An automatic pressure supplement and pressure release process system for low-pressure tanks of atmospheric pressure tanks

Abstract

The present invention discloses an automatic pressurization and relief process system for low-pressure tanks of atmospheric tanks, which includes a user unit, a pressure supplementing unit, a pressure relief unit, and a PLC control unit. The user unit includes at least one atmospheric tank, and the atmospheric tank is equipped with a second A pressure supplement valve and a first pressure relief valve, the pressure supplement unit includes a high-pressure tank, the high-pressure tank is provided with a first regulating valve and a second regulating valve, and the pressure relief unit includes a first heat exchanger, a low-pressure tank, and a second heat exchanger , the low-pressure tank is provided with a gas-liquid material inlet, a liquid-phase material outlet, a second gas-phase material outlet, and a second liquid-phase material inlet. The first heat exchanger inlet is connected to the second regulating valve and the first pressure relief valve in parallel through a pipeline. The outlet of the first heat exchanger is connected to the gas-liquid material inlet through a pipeline, the inlet of the second heat exchanger is connected to the second gas-phase material outlet through a pipeline, the first outlet of the second heat exchanger is connected to the second liquid-phase material inlet through a pipeline, and the first regulating valve It communicates with the first pressure supplement valve through the pipeline, automatically supplements and releases pressure, eliminates non-condensable gas, and eliminates the emission of VOCs.

Description

technical field [0001] The invention relates to the field of petrochemical industry, in particular to an automatic pressure supplement and pressure release process system for a low-pressure tank of an atmospheric tank. Background technique [0002] Storage tanks are widely used storage equipment in petrochemical production. They are used to store various raw oils, semi-finished oils, refined oils, aromatic products and liquefied gas in the oil refining industry. Atmospheric storage tanks usually need to keep the operating pressure in the storage tank stable at all times and not exceed the set pressure. [0003] In the prior art, in order to ensure the stable pressure of the atmospheric storage tanks of petrochemical enterprises, one of the commonly used methods is to install a breathing valve to ensure that the pressure of the tank remains atmospheric. During the storage process, the emission of VOCs will continue to occur, which is called "big breath" exhaled emission and ...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, in order to ensure the stable pressure of the atmospheric storage tanks of petrochemical enterprises, one of the commonly used methods is to install a breathing valve to ensure that the pressure of the tank remains atmospheric. During the storage process, the emission of VOCs will continue to occur, which is called "big breath" exhaled emission and "small breath" exhaled emission, causing pollution; the second method is to set up a nitrogen blanketing system, although this method avoids chemical material tanks. Mix in air. When the pressure in the tank drops, supplement nitrogen instead of inhaling air, but when the pressure in the tank rises, it still needs to release VOCs to the atmosphere; method 3 is to connect the outlet of the breathing valve on the basis of method 1 or method 2, and concentrate The disadvantage of this method is that nitrogen or air is entrained, VOCs treatment is difficult, and VOCs emissions will still be generated after treatment

Images