Steam flow meters are more accurate and have better practicality. However, there are different measuring instruments in steam flow measurement. Therefore, the choice of these instruments will affect the flow meter results. For this reason, we need to analyze and select the right tool to achieve accurate measurement data.
1. The application of steam flow measurement principles
1.1 Ensure that the value of monitoring
Steam flow meters in the instrumentation and equipment have advanced levels. We can operate remotely regarding data collection, transmission, and analysis. Through the computer, the operation of the terminal will be able to break the time constraints, geographical restrictions, and spatial restrictions.
1.2 Real-time detection
The global real-time nature allows the operation of individual instruments and equipment to be monitored and the operating parameters of each link to be recorded in an automated manner. Therefore, we have to analyze the flowmeter according to its characteristics and gain a comprehensive understanding of the advantages of various metering instruments.
We should set up a scientifically sound remote monitoring system and optimize and improve it in conjunction with the actual operational requirements of the measurement project of the unit carrying out the measurement work—real-time monitoring of the meter data at each stage and dynamic data comparison.
1.3 Realising global detection
Effective global remote monitoring to quickly and accurately locate the causes of measurement data errors and then analyze the specific causes of errors or faults. As a result, minimize the chances of error events and control metering data effectively.
1.4 Selecting a standard measurement method
When we want to improve measurement accuracy, we should use appropriate and accurate measurement instruments. When we control the regular operation of steam flow meters, the standard way is to select the steam flow measurement method reasonably. At the same time, it is essential to choose throttling equipment that meets the relevant standards as far as possible so that staff can make intelligent differential measurements of the meter based only on the actual variation in flow rate.
2. Analysis of the causes of steam metering discrepancies
There is no absolute way to avoid steam metering discrepancies. However, significant errors can mean substantial economic losses. In general, the causes of steam loss discrepancies derived from metering instruments include errors in the device itself, and “zero error” cannot be achieved.
Therefore, no matter what method is used to reduce the variance, a detailed analysis of the causes of the conflict is required so that it can keep permissible errors within a specific range.
2.1 Temperature factors in the external environment.
Long steam pipelines pass through a number of different regions. When there is a significant temperature difference between regions, it isn’t easy to ensure the accuracy of the measurement instruments. Even when discrepancy analysis is carried out, it is impossible to recover 100% of the accuracy of the measurement under standard conditions, which in turn causes errors in steam delivery.
2.2 Accumulation of measurement instrumentation errors.
In measuring steam flow, measuring instruments are inevitably subject to measurement errors due to the limitations of multiple interfering factors. Although the size of each error is within the allowable range of control, the long transport pipeline means that many minor errors are accumulated, and the final comprehensive measurement results will produce significant errors.
3. Steam flow measurement methods
3.1 Vortex flowmeter
The vortex flowmeter is more frequently used, which has the characteristics of simplicity in the structure. The application process is easy to operate, and the initial installation and later maintenance are more convenient, which is why the vortex flowmeter is widely used mainly.
The vortex flowmeter sensor does not act directly on the base medium, so the application process does not produce too much wear and tear. As a result, it has a relatively long service life and can play a more significant energy-saving advantage.
Nevertheless, there are certain limitations in the use of vortex flow meters. In particular, the vortex flowmeter in the Reynolds number influence environment, the piezoelectric crystal installation options can only be stress type, which leads to the operation of the vortex flowmeter is easily affected by the surrounding environment, and thus the measurement data errors.
4. Selection path
4.1 Economic comparison
The use of steam flowmeter companies are generally thermal companies; according to their business requirements, thermal companies need to trade with thermal power plants.
Therefore, we should pay attention to two points in selecting the flowmeter: one is the accuracy level of the flowmeter must be high enough, and the other is the economic efficiency must meet the needs of the thermal company.
4.2. ancillary equipment
The vortex flowmeter’s measurement advantages over the throttling differential pressure flowmeter are more pronounced, but the flowmeter’s shortcomings are also more prominent. The vortex flowmeter can only display the volume flow rate under working conditions, leading to the flowmeter’s inability to achieve trade measurement effectively.
For the measurement needs, vortex flow timing is also equipped with RTD, pressure transmitter, and flow computer. As a result, the accuracy level of the vortex flowmeter is well 1.0, and the choice of long-necked, high-temperature type is suitable.
The RTD should be inserted at a depth of about 150mm, with a temperature casing, and the temperature measurement range to maintain between 0 ~ 400 ℃, the pressure transmitter pressure measurement range of 0 ~ 3MPa.
When we take the mechanical installation, vortex flowmeter vortex stability is poor. In order not to affect the vortex flowmeter vortex stability, the flow adjustment valve must be installed in the flowmeter downstream. In addition, to reduce the impact on the vortex stability of the vortex flowmeter, the pressure transmitter and RTD should also be installed downstream of the flowmeter. During installation, the worker will install the pressure transmitter first, followed by the RTD downstream at intervals of 1D to 2D.
When installation, the steam flow meter system should strictly follow national standards. Commonly used installation methods are mechanical installation and electrical installation, two kinds.
When we use mechanical installation, we need to pay attention to the problem of pipeline vibration. If the site’s steam pipeline vibration is intense or factors such as train travel trigger external vibration, a vortex flowmeter must be installed in the front and rear of the anti-vibration soft joints.
Through a comprehensive comparison, selection, and installation, combined with the needs of the thermal enterprise trade settlement, the steam measurement meter in the choice of vortex flow meter is more appropriate.
We choose the vortex flowmeter system for measurement work. The measurement results obtained were more accurate. Enterprises for the vortex flowmeter steam metering system to invest fewer resources, cost-effective excellent, worthy of steam measurement in a wide range of applications.