is determined by the rotor shape and material.
• Electric Machine
  The electrical machine or integrated MG is coupled to the flywheel, to enable the energy conversion and charging process of the flywheel. The machine, acting as a motor, charges the flywheel by accelerating it and drawing electrical energy from the source. The stored energy on the flywheel is extracted by the same machine, acting as a generator, and hence, the flywheel is slowed down during discharge.
• Power Electronics
  The energy conversion in a FESS is accomplished by the electrical machine and a bi-directional power converter. The power electronic converter topologies that can be used for FESS applications are DC-AC, AC-AC, and AC-DC-AC, or a combination of these. The switching devices of the power converters are selected, based on their operational characteristics and application.
• Bearings
  Bearings are required to keep the rotor in place with very low friction, yet provide a support mechanism for the flywheel. The bearing system can be mechanical or magnetic, depending on the weight, lifecycle life, and lower losses.
• Housing
  The housing has two purposes: to provide an environment for low gas drag and for the containment of the rotor in the event of a failure. The aerodynamic drag loss in an FESS increases with the cube of the rotational speed, if the system is operated in atmospheric pressure. These losses are reduced by mounting the flywheel in a vacuum enclosure to improve the system performance and safety. The housing or enclosure is the stationary part of the flywheel and is usually made of a thick steel or other high strength material, such as composites. The container holds the rotor in a vacuum to control rotor aerodynamic drag losses by maintaining the low pressure inside the device, thus withstanding failures as a result of any possible rotor failures.

What do we do for Flywheel Energy Storage with our metal fabrication service?

As an innovative metal fabricator, we at Openex strive to offer best-in-class manufacturing and assembly capabilities for the renewable energy industry through our,

• design-for-manufacture optimization
• collaborative design assistance
• high-velocity manufacturing processes
• planning and rapid production control
• global supply chain management

Our featured services don’t just make the metal fabrication process run smoothly, we save our customers time and money by providing efficient and top-quality products.

Openex specializes in fabricating and machining for a variety of different industries as well as flywheel energy storage. Since each product is custom built you can choose whatever interior and exterior options best fit your business needs.

Our Full-Service Metal Fabrication - metal cutting and sheering, metal forming, bending, and rolling, welding, CNC machining, sheet metal assembly, and quality inspection

Machining Services: Multi-Axis Machining, 5-Axis Machining, CNC Milling | Vertical and Horizontal, CNC Turning | Vertical and Horizontal, CNC Engineering, CMM Inspection

Material Types: castings, forgings, fabricated weldments, billets, bar stock, and plate

Metal Materials we worked: Stainless steel, Carbon Steel, aluminum, brass, bronze, chromium, copper, Monel, nickel,  titanium, zinc, and many other superalloys.

Contact us at sales3@openex.com.cn or call us at +86 186 5928 0806 for more information about flywheel energy storage and to receive a free project quote today.