Solar desalination systems have received special attention as one of the innovative and sustainable solutions to deal with the global water scarcity crisis. These systems have been developed in two general categories: active and passive, but they still face challenges such as the requirement for solar tracking mechanisms, lack of effective thermal management, and thermal energy loss during evaporation and distillation issues that have resulted in a decrease in the final efficiency of these technologies. In this study, with the aim of improving thermal performance and reducing dependence on the solar tracking mechanism, a compact multi-stage conical solar desalination system was designed and evaluated. This novel system reduced the distance between the condenser and the evaporator and heated the subsequent stage using the latent heat generated during the previous stage\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'s distillation process. This design lessens the need for external energy input and permits energy reuse. Also, by using the conical geometric structure, the optimal angle of solar radiation reception is maintained, and the problem of the need for solar tracking systems is solved. In the first step, the effect of system compactness and reducing the distance between the evaporator and condenser on thermal performance was investigated, and the results showed that this compactness led to a 60% increase in the amount of fresh water production. Among the single-stage systems, the highest efficiency of fresh water production of 25.1% was recorded. Subsequently, by adding more stages to the optimized configuration, the system performance was significantly improved. So that increasing the number of stages from one to three led to a 74% increase in fresh water production, and the thermal efficiency of the three-stage system reached 43.79%. In the final step, the effect of creating fine grooves on the surface of the distillers was investigated in order to effectively guide the distilled droplets and increase the condensation rate. Experimental results show that the use of 32 grooves on the condenser surface, compared to a three-stage system without grooves, resulted in a 21.8% improvement in fresh water production.

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