What is the Enthalpy of Water at 45 Degrees and 1.2 Bar Pressure?

In summary, the conversation discusses finding the enthalpy of water at a temperature of 45 degrees and pressure of 1.2 bar. The homework equations and attempt at a solution are mentioned, with the speaker seeking help with finding the enthalpy of the fluid. The expert suggests looking up values in the steam tables and mentions a specific value for compressed water. The importance of specifying quality in order to determine the other enthalpy value is also mentioned.
  • #1
target
2
0

Homework Statement


Finding the enthalpy of water with the following known data:
Water, temperature 45 degrees, pressure 1.2 bar


Homework Equations


Q' = m'(steam) * h(gas) - m'(steam) - h(fluid)


The Attempt at a Solution


I need to find the enthalpy of water under the circumstances above, to calculate a quantity of heat transferred by condensing steam. However I seem to be unable to find the enthalpy of the fluid. All attempts to find the enthalpy, I end up with either tables of saturated water or compressed water at pressures way above 1.2bar. Anybody can help me with the problem?
 
Physics news on Phys.org
  • #2
Just look the values up in the steam tables.

I am assuming that you are using degree C because your pressure is in bars. From my copy of the NBS/NRC Steam Tables I have the following value.

h for compressed water is 188.51 kJ/kg @ 45 C and 1.2 bars.

You haven't specified at quality and you clearly do not have superheated steam because the saturation temperature @ 1.2 bar is 104.81 C and you are well below that temperature. Therefore, you have a liquid-vapor mixture which means that you need a quality value in order to determine the other enthalpy value that you need.

Do you follow?

Thanks
Matt
 

Related to What is the Enthalpy of Water at 45 Degrees and 1.2 Bar Pressure?

What is "Compressed water enthelpy"?

Compressed water enthelpy is a thermodynamic property of water that describes the amount of energy required to compress a specific amount of water at a given temperature and pressure.

How is "Compressed water enthelpy" calculated?

Compressed water enthelpy is typically calculated using the equation h = u + Pv, where h is the enthelpy, u is the internal energy, P is the pressure, and v is the specific volume of water.

What is the unit of measurement for "Compressed water enthelpy"?

The unit of measurement for compressed water enthelpy is typically joules per kilogram (J/kg) in the SI system, or calories per gram (cal/g) in the cgs system.

What is the significance of "Compressed water enthelpy" in science?

Compressed water enthelpy is an important property in various fields of science, including thermodynamics, chemistry, and engineering. It is used to understand and predict the behavior of water under different conditions, and is also useful in the design and operation of industrial processes involving water.

How does "Compressed water enthelpy" differ from other thermodynamic properties of water?

Unlike other thermodynamic properties of water, such as temperature and pressure, compressed water enthelpy takes into account the energy required for the compression of water. This property is particularly important in high pressure systems or in processes that involve the compression of water, such as water treatment or desalination.

Back
Top