Condensation in steam turbines. Final report

Technical Report · Sun Aug 01 04:00:00 EDT 1982

OSTI ID:6872892

Kantola, R A

Condensation of water from moist air or steam has been an active research area for over eighty years. Research has been concentrated on the condensation of steam in turbines, where the moisture-induced efficiency losses and possibilities of erosion damage impose a lower limit on the expansion of the steam so that no more than a 10 to 12% moisture content is reached. In order to accurately assess and reduce the mechanical and thermodynamic losses (which can be as high as 4 to 8 percentage points of efficiency), the thermodynamic conditions at nucleation onset and the kinetics of the subsequent droplet growth must be accurately known. To overcome objections to prior data, a subsonic technique for investigating steam condensation has been developed which uses a non-steady expansion wave to provide a controlled but rapid expansion of slightly superheated steam. An optical measurement system uses the attenuation of laser light at two wavelengths to determine the droplet size and number density time histories. Fast response pressure transducers are used to determine the steam pressure during this transient test. Through the use of high speed digital recorders to capture the data, an accurate determination of the thermodynamic conditions at onset as well as a detailed description of the droplet growth kinetics has been obtained. The quality of the data is very high. The basic issue of what mechanism controls droplet growth rate has been raised. It is extremely important to know whether isolated droplet growth via impinging steam molecules is dominant or whether agglomeration plays a major role. The knowledge of when these different mechanisms are controlling can be of vital importance in trying to reduce the moisture-induced losses in steam turbines.

• Research Organization: General Electric Co., Schenectady, NY (USA). Corporate Research and Development Dept.
• OSTI ID: 6872892
• Report Number(s): EPRI-CS-2528; ON: DE82906486
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200104* -- Fossil-Fueled Power Plants-- Components
CHEMICAL REACTION KINETICS
DATA ACQUISITION SYSTEMS
DROPLETS
EFFICIENCY
FLUID FLOW
FOSSIL-FUEL POWER PLANTS
KINETICS
LASERS
LIGHT SCATTERING
MACHINERY
NUCLEATION
PARTICLES
PHYSICAL PROPERTIES
POWER PLANTS
REACTION KINETICS
SCATTERING
SIZE
STEAM
STEAM TURBINES
TEST FACILITIES
THERMAL POWER PLANTS
THERMODYNAMIC PROPERTIES
TURBINES
TURBOMACHINERY
TWO-PHASE FLOW
VAPOR CONDENSATION