Which one contains more internal energy: (steam at 20 KG of pressure and 460 degrees temperature) or (steam at 100 KG of pressure and 460 degrees temperature)?
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Who more and why? How to understand it?
Internal energy seems to be related to temperature and mass. Water vapor with the same mass should have the same internal energy, right? If the volumes are equal, then the 100 KG sample will definitely have more internal energy, after all, it has a greater mass
Internal energy seems to be related to temperature and mass. Water vapor with the same mass should have the same internal energy, right? If the volumes are equal, then the 100 KG sample will definitely have more internal energy, after all, it has a greater mass
I think your question isn’t comprehensive enough – what about quality and volume? It seems that temperature and pressure alone can’t be used for comparison, right? This is how I understand it; I’m not sure if it’s correct
The internal energy of a certain amount of an ideal gas or any other homogeneous substance depends not only on temperature but also on its volume or pressure; that is, the internal energy U is a function of T, V, or T, p.
Based on a mass of 1,000 kilograms, what do everyone think?
I wonder if it’s because my understanding is too simple? Just check Spycatcher’s website; it’s easy, right? The so-called energy of steam consists of the heat associated with its phase change and the heat resulting from a temperature drop. If the pressure applied is absolute pressure, at 2.1 Mpa the saturation temperature is 217 degrees, and the enthalpy of the steam is 3376.9 KJ/KG. At 10 Mpa, the corresponding temperature is 311 degrees, with an enthalpy of 3266.91 KJ/KG. At 460 degrees, both types of steam are in a superheated state. http://www.spiraxsarco.com/cn/resources/steam-tables/superheated-steam.asp
A bit confused? Why does steam at a pressure of 20 KG have a greater internal energy or enthalpy than steam at a pressure of 100 KG? ? ? I don’t understand
Internal energy seems to be related to temperature and mass. Water vapor with the same mass should have the same internal energy, right? If the volumes are equal, then the 100 KG sample will definitely have more internal energy, after all, it has a greater mass
Internal energy = work done + heat absorbed. After 100 kilograms of pressurized steam does work, it can turn into 20 kilograms of steam; therefore, its internal energy is greater.
Conversely, it is only by doing positive work on 20 kilograms of steam that it is possible to turn it into 100 kilograms of steam. At the same temperature, the 100 kilograms of steam has received more work, so its internal energy is greater