The combined cycle is a cycle that composed by two independent power cycles using different working fluids throw energy exchange. Gas-steam combined cycle is the cycle that combine the gas cycle (Brayton cycle) with steam cycle (Rankine cycle) through high temperature exhaust gas of turbine (or gas internal combustion engine) generate steam in the waste heat boiler, and then the steam was sent to steam turbine to generate power.
In electric power generation a combined cycle is an assembly of heat engines that work in tandem from the same source of heat, converting it into mechanical energy, which in turn usually drives electrical generators. The principle is that the exhaust of one heat engine is used as the heat source for another, thus extracting more useful energy from the heat, increasing the system's overall efficiency. This works because heat engines are only able to use a portion of the energy their fuel generates (usually less than 48%). In an ordinary (non combined cycle) heat engine the remaining heat (e.g., hot exhaust fumes) from combustion is generally wasted.
The Gas Generator Sets are being released a lot of heat when running (include the high-temperature exhaust gas, etc.), the principle of this system is heat into electricity. The specific process is the heat released through the gas generator of waste heat recovery boilers to generate steam, steam-driven turbine generator sets for power generation.
In recent years, because of the gas turbine single power and thermal efficiency has been greatly improved, especially in combined cycle theory research, product development and power plant operational practices become more mature, Current large-scale gas turbine power alone has more than 500MW, thermal efficiency over 40%; consisting of a combined cycle power has reached 700MW or more, Thermal efficiency of about 50-60% has been reached. Its thermal efficiency is high, not only far exceed the existing coal-fired steam turbine power plants, even more than the super-critical parameters of a coal-fired steam turbine power plants but also superior. The world combined-cycle power plant positive large-scale and efficient development.
1 Diesel (or Gas) Combined Cycle Power Plant
To meet the requirements of high efficiency and environmental friendliness in the production of power, we provide a power cycle process for stationary power plants utilising the exhaust heat of the lue gas of diesel engines for the production of live steam in a bottoming process. The steam is expanded in a steam turbine, which therefore produces electrical energy according to the Clausius-Rankine-cycle. This additional electrical energy is produced without any higher consumption of fuel, which is the most important advantage of the Diesel (or Gas) Combined Cycle (DCC).
● Waste heat boiler systems
including the system of the SP furnace, ACQ furnace, Superheater, soft water heater, dust collector, smoke box components, cleaning equipment, ash handling devices as well as flue gas process piping, etc.
● Power generation systems
including steam turbines,generators and other systems.
2 Combined Cycle Gas Turbine (CCGT) Power Plant
Combining two or more thermodynamic cycles results in improved overall efficiency, reducing fuel costs. In stationary power plants, a widely used combination is a gas turbine (operating by the Brayton cycle) burning natural gas or synthesis gas from coal, whose hot exhaust powers a steam power plant (operating by the Rankine cycle). This is called a Combined Cycle Gas Turbine (CCGT) power plant, and can achieve athermal efficiency of around 50-60%, in contrast to a single cycle steam power plant which is limited to efficiencies of around 34-42%. Many new gas power plants in North America and Europe are of this type. Such an arrangement is also used for marine propulsion, and is called a combined gas and steam (COGAS) plant. Multiple stage turbine or steam cycles are also common.
● Waste heat boiler systems
including the system of the heat recovery boiler, deaerators, condensers, Superheater, soft water heater, smoke box components, cleaning equipment, ash handling devices as well as flue gas process piping, etc.
● Power generation systems
including steam turbines, generators and other systems.