The method is called regenerative feed heating and the cycle is called the regenerative cycle. This is implemented by extracting or bleeding small quantities of steam from suitable points throughout the turbine stages, utilizing the heat content of the extracted or bled steam.
What is the purpose of feed heating?
Introduction. A feedwater heater is used in a conventional power plant to preheat boiler feed water. The source of heat is steam bled from the turbines, and the objective is to improve the thermodynamic efficiency of the cycle.
What are the effects of regenerative feed water heating for the same turbine output?
Explanation: Effect of regeneration: (i) Efficiency increases & heat rate decreases, due to increase in mean temperature of heat addition. (ii) For the same turbine output steam flow increases (a bigger boiler is required) due to bleeding of steam to heat the feed water.
What is the effect of regenerative feed water heating on the size capacity of boiler and condenser Why?
Explanation: Increase in steam rate increases by regeneration, i.e., more steam has to circulate per hour to produce unit shaft output. Hence, it increases boiler size. Sanfoundry Global Education & Learning Series – Power Plant Engineering.
What is the purpose of feed water heater in regenerative Rankine Cycle?
A feedwater heater is a power plant component used to pre-heat water delivered to a steam generating boiler. Preheating the feedwater reduces the irreversibilities involved in steam generation and therefore improves the thermodynamic efficiency of the system.
What is the basic principles of regeneration?
What is the basic principle of regeneration? Explanation: In regeneration steam from condenser is circulated through turbine to increase steam temperature before it enters boiler. Explanation: Feedwater is preheated so as to decrease the fuel consumption which increases efficiency.
What is a regenerative cycle?
Definition of regenerative cycle : a cycle in a steam engine using heat that would ordinarily be lost: such as. a : a multiple-expansion steam-engine cycle in which the receivers are used as successive feed-water heaters.
When regenerative process is used in steam turbine when increased?
Irreversible engines—Open cycles 8.5 can be related to the specific enthalpy of the flue gases at state 5, h5, using the effectiveness of the heat exchanger. It is defined as the ratio of the heat transfer from the hot to the cold stream to the maximum possible heat transfer.
Why is closed feed used with high pressure steam bleeding and open feed water heater is used with low pressure steam bleeding?
Closed feed water heater employs indirect mode of heat transfer, i.e extracted steam or bleed steam from the turbine transfers its heat indirectly to feed water in shell and tube heat exchanger. Since the steam and water are not mixing directly, so both steam and water circuits are at different pressures.
Why regeneration of steam is adopted?
Advantages of Regeneration cycle: Heat supplied to boiler becomes reduced. Thermal efficiency is increased since the average temperature of heat addition to the cycle is increased. Due to bleeding in the turbine, erosion of turbine due to moisture is reduced.
What is reheat regenerative Rankine Cycle?
Reheat of reheat regenerative steam power cycle increases its efficiency by increasing the average temperature of heat reception. … The invention applies reversible reheating in addition to the regular reheating and uses smaller temperature differences across feed water heaters than the regular cycle.
What is the effect of reheat on steam quality?
The quality of steam at the exit of the turbine is improved by reheating i.e. x 4s > x 4’s, so blade erosion reduces because water droplets in exhaust become less. It may also be noted that as the reheat pressure decreases, the quality of steam in a turbine exhaust (x 4) increases.
What is regenerative cycle thermal efficiency?
The efficiency of the regenerative cycle may be defined as the ratio of the heat converted into work (in British Thermal Units per pound of steam) to the heat supplied to 1 lb. of steam in the boiler plant. … The object of the paper is to illustrate the advantage derived from working in terms of unavailable heat.
What is an open feed water heater?
An open feedwater heater is basically a mixing chamber, where the steam extracted from the turbine mixes with the water exiting the pump. In an ideal condition, the water leaves the heater as a saturated liquid at the heater pressure.
What are feed water heaters why they are used in steam power plants?
7 FEEDWATER HEATERS. The feedwater heaters are constructed of tubes through which feedwater is passed. The water is heated by steam from the turbine. The steam being at a higher temperature condenses on the outside of the tubes and gives up its latent heat to the feedwater.
Why boiler feed water is heated?
Boiler feedwater, consisting of fresh water plus returned condensate, is heated in the deaerator to full saturation temperature corresponding to the steam pressure. The purpose is to scrub out and carry away dissolved gases, especially oxygen.
What are the types of regeneration?
Types of regeneration : Regeneration is of two main type – Reparative and Restorative.
What is restorative regeneration?
The regeneration of severed body parts from a small left out fragment of the body is referred to as restorative regeneration. Thus, the correct answer is option B, ‘Formation of a new organism from a piece of the body of the parent‘.
Why is cellular regeneration important?
Regeneration is a natural process that allows plants and animals to replace or restore damaged or missing cells, tissues, organs, and even entire body parts to full function. Scientists are studying regeneration for its potential uses in medicine, such as treating a variety of injuries and diseases.
Does regeneration increase efficiency?
In the regeneration process, there is a reduction in heat supplied to the gas but there is no effect on the turbine and compressor work. Therefore, the regeneration will not increase the work ratio in the turbine but the efficiency of the turbine increases in the regeneration process.
What is regenerative gas turbine?
Regenerative is a thermodynamic process that utilizes the remaining energy in the exhaust gases from the gas turbine to heat the air entering to the gas turbine. This process can be made by heat exchange between the exhaust gases and compressed air by utilizing shell and tube heat exchanger.
What does the regenerative system on a gas turbine do?
Regenerators can be used for exhaust-gas heat exchange or for intercooling in gas-turbine systems. As an exhaust-gas heat exchanger, a regenerator recovers heat from the exhaust and uses it to preheat the compressed air before the compressed air enters the combustor.
How does a feed water heater affect the performance of a steam power plant?
The Feedwater heaters increase the Rankine cycle efficiency by raising the temperature of feed water that is piped into the steam generator, in such a way that the necessary thermal energy transferred to the steam to increase the enthalpy of the system will be lower. … This reduces the steam required by that heater.
Is a type of feed heater the steam mixed directly with feed water before entering the boiler?
Open or Direct Contact Feed Water Heaters: In open or direct contact feed water heater, the extraction steam is mixed directly with incoming sub-cooled feed water; to produce saturated water at extraction steam pressure Fig.
Which device utilizes the heat of steam for heating feed water?
Superheater: A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbines for electricity generation, steam engines, and in processes such as steam reforming.
What is heat reheat process?
Reheating is a method of improving Rankine cycle efficiency which consists of inter-stage heating of the expanding steam. After the first stage of expansion which typically reduces initial steam pressure by one-fourth, the steam is heated up (or close) to the maximum heat source temperature.