Design and experimental analysis of solar water desalination system (original) (raw)

Design and experimental analysis of solar water desalination system Engineering

2013

There is almost no water left on earth that is safe to drink without purification after 20-25 years from today. This is a seemingly bold statement, but it is unfortunately true. Only 1% of Earth's water is in a fresh, liquid state, and nearly all of this is polluted by both diseases and toxic chemicals. For this reason, purification of water supplies is extremely important. Keeping these things in mind, we have devised a model which will convert the dirty/saline water into pure/potable water using the renewable source of energy (i.e. solar energy). The basic modes of the heat transfer involved are radiation, convection and conduction. The results are obtained by evaporation of the dirty/saline water and fetching it out as pure/drinkable water. The designed model produces 1.5 litres of pure water from 14 litres of dirty water during six hours. The efficiency of plant is 64.37%. The TDS (Total Dissolved Solids) in the pure water is 81ppm.

A new Solar Desalination System Design and Heat Recovery

Journal of Engineering Research, 2019

The work evaluates experimentally technique to improve fresh water production by careful energy recovery in the vapour condensation processes; the recovered heat in turn on drives additional evaporation and preheats the feedwater. A pilot plant is designed and constructed in an arid area with 2 m 2 solar evaporation collector area to evaluate the process. This unit is tested on cold and hot days. The effect of main parameters on fresh water production of the unit is studied. The experimental results show that, the production rate and efficiency of the system are strongly affected by solar radiation and level water in solar evaporation collector. Within the studied ranges, the maximum productivity reached to 16.1 kg/ m 2 day at Tvap,av = 87.6 o C , solar radiation 842 W/m 2 and level water 1.912 kg. According to these results, fresher water production of the present system is higher than that solar still desalination system in the previous studies.

Study of a water desalination unit using solar energy

Desalination and Water Treatment, 2009

This paper presents the study of a water desalination new design process working with the humidification-dehumidification (HD) method using solar energy. This process was developed in order to boost the productivity of the solar multiple condensation evaporation cycle unit which is located at the national school of engineering of Sfax, Tunisia, by integrating into the latter a flat-plate solar air collector and a humidifier. The HD process is essentially composed of a flat-plate solar air collector, a flat-plate solar water collector, a humidifier, an evaporation tower and a condensation tower. A general model based on heat and mass transfers in each component of the unit has been developed in a steady-state regime. The obtained set of ordinary differential equations has been converted to a set of algebraic system of equations by the functional approximation method of orthogonal collocation. The developed model is used to simulate the HD system in order to investigate the steady-state behavior of each component of the unit and the entire system exposed to a variation of the entrance parameters and meteorological conditions.

Analysis of an innovative water desalination system using low grade solar heat

This paper presents a theoretical analysis and preliminary experimental results for an innovative water desalination system using low-grade solar heat. The system utilizes natural means (gravity and atmospheric pressure) to create a vacuum under which water can be rapidly evaporated at much lower temperatures and with less energy than conventional techniques. The system consists of an evaporator connected to a condenser. The vapor produced in the evaporator is driven to the condenser where it condenses and is collected as a product. The effect of various operating conditions, namely, withdrawal rate, depth of water body in the evaporator, temperature of the heat source, and condenser temperature, on the system performance were studied. Numerical simulations and preliminary experimental results show that the performance of this system is superior to a flat-basin solar still, and the output may be twice that of a flat-basin solar still for the same input. Vacuum equivalent to 4 Wa (abs) or less can be created depending on the ambient temperature at which condensation takes place.

Investigation of a novel small-scale solar desalination plant

International Journal of Low-Carbon Technologies, 2006

The investigation of a novel solar energy desalination plant is the subject of this paper. In this plant, the evaporation occurs at low pressure and temperature. The novelty of the process lies in the reduction of the pressure simply due to the height of the evaporator. A mathematical model was developed and a prototype plant was constructed and tested by varying the heat input, evaporator pressure and feedwater flowrate at different working temperatures. Experimental results are very close to the theoretical results and indicate the validity of the model and the potential of the system.

Proposal of a Solution for Water Desalinization Using Solar Energy

Revista Brasileira de Engenharia de Biossistemas

Water is abundant on Earth, only about 2.5% is freshwater, and because most of that water is stored as glaciers or deep groundwater, only a small amount of water is easily accessible to humans and animals. This study's motivation is to find a solution for lacking freshwater, converting brackish and seawater to potable water. The main goal was to produce potable water with high-efficiency production using solar energy. The system's main components were the absorber plate painted black, glass cover, insulation, and vessels to collect fresh water. The absorber plate is painted black to absorb solar radiation, preventing its reflection. The plate delivers higher temperatures for saline water to be evaporated and condensed afterward. The basin liner was made of an iron sheet, and the cover is made of ordinary glass, while the basin was covered with glass using silicon rubber. We used 30-degree single slope solar to identify the efficiency of using black stone without using black ...

Experimental Study of a Solar Thermal Desalination Unit

Volume 6B: Energy, 2013

Scarcity of potable water causes a serious problem in arid regions of the world where freshwater is becoming insufficient and expensive. Warm regions in the Middle East and North Africa are considered among the severest water shortage places. The objective of this project is to study the potential of using solar energy to run existing multi-stage flash (MSF) desalination units in the Arabian Gulf. One problem with MSF is the low efficiency of the system because of the bulk energy required for heating. Exploitation of solar energy in thermal desalination processes is a promising technology because of the ubiquitous nature of sun's energy. Experimental studies were conducted on a single flash desalination unit. The pilot unit demonstrates the use of solar radiation as the thermal energy input. The process starts by preheating seawater through a vacuumed condenser. Seawater, then, flows inside a circulation tank to be indirectly heated by a heat transfer fluid. The heat transfer fluid circulates inside a flat plate solar collector facing south to absorb solar energy. After raising its temperature, seawater goes through an expansion valve and flashes in a vacuumed chamber to form brine and vapor. The vapor transfers to the condenser and condenses to form potable water by losing its latent heat of vaporization to incoming seawater. The flow rate of the working fluid is controlled via a control valve based on a set point temperature reference. The experiments were carried out using different values of the controlling variables to enhance analysis and validate results.

SOLAR DESALINATION: A CRITICAL REVIEW

IAEME, 2019

Rapid population growth and insufficient conservation of water resources in water scarce regions are but two reasons for the predicted water shortages that are likely to plague future generations. Desalination, over the last two decades, has seen major strides made in the production of potable water in large scale projects. Through continuous research and development new and improved methods have been found and implemented across the world. The viability of desalination as a reliable alternative potable water source has been proven on numerous occasions through various studies, projects and devices. This paper reviews the need for research into alternative water purification methods in general, desalination methods in particular, their working principles and mathematical modelling. The economics of thermal and membrane based desalination is noted.

Mathematical Model Development for a New Solar Desalination System

Energy Conversion and Management, 2008

Supply of adequate quantities of fresh potable water is one of the most serious problems confronting human especially when we know that one third of the world population are suffering from water shortage and it is expected to reach two thirds in the near future. Therefore, desalination, as a non-conventional water resource, has become one of the most interesting alternative water sources to partially face the fresh water shortage in the near future. The objective of this study is to obtain a general mathematical model for a newly developed solar still that uses parabolic reflector-tube absorber desalination technology. A computer program has been developed to simulate the still operation and to solve the governing heat and mass transfer action, which occurs during the operation. The program will then be used to study the still production in different cases. The study revealed that increasing the solar intensity, ambient temperature, efficiency of reflector material, reflector aperture area, and evaporation area increases the unit productivity. On the other hand, increasing wind velocity, saline water depth, condenser emissivity, and condenser thickness have a small effect on the productivity.