How does a Diesel Power Plant Generate Electricity?

We know well most diesel-based power plants a standby power plants. This type of power plant generates a low amount of electrical energy (50 MW, 100 MW, etc.). But how does a diesel power plant generate electricity? A diesel generator is used in such a power plant. Diesel generator converts the chemical energy of diesel fuel into mechanical energy by diesel combustion.

If electricity is produced by this process at any certain location it is called a diesel power plant. The diesel engine is a rotating mechanical device. The diesel engine is used as the prime mover to generate electricity by a special plant which is called a diesel power station.

How Does a Diesel Power Plant Generate Electricity?

A diesel power plant generates electricity using a diesel engine. It is coupled to an electrical generator that converts mechanical energy into electrical energy. So, let’s see the entire process of how does diesel power plant generates electricity.

1. Combustion of Diesel Fuel

The primary component of this power plant is the diesel engine. Diesel fuel is injected into the engine’s combustion chamber, where diesel is mixed with compressed air. Unlike gasoline engines, diesel engines do not require a spark plug for ignition. The fuel ignites due to the high temperature resulting from the compression of air within the cylinder. This combustion process releases energy in the form of heat.

2. Mechanical Energy Production

The heat produced from the diesel combustion causes an increase in pressure within the engine cylinders by driving the pistons downward and upward. This linear motion of the pistons is converted into rotational motion by a crankshaft. The crankshaft is connected to the pistons. The crankshaft then starts, rotating, and converts the piston’s reciprocating motion into a continuous rotary motion.

3. Generator Operation

The rotating crankshaft is connected to an electrical generator. As the crankshaft rotates, it spins the generator rotor within a magnetic field. Thus EMF is induced in the generator’s windings through electromagnetic induction. This current is then transferred through the generator’s output terminals to the electrical transformers. Transformer step up that generated voltage and send it to the grid. At last, this power is sent to the consumer load center by some special process and steps.

4. Voltage Regulation and Control

The voltage regulators and control systems are included in this power plant to maintain a stable and consistent voltage output. These systems monitor the electrical load demand and adjust the fuel supply to the engine. This process ensures that the generator produces electricity at the required voltage and frequency.

5. Cooling and Lubrication

Diesel engines require effective cooling and lubrication systems to dissipate heat and reduce friction. Cooling system and lubrication ensure efficient operation and prolong the engine’s lifespan. Cooling systems use coolant circulated through the engine. Lubrication systems provide oil to reduce friction between moving parts, ensuring smooth operation and prolonging the engine’s lifespan.

Does a Diesel Power Plant have Prime Movers?

Yes, a diesel engine works as a prime mover that is coupled with the alternator. The Prime mover of the diesel power station is a two-stroke or four-stroke multi-cylinder diesel engine. Rotating energy is induced due to the diesel combustion in the diesel engine, and the alternator shaft is connected to the diesel engine shaft. In this case, the alternator shaft starts rotating at the same speed as the diesel engine shaft.

The alternator converts diesel engine rotational energy or mechanical energy into electrical energy. It is noted that diesel-based power plants are used as standby power plants. In most cases, this type of power plant capacity is lower around 50 MW. Whenever load demand becomes higher than the actual load then such a standby power plant is started to meet the load demand.

The working principle of the diesel power plant is not complex. The diesel engine works as the prime mover and the diesel engine is coupled with the alternator. Whenever the diesel engine rotates the rotor of the alternator also rotates then mechanical energy is converted into electrical energy.

Diesel Power Plant Operation and Maintenance

Diesel power plant operation and maintenance are not as complex as steam and nuclear power plants. The main operation of a diesel power plant is diesel burns inside the diesel engine and mechanical energy is induced due to the flow of working fluid.

How does Diesel Power Plant Generate Electricity

This mechanical energy is converted into electrical energy with the help of an alternator. However, Maintenance is one of the most common factors for all electrical power plants. All the power stations required maintenance. This power plant is one of the most important and sensitive power plants. The maintenance of a diesel power plant can be divided into two main parts, such as

  • Maintenance schedule
  • Maintenance activities

Maintenance Schedule

The maintenance schedule is a crucial thing. Schedule maintenance means periodic checking of various factors, such as temperature, diesel pressure, filter cleaning, coolant temperature checking, exhaust gases, and many more. The maintenance schedule is a regular process. This power plant is inspected regularly to avoid an unexpected situation.

Maintenance Activities

A maintenance activity is a regular activity that is extremely needed every day. Regular maintenance activities mean continuous inspection of fuel, the coolant of the oil, oil level, fuel system, fuel reservation, making sure all the devices are working properly, continuous monitoring and checking the generation capacity, and many more. All the components inspection of this power plant is regular maintenance. However, there is some basic maintenance of diesel power plants:

  • To maintain the operating condition of the diesel engine every half hour.  
  • To maintain the correct record of the instrument reading in the log sheet.
  • Clean the fuel tank at regular intervals.
  • To maintain the record of instrument temperature, pressure, electrical load, flow, etc.
  • To check the level of fuel oil periodically.

Where is the Diesel Power Plant Located?

Location is one of the crucial factors in power plants. It is because there is a large number of factors involved with the power plant such as many types of equipment installed, location price, water availability, transmission cost, etc. For this reason, whenever an engineer intends to design a power station then first of all they think about the place. However, we will discuss here how to select a diesel power plant location and then you will also get a better concept of how does diesel power plant generates electricity.

  • Distance from the load center.
  • Required land for diesel-based power plant.
  • Water source/necessity of water.
  • Oil transport facilities.
  • Distance from the populated area.

1. Distance From the Load Center

It means you can select a place nearer to the load center. This is because diesel-based power plant contains low power, due to reduced transmission losses, and are used as the peak load or standby power plant. For this reason, it can be located near the load center.

2. Required Land for this Power Plant

We know well that a diesel power plant is a standby power plant and it is usually run whenever load demand becomes higher than the base load (running period 5 pm to 12 am). Due to its low generation capacity and low amount of equipment installed that’s why it does not require a large space. It can be installed in a small area compared to the steam power plant, or thermal power plant

3. Water Source or Necessity of Water

Water is highly essential for all power plants. It runs on a diesel engine and no steam is generated here. For this reason, no more water is required for it. But a low amount of water is necessary for the cooling and some other things. For this reason, any source of water supply is considered for this power plant.

4. Oil Transport Facilities

Oil is only the fuel for this power plant. Diesel is transportable anyhow (by road or rail). You should find a location where transportation facilities are good. On the other hand, it can be located where an oil source is available. So, keep in mind that before setting up such a plant keep in mind this oil transport facility.

5. Distance From the Populated Area

Diesel is flammable and diesel is the main fuel for this power plant. This power plant makes some noise due to the running of the diesel engine and it is also responsible for nuisance from the exhaust. For this reason, the diesel power plant should be located far away from the populous area.

What is The Overall Efficiency of Diesel Power Plant?

Efficiency is one of the important things for every sphere. If the output power is divided by the input power and multiplied by 100 then we will get efficiency. If the efficiency becomes high then the output power of the power plant will be high. So output power depends on efficiency. However, the overall efficiency of a diesel power plant is quite higher than a steam power plant. The overall efficiency of diesel-based power plants is about 35%. However, let’s see how to find overall efficiency. Here is the efficiency formula:  


Why Diesel is Worse than Petrol?

Oil and diesel are obtained from unrefined oil that is obtained from the natural source of energy. Why petrol is not used to generate electricity? Sometimes this question comes to mind. Diesel burns inside the diesel engine and the product of this combustion acts as the working fluid to generate mechanical energy.

However, let’s try to find the actual answer to why diesel is worse than petrol or why petrol is not used to generate electricity. The petrol engine works on the Otto cycle and the diesel engine works on the diesel cycle.    

On the other hand, Diesel is a type of fuel oil that is created from petroleum. It is typically used in diesel engines because it has a higher energy density than gasoline. Diesel also has a higher boiling point, which makes it easier to start in cold weather. The main reason why diesel is used in the diesel power plant is that it has a higher density than gasoline. This means that there will be more energy per volume with diesel fuel compared to gasoline.

Diesel engines also have the advantage of being able to operate in extreme temperatures and are more efficient, which reduces pollution when compared to other types of engines such as gas or electric motors. However, the use of oil power plants increased significantly after World War II when the invention of the turbocharger made diesel engines more powerful and efficient than gasoline engines. Due to this reason, diesel is used instead of petrol.

Difference Between Steam Power Plant and Diesel Power Plant

Steam power plantDiesel power plant
Steam power plants are located where coal and water are available.Its initial cost is low compared to some other power stations.
The starting time of the steam power station is moreThe starting time of the steam power station is more
Coal is highly responsible for polluting the atmosphere and it is not cleanRunning costs are higher than steam power stations, and some other power stations due to the high price of oil.  
Coal transportation cost is high because huge coal is required to generate bulk electricity.Oil transportation cost is low compared to the steam power station because a low amount of diesel requires generating 50 MW power.
The starting time of the steam power station is moreThe diesel power station is less harmful compared to the steam power station.
Such power plant’s overall efficiency is about 25%The overall efficiency of diesel power stations is about 35%
Starting time of the steam power station is moreStarting time is less and it can be started within a concise time

Application of Diesel Engine Power Plant

This power plant can be placed at any place. If you have low demand of 2 to 5 MW then you can also meet your load demand by driving a diesel engine. However, we have asked above how diesel power plants generate electricity. Alright, let’s see the applications. 

  • It can be started at any time.
  • In remote areas where no electricity is available, the diesel power station can be located there.
  • It can be used as the standby power plant and it can be started whenever load demand is higher than the based load. 
  • It can be run as a mobile power station, transportation facilities, and others.
  • If industrial load demand becomes under 500KW then such a power plant can be installed.

Final Word

The diesel engine works on a thermodynamic cycle. A generator generates electricity through a diesel engine. The diesel engine runs and works as the prime mover and the engine shaft is connected to the alternator and the alternator generates electricity. Such a power plant is also called a peak load power plant.

The starting time of the peak load power plant is from 5 pm to 12 am. If load demand becomes balanced then such power station is completely stopped. However, we have referred to some crucial steps to let you know how diesel power plants generate electricity. We hope this crucial information is sufficient to let you know how diesel power plants generate electricity. So visit openread to know more about some other power plants.

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