Compressor pressure ratio

CONDITION MONITORING OUTPUTS Loss in Compressor Flow Through Put Loss in Compressor Pressure Ratio Fuel Cost Penalty Projected Increase in Fuel Cost After One Month Operation Surge Point Deterioration Trend and Anticipated Outage Date... 

The increase in compressor pressure ratio decreases the operating range of the compressor. The operating range of the compressor stretches from the surge line at the low flow end of the compressor speed line to the choke point... 

Fig. 2.9 illustrates this approach of tracing exergy through a plant. The various terms in Eq. (2.49) are shown for an irreversible open gas turbine plant based on the JB cycle. The compressor pressure ratio is 12 1, the ratio of maximum to inlet temperature is 5 1 (T,nax = 1450 K with To = 290 K), the compressor and turbine polytropic efficiencies are... 

Calculation of the specific work and the arbitrary overall efficiency may now be made parallel to the method used for the a/s cycle. The maximum and minimum temperatures are specified, together with compressor and turbine efficiencies. A compressor pressure ratio (r) is selected, and with the pressure loss coefficients specified, the corresponding turbine pressure ratio is obtained. With the compressor exit temperature T2 known and Tt, specified, the temperature change in combustion is also known, and the fuel-air ratio / may then be obtained. Approximate mean values of specific heats are then obtained from Fig. 3.12. Either they may be employed directly, or n and n may be obtained and used. 

The results of calculations for the cooling air flow fractions in the first (nozzle guide vane) row of the turbine, ba.sed on the assumptions outlined in Section 5.2 for film cooled blading, are illustrated in Fig. 5.1. The entry gas temperature Tgi was taken as the combustion temperature Tcoi = Ty and the cooling air temperature as the compressor delivery temperature T2. The cooling air required is. shown here as a fraction of the exhaust gas flow, i.e. as ip/( 1 + ip), plotted against compressor pressure ratio and combustion temperature for an allowable blade metal temperature, Tpi = 800°C. Also shown are... 

The cooling fraction obviously increases with combustion temperature, but the compressor pressure ratio (and hence the cooling air temperature Tj) is also critically important. It is seen that the arbitrary assumptions made for i/ in Chapter 4 (linearly increasing with the combustion temperature cot would be approximately valid for a cycle with a pressure ratio just below 30. 

Available horsepower from a gas turbine is a function of air compressor pressure ratio, combustor temperature, air compressor and turbine efficiencies, ambient temperature, and barometric pressure. High ambient temperatures and/or low barometric pressure will reduce available horsepower while low ambient temperatures and/or high barometric pressure will increase available horsepower. All industrial turbines will have high-temperature protection, but in areas subject to very low ambient temperatures horsepower limiting may be required. 

Air enters the compressor of an ideal Brayton cycle at 100 kPa and 300 K with a volumetric flow rate of 5m /sec. The compressor pressure ratio is 10. The turbine inlet temperature is 1400 K. Determine (a) the thermal efficiency of the cycle, (b) the back-work ratio, and (c) the net power developed. 

Increasing the average temperature during the heat-addition process with a reheater without increasing the compressor pressure ratio increases the net work of the Brayton cycle. A multistage turbine is used. Gas is reheated between stages. 

The centrifugal compressor is a machine that converts the momentum of gas into a pressure head. The compressor pressure ratio (PD/P,) varies inversely with mass flow (W). For a compressor running at constant speed (co), constant inlet temperature (Tj), and constant molecular weight, the discharge pressure may be plotted against mass flow (Curve I in... 

Dimensional analysis applied to compressor pressure ratio... 

Further examination of the expression for the refrigeration effect B indicates that for a fixed load return temperature, the refrigeration effect depends largely upon the heat exchanger AT and the expander efficiency ex. The relationship between refrigeration effect and compressor pressure ratio is shown in Fig. 3 for various AT s and for an expander efficiency ex = 0.65, and again in Fig, 4 for various expander efficiencies and for a cold end AT = 4°R. 

These factors, which are component efficiencies, compressor pressure ratio, and turbine inlet temperature, are mainly determined by the design of the engine. 

The compressor pressure ratio and the turbine inlet temperature have a great influence on the unit thermal efficiency and the specific output. Further, those two factors interact in such a way that a certain pressure ratio is optimum for a certain turbine inlet temperature. See Figs. T-48 and T-49. 

Typical pressure ratios used were 1.5 to 3.0 lately, modern turbochargers have used pressure ratios of 3.2 to 3.5 and higher. The turbine pressure ratio is somewhat smaller than the compressor pressure ratio because of the pressure drop in the engine. 

Compressor Pressure Ratio Based on SNPP Heat Balance Section 6 and Brayton Turboaltemator Section 9.1. 

Reactor Outlet Temperature = 1150 K Compressor Outlet Pressure = 2.0 MPa Compressor Pressure Ratio = 2.0 He-Xe Coolant Molecular Weight = 31.5 g/mol Electrical Power Rating = 185 kWe Maximum Radiator Water Temperature = 505 K... 

Compressor Pressure Ratio Sensitivity - Design Case.23... 

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