Why exhaust temperature is high in steam turbine?

High exhaust temperature from a steam turbine indicates that efficiency of the turbine has reduced due to scaling or some other effects. Additionally, a higher exhaust temperature could result in overstressing turbine blades since as temperature increases the strength of material decreases.

What is exhaust hood temperature in steam turbine?

So, typical steam turbine exit would be 1–2 psi less than ambient and saturated steam, so temperatures would be in the range of 220–250 F.

What is churning effect in steam turbine?

Churning means heat generated through friction. We give steam to roll turbine. But sometimes that steam is more then enough to take the full rpm.

What is the temperature of the exhaust gases from gas turbines?

Gas turbine exhaust is quite hot, up to 800 to 900° F for smaller industrial turbines and up to 1,100° F for some new, large central station utility machines and aeroderivative turbines. Such high exhaust temperatures permit direct use of the exhaust.

How do you calculate work done by a steam turbine?

The unit work equation is: wt = (inlet steam enthalpy – cold reheat enthalpy) + (hot reheat enthalpy – turbine exhaust enthalpy). In this case, wt = (1,474.1 – 1,248.1) + (1,526.5 – 1,003.9) = 748.6 Btu/lbm. As can be seen, reheating considerably increases the work output as compared to the non-reheat example.

What is an exhaust temperature sensor?

As its name suggests, the exhaust gas temperature sensor measures the temperature of the exhaust gas. In diesel engines, exhaust gas temperature sensors are also used to monitor the temperature of the diesel particulate filter (DPF) to establish the correct temperature for regeneration, reducing harmful emissions.

How do you warm up a steam turbine?

1. Crack open the steam supply isolating valve and warm up the steam pipe to the turbine stop valve.
2. Crack open the main stop valve sufficient only to admit steam to the turbine casing, via the nozzles for warming through purpose.

What is exhaust hood in turbine?

Exhaust hoods are static components, interposed between the turbine exit and the condenser, designed. to convert the kinetic energy leaving the rotor last stage into static pressure via a flow deceleration.

What is exhaust temperature in turbine?

Why do steam turbine exhausts get hot?

Re: Steam Turbine Exhaust Hood Temperature. Windage is essentially friction which occurs when the turbine blades contact the near-stationary steam. The windage losses cause heating of the blades in the last few stages of the turbine. Second, there is insufficient steam to absorb the heat from the blades.

Why does the exhaust temperature of LP turbine increase during low load?

LP exhaust temperature raises because during low load conditions steam flow will be less in LP turbine due to which aerodynamic flow pattern of steam will get disturbed . The steam gains the heat from the hot components of the turbine and gets heated up . Due to this exhaust temperature of steam will be high

How hot does a 150 MW condensing steam turbine get?

We have (4) 150 MW Parson condensing steam turbines. The high exhaust hood temperature alarm is set at 90 deg C but it is considered that operating at 120 deg C for 15 minutes without the cooling sprays may be tolerable,…

What is steam turbine?

Steam turbines are designed for particular load condition that is rated condition. For example say X mW at X TPH with pressure X kg/cm2. After vacuum pulling, turbine is rolled. It is generally started as per cold start up curve. There is soaking point wherein it is rolled at particular rpm for particular time.