Regenerative Air Standard Gas Turbine

In summary: The total entropy generation will be the sum of the entropy generated in each component. In summary, the addition of intercooling and reheating in the regenerative gas turbine cycle increases the thermal efficiency compared to regeneration alone. To determine the entropy generation, the change in entropy of the working fluid needs to be calculated for each component.
  • #1
husanim2
1
0
Hi there, can anyone shed some light on regenerative gas turbine cycle. How to work problems of this sort.

DATA:
compressor intake: 0.95 bars @ 22 `C
pressure ratio 6:1 (compressor), 82% efficient

turbine inlet: 1100 K. 85% efficient.

regenerative effectiveness: 70%

Intercooling and reheating added to the cycle. pressure ratios across the 2-stage compressor and 2-stage turbines and set equal to provide minimum work input and max. output.


Determine:
(a) the effect of the addition of the intercooling and reheating on the thermal efficiency obtained with regeneration alone.
(b) the entropy generation in the compressor, turbine. and regenerator.

Thank you.
Husani
 
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  • #2
ANSWER:a) The addition of the intercooling and reheating will increase the thermal efficiency of the regenerative cycle compared to the efficiency obtained without these components. This is because the intercooling reduces the working fluid temperature in the compressor, which increases the mass flow rate of the gas and thus improves the thermodynamic efficiency of the cycle. The reheating further increases the working fluid temperature, thus increasing the output of the cycle. b) To calculate the entropy generation in the compressor, turbine, and regenerator, you will need to calculate the change in entropy of the working fluid as it passes through each component. This can be done by calculating the change in enthalpy of the working fluid at each state and then using the entropy equation.
 
  • #3


Hello Husani,

A regenerative air standard gas turbine is a type of gas turbine that incorporates a regenerator in its cycle. A regenerator is a device that recovers heat from the exhaust gases of the turbine and uses it to preheat the air entering the compressor. This results in an increase in efficiency and power output of the turbine.

To solve problems related to this type of turbine, we need to use the Brayton cycle, which is a theoretical cycle that describes the operation of a gas turbine. The Brayton cycle consists of four processes: isentropic compression, constant pressure heat addition, isentropic expansion, and constant pressure heat rejection.

To solve the given problem, we need to first calculate the specific enthalpy at each stage of the cycle. Using the given data, we can calculate the specific enthalpy at the compressor inlet, compressor outlet, turbine inlet, and turbine outlet. We can then use these values to calculate the heat added and rejected in each process of the cycle.

(a) The addition of intercooling and reheating to the regenerative cycle will increase the efficiency obtained with regeneration alone. This is because intercooling reduces the temperature of the air entering the compressor, resulting in a decrease in the work required to compress the air. Reheating also increases the temperature of the air entering the turbine, resulting in an increase in the power output. Therefore, the addition of intercooling and reheating will improve the overall efficiency of the gas turbine.

(b) To determine the entropy generation in the compressor, turbine, and regenerator, we need to calculate the specific entropy at each stage of the cycle. Using the calculated values of specific enthalpy and specific entropy, we can determine the entropy generation in each process of the cycle. The compressor and turbine will have some entropy generation due to irreversibilities, but the regenerator will have minimal entropy generation as it is a heat exchanging device.

I hope this helps to shed some light on the regenerative gas turbine cycle. If you need further assistance with specific calculations, please provide more details and I will be happy to help. Best of luck with your problem-solving!
 

1. What is a Regenerative Air Standard Gas Turbine?

A Regenerative Air Standard Gas Turbine is a type of gas turbine that uses air as the working fluid to generate power. It is called "regenerative" because it uses a heat exchanger to recover some of the waste heat from the exhaust gases and preheat the compressed air before it enters the combustion chamber. This increases the efficiency of the turbine.

2. How does a Regenerative Air Standard Gas Turbine work?

A Regenerative Air Standard Gas Turbine works by compressing air, mixing it with fuel, and combusting the mixture in the combustion chamber. The hot exhaust gases then pass through a heat exchanger, where they transfer some of their heat to the compressed air. The preheated air then enters the combustion chamber, where it is further heated and expanded to drive the turbine blades and generate power.

3. What are the advantages of a Regenerative Air Standard Gas Turbine?

The main advantage of a Regenerative Air Standard Gas Turbine is its increased efficiency. By preheating the compressed air, the turbine is able to generate more power with less fuel. This translates to lower fuel costs and reduced emissions. Additionally, the use of air as the working fluid makes the turbine more environmentally friendly compared to other types of gas turbines.

4. What are the applications of a Regenerative Air Standard Gas Turbine?

A Regenerative Air Standard Gas Turbine is commonly used in power generation, particularly in combined cycle power plants. It can also be used in industrial processes such as natural gas compression, chemical processing, and oil refining. Additionally, smaller units can be used for heating and cooling in buildings.

5. How does a Regenerative Air Standard Gas Turbine compare to other types of gas turbines?

Compared to other gas turbines, a Regenerative Air Standard Gas Turbine has higher efficiency and lower emissions. However, it may have a higher initial cost due to the added heat exchanger. It also has a more complex design and may require more maintenance. Its use is most suitable for applications where efficiency and emissions reduction are a priority.

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