MAFUTA YA DIZELI YALIVYO NA MAENDELEO YA UBOLESHWAJI WAKE.(DIESEL FUEL & DIESEL IMPROVEMENTS AND BIODIESEL)

Diesel Fuel

Petroleum fuel starts off as crude oil that's naturally found in the Earth. When crude oil is processed at refineries, it can be separated into several different kinds of fuels, including gasoline, jet fuel, kerosene and, of course, diesel.

If you have ever compared diesel fuel and gasoline, you know that they are different. They certainly smell different. Diesel fuel is heavier and oilier. It evaporates much more slowly than gasoline -- its boiling point is actually higher than the boiling point of water. You will often hear diesel fuel referred to as "diesel oil" because it's so oily.

Diesel fuel evaporates more slowly because it is heavier. It contains more carbon atoms in longer chains than gasoline does (gasoline is typically C9H20, while diesel fuel is typically C14H30). It takes less refining to create diesel fuel, which is why it used to be cheaper than gasoline. Since 2004, however, demand for diesel has risen for several reasons, including increased industrialization and construction in China and the U.S.

Diesel fuel has a higher energy density than gasoline. On average, 1 gallon (3.8 L) of diesel fuel contains approximately 155x10⁶ joules (147,000 BTU), while 1 gallon of gasoline contains 132x10⁶ joules (125,000 BTU). This, combined with the improved efficiency of diesel engines, explains why diesel engines get better mileage than equivalent gasoline engines.

Diesel fuel is used to power a wide variety of vehicles and operations. It of course fuels the diesel trucks you see lumbering down the highway, but it also helps move boats, school buses, city buses, trains, cranes, farming equipment and various emergency response vehicles and power generators. Think about how important diesel is to the economy -- without its high efficiency, both the construction industry and farming businesses would suffer immensely from investments in fuels with low power and efficiency. About 94 percent of freight -- whether it's shipped in trucks, trains or boats -- relies on diesel.

                                                       A sample of diesel fuel

HEBU TUANGALIE KATI YA INJINI ZA DIZELI NA PETROL ( DIESEL ENGINES VS GASOLINE ENGINES)

Diesel Engines vs. Gasoline Engines

In theory, diesel engines and gasoline engines are quite similar. They are both internal combus­tion engines designed to convert the chemical energy available in fuel into mechanical energy. This mechanical energy moves pistons up and down inside cylinders. The pistons are connected to a crankshaft, and the up-and-down motion of the pistons, known as linear motion, creates the rotary motion needed to turn the wheels of a car forward.

Both diesel engines and gasoline engines covert fuel into energy through a series of small explosions or combustions. The major difference between diesel and gasoline is the way these explosions happen. In a gasoline engine, fuel is mixed with air, compressed by pistons and ignited by sparks from spark plugs. In a diesel engine, however, the air is compressed first, and then the fuel is injected. Because air heats up when it's compressed, the fuel ignites.

The diesel engine uses a four-stroke combustion cycle just like a gasoline engine. The four strokes are:

·         Intake stroke -- The intake valve opens up, letting in air and moving the piston down. ­

·         Compression stroke -- The piston moves back up and compresses the air.

·         Combustion stroke -- As the piston reaches the top, fuel is injected at just the right moment and ignited, forcing the piston back down.

·         Exhaust stroke -- The piston moves back to the top, pushing out the exhaust created from the combustion out of the exhaust valve.

Remember that the diesel engine has no spark plug, that it intakes air and compresses it, and that it then injects the fuel directly into the combustion chamber (direct injection). It is the heat of the compressed air that lights the fuel in a diesel engine. In the next section, we'll examine the diesel injection process.

COMPRESSION

When working on his calculations, Rudolf Diesel theorized that higher compression leads to higher efficiency and more power. This happens because when the piston squeezes air with the cylinder, the air becomes concentrated. Diesel fuel has a high energy content, so the likelihood of diesel reacting with the concentrated air is greater. Another way to think of it is when air molecules are packed so close together, fuel has a better chance of reacting with as many oxygen molecules as possible. Rudolf turned out to be right -- a gasoline engine compresses at a ratio of 8:1 to 12:1, while a diesel engine compresses at a ratio of 14:1 to as high as 25:1.

HEBU TUANGALIE NAMNA INJINI YA DIZELI INAVYOFANYA KAZI ( HOW DIESEL ENGINE WORK )

How Diesel Engines Work

One of the most popular  articles is How car work, which explains the basic principles behind internal combustion, discusses the four-stroke cycle and talks about all of the subsystems that help your car's engine to do its job. For a long time after we published that article, one of the most common questions asked (and one of the most frequent suggestions made in the suggestion box) was, "What is the difference between a gasoline and a diesel engine?"

Diesel's story actually begins with the invention of the gasoline engine. Nikolaus August Otto had invented and patented the gasoline engine by 1876. This invention used the four-stroke combustion principle, also known as the "Otto Cycle," and it's the basic premise for most car engines today. In its early stage, the gasoline engine wasn't very efficient, and other major methods of transportation such as the steam engine fared poorly as well. Only about 10 percent of the fuel used in these types of engines actually moved a vehicle. The rest of the fuel simply produced useless heat.

The 4.5-liter V-8 Duramax improves efficiency by 25 percent when compared with gasoline engines, while reducing pollutants and emissions. 

                                                 Rudolf Diesel, inventor of the diesel engine.

I­n 1878, Rudolf Diesel was attending the Polytechnic High School of Germany (the equivalent of an engineering college) when he learned about the low efficiency of gasoline and steam engines. This disturbing information inspired him to create an engine with a higher efficiency, and he devoted much of his time to developing a "Combustion Power Engine." By 1892 Diesel had obtained a patent for what we now call the diesel engine.

If diesel engines are so efficient, why don't we use them more often? You might see the words "diesel engine" and think of big, hefty cargo trucks spewing out black, sooty smoke and creating a loud clattering noise. This negative image of diesel trucks and engines has made diesel less attractive to casual drivers in the United States -- although diesel is great for hauling large shipments over long distances, it hasn't been the best choice for everyday commuters. This is starting to change, however, as people are improving the diesel engine to make it cleaner and less noisy.

If you haven't already done so, you'll probably want to read How Car Engine Work first, to get a feel for the basics of internal combustion. But hurry back -- in this article, we unlock the secrets of the diesel engine and learn about some new advancements.

MFUMO WA VALVE ZA INJINI (ENGINE) UNAVYOTUMIKA (ENGINE VALVE TRAIN )

Engine Valve Train

Most engine subsystems can be implemented using different technologies, and better technologies can improve the performance of the engine. Let's look at all of the different subsystems used in modern engines, beginning with the valve train.

 The camshaft

The valve train consists of the valves and a mechanism that opens and closes them. The opening and closing system is called a camshaft. The camshaft has lobes on it that move the valves up and down

Most modern engines have what are called overhead cams. This means that the camshaft is located above the valves, as you see in Figure 5. The cams on the shaft activate the valves directly or through a very short linkage. Older engines used a camshaft located in the sump near the crankshaft. Rods linked the cam below to valve lifters above the valves. This approach has more moving parts and also causes more lag between the cam's activation of the valve and the valve's subsequent motion. A timing belt or timing chain links the crankshaft to the camshaft so that the valves are in sync with the pistons. The camshaft is geared to turn at one-half the rate of the crankshaft. Many high-performance engines have four valves per cylinder (two for intake, two for exhaust), and this arrangement requires two camshafts per bank of cylinders, hence the phrase "dual overhead cams."

TUANGALIE BAADHI YA MATATIZO YA INJINI ( ENGINE PROBLEMS )

Engine Problems

So you go out one morning and your engine will turn over but it won't start... What could be wrong? Now that you know how an engine works, you can understand the basic things that can keep an engine from running. Three fundamental things can happen: a bad fuel mix, lack of compression or lack of spark Beyond that, thousands of minor things can create problems, but these are the "big three." Based on the simple engine we have been discussing, here is a quick rundown on how these problems affect your engine:

LEO NITAONGELEA MISINGI YA SEHEMU ZA INJINI ( BASIC ENGINE PARTS )

Basic Engine Parts

The core of the engine is the cylinder, with the piston moving up and down inside the cylinder. The engine described above has one cylinder. That is typical of most lawn mowers, but most cars have more than one cylinder (four, six and eight cylinders are common). In a multi-cylinder engine, the cylinders usually are arranged in one of three ways: inline, V or flat (also known as horizontally opposed or boxer), as shown in the following figures.

Different configurations have different advantages and disadvantages in terms of smoothness, manufacturing cost and shape characteristics. 

These advantages and disadvantages make them more suitable for certain vehicles.

Let's look at some key engine parts in more detail.

LEO TUANGALIE INJINI ( ENGINE ) ZA MAGARI NA JINSI ZINAVYOFANYA KAZI (HOW CAR ENGINES WORK )

KIMSINGI KUNA AINA MBILI KUU ZA INJINI ( ENGINE )

1. INJINI YA MAPIGO MANNE ( FOUR STROKE ENGINE )
2. INJINI YA MAPIGO MAWILI ( TWO STROKE ENGINE )

LEO TUANGALIE INJINI YA MAPIGO MANNE ( FOUR STROKE ENGINE )

INTRODUCTION TO HOW CAR ENGINE WORKS.

Have you ever opened the hood of your car and wondered what was going on in there? A car engine can look like a big confusing jumble of metal, tubes and wires to the uninitiated.

You might want to know what's going on simply out of curiosity. Or perhaps you are buying a new car, and you hear things like "3.0 liter V-6" and "dual overhead cam" and "tuned port fuel injection" What does all ­of that mean?

In this article, we'll discuss the basic idea behind an engine and then go into detail about how all the pieces fit together, what can go wrong and how to increase performance.

The purpose of a gasoline car engine is to convert gasoline into motion so that your car can move. Currently the easiest way to create motion from gasoline is to burn the gasoline inside an engine. Therefore, a car engine is an internal combustion engine -- combustion takes place internally.

Two things to note:

·         There are different kinds of internal combustion engines. Diesel engine are one form and gas turbine engines are another. See also the articles on HEMI engine, rotary engine and two stroke engine Each has its own advantages and disadvantages.

·         There is such a thing as an external combustion engine. A steam engine in old-fashioned trains and steam boats is the best example of an external combustion engine. The fuel (coal, wood, oil, whatever) in a steam engine burns outside the engine to create steam, and the steam creates motion inside the engine. Internal combustion is a lot more efficient (takes less fuel per mile) than external combustion, plus an internal combustion engine is a lot smaller than an equivalent external combustion engine. This explains why we don't see any cars from Ford and GM using steam engines.

Let's look at the internal combustion process in more detail in the next section

The Corvette ZR1's supercharged 6.2-liter V8 engine produces 620 horsepower standard.

MDAU WA BLOG HII LEO TUMALIZIE MFUMO WA MWISHO KATIKA BREKI UNAOJULIKANA KAMA BREKI KEBO AU ( EMERGENCY BRAKE )

You're 16 years old. Your father has decided it would be a great idea to take you to the steepest hill in town and make you stop precariously at the stop sign that is halfway up the hill. You're driving a stick shift. As you stop, he reaches over and puts on the emergency brake. You notice three cars pulling up behind you. Your father snickers. You break into a cold sweat. But for a second, you feel safe. Because the emergency brake is on. But what exactly is holding you in place?

Emergency brakes are a secondary braking system installed in motor vehicles. Also known as e-brakes, hand brakes and parking brakes, emergency brakes are not powered by hydraulics and are independent of the service brakes used to slow and stop vehicles. There are state and federal laws requiring emergency brakes for motor vehicles

There are four types of emergency brakes:              

·         Stick lever, which is generally found under the instrument panel (found in older-model vehicles)

·         Center lever, which is found in between separated front seats

·         Pedal, which is found to the left of the floor pedals

·         Electric or push button, which are found among st the other console controls

Because most modern braking systems have fail safe measures and warning systems, such as on-dash brake-warning lights and low-fluid sensors, the emergency brake is most often used as a parking brake device. But the e-brake is called an emergency brake for a reason -- using it can save your life.

Read on to discover how emergency brakes keep you from rolling down that hill.

 This one little lever can mean the difference between a car staying put or rolling into the house down the hill. 

   

LEO TUANGALIE AINA YA PILI YA MFUMO WA BREKI YA UPEPO ( AIR BRAKE SYSTEM )

Air brake (road vehicle)

Air brakes or more formally a compressed air brake system is a type of friction brake for vehicles in which compressed air pressing on a piston is used to apply the pressure to the brake pad needed to stop the vehicle. Air brakes are used in large heavy vehicles, particularly those having multiple trailers which must be linked into the brake system, such as trucks, buses, trailers, and semi-trailers in addition to their use in railroad trains. George Westinghouse first developed air brakes for use in railway service. He patented a safer air brake on March 5, 1872. Westinghouse made numerous alterations to improve his air pressured brake invention, which led to various forms of the automatic brake. In the early 20th century, after its advantages were proven in railway use, it was adopted by manufacturers of trucks and heavy road vehicles

MFUMO WA BREKI ( BRAKE ) KATIKA MAGARI. KUNA AINA TATU YA MFUMO WA BREKI KATIKA MAGARI.

1. BREKI YA MAFUTA ( HYDRAULIC BRAKE )
2. BREKI YA UPEPO     ( AIR BRAKE )
3. BREKI YA KEBO       ( CABLE BRAKE )

LEO TUANGALIE AINA YA KWANZA YA BREKI ZA MAFUTA (HYDRAULIC BRAKE) 

Brake systems are designed to slow the vehicles wheel movement through friction. There are primarily two brake types of systems, ABS and non ABS (anti-lock brake system). Both systems work on basic hydraulics and utilize a brake master cylinder (connected to the brake pedal) that supplies brake fluid pressure to the front brake calipers and rear wheel cylinder or brake calipers if so equipped.  The brake system requires hydraulic force that is many times greater than the force applied by the foot. This added hydraulic force is achieved by leverage multiplication.

Power brake systems utilize either vacuum (vacuum assist) or power steering (hydro-boost) to multiply the force without added pedal effort. When the brake pedal is forced down brake fluid from the master cylinder is transferred to the brake caliper piston, pressurized fluid is transmitted to the brake calipers or wheel cylinders.

MDAU WA BLOG HII ANGALIA HATUA YA MWISHO YA MFUMO WA UPOZAJI KATIKA INJINI (ENGINE) KWA KUTUMIA HEWA.

Common Uses for Air-cooled Engines

The air-cooled engine has had a long and well-loved history. At least, depending on whom you talk to. In the 1960s and 1970s some car makers used air-cooled engines to power their vehicles. The 1964 Porsche 911 may be one of the fastest air-cooled engines, but the Volkswagen air-cooled engine may be one of the most beloved. It was used in the original Beetle.

You'd be hard-pressed to find an air-cooled engine rolling of the auto assembly line these days, but that doesn't necessarily mean they're anywhere near dead.

If you hop on a motorcycle, all-terrain vehicle, or even a common riding mower then you're probably experiencing an air-cooled engine (although some motorcycles are liquid-cooled). But it's aircraft that have had the longest running air-cooled track record because many helicopters and small planes have remained air-cooled right from the beginning.

Aircraft have had the longest running air-cooled track record because many helicopters and small planes have remained air-cooled right from the start.

AINA YA PILI YA MFUMO WA UPOZAJI WA INJINI ( ENGINE) NI KWA NJIA YA HEWA. MDAU WANGU FUATANA NAMI UELEWE UTENDAJI KAZI WA MFUMO HUU.

How an Air-cooled Engine Works

KEEPING COOL

·         How Car Cooling Systems Work

·         How does the thermostat in a car's cooling system work?

·         How Automotive Air Conditioning Works

Maybe you haven't given much thought to how your engine keeps its cool. That's understandable. As long as it works, there's no point in thinking too much about it, right? But do you even know what kind of cooling system your car has?

If you have a modern car, you probably have a water-cooled engine that uses a water and coolant mixture to, well, cool the engine. But some engines don't need coolant. They don't have radiators and they don't regulate the internal temperature of the engine. It sounds a little like magic, but it's not.

It's a throwback technology that's really no technology at all. These engines are called air-cooled engines and chances are you've seen one, even if you didn't recognize it

MDAU WA BLOG HII ENDELEA KUANGALIA UPOZAJI ZAIDI KATIKA INJINI ( ENGINE) ZA MAGARI.

Fluid

Cars operate in a wide variety of temperatures, from well below freezing to well over 100 F (38 C). So whatever fluid is used to cool the engine has to have a very low freezing point, a high boiling point, and it has to have the capacity to hold a lot of heat.

Water is one of the most effective fluids for holding heat, but water freezes at too high a temperature to be used in car engines. The fluid that most cars use is a mixture of water and ethylene glycol (C₂H₆O₂), also known as antifreeze. By adding ethylene glycol to water, the boiling and freezing points are improved significantly

MDAU WA BLOG HII ANGALIA ZAIDI UTENDAJI WA MFUMO HUU WA UPOZAJI KATIKA INJINI ( ENGINE )

Plumbing

The cooling system in your car has a lot of plumbing. We'll start at the pump and work OUR way Through the system, and in the next sections we'll talk about EACH part of the system in more detail.

The pump sends the fluid into the engine block, here it makes its way Through PASSAGES in the engine around the cylinders. Then it Returns Through The cylinder head of the engine. The thermostat is located Where the fluid leaves the engine. The plumbing around the thermostat sends the fluid back to the pump directly if the thermostat is closed. If it is open, the fluid goes Through the radiator first and then back to the pump.

FUATILIA MISINGI YA UPOZAJI KATIKA INJINI ( ENGINE )

The Basics

Inside  your  car's engine  fuel is constantly burning. A lot of the heat from this Combustion goes right out the exhaust system, BUT some of it soaks into the engine, Heating it up. The engine runs its best When coolant is about 200 Degrees Fahrenheit (93 Degrees Celsius). At this temperature:

·          The Combustion chamber is hot Enough to completely vaporize the fuel, providing better Combustion and Reducing emissions.

·          The oil used to lubricate the engine has a lower viscosity (it is thinner), so the engine parts more Move freely and the engine wastes less power moving its own components around.

·          Metal parts wear less.

There are two types of cooling systems found on cars: liquid-cooled and air-cooled.

HATUA YA KWANZA YA UTENDAJI KAZI WA MFUMO WA UPOZAJI KATIKA INJINI (ENGINE).

How Car Cooling Systems Work

Car Engine Pictures

Diagram of a cooling system: how the plumbing is connected. Want to learn more? Check out these car engine pictures.

·          

Although gasoline engines have improved a lot, they are still not very efficient at turning chemical energy into mechanical power. Most of the energy in the gasoline (perhaps 7­0%) is converted into heat, and it is the job of the cooling system to take care of that heat. In fact, the cooling system on a car driving down the freeway dissipates enough heat to heat two average-sized houses! The primary job of the cooling system is to keep the engine from overheating by transferring this heat to the air, but the cooling system also has several other important jobs.

The engine in your car runs best at a fairly high temperature. When the engine is cold, components wear out faster, and the engine is less efficient and emits more pollution. So another important job of the cooling system is to allow the engine to heat up as quickly as possible, and then to keep the engine at a constant temperature.

In this article, we'll learn about the parts of a car cooling system and how they work. First, let's look at some basics.

COOLING SYSTEM ( MFUMO WA UPOZAJI )

Mfumo huu wa upozaji katika Magari makubwa (Truck Car) upo wa aina mbili.

1. Upozaji kwa kutumia maji.
2. Upozaji kwa kutumia hewa.
Leo tuangalie mfumo wa upozaji kwa kutumia maji katika Injini za magari makubwa kwa njia ya mchoro.

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