Heat Transfer Flashcards
Define heat
energy produced / transferred from one body, region, set of components or thermodynamic system to another in any way other than as work
List the types of heat transfer
- Conduction
- Convection
- Radiation
Describe:
Conduction
transfer through solids or fluids that dont move
Describe:
Convection
transfer by fluids that move
Describe:
Radiation
transfer by electromagnetic waves
What is steady state heat flow?
The system’s temp and heat flow rate stay constant
Provide an example of steady state heat flow
heat exchanger with steady flows of steam and product
What is transient (unsteady state) heat flow?
The system’s temp and heat flow rate change with time
Provide an example of transient heat flow
Warming up something taken from a freezer or fridge
What is the purpose of studying heat transfer? (3)
1- rate of heat transfer will determine time process takes
2- design of equipment
3- evaluate equipment performance
Formal definition of Specific Heat (Cp)
The amount of heat required to raise the temp of **1kg **of material by **1C **at a constant pressure (Unit = K/kg C)
A measure of how much heat it requires to change somethin’s temp
Define Thermal Conductivity (k)
The amount of heat that is conducted through a unit thickness of a material per second at a **constant temp difference **across the material (units: W/(m *C)
A materials ability to conduct heat
Describe thermal conductivity
A measure of:
1- how well a material conducts heat
2 - how easily it flows through the material
for a given temp difference
Based on the distance through materials (per length)
