Evaporative heat transfer in vertical tubes at geothermal brine conditions: a preliminary investigation

Technical Report · Fri Jun 01 04:00:00 EDT 1973

DOI:https://doi.org/10.2172/4329353· OSTI ID:4329353

Harley, P H; Eissenberg, D M

Overall heat-transfer coefficients were obtained in a single-tube loop for a smooth tube and two fluted tubes proposed for use in a geothermal brine upflow VTE pilot plant. Tests were run at steam temperatures from 250 to 390 deg F, flow rates of 0.5 to 2.5 gpm, and steam to brine DELTA Ts of 10 to 30 deg F using demineralized water and 3% NaCl solutions. In each case the liquid entering the tube flashed through a DELTA T equal to the steam- brine DELTA T. The tubes tested were a 3/4-in. smooth stainless steel tube, a 1-in. double- fluted CuNi tube, and a 7/8-in. double-fluted Al brass tube. Average heat transfer coefficients using 3% NaCl were as follows: for the stainless steel tube, 550 Btu/hr/ deg F/ft/sup 2/ at 250 to 765 at 390 deg F; for the CuNi tube, 2000 at 250 to 2600 at 390 deg F; for the aluminum brass tube, 1750 at 250 deg to about 2650 at 390 deg F. Flow rate and DELTA T, in general, had only small effects on the coefficients. (auth)

• Research Organization: Oak Ridge National Lab., Tenn. (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-29-020413
• OSTI ID: 4329353
• Report Number(s): ORNL-TM--4135
• Country of Publication: United States
• Language: English

Related Subjects

*BRINES-- DESALINATION
*GEOTHERMAL ENERGY-- HEAT TRANSFER
*HEAT EXCHANGERS-- GEOTHERMAL ENERGY
DISTILLATION
EVAPORATION
FLASH HEATING
Geothermal Legacy
HIGH TEMPERATURE
MEDIUM TEMPERATURE
MOCKUP
N42300 -- Engineering--Heat Transfer & Fluid Flow
N80200* --Energy Utilization & Economics
PERFORMANCE TESTING
STEAM
TUBES