Final answer:
Water for cooling in a turbine engine is injected at the condenser, where steam from the turbo machinery is condensed by circulating around tubes filled with water from a cold source like a river, ocean, or cooling towers.
Step-by-step explanation:
Water is injected into a turbine engine at the condenser for cooling purposes. In a power plant, after steam has passed through the turbines, it needs to be converted back to water to be reused in the steam generators. This process happens in the condenser, where the steam is circulated around tubes carrying cooling water from a potential cold water source. This source can be a natural body such as a river or ocean, or it can be cooling towers designed specifically for this purpose. The warm water coming out of these tubes, which has absorbed heat from the steam, is then typically pumped back into the source, whether it is the lake, river, or cooled via cooling towers before being released or cycled back into the system.