What is heat transfer analysis?
The Heat transfer simulation type allows the calculation of the temperature distribution and heat flux in solids under thermal loads (for example, convection and radiation). Both steady-state and transient simulations are supported.
What is the most common type of heat exchanger used in the process industries?
The shell-and-tube heat exchanger is probably the most common type found in industry. It is widely used in the process industries as well as in many types of HVAC equipment.
How do you evaluate a heat exchanger performance?
The simplest indicator of the performance of a heat exchanger is the temperature change of the fluid under consideration. From our high school lessons on thermodynamics, we can recall that the rate of heat transfer is the product of the rate of heat capacity and the temperature change.
What is effective heat exchanger?
Effectiveness of a heat exchanger. The effectiveness (ϵ) of a heat exchanger is defined as the ratio of the actual heat transfer to the maximum possible heat transfer.
What is meant by NTU?
NTU stands for Nephelometric Turbidity unit, i.e. the unit used to measure the turbidity of a fluid or the presence of suspended particles in water. The higher the concentration of suspended solids in the water is, the dirtier it looks and the higher the turbidity is.
How do you calculate lmtd?
by definition given above, LMTD for counter current flow = (60-50) / ln(60/50) = 10 / 0.1823 = 54.850C. For co-current heat exchanger, ΔT1 = TH1 – TC1 = 100 – 30 = 700C (At first end hot and cold fluids enter the heat exchanger.)
What happens when lmtd is zero?
Zero LMTD means no further heat transfer is possible and if heat transfer is to be done than infinite area is required, which is not possible. The LMTD is a logarithmic average of the temperature difference between the hot and cold feeds .
What is the purpose of using lmtd correction factor?
here F (< 1) is interpreted as a geometric correction factor, that when applied to the LMTD (Log Mean Temperature Difference) of a counter flow heat exchanger, provides the effective temperature difference of the heat exchanger under consideration.
Which is more efficient parallel flow or counterflow?
Counter flow heat exchangers are inherently more efficient than parallel flow heat exchangers because they create a more uniform temperature difference between the fluids, over the entire length of the fluid path.
What are the limitations of lmtd method?
Assumptions and limitations However, if the specific heat changes, the LMTD approach will no longer be accurate. A particular case for the LMTD are condensers and reboilers, where the latent heat associated to phase change is a special case of the hypothesis.
Which mode is more dominant in heat conduction?
Convection
What is lumped heat capacity analysis?
The lumped-heat-capacity method of analysis is used in which no temperature gradient exists. This means that the internal resistance of the body (conduction) is negligible in comparison with the external resistance (convection). i.e small h and large k.
What is the maximum efficiency for parallel flow heat exchanger?
What is the maximum efficiency for parallel flow heat exchanger? Explanation: No matter how large the exchanger be or how high be the flow of overflow at transfer coefficient, the maximum efficiency for parallel flow heat exchanger is 5%.
Where does parallel flow heat exchanger used?
In general, parallel flow heat exchangers considered less efficient than counter flow heat exchangers in terms of transferring heat from one fluid to another. However, there are applications where parallel flow has its benefits, such as when limiting the transfer of heat is recommended.
How are heat exchangers classified?
Heat exchangers are classified according to transfer processes into indirect- and direct- contact types. FIGURE 1.2 (a) Classification according to process function; (b) classification of condensers; (c) classification of liquid-to-vapor phase-change exchangers.