Kondensaatioturbiinissa

Kondensaatioturbiinissa, or condensing turbine, refers to a type of steam turbine that operates in a condensed steam environment. In this configuration the turbine exhaust is cooled and condensed into a liquid, typically water, which is then reused as the turbine feed. The process allows for higher thermal efficiency because the exhaust pressure can be lowered to near vacuum, enabling further work to be extracted from the steam before it is condensed.

The basic operating principle involves expanding superheated steam within a series of stages. Each stage contains rotating blades that transfer kinetic energy from the steam to a rotor. After passing through the final rotor stage, the steam is expelled into a condenser where it condenses at nearly atmospheric pressure. The condensate is collected, cooled if necessary, and sent back to the boiler or feedwater heater. This closed-loop system maximizes the use of heat input, reduces water consumption, and limits steam losses.

Condensing turbines are employed in both power generation and industrial processes where high efficiency is paramount. Combined-cycle gas power plants use condensing steam turbines to recover waste heat from gas turbines, significantly raising overall plant efficiency. In process industries such as oil refining and chemical manufacturing, the condensate from a turbine can serve as a high-purity feedwater source.

Historically, condensing turbines emerged in the early 20th century as boiler and turbine designs advanced beyond simple single-stage machines. Advances in materials science, blade shaping, and vacuum technology have sustained their continued relevance. Advantages of the system include increased efficiency, reduced water usage, and lower emissions due to less fuel requirement. Disadvantages involve higher capital costs, the need for robust condenser infrastructure, and sensitivity to feedwater temperature fluctuations. Future developments focus on low-temperature condensers, advanced alloys, and integration with renewable heat sources, aiming to further improve efficiency and reduce environmental impact.