CN102913753A

CN102913753A - Storage and gasification project output system of LNG (Liquefied Natural Gas) receiving terminal as well as method

Info

Publication number: CN102913753A
Application number: CN2012104425745A
Authority: CN
Inventors: 陈强; 刘书华; 李雁军; 张剑光; 贺珉; 薛广华; 黄炜; 陈彩虹; 罗方敏
Original assignee: GUANGDONG HUANQIU WIDE INDUSTRY ENGINEERING Co Ltd
Current assignee: GUANGDONG HUANQIU WIDE INDUSTRY ENGINEERING Co Ltd
Priority date: 2012-11-07
Filing date: 2012-11-07
Publication date: 2013-02-06
Anticipated expiration: 2032-11-07
Also published as: CN102913753B

Abstract

The invention discloses a storage and gasification project output system of an LNG (Liquefied Natural Gas) receiving terminal, which includes equipment as follows: a plurality of LNG storage tanks, high-pressure pumps fixed and mounted in high-pressure pump wells, a gasifier, a BOG (Boil Off Gas) compressor, and natural gas medium- and low-pressure delivery pipes, wherein the plurality of high-pressure pump wells are arranged in the LNG storage tanks and extend out of the LNG storage tanks, and BOG pipe ports are arranged on the bodies of the LNG storage tanks; LNG high-pressure pipes are connected with high-pressure pump outlets, extend out of the high-pressure pump wells and converge at an LNG high-pressure main; and the natural gas medium- and low-pressure delivery pipes are connected with an outlet of the BOG compressor, and are introduced to natural gas medium- and low-pressure pipe networks. According to the invention, the problems that pressures at inlets of the high-pressure pumps are difficult to control and the high-pressure pumps suffers from cavitation easily are solved; the problems that the liquid level and the pressure of an after-condenser are difficult to control and the BOG compressor bumps are solved; and the purposes of simplifying the process control, reducing the investment, saving the energy, lowering the consumption and facilitating the operation are achieved.

Description

The storage of LNG receiving station gentle chemical industry journey output system and method

Technical field

The present invention relates to conveying and the BOG treatment process of LNG.

Background technique

LNG receiving station also claims LNG Liquefied natural gas receiving station, and then the device of transport gas is integrated outward to refer to receive, store LNG Liquefied natural gas.In LNG receiving station project, generally comprise Wharf Engineering, gasification engineering (storing and gasification), engineering in pipeline three parts.Wherein, the technology controlling and process that the gasification engineering is related and manufacturing equipment technical difficulty are high, and whole project is had crucial impact.

As shown in Figure 1, the general gasifying process that adopts of LNG receiving station is again condensation gasification output technique at present, its technological process is generally: the LNG in the LNG storage tank 1 is divided into two strands after low pressure pump 2 pressurizations, one enters after-condenser 4 tops, with directly contact mixing from LNG storage tank 1 and through the BOG of pressure treatment in after-condenser 4 is interior, the BOG that enters after-condenser 4 all is condensed into liquid; Another strand with mix from after-condenser 4 condensed fluid out after enter high-pressure service pump 5, after high-pressure service pump pressurization, be delivered to vaporizer 6, enter long distance pipeline after the gasification.

After-condenser in this flow process mainly contains two functions: the first provides enough BOG and LNG contact space, utilizes the LNG cold energy that BOG is liquefied again, saves the energy consumption of gas pressurized; Another function is the suction side buffer container as the LNG high-pressure service pump, guarantees the generation of stablizing, avoid cavitation phenomenons of high-pressure service pump inlet pressure.

In above-mentioned prior art, need to be at gasification engineering installation after-condenser, high-pressure service pump is placed on outside the LNG storage tank.This way can be brought following shortcoming:

1, after-condenser is as high-pressure service pump suction side buffer container, and key is to control liquid level and the pressure stability of after-condenser, and condensation relates to pressure control, liquid level control, flow control again, technology controlling and process is complicated, investment is high, and after-condenser liquid level and pressure easily fluctuate, fluctuation of service.

2, different periods and season, the variable quantity of natural gas load is quite large, and rock gas defeated fluctuation of load meeting outward causes that the after-condenser liquid level is unstable.When liquid level is hanged down, BOG cooling deficiency in the after-condenser, the after-condenser liquidus temperature raises, and BOG can separate out in the suction side of high-pressure service pump, causes the high-pressure service pump cavitation.When the after-condenser liquid level is high, fail the aeration valve of pipe network outward opens from rock gas, the gas consumption that fills into partly enter the LNG of after-condenser, thereby the BOG that can't be liquefied makes the after-condenser pressure rise, thereby make part BOG be back to the suction port of compressor, do the virtual work power consumption except causing the BOG compressor, even BOG may advance compressor by Tapes liquid, cause the BOG compressor to jump car, the LNG pressure of storage tank is raise.

3, high-pressure service pump is back in the after-condenser, and this part LNG circulates between high-pressure service pump and after-condenser, not only causes the high-pressure service pump energy loss, also causes the after-condenser temperature to raise, and BOG cools off not enough, causes easily the high-pressure service pump cavitation.

4, after-condenser need to provide enough BOG and LNG contact space, and will guarantee stable liquid level, so the after-condenser volume is large, and inner piece is many, and equipment investment is high.

Summary of the invention

The object of the invention is to solve the narrow limitation of prior art and the shortcoming of existence, the present invention provides a kind of cancellation after-condenser, the technological method that adopts LNG tank inner high voltage pump directly to export.

In order to reach the foregoing invention purpose, the present invention has adopted following technological scheme: the gentle chemical industry journey of the storage of LNG receiving station output system comprises following equipment:

Several LNG storage tanks are provided with several high pressure pump sumps in the described LNG storage tank, the high pressure pump sump extends to outside the LNG storage tank, is provided with the BOG interface tube on the LNG storage tank tank body;

Be mounted on the high-pressure service pump in the high pressure pump sump, the LNG high-voltage tube connects the high-pressure service pump outlet and extends to outside the high pressure pump sump, and is collected to the LNG high-pressure main;

Vaporizer, described vaporizer is connected in described LNG high-pressure main by pipeline;

The BOG compressor, described BOG compressor is connected with described BOG interface tube by the BOG delivery pipe;

In the rock gas, static pressure line, in the described rock gas, static pressure line be connected in the BOG compressor outlet and lead in the rock gas, low pipe network.

Further, many BOG delivery pipes compile to BOG delivery main, and BOG delivery main is connected in the BOG compressor by pipeline.

Described BOG compressor is provided with some, by the pipeline parallel connection.

Described high-pressure service pump is vertical immersed pump.

The gentle chemical industry journey of the storage output intent of a kind of LNG receiving station, it may further comprise the steps:

Adopt the LNG storage tank that LNG is stored;

The high pressure pump sump is set in the LNG storage tank, and high-pressure service pump is installed in the interior high pressure pump sump of LNG storage tank, and high-pressure service pump is delivered to vaporizer with the LNG liquid booster pump in the LNG storage tank;

Shoot the BOG that comes in the LNG storage tank and be delivered to the BOG compressor by the BOG delivery pipe, be sent in the rock gas after the compression, low-pressure pipe network.

The present invention has improved the device of LNG receiving station, the cancellation after-condenser, high-pressure service pump is put into the high pressure pump sump of LNG storage tank, and directly through entering vaporizer after the pressurization of tank inner high voltage pump, the BOG that the LNG storage tank evaporates directly is delivered in the rock gas after the compression LNG, the low pressure urban pipe network in the storage tank.The invention solves the problem of the difficult control of high-pressure service pump inlet pressure, the easy cavitation of high-pressure service pump.The cancellation after-condenser, the BOG treatment process adopts directly compression output technique, BOG process BOG compressor compresses is to outer defeated pipe network in the storage tank, after-condenser liquid level, the difficult control of pressure have been solved, BOG Tapes liquid advances compressor and causes the BOG compressor to jump the problems such as car, reaches simple flow control, reduce cost, energy-saving and cost-reducing, simple to operate purpose.The present invention drops into minimizing 41% than equipment and the material of tratitional technology; Floor space reduces 62.4%; The moving devices consume of technique reduces by 16.4%, and resulting fuel gases calorific value is higher than traditional output intent.In sum, the technology of the present invention manufacturing equipment is few, construction investment is few, floor space is few, energy consumption is low, and process control is simple, and operation is more easy.

Description of drawings

Fig. 1 is the equipment flowsheet of prior art.

Fig. 2 is equipment flowsheet of the present invention.

Wherein, LNG storage tank 1 low pressure pump 2 BOG compressors 3 after-condensers 4 high-pressure service pumps 5 tank inner high voltage pumps 5 ' vaporizer 6 LNG high-pressure mains 7 BOG delivery mains 8 rock gas low pressure urban pipe networks 9

Embodiment

As shown in Figure 2, in LNG receiving station project, arranging in several LNG storage tank 1(such as this example is 2), be provided with the high pressure pump sump in the LNG storage tank 1, the high pressure pump sump extends to outside the LNG storage tank.Tank inner high voltage pump 5 ' is arranged in the high pump pump sump of LNG storage tank 1, the LNG high-voltage tube connects the high-pressure service pump outlet and extends to outside the high pressure pump sump.Be provided with the BOG interface tube on the tank body of LNG storage tank.High-pressure service pump among the present invention refers to be placed in the interior pump sump of LNG storage tank, the vertical immersed pump of LNG of outlet design pressure 〉=2.0MPag.

LNG in the LNG storage tank 1 is delivered to outside the LNG storage tank by the LNG high-voltage tube through the 5 ' pressurization of tank inner high voltage pump, then is collected to LNG high-pressure main 7, enters vaporizer 6.Carry and be collected to BOG delivery main 8 from the BOG gas that the LNG storage tank evaporates through the BOG delivery pipe.Many BOG compressors 3 are set, and it are connected in parallel, from BOG compressor 3 compressed BOG pressurized gas out be sent to the rock gas, low pressure urban pipe network 9.

The aboveground safety check that is provided with of high-pressure service pump, the LNG in the LNG storage tank can unidirectional inflow high-pressure service pump well in, LNG can not flow back in the LNG storage tank in the high pressure pump sump.

The present invention is fit to LNG receiving station field, take certain conventional scale as 300x10 ⁴The LNG receiving station of t/a is example, tradition again condensation gasification output technique and technology of the present invention compare, comparative result sees Table 1.

Wherein, LNG receiving station condition: conventional scale is 300x10 ⁴T/a, the gasification output flow is 700t/h, Gao Long-distance Transmission Pipeline pressure 4.0Mpag, rock gas low pressure urban pipe network pressure 0.3Mpag, 2 160,000 sides are contained concrete LNG storage tank entirely, and without impact, so the LNG storage tank does not participate in comparison on the LNG storage tank for two kinds of technique.

Table 1

As seen from the above table, only equipment and Master Cost (not comprising installation fee), the present invention lacks 41% than conventional process techniques; Floor space, the present invention lacks 62.4% than conventional process techniques; The technique power equipment consumes, and the present invention lacks 16.4% than conventional process techniques.

Claims

1.LNG the gentle chemical industry journey of the storage of receiving station output system is characterized in that comprising following equipment:

2. the gentle chemical industry journey of the storage output system of LNG according to claim 1 receiving station, it is characterized in that: many BOG delivery pipes compile to BOG delivery main, and BOG delivery main is connected in the BOG compressor by pipeline.

3. the gentle chemical industry journey of the storage output system of LNG according to claim 2 receiving station, it is characterized in that: described BOG compressor is provided with some, by the pipeline parallel connection.

4. the gentle chemical industry journey of the storage output system of LNG according to claim 1 receiving station, it is characterized in that: described high-pressure service pump is vertical immersed pump.

5. the gentle chemical industry journey of the storage of LNG receiving station output intent is characterized in that may further comprise the steps:

Adopt the LNG storage tank that LNG is stored;