Economic flow rate? Fluid sound speed? Throttle? !

The throttle controls the maximum flow rate. Ignoring the economic flow rate, the maximum flow rate that can pass is achieved when the liquid flashes and the gas reaches sonic speed.

Which parameter controls the maximum flow velocity of the throttle element? Flow coefficient? The maximum flow rate corresponds to the maximum flow volume! Maximum gas flow velocity = gas speed of sound? What about the liquid? What is its maximum flow rate, without any phase change occurring? ! Thank you. . . . . . . .

Conversely, for a flow restrictor that is already installed in the pipeline (such as a flow control orifice), the flow rate increases as the pressure difference across it increases. 1. The gas flows until it reaches the sonic speed at the throat; at this point the pressure difference is at its maximum and the flow rate is also at its maximum. If the pressure downstream is reduced further (in an attempt to increase the pressure difference and thus the flow rate), the flow rate reaches its saturation point and no longer increases. In other words, for a gas, if the pressure P2 downstream can be maintained to satisfy the pressure difference for choked flow, then the maximum flow rate can be achieved. The maximum flow rate is related to P1, the orifice area, and Cp/Cv; it has no relation to the pipe size or the differential pressure across the orifice. Venting is a great example. If the pressure at P2 gradually increases, it is possible to \"escape\" from the condition of choked flow; in that case, the flow rate becomes related to the pressure difference, but it will definitely be lower than in the choked flow condition. As another example, during the transfer of gas between two tanks, a flow control orifice plate is used to regulate the rate of pressure release. At the beginning of the pressure release process, flow is at its maximum because of the obstruction (with atmospheric pressure on the downstream side); as the pressure in the lower-pressure tank gradually increases and the pressure difference decreases, the condition of obstruction is no longer present, and the flow rate drops. By drawing a Q-P1 curve, you can roughly predict the pressure relief time. 2. For liquids, it’s similar: the maximum flow rate occurs when the liquid inside the throttling element flashes. Without flashing, solve using Bernoulli’s equation for flow velocity Vs and pressure drop. The so-called flow-limiting orifice plate is used to limit the “maximum flow rate”. @jiaguoyun

Uh, okay, very detailed, thank you. . . . . .