The main task of a power plant is to convert energy from other forms such as chemical energy, nuclear energy, gravitational potential energy, etc. into electrical energy. There are different types of power plants and they are divided into several categories based on the primary energy and how they are converted into electrical energy, which is beyond the scope of this discussion. In general, in Iran, biofuel, fossil, geothermal, hydroelectric, nuclear, solar, wind and a limited number of other types of power plants are used to produce electricity. Obviously, each power plant needs its own equipment, depending on the type of working conditions, but some of these equipments are common among all power plants.
At the same time with the development of power plants and its modernization, the following should also be considered:
1- better use of existing power plants and facilities, 2- reduction of operating and maintenance costs, 3- cost reduction The fuel consumed by power plants, 4- new capacities, 5- technology to preserve the environment and renewable energies, 6- transmission.
Better use of existing power plants
Electrification companies do not always have a strong incentive to use the maximum potential of power plants and generate electricity to the maximum extent. Electricity production management companies are almost constant, as a result, in production management companies, the focus is only on building new power plants to improve the economic performance of existing power plants. Until 1997, the average capacity utilization rate of OECD power plants is only about 50%. The range of the average value for the countries is between 40% and 60%. The minimum value of the average utilization rate in other industries is 75%, which is higher than the average utilization rate of power plants.
Reduction of fuel costs
In a non-competitive system, fuel costs are simply passed on to the consumer. And this makes there is no longer the slightest incentive to minimize fuel costs. The regulator or the electricity regulation organization (= electricity market regulation board) in Italy has listed the lack of motivation as one of the reasons for the increase in fuel costs. In a competitive system, the incentive to use fuel better makes companies unable to impose or transfer fuel costs to their consumers or subscribers.
Decreasing fuel costs does not mean that there will be no need to increase the efficiency of power plants. It is obvious that at the same time with the serious reduction of power plant fuel costs, it is necessary to think about ways to improve the efficiency of power plants by using new technologies. It is necessary to improve the efficiency of the power plant in any way and in different parts of the power plant.
Power plant efficiency
The main activities to improve the performance of existing power plants are related to steam turbine and steam cycle technologies. Increasing the turbine efficiency from 1% to 10% is generally attainable, which increases the efficiency of the power plant by a few percent. Some turbine vendors and manufacturers have revolutionized the maintenance schedule and increased the efficiency of existing steam turbines.
They have also reduced maintenance costs. (eg: 1998 and Giovando). They have also upgraded the old gas turbines. (1999 and Valenti). Upgrading or using new process control systems for old power plants can improve fuel efficiency. Digital control systems, after monitoring the variables, transfer it to the computer program to measure fuel performance or power plant efficiency. If the fuel efficiency drops, the operator of the power plant or the control system can perform a corrective action.
Using cheap and low quality coal
If low-quality coal is used for boiler fuel in a power plant, of course there is a possibility of reducing the fuel cost, but it will cause a decrease in the efficiency or output of the boiler, and as a result, the repair and maintenance costs will also increase (Carpenter and 1998). The table below presents the data of power plants with the ability to use multiple fuels.
Power plants are trying hard to use cheap fuels along with the main fuel of their power plants, of course, without disturbing the operation of the power plant. . Worn and shredded car tires (worn and used tires), heavy fuel waste, urban waste, wood waste and other cheap materials known as feedstock, which are added to power plant fuel. Used tires are used even in cement factories. Oil coke is also a fuel that is used a lot in American coal-burning power plants and its consumption has grown a lot.