How do you calculate heat loss in a pipe?
Heat loss from steel pipes at various temperature difference between pipes and ambient air:
- 1 kW (kJ/s) = 102.0 kpm/s = 859.9 kcal/h = 3,413 Btu/h = 1.360 hk = 1.341 hp = 738 ft lb/s = 1,000 J/s = 3.6×106 J/h.
- 1 m (metre) = 3.2808 ft = 39.37 in = 1.0936 yd = 6.214×10–4 mile.
How do you calculate latent heat loss?
Latent heat calculation
The specific latent heat is different for solid to liquid transition and liquid to gas transition. For example, if we want to turn 20 g of ice into water we need Q = 20 g * 334 kJ/kg = 6680 J of energy. To turn the same amount of water into vapor we need Q = 45294 J .
What is latent heat of vaporization of water?
The heat of vaporization of water is about 2,260 kJ/kg, which is equal to 40.8 kJ/mol. The vaporization is the opposite process of condensation. The heat of condensation is defined as the heat released when one mole of the substance condenses at its boiling point under standard pressure.
What is latent heat loss?
Latent heat is the energy absorbed by or released from a substance during a phase change from a gas to a liquid or a solid or vice versa.
What is heat loss in pipe?
To simplify heat loss calculations, pipe heat loss is based on the heat loss per linear foot rather than the entire area of any given length. Also, for pipe insulation, the outer area of insulation is greater than the inner area due to wrapping insulation around the cylindrical shape of a pipe.
How is Au value calculated?
U Value is the reciprocal of all resistances of the materials found in the building element. To calculate the U-Value of the building element the R-Value of all the different components that make up that element will be considered. U-Value (of building element) = 1 / (Rso + Rsi + R1 + R2 …)
What is the formula of total latent heat?
It is a measurement of the amount of heat energy (Q) emitted or absorbed per mass (m) during a phase shift. The formula Q = mL is used to describe it. It’s commonly referred to as the material’s “latent heat.” The joule per kilogramme J/kg is the SI unit.
What is the value of latent heat of fusion and vaporization of water?
The heat of fusion for water at 0 °C is approximately 334 joules (79.7 calories) per gram, and the heat of vaporization at 100 °C is about 2,230 joules (533 calories) per gram.
What is energy formula?
The energy stored in an object due to its position and height is known as potential energy and is given by the formula: P.E. = mgh. Unit. The SI unit of energy is Joules (J).
What are the three types of latent heat?
Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process. Two common forms of latent heat are latent heat of fusion (melting) and latent heat of vaporization (boiling).
What happens when latent heat is released?
Latent heat of condensation is energy released when water vapor condenses to form liquid droplets. The latent heat of condensation is defined as the heat released when one mole of the substance condenses.
What is latent heat of fusion of water?
We know that the Latent heat of fusion of water is 334 Joules per gram or 334000 Joules per Kilogram.
What are the 4 types of latent heat?
In essence, this energy that is required by a substance to either freeze, melt or boil is said to be latent heat.
- Early Developments of the Concept. …
- Types of Latent Heat Transfer. …
- Latent Heat of Fusion. …
- Latent Heat of Vaporization. …
- Reasonable Heat and Meteorology. …
- Instances of Latent and Sensible Heat. …
- Specific Latent Heat.
Why is latent heat called so?
Latent heat, also called heat of transformation, is the heat given up or absorbed by a unit mass of a substance as it changes from a solid to a liquid, from a liquid to a gas, or the reverse of either of these changes. It is called latent because it is not associated with a change in temperature.
Why latent heat decreases with increase in pressure?
With the increase in pressure the boiling point of the liquid increases and a lesser amount of energy needed to overcome the intermolecular force thus the latent heat of steam required is decreased.
Does latent heat of vaporization of water change with pressure?
The latent heat of vaporization of water means the amount of heat required to break the intermolecular forces and convert it into the gaseous phase. As there is an increase in the pressure more heat is required to overcome the pressure force acting. Therefore, the latent heat is more.
Why does latent heat decrease with temperature?
The latent heat goes down, because the latent heat is the difference of specific heat of steam – specific heat in water. Since water has a higher specific heat, it catches up on the steam until it reaches the value of steam, and then the least energy is for water to be a gas, rather than a liquid.
Does latent heat depend on pressure?
None, the latent heat of a material is based on it’s molecular structure and bonds, pressure has no bearing on latent heat of a material. Pressure will have an effect on the sensible temperature at which a material will change state, but no effect on the latent heat of that state change.
What increases heat of vaporization?
In general the energy needed differs from one liquid to another depending on the magnitude of the intermolecular forces. We can thus expect liquids with strong intermolecular forces to have larger enthalpies of vaporization.
How does pressure affect enthalpy of vaporization?
Since higher vapor pressure means easier boiling, it also means easier vaporization and thus lower ΔHvap . So, ΔHvap decreases at higher pressure for a constant temperature.
