Turbo-Alternators
Barber-Nichols, Inc. (BNI) has extensive experience designing and manufacturing compact, high-speed turbine driven alternators (Turbo-Alternators). High power Turbo-Alternators utilizing gearbox reduction have been developed by BNI since 1980. Recent designs have focused on high-speed, single-shaft, permanent magnet machines utilizing radial in-flow, and axial impulse turbines. These applications have been developed for waste heat recovery, geothermal, and Brayton cycle applications.
Related Product:
Turbo-Generators for Industrial Waste Heat Recovery & Power Generation Applications
An increasing number of applications require the efficiency, size, and hermetic characteristics of a single shaft Turbo-Alternator. The decreasing cost of the power electronics utilized in the rectification/inverter equipment has 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 test.
Fluids at temperatures reaching 927oC (1,700oF) 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 make additional electric power. A turbo-alternator was design 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 inflow 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.
Case Study 3: Barber-Nichols designed and built a 6kW 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.