# A Novel Configuration of Hybrid Reverse Osmosis, Humidification–Dehumidification, and Solar Photovoltaic Systems: Modeling and Exergy Analysis

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^{2}

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## Abstract

**:**

## 1. Introduction

^{3}/day. With a feed pressure of 63 bar, the SEC was 15 kWh/m

^{3}. Additionally, an investigation by Mohamed et al. [12] examined the financial viability of a PV–RO system in two scenarios: with and without batteries. Even though the SEC dropped when the system with batteries was examined, the price rose from EUR 7.5 to EUR 8.3 per cubic meter owing to the high level of investment and expense required for replacement. Kettani and Bandelier [13] presented a techno-economic analysis of a PV-RO desalination system on a major scale. For a plant with a capacity of 275,000 m

^{3}/day, they estimated a freshwater cost of around USD 1 per cubic meter.

^{2}/d with forced convection and an evaporator temperature of 64.3 °C; this was higher than the 0.789 kg/m

^{2}/d obtained using a free convection process. From this study, it can be concluded that the integration of solar PV systems is more appropriate for small-scale HDH systems and is favorable for remote areas away from electric power supplies. Using thermal energy recovery (TES) technology, Giwa et al. [16] studied the various environmental circumstances that affected a PV–HDH system’s productivity. Using an HDH desalination unit that was combined with PV/T modules, Gabrielli et al. [17] investigated the effect of the design and the working environment on the performance of the system. In a theoretical study, Rafiei et al. [18] investigated how the operating circumstances affected the amount of freshwater produced by an HDH desalination system that used a solar dish concentrator and a PV/T system. Mahmoud et al. [19] hypothetically evaluated the performance of a hybrid solar distiller/HDH desalination system with incorporated PV panels and solar concentrators.

^{3}, the suggested system achieved a maximum hourly production of 192–200 L.

## 2. Description of Systems and Models

#### 2.1. Reverse Osmosis Desalination System

#### 2.2. Humidification–Dehumidification Desalination System

- Fluid properties are constant: c
_{p,a}, c_{p,w}, c_{p,v}, c_{p,R}, and h_{fg}, which are the specific heat at a constant pressure of air, water, vapor, and refrigerant, in addition to the latent heat of vaporization, respectively. - Ambient temperature (T
_{amb}): 25 °C. - The pressure drop in the RO filter is 14 kPa.
- Isentropic efficiency of the pressure exchanger: 96%.
- Isentropic efficiency of all the pumps: 75%.

#### 2.3. Solar Energy Integration

^{2}.

#### 2.3.1. Sizing of the PV System Panels

_{L}is the average daily energy yield, as given in Table 10, G

_{avg}is the average solar energy input per day, and TCF is the temperature correction factor assumed to equal 0.8. ${\eta}_{pv}$ is the PV module efficiency, while ${\eta}_{B}$ and ${\eta}_{Inv}$ are the battery efficiency of 90% and inverter efficiency of 93%, respectively.

^{2}; thus, the PV peak power is given as follows:

#### 2.3.2. Battery Storage Capacity

_{C}is the number of successive cloudy days at the location [38], which is seven days based on the chosen location, and DOD is the maximum depth of drain of the battery, which is 80%. Consequently, the ampere-hour could be obtained by dividing the storage capacity by the DC bus voltage. According to the battery ampere-hour, the total number of the battery could be estimated.

#### 2.3.3. Battery Charge Controller

_{sc}.

#### 2.3.4. Inverter

#### 2.3.5. Results of the Design

## 3. Exergy Analysis

_{0}, P

_{0}) while maintaining the same concentration of all system elements. Therefore, a thermo-mechanical equilibrium with the environment is achieved. Chemical exergy is the amount of work that can be conducted when the concentration of each substance in the system varies to the concentration in the environment at the same pressure and temperature as the environment (T

_{0}, P

_{0}). As a result, a state of chemical equilibrium arises. The mathematical description of the flow exergy may be stated as considering the physical and chemical exergy as follows [40,41]:

_{0}” are determined at the dead state temperature and pressure (T

_{0}, P

_{0}) but the initiation composition or concentration of the flow stream. ${\mu}_{i,0}$ is the chemical potential of “i” at T

_{0}and P

_{0}when the composition is that of the state under consideration and ${\mu}_{i,0}^{*}$ represents the chemical potential of “i” when, at T

_{0}and P

_{0}, the system reaches chemical equilibrium with the environment. ${w}_{i}$ is the mass fraction of component “i”.

_{0}= 25 °C, P

_{0}= 101.325 kPa, $\omega $

_{0}= 0.0099 kg vapor/kg dry air, and the concentration of salted feed water: TDS

_{0}= 35,000 ppm.

#### 3.1. Exergy Balance of the Desalination Systems

#### 3.2. Exergy Analysis of the Solar PV Panel

^{2}) and G is the solar radiation intensity (W/m

^{2}) defined based on the chosen location.

^{−8}W/m

^{2}K

^{4}and ${T}_{sky}$ is the effective temperature of the sky defined by Watmuff et al. [48], as follows:

_{pv,m}, can be determined using the nominal operating cell temperature, NOCT, which is defined as the temperature reached by open-circuited cells in a module under the conditions G = 800 W/m

^{2}, ${T}_{amb}$ = 20 °C, and ${V}_{w}$ = 1 m/s [47].

## 4. Results

#### 4.1. Exergy Analysis of the RO–HDH–PX System

#### 4.2. Exergy Analysis of the Stand-Alone Solar PV System

#### 4.3. Exergy Analysis of the RO–HDH–PX System Integrated with Solar PV

#### 4.4. Cost Analysis of the RO–HDH–PX–PV Hybrid Desalination System

_{x}is the present worth value of the batteries or RO membranes.

^{3}at a feedwater pressure of 5 MPa.

## 5. Conclusions

- The exergy analysis of the RO–HDH–PX system indicated that the condenser was responsible for the major exergy destruction, (from 43% to 49%, depending on the operation conditions). The highest exergy efficiency reached by the overall system was 23%.
- The exergy analysis for the solar PV system revealed that the exergy efficiency is much higher in winter than in summer (reaching 7.5%) due to the high thermal losses.
- The integration of the solar PV system increased the sustainability of the hybrid RO–HDH–PX system. The system implemented with battery storage showed a low freshwater cost compared to that without a battery. The unit cost of freshwater ranged from USD 3.22/m
^{3}to USD 5.1/m^{3}when a battery was used; in contrast, it varied from USD 3.96/m^{3}to USD 7.1/m^{3}in the system without battery storage.

## Author Contributions

## Funding

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## Nomenclature

$\mathit{A}$ | Surface area (m^{2}) |

AA | Water permeability coefficient (kg/m^{2}sPa) |

B | Salt permeability coefficient (kg/m^{2}s) |

$\mathit{C}$ | Concentration (ppm) |

${\mathit{C}}_{\mathit{m}}$ | Concentration polarization (ppm) |

${\mathit{c}}_{\mathit{p}}$ | Specific thermal capacity (kJ/kgK) |

d | Diameter (m) |

dd | Inflation rate (%) |

d_{h} | Hydraulic diameter (m) |

D_{s} | Solute diffusivity (m^{2}/s) |

E | Evaporator |

$\dot{\mathit{E}}$ | Exergy (kJ) |

${\mathit{e}}_{\mathit{f}}$ | Specific flow exergy (kJ/kg) |

FF | Fill factor |

FS | Feed space (μm) |

G | Solar radiation intensity (W/m^{2}) |

h | Specific enthalpy (kJ/kg) |

${\mathit{h}}_{\mathit{c}\mathit{o}\mathit{n}\mathit{v}}$ | Convective heat transfer coefficient (W/m^{2}/K) |

${\mathit{h}}_{\mathit{r}\mathit{a}\mathit{d}}$ | Radiative heat transfer coefficient (W/m^{2}/K) |

ii | Interest rate (%) |

$\mathit{I}$ | Current (A) |

$\mathit{J}$ | Flux (kg/m^{2}s) |

k | Thermal conductivity (W/mK) |

${\mathit{K}}_{\mathit{m}}$ | Mass transfer coefficient (m/s) |

$\mathit{L}/\mathit{G}$ | Atomized water to airflow mass ratio |

$\dot{\mathit{m}}$ | Mass flow rate (kg/s) |

mu | Dynamic viscosity (Ns/m^{2}) |

Nc | Largest number of continuous cloudy days on the site |

P | Pressure (kPa) |

Q | Volume flow rate (m^{3}) |

Ra | Specific gas constant (J/kgK) |

Re | Reynolds number |

s | Specific entropy (kJ/kgK) |

Sc | Schmidt number |

S_{m} | Specific surface area (m^{2}) |

T | Temperature (K) |

U | Overall heat transfer coefficient (W/m^{2}.K) |

V | Voltage (V) |

${\mathit{V}}_{\mathit{w}}$ | Speed (m/s) |

Abbreviations | |

CAOW-AH | Closed-air, Open-water, and air heated |

CAOW-WH | Closed-air, Open-water, and water heated |

DOD | Maximum permissible depth of discharge of the battery |

ED | Electro-Dialysis |

ERD | Energy recovery device |

GOR | Gain output ratio |

HDH | Humidification–Dehumidification |

LCC | Life cycle cost |

MC | Maintenance cost |

MED | Multi-Effect Distillation |

MSF | Multi-Stage Flash |

N | Age of the system |

NOCT | Normal Operation Cell Temperature |

OACW | Open-air, Closed-water |

OAOW-WH | Open-air, Open-water, and water heated |

PW | Present worth |

PX | Pressure exchanger |

RO | Reverse Osmosis |

TCF | Temperature correction factor |

TV | Throttle valve |

TDS | Total Dissolved Salts |

WCHE | Water Cooled Heat Exchanger |

Subscript | |

0 | Dead State |

a | Air |

amb | Ambient |

avg | Average |

bw | Brine |

comp | Heat pump compressor |

cond | Heat pump condenser |

Conv | Heat transfer by convection |

cw | Cooling water |

D | Destruction |

E | Heat pump evaporator |

Exp | Heat pump expansion device |

F | Fuel |

f | Feed seawater |

FP | Feed pump |

FW | Freshwater |

H | Humidifier |

HPP | High-pressure pump |

in | Inlet |

L | Losses |

m | Module, maximum |

ma | Moist air |

o | Environmental condition |

OC | Open circuit |

out | Outlet |

P | Product |

p | Permeate |

pv | Solar photovoltaic |

R | Refrigerant |

rad | Heat transfer by radiation |

SC | Short-circuit |

sw | Seawater |

s | Salt |

tot | Total |

v | Water vapor |

vap | Water vapor |

w | Pure water |

Superscript | |

CH | Chemical |

PH | Physical |

Greek Symbols | |

$\mathit{\alpha}$ | Porosity |

π | Osmotic Pressure (MPa) |

$\mathit{\rho}$ | Density (kg/m^{3}) |

$\mathit{\sigma}$ | Stefan Boltzmann’s Constant (5.67 × 10^{−8}) [W/m^{2}K^{4}] |

υ | Seawater-specific volume (m^{3}/kg) |

$\mathit{\u0273}$ | Energy efficiency (%) |

${\mathit{\eta}}_{\mathit{I}\mathit{I}}$ | Exergy efficiency (%) |

${\u2206\mathit{P}}_{\mathit{f}}$ | Pressure drop (MPa) |

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**Figure 1.**The schematic diagram for the hybrid desalination system (RO–HDH–PX) using a pressure exchanger.

**Figure 4.**Percentage of exergy destruction of RO–HDH–PX system at feed pressure and salinity of 5 MPa and 45,000 ppm.

**Figure 5.**Percentage of exergy destruction of RO–HDH–PX system components at the feed flow rate, pressure, and salinity of 602 kg/h, 5 MPa, and 45,000 ppm, respectively.

**Figure 7.**The exergy efficiency of the hybrid RO–HDH–PX–PV system in 2/2022 for different feed water flow rates at (

**a**) 5 MPa and 35,000 ppm; (

**b**) 6.5 MPa and 35,000 ppm; (

**c**) 5 MPa and 45,000 ppm; and (

**d**) 6.5 MPa and feed salinity 45,000 ppm.

**Figure 8.**The exergy efficiency of the hybrid RO–HDH–PX–PV system in 7/2022 for different feed water flow rates at (

**a**) 5 MPa and 35,000 ppm; (

**b**) 6.5 MPa and 35,000 ppm; (

**c**) 5 MPa and 45,000 ppm; and (

**d**) 6.5 MPa and feed salinity 45,000 ppm.

**Figure 9.**The unit cost of freshwater for the hybrid RO–HDH–PX–PV system: with and without a battery storage system.

Parameters | Humidification–Dehumidification System | Reverse Osmosis System |
---|---|---|

Membrane type | - | SW30-4040 |

Air mass flow rate (kg/h) | 936 | - |

Feedwater mass flow rate (kg/h) | 219–345 | 383–602 |

Air inlet temperature (°C) | 25 | - |

Water inlet temperature (°C) | 25 | 25 |

Feedwater pressure (MPa) | 0.15 | 5–6.5 |

Recovery ratio (%) | - | 43.86 |

Feedwater Salinity (ppm) | Based on RO brine | 35,000–45,000 |

**Table 2.**Characteristics of the Film-Tec spiral wound membrane element used in the reverse osmosis system (DuPont, Wilmington, DE, USA).

Element Type | SW30-4040 |
---|---|

Active area (m^{2}) | 7.4 |

Length of the element (m) | 1016 |

Diameter of the element (mm) | 99 |

Feed space (μm) | 711.2 |

Feed flow rate range (m^{3}/h) | 0.1–3.6 |

Permeate flow (m^{3}/d) | 7.4 |

Stabilized salt rejection (%) | 99.75 |

Maximum operating pressure (MPa) | 6.9 |

Pure water permeability constant, A (kg/m^{2}.s.Pa) | 9.058 × 10^{−10} |

Salt permeability constant, B (kg/m^{2}.s) | 2.11 × 10^{−10} |

**Table 3.**Thermodynamic properties at different locations for the RO–PX unit at a feedwater flow rate of 602 kg/h.

Point | Temperature (°C) | Pressure (kPa) | Mass Flow Rate (kg/h) | Total Dissolved Salts (ppm) |
---|---|---|---|---|

1 | 25 | 101.325 | 240.64 | 35,000 |

2 | 25 | 500 | 240.64 | 35,000 |

3 | 25 | 486 | 240.64 | 35,000 |

4 | 25 | 6500 | 240.64 | 35,000 |

5 | 25 | 6500 | 601.61 | 35,000 |

6 | 25 | 101.325 | 257 | 62.69 |

7 | 25 | 6350 | 337.78 | 62290 |

8 | 25 | 150 | 337.78 | 62290 |

9 | 25 | 101.325 | 361 | 35,000 |

10 | 25 | 5706.7 | 361 | 35,000 |

11 | 25 | 6500 | 361 | 35,000 |

**Table 4.**Characteristics of the Film-Tec spiral wound reverse osmosis membrane elements used in the model validation (DuPont, Wilmington, DE, USA).

Element Type | SW30-4040 | SW30XLE-400i |
---|---|---|

Active area (m^{2}) | 7.4 | 37.2 |

Length of the element (m) | 1016 | 1.016 |

Diameter of the element (mm) | 99 | 201 |

Feed space (μm) | 711.2 | 711.2 |

Feed flow rate range (m^{3}/h) | 0.1–3.6 | 19.3 |

Permeate flow (m^{3}/d) | 7.4 | 34 |

Stabilized salt rejection (%) | 99.75 | 99.7 |

Maximum operating pressure (MPa) | 6.9 | 8.3 |

Pure water permeability constant, A (kg/m^{2}.s.Pa) | 9.058 × 10^{−10} | 3.5 × 10^{−9} |

Salt permeability constant, B (kg/m^{2}.s) | 2.11 × 10^{−10} | 3.2 × 10^{−5} |

Parameters | Test 1 | Test 2 | Test 3 | |||
---|---|---|---|---|---|---|

Lu et al. [36] | Model Values | Lu et al. [36] | Model Values | Lu et al. [36] | Model Values | |

Feed water mass flow rate (m^{3}/h) | 264 | 264 | 264 | 264 | 264 | 264 |

Permeate water mass flow rate (m^{3}/h) | 120 | 120 | 120 | 120 | 120 | 120 |

Feed water concentration (ppm) | 48,000 | 48,000 | 42,000 | 42,000 | 38,000 | 38,000 |

Feed water pressure (MPa) | 8.1 | 8.1 | 7.3 | 7.3 | 6.7 | 6.7 |

Permeate water concentration (ppm) | 380 | 383.1682 | 330 | 341.9592 | 300 | 318.8987 |

**Table 6.**Thermodynamic properties at different locations for the HDH unit for a 936 kg/h flow of air and 219 kg/h flow of feed water.

Point | Temperature (°C) | Pressure (kPa) | Mass Flow Rate (kg/h) | Specific Enthalpy (kJ/kg) |
---|---|---|---|---|

a1 | 25 | 101.314 | 936 | 50.33 |

a2 | 50 | 101.314 | 936 | 62.57 |

a3 | 32.2 | 101.314 | 957.95 | 87.19 |

a4 | 31.4 | 101.314 | 957.95 | 86.69 |

a5 | 26.8 | 101.314 | 953.93 | 77.99 |

SWin | 25 | 125 | 270 | 99.79 |

SWout | 28.3 | 101.325 | 270 | 110.71 |

F_{in} | 25 | 150 | 219.33 | 99.79 |

Bout | 25 | 101.325 | 210.93 | 95.44 |

FWout | 18.63 | 101.325 | 4.018 | 76.09 |

**Table 7.**Thermodynamic properties of the refrigerant at different locations for the heat pump cycle.

Point | Pressure (kPa) | Specific Enthalpy (kJ/kg) | Mass Flow Rate (kg/h) |
---|---|---|---|

R1 | 2000 | 468 | 57.6 |

R2 | 2000 | 275 | 57.6 |

R3 | 2000 | 268.71 | 57.6 |

R4 | 450 | 260.2 | 57.6 |

R5 | 450 | 418.3 | 57.6 |

R6 | 450 | 421.5 | 57.6 |

Parameters | El-Maghlany et al. [3] Experimental Data | Model Values | Relative Error (%) |
---|---|---|---|

Feed seawater mass flow rate (kg/h) | 132 | 132 | 0 |

Feed air flow mass rate (kg/min) | 15.71 | 15.71 | 0 |

Inlet air temperature (°C) | 25 | 25 | 0 |

Inlet feed water temperature (°C) | 15 | 15 | 0 |

Inlet-specific enthalpy to heat pump condenser ${h}_{R,1}$ (kJ/kg) | 470 | 485 | 3.19 |

Inlet-specific enthalpy to heat pump evaporator ${h}_{R,4}$ (kJ/kg) | 275 | 290 | 5.45 |

Freshwater produced (kg/h) | 3.22 | 3.18 | 1.24 |

The temperature of freshwater (°C) | 20.6 | 19.85 | 3.64 |

**Table 9.**Specification and geometry of the HDH unit [3].

Parameters | Values |
---|---|

Heat pump condenser fins | 195 |

Heat pump condenser volume (m^{3}) | 0.53 × 0.4 × 0.25 |

Fin pitch in the condenser (m) | 0.02 |

Humidifier volume (m^{3}) | 0.53 × 0.4 × 1.5 |

Water-cooled heat exchanger fins | 169 |

Water-cooled heat exchanger volume (m^{3}) | 0.53 × 0.4 × 0.2 |

Heat pump evaporator fins | 177 |

Fin pitch in the evaporator (m) | 0.02 |

Heat pump evaporator volume (m^{3}) | 0.53 × 0.4 × 0.2 |

Compressor power (kW) | 2 |

Feed pump power (kW) | 0.22 |

**Table 10.**Energy consumption per day of the RO–HDH–PX hybrid system at different operating conditions.

Total Seawater Feed Flow Rate (m^{3}/h) | 383 | 438 | 492 | 547 | 602 |
---|---|---|---|---|---|

At feed pressure, 5 MPa | |||||

Without battery usage (kWh/day) | 15.7 | 16.2 | 16.7 | 17.13 | 17.6 |

Using battery (kWh/day) | 37.8 | 38.9 | 40 | 41.1 | 42.2 |

At feed pressure, 6.5 MPa | |||||

Without battery usage (kWh/day) | 16.7 | 17.3 | 17.9 | 18.5 | 19.1 |

Using battery (kWh/day) | 40.1 | 41.504 | 43 | 44.4 | 45.8 |

Parameters | Value |
---|---|

Nominal output power (P_{mmp}) | 420 W |

Nominal voltage (V_{mmp}) | 31.77 V |

Nominal current (I_{mmp}) | 13.15 A |

Short circuit current (I_{sc}) | 14.05 A |

Open circuit voltage (V_{oc}) | 37.81 V |

Module efficiency ${\mathit{\eta}}_{\mathit{p}\mathit{v}}$ | 21.4% |

Number of cells | 108 cell |

Module Dimensions | 1722 × 1134 × 30 mm |

Normal Operation Cell Temperature (NOCT) | 41 °C $(\pm 3\xb0\mathrm{C})$ |

Items | At Feed Pressure, 5 MPa | At Feed Pressure, 6.5 MPa | ||
---|---|---|---|---|

System approach | Without battery | Utilizing battery | Without battery | Utilizing battery |

Number of solar PV module | 11–12 | 25–28 | 11–13 | 27–31 |

Number of batteries (12 V–220 A) | - | 75–84 | - | 80–91 |

Solar inverter capacity (kW) | 3 | 3 | 3 | 3 |

Battery charger capacity (kW) | - | 14.4 | - | 14.4 |

Components | Exergy Balance |
---|---|

HDH system | |

Fan and Condenser | ${\dot{E}}_{D,cond,fan}=\left({\dot{E}}_{x,R1}-{\dot{E}}_{x,R2}\right)+{\dot{W}}_{Fan}-\left({\dot{E}}_{x,a2}-{\dot{E}}_{x,a1}\right)$ |

Humidifier | ${\dot{E}}_{D,humi}=\left({\dot{E}}_{x,a2}^{PH}-{\dot{E}}_{x,a3}^{PH}\right)-\left({\dot{E}}_{x,Bout}-{\dot{E}}_{x,Fin}\right)-\left({\dot{E}}_{x,a3}^{CH}-{\dot{E}}_{x,a2}^{CH}\right)$ |

Water-cooled heat exchanger | ${\dot{E}}_{D,WCHE}=\left({\dot{E}}_{x,a3}-{\dot{E}}_{x,a4}\right)-\left({\dot{E}}_{x,Bout}-{\dot{E}}_{x,Fin}\right)$ |

Evaporator | ${\dot{E}}_{D,E}=\left({\dot{E}}_{x,R5}-{\dot{E}}_{x,R4}\right)-\left({\dot{E}}_{x,a4}-{(\dot{E}}_{x,a5}+{\dot{E}}_{x,FWout})\right)$ |

Heat exchanger | ${\dot{E}}_{D,HE}=\left({\dot{E}}_{x,R2}-{\dot{E}}_{x,R3}\right)-\left({\dot{E}}_{x,R5}-{\dot{E}}_{x,R6}\right)$ |

Compressor | ${\dot{E}}_{D,comp}={\dot{W}}_{comp}-\left({\dot{E}}_{x,R1}-{\dot{E}}_{x,R6}\right)$ |

Overall HDH system exergy efficiency | ${\epsilon}_{HDH}=\frac{{\dot{E}}_{x,a5}+{\dot{E}}_{x,FWout}}{{\dot{W}}_{comp}+{\dot{W}}_{Fan}+{\dot{W}}_{feedpump,1}+{\dot{W}}_{feedpump,2}+{\dot{E}}_{x,Fin}}$ |

HDH exergy losses | ${\dot{E}}_{L}={\dot{E}}_{x,Bout}+{\dot{E}}_{x,SWout}$ |

RO system | |

Feed pump and Filter | ${\dot{E}}_{D,FP}={\dot{W}}_{FP}-\left({\dot{E}}_{x,3}-{\dot{E}}_{x,1}\right)$ |

High-pressure pump | ${\dot{E}}_{D,HPP}={\dot{W}}_{HPP}-\left({\dot{E}}_{x,4}-{\dot{E}}_{x,3}\right)$ |

Pressure exchanger pump | ${\dot{E}}_{D,PXpump}={\dot{W}}_{PX,pump}-\left({\dot{E}}_{x,11}-{\dot{E}}_{x,10}\right)$ |

Reverse osmosis module without ERD | ${\dot{E}}_{D,RO}=\left({\dot{E}}_{x,4}^{PH}-{\dot{(E}}_{x,5}^{PH}-{\dot{E}}_{x,7}^{PH})\right)-\left({\dot{(E}}_{x,5}^{CH}-{\dot{E}}_{x,7}^{CH})-{\dot{E}}_{x,4}^{CH}\right)$ |

Reverse osmosis module using pressure exchanger | ${\dot{E}}_{D,RO}=\left({\dot{E}}_{x,5}^{PH}-{\dot{(E}}_{x,6}^{PH}-{\dot{E}}_{x,7}^{PH})\right)-\left({\dot{(E}}_{x,6}^{CH}-{\dot{E}}_{x,7}^{CH})-{\dot{E}}_{x,5}^{CH}\right)$ |

Pressure exchanger | ${\dot{E}}_{D,PX}=\left({\dot{E}}_{x,7}-{\dot{E}}_{x,8}\right)-\left({\dot{E}}_{x,10}-{\dot{E}}_{x,9}\right)$ |

Overall RO–PX system exergy efficiency | ${\epsilon}_{RO-PX}=\frac{{\dot{m}}_{permeate}.{e}_{permeate}^{CH}+{\dot{m}}_{brine}({e}_{brine}^{PH}+{e}_{brine}^{CH}-{e}_{seawater}^{PH})}{{\dot{W}}_{pumps}+{\dot{m}}_{permeate}({e}_{seawater}^{PH}-{e}_{permeate}^{PH})}$ |

Hybrid system | |

Overall RO–HDH–PX system exergy efficiency | ${\epsilon}_{RO-HDH-PX}=\frac{{\dot{E}}_{P,tot}}{{\dot{E}}_{F,tot}}=\frac{{\dot{E}}_{x,permeate}+{\dot{E}}_{x,a5}+{\dot{E}}_{x,FWout}}{\sum {\dot{W}}_{tot}-({\dot{E}}_{x,SWout}-{\dot{E}}_{x,SWin})}$ |

Total exergy loss | ${\dot{E}}_{loss}={\dot{E}}_{x,Bout}$ |

System Components | Cost (USD) | System Components | Cost (USD) |
---|---|---|---|

RO system | Solar PV system | ||

Seawater FP | 750 | Solar PV panel | 0.188/W |

Seawater HPP (4.5 MPa delivery pressure) | 1500 | Solar inverter | 290 |

Seawater HPP (6.5 MPa delivery pressure) | 2000 | Battery | 59.9/kWh |

RO membrane Film-tec SW30-4040 | 464/element | Battery Charge Controller | 375 |

Pressure exchanger | 2000 | ||

HDH system | |||

Centrifugal fan | 100 | Feed pump I | 40 |

Flexible duct | 15 | Heat pump evaporator | 40 |

Compressor | 464 | Piping | 40 |

Heat pump condenser | 50 | Steel construction stands | 150 |

Water eliminator | 20 | Insulated ducts | 30 |

Control panel | 25 | ||

Two water sprayers | 5 | ||

Installation | 10% of capital cost | ||

Maintenance ($\mathbf{M}/\mathbf{y}\mathbf{r}$) | 5% of capital cost/year |

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## Share and Cite

**MDPI and ACS Style**

Tourab, A.E.; Blanco-Marigorta, A.M.; Elharidi, A.M.; Suárez-López, M.J.
A Novel Configuration of Hybrid Reverse Osmosis, Humidification–Dehumidification, and Solar Photovoltaic Systems: Modeling and Exergy Analysis. *J. Mar. Sci. Eng.* **2024**, *12*, 19.
https://doi.org/10.3390/jmse12010019

**AMA Style**

Tourab AE, Blanco-Marigorta AM, Elharidi AM, Suárez-López MJ.
A Novel Configuration of Hybrid Reverse Osmosis, Humidification–Dehumidification, and Solar Photovoltaic Systems: Modeling and Exergy Analysis. *Journal of Marine Science and Engineering*. 2024; 12(1):19.
https://doi.org/10.3390/jmse12010019

**Chicago/Turabian Style**

Tourab, Ahmed E., Ana María Blanco-Marigorta, Aly M. Elharidi, and María José Suárez-López.
2024. "A Novel Configuration of Hybrid Reverse Osmosis, Humidification–Dehumidification, and Solar Photovoltaic Systems: Modeling and Exergy Analysis" *Journal of Marine Science and Engineering* 12, no. 1: 19.
https://doi.org/10.3390/jmse12010019