As you can see, both equations use the ideal gas low with the universal gas constant in J/kg.k
Both equations are used in published articles as follows:
"Application of dynamic programming to the optimal management of a hybrid power plant with wind turbines, photovoltaic panels and compressed...
Many thanks for your answers.
As you said, I (the OP) need to give my head a shake.
The used air receiver equation in my model doesn't depend on the compressor pressure. As more air mass flows to the air receiver, its pressure increases. Then, I found it exceeds the air compressor discharge...
I am trying to simulate the performance of a compressed air energy storage system.
I have modeled the compressor using the following equation
The compressed air pressure in the tank is changing according to the following equation
The outlet pressure of the compressor is 15 bar and the...
The first equation and third equation in my post.
n/(n-1) in the first equation and 1/(gamma -1) in the third and ASME equation.
n or gamma or K are the same = 1.4 the ratio of specific heat of the fluid. I hope my question is clear.
Thank you @shvet for your reply.
The ASME equation is the same as the third equation in my post. However, is it (1/(gamma - 1)) or (gamma/(gamma - 1)) ?
Thank you @Snickster for your reply but I asked you about the missing gamma between the first and third equation. In the third equation you can see P/(gamma - 1) while in the first equation it is P*gamma/(gamma - 1).
Thank you @Snickster for your reply.
However, regardless of the volume, in the third equation you can see P/(gamma - 1) while in the first equation it is P*gamma/(gamma - 1).
Hello all,
For a vessel with a constant volume of 8 m^3 with a 15 bar pressurized air in it. What is the contained energy in the vessel?? If the pressure changes from 15 bar to 7 bar or to 20 bar; how much energy does the vessel lose or gain ? Assuming isentropic processes with n or k = 1.4
I...
Many thanks @goutam for your reply.
As you said, when I add " - (P_B-P_A)V_B " to the third equation. It gives me the same answer as Equations 1 and 2.
So, should I don't consider the effect of constant pressure at tank outlet as equation 3 suggests or equation 1 and 2 represent the isothermal...
For an Isothermal compression process of air in a vessel with constant volume, I found the following expressions
Two of them give the same exact answer while the third one gives a different answer I don't know why.
For adiabatic air compression, I found these two expressions which give...
Ok let's say I have an available energy of 26 kWh per day and about half of it will be stored during the day. Taking into consideration the compression efficiency of 85% so I will have about 11 kWh to be stored.
There will be losses in terms of heat (I want to store this heat to be used during...
Many thanks goutam_freelance for your help.
we will have the heat exchanger to store the heat generated durning compression in a water tank to be used during expansion. Meanwhile the cold temperature resulted from expansion will be used to cool the air during compression to have an adiabatic...
Many many thanks for your kind replys and help.
I just wanted some help in terms of thermodynamics to test different pressure ratio for the same amount of energy to see its effect on the expected air bottle size.
If the air motor works at a certain pressure, what should be the minimum and...
Hi All
For a PV project of 5 kW, we will use a CAES.
The preliminary design will consist of a compressor - 2 heat exchanger - Air receiver - air motor - generator - 2 water tanks as a thermal storage units to have an adiabatic systems.
For a 5 kW PV plant, an energy of 20 to 26 kWh is expected...
