THERMOELECTRIC POWERED CAR 1. AIM OF THE PROJECT This concept behind the project is thermoelectric generation that has been known from sometime, but the practical implementation of this concept is quite difficult. The idea behind this project is to make a Car that is powered by thermoelectric source, i. e. to build a car that moves with temperature difference. This concept has not been explored earlier but a lot of research can be done in this regard.
We will be presenting a practically running model of a car driven by a simple heat source with the help of thermoelectric generator. 2. CONCEPT The world wastes a lot of heat. Between half and two-thirds of the fuel we burn to create energy is dissipated as heat into the atmosphere. While it has been long known that waste heat can be converted into energy, the low efficiency of early thermoelectric generation systems was such that it limited the process’s usefulness. TEGS can take waste heat from energy generation or industrial processes and convert it into electricity.
TEGS can provide electricity to a load directly when a constant heat source is available, or they can be used in combination with batteries if the heat source is not constant. A typical TEG is made of bismuth-telluride semiconductors sandwiched between two metallized ceramic plates. Because TEGS eliminate the need for wires and batteries, their primary applications have been in remote places where the use (and replacement) of batteries is impractical or impossible, such as in offshore engineering operations, lighthouses, oil pipelines and remote telemetry and data collection in satellites and spacecraft. NASA’s Curiosity rover uses radioisotope thermoelectric generators that produce power by converting the heat generated by the decay of plutonium-238 fuel into lectricity. ) They have a number of small but increasingly important applications in manufacturing, data centers, the automotive industry and in military applications. Our Idea is to convert this concept into a vehicle or a car that is powered directly from heat without any fuel. That is to make a thermoelectric powered car.
It is different from the solar powered car that runs with the help of light and works only in day time, in a way that Thermoelectric powered car is a powerful and efficient method to drive the car with the help of temperature difference, that one side of the eltier plate involved is heated and other side is cooled by placing appropriate heat sink over it that is cooled with the help of normal atmospheric air while the car will be moving. 3.
PRINCLIPLE OF OPERATION BEHIND THERMOELECTRIC POWERED CAR This concept is very useful in terms that it adds up to other renewable sources of energy and can be used in place of other non-conventional sources of energy like wind, solar, tides, geothermal heat, etc. This is a new concept for electricity generation using temperature difference between Junctions of a peltier element to be used in our project. The complete Thermo Electric Generator would be based on Seebeck Effect that is reverse of peltier effect.
The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice-versa. A thermoelectric device creates a voltage when there is a different temperature on each side. Conversely, when a voltage is applied to it, it creates a temperature difference. At the atomic scale, an applied temperature gradient causes charge carriers in the material to diffuse from the hot side to the cold side, similar to a classical gas that expands when heated; hence inducing a thermal current. A Peltier cooler can also be used as a thermoelectric generator.
When operated as a generator, one side of the device is heated to a temperature greater then the other side, and as a result, a difference in voltage will build up between the two sides (the Seebeck effect). 3. NEED AND SIGNIFICANCE OF THERMOELECTRIC POWERED CAR Less than 30% of the energy in a gallon of gasoline reaches the wheels of a typical car; most of the remaining energy is lost as heat. Since most of the energy consumed by an internal combustion engine is wasted, capturing much of that wasted energy can provide a large increase in energy efficiency.
For example, a typical engine producing 100 kilowatts of driveshaft power expels 68 kilowatts of heat energy through the radiator and 136 kilowatts through the exhaust. The possibilities of where and how to utilize this lost energy are explored with this project. The solution of recovering heat energy from the car engine through a thermoelectric generator using peltier plates has been proposed. This electricity generated through the thermoelectric generator from waste heat of the engine could be used to charge the car batteries or operate any electrical device within or outside the car.
Also, in other application of this thermoelectric generator that is, Electricity generation from glaciers / ice is another alternative for electricity generation through other non – renewable resources of electricity and yet to be explored. The idea behind this project is to utilize a small temperature difference between the ice / cold water and some atmospheric heat to produce electricity and drive a car using this electricity by designing an efficient thermoelectric powered car. 4.
EFFICIENCY CALCULATION The efficiency of an ATEG is governed by the thermoelectric conversion efficiency of he materials and the thermal efficiency of the two heat exchangers. The ATEG efficiency can be expressed as: (OV = (CONV x (HX x p Where: (OV : The overall efficiency of the ATEG (CONV : Conversion efficiency of thermoelectric materials (HX: Efficiency of the heat exchangers p : The ratio between the heat passed through thermoelectric materials to that passed from the hot side to the cold side 4.
PROPOSED WORKING OF THERMOLECTRIC POWERED CAR The design would include the use of Peltier plates as the base material for thermoelectric conversion. This system utilizes the low temperature difference etween two hot and cold Junctions of peltier element to generate pollution free electricity without any moving or bulky parts using the latest technology of thermoelectric generation using peltier plates. This system should be economical, easy to implement and does not produce any pollution as other generators available in the market.
The amount of electrical power generated is given by 12RL, or VI. Thermoelectric Generator (TEG’s) are constructed using two dissimilar semi- conductors, one n-type and the other p-type (they must be different because they need to have different electron densities in order for the effect to work). The two semiconductors are positioned thermally in parallel and Joined at one end by a conducting cooling plate (typically of copper or aluminum).
A voltage is applied to the free ends of two different conducting materials, resulting in a flow of electricity through the two semiconductors in series. And when the temperature difference is maintained by heating element in one side and cooling element in other side, thermoelectric current flows through the Junction and voltage is obtained at the output of TEG. As a result of the temperature difference, Peltier cooling causes heat o be absorbed from the vicinity of the cooling plate, and to move to the other (heat sink) end of the device.
Peltier Plate inner view and actual picture is shown below: Figure 1: a) Peltier Plate actual View b) Peltier Plate TEG inner view The heat is carried through the cooler by electron transport and released on the opposite (“hot”) side as the electrons move from a high to low energy state. When the two materials are connected to each other by an electrical conductor, a new equilibrium of free electrons is established. Potential migration creates an electrical field across each of he connections.
When current is subsequently forced through the unit, the attempt to maintain the new equilibrium causes the electrons at one connection to absorb energy, while those at the other connection release energy. In practice many TEG pairs (or couples), such as described above, are connected side-by-side, and sandwiched between two ceramic plates, in a single TEG unit. Figure 2: Proposed Working of a Thermoelectric Generator The heat pumping capacity of a cooler is proportional to the current and the number of pairs in the unit. 5. PROPOSED DESIGN OF THERMOELECTRIC POWERED CAR
Thermoelectric Powered Car should include a heat source that provides the high temperature, and the heat flows through a thermoelectric converter to a heat sink, which is maintained at a temperature below that of the source. This would be done with the help of a Heat Sink. The temperature differential across the converter produces direct current (DC) to a load (RL) having a terminal voltage (V) and a terminal current (l). This voltage is then provided to the car that has Chassis as shown in the proposed design , a heat exchanger , heat sink , mechanical couplings and peltier plates.
There is no intermediate energy conversion process. For this reason, thermoelectric power generation is classified as direct power conversion. Heat Sink Heat Exchanger Copper Sheet Pillar Rods Peltier Plate Aluminum Sheet Heat source Chassis Figure 2: Proposed Design of thermoelectric car 6. FACILITIES REQUIRED 1. Peltier Plates (TEC-12706), operating voltage: 12V, size: 4 x 4 cm, thickness : 5mm 2. Heat Sink: To be designed to increase the surface area of cold Junction of peltier plate to increase the electricity and efficiency of the thermoelectric generator .
Material: Aluminium 3. Heat sink compound and Thermal paste (Adhesives) to mount peltier element on heat sink. 4. Base container 9Aluminium) for setup of the generator 5. Clamps to mount heat sink on base plates 6. Support shafts to provide height to heat sink (Aluminium) 7. Other tools and equipments: Nut-bolt pairs, screwdrivers, multimeters, Drillling machine, lathe machine, surface grinding machine 8. Output devices, load to show the generated electricity. 9. Chassis of Car 10. Wheels and hubs 11. Clamps for mounting wheels 12. Motors (12V??0 rpm) 7.
PROPOSED PLACE OF WORK: College mechanical workshop Industry for machining: KB tools and equipments, E-97, Industrial Area, Phase-7, Mohali APPLICATIONS Self-powering machine sensors. Manufacturing facilities and data centers run large amounts of equipment that must be kept cool to operate at maximum efficiency. Sensors can help make sure equipment doesn’t overheat, but sensors that, themselves, must be plugged in add to the heat loads. TEG-powered sensors located at machine hot spots can power themselves using ambient heat while monitoring and communicating problems to operations personnel.
The sensors can provide information such as temperature, humidity, wear and tear, and whether parts need maintenance or replacement. If these intelligent network sensors are activated only hen sending or receiving data, the amount of energy they require is tiny (on the milliwatt scale), and only the smallest thermoelectric generators/sensors are required. Printed thermogenerators. While printed electronics, an application of nanotechnology, have the potential to revolutionize the electronics industry, thermogeneration may also a beneficiary.
Researchers at Germanys Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM) will soon introduce a printed thermogenerator that can be tailored exactly to technical interfaces. In the case of self-powered machine sensors, components often need to e highly customized to particular machines and operations. The new printed thermogenerators ultimately mean that manufacturers, data centers and others that operate complex machinery might literally customize and print, on their own, the sensors they require ??” sensors that are less susceptible to faults because the energy supply can be adapted directly to the equipment. Generative manufacturing processes produce both sensors and sensor networks, as well as the required elements for energy harvesting, such as thermo generators, by directly depositing functional structures, which have an ink or paste base, using ink-jet, aerosol-jet, creen-printing or dispensing processes,” says Dr. Volker Z?¶llmer, head of functional structures at ‘FAM. “Not only can electrical circuit boards and sensor elements be attached to different interfaces but it is also possible to produce structures which harvest energy. Automotive. Heat from the exhaust of internal combustion engines can be harvested into energy with the addition of a thermoelectric generator in the vehicle. With car exhaust reaching temperatures of about 1 ,300 deg F, the enormous delta temperature could be capable of generating between 500 and 750 watts of lectricity, which could, for example, charge a battery in a hybrid vehicle or reduce the load on a car’s alternator, improving fuel economy. Military.
Given how enthusiastic the U. S. military is as of late to develop and further advance alternative energy sources, thermogeneration has attracted the attention of military researchers. The U. S. Army Research Laboratory (ARL) is currently looking for ways to harness, package and shrink TEG technology in hopes that it could lead to wearable power sources on soldiers ??” using the temperature difference between body heat and outside air ??” or to more efficient military vehicles.