Simple Rankine Cycle

The Rankine cycle or Rankine Vapor Cycle is the process widely used by power plants such as coal-fired power plants or nuclear reactors. In this mechanism, a fuel is used to produce heat within a boiler, converting water into steam which then expands through a turbine producing useful work.

What are the four process of Rankine cycle?

A combined heat and power boiler is equipped with the Rankine cycle to produce electricity. This cycle is composed of four key parts: the generation of high-pressure steam, a turbine, a condenser, and a pump. Steam is generated in the boiler and then transferred to the turbine.

Why do we use Rankine cycle?

Rankine cycle, in heat engines, ideal cyclical sequence of changes of pressure and temperature of a fluid, such as water, used in an engine, such as a steam engine. It is used as a thermodynamic standard for rating the performance of steam power plants.

Is a Rankine cycle a power cycle?

Steam Rankine cycle is known as one of the main power-generating cycles, which consists of four key devices, namely a boiler (heat exchanger), a steam turbine, a condenser (heat exchanger), and a pump, as illustrated in Fig.

What is Rankine cycle and its process?

The Rankine cycle is an idealized thermodynamic cycle describing the process by which certain heat engines, such as steam turbines or reciprocating steam engines, allow mechanical work to be extracted from a fluid as it moves between a heat source and heat sink.

What is the difference between Carnot and Rankine cycle?

Carnot cycle is a theoretical cycle whereas the Rankine cycle is a practical one. Carnot cycle ensures the maximum efficiency under ideal conditions, but the Rankine cycle ensures the operation in real conditions. The efficiency obtained by the Rankine cycle is always lower than that of the Carnot cycle.

How many processes are in Rankine cycle?

According to the T-S diagram given below, the ideal Rankine cycle consists of four processes. Process 1-2: Isentropic compression in a pump. The working fluid is pushed from low to high pressure in this chamber.

What is the unit of heat rate?

The heat rate is the quantity of heat required to produce 1 kWh (also known as Unit) of electricity. Its unit is kCal/kWh (but in certain cases it is kJ/kWh).

What is the formula for efficiency of Rankine cycle?

Thermal Efficiency of Rankine Cycle: In general, the thermal efficiency, η th, of any heat engine is defined as the ratio of the work it does, W, to the heat input at the high temperature, Q H. The thermal efficiency, ηth, represents the fraction of heat, QH, converted to work.

What is the pump in Rankine cycle?

The Rankine cycle system consists of a pump, boiler, turbine, and condenser. The pump delivers liquid water to the boiler. The boiler heated by the solar heat converts water to superheated steam. This steam is used to run the turbine which powers the generator.

What are the types of fuel used in Rankine cycle?

This section introduces the ideal cycle for vapor power cycle - Rankine cycle. Vapor power plants generate electrical power by using fuels like coal, oil or natural gas.

How do you make a Rankine cycle?

The Rankine cycle operates in the following steps:

1. 1-2-3 Isobaric Heat Transfer. High pressure liquid enters the boiler from the feed pump (1) and is heated to the saturation temperature (2).
2. 3-4 Isentropic Expansion. ...
3. 4-5 Isobaric Heat Rejection. ...
4. 5-1 Isentropic Compression.

Why is the Rankine cycle more efficient?

5: The effect of increasing the boiler pressure on the ideal Rankine cycle. Increasing the operating pressure of the boiler leads to an increase in the temperature at which heat is transferred to the steam and thus raises the efficiency of the cycle.

Is Rankine cycle reversible?

Although the ideal Rankine cycle is internally reversible, there are still external irreversibilities because of the temperature change in the heat addition process. The actual Rankine cycles deviate somewhat from the ideal ones. In actual Rankine cycles, the turbines and pumps are not isentropic.

What is Rankine cycle TS diagram?

thermal power plant works on principle of the Rankine Cycle shown in Fig. 2[5]The cycle consists of four processes: (1-2) Isentropic compression on pump; (2-3) Constant pressure heat addition in a boiler; (3-4) Isentropic expansion in a turbine; (4-1) Constant pressure heat rejection in a condenser.

Which heat is added in Rankine cycle?

Supplementary fining is done before the heat exchange between the condenser of brayton cycle and boiler of Rankine cycle. The fraction of total heat supplied that is used for supplementary heating is 0.2.

What is boiler pressure in Rankine cycle?

Boiler Pressure Typically most nuclear power plants operate multi-stage condensing steam turbines. The high-pressure stage receives steam (this steam is nearly saturated steam – x = 0.995 – point C at the figure; 6 MPa; 275.6°C).

Why is Rankine cycle less efficient than Carnot?

Energy rejection The thermal efficiency of a Rankine cycle is lower then that of a Carnot cycle operating between the same temperature levels. This is primarily because of the fact that the energy transfer as heat in the boiler does not take place at constant temperature in the Rankine cycle.

Who invented Rankine?

The Rankine scale (/ˈræŋkɪn/) is an absolute scale of thermodynamic temperature named after the University of Glasgow engineer and physicist Macquorn Rankine, who proposed it in 1859.

What is the difference between Rankine cycle and Brayton cycle?

Idealized Brayton- and Rankine-MHD cycles are considered for use in space. The Brayton-MHD cycle uses neon as the working fluid; the Rankine-MHD uses lithium. Both are seeded with cesium.