Feasibility of a Solar Panel-powered Liquid Desiccant Cooling System for Greenhouses


Book Description

To investigate the technical feasibility of a novel cooling system for commercial greenhouses, knowledge of the state of the art in greenhouse cooling is required. An extensive literature review was carried out that highlighted the physical processes of greenhouse cooling and showed the limitations of the conventional technology. The proposed cooling system utilises liquid desiccant technology; hence knowledge of liquid desiccant cooling is also a prerequisite before designing such a system. Extensive literature reviews on solar liquid desiccant regenerators and desiccators, which are essential parts of liquid desiccant cooling systems, were carried out to identify their advantages and disadvantages. In response to the findings, a regenerator and a desiccator were designed and constructed in lab. An important factor of liquid desiccant cooling is the choice of liquid desiccant itself. The hygroscopicity of the liquid desiccant affects the performance of the system. Bitterns, which are magnesium-rich brines derived from seawater, are proposed as an alternative liquid desiccant for cooling greenhouses. A thorough experimental and theoretical study was carried out in order to determine the properties of concentrated bitterns. It was concluded that their properties resemble pure magnesium chloride solutions. Therefore, magnesium chloride solution was used in laboratory experiments to assess the performance of the regenerator and the desiccator. To predict the whole system performance, the physical processes of heat and mass transfer were modelled using gPROMS' advanced process modelling software. The model was validated against the experimental results. Consequently it was used to model a commercials-scale greenhouse in several hot coastal areas in the tropics and sub-tropics. These case studies show that the system, when compared to evaporative cooling, achieves 3°C-5.6°C temperature drop inside the greenhouse in hot and humid places (RH>70%) and 2°C-4°C temperature drop in hot and dry places (50%







Sustainable Air Conditioning Systems


Book Description

Air conditioning system is one of the major consumers of electrical energy in many parts of the world today. It represents between 40 and 70% of the energy consumption in commercial buildings. The demand of energy for air conditioning systems is expected to increase further in the next decades due to the population growth, the new economic boom, and the urbanization development. The rapid growth of air conditioning and electricity consumption will contribute further to climate change if fossil and nonrenewable resources are used. More energy-efficient and renewable energy-based air conditioning systems to accomplish space cooling are needed. This book intends to provide the reader with a comprehensive overview of the current state of the art in sustainable air conditioning technologies and focus on the most recent research and development on green air conditioning systems including energy-efficient and renewable energy-based air conditioning systems.




Design of a Solar assisted Liquid Desiccant based evaporative Cooler


Book Description

Academic Paper from the year 2017 in the subject Engineering - Power Engineering, Eastern Mediterranean University, language: English, abstract: The increase of occupant comfort demands are leading to rising requirement for air conditioning, but deteriorating global energy and environment crisis are starving for energy saving and environmental protection. The need to come up with the new energy saving as well as environmental friendly air conditioning systems has been more urgent than ever before. In hot and humid areas, the liquid desiccant air-conditioning systems based on evaporative cooling was proposed as a promising invention. This system overcomes the difficulty of evaporative cooler increased humidity with cooling, which makes it unsuitable for hot and humid climates, by dehumidifying the air first and then cooling it inside an evaporative cooler with water. The heating effect of dehumidification process is compensated by cooling water circulation. The use of dehumidifier in conjunction with an evaporative cooler increases the efficiency of the system. Some of the advantages of using this system are: it can remove the air latent load, environmental friendly, removes the pollutants from the process air and reduces the amount of the electrical energy consumed. The primary objective of this project is to design a solar based liquid desiccant evaporative system to purify and supply cool air. Liquid desiccant dehumidification has been proven to be an effective method to extract the moisture of air with relatively less energy consumption, especially compared with conventional vapor compression system. Inside the dehumidifier we used calcium chloride solution which after some period of time gets diluted with water and loses its moisture absorbing capacity and therefore, needs to be heated in the solar collector to ensure that the liquid desiccant does not lose its absorption capacity. In this project, several different aspects in solar assisted liquid desiccant based evaporative cooler have been considered. Some of these aspects include the availability of the materials, manufacturability of the product, sustainability of the product, health and safety regulations and the environmental effects of the product.







Solar Energy and Nonfossil Fuel Research


Book Description

This directory--the first annual compilation of agriculture-related solar energy research--is designed to provide the scientist, technician, and inventor; government and industry; and farmers and other interest laymen with an overview of the diverse and intense efforts being mounted by our society to find alternate energy sources.




Solar Cooling


Book Description

Cooling buildings is a major global energy consumer and the energy requirement is growing year by year. This guide to solar cooling technology explains all you need to know about how solar energy can be converted into cooling energy. It outlines the difference between heat-driven and photovoltaic-driven systems and gives examples of both, making clear in what situations solar cooling technology makes sense. It includes chapters on: • solar thermal collectors • solar cooling technologies • cold distribution • storage components • designing and sizing • installation, operation and maintenance • economic feasibility • potential markets • case studies. Solar Cooling is for engineers, architects, consultancies, solar thermal technology companies, students and anyone who is interested in getting involved with this technology.




Solar Energy Update


Book Description