How does a minimum flow bypass system work?
How does a minimum flow bypass system work?
External minimum flow bypass systems incorporate an external sensing transmitter, controller, conventional two way control valve and flow orifice assembly. An internal minimum flow bypass system incorporates all of the above components internal to the minimum flow bypass valve.
What is the response of a bypass control valve?
The bypass control valve also must exhibit rapid transient response in the open direction. In the case of dual pump simultaneous operation, the amount of flow to be recirculated to the reservoir will be equal to the normal bypass flow of one pump plus the full flow of the stand-by pump.
Which is the best on off bypass control?
On-off bypass control using flow switches and a solenoid valve is simple and relatively inexpensive. It does not waste energy and does not allow the pump to operate at the end of its curve. ARC valves and proportional controls are costly.
How are the bypass valves in an expander controlled?
The manufacturer of this system has developed a control strategy by which the bypass valves are controlled in the event of an expander trip. This enables the valves to precisely assume the position in which, in conjunction with the downstream orifice chambers, they precisely emulate the flow loss caused by the expander prior to the trip event.
Why is bypass ratio important in lift fan installation?
BPR is also quoted for lift fan installations where the fan airflow is remote from the engine and doesn’t physically touch the engine core. Bypass provides a lower fuel consumption for the same thrust, measured as thrust specific fuel consumption (grams/second fuel per unit of thrust in kN using SI units ).
When does the bypass switch return to normal?
When the link comes back up again, the bypass switch returns to bypass-off normal. Some bypass switches send a heartbeat packet through the monitoring appliance in order to ensure that the appliance is passing traffic.
What is the bypass ratio of a turbofan engine?
The bypass ratio ( BPR) of a turbofan engine is the ratio between the mass flow rate of the bypass stream to the mass flow rate entering the core. A 10:1 bypass ratio, for example, means that 10 kg of air passes through the bypass duct for every 1 kg of air passing through the core.
What happens when the bypass ratio is increased?
Quote: “When the bypass ratio is increased to 10-20 for very efficient low speed performance, the weight and wetted area of the fan shroud (inlet) become large, and at some point it makes sense to eliminate it altogether. The fan then becomes a propeller and the engine is called a turboprop.