Sharif Digital Repository

Natural Gas is one of the most important energy resources in the world. The U.S energy information administration(EIA) has reported that natural gas consumption will increase until 2030 in all participating sectors including industrial, domestic and electricity production.Although the use of natural gas as a source of energy has many advantages, natural gas physical condition made it’s transfer so challenging. Among the various types of transmission methods, using pipline is so conventional. Natural gas can be transmited through pipelines in a safe and reliable manner upto thousands of kilometers. For this reason, operation monitoring and control of gas transmission networks are so... 

Nowadays, micro systems in many area of science and technology have special importance and status. The main function of these systems is based on the deformation of a beam at micro scale. Therefore study of behavior and control of micro-beams will have a great importance. Among micro-beams, clamped-free and clamped-clamped micro beams that actuated by piezoelectric and electrostatic actuators have wider applications. For example, clamped-free micro-beams are used in atomic force microscopy (AFM), micro switches, mass sensors and micro-accelerometers and clamped-clamped micro-beams are used in micro mirrors and Grating Light Valves (GLV). In this thesis, the studied system is clamped-free... 

Many spacecrafts and satellites have long flexible components, the most common ones are the satellites with flexible solar panels, which are used to provide the satellite energy. The governing equations of the satellite rigid motion along with the solar panels vibrations are the combination of the coupled partial and ordinary differential equations. Various reasons, such as the satellite maneuvers and the external disturbances, cause the vibration of panels. Due to the dependence between the governing equations of the satellite rigid motion and the flexible components vibrations, these vibrations affect the satellite rigid dynamics and the control aims; therefore, in addition to the... 

Three different feedback linearization control methods are applied to nonlinear control of type I diabetes mellitus model. One is exact FBL and the two others are approximate manners based on approximations of the nonlinear system and its duality one-form, utilizing uniform approximation and a homotopy operator, respectively. An extended luenberger observer is also employed to observe the required states of designed compensators. The nonlinear compensators are designed based on a minimal model and applied to the minimal model, as well as Sorensen’s physiological model. In addition to the mentioned close-loop control strategies, a discrete control strategy based on an optimization problem is... 

Gas transmission networks play an important role in multi-vector energy networks. Therefore, reliable and efficient control of gas transmission networks with the minimum energy consumption is utmost task and is still an active research area. This work, introduces a distributed, model-free, and game-theoretic approach comprising a simultaneous game followed by a sequential game, to achieve the control objectives in gas transmission networks. The cooperative game approach is adopted for this purpose. In the proposed method two fuzzy inference systems have been used to obtain the payoff of each player in the game of gas transmission network control, the first one has been used to determine the... 

The development of computers and their related software packages provided engineers with the ability to simulate complex chemical processes. These simulations were the stepping stone for in-depth knowledge of the processes and also a prerequisite for the chemical process optimizations. From then, realistic simulation and optimization were always a primary concern for chemical engineers. To address this concern, they go beyond the one-dimensional design approach toward the two-dimensional design-operation systems, and the design-control interaction of the chemical processes afterward. Moreover, optimizing chemical processes from the aspect of energy and water, separately, gained lots of... 

Due to the operation of proton exchange membrane fuel cell (PEMFC), temperature will rise because of the electrochemical reactions and control of temperature is one of the most important sections that has influence on the performance of the fuel cell. In this study three alternative for cooling and controlling the temperature situation is proposed and compared. the experimental setup consists of the simulated fuel cell that produce heat just like PEMFC and number of thermosyphon miniature heat pipes for evoke the heat and three types of condenser that makes three different scenario for this cooling setup. Free convection, force convection using Fan and force convection using circulating... 

Fuel cells are a reliable technology for electrical power generation, widely regarded as a promising alternative for stationary and mobile applications. In order to supply vehicle required power, fuel cell must possess suitable transient response. In this work, a mathematical zero dimensional control-oriented model for a PEM fuel cell stack is developed. Afterwards, to increase the efficiency, four parameters including cathode air inlet flow rate, return manifold cross section area, anode hydrogen inlet flow rate and hydrogen humidity are optimized in different vehicle current demand. Also, in order to decrease water production inside the fuel cell membrane, considered parameters are... 

Diabetes is one of the most epidemic metabolic disease which needs to be controlled through medications. The main objective of this study is to model and control diabetes type1 with exercise. It is important to choose an appropriate yet simple model based on which the design of the controller is accomplished (Bergman model is the one which is appropriate for this purpose). On the other hand, a comprehensive model which is used as the virtual patient has been chosen to assess the performance of the controller designed based on simple mode. The chosen comprehensive model is Cinar’s model. A good control of diabetes was achieved when the glucose blood (GB) of the two models almost had the same... 

In this project, modeling, simulation, and control of the Saccharomyces Cerevisiae were studied. In the first section, simulation and control of a structural model of saccharomyces Cerevisiae were performed. Fuzzy Logic Controller (FLC) as a model-independent controller and Global Linearization Controller (GLC) as a model-based controller were designed. Additionally, two types of Kalman filters were designed to predict all states of the structural model: 1-Extended Kalman Filter (EKF), 2- Unscented Kalman Filter (UKF). As a concise explanation, the control action of the GLC is a function of all states of the model, and since that measuring all metabolites is not practical, the EKF and UKF... 

The kidney is one of the most complicated organs in terms of structure and physiology, in part because it is highly vascularized. Previous investigations have focused on specific characteristics like length and diameter. There are a few methods like those which are based on image processing techniques, that have been focused on all features as a unique structure. The clear drawback of these approaches is inability to justify growth and changes. Lindenmayer system (L-system) is parallel rewriting method and a type of graph grammars. L-system can justify growth and all characteristic changes and adopt itself to them. Parametric rewriting rules incorporating within physiological laws of the... 

Kidney is one of the most complicated organs in terms of functionality and physiology due to its complicated unique vascular structure. Previous investigations have focused on specific characteristics like length and diameter. Most of these methods are based on Image Processing techniques which prevent a comprehensive study in growth and changes of the vascular system. Lindenmyaer system (L-system) is a parallel rewriting system and a type of formal grammar and had been used to create graphs and natural patterns. By absorbing the physiological characteristics of the kidney and integrating them into parametric L-system, a highly dense and accurate vascular system could be generated with few... 

The industrial paradigm shift toward intelligent and sustainable management stimulates policymakers to leverage artificial intelligence for the decentralized planning of chemical industries with energy networks. By doing so, this work firstly presents a simulation framework to investigate the rigorous transient behavior of integrated systems comprising natural gas and power transmission networks, along with a chemical plant whose feedstock is natural gas. This framework entails dynamic models for the gas transmission network and the SynGas plant, and a continuous-time AC-power flow formulation with dispatchable loads. It addresses the following key challenges: (i) analyzing energy and... 

Process optimization is a technique by which the plant operating condition is obtained such that a specific objective is achieved while the other process requirements are still met. These requirements can include product quality specifications, physical equipment limitations, and the constraints corresponding to the environmental, health, and safety issues. Frequently, this objective is an economic one. In the process optimization, the use of improper optimization techniques may lead to impractical results. One of these strategies is the plant wide optimization. In order to show the effect of plant wide optimization, one should use a complicated enough process as a bench mark of the... 

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... 

Industrial water systems often allow efficient water uses via water reuse and/or recirculation. The design of the network layout connecting water-using processes is a complex problem which involves several criteria to optimize. The general problem can be formulated as a non-convex nonlinear program (NLP), but due to the presence of bilinear terms, it may be difficult for local optimization solvers to attain global optimal solutions. To overcome this difficulty, this paper presents a hybrid approach combining the global optimization power of evolutionary algorithms and speed and accuracy of mathematical programming technics.By this strategy, local solutions can be avoided and the... 

Monitoring and control of gas transmission networks are very challenging and important, this is due to the fact that interactions between various elements in the transmission network severely affect network’s overall performance. This makes it crucial for the monitoring and control systems to take into account the topology of the network, in their decision making and control scenario’s. On the other hand, in the event of any abnormality in the network behavior, , in order to accurately and quickly detect the cause of the abnormal conditions, there is a need for rapid and effective analysis of the network based on the measurements made therein and to identify the key and effective situations... 

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... 

Monitoring of the water transmission networks is an essential factor to regard efficient, safe and economical strategic considerations. Several parameters (fluid pressure, fluid flow and fluid temperature in some cases) are measured to monitor the water transmission networks. The number and location of these measurements in deferent positions affect the cost and quality of the network states monitoring. It is obvious that measuring the all parameters and states of the network is not cost-effective even when it is possible. The conventional sensor-location methods have been developed based on the pressure variation stemmed from a leakage in the network. This study proposes a new procedure to...