Large train crane pipe loading metering system

Abstract

The invention relates to a large train crane pipe loading metering system which comprises a naphtha flowmeter, a gasoline flowmeter and a diesel oil flowmeter, a large loading valve, a small loading valve, a stop valve and a crane pipe. The loading valves and the stop valve are located on an oil conveying header pipe, a naphtha pipeline and a gasoline pipeline are connected in parallel to be used in common, and the valves are arranged for loading type selection. The gasoline flowmeter is installed on the ground, the backpressure of the flowmeter is improved, oil product vaporization is prevented, oil product metering accuracy and the automatic metering level are improved, and the loading metering system is controlled by a DCS control unit. Flowmeter on-line calibration ports are reserved in the oil conveying header pipe. According to the large train crane pipe loading metering system, high-precision mass flowmeter on-line calibration is utilized, the problems of inaccurate metering caused by off-line verification of the flowmeters are solved, single train loading metering is achieved after the system is implemented, the largest error is smaller than 200 kg, the accuracy of the whole train is larger than 0.2, and a trade custody transfer metering method and the calibration method are accepted by oil product clients.

Description

technical field [0001] The invention belongs to the technical field of petroleum loading and metering, and relates to a quantitative loading and metering system of a large crane tube for a train, in particular to a quantitative loading and metering system for a large crane tube for a trade handover. Background technique [0002] Petroleum product loading measurement is an important link in petrochemical production and trade. Petroleum products are mainly transported to the factory by railway oil tank cars. The oil tank cars need to be loaded with crane pipes, and the measurement method is rail scale weighing or measuring ruler. The rail scale weighs the weight of the empty car before loading, and weighs the weight of the heavy car after loading. The weight of the heavy car minus the weight of the empty car is the weight of the oil product. The gauge measurement is to measure the oil level height with a gauge after loading, and calculate the weight of the loaded oil accordin...

AI Technical Summary

Problems solved by technology

The problem with these two methods is that the measurement process is cumbersome, the automation level and measurement accuracy are low, the manual workload is large, and they are easily affected by external factors, which cannot meet the needs of refined management of refining and chemical enterprises.

Loading with large crane tubes and using Coriolis mass flowmeters for measurement can solve the problems existing in the above-mentioned loading and measurement process. However, in the existing technology, the meter is installed at the highest point of the loading platform, and the back pressure of the flowmeter is lower than that of the oil product. Steam pressure, resulting in inaccurate measurement of the flowmeter, sometimes the difference of a single vehicle exceeds 200k, and the measurement error of the entire train loading is > 0.2%

As a custody transfer flowmeter, it must be verified every year. The flowmeter must be dismantled and sent to the flow laboratory for offline verification. After reinstallation, the installation status of the flowmeter needs to be adjusted several times and data comparisons are required to ensure accurate measurement, and it is not guaranteed to be loaded. Metering System Accuracy

Therefore, the quantitative loading measurement of the crane tube on the train is unstable and cannot be recognized by customers. It is difficult to use it as a custody transfer measurement method, and it has become a bottleneck restricting the measurement of refined oil railway loading and delivery in refining and chemical enterprises.

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