Turbine exit condition

The turbine exit condition (for reversible cooled cycles)... 

Configurations that incorporate shared heat exchangers require isolation valves in hotter portions of the loop. In order to share a recuperator and gas cooler, multiple valves are required to successfully switch from an operating Brayton unit to a spare unit. The number of valves is further increased in this case given the bearing and alternator cooling arrangement that draws cold gas from the compressor inlet. Some of these valves must operate at the turbine exit conditions ( 900 K). 

It is not normal for a nozzle to discharge into a large volume, since, in a turbine, the nozzle discharges almost directly into the blade, and there is little space for a further expansion. An untypically low value of riim was chosen, namely 0.5, in an attempt to account for the unusual exit conditions present in the experiment. As is clear from Figure A6.3, this does not produce perfect matching, but this is not considered a major disadvantage because the conditions of the experiment are unlikely to be repeated in a real turbine. 

An adiabatic steady-state turbine is being designed to s ve as an energy source for a small electrical generator. The inlet to the turbine is steam at 600= C and 10 bar. with a mass flow rate of 2.5 kg/s through an inlet pipe that is 10 cm in diameter. The conditions at the turbine exit are T = 400°C and P — 1 bar. Since the steam expands through the turbine, the outlet pipe is 25 cm in diameter. Estimate the rate at which work can be obtained from this turbine. 

The dryness fraction of 0.88 indicates that the stream leaving the turbine is 88 per cent steam and 12 per cent water. A constant entropy expansion is the ideal expansion for the production of maximum work, and more advanced work would show that the exit conditions are 5 bar and 152°C. 

Figure 8-2. NsDs diagram for a turbine stage. Efficiency is on a total-to-total basis that is, it is related to inlet and exit stagnation conditions. Diagram values are suitable for machine Reynolds number Re > 10 . (Balje, O.E., A Study of Reynolds Number Effects in Turbomachinery, Journal of Engineering for Power, ASME Trans., Vol. 86, Series A, p. 227.)...

Karamanis, N. Martinez-Botas, R.F., Su, C.C., Mixed Flow Turbines Inlet and Exit flow under steady and pulsating conditions, ASME 2000-GT-470. 

This design has a number of tubes embedded inside the turbine biade to provide ehanneis for steam. In most cases these tubes are constructed from copper for good heat-transfer conditions. Steam injection is becoming the prime source of cooiing for gas turbines in a combined cycie appiication. The steam, which is extracted from the exit of the HP Turbine, is sent through the nozzie biades, where the steam is heated, and the biade metai temperature decreased. The steam is then injected into the flow stream entering the IP steam turbine. This increases the overaii efficiency of the combined cycie. 

Cost of 3 barg steam. Here, 10 barg steam from the exit of the first turbine is assumed to be expanded to 3 barg in another turbine. From steam tables, inlet conditions of 10 barg and 251°C are ... 

Natural gas expander cycles can be utilized at places with a high-pressure main gas pipeline and a low-pressure distribution line. The natural gas is expanded in a turbine, thereby cooling the exit gas. Dependent on the inlet conditions, the exit temperature will be so low that a part of the gas is condensed, typically around 12 to 30 %. The liquid is separated from the gas flow in a liquid-vapour separator as shown in Figure 11. 

Your company produces small power plants that generate electricity by expanding waste process steam in a turbine. One way to ensure good efficiency in turbine operation is to operate adiabatically. For one turbine, measurements showed that for 1000 Ib/hr steam at the inlet conditions of 500 F and 250 psia, the work output from the turbine was 86.5 hp and the exit steam leaving the turbine was at 14.7 psia with 15% wetness (i.e., with a quality of 85%). 

Maximum work => reversible process => S en - 0 (see Sec. 3.2) => S) = S2. Thus the inlet and exit turbine conditions are connected by a vertical line on the Mollier diagram. 

A steam turbine expands steam from 500 "C, 40 bar to 1 bar. The efficiency of the turbine is 80%. Determine the amount of work produced and the conditions at the exit. 

This has the inverse form of the turbine efficiency in order to produce a number less than ioo%. In the typical problem we know the inlet conditions (pressure and temperature), the outlet pressure, and the compressor efficiency. The calculation of the required work and of the exit temperature is done in complete analogy to the turbine calculation first we compute the reversible work under the condition of isentropic operation, then we use the known efficiency to calculate the work. Finally, we calculate the enthalpy of the exit stream from the energy balance this enthalpy and the known exit pressure are used to obtain all other properties at the outlet. These steps are demonstrated graphically on the Mollier chart in Figure 6-q. 

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