Cryogenic liquid automatic filling system and method

Abstract

The invention provides a cryogenic liquid automatic filling system and method. The filling system includes a filling pump; an inlet pipe is connected with a storage tank, and provided with an inlet control valve; two paths of the outlet pipes of the filling pump are provided, wherein one filling pipe is connected to a filling position, and a reflux pipe is connected to the filling pipe and returns back to the storage tank; the filling pipe is provided with an outlet control valve, and a pressure difference transmitter is arranged on the filling pipeline near the filling position; the reflux pipe is provided with a reflux valve; a weighing device is arranged in the filling position; a liquid level gauge is arranged in the storage tank; a thermometer is arranged on the filling pump; and a controller is respectively electrically connected with the inlet control valve, the outlet control valve, the pressure difference transmitter, the reflux valve, the weighing device, the liquid level meter and the thermometer. The cryogenic liquid automatic filling system and method automatically realize precooling and filling; and the filling process is stable, safe and efficient, and greatly reduces labor costs.

Description

technical field [0001] The invention relates to air separation technology, in particular to a cryogenic liquid automatic filling system and method. Background technique [0002] With the continuous development of the national economy and the continuous improvement of the industrialization process, the gas industry has developed rapidly, and the market demand for cryogenic liquids has continued to rise. The current means of transportation for cryogenic liquids is mainly high-vacuum cryogenic tankers. Due to the high production cost of cryogenic liquids, during the transportation of liquids, the loss of cryogenic liquids should be strictly controlled to ensure the accuracy of filling volume and improve the safety operation awareness and operation skills of filling personnel. [0003] There are two main filling methods for cryogenic liquid tankers: pressure transmission (self-pressurized transmission) and filling pump filling. Pressure filling is to use the evaporator to vapo...

AI Technical Summary

Problems solved by technology

The opening and closing of liquid pumps and valves requires human intervention. This control method is more dependent on people, and the pressure is controlled based on experience. The operation process is more complicated. If the time is too long, it will cause energy loss; if the time is too short, the filling efficiency will be reduced

The time control of the cold pump is arbitrary. In the event of an emergency in the liquid filling process, there is no mandatory cut-off measure. Especially when filling gases with a high risk factor such as liquid oxygen and liquid hydrogen, manual control poses a greater safety hazard

[0006] The on-site PLC controls the switch of the pump and valve, and the pre-cooling state of the pump can be controlled by the on-site PLC. Although this control method continuously feeds back through the relevant sensors, the automatic filling process can be realized, but because the PLC is not compatible with the weighbridge and analyzer Wait for the connection of peripheral equipment, so the automatic pump stop operation cannot be realized, and the pump stop requires human intervention, so the filling volume is not accurate enough.

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