Rankine cycle steam engine

An external combustion engine that has been widely supported as a low-emission power source is the Rankine cycle steam engine. Many different types of expanders can be used to convert the energy in the working fluid... 

Power generation using steam or gas turbines is now well established, however power recovery by the pressure reduction of process fluids is more difficult and less common. In general, the equipment is not considered to be particularly reliable. Rankine cycle heat engines have been developed/adapted to use relatively low-grade waste-heat sources (particularly from organic fluids) to generate power in the form of electricity or direct drives. They tend to be used when the heat source... 

Frechette LG, Lee C, Arslan S, Liu YC (2003) Design of a microfabricated Rankine cycle steam turbine for power generation. In Proceedings of the ASME international mechanical engineering congress, Washington, DC, 16-21 Nov 2003... 

After investigating the electrochemical process first described by Sir William Grove in 1839, Ostwald in 1894 predicted that the twentieth century would become the Age of Electrochemical Combustion, with the replacement of steam Rankine cycle heat engines by much more efficient, pollution-free fuel cells (8. ... 

The basic steam cycle for a steam turbine installation is called a Rankine cycle (named after Scottish engineer and physicist William John Macquorn Rankine). This cycle consists of a compression of liquid water, heating and evaporation in the heat source (a steam boiler or nuclear reactor), expansion of the... 

A four-stage turbine with reheat and three-stage regenerative steam Rankine cycle as shown in Fig. 2.36a was designed by a junior engineer. The following design information is provided ... 

A closed-cycle steam Rankine cycle without superheating has been designed by a junior engineer as illustrated in Fig. 2.37a with the following preliminary design information ... 

The thermal efficiency of this cycle is that of a Carnot engine, given by (5.8). As a reversible cycle, it could serve as a standard of comparison for actui steam power plants. However, severe practical difficulties attend the operatk of equipment intended to carry out steps 2 3 and 4 1. Turbines that take i saturated steam produce an exhaust with high liquid content, which causes sevel erosion problems, t Even more difficult is the design of a pump that takes in mixture of liquid and vapor (point 4) and discharges a saturated liquid (poll 1). For these reasons, an alternative model cycle is taken as the standard, at lei for fossil-fuel-buming power plants. It is called the Rankine cycle, and diSei from the cycle of Fig. 8.2 in two major respects. First, the heating step 1 2 ... 

Steam-engine Economy.— The steam rate of an engine depends primarily on the initial pressure and superheat, back pressure and ratio of expansion. The following tables refer to perfect engines (Rankine cycle). The probable... 

Rankine cycle - A thermodynamic cycle which can be used to calculate the ideal performance of a heat engine that uses a condensable vapor as the working fluid (e.g., a steam engine or a heat pump). 

Rankine Cycle - The thermodynamic cycle that Is an Ideal standard for comparing performance of heat-engines, steam power plants, steam turbines, and heat pump systems that use a condensable vapor as the working fluid efficiency is measured as work done divided by sensible heat supplied. 

Consider a steam engine that operates in a Rankine cycle, as illustrated below ... 

Rankine cycle A cycle of operations in a heat engine. The Rankine cycle mote closely approximates to the cycle of a teal steam engine that does the Carnot cycle. It therefore predicts a lower ideal thermal efficiency than the Carnot cycle. In the Rankine cycle (see illustration), heat is added at constant pressure Pi, at which water is converted in a boiler to superheated steam the steam expands at constant entropy to a pressure pz in the cylinder heat is rejected at constant pressure pj in a condenser the water so formed is compressed at constant entropy to pressure p, by a feed pump. The cycle was devised by William Rankine (1820-70). 

This question has been around since Clausius invented the term in 1865, and the answer takes on many forms. Some follow the historical route, from steam engines, to Carnot, Clausius, Thompson, Joule, Rankine, and so on. A particularly lucid, concise account of this history is Purrington (1997). A central feature of this approach is Carnot cycles, as used by Clausius to deduce the existence of the entropy parameter. This approach is rather abstract, and needs some manipulation to be seen to be connected to thermodynamic potentials and chemical reactions. Others emphasize the impossibility of some processes, or the availability of energy, and some have a rather unique viewpoint, such as Reiss (1965), who considers entropy as the degree of constraint. ... 

Rankine cycle An ideal reversible thermodynamic cycle used in steam power plants (see Fig. 49) that more closely approximates to the cycle of a real steam engine than the Carnot cycle and converts heat into mechanical work. It involves water being introduced under pressure into a boiler and evaporation taking place, followed by expansion of the vapour without the loss of heat, ending in condensation. The cycle therefore consists of four stages i) steam passes from the boiler to the cylinder at constant pressure ii) the steam expands adiabatically to the condenser pressure iii) heat is given to the condenser at constant temperature iv) condensation is completed and the condensate is remrned to the boiler. In the Rankine cycle, the work done is equivalent to the total heat in the steam at the end of the adiabatic expansion subtracted from the total heat in the steam at the beginning of the expansion. The heat supplied is equal to the sensible heat in the condensed steam subtracted from the total heat. 

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