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System principle for water desalination integrated in a greenhouse roof.

System principle for water desalination integrated in a greenhouse roof.

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Article
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This paper is focused on applications in remote and arid locations where the source water is assumed to be brackish. In this concept the roof transmission is reduced as solar irradiation is absorbed by flowing water on a glass sheet covered by a top glass sheet. Fresh water is evaporated, condensed on the top glass and collected at the roof eaves.F...

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Context 1
... basic principle of a system concept for roof- integrated water desalination in greenhouses is illus- trated in Fig. 1. The central part of the system is a roof that includes a thin layer of flowing saline water on a sloped glass sheet covered by a top glass sheet. The lower glass is only partly light transparent and a sub- stantial proportion of the solar irradiation is absorbed. The remaining proportion is transmitted into the ...
Context 2
... clear glass at the top and a semi-transparent glass in the bottom. The bottom glass, used as solar energy absorber, has a high absorption in the solar spectrum (about 56%) and the transmission is about 25%. The details of the module are described by Chaibi (2002). The module is connected to equipment for water supply, collection and flow control (Fig. 1). Saline water is contained in a storage tank with 20 mm of mineral wool for thermal insulation and a volume of 100 l. The produced fresh water is collected in Fig. 2. Field experiment with a greenhouse system including water desalination at the National Research Institute for Rural Engi- neering, Water and Forestry (INRGREF). a storage ...

Citations

... In the greenhouse-based concept two different configurations have been investigated. The first configuration consists of the solar thermal still being oriented and installed on the sun facing part of the greenhouse roof [102]. While in the second configuration, the basin of the solar still is horizontally oriented and located below the glass roof of the greenhouse [103]. ...
Article
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The demand for high-quality freshwater is increasing due to global population growth, intensifying agricultural practices and expanding industrial development. Additionally, many global regions have low levels of rainfall which makes them arid and incapable of supporting large human populations or agriculture. Currently, large quantities of fossil fuels are used to generate the power needed to drive energy intensive desalination processes that deliver high-quality freshwater to many of these regions. However, the use of fossil fuels has led to high greenhouse gas emissions, environmental degradation and global warming. Solar-thermal desalination is a low-cost, sustainable and eco-friendly strategy for producing high-quality freshwater without using energy derived from fossil fuels. However, in spite of recent developments to advance solar-thermal desalination, the most effective strategies for achieving higher performance levels still remains elusive. To tackle this problem, the present article reviews several solar-thermal still configurations, including materials, system design parameters, influencing factors and operational parameters. Moreover, recent material advances in plasmonic nanoparticle-based volumetric systems, nanomaterial enhanced phase change materials and interfacial solar evaporators are discussed. These new material advances can have the potential to significantly improve the conversion of light-to-heat, enhance vapor generation and promote greater water production rates.
... Solar stills may be employed on the roof of greenhouses [47] or inside [26,48], to yield the required freshwater for irrigation. When a roof configuration is employed, the roof is made up of a two-layer glass, where the saline water flows down the first layer, evaporates by solar radiation, and produces freshwater when contacting the inner surface of the second layer. ...
... The produced freshwater is sent to the crops with gravity; thus, reducing the required electrical power for water pumping [13]. Ref. [47] has assessed a roof-integrated solar still in a greenhouse in Tunisia (see Fig-13c). The solar collector arrangements on the roof decrease the roof transparency, by absorbing the solar irradiation, in addition to their role in evaporating water and producing freshwater. ...
... Integrating a solar still with a greenhouse improves the overall efficiency and reduces the capital cost. However, it fails to maintain an appropriate environment for the crops [47][48]. On the other hand, greenhouses need a certain humidity and temperature, which adversely affect the productivity of solar stills, when positioned on the roof of the greenhouse. ...
Article
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This paper is motivated by the crisis of freshwater in remote areas around the world and responds to the growing need for sustainable food production in arid lands. It focuses on utilizing solar energy to yield freshwater from the sea or brackish water with less environmental impacts, for greenhouses, which can produce sustainable food all over the year. The integration of various solar‐driven desalinations such as solar still, humidification‐dehumidification, reverse osmosis, electrodialysis, and multieffect and multistage flash with greenhouses are evaluated, for better sustainability towards greenization. The paper first discusses the specifications of solar‐driven desalinations and compares their advantages and limitations. Then, different types of greenhouses are introduced, and their total water requirement is discussed based on their locations, crop type, greenhouse technology, irrigation type, and environmental conditions, as well as their cooling and heating strategies. Later, the existing integration of solar‐driven desalinations with greenhouses are reviewed, and their advantages and limitations are deliberated. Finally, the paper discusses the criteria to be considered when selecting solar‐driven desalinations for greenhouses and presents a detailed comparison between the water production rate and cost as well as the energy consumption of these systems. In the end, the most appropriate combinations of solar‐driven desalinations with greenhouses are recommended based on their water requirement and production cost.
... This provided increased control over the desalination system's surroundings leading to increased water production by the solar desalination system. Chaibi and Jilar [16] conducted an experimental investigation on greenhouse solar desalination system integration in the Tunisian National Research Institute from 2000 to 2003. Their results show that such a system occupies an overall 50% of a wide-span greenhouse's roof surface and is capable of collecting the annual water required for a low canopy crop. ...
Article
In the present study a solar water desalination system with humidification-dehumidification (HD) cycle is designed, integrating a solar still (as a solar humidifier) and a new subsurface condensation mechanism. Mass and energy balances are written for both solar humidifier and subsurface condenser in thermodynamic analysis of the system. Obtained nonlinear equations are analyzed numerically to explore the impact of the cycle's parameters on fresh water production. The results of the analysis indicate that the rate of water production can reach above 264.86 (kg/day) and the produced water, passing through the pores on the tubes, can be used to irrigate plant roots or collected as drinking water. According to this design and numerical simulation, it is demonstrated that the new subsurface condensation can be a promising strategy for subsurface irrigation method; and the new mechanism allows farmers to use saline water for agricultural purposes by utilizing solar energy, particularly in arid areas.
... The relative humidity inside the GH is found to vary between 20% and 35% above ambient conditions, satisfying the comfort zone of the plant growth. Chaibi and Jilar [39] performed computer simulations and field experiments to compare the performance of on-roof integrated semi-transparent desalination units in GHs with that of the conventional single glazed GHs in Tunisia. The results show that the proposed system with 50% coverage of the roof area and pre-heated water feed to the desalination units can satisfy the annual water demand for a low canopy crop. ...
Article
This study is an analytical investigation for the performance of a new stand-alone agriculture Green House (GH) integrated with on-roof Transparent Solar Stills (TSS) to be a self-sufficient of irrigation requirements. This system utilizes the surplus solar energy via direct solar desalination in TSS and Humidification-Dehumidification (HDH) process as two sources for water production. The effect of using the on-roof TSS on the GH performance, the power required for heating and fans operation at different climate conditions is discussed. The paper investigates the effect of the fresh air ratio and the bypass ratio for the condenser of the cooling system on the internal micro-climatic conditions of the GH. For different climatic conditions of Borg-Elarab, Egypt, controlling both the condenser bypass and fresh air ratios can be used to satisfy the required micro-climate conditions and water requirements for plant growth and minimize the power consumption for cooling system. The results show that the daily average temperature inside the GH can be increased during winter. Furthermore, the system can produce a sufficient amount of fresh water during summer. The system can only produce a maximum amount of water of 2.44 L/m².day during the coldest day which indicates the need for additional solar stills to be installed if a higher amount of water is required. In general, recovering the extra solar radiation to either produce fresh water via on-roof TSS or reduce the power consumption by cooling, heating and ventilation systems is the main advantage of the new proposed GH system. This work is a good applied example for food, water, energy and climate change Nexus which covers the main elements of Sustainable Development Goals (SDGs).
... (Berroug et al., 2011). -The glass absorptivity (Chaibi and Jilar, 2004), glass density (Sethi, 2009), the specific heat of glass (Sethi, 2009), glass transmissivity (Singh and Tiwari, 2000) and glass emissivity are 0.06, 2500 kg/m 3 , 4190 J/kg k, 0.9 and 0.92. -The GH floor emissivity and absorptivity are 0.93 and 0.4 respectively (Sharma et al., 1999). ...
Article
This study investigates, analytically, the design of a new stand-alone agriculture Green House (GH) designed to be a self-sufficient of energy and irrigation requirements. This design uses Transparent Photo Voltaic (TPV) for electrical power generation and humidification-Dehumidification process for water production. The paper investigates the effect of the location of the condenser(s) for the cooling system, the condenser bypass and fresh air ratios on the internal micro-climatic conditions of the GH. For the hot climatic conditions of Abu Dhabi, UAE, controlling both the condenser bypass and fresh air ratios can be used to satisfy the required micro-climate conditions for plant growth, minimize the power consumption for refrigeration cycle and maximize the water production. According to the operating conditions, water production ranges between 8.3 and 13 L/m2 day which is sufficient for plant needs while the generated electrical power of the TPV is about 10% of the electrical energy requirements which indicates the need for additional PV panels to be installed with the GH system.
... The yield reduction was about 25% for a desalination case with the capacity to cover the water demand corresponding to a lettuce crop. Goosen et al. [7] developed a thermodynamic model with an aim to develop humidificationdehumidification desalination technology for farms in arid coastal regions who suffer from salt infected soils and shortages of potable groundwater. The specific aim of their research was to determine the influence of greenhouse-related parameters on a process, called Seawater Greenhouse, which combines fresh water production with growth of crops in a greenhouse system. ...
Article
The present work discusses the performance evaluation of a solar still integrated with a greenhouse for the climatic conditions of Gangetic Bengal which witness a hot and humid climate for greater part of a year. A thermal model as available in literature [3] has been used for analyzing the performance of the greenhouse integrated solar still for the climatic conditions of Gangetic Bengal. Plant and water temperature, as a function of climatic and design parameters, were obtained by solving coupled single-order differential equations using the Runge-Kutta method. A computer code has been developed using MATLAB software to compute the greenhouse room air temperature, temperature of the transparent cover, basin liner temperature and the mass of the distillate along with the plant and water temperature. The study revealed that the maximum amount of distillate production took place in the month of April and is significantly high during the other summer months. This distillate can be used as potable water for use in rural areas where it is scarce. Thus, this integrated system reinforces the viability of generation of substantial amount of fresh water along with sustainable crop production in the rural parts of Gangetic Bengal in Indian subcontinent.
... System principles for water desalination integrated in a greenhouse roof [44]. et al. [30] showed that double-basin type stills produced about 56% higher yield than single effect stills. In multi-effect multi-wick type solar stills (Fig. 13) the availability of latent vaporization heat is maximized and equalized for least water depths in each effect, ...
Article
Due to the current fossil fuel crisis and associated adverse environmental impacts, renewable energy sources (RES) have drawn interest as alternatives to fossil fuels for powering water desalination systems. Over the last few decades the utility of renewable energy sources such as solar, geothermal, and wind to run desalination processes has been explored. However, the expansion of these technologies to larger scales is hampered by techno-economic and thermo-economic challenges. This paper reviews the state-of-the-art in the field of renewable energy-powered thermal desalination systems (RE-PTD) to compare their productivity and efficiency through thermodynamic, economic, and environmental analyses. We performed a comparative study using published data to classify RE-PTD systems technologies on the basis of the energy collection systems that they use. Among RE-PTD systems, solar energy powered-thermal desalination systems demonstrate high thermo-environ-economic efficiency to produce fresh water to meet various scales of demand.
... This section provides the latest comprehensive review on the seawater greenhouse (SWGH) technology. In this review, although the SWGH principle falls within the general themes of the "humidification-dehumidification techniques in solar desalination" and the "integrated solar still-greenhouse systems", both topics are not considered here as they were the focus of other investigators [12][13][14][15][16][17]. This review will solely focus on the SWGH technology. ...
... The idea to upscale the solar still concept by integrating large evaporation basins into a crop producing greenhouse has been around for some time [8]. A considerable number of studies on different still-greenhouse designs are available in the literature [9][10][11][12]. In general terms, the aim is to tailor and optimise the HD process inside a greenhouse, while making use of the structural components of the greenhouse itself, primarily as a condensing surface. ...
Article
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Several simple vapour cooling and pre-condensing concepts were assessed for the purpose of mitigating bubble column vapour temperatures, a critical aspect for the development of a bubble column driven greenhouse desalination system. Particular emphasis was on low-energy demand of the devices, ease of manufacture, low investment cost and technical and operational appropriateness for local people in remote places. Under laboratory conditions, the copper tube type I and II concepts achieved water recovery rates of between 65 and 75%. The water-tank cooled tube achieved 83% condensate recovery, albeit at the cost of large cooling water requirements, whereas the air cooled and passive sleeve-cooled bubble condenser columns achieved condensate recovery rates of at least 50% under favourable ambient conditions. A “self-cooling” effect was observed for the passive sleeve columns that could perhaps be tailored to produce small quantities of potable water in hot and arid regions. The effectiveness–NTU method was used to allow for a meaningful comparison between the devices. While the majority of the tested concepts represented a “single-stage” approach to the humidification–dehumidification cycle, it is stressed that a well-designed latent heat recovery system would be crucial for the economic viability of a bubble greenhouse.
... Fossil fuels drive most of the desalination plants, and renewable energy derives only 0.02%. A simple, inexpensive desalination system that operates by renewable energies becomes a sustainable need [10,11]. Direct solar desalination method is used for small production systems, such as solar stills. ...
Article
Full-text available
A desertic region always suffers from a lack of fresh water in a large portion of its area. In these areas, available water from swamps or ground water wells is brackish water, and it must be purified or distillated. In this paper, we introduce a simple distillation system accompanied with a concentrating unit. This system was assembled and installed with very low costs. Also, paraffin wax was used in this study as phase change materials to absorb heat from the heated water. The concentrating system, which consists of a dish accompanied by a drum as a storage device and pipes assembly fixed at dish focal, was used to heat brackish water. The conical distiller was fabricated to contain PCM under its base to increase the stored energy. Tests were conducted at Baghdad, Iraqi wintertime 2013–2014. The study declares that this system is suitable to desert weathers with acceptable productivity compared with other existing systems. Adding PCM to the concentrating distillation system increased system working hours, increased concentrating efficiency with about 50.47%, increased system heating efficiency with about 157.8%, and increased system productivity with about 783%. Comparing this study with other Iraqi studies and those in literature gave convincing agreement. This study contains valuable information for researchers, industrials, and investors interested in solar water desalination system investment in Iraq and desertic weather countries.