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A Rankine cycle with two steam turbines and a single open feedwater heater. A feedwater heater is a power plant component used to pre-heat water delivered to a steam generating boiler. [1] [2] [3] Preheating the feedwater reduces the irreversibilities involved in steam generation and therefore improves the thermodynamic efficiency of the system ...
In this context they are often referred to as feedwater heaters and heat the condensate from turbines before it is pumped to the boilers. Economizers are commonly used as part of a heat recovery steam generator (HRSG) in a combined cycle power plant. In an HRSG, water passes through an economizer, then a boiler and then a superheater. The ...
Feedwater pumps range in size up to many kilowatts and the electric motor is usually separated from the pump body by some form of mechanical coupling. Large industrial condensate pumps may also serve as the feedwater pump. In either case, to force the water into the boiler, the pump must generate sufficient pressure to overcome the steam ...
Both effects will reduce the pipe's overall thermal efficiency when used as a heat exchanger. Boiler feedwater is the water which is supplied to a boiler. The feed water is put into the steam drum from a feed pump. In the steam drum the feed water is then turned into steam from the heat. After the steam is used, it is then dumped to the main ...
Pulp and Paper manufacturing plants; Refining units; Besides, they are frequently employed in power generation plants where large quantities of steam (ranging up to 500 kg/s) having high pressures i.e. approximately 16 megapascals (160 bar) and high temperatures reaching up to 550 °C are generally required.
Unlike conventional boilers the heat remaining in the exhaust gases is used to preheat the water supply for the main boiler using a secondary heat exchange mechanism. This mechanism, known as the feedwater heater is essentially a secondary boiler. The preheated feedwater is fed at full boiler pressure into the main boiler via clack valves.
The efficiency of a conventional steam–electric power plant, defined as energy produced by the plant divided by the heating value of the fuel consumed by it, is typically 33 to 48%, limited as all heat engines are by the laws of thermodynamics (See: Carnot cycle). The rest of the energy must leave the plant in the form of heat.
The purpose of the feedwater spray nozzle and the preheat section is to heat the boiler feedwater to its saturation temperature to facilitate stripping out the dissolved gases in the following deaeration section. The preheated feedwater then flows into the deaeration section (F), where it is deaerated by the steam rising from the sparger system.