Turbines expander sections

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. 

The value of the exergoeconomic factor / for the gas turbine expander (GT) is within the range of the target values (between 25 and 65%, Section IV.B). Therefore, no recommendations can be derived from the thermoeconomic evaluation of the gas turbine expander. 

Expanders have not been the essence of reliability. It is not that the expander design in itself has any significant problems. The problems for the most part seem to be related to the application. Most of the failures have been the result of the expander ingesting foreign substances, such as the catalyst in a catalytic cracking unit heat recovery application. Unlike the expansion section of the gas turbine, the inlet temperature is not as high, therefore, temperature is not a significant factor in reliability reduction. 

Reheat involves steam-to-steam heat exchange using steam at boiler discharge conditions. In the reheat cycle, after partially expanding through the turbine, steam returns to the reheater section of the boiler, where more heat is added. After leaving the reheater, the steam completes its expansion in the turbine. The number of reheats that are practical from a cycle efficiency and cost colisidcratioli is two. 

As the cross-sectional area expands beyond the entrance, flow separation occurs and results in turbulence and eddies, which continue as the air goes through the passages around the turbinates. The linear velocity... 

A number of other optimization strategies will be discussed later in this chapter. The savings resulting from replacing the letdown valves with expander turbine generators will be discussed in Section 2.13. The optimization of multistage chillers will be covered in connection with hydrogen liquefaction in Section 2.15.3, and coolant distribution controls will be covered under pump optimization in Section 2.17.2. 

Some of the compressor energy that was introduced by CP-1 is recovered in the expander turbine generator (ETG-1) as the working fluid pressure is reduced from that of the condenser (CO-2) to that of the evaporator (EV-1). The compressor station operation is optimized under differential temperature control (ATC-7) by the control system described in detail in Section 2.5.3 (see Figures 2.20 and 2.22). The electricity generated by ETG-1 is used to lower the total power consumption of the plant. 

Section II of the turbine and the second feedwater heater are shown in Fig. In doing the same calculations as for section I, we assume that each kilogram steam leaving section II expands from its state at the turbine entrance to the exit... 

Example 4.17 Ideal reheat regenerative cycle A steam power plant is using an ideal reheat regenerative Rankine cycle (see Figure 4.23). Steam enters the high-pressure turbine at 9000 kPa and 773.15 K and leaves at 850 kPa. The condenser operates at 10 kPa. Part of the steam is extracted from the turbine at 850 kPa to heat the water in an open heater, where the steam and liquid water from the condenser mix and direct contact heat transfer takes place. The rest of the steam is reheated to 723.15 K, and expanded in the low-pressure turbine section to the condenser pressure. The water is a saturated liquid after passing through the water heater and is at the heater pressure. The work output of the turbine is 75 MW. Determine the work loss at each unit. 

K, and expanded in the low-pressure turbine section to the condenser condition. The water is a saturated liquid after leaving the water heater at the heater pressure. The work output of the turbine is 80 MW. Determine the work loss at each unit if the surroundings are at 300 K. 

Reheat Turbine After the steam has expanded through several stages, it leaves the turbine and passes through a section of the boiler, where superheat is added. The superheated steam is then returned to the turbine for further expansion. 

The product gas of the methanation section contains mainly CHi, Hj, HjO, and CO2. Removing H1O from this stream results in SNG as the final product, which leaves the system at high pressure. The heat released from the hydrogasifier product gas, and the heat generated in the methanation reactors, are used to generate superheated steam (40 bar and 540°C), which enters a steam turbine. A fraction of partly expanded steam is used to dry the biomass, while the remaining part of the steam is used for power generation. 

The products leaving the main process loop shown in Figure 3 are further handled in sections not shown in the Figure. The gas phase stream is expanded. The possibility of recuperation of work by means of an expansion turbine is under study. Then, the stream is further cooled and treated in such a way that biocrude and water are routed to the liquid streams as much as possible. For the OD contained in the gas stream, it is desired to leave them in the gaseous phase. 

The work extracted from the expanding uid (HA-HC), may be utilized to generate electricity, compress gas, or just be dissipated in an ambient blower or oil friction brake (see Section 3.2.2.4). The net result is that as refrigeration is generated across the turbine, less refrigeration is needed from the incoming air and the air compressor discharge pressure can be run at much lower pressures. Cycles termed low-pressure cycles ensued from this development. 

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