The temperature issue of the backpressure steam in backpressure turbines
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Steam inlet pressure: 4.0 MPa, 420℃； Exhaust pressure: 0.45 MPaA. Question: What is the appropriate exhaust temperature? Is overheating discharge necessary? This post was last edited by kevin2008 on 2009-4-4 23:08]
It should be superheated steam. Its temperature should be around 200–220 degrees.
Temperature issue of the backpressure steam in backpressure turbines; inlet steam pressure: 4.0 MPa, 420℃； Exhaust pressure: 0.45 MPaA. Question: What is the appropriate exhaust temperature? Is overheating discharge necessary? To answer the original poster’s question, it is first necessary to understand what a back-pressure steam turbine is. A back-pressure steam turbine is one in which, after working inside the turbine, the steam is discharged at a pressure higher than atmospheric pressure and then supplied to heat users through pipelines. So, the backpressure steam mentioned by the original poster in the question is the exhaust steam generated after a backpressure turbine has done work. Since the original poster has specified that the exhaust pressure is 0.45 MPa, the exhaust temperature can be determined using a hysteresis diagram, as temperature and pressure are related to each other.
Correct. Generally, back-pressure exhaust systems operate in parallel with the piping network; the pressure remains stable at the level of the system pressure, while the temperature is usually slightly above the saturation pressure.
The temperature is generally between 210 and 250 degrees; it must be superheated before being discharged. It is usually about 30 degrees higher than the saturated vapor pressure at that pressure, otherwise condensation may occur, leading to fluctuations in the turbine operation.
An excessively high backpressure exhaust temperature also hinders power generation efficiency