INTRODUCTION

We can access a very low percentage of water from the ground. Therefore, there is a need to develop potable water and self-sustainable systems. Water purification is required due to polluted water to freshwater throughout the world. Consumption of polluted water is increasing death rates by increasing diseases in human beings. In present days, system availability is not self-sustainable. Electricity is needed which generates it causes pollution. Therefore, the better solution is a renewable energy source that can reduce the potable water problem. Lawrence and Tiwari [1] developed the empirical relations for the inside coefficients of heat transfer from the natural flow with a heat exchanger in a solar distiller unit. Popiel and Wojtkowiak [2] studied the thermo-physical properties of the base fluid. Pak and Cho [3] evaluated various correlations for different properties. G. N. Tiwari [4] studied the fundamental design of the solar still. Hwang et al. [5] analyzed the heat transfer coefficient for Al₂O₃ nanofluids. Barden [6] improved the thermo-physical properties of the base fluid; the heat transfer coefficients could also be improved. Due to their superior thermo-physical characteristics, nanoparticles are easily deferred. The nanofluids are developing fluids with extremely quick heat transfer properties. Additionally, the base fluid’s qualities could be enhanced by customizing the size and shape. Tiwari and Tiwari [7] expressed few merits of solar distillers over other distillation technologies such as filters, membranes, and batteries, no definitive resource of energy, and primarily low investment. Ho et al. [8] numerically analyzed nanofluids for natural convection in a square enclosure: effects due to uncertainties of viscosity and thermal conductivity. Otanicar and Golden [9] analyzed the enviro economic aspect of solar collectors using nanofluid and found it neutralizes 74 kg for a life span of 15 years. Patel et al. [10] found the thermal conductivity of nanofluids. Singh et al. [11] theoretically investigated entropy generation for nanofluids. Elzen et al. [12] analyzed emission reductions, abatement costs, and carbon prices. Khanafer and Vafai [13] This work presented the thermophysical properties of nanofluids. Khullar and Tyagi [14] analyzed and reported emissions of 103 kg approx./household/year reduced for a solar heating device for nanofluids. Faizel et al. [15] analyzed based on the cost of flat plate collector (FPC) using tin oxide, copper oxide, titanium oxide, and aluminum oxide ) nanofluids. It is discovered that the high density, low specific heat, and thermal conductivity of CuO nanofluid are more appropriately attributed to its performance.Liu et al. [16] have evaluated the economic analysis of the integrated solar distiller unit of the evacuated tube. Kabeel et al. [17] analyzed the sole inclined solar distiller unit with vacuum as a water-based nanofluid. Elango et al. [18] analyzed practically single-slope solar distillers as thermal energy, exergy, and productivity using different nanofluids. Omara et al. [19] analyzed the performance of corrugated wick type and simple solar distiller units using nanofluids. Tiwari et al. [20] analyzed experimentally active solar distillers that exergoeconomic and environmental economic using water-based nanofluid the photovoltaic thermal flat plate collector is met potable water requirements daily. Environmental damage has been estimated to cost $6.29 annually. Sharon and Reddy [21] analyzed the annual economic performance of an active solar distiller loaded with saline water. Sahota et al. [22, 24] analyzed the passive double slope solar distiller unit performance using nanofluids and concluded that the aluminum oxide-based nanofluid gives better performance than others. Singh et al. [23] analyzed the energy matrix and existence cycle conversion efficiency for conventional single and double slope distiller units and found 0.144. and 0.137 per unit cost, respectively, and exergoeconomic parameters. Singh and Tiwari [25] analyzed the energy matrices and life cycle cost of an active partly PVT-CPC solar distiller. Shashir et al. [26] analyzed the performance of nanoparticles like copper oxide and graphite micro-flakes on solar distiller units with different cooling on the cover of toughened glass. It is concluded the solar yield increases and copper oxide 47.8% and 57.6%. Sahota et al. [27] studied the performance of PVT-FPC double slope solar distiller unit with or without helical coil heat exchanger using nanofluid and found water-based nanofluid performance was better with a heat exchanger. Saleha et al. [28] analyzed the effect of solvent and found it effective in solar distiller units. Chen et al. [29] analyzed that experimentally found the stability of weak luminous was very good with nanofluid in solar distiller unit and the effect of brackish water’s constancy, ocular and thermal properties using nanofluid feasible. Mahian et al. [30] studied and found a significant temperature lower than 50 °C, in a heat exchanger and found a 2 times greater amount of water than without a heat exchanger. Additionally, water nanoparticles improve evaporation at low temperatures. It is crucial to assess the cost-effectiveness of renewable energy systems based on payback. Sahota et al. [31] analyzed environmental economics and exergoeconomics for passive double slope solar distiller with water-loaded nanofluid (CuO,Al2 O3,TiO2) and found payback time of energy of the system is low and the cost of environmental per annum is higher on mitigation with nanofluid. Singh and Tiwari [32] analyzed the augmentation in energy matrices of N-PVT-FPC partly double slope solar distiller. Joshi and Tiwari[33] analyzed single slope N^th-identical photovoltaic thermal compound parabolic concentrator collector N-PVT-CPC. Dharamveer et al. [34] reviewed nanofluid-loaded desalination. Kumar and Singh [35] analyzed the Energy and exergy of active solar stills using a compound parabolic concentrator. Shanker, et al.[36]  analyzed the performance of the C.I. engine using biodiesel fuel by modifying injection timing and injection pressure Anup et al. [37] analyzed using FEA of refrigerator compartment for optimizing thermal efficiency. Kumar and Singh.[38]optimized thermal behavior of a small heat exchanger. Zhang et al. [39] presented in the area of sustainable energies focuses on utilizing green and clean technologies. Dhivagar et al. [40] analyzed single slope grate crude shrewd solar distiller units for energy, exergy, and economic aspects. Dharamveer and Samsher [41] studied the active and passive solar still behavior on energy matrices and enviroeconomics. Arora et al. [42] analyzed double slope solar distiller N-PVT-CPC using carbon nanotubes for water generation. Dharamveer et al. [43] analytically studied N^th identical photovoltaic thermal (PVT) compound parabolic concentrator (CPC) active double slope solar distiller with a helically coiled heat exchanger using C_uO Nanoparticles. Dharamveer, et al. [44] analyzed an N-identical active single-slope solar distiller with a helically coiled heat exchanger using CuO nanoparticles. Kumar and Singh, [45] compared single-phase microchannels for heat flow Experimental and using CFD. Subrit and Singh. [46] analyzed thermal of coal and waste cotton oil liquid produced by pyrolysis of diesel engine fuel was carried out by. Shahsavar et al. [47] Compared energy, exergy, environmental, exergoeconomic, and enviro economic analysis of building integrated photovoltaic/thermal, earth-air heat exchanger, and hybrid systems. Numerous studies on passive and active solar stills have been conducted, according to the current literature survey. However, not much investigation on active solar still filled with water-based nanofluids was studied. Based on energy and exergy, Dharamveer et al. studied a hybrid double slope. No scholars have examined the economic, and environmental, using nanofluid. Furthermore, no studies have been conducted for CPC, ETC double slope basin type solar distiller using nanofluid. Thus, the proposed study will examine the impacts of active solar still double slope with CPC and filled with water containing Al₂O₃ nanofluid on energy matrices based such as energy payback time, energy payback factor, life cycle cost conversion efficiency, and productivity, of solar desalination systems will be thoroughly examined. The effectiveness of the suggested approach will also be evaluated in comparison to the findings of past studies.

MATERIALS AND METHODS

To determine the following objectives the methodology is adopted as energy matrices analysis of hybrid solar distiller basin type double slope with heat exchanger using Al₂O₃ nanoparticles.

System Description

Working of double slope solar desalination incorporating PVT with CPC collector using nanoparticles (N-PVT-CPC-DS-HE) is shown. Representation of solar still is followed the greenhouse principle. The parameters used for the distiller unit are given in Table 1 and Table 2. The basin of the solar distiller is connected in series with N-CPC and incorporated with a helically coiled heat exchanger. Solar radiation received on the glass cover is transferred to the water surface and thereafter absorbed by the surface. Later on, reflected water received heat on the top cover and rest portion and then move to the liner where the maximum amount absorbed and liner temperature increased and transfer this heat to water. Thus the temperature of water in the basin is increased and water gets evaporated. Collectors also heat the water in the basin. Water is heated and evaporates in this manner. The distillate trickles forward to the passage attached to the bottom side as the vapor reaches the interior face of the condenser, where film-wise condensation takes place. Then, the beaker receives the distilled water that was siphoned off.

Fig. 1 represents 25% PVT incorporating hybrid solar still. Collectors are put south facing at an angle of 45º which are connected in series as the input of the second collector is attached to the first collector output. Radiation that falls on the collector directly gets absorbed and beam irradiation is reflected on the parabolic concentrator. Similarly, irradiation falls on PV modules that generate electricity which is further used for operating pumps (D.C) and access energy can be further used for any electrical appliances according to need. Table 2 represents the specifications of the proposed system. The inclination angle of the system is 30º and the orientation of the system is the southern face. The basin liner is absorbed maximum radiation which falls on the glass cover. The basin fluid gets heat from the heat exchanger through Al₂O₃ nanoparticles. As per a prior study, it is obvious that a helically coiled heat exchanger is more effective than any other design. The Al₂O₃ nanoparticles exchange more heat in active solar still because it covers more surface area due to increasing volume due to heat exchanger. The system gets thermal energy via a combination of double-slope basins incorporating with PVT-CPC collector unit and it absorbs heat externally from a collector and internally from a basin. Basin water temperature increases via heat exchanger nanoparticles. Ultimately by releasing latent heat the vapor gets condensed, and collected at the lower end of the inclined glass cover of the basin.

This sort of system produced electricity as well as potable water. The other quality of this sort of system is i.e. low maintenance, easy to install, and useful for large and small demands of potable water as well as industrial purpose. Lot of advantages of such a system but in this work, we emphasize producing potable water only therefore according to making the system self-sustainable the PVT is provided otherwise 50%, 75%, and 100% can also be used. 

Though, the proposed system-A is compared with the previous System-B based on basin water temperature, inside glass cover temperature, water outlet temperature, the overall thermal energy of collectors, overall exergy, overall electrical exergy, and potable water amount. Sedimentation possibility in nanofluid is more. Therefore nanoparticles size leads to a change in aggregation. The value of size matters to change in aggregation. Later on, more sophisticated equipment is needed to remove it.

Governing equations

To develop the characteristic equation, the following assumptions are:

Constant water level

Negelectedohmic losses

No leakage

Over the entire surface film condensation

Steady-state partially covered active solar stills

The governing equations of the system are as follows:

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Analysis based on matrices and cost conversion based on the life span of hybrid active double slope solar distiller unit using Al₂O₃ nanoparticles -

Energy matrices inform about the time of energy payback (EPT), energy payback factor (EPF), and life cycle conversion efficiency for the lifetime period (LCCE) [27].

Energy Payback Time (EPT) [27]

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Methodology to be Adopted

The following steps are included in the approach used to study the suggested system (Fig. 2):

Step-I

The proposed systems for the yearly are calculated using the Lui-Jordon formula for global and beam irradiation. Calculate daily solar radiation further by multiplying the number of days given in a month by the number of clear, hazy, hazy, cloudy, and cloudy days.

Step-II

The temperature of basin water is calculated based on hourly, monthly, and annual data, and all settings are tuned to maximize the collector’s output temperature.

Step-III

Energy matrices such as efficiency of life cycle cost, Factor energy payback, energy payback time, and productivity have been evaluated.

Step-IV

Comparing proposed systems to the prior system using numerically computed values.

RESULT AND DISCUSSION

The solar irradiation on a flat area and surroundings temperature have been computed using IMD Pune data, India. By entering the pertinent data in MATLAB, the Liu and Jordan formula may be used to determine how much radiation was applied to N-PVT-CPCs. The values of beam radiation Ib, solar radiation Eastside ISE, Westside ISW, and ambient temperature Ta in kW/m² and ºC, respectively, are shown in Fig. 3. Below Fig.4 shows a variation of the thermal exergy month-wise of proposed system-A.

Energy matrices and a life cycle cost conversion analysis are required for the hybrid active double slope solar distiller unit

Embodied energy (E_in), the conversion efficiency of the life cycle (LCCE), energy payback factor (EPF), and energy payback time for (N-PVT-DS-FPC-HE) and (N-PVT-DS-CPC-HE) are shown in Fig. 5, Fig. 6, and Fig. 7 for 15, 20 and 30 years respectively.

The number of energy matrices based on energy and exergy for proposed system-A is found that system-A is better to system-B. EPT based on energy and exergy is 16.16% and 17.84% higher, respectively. EPF based on energy and exergy is relatively less13.91% and 14.88%, respectively. LCCE based on energy and exergy is appreciably greater for system-A than system-B: 5.55%, 6.38%, and 7.15% for 15, 20, and 30 years of life considered, respectively.

Economic analysis is required to determine whether hybrid active solar still uses Nanoparticles (Al₂O₃)

It is economically feasible for system-A and System-B annually. Total yearly cost, fixed annual cost, yearly maintenance cost, and yearly water generation for system-A and system-B are shown during 30 years, at respective interest rates of 1%, 3%, and 5% respectively are represented in Fig. 8, and Fig. 9.

The cost of distillation relies on the rate of interest, as results over 30 years are shown in Fig.8. While the cost of distillate will reduce as system life increases, the price of distillate will climb annually as interest rates rise. For system-A and system-B, the cost of distillate is 0.69, 0.96, and 1.27 (/kg), and 0.72, 1.012, and 1.33 (/kg), respectively, over 30 years at interest rates of 1%, 3%, and 5%. According to the cost of distillation, it is concluded that the proposed system-A performs better than system B.

CONCLUSION AND FUTURE SCOPE

The proposed system and previous system performance have been studied using characteristic equations and Al₂O₃ nanoparticles and found better than the previous system.

Conclusions

The following conclusions are made by the annual analysis of the proposed systems with Al₂O₃ nanoparticles. 

The proposed system-A gives better annual performance than system-B based on thermal exergy, energy, yield is 8.5%, and productivity 5.17% greater with Al₂O₃ nanoparticles. 

Al₂O₃ nanoparticles-based system-A gives better results on annual performance and economics as compared to system-B. 

Based on thermal energy, thermal exergy, energy, and exergy-based, Energy payback time (EPT) is 16.16%, Energy payback factor (EPF) is 13.91%, Efficiency of life cycle cost (LCCE) is 7.15% greater than the previous research, it is found that system-A outperforms system-B (previous).

System-A has a lower distillation cost than System B (previous). The yearly cost of distillate for systems A and B is 0.69, 0.96, and 1.27 (/kg), and 0.72, 1.012, and 1.33 (/kg), respectively, based on a 30-year basis at interest rates of 1%, 3%, and 5%. According to distillate cost, it is discovered that system-A performs better than system B.

Future scope

This work can be further expanded using research with PCM material in CPC up to a specific level. 

Energy and exergy can be studied for different nanoparticles

energy matrices, EPT, EPF, and LCCE can be studied for different nanoparticles

Research on the environmental and economic benefits of various nanoparticles is possible. Different sizes, and shapes of nanoparticles can be investigated.

The partial covered 50%, 75%, and 100% can be studied.