CN209639358U - A kind of LNG cold energy use air separation unit system - Google Patents

Abstract

The utility model discloses a kind of LNG cold energy use air separation unit systems comprising LNG heating heating system (1) and air separation unit (2)；The air separation unit (2) includes that air compressor machine (7), forecooler (5), molecular sieve (8), heat exchanger (4), ice chest (3) are sequentially connected by air pipe line；LNG heating heating system (1) includes LNG storage tank (14), LNG liquid phase booster pump and LNG transfer pipeline；The sequentially connected LNG storage tank of LNG transfer pipeline (14), LNG liquid phase booster pump, heat exchanger (4), forecooler (5)；The utility model LNG cold energy use air separation unit system utilizes free LNG cold source cold energy, carries out compression and cooling liquid to air, LNG cold source is on the one hand utilized, and on the other hand reduces the comprehensive energy consumption of deep cooling compression space division system.

Description

A kind of LNG cold energy use air separation unit system

Technical field

The utility model belongs to liquefied natural gas (LNG) and cryogenic air separation unit device field, specifically proposes a kind of LNG cold energy benefit With air separation unit system.

Background technique

It is planned according to China's energy Long-and Medium-term Development, natural gas will become a bright spot of our country energy development strategy and green One of color energy pillar.Within following time, China will a large amount of inlet natural gas, wherein most natural gas will be with liquefaction The mode of natural gas (LNG) is transported to China.The LNG of a large amount of imports, while a large amount of cold energy is carry, if cannot be effectively Utilize these cold energy, it will cause huge energy waste and environmental pollution.Therefore, these cold energy how are effectively utilized, just Become it is particularly important with it is necessary.

Still further aspect, large-scale space division device is in steel, chemical industry and ammonia synthesizing industry using more and more extensive, large-scale sky The implementation of separating device new projects is more and more, and always energy consumption increases year by year for society shared by energy consumption.Air separation plant is exactly with air for original Air is become liquid by the method for compression depth of round freezing, gradually separated from liquid air using rectifying by material The equipment for producing the inert gases such as oxygen, nitrogen and argon gas.

The method huge energy consumption of the compression depth of round freezing of mainstream at present, therefore, the highly energy-consuming of large-scale space division device at For the important bottleneck for hindering Air separation industry development.

In view of this, proposing the utility model.

Summary of the invention

The purpose of this utility model is to provide a kind of LNG cold energy use air separation unit systems, to solve above-mentioned existing LNG The problem of cold source waste and cryogenic air separation unit refrigeration huge energy consumption.

In order to realize the goal of the invention, the utility model adopts the following technical solution:

A kind of LNG cold energy use air separation unit system comprising LNG heating heating system and air separation unit；The space division Device includes that air compressor machine, forecooler, molecular sieve, heat exchanger, ice chest are sequentially connected by air pipe line；The LNG heating heating system System includes LNG storage tank, LNG liquid phase booster pump and LNG transfer pipeline；The sequentially connected LNG storage tank of the LNG transfer pipeline, LNG Liquid phase booster pump, heat exchanger, forecooler.

Preferably, the forecooler setting single-stage or multi-stage heat exchanger.

Preferably, the heat exchanger is plate heat exchanger or shell-and-tube heat exchanger or finned tube exchanger.

Preferably, the heat exchanger setting single-stage or multi-stage heat exchanger.

Preferably, the air separation unit includes at least one of expanding machine, supercharger, oxygen compressor, nitrogen compressor, the pneumatics At least one of machine, expanding machine, supercharger, oxygen compressor, nitrogen compressor are driven using electronic or steam turbine.

Preferably, the gas products such as space division product oxygen, nitrogen or argon gas of the air separation unit production, are filled using high pressure The filling steel cylinder of steel loading bottle, liquid phase or the storage of liquid phase low-temperature storage tank.

Preferably, LNG cold source provides required low temperature environment for the liquid phase low-temperature storage tank of the space division gas products.

Preferably, the LNG liquid phase storage tank setting is one or more, and vacant storage tank can utilize in multiple LNG storage tanks It keeps the temperature low temperature environment and stores liquid phase space division gas products.

Beneficial effect

1, the utility model efficiently uses LNG cold energy, avoid LNG harbour or Large LNG device to it is empty, to seawater or river The variation of local ambient temperature caused by water released cold quantity influences；

2, the utility model can carry out sky in the case where the large supercharged machine and expanding machine in no cryogenic air separation unit device Gas separation, reduces the comprehensive energy consumption and project investment of air separation unit；

3, the utility model utilizes the low temperature environment of LNG manufacture, can greatly reduce the loine pressure grade of air separation unit, from And reduce the relevant investment of air separation unit air pipe line.

Detailed description of the invention

Fig. 1 is that the overall structure of the utility model LNG cold energy use air separation unit system is illustrated；

The relation curve of temperature and LNG cold energy in Fig. 2 the utility model LNG cold energy use air separation unit system.

Description of symbols

Further clearly to illustrate the connection relationship between the structure of the utility model and each component, give following attached Icon note, and be illustrated.

LNG heating heating system 1, air separation unit 2, ice chest 3, heat exchanger 4, forecooler 5, three-level LNG heat-exchanger rig 6 are empty Press 7, molecular sieve 8, level-one plate heat exchanger 9, second level plate heat exchanger 10, oxygen compressor 11, nitrogen compressor 12, storage tank 13, LNG storage Tank 14.

Description of symbols through the above attached drawings can be more clearly understood and illustrate in conjunction with the embodiments of the present invention The technical solution of the utility model.

Specific embodiment

The utility model is described in further detail combined with specific embodiments below, so that those skilled in the art can be more Good understanding the utility model can be simultaneously practiced, but the utility model range claimed is not limited to be embodied Range described in mode.It should be noted that in the absence of conflict, in the embodiment and embodiment in the application Feature can mutual any combination.

Embodiment one

A kind of LNG cold energy use air separation unit system, as Figure 1-Figure 2, the LNG cold energy use air separation unit system Including LNG heating heating system 1 and air separation unit 2, the LNG heating heating system 1 includes LNG storage tank 14, LNG delivery pipe Road, LNG liquid phase booster pump, LNG cold energy use space division heat-exchanger rig.The LNG cold energy use space division heat-exchanger rig includes multistage LNG heat-exchanger rig；The LNG cold energy use space division heat-exchanger rig includes heat exchanger 4, forecooler 5 and three-level LNG heat-exchanger rig 6. The LNG transfer pipeline is sequentially connected LNG storage tank 14, LNG liquid phase booster pump, LNG cold energy use multistage space division heat-exchanger rig；I.e. The LNG transfer pipeline is sequentially connected LNG storage tank 14, LNG liquid phase booster pump, heat exchanger 4, forecooler 5 and three-level LNG heat exchange dress 6 are set, is natural gas by the LNG gasification in three-level LNG heat-exchanger rig 6.LNG in the LNG storage tank 14 by heat exchanger 4 into The primary heating of row；And by forecooler 5 after primary heating, secondary temperature elevation is carried out in forecooler 5, is changed eventually by three-level LNG Thermal 6, gasification is natural gas after three-level LNG heat-exchanger rig 6 heat up three times.That is heat exchanger 4, forecooler 5 and three-level The temperature of LNG in LNG heat-exchanger rig 6 successively increases.

The air separation unit 2 includes air compressor machine 7, forecooler 5, molecular sieve 8, three-level LNG heat-exchanger rig 6, ice chest 3 and air Pipeline.The air pipe line is sequentially connected air compressor machine 7, forecooler 5, molecular sieve 8, heat exchanger 4, ice chest 3, and air passes through forecooler 5, heat exchanger 4, ice chest 3, and LNG cold energy is absorbed, air deep-cooling is cooled down and is liquefied.The ice chest 3 and product supercharger, storage tank 13 It is connected；The product supercharger includes oxygen compressor 11, nitrogen compressor 12.The storage tank 13 or storage tank low temperature liquid phase storage device, The final air separation products such as the liquid nitrogen, liquid oxygen, liquid argon of its acquisition that can store air separation unit.The ice chest 3, which is equipped with, to be produced Product delivery outlet；The oxygen compressor 11, nitrogen compressor 12, storage tank 13 are connected with the output of products mouth on ice chest 3, to compress space division dress Separating obtained gaseous product is set, and obtains the gaseous product (gases such as oxygen or nitrogen of high-pressure cylinder storage that high pressure mode stores Product).Preferably, the gas products such as space division product oxygen, nitrogen or argon gas of the air separation unit production, using high-pressure filling The filling steel cylinder of steel cylinder, liquid phase or the preservation or for sale of liquid phase low-temperature storage tank form.

LNG saturation temperature at various pressures, density, latent heat of vaporization relation table show as LNG temperature increases, gas Change latent heat is smaller, and cooling effect successively decreases；Opposite, as LNG temperature reduces, gasification latent heat is bigger, and cooling effect is passed Increase.Since the LNG temperature in forecooler 5, heat exchanger 4 is successively successively decreased, cooling effect is correspondingly incremented by successively.The space division dress It sets in 2 and successively passes through forecooler 5, heat exchanger 4, ice chest 3 by the air of air compressor machine 7, to cool down step by step, final cryogenic air, Obtain air separation products.Correspondingly, the LNG in the LNG heating heating system 1 successively passes through heat exchanger 4, forecooler 5, with It heats up step by step, to gasify as natural gas.

Forecooler 5 carries out precooling treatment to air in the air separation unit 2, the air warp by 5 precooling treatment of forecooler Over-molecular sieve 8 passes through heat exchanger 4 through treated the air of over-molecular sieve 8；The heat exchanger 4 is to carry out secondary cooling to air Processing, and by ice chest 3 after secondary cooling, the ice chest 3 carries out cooling treatment three times to air；It is obtained after ice chest 3 Obtain the resulting gaseous product of air separation unit.

Preferably, the heat exchanger 4 is plate heat exchanger or shell-and-tube heat exchanger or finned tube exchanger.

Preferably, the heat exchanger 4 includes multi-stage heat exchanger, that is, includes at least level-one plate heat exchanger 9.

Preferably, the heat exchanger 4 is setting single-stage heat exchanger, i.e., the described heat exchanger 4 is level-one plate heat exchanger 9.

Preferably, the heat exchanger 4 includes second level plate heat exchanger 10 and level-one plate heat exchanger 9, and LNG is by changing at this time When hot device 4, LNG carries out secondary temperature elevation and heats up three times；When corresponding air passes through heat exchanger 4, air is cooled down twice Cool down three times.

Preferably, ice chest 3 can be that the gaseous product in liquid nitrogen, liquid oxygen, liquid argon or the storage tank 13 obtained by ice chest 3 supplies Answer cold source.That is, low temperature environment needed for the liquid phase low-temperature storage tank of the space division gas products can utilize LNG cold source.

Preferably, single-stage is arranged in the forecooler 5 or air is pre-chilled in multi-stage heat exchanger, according to air mass flow and can The heat exchanger series of chilldown system is rationally arranged in the LNG cold source quantity utilized.

Preferably, the three-level LNG heat-exchanger rig 6 can absorb the heat of air, surface water, seawater etc., make LNG three times Heating.

Preferably, the LNG storage tank 14 can be set one or more, and vacant storage tank can benefit in multiple LNG storage tanks Low temperature environment, which is kept the temperature, with it stores liquid phase space division gas products.That is the liquid nitrogen obtained of air separation unit 2, liquid oxygen, liquid argon or storage tank The lower return LNG storage tank 14 of gaseous product connection in 13.

Preferably, the gaseous product in the liquid nitrogen obtained of air separation unit 2, liquid oxygen, liquid argon or storage tank 13 connects next stage Heat exchanger.

LNG cold energy use air separation unit system utilizes free LNG cold source cold energy in the present embodiment, compresses to air And cooling liquid, LNG cold source is on the one hand utilized, on the other hand reduces the comprehensive energy consumption of deep cooling compression space division system.

Embodiment two

The present embodiment two is identical as one principle of embodiment, and difference is, the air separation unit includes expanding machine, pressurization Machine, the equipment such as air compressor machine, expanding machine, supercharger, oxygen compressor or nitrogen compressor in the air separation unit use electronic or vapor wheel Machine drives.

Specifically, the air separation unit is connected with thermal power plant's generating set system.Thermal power plant's generating set includes Big steam turbine, generator and peak regulation control module, the peak regulation control module receive the peak regulation instruction of grid dispatching center；It is described Air separation unit is connected with the jet chimney of generator and/or thermal power plant's generating set, and the peak regulation control module can will be sent out The electric power of motor and/or the steam of thermal power plant's group are adjusted to air separation unit, to drive air separation unit.

The i.e. described air separation unit one side is connected with the jet chimney of thermal power plant's generating set, to be steamed using peak regulation of power plant Vapour driving；On the other hand can be connected with generator, to be powered using generator to air separation unit.The air separation unit uses Electronic and/or steam turbine drives.Arrangement above can efficiently use the peak regulation surplus electricity of thermal power generation unit, thermal energy meets The equipment of air separation unit energizes, and reduces the energy consumption of extraneous supplement driving air separation unit, avoids energy waste, improve using energy source Rate enables modern thermal power plant transition to become the synthesis of electric energy, thermal energy, compressed air and various air separation gas products Property factory.

Embodiment three

A kind of LNG cold energy use air separation unit multi-stage heat exchanger design method, the LNG cold energy use air separation unit multistage are changed Thermal design uses LNG cold energy use air separation unit system described in above embodiments.The specific method is as follows for it:

S1: according to the temperature, pressure flow parameter of LNG storage tank reserves and final output natural gas, available LNG is calculated Cold source general refrigeration ability Q_LNG；

S2: according to LNG cold source general refrigeration ability Q_LNGThe final pressure of the space division gas products oxygen or nitrogen that are produced with expectation, Temperature, the accessible air total flow F for carrying out air-fluidized sucking air compressor machine of budgetary estimate_{It is empty}；

S3: it according to system equipment process, calculates in detail in air total flow F_{It is empty}Under, utilize LNG cold source general refrigeration ability Q_LNGIt is changing Achievable temperature decline numerical value is respectively T in hot device 4, forecooler 5_{Heat exchanger drops}、T_{Drop pre-cooling}；

Wherein T_{Heat exchanger drops}=T_{Sky 2}-T_{Sky 3}；T_{Drop pre-cooling}=T_{Sky 1}-T_{Sky 2}；T_{Sky 1}Temperature before entering forecooler for air, T_{Sky 2}For air The temperature of forecooler and air enter the temperature before heat exchanger out；T_{Sky 3}Go out temperature when heat exchanger for air；

S4: according to system equipment process and T_{Heat exchanger drops}The heat exchanger series in heat exchanger 4 is rationally arranged in numerical value.

Wherein, the cold source general refrigeration ability Q_LNGCalculation formula are as follows:

Q_LNG=Q_{LNG latent heat}+Q_{Gas lift temperature}=F_LNG*q_{LNG latent heat}+F_LNG*(T_For-T₁)*C_{P gas}=Q_{Heat exchanger}+Q_Forecooler

Q_{LNG latent heat}=F_LNG*q_{LNG latent heat}

Q_{Gas lift temperature}=F_LNG*(T_For-T₁)*C_{P gas}

Q_{Heat exchanger}=F_LNG*(T₂-T₁)*C_{P gas}=F_{It is empty}*(T_{Sky 2}-T_{Sky 3})*C_{P is empty}

Q_Forecooler=F_LNG*(T₃-T₂)*C_{P gas}=F_{It is empty}*(T_{Sky 1}-T_{Sky 2})*C_{P is empty}

Wherein:

Q_LNGFor LNG cold energ amount, kJ/h；

F_LNGFor LNG stream amount kg/h；

q_{LNG latent heat}For the gasification latent heat kJ/kg of LNG, the data according to the form below 1 are got divided by 4.18kCal/kJ conversion；

C_{P gas}Unit is kJ/kg DEG C of specific heat capacity of gaseous state LNG；

C_{P is empty}Unit is kJ/kg DEG C of specific heat capacity of gaseous air.

Saturation temperature, density, the latent heat of vaporization of 1 LNG of table at various pressures

Saturation pressure (MPag)	0	0.2	0.4	0.6	0.8	1.0	1.2	1.4	1.6
										Saturation temperature DEG C	-162	-146	-138	-132	-126	-122	-118	-115	-112
Density kg/m3	424	400	386	374	365	356	348	340	333
										Latent heat of vaporization kcal/kg	122	115	110	106	102	98	94	91	87

The utility model on the one hand effective use LNG cold energy, avoid LNG harbour or Large LNG device to it is empty, to seawater Or the variation of local ambient temperature caused by river water released cold quantity influences；It on the other hand, can be big in no cryogenic air separation unit device Air separation is carried out in the case where type supercharger and expanding machine, reduces the comprehensive energy consumption and project investment of air separation unit；Furthermore The low temperature environment manufactured using LNG, can greatly reduce the loine pressure grade of air separation unit, to reduce air separation unit air hose The relevant investment in road.

In the description of the present application, belonging to " installation ", " connected ", " connection ", " fixation " etc. be shall be understood in a broad sense, such as " connection " may be a fixed connection, can also with when be detachably connected, or be integrally connected；It can be directly connected, be also possible to It is connected by intermediary brief introduction.For the ordinary skill in the art, above-mentioned art can be understood as the case may be The concrete meaning of language in this application.

In the description of this specification, the description meaning of term " one embodiment " " some embodiments " " specific embodiment " etc. Refer to that particular features, structures, materials, or characteristics described in conjunction with this embodiment or example are contained at least one implementation of the application In example or example, in the present specification, identical embodiment or implementation are not necessarily referring to the schematic illustration of above-mentioned term Example.Moreover, description particular features, structures, materials, or characteristics can in any one or more of the embodiments or examples with Suitable mode combines.

It is described interior although those skilled in the art should be understood that embodiment disclosed by inventive embodiments is as above Hold only the utility model and the embodiment that uses, the embodiment being not intended to limit the utility model for ease of understanding.It is any The utility model embodiment those skilled in the art, in the premise for not departing from spirit and scope disclosed by the utility model Under, any modification and variation, but the patent protection of the utility model embodiment can be carried out in the form and details of implementation Range, must still be subject to range defined in the attached claims.

Claims (8)

1. a kind of LNG cold energy use air separation unit system, it is characterised in that: it includes LNG heating heating system (1) and space division dress Set (2)；The air separation unit (2) includes that air compressor machine (7), forecooler (5), molecular sieve (8), heat exchange are sequentially connected by air pipe line Device (4), ice chest (3)；LNG heating heating system (1) includes LNG storage tank (14), LNG liquid phase booster pump and LNG delivery pipe Road；The sequentially connected LNG storage tank of LNG transfer pipeline (14), LNG liquid phase booster pump, heat exchanger (4), forecooler (5).

2. LNG cold energy use air separation unit system according to claim 1, it is characterised in that: forecooler (5) setting Single-stage or multi-stage heat exchanger.

3. LNG cold energy use air separation unit system according to claim 1, it is characterised in that: the heat exchanger (4) is plate Formula heat exchanger or shell-and-tube heat exchanger or finned tube exchanger.

4. LNG cold energy use air separation unit system according to claim 3, it is characterised in that: heat exchanger (4) setting Single-stage or multi-stage heat exchanger.

5. LNG cold energy use air separation unit system according to claim 1, it is characterised in that: air separation unit (2) packet Include at least one of expanding machine, supercharger, oxygen compressor, nitrogen compressor, the air compressor machine, expanding machine, supercharger, oxygen compressor, nitrogen pressure At least one of machine is driven using electronic or steam turbine.

6. LNG cold energy use air separation unit system according to claim 1, it is characterised in that: the air separation unit (2) is raw The gas products such as space division product oxygen, nitrogen or the argon gas of production, using high-pressure filling steel cylinder, the filling steel cylinder of liquid phase or liquid phase low temperature Storage tank storage.

7. LNG cold energy use air separation unit system according to claim 1 or 6, it is characterised in that: LNG cold source is described Low temperature environment needed for the liquid phase low-temperature storage tank of space division gas products provides.

8. LNG cold energy use air separation unit system according to claim 1, it is characterised in that: the LNG liquid phase storage tank is set Set one or more, vacant storage tank can be kept the temperature low temperature environment storage liquid phase space division gas using its and be produced in multiple LNG storage tanks Product.