Thermodynamics: Brayton Refrigeration Cycle with Regenerator

In summary, the conversation discusses a brayton refrigeration cycle with a regenerator and irreversible components. The given values include inlet temperature, outlet temperatures, mass flow rate, turbine and compressor efficiency, and pressure ratio. The specific enthalpy values at different stages of the cycle are also given. The goal is to find the regenerator effectiveness and determine the specific enthalpy values at stages 4 and 6. The conversation mentions that for an ideal regenerator, h4 would be equal to h1, but due to the turbine efficiency, this may not be the case. The regenerator effectiveness is calculated using the equation Et=(h1-h3)/(h4-h3) and approaches 1 as h4
  • #1
Robin Ghoul
2
0
I have a brayton refrigeration cycle with a regeneator same as the picture below only with irreversible regenrator, compressor and turbine (And different values).
p-10e-1a_12666_image010.gif

The given in my problem are:
Ti=0 C, T3= 35 C, T5= -80 C, mass flow rate m= 0.4 kg/s
Turbine efficiency Et=0.85, Compressor efficiency =0.8 and pressure ratio =5
I found h1=273.3 KJ/Kg, h2=552.27 KJ/Kg, h3= 308.5 KJ/Kg, h5=193 KJ/kg
I need to find the regenerator effectiveness
My question are:
1-How to find h4 and h6
2-What is the regenrator efficiency in this case I know if the regenerator was ideal the h4=h1, but I am unable to find the real h4, maybe it has to do with the turbine efficiency but I only have the real h5 I need h5s to find h4...
As fir the regenerator effectiveness I thought it would be Et=(h1-h3)/(h4-h3).. as h4 approaches h1, the effectiveness approaches 1
 
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  • #2
Also, specific heats are at room temperature
 

FAQ: Thermodynamics: Brayton Refrigeration Cycle with Regenerator

What is the Brayton refrigeration cycle with regenerator?

The Brayton refrigeration cycle with regenerator is a thermodynamic cycle used in refrigeration systems to produce a cooling effect. It involves compressing a working fluid, cooling it by rejecting heat, expanding it to a lower pressure, and then heating it back up before repeating the cycle.

How does the regenerator in the Brayton cycle improve efficiency?

The regenerator in the Brayton cycle is a heat exchanger that allows for the transfer of heat between the high and low pressure sections of the cycle. This allows for some of the heat from the working fluid to be recovered and used to preheat the fluid before entering the compressor, resulting in a more efficient cycle.

What is the difference between the Brayton refrigeration cycle and the Brayton power cycle?

The main difference between the Brayton refrigeration cycle and the Brayton power cycle is the direction of energy flow. In the refrigeration cycle, the working fluid is used to absorb heat and produce a cooling effect, while in the power cycle, the working fluid is used to produce mechanical work.

What are the main components of a Brayton refrigeration cycle with regenerator?

The main components of a Brayton refrigeration cycle with regenerator include a compressor, condenser, expander, evaporator, and regenerator. Some systems may also include a heat exchanger, valves, and a refrigerant or working fluid.

What are the advantages of using a Brayton refrigeration cycle with regenerator?

There are several advantages to using a Brayton refrigeration cycle with regenerator, including improved efficiency, lower operating costs, and the ability to use a variety of working fluids. It also has a simple and compact design, making it suitable for a wide range of applications.

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