LNG storage tank automatic pre-cooling system based on efficient communication and pre-cooling method

Abstract

The invention provides an LNG storage tank automatic pre-cooling system based on efficient communication and a pre-cooling method. A CFD numerical simulation module is used for conducting pre-cooling process simulation, and initial flow parameters are provided for the pre-cooling process; and the point positions are installed on a storage tank in a modularized manner, and signal transmission between all sensors in the pre-cooling system and an integrated operation platform is achieved through 5G technology. According to the LNG storage tank automatic pre-cooling system and the pre-cooling method, limit values of parameters such as temperature drop rate, thermal stress, temperature difference between two adjacent points, inner tank pressure and the like are set on the basis of the integrated operation platform, monitoring results and the limit values are compared and analyzed, and then an electric control valve module and a variable frequency pump module are automatically adjusted, so that the conveying flow of a pre-cooling medium is adjusted, and it is guaranteed that the pre-cooling process is stably and safely carried out. According to the LNG storage tank automatic pre-cooling system and method, automatic, integrated and integrated control over the pre-cooling process can be achieved, monitoring personnel do not need to be arranged at monitoring points for a long time, potential safety hazards are avoided, manpower and material resources are saved, pre-cooling control is more accurate, and the pre-cooling efficiency is high.

Description

technical field [0001] The invention belongs to the technical field of LNG storage tank precooling, and in particular relates to an automatic precooling system and a precooling method for an LNG storage tank based on high-efficiency communication. Background technique [0002] LNG storage tank refers to a storage tank specially used to store liquefied natural gas, liquefied natural gas referred to as LNG. For LNG storage tanks, when low-temperature liquid suddenly flows into the normal temperature pipeline, the pipeline will shrink rapidly, the bottom of the pipeline is in direct contact with the low-temperature LNG, and the top temperature is higher, which will cause the "banana effect" of the pipeline, so the LNG storage tank needs to be inspected Pre-cool. [0003] In the current pre-cooling process, the initial parameters of pre-cooling usually use empirical data, which is poorly adaptable to different types of storage tanks, and reasonable parameters cannot be determin...

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Problems solved by technology

[0003] In the current pre-cooling process, the initial parameters of pre-cooling usually use empirical data, which is poorly adaptable to different types of storage tanks, and reasonable parameters cannot be determined for different types of storage tanks, resulting in blindness in the initial stage of pre-cooling operations; and the traditional The pre-cooling process mostly adopts the wiring monitoring method. The temperature and stress sensors are installed in the position where the storage tank is easy to observe. The installation position of the sensor is limited. It is difficult to wire and monitor the possible stress concentration, especially for large storage tanks. , and there are safety risks in the wiring process; in addition, it is difficult to read the instrument parameters in complex spaces, making it difficult to grasp the pre-cooling parameters in real time

[0004] In the traditional pre-cooling method, the staff manually calculates the temperature change rate and the temperature difference data between two adjacent points according to the temperature change, and manually adjusts the valve accordingly, resulting in delays, poor precision, and low timeliness in the adjustment process.

The pre-cooling process of LNG storage tanks lasts for a long time. Therefore, when using the traditional pre-cooling method, it is necessary to arrange special personnel to conduct regular inspections on the data of the monitoring points, which will waste a lot of manpower and material resources, and it is difficult to grasp the pre-cooling process in real time. Temperature changes and stress changes; at the same time, there is a risk of refrigerant leakage during the pre-cooling process, which cannot fully guarantee the safety of personnel

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