|In a gas-turbine power plant. there is a limit on the maximm temperature at the turbine inletimposed by metallurgical considerations of tlie turbine blades, In order to increase the efficiency,one consideration is to increase the conmpressor pressure ratio keeping the turbine inlettemperature constant. Increasing the compressor pressure ratio will also decrease the net workdeveloped per unit mass flow rate,Consider a gas-turbine power plant operating on a simple Brayton Cycle with air as the workingfluid. The air enters the turbine at 1100 K and leaves at 110 kPa and 660 K. Heat is rejected tothe surroundings at a rate of 6750 kJ/s, and air flows through the cycle at a rate of 18 kg/s.Assuming both the turbine and the compressor to be isentropic. determine the best compressionratio for optimum efficiency and net work per unit mass flow rate of the plant.To solve this problem, you are asked to design a compression #3aio of a gas-turbine powerplant that will provide the best combination of plant thermal efficiency and net work output perunit mass flow rate.(a) Discuss your new design of the compression ratio to satisfy the problems requirement.(b) Compute the thermal efficiencies and net work per unit mass flow rates for severalcompression ratios keeping the turbine inlet temperature constant at 1100 K. Plot thethermal efficiency and the flow work vs pressure ratio on a single plot. Analyze theresults and suggest an optimum compressor pressure based on your plot. Account forthe variation of specific heats with temperature in evaluating the air properties.Clearly list all the assumptions you use for your calculations. Show all steps in yourcalculations and type equations directly in Microsoft Word.

In a gas-turbine power plant, there is a limit on the maximum temperature at the turbine inlet…

In a gas-turbine power plant, there is a limit on the maximm temperature at the turbine inlet imposed by metallurgical considerations of tlie turbine blades, In order to increase the efficie one consideration is to increase the compressor pressure ratio keeping the turbine inlet temperature constant. Increasing the compressor pressure ratio will also decrease the net wor developed per unit mass flow rate. Consider a gas-turbine power plant operating on a simple Brayton Cycle with air as the work fluid. The air enters the turbine at 1100 K and leaves at 110 kPa and 660 K. Heat is rejected the surroundings at a rate of 6750 kJ/ s, and air flows through the cycle at a rate of 18 kg/s. Assuming both the turbine and the compressor to be isentropic, determine the best compress ratio for optinmum efficiency and net workper nit mass flow rate of the plant. To solve this problem vou latel aske desion a compression #tio of a gas-turbine

In a gas-turbine power plant, there is a limit on the maximm temperature at the turbine inlet imposed by metallurgical considerations of tlie turbine blades, In order to increase the efficie one consideration is to increase the compressor pressure ratio keeping the turbine inlet temperature constant. Increasing the compressor pressure ratio will also decrease the net wor developed per unit mass flow rate. Consider a gas-turbine power plant operating on a simple Brayton Cycle with air as the work fluid. The air enters the turbine at 1100 K and leaves at 110 kPa and 660 K. Heat is rejected the surroundings at a rate of 6750 kJ/ s, and air flows through the cycle at a rate of 18 kg/s. Assuming both the turbine and the compressor to be isentropic, determine the best compress ratio for optinmum efficiency and net workper nit mass flow rate of the plant. To solve this problem vou latel aske desion a compression #tio of a gas-turbine

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter45: Domestic Refrigerators And Freezers

Section: Chapter Questions

Problem 20RQ: Welded ______sealed compressors are normally used in household refrigerators.

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A steady-flow system operating on the ideal Ericsson cycle can achieve the Carnot efficiency. One of the salient features of this cycle is the isothermal expansion through a heated turbine, as shown in Fig. a. Heat is added to the turbine such that the outlet temperature is equal to the inlet temperature, i.e. T₁=T₂, and the overall pressure ratio for this process is rₚ=P₁/P₂. However, an isothermal expansion through a heated turbine is very difficult to achieve in practical engineering applications. An alternate approach is two use a multi-stage expansion process with reheating. In this approach, the gas expansion process is carried out in multiple stages with reheating in between each stage. Consider the two-stage turbine expansion with reheating shown in Fig. b. The gas enters the first stage of the turbine at state A1, is expanded isentropically to an intermediate pressure Pₐ₂, is reheated at constant pressure to state B1, and is expanded in the second stage isentropically to the…
A steady-flow system operating on the ideal Ericsson cycle can achieve the Carnot efficiency. One of the salient features of this cycle is the isothermal expansion through a heated turbine, as shown in Fig. a. Heat is added to the turbine such that the outlet temperature is equal to the inlet temperature, i.e. T₁=T₂, and the overall pressure ratio for this process is rₚ=P₁/P₂. However, an isothermal expansion through a heated turbine is very difficult to achieve in practical engineering applications. An alternate approach is two use a multi-stage expansion process with reheating. In this approach, the gas expansion process is carried out in multiple stages with reheating in between each stage. Consider the two-stage turbine expansion with reheating shown in Fig. b. The gas enters the first stage of the turbine at state A1, is expanded isentropically to an intermediate pressure Pₐ₂, is reheated at constant pressure to state B1, and is expanded in the second stage isentropically to the…
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A 1200 kW water-cooled chiller has a centrifugal compressor with refrigerant R134a as the working fluid. The compressor runs at 9600 rev/min and has a slip factor of 0.95 and an overall isentropic efficiency of 90%. The impeller tip speed is not to exceed 160m/s. The evaporating and condensing temperatures are 2°C and 40°C respectively. Assuming that there is no superheating and sub-cooling, a) sketch the refrigration cycle on a P-h diagram (please indicate the pressures and specific enthalpies of all points in the cycle); b) determine the mass flow rate of the refrigerant R134a; c) determine the coefficient of performance of the chilled water plant; and discuss the possible measures to uplift the plant COP d) determine the number of stages and the impeller tip diameters, assuming that all stages would share same work input and each stage compression would have the same impeller tip diameter. e) Please also comment how the slip factor can affect the energy performance of the…