Mechanical Engineering Project Idea - 3 | Thermo-Electric Power Generation from Automobile Engine Exhaust

THERMOELECTRIC POWER GENERATION FROM AUTOMOBILE ENGINE EXHAUST

📜 Table of Content

👉  Abstract

👉  Introduction

👉  Peltier Module

👉  Synthesis of Bi2Te3

👉  Working of Peltier Module

👉  Advantages

👉  Dis-Advantages

👉  Conclusion

ABSTRACT:

The prerequisite of power is expanding each day and now a days, car is assuming a significant part in transportation. There are different techniques to reuse the waste warmth emanated through vehicle as exhaust. For this, in this paper Peltier module is utilized. The entire task depends on Seebeck impact which expresses that "when two closures of two unique metal channels are presented to two distinct temperatures, the electrons at hot intersection at higher warm speeds diffuse into the cool intersection". Peltier module is a gadget comprised of different p-type and n-type semiconductors associated in corresponding to one another. It has hot and cold intersections.

The hot intersection is in touch with the exhaust and the chilly intersection is in touch with the environment or some coolant for delivering temperature distinction, this temperature contrast brings about voltage age. The voltage created is additionally intensified like different electrical circuits like voltage sponsors, transformers, rectifiers, inverters, and so forth By this load of game plans the last voltage can be applies for helpful apparatuses according to the prerequisites.

  

INTRODUCTION:

In this cutting edge time, the requirement for power builds step by step and furthermore requires productive electric force age techniques.The conventional and most popular method of power generation is by Power Plants approximately 60 to 80% and rest by renewable energy sources. Be that as it may, every one of these force age frameworks requires significant expenses for their activity and are additionally not as much proficientIn this century, transportation have got a lot simpler via vehicles (business and non-business). To control these vehicles a more prominent measure of warmth is required, which can be produced by ignition of powers, however the greatest measure of warmth is lost through exhaust frameworks (about 35%), as well as some amount from cooling systems and lubrication systems and through extended surfaces (called as fins).

As per exploration and overview by Research and Development office, there are numerous arrangements carried out to recuperate the waste warmth into some helpful application, one of which is power age. The transformation of waste warmth straightforwardly to electric force is conceivable and should be possible by presenting an electronic gadget most prevalently known as "Peltier Module" or "Thermoelectric Generator". This module was imagined by the notable researcher "Thomas John See beck" in the year 1821. The working principle is “Seebeck effect”. The warmth from exhaust framework is used for age of electrical force by considering modules working philosophy. This module is favourable and proficient over ordinary techniques, and furthermore uses the greatest measure of waste warmth energy for age of voltage.

 

PELTIER MODULE:

Peltier gadget comprises various p-type and n-type semiconductors associated in corresponding to one another, and it has two principle intersections say, "hot" and "cold". These two intersections are actually inverse in heading to one another. Hot side is constantly applied to the warmth source, so it can separate warmth and the virus side can be associated with the cooling medium, for example, a water cooling and oil cooling, or it tends to be presented to the environmental air or most presumably it is associated with aluminium balances for better convective warmth move. The material used to make peltier module is Bismuth Telluride (Bi2Te3), Sb2Te3 for p-type and Bi2Se3 for n-type material.

 

SYNTHESIS OF BISMUTH TELLURIDE (BI2Te3):

Initially, black precipitation of Bi2Te3 nano-powder was existed by mixing the tellurium and bismuth nano particles and is stirred at 423 K for 1 hour. His combination was permitted to cool to room temperature. The combination is then centrifuged and washed with ethanol multiple times obligatorily, and the stove is utilized to dry this arrangement at 343 K till 1 day. Through the examination, the accompanying response is known as (ST-Bi2Te3).The reaction is repeated by adding (0.6 g of NaOH) and also by adding (0.2 g of EDTA or PVP). Through this combination, the accompanying nano structure is noticed.

 

WORKING OF PELTIER MODULE:

A Peltier module or thermoelectric generator deals with the standard normally called as "Seebeck impact". Seebeck effect states that “In two dissimilar materialswhen the heat gets transferred from hot junction to the cold junction it produces electrical voltage.” By the reference of this statement it means that the amount of heat gets transferred from hot side to the cold side of the module by the mode of heat transfer commonly called as heat conduction. This heat is conducted through the material which is a semiconductor. The propensity of this semiconducting gadget is to temperamental because of warming and this precariousness of the electrons brings about creation of voltage yet of a modest quantity relying on the extraction of warmth from the warmth source. 

The voltage age is conceivable just if the base temperature distinction between the hot side and cold side of the module is 27 ºC. The voltage can additionally be enhanced according to the necessary applications by utilizing different electrical circuits like voltage sponsors, inverters, transformers, rectifiers, and so forth The real presentation of this module is involved by a term called "figure of legitimacy (ZT)". The figure of legitimacy is a mathematical articulation which addresses the presentation or effectiveness of the electronic device.

The peltier modules are introduced at the auto fumes, by and large before the suppressor or silencer. The immediate contact of the peltier module with the silencer can be destructive and can cause harm. Thus, this issue can be overwhelmed by putting a peltier module on the metal square or any material which have higher warm conductivity. Aluminium has a decent warm conductivity and is most appropriate for the peltier module.

This aluminium block fits on the exhaust gas pipe and on the aluminium block the peltier module is fitted with the assistance of staying substances which can lead warmth like oil. According to survey about 30 to 40% of heat is lost through the automobile exhaust, the module can utilize about 10 to 20% of the heat for the power generation. The immediate transformation of warmth energy electrical force can't be steady or in purged structure, this issue can be tackled by introducing different electronic gadgets to create a steady yield which can be use for required application.

  

HEAT TRANSFER THROUGH ALUMINIUM BLOCK:

Heat transfer is the base for power generation. Move of warmth happens mostly in three modes viz. Conduction, Convection and Radiation. These three modes permits the warmth to move in solids, fluids and gasses. Warmth move is only the energy cooperation between two substances which are in actual contact with one another. Heat transfer deals with the rate at which energy transfer takes place from one equilibrium state to another. As indicated by thermodynamics, energy is a way of work which manages the examination of a cycle working in a framework and is free of harmony states. In this paper, we intended to determine a short connection of warmth move through the hot exhaust gasses to the aluminium obstruct to the external finish of the square. For effortlessness of estimations, we expect that the external square part of the aluminium block is changed over into round divide having comparable surface region as displayed in beneath figure.

The genuine warmth led in the exhaust pipe and the square is given by,

Q = [2πL.ka (tg - t2) / ln(r2 /r1) + 2πL.kb (t2 – ta) / ln(r3 /r2)]

From above value of heat, it can be concluded that this is the minimum amount of heat required to generate the voltage in the peltier module. The worth of warmth, not exactly this won't bring about any voltage age. This heat transfer in the module can be varied depending upon the modal used and its respective cross-sectional area and thickness. The temperature limits of the module is to be inspected before its use, otherwise this results in severe damage to the modules.

 

 

ALUMINIUM BLOCK AS A HEAT EXTRACTION MATERIAL:

The aluminium is utilized for the peltier modules to lay on it for utilization of warmth. Aluminium (Al) is the best material for the extraction of warmth from the hot exhaust pipe. It is also possible to install aluminium fins rather than solid aluminium block, but the thing is that as the surface area is greater heat transfer will be greater. Aluminium fins have grooves on their surfaces and hence is not much suitable for module to cover the surface area evenly. In this case, solid aluminium block having a hollow cylindrical cutting exactly in middle which is to be fixed on the exhaust gas pipe. 

Aluminium increases the rate of heat transfer and is good for the two main modes of heat transfer i.e. conduction and convection. But this material also have some limitations such as bit can withstand temperatures only up to 660 ºC. The addition of various materials to aluminium like copper, zinc, magnesium, silicon, manganese, chromium, lead, titanium, etc. for the production of aluminium alloys. By making alloys of aluminium the material gets more strong and cannot be easily face any wear and tear. Subsequently, aluminium is most appropriate for the warmth extraction from exhaust pipe. Beneath figure shows the perspectives on peltier modules mounted on aluminium block on each side.

 

ADVANTAGES AND DISADVANTAGES OF THERMOELECTRIC POWER GENERATION

ADVANTAGES:

• It is noiseless type of power generation.
• The module used is light in weight.
• Cost of modules is less for low temperatures and voltage.
• Voltage fluctuations is less or sometimes zero.
• No maintenance is required.

 

DIS-ADVANTAGES: 

• There is a serious harm to the framework because of vehicular mishaps.
• Module if once harmed, it is to be changed on the grounds that it is non-repairable.
• Cost of modules is more at high temperatures and voltage.
• Short circuit can take place.

 

CONCLUSION:

There is an increase in the demand for energy to our day to day activities this project aim is to conserve the electrical energy to some extent, by trapping the waste heat from automobile. The automotive thermoelectric generator is based on the vehicle based heat recovery. The arrangement of thermoelectric module is illustrated for greater output by heating and cooling the opposite sides of peltier module. It mainly works on the principle of Seebeck effect, according to which temperature difference between two dissimilar semiconductors produces in this generated voltage are stimulized with the help of a boost converter. This can also be applicable in appliances such as LED bulbs, CFL bulbs, mobile charging, Battery charging (12 volts to 48 volts depending upon generation voltage). Additionally, because of this new procedure, the waste warmth can be valuable yet in the other type of energy. This increases energy saving and can also be called green technology for power generation.

 

This Project is analyzed by one of my friend and I have taken the permission to publish such a good idea project on my website. To help other student in their projects and assignments.

Project Credit:  Juzair Haider , Mechanical Engineer

Full Research Paper : IRJMETS

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