Steam turbine evaluation
Steam turbine evaluation
(OP)
Hi everybody,
As it was mentioned in the texts, the power of steam turbine (non-condensing type)could be calculated through the thermodynamic laws (enthalapy balance). An important point is that the turbine steam outlet temperature should be measured. But I have read a short sentence that by usual equipment(thermowell and thermocouple), the measeured temperature has not enough accuracy. Does anybody have idea and explanation for the reasons? And what are the methods for accurate measuring the outlet steam temperature?
Thanks
As it was mentioned in the texts, the power of steam turbine (non-condensing type)could be calculated through the thermodynamic laws (enthalapy balance). An important point is that the turbine steam outlet temperature should be measured. But I have read a short sentence that by usual equipment(thermowell and thermocouple), the measeured temperature has not enough accuracy. Does anybody have idea and explanation for the reasons? And what are the methods for accurate measuring the outlet steam temperature?
Thanks





RE: Steam turbine evaluation
Accurate temperature measurements both at the inlet and at the exhaust require calibrated thermocouples. Typical thermocouples have an accuracy of 0.75% of range or 4 degrees Fahrenheit (2.2 degrees Celsius), whichever is greater. See ASME PTC 19.3 for guidance on temperature measurements.
If you want to calculate power, measuring steam flow accurately is much more difficult than measuring temperature. However, you can calculate the efficiency of the turbine easily, using the enthalpies of state points at the inlet and at the exhaust along with the isentropic enthalpy at the exhaust. If you want to evaluate steam turbine performance, efficiency may be sufficient.
Best of luck!
RE: Steam turbine evaluation
rmw