What are the factors affecting heat transfer?

Factors that affect rate of heat flow include the conductivity of the material, temperature difference across the material, thickness of the material, and area of the material. Different materials have greater or lesser resistance to heat transfer, making them better insulators or better conductors.

How do you find the overall heat transfer coefficient of a heat exchanger?

Composition

= the overall heat transfer coefficient (W/(m2•K))
= the contact area for each fluid side (m2) (with and expressing either surface)
= the thermal conductivity of the material (W/(m·K))
= the individual convection heat transfer coefficient for each fluid (W/(m2•K))
= the wall thickness (m).

In which of the following heat exchange processes the value of overall heat transfer coefficient will be highest?

Which one is having highest value of overall heat transfer coefficient? Explanation: Overall heat transfer coefficient for feed water heaters is 8500 W/m2 K while that of steam, alcohol condensers and ammonia condensers are 5000 W/m2 K, 630 W/m2 K and 1400 W/m2 K.

What is the overall heat transfer coefficient?

The overall heat transfer coefficient, or U-value, refers to how well heat is conducted through over a series of resistant mediums. Its units are the W/(m2°C) [Btu/(hr-ft2°F)].

What is the formula for change in temperature?

When heat transfer is involved, use this formula: change in temperature = Q / cm to calculate the change in temperature from a specific amount of heat added. Q represents the heat added, c is the specific heat capacity of the substance you’re heating, and m is the mass of the substance you’re heating.

What is the formula for isothermal process?

For an ideal gas, from the ideal gas law PV = NkT, PV remains constant through an isothermal process. A curve in a P-V diagram generated by the equation PV = const is called an isotherm. For an isothermal, reversible process, the work done by the gas is equal to the area under the relevant pressure -volume isotherm.

Is work done in an adiabatic process?

When an ideal gas is compressed adiabatically (Q=0), work is done on it and its temperature increases; in an adiabatic expansion, the gas does work and its temperature drops.

Can a process be isothermal and adiabatic?

If a process is both isothermal and adiabatic, it is implied that the work done on the system is being stored somewhere other than the internal energy of the working fluid. (Or conversely, if the system is doing work, the energy is coming from somewhere other than internal energy.)

What is ∆ U in adiabatic process?

According to the definition of an adiabatic process, ΔU=wad. Therefore, ΔU = -96.7 J. Calculate the final temperature, the work done, and the change in internal energy when 0.0400 moles of CO at 25.0oC undergoes a reversible adiabatic expansion from 200.

Is adiabatic constant pressure?

The assumption that a process is adiabatic is a frequently made simplifying assumption. For such an adiabatic process, the modulus of elasticity (Young’s modulus) can be expressed as E = γP, where γ is the ratio of specific heats at constant pressure and at constant volume (γ = CpCv ) and P is the pressure of the gas .

How is adiabatic constant calculated?

For an ideal monoatomic gas (e.g. Helium, Argon etc), the adiabatic index is 5/3 or 1.67. For monoatomic gases, CV = 3R/2 and CP = 5R/2 (where R is universal gas constant).

How is adiabatic calculation?

Adiabatic process The following formula is valid: p₁ * V₁γ = p₂ * V₂γ , where γ = Cp / Cv is known as heat capacity ratio. The work done by the gas is opposite to its initial internal energy change W = -ΔU .

How do you calculate the adiabatic process?

Work Done in an Adiabatic Process

For an adiabatic process of ideal gas equation we have.
Suppose in an adiabatic process pressure and volume of a sample of gas changes from (P1, V1) to (P2, V2) then we have.
Work done by gas in this process is.
Now Since P1V1=nRT1 P 1 V 1 = n R T 1 and P2V2=nRT2 P 2 V 2 = n R T 2 , Work done can be expressed as.

Does adiabatic mean no temperature change?

An adiabatic process has a change in temperature but no heat flow. The isothermal process has no change in temperature but has heat flow.