Experimental results for capacity and heat transfer coefficient during steam condensation in a power-plant air-cooled condenser are presented. The condenser test section is a flattened steel tube with brazed aluminum fins. The tube is 5.7 m long with inner dimensions of 216 mm × 16 mm. The cooling air is in crossflow to the steam, with velocity at the fin inlet of 2.4–3.0 m s−1. Condensation pressures range from 70–105 kPa, with the tube inclined from 0–49° downwards. Adiabatic visualization sections at the tube inlet and outlet provide identification of annular flow at the inlet and stratified flow at the outlet. Steam-side heat transfer coefficient is found to depend on wall-steam temperature difference, with minimal dependence on quality or vapor Reynolds number. As a result, steam-side heat transfer coefficient does not decrease significantly along the condenser length, as is common for smaller condenser tubes with higher mass flux. There is a slight decrease in steam-side heat transfer coefficient near the condenser outlet due to a build-up of condensate at the tube bottom. Overall condenser heat transfer coefficient is found to decrease near the condenser outlet due to an increase in the thickness of the stratified condensate layer.
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanical Engineering
- Fluid Flow and Transfer Processes