Types of engines and how they work

Engines are machines that convert a source of energy into physical work. If you need something to move around, an engine is just the thing to slap onto it. But not all engines are made the same, and different types of engines definitely don’t work the same.
Probably the most intuitive way to differentiate between them is the type of energy each engine uses for power.

Thermal engines

Internal combustion engines (IC engines)

External combustion engines (EC engines)

Reaction engines

Electrical engines

Physical engines

Thermal engines

In the broadest definition possible, these engines require a source of heat to convert into motion. Depending on how they generate said heat, these can be combustive (that burn stuff) or non-combustive engines. They function either through direct combustion of a propellant or through the transformation of a fluid to generate work. As such, most thermal engines also see some overlap with chemical drive systems. They can be airbreathing engines (that take oxidizer such as oxygen from the atmosphere) or non-airbreathing engines (that have oxidizers chemically tied in the fuel).

Internal combustion engines

Internal combustion engines (IC engines) are pretty ubiquitous today. They power cars, lawnmowers, helicopters, and so on. The biggest IC engine can generate 109,000 HP to power a ship that moves 20,000 containers. IC engines derive energy from fuel burned inside a specialized area of the system called a combustion chamber. The process of combustion generates reaction products (exhaust) with a much greater total volume than that of the reactants combined (fuel and oxidizer). This expansion is the actual bread and butter of IC engines — this is what actually provides the motion. Heat is only a byproduct of combustion and represents a wasted part of the fuel’s energy store, because it doesn’t actually provide any physical work.

IC engines are differentiated by the number of ‘strokes’ or cycles each piston makes for a full rotation of the crankshaft. Most common today are four-stroke engines, which break down the combustion reaction in four steps:

Induction or injection of a fuel-air mix (the carburate) into the combustion chamber.

Compression of the mix.

Ignition by a spark plug or compression — fuel goes boom.

Emission of the exhaust.

External combustion engines

External combustion engines (EC engines) keep the fuel and exhaust products separately — they burn fuel in one chamber and heat the working fluid inside the engine through a heat exchanger or the engine’s wall. That grand daddy-o of the Industrial Revolution, the steam engine, falls into this category.

In some respects, EC engines function similarly to their IC counterparts — they both require heat which is obtained by burning stuff. There are, however, several differences as well.

EC engines use fluids that undergo thermal dilation-contraction or a shift in phase, but whose chemical composition remains unaltered. The fluid used can either be gaseous (as in the Stirling engine), liquid (the Organic Rankine cycle engine), or undergo a change of phase (as in the steam engine) — for IC engines, the fluid is almost universally a liquid fuel and air mixture that combusts (changes its chemical composition). Finally, the engines can either exhaust the fluid after use like IC engines do (open-cycle engines) or continually use the same fluid (closed-cycle engines).

How Diesel Engines Work

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 convert 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 following graphic shows the diesel cycle.

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 intakes air and compresses it; instead it 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.

How Do Diesel Vehicles Work?

Diesel vehicles are similar to gasoline vehicles because they both use internal combustion engines. One difference is that diesel engines have a compression-ignited injection system rather than the spark-ignited system used by most gasoline vehicles. In a compression-ignited system, the diesel fuel is injected into the combustion chamber of the engine and ignited by the high temperatures achieved when the gas is compressed by the engine piston. Unlike the emission control systems on gasoline vehicles, many diesel vehicles have additional aftertreatment components that reduce particulate matter and break down dangerous nitrogen oxide (NOx) emissions into harmless nitrogen and water. Diesel is a common transportation fuel, and several other fuel options use similar engine systems and components.
Aftertreatment system: This system is comprised of multiple components, which are responsible for filtering the engine exhaust gas to meet tailpipe emission requirements. After the exhaust gas of the engine is filtered through the diesel particulate filter (DPF) and the diesel oxidation catalyst to reduce particulate matter, diesel exhaust fluid (DEF) is injected into the exhaust gas mixture, then reduced to nitrogen and water by chemical conversion within the selective catalytic reducer (SCR) before being released into the atmosphere via the vehicle's tailpipe.Battery: The battery provides electricity to start the engine and power vehicle electronics/accessories.Diesel exhaust filler: This port is for filling the diesel exhaust fluid tank.Diesel exhaust fluid (DEF) tank: This tank holds diesel exhaust fluid, an aqueous urea solution, which is injected into the exhaust stream during selective catalytic reduction.
Electronic control module (ECM): The ECM controls the fuel mixture, ignition timing, and emissions system; monitors the operation of the vehicle; safeguards the engine from abuse; and detects and troubleshoots problems.Fuel filler: A nozzle from a fuel dispenser attaches to the receptacle on the vehicle to fill the tank.Fuel line: A metal tube or flexible hose (or a combination of these) transfers fuel from the tank to the engine's fuel injection system.Fuel pump: A pump that transfers fuel from the tank to the engine's fuel injection system via the fuel line.Fuel tank (diesel): Stores fuel on board the vehicle until it's needed to power the engine.Internal combustion engine (compression-ignited): In this configuration, fuel is injected into the combustion chamber and ignited by the high temperature achieved when a gas is greatly compressed.Transmission: The transmission transfers mechanical power from the engine and/or electric traction motor to drive the wheels.

Portable generator maintenance: oil and fuel

When preparing your portable generator for use, especially when being used as a backup power source, It is important to perform proper maintenance. There are many components that you must maintain on your generator, but we’re going to focus on two of the most important: oil and fuel. Here are some important tips to remember when maintaining your portable generator:

1. OIL
It’s essential to maintain your generator by regularly servicing the oil in the engine. The last thing you want during an emergency is to have your portable generator’s engine shut down from lack of oil. Especially when you’re relying on it to power necessary appliances in your home.
Every time you used your generator, you should check the engine oil level. Usually every 100 hours—or every season—you should change the oil. However, if you use your portable generator in any extreme conditions, such as in a dirty or dusty environment, or in extremely hot weather, you should change the oil more frequently. Additionally, when disposing of oil, make sure to return it to a collection center to avoid pollution.
Before we talk about maintenance for your fuel, let’s discuss the fuel requirements for your portable generator:

Use clean, fresh, unleaded gasoline

Fuel must have a minimum rating of 87 octane/87 AKI

While up to 10% ethanol is acceptable, non-ethanol-premium fuel is recommended

DO NOT use E85, gas/oil mix, or modify the engine to run on alternate fuels

Depending on the portable generator model, you will either need to keep an eye on the fuel gauge, or you will need to manually check the fuel level. When refueling, you should always turn the generator off and let it cool down a bit first. This will allow hot components to cool and avoid a fire if gasoline is splashed or spilled.

When you’re not using the portable generator consistently, it is recommended you start and run it for a half hour every thirty days as a way of “exercising” the generator. If you are storing your generator between uses, make sure it’s in a dry, safe place to prevent moisture, which can cause rust to accumulate in the fuel tank. Here a just a few more guidelines to follow:

Add fuel stabilizer if your portable generator is being stored for over 30 days

If fuel stabilizer is added, prepare and run the engine for long term storage

Run the engine for 10-15 minutes to circulate the stabilizer

Do NOT store fuel from one season to the next unless properly treated with fuel stabilizer

If fuel stabilizer is not used, drain the fuel tank prior to storage.

By following these easy steps for your fuel and oil, and maintenance for other generator components, you can ensure that your portable generator will be ready when you need it—protecting you and your family from whatever outage situation comes your way.

Why use a diesel welder?

The welding generator driven by the diesel is used for the welding purposes where electric power supply is erratic or non existent.

A welder generator creates power for welding without reliance on mains electricity. Simply fill up the fuel tank, just as you would for a regular generator, and the welder generator will power your welding equipment wherever you need it. As a result, welder generators have become essential equipment for onshore, offshore, constructions sites, farms, industry and more.Certainly you can! One of the biggest advantages of a welder generator is that it can be used as a stand-alone generator. This saves you space, money and hassle in running two separate machines. So when you aren’t using the machine for welding, you can use the generator power for work lights, emergency power or to run power tools. You can plug tools and appliances directly into its outlets as normal.

Hurricanes, ice storms, and natural disasters of all kinds leave countless people without electricity each year. Instead of buying a machine that only generates emergency power, it may be a better investment to invest in a welding generator and get two machines for the price of one. With recording breaking temperatures, floods and an ample amount of snowfall and ice around the world, many people lose electricity due to power lines coming down. Summer brings its own set up challenges; severe thunderstorms, tropical storms, and hurricanes can devastate entire regions.

When you desperately need lights, tools and appliances, a generator becomes worth its weight in gold. If you need power in the field, such as for emergency equipment repair, construction or farm/ranch work, portable generators also make sense for everyday use.