Waste heat recovery boilers exploit the gas turbine exhaust and produce superheated steam at around 30 bar for the steam turbine genset. The most popular system is a system combined of two cycles gas cycle brayton cycle which works on higher temperatures and steam cycle rankine cycle which works on lower temperatures. Some sources cited in this paper may be informal documents that are not. It addresses the testing and calculating of turbinegenerator. Combined cycle gas turbine ccgt integrates two cycles brayton cycle gas turbine and rankine cycle steam turbine with the objective of increasing overall plant efficiency. In this typical example, of the 100% energy in the input fuel. In a backpressure steam turbine, energy from highpressure inlet steam is efficiently converted into electricity and lowpressure exhaust steam is provided to a plant process.
Design, manufacture and testing of a 2 kw npentane turbine were carried out. The turbine entry temperature in a gas turbine brayton cycle is considerably higher than the peak steam temperature. Steamturbine bypass system is being installed at a 250mw, 1by1 combinedcycle plant. Steamturbine principles and practice by croft, terrell, 1880publication date 1923 topics steamturbines. Modern combined cycle gas turbine ccgt plants, in which the thermodynamic cycle of consists of two power plant cycles e. Hp a and ip c valve bodies await receipt of actuators and valve gear. In other words thermal analysis of the ideal rankine. Combined gas and steam cogas is the name given to marine compound powerplants comprising gas and steam turbines, the latter being driven by steam generated using the heat from the exhaust of the gas turbines. The downstream heat recovery steam generator, hrsg is unfired, dual pressure units having natural circulation evaporators. C p steam generator tacgt aero pumps st generates electrical generates electrical figure 2 diagram of a combined cycle power plant in the turbine cycle, air is compressed to the operating pressure of the gas turbine and heated in a. The cycle includes superheating and reheating to prevent condensation at the. How exactly the exhaust pressure for a steam turbine is selected. Net work done ii now consider a combined cycle system. Steam enters the turbine at 3 mpa and 350 oc and is condensed in the condenser at a pressure of 10 kpa.
Director npti, nagpur costing of thermal power generation major cost is fuel cost in thermal power generation. To study the working of impulse and reaction steam turbines 4. The steam extracted from the npp steam turbine for feed heaters will expand in the turbine and give more power output. A vapor power cycle considers steam as the working fluid might be two phases the use of steam as working fluid low cost availability. Cycle complement each other to form efficient combinedcycles. Optimization of ccgt power plant and performance analysis. Rankine developed a complete theory of the steam engine and indeed of all heat engines. Steam turbines for ultrasupercritical power plants ge.
Combined heat and power technology fact sheets series. The steam turbine exhaust steam is next condensed into liquid water, which is then pumped back to steam generator to complete the cycle. The major components that make up a combined cycle are compressor, gas turbine, hrsg, and steam turbine as shown in fig. The results of analysis and evaluation of the irreversibility of htgr reactor system using a steam turbine cycle shows that the reactor is a component of the least efficient, 61. When an organic working fluid such as r4a is used in the rankine cycle, the cycle is sometimes referred to as. I understand that depending on the turbine size, there is a sweet spot at which the increase in efficiency by lowering the exhaust. Pump turbine question consider a coalfired steam power plant that produces 300mw of electric power. Energy conservation in steam turbine steam turbine. Boiler, turbine, condenser, pump, carnot cycle for steam, disadvantages of carnot cycle application, rankine cycle and. The efficiency analysis of different combined cycle power.
Brine defined in this study is separated hot water at a separated steam geothermal plant. In this way, some of the otherwise lost energy can be reclaimed and the specific fuel consumption of the plant can be decreased. Rankine cycle with regeneration and reheat pdf file 627. Study of equipment prices in the power sector esmap. Elec0047 power system dynamics, control and stability. The efficiency of the rankine cycle can increase by expanding the steam in the turbine in two stages, and reheat it in between. Nov 30, 2016 typically, a combined cycle power plant comprises of gas turbine generators fitted with either a once through steam generator otsg or a heat recovery steam generator hrsg and steam turbine s. Combined gas turbine and steam turbine integrated electric drive system coges in a coges system gensets are driven by gas and steam turbines. These losses are denoted by i, ii, iii and iv areas t x is the temperature of water used for cooling the condensate. The coal used has a heating value energy released when the fuel is burned of 29 300 kjkg. The most common type of combined cycle power plant utilizes gas turbines and is called a combined cycle gas turbine ccgt plant.
Combined gas turbine and steam turbine integrated electric. Vanita thakkar 17 more about rankine cycle with reheat more possibilities in reheat cycle. A turbine designed to do this is called a backpressure turbine. Download download rankine cycle with regeneration and reheat pdf file. Backpressure turbines the diagram shows the basic circuit. Show the cycle on a ts diagram with respect to saturation lines, and determine a the quality of the steam. This cycle makes use of the inherent characteristics of the gas turbine process, where combustion takes place and, following expansion in the turbine, heat is rejected at a. The distinguishing feature of combinedcycle power cc plant is the joint production of electricity from a gas turbine and steam turbine, where the high heat content of the gas turbine. Aug 19, 20 a condenser installed at the exhaust or low pressure end of the turbine receives and condenses the steam prior to it being pumped back to the boiler. Because gas turbines have low efficiency in simple. Steam flow forced through slits in stator ring purple, impinging on turbine blades, spinning turbine wheel red. The distinguishing feature of combined cycle power cc plant is the joint production of electricity from a gas turbine and steam turbine, where the high heat content of the gas turbine. Typically, a combinedcycle power plant comprises of gas turbine generators fitted with either a once through steam generator otsg or a heat recovery steam generator hrsg and steam turbines.
By bleeding steam from an intermediate stage in the expansion process. Principles of operation of a steam turbinewhen high temperature steam passes through a steam turbine. Bottoming cycles are seldom 1 economical, since the electricity is gener. Modelling of a watersteam cycle of the combined cycle. A combined cycle gas turbine ccgt integrates two cycles brayton cycle gas turbine and rankine cycle steam turbine with the objective of increasing overall plant efficiency. The combined cycle includes a turbine cycle gas turbine, which uses natural gas as fuel and a steam cycle. Modern steam power plants have steam temperature in the range of. The generator electricity output is tied to the amount of steam. In 1859, a scottish engineer, william john macquorn rankine advanced the study of heat engines by publishing the manual of the steam engine and other prime movers.
If the tailrace runs downhill, there is a corresponding loss of headthe wheel setting should have been lower. Mar 08, 2015 vanita thakkar 17 more about rankine cycle with reheat more possibilities in reheat cycle. Steam cycle power plants are often referred to as thermal power plants. The overall structure of the gas turbine and steam power plant are depicted in figure 5 and figure 6 respectively.
A turbine designed to do this is called a passout turbine. Consider a steam power plant operating on the ideal rankine cycle. Pdf power plant lecture notes chapter6 gas turbines. Effect of size on cost of gas turbine combined cycle units. A velocitycompounded impulse stage consist of a row of fixed nozzles followed by two or more rows of moving blades and fixed blades without expansion. In combined cycle, approximately 12 mw gt26 or 10 mw gt24 is indirectly produced by the steam turbine through the heat released in the gas turbine cooling. In the impulse turbine, the steam is expanded in fixed nozzles and remains at constant pressure when passing over the blades. Desuperheated steam is routed to sparger in steamturbine exhaust duct special report s t e a m t u r b i n e bypass systems a. The steam turbine is of bhel make having a capacity of 129 mw. Pdf power plant lecture notes chapter4 steam turbine. Reheating to a temperature less than the inlet temperature of steam in the hp turbine.
The turbine exhaust steam has a lower temperature than the superheated steam created when pressure is reduced through a prv. Combining the nuclear power plant steam cycle with gas. For solid fuels such as coal, this is the only practical power plant design, unless the solids are transformed to gases or liquids before combustion. Summary the ideal rankine cycle schematic and ts diagram. Steam power plant cycles simple vapor cycle and its components. Special report s t e a m t u r b i n e bypass systems. In the second, the socalled bottoming cycle, heat recovered from the hightemperature process is used to generate electrical power. The small steam turbine automatically reduces the pressure of steam from higher value to the required lower value. Light liquid and gas fuels can also use a gas turbine cycle or a combined gas turbinesteam turbine cycle, but these fuels. Design and testing of npentane turbine for 2 kw model of. This is accomplished by utilising the exhaust of gas turbine through a wasteheat recovery boiler to run a steam turbine.
In this thermodynamic cycle, water is pumped to high pressure. Combined cycle power plants the trend in power plant design is to generate power with a gas turbine and use the exhaust heat to generate steam that. Load shearing between prime mover over the entire operating range of combined cycle power plant. In this type, the total pressure drop expansion of the steam take place only in the first nozzle ring.
Comparison of combined heat and power generation plants. In modern gas turbine the temperature of the exhaust gases is in the range of 500. Steam turbines in combined cycles a performance test code for engineers worldwide asme ptc 6. Curtis turbine, rateau turbine, or browncurtis turbine are impulse type turbines. Large landbased electric powerplants built using this. Modeling of gas turbine engines, heat recovery steam generators, and combined cycles using pepse by gene l.
The power plant operates on a simple ideal rankine cycle with turbine inlet conditions of 5 mpa and 450oc and a condenser pressure of 25 kpa. This new edition gives readers the latest technological developments and practical examples from existing, stateoftheart combinedcycle plants. The leaving velocity and exhaust loss from a steam turbine may be likened to the tailrace loss of a water wheel. C p steamgenerator tacgt aero pumps st generates electrical generates electrical figure 2 diagram of a combined cycle power plant in the turbine cycle, air is compressed to the operating pressure of the gas turbine and heated in a. The topping cycle is a gas turbine cycle and the bottoming cycle is a nonideal reheat rankine cycle. The topping cycle of plant consists of two gas turbines of 115 mw capacity of ge make frame 9e.
For large industrial chp applications, an extraction condensing type of steam turbine can be used in a combined cycle plant with the steam turbine extracting a portion of the steam for process use. It addresses the testing and calculating of turbine generator. Small steam turbine 100 is designed for fueling generators and for electricity production. To find calorific value of a sample of fuel using bomb calorimeter. The highpressure steam then undergoes an isentropic expansion in a conventional steam turbine. Rankine cycler lab experiment manual turbine technologies. This is accomplished by utilising the exhaust of gas turbine through a wasteheat recovery boiler to run a. This example models a steam turbine system based on the rankine cycle. Together with rudolf clausius and william thomson lord kelvin, he was a contributor to the. The steam cycle is standard except for these modifications. This real cycle of the steam turbine unit differs from the ideal thermodynamic cycle apbbhta because of irreversible losses in the pump, steam pipe, turbine and condenser. Performance analysis of ccgt power plant using matlab. A schematic of the overall heat engine, which can be thought of as composed of an upper and a lower heat engine in series, is given in figure 8. Light liquid and gas fuels can also use a gas turbine cycle or a combined gas turbine steam turbine cycle, but these fuels.
Modelling of a watersteam cycle of the combined cycle power. Impulse turbine and reaction turbine nuclear power. In short, combining the gas turbine gt cycle with the npp can significantly increase the efficiency of both cycles and increases their power output. The gear can be found on the base frame, which also includes a complete oil kit. Jun 01, 2014 a combined cycle gas turbine ccgt integrates two cycles brayton cycle gas turbine and rankine cycle steam turbine with the objective of increasing overall plant efficiency. Running a steam turbine together with a steam reducing station. This project is dedicated to support the study of the 2 kw model of binary cycle power plant using geothermal brine as the energy source. The heat input to the combined cycle is the same as that for the gas turbine, but the work output is larger by the work of the rankine cycle steam turbine.
Combinedcycle plant simulation toolbox for power plant. The high pressure liquid water is then ready for its next pass through the steam generator to state 1 and around the rankine cycle again. Steam enters the turbine at 10 mpa and 500c and is cooled in the condenser at a pres sure of 10 kpa. The gas side of the system is same as the problem given in i. Reaction turbine 2 iii steam turbine operating range 2 3. Steam turbines in combined cycles american society of. The steam turbine is a turbine in which the potential energy of heated and compressed steam produced in a special device, a steam generator, or steam of natural origin for example, from geothermal springs is converted into kinetic energy when the steam expands in the turbine blade cascades and then into mechanical work on the rotating shaft. The stator for tr 100 is connected to the gear, which allows transformation of the rotations from the turbine rotor to the electricity for asynchronous generator. Such combined cycle power plants are capable of achieving electric generation efficiencies of over 50 percent. A gas power cycle considers air as the working fluid single phase a vapor power cycle considers steam as the working fluid might be two phases the use of steam as working fluid low cost availability high enthalpy of vaporization carnot cycle give maximum thermal efficiency but not be suitable to use for analyzing. This divides the velocity drop across the stage into several smaller drops. Steam turbine 1 content chapter description page i purpose 2 ii steam turbine types 2 2.
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