What are the functions of nozzle, diffuser, and throttle valve in turbines and compressors?
In turbines and compressors, nozzles, diffusers, and throttle valves each play distinct roles in controlling fluid flow and energy conversion:
1. Nozzle
A nozzle in a turbine or compressor converts thermal or pressure energy into kinetic energy by accelerating the fluid flow. As the fluid passes through the nozzle, its velocity increases while pressure decreases. In turbines, this high-velocity flow then impacts the turbine blades to produce rotational energy. In compressors, nozzles control the entry of fluid to ensure optimal compression efficiency.
2. Diffuser
A diffuser has the opposite effect of a nozzle, gradually reducing the fluid’s velocity and converting kinetic energy back into pressure. In compressors, the diffuser slows down the high-speed compressed fluid from the impeller, increasing its pressure before it exits the compressor. In turbines, diffusers help to recover pressure from the exhaust flow, reducing losses and improving efficiency.
3. Throttle Valve
The throttle valve controls the fluid flow rate by restricting the passage through which the fluid moves. By partially closing the valve, it creates a pressure drop that reduces the fluid’s energy and flow rate. In turbines, throttle valves are used to regulate power output by adjusting the steam or gas flow entering the turbine. In compressors, they help in maintaining system stability and managing discharge pressure under variable load conditions.
- Nozzle: Increases fluid velocity, decreases pressure.
- Diffuser: Decreases fluid velocity, increases pressure.
- Throttle Valve: Controls flow rate and pressure, managing power output and stability.
Each component enhances performance and control of turbines and compressors by managing energy transfer effectively