steam_0912

# steam_0912 - STEAM TABLES REVIEW OF DEFINITIONS AND UNITS...

This preview shows pages 1–2. Sign up to view the full content.

STEAM TABLES REVIEW OF DEFINITIONS AND UNITS Specific volume ( V’) V’=V/m=1/ρ . Unit: m 3 /kg Internal energy ( E i ) Internal energy is the sum of the kinetic energy due to molecular motion and potential energy intermolecular attractive (or repulsive) forces. Enthalpy and specific Enthalpy Enthalpy is a measure of the quantity of energy contained in a thermodynamic system. H = E i + p V Internal energy (U), enthalpy (H), work (W), and heat (Q) are all measured in kJ. Specific enthalpy ( H’ ) is the enthalpy contained in one kg of a substance. Unit: kJ/kg H = m H’ Sensible and latent Heat Sensible heat causes a temperature change but the body does not change its phase. Q= m. c p . (T fin -T in ) C p : specific heat capacity, the amount of heat required for 1 kg of a given material to rise temperature by 1°C. (or heat released to decrease temperature by 1 °C). Unit: kJ/kg °C. Q is positive when the body is gaining energy and negative when the body is losing energy through heat transfer. Latent heat specifies the amount of heat needed to cause a given change of state of 1 kg of a given material with no change in its temperature. It is further divided into latent heat of boiling (or vapourization) and latent heat of melting (or freezing). Unit: kJ/kg, Q= m. H latent Latent heat is positive when it is supplied to the body (melting and boiling), and negative

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 5

steam_0912 - STEAM TABLES REVIEW OF DEFINITIONS AND UNITS...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online