ZERO EMISSION POWER PLANTS USING SOLID OXIDE FUEL CELLS AND OXYGEN TRANSPORT MEMBRANES

Computer Engineering electronics Engineering Civil Engineering

Praxair has been developing oxygen separation systems based on dense walled, mixed electronic, oxygen ion conducting ceramics for a number of years. The oxygen separation membranes find applications in syngas production, high purity oxygenproduction and gas purification. In the SOFC afterburner application the chemical potential difference between the high temperature SOFC depleted fuel gas and the supplied air provides the driving force for oxygen transport. This permeated oxygen subsequently combusts the residual fuel in the SOFC exhaust.A number of experiments have been carried out in which simulated SOFC depleted fuel gas compositions and air have been supplied to either side of single OTM tubes in laboratory-scale reactors. The ceramic tubes are sealed into high temperature metallic housings which precludes mixing of the simulated SOFC depleted fuel and air streams. In early tests, although complete oxidation of the residual CO and H2 in the simulated SOFC depleted fuel was achieved, membrane performance degraded over time. The source of degradation was found to be contaminants in the simulated SOFC depleted fuel stream. Following removal of the contaminants, stable membrane performance has subsequently been demonstrated. In an ongoing test, the dried afterburner exhaust composition has been found to be stable at 99.2% CO2, 0.4% N2 and 0.6%O2 after 350 hours online. Discussion of these results is presented.A test of a longer, commercial demonstration size tube was performed in the SWPC test facility. A similar contamination of the simulated SOFC depleted fuel stream occurred and the performance degraded over time. A second test is being prepared.Siemens Westinghouse and Praxair are collaborating on the preliminary design of an OTM equipped Afterburner demonstration unit. The intent is to test the afterburner in conjunction with a reduced size SOFC test module that has the anode gas separation features incorporated into the hardware.

WELDING ROBOTS

Welding technology has obtained access virtually to every branch of manufacturing; to name a few bridges, ships, rail road equipments, building constructions, boilers, pressure vessels, pipe lines, automobiles, aircrafts, launch vehicles, and nuclear power plants. Especially in India, welding technology needs constant upgrading, particularly in field of industrial and power generation boilers, high voltage generation equipment and transformers and in nuclear aero-space industry. Computers have already entered the field of welding and the situation today is that the welding engineer who has little or no computer skills will soon be hard-pressed to meet the welding challenges of our technological times. In order for the computer solution to be implemented, educational institutions cannot escape their share of responsibilities. Automation and robotics are two closely related technologies. In an industrial context, we can define automation as a technology that is concerned with the use of mechanical, electronics and computer-based systems in the operation and control of production. Examples of this technology include transfer lines, mechanized assembly machines, feed back control systems, numerically controlled machine tools, and robots. Accordingly, robotics is a form of industrial automation. There are three broad classes of industrial automation- fixed automaton, programmable automation, and flexible automation. Fixed automation is used when the volume of production is very high and it is therefore appropriate to design specialized equipment to process the product very efficiently and at high production rates. A good example of fixed automation can be found in the automobile industry, where highly integrated transfer lines consisting of several dozen work stations are used to perform machining operations on engine and transmission components. The economics of fixed automation are such that the cost of the special equipment can be divided over a large number of units

VEHICLE OPERATOR SAFETY

In extreme outdoor conditions, vehicles are designed to perform arduous tasks .Vehicles must navigate on uneven surfaces while lifting and moving heavy loads in areas like industries such as construction, agriculture and forestry. For vehicle operators, the chances of tipping or rolling over are high, and safety is a concern. Operator

Underwater acoustic communication

Underwater acoustic communication is a technique of sending and receiving message below water . There are several ways of employing such communication but the most common is using hydrophones. Under water communication is difficult due to factors like multi-path propagation, time variations of the channel, small available bandwidth and strong signal attenuation, especially over long ranges. In underwater communication there are low data rates compared to terrestrial communication, since underwater communication uses acoustic waves instead of electromagnetic waves.

ULTRASONIC TECHNIQUES FOR HIDDEN CORROSION DETECTION

Corrosion is one of the serious problem affecting airforce and other aviation industries. It affects the aircraft on its wings, surface, between joints and fasteners. The presences of corrosion underneath the paints of surface and between joints are not easy to be detected. The unnoticed presence of corrosion may cause the aircraft to crash leading to human and money loses. To detect the corrosion present on the metal surface, various methods and tests are used. These tests conducted should be such that it does not destroy or disassemble the plane to parts or damage its surface. Hence for the further use of the plane, Non-destructive tests (NDT) are carried out.

ULTRASONIC METAL WELDING

In 1938, Lludwig Bergman and some colleagues were experimenting with ultrasonic Waves and their effects on metal. He found that many metals could be combined by using ultrasonic welding that could not be joined by any other method. It was also found that any metal could be strengthened by subjecting the metal in its molten state to ultrasonic vibrations. The ultrasonic effect upon the molten metal generates a smaller grain size, giving the metal more strength. Ultrasonic welding combines pressure and high frequency vibration motions to form a solid state bond. The range ultrasonic frequency used in this welding is from 20kHz to 60kHz. This cool, strong weld capable of joining such combination as aluminium to steel, aluminium to tungsten, aluminium to molybdenum and nickel to brass. Ultrasonic welding has also made it possible to join metals with vastly different melting temperatures, making strong rigid joints. Thus many applications previously considered unweldable can now revaluated.

TWO STROKE USING REED VALVES

In developing countries a large number of private vehicles used two stroke engines. A large percentage of them employ two stroke engines because of their simplicity, high power to weight ratio and low cost of maintenance. Although two stroke engines are less efficient and more polluting they may continue to popular due to low cost and maintenance. The most serious drawback of a two stroke S.I. engine is its higher fuel consumption and higher unburned hydrocarbon emissions when compared with four stroke engine. Fresh charge loss during the scavenging process of a two stroke S.I engine is known to be the principal reason for its high specific fuel consumption and high hydrocarbon emissions. During scavenging process a part of the fresh charge mixes with the residual exhaust gas as it scavenges the cylinder while some of it is loss due to short circuiting. The net effect is that 25%-40% of the charge may be wasted resulting in high fuel consumptions.

TWIN TURBO

Twin-turbo refers to a turbocharged engine, in which two turbochargers compress the intake charge. There are two commonly used twin turbo configurations- parallel twin-turbo and sequential twin-turbo. A third kind of twin-turbocharging, staged turbocharging, is used in diesel automobile racing applications.

TURBOFAN ENGINE

Jet Propulsion is the thrust imparting forward motion to an object, as a reaction to the rearward expulsion of a high-velocity liquid or gaseous stream.A simple example of jet propulsion is the motion of an inflated balloon when the air is suddenly discharged. While the opening is held closed, the air pressure within the balloon is equal in all directions; when the stem is released, the internal pressure is less at the open end than at the opposite end, causing the balloon to dart forward. Not the pressure of the escaping air pushing against the outside atmosphere but the difference between high and low pressures inside the balloon propels it. An actual jet engine does not operate quite as simply as a balloon, although the basic principle is the same. More important than pressure imbalance is the acceleration due to high velocities of the jet leaving the engine. This is achieved by forces in the engine that enable the gas to flow backward forming the jet.

TRANSIT MIXER & CONCRETE PUMP

In a Ready Mix Concrete (R M C) batching plant, there are two units Mixing unit and Delivery unit. The transit mixer and concrete pumps are the delivery units of a RMC plant. The transit mixer used to deliver the RMC of same workability and quality at work site and the concrete pump is used to deliver the RMC at the desired place as per requirements. Before discussing about Transit mixer and concrete pump, must discuss about the significance of RMC

Total Quality Management

Total quality management or TQM is an integrative philosophy of management for continuously improving the quality of products and processes. It is used around the world.TQM functions on the premise that the quality of products and processes is the responsibility of everyone who is involved with the creation or consumption of the products or services offered by an organization. In other words, TQM capitalizes on the involvement of management, workforce, suppliers, and even customers, in order to meet or exceed customer expectations. Considering the practices of TQM as discussed in six empirical studies, Cua, McKone, and Schroeder (2001) identified the nine common TQM practices as cross-functional product design, process management, supplier quality management, customer involvement, information and feedback, committed leadership, strategic planning, cross-functional training, and employee involvement.

TOTAL PRODUCTIVE MAINTENANCE

Maintenance has a far greater impact on corporate profitability than most managers are willing to consider, much less admit .And, as the competitive environment in the world continues to increase the pace, companies are looking for new strategies to save on costs, develop employees to face future challenges and bring about a new culture at work place. This has become imperative to stay in business and have an edge over the competition. In this situation, a number of strategies like Total Quality Management, Kaizen, quality circles, ISO certification, six sigma and Total productive Maintenance are available and it is the management choice to selectively implement these in their workplace. Seiichi Nakajima (1988) has defined TPM as an innovative approach to maintenance that optimizes equipment effectiveness, eliminates breakdowns, and promotes autonomous maintenance by operators through day-to-day activities involving the total work force. Thus, TPM is not a specific maintenance policy, it is a culture, a philosophy and a new attitude towards maintenance.

THERMAL SHOCK ON INTERFACIAL ADHESION OF THERMALLY CONDITIONED

The fiber/matrix adhesion is most likely to control the overall mechanical behavior of fiber-reinforced composites. An interfacial reaction may result in various morphological modifications to polymer matrix microstructure in proximity to the fiber surface. The interactions between fiber and polymer matrix during thermal conditioning and thermal shock are important phenomena. Thermal stresses were built-up in glass fiber reinforced epoxy composites by up-thermal shock cycles (negative to positive temperature exposure) for different durations and also by down-thermal shock cycles (positive to negative temperature exposure). The concentration of thermal stresses often results in weaker fiber/matrix interface. A degradative effect was observed in both modes for short shock cycles and thereafter, an improvement in shear strength was measured. The effects were shown in two different crosshead speeds during short-beam shear test.

THERMAL BARRIER COATINGS

Heat engines are based on considering various factors such as durability, performance and efficiency with the objective of minimizing the life cycle cost. For example, the turbine inlet temperature of a gas turbine having advanced air cooling and improved component materials is about 1500oC. Metallic coatings were introduced to sustain these high temperatures. The trend for the most efficient gas turbines is to exploit more recent advances in material and cooling technology by going to engine operating cycles which employ a large fraction of the maximum turbine inlet temperature capability for the entire operating cycle. Thermal Barrier Coatings (TBC) performs the important function of insulating components such as gas turbine and aero engine parts operating at elevated temperatures. Thermal barrier coatings (TBC) are layer systems deposited on thermally highly loaded metallic components, as for instance in gas turbines. TBC

SWARM ROBOTICS

Swarm robotics is a new approach to the coordination of multirobot systems which consist of large numbers of mostly simple physical robots. It is supposed that a desired collective behavior emerges from the interactions between the robots and interactions of robots with the environment. This approach emerged on the field of artificial swarm intelligence, as well as the biological studies of insects, ants and other fields in nature, where swarm behaviour occurs.

SPACE SHUTTLES AND ITS ADVANCEMENTS

The successful explortion of space requires a system that will reliably transport payloads into space and return back to earth; without subjecting them an uncomfortable or hazardous environment. In other words, the space crafts and its pay loads have to be recovered safely into the earth. The space shuttle used at older times were not re-usable. So NASA invented re-usable space shuttle that could launch like a rocket but deliver and land like an aeroplane. Now NASA is planning to launch a series of air-breathing planes that would replace the space shuttle. A Brief History Of The Space Shuttle Near the end of the Apollo space program, NASA officials were looking at the future of the American space program. At that time, the rockets used to place astronauts and equipment in outer space was one-shot disposable rockets. What they needed was a reliable, but less expensive, rocket, perhaps one that was reusable. The idea of a reusable "space shuttle" that could launch like a rocket but deliver and land like an airplane was appealing and would be a great technical achievement. NASA began design, cost and engineering studies on a space shuttle. Many aerospace companies also explored the concepts. In 1972 NASA announced that it would develop a reusable space shuttle or space transportation programme (STS).NASA decided that the shuttle would consist of an orbiter attached to solid rocket boosters and an external fuel tank because this design was considered safer and more cost effective.

SPACE ROBOTICS

Robot is a system with a mechanical body, using computer as its brain. Integrating the sensors and actuators built into the mechanical body, the motions are realised with the computer software to execute the desired task. Robots are more flexible in terms of ability to perform new tasks or to carry out complex sequence of motion than other categories of automated manufacturing equipment. Today there is lot of interest in this field and a separate branch of technology

SOLAR POWERED VEHICLES

In the present situation energy crisis is an important unsolvable problem so we must find out some other ways to trust all sources such as solar energy, hydro power, tidal power, wind power etc. Using solar power to produce electricity is not the same as using solar to produce heat. Solar thermal principles are applied to produce hot fluids or air. Photovoltaic principles are used to produce electricity. A solar panel (PV panel) is made of the natural element, silicon, which becomes charged electrically when subjected to sun light. Solar panels are directed at solar south in the northern hemisphere and solar north in the southern hemisphere (these are slightly different than magnetic compass north-south directions) at an angle dictated by the geographic location and latitude of where they are to be installed. Typically, the angle of the solar array is set within a range of between site-latitude-plus 15 degrees and site-latitude-minus 15 degrees, depending on whether a slight winter or summer bias is desirable in the system. Many solar arrays are placed at an angle equal to the site latitude with no bias for seasonal periods.

SOLAR CAR

A solar car is an electric vehicle powered by solar energy obtained from solar panels on the car. Solar panels cannot currently be used to directly supply a car with a suitable amount of power at this time, but they can be used to extend the range of electric vehicles. They are raced in competitions such as the World Solar Challenge and the North American Solar Challenge. These events are often sponsored by Government agencies such as the United States Department of Energy keen to promote the development of alternative energy technology such as solar cells and electric vehicles. Such challenges are often entered by universities to develop their students engineering and technological skills as well as motor vehicle manufacturers such as GM and Honda.

SMART MATERIALS

Over the past century, we have learned how to create specialized materials that meet our specific needs for strength, durability, weight, flexibility, and cost. However, with the advent of smart materials, components may be able to modify themselves, independently, and in each of these dimensions. Smart materials can come in a variety of sizes, shapes, compounds, and functions. But what they all share- indeed what makes them "smart"-is their ability to adapt to changing conditions. Smart materials are the ultimate shape shifters. They can also alter their physical form, monitor their environment, and even diagnose their own internal conditions. They can also do all of this while intelligently interacting with the objects and people around them. More boldly, it is highly likely that once smart materials become truly ubiquitous-once they are seamlessly integrated into a webbed, wireless, and pervasive network -smart materials will challenge our basic assumptions about, and definitions of "living matter." A smart fluid developed in labs at the Michigan Institute of Technology