Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
  • F04D27/009—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids by bleeding, by passing or recycling fluid
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/58—Cooling; Heating; Diminishing heat transfer
  • F04D29/582—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps
  • F04D29/5846—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps cooling by injection
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
  • F04D17/08—Centrifugal pumps
  • F04D17/10—Centrifugal pumps for compressing or evacuating
  • F04D17/12—Multi-stage pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
  • F04D27/006—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids by influencing fluid temperatures
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/70—Suction grids; Strainers; Dust separation; Cleaning
  • F04D29/701—Suction grids; Strainers; Dust separation; Cleaning especially adapted for elastic fluid pumps
  • F04D29/706—Humidity separation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
  • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
  • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
  • F25J3/04006—Providing pressurised feed air or process streams within or from the air fractionation unit
  • F25J3/04012—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of warm gaseous streams; details of intake or interstage cooling
  • F25J3/04018—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of warm gaseous streams; details of intake or interstage cooling of main feed air
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2205/00—Processes or apparatus using other separation and/or other processing means
  • F25J2205/02—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum
  • F25J2205/04—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum in the feed line, i.e. upstream of the fractionation step
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
  • F25J2230/02—Compressor intake arrangement, e.g. filtering or cooling
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2245/00—Processes or apparatus involving steps for recycling of process streams
  • F25J2245/02—Recycle of a stream in general, e.g. a by-pass stream

Definitions

• the present invention relates to the general field of methods for compressing gaseous fluids, and more particularly to air compression processes.
• the objects assigned to the invention are intended to further improve the efficiency of the compression of a gaseous fluid, and to propose for this purpose a new compression process which offers a significant efficiency gain over known methods. , while maintaining a relative simplicity of implementation.
• a gaseous fluid compression process comprising a refrigerant injection step (a) in which a refrigerant substance is sprayed into the gaseous fluid to be compressed.
• a step (b) of compression during which the passage of said gaseous fluid charged with cooling substance through a compressor in order to compress said gaseous fluid, said method being characterized in that the mass flow rate of the cooling substance injected into the gaseous fluid represents between 1% and 5% of the mass flow rate of the gaseous fluid to be compressed, and in that the cooling substance is sprayed in the form of particles of maximum dimension less than or equal to 25 ⁇ .
• the spraying of the refrigerant substance in a relatively large quantity in the form of microparticles, or micro-droplets creates a particularly homogeneous diphasic medium whose average density, and more particularly the "homogeneous density", is greater than that gaseous fluid alone, which makes it possible to confer a high kinetic energy on the gaseous fluid thus charged with refrigerant substance and driven by the compressor, and consequently to promote the increase of the dynamic pressure of said gaseous fluid during its entrainment by the compressor .
• the compression ratio that is to say the ratio between the pressure at the compressor outlet and the inlet pressure of said compressor, is thus improved by a first effect, of mechanical order.
• the injection in excess of the cooling substance, and in particular water makes it possible to obtain a second effect, of a thermal nature: only a part of said cooling substance vaporizing (or sublimating) during the compression , the method makes it possible to exploit not only the latent heat of said refrigerant substance, when the state of the refrigerant substance vaporizes (or sublimates), but also the specific heat of said refrigerant, when heating from the refrigerant substance which remains in the condensed state.
• the fineness of the particles (or droplets) contributes advantageously to improve the quality and homogeneity of heat exchange.
• Figure 1 shows a schematic view of an installation for implementing a method according to the invention.
• the present invention relates to a method for compressing a gaseous fluid 1.
• Said gaseous fluid 1 may be formed of a single gas, or alternatively of a mixture of several gases.
• said gaseous fluid to be compressed will be formed by air, as mentioned for purely illustrative purposes in FIG.
• a process according to the preamble of claim 1 is known from EP-A-2610465 and JP-A-2008190335.
• the method comprises a step (a) of refrigerant injection during which a cooling substance 3 is sprayed into the gaseous fluid to be compressed 1, and then a compression step (b), during which one forces the passage of said gaseous fluid 1 charged with refrigerant substance 3 through said compressor 2 to compress said gaseous fluid.
• the refrigerant substance 3 will preferably be injected upstream of the compressor 2, as shown in FIG. 1.
• the refrigerant substance can be injected at the wheel of the compressor 2, in the case of a centrifugal compressor.
• the mass flow rate Q3 of the refrigerant substance 3 injected into the gaseous fluid represents between 1% and 5% of the mass flow rate Q1.
• gaseous fluid to be compressed that is to say that there is: 0.01 x Q1 [kg / s] ⁇ Q3 [kg / s] ⁇ 0.05 x Q1 [kg / s].
• the mass flow rate Q3 of the refrigerant substance 3 will thus be less than or equal to, or even strictly less than, 5% of the mass flow rate Q1 of the gaseous fluid to be compressed 1, and preferably greater than or equal to, or even more strictly than, 1% of said mass flow rate.
• said refrigerant mass flow rate Q3 may be equal to or between 2% and 3%, or even 4%, depending on the adjustment value which will make it possible to obtain the best performances.
• the refrigerant substance 3 is sprayed in the form of particles of maximum dimension less than or equal to 25 ⁇ .
• the particles of refrigerant substance 3 will have a maximum dimension of less than or equal to 10 ⁇ , and, by way of preferential example, of the order of 5 ⁇ .
• the refrigerant particles are assimilated to spheres or spherical droplets, their diameter will be less than or equal to the aforementioned values.
• cooling substance 3 in an even finer form, for example in the form of particles smaller than 5 ⁇ or even 2 ⁇ .
• the creation, preferably upstream of the compressor, of a gaseous fluid 1 charged with refrigerant substance 3, forming a two-phase medium that is both homogeneous and denser than the gaseous fluid alone, is particularly conducive not only to the capture and evacuation by the refrigerant 3 of the heat produced by the compression, and therefore to obtain a quasi-isothermal compression, but also to the dynamic compression of the fluid loaded.
• the heat extraction is optimized, in particular because, due to the excess dosage of refrigerant substance initially present in a condensed state (liquid or solid), only a portion of said refrigerant substance 3 changes state, and more particularly vaporizes or sublimes, during compression, which makes it possible to exploit not only the latent heat of the substance refrigerant 3, during the change of state of the refrigerant substance concerned, but also the specific heat of said refrigerant substance, during heating from a refrigerant substance which remains in the condensed state.
• Any suitable refrigerant 3, and more particularly any substance capable of effecting a phase change, in this particular case, during compression to capture heat may be suitable.
• the cooling substance 3 is formed mainly, and preferably exclusively, by water, and more particularly by droplets of water injected in liquid form.
• This water is preferably demineralized before it is introduced into the refrigeration circuit.
• the refrigerant substance 3 may contain, if necessary mainly or even exclusively, ice water or dry ice, injected in the form of solid particles.
• the dry ice can advantageously capture the heat generated by the compression of the gaseous fluid 1 sublimating at least partially during said compression.
• the compression is preferably carried out by means of a dynamic compressor 2, and more particularly by means of a centrifugal compressor 2 (or "radial compressor”).
• dynamic compressor is meant, as opposed to “volumetric” compressors in which the reduction of a closed volume of gas is forced to increase the pressure, a compressor 2 which allows to obtain a pressure increase by adding the kinetic energy to a continuous stream of fluid, thanks to a rotor or a compression stage, said kinetic energy thus acquired being then transformed into an increase of the static pressure by braking the flow through a diffuser.
• Such a dynamic compression mode is indeed particularly suitable for the acceleration and the dynamic compression of the relatively dense two-phase fluid created by the addition, in the gaseous fluid 1, of the refrigerant substance 3 in the proportions and conditions provided for by the 'invention.
• the method comprises a step (c) of recycling the refrigerant substance during which the cooling substance 3 is separated from the gas stream 1 at the outlet of the compressor 2, by means of a separator 4 such as a condenser or a mist separator, in order to recover at least a part, preferably a majority or even all, said refrigerant substance 3.
• a separator 4 such as a condenser or a mist separator
• the refrigerant substance 3 thus collected and recycled will preferably be cooled before being reinjected into the compressor.
• recycling makes it possible to achieve substantial savings in refrigerant substance 3, and more particularly to considerably reduce the water consumption of the installation that implements the process.
• mist eliminator allowing a mechanical separation of the refrigerant substance 3 by inertia by means of plates or baffles, with the use (nevertheless possible, see combinable with the precedent) of a condenser with thermal operation.
• step (c) of recycling part of the atmospheric water which was initially contained in the air (in the gaseous fluid 1) and which condensed during compression or following said compression, and this atmospheric water is used to purge, which is symbolized by a bleed valve 6 in Figure 1, the circuit 5 for recycling its impurities.
• the quantity of water withdrawn by the separator 4 exceeding the amount of water initially added as the refrigerant substance 3 upstream of the compressor 2 can be used as the difference, which corresponds to the volume of the atmospheric water of which freed compressed air, as rinsing liquid from the recycling circuit 5.
• the gaseous fluid to be compressed 1 is formed by di-nitrogen, and the refrigerant substance 3 by liquid nitrogen, advantageously injected in the form of droplets.
• the compression ratio per compressor stage 2 that is to say the ratio between the compressor outlet pressure and the compressor inlet pressure, may be greater than 2, at 2.5 or even substantially equal to or greater than 5.
• the invention thus makes it possible to significantly increase the performance of the compressor, so that it becomes possible to produce compression operations in a single compression stage which previously required several stages of successive compressors.
• a compressor 2 operating according to the invention makes it possible to obtain, with an inlet pressure of the order of 1 bar (pressure atmospheric), an outlet pressure of the order of 5 bar at 6 bar with two stages of compression instead of 3 usually.
• the temperature increase (with respect to the input ambient temperature) caused by the compression is very largely contained by the refrigeration, and may in particular remain below + 50 ° C.
• the invention makes it possible, at constant compressor wheel size 2, and with respect to operation without injection of refrigerant substance, to increase the compression ratio of the order of 2% to 5% for a given flow rate Q 1 of gaseous fluid 1, or conversely, of increasing the flow rate Q 1 of gaseous fluid 1 treated from 2% to 5% at a given compression ratio constant, which makes it possible to gain in productivity.
• the outlet temperature was close to 70 ° C
• the increase in compression ratio could reach 5%, and was generally included, over said operating range, between 2% and 5%.
• the invention makes it possible to significantly increase the compression ratio of the compressor 2 over the entire operating range of the latter, since the minimum flow point, called the “pumping point", below which the compressor can no longer function stably, up to the point of maximum flow, obtained when said compressor operates with a low resistance downstream.
• the operating ranges envisaged may in particular extend from 50,000 m 3 / h to 100,000 m 3 / h.
• said operating ranges may be between 5,000 m 3 / h and 500,000 m 3 / h (that is to say, correspond to all interval, regardless of its width, which is strictly contained between these two extreme values), or even fully cover a range that extends, preferably continuously, from 5,000 m 3 / h to 500,000 m 3 / h.
• the invention also relates of course to a gaseous fluid compression installation, and in particular to a compressed air production installation, arranged to implement the method according to the invention.
• It relates in particular to facilities capable of handling a large flow of gaseous fluid 1 to be compressed, of the order of 10 4 m 3 / h to 10 6 m 3 / h.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Applications Claiming Priority (2)

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• 2013
  • 2013-12-10 FR FR1362362A patent/FR3014504A1/fr active Pending
• 2014
  • 2014-12-02 US US15/102,940 patent/US10344768B2/en active Active
  • 2014-12-02 CN CN201480066818.1A patent/CN106062339A/zh active Pending
  • 2014-12-02 WO PCT/FR2014/053117 patent/WO2015086951A1/fr active Application Filing
  • 2014-12-02 EP EP14821775.5A patent/EP3080415A1/de not_active Withdrawn

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