Efficiency of water spraying on a heat exchanger: Local characterization with the impacted surface

In the present paper, water spraying is designed for an embedded air conditioning application. A pilot designed for air conditioning conditions was built and equipped with a set of atomizer. The results obtained with this pilot show that heat transfer enhancement is higher at low heat exchanger surface temperature. Moreover, a thermal image analysis has highlighted that the surface impacted by the spray excluding the clogged parts is appropriate to express the local efficiency of the spray. Indeed, this surface reaches a steady-state approximately after the same time than heat transfer enhancement. This surface depends on heat-exchanger surface temperature, and not on the air flow. Finally, the efficiency of water spraying on a heat exchanger is correlated with the impacted surface.