Baseline data on film coefficient for heating isobutane inside a tube at 4. 14 MPa (600 psia)

Conference · Sun Apr 01 04:00:00 EST 1979

OSTI ID:5885546

Tleimat, B W; Laird, A D.K.; Hsu, I C; Rie, H

Research designed to obtain heat transfer baseline data on working fluids in geothermal binary cycle systems is described. The working fluid loop simulates the binary cycle with steam as the heating fluid and a throttling valve instead of the turbine. Data on film coefficient for heating isobutane in the supercritical region (critical pressure 3.65 MPa) inside a tube at 4.14 MPa (600 psia) and at various temperatures and flow rates are presented. The isobutane was heated in a horizontal, type 316 stainless steel, instrumented tube by steam condensing on the outside. The tube was fitted with a total of fifteen thermocouples imbedded in the wall of the tube at 45 deg radially above a horizontal plane through the axis at five stations located equally along the length of the tube. The inside and outside wall temperature of the tube at each of the five stations was calculated from the location of the imbedded thermocouples and their temperatures. The heat rate was determined by measuring the rate of condensing steam on the outside of the tube under each of four sections by means of specially designed vapor-traced meters. The temperature of the isobutane inside the heater tube was measured by means of a traveling platinum resistance thermometer equipped with a mixing head at its tip and the temperature of the steam in the steam chest outside of the tube was measured by means of a platinum resistance thermometer. Film coefficients for the heating of isobutane in the range of 0.6 to 2.5 kW/m/sup 2/C (115 to 400 Btu/hr ft/sup 2/F) were obtained for Reynolds number between 3 x 10/sup 4/ to 2 x 10/sup 5/. A plot of these data on log-log paper showed that they are correlated by an empirical equation.

• Research Organization: California Univ., Berkeley (USA). Lawrence Berkeley Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5885546
• Report Number(s): LBL-9720; CONF-790808-21
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150802* -- Geothermal Power Plants-- Power Plant Systems & Components
2-METHYLPROPANE
36 MATERIALS SCIENCE
360603 -- Materials-- Properties
ALKANES
BINARY-FLUID SYSTEMS
ENERGY TRANSFER
FILMS
FLOW RATE
FLUIDS
Geothermal Legacy
HEAT TRANSFER
HEATING
HIGH TEMPERATURE
HYDROCARBONS
MEDIUM PRESSURE
ORGANIC COMPOUNDS
TEMPERATURE MEASUREMENT
TUBES
WORKING FLUIDS