Operating Principle of Thermal Power Plant
In a thermal power station, fuel is burned and is used to convert water into steam at the required pressure and temperature. The fuel normally used is oil, coal, or gas but coal is most commonly used. For efficient combustion, enough air is supplied. The gaseous product of combustion gives most of its heat to the water boilers and super haters. Water in the boiler is converted into steam by the heat supplied by fuel combustion in the furnace.
The steam is super-heated in the superheater. The super steam is supplied to the turbine at the throttle valve (control valve). The steam expands and gives it potential energy to the turbine. The turbine converts this energy into mechanical energy and arrives at the electric generator. The electric generator converts mechanical energy into electrical energy after expansion through the turbine the steam goes through the condenser. Where the exhaust steam is condensed back into condensate water and is pumped back to the boiler by the condensate pump.
The same water is used repeatedly, some water may be lost by the leakage through steam traps at various stages in the pumping system. Therefore, some water is added in the feed to make up water.
Parts of Thermal Power Plant:
The thermal power plant consists of the following parts which are given below.
- Supper heater
- Steam turbine
- Electric generator
- Condensate pump
- Feed water heater
- Makeup water system
- Feed water pump
Boiler -----> Superheater
Economizer Steam Turbine
Makeup Water System --> Condenser
Feed Water Pump ---> Electric Generator
Feed Water Heater --> Condensate Pump
The boiler is a device for producing steam under pressure. It converts water into steam at the required pressure of quality as nearly dry as possible. The boiler consists of large drums in which a large number of tubes are provided. There are two types of boilers.
- Fire tube
- Water tube
In fire tube boilers the hot gases produced from the combustion of the fuel in the furnace are led through the tubes after circulating through the entire tubing system inside the boiler. The gases leave the boiler water circulates around the tubes and continuously takes heat from the tube.
Water tube boiler
In this type the water occupies the interior of the tubes and the hot gasses pass over them. Generally, a water tube boiler is used for the electric power station.
After passing over the tubes and drum of the boiler the flue bases still has heat energy also the steam given out from the boiler is not completely dry and has some vapors in it. Therefore, to make use of the heat of flue gasses it is given to the superheater in order to make it completely dry to raise its pressure and temperature to a value as required by the steam turbine.
It is a device for converting the heat energy of steam into mechanical energy. It consists of wheels which are fixed the number of blades. There are two types of steam turbines.
An Impulse Turbine thermal power plant is a type of power generation facility that utilizes the principle of impulse turbines to convert thermal energy into mechanical energy and, ultimately, electrical energy. This type of power plant is commonly used in the field of power generation and is typically associated with steam power plants.
Here's an overview of how an Impulse Turbine thermal power plant works:
- Boiler: The process begins in the boiler, where a fuel source such as coal, natural gas, or oil is burned to generate high-temperature steam. This steam is produced under high-pressure and high-temperature conditions.
- Nozzles: The high-pressure, high-temperature steam is then directed through a series of specially designed nozzles. These nozzles are strategically placed to release the steam in a controlled manner, creating a high-velocity jet of steam.
- Turbine Blades: The high-velocity steam jet is directed onto a set of turbine blades. These blades are typically arranged in a wheel-like structure. As the high-velocity steam strikes the blades, it imparts a significant amount of kinetic energy to them.
- Rotation of Turbine: The kinetic energy transferred to the turbine blades causes them to rotate rapidly. This rotation is the result of the impulse action of the steam jet. The mechanical energy generated by the rotating blades is harnessed and used to drive a generator.
- Generator: The rotating turbine is connected to a generator. As the turbine spins, it turns the generator's rotor, which is located within a magnetic field. This motion induces an electrical current in the generator's windings, resulting in the generation of electrical power.
- Electricity Generation: The electrical power generated by the generator is typically in the form of alternating current (AC). It can then be further processed and transmitted through the power grid to meet the electrical needs of homes, businesses, and industries.
- Condensation: After passing through the turbine, the steam is often condensed back into water using a condenser. This condensed water is then returned to the boiler to begin the cycle anew.
A reaction turbine is a type of hydraulic turbine used in power generation that operates on the principle of both impulse and reaction forces to convert fluid energy into mechanical energy and eventually into electrical energy. These turbines are commonly used in hydroelectric power plants to harness the energy of flowing water.
Here's how a reaction turbine works:
- Water Inlet: The process begins with the intake of pressurized water from a reservoir or river. This water is directed into the turbine through a system of pipes or penstocks.
- Guide Vanes: As the high-pressure water enters the turbine, it encounters a set of guide vanes or nozzles. These guide vanes are adjustable and serve to control the flow and direction of the water. They also help to maintain a uniform flow of water onto the next stage of the turbine.
- Runner Blades: The high-velocity water jet from the guide vanes is directed onto a set of runner blades. The runner is a rotating component of the turbine, and its blades are shaped in a way that allows them to efficiently capture the kinetic energy of the water.
- Pressure Reduction: As the water impacts the runner blades, it undergoes a pressure reduction. This reduction in pressure results in an increase in velocity, as described by Bernoulli's principle. The kinetic energy of the water is transferred to the runner blades, causing them to rotate.
- Rotation of Turbine: The rotation of the runner blades is what generates mechanical energy in the form of rotational motion. This motion is then used to drive a generator.
- Generator: The rotating turbine is connected to a generator. As the turbine spins, it turns the generator's rotor, which is located within a magnetic field. This motion induces an electrical current in the generator's windings, leading to the generation of electrical power.
- Electricity Generation: The electrical power generated by the generator is typically in the form of alternating current (AC). It can be further processed and transmitted through the power grid to meet the electrical needs of homes, businesses, and industries.
- Water Discharge: After passing through the runner blades, the water is partially depleted of its energy. It exits the turbine and is typically discharged back into the river or reservoir, allowing for a continuous cycle.
Reaction turbines are highly efficient and are particularly well-suited for low-head and high-flow situations, where a large volume of water is available with relatively small changes in elevation. They are a key component in many hydroelectric power plants, contributing to the generation of renewable and sustainable electrical energy.
The steam turbine drives the AC generator. These are sometimes four-pole machines with a speed of 1500rpm for 50 cycles per second frequency or 1800rpm for 60 cycles per second frequency. But most of the time they are three-phase type machines. All the high-capacity generators are two poles with a speed of 3000rpm for 50 Hz or 3600rpm for 60 Hz frequency. A turbine generator consists of a stator and a rotor.
It is a device used for condensing the exhaust steam. Hence it produces a vacuum and illuminates back pressure. There are two types of condensers.
A jet condenser is a type of heat exchanger device used in power plants and industrial processes to condense steam or vapor into liquid form. It plays a crucial role in the thermodynamic cycle of many power generation systems, including steam power plants, by helping to improve overall efficiency.
Here's how a jet condenser works:
- Introduction of Steam: The process begins with the introduction of high-pressure steam or vapor, typically exhausted from a steam turbine or other industrial equipment, into the jet condenser. This steam may be in a superheated state.
- Nozzles: Inside the jet condenser, there are nozzles or a specially designed nozzle system. These nozzles spray a flow of relatively cool and low-pressure water, often referred to as the cooling water or condenser water, into the path of the incoming steam.
- Contact and Mixing: When the high-pressure steam comes into contact with the cool water spray, it undergoes rapid cooling and condensation. This occurs because the cool water absorbs heat from the steam, causing the steam to lose its thermal energy and transform into liquid water.
- Formation of a Condensate: As the steam condenses, it forms a liquid condensate. This condensate collects at the bottom of the jet condenser, forming a pool of water.
- Suction and Extraction: A vacuum or low-pressure zone is maintained within the jet condenser. This low pressure helps in creating a pressure difference between the inlet of the steam and the outlet of the condenser. The pressure difference encourages the flow of steam and non-condensable gases (such as air and carbon dioxide) into the condenser.
- Non-Condensable Gas Removal: The non-condensable gases are separated from the condensate and removed from the jet condenser to prevent them from interfering with the condensation process. This ensures that the steam can condense efficiently.
- Cooling Water Cycle: The cooling water used to condense the steam is typically a closed-loop system. After being sprayed into the condenser, it absorbs heat from the steam and becomes heated. This warm water is then pumped out of the condenser and through a cooling system (often a cooling tower or a river) to dissipate the heat. Once cooled, the water is recirculated back into the condenser to repeat the process.
Jet condensers are effective in converting steam back into liquid form, allowing for the efficient use of steam in power generation cycles. By condensing the steam, they create a vacuum, which can improve the efficiency of steam turbines in power plants. Jet condensers are a vital component in thermal power generation systems, contributing to the overall energy conversion process.
A surface condenser is a critical component used in various industrial processes and power generation systems, particularly in steam power plants and chemical refineries. Its primary function is to convert steam or vapor back into liquid form by passing it through a heat exchanger with cooling water. This process is crucial for efficient energy generation and preservation.
Here's how a surface condenser works:
- Introduction of Steam: The surface condenser begins its operation by receiving high-pressure steam or vapor, which is typically exhausted from a steam turbine, process equipment, or industrial applications. This steam may be superheated, which means it has a high temperature and pressure.
- Steam Inlet: The incoming steam is directed into the surface condenser, usually through a series of tubes or a tube bundle. These tubes are often made of materials that provide good thermal conductivity, such as copper, stainless steel, or titanium.
- Cooling Water Circulation: Concurrently, a separate system circulates cooling water around the outside of the tubes. This cooling water can come from various sources, such as cooling towers, rivers, or cooling ponds. The cooling water is maintained at a lower temperature than the incoming steam.
- Heat Exchange: As the high-temperature steam flows through the interior of the tubes, it comes into contact with the cooler outer surface of the tubes. Heat is transferred from the steam to the cooling water, causing the steam to undergo rapid cooling and condensation.
- Condensate Collection: As the steam loses heat, it transitions from a vapor state to a liquid state and forms condensate. This liquid condensate collects at the bottom of the surface condenser.
- Non-Condensable Gas Removal: In addition to the condensate, non-condensable gases (such as air and carbon dioxide) that may be present in the steam are also removed from the condenser. These gases are typically vented to the atmosphere.
- Vacuum Creation: A vacuum or low-pressure zone is maintained within the surface condenser. This vacuum is crucial because it helps create a pressure differential between the inlet of the steam and the outlet of the condenser. The pressure difference encourages the flow of steam and non-condensable gases into the condenser.
- Condensate Extraction: The liquid condensate is typically pumped out of the condenser and sent to other parts of the power plant or industrial process for reuse or further treatment.
Surface condensers play a vital role in power generation, particularly in steam power plants, as they allow for the efficient use of steam by enabling its recondensation. By converting the steam into liquid form, surface condensers facilitate the recycling of steam in a closed-loop system, improving overall energy efficiency and preserving valuable water resources.
In a thermal power plant, a condensate pump is a crucial component of the steam cycle and plays a vital role in the efficient operation of the plant. Its primary function is to pump the condensed water (condensate) from the condenser back into the boiler, completing the closed-loop cycle. Here's how a condensate pump works and why it is essential:
Operation of a Condensate Pump:
- Collection of Condensate: In a thermal power plant, steam is used to drive turbines that generate electricity. After the steam passes through the turbines, it enters the condenser, where it is rapidly cooled and condensed into water. This condensed water, known as condensate, collects at the bottom of the condenser.
- Condensate Quality Control: The condensate must be of high quality and free from impurities to prevent corrosion and scaling in the boiler and other parts of the steam cycle. It typically goes through various treatment processes to remove impurities and maintain the desired water quality.
- Pumping Condensate: Once the condensate is collected and treated, it needs to be pumped back into the boiler to be converted into steam again. This is where the condensate pump comes into play.
- Pressurization: The condensate pump pressurizes the condensate to a level suitable for reintroduction into the boiler. This is necessary because the pressure in the condenser is typically lower than the pressure required in the boiler. The pump ensures that the condensate can overcome this pressure difference and return to the boiler.
- Return to the Boiler: The pressurized condensate is sent back to the boiler, where it is heated once again to become steam. This closed-loop cycle continues, allowing the power plant to efficiently utilize the same water repeatedly.
Importance of Condensate Pumps:
- Efficiency: Condensate pumps are critical for maintaining the thermal efficiency of the power plant. By returning the condensed water to the boiler, they reduce the need for additional water intake and minimize heat loss associated with using new water.
- Water Conservation: They contribute to water conservation by allowing the power plant to recycle and reuse water, reducing the overall water consumption of the plant.
- Reduced Energy Consumption: Condensate pumps help reduce energy consumption because it takes less energy to heat preheated water (condensate) compared to starting with cold water. This contributes to improved overall plant efficiency.
- Preventing Corrosion: Properly functioning condensate pumps help prevent corrosion and scaling in the boiler and other parts of the steam cycle by ensuring that the condensate is of high quality and properly treated.
- Maintaining Stable Operations: A reliable condensate pump helps maintain the stable and continuous operation of the power plant by ensuring a consistent supply of water to the boiler.
In summary, a condensate pump is a vital component of a thermal power plant's steam cycle, contributing to energy efficiency, water conservation, and the overall reliability of the plant's operations. It plays a key role in maintaining a closed-loop system where water is efficiently recycled and reused in the generation of steam and electricity.
Feed water heater
A feedwater heater is an essential component in many steam power plants, particularly in large thermal power plants. Its primary function is to preheat the cold water that will be used as feedwater to the boiler, thus improving the overall efficiency of the power plant. Here's how a feedwater heater works and why it's important:
Operation of a Feedwater Heater:
- Cold Water Inlet: The feedwater heater starts with the introduction of cold water from an external source, such as a river, lake, or cooling system, into the heater.
- Steam Extraction: High-pressure and high-temperature steam is extracted from various stages of the steam turbine. This steam is typically at a point where its energy can be effectively used to heat the incoming cold water. Steam extraction points are strategically chosen to maximize heat transfer.
- Heat Exchange: The cold water is passed through a heat exchanger where it comes into direct contact with the extracted steam. As the cold water flows through the heat exchanger, it absorbs heat from the steam. This heat transfer causes the cold water to heat up and become preheated feedwater.
- Outlet to Boiler: The now preheated feedwater is then directed to the boiler, where it will be further heated to produce steam. By preheating the feedwater, the boiler requires less energy to raise the temperature of the water to steam-producing levels.
Importance of Feedwater Heaters:
- Increased Efficiency: One of the primary benefits of feedwater heaters is their contribution to increased power plant efficiency. Preheating the feedwater reduces the amount of energy required to convert it into steam in the boiler. This means that less fuel is needed to achieve the same power output, resulting in fuel savings and reduced emissions.
- Reduced Thermal Stress: Preheating the feedwater also reduces thermal stress on the boiler components. Cold water entering the boiler can cause rapid temperature changes, which can lead to thermal stress and potential damage to the boiler. By preheating the water, these temperature fluctuations are minimized.
- Improved Heat Rate: The heat rate of a power plant is a measure of its efficiency, and feedwater heaters contribute to improving this metric. A lower heat rate means the power plant can generate a given amount of electricity using less fuel, which is economically advantageous.
- Water Conservation: By reusing and preheating the feedwater, feedwater heaters contribute to water conservation in power plant operations. They reduce the overall water consumption of the plant by minimizing the need for additional water intake.
- Steam Extraction Benefits: Steam extraction for feedwater heating also provides a means of controlling and balancing the temperature and pressure levels within the various stages of the steam turbine, improving turbine efficiency and power generation.
In summary, feedwater heaters are critical components in steam power plants that enhance overall efficiency, reduce fuel consumption, and promote responsible water usage. They achieve this by preheating the cold water before it enters the boiler, thus optimizing the power generation process and contributing to the sustainability and cost-effectiveness of thermal power generation.
Makeup water system
A makeup water system is an integral part of various industrial processes and facilities, including power plants, industrial boilers, and cooling systems. Its primary purpose is to supply fresh water to compensate for water losses due to evaporation, leaks, blowdowns, or other factors in these systems. Here's how a makeup water system works and why it is important:
Operation of a Makeup Water System:
- Water Supply: The makeup water system begins with a reliable source of fresh water, which can be derived from various sources such as municipal water supplies, rivers, lakes, wells, or reservoirs. This source provides the necessary makeup water to the industrial process.
- Water Treatment: Depending on the source water quality and the specific requirements of the industrial process, the makeup water is often subjected to water treatment processes. These treatments may include filtration, chemical treatment to remove impurities, softening, and sometimes demineralization to ensure that the water meets the quality standards required for the process.
- Supply to the System: The treated makeup water is then supplied to the industrial process or system where it is needed. Different industrial processes may have different makeup water requirements. For example, in power plants, makeup water is essential for replenishing water lost through steam generation and cooling processes.
- Control and Monitoring: Makeup water systems are equipped with control systems and monitoring instruments to ensure that the water supply is maintained at the desired level and quality. These systems may include pumps, valves, sensors, and alarms to regulate and alert operators when adjustments are needed.
Importance of Makeup Water Systems:
- Maintaining Water Balance: In industrial processes such as power generation, boilers, and cooling systems, water losses occur due to evaporation, blowdown (controlled discharge to remove impurities), and leaks. Makeup water systems help maintain the necessary water balance by replacing lost water, ensuring the continuous operation of these processes.
- Preventing Equipment Damage: A makeup water system helps prevent equipment damage and corrosion by maintaining the required water levels and water quality. Low water levels or poor-quality water can lead to overheating, scaling, and equipment malfunction.
- Optimizing Efficiency: Makeup water systems contribute to the efficiency of industrial processes. In cooling systems, for example, a consistent supply of makeup water helps maintain cooling effectiveness, ensuring that equipment operates at the desired temperature and efficiency.
- Water Conservation: While makeup water systems supply fresh water, they can also be designed to optimize water use and minimize waste. Water treatment processes can help recycle and reuse water to reduce overall consumption.
- Compliance and Environmental Responsibility: Meeting water quality standards and regulatory requirements is essential for environmental compliance. Makeup water systems play a role in ensuring that industrial facilities adhere to these standards and minimize their environmental impact.
In summary, makeup water systems are essential components in industrial processes and facilities, ensuring the reliable and efficient operation of equipment while managing water losses and maintaining water quality. They contribute to water conservation efforts, compliance with regulations, and the overall sustainability of industrial operations.
Feed water pump
A feed water pump is a critical component in various industrial processes, particularly in steam power plants and boilers. Its primary function is to deliver water from a water source to the boiler, where it is converted into steam to generate electricity or provide heat for industrial processes. Here's how a feed water pump works and why it's important:
Operation of a Feed Water Pump:
- Water Source: The feed water pump begins its operation with a water source, which can be a reservoir, river, well, or other water supply. This source provides the raw water that will be converted into steam.
- Water Treatment: Raw water is often treated to remove impurities and ensure it meets the required quality standards. Water treatment processes may include filtration, chemical treatment, softening, and demineralization.
- Pump Operation: The feed water pump is responsible for pressurizing and delivering the treated water to the boiler. These pumps are typically high-pressure, centrifugal, or positive-displacement pumps designed to handle the demanding conditions of boiler feedwater.
- Boiler Supply: The pressurized water is directed into the boiler, where it is heated to produce steam. In the boiler, the water undergoes a phase change from a liquid to a gas as it absorbs heat. This steam is then used for various applications, such as driving steam turbines in power plants or providing heat for industrial processes.
Importance of Feed Water Pumps:
- Maintaining Water Levels: Feed water pumps play a crucial role in maintaining the appropriate water levels in the boiler. Insufficient water supply can lead to overheating and equipment damage, while excess water can cause inefficiencies and water carryover issues.
- Efficiency: A reliable feed water pump ensures that the boiler operates at its desired efficiency levels. Proper water circulation and heating are essential for efficient energy conversion.
- Preventing Damage: Feed water pumps help prevent equipment damage and corrosion by ensuring that the boiler receives a continuous supply of high-quality water.
- Safety: Proper water levels and supply are vital for safe boiler operation. Low water levels can result in overheating, while high water levels can cause water carryover and damage downstream equipment.
- Regulation: Feed water pumps are equipped with control systems and monitoring instruments to regulate water supply and ensure that water levels are maintained within safe and optimal ranges.
In summary, feed water pumps are critical components in power plants, boilers, and industrial processes that rely on steam generation. They ensure the delivery of treated water to the boiler, facilitating the production of steam for electricity generation and industrial heating applications. Properly functioning feed water pumps are essential for equipment longevity, efficiency, and overall operational safety.
An economizer is a heat exchanger device commonly used in steam power plants and industrial boiler systems to improve energy efficiency. Its primary function is to capture waste heat from the flue gases leaving the boiler or furnace and use it to preheat the feedwater entering the boiler. Here's how an economizer works and why it is important:
Operation of an Economizer:
- Flue Gas Heat Recovery: The economizer begins its operation after the combustion process in the boiler or furnace. As fuel is burned, it releases heat energy, which is used to produce steam or heat a fluid. The combustion process generates hot flue gases, which contain a significant amount of heat energy.
- Economizer Installation: An economizer is typically installed in the flue gas stack or ductwork downstream of the boiler or furnace. It consists of a series of tubes or finned surfaces through which the flue gases pass.
- Heat Exchange: The hot flue gases flow through the economizer's tubes or surfaces. Simultaneously, the feedwater that is on its way to the boiler also passes through the economizer. The feedwater is heated by absorbing heat from the hot flue gases, preheating it before it enters the boiler.
- Preheated Feedwater: After passing through the economizer, the feedwater is significantly warmer than it was before. This preheating process reduces the amount of heat energy needed in the boiler to convert the water into steam. The warmer feedwater requires less fuel to reach the desired steam temperature and pressure, resulting in improved energy efficiency.
Importance of Economizers:
- Energy Efficiency: Economizers are crucial for improving the overall energy efficiency of industrial boilers and power plants. By preheating the feedwater, they reduce the amount of fuel required to achieve the desired steam conditions, leading to energy savings.
- Fuel Savings: The reduced fuel consumption resulting from economizer use translates into cost savings for industries and power plants. Lower fuel consumption not only reduces operational expenses but also lowers greenhouse gas emissions.
- Extended Equipment Life: Economizers help reduce the temperature of the flue gases exiting the boiler. This can help mitigate the potential for corrosion and thermal stress on downstream equipment, extending their operational lifespan.
- Environmental Benefits: By lowering fuel consumption and emissions, economizers contribute to environmentally responsible industrial practices, aligning with sustainability goals and regulations.
- Conservation of Resources: Economizers help conserve valuable resources, such as fuel and water, by making the most efficient use of them in the steam generation process.
In summary, economizers are vital components in industrial boiler systems and power plants, as they recover waste heat from flue gases and use it to preheat feedwater. This process significantly improves energy efficiency, reduces fuel consumption, lowers operational costs, and supports environmentally friendly practices, making economizers an essential part of energy-efficient and sustainable industrial operations.
Uses of Thermal Power Plant
Thermal power plants are versatile and widely used for generating electricity and providing heat for various industrial processes. Here are some of the primary uses of thermal power plants:
- Electricity Generation: The most common use of thermal power plants is for the generation of electricity. These plants produce electrical power by converting thermal energy, usually from the combustion of fossil fuels or nuclear reactions, into mechanical energy and then into electrical energy through generators. This electricity can be distributed through power grids to homes, businesses, and industries for various purposes.
- Industrial Processes: Thermal power plants can provide high-temperature steam and hot water, which are essential for numerous industrial processes. Industries such as manufacturing, chemical processing, food production, and papermaking rely on thermal power plants to generate the heat needed for their operations.
- Heating and District Heating: In some regions, thermal power plants are used to provide district heating systems. They distribute hot water or steam through a network of pipes to heat residential and commercial buildings. This helps reduce the reliance on individual heating systems and is particularly common in cold climates.
- Desalination: Thermal power plants can be used for desalination processes. The waste heat produced during electricity generation is used to evaporate seawater and then condense it into fresh water. This is especially valuable in arid regions where fresh water is scarce.
- Cogeneration (Combined Heat and Power): Some thermal power plants are designed for cogeneration, which means they simultaneously produce electricity and useful heat. Cogeneration systems are highly efficient because they maximize the utilization of thermal energy. The excess heat can be used for space heating, industrial processes, or other applications.
- Steam Propulsion: In marine applications, such as ships and naval vessels, thermal power plants are used to provide steam propulsion. These plants generate steam to drive turbines, which, in turn, power the ship's propulsion system.
- Drying Processes: Industries that require drying as part of their manufacturing processes, like the paper and textile industries, often use thermal power plants to supply the necessary heat for drying.
- Research and Development: Thermal power plants are used in research and development settings to study the efficiency of various energy conversion processes, test new technologies, and explore ways to reduce emissions and improve overall performance.
- Emergency and Backup Power: In some cases, thermal power plants serve as emergency or backup power sources for critical facilities, such as hospitals, data centers, and military installations. These plants can quickly provide electricity in the event of grid failures or other emergencies.
- Peak Load Balancing: Thermal power plants can be used to balance peak loads in power grids. They can be quickly brought online to meet high electricity demand during peak usage times, helping to stabilize the grid.
The versatility of thermal power plants makes them integral to various sectors of the economy, ensuring a reliable supply of electricity, heat, and other essential services to meet the needs of modern society. However, it's worth noting that there is growing interest in renewable energy sources to reduce the environmental impact associated with traditional fossil fuel-based thermal power generation.
Water Circulation System in Thermal Power Plant
Open Water Circulation System
In an open water circulation system water for cooling the exhaust steam in a condenser may be circulated from a river or canal by pumps. After use this water is returned to the river or canal.
Close Water Circulating System
In this system, water is obtained from a tube well and stored in a tank, from which it is pumped into the condenser. The water produces heat from the exhaust steam and gets warm. This hot water is passed to a cooling tower where the water falls from a height of 8 meters to 10 meters. Through the bottom of the cooling tower. Water from the base of the cooling tower is pumped to the condenser and the cycle is repeated.
Site Selection for Thermal Power Plant
The following factors should be considered while selecting a site for the steam power plant.
- Prices of land should be reasonable and further extension should be possible in the future.
- The soil strength should be enough to withstand the weight of buildings and heavy machinery
- Enough quantity of water should be available for condenser and cooling purposes.
- It should be away from the populated area to minimize the environmental pollution.
- There should be enough place for storing fuel and for disposal of ash.
- Facilities infrastructure should exist for the transportation of fuel and machinery to the site.
- The cost of fuel should be less in the selected area. The station should be near the fuel station.
- The steam station should not be away from the load center in order to reduce the transmission cost and losses.
Advantages & Disadvantages of Thermal Power Plant
Here are some key advantages and disadvantages of thermal power plants:
- Reliable and proven technology. Thermal plants have been used for decades. The processes are well-understood.
- Provide a constant supply of power. Unlike renewables like solar or wind, thermal plants can generate power continuously.
- Economy of scale. Large thermal plants can produce electricity at low per-unit costs.
- Existing infrastructure. Thermal plants use existing transmission and distribution infrastructure for electricity.
- High load factor. Thermal plants typically have high capacity factors of around 70-80%.
- Low operational costs. Mature technology means lower costs for operations and maintenance.
- Pollution. Thermal plants produce considerable air pollution and greenhouse gases.
- Requires fuel. Dependent on the supply of coal, gas, or other fuels. Vulnerable to fuel price volatility.
- Water usage. Large amounts of water are needed for cooling and steam generation.
- Inflexible operation. Thermal plants cannot vary output quickly in response to demand fluctuations.
- Long time to build. Takes several years to construct large-scale thermal power plants.
- Land use. Thermal plants require sizable areas to accommodate equipment.
In summary, thermal power provides reliable, scalable power generation but with environmental impacts. Renewables are emerging as cleaner alternatives but currently lack the dispatchability of traditional thermal plants.