Steam turbine heat rate pdf

Heat rate optimization of coal power plants 26 28 january 2016, singapore. The majority of these chp steam turbines are used at. For firm performance values please contact the power generation team at elliott group. The average heat rates above are weighted by net summer capacity. It is the rate of heat input required to generate unit power. We live today in the era of revolutions in electronics and. Steam turbines are widely used for combined heat and power chp applications in the. The turbine heat rate of a steam turbogenerato is the ratio of thermal input. Using the steam property calculator, properties are determined using inlet pressure and the selected second parameter temperature, specific enthalpy, specific entropy, or quality. The trend in power plant design is to generate power with a gas turbine and use the exhaust heat to generate steam that provides additional power through a steam turbine. In this analysis energy efficiency, exergy destructions, exergy efficiency and turbine heat rates are evaluated at 40%, 50%, 60%, 70 % and 80 % maximum continuos rating condition of steam turbine. Pdf heat rate modeling in thermal power plants researchgate. Calculate the heat rate if steam enters a turbine at 400 o f at atmospheric pressure and leaves the turbine at 200 o f. The heat rate is the amount of energy required by an electrical generator or a power plant to produce one kilowatt hour kwh of electricity.

Ge gas turbine performance characteristics generator drive gas turbine ratings ge generator drive product line model fuel iso base heat heat exhaust exhaust exhaust exhaust pressure rating rate rate flow flow temp temp ratio. Steam at 500 lb flows through the turbine each hour during normal operation. Since a steam turbine is costly equipment a decision must be taken regarding replacing or retrofitting after careful consideration of actual technical condition and efficiency. Steam turbines are widely used for chp applications in the u. The efficiencies in table 1 are simplified values for the purpose of estimating industrial type steam turbine generators. The objective of this code is to determine the efficiency and heat rate for the. In this bottoming cycle process, of the 100% energy in the input fuel, typically. Because power is the rate of energy utilization, efficiency can also be expressed as a power ratio.

Coal combined cycle represents integrated gasification units. In certain cases, the efficiency of individual components like steam turbine is addressed specifically where performance deterioration is. In this study, effects of different flow rate on steam turbine isentropic efficiency and power plant performance have analyzed. It will be necessary to obtain the following operating data from the field. Some come at a high cost but also deliver much savings. First, consider the variation of the hourly heat consumed by the turbinegenerator with the load produced. How to calculate the steam turbine heat rate answers. Ger3945a steam turbines for ultrasupercritical power. A steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. The lp turbine outlet enthalpy depends on the condenser pressure. Even at best boiler efficiency, unit heat rate can be worse by 10 % due to high steam demand.

Practical steam turbine performance calculations using flex lives steam flex routine or by manual methods a steam turbine s power andor efficiency can be quickly and accurately calculated using flexwares steam flex steam properties program. Range and applicability of heat rate improvements unece. Analysis of heat rate improvement potential at coalfired. Ge gas turbine performance characteristics ge power systems ger3567h 1 table 1. Any other relevant data, such as anticipated capacity factor, or a weighting of various anticipated load points, should be specified to the turbine designer in requests for quotations.

Pdf performance analysis of a steam turbine power plant. Even best run units have potential for heat rate improvement. The performance of a power plant is influenced not only by the steam turbines, but also by the choice of steam turbine cycle. In general, most aeroderivative machines will require speedreduction. Its modern manifestation was invented by charles parsons in 1884 the steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple stages in the expansion of the steam, which results. It is british practice to specify performance and test at these four loads. Plant heat rate is a measure of the combined performance of the gas turbine cycle, the steam turbine cycle, and any other associated auxiliaries. Heat rate basics industrial wiki odesie by tech transfer. It is defined as heat energy used by the turbine cycle to generate one unit of electrical energy. Heat rate formula steam turbine heat rate calculation.

Heat rate can also be defined as the ratio between thermal power inputs to electrical power output. In its simplest form, a steam turbine consist of a boiler steam generator, turbine, condenser, feed pump and a variety of auxiliary devices. Performance monitoring is an essential tool for overall. In this paper, an attempt has been made to justify the operating turbine heat. The sequence of these activities is shown in figure 2. Where, rh is heat rate in btuhr, ws is steam flow in lbhr, c specific heat capacity in btulb. Final thermal power plant cover bureau of energy efficiency. It is recommended for use in conducting acceptance test of steam turbines and any other situation in which performance levels must be determined with minimum uncertainty.

Steam turbine rehabs improve heat rates power engineering. Heat rate improvements are a key enabling technology. Unlike gas turbine and reciprocating engine chp systems where heat is a byproduct of power generation, steam turbines normally generate electricity as a byproduct of heat steam. Performance 16 93 hiope the rankine cycle, the basic cycle used for electric power generation, mainly consists of four components. Ger4190 steam turbine thermal evaluation and assessment. In estimating the performance of a real steam turbine cycle offdesign it is essential to ensure that the flows as determined by heat balance conditions are compatible with the flowpassing.

Three basic phases can be distinguished in the process of steam turbine unit start. Power engineering examines how a steam turbine upgrade can help meet. Such combined cycle power plants are capable of achieving electric generation efficiencies of over 50 percent. The plant heat rate is the ratio of fuel energy into the plant. Since primary flow is measured in the feedwater line, any leakage. Impulse and reaction principles, compounding, velocity diagrams for simple and multistage turbines, speed regulationsgovernors and nozzle governors. Ger3582e steam turbines for stag combinedcycle power. Thermodynamic model and offdesign conditions steam power plants are operated by rankine cycle which includes steam boilers, steam turbines, condensers, heat exchangers, pumps and valves.

Effect of condenser backpressure on power plant heat rate and. Energy and monetary savings estimation the improvement in turbine performance parameters and the savings are as shown below. Figure 1 is an illustrative exhaust loss curve for a condensing steam turbine. This characteristic is known as willans line fig 1. In general, a steam turbine is a rotary heat engine that converts thermal energy contained in the steam to mechanical energy or to electrical energy. The industrial revolution began with the invention of a heat engine the steam engine. Unlike with reciprocating engines, for instance, compression, heating and expansion are. Ge power systems gas turbine and combined cycle products. Capacity test when a repeatable measurement of primary flow cannot be obtained, another practical, effective method of trending the performance steam turbine thermal evaluation and assessment ge power systems ger4190 2. Effect of condenser backpressure on power plant heat rate. Heat rate is reported at full load conditions for electric utilities and independent power producers.

Combined heat and power technology fact sheets series. Gross heat rate turbine speed compressor pressure ratio. The efficiency of the turbogenerator is simply calculated from this. The epas clean power plan calls for a 6percent improvement in heat rates, or fuel efficiencies, at coalfired power plants. This may include more than one gas turbine and steam turbine. Unit iii unit iii steam nozzles and turbines flow of steam through nozzles, shapes of nozzles, effect of friction, critical pressure ratio,supersaturated flow. Ge power systems gas turbine and combined cycle products ms9001h ms9001fb ms7001fb ms9001fa ms7001fa ms9001e ms7001ea ms6001fa ms6001c heavy duty output heat rate page two eight eight five six ten eleven seven thirteen fourteen igcc integrated gasification combined cycle overview sixteen small heavyduty and aero turbine products overview.

Isentropic efficiencies of steam turbines can range from 2090%. But some require little investment but provide substantial benefits. There are various upgrades available to reduce steam turbine heat rate. Heat rate can be further divided to compare units at the same plant, where you might compare power block 1 to power block 2. The principles of correct conducting startups have been developed over the longterm operation of steam turbines and contain experience of turbine designers, constructors and operators. Improving the heat rate in coal power plants ene day 1 steam power plants, steam generators, steam turbines, steam turbine auxiliaries. The specific enthalpy is then multiplied by the mass flow to get the energy flow. The repeatable determination of the turbine cycle heat rate also depends on cycle isolation. Curves for important parameters that affect the heat rate of the steam cycle. F, well, it is the rate of heat input required to generate unit power. At a presentation at power gen international, muhammad saqib riaz, manager steam turbine engineering at mitsubishi hitachi power systems explained. What is heat rate of turbinecycle heat rate is the heat input requiredper unit of power generated, forspecific fuel being fired and specificsite conditions. These steam turbine chp installations have an average capacity of 37 mw and a combined capacity of 26 gw, representing 32 % of the installed chp capacity in the united states.

Bee code cogeneration prepared for bureau of energy efficiency, under ministry of power, government of india. Heat regeneration causes a decrease in the mass flow rate through lowpressure stage of the steam turbine, thus increases lp isentropic turbine efficiency. This code provides procedures for the accurate testing of steam turbines. Achievable level of performance of a unit could be better than design \ guaranteed on account of margins. The heat of steam is converted to mechanical energy in the steam turbine and then to electrical energy in the generator. What is steam turbine description and characteristics. First step in decision making is assessment of energy performance of steam turbine, which requires heat balance calculations. Tandemcompound singlereheat supercritical steam turbine. Energy performance assessment of cogeneration and turbine bureau of energy efficiency 50 figure 3. Note that at the last stage of expansion the steam has very high specific volume.