Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
  • F01D25/002—Cleaning of turbomachines
• • 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
  • F04D29/705—Adding liquids

Definitions

• the invention relates to a method and a device for removing dirt deposited in an internal part of a turbomachine and, in particular, to the removal of dirt from an internal part of a turbomachine.
• '' a centrifugal compressor without stopping compressor production.
• the fouling of the internal parts of turbomachinery, and in particular of centrifugal compressors, is a phenomenon that the user can hardly control or prevent.
• the conduct of the process implemented in the turbomachine can be modified significantly.
• the pressure and temperature levels or the flow rates in the compressor can be modified due to the formation of deposits in the aerodynamic channels such as the blades or the diffusers of the compressor.
• the mechanical elements of the turbomachine can be subjected to stresses leading to their deterioration. It is therefore necessary to protect these mechanical elements.
• imbalances or variations in thrust generated by deposits on the dynamic parts of the turbomachine and fouling of the internal linings can induce vibrations which are detrimental to the smooth running of the turbomachine.
• fouling of the internal parts of turbomachinery and in particular of centrifugal compressors is a general phenomenon which occurs in all cases during normal operation of the turbomachine. This fouling can reach a level such that it becomes necessary to stop the turbomachine and therefore the current production or manufacturing cycle. It is therefore entirely desirable to have means for removing dirt from the dirty internal part of a turbomachine or limiting the deposition of dirt in this internal part.
• Cleaning processes are also known which are applied outside the sector of the operation of turbomachinery and which use a solvent constituted by a dense fluid under pressure such as carbon dioxide, in the liquid state or even in the supercritical state. .
• carbon dioxide can be used in place of organic solvents.
• Carbon dioxide C0 2 has a critical point at a pressure of 73 bars (7.3 MPa) and at a temperature of 31 ° C.
• These cleaning methods use carbon dioxide at a pressure higher than the critical pressure and at a temperature which can be lower than the critical temperature, the carbon dioxide then being liquid, or even at a temperature higher than the critical temperature, the carbon dioxide then being in a supercritical state intermediate between the liquid and gaseous states.
• C0 2 The pressure and critical temperature values of C0 2 , which are not very difficult to reach, allow fairly easy industrial applications. In the supercritical state, C0 2 dissolves in particular most of the organic compounds.
• turbochargers which have an inlet into which a gas intervening in a process in which the gas undergoes a physical or chemical transformation is introduced, it is generally desirable to continuously carry out the removal of dirt inside the turbocharger, during the operation of this turbocharger. It is possible to introduce into the process gas stream, at the inlet of the turbocharger, a substance capable of dissolving the dirt deposited inside the turbocharger.
• a fluid is recovered consisting of the process gas and the substance in the supercritical state containing the soils in the dissolved state. It is then necessary to carry out a separation of the process gas and the fluid constituted by the substance containing the soils in the dissolved state.
• the regeneration of the substance can only be carried out by lowering the pressure of the substance below the critical pressure, so as to obtain the substance in the gaseous state, and by effecting the separation of the impurities from the substance in the gaseous state.
• the object of the invention is therefore to propose a method for removing dirt in an internal part of a turbomachine during the operation of the turbomachine which comprises an inlet and an outlet for a process gas, into which is introduced, at the inlet of the turbomachine, in the process gas, a substance in the dense state, in particular supercritical, a fluid consists of the process gas and the substance containing impurities constituted by, at the outlet of the turbomachine dirt in the dissolved state, continuous separation is carried out on the fluid to obtain a stream of process gas and a stream of the substance containing the impurities and the substance is recycled in the dense state at the inlet of the turbomachine, this process being able to be implemented industrially, under conditions economic.
• a process gas into which is introduced, at the inlet of the turbomachine, in the process gas, a substance in the dense state, in particular supercritical, a fluid consists of the process gas and the substance containing impurities constituted by, at the outlet of the turbomachine dirt in the dissolved state
• the impurities are separated from the substance in the gaseous state in the fraction of the stream in the gaseous state, the pressure of the substance in the fraction of the stream separated from the impurities is raised and the substance is reintroduced from the stream fraction, in the dense state, in the residual current of the substance containing the impurities before its introduction into the process gas at the inlet of the turbomachine.
• Figure 1 is a schematic view of the cleaning and recycling circuits of the turbocharger.
• FIG. 2 is a temperature-entropy diagram showing the variations in temperature and entropy of the fluids in the circuits shown in FIG. 1.
• FIG. 3 is a pressure-temperature diagram showing the variations in pressure and temperature of the fluids in the circuits of the installation shown in the figure.
• turbocharger 1 used to pressurize a process gas which can be a gas produced or used in an industrial installation, such as a chemical or petrochemical installation.
• the compressor 1 has a low pressure inlet 11 connected to a pipe 2 for the arrival of a process gas and a high pressure outlet 12 connected to a use line 3 via a heat exchanger 5 and a separator 6.
• the separator 6 comprises an inlet pipe 13 receiving the gas coming from the outlet 12 of the compressor via the heat exchanger 5, a first outlet constituted by the use pipe 3 and a second outlet constituted by a line 7 connected via an adjustment valve 8, an intermediate line 14, a heat exchanger 9, a recycling line T and a non-return valve 10 to line 2 inlet of the process gas at the inlet 11 of the turbocharger.
• the fluid introduced into the pipe 2 downstream of the non-return valve 10 is a fluid in a dense state, such as a fluid in the supercritical state and preferably carbon dioxide C0 2 in the supercritical state.
• the C0 2 in the supercritical state, mixed with the process gas, is introduced into the inlet 11 of the turbocharger and circulates inside the turbo-compressor, in contact with the mobile or fixed internal elements of the turbocharger, such as the turbocharger fins and diffusers. Pressurizing the process gas inside the turbocharger 1 makes it possible to maintain the CO 2 in the supercritical state. In this state, the C0 2 very quickly dissolves the dirt deposited on the internal elements of the turbocharger.
• the impurities dissolved in C0 2 in the supercritical state which are generally in the liquid state, constitute, with the C0 2 in the supercritical state and the process gas at high pressure, a mixture of fluids whose temperature is adjusted in the heat exchanger 5 according to the use of the process gas and to liquefy the C0 2 containing the impurities.
• the fluid mixture, adjusted in temperature is sent via line 13 inside the separator 6 which separates the process gas which is evacuated via line 3 and liquid C0 2 containing the dissolved impurities which is evacuated by line 7, at a flow rate Q.
• a second circuit 17 is used to reduce the content of dissolved impurities in the dissolving substance, that is to say the CO 2 separated from the process gas in the separator 6.
• the second circuit, or circuit for separating impurities, 17 comprises a decompression valve 18, a gas and liquid separator 19 and a compressor 20 placed in series with one another and in bypass on line 7, of on either side of the adjustment valve 8.
• the adjustment of the valve 8 makes it possible to pass a predetermined fraction q of the flow rate Q of C0 2 liquid circulating in the pipe 7, in the dirt separation circuit 17, the residual current Qq being received in the part 14 of the pipe 7, downstream of the adjustment valve 8.
• the C0 2 of the flow fraction q sampled in the circuit 17 is therefore in the gaseous state in the part 15 of the circuit 17, upstream of the valve 18.
• the mixture of gases and impurities constituted by the soiling the liquid state enters the separator 19 which separates the gaseous CO 2 and the soiling in the liquid state which is removed from the separator 19, as shown by the arrow 21.
• the purified C0 2 gas is compressed by the compressor 20, which can be constituted by a rotary volumetric type compressor or by a high pressure pump, so that its pressure becomes higher than the critical pressure of the C0, i.e. 7.3 MPa .
• the purified supercritical C0 2 is reintroduced into the intermediate line 14, in the residual current Qq consisting of C0 2 containing liquid impurities.
• the turbocharger can operate continuously with the removal of dirt depositing in its internal part, if the flow q taken from line 7 is sufficient to maintain a state of unsaturation in impurities of supercritical CO 2 introduced into the inlet of the turbocharger.
• the advantage of the process of the invention is to limit the size and the power of the compressor or pump 20. It is therefore necessary to choose a compromise allowing continuous operation of the turbocharger without excessive fouling with a moderate cost d installation and operation of the dirt separation circuit.
• FIG. 2 representing a temperature diagram T-entropy S relating to the circuit represented in FIG. 1, the curve for the change of state 22 of carbon dioxide and the isobars 23 and 24 corresponding to the suction pressure are shown. at the discharge pressure of the turbocharger 1, respectively.
• the top of curve 22 corresponds to the critical point of the carbon dioxide, the left part of curve 22 starting from the critical point corresponding to the boiling curve of C0 2 and the part located to the right of the critical point of the curve 22 corresponding to the dew curve.
• the part of the diagram situated on the right of curve 22 corresponds to the gaseous state and the part situated on the left to the liquid state of C0 2 .
• the different points represented in FIG. 2 and bearing the references 11, 12, 13, 14, 15 and 16 correspond to the elements of the circuits of FIG. 1 having the same references.
• the compression inside the turbocharger is represented by segment 11, 12, the reference point 12 being on curve 24.
• thermodynamic evolution of the main fluid stream, from the inlet of the separator 6 to the inlet of the turbocharger 11, is reflected by the segment 13, 14 between the curves 24 and 23 and the segment 14, 11 on the curve 23 corresponding to the suction pressure.
• the flow portion q sampled by the impurity separation circuit 17 goes from the liquid state to the gaseous state by expansion, then from the gaseous state to the supercritical state by compression.
• thermodynamic cycle corresponding to the circuit of FIG. 1 has also been represented in the pressure-temperature diagram of FIG. 3.
• the C0 2 used in the turbocharger (segment 11, 12) is in the supercritical state and that it passes to the liquid state by cooling in the exchanger 5 (segment 12, 13).
• the residual flow Qq of C0 2 containing impurities passes from the liquid state to the supercritical state by reheating in the exchanger 9 (segment 14,11).
• the flow fraction sampled q goes from the liquid state to the gaseous state, as represented by the segment 13.15, the point 15 being in the domain 31 below the curve 25, corresponding to the gaseous CO 2 .
• the process according to the invention makes it possible to carry out the removal of impurities in the turbocharger, continuously, during the operation of the turbocharger, insofar as the sampled flow q is sufficient to avoid saturation of the C0 2 by impurities from dirt dissolved in the internal part of the turbocharger.
• the invention is not limited to the embodiment which has been described.
• substances other than C0 2 in the dense state in particular supercritical.
• Such substances may for example be water (H 2 0) in certain cases, if it does not contain acid compounds, or light alkanes such as propane (C 3 H 8 ) or pentane (CsH ⁇ 2 ).

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Extraction Or Liquid Replacement (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=9541397

Family Applications (1)

Country Status (5)

Families Citing this family (7)

Family Cites Families (4)

• 1999
  • 1999-01-29 FR FR9901046A patent/FR2789127B1/fr not_active Expired - Fee Related
• 2000
  • 2000-01-05 EP EP00900528A patent/EP1147293B1/de not_active Expired - Lifetime
  • 2000-01-05 DE DE60010042T patent/DE60010042T2/de not_active Expired - Fee Related
  • 2000-01-05 WO PCT/FR2000/000012 patent/WO2000045033A1/fr active IP Right Grant
• 2001
  • 2001-05-29 NO NO20012639A patent/NO20012639D0/no unknown

Non-Patent Citations (1)

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