21. March 2016

Is an ultra-high-speed turbo compressor the right compressor for your application?

“The technical application is defined, the pressure rise and the mass flow are determined, but which compressor type is the right one for this application?”

These or similar questions arise for many engineers and system application developers. This article provides an overview of available compressor concepts. Additionally it points out the advantages and disadvantages of an ultra-high-speed turbo compressor. Unfortunately the answer to this seemingly simple question is so wide that an individual examination is indispensable. Take the first step and use our free service, which is described at the end of the article.

The table shown below provides some examples of how different the compressor requirements for various applications can be.

Example 1:
Compressor for
fuel cell vehicles
Example 2:
Filling of
a compressed
air bottle
Example 3:
Cooling of an electrical component
FluidAirAirAir
Pressure ratio1:1.7
low - medium
1:200 - 300
very high
~1:1.05
low - medium
Mass flow~15 g/s~3 - 7 g/s~1 - 500 g/s
Main challenge in system designEfficiency, low system weightHigh pressure ratioHigh volume flow
Additional requirementsOil free compressionContinuous check of the fluid compositionLow system costs
Possible
compressor
types
Turbo compressor,
scroll compressor, side channel compressor
Piston compressorBlower

Table 1: Examples for different system requirements

The figure below shows the various compressor concepts which are used to transport or compress gas fluids. The main division takes place at the top level between the intermittently working displacement machines and the continuously working turbo machines. Afterwards the branches are divided on basis of the compressor type. This reduced selection already shows the amount of different compressor concepts. Additionally the difficulty in selecting the right compressor type is illustrated.

Figure 1: Overview of different compressor types

Each compressor has its own pros and cons as well as a suitable area of application. Different compressor concepts have been compared in publications for the use in fuel cells or heat pumps for aerospace applications.

The advantages and disadvantages of the ultra-high-speed turbo compressor technology are summarized in the table below.

Advantages high-speed turbo compressors

  • High rotational speed ⇒ small dimensions ⇒ high power density ⇒ low weight
  • Only one rotating component without oscillating masses ⇒ low system complexity
  • High efficiency of the energy conversion
  • Stationary continuous flow ⇒ no pressure ripples
  • High reliability, availability and long life times
  • Proven technology
  • Maintenance and inspection friendly
  • Oil free compression when using gas or magnetic bearings
  • Can be used for different fluids
  • Adaptable construction
  • Low noise level because no low-frequency noise is present at high-speed turbomachines
  • Low moment of inertia ⇒ fast control

Disadvantages high-speed turbo compressors

  • Dynamic working principle ⇒ restrictions in the operating range (surge line / choke line)
  • Stationary continuous flow ⇒ limited pressure rise per compressor stage (unlike other compressor types); higher pressure ratios are only possible with multi-stage compressors
  • High power density ⇒ small dimensions ⇒ high thermal loads
  • Miniaturization ⇒ high demands on manufacturing tolerances

Innovations from research and development, improved materials and new production technologies now allow the miniaturization of turbo compressors. This in turn opens up new application possibilities of the turbo compressor technology in areas where only small membrane-, piston- or rotary compressors were used in the past. Figure 2 shows the miniaturization possibilities with the example of the Celeroton CT-15-150.

Figure 2: New application areas with the use of ultra-high-speed turbo compressors

The advantages of turbo compressors, such as small volume and weight as well as high efficiency, can now also be used for these applications. We already reported on this in a separate article.

Figure 3: Miniaturisation - Celeroton CT-15-150

Free feasibility check

Are you unsure whether the ultra-high-speed turbo compressor technology is suitable for your application? We offer you a free check. Please provide us the following information via e-mail or by phone:

  • Fluid
  • Are the conditions constant at the inlet (typical) or at the outlet of the compressor (vacuum applications)?
  • Pressure and temperature at the inlet of the compressor
  • Pressure ratio or desired pressure rise at the outlet of the compressor
  • Mass flow or volume flow (indicate if the volume flow is at inlet or outlet)

We will then check using your information the following aspects for you:

  • Can your specifications be covered with one of our products or a product modification
  • Can your specifications be covered by a custom specific design with Celeroton as a partner

We look forward to you contacting us (moc.notorelec@ofni or phone +41 44 250 52 20) in order to check your application suitability for our turbo compressor technology.