Technical Development for S-CO2 Advanced Energy Conversion
- Univ. of Wisconsin, Madison, WI (United States)
- Texas A & M Univ., College Station, TX (United States)
This report is divided into four parts. First part of the report describes the methods used to measure and model the flow of supercritical carbon dioxide (S-CO2) through annuli and straight-through labyrinth seals. The effects of shaft eccentricity in small diameter annuli were observed for length-to-hydraulic diameter (L/D) ratios of 6, 12, 143, and 235. Flow rates through tooth-cavity labyrinth seals were measured for inlet pressures of 7.7, 10, and 11 MPa with corresponding inlet densities of 325, 475, and 630 kg/m3. Various leakage models were compared to this result to describe their applicability in supercritical carbon dioxide applications. Flow rate measurements were made varying tooth number for labyrinth seals of same total length. Second part of the report describes the computational study performed to understand the leakage through the labyrinth seals using Open source CFD package OpenFOAM. Fluid Property Interpolation Tables (FIT) program was implemented in OpenFOAM to accurately model the properties of CO2 required to solve the governing equations. To predict the flow behavior in the two phase dome Homogeneous Equilibrium Model (HEM) is assumed to be valid. Experimental results for plain orifice (L/D ~ 5) were used to show the capabilities of the FIT model implemented in OpenFOAM. Error analysis indicated that OpenFOAM is capable of predicting experimental data within ±10% error with the majority of data close to ±5% error. Following the validation of computational model, effects of geometrical parameters and operating conditions are isolated from each other and a parametric study was performed in two parts to understand their effects on leakage flow. Third part of the report provides the details of the constructed heat exchanger test facility and presents the experimental results obtained to investigate the effects of buoyancy on heat transfer characteristics of Supercritical carbon dioxide in heating mode. Turbulent flows with Reynolds numbers up to 60,000, at operating pressures of 7.5, 8.1, and 10.2 MPa were tested in a round tube. Local heat transfer coefficients were obtained from measured wall temperatures over a large set of experimental parameters that varied inlet temperature from 20 °C to 55 °C,mass flux from 150 to 350 kg/m2s, and a maximum heat flux of 65 KW/m2. Horizontal, upward and downward flows were tested to investigate the unusual heat-transfer characteristics to the effect of buoyancy and flow acceleration caused by large variation in density. Final part of this report presents the simplified analysis performed to investigate the possibility of using wet cooling tower option to reject heat from the supercritical carbon dioxide Brayton cycle power convertor for AFR-100 and ABR-1000 plants. A code was developed to estimate the tower dimensions, power and water consumption, and to perform economic analysis. The code developed was verified by comparing the calculations to a vendor quote. The effect of ambient air and water conditions on the sizing and construction of the cooling tower as well as the cooler is studied. Finally, a cost-based optimization technique is used to estimate the optimum water conditions which will improve the plant economics.
- Research Organization:
- Univ. of Wisconsin, Madison, WI (United States); Texas A & M Univ., College Station, TX (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE)
- DOE Contract Number:
- AC07-05ID14517
- OSTI ID:
- 1215518
- Report Number(s):
- DOE/NEUP-11-3039; 11-3039; TRN: US1600278
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
CARBON DIOXIDE
SUPERCRITICAL STATE
LENGTH
MECHANICAL SHAFTS
PRESSURE RANGE MEGA PA 01-10
PRESSURE RANGE MEGA PA 10-100
EXPERIMENTAL DATA
GEOMETRY
ORIFICES
SEALS
FLOW RATE
DENSITY
COMPARATIVE EVALUATIONS
ENERGY CONVERSION
DATA COVARIANCES
LEAKS
INTERPOLATION
TURBULENT FLOW
EQUILIBRIUM
VALIDATION
PARAMETRIC ANALYSIS
DESIGN
FLUID MECHANICS
COMPUTERIZED SIMULATION
MATHEMATICAL MODELS
HEAT EXCHANGERS
TEST FACILITIES
HEAT TRANSER
BUOYANCY
TEMPERATURE RANGE 0273-0400 K
OPEN-CYCLE COOLING SYSTEMS
COOLING TOWERS
FEASIBILITY STUDIES
BRAYTON CYCLE POWER SYSTEMS
SIZE
ECONOMIC ANALYSIS
ENERGY CONSUMPTION
WATER USE
OPTIMIZATION