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What is the quenching and liquid blow phenomenon of the LNG Storage Tank?

Nov. 04, 2019

  The LNG Storage Tank is a storage tank dedicated to storing LNG. The LNG storage tank is a mezzanine storage tank. Since the liquid natural gas temperature is lower than -162 degrees Celsius, the LNG storage tank is also a low-temperature storage tank. In order to meet the requirements of liquefied natural gas, LNG storage tanks should be jacketed to ensure the temperature inside the tank. Many people may have heard that LNG storage tanks are quenching and liquid shocking, but they don't know what the situation is. The low-temperature storage tank manufacturers will give a brief introduction.

LNG Storage Tank

LNG Storage Tank

  Due to the intermittent nature of the LNG vehicle refueling, the equipment in the refueling station repeatedly starts and stops, and the opening or closing of the valve or the pump causes the flow velocity of the liquid in the pipeline to suddenly change, sometimes it may be a drastic change and the momentum of the liquid also changes. The pressure inside the pipe rises or falls rapidly, accompanied by the sound of liquid hammering, a phenomenon called a liquid hammer (or water hammer). The liquid impact will cause a drastic change in the pressure inside the pipeline, and the pressure will suddenly rise. In severe cases, the pipeline may burst, and the rapid pressure drop will cause the pipeline to be under pressure, which will cause the pipeline to be unstable and cause the pipeline to vibrate.

  Quenching refers to the rapid cooling of pipes or equipment in a short period of time. Due to the intermittent operation of the LNG refueling station, during the process of abruptly starting the refueling or unloading after the system is running, especially the running start may cause quenching. The quenching phenomenon will form a temperature gradient at the top and bottom of the pipeline, causing the pipeline between the two supports to flex. Due to the large flexural stress, the pipeline is at risk of breaking.

  As an LNG Transport Trailers Manufacturer, it is recommended preventing the occurrence of quenching and water hammer. In the design, the cold shrinkage of the pipeline caused by the low temperature characteristics of the medium in the pipeline should be taken into consideration and a reasonable pipeline compensation method should be set; before the gas station is operated Pre-cooling of equipment and pipelines must be carried out; the speed of opening and closing of pumps and valves must not be too fast during operation. It is recommended to use valves with longer strokes, such as low-temperature shut-off valves, to prevent sudden rise and fall of pressure.

  Cryogenic storage tank: The cryogenic liquid carbon dioxide storage tank uses the "combination, safety system valve" to work simultaneously with two sets of safety valves. When the safety valve is regularly checked, one side can be closed and the other side can continue to work to ensure the safe operation of the storage tank.

  Cryogenic Liquid Tank safety accessories should be inspected regularly. General pressure gauges, level gauges, safety valves, and sheet devices are calibrated or replaced annually. When the pressure inside the tank exceeds 1.6kg, the gaseous oxygen is released from the pressure control valve to ensure that the pressure inside the tank is constant and safe. The inspection of the pressure gauge mainly checks whether the range is in compliance with the requirements and whether the form is diaphragm type. Therefore, there must be venting pipes and valves. The working pressure of the tank is adjusted, and the pressure in the tank is adjusted by adjusting the pressure regulating valve RPE. When the boost regulating valve is adjusted, the tank is fully filled.

  The booster valve has a booster valve at the booster gas outlet. The connection method is: connecting a pipe from the inlet pipe or the outlet pipe, connecting to the external supercharger, and then connecting the above components in turn, then the outlet pipe after the safety valve, also called the return pipe, connecting Going to the venting tube of the tank, you can handle the problem of insufficient pressure.