Table of Contents
- 1 What is pump work in Rankine cycle?
- 2 Why is the first law of thermodynamics called the law of conservation of energy?
- 3 Which of these is sometimes neglected in a Rankine cycle?
- 4 What is net specific work output?
- 5 What is the net heat rejected in a Rankine cycle?
- 6 Why is a Rankine turbine more efficient than a Carnot engine?
What is pump work 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. Then the liquid is pressurized by the pump and goes back to the boiler.
Why is the first law of thermodynamics called the law of conservation of energy?
The exchanges of external work and heat complete the energy balance. That is why the first law of thermodynamics is referred to as the conservation of energy principle, meaning that energy can neither be created nor destroyed, but rather transformed into various forms as the fluid within the control volume changes.
Why is Rankine cycle is considered as most practical cycle?
The efficiency of the Rankine cycle is limited by the high heat of vaporization of the working fluid. This low steam turbine entry temperature (compared to a gas turbine) is why the Rankine (steam) cycle is often used as a bottoming cycle to recover otherwise rejected heat in combined-cycle gas turbine power stations.
Why is the Rankine cycle modified?
In order to overcome the above-mentioned difficulty, the Rankine cycle is slightly modified where the expansion stroke of the piston is stopped at point 5 by cutting the toe of the Rankine cycle and the steam is expanded at constant volume. …
Which of these is sometimes neglected in a Rankine cycle?
Which of these is sometimes neglected? Explanation: Pump Work is very small as compared to Turbine Work & so is often neglected. Explanation: The relation between Heat Rate & Efficiency is, Heat Rate = Efficiency of a Rankine Cycle.
What is net specific work output?
specific work output (Unit kW. For a gas turbine, the shaft work produced per unit mass of gas flowing through the turbine. It is equal to the shaft power divided by the mass flow rate of gas…. Preface.
How is net power calculated?
The metric unit for work is a joule. A joule is equal to one Newton-meter, which is the amount of work needed to move a 1 Newton force a distance of 1 meter. When you divide work by time, you get power, measured in units of joules per second.
How does a Rankine cycle work?
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 is the net heat rejected in a Rankine cycle?
The net heat rejected is given by Qre = H4 – H1 During a Rankine cycle, work is done on the fluid by the pumps between states 1 and 2 (isentropic compression). Work is done by the fluid in the turbine between stages 3 and 4 (isentropic expansion).
Why is a Rankine turbine more efficient than a Carnot engine?
Since Carnot’s principle states that no engine can be more efficient than a reversible engine ( a Carnot heat engine) operating between the same high temperature and low temperature reservoirs, a steam turbine based on the Rankine cycle must have lower efficiency than the Carnot efficiency.
What did Rankine contribute to the steam engine?
Rankine developed a complete theory of the steam engine and indeed of all heat engines. Together with Rudolf Clausius and William Thomson (Lord Kelvin), he was a contributor to the thermodynamics, particularly focusing on the first of the three thermodynamic laws.