1、 Overview

The unique design of the integrated V-cone flowmeter expands the flow measurement range and avoids some limitations of traditional differential pressure flowmeters, resulting in better performance. The YC-V series V-cone flowmeter is a conical flow restrictor suspended at the center of the pipeline, which obstructs the flow of the medium, reshapes the velocity curve, and measures media including water, steam, air, natural gas, coke oven gas, and organic gases. The medium conditions can range from deep low temperature to supercritical state. The working temperature is 450 ℃ and the pressure is 25Mpa. It can measure a high Reynolds number of 5 * 106 and a low Reynolds number of 8 * 103 or even lower. Generate a full-scale differential pressure signal ranging from less than 0.1 kPa to tens of kPa.

2、 Working principle

The integrated V-cone flowmeter is a differential pressure flow meter, and flow meters designed based on differential pressure principles have been in use for over a hundred years. The principle of differential pressure is based on the energy conversion principle in sealed pipelines, which means that for stable fluids, the flow rate is proportional to the square root of the flow velocity of the medium in the pipeline. When the medium approaches the cone, its pressure is P1. As the medium passes through the cutoff area of the cone, the velocity increases and the pressure decreases to P2. Both P1 and P2 are led to the differential pressure transmitter through the pressure tap of the cone flowmeter. When the flow rate changes, the differential pressure value between the two pressure taps of the cone flowmeter will increase or decrease.

The calculation formula used by the V-cone flowmeter for flow calculation is the same as other differential pressure flow meters, but its unique design of the cutoff element forces the medium in the center of the pipeline to flow around the cone, which has many advantages compared to other differential pressure flow meters. We can use the ideal state flow velocity curve distribution diagram to understand the performance of a conical flowmeter. The fluid in the pipeline is not subject to any interference or obstruction, which is what we call the ideal flow state. Its velocity distribution is uniform, with almost zero velocity near the pipe wall, * velocity near the center of the pipeline, and almost zero velocity near the pipe wall, due to the frictional force of the pipe wall on the medium. Due to the suspension of the cone at the center of the pipeline, it directly contacts the high-speed zone of the fluid, forcing the fluid in the high-speed zone to mix with the fluid in the low-speed zone near the pipe wall, thereby making the flow velocity uniform. So even if the flow rate is very low, the conical flowmeter can still generate the correct differential pressure through continuous action of high flow velocity between the fluid and the center of the pipeline. In reality, it is difficult to achieve uniform distribution of flow velocity, and any changes in the pipeline can have an impact on the fluid, such as bends, valves, diameter reduction, expansion, pumps, tees, etc. Cone flowmeters use cones to reshape the upstream flow velocity distribution curve, ensuring measurement accuracy even in extremely harsh conditions.

3、 Characteristics

Flow meter accuracy: ± 0.5%, ± 1.0%, ± 1.5%. The system accuracy should refer to the application conditions and the accuracy of the secondary meter.

Good repeatability: better than ± 0.1%

Range width ratio: Normally 10:1, it can be increased if necessary.

Low requirements for straight pipe section: The front 0-3D straight pipe section and the back 0-1D straight pipe section of the flowmeter can ensure measurement accuracy. Experimental results have shown that V-cone flow meters can approach single bent pipes or double bent pipes with different planes with little impact on accuracy.

Good long-term stability: The design of the cone shape ensures that the fluid flows through the cone in a gradual process without sudden changes, and the β value can remain unchanged for a long time. The instrument can be used for a long time without calibration.

Signal stability: All differential pressure flow meters will have "signal fluctuations", which means that even if the fluid is very stable, the signal generated by a throttling element will fluctuate. For orifice plates, the vortices formed after the throttling element are longer, and these long vortices will produce high amplitude and low frequency fluctuation signals, which will interfere with the reading of the differential pressure gauge. Cone flow meters will form small vortices downstream, producing low amplitude and high frequency fluctuation signals.

Small pressure loss: Due to the absence of protruding baffles, the pressure loss of the conical flowmeter is 3/4 lower than that of the orifice plate.

No retention dead zone: The "blowing" design of the cone does not have a dead zone, so there will be no accumulation of fluid debris, sticky slag or impurities on the cone.

The function of the mixer: The vortex generated downstream of the V-cone flowmeter is a short vortex, which can mix the medium downstream. Therefore, currently, while working as a flowmeter, the V-cone flowmeter can also be used as a static stirrer in many fields, which can quickly and fully stir the medium evenly.

4、 Application

Media: coal gas, natural gas (including humidity below 5%), various hydrocarbons (including humid HC gases), various rare gases (hydrogen, helium, argon, oxygen, nitrogen, etc.), wet chloride gases, air (including air containing water, SiO2 particles, and other suspended solids), flue gas, saturated steam (including two-phase flow of steam and water), superheated steam, water, etc.

Conditions: From cryogenic to supercritical state, with a maximum temperature of 450 ℃ and a pressure of 25Mpa.

Calculation: Each conical flowmeter is calculated using specialized software based on the properties, pressure, and temperature of the fluid. Users can choose the beta value based on their application conditions (composition of the measured medium, temperature, pressure, pipe diameter, * flow rate, common flow rate, * small flow rate, allowable * pressure loss).

Maintenance: The conical flowmeter is maintenance free and does not require regular maintenance and calibration.

5、 Installation diagram