CN202708596U - Liquefied natural gas (LNG) receiving terminal open rack vaporizer (ORV) gasification device suitable for working condition of sea water high in sand content - Google Patents

Abstract

An LNG receiving terminal ORV gasification device suitable for high-sand seawater working conditions, the seawater pipeline (2) is equipped with a grille (1) at the end of the water intake, and the other end is respectively connected to two mutually connected pipes (3) The standby natural sedimentation tank (4), the suction pipes (5) of the two mutually standby seawater pumps (6) respectively extend into the two natural sedimentation tanks, and the outlets of the seawater pumps are respectively connected to the ORV through the filter (7) Vaporizer (8). The utility model has the advantages of few moving elements, simple structure, low operation cost, energy saving, environmental protection and high safety.

Description

LNG receiving terminal ORV gasification device suitable for high sandy seawater conditions

technical field

The utility model relates to an LNG receiving terminal ORV gasification device suitable for high-sand seawater working conditions. The device can provide sand removal from seawater sedimentation, filter sand removal, and regasification of liquefied natural gas through an ORV open-frame gasifier. A full set of LNG gasification production process including seawater discharge and natural gas export.

Background technique

The LNG receiving station is the terminal station for receiving offshore LNG transportation, where LNG is received, stored, gasified, and exported to the downstream natural gas pipeline network. In the LNG receiving station, the gasifier is the main equipment of the gasification system. At present, the global LNG receiving stations mainly use four types of gasifiers, namely, the open rack gasifier (ORV), the submerged combustion gasifier ( SCV), liquid medium vaporizer (IFV) and ambient air vaporizer (AAV). An open frame gasifier is a heat exchanger that utilizes water as a heating source. At present, most of the LNG receiving stations in the world are built on the coast or near the beach, which is convenient for large ships to dock. Sufficient seawater has become the most commonly used heat source for open-frame gasifiers. Compared with fresh water resources, its low cost and sufficient resources are more advantageous. Considering that LNG will pass directly through the gasifier, the heat exchange tube bundle of the gasifier must be made of low temperature resistant material (-162°C), usually made of aluminum alloy. Since the outer wall of the heat exchange tube bundle is in direct contact with seawater, its outer wall should be treated with anticorrosion. The mechanical manufacture of the open frame gasifier is very simple. The main external interfaces are the LNG inlet, the gasified LNG outlet and the seawater inlet and outlet. The heat exchange tube is installed in the box. The vaporizer is hung on the bracket for easy maintenance. Since the open-frame gasifier has no moving parts, few instrument components are used, and the switch of the equipment can be controlled remotely, so maintenance is easy, and changing the operating load of the gasifier is also very simple, just change the amount of seawater flowing to the spray system and the amount of LNG flowing through the pipeline. The open-frame gasifier is composed of many monomers, and part of the tube bundle can be isolated to reduce the load. The open frame gasifier has a high level of safety. Because the system has no open flames, small leaks from hydrocarbon-containing pipelines can volatilize into the atmosphere.

When choosing an open-frame gasifier, the properties and parameters of seawater must be considered, because the open-frame gasifier has high requirements for the sediment content of seawater. If it is lower than 80 mg/L, if it is higher than this value, other methods should be considered to treat the sand in seawater to make it meet the requirements.

Most of the traditional LNG receiving station gasification system technology directly introduces seawater into the ORV open-frame gasifier. Under the condition of high sandy seawater, the surface coating of the ORV open-frame gasifier will be severely worn, which will affect its use. life.

Contents of the invention

The purpose of this utility model is to provide an LNG receiving terminal ORV gasification device suitable for high-sand-concentrated seawater conditions, which can greatly reduce the sand content of seawater, slow down the wear rate of equipment and reduce operating costs.

The utility model provides an LNG receiving terminal ORV gasification device suitable for high-sand seawater working conditions. The end of the water intake of the seawater pipeline is equipped with a grille, and the other end is respectively connected to two natural settlement sedimentation tanks for each other through two branch pipes. , the suction pipes of the two seawater pumps that serve as spares for each other extend into the two natural sedimentation tanks respectively, and the outlets of the seawater pumps are respectively connected to the ORV vaporizer through the filter.

In the above, the water intake end of the seawater pipeline is installed 4-8 meters below the sea level; the suction pipe of each natural sedimentation tank is located above the mud-water interface; Flush device.

Compared with the prior art, the LNG gasification system described in the utility model adopts a combined method, that is, the water intake grille removes seawater floats, the sedimentation tank removes most of the sediment, and the filter filters out seawater particles with a particle size greater than 20 μm. The combination of the three processes of sand can achieve the requirement that the seawater entering the ORV should have a sediment concentration of less than 80 mg/L. It technically solves the problem of wear and shortened service life of ORV vaporizer equipment in high sandy seawater.

The utility model has the advantages of less moving parts, simple structure, low operation cost, energy saving, environmental protection and high safety. It is suitable for large-scale LNG receiving terminals built in high sandy sea areas.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

Referring to Fig. 1, the LNG receiving terminal ORV gasification device provided by the utility model is suitable for the working condition of high sandy seawater, the end of the water intake of the seawater pipeline 2 is installed with a grille 1, and the other end is respectively connected to two interconnected pipes through two branch pipes 3. For the standby natural sedimentation tank 4, the suction pipes 5 of two mutually standby seawater pumps 6 extend into the two natural sedimentation tanks 4 respectively, and the outlets of the seawater pump 6 are respectively connected to the ORV vaporizer 8 through a filter, wherein Valve 9 is installed on two branch pipes 3 and two suction pipes 5 .

The water intake end of the seawater pipeline 2 is installed at 4-8 meters below the sea level, and then led to the natural sedimentation tank 4 by the sea level, and the water intake end of the seawater pipeline 2 is installed with a grille 1 for filtering sea creatures and other suspended solids.

The two natural settlement sedimentation tanks 4 are mutually backup, respectively controlled by four valves 9 on/off, and one of the tanks is regularly deactivated to remove the sediment at the bottom of the tank, and the switching period of the two tanks is determined by the amount of sediment at the bottom of the tank; The natural sedimentation tank 4 can be sterilized by adding hypochlorous acid seawater bactericide, but no power equipment is required, and the stratification of sediment and seawater can be realized only by the gravity settlement after the seawater is left still; the volume of a single pool is watered by the ORV vaporizer Quantity calculation is confirmed.

The seawater clarified by standing still is sent to the filter 7 by the seawater pump 6 as a backup for further filtration, and the suction port of the suction pipe 5 of each natural sedimentation tank is located above the mud-water interface; the filter 7 adopts a 20 μm filter screen, And configure backwashing device.

The filtered seawater enters the ORV gasifier 8 to exchange heat with LNG. ORV, also known as liquid film falling vaporizer, is composed of vertical heat exchange plates, and the plates are assembled by specially designed heat exchange tubes at the top and bottom. LNG enters from the bottom manifold, passes through the heat exchange plate, exchanges heat with the seawater film flowing down from the top, and then gasifies into NG. After the heat exchange, the seawater is discharged back to the sea through the pipeline.

Claims (4)

1. one kind is applicable to the LNG receiving terminal ORV gasification installation that height contains sea of sand water condition, it is characterized in that, grid (1) is installed in the intake end of seawater pipeline (2), the other end connects respectively two each other natural subsidence deposition tanks (4) for subsequent use through two arms (3), two each other the drinking-water pipe (5) of sea water pump (6) for subsequent use to stretch into respectively this two natural subsidence deposition tank (4) inner, the outlet of sea water pump (6) is passed through respectively filter (7) and is connect ORV vaporizer (8).

2. according to claim 1ly be applicable to the LNG receiving terminal ORV gasification installation that height contains sea of sand water condition, it is characterized in that, the intake end of seawater pipeline (2) is installed in b.s.l. 4-8 rice.

3. according to claim 1ly be applicable to the LNG receiving terminal ORV gasification installation that height contains sea of sand water condition, it is characterized in that, the pump mouth of the drinking-water pipe (5) of each natural subsidence deposition tank (4) is positioned on the water sludge interface.

4. according to claim 1ly be applicable to the LNG receiving terminal ORV gasification installation that height contains sea of sand water condition, it is characterized in that, filter (7) adopts 20 μ m filter screens, and the configuration back purge system.

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