In thermal desalination, what impact does decreasing the condenser temperature have on system efficiency?

In thermal desalination, decreasing the condenser temperature generally increases the system's efficiency, but only up to a certain point, after which further reductions may have diminishing returns or even negative impacts. The condenser's role is to condense the steam produced during the evaporation process back into liquid water, releasing the latent heat of condensation. A lower condenser temperature increases the temperature difference between the condensing steam and the cooling water, which enhances the heat transfer rate and allows more steam to condense. This leads to a higher distillate production rate. Moreover, a lower condensing temperature lowers the pressure in the system, which can improve the thermodynamic efficiency of the evaporation process. However, there are practical limitations to how low the condenser temperature can be reduced. The condenser temperature is limited by the temperature of the available cooling water. It is not possible to cool the condenser below the temperature of the cooling water. Also, excessively low condenser temperatures can increase the cost of cooling water pumping and treatment. The relationship is not linear; the efficiency gains from lowering the condenser temperature diminish as the temperature approaches the cooling water temperature. Furthermore, maintaining a very low condenser temperature may require more sophisticated and energy-intensive cooling systems. The optimal condenser temperature is a balance between maximizing heat transfer, minimizing cooling water costs, and maintaining overall system reliability.