A thermosyphon consists of a closed container thatabsorbs

Chapter 10, Problem 10.73

(choose chapter or problem)

A thermosyphon consists of a closed container thatabsorbs heat along its boiling section and rejects heatalong its condensation section. Consider a ther-mosyphon made from a thin-walled mechanicallypolished stainless steel cylinder of diameter D. Heatsupplied to the thermosyphon boils saturated water atatmospheric pressure on the surfaces of the lowerboiling section of length Lband is then rejected by condensing vapor into a thin film, which falls bygravity along the wall of the condensation section oflength Lcback into the boiling section. The two sec-tions are separated by an insulated section of length Li.The top surface of the condensation section may betreated as being insulated. The thermosyphon dimen-sions areD?20 mm, Lb?20 mm, Lc?40 mm, andLi?40 mm.(a) Find the mean surface temperature, Ts,b, of theboiling surface if the nucleate boiling heat fluxis to be maintained at 30% of the critical heatflux.(b) Find the total condensation flow rate, , and themean surface temperature of the condensation sec-tion, Ts,c.