What is the maximum flow rate for high-pressure gases?
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RT, it’s used in our equipment; the total length of the pipeline is around 3-4 meters, the pressure is 6 MPa, and it uses compressed air. The flow rate is 1500 NM3/h; I think a pipe with an outer diameter of 3/4” and an inner diameter of 15.7 would be suitable, which would result in a flow velocity of around 35.7 m/s. There are also elbows and other fittings, and in some areas the diameter might be smaller, so the maximum flow velocity could reach 40 m/s. I’m not sure if this will work. .
Additionally, the section of pipe before and after this can withstand a pressure drop of up to 1 MPa.
For pure high-pressure dry compressed air, the optimal flow rate is 0.5 to 3 meters per second; for high-pressure waste steam, it is 80 to 100 meters per second. Have you taken into account the issue of pressure drop?
I don’t know what type of gas the original poster is referring to. If it’s waste steam, its flow rate is 80 when it comes from a pressurized container, and 15–30 when it comes from a container at atmospheric pressure. If it’s high-pressure waste gas, the flow rate is 80–100 (note the difference between gas and steam). If it is a compressed gas. 6 MPa, flow rate of 3 to 0.5 or higher. Note: 1. Deflated gas refers to gas whose pressure gradually decreases as air is released. 2 Compressed gas: the higher the pressure, the lower the flow rate.
The optimal flow rate for compressed air at this pressure level, used for transportation, is 0.5–3.0. Exceeding this flow rate is not only inefficient but also requires that both pressure and flow rate be met; as a result, the pressure upstream must increase accordingly, raising the safety requirements. All these factors can be measured with data; if you accept that data, then it’s not impossible
Second point: the higher the pressure, the lower the flow rate. The choice of flow rate depends on many factors, such as cost-effectiveness and safety (for example, too high a flow rate can lead to static electricity, noise, etc.). You can think of it this way: from an economic perspective, the higher the pressure, and the higher the flow rate as well, the greater the flow volume that can be transported through the same pipe; at the same time, more energy is required upstream. It is naturally uneconomical. So for the same pipe and the same flow rate, if the pressure is high, choosing a lower flow velocity makes it more economical. Above, I have only mentioned one way of understanding it. It should be noted that many people believe it is the flow rate that determines the pipe diameter. It’s not actually like that. It can be said that, under the conditions of a certain flow rate and pressure, the pipe diameter determines the flow velocity. After selecting different pipe diameters, check whether the flow rate is economical in order to choose an appropriate flow rate. The poster should refer to the recommended flow velocity values in the \"Chemical Process Handbook\" or the \"Technical Specifications for the Design of Process Systems\" (HG/T20570.6-95). These flow rates are based on experience from engineering practice.
It is discharged from a 40L cylinder, where the pressure of the gas inside ranges from 6 to 15 MPa; it is uncompressed air that is not dried (the air is pumped into the cylinder by an air compressor, and it contains saturated water). After passing through a pipe of about 3 meters, it goes to the pressure reducing valve; after that, it follows the normal process. It refers to the approximately 3-meter-long pipeline between the gas cylinder and the pressure regulator; due to construction and space constraints, the smaller it is, the better. I just want it to be able to flow through; it doesn’t matter if the flow rate is insufficient later on due to the small pipe diameter. According to the current design, the flow velocity should be around 40 m/s; I’m worried that the fluid won’t be able to pass through. When used on ships, saving space and weight represents the greatest economic benefit, regardless of the amount of energy loss. Of course, noise is not a factor to consider either.