HİBRİD VE ELEKTRİKLİ ARAÇLAR

Transcription

1 HİBRİD VE ELEKTRİKLİ ARAÇLAR DİĞER HİBRİD UYGULAMALAR Abdullah DEMİR, Dr. «Her tercih bir vazgeçiştir»

2 DİZEL HİBRİD ARAÇLAR Diesel Hybrids HEVs can also be built around diesel vehicles. All topologies explained earlier, such as series, parallel, series parallel, and complex HEVs, are applicable to diesel hybrids. Due to the fact that diesel vehicles can generally achieve higher fuel economy, the fuel efficiency of hybridized diesel vehicles can be even better when compared to their gasoline counterparts. Vehicles such as delivery trucks and buses have unique driving patterns and relatively low fuel economy. When hybridized, these vehicles can provide significant fuel savings. Hybrid trucks and buses can be series, parallel, series parallel, or complex structured and may run on gasoline or diesel. Diesel locomotives are a special type of hybrid. A diesel locomotive uses a diesel engine and generator set to generate electricity. It uses electric motors to drive the train. Even though a diesel locomotive can be referred to as a series hybrid, in some architectures there is no battery for the main drive system to buffer energy between the I/G set and the electric motor. This special configuration is sometimes referred to as simple hybrid. In other architectures, batteries are used and can help reduce the size of the generator, and can also be used for regenerative energy capture. The batteries, in this case, can also be utilized for short-term high current due to torque needs, without resorting to a larger generator. Chris Mi, M. Abul Masrur, David Wenzhong Gao, Hybrid Electric Vehicles - Principles And Applications With Practical Perspectives, ISBN , 2011.

3 Michael Conrad, Hydraulic Hybrid Vehicle Technologies, Bosch Rexroth Corporation, Clean Technologies Forum, September 09, 2008

4 Chris Mi, M. Abul Masrur, David Wenzhong Gao, Hybrid Electric Vehicles - Principles And Applications With Practical Perspectives, ISBN , HİDROLİK HİBRİD ARAÇLAR A typical hydraulic hybrid is shown in Figure. Hydraulic systems can provide a large amount of torque, but due to the complexity of the hydraulic system, a hydraulic hybrid is considered only for large trucks and utility vehicles where frequent and extended period of stops of the engine are necessary. Figure: A parallel hydraulic hybrid vehicle (LP, Low Pressure)

5 Hydraulic Energy Storage System Energy can also be stored by using a hydraulic system, where it is stored in the form of a compressed fluid or gas in a cylinder or similar means, known as an accumulator. To pressurize a compressible fluid, one needs mechanical power and energy, which can come from an IC engine or any other engine used to activate a hydraulic pump. Of course, in this case the original source of energy which drives the engine is chemical energy of the gasoline or diesel. While extracting the energy back from the hydraulic storage, one can use a hydraulic motor. The system-level scheme for realizing a hydraulic energy storage and extraction mechanism is shown in Figure A. In this figure, the dashed lines indicate the fluid flow path. In Figure A, chemical energy of the gasoline or diesel will drive an IC engine. The engine will drive a hydraulic pump which will basically draw an incompressible fluid from a low-pressure reservoir and increase its pressure. The high-pressure incompressible fluid can be used to drive a hydraulic motor which can drive some mechanical load. In the hydraulic motor, the mechanical fluid enters at high pressure and exits at low pressure, doing mechanical work in the process. Upon exiting the hydraulic motor, the low-pressure fluid flows to the low-pressure reservoir and the fluid flow circuit is completed. Chris Mi, M. Abul Masrur, David Wenzhong Gao, Hybrid Electric Vehicles - Principles And Applications With Practical Perspectives, ISBN , 2011.

6 Hydraulic Energy Storage System The high pressure reservoir fluid can also move a piston or similar mechanism which in turn can push against a compressible gas. This compression will cause energy to be stored in the gas. Once some predefined pressure has been achieved, a valve can be used to prevent further pressurization of the gas. While extracting energy from the accumulator, an appropriate valve can be opened and the compressed gas will work against some piston and pressurize the incompressible fluid in the high-pressure reservoir, which in turn will drive a hydraulic motor. In Figure X, it can be seen that the dashed fluid flow path forms a closed loop system. It can also be seen that the fluid path can be bidirectional between the accumulator and the high-pressure fluid reservoir. Note that energy itself is stored in the compressible gas or fluid. The incompressible fluid (liquid) provides a flexible path or actuator, which replaces any mechanical linkage which otherwise would have been used for actuation. Note also that an accumulator by itself is not of much use without the peripheral equipment or subsystems shown in Figure A, since ultimately the goal is to be able to use the stored energy in a beneficial manner when needed, or, when extra energy is available, to store it in the accumulator. All the above items shown in Figure A together form the overall hydraulic energy extraction and storage system mechanism. Chris Mi, M. Abul Masrur, David Wenzhong Gao, Hybrid Electric Vehicles - Principles And Applications With Practical Perspectives, ISBN , 2011.

7 Hydraulic Energy Storage System Figure A: Generic scheme for hydraulic energy storage and extraction Chris Mi, M. Abul Masrur, David Wenzhong Gao, Hybrid Electric Vehicles - Principles And Applications With Practical Perspectives, ISBN , 2011.

8 Hydraulic Energy Storage System In a hydraulic system, the energy is stored in the form of a compressed fluid in a cylinder or by similar means. To pressurize the fluid needs energy, which comes from the ICE, to activate a hydraulic pump. While extracting the energy, we can use a hydraulic motor. In other words, the hydraulic pump is analogous to an electric generator, the hydraulic motor to an electric motor, and the pressurized fluid in the cylinder to a battery. Thus we see that the hydraulic system has a one to one equivalence to an electrical system. Although typically people assume the theoretical efficiency of the hydraulic pump, motor, and storage to be very high, around 90%, in reality they will be nearer to 70%, which is still much higher than that of an ICE. Hence all the items noted above to justify the use of a hydraulic system in a hybrid vehicle hold true. Hybrid Electric Vehicles: Principles and Applications with Practical Perspectives, Second Edition. Chris Mi and M. Abul Masrur. Published 2018 by John Wiley & Sons Ltd.

9 In the hydraulic hybrid vehicle (HHV) architecture shown in Figure C, the alternator has been replaced by a hydraulic pump, the electric motor has been replaced by a hydraulic motor, the battery has been replaced by a hydraulic accumulator, the HEV controller has been replaced by a HHV controller, and the power electronics system has been replaced by the hydraulic valve system. Hybrid Electric Vehicles: Principles and Applications with Practical Perspectives, Second Edition. Chris Mi and M. Abul Masrur. Published 2018 by John Wiley & Sons Ltd.

10 Hybrid Electric Vehicles: Principles and Applications with Practical Perspectives, Second Edition. Chris Mi and M. Abul Masrur. Published 2018 by John Wiley & Sons Ltd.

11 Hydraulic Energy Storage System The accumulator includes a highpressure (HP) accumulator containing some benign gas like nitrogen. The pressure in this cylinder can be as high as psi (21 35 MPa), whereas the low-pressure (LP) cylinder pressure can be very low, on the order of a few hundred psi. The IC engine drives a pump, which takes the fluid from the LP cylinder side, pumps it to a very high pressure, and then delivers it to the HP cylinder side and the mechanical energy can be ultimately stored in the form of HP gas. To drive the vehicle s wheels, the HP fluid from the HP cylinder side passes through a hydraulic motor drive assembly. The hydraulic motor takes in the HP fluid, converts it to mechanical power at the wheels, and when the fluid has passed through the hydraulic motor, its pressure drops and it is transferred to the LP cylinder. Note that the amount of energy storage in the hydraulic accumulator system is rather low in terms of kilowatt hours per kilogram. For example, the energy storage density in a hydraulic accumulator can be about 1.9 Wh/kg [2], whereas a battery can have an energy density of Wh/kg. However, the power density of a hydraulic system can be 2500 W/kg, whereas the electrical system power density can be about 650 W/kg. It is therefore apparent that the hydraulic hybrid system is very suitable for a high-power and relatively low-energy system, particularly where short bursts of high-power acceleration and deceleration are involved. Chris Mi, M. Abul Masrur, David Wenzhong Gao, Hybrid Electric Vehicles - Principles And Applications With Practical Perspectives, ISBN , 2011.

12 Hybrid Electric Vehicles: Principles and Applications with Practical Perspectives, Second Edition. Chris Mi and M. Abul Masrur. Published 2018 by John Wiley & Sons Ltd.

13 Hydraulic Energy Storage System HHVs offer the benefit of regeneration when a vehicle is slowing down, and the ability to use the captured energy to accelerate again thereafter. As noted earlier, the specific energy of the hydraulic system or watt hours per kilogram is relatively low compared to a battery. However, it can still be good enough for braking applications, since, during braking, in general the power is high but the energy involved is typically low. Hence hydraulic storage can be quite adequate for the purpose. The regeneration process is shown in Figure. In this diagram it can be seen that the efficiencies of the hydraulic pump and motor are both a little over 90%. The efficiency of the accumulator (HP and LP together) is about 98%. Hence the efficiency of the whole regeneration process is about 82%. In another situation for a hybrid truck, the regenerative efficiency was shown to be 61%, which is still quite good. One advantage of the hybrid hydraulic system is that the technology is very mature and has been around for many years. Components used in a hydraulic system, like the ones indicated in Figure 4, have a very high efficiency. Chris Mi, M. Abul Masrur, David Wenzhong Gao, Hybrid Electric Vehicles - Principles And Applications With Practical Perspectives, ISBN , 2011.

14 Hybrid Electric Vehicles: Principles and Applications with Practical Perspectives, Second Edition. Chris Mi and M. Abul Masrur. Published 2018 by John Wiley & Sons Ltd.

15 sons/van_latex_lesson01/van_latex_lesson01.xml

16 EATON - Hydraulic Launch Assist POCLAIN HYDRAULICS CleanStart NAVISTAR IRISBUS HYNOVIS EPA HYDRAULIC POWER-TRAINS

17 HYDRAULIC LAUNCH ASSIST These hydraulic hybrids have been demonstrated to have higher power capabilities for start and stop duty cycles. Fuel efficiency gains due to regenerated braking energy in heavy duty hydraulic hybrid vehicles were up to 70% for series hybrids, and up to 30% in parallel drive-trains. Background, Research Needs, Stakeholder and Expert Input, Research Recommendations, and Research and Technology (R&T) Roadmaps, DECEMBER 2010 /

18 HATIRLATMA Michael Conrad, Hydraulic Hybrid Vehicle Technologies, Bosch Rexroth Corporation, Clean Technologies Forum, September 09, 2008

19 Michael Conrad, Hydraulic Hybrid Vehicle Technologies, Bosch Rexroth Corporation, Clean Technologies Forum, September 09, 2008

20 HYDRAULIC LAUNCH ASSIST Figure a Eaton Parallel Hydraulic Hybrid Schematic Background, Research Needs, Stakeholder and Expert Input, Research Recommendations, and Research and Technology (R&T) Roadmaps, DECEMBER 2010 /

21 HYDRAULIC LAUNCH ASSIST Figure b - The Eaton series hydraulic hybrid drive schematic Background, Research Needs, Stakeholder and Expert Input, Research Recommendations, and Research and Technology (R&T) Roadmaps, DECEMBER 2010 /

22 HYDRAULIC LAUNCH ASSIST - EATON

23 HYDRAULIC LAUNCH ASSIST - EATON

24 HYDRAULIC LAUNCH ASSIST - EATON Parallel Hydraulic Hybrid Architecture Maximum rated pressure bar psi Eaton Hydraulic Launch Assist (HLA) TRSM1200 / June 2012

25 HYDRAULIC LAUNCH ASSIST - EATON HLA Hybrid Components and Connector Locations Eaton Hydraulic Launch Assist (HLA) TRSM1200 / June 2012

26 HİDROLİK HİBRİDLERDE START-STOP SİSTEMİ Hydraulic starter (1) Hydraulic pump (2) Sequence valve (3) Hydraulic accumulator (4) Tank (5) Electronic control unit (6) CleanStart System, 2014

27 HİDROLİK HİBRİDLERDE START-STOP SİSTEMİ CleanStart consists of a hydraulic starter (1), which directly drives the engine crankshaft. Its function is to provide instant torque higher than the resisting torque of the engine (inertia and compression ratio), that is a maximum torque of 550 Nm. The compactness of this starter allows for an original positioning, directly into the engine pulley. The power density of the hydraulic starter enables greater responsiveness and a start-up in less than 0.5 seconds, while reducing energy losses. The hydraulic pump (2) pressurises the accumulator in preparation for the next engine start-up. A sequence valve (3) directs the pump flow for the time required to pressurise the accumulator. The stored energy (volume of oil under pressure) is sufficient to power the hydraulic starter for at least one start-up sequence. The hydraulic accumulator (4) stores the hydraulic energy necessary for starting up the engine. Since the batteries are not needed at every start-up, their life span is conserved. Fully recyclable, it furthermore presents a weight/power ratio that is very favourable when compared with batteries. The tank (5), which holds the oil. The electronic control unit (6) ensures the accumulator filling and draining sequences, provides system status updates and sends diagnostics. CleanStart System, 2014

28 HİDROLİK HİBRİDLERDE START-STOP SİSTEMİ

29 HİDROLİK HİBRİDLERDE START-STOP SİSTEMİ Contributes to urban transportations and city attractiveness When bus engine is stopped: Silence and absence of vibrations for passengers, driver and surroundings No emissions while the bus is stopped helps keep cleaner and safer air Environmentally friendly: Typical annual CO2 reduction for a 100 bus fleet : 540 ton CO2/year (1) Silence during 30% of bus operation time Recyclable hydraulic components No specific battery dedicated to engine restarts Savings and operating costs: Typical annual fuel savings for a 100 bus fleet : liters/year (~ 10%) (2) Transparent in bus maintenance programs 3 years engine operation saved after 10 years (2) (1) Calculation based on fuel savings measurement on a bus equipped with CleanStart in real operation (2) According to experimentation and measurement on a bus equipped with CleanStart in real operation

30 Michael Conrad, Hydraulic Hybrid Vehicle Technologies, Bosch Rexroth Corporation, Clean Technologies Forum, September 09, 2008