A numerical analysis of condenser performance of a seawater desalination system

摘要

This thesis presents the numerical analysis of three type condensers for desalination of seawater system. The condensers that were analyzed were a finned tube condenser that was built in Malaysia desalination plant, a cooling tube condenser in Jordan, and a common plate finned tube condenser. The goal of the analysis is to observe the thermal performance parameters of a condenser such as heat and mass transfer coefficient, surface effectiveness and condensate flow rate. The parameters that were changed in the analysis were the face velocity of air, the water velocity, and the number of rows of tubes. The numerical analysis was done based on basic heat exchanger analysis using e-NTU method for a dry case, and using a j-factor correlation that was developed by McQuiston for studying the wet case. Results from the basic heat exchanger analysis showed the air humidity ratio profile and temperature profile of air and water at the outlet of the condenser. The exit air temperature and humidity ratio were inversely proportional to the length of the condenser, whereas the temperature of the water at the outlet was proportional to the length of the condenser. Results from the j-factor correlation method show that the heat and mass transfer coefficient of the system increased when the number of rows of tubes, face velocity and water velocity increased. Similarly, the analysis showed that the condensate flow rate was highly influenced by the face velocity. In addition, the surface effectiveness was inversely proportional to the face velocity.