Non Conventional Energy sources objectivesunit-2

Load data calibration: For payload and any supplementary loads. Identification experiments. Repeatability tests and ISO 9283:1998.
UNIT V: (10 Periods)
Robot Control: Transfer function and state-space representation of a robotic joint, feedback control system, Proportional, Derivative and Integral (PID) control. Gain tuning.
Workspace and Operator Safety, Safety triggers and functions, Workspace monitoring and marking forbidden zones, External and Internal Safety devices, Norms and Regulations. Introduction to Industrial robot programming.
Total Periods: 48

TEXT BOOKS
1.Introduction to Robotics, 2nd Edition, S. K. Saha, McGraw Hill Education, (India) Pvt.
Ltd., New Delhi, 2008.
2. Introduction to Robotics: Mechanics and Control, 3rd Edition, John J. Craig, Pearson
Publishers, 2008.
REFERENCES:
1.Robot Modeling and Control, 2nd Edition, Mark W. Spong, Seth Hutchinson, M.
Vidyasagar, Wiley (India), 2020.
2.Technical Specifications sheet of Industrial Robots of KUKA, ABB, FANUC, YASKAWA
downloadable from respective websites of the manufacturers
COURSE OBJECTIVES:
The objectives of this course are to:
• Fundamentals of composite materials, including their classification, and to familiarize them with various fiber-reinforced plastic processing techniques used in manufacturing.
• Understanding of the micro- and macro-mechanical behavior of composite laminas.
• Equip theoretical and analytical tools for evaluating the strength and mechanical behavior of composite laminates
• Introduce metal matrix composites (MMCs), focusing on reinforcement materials, base metal selection, fabrication techniques.
• Deep understanding of micromechanics-based failure analysis in unidirectional composite laminas, and the selection of appropriate failure criteria.

COURSE OUTCOMES:
After successful completion of the course, students will be able to:
CO1: Classify and describe the characteristics of different types of composite
materials, and explain and apply various fiber-reinforced plastic processing
methods.
CO2: Evaluate the elastic moduli of composite laminas, apply Hooke's law to different material types and solve numerical problems.
CO3: Analyze the failure of composite laminates, and perform macro-mechanical
analysis using Classical Laminate Theory (CLT), for various laminate
configurations through numerical problem-solving.
CO4: Identify and select appropriate reinforcements and base metals for MMCs,
understand and apply various fabrication processes.
CO5: Analyze and evaluate the failure mechanisms of unidirectional lamina using
micromechanical models and apply suitable failure theories through practical
examples.UNIT I: (10 Periods)
Introduction to Composite Materials:
Introduction to Composite Materials: Definition, classification and characteristics of composite Materials – fibrous composites, laminated composites, particulate composites. Applications: Automobile, Aircrafts. missiles. Space ha

1. UNIT –II SOLAR COLLECTORS

2. Introduction Solar Energy can be utilized directly by two ways: Solar Thermal Solar thermal systems provides thermal energy for solar various processes. Ex: In cold climate region, large amount of low grade thermal energy is required to heat air for comfort and hot water for washing cleaning and other domestic and industrial needs. 2. Solar Photovoltaic

3. Solar Collector: Solar Collector is a device for collecting solar radiation and transfer the energy through a fluid into usable form. i.e heat or electricity. Solar Collectors are two types: 1. Non Concentrating or Flat Plate Collectors. 2. Concentrating (focusing) type solar Collectors.

4. Principle of Conversion of solar Radiation into Heat:

5. Principle of Green House Effect:

6. Important features of Solar collectors: 1 . Collector Efficiency: is defined as the ratio of the actually absorbed (collected and transferred to heat) by the collector to the energy incident on the Collector . 2. Concentration Ratio (CR): is defined as the ratio of the area of aperture (space) of the system to the area of the receiver . The aperture of the system is the projected area of the collector facing the beam. 3. Temperature Range : is the range of the temperature to which the heat transport fluid is heated up by the collector.

7. Flat Plate Collector: In flat-plate collectors there is no optical concentration of sunlight and they are generally stationary and hence the concentration ratio is only 1 and temperature range is less than 100 C. 2. They are made in rectangular panels from about 1.7 to 2.9 sq.m in area and are relatively simple to construct and erect. 3. These are collect both direct and diffuse solar radiation. They are collect the solar radiation even in cloudy days when there is no direct radiation.

8. Flat Plate Collector: A flat plate collector is basically a black surface that is place d at a convenient path of the sun. And a typical flat plate collector is a metal box with a glass or plastic cover (called glazing) on top and a dark-colored absorber plate on the bottom. The sides and bottom of the collector are usually insulated to minimize heat loss .

9. Flat Plate Collector: Flat plate solar collectors may be divided in to TWO classifications based on the type of heat transfer fluid. Liquid Heating Collector: used for Heating water & non Freezing . Air or Gas heating collectors : employed as solar air heater.

10. Flat Plate Collectors components: Absorber plate: It is usually made of copper, steel or plastic. The surface is covered with a flat black material of high absorptance . If copper or steel is used it is possible to apply a selective coating that maximizes the absorptance of solar energy and minimizes the radiation emitted by plate. Flow passages: The flow passages conduct the working fluid through the collector. If the working fluid is a liquid , the flow passage is usually a tube that is attached to or is a part of absorber plate. If the working fluid is air , the flow passage should be below the absorber plate to minimize heat losses. Cover plate: To r e duce convective and radiative heat losses from the absorber , one or two transparent covers are generally placed above the absorber plate. They usually be made from glass or plastic.

11. Flat Plate Collectors components: Insulation: These are some materials such as fibre glass & Styro -foam and they are placed at the back and sides of the collector to reduce heat losses. Enclosure (or) Casing (or) Container: A box that the collector is enclosed in holds the components together, protect them from weather, facilitates installation of the collector on a roof or appropriate frame.

12. 1. A Typical Liquid Collectors:

13. 1. A Typical Liquid Collectors: A. Absorber plate & Flow passages: Absorber plate basically consists of flat surface with high absorptivity for solar radiation. The absorber plate is usually made from a metal sheet 1 to 2mm in thickness. Flow Passages (tubes) is usually made with metal with diameter of 1 to 1.5 cm. They are soldered, brazed and clamped to the bottom of the absorber plate with the pitch ranging from 5 to 15 cm. Heat is transferred from the absorber plate to a point of use by circulation of fluid across the solar heated surface.

14. B. Cover plates : A cover plate for a collector should have a high transmittance for solar radiation and should not detoriate with time. The material most commonly used is glass. A 3m m to 4 mm thick sheet of window glass transmits 85 percent of solar energy at normal incidence a nd all glass is practically opaque (Not reflecting light) to long-wavelength (Infra-red re radiation) radiation emitted by the absorber plate. Usually 1 or 2 covers with a specific ranging from 1.5 to 3 cm. Each plate reflects about 15% of the incoming sunlight. Advantages of Second glass: Losses due to air convection are reduced. This is important in windy areas. Radiation losses in the infrared spectrum are reduced by a further 25%. Some plastic materials can be used for collector glazing.They are cheaper and lighter than glass and, because they can be used in very thin sheets, they often have higher transmittance. However, they are not as durable as glass and they often degrade with exposure to ultraviolet radiation or high temperatures

15. C. Enclosure / Insulation : There is some loss of heat to the surrounding from the top of the cover by convection, conduction and radiation . The rate of heat loss increases the temperature of air space rises, this affects the overall efficiency of solar collector. The collector enclosure is usually made from steel, al u minium or fiber glass. And order to prevent heat from escaping through the back of the collector, a layer of insulation is placed behind the absorber plate. Figure : Cross Section of an Insulation Part of a Flat-Plate Collector

16. Heat Transport System:

17. In Simple type of flat-plate collectors, the absorber is a blackened sheet with close corrugations (to shape into folds or parallel and alternating ridges and grooves.) running from top to bottom. A problem with this design is that in cold weather, moisture may condense on the inside of the transparent cover plate and thus decrease the transmission of the solar radiation. Water is a very effective heat transport medium, but it suffers from certain drawbacks. 1. Possibility of freezing in the collector tubes in cold climates during cold nights. Remedy: Ethylene glycol is added to prevent freezing, but this generally adds to the complexity of the heating system. 2. Corrosion (rust) of the metal tubes by the water. Remedy: Corrosion can be minimized by using copper tubing (or) aluminum tubing.

18. 2. A Typical Air Collectors (or) Solar Air Heater: In this flat plate collector air stream is heated by the back side of the collector plate. Fins attached to the plate increases contact surface. The back side of the collector is heavily insulated with mineral wool or some other material. Air is medium for heat transport system in solar collectors.

19. To decrease the power required to pump the necessary volume of air through tubes, wider flow channels are used. Ex: Air may be passed through a space between the absorber plate and insulator with baffles arranged to provide a long ( Zig - Zag ) flow path shown figure below. The use of air as the heat transport fluid eliminates both freezing and corrosion problem, and small air leaks are leaks of less concern than water. The heated air can be used directly for space heating.

20. Drawbacks: Large duct sizes and higher flow rates, with increased pumping power are required for air than when water is the heat transport medium. The transfer of heat from air to water in a hot water supply system is inefficient. Applications: Solar air heaters are used 1. Drying or Curing of agriculture products. 2. Space heating for comfort. 3. Regeneration of dehumidifying agents. 4. Seasoning of timber. 5.Curing of industrial products such as plastics.

21. Basically air heaters are two categories: Non-porous absorber: in which the air stream does not flow through the absorber Plate. Air may flow below or behind the absorber plate. Porous absorber: in which the air stream does flow through the absorber plate. This includes slit and expanded metal, transpired honey comb and over lapped glass plate absorber.

22. Non-porous absorber: A non-porous absorber may be cooled by the air stream flowing over both sides of the plate as shown in Fig.(a). In most common design the air flows behind the absorbing surface. In this the convective losses increase from cover plate and therefore is not recommended if the air inlet temperature rise at the collector are large, as shown in Figure (b).

23. Due to low heat transfer rates of the air, the efficiencies are lower than liquid solar radiation heater under the same radiation intensity. Performance of air heater is improved by: 1. Roughing the rear (back) of the plate. 2. Adding fins to increases the heat transfer surface. A Solar collector with V-corrugated copper foil is illustrated in Fig.(c).

24. Collector with Porous Absorbers: The main drawback of the non-porous absorber plate is the necessity of absorbing all incoming radiation over the projected area from a thin layer over the surface, which is in order to in few microns. Unless selective coating area is used, radiative losses from the absorber plate are excessive, therefore collector efficiency cannot be improved. Due to adding fins to increase the heat transfer surface and turbulence rate. The difficulty with turbulence is the pressure drop across the collector. The above defects can be eliminated by using Porous type collectors in two ways. 1. The solar radiation penetrates to greater depths and is absorbed gradually depending on the matrix density. Any improper selection of the matrix and the thickness may result in reduced efficiencies. 2. The pressure drop for the matrix is usually lower than the non-porous absorber with flow behind the plate since flow per unit cross-section would be much lower.

25. The solar air heating utilizing a transpired honey comb [fig (b)] is also very favorable from the pressure drop stand point since the flow cross-section is much larger. There is a method of using crushed glass layers to absorb solar radiation and heat the air. A porous bed, as shown in fig 3.37(c) made by forming layers of broken bottles ,may be readily used for agriculture drying purposes with minimal expenditure. The overlapped glass plate air heater as shown in fig 3.37(d) can be considered as a form of porous matrix, although overall flow direction is along the absorber glass plates instead of being across the matrix.

26. Applications of Solar Air Heater: Heating Buildings Drying agriculture produce and lumber. Heating Green Houses. Air conditioning buildings utilizing desiccant beds or a absorption refrigeration process. Using air heaters as the heat sources for a heat engine such as a Brayton or Stirling Cycle. Advantages of Flat Plate Collectors: It uses both Beam and Diffuse solar Radiation. They do not required orientation towards the sun. They require little maintenance. They are mechanically simpler than the concentrating reflectors.

27. Conclusion Flat Plate Collectors are used for water heating, are long lasting and also in long term they are cheaper than the other water heating systems. However, they requires large areas if high energy output. Then solar energy is free if we do not include the initial cost for installation and the maintenance. Finally, besides these we should remember by using solar energy we can protect nature.

28. Introduction to Concentrating type Solar Collectors For applications such as air conditioning, central power generation, and numerous industrial heat requirements, flat plate collectors generally cannot provide carrier fluids at temperatures sufficiently elevated to be effective. They may be used as first-stage heat input devices; the temperature of the carrier fluid is then boosted by other conventional heating means. Alternatively, more complex and expensive concentrating collectors can be used. These are devices that optically reflect and focus incident solar energy onto a small receiving area. As a result of this concentration, the intensity of the solar energy is magnified, and the temperatures that can be achieved at the receiver (called the "target") can approach several hundred or even several thousand degrees Celsius. The concentrators must move to track the sun if they are to perform effectively.

29. 2. Concentrating Collectors: Concentrating, or focusing, collectors intercept direct radiation over a large area and focus it onto a small absorber area. These collectors can provide high temperatures more efficiently than flat -plate collectors, since the absorption surface area is much smaller. However, diffused sky radiation cannot be focused onto the absorber. Most concentrating collectors require mechanical equipment that constantly orients the collectors toward the sun and keeps the absorber at the point of focus. Therefore; there are many types of concentrating collectors. 

30. Types Line Focusing Collectors (or) Parabolic Trough Collectors. Mirror Strip Reflector. Fresnel lens Collector. Flat Plate Collector with Adjustable mirrors. Compound Parabolic Concentrator (CPC).

31. Line Focusing Collectors (or) Parabolic Through Collectors: Parabolic troughs are devices that are shaped like the letter “u”. The troughs concentrate sunlight onto a receiver tube that is positioned along the focal line of the trough. Sometimes a transparent glass tube envelops the receiver tube to reduce heat loss.

32. These solar collectors use mirrored parabolic troughs to focus the sun's energy to a fluid carrying receiver tube located at the focal point of a parabolically curved trough reflector . It is shown in the figure below.

33. The energy from the sun sent to the tube heats oil flowing through the tube, and the heat energy is then used to generate electricity in a conventional steam generator. Many troughs placed in parallel rows are called a "collector field." The troughs in the field are all aligned along a north south axis so they can track the sun from east to west during the day, ensuring that the sun is continuously focused on the receiver pipes. Individual trough systems currently can generate about 80 MW of electricity.

34. 2. Mirror Strip Reflector: This is a Line focusing collector in which a plane or Slightly Curved (concave) mirror strips are mounted on a flat base. The individual mirrors are placed in such angles that the reflected solar radiation can fall on to the same focal line where the collector pipe is placed as shown in the fig. When changes in the sun’s elevation in viewing of focusing of the reflected radiation on to a focal line, either collector pipe is to be moved continuously keeping mirror strips in fixed condition, or the angle of the mirrors are allowed to be adjusted continuously keeping the collector pipe in fixed position.

35. 3. Fresnel lens Collector: This is also a line focusing type collector. In this type collector, the focusing achieved by using Fresnel lens where reflection takes place. The Fresnel lens refraction type of focusing collector as shown in figure. The Fresnel lens is made flat on one side and other side , fine longitudinal grooves are kept. The angles of these grooves are made in such a manner that solar radiation can be focused on a line. A typical Fresnel lens which is usually used, is having overall length of about 4.7m and width of about 0.05m. It is usually made of extruded acrylic plastic sheets.

36. Receiver Pipe: The receiver pipe of a parabolic line focusing collector as shown in figure below . The Solar radiation absorber is a central steel pipe with a treated surface . A Hallow steel plug with in the absorber pipe restrict the flow of the heat transfer fluid to a narrow annular region. This results in a high flow velocity of the fluid and consequently a high rate of heat transfer from the absorber. The absorber pipe is usually enclosed in a glass (Pyrex) jacket in order to decrease thermal losses by convection and radiation. The space between the pipe and the jacket is sometimes evacuated to reduce convection losses. The diameter of the glass jacket may be about 5cm, absorber pipe about 3 cm and annulus between the pipe and the plug may be as little as 2.5 cm wide.

37. In Fresnel lens collector, the solar radiation is focused into the absorber from the top , rather than from the bottom as in the parabolic (reflection) type. A modified absorber design as shown in figure below.

38. Point focusing Collector (Paraboloidal Type): The earlier mention collectors are considered under the focusing type. The paraboloid dish collector is of point focusing type. In the line focusing type, the receiver is placed at the focus, i.e. along the focal line. In the point focusing type the receiver is placed at the focus point of the concentrator. This system is made with a dish with diameter of 6.6 m and is 200 curved mirror segments forming a Paraboloidal surface. The absorber is a cavity made of a Zirconium-Copper alloy. Black chrome is used as a selective coating. The dish can be turned automatically about two axis (up down & left-right) so that the sun is always kept in a line with the focus and the base (vertex) of the Paraboloidal dish. Thus the sun fully tracked at essentially all times.

39. The concentration ratio are very high in the case of parabolic system and therefore can be used where high temperatures are required. Concentration ratios of about 30 to 100 or high and temperature ranges are 300 to 500 C or higher. Collector designed is necessary for high concentration ratios and which is broadly classified as:

40. The six 9 kWe dish/ Stirling units (projects DISTAL I and DISTAL II) under (Source: PSA, Spain)

41. Collector designed is necessary for high concentration ratios and which is broadly classified as: The linear focus collector in the form of a parabolic trough or the ones employing faceted mirror strips. Spherical and conical mirror with aberrated foci. Central Receiver Collector, Such as the Paraboloidal mirror and the tower power plant using heliostat mirrors.

42. Central Receiver Collector: A System equivalent to a very large Paraboloidal reflector consists Of a number of mirror distributed over an area on the ground. Each mirror is called a heliostat can be steered independently about two axes so that the reflected solar radiation is always directed Towards an absorber mounted on a tower. This type of collector is classified as Central Receiver Collector . This is mostly used in tower power plants for generation of Electrical Energy.

43. In the typical Central Receiver, the mirror is composed of many small mirrors; each with its own heliostat to follow the sun. The heliostats generally placed in the horizontal Plane. The basic difference between a single mirror concentrator and the heliostat system is that the heliostat system has a dilute mirror. This means that the entire surface within the system is not covered with mirror surface. This diluteness is generally termed as the fill factor . A central receiver with a fill factor of 40% means that 40% of the land area is covered by the mirror.

44. (4). Flat Plate collector with adjustable mirrors: (Concentrating Collectors: Non-Focusing Type ) It consists of a flat plate facing south with mirrors attached to its north and south edges as shown in Figure. The mirrors (reflectors) are set at the proper angle they reflect solar radiation on to the absorber plate. Apart from the reflected radiation, absorber plate also receives normal radiation falling on it. Concentration Ratios are normally in the range of 1 to 4 and operating temperature of 130 and 140 C.

45. (4). Compound Parabolic Concentrator (CPC): CPC is a non- focusing type collector. The concentrators are of curved segments which are parts of two parabolic. Solar radiation from many directions gets reflected towards the bottom of the trough. It collects both direct and diffuse radiations on a small area. Concentration Ratios are normally in the range of3 to 10 and operating temperature of 100 - 150 C. The operating temperature can be improved i.e.300 C by using selectively coated, vacuum enclosed receivers which decrease thermal losses from collector.

46. CPC reflectors can be designed for any absorber shapes: EX: (a). Flat one sided absorber. (b). Flat two sided Absorbers. (c). Wedge-Like Absorber (d). Tubular Absorber. For economic as well as for thermal reasons the fin and the tubular type absorber is preferred. Advantages of Compound Parabolic Concentrator (CPC): There is no need for tracking because it has high acceptance angle, only seasonal adjustments are required. The efficiency for accepting diffuse radiation is much larger than conventional concentrators. Its concentration ratio is equal to the maximum value possible for a given acceptance angle.

47. Advantages of Concentrating Concentrator: CC are simpler than the flat plate collectors because of less reflected surface material. Cost per unit area of the solar collecting surface is potentially less than that for FP Collectors. A smaller absorber area and insulation intensity is greater. Heat lost is less & Collector efficiency is more due to small absorbing area & high vacuumed insulation. High temperatures occurs due to more insulation on the absorber. CC are used electric power generation when not used for heating or cooling. Operating time per year can be more. Initial installation cost can be regained by saving of energy in shorter period of time. Heat storage costs are less. Little or no antifreeze is required for protect the absorber.

48. Disadvantages of Concentrating Concentrator: It collect only beam radiation. The costly oriented systems have to be used to track the sun. Additional requirements of maintenance particular to retain the quality of reflecting surface against dirt, weather, oxidation. Non uniform flux on the absorber where as uniform flux in FFC. Additional optical losses such as reflectance losses and the intercept losses, so they introduce additional factors in energy balances. High initial cost.