Solar Thermal Absorption Cooling - Heat Rejection by Pulsed Water Spraying on a Hybrid Cooler
Abstract
A hybrid cooler was installed for heat rejection in the mid temperature range of the absorber condenser unit of a LiBr-H2O solar thermal driven absorption cooling system. The heat rejection efficiency generally is increased by continuous water sprinkling on the heat conducting surface of the heat exchanger and the water evaporation thereof e.g. because of latent cooling. To reduce the water consumption the cooler heat exchanger was pulse-sprayed through nozzles. By decreasing the pulse cycle time the return fluid temperature to the absorber condenser unit of the absorption cooling machine could be lowered and finally reached the fluid temperature of the open cooling tower for comparison. On the contrary the water use is increased by a lower pulse cycle time because the total water spraying time is increased. A strong inhomogeneity of the temperature distribution on the hybrid cooler heat exchanger could be observed.