In this article, you will get knowledge about Power Plant Engineering. Also, we will know about various power plants.
What is Power Plant Engineering?
One of the most important disciplines in engineering is Power Plant Engineering. It is the discipline of engineering that discusses machines, machinery, and space of the power plant, from technical concerns to development, and finally, everything to power plant engineering. It is also an issue of power plant engineering to protect the environment while increasing profit at a cheaper cost. The engineering and technology needed to provide electric power for central stations. Instead of producing electricity for homes, the field is concentrated on building capacity for communities and industry.
What is Power Plant?
A power plant is a facility or organization that generates electricity by utilizing mechanical energy with specific processes. It is where the electrical power is created by converting mechanical energy through several instruments and then transported to nearby or distant locations by following the appropriate engineering mechanism. A power plant that generates energy for a human may also be called a power station, generating station, or powerhouse.
Types of Power Plants:
Based on the conversion of energy from various sources into electricity, power plants can be classified into the following categories:
- Hydro Electric Power Plant
- Nuclear Power Plant
- Diesel Power Plant
- Solar Power Plant
- Gas Power Plant
- Wind Turbine Plant
- Steam Power Plant
Division of power plants Engineering:
The power plant is divided into two segments depending on the demand or load.
- Base Load Power Plant
- Peak Load Power Plant
Base Load Power Plant:
Baseload power is the bare minimum of electricity required to be delivered to the grid as per requirement at any moment. Power plants must keep up with daily patterns in energy use. Still, it is not ideal for them to always provide as much electricity as is required. Some of the Baseload power facilities, such as coal-fired and peaking power plants, produce the bare minimum amount of electricity needed. Sometimes the Baseload power is sufficient since daily electricity demand variations cause huge fluctuations.
Peaking power, or electricity delivered to match fluctuating demand for electricity, is very necessary for the system. Then consistent and dependable sources of electricity are required to supply Baseload power. They can also occasionally be dispatched to supplement unreliable, intermittent power sources. Mostly Baseload power plants use non-renewable fuel year-round and have significant capacity factors. Nuclear and coal-fired power stations are some examples of Baseload power sources.
Peak Load Power Plants:
Peak-load power plants are specially designed power plants, which only operate when the electricity demand is at its highest. A peaking power plant or Peaker is another name for the peak load power plant. Because here the cost of producing energy for a peak load plant is higher than it is for a base load plant, peak load power plants are often only used for brief periods or at specific requirements.
The busiest times are typically the sweltering afternoons when air conditioners and refrigerators run at full speed. Various examples of power generating facilities employed as peak load facilities are Gas turbine power plants, solar power plants, wind turbine power plants, diesel engine power plants, and occasionally small-scale hydroelectric power plants.
Division of Power Plant Engineering Location:
The power plant is likewise split into two portions based on its location.
- Central Power Plant
- Isolated Power Plant
Central Power Plant:
A central power plant is a required sizable electric power production facility that produces electricity for distribution to several consumers. Large-scale power production at centralized facilities is called “centralized generation.” These facilities are generally connected to a system of high-voltage transmission lines and situated far from end consumers for those it requires. The electric power grid distributes the electricity produced by centralized generating to various end consumers.
Facilities for centralized generation can be wind farms, hydroelectric dams, fossil fuel-fired power plants, and more. Centralized electricity is seen as a more dependable, constant, and frequently more straightforward electricity supply. Because of this, it is more practicable for the typical home to maintain its status and obtain electricity from reliable sources.
Isolated Power Plant:
An isolation power system offers an ungrounded electrical supply for various uses it can use within a hospital or medical office facility. These types of isolated power systems remain operational in case of a single line-to-ground fault. These devices also remove the risk of electric shock to patients who may be more vulnerable to the leakage current and unable to move in their beds, and it may be the most needed aid for a place like a hospital. If there is a malfunction happens, the system alarm in the isolation panel goes off. Because no ground fault protection or overcurrent protective device trips when the alarm is activated and the crucial medical equipment remains operational.
The isolation panel’s system alarm turns on in case of a problem. Because neither ground fault nor overcurrent protective mechanism triggers when the alarm goes off, the vital medical equipment continues to function for the patients. A single ground fault that sets off a notice must be fixed as quickly as possible within a “safe” period since a second ground fault might activate the short circuit protection and shut down the whole operating room and like this the isolated power plant works.
Diesel Power Plant:
Diesel power generates electricity by turning alternators using a diesel engine. This power plant is called a diesel power plant since the diesel engine is the prime mover. Diesel combustion results in the production of rotational energy. The same shaft of the diesel engine is used to connect the alternator. Moreover, the alternator transforms the diesel engine’s rotational energy into electrical power. The diesel power plant is typically used to produce electrical energy at the load end and for small-scale manufacturing. In addition, in emergencies, the diesel engine delivers load when grid power is unavailable.
The central part of a diesel power plant is the diesel engine. The engines are divided into two- and four-stroke categories. To create power, machines are often directly linked to the generator. In diesel engines, pressurized air is introduced into the cylinder. Fuel is delivered after the compression stroke. While the fuel burns, expanding gases from the fire exert force on the piston. The generator and engine shaft are directly connected. The burned gases are released into the atmosphere after combustion.
Steam Power Plant Generation:
A steam power plant comprises a boiler, steam turbine, generator, and various auxiliary components. The boiler produces high-pressure, high-temperature steam. The steam turbine transforms steam thermal energy into mechanical energy. The mechanical energy is subsequently converted into electric power via the generator. Highly efficient and environmentally friendly power plants will help to provide a steady supply of electricity while reducing the environmental effect.
A steam power plant converts the thermal energy supplied by coal combustion into electrical energy. This type of power plant is widely utilized across the world. Owing to the abundance of fuel (coal), this power station set can create significant amounts of electrical power. These power facilities are utilized as Baseload power plants in most countries. This is because steam power stations are expensive to build and cannot be used to meet peak loads, which often occur in the near term.
Factors Influencing the Location of a Steam Power Generation Plant:
Steam-powered power plants operate at near total capacity 24 hours a day. Power plants have an average lifespan of 30 to 40 years. The following is a list of elements that influence the location of a steam power plant.
Supply of fuel:
A steam power station should be located near coal mines to save fuel transportation costs. A steam power plant that runs on coal or oil requires a considerable fuel yearly. The steam power plant should be near coal mines to reduce fuel transportation costs. But, if such a plant is to be built in an area where coal is not accessible, it must be located near a gasoline station.
Nature of land and its price:
The location must have a high bearing capacity of at least 10 N/sq mm to support the plant’s dead weight. Hence, the price of the plant’s foundation would be reduced.
Availability of water:
The station must be near a riverbank or canal for continuous water delivery. During the year, the steam power plant uses water as a working solution, which is frequently evaporated and condensed. It also requires 2% of the steam produced as makeup water to compensate for its loss.
The station must be properly connected to major transportation lines, such as rail or road. For example, a new steam power plant frequently requires materials and machinery delivery. As a result, enough transportation infrastructure must exist, i.e., the factory should be adequately connected to other land areas through trains, roads, and so on.
Steam Power Station Efficiency:
Due to two issues, the steam power station’s total efficiency could be better (around 29%). First, a significant quantity of heat is lost in the condenser, and second, heat losses occur at various stages of the plant. Heat lost in the condenser cannot be recovered.
Without a temperature difference, heat cannot be turned into mechanical energy. The larger the temperature fluctuation, the higher the conversion of heat energy to mechanical energy. This necessitates keeping the steam in the condenser at the lowest possible temperature. But we know that the bigger the temperature differential, the greater the heat loss value. This shows how efficient such plants are on average.
Principal Component of a Steam Power Generation:
The principal components of steam power plants are:
The boiler has the capability to convert water into steam. Water is recycled to vapor by heating the water in the tubes using energy derived from fuel combustion. The combustion process is continuously carried out in the combustion chamber using fuel and airflow from the surface. The resultant steam consists of superheated fumes with high temperature and pressure. The amount of vapor produced is being determined by the surface area of heat transfer, the flow rate, and the heat of combustion used. A water tube boiler is a boiler system made out of water-filled pipes.
Mainly the steam turbine converts the thermal energy in the steam into rotational motion. Steam is used with a high load and temperature to drive turbine blades on the shaft, causing the post to revolve. Owing to the completion of the turbine, the pressure and heat of the steam entering the turbine have been reduced to saturated vapor. This steam is then sent to the condenser, and the spinning power is utilized to power a generator. Currently, practically all steam turbines are condensing turbines.
Condensers are devices that convert steam to water. The steam flow into a chamber housing tubes causes the alterations. Outside the lines, steam circulates while cooling water flows within. This is known as a surface condenser. Seawater is commonly used as a coolant. The heat transfer rate is affected by the velocity of cooling water, sanitation devices, and the temperature difference between the steam and cooling water.
At saturated weight and temperature, the transformation technique into water vapor occurs. The condenser is under vacuum in this scenario. The maximum temperature of condensate water is near the outdoor air temperature because the cooling water temperature is equivalent to the external temperature. If the heat transmission rate is really slowed, the pressure and temperature will be affected.
The basic concept of a power plant’s activity is electricity. The generator generates electrical energy and a function generator turns mechanical force into electrical power in the shape of a circle with the origin of magnetic induction. The generator is made up of a stator and a rotor, when the rotor rotates, and creates a magnetic field. A stator magnetic field station comprises a casing that houses coils. In contrast, a rotor magnetic field station includes a core that houses a ring.
An alternator receives power from the steam turbine. Then electrical energy is created when the turbine rotates the alternator. This produced electrical voltage is then stepped up by a transformer and transmitted to where it will be used.
The working system of the steam power generation plant:
In a steam power plant, the working steam cycle is a final cycle that employs the same fluid regularly. Then, enough water is poured into the boiler to cover the whole heat transfer surface area. Water in the boiler is warmed by the hot gases of combustion fuel mixed with air and helps torture into the vapor phase.
With pressure and temperature, the steam created by the boiler is directed to conduct work on the turbine in the order of rotation to give mechanical power. The former steam comes out of the turbine. Then it moves into the condenser to be frozen with cooling water to again be converted to water. The condensate water is then reused as boiler-feedwater and this is a continuous process. The turbine’s rotation turns a generator directly connected to the turbine. As a result, as the turbine rotates, the generator output terminals generate energy. This is the energy that gets transferred.
Advantages of Steam Power Plant:
Here are a few advantages of steam power plants:
- Here the fuel utilized is less expensive.
- They can react very fast to changes in plant load.
- In comparison to hydropower plants, in this space less space is required.
- Steam may be used as a process steam in a variety of businesses as required.
- They may be easily overloaded by up to 20%. Electric power generation costs cheaper to build and operate than that of diesel facilities.
- It can be easily situated near the desired load center, lowering transmission line costs and energy loss in transmission lines.
Disadvantages of Steam Power Plants:
Here are a few Disadvantages of Steam Power Plants:
- The expense of operation and maintenance is substantial.
- Before the plant can be put into service, it must be well constructed.
- It’s very common that a large amount of water is required.
- Coal and ash management is a specific issue.
- The efficiency of the load portion could be better.
- Pollution causes health issues for workers and residents near thermal power plants.