Sharif Digital Repository

Agriculture is one the most water consuming sections in the world and roughly 60% of water demand is dedicated for this purpose. A seawater greenhouse manages to combine fan and pad greenhouse with humidification-dehumidification desalination in order to achieve water production next to agriculture products using moister in air which was used for cooling. The most important aspect of a seawater greenhouse is the amount of produced water. Many research on the condenser type and materials have been conducted in order to achieve a better performance, suggesting the utilization of a low temperature water source for the condenser. In this research, using a thermodynamic correlations to model the... 

The purpose of this study is to develop a simulated model of a greenhouse using two different ventilation systems, a fan&pad system and an air-soil converter equipped with a sprinkler in order to compare the cooling performance of these two systems in hot seasons. The main focus of the analysis of the results is on how the temperature and humidity are distributed throughout the greenhouse space. In order to develop a three-dimensional model with computational fluid dynamics method, greenhouse simulation in Ansis software has been used. The development of ventilation model in the greenhouse is done by creating boundary conditions using optimal design. Also, to simulate soil-air conditioning... 

Industrial symbiosis(IS) is a promising approach toward sustainable development goals. Among common modeling techniques, agent-based modeling holds a special place in IS simulation due to its bottom-up nature. However, the role of essential technologies in supply chain of IS has been poorly studied in the literature. In this work, first, an agent-base model is developed based on economic and environmental incentives of IS stakeholders employing optimization and non-cooperative game theory. Then, essential technologies in each potential symbiotic relation are integrated into the model to investigate their impact. The result suggests, to facilitate IS through environmental policy making, on... 

CO2 capture and utilization (CCU) is a promising approach to reduce and control emissions from the industry and energy sector, while also creating new jobs and value-added products. However, one of the main barriers to the widespread adoption of CCU is the high investment and operating costs, which limit its implementation to mostly government-supported research projects. To overcome this barrier, structural optimization and identification of optimal routes and formation of industrial symbiosis networks are needed. In this research, we developed a comprehensive superstructure that includes sources and sinks (in a case study), CO2 capture and separation material and technology combinations... 

To meet the high energy demand in greenhouse cultivation, clean technologies have been suggested. This research provides a computational and modeling framework to examine the integration of three systems including a photovoltaic panel, earth_air heat exchanger, and industrial symbiosis, to produce three types of energy (electricity cooling, and heating) in a Venlo-type greenhouse. To estimate the minimum energy required to maintain environmental parameters in optimal plant conditions, an energy demand model was developed with the ability to consider the effect of energy stored in the ground. For a greenhouse in Tehran, the annual heating requirement was calculated as 432 kWh/m2 and 227... 

Given the growth of the world's population along with the increase in the percentage of urban population by 2050, the way of responding to food consumption will change in the future. Controlled Environment Agriculture will largely account for future food supply. Vertical Farming is one of these systems. But despite the efficiency of these systems in terms of land and water and also not being affected by weather conditions, the main challenge in these systems is the consumption of energy use per unit of crop production. The cost of energy is about 25 to 40 percent of the total costs. The purpose of this study is to develop an integrated dynamic model for the determination of vertical farm... 

The present study aims to reduce the carbon footprint of greenhouse products to provide a decision tool for sustainable development of greenhouses. In order to provide this decision tool, the impact of four scenarios or energy-efficient technology for greenhouse heating, including: combine heat and power system(CHP), new greenhouse covering material, industrial symbiosis, and solar collector on the carbon footprint of greenhouse products has been studied because one of the main factors in the release of carbon footprints of greenhouse products is the use of fossil fuels for greenhouse heating. Energy modeling has been used to estimate the amount of heating, cooling, and artificial lighting... 

The water crisis caused by climate change and anthropogenic activities in Iran has affected the daily lives of the people, and since the agricultural sector has a large share of water consumption, greenhouse cultivation and indoor farming has been developing in this country, to improve water productivity. Considering that the main source of energy supply in greenhouses is fossil fuels, in this work, the possibility of improving Industrial Symbiosis (IS) between greenhouses and waste heat sources in industries by employing the Organic Rankin Cycle (ORC) has been studied, in order to meet the heating demand of greenhouses in a more sustainable and eco-friendly way.Based on that, by modeling... 

Heating demand required for greenhouses is mainly met by fossil fuels. On the other hand, anxieties over usage of fossil fuels have led the societies to move toward renewable energies. With this in mind, the purpose of this research is to analyze using both solar energy for satisfying the heating demand of greenhouses and heat storage for compensating the intermittence of renewable energy.Considering the mentioned points, in the current research, a linear optimization framework has been developed for design and operation of energy systems including long-term heat storage to meet heating demand of greenhouses. The objective of this framework is to minimize annual cost. The developed method... 

The main purpose of this research is analyzing the energy stream of clean food production by using Iran's power plants sourced waste heat. In order to achieve this goal, at first, greenhouse heating demand model according to the type of crops and geographic location of greenhouse, heat transport from power plant to greenhouse model, and heat exchanger model is presented. Then, the potential of constructing clean greenhouse around power plants has been evaluated by using the concept of industrial symbiosis and by integrating greenhouse energy demand, waste heat transport, and heat exchanger models into industrial symbiosis concept framework and also by economical and geographical assessments.... 

Meeting the energy demand of agricultural greenhouses has turned out to be the most important challenge of greenhouse cultivation. In this study, it is proposed to use the concept of industrial symbiosis between agricultural greenhouses and biogas plants to face this challenge. The main purpose of the study is to investigate the potential clean greenhouse area that may be supported by the proposed symbiotic network, in order to provide a decision-making tool for the relevant policymakers. The methodology is based on the agent-based input-output matching economic analysis. The amount of biogas produced by poultry and cattle manure is estimated to be 0.6 (m3 / kg VS) and 0.47 (m3 / kg VS)... 

The purpose of this research is developing an analytical and decision-making tool that examines the interactions between greenhouse energy demand and yield production. Greenhouseholders can use the analytical tool to design and operate existintg and newly built greenhouses in an optimal way. Becides, the decision making tool helps planners and policymakers to improve the performance of greenhouses and extend greenhouse cultivation with respect to their economic or environmental objectives.In order to develop this decision making tool, existing models for greenhouses have been investigated and various algorithms have been combined to develop an integrated energy demand-plant growth model. The... 

The operating conditions of the battery in renewable energy systems affect its electrochemical behavior and degradation process. Recent research mainly estimates battery lifetime through conventional methods such as counting the number of equivalent battery life cycles or based on simple experimental models that may lead to optimistic predictions in battery service period. In this study, a reduced-order thermoelectrochemical-aging battery model is developed for the application of renewable energy systems and the battery degradation analysis is investigated by this model. The proposed microscopic model evaluates the effect of battery operating conditions such as state of charge, current and... 

The population growth and scarcity of resources such as water and land make the food security as one the most important critical priorities in the world. Development of food production in greenhousesinstead of the traditional agriculture in rural areas is an efficient and applicable approache to reach food security and optimum use of water resources. However, this requires more capital. An important part of this cost is related to the cost of energy supply for heating and cooling in order to provide a suitable condition for the growth of plants. Optimal design of a rural energy supply and optimal operation of existing greenhouses to maximize the benefit of the greenhouse owners and to... 

Nowadays, one of the most important challenges in developing and operating greenhouses in the agricultural sector is to supply them with energy. Hence, in recent years, the development of greenhouses with the goal of increasing energy efficiency and reducing production costs has been considered by the hands-on-cluster of this field. As a result, one of the main goals for the development of high-productive greenhouses is to reduce the energy consumption index for the production of a unit of product. Another challenge in the greenhouse is the high consumption of water for evaporative cooling systems. On the other hand, the supply systems for heating, cooling and ventilation should be able to... 

CCHP systems have attracted much attention in recent decades due to their economic and environmental benefits and high returns. Therefore, in this research due to the necessity of using high energy efficiency technologies and low cost of operation while also releasing minimum environmental pollutants such as carbon dioxide, a Solar-assisted CCHP system is studied. The performance of the CCHP systems is deeply dependent on the operation strategy of the system. In this research, in order to improve the techno-economic performance of the system, an optimization model is applied to optimize the proposed operation strategy using minimum distance methodology. In order to measure the proposed... 

In the last three decades, the world has experienced enormous increases in energy consumption as a consequence of the economic and population growth. This causes renewable energy and energy recovery to become a requirement in building designs rather than option. A direct expansion (DX) air conditioning system is an efficient way to supply fresh and dehumidified air to a built environment a long side it plays a key role in preventing the spread of respiratory diseases. To improve the efficiency of a conventional DX system in hot and humid regions, fresh air dehumidification and conditioning systems with energy recovery measures are the key equipment to reach such a goal. To achieve this goal... 

Evaporative cooling systems are of most common cooling systems which their electricity consumption is much lower than vapor compression cooling systems. Enhancement of these system’s performance could help to propagate these systems and also decrease the electricity consumption and corresponding emissions in large scale. In this thesis, first a modified cycle is proposed for evaporative cooling. Then, in order to use evaporative cooling in humid climates, a desiccant wheel is implemented in this modified evaporative cooler. As using evaporative cooling will cause high water consumption, a novel cycle is proposed for desiccant based evaporative cooling which is able to cover system water... 

Fuel cell is a very attractive technology for clean electricity production and has a wide range of applications from industry to transportation and power generation. There are several issues that prevent the development of this technology widely. Rapid degradation of fuel cells during operation is one of them. Online monitoring of operational parameters in order to control and optimize the effective variables of power generation and life of the fuel cell considered as an important way to mitigate fuel cell’s degradation. In this research, a set of models were developed to calculate the voltage, current, corrosion, as well as the fuel cell system state variables instantaneously. Two robust... 

With regard to an increasing world population and the constant capacity of water resources, new and valid methods should be implemented to preserve freshwater resources and accordingly produce drinking water. In the present study, a solar hybrid system was studied by experimental and theoretical means to facilitate the transformation of waste heat from photovoltaic module (PV module) into useful heat that can be used in a solar desalination (SD) system for freshwater production purposes. The study aimed to fabricate a SD system by using both PV module and thermosyphon heat pipes (THPs) technologies in a single system. In the modeling section, the goal is to present a comprehensive model...