Analysis of condensers
In a typical design problem, the final objective is to find the heat transfer area A required from given input.
Fig: Refrigeration cycle on T-s diagram
From, the total heat rejected in the condenser, Q is given by:
The required condenser area is then given by the equation:
where U is the overall heat transfer coefficient
A is the heat transfer area of the condenser, and
ΔTm is mean temperature difference between refrigerant and external fluid
- In a typical design problem, the final objective is to find the heat transfer area A required from given input.
- From the above equation it can be seen that to find heat transfer area, one should know the amount of heat transfer rate across the condenser (Qc), the overall heat transfer coefficient (U) and the mean temperature difference.
- The heat transfer rate in the condenser depends on the refrigeration capacity of the system and system COP.
- The overall heat transfer coefficient depends on the type and design of condenser.
- The mean temperature difference depends on the operating temperature of the refrigeration system, type of the condenser and the external fluid.
- In a typical rating problem, the objective is to find the rate of heat transfer when other parameters are fixed.