http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/498 2026-04-07T01:55:34Z http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/547 Design, construction and performance analysis of a solar powered dual mode desalination system for water purification Shishir, Asif Jaman Human life is based on water. Safe drinking water is one of our fundamental needs. Water is one of the most abundant resources on earth covering 75% of the planet’s surface. About 97% of the earth’s water is salt water in the oceans, and a tiny 3% is fresh water. Sea water contains large amount of salts. The salts exist in the form of chloride, sulfate, sodium, magnesium, potassium etc. Chloride and sulfate contribute to about 55% and 31% of sea salts respectively. Eating small quantities of saline water are not harmful, but more can be dangerous, ultimately producing fatal seizures, heart arrhythmias and kidney failure. Other than salts, there are many other unwanted elements, like bacteria, Parasites and heavy metals in the water. Major parts of Bangladesh do not have access to safe drinking water. Fresh water which was once obtained from rivers, lakes and ponds in plenty is now becoming scarce because of industrialization and population explosion. Increased irrigation of land for producing larger amount of food adds to the fresh water scarcity. Also, the available portable water is now increasingly being polluted by industrial and sewage waste. Therefore, there is need to purify the water to make suitable for drinking. It would be feasible to address the water-shortage problem with seawater desalination; however, the separation of salts from seawater requires large amounts of energy which, when produced from fossil fuels, can cause harm to the environment. Therefore, there is a need to employ environmentally friendly energy sources in order to desalinate seawater. As a part of my thesis, I have made a single basin single slope desalination device, where I used dual mode thermal energy for quick vaporization. One is the thermal energy trapped from solar radiation through a transparent top cover. Another one is the thermal energy of DC heaters powered by Photovoltaic module. Designed device is renewable energy (Solar) based and environmentally-friendly. This can be used for water heating, desalination and purification. This report covers introduction into desalination, comparative analysis of current desalination technologies. Some general concepts are given for the proper selection of desalination method. Description of designed desalination device is given in detail. After that, its construction, total cost, performance, efficiency and results are given here. Device maintenance, drawbacks and few related points etc. are also studied. From this research, I have concluded that, solar powered dual mode desalination may not be a viable option at the present price structure, further research for efficiency improvement of device could make solar assisted desalination one of the most economically advantageous device. This thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Renewable Energy Technology. 2016-11-20T00:00:00Z http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/546 Design, construction and performance study of a low cost solar dryer for food preservation in Bangladesh Biswas, Pias Kumar The solar drying system utilizes solar energy to heat up air and to dry any food substance loaded, which is beneficial in reducing wastage of agricultural product and helps in preservation. The objective of the thesis is to design, develop and evaluate performance of an indirect solar dryer using thermal energy storage for the drying of vegetables and other foods. Later the future prospects in Bangladesh have been discussed in details. This design was employed by measuring various features such as cost, efficiency, durability and has compared with the performance testing through parameters such as temperature, air velocity, collector efficiency and weight loss. It was shown that the use of this type of solar dryer reduced the drying time significantly and essentially provide better product quality compared with conventional drying method. The effect of temperature to moisture contents against time and rate of drying are studied in this thesis. This thesis is submitted to the Institute of Energy at the University of Dhaka in partial fulfillment of the requirements for the Degree of Masters of Science in Renewable Energy Technology. 2016-11-20T00:00:00Z http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/545 Study of the present scenario of solar irrigation in Bangladesh and design of a new irrigation model to make the solar Irrigation system more feasible Al-Amin; Tanni, Tasmiah Fatema Bangladesh has a primarily agrarian economy. Irrigation plays a very important role in our agriculture as well as on our economy. During dry season, irrigation of the whole country faces an acute crisis due to load shedding of 1248 MW. As Bangladesh has good solar resources, with high availability during the peak irrigation season. Therefore, solar pumping of water for irrigation presents an innovative and environment-friendly solution for its largely agro-based economy. Infrastructure Development Company Ltd (IDCOL) is providing financial support to solar irrigation. Already 450 irrigation pumps are installed by IDCOL in different divisions of Bangladesh. In this paper, 450 project’s data are analyzed and the findings are shown by different important graphs. Different division’s radiation, water head and required water are mainly focused in the analysis which will be very supportive for upcoming irrigation projects. To accomplish the analysis on solar irrigation a practical field visit has been made at Poradaho, Kushtia.Thisis a project of Bright Green Energy Foundation (BGEF) and financed by IDCOL. After visiting the project and talking with the farmer, a comparison between solar pump and diesel pump is found which is very significant. In addition, the idea of mini-grid along with irrigation is originated considering the huge load shedding of that area. People of that area remain without electricity for approximately 6-8 hours in a day. For this mini-grid purpose, a small survey was also conducted on 50 houses of that rural area about their electricity demand during the time of load shedding. The mini-grid will be power by the extra energy coming from the irrigation panel. This is done simply by changing the run time of the motor in an efficient way. The run time of the motor varies with different seasons. HOMER software is used to calculate the cost analysis of the proposed model for irrigation along with ac min-grid. In this model, two welfares derive at a time. The first one is that rural farmer can get water for irrigation with a lower installment which is shown in the paper. The second one is the demand of electricity of rural people during load shedding can also be fulfilled from the ac mini-grid. Therefore, the overall cost will be minimized and the new irrigation system will be more feasible for rural farmers as well as for the owner also. This thesis is submitted to the Institute of Energy at the University of Dhaka in partial fulfillment of the requirements for the Degree of Masters of Science in Renewable Energy Technology. 2016-11-20T00:00:00Z http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/544 Opportunities in implementation of sustainable and renewable energy policy in Bangladesh Rahat, Munshi H. M. Bangladesh is a developing country which is facing severe energy crisis. The energy consumption over the time will increase also. Aside from that Bangladesh is also one of the vulnerable country due to climate change of the world. In order to satiate the energy crisis Bangladesh need to find an environment friendly way for energy production. Bangladesh has good potential for harnessing renewable energy sources such as solar, biomass, wind, and mini-hydropower. According to Goldman Sachas it is one of the “next 11” country also (Goldman Sachas). Renewable energy is the balanced point for energy production which can produce energy without harming the environment. This Work is focused on to put light on renewable energy sources that can fix our energy crisis in a sustainable way and hence find new opportunities. It does so through a critical review of policy and institutional settings, as well as present status and lessons learnt from pilot demonstration of a number of RET projects undertaken by different organizations. The aim of this study is to help the policy makers in formulating renewable and sustainable energy policies and future plans for Bangladesh through this field oriented argument. This dissertation submitted to the Institute of Energy University of Dhaka for the degree of M. S. in Renewable Energy Technology. 2016-11-20T00:00:00Z