CN206131511U - A ejector that is used for liquefied natural gas to draw penetrating low temperature evaporation gas - Google Patents

Abstract

The utility model relates to an ejector that is used for liquefied natural gas to draw penetrating low temperature evaporation gas, its characterized in that: including a spray tube, the one end of spray tube is the entrance point, and the other end is the exit end, the spray tube sets up a suction chamber, a mixing chamber and a diffusion room by the entrance point to the exit end in order, the mixing chamber is a straight pipeline section, the diffusion room is an expansion pipeline, the suction chamber is a shrink pipeline section with the junction of mixing chamber, the entrance point setting of spray tube earlier on the nozzle that the suction chamber extends, the nozzle adopts the collapsible tube structure, one side of suction chamber sets up one and draws and penetrate the pipe.

Description

For the injector of liquefied natural gas injection low-temperature evaporation gas

Technical field

This utility model is related to a kind of injector for liquefied natural gas injection low-temperature evaporation gas, belongs to natural gas storage Technical field.

Background technology

LNG (Liquefied Natural Gas, liquefied natural gas) receiving station typically carry LNG reception, storage and The outer transmission function of gasification.As LNG is cryogen, although LNG plant has good insulation, during production run A certain amount of BOG (Boiled Off Gas, boil-off gas) is produced inevitably, with the increase of BOG quantity, LNG storages Temperature and pressure in system can be raised.If LNG storage tank internal pressure can be led higher than the safety relief pressure of default Tank deck relief valve is caused to open, the BOG that directly releases burns to flare system, with the pressure of stabilisation systemss.This large amount of discharge BOG's Blood pressure lowering mode can cause the huge waste of natural gas.

Therefore, BOG processing systems are one of key issues of necessary emphasis consideration in the LNG receiving stations design phase.At present LNG receiving stations process the mode of BOG mainly following two：1st, BOG is condensed into LNG and is reclaimed by BOG condensation technologies again, This needs LNG receiving stations to keep higher outer defeated traffic demand；2nd, direct compress technique, the BOG in LNG storage tank is through low pressure pressure After contracting machine and high pressure compressor are pressurized to the pressure needed for pipe network transmission successively, it is directly entered multi-purpose station pipeline and delivers to downstream user. Additionally, more and more LNG receiving stations also need the Middle Voltage to short-distance and medium-distance direct in addition to it need to supply to the defeated pipe network of high pressure length Supply, therefore outer defeated natural gas is divided into high pressure (about 9MPa) for some LNG receiving stations and middle pressure (about 4.0MPa) is conveyed.In Pressure natural gas often need to can be conveyed after the pressure needed for high pressure is adjusted to.

In prior art, it is to reclaim BOG, pressure, high pressure compressor, after-condenser in the generally setting of LNG receiving stations, and adjust The equipment such as pressure valve, had both needed energy to need energy that natural gas is adjusted to middle pressure by high pressure to compress BOG, again, caused equipment throwing The problems such as money height, high energy consumption, cumbersome, complex process, and also there is the application restriction of duty requirements.

The content of the invention

For the problems referred to above, the purpose of this utility model be to provide one kind boil-off gas can be made to condense again and it is simple for structure, The injector for liquefied natural gas injection low-temperature evaporation gas of process is simple.

For achieving the above object, this utility model is employed the following technical solutions：It is a kind of to be used for liquefied natural gas injection low temperature The injector of boil-off gas, it is characterised in that：Including a jet pipe, one end of the jet pipe is entrance point, and the other end is the port of export, institute State jet pipe and one suction chamber, a mixing chamber and a diffusion room are sequentially arranged by entrance point to the port of export, the mixing chamber is one straight Pipeline section, the diffusion room are an expansion pipe, and the suction chamber is a contraction pipeline section with the junction of mixing chamber；In the jet pipe Entrance point one nozzle extended to the suction chamber is set, the nozzle is using shrinking tubular construction；The one of the suction chamber Side arranges an induction tunnel.

The length of the mixing chamber is 630mm, and a diameter of 79～80mm of the mixing chamber, the outlet of the diffusion room are straight Footpath is 120mm, and the length of the diffusion room is 293～295mm；The outlet diameter of the nozzle is 68mm, and the nozzle goes out Mouth is 94.8～95mm with the axial distance of the mixing chamber.

Due to taking above technical scheme, which has advantages below to this utility model：LNG is through nozzle of the present utility model Into the inside of jet pipe, sprayed by jet expansion after the runner of nozzle interior shrinkage type, into suction chamber；Transported according to fluid Dynamic Bernoulli equation understands that flow velocity increase can make pressure diminish, therefore, accelerate the LNG for spraying suck indoor formation Low pressure, so that BOG is entered suction chamber by injection through induction tunnel；The fluid-mixing of LNG and BOG enters in the mixing interior of jet pipe Row sufficiently mixing and heat exchange, BOG are condensed by LNG, and fluid enters diffusion room afterwards, and in diffusion room, the pressure of fluid is obtained Go up, the pressure loss of whole device is controlled within the acceptable range；This utility model can realize condensing again for BOG, The equipment such as after-condenser, pressure regulator valve need not be set, and technical process is simple, economy is projected.

Description of the drawings

Fig. 1 is overall structure diagram of the present utility model；

Fig. 2 is scale diagrams of the present utility model；

Fig. 3 is the liquid phase volume fraction of injector radial section in instantiation, and what wherein abscissa was represented is injector The length of axis.

Specific embodiment

With reference to the accompanying drawings and examples this utility model is described in detail.

As shown in Figure 1 and Figure 2, this utility model includes a jet pipe 1, and one end of jet pipe 1 is entrance point, and the other end is outlet End, jet pipe 1 are sequentially arranged a suction chamber 2, a mixing chamber 3 and a diffusion room 4 by entrance point to the port of export, wherein, mixing chamber 3 is One flat segments, diffusion room 4 are an expansion pipe, and suction chamber 2 is a contraction pipeline section with the junction of mixing chamber 3.In jet pipe 1 Entrance point arranges a nozzle 5 extended to suction chamber 2, and nozzle 5 is using contraction tubular construction.One is arranged in the side of suction chamber 2 to draw Penetrate pipe 6.

In a preferred embodiment, the length of mixing chamber 3 is 630mm, a diameter of 79～80mm of mixing chamber 3, is expanded The outlet diameter of pressure chamber 4 is 120mm, and the length of diffusion room 3 is 293～295mm；The outlet diameter of nozzle 5 be 68mm, nozzle 3 The axial distance of outlet and mixing chamber 3 be 94.8～95mm.

The course of work of the present utility model and principle are as follows：LNG is entered in jet pipe 1 through nozzle of the present utility model 5 Portion, exports ejection by nozzle 5, after the runner of 5 inside shrinkage type of nozzle into suction chamber 2.According to the Bai Nu of fluid motion Sharp equation understands that flow velocity increase can make pressure diminish, therefore, accelerate the LNG for spraying form low pressure in suction chamber 2, from And make BOG be entered suction chamber 2 by injection through induction tunnel 6.The fluid-mixing of LNG and BOG is filled in the mixing interior of jet pipe 1 The mixing for dividing and heat exchange, BOG are condensed by LNG.Fluid enters diffusion room 4 afterwards, and in diffusion room 4, the pressure of fluid is returned Rise, the pressure loss of whole device is controlled within the acceptable range.This utility model can realize condensing again for BOG, nothing The equipment such as after-condenser, pressure regulator valve need to be set, and technical process is simple, economy is projected.

Workflow of the present utility model is described in detail with reference to a specific embodiment：

Certain LNG supplied materials pressure is 2.0MPaG, and temperature is -160 DEG C, and the LNG under this pressure and temperature is in supercool shape State, BOG pressure are 0.025MPaG, and temperature is -140 DEG C.As LNG enters this utility model injector, BOG is inhaled into this reality With new injector and be in supercooled state LNG absorb.The BOG of absorption can be condensed by LNG completely, this utility model injection The mass ratio of induced-to-inducing air of device, the i.e. mass flow of driven fluid BOG and the ratio of driving fluid LNG mass flows, are 23.4%, are somebody's turn to do The maximum hour yield of receiving station BOG is 165t/h, control the flow of LNG for 705.0t/h when by by receiving station BOG most During size, yield is disposed, and mixed export LNG pressure is 1MPa.

This utility model is only illustrated with above-described embodiment, and the structure of each part, set location and its connection are all can It is with what is be varied from, on the basis of technical solutions of the utility model, all individual part to be carried out according to this utility model principle Improvement and equivalents, should not exclude outside protection domain of the present utility model.

Claims (2)

1. a kind of injector for liquefied natural gas injection low-temperature evaporation gas, it is characterised in that：Including a jet pipe, the jet pipe One end be entrance point, the other end is the port of export, and the jet pipe is sequentially arranged a suction chamber, a mixing by entrance point to the port of export Room and a diffusion room, the mixing chamber are a flat segments, and the diffusion room is an expansion pipe, the suction chamber and mixing chamber Junction be one shrink pipeline section；In the entrance point of the jet pipe, one nozzle extended to the suction chamber, the nozzle are set Using contraction tubular construction；In the side of the suction chamber, one induction tunnel is set.

2. the injector of liquefied natural gas injection low-temperature evaporation gas is used for as claimed in claim 1, it is characterised in that：It is described mixed The length for closing room is 630mm, a diameter of 79～80mm of the mixing chamber, and the outlet diameter of the diffusion room is 120mm, described The length of diffusion room is 293～295mm；The outlet diameter of the nozzle is 68mm, the outlet of the nozzle and the mixing chamber Axial distance be 94.8～95mm.