Barber-Nichols Inc. (BNI) has extensive experience designing and producing compact, high-speed turbo-alternators.  High power (up to 6 MW) turbine-generators utilizing gearbox reduction have been developed by BNI since 1980, but recent smaller capacity designs (up to 400 kW) have utilized a high-speed, single-shaft, permanent magnet architecture.  This approach allows the machine to operate at the optimium speed for turbine efficiency without the challenges of engineering a high reduction ratio gearbox for a one-off application.  Low hour duty machines can be offered with rolling element bearings, while longer mean time between refurbishment machines can be fitted with foil bearings.  Both radial in-flow, and axial impulse designs are available to best match your duty. BNI also offers the power electronics products to control the turbine-alternator or invert the power to grid conditions as needed.

Model FCE-01-000 Turbine Alternator   Model FCE-01-000 Turbine Alternator In Direct Carbonate Fuel Cell Stack
Model FCE-01-000 Bottoming Turbine Alternator
in Direct Carbonate Fuel Cell Stack

An increasing number of applications require the efficiency, size, and hermetic characteristics of a single-shaft turbine-alternator. The decreasing cost of the power electronics utilized in the rectification/inverter equipment made this an economically viable alternative for many systems that have traditionally utilized gearboxes and low-speed generators.  The hermetically sealed design eliminates maintenance-intensive shaft seals.

Power levels from 3 kW to 75 kW have been built and tested.

Model BNPM-06-000 Turbine AlternatorFluids at temperatures reaching 927 oC (1,700 oF) include:

  • Jet Propellant (JP-8)
  • HFC-245fa Vapor
  • Toluene
  • Hydrogen Mixture Fuel Cell Byproduct Gas
  • High-Pressure Steam

Case Study 1: Waste heat from an industrial fuel cell process was utilized to make additional electric power.  A turbo-alternator was designed to make 60 kW of electric power utilizing a high-speed permanent magnet alternator.  The design featured ball bearings that utilized a process fluid, diesel fuel, to lubricate the ball bearings.

Case Study 2: A turbo-generator was designed to use in an Organic Rankine Cycle (ORC) for a stand-by power application.  A Switched Reluctance (SR) motor/alternator was designed with a radial in-flow turbine.  The SR machine was utilized in motoring mode when the machine was in standby mode.  The SR machine has inherently low rotating losses at low power levels.  When power was needed, the organic Rankine fluid was applied to the turbine and the SR machine generated up to 10 kW of electrical power.

Uninterruptible Power System

Uninterruptible Power SystemBarber-Nichols designed and built a 6 kW Uninterruptible Power System that utilized a High Inertia Turbine (HIT 6).  The alternator is situated between the turbine wheel and the 2.0 kg (4.5 lb) fly wheel. When the unit is on standby the alternator acts as an electrical motor, consumes a small amount of power, and maintains the unit's rotational speed at 60,000 rpm. In the event of a power failure, the alternator, now driven by the fly wheel's inertia, immediately begins generating electrical power. After two seconds, propane flowing to the turbine takes over and the alternator continues generating electricity for as long as is necessary.

Barber-Nichols Inc. | 6325 West 55th Avenue Arvada, CO 80002 | Phone: (303) 421-8111 | Fax: (303) 420-4679 © 2015 Barber-Nichols Inc.