## 2 Systems Description  
Figure 1 depicts a schematic design of the basic system, and the modified suggested solar-driven multi-generation system with a heat recovery unit (MGS-I and MGS-II). By connecting solar ORC to a DCS and HDH desalination unit, the suggested system is designed to produce power, space cooling/domestic heating, and fresh water. An evacuated tube solar collector and a thermal storage tank are components of the solar system. A thermal oil (Therminol-VP1) is utilized as the working fluid for the solar field loop because of its capacity to maintain the liquid phase at temperatures up to 400 \({}^{\circ}\)C [23]. The basic system (MGS-I), which serves as a reference system, and the modified system are the systems that were investigated (MGS-II). As depicted in Figure 1, the MGS-I can produce energy, space cooling, and freshwater (a). The system has four major cycles: two closed cycles (the solar and the ORC) and two open cycles (air and water cycles). Figure 1: _Cont._  
In the solar field cycle, evacuated tube solar collectors are used to charge the TES-1 tank when it is sunny (state points t1 and t2), which is then used to provide the system with constant energy demand through the ORC evaporator both during the day and at night (state points t3 and t4). The ORC cycle uses an evaporator to transfer heat from the thermal oil to the ORC fluid, which is then expanded through the turbine to produce electricity using a linked generator after becoming superheated to (f3) and evaporating. To maintain the same temperature at the state points (a8 and w3), the ORC fluid exits the turbine at (f4). It is delivered to the triple channel heat exchanger's condenser, where it is condensed at (f1), and waste heat is recovered for the DCS and HDH units. The cycle is finished by pumping the ORC liquid to (f2) and then back to the evaporator. The ORC fluid leaves the turbine at position (f4). It is transported to the triple channel heat exchanger's condenser, where it condenses at position (f1) and recovers waste heat for the DCS and HDH units to maintain the temperature at state points (a8 and w3). To complete the cycle, the ORC liquid is subsequently piped to (f2) and finally pushed back to the evaporator. Process air enters the desiccant wheel (DW) at (a1) in the air cycle, where it is dehumidified and heated to (a2) before passing via the heat exchanger (HE-1), where it is cooled to (a3). The process air enters the direct evaporative cooler (DEC-1), which is cooled and humidified at (a4) before entering the air-conditioned chamber. The return air from the conditioned space at (a5) is directed to the direct evaporative cooler (DEC-2), where it is cooled and humidified before leaving at (a6). The heat exchanger (HE-1) is then used to heat the return air (a7). The return air (regeneration air) then passes through a heat exchanger (HE-2) to recover some of the waste ORC condenser heat to reach the necessary regeneration temperature (a8) before passing through DW (reactivation part), where it is cooled and humidified to the required regeneration temperature (a9). Finally, the HDH system delivers the humidified and cooled regeneration air from the DW to the humidifier, where it is humidified and cooled at (a10) before being given to the dehumidifier and is dehumidified at (a11). Figure 2a for the basic multi-generation system shows the psychrometric cycle of the air (MGS-I). Figure 1: Schematic diagram of proposed multi-generation systems: (**a**) MGS-I; (**b**) MGS-II. In the water cycle, seawater at (w1) is pumped through the water treatment unit (TU) to remove turbidity, bacterial content, and total dissolved solids, which cause fouling and scaling in the tubes and then passes through the dehumidifier coil to dehumidify the humid air that came from the humidifier to produce desalinated water at (w5). The desalinated water is sent through a chemical treatment unit (CTU) to make it fresh/potable water with a salinity of 500 ppm, which is the WHO's (World Health Organization) approved value.