STUDY OF INNOVATIVE REGENERATIVE BRAKE FOR AUTOMOBILES

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1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 8, August 2017, pp , Article ID: IJMET_08_08_003 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed STUDY OF INNOVATIVE REGENERATIVE BRAKE FOR AUTOMOBILES A Somaiah, K. Viswanath Allamraju, G.Sarat Raju Department of Mechanical Engineering, Institute of Aeronautical Engineering, Hyderabad, India BLN Krishna Sai Department of Mechanical Engineering, MLR Institute of Technology, Hyderabad, India ABSTRACT A system and a method for reducing fuel consumption by Pneumatic Regenerative Braking with Heat Recovery system for an automobile are disclosed. The system includes Flanged sleeve (4) which transmits mechanical Power from a vehicle wheel to V-belt pulley and vice-versa, magnetic clutch plate (5) which is energized when power transmission is required to take place i.e., vehicle to air tank and air tank to vehicle, V- belt pulley and V-belt for power transmission, Air compressor to convert kinetic energy to potential energy, Pneumatic valve to direct the hot air in the required direction, Air tank to store the air under pressure and heat it, Inlet air pipe to guide the air from radiator to air compressor, Exhaust gases inlet pipe to direct the exhaust gases to the air tank, Exhaust gases baffle to direct the exhaust gases to the air tank for heating the air, Control unit to run pneumatic valve and magnetic clutch with brake operation. Key words: Regenerative Braking, Pneumatic Braking, Heat Recovery, Automotive Regeneration. Cite this Article: Study of Innovative Regenerative Brake For Automobiles, A Somaiah, K. Viswanath Allamraju, G.Sarat Raju and BLN Krishna Sai, International Journal of Mechanical Engineering and Technology, 8(8), 2017, pp I. INTRODUCTION The design of an automobile is very typical due to the fact that the peak performance of the modern vehicle is estimated to be only 25 30%. It implies that, though the vehicle engine is running at higher possible thermal efficiency, 70 75% of the total heat energy generated due to combustion of the air-fuel mixture is wasted and consequently not converted into useful work. This waste of the heat energy is due to two major reasons. Firstly, almost half of the wasted energy is estimated to be carried away by the exhaust gasses. Secondly, the remaining 20 editor@iaeme.com

2 A Somaiah, K. Viswanath Allamraju, G.Sarat Raju and BLN Krishna Sai is estimated to be passed via cylinder walls or cylinder head into the cooling system of the engine and rejected to the atmosphere via the radiator. Further, a major part of the work generated is wasted in applying the brake while decelerating and stopping of the vehicle. Hence, for the above reasons, only about 25-30% of the fuel combustion energy is available to move the vehicle which leads to more and more consumption of the fuel. Consequently, diminishing of fossil energy resources and environmental pollution are worrying the world. Both these problems are proportional to the quantum of fuels consumed. In view of this, it is worthwhile to save fuels even though it requires little higher investment. One of the existing methods is electrical regenerative braking where the vehicle kinetic energy is converted into electrical energy and utilized to charge the battery. In this method, overall efficiency is low because of four energy conversions as shown below. Mechanical Electrical Chemical Electrical Mechanical Figure 1 Energy Conversions Also, this system has limitations on the part of the energy which can be recovered due to limitations on the capacity of the generator. Proposed pneumatic regenerative braking with heat recovery system for an automobile is aimed at saving a portion of the energy being lost while braking the vehicle, heat energy lost through radiator cooling air and heat energy lost through exhaust gasses. The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements of the disclosure or delineate the scope of the disclosure. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description thesis presented later. A complete appreciation of the present disclosure and the scope thereof can be obtained from the accompanying drawings which are briefly summarized below and the following detailed description of the presently preferred embodiments. Exemplary embodiments of the present disclosure are directed towards PRBWHRS saving a portion of the energy being lost while braking the vehicle, the heat energy lost through the radiator cooling air and the heat energy lost through the exhaust gasses. Also, capacity limitations can easily be overcome by increasing compressor pressure.in the proposed system the energy conversions are reduced to two as shown below Mechanical & Heat Pneumatic Pressure Energy & Heat Mechanical & Heat Figure 2 Reduced Energy Conversions On application of brake proposed regenerative braking system draws hot air from the radiator and compressed to store in the air tank. Then heat from exhaust gasses is added to the compressed air. As soon as the braking phase is complete and acceleration phase starts the air at high temperature and pressure from air tank is directed to the compressor to make the compressor to work as air-engine and accelerate the vehicle. Thus the energy being lost while braking and heat being lost through the cooling air and exhaust gasses are utilized to accelerate the vehicle editor@iaeme.com

3 Study of Innovative Regenerative Brake For Automobiles 2. PROBLEM DESCRIPTION The above-mentioned and other features and advantages of this present disclosure, and the manner of attaining them, will become more apparent and the present disclosure will be better understood by reference to the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, wherein in Fig. 3 is a diagram depicting a system for saving braking energy, heat energy from radiator air and exhaust gasses. Top View Figure 3 Pneumatic Regenerative braking with heat recovery system (PRBWHRS) 1. Vehicle rear wheel axle 2. Axle casing 3. Tapered roller bearings 4. Flanged sleeve (Hub) 5. PRBWHRS Clutch plate 6. V- belt pulley 7. V- belt 8. Air compressor 9. Pneumatic Valve 10. Air tank 11. Inlet air pipe from radiator 12. Exhaust gasses inlet pipe 13. Exhaust gas baffle 14. Vehicle Rear Wheel 15. Control Unit 16. Brake 22 editor@iaeme.com

4 A Somaiah, K. Viswanath Allamraju, G.Sarat Raju and BLN Krishna Sai It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of including, comprising or having and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms a and an herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. Further, the use of terms first, second, and third, and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Moving vehicle possesses kinetic energy which is equal to 0.5mʋ 2, where m is mass in kg and ʋ is velocity m/sec. A vehicle of weight 10000kg travelling at 60Kmph posses 13,88,880 Nm. If the vehicle is stopped by using conventional brake this energy is lost in the form of heat. Instead of applying conventional brake if an air compressor is connected to the vehicle wheel through a magnetic clutch as shown in fig. Vehicle kinematic energy is converted to pressure energy and stored in the air tank. Then heat energy is added from exhaust gasses. Now to start the vehicle release the brake and allow air on the appropriate side of the piston of the air compressor to make it work as an air engine utilizing the compressed air from the air-tank. Thus the kinetic energy of the vehicle is directed to air tank while braking and heat energy is added from exhaust gasses. Then this heated compressed air is utilized to accelerate the vehicle. This energy recovery takes place in case of intermediate speed reductions also. The present disclosure generally relates to energy saving and more specifically to the Regenerative braking used in automobiles, heat energy recovery from radiator air and exhaust gasses. A considerable amount of energy is being lost while using a vehicle in the form of 1) Heat through radiator 2) Heat through exhaust gasses 3) By the application of brake while reducing the speed or stopping. An attempt has been made to save some portion of the energy being lost in the form indicated above. Fig. 3 illustrates a schematic diagram of pneumatic regenerative braking system with heat recovery system (PRBWHRS). PRBWHRS consists of a flanged sleeve (4) with internal splines engages clutch plate with external splines. The clutch plate (5) is attracted by V-Pulley whenever voltage is applied to the magnetic coil in the V-Pulley. Whenever voltage applied flanged sleeve, clutch plate, V-pulley rotates together along with vehicle wheel. The V-belt drive from V-pulley drives the double acting air compressor (8). Air from the air compressor is fed to air tank (10) through the valve (9). Air compressor draw the hot air from the radiator outlet air and also the exhaust gasses are directed through the baffles around the air tank to heat the air in the air tank. Whenever brake is applied to slow down the vehicle, the electromagnet in the pulley is energized. Then the energy from the moving vehicle is utilized to drive the compressor. The compressor draws the hot air from the outlet air of radiator and stores the energy in the air tank in the form of pressure energy. Now the heat is added to the air in the airtank from exhaust gasses. As soon as the braking phase is complete outlet and inlet passages are interchanged by operating the pneumatic valve (9). Then the air compressor works as airengine utilizing the hot air in the air tank. Thus a portion of the heat energy being lost through radiator air, exhaust gasses and mechanical energy lost while braking is recovered. Quantum of energy recovery is assessed at 3.5% as given below editor@iaeme.com

5 Study of Innovative Regenerative Brake For Automobiles 3. RESULTS Two double acting compressors with 130mm piston diameter and 130mm stroke length, m 3 Swept volume and V-belt drive ratio four, are proposed, which lead to m 3 volume of air compressed in one revolution of the vehicle wheel. Energy transferred during one revolution of vehicle wheel can be calculated using the formula to calculate work done /m 3 of air compressed as follows n P 2 Workdone = P 1 n 1 P1 As there will be some loss of heat the value of n is taken as 1.3, and at various assumed pressures of 9 bar, 18 bar and 27 bar the work done comes out to be 8008 Nm, Nm, and Nm respectively. The average work done is 8281 Nm and if the compressor efficiency is assumed to be 50%, then the total work input to the compressor would be Nm for one revolution of the vehicle wheel rotation before the vehicle comes to rest. Considering the wheel diameter 0.8m, the total number of revolutions of the vehicle wheel before the vehicle comes to rest would be 84 and the vehicle moves to 211m before comes to rest.temperature and pressure of compressor air can be calculated as T1 = 308 K, P1 = 1 bar = 10 5 N/m 2, P 2 = N/m 2, and T2 = 656 K using isentropic law applied to ideal gas equation as follows T T 2 1 P 2 = P 1 The volume of air compressed before the vehicle coming to rest would be 2.35m 3 at 1 bar and at 27 bar it can be calculated as 0.11m 3 using ideal gas equations. It is proposed to provide two air tanks of diameter 0.41m and length 0.41m and hence the volume of each air tank would be 0.54m 3. Therefore when the vehicle is at rest, 0.11m 3 of air at 27 bar and 656 K is available in the air tanks. Heat addition from exhaust gasses, suppose the air in the tank is heated to 823 K (550 0 C) utilizing the heat from exhaust gasses, then the pressure would be raised to bar and this air would be utilized to run the compressor as air engine. Then the work done would be 12,72,916 Nm, and if the efficiency of air engine is assumed as 50%, then the output from the air engine would be 6,36,458Nm. As detailed above 6,36,458 Nm is recovered out of the kinetic energy Nm which is being lost while braking the vehicle. It is approximately equal to 50% of the energy being lost while braking the vehicle. This recovery can be further improved by optimizing the input air temperature, utilizing the heat from radiator air, peak pressure and maximum temperature. With the above arrangement, it is possible to recover definitely half the energy being lost while braking and the same value is used for further calculation. The total energy lost in braking is estimated as 7% and hence, 3.5% percentage mechanical energy would be recovered. Mechanical energy saving of 3.5% will save 14% fuel, considering 25% of thermal efficiency. World consumption of petroleum fuels can be estimated as 9 X 10 7 barrels per day and 45% out of this is consumed in the transport sector. Hence quantity consumed in the transport sector is 4.05 X 10 7 barrels/day. So estimated quantity of fuel saved is X 10 7 barrels per day. Considering the fuel cost of barrel oil as $60, the total cost of saving would be $340Millions/day. Hence, expected saving in rupees would be Rs 2040 Crores/day.CO2 emission in 2012 is found to be 6526 X 10 6 and 28% of this, 1827 X 10 6 tons, is contributed from the transport sector. Reduction with proposed Pneumatic Regenerative Braking With Heat Recovery System (PRBWHRS), considering 14% saving in fuel would be X 10 6 tons. n 1 n n 1 n editor@iaeme.com

6 A Somaiah, K. Viswanath Allamraju, G.Sarat Raju and BLN Krishna Sai 4. CONCLUSIONS Pneumatic Regenerative Braking with Heat Recovery System (PRBWHRS) for an automobile comprising, Flanged sleeve (4) which transmits mechanical Power from a vehicle wheel to V- belt pulley. PRBWHRS magnetic clutch plate (5) which is energized whenever power transmission is required to take place i.e., the vehicle to the air tank and air tank to the vehicle. V-belt pulley and V-belt for power transmission, Air compressor to convert kinetic energy to potential energy Pneumatic valve to direct the hot air in the required direction. Air tank to store the air under pressure and heat it, Inlet air pipe to guide the air from radiator to air compressor. Exhaust gasses inlet pipe to direct the exhaust gasses to the air tank. Exhaust gasses baffle to direct the exhaust gasses to the air tank for heating the air. REFERENCES [1] J. Breckling, Ed., The Analysis of Directional Time Series: Applications to Wind Speed and Direction, ser. Lecture Notes in Statistics. Berlin, Germany: Springer, 1989, vol. 61. [2] S. Zhang, C. Zhu, J. K. O. Sin, and P. K. T. Mok, A novel ultrathin elevated channel lowtemperature poly-si TFT, IEEE Electron Device Lett., Volume 20, pp , Nov [3] M. Wegmuller, J. P. von der Weid, P. Oberson, and N. Gisin, High-resolution fiber distributed measurements with coherent OFDR, in Proc. ECOC 00, 2000, paper , p [4] R. E. Sorace, V. S. Reinhardt, and S. A. Vaughn, High-speed digital-to-rf converter, U.S. Patent , Sep. 16, [5] M. Shell. (2007) IEEEtran webpage on CTAN. [Online]. Available: [6] FLEX Chip Signal Processor (MC68175/D), Motorola, [7] PDCA12-70 data sheet, Opto Speed SA, Mezzovico, Switzerland. [8] A. Karnik, Performance of TCP congestion control with rate feedback: TCP/ABR and rate adaptive TCP/IP, M. Eng. thesis, Indian Institute of Science, Bangalore, India, Jan [9] J. Padhye, V. Firoiu, and D. Towsley, A stochastic model of TCP Reno congestion avoidance and control, Univ. of Massachusetts, Amherst, MA, CMPSCI Tech. Rep , [10] Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specification, IEEE Std , [11] Raj Kumar Yadav, Vikas Mukhraiya and Shwetank Soni, Thermal Analysis of Brake - A Review. International Journal of Design and Manufacturing Technology 8(1), 2017, pp [12] Sameer Ingale, Sanket Kothawade, Aditya Patankar and Rohit Kulkarni, Design and Analysis of A Brake Caliper. International Journal of Mechanical Engineering and Technology, 7(4), 2016, pp [13] S. M. Metev and V. P. Veiko, Laser-Assisted Microtechnology, 2nd ed., R. M. Osgood, Jr., Ed. Berlin, Germany: Springer-Verlag, editor@iaeme.com