PROJECT PAPER SCIENCE PROJECT OSN PERTAMINA 2015

PROJECT PAPER SCIENCE PROJECT OSN PERTAMINA 2015 Utilization of Wasted Heat in Vehicles Exhaust from Engine Combustion for Vehicles Electricity System based on Thermoelectricity Principle Ranik Chairunisa Akbar Wahyu Tri Wibowo Rizki Nafiar Rafiandi FACULTY OF INDUSTRIAL TECHNOLOGY SEPULUH NOPEMBER INSTITUTE OF TECHNOLOGY 0

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ABSTRACT Thermoelectric module generator can generate a voltage when there is temperature difference on both sides. In cars transportation, unfortunately 40% of energy in cars is lost into only exhaust heat. The wasted heat from the combustion of engine vehicles can be converted into electricity using thermoelectric. This work has successfully generated 1 Volt by the given condition of 300 C in the exhaust for each thermoelectric module using TEC12706. Our thermoelectric exhaust design is made of 84 thermoelectric modules with the length of 48.4 cm, width and height is 16.5 cm. It is approximately just as big as the exhaust in regular cars exhaust. Many advantages can be used after gaining extra voltage from the thermoelectric exhaust. Beside for regular electricity usage such as car audio, we can also utilize it for other electricity use, such as; stability controls, Telematics for Accurate Satellite Positioning, Collison Avoidance Systems, OnStar Communications System, Steer-By-Wire Systems, Navigation Systems, Electronic Braking, Additional Power Train and Body Controllers, Sensors that Optimize Vehicle Safety, etc. We are working on how it can reach its highest efficiency, so it can actually replace dynamo charge which will reduce the load of spin machine to charge the accumulator or power bank in car. So, the use of oil will be more efficient and the car acceleration will be better. Keywords: thermoelectric, temperature difference, voltage, and waste heat. 2

INTRODUCTION According to OICA, global auto industries which drives economic progress. In 2009, total cars produced worldwide were over 47,772,598 cars. And last year, total cars produced were 65,638,451. We can see that in only 5 years, such different happened. 47,772,598 and 65,638,451 is really a wide gap for cars production. Figure 1. Total Worldwide Cars Production Graphic Figure 1. also shows us that every year the amount of cars production all over the world is increasing and is predicted to keep increasing for the next 50 years. But it is such an unfortunate to know the fact that unfortunately 40% of energy in cars is lost into only exhaust heat, as shown in the Figure 2. This means that if we choose Indonesia as an example, where approximately 65 million liters of oil is used for vehicles fuel per day, 26.000.000 liters are wasted to contribute in global warming issue every day. 3

Figure 2. Total Worldwide Cars Production Graphic Such heat would gradually catalyze the global warming issue the world has been dealing with, since the earth temperature is increasing as well. Aside from the global warming problem, the combustion smoke will also contribute in the growth of pollution level. Researchers from Laboratory for Aviation and the Environment in Massachusetts Institute of Technology have come out with some sobering new data on air pollution impact on human health. In a state-by-state analysis, the researchers found that human suffer the worst health impacts from air pollution which mostly attributed to road transportation and to commercial and residential emissions (from heating and cooking). It is such an irony compared to the aforementioned information if we do nothing regarding this energy waste issue. Where on the other hand, the world s demands on the limited natural resources that are used to power industrial society are diminishing as the demand rises. These natural resources are in limited supply. While they do occur naturally, it can take hundreds of thousands of years to replenish the stores. It is such a great opportunity to harness the waste heat in vehicle s exhaust from the engine combustion since it can generate electricity caused by the temperature difference on both of its side. The objectives of this study is to harness the waste heat in vehicles exhaust to generate voltage in order to supply the electricity system need in vehicles. However, 4

this study has not finished yet, as we still continue to find the way to reach its highest efficiency. This study expects to produce an innovative and applicable device that can be used to replace the existing exhaust which only produce waste heat. This topic can also answer the energy crisis concern the world has been dealing with, as it is convenient with the law of energy conservation which states that the total amount of energy in a system remains constant or is conserved, although energy within the system can be changed from one form to another or transferred from one object to another. Energy cannot be created or destroyed, but it can be transformed. In this study, we would like to transform thermal energy into electric energy. 5

LITERATURE STUDY Thermoelectricity Thermoelectricity deals with the direct conversion of heat into electricity, and vice versa, in solid or liquid conductors by means of three interrelated phenomena the Seebeck effect, the Peltier effect, and the Thomson effect. Thomas Johann Seebeck discovered that when two different current carrying conductors are joined into a loop, with a temperature difference maintained between the two junctions formed by the loop, an electromotive force (emf) is generated. Such a loop is called a thermocouple, the emf generated is known as a thermoelectric emf or Seebeck voltage, and the phenomenon is known as the Seebeck effect. The Seebeck effect is defines as: Vo T ; where Vo is the emf generated, ΔT is the temperature difference between the junctions, and α is the seebeck coefficient defined as the ratio of the electric field to the temperature gradient along the conductor. Seebeck concluded that the magnitude of the emf generated was proportional to the temperature difference, depended on the type of conducting material, and is not a function of temperature distribution along the conductors. Thermoelectric Generator (TEG) The Seebeck concept illustrates if two pieces of metal material (usually semiconductor) connected in different temperatures, then the material will generate electricity. This concept when applied to motor vehicles with exhaust gas ranging between 200 C-300 C and ambient temperature between 30-35 C will generate electromotive force (emf) which can be used to drive motor or stored in batteries. The Seebeck concept is the foundation of the thermoelectric modules which uses principles of thermodynamics. Thermoelectric modules are the basic building blocks within thermoelectric power generators or coolers. Modules consists of two or more elements of semiconductor materials that are connected electrically in series and thermally in parallel. The thermoelectric elements and their electrical interconnects are sandwiched between two ceramic substrates. Figure 3. shows the arrangement of the different constituents of a thermoelectric module. The main constituents of a thermoelectric 6

module are (1) thermoelectric elements (or legs), (2) ceramic substrates, (3) electrical conductors, and (4) lead wires. Figure 3. Thermoelectric Module Combustion Motor Combustion motor is a motor generated from fuel (gasoline and solar) combustion. Every motor constructed from cylinder block and piston. Not all of heat generated from combustion process used for mechanical processes. The concept of efficiency explains that the ratio between useful energy with input energy never reach 100%. In gasoline motor, the thermal efficiency of gasoline internal combustion engines ranging between 15-35%. Residual heat discharged into environment through exhaust gas, engine wall, and exhaust. Cooling System Cooling system is used to maintain the temperature difference on both of exhaust side. The cooling process is the transfer of thermal energy or heat process from a higher temperature substance to other substances which has lower temperature. The working of the water cooling system on the machine begin from the condition of the engine temperature is still cold or the atmosphere temperature, then the expected engine heat up rapidly to achieve the desired working temperature (80 C to 1000 C) and subsequent maintaining the working temperature of the machine. It will not let the engine temperature under these limits and not to the temperature of the engine above the upper limit of the above (overheating). 7

METHODOLOGY Basically, this system contains 3 main items namely the exhaust, TEGs arrangement, and the additional radiator (for motor cycle only). This system will be tested to know how much voltage could be produced from the utilization of wasted heat in vehicles exhaust system. Detail of the research is provided below: Place of Research : Power System Simulation Laboratory, Electric Energy Conversion Laboratory, and field test on boarding house. Materials and Utilities - Materials : TEGs, small wire, radiator s water, electronic components (resistors, capacitors, inductors), PCB. - Utilities : motorcycle s exhaust, additional radiator, multimeter, stopwatch, solder, radiator s controller, water pump. Workflow : Start Field Observation Literature Study Wasted heat from vehicles exhaust 1. Thermoelectricity 2. TEGs 3. Combustion Motor 4. Coolant System System-Designing System-making 1. Main System 2. Coolant System 3. Controller System-testing & Evaluation 1. Field test using motorcycle s exhaust 2. Laboratory test Analysis 8

A A 1. Power-Generation Analysis 2. Efficiency 3. System s Lifetime 4. Economic Aspect Making conclusion End Field Observation Field observation is the first method in order to collect data about the wasted heat in vehicles exhaust from engine combustion. We used the motorcycle Honda Supra X 125cc as valid sample to gather data about temperature on exhaust when the motorcycle is in operation. Literature Study The second method is literature study to collect data and to compare from our field observation. We did this stage by reading a scientific paper, final project, thesis, and another valid information. System-Designing The temperature in vehicle s exhaust is 400 C by average, but the average heat in the surface of TEG only 300 C because there is energy loss around 100 C when propagation process passed in iron and other metals. On the cold side, a separate additional coolant radiator should be used because the average temperature in radiator is only 120 C in average and the desired cooling temperature is 50 C. So, the TEGs will obtain temperature difference of 250 C. Main System We designed an exhaust with the arrangement of 84 TEGs as shown in Figure 4. The exhaust has 4 sides in square, each side will contain 21 pieces of TEGs. The hot side of TEG is attached to vehicle s exhaust surface and the cold side is attached to the coolant pipe that is also connected to the radiator. In order to produce voltage according 9

to the need for motor starting in vehicles optimally, the TEGs are arranged in series and parallels order. Figure 4. Thermoelectric Exhaust Design Coolant System In order to maintain the temperature of TEG s cool side, we need to design coolant system. For more detail, we illustrate it as shown in Figure 5. The coolant system of TEG is constructed by an additional radiator, water pump, reservoir tank, and a controller. The function of radiator is to cool down the high-temperature water on the cool side of TEGs. Reservoir tank will be used as a water storage which come from radiator. Water pump plays a role as a water supplier from reservoir tank into the TEGs. All of this system will be controlled by a controller. Figure 5. Thermoelectric Exhaust Cooling System Controller When designing the controller, we do the simulation of the circuit using ISIS Proteus simulation program before we print it on PCB, as shown in Figure 6. The controller consists of microcontroller chip, temperature sensor, relay, and mini LCD. Temperature sensor functioned as a detector on water s temperature and the result will going to microcontroller. The output of microcontroller data will be channeled into relay as the on-off switch of water pump. If water in TEG is on high temperature, the 10

water-changing process happened rapidly. The temperature of cooling water should be in constant value at 50 C. Figure 6. Simulation and Circuit Design of Controller System-Making In this stage, we are making the whole system including the main exhaust compiled with TEGs arrangement, the coolant system attached to the cool side of TEGs, and the controller for the coolant system. After that, we put this system on the sample motorcycle. This process was done in electric energy conversion laboratory and in the boarding house. System-Testing and Evaluation The system-testing was done by attaching the system to the exhaust of the sample motorcycle. This stage was held in the laboratory and in our boarding house. After the system attached well, we start to test the performance of our system by starting the motorcycle. Data obtained from the test was noted and we also did some evaluation to make better performance of system. Analysis We need to know another aspect of the implementation of this system. After get optimum performance from the previous step, we should analyze the implementation by the power generation, efficiency, lifetime, and also the economic aspect related to the investment cost of this system. Conclusion After the whole steps are done, we should make a conclusion based on some parameters, namely the capacity of the TEGs to support the vehicles electricity system, system performance, and possibility of large implementation. 11

RESULT With temperature of 300 C, each TEC12706 generate voltage as shown in Table 1. We plan that our thermoelectric exhaust will produce 12 Volt for regular vehicles motor starting by arranging 84 thermoelectric modules, 12 thermoelectric modules in series and 40 thermoelectric modules in parallel. We succeed in generating 1 Volt within 10 minutes for each thermoelectric module. Minutes Voltage (Volt) 1.5 0.3 4 0.6 10 1 Table 1. Voltage Generated by Each Module of TEC12706 We progress 40% of our whole project, but we have successfully 100% generate voltage matching with our ideal design. Our design is ideally meant for cars since the cost is more suitable, we face difficulties in making the prototype for cars. We are still working to find how this innovation can reach its highest efficiency, so it can replace dynamo charge which will reduce the load of spin machine to charge the accumulator or power bank in cars. To make the use of oil be more efficient and the car acceleration be better. Basically our thermoelectric exhaust is very practical, since it do not change the basic design of machine system and easily integrated with the existing system. 12

REFERENCE Robert R. Heikes and Roland W. Ure, Jr. Thermoelectricity: Science and Engineering. Interscience Publishers, 1961. Roe D.M, G. Min. 1994. Handbook of thermoelectrics, Peltier devices as generator. Florida: CRC Press LLC. Koestoer, Raldi Artono dkk. 2009. Potensi Pembangkit Daya Termoelektrik untuk Kendaraan Hibrid. Skripsi. Fakultas Teknik. Universitas Indonesia. Depok. Karri, Madhav A. 2005. Modeling of an Automotive Exhaust Thermoelectric Generator. Thesis. Department of Mechanical and Aeronautical Engineering : Clarkson University. Setyawan, Eko SB dkk. 2010. BUKU PINTAR SEPEDA MOTOR;Panduan praktis pengguna sepeda motor. Yogyakarta: Media Pressindo. Richard O., Buckius dan Howell John. 1987. Fundamentals of Engineering Thermodynamics. New York: McGraw-Hill Rajput, R.K. 2010. Thermal Engineering. New Delhi: Print Man. Bintoro. 2014. SISTEM PENDINGINAN AIR PADA MESIN MOBIL. Malang : Departemen Otomotif VEDC Malang 13

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