Thermodynamics

also by contacting some condenser manufacturers. In a report,describe the various types, the way they are designed, the limitationon each type, and the selection criteria.10–132 Steam boilers have long been used to provideprocess heat as well as to generate power. Write anessay on the history of steam boilers and the evolution ofmodern supercritical steam power plants. What was the roleof the American Society of Mechanical Engineers in thisdevelopment?10–133 The technology for power generation using geothermalenergy is well established, and numerous geothermalpower plants throughout the world are currently generatingelectricity economically. Binary geothermal plants utilize avolatile secondary fluid such as isobutane, n-pentane, andR-114 in a closed loop. Consider a binary geothermal plantChapter 10 | 605with R-114 as the working fluid that is flowing at a rate of 600kg/s. The R-114 is vaporized in a boiler at 115°C by the geothermalfluid that enters at 165°C, and is condensed at 30°Coutside the tubes by cooling water that enters the tubes at18°C. Based on prior experience, the average heat flux basedon the outer surface of the tubes can be taken to be 4600W/m 2 . The enthalpy of vaporization of R-114 at 30°C is h fg 121.5 kJ/kg.Specify (a) the length, diameter, and number of tubes andtheir arrangement in the condenser to minimize overall volumeof the condenser; (b) the mass flow rate of coolingwater; and (c) the flow rate of make-up water needed if acooling tower is used to reject the waste heat from the coolingwater. The liquid velocity is to remain under 6 m/s andthe length of the tubes is limited to 8 m.