Pdf power plant lecture notes chapter2 steam power. A simple rankine cycle works between pressures 28 bar and 0. Assuming that 75% of this energy is transferred to the steam in the boiler and that the electric generator has an. The organic rankine cycle orc is a well known technology since the early 1980s. Optimizing an organic rankine cycle system for electricity generation from waste heat is a complex process, hence i need simulation package for application. Susan krumdieck1 1university of canterbury, private bag 4800, christchurch 8140 new zealand 2hamburg university of technology, germany.
Impulse turbine efficiency calculation methods with organic. Problems with the are solved using ees, and complete solutions together with parametric studies are included on the. Calculate the cycle thermal efficiency and the moisture content of the steam leaving the lowpressure turbine. Cold liquid at initial temperature is pressurized reversibly to a high pressure by a. The steam at the highpressure turbine inlet is at 1500 psia and 800 o f and the effluent is saturated vapor the steam is reheated to 750 o f before it enters the low pressure turbine where the steam is let down to 20 psia. Common examples of systems that contain more than one phase are a. Jan 21, 2020 the organic rankine cycle orc is named for its use of an organic, high molecular mass fluid with a liquidvapor phase change, or boiling point, occurring at a lower temperature than the water. Before you start this tutorial you should be familiar with the following. In this case the turbine operates at steady state with inlet conditions of 6 mpa, t 275. Saturated vapor enters the turbine at 9 mpa and saturated liquid exits the condenser at 0. Problems with the are solved using ees, and complete solutions together with parametric studies are included on the enclosed dvd. Calculate the cycle efficiency, work ratio and specific steam. The mercury rankine system has been under development for space applications for about eight years and many system problems have been solved.
The organic rankine cycle orc is named for its use of an organic, high molecular mass fluid with a liquidvapor phase change, or boiling point, occurring at a lower temperature than the water. The coal used has a heating value energy released when the fuel is burned of 29 300 kjkg. The mass flow rate of steam through the boiler for a net power output of 250 mw and the thermal efficiency of the cycle are to be determined. The steam at the highpressure turbine inlet is at 1500 psia and 800 o f and the effluent is saturated vapor. B power cycles with twophase media vapor power cycles. Concept of regenerative rankine cycle with feedwater heater will provide better positive result in respect of increase in thermal efficiency of the rankine cycle or in simple way we can say that thermal efficiency of the steam power cycle will be improved quite good by using the concept of regenerative rankine cycle with feedwater heater as compared with reheat cycle. There are several features that should be noted about figure 8. Impulse turbine efficiency calculation methods with. This lesson will help you gain more proficiency on the theoretical concepts which were discussed earlier on rankine cycle. The ideal regenerative rankine cycle the analysis of the rankine cycle using the second law showed that the largest exergy destruction major irreversibilities occurs during the heataddition process. Thermodynamic optimization of an organic rankine cycle for. Produces work from heat by wasting a fraction of heat input to a low temperature reservoir t oc s kjkgk 4 3 2 1 characteristics 1.
In the simple rankine cycle, steam flows to a turbine, where part of its energy is. In this lesson, harshit agarwal solves problems pertaining to brayton cycle. Then, you can go back and apply the 1st law to each process in the cycle to evaluate q and w s as need. What is the effect of increasing the boiler pressure on. A schematic of the components of a rankine cycle is shown in figure 8. Steam enters the turbine at 3 mpa and 350c and is condensed in thecondenser at a pressure of 10 kpa. By adoption of the working fluid to an existing waste heat. Consider condenser pressures from 10 kpa to 200 kpa. Calculate a the power input to the compressor, in kw. Calculate the thermal efficiency of a simple rankine cycle for which steam leaves the boiler as saturated vapor at 3 x 10 6 nm 2 and is condensed to saturated liquid at 7000 nm 2. Let assume the closed brayton cycle, which is the one of most common thermodynamic cycles that can be found in modern gas turbine engines. If heat absorbed by the engine q 1 10,000 joule, what is the work done by the carnot engine known. Jan 17, 2017 lecture series on steam and gas power systems by prof. Consider a simple ideal rankine cycle with fixed turbine inlet temperature and condenser pressure.
Figure another issue worth discussing heat from the super heated steam. Pump, carnot cycle for steam, disadvantages of carnot cycle application, rankine cycle and its components. Deviation of actual vapor cycle from the ideal rankine cycle click to view movie 46. Mercury has been contained successfully at the required operating temperatures, and operation in a zero g field has been demonstrated for brief intervals. Chapter 9 vapor and combined power cycles 927 941 also solved by ees on enclosed cd a steam power plant operates on an ideal regenerative rankine cycle with two feedwater heaters, one closed and one open. If an object has a weight of 10 lbf on the moon, what would the same object.
Normally in solving problems involving turbines, the turbine efficiency is. View homework help chapter 9 rankine cycle problems solutions. Design and build of a 1 kilowatt organic rankine cycle power. Neglecting change in kinetic and potential energy, the power required by the compressor is w c mh 2h 1 7. Engineering problem solving this video gives a brief overview of. To solve this problem, h 2 o requires a too high degree of. Thermodynamic properties naval sea systems command.
Rankine cycle thermodynamic simulator of knowledgebased. The steam is reheated to 750 o f before it enters the low pressure turbine where the steam is let down to 20 psia. By utilizing a reheat process inside the rankine cycle, it could practically solve the excessive moisture problem in the turbines. Isentropic compression water enters the pump as state 1 as saturated liquid and is compressed isentropically to the operating pressure of the boiler. In this case assume a helium gas turbine with single compressor and single turbine arrangement. One approach to solving cycle problems of this nature is to work your way around the cycle until you have evaluated all the properties to complete the table shown above. The cycle is shown on, and coordinates in figure 8.
Summary the ideal rankine cycle schematic and ts diagram. The following schematic of a simple rankine cycle consists of steam leaving a. Power plant lecture notes chapter2 steam power plant cycles. Rankine cycle, is the ideal cycle for vapor power plants. Gas power cycles our study of gas power cycles will involve the study of those heat engines in which the working fluid remains in the gaseous state throughout the cycle. Water is the working fluid in an ideal rankine cycle with reheat. Rankine cycle with isopentane as working fluid used as a recovery system is the most optimal solution. The rates of heat addition and rejection, and the thermal efficiency of the cycle are to be determmed.
If the mass flow rate of steam is 126 lb m s, determine a. Problem 921 calculate the thermal efficiency of a simple rankine cycle for which steam leaves the boiler as saturated vapor at 3 x 106 nm 2 and is condensed to saturated liquid at 7000 nm 2. If heat absorbed by the engine q 1 10,000 joule, what is the work done by the carnot engine. Let assume the rankine cycle, which is the one of most common thermodynamic cycles in thermal power plants. Pentane, instead of water therefore its called organic rankine cycle. Dahlqvist approved 20121016 examiner damian vogt supervisor jens fridh commissioner contact person 1 abstract a turbine was investigated by various methods of calculating its efficiency.
In this lesson, harshit agarwal solves problems pertaining to rankine cycle. It is then reheated to 400c and expands to 10 kpa in the lowpressure turbine. It has been read that a brayton rankine combined power plant produces 9 mw with the gas turbine and 2 mw with the steam turbine, with gases entering the gas turbine at 1. In the rankine cycle, the mean temperature at which heat is supplied is less than the. Rankine cycle is a heat engine comprised of four internally reversible processes. Class xi chemical thermodynamics chemistry carnot cycle solved numericals to get full chapters visit our.
The key is that the cycle is an ideal rankine cycle. Jan 23, 2020 the bleed level in regenerative rankine cycle depend on many issues. Steam is then reheated at constant pressure to 4500c before it expands in the lowpressure turbine. An introduction to thermodynamics applied to organic rankine cycles by. Brayton cycle reading problems 98 910 978, 984, 9108 open cycle gas turbine engines after compression, air enters a combustion chamber into which fuel is injected the resulting products of combustion expand and drive the turbine combustion products are discharged to the atmosphere. Therefore any attempt to reduce the exergy destruction should start with this process. First of all one of the most important thing is the numbers of regenerative heat exchangers because that depend on the fuel cost. Read pdf carnot cycle problems and solutions carnot cycle problems and solutions. Organic rankine cycle system includes five major types of equipment. An introduction to thermodynamics applied to organic. The ideal rankine cycle does not involve any internal irreversibilities and consists of the following four processes. We can use a rankine cycle to convert a fossilfuel, nuclear, or solar power.
Application of the first law of thermodynamics to the control. Ideal reheat rankine cycle the moisture content of the steam is increased to unacceptable level when the boiler pressure is increased. Tutorial questions reheat rankine cycle slideshare. From this equation we see not only the reason that the cycle efficiency is less than that of a carnot cycle, but the direction to move in terms of cycle design increased if we wish to increase the efficiency. The pump and turbine have isentropic efficiencies of 0. Problems designated by a c are concept questions, and students are encouraged to answer them all. The rankine cycle is the ideal cycle for vapor power plants. Its electrical output is 1741 kw, exergetic efficiency 27,6% and the system pays back in 6 years. Consider an ideal steam reheat cycle where steam enters the highpressure turbine at 3. A large amount of orc power plants have been built, mainly for geothermal, waste heat recovery and combined heat and power applications. This lesson will help you gain more proficiency on the theoretical concepts which were discussed earlier on brayton cycle. Organic rankine cycle orc power systems sciencedirect. In this case assume a simple cycle without reheat and without with condensing steam turbine running on saturated steam dry steam. Oct 09, 20 mechanical engineering thermodynamics lec 21, pt 1 of 5.
The condenser pressure, the net power output, and the thermal efficiency are. Popular applications include cogeneration from biomass and electricity generation from. The ideal regenerative rankine cycle concordia university. This technique is commonly used in modern steam power plants. One of key parameters of such engines is the maximum turbine inlet temperature and the compressor pressure ratio pr p. Mechanical engineering thermodynamics lec 21, pt 1 of 5.
Thermodynamics problem 5 steam leaves the boiler in a steam turbine plant at 2 mpa, 3000c and is expanded to 3. Exercise 1consider a steam power plant operating on the ideal rankine cycle. Technologies and applications provides a systematic and detailed description of organic rankine cycle technologies and the way they are increasingly of interest for costeffective sustainable energy generation. Introduction in this article, we present a numerical solver for the simulation of an organic rankine cycle orc for the study of cogeneration, i. Thermodynamic optimization of an organic rankine cycle for power generation from a low temperature geothermal heat.
Construct plots of the net power output of the cycle and the thermodynamic efficiency as functions of the operating pressure of the condenser. Rankine cycle the rankine cycle is the usual system adopted for conversion. The two common source of irreversiblities are the friction and undesired heat loss to the surroundings. The working fluid is usually water, but can also be organic fluid such as freon or butane which work at lower temperatures than. Ideal reheat rankine cycle efficiencysample calculation. Ideal reheat rankine cycle efficiencysample calculation free download as word doc. Solving with numerical values, we obtain the net power produced by the cycle per kgs. Thermodynamics i spring 14321433h 20112012h saturday. Various items for this system per unit of mass flow rate through the boiler are to be determined. Problems and solutions, chapter9 engineering thermodynamics.
He explains each single step while solving the problem and elaborates each concept associated with it. It consists basically of a high pressure boiler, a steam turbine, a condenser and a circulating pump to bring the liquid back to the boiler. Design and build of a 1 kilowatt organic rankine cycle power generator david meyer1, choon wong1, frithjof engel2 and dr. Carnot cycle problems and solutions solved problems in. Applied thermodynamics tutorial 1 revision of isentropic efficiency advanced steam cycles introduction this tutorial is designed for students wishing to extend their knowledge of thermodynamics to a more advanced level with practical applications. Lecture series on steam and gas power systems by prof. Impulse turbine efficiency calculation methods with organic rankine cycle johan e. It produces only small net power outputs for the plant size because dry saturated steam is used at inlet to the turbine.
231 114 744 149 633 291 359 1435 1122 296 80 1095 1108 843 213 138 1401 786 1290 264 1457 233 509 393 698 178 1413 1226 378 1026 1332 1449 1200 150 1425 880 1422 1381 550 110 291 1473 697 1201 850 1490 1424 1112