fuel cell car

   

Fuel Cell Stacks

This is the heart of the hydrogen fuel cell car—the fuel cell stacks. Their maximum output is 86 kilowatts, or about 107 HP. Because hydrogen fuel cell stacks produce power without combustion, they can be up to twice as efficient as internal combustion engines. They also produce zero carbon dioxide and other pollutants. For more information on the stacks.

Fuel Cell Cooling System

This has several parts. Perched at an angle at the front of the vehicle is a large radiator for the fuel cell system, while two radiators for the motor and transmission lie ahead of the front wheels below the headlights. The car also has a cooling pump located near the fuel cell stacks to stabilize temperature within the stacks.

Ultra capacitor

This unit serves as a supplementary power source to the fuel cell stack. Like a large battery, the ultra capacitor recovers and stores energy generated during deceleration and braking. It uses this energy to provide a "power assist" during startup and acceleration.

Hydrogen Tanks

Space in a car is limited, yet hydrogen is the most dispersive element in the universe and normally requires lots of room. A challenge for manufacturers is how to compress the gas into tanks small enough to fit in a compact car and yet still provide enough fuel for hundreds of miles of driving between refueling. The two high-pressure hydrogen tanks in this vehicle can hold up to 3.75 kilograms of hydrogen compressed to roughly 5,000 PSI—enough to enable an EPA-rated 190 miles of driving before refueling, the manufacturer says.

Electric Motor

(General area only—motor not visible) The electric motor offers a maximum output of 80 kilowatts, enabling a top speed of about 93 miles per hour. The manufacturer says this vehicle can also start in subfreezing temperatures (down to about -4°F), a perennial problem in fuel cell prototypes. Being electric, the engine and the car as a whole are quiet, with none of the vibration or exhaust noise of a gas-powered automobile.

Air Pump

(General area only—air pump not visible) Run by a high-voltage electric motor, this pump supplies air at the appropriate pressure and flow rate to the fuel cell stacks. The air, in turn, mixes with the stored hydrogen to create electricity.

Humidifier

The humidifier monitors and maintains the level of humidity that the fuel cell stack needs to achieve peak operating efficiency. It does this by recovering some of the water from the electrochemical reaction that occurs within the fuel cell stack and recycling it for use in humidification.

Power Control Unit

(General area only—power control unit not visible) This controls the vehicle’s electrical systems, including the air and cooling pumps as well as output from the fuel cell stacks, electric motor, and ultra capacitor.

Cabin

With the fuel cell stacks hidden beneath the floor and the hydrogen tanks and the ultra capacitor beneath and behind the rear seats, respectively, the four-passenger cabin is isolated from all hydrogen and high-voltage lines. Hydrogen gas is colorless and odorless, and it burns almost invisibly. In case of a leak, therefore, the manufacturer has placed hydrogen sensors throughout the vehicle to provide warning and automatic gas shut-off. Also, in the event of a collision, the electrical source power line shuts down.

Hydrogen Filler Mouth

(Not visible—located on other side of vehicle) Drivers would fill the car with hydrogen just as they do with gasoline, through an opening on the side of the vehicle. The main difference is that a fuel cell car must be grounded before fueling to rid the car of hazardous static electricity. For this reason, this model has two side-by-side openings, with the latch to open the hydrogen filler mouth located inside the opening for the grounding wire. The manufacturer says filling up this model’s two tanks at a hydrogen filling station would take about three minutes.

Note

The limited-production vehicle seen in this feature is a Honda 2005 FCX, which is typical of the kinds of hydrogen fuel cell automobiles that some major automakers are now researching and developing. With such vehicles at present costing about $1 million apiece, none is currently for sale, though hundreds of fuel cell cars are now undergoing tests on the world’s roads.

Kinetic Energy Recovery System

The introduction of Kinetic Energy Recovery Systems (KERS) is one of the most significant technical introductions for the Formula One Race. Formula One have always lived with an environmentally unfriendly image and have lost its relevance to road vehicle technology. This eventually led to the introduction of KERS.

KERS is an energy saving device fitted to the engines to convert some of the waste energy produced during braking into more useful form of energy. The system stores the energy produced under braking in a reservoir and then releases the stored energy under acceleration. The key purpose of the introduction was to significantly improve lap time and help overtaking. KERS is not introduced to improve fuel efficiency or reduce weight of the engine. It is mainly introduced to improve racing performance.

KERS is the brainchild of FIA president Max Mosley. It is a concrete initiative taken by F1 to display eco-friendliness and road relevance of the modern F1 cars. It is a hybrid device that is set to revolutionize the Formula One with environmentally friendly, road relevant, cutting edge technology.

Components of KERS

The three main components of the KERS are as follows:

• An electric motor positioned between the fuel tank and the engine is connected directly to the engine crankshaft to produce additional power.
• High voltage lithium-ion batteries used to store and deliver quick energy.
• A KERS control box monitors the working of the electric motor when charging and releasing energy.

A – Electric motor

B – Electronic Control Unit

C – Battery Pack

Working Principle of KERS

Kinetic Energy Recovery Systems or KERS works on the basic principle of physics that states, “Energy cannot be created or destroyed, but it can be endlessly converted.”

When a car is being driven it has kinetic energy and the same energy is converted into heat energy on braking. It is the rotational force of the car that comes to stop in case of braking and at that time some portion of the energy is also wasted. With the introduction of KERS system the same unused energy is stored in the car and when the driver presses the accelerator the stored energy again gets converted to kinetic energy. According to the F1 regulations, the KERS system gives an extra 85 bhp to the F1 cars in less than seven seconds.

This systems take waste energy from the car’s braking process, store it and then reuse it to temporarily boost engine power. This and the following diagram show the typical placement of the main components at the base of the fuel tank, and illustrate the system’s basic functionality – a charging phase and a boost phase. In the charging phase,

kinetic energy from the rear brakes (1)

is captured by an electric alternator/motor (2),

controlled by a central processing unit (CPU) (3),

which then charges the batteries (4).

 

In the boost phase, the electric alternator/motor gives the stored energy back to the engine in a continuous stream when the driver presses a boost button on the steering wheel. This energy equates to around 80 horsepower and may be used for up to 6.6 seconds per lap. The location of the main KERS components at the base of the fuel tank reduces fuel capacity (typically 90-100kg in 2008 ) by around 15kg, enough to influence race strategy, particularly at circuits where it was previously possible to run just one stop. The system also requires additional radiators to cool the batteries. Mechanical KERS, as opposed to the electrical KERS illustrated here, work on the same principle, but use a flywheel to store and re-use the waste energy.

Types of KERS

There are basically two types of KERS system:

Electronic KERS

Electronic KERS supplied by Italian firm Magneti Marelli is a common system used in F1 by Red Bull, Toro Rosso, Ferrari, Renault, and Toyota.

The key challenge faced by this type of KERS system is that the lithium ion battery gets hot and therefore an additional ducting is required in the car. BMW has used super-capacitors instead of batteries to keep the system cool.
With this system when brake is applied to the car a small portion of the rotational force or the kinetic energy is captured by the electric motor mounted at one end of the engine crankshaft. The key function of the electric motor is to charge the batteries under barking and releasing the same energy on acceleration. This electric motor then converts the kinetic energy into electrical energy that is further stored in the high voltage batteries. When the driver presses the accelerator electric energy stored in the batteries is used to drive the car.

Electro-Mechanical KERS

The Electro-Mechanical KERS is invented by Ian Foley. The system is completely based on a carbon flywheel in a vacuum that is linked through a CVT transmission to the differential. With this a huge storage reservoir is able to store the mechanical energy and the system holds the advantage of being independent of the gearbox. The braking energy is used to turn the flywheel and when more energy is required the wheels of the car are coupled up to the spinning flywheel. This gives a boost in power and improves racing performance.

Limitations of KERS

Though KERS is one of the most significant introductions for Formula One it has some limitations when it comes to performance and efficiency. Following are some of the primary limitations of the KERS:

• Only one KERS can be equipped to the existing engine of a car.
• 60 kw is the maximum input and output power of the KERS system.
• The maximum energy released from the KERS in one lap should not exceed 400 kg.
• The energy recovery system is functional only when the car is moving.
• Energy released from the KERS must remain under complete control of the driver.
• The recovery system must be controlled by the same electronic control unit that is used for controlling the engine, transmission, clutch, and differential.
• Continuously variable transmission systems are not permitted for use with the KERS.
• The energy recovery system must connect at one point in the rear wheel drive train.
• If in case the KERS is connected between the differential and the wheel the torque applied to each wheel must be same.
• KERS can only work in cars that are equipped with only one braking system.

New Battery Technology

Of all the criticisms of electric vehicles, probably the most commonly-heard is that their batteries take too long to recharge – after all, limited range wouldn’t be such a big deal if the cars could be juiced up while out and about, in just a few minutes. Well, while no one is promising anything, new batteries developed at the University of Illinois, Urbana-Champaign do indeed look like they might be a step very much in the right direction. They are said to offer all the advantages of capacitors and batteries, in one unit.

 

"This system that we have gives you capacitor-like power with battery-like energy," said    U Illinois’ Paul Braun, a professor of materials science and engineering. "Most capacitors store very little energy. They can release it very fast, but they can’t hold much. Most batteries store a reasonably large amount of energy, but they can’t provide or receive energy rapidly. This does both."

The speed at which conventional batteries are able to charge or discharge can be dramatically increased by changing the form of their active material into a thin film, but such films have typically lacked the volume to be able to store a significant amount of energy. In the case of Braun’s batteries, however, that thin film has been formed into a three-dimensional structure, thus increasing its storage capacity.

Batteries equipped with the 3D film have been demonstrated to work normally in electrical devices, while being able to charge and discharge 10 to 100 times faster than their conventional counterparts.

To make the three-dimensional thin film, the researchers coated a surface with nano scale spheres, which self-assembled into a lattice-like arrangement. The spaces between and around the spheres were then coated with metal, after which the spheres were melted or dissolved away, leaving the metal as a framework of empty pores. Electro polishing was then used to enlarge the pores and open up the framework, after which it was coated with a layer of the active material – both lithium-ion and nickel metal hydride batteries were created.

The system utilizes processes already used on a large scale, so it would reportedly be easy to scale up. It could also be used with any type of battery, not just Li-ion and NiMH.

The implications for electric vehicles are particularly exciting. "If you had the ability to charge rapidly, instead of taking hours to charge the vehicle you could potentially have vehicles that would charge in similar times as needed to refuel a car with gasoline," Braun said. "If you had five-minute charge capability, you would think of this the same way you do an internal combustion engine. You would just pull up to a charging station and fill up."

Braun and his team believe that the technology could be used not only for making electric cars more viable, but also for allowing phones or laptops to be able to recharge in seconds or minutes. It could also result in high-power lasers or defibrillators that don’t need to warm up before or between pulses.

Floating Solar Power Plants

There’s a lot of surface area on this planet for solar panels. The ocean’s are a vast area to utilize this solar technology.  But,  the weather can make the installation and use of floating solar arrays difficult.  That’s not the case with LSAs (Liquid Solar Arrays) by Sunengy Pty LTD.

The floating solar power units, called Liquid Solar Arrays (LSA), use concentrated photovoltaic technology where a lenses direct the light onto solar cells and move throughout the day to follow the sun.

The company says the advantage to floating a solar power plant is that it erases the need for expensive structures to protect it from inclement weather and high winds — when rough weather comes along, the lenses just submerge.  Floating on water, whether it be the ocean, a lake or a tiny pond, also keeps the solar cells cool, which increases their efficiency and lifespan.

“The LSA system is based on floating solar collectors made mostly of plastic. Each has a very small area of silicon photovoltaic cells at the water surface with a large, thin plastic focusing lens rotating slowly above to track the sun. The water cools the silicon cells and in bad weather the lens is protected by rotating it fully under the water to avoid damage in high winds. ”

What is liquid solar array technology: In this technology, lens and photo voltaic cells are made to float on the water.  These absorb solar energy during the day.  There is no need to undertake any construction in water as these are made to float with the new technology.  This can withstand all adverse weather conditions.  This new technology will convert the dam into a big battery.  Solar energy can be stored without any cost.  Liquid Solar Array technology provides an opportunity to maintain water resources more effectively.

Special features of LSA: LSA technology is cheap and it can even withstand cyclones.  Land is not needed for establishing this plant and so there will not be any problems for procuring the land.  In India, there is 30 thousand square kilometers of water area and even if 1% of it is utilized for this technology, electricity that is equal to the electricity produced by 15 big thermal electricity plants can be produced.

mechanical interview questions

What is the purpose of scrapper ring

Scrap the excess lube oil from the cylinder walls. There by preventing oil from entering combustion zone.

• How catalyst converter works?

In Fuel Cell, a catalyst is a substance that causes or accelerates a chemical reaction without itself being affected. Catalysts participate in the reactions, but are neither reactants nor products of the reaction they catalyze.

• WHAT WILL HAPPEN IF RELIEF VALVE IN HYDRAULIC SYSTEM FAILS?

The main function of pressure relief valve is to maintain the pressure inhydraulic system. It is one mounting which is used for safety. When pressure increases then safety valve comes into action & if the valve get fail the system get damage due toexcessive pressure.

• What does CC Stand for?

CC is the abbreviated form of cubic centimeter. It is the unit by which the capacity of an engine is designated. It is the volume between TDC and BDC. It represents the quantity of fuel-air mix or exhaust gas that is pumped out in a single piston stroke. Alternatively it can represent the volume of the cylinder itself.

• We have read that when the piston goes up and down then the engine works i.e. the suction,compression etc etc. then what happens in the case of big vehicles, which start at stable condition, i.e. how does their piston moves when they are at rest. how suction,compression etc

Smaller vehicles like bikes, cars are started with the help of motors. initially, motors turn the crank shaft tillsufficient suction pressure is reached. when sufficient suction pressure is reached, the engine starts to suck the fuel in and then the cycle begins when the fuel is taken in and ignited. similarly, for huge engines, instead of motors, we use starting air. air at a pressure of 10-30 bar is fed to the engine which is at rest. this air rotates the engine till it attains sufficient suction pressure. once the pressure is reached, the cycle starts and it starts firing.

• What is the difference between S.S to EN8

SS- Stainless steel
En- Medium carbon steel
SS is Non Magnetic material & EN8 is Magnetic material
SS is Corrosion resistant & EN8 is Magnetic material

• The Compression ratio of Petrol engine is always less than Compression Ratio of Diesel engine why?

Petrol is not self igniting , it needs spark to flame up in chamber. Where as diesel is self igniting in dieselengine , to attain that state it requires high temp &pressure. This temperature & pressure is more than what’s required in Petrol Engines by property of that fluid .

• What is the temperature of space ?

The short answer is that the temperature in space is approximately 2.725 Kelvin. That means the universe is generally just shy of three degrees above absolute zero – the temperature at which molecules themselves stop moving. That’s almost -270 degrees Celsius, or -455 Fahrenheit.

• How to calculate the speed of conveyer in Meter Per Minute

Measure the diameter of the rollers around which the conveyor belt is wrapped. Multiply the diameter of the roller by pi (3.14159). This calculation will yield the circumference of the rollers. Every time the roller spins one revolution, the conveyor will be moved a linear distance equivalent to the circumference of the roller. Pi is a dimensionless factor, meaning it does not matter whether inches, centimeters or any other units of measurement are used. Measure the revolutions per minute (RPM) of the rollers. Count how many full revolutions (rotations) are made by the roller in one minute. Multiply the RPM by the circumference of the roller. This calculation will give the linear distance traversed by a point on the conveyor belt in one minute.

Portable Solar Power Plant, Water Purifier And Fuel Cell In One |

In many areas of the world, and also during times of natural disasters, clean drinking water and access to power are scarce.  The company The Essential Element has designed the Hydra water purifier and fuel cell to take care of both of those problems at once.

The Hydra is equipped with a 2.88 kW solar panel array that runs a pump that pushes water through a self-cleaning filtration device (capable of purifying 87,000 liters a day), juices up lead-acid gel batteries and runs an electrolyzer that splits some of that water to fill a .37 cubic-meter tank with pressurized hydrogen.

The fuel cell can be used to power communication devices or a camp stove.  The whole device can easily be set up and collapsed for easy transport and includes PV mats that can be plugged into the device for extra power.