Compressor section

Besides Ti—6A1—4V, significant quantities of the a—P ahoys Ti—6A1—2Sn—4Zr—6Mo and Ti—17 are used in the compressor section of gas turbine engines. These ahoys have higher strength capabhity than Ti—6A1—4V. 

The compressor section with inlet and outlet flanges. 

The calculation of the turbine expander module depends whether or not this is a single shaft gas turbine or a multiple shaft gas turbine. In aero-derivative turbines, there are usually two or more shafts. In the latest aero-derivative turbines, there are usually two compressor sections, the LP compressor section, and the HP compressor section. This means that the turbine has three shafts the third shaft is the power shaft. The turbines that drive the compressor section are known as the gasifier turbines, and the turbine, which drives the generator, is the power turbine. The gasifier turbine produces the work to drive the compressor. 

Hie best overall efficiency of a turbine can be ensured by maintaining tile efficiency of the air compressor section. Conversely, allowing the air compressor efficiency to deteriorate will deteriorate the overall thermal efficiency of the turbine. Air compressor efficiency can be draslically reduced in a very short time when dirt, salt water mist, or similar air con-... 

Figure 12-40E. Barrel type compressor section, horizontal mounting. (Used by permission Cooper-Cameron Corporation.)...

Unit Gas Turbine Compressor Section Turbine Section ... 

GTs are constant-volume machines, such that a fixed-speed GT air compressor section draws a nearly constant volumetric flow of inlet air, independent of ambient air conditions. Air density drops with increased altitude (reduced barometric pressure), increased ambient temperature, and, to a lesser degree, increased water content (specific humidity). 

At a facility in Pasadena, Texas, a serious fire and explosion occurred on a compressor section involving failure of a check valve, h) During the investigation by regulators, it was disclosed that a similar occurrence had recently taken place. The company was cited for failure to adequately apply lessons learned from previous incidents. 

In a gas turbine the air is compressed in a compressor section prior to addition of the fuel. For modem industrial gas turbines operating at pressures of 12-16 bar the eompressive heating results in an air temperature of 350-410 °C at the catalyst inlet. Some combustion catalysts currently under development can operate at inlet temperatures in the range 380 390 °C [7]. Catalysts with very high activity are required in order to achieve ignition temperatures in this range. 

Row through the compressor section will be adiabatic, so that dq = 0, and the height difference will be negligible, so that dz — 0. Further, the difference between the inlet and outlet velocities is small for both axial and centrifugal compressors so that cdc 0. Accordingly the differential of specific work is given by ... 

Integrating over the compressor section gives the specific work done on the gas, —tv, as... 

Compressor section efficiencies at the design point are in the mid-80s per cent for an axial compressor and in the high 70s per cent for a centrifugal compressor. Using equation (17.64) in conjunction with equation (17.59), the isentropic efficiency of the section may be expressed in terms of enthalpy differences as... 

As a consequence of equation (17.74) and the characteristic gas equation (3.2), the actual temperature ratio across a compressor section operating at a polytropic efficiency, rip, will be given by... 

The fact that the isentropic efficiency varies with pressure ratio for a constant value of polytropic efficiency has led some to regard the polytropic efficiency as a preferable foundation on which to base their analysis of the compressor section. Instead of taking the isentropic specific work as our ideal against which to measure the actual specific work, it is possible to devise a new ideal measure, the poly tropic specific work, —Wp, defined so that its ratio to the actual specific work is the polytropic efficiency, r/p-. 

The power absorbed by the compressor section is given by equation (17.68). We may use equation (17.80) to express the power in terms of polytropic specific work/ polytropic head and polytropic efficiency ... 

The manufacturer will normally supply a set of curves for each compressor section (Figure 17.7), at the design speed with further curves at +/ — 10% or +/ — 20% speed. The surge line will be marked, indicating the region of unstable operation that must be avoided. The manufacturer should also specify the polytropic efficiency. 

Instead of considering polytropic head, it is possible to carry out an alternative dimensional analysis based on inlet and outlet pressures of a compressor section. We will begin by assuming that the compression process may be represented using the parameter set ... 

Similarly, the specific enthalpy at the outlet of each compressor section is given by ... 

The compressor station consists of two sections of compressor machines, air tanks, a group of compressed air coolers, piping for air and for lubricating oil. The first section of compressor machines includes the first four stages of compression. After each stage, the air is cooled down from 125-130 to 40°C. Moisture is also removed during each intermediate period between successive stages of compression. The second compressor section includes one opposite piston compressor machine. 

Molten hahdes are particularly corrosive, and this subtype of hot corrosion deserves further discussion. It is encountered in the compressor sections of turbines in ships, off-shore platforms, and aircraft operated over the seas. Salt mixed with water vapor enters the turbines, where corrosive attack takes place. Other examples of hot corrosion via molten hahdes are reactors or pieces of industrial equipment that contain traces of NaCl, KCl, BaCl2, or other hahde salts and operate at temperatures high enough to melt the salts. 

The power conversion vessel contains the turbomashine and three compact heat exchangers. The turbomashine consists of a generator. turbine and two compressor sections, mounted on a single shaft suspended by magnetic bearings. 

The common rotor shaft of HP turbine and HP compressor was supported on two bearings provided with multiple plain surfaces. The compressor section of the rotor shaft was made of one forged piece using low-alloyed steel. This semi-finished forging was then machined to a... 

The frequency spectrum of the analysed microphone signals consists of a stochastic, broad spectrum of noise contributions and of the narrow spectrum of rotation frequencies of the turbomachinery. The compressor section contributes a fundamental frequency of 2800 Hz and the turbine section a fundamental frequency of 4200 Hz. The averaged total sound power within the helium-circuit and its piping increases with the power of the drive motor up to a maximum level of 160 dB. The total sound power as dependant on the drive power at measuring point 13 is shown in Fig 28. 

Air enters the jet engine through the air intake. It is then compressed in the compressor section. The compressed air next enters the combustion section, where fuel is added and ignited. The burning air-ftiel mixture expands and forces the turbine wheels to rotate before it exits through the engine exhaust ducts. The turbine wheels are connected to the compressor and provide the energy to turn the compressor. The... 

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