My Final Year Project Free Essays

string(212) " extensive experience in installing solar thermal energy systems throughout India and armed with ever improving production facility, Gadhia Solar is the pioneer and market leader in solar thermal energy systems\." A REPORT ON AUTOMATED STEAM JACKETED COOKING VESSEL BY PRATAP DESHMUKH 2008A8PS251G AT GADHIA SOLAR ENERGY SYSTEMS PVT. LTD. A Practice School II station of BIRLA INSTITUTE OF TECHNOLOGY SCIENCE, PILANI (JANUARY – JUNE 2012) A REPORT ON AUTOMATED STEAM JACKETED COOKING VESSEL BY PRATAP DESHMUKH 2008A8PS251G B. We will write a custom essay sample on My Final Year Project or any similar topic only for you Order Now E. (Hons) ELEC. INSTR. Prepared in partial fulfillment of the requirements of the Course No. BITS C412 (Practice School II) AT GADHIA SOLAR ENERGY SYSTEM PVT. LTD. A Practice School- II station of BIRLA INSTITUTE OF TECHNOLOGY SCIENCE, PILANI JANUARY – JUNE 2012) ACKNOWLEDGEMENT I would like to thank the Managing Director and Coordinator of Gadhia Solar Energy Systems Pvt. Ltd. , Mr. Badal Shah, for giving us this wonderful opportunity. I would also like to thank my mentor Dr. Vivek Wasekar, Vice President RD and Mr. Veera Prasad Gadde Deputy General Manager, RD, for being a constant source of guidance and support throughout my project. I am also grateful to the Vice Chancellor, BITS Pilani, Prof. B. N. Jain, and the Practice School Division Dean, Mr G. Sundar for giving us this opportunity to gain valuable work experience. I am extremely thankful to our faculty in charge, Mr. Pavan Kumar Potdar for conducting the programme in an effective manner. PRATAP DESHMUKH 2008A8PS251G Page | 0 BIRLA INSTITUTE OF TECHNOLOGY SCIENCE, PILANI (RAJASTHAN) Practice School Division Station: Gadhia Solar Energy Systems Pvt Ltd Duration: 06 January 2012 – 20 June 2012 Date of Submission: 30 March 2012 Title of the Project: AUTOMATED STEAM JACKETED COOKING VESSEL NAME PRATAP DESHMUKH ID NO 2008A8PS251G DISCIPLINE B. E. (Hons) ELEC. INSTR. Centre: Valsad, Gujrat. Name of expert: Dr. Vivek Wasekar (Associate Manager, Instrumentation Dept. ) Name of the PS Faculty: Mr. Pavan Kumar Potdar Key Words: Steam cooking, Jacketed Vessel, PLC, Ladder Logic, solar, cooking. Project Areas: A development project of a automated cooking system for steam cooking vessel Abstract: This report covers the details of the project undertaken by me at Gadhia Solar Energy Systems Pvt. Ltd. to develop and implement the automation of Steam cooking with a steam jacketed cooking vessel. It also focuses on the technical and design aspects of the new system and provides a detail study of observations after implementation of the system (Signatures of Student) __________________ 25 March 2012 (Signature of PS faculty) __________________ 30 March 2012 Page | 1 BIRLA INSTITUTE OF TECHNOLOGY SCIENCE, PILANI (RAJASTHAN) Practice School Division Response Option Sheet Station: Gadhia Solar Energy Systems Pvt. Ltd. ID No. Name(s): Pratap Deshmukh Centre: Valsad, Gujrat 2008A8PS251G Title of the Project: AUTOMATED STEAM JACKETED COOKING VESSEL Code No. 1. 2. 3. Response Options A new course can be designed out of this project. The project can help modification of the course content of some of the existing courses. The project can be used directly in some of the existing Compulsory Discipline Courses (CDC)/Discipline Courses Other Than Compulsory (DCOC)/Emerging Area (EA) etc. Courses The project can be used in preparatory courses like Analysis and Application Orientated Courses (AAOC)/ Engineering Sciences (ES)/Technical Arts (TA) and Core Courses This project cannot come under any of the above mentioned options as it relates to the professional work of the host organization. Course No. (s) Name 4. 5. YES Signatures of Students) __________________ (Signature of PS faculty) __________________ Page | 2 Abstract: Gadhia Solar is an innovative Solar Thermal Energy Company, focused on providing energy solutions by using Parabolic Concentrated Technology, backed by technical support from HTT GmbH of Germany. Since its inception, Gadhia Solar has been a technologically, solution focused company driven by strong passion for environmental and social contribution combined with high creativity and integrity. The company is into researching and developing new alternatives to harvest the unfathomable source of energy. Automated Steam Jacketed Vessel is a new kind of cooking vessel in itself. The vessels used for soalr thermal cooking are one with direct injection of steam and have limited usability. But with jacketed cooking vessel, any kind of food item can be cooked since the food does not come in contact with the steam. For cooking food, the temperature of the vessel should be maintained in the bracket of 80-120OC which will not only cook the food faster, but also won’t burn it. The vessel was designed with the help of Dr. Vivek Wasekar and for automation of the cooking process; I worked with Mr. Veera Prasad Gadde. For the automation, a Programmable Logic Controller (PLC) is being used which will read the temperature inside the vessel with the help of a Resistance Temperature Detector (RTD) and thereby control the cooking process. Two Solenoid Valves are being used to control the flow of steam and the condensate inside the jacket. And also a pressure regulator is being used to regulate the pressure of the steam from the header. The parabolic dishes will generate the steam inside the header. When the outlet of the header is opened, the steam at high pressure at around 15 bar will be let into the outlet. The pressure regulator will regulate the pressure of the steam to a value of around 3 bar which will go towards first solenoid valve. When the cooking process is started, the first valve will open and let the steam into the jacketed vessel. The steam will raise the temperature and thereby cook the food. For the initial implementation, three food items have been considered i. e. rice, dal and vegetables. According to the food item being cooked, the controller will decide the temperature and time for cooking and proceed with the cooking. The second solenoid valve will remove the condensate from the jacket of the vessel. Two different loops will be simultaneously controlling both valves till the process is stopped or completed. Page | 3 About the company: Using the power of sun as source of energy, Gadhia Solar has implemented some of the world’s largest Solar Thermal Systems in last two decades. Be it industrial, agricultural, institutional or domestic, Gadhia Solar has been a pioneering company with major breakthrough in this area. With extensive experience in installing solar thermal energy systems throughout India and armed with ever improving production facility, Gadhia Solar is the pioneer and market leader in solar thermal energy systems. You read "My Final Year Project" in category "Essay examples" Gadhia Solar has achieved the ability to develop various applications based on Solar Concentrators like: Solar Cooking Applications o Steam Cooking o Thermic Oil based Cooking, o Direct Cooking, o Small Cookers for Family Solar Power Plants Solar Air-Conditioning Space Heating Systems Process Heat for Various Industrial Applications Large Scale Drinking Water Systems Solar Hot Water of up to 90 0C Solar Incineration Solar Crematorium Waste Water Evaporation Solar Desalination Solar Water / Milk Pasteurization Specialized in solar thermal technology for the last two decades, Gadhia Solar is able to provide innovative and cost effective energy solutions for various applications on turnkey basis. Gadhia Solar has a highly focused and dedicated team for research and development in Germany and complimented by a well equipped and automated manufacturing in India. Page | 4 List of Figures Figure 1: Previous Direct Steam Injection Cooking Vessel†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. 14 Figure 2: Steam Jacketed Cooking Vessel. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. 16 Figure 3: Steam Flow Diagram †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. 17 Figure 4: Logic Diagram for controlling cooking procedure†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ 20 Figure 5: Logic Diagram for controlling cooking and Condensate Valve à ¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. 21 Page | 5 TABLE OF CONTENTS CHAPTER NO. TITLE ACKNOWLEDGEMENT ABSTRACT SHEET RESPONSE OPTION SHEET ABSTRACT OF PROJECT ABOUT THE COMPANY LIST OF FIGURES PAGE NO. 0 1 2 3 4 5 1. . 2. 1 2. 2 2. 3 2. 4 3 3. 1 4. 5. 5. 1 5. 2 5. 3 6. Introduction Solar Thermal Cooking Scheffler Reflectors. Steam Generation Current Procedure of Cooking Current Design of Vessel Steam Jacketed Cooking Vessel Designing the vessel. Steam Flow with Diagram Automation Instruments Required Logic Diagram Programming Completed Work and Implementation References 7 9 9 12 13 15 16 16 17 18 18 20 22 23 24 Page | 6 1. Introduction: Gadhia Solar Energy Systems Pvt Ltd. has been making Scheffler reflectors for various purposes. The basic idea that leads to the development of the Scheffler- Reflectors was to make solar cooking as comfortable as possible. At the same time the device should be build in a way that allows it to be constructed in any rural welding workshop after a certain period of training. The locally available materials must be sufficient for the construction of the reflector. The movement started when the first well functioning Scheffler-Reflector (size: 1,1m x 1,5m) was successfully built by Mr. Wolfgang Scheffler in 1986 at a mission-station in North-Kenya. Since then the technology has been continuously improved and passed on to many motivated people. This lead to the use of Scheffler reflectors in not just cooking but also other applications like VAM, cold storage, etc. For cooking application, these Scheffler-reflectors are used to generate steam in the header pipe. The water inside the header is heated with the reflector and due to the continuous input of heat; steam at high pressure is generated inside the header. When the outlet of the header is opened, this steam at a higher temperature and pressure is used for cooking. A valve is connected to the steam line which goes to the cooking vessel. When the valve is opened, the steam is let into the vessel and hence the food is cooked with it. Gadhia Solar Energy Systems Pvt Ltd has installed many solar cooking systems in India. They have installed the world’s largest solar parabolic concentrated technology systems at Shri Saibaba Sansthan Trust, Shirdi. This system uses the same Scheffler- reflectors to produce steam from water and uses that generated steam to cook the food. The solar cooking vessels used currently are being operated manually and needs at least one labor per cooking vessel to operate. The cooking is done by direct injection of steam into the vessel. When the food is cooked by direct injection of steam into the food, as the steam is at high pressure and temperature, it comes out of the vessel. Therefore all of the energy of the steam cannot be utilized for cooking. This increases the heat losses and also increases the cooking time. Also due to the type of vessel, it is not possible to cook different types of food. Risk of contamination is also involved if the water source is not clean. So for this purpose a new design of cooking vessel was proposed. This vessel used the energy of steam to heat the food without coming in contact with it. The Steam Jacketed Cooking Vessel Page | 7 was designed to solve the problems which were faced by the earlier used cooking vessel. In this vessel, the steam was being passed in the jacket around the cooking vessel. As the steam condenses inside the jacket, it transfers its heat energy to the food inside and cooks the food. For the Automation of the cooking process, a Programmable Logic Controller is used which will control the temperature inside the cooking vessel and cook the food accordingly. The temperature inside the vessel will be measured by a RTD (Resistance Temperature Detector). This reading will be processed by the PLC as an Analog Input, and according to the food item selected to be cooked, the PLC will select the cooking temperature and time and start the process on user’s command. The process can be controlled by a START button, STOP button, and food type selection button defining RICE, DAL and VEGETABLE for each button. The operator first needs to select the type of food that has to be cooked. According to the selection, respective LED will turn on which will show the food item selected. Even after selecting an item, the choice can be changed to another food item. After selection, the START button is required to be pressed which will start the cooking. The cooking algorithm will take care of the temperature and the time required for cooking. If the food gets cooked before the timer gets over, or something goes wrong with the process, the operator can manually shut everything down by pressing STOP button. This cooking vessel will increase the types of food that can be cooked with steam. The automation of the vessel will reduce the need of manual labor and will also cook the food faster at optimum temperatures. Page | 8 2. Solar Thermal Cooking: 2. 1 The Scheffler Reflector: The Idea The basic idea that leads to the development of the Scheffler- Reflectors was to make solar cooking as comfortable as possible. At the same time the device should be build in a way that allows it to be constructed in any rural welding workshop in southern countries after a certain period of training. The locally available materials must be sufficient. The Technology To make cooking simple and comfortable the cooking-place should not have to be moved, even better: it should be inside the house and the concentrating reflector outside in the sun. The best solution was an eccentric, flexible parabolic reflector which rotates around an axis parallel to earth-axis, synchronous with the sun. Additionally the reflector is adjusted to the seasons by flexing it in a simple way. How does this work? The reflector is a small lateral section of a much larger paraboloid. The inclined cut produces the typical elliptical shape of the Scheffler-Reflector. The sunlight that falls onto this section of the paraboloid is reflected sideways to the focus located at some distance of the reflector. The axis of daily rotation is located exactly in north-south-direction, parallel to earth axis and runs through the centre of gravity of the reflector. That way the reflector always maintains its gravitational equilibrium and the mechanical tracking device (clockwork) doesn’t need to be driven by much force to rotate it synchronous with the sun. The focus is located on the axis of rotation to prevent it from moving when the reflector rotates. The distance between focus and centre of the reflector depends on the selected parabola. During the day the concentrated light will only rotate around its own centre but not move Page | 9 ideways in any direction. That way the focus stays fixed, which is very useful, as it means the cooking-pot doesn’t have to be moved either. In the course of the seasons the incident angle of the solar radiation varies + / – 23. 5 ° in relation with the perpendicular to earth-axis. The paraboloid has to perform the same change of inclination in order to stay directed at the sun. Otherwise it’s not possible to obtain a sharp focal point. But the centre of the reflector and the position of the focus are not allowed to move. This is only possible by shaping the reflector after another parabola for each seasonal inclinationangle of the sun, i. e. for each day of the year. This means the reflector has to change its shape. The reflector-frame is build for equinox. By inclining and elastically deforming the reflectorframe all other parabolas can be achieved with sufficient accuracy. Changing the inclination and deforming the reflector are mechanically combined: the two pivots, at each side of the reflector-frame, and a pivot in the centre of the reflector, do not form a line, but the second is located below. That way inclining the reflector leads to a change in its depth, the centre of the reflector is lifted up (big radius of crossbars) or pressed down (small radius of crossbars) relative to the reflector-frame. It’s enough to adjust the upper and lower end of the reflector to their correct position to obtain a sufficiently exact reflector-shape. The setting is done by a telescopic bar at each end of the reflector. Adjusting the reflector-shape has to be done manually every 2-3 days. When all concentrated light enters the opening of the cooking-place installed at the focal point the correct reflectorshape is achieved. After passing the opening the light is redirected by a small reflector (secondary reflector) to the black bottom of the cooking pot. There it is absorbed and transformed into heat. The efficiency for cooking, i. e. heating water from 25 °C to 100 °C, can reach up to 57% and depends on the cleanliness of the eflector-surface and the state of insulation of the cooking-pot. At the focalpoint itself we have measured optical efficiency of up to 75% (with 2mm ordinary glass mirrors). Depending on the season an elliptical reflector of 2,8m x 3. 8m (standard size of 8m? Sche fflerReflector) collects the sunlight of a 4,3m? to 6,4m? area, measured perpendicular to the direction of the incident light (aperture). That way the cooking power varies with the season. As an average a 8m? Reflector can bring 22 liters of cold water to boiling temperature within one hour (with 700W/m? direct solar radiation). Page | 10 There are many options for the design of the cooking-place. Mostly it is integrated into a kitchen building and provides the possibility to use firewood for cooking when the sun doesn’t shine. Depending on the type of food which is cooked there is no need for a secondary reflector. This increases the efficiency and simplifies maintenance. Instead of a cooking-place a backing-oven, steam-generator or heat-storage can be installed at the focal-point. Page | 11 2. 2 Steam Generation: With the use of the Schefflor Reflectors, steam at high temperature and pressure can be generated with ease. Steam in saturated temperature can be made available at high pressure by concentrating the focus and heating the water in a closed system with the focused heat. The focus of the reflector has to be concentrated onto a receiver of the header pipe. The receiver is painted black to absorb most of the radiation incident on it. The temperature of the focus of a 16m2 Scheffler Reflector can be as high as 700oC and at the receiver it is around 230oC. At such high temperatures, the water inside the header is being heated. Because of the continuous heat supply from the reflector, the water inside the header gets converted into steam. With time, more steam is being generated and pressure inside the header increases. It is possible to get pressure of 15 barg in around 4 hours using four 12. 5 m2 Scheffler Reflectors under ideal conditions and this steam can be used to cook two batches of 25kg of rice. Page | 12 2. Current procedure of cooking: The current procedure for cooking is by direct injection of steam into the cooking vessel. The food cooked by this procedure consists of mainly rice, dal and some vegetables. All of them are cooked in direct steam. First the outlet valve of the header is opened to a little extent. The drain valve at the vessel is opened to remove the condensate. After every cooking session, there is leftover condensate in the steam line. Since that condensate should not come in contact with food, it needs to be drained out first. After the condensate is removed, the condensate valve is closed and the steam is let into the cooking vessel. The cooking vessel contains a predefined amount of water with the food to be cooked. The steam is passed through the mixture, the temperature increases and the cooking starts. Also the operator needs to stir the mixture at regular intervals. In a 100 liters cooking vessel, it takes almost 15 minutes to cook around 28 kilograms of rice. Since the process involves direct injection of steam, the water used reaches the boiling quickly and the food gets cooked faster. But during cooking, after the water has reached its boiling point, a huge amount of steam goes starts to escape the vessel as the vessel has an open lid. This results into loss of a lot of heat energy which could have been used in cooking the rice quickly. When the food gets cooked, the stand of the vessel has a tilting arrangement with the help of which the operator can take out the food from the vessel. So all the valves are closed and then the vessel is tilted to take the food out. The food is not processed after that, it is collected and served directly. Page | 13 2. 4 Current Design of vessel The current design of the cooking vessel is very effective for direct steam cooking. But for the food items which cannot be cooked by steam directly, it is very difficult for the operator to cook such foods. As mentioned the current design uses a direct injection system. The steam from header is carried by the steam line to the vessel where it is regulated with the help of a ball valve. The construction of the vessel is made to facilitate cooking with the help of steam. The vessel’s bottom dish is a regular torispherical dish and it has a shell of same diameter of that of the bottom dish. There is another plate with a defined curvature above the bottom dish with small holes in it. This plate is for passing the steam into the cooking material. When food is put into the vessel, some predefined amount of water is added with it. So during cooking process, the water gets heated initially and then the cooking starts. Due to direct injection of steam at temperature greater than 100oC, the water reaches boiling point in a short period of time. Thus the cooking process starts. The operator closes the valve when he thinks that the food is appropriately cooked. Figure 1: Previous Direct Steam Injection Cooking Vessel Page | 14 The present design has some benefits, but there is also another side to it. There are some problems with the current design which cannot be rectified without changing the design. The Advantages and Disadvantages of the present design are listed below. Advantages: 1. It facilitates faster cooking time. 2. Since less material is used in manufacture, it saves manufacturing cost. 3. The design is simple which reduces manufacturing time. 4. As it is lighter, it is easier to transport. Disadvantages: 1. There are substantial heat losses during the cooking process. 2. Since the operators cook in an open lid vessel to keep a watch on the food, lot of steam escapes the vessel resulting decreasing the efficiency of process. 3. If the condensed water in the steam line is contaminated, then there are chances of the food getting contaminated. 4. As the outer shell is not insulated, operator has to be cautious or it could lead to injuries. Page | 15 3. Steam Jacketed Cooking Vessel. 3. 1 Designing the Vessel. The design of the vessel was to be made in such a way that it is easy and economic to manufacture. The material chosen for the pilot project of Steam Jacketed Cooking Vessel was Stainless Steel of the grade 304. This material was chosen as it is not affected by steam and it also resists corrosion. The size of the vessel was chosen to be 100 liters. The dimensions of the inner vessel were taken from the existing direct steam injection vessel whose volume was 10 liters. Then according to the pressure calculations, the thickness of the sheet and volume of the jacket was defined. The thickness of the vessel is defined as 4mm and volume of the jacket is approximately 1 cubic m for a pressure of 3 barg inside the jacket of the vessel. The vessel is having 3 openings in the outer shell. Two of them are on the horizontal shell and one is in the bottom of the outer dish end. Out of the three openings, one is used for steam injection, one for a safety valve and the bottom one for removal of condensate. All the openings are of 1 inch diameter and will have pipes welded to it for injection of steam, safety valve and condensate removal. The vessel will have two more openings which will be used to mount the RTD and the temperature gauge to measure the temperature inside the vessel. The final drawing of the vessel is shown in FIG 1. Figure 2: Steam Jacketed Cooking Vessel. Page | 16 4. Steam Flow Diagrams. Water is supplied to the header tank from an overhead tank. Either the overhead tank is at a greater height than that of header, or a sometimes a small pump is used to pump water into the Header. The Solar Concentrators are focused on the receivers mounted on the header pipe. The receivers are painted black to absorb maximum amount of radiation incident on it. These receivers heat the water inside the header and generate steam at higher pressure. This generated steam is vented to the Steam line and the pressure is controlled by the Pressure regulating valve. The solenoid valve SOV1 controls the steam input into the vessel. Thus the temperature inside the vessel can be controlled by controlling SOV1. As the steam is let inside, it will condense after giving its heat. For removal of this condensate, another solenoid valve has been provided SOV2. This valve will remove the condensate at regular intervals. Figure 3: Steam Flow Diagram Page | 17 5. Automation 5. 1 Instruments required. 1. Programmable Logic Controller: A programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines. Unlike general-purpose computers, the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed-up or nonvolatile memory. A PLC is an example of a real time system since output results must be produced in response to input conditions within a limited time, otherwise unintended operation will result. 2. 2-way ON/OFF Solenoid Valve A solenoid valve is an electromechanical valve for use with liquid or gas. The valve is controlled by an electric current through a solenoid: in the case of a two-port valve the flow is switched on or off; in the case of a three-port valve, the outflow is switched between the two outlet ports. For this application, two valves will be used. One will be controlling the steam injection into the jacket. The other valve will be taking care of condensate removal from the jacket. 3. Resistance Temperature Detector. Resistance temperature detectors (RTDs) are sensors used to measure temperature by correlating the resistance of the RTD element with temperature. Most RTD elements consist of a length of fine coiled wire wrapped around a ceramic or glass core. The element is usually quite fragile, so it is often placed inside a sheathed probe to protect it. The RTD element is made from a pure material whose resistance at various temperatures has been documented. The material has a predictable change in resistance as the temperature changes; it is this predictable change that is used to determine temperature. Page | 18 For this application, we will be using a PT-100 RTD with a thermowell. The RTD will be mounted inside the thermowell for its protection from the steam inside the jacket. Thermowell also enables us to change the RTD with ease in case the RTD fails. 4. Pressure Regulator: A pressure regulator is a valve that automatically cuts off the flow of a liquid or gas at a certain pressure. Regulators are used to allow high-pressure fluid supply lines or tanks to be reduced to safe and/or usable pressures for various applications. Since the header pressure is much more than needed for the application, the pressure will be reduced using a Pressure Regulator. The pressure needed for the application is 3 barg while the header can supply pressure 0-15 barg. To have a steady supply of steam and maintain the pressure and temperature, we will be using a pressure regulator. 5. Temperature Gauge with Thermowell: Temperature Gauge is a device that measures temperature or temperature gradient using a variety of different principles. A Temperature gauge has two important elements: the temperature sensor in which some physical change occurs with temperature, plus some means of converting this physical change into a numerical value. A temperature gauge mounted inside a threaded thermowell will be used. Since the temperature reading needed is of the food inside the vessel, the temperature gauge will be mounted on the side of the vessel just like the RTD. The thermowell will protect the Temperature Gauge rom steam inside the jacket of the vessel. Page | 19 5. 2 Logic Diagram: The first diagram displays the logic for controlling cooking process. With turning the device ON, it will start the procedure. According to the outcome of the decision block, it will decide and execute. Figure 4: Logic Diagram for controlling cooking procedure Page | 20 The algorithms given below control the cooking of the food by maintain a specific temperature bracket inside the vessel.  ±3oC range is provided so that the solenoid valves won’t switch ON/OFF at particular temperature which could result in damage. The second logic is for the condensate valve SOV2 which will be ON/OFF at regular intervals. Figure 5: Logic Diagram for controlling cooking and Condensate Valve Page | 21 5. 3 Programming Most of the Programmable Logic Controllers use a different programming language. The language used by them is called Ladder Logic. Ladder logic is a programming language that represents a program by a graphical diagram based on the circuit diagrams of relay logic hardware. It is primarily used to develop software for programmable logic controllers (PLCs) used in industrial control applications. The name is based on the observation that programs in this language resemble ladders, with two vertical rails and a series of horizontal rungs between them. The previously shown logic will be made in Ladder Logic. It will then be downloaded into the flash memory of the Programmable Logic Controller. The PLC will execute the logic and accordingly it will monitor and process the parameters involved. In this project, the opening and closing of both valves and will be monitoring the temperature during the process. The program is made on proprietary software which is supplied by the vendor of the PLC. Every PLC make has specific software which is used to build the program and download the program into the PLC. It can also be used to change the process parameters in online mode. The software also provides offline simulation of the process. For data logging purposes, usually different software is used. The Ladder Logic for the project is under construction and will be finished by the time procurement of all the instruments is done. The parameters which need to be used in the logic will be found out during the processing of the procurement of instruments. During the period of procurement, the manufacturing of the vessel and designing the ladder logic will be done. Page | 22 6. Completed Work and Implementation: From the start, the project has been progressed according to the timeline. Now, all the instruments and material needed for the project has been indented and is in process. Some of the instruments have been dispatched. But for procuring the entire indent, it is going to take some more time. Meanwhile, since the Logic is available, the ladder program is being made and is approaching completion. Also, the manufacturing of vessel is in process and the vessel will be ready by the end of next week. After program is completed, some more time will be given to test it in offline mode and debug the program is any bugs are found. After all the materials are processed and the final values for the process parameters are found out, the project will enter the implementation and testing phase. The entire infrastructure needed for the cooking vessel and the instruments will be constructed on the site. For different types of foods, the values initially found out of temperature and time will be used. If the parameters are not off by some amount, they will be rectified and the control will be made as efficient as possible. During the implementation, various temperature and time readings will be taken. For every type of food item, a detailed sheet should be made which will have all the parameters. According to the observed readings, new and better parameters will be decided which should reduce the cooking time and also increase the efficiency. Page | 23 References: The Scheffler – reflector http://www. solare-bruecke. org/ www. en. wikipedia. com http://www. spiraxsarco. com/resources/resources. asp www. mnre. gov. in Page | 24 How to cite My Final Year Project, Essay examples