Combined-cycle plants can adapt to electricity demand or production needs . This type of plants can operate at full capacity with high demand and can bring its operation capacity down to a 45% partial load. This allows the infrastructure to produce what is necessary, avoiding market imbalances or production surpluses.
What are the main components in a combined cycle power plant?
The major components of a combined cycle plant are a gas turbine, a heat recovery steam generator, a steam turbine, and balance of plant systems .
What is combined cycle power plant CHPP?
The approach is called “ combined heat and power ” (CHP). In stationary and marine power plants, a widely used combined cycle has a large gas turbine (operating by the Brayton cycle). The turbine’s hot exhaust powers a steam power plant (operating by the Rankine cycle). This is a combined cycle gas turbine (CCGT) plant.
What is the difference between HRSG and boiler?
Most of the HRSG’s are internally insulated so that expansion does not affect the external surfaces and the structures. Conventional boilers on the other hand are top supported and free to expand so the insulation is on the outside.
What happens to the availability in a combined cycle plant?
What happens to the availability in a combined cycle plant? Explanation: There is a great thermal irreversibility & a decrease of availability because of heat transfer from combustion gases to steam through such a large temperature difference. 4.
What is the advantage and disadvantage of combined cycle power plant?
Combined cycle plants use less fuel per kWh and produce fewer emissions than conventional thermal power plants , thereby reducing the environmental damage caused by electricity production. Comparable with coal fired power plant burning of natural gas in CCPT is much cleaner.
What is the efficiency of a combined cycle power plant?
The overall electrical efficiency of a combined-cycle power system is typically in the range of 50–60% — a substantial improvement over the efficiency of a simple, open-cycle application of around 33%.
What are the advantages of combined cycle power plant Mcq?
Cogeneration of heat & electricity is possible in a Combined cycle plants. Explanation: One of the major advantages of a combined cycle plants is the cogeneration of heat & electricity. 10. Efficiency of Natural gas fired Combined cycle plants is more than that of coal-fired plants.
Which type of boiler is used in combined cycle power plant?
Heat recovery steam generator
HRSG without afterburner is the most common type of boiler used in combined cycles. In fact, it is a heat exchanger in which the heat of gases is transferred to the steam-water cycle by convection.
How can you increase the efficiency of a combined cycle power plant?
Efficiency of combined cycle power plant may be improved by reducing internal irreversibility of processes in the thermodynamic cycle of the power plant . It is necessary to transfer between working substances of gas and steam cycles considerable part of the heat, supplied in the gas cycle.
What is the environmental impact of a combined cycle plant?
Combined-cycle technology uses both a gas turbine and a steam turbine to generate electricity burning natural gas, a fuel with a lower environmental impact than other fossil fuels . The exhaust heat from the gas turbine is used to generate steam, generating electricity twice and minimizing waste.
How does a duct burner work?
Duct burners use supplementary firing to increase the heat energy of a gas turbine’s exhaust(GTE) ,making it possible to increase the output of a downstream heat-recovery steam generator (HRSG). Grid type systems were designed to reduce the pressure drop and spread the heat out across the duct.
What is duct firing in combined-cycle?
Duct firing in the heat recovery steam generator (HRSG) of a gas turbine combined cycle power plant is a commonly used method to increase output on hot summer days when gas turbine airflow and power output lapse significantly .
What is the difference between combined-cycle and cogeneration?
Co-generations uses waste heat for many different processes, such as space heating or drying. Combined-cycle power generation is a two-cycle electricity generation process that uses the heat from the first cycle to run a second cycle.
Where is HRSG used?
Heat recovery can be used extensively in energy projects . In the energy-rich Persian Gulf region, the steam from the HRSG is used for desalination plants. Universities are ideal candidates for HRSG applications. They can use a gas turbine to produce high reliability electricity for campus use.
What is pinch point in HRSG?
Pinch point is the difference between the gas temperature leaving the evaporator and saturation temperature =Tg3-ts. Fig 1: HRSG temperature profiles. Approach point is the difference between saturation temperature and feed water temperature entering the evaporator= ts -tw2.
What is the difference between HRSG and Whrb?
A waste heat recovery boiler (WHRB) is different from a heat recovery steam generator (HRSG) in the sense that the heated medium does not change phase .
What is the difference between simple cycle and combined-cycle?
Simple cycle efficiencies are in the range of 35% to 40%, while combined cycle efficiencies are in the range of 55% to 61% . For every MW generated, a combined cycles burns about 35% less fuel than a simple cycle and, consequently, produces 35% less carbon dioxide. Fewer starts means less CO generation.
How do you calculate combined-cycle efficiency?
The combined cycle efficiency is the total work output divided by the heat input of the topping cycle .
What is the thermal efficiency of a combined-cycle?
Advantages and Features that Make the GTCC the Mainstream for New Thermal Power Generation Facilities. In comparison with thermal efficiency of about 40% in steam power generation, combined cycle power generation features a thermal efficiency of at least 60% (with both figures on the lower heating value basis).
