EP2392825A2 - Method for controlling the operation of a multistage boil-off gas (BOG) compressor - Google Patents
Method for controlling the operation of a multistage boil-off gas (BOG) compressor Download PDFInfo
- Publication number
- EP2392825A2 EP2392825A2 EP11166316A EP11166316A EP2392825A2 EP 2392825 A2 EP2392825 A2 EP 2392825A2 EP 11166316 A EP11166316 A EP 11166316A EP 11166316 A EP11166316 A EP 11166316A EP 2392825 A2 EP2392825 A2 EP 2392825A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- temperature
- pressure stage
- bog
- low pressure
- compression section
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 54
- 230000006835 compression Effects 0.000 claims abstract description 84
- 238000007906 compression Methods 0.000 claims abstract description 84
- 239000003949 liquefied natural gas Substances 0.000 claims abstract description 35
- 238000006073 displacement reaction Methods 0.000 claims description 69
- 239000007789 gas Substances 0.000 abstract description 87
- 238000010586 diagram Methods 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 8
- 238000007796 conventional method Methods 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 239000003345 natural gas Substances 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 238000009834 vaporization Methods 0.000 description 2
- 230000008016 vaporization Effects 0.000 description 2
- 239000000498 cooling water Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/06—Control using electricity
- F04B49/065—Control using electricity and making use of computers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B25/00—Multi-stage pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/10—Other safety measures
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B2205/00—Fluid parameters
- F04B2205/10—Inlet temperature
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B2205/00—Fluid parameters
- F04B2205/11—Outlet temperature
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B2205/00—Fluid parameters
- F04B2205/11—Outlet temperature
- F04B2205/112—Outlet temperature between two stages in a multi-stage pump
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B2207/00—External parameters
- F04B2207/01—Load in general
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2221/00—Handled fluid, in particular type of fluid
- F17C2221/03—Mixtures
- F17C2221/032—Hydrocarbons
- F17C2221/033—Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2223/00—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel
- F17C2223/01—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel characterised by the phase
- F17C2223/0146—Two-phase
- F17C2223/0153—Liquefied gas, e.g. LPG, GPL
- F17C2223/0161—Liquefied gas, e.g. LPG, GPL cryogenic, e.g. LNG, GNL, PLNG
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2223/00—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel
- F17C2223/03—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel characterised by the pressure level
- F17C2223/033—Small pressure, e.g. for liquefied gas
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2223/00—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel
- F17C2223/04—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel characterised by other properties of handled fluid before transfer
- F17C2223/042—Localisation of the removal point
- F17C2223/043—Localisation of the removal point in the gas
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2223/00—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel
- F17C2223/04—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel characterised by other properties of handled fluid before transfer
- F17C2223/042—Localisation of the removal point
- F17C2223/046—Localisation of the removal point in the liquid
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2225/00—Handled fluid after transfer, i.e. state of fluid after transfer from the vessel
- F17C2225/01—Handled fluid after transfer, i.e. state of fluid after transfer from the vessel characterised by the phase
- F17C2225/0107—Single phase
- F17C2225/0123—Single phase gaseous, e.g. CNG, GNC
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2225/00—Handled fluid after transfer, i.e. state of fluid after transfer from the vessel
- F17C2225/03—Handled fluid after transfer, i.e. state of fluid after transfer from the vessel characterised by the pressure level
- F17C2225/035—High pressure, i.e. between 10 and 80 bars
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2227/00—Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
- F17C2227/01—Propulsion of the fluid
- F17C2227/0128—Propulsion of the fluid with pumps or compressors
- F17C2227/0135—Pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2227/00—Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
- F17C2227/01—Propulsion of the fluid
- F17C2227/0128—Propulsion of the fluid with pumps or compressors
- F17C2227/0157—Compressors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2227/00—Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
- F17C2227/01—Propulsion of the fluid
- F17C2227/0128—Propulsion of the fluid with pumps or compressors
- F17C2227/0171—Arrangement
- F17C2227/0185—Arrangement comprising several pumps or compressors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2227/00—Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
- F17C2227/03—Heat exchange with the fluid
- F17C2227/0302—Heat exchange with the fluid by heating
- F17C2227/0309—Heat exchange with the fluid by heating using another fluid
- F17C2227/0316—Water heating
- F17C2227/0318—Water heating using seawater
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2227/00—Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
- F17C2227/03—Heat exchange with the fluid
- F17C2227/0367—Localisation of heat exchange
- F17C2227/0388—Localisation of heat exchange separate
- F17C2227/0393—Localisation of heat exchange separate using a vaporiser
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2250/00—Accessories; Control means; Indicating, measuring or monitoring of parameters
- F17C2250/03—Control means
- F17C2250/032—Control means using computers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2250/00—Accessories; Control means; Indicating, measuring or monitoring of parameters
- F17C2250/04—Indicating or measuring of parameters as input values
- F17C2250/0404—Parameters indicated or measured
- F17C2250/043—Pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2250/00—Accessories; Control means; Indicating, measuring or monitoring of parameters
- F17C2250/04—Indicating or measuring of parameters as input values
- F17C2250/0404—Parameters indicated or measured
- F17C2250/0439—Temperature
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2250/00—Accessories; Control means; Indicating, measuring or monitoring of parameters
- F17C2250/06—Controlling or regulating of parameters as output values
- F17C2250/0605—Parameters
- F17C2250/0636—Flow or movement of content
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2250/00—Accessories; Control means; Indicating, measuring or monitoring of parameters
- F17C2250/07—Actions triggered by measured parameters
- F17C2250/072—Action when predefined value is reached
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2260/00—Purposes of gas storage and gas handling
- F17C2260/02—Improving properties related to fluid or fluid transfer
- F17C2260/023—Avoiding overheating
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2265/00—Effects achieved by gas storage or gas handling
- F17C2265/03—Treating the boil-off
- F17C2265/032—Treating the boil-off by recovery
- F17C2265/037—Treating the boil-off by recovery with pressurising
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2265/00—Effects achieved by gas storage or gas handling
- F17C2265/05—Regasification
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2270/00—Applications
- F17C2270/01—Applications for fluid transport or storage
- F17C2270/0134—Applications for fluid transport or storage placed above the ground
- F17C2270/0136—Terminals
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2270/00—Applications
- F17C2270/05—Applications for industrial use
- F17C2270/0581—Power plants
Definitions
- the present invention relates to a method for controlling the operation of a BOG multistage displacement compressor that compresses boil off gas (hereinafter referred to as "BOG"), which is vaporized naturally within a tank storing liquefied natural gas (LNG), and supplies the BOG to a plant. More particularly, the present invention relates to a method for controlling the operation of a BOG multistage displacement compressor, by which its low pressure stage-side discharge gas temperature is controlled not to exceed a temperature allowable for the operation of a low pressure stage compressor.
- BOG boil off gas
- a BOG generated by natural vaporization within an LNG storage tank, is pressurized to a pressure, which is suitable for delivery of natural gas to a power generation plant, city gas equipment or the like, by a BOG compressor, and then the BOG is joined together with a natural gas, which is discharged from an evaporator and main part of the gases, then the thus-joined gases are delivered to each of above equipment.
- the temperature of BOG becomes higher at higher compression rate.
- the temperature of BOG discharged from the LNG storage tank rises to near a normal temperature
- the temperature of suction gas of the BOG compressor rises to a high temperature near the normal temperature (e.g., 30°C).
- the discharge pressure is 0.9 MPa, for example, the temperature of the discharge gas from the BOG compressor rises to about 300°C that exceeds a temperature allowable for the operation of the compressor, e.g., 180°C, and thus the operation can not be continued.
- Fig. 6 is a diagram showing the structure of LNG and BOG treatment equipment, to which a conventional operation controlling method is applied.
- a BOG multistage compressor 38 related to this conventional technique includes a three-way valve 43, a cooler 45, temperature sensors 41, 42 and a control unit 46 for switching the three-way valve 43.
- two operation modes can be switched by switching the three-way valve 43; two operation modes include an operation mode 1 in which discharge gas from a low pressure stage-side compression section 39 is cooled by the cooler 45, the discharge gas having thus lowered temperature is supplied to a high pressure stage-side compression section 40, and an operation mode 2 in which discharge gas from the low pressure stage-side compression section 39 is supplied to the high pressure stage-side compression section 40 without passing through the cooler 45.
- the temperature of discharge gas from the high pressure stage-side compression section 40 can be made lower than that in the operation mode 2.
- the operation mode 1 is carried out in the case where, at the start-up of the BOG multistage compressor 38, the suction gas temperature of the lower pressure stage-side compression section 39 is higher (e.g., 30°C than that in a steady operation (e.g., -130°C), and there is a fear that the temperature of discharge gas from the high pressure stage-side compression section 40 exceeds a temperature allowable for the operation.
- the operation mode 2 is carried out in a steady operation of the BOG multistage compressor 38.
- Switching between the two operation modes is performed in the following manner.
- the control unit 46 switches the three-way valve 43 to stop the operation in the operation mode 2 and start the operation in the operation mode 1.
- the control unit 46 stops the operation in the operation mode 1 and starts the operation in the operation mode 2.
- the low pressure stage-side discharge gas is cooled by the cooler 45, and the discharge gas having thus lowered temperature is supplied to the high pressure stage-side compression section 40 (operation mode 1), thereby preventing the temperature of the high pressure stage-side discharge gas from exceeding the temperature allowable for the operation.
- the BOG multistage compressor 38 related to the above conventional technique has a function of controlling the temperature of discharge gas from the high pressure stage-side compression section 40, but does not have a function of controlling the temperature of discharge gas from the low pressure stage-side compression section 39. Therefore, for preventing the low pressure stage-side discharge gas temperature from exceeding the temperature allowable for the operation of the low pressure stage side, it is necessary to reduce a low pressure stage-side compression ratio.
- the low pressure stage-side compression section 39 in the BOG multistage compressor 38 sucks in gas at about -140°C to -130°C, for example, and discharges gas at about -50°C to -40°C, for example.
- the low pressure stage-side compression section 39 has such a character that it is not cooled with cooling water. Therefor, the temperature allowable for the operation is limited for the low pressure stage in the BOG multistage compressor 38, in comparison to the high pressure stage of the BOG multistage compressor 38 and a compressor that sucks in gas at normal temperature.
- Patent Document 1 Japanese Patent Laid-Open No. 2002-213366
- a method for controlling the operation of a BOG multistage displacement compressor including plural stages of displacement compression sections, which are connected with each other, for compressing BOG generated from liquefied natural gas includes: in case of a predetermined condition, making a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section in the BOG multistage displacement compressor (load ratio) smaller than load ratios in case of conditions other than the predetermined condition.
- the "load” as referred to herein indicates a nominal value of a ratio between "a gas treatment volume attained by a capacity adjusting device” and "a gas treatment volume in case of the capacity adjusting device being not operated” (the "gas treatment volume in case of the capacity adjusting device being not operated” corresponds to a treatment volume at 100% load).
- suction temperature of the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and the predetermined condition is a condition where a detected temperature of the suction temperature is not lower than a first preset temperature, in the method for controlling the operation of a BOG multistage displacement compressor according to the above first aspect.
- discharge temperature from the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and the predetermined condition is a condition from judgment that a detected temperature of the discharge temperature is not lower than a second preset temperature until judgment that the detected temperature has reached a third preset temperature lower than the second preset temperature, in the method for controlling the operation of a BOG multistage displacement compressor according to the above first aspect.
- a method for controlling the operation of a BOG multistage displacement compressor including plural stages of displacement compression sections, which are connected with each other, for compressing BOG generated from liquefied natural gas includes: in case of a predetermined condition, making a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section in the BOG multistage displacement compressor (load ratio) smaller than load ratios in case of conditions other than the predetermined condition. Since the operation is performed at a low load ratio R, that is, the compression ratio of the low pressure stage compression section is made smaller, the temperature of low pressure stage-side discharge gas consequently drops. Thus, even when the temperature of low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the low pressure stage-side discharge gas temperature from exceeding the temperature allowable for the operation.
- suction temperature of the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and the predetermined condition is a condition where a detected temperature of the suction temperature is not lower than a first preset temperature. Therefore, even when the temperature of the low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the temperature of the low pressure stage-side discharge gas from exceeding the temperature allowable for the operation, as similarly as in the above first aspect.
- discharge temperature from the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and the predetermined condition is a condition from judgment that a detected temperature of the discharge temperature is not lower than a second preset temperature until judgment that the detected temperature has reached a third preset temperature lower than the second preset temperature. Therefore, even when the temperature of the low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the temperature of the low pressure stage-side discharge gas from exceeding the temperature allowable for the operation, as similarly as in the above first aspect.
- the temperature of discharge gas from the low pressure stage compression section which is an object of the control, is directly detected, and the detected temperature is used as an input for the control, it is possible to surely prevent the temperature of low pressure stage-side discharge gas from exceeding the temperature allowable for the operation, even when the low pressure stage-side discharge gas temperature changes greatly as a result of a change in the amount of gas the supply destination demands.
- a method for controlling the operation of a BOG multistage displacement compressor according to a first embodiment of the present invention will be described by exemplifying a case, in which a reciprocating compressor is applied to the BOG multistage compressor, with reference to Figs. 1 and 2 .
- Fig. 1 is a system diagram of LNG and BOG treatment equipment, to which the method for controlling the operation of a BOG multistage displacement compressor of the first embodiment of the present invention is applied.
- Fig. 2 is a diagram showing changes of BOG temperature with time just after a start-up in case the method for controlling the operation of a BOG multistage displacement compressor of the first embodiment of the present invention is used.
- the BOG multistage displacement compressor is a BOG multistage compressor 8 that is for compressing BOG generated by natural vaporization within an LNG storage tank 2 that stores liquefied natural gas (LNG) 1 and for supplying the thus-compressed BOG to a plant (not shown).
- the BOG multistage compressor 8 is a reciprocating compressor including a low pressure stage compression section 9 and a high pressure stage compression section 10.
- the capacity of the low pressure stage compression section 9 can be adjusted by a low pressure stage capacity adjusting device 21 including a suction valve unloader 9a and a head end unloader 9b.
- the capacity of the high pressure stage compression section 10 can be adjusted by a high pressure stage capacity adjusting device 22 including a suction valve unloader 10a and a head end unloader 10b.
- an LNG conducting line 3 is connected to the LNG storage tank 2 for liquefied natural gas (LNG) 1.
- An LNG pump 4 and an evaporator 5 using sea water, for example, for evaporating LNG are connected to the line 3.
- a gas conveying line 6 for conveying vaporized gas is connected to, for example, a gas turbine in a power generation plant (not shown).
- a BOG delivery line 7 is connected to the top of the LNG storage tank 2 and the BOG multistage compressor 8 is connected to the BOG delivery line 7.
- the BOG multistage compressor 8 is configured such that both low pressure stage compression section 9 and high pressure stage compression section 10 are simultaneously driven by a single drive motor 11.
- the BOG delivery line 7 is connected to a suction side of the low pressure stage compression section 9.
- An intermediate line 12 connects a discharge side of the low pressure stage compression section 9 with a suction side of a high pressure stage compression section 10.
- a discharge line 17 disposed on a discharge side of the high pressure stage compression section 10 in the BOG multistage compressor 8 is connected to the gas conveying line 6 through a confluence section 23.
- a pressure sensor 24 is provided in the LNG storage tank 2 for detecting the pressure of BOG therein. Its detected value is inputted to a control unit 25.
- the control unit 25 controls the operation of the BOG multistage compressor 8 in such a manner that when the pressure of BOG in the tank 2 detected by the pressure sensor 24 exceeds a preset pressure, the compressor 8 is turned on, while when the pressure of BOG in the tank 2 has lowered to a predetermined value, the compressor 8 is turned off.
- a temperature curve A represents a low pressure stage-side suction gas temperature
- a temperature curve B represents a low pressure stage-side discharge gas temperature at position P1 on the intermediate line 12 shown in Fig. 1 .
- the suction gas temperature of the low pressure stage compression section 9 (temperature of BOG delivered from the LNG storage tank 2) keeps the substantially same value as a value at the start-up for an extremely short time, and thereafter drops gradually as indicated by the temperature curve A in Fig. 2 .
- a load ratio R of the BOG multistage compressor 8 (a ratio of a load on the low pressure stage compression section 9 to a load on the high pressure stage compression section 10 in the BOG multistage compressor 8) is the same as in a steady operation
- the low pressure stage discharge gas temperature starts from a value at the start-up and once rises to a peak temperature, as indicated by a two-dot chain line in the temperature curve B shown in Fig. 2 , and then gradually drops according to the change of the temperature curve A.
- the low pressure stage-side discharge gas temperature starts from the value at the start-up, exceeds a temperature Th1 allowable for the operation, once rises to the peak temperature and then drops gradually, as indicated by the two-dot chain line in the temperature curve B shown in Fig. 2 .
- the control unit 25 Upon start-up of the BOG multistage compressor 8, the control unit 25 compares temperature of low pressure stage-side suction gas, which is detected by a temperature sensor 26, with a first preset temperature T1 preset in the control unit 25. Then, if the detected temperature of the low pressure stage-side suction gas is not lower than the first preset temperature T1, the control unit 25 controls the operation of the low pressure stage capacity adjusting device 21 and that of the high pressure stage capacity adjusting device 22 so that the load ratio R becomes lower than that in a steady operation. The control unit 25 controls so as to set a low pressure stage-side load and a high pressure stage-side load of to 25% and 50%, respectively, for example.
- the low pressure stage-side discharge pressure is reduced, and the low pressure stage-side discharge gas temperature is consequently inhibited from rising and suppressed to a temperature not higher than the temperature Th1 allowable for the operation, as indicated by the temperature curve B in Fig. 2 .
- the low pressure stage-side suction gas temperature gradually reduces as mentioned above.
- the control unit 25 compares the temperature of low pressure stage-side suction gas, which is detected by the temperature sensor 26, with the first preset temperature T1. As a result of the comparison, if the detected temperature of the low pressure stage-side suction gas reaches (or becomes lower than) the first preset temperature T1, the control unit 25 controls the operation of the low pressure stage capacity adjusting device 21 and that of the high pressure stage capacity adjusting device 22 so as to make the load ratio R the same as that in a steady operation.
- control unit 25 controls so as to set both low and high pressure stage-side loads to 100%.
- the temperature of the low pressure stage-side discharge gas rises temporarily, but does not reach Th1. Thereafter, the low pressure stage-side suction gas temperature and the low pressure stage-side discharge gas temperature drop gradually and reach a stable state where each of them is maintained within a certain range.
- the suction temperature of the low pressure stage compression section 9 of the multistage displacement compressor 8 is made detectable, and the above predetermined condition is a condition where the detected suction temperature is not lower than the first preset temperature T1. Therefore, as described above, even when the temperature of low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the temperature of low pressure stage-side discharge gas from exceeding the temperature allowable for operation.
- both first stage-side compression section 9 and second stage-side compression section 10 are operated at 100% load (Comparative Example-1 in Table 1).
- the first stage-side compression section 9 is operated at 25% load and the second stage-side compression section 10 is operated at 50% load by the capacity adjusting devices 21 (the suction valve unloader 9a, the head end unloader 9b and the like) and 22 (the suction valve unloader 10a, the head end unloader 10b and the like) in the first and second stage-side compression sections 9 and 10. That is, load ratio at the start-up is smaller than load ratio in a steady operation (see Example in Table 1).
- Table 1 states at the start-up of conventional BOG multistage displacement compressors are listed in Table 1 to show the effect of the present invention.
- One is an operation state in which both first stage-side compression section 9 and second stage-side compression section 10 operate at 25% load (Comparative Example-3 in Table 1).
- the other is an operation state in which both first and second stage-side compression sections 9 and 10 operate at 50% load (Comparative Example-2 in Table 1).
- the load ratio is the same as in a steady operation.
- Table 2 shows, for each of the operation examples in Fig. 1 , suction and discharge temperatures of the first stage-side compression section 9, and suction and discharge gas pressures of the first stage-side compression section 9 and the second stage-side compression section 10.
- the first stage-side discharge temperature is about -50°C.
- the first stage-side discharge temperature reaches as high as about 155°C (more particularly, 153°C and 156°C in Comparative Examples-2 and -3, respectively), as shown in Comparative Examples-2 and -3 in Table 2.
- the first stage-side discharge temperature is suppressed to about 135°C (more particularly, 136°C in Example), as shown in Example in Table 2.
- the first stage-side discharge pressure is suppressed to about 335 kPa in Example, in comparison to about 405 kPa (more particularly, 404 kPa) in Comparative Examples-2, 3, by making the load ratio smaller than that in a steady operation,.
- a method for controlling the operation of a BOG multistage displacement compressor according to a second embodiment of the present invention will be described by exemplifying a case, in which a screw compressor is applied to the BOG multistage compressor, with reference to Fig. 3.
- Fig. 3 is a system diagram of LNG and BOG treatment equipment, to which the method for controlling the operation of a BOG multistage displacement compressor according to a second embodiment of the present invention is applied.
- This second embodiment of the present invention differs from the first embodiment in the type of a BOG multistage displacement compressor and the structure of both low and high pressure stage capacity adjusting devices. Since the second embodiment has the completely same structure as in the first embodiment except the above differences, the same components as in the first embodiment are given the same reference numerals, and the differences will be described below.
- the capacity of the low pressure stage compression section 9 is adjusted by the low pressure stage capacity adjusting device 21 that includes the suction valve unloader 9a and the head end unloader 9b, while the capacity of the high pressure stage compression section 10 is adjusted by the high pressure stage capacity adjusting device 22 that includes the suction valve unloader 10a and the head end unloader 10b.
- a BOG multistage compressor 18 to which the method for controlling the operation of a BOG multistage displacement compressor according to the second embodiment shown in Fig. 3 is applied and which includes a screw type compressor, the capacity of a low pressure stage compression section 19 is adjusted by a low pressure stage capacity adjusting device that includes a slide valve 19a, while the capacity of a high pressure stage compression section 20 is adjusted by a high pressure stage capacity adjusting device that includes a slide valve 20a.
- a suction temperature of the low pressure stage compression section 19 of the BOG multistage displacement compressor 18 is made detectable, and the above predetermined condition is a condition in which the detected suction temperature is not lower than a first preset temperature T1, as similarly as the first embodiment. Therefore, even when the temperature of low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the temperature of low pressure stage-side discharge gas from exceeding a temperature allowable for the operation.
- a method for controlling the operation of a BOG multistage displacement compressor according to a third embodiment of the present invention will be described by exemplifying a case where a reciprocating compressor is applied to the BOG multistage compressor with reference to Figs. 4 and 5 .
- Fig. 4 is a system diagram of LNG and BOG treatment equipment, to which the method for controlling the operation of a BOG multistage displacement compressor according to a third embodiment of the present invention is applied.
- Fig. 5 is a diagram showing changes of BOG temperature with time just after a start-up in case the method for controlling the operation of a BOG multistage displacement compressor of a third embodiment of the present invention is used.
- This third embodiment of the present invention differs from the above first embodiment in a mounting position of a temperature sensor and a method for controlling the operation. Since the third embodiment has the completely same structure as in the first embodiment except the differences, the same components as in the first embodiment are given the same reference numerals, and the differences will be described below.
- the temperature of low pressure stage-side suction gas is detected by the temperature sensor 26 disposed in the BOG delivery line 7, and the operation is controlled, by the operation controlling method (No.1).
- the temperature of low pressure stage-side discharge gas is detected by a temperature sensor 27 disposed in the intermediate line 12, and the operation of is controlled by an operation controlling method (No. 2) that will be described below.
- the control unit 25 compares the temperature of low pressure stage-side discharge gas, which is detected by the temperature detector 27, with a second preset temperature T2, which is preset in the control unit 25. As shown in Fig. 5 , in an extremely short period just after start-up, the detected temperature of low pressure stage-side discharge gas is lower than the second preset temperature T2. Thus, during this period, the load ratio R is the same as that in a steady operation.
- control unit 25 controls the operation of the low pressure stage capacity adjusting device 21 and that of the high pressure stage capacity adjusting device 22 so as to make the load ratio R lower than that in a steady operation.
- control unit 25 controls so as to set a low pressure stage-side load and a high pressure stage-side load to 25% and 50%, respectively.
- the low pressure stage-side discharge pressure is reduced, and the low pressure stage-side discharge gas temperature is consequently inhibited from rising and suppressed to a temperature not higher than the temperature Th1 allowable for the operation, as indicated by the temperature curve B in Fig. 5 .
- the low pressure stage-side suction gas temperature gradually reduces as mentioned above.
- the control unit 25 controls the operation of the low pressure stage capacity adjusting device 21 and that of the high pressure stage capacity adjusting device 22 so as to make the load ratio R to be the same as that in a steady operation. For example, the control unit 25 sets both the low pressure stage-side load and the high pressure stage-side load to 25%. As a result, the temperature of low pressure stage-side discharge gas rises temporarily, but does not reach Th1. Thereafter, the low pressure stage-side suction gas temperature and the low pressure stage-side discharge gas temperature drop gradually and reach a stable state where each of them is maintained within a certain range.
- the discharge gas temperature of the low pressure stage compression section 9 of the BOG multistage displacement compressor 8 is made detectable, and a predetermined condition is a condition from judgment that the detected temperature of the discharge temperature is not lower than the second preset temperature T2 until judgment that the detected temperature has reached the third preset temperature T3 lower than the second preset temperature T2. Therefore, even if the temperature of low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the temperature of low pressure stage-side discharge gas from exceeding the temperature allowable for the operation.
- the method for controlling the operation of a BOG multistage displacement compressor includes: in case of a predetermined condition, making a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section in the BOG multistage displacement compressor (load ratio) R smaller than load ratios in case of conditions other than the predetermined condition. Since the operation is consequently performed at a low load ratio R, that is, the compression ratio of the low pressure stage compression section is made smaller, the temperature of low pressure stage-side discharge gas consequently drops. Thus, even when the temperature of low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the low pressure stage-side discharge gas temperature from exceeding the temperature allowable for the operation.
- the methods for controlling the operation of a BOG multistage displacement compressor according to the present invention have been described by exemplifying a reciprocating compressor and a screw type compressor, and the capacity adjusting devices are described by exemplifying suction valve unloaders, head end unloaders and slide valves.
- the present invention is, however, not limited thereto, but the method for controlling the operation of a BOG multistage displacement compressor according to the present invention is also applicable to various types of displacement compressors and BOG displacement compressors having capacity adjusting devices of various structures.
- LNG Liquefied natural gas
- 2 LNG storage tank
- 3 LNG conducting line
- 4 LNG pump
- 5 Evaporator
- 6 Gas conveying line
- 7 BOG delivery line
- 8 BOG multistage (displacement) compressor (Reciprocating compressor)
- 9 Low pressure stage compression section (First stage-side compression section)
- 9a Suction valve unloader
- 9b Head end unloader
- 10 High pressure stage compression section
- 10a Suction valve unloader
- 10b Head end unloader
- 11 Drive motor
- 12 Intermediate line
- 17 Discharge line
- 18 BOG multistage (displacement) compressor (Screw type compressor)
- 19a Slide valve
- 20 High pressure stage compression section
- 20a Slide valve
- 21 Low pressure stage capacity adjusting device
- 22 High pressure stage capacity adjusting device
- 23 Confluence section
- 24 Pressure sensor
- 25 Control unit
- 26, 27 Temperature sensor
- a method for controlling the operation of a BOG multistage displacement compressor including plural stages of displacement compression sections, which are connected with each other, for compressing BOG generated from liquefied natural gas includes: in case of a predetermined condition, making a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section in the BOG multistage displacement compressor (load ratio) smaller than load ratios in case of conditions other than the predetermined condition.
- load ratio a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section in the BOG multistage displacement compressor (load ratio) smaller than load ratios in case of conditions other than the predetermined condition.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Control Of Positive-Displacement Pumps (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
Description
- The present invention relates to a method for controlling the operation of a BOG multistage displacement compressor that compresses boil off gas (hereinafter referred to as "BOG"), which is vaporized naturally within a tank storing liquefied natural gas (LNG), and supplies the BOG to a plant. More particularly, the present invention relates to a method for controlling the operation of a BOG multistage displacement compressor, by which its low pressure stage-side discharge gas temperature is controlled not to exceed a temperature allowable for the operation of a low pressure stage compressor.
- In an LNG plant, a BOG, generated by natural vaporization within an LNG storage tank, is pressurized to a pressure, which is suitable for delivery of natural gas to a power generation plant, city gas equipment or the like, by a BOG compressor, and then the BOG is joined together with a natural gas, which is discharged from an evaporator and main part of the gases, then the thus-joined gases are delivered to each of above equipment.
- Because the BOG is adiabatically compressed in the BOG compressor, the temperature of BOG becomes higher at higher compression rate. Particularly at the time of start-up of the BOG compressor, the temperature of BOG discharged from the LNG storage tank rises to near a normal temperature, and the temperature of suction gas of the BOG compressor rises to a high temperature near the normal temperature (e.g., 30°C). If the compression of the BOG is continued without applying any process to the BOG, and if the discharge pressure is 0.9 MPa, for example, the temperature of the discharge gas from the BOG compressor rises to about 300°C that exceeds a temperature allowable for the operation of the compressor, e.g., 180°C, and thus the operation can not be continued.
- A conventional technique for solving such a problem of the BOG compressor will be described below with reference to
Fig. 6. Fig. 6 is a diagram showing the structure of LNG and BOG treatment equipment, to which a conventional operation controlling method is applied. - A BOG
multistage compressor 38 related to this conventional technique includes a three-way valve 43, a cooler 45,temperature sensors 41, 42 and acontrol unit 46 for switching the three-way valve 43. In the BOGmultistage compressor 38, two operation modes can be switched by switching the three-way valve 43; two operation modes include anoperation mode 1 in which discharge gas from a low pressure stage-side compression section 39 is cooled by the cooler 45, the discharge gas having thus lowered temperature is supplied to a high pressure stage-side compression section 40, and anoperation mode 2 in which discharge gas from the low pressure stage-side compression section 39 is supplied to the high pressure stage-side compression section 40 without passing through the cooler 45. - In the
operation mode 1, the temperature of discharge gas from the high pressure stage-side compression section 40 can be made lower than that in theoperation mode 2. Theoperation mode 1 is carried out in the case where, at the start-up of the BOGmultistage compressor 38, the suction gas temperature of the lower pressure stage-side compression section 39 is higher (e.g., 30°C than that in a steady operation (e.g., -130°C), and there is a fear that the temperature of discharge gas from the high pressure stage-side compression section 40 exceeds a temperature allowable for the operation. On the other hand, theoperation mode 2 is carried out in a steady operation of the BOGmultistage compressor 38. - Switching between the two operation modes is performed in the following manner. In other words, when the temperature of high pressure stage-side discharge gas is detected to be higher than a preset temperature by the
temperature sensor 41, thecontrol unit 46 switches the three-way valve 43 to stop the operation in theoperation mode 2 and start the operation in theoperation mode 1. On the other hand, when conditions; which indicate that there is no fear of the high pressure stage-side discharge gas temperature exceeding the temperature allowable for the operation, are satisfied, thecontrol unit 46 stops the operation in theoperation mode 1 and starts the operation in theoperation mode 2. By this operation controlling method, it is possible to prevent the discharge gas temperature from the high pressure stage-side compressor 40 from exceeding the temperature allowable for the operation (see Patent Document 1). - That is, according to the above conventional technique, when there is a fear that the temperature of the high pressure stage-side discharge gas may exceed the temperature allowable for the operation, the low pressure stage-side discharge gas is cooled by the cooler 45, and the discharge gas having thus lowered temperature is supplied to the high pressure stage-side compression section 40 (operation mode 1), thereby preventing the temperature of the high pressure stage-side discharge gas from exceeding the temperature allowable for the operation.
- The BOG
multistage compressor 38 related to the above conventional technique has a function of controlling the temperature of discharge gas from the high pressure stage-side compression section 40, but does not have a function of controlling the temperature of discharge gas from the low pressure stage-side compression section 39. Therefore, for preventing the low pressure stage-side discharge gas temperature from exceeding the temperature allowable for the operation of the low pressure stage side, it is necessary to reduce a low pressure stage-side compression ratio. - In this case, however, the number of stages in the compressor increases, resulting in increase of size and cost. In a steady operation, the low pressure stage-
side compression section 39 in the BOGmultistage compressor 38 sucks in gas at about -140°C to -130°C, for example, and discharges gas at about -50°C to -40°C, for example. Thus, the low pressure stage-side compression section 39 has such a character that it is not cooled with cooling water. Therefor, the temperature allowable for the operation is limited for the low pressure stage in the BOGmultistage compressor 38, in comparison to the high pressure stage of the BOGmultistage compressor 38 and a compressor that sucks in gas at normal temperature. - [Patent Document 1]
Japanese Patent Laid-Open No.2002-213366 - Accordingly, it is an object of the present invention to provide a method for controlling the operation of a BOG multistage displacement compressor, capable of preventing the temperature of low pressure stage-side discharge gas from exceeding a temperature allowable for the operation, even when the temperature of low pressure stage-side suction gas is higher than that in a steady operation.
- For achieving the above-mentioned object, according to a first aspect of the present invention, there is provided a method for controlling the operation of a BOG multistage displacement compressor including plural stages of displacement compression sections, which are connected with each other, for compressing BOG generated from liquefied natural gas, includes: in case of a predetermined condition, making a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section in the BOG multistage displacement compressor (load ratio) smaller than load ratios in case of conditions other than the predetermined condition.
- The "load" as referred to herein indicates a nominal value of a ratio between "a gas treatment volume attained by a capacity adjusting device" and "a gas treatment volume in case of the capacity adjusting device being not operated" (the "gas treatment volume in case of the capacity adjusting device being not operated" corresponds to a treatment volume at 100% load).
- According to a second aspect of the present invention, suction temperature of the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and the predetermined condition is a condition where a detected temperature of the suction temperature is not lower than a first preset temperature, in the method for controlling the operation of a BOG multistage displacement compressor according to the above first aspect.
- According to a third aspect of the present invention, discharge temperature from the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and the predetermined condition is a condition from judgment that a detected temperature of the discharge temperature is not lower than a second preset temperature until judgment that the detected temperature has reached a third preset temperature lower than the second preset temperature, in the method for controlling the operation of a BOG multistage displacement compressor according to the above first aspect.
- According to a first aspect of the present invention, a method for controlling the operation of a BOG multistage displacement compressor including plural stages of displacement compression sections, which are connected with each other, for compressing BOG generated from liquefied natural gas, includes: in case of a predetermined condition, making a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section in the BOG multistage displacement compressor (load ratio) smaller than load ratios in case of conditions other than the predetermined condition. Since the operation is performed at a low load ratio R, that is, the compression ratio of the low pressure stage compression section is made smaller, the temperature of low pressure stage-side discharge gas consequently drops. Thus, even when the temperature of low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the low pressure stage-side discharge gas temperature from exceeding the temperature allowable for the operation.
- According to the method for controlling the operation of a BOG multistage displacement compressor according to a second aspect of the present invention, suction temperature of the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and the predetermined condition is a condition where a detected temperature of the suction temperature is not lower than a first preset temperature. Therefore, even when the temperature of the low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the temperature of the low pressure stage-side discharge gas from exceeding the temperature allowable for the operation, as similarly as in the above first aspect.
- According to the method for controlling the operation of the BOG multistage displacement compressor according to a third aspect of the present invention, discharge temperature from the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and the predetermined condition is a condition from judgment that a detected temperature of the discharge temperature is not lower than a second preset temperature until judgment that the detected temperature has reached a third preset temperature lower than the second preset temperature. Therefore, even when the temperature of the low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the temperature of the low pressure stage-side discharge gas from exceeding the temperature allowable for the operation, as similarly as in the above first aspect.
- Since the temperature of discharge gas from the low pressure stage compression section, which is an object of the control, is directly detected, and the detected temperature is used as an input for the control, it is possible to surely prevent the temperature of low pressure stage-side discharge gas from exceeding the temperature allowable for the operation, even when the low pressure stage-side discharge gas temperature changes greatly as a result of a change in the amount of gas the supply destination demands.
-
-
Fig. 1 is a system diagram of LNG and BOG treatment equipment, to which a method for controlling the operation of a BOG multistage displacement compressor according to a first embodiment of the present invention, is applied; -
Fig. 2 is a diagram showing changes in BOG temperature with time just after start-up in case the method for controlling the operation of a BOG multistage displacement compressor according to a first embodiment of the present invention is used; -
Fig. 3 is a system diagram of LNG and BOG treatment equipment, to which a method for controlling the operation of a BOG multistage displacement compressor according to a second embodiment of the present invention, is applied; -
Fig. 4 is a system diagram of LNG and BOG treatment equipment, to which a method for controlling the operation of a BOG multistage displacement compressor according to a third embodiment of the present invention, is applied; -
Fig. 5 is a diagram showing changes in BOG temperature with time just after start-up in case the method for controlling the operation of a BOG multistage displacement compressor according to a third embodiment of the present invention is used; and -
Fig. 6 is a diagram showing the structure of LNG and BOG treatment equipment, to which a conventional operation controlling method is applied. - First, a method for controlling the operation of a BOG multistage displacement compressor according to a first embodiment of the present invention will be described by exemplifying a case, in which a reciprocating compressor is applied to the BOG multistage compressor, with reference to
Figs. 1 and2 .Fig. 1 is a system diagram of LNG and BOG treatment equipment, to which the method for controlling the operation of a BOG multistage displacement compressor of the first embodiment of the present invention is applied.Fig. 2 is a diagram showing changes of BOG temperature with time just after a start-up in case the method for controlling the operation of a BOG multistage displacement compressor of the first embodiment of the present invention is used. - The BOG multistage displacement compressor according to the first embodiment of the present invention is a BOG multistage compressor 8 that is for compressing BOG generated by natural vaporization within an
LNG storage tank 2 that stores liquefied natural gas (LNG) 1 and for supplying the thus-compressed BOG to a plant (not shown). The BOG multistage compressor 8 is a reciprocating compressor including a low pressurestage compression section 9 and a high pressurestage compression section 10. The capacity of the low pressurestage compression section 9 can be adjusted by a low pressure stage capacity adjustingdevice 21 including asuction valve unloader 9a and ahead end unloader 9b. The capacity of the high pressurestage compression section 10 can be adjusted by a high pressure stage capacity adjustingdevice 22 including asuction valve unloader 10a and ahead end unloader 10b. - On the other hand, an LNG conducting
line 3 is connected to theLNG storage tank 2 for liquefied natural gas (LNG) 1. An LNG pump 4 and an evaporator 5 using sea water, for example, for evaporating LNG are connected to theline 3. Further, a gas conveying line 6 for conveying vaporized gas is connected to, for example, a gas turbine in a power generation plant (not shown). ABOG delivery line 7 is connected to the top of theLNG storage tank 2 and the BOG multistage compressor 8 is connected to theBOG delivery line 7. - The BOG multistage compressor 8 is configured such that both low pressure
stage compression section 9 and high pressurestage compression section 10 are simultaneously driven by asingle drive motor 11. TheBOG delivery line 7 is connected to a suction side of the low pressurestage compression section 9. Anintermediate line 12 connects a discharge side of the low pressurestage compression section 9 with a suction side of a high pressurestage compression section 10. Adischarge line 17 disposed on a discharge side of the high pressurestage compression section 10 in the BOG multistage compressor 8 is connected to the gas conveying line 6 through aconfluence section 23. - A
pressure sensor 24 is provided in theLNG storage tank 2 for detecting the pressure of BOG therein. Its detected value is inputted to acontrol unit 25. Thecontrol unit 25 controls the operation of the BOG multistage compressor 8 in such a manner that when the pressure of BOG in thetank 2 detected by thepressure sensor 24 exceeds a preset pressure, the compressor 8 is turned on, while when the pressure of BOG in thetank 2 has lowered to a predetermined value, the compressor 8 is turned off. - Next, the method for controlling the operation according to the first embodiment of the present invention, carried out in this equipment, will be described with reference to
Fig. 2 also. InFig. 2 , a temperature curve A represents a low pressure stage-side suction gas temperature, while a temperature curve B represents a low pressure stage-side discharge gas temperature at position P1 on theintermediate line 12 shown inFig. 1 . - Upon start-up of the BOG multistage compressor 8, the suction gas temperature of the low pressure stage compression section 9 (temperature of BOG delivered from the LNG storage tank 2) keeps the substantially same value as a value at the start-up for an extremely short time, and thereafter drops gradually as indicated by the temperature curve A in
Fig. 2 . In the case where a load ratio R of the BOG multistage compressor 8 (a ratio of a load on the low pressurestage compression section 9 to a load on the high pressurestage compression section 10 in the BOG multistage compressor 8) is the same as in a steady operation, the low pressure stage discharge gas temperature starts from a value at the start-up and once rises to a peak temperature, as indicated by a two-dot chain line in the temperature curve B shown inFig. 2 , and then gradually drops according to the change of the temperature curve A. - Accordingly, in case the gas treatment volume ratio R is the same as in a steady operation, the low pressure stage-side discharge gas temperature starts from the value at the start-up, exceeds a temperature Th1 allowable for the operation, once rises to the peak temperature and then drops gradually, as indicated by the two-dot chain line in the temperature curve B shown in
Fig. 2 . - Upon start-up of the BOG multistage compressor 8, the
control unit 25 compares temperature of low pressure stage-side suction gas, which is detected by atemperature sensor 26, with a first preset temperature T1 preset in thecontrol unit 25. Then, if the detected temperature of the low pressure stage-side suction gas is not lower than the first preset temperature T1, thecontrol unit 25 controls the operation of the low pressure stagecapacity adjusting device 21 and that of the high pressure stagecapacity adjusting device 22 so that the load ratio R becomes lower than that in a steady operation. Thecontrol unit 25 controls so as to set a low pressure stage-side load and a high pressure stage-side load of to 25% and 50%, respectively, for example. - As a result of such an operation controlling method, the low pressure stage-side discharge pressure is reduced, and the low pressure stage-side discharge gas temperature is consequently inhibited from rising and suppressed to a temperature not higher than the temperature Th1 allowable for the operation, as indicated by the temperature curve B in
Fig. 2 . The low pressure stage-side suction gas temperature gradually reduces as mentioned above. - The
control unit 25 compares the temperature of low pressure stage-side suction gas, which is detected by thetemperature sensor 26, with the first preset temperature T1. As a result of the comparison, if the detected temperature of the low pressure stage-side suction gas reaches (or becomes lower than) the first preset temperature T1, thecontrol unit 25 controls the operation of the low pressure stagecapacity adjusting device 21 and that of the high pressure stagecapacity adjusting device 22 so as to make the load ratio R the same as that in a steady operation. - For example, the
control unit 25 controls so as to set both low and high pressure stage-side loads to 100%. As a result, the temperature of the low pressure stage-side discharge gas rises temporarily, but does not reach Th1. Thereafter, the low pressure stage-side suction gas temperature and the low pressure stage-side discharge gas temperature drop gradually and reach a stable state where each of them is maintained within a certain range. - Thus, according to the method for controlling the operation of a BOG multistage displacement compressor according to the first embodiment of the present invention, the suction temperature of the low pressure
stage compression section 9 of the multistage displacement compressor 8 is made detectable, and the above predetermined condition is a condition where the detected suction temperature is not lower than the first preset temperature T1. Therefore, as described above, even when the temperature of low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the temperature of low pressure stage-side discharge gas from exceeding the temperature allowable for operation. - An example of the method for controlling the operation of a BOG multistage displacement compressor according to the first embodiment of the present invention will be described below also with reference to
Fig. 1 . - In a steady operation of the multistage displacement compressor, both first stage-
side compression section 9 and second stage-side compression section 10 are operated at 100% load (Comparative Example-1 in Table 1). According to the BOG multistage displacement compressor according to the first embodiment of the present invention, in case of the above predetermined condition, such as a start-up, the first stage-side compression section 9 is operated at 25% load and the second stage-side compression section 10 is operated at 50% load by the capacity adjusting devices 21 (thesuction valve unloader 9a, thehead end unloader 9b and the like) and 22 (thesuction valve unloader 10a, thehead end unloader 10b and the like) in the first and second stage-side compression sections - In Table 1, states at the start-up of conventional BOG multistage displacement compressors are listed in Table 1 to show the effect of the present invention. One is an operation state in which both first stage-
side compression section 9 and second stage-side compression section 10 operate at 25% load (Comparative Example-3 in Table 1). The other is an operation state in which both first and second stage-side compression sections - Table 2 shows, for each of the operation examples in
Fig. 1 , suction and discharge temperatures of the first stage-side compression section 9, and suction and discharge gas pressures of the first stage-side compression section 9 and the second stage-side compression section 10. As shown in Comparative Example-1 in Table 2, in a steady operation of the BOG multistage displacement compressor, the first stage-side discharge temperature is about -50°C. In operations at the start-up of the conventional BOG multistage displacement compressor, however, the first stage-side discharge temperature reaches as high as about 155°C (more particularly, 153°C and 156°C in Comparative Examples-2 and -3, respectively), as shown in Comparative Examples-2 and -3 in Table 2. - On the other hand, in the operation at the start-up of the BOG multistage displacement compressor according to the first embodiment of the present invention, the first stage-side discharge temperature is suppressed to about 135°C (more particularly, 136°C in Example), as shown in Example in Table 2. This is because the first stage-side discharge pressure is suppressed to about 335 kPa in Example, in comparison to about 405 kPa (more particularly, 404 kPa) in Comparative Examples-2, 3, by making the load ratio smaller than that in a steady operation,.
- Next, a method for controlling the operation of a BOG multistage displacement compressor according to a second embodiment of the present invention will be described by exemplifying a case, in which a screw compressor is applied to the BOG multistage compressor, with reference to
Fig. 3. Fig. 3 is a system diagram of LNG and BOG treatment equipment, to which the method for controlling the operation of a BOG multistage displacement compressor according to a second embodiment of the present invention is applied. - This second embodiment of the present invention differs from the first embodiment in the type of a BOG multistage displacement compressor and the structure of both low and high pressure stage capacity adjusting devices. Since the second embodiment has the completely same structure as in the first embodiment except the above differences, the same components as in the first embodiment are given the same reference numerals, and the differences will be described below.
- In the BOG multistage compressor 8, to which the method for controlling the operation of a BOG multistage displacement compressor according to the first embodiment is applied and which includes a reciprocating compressor, the capacity of the low pressure
stage compression section 9 is adjusted by the low pressure stagecapacity adjusting device 21 that includes thesuction valve unloader 9a and thehead end unloader 9b, while the capacity of the high pressurestage compression section 10 is adjusted by the high pressure stagecapacity adjusting device 22 that includes thesuction valve unloader 10a and thehead end unloader 10b. - On the other hand, in a BOG
multistage compressor 18, to which the method for controlling the operation of a BOG multistage displacement compressor according to the second embodiment shown inFig. 3 is applied and which includes a screw type compressor, the capacity of a low pressurestage compression section 19 is adjusted by a low pressure stage capacity adjusting device that includes aslide valve 19a, while the capacity of a high pressurestage compression section 20 is adjusted by a high pressure stage capacity adjusting device that includes aslide valve 20a. - According to such a method for controlling the operation of a BOG multistage displacement compressor according to a second embodiment of the present invention, a suction temperature of the low pressure
stage compression section 19 of the BOGmultistage displacement compressor 18 is made detectable, and the above predetermined condition is a condition in which the detected suction temperature is not lower than a first preset temperature T1, as similarly as the first embodiment. Therefore, even when the temperature of low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the temperature of low pressure stage-side discharge gas from exceeding a temperature allowable for the operation. - Next, a method for controlling the operation of a BOG multistage displacement compressor according to a third embodiment of the present invention will be described by exemplifying a case where a reciprocating compressor is applied to the BOG multistage compressor with reference to
Figs. 4 and5 .Fig. 4 is a system diagram of LNG and BOG treatment equipment, to which the method for controlling the operation of a BOG multistage displacement compressor according to a third embodiment of the present invention is applied.Fig. 5 is a diagram showing changes of BOG temperature with time just after a start-up in case the method for controlling the operation of a BOG multistage displacement compressor of a third embodiment of the present invention is used. - This third embodiment of the present invention differs from the above first embodiment in a mounting position of a temperature sensor and a method for controlling the operation. Since the third embodiment has the completely same structure as in the first embodiment except the differences, the same components as in the first embodiment are given the same reference numerals, and the differences will be described below.
- In other words, according to the method for controlling the operation of the BOG multistage displacement compressor 8 according to the above first embodiment, the temperature of low pressure stage-side suction gas is detected by the
temperature sensor 26 disposed in theBOG delivery line 7, and the operation is controlled, by the operation controlling method (No.1). On the other hand, according to the method for controlling the operation of the BOG multistage displacement compressor 8 according to this third embodiment shown inFigs. 4 and5 , the temperature of low pressure stage-side discharge gas is detected by atemperature sensor 27 disposed in theintermediate line 12, and the operation of is controlled by an operation controlling method (No. 2) that will be described below. - According to this operation controlling method (No. 2), upon start-up of the BOG multistage compressor 8, the
control unit 25 compares the temperature of low pressure stage-side discharge gas, which is detected by thetemperature detector 27, with a second preset temperature T2, which is preset in thecontrol unit 25. As shown inFig. 5 , in an extremely short period just after start-up, the detected temperature of low pressure stage-side discharge gas is lower than the second preset temperature T2. Thus, during this period, the load ratio R is the same as that in a steady operation. If the detected temperature of low pressure stage-side discharge gas is not lower than the second preset temperature T2, thecontrol unit 25 controls the operation of the low pressure stagecapacity adjusting device 21 and that of the high pressure stagecapacity adjusting device 22 so as to make the load ratio R lower than that in a steady operation. - For example, the
control unit 25 controls so as to set a low pressure stage-side load and a high pressure stage-side load to 25% and 50%, respectively. As a result, the low pressure stage-side discharge pressure is reduced, and the low pressure stage-side discharge gas temperature is consequently inhibited from rising and suppressed to a temperature not higher than the temperature Th1 allowable for the operation, as indicated by the temperature curve B inFig. 5 . The low pressure stage-side suction gas temperature gradually reduces as mentioned above. - Further, if the temperature of low pressure stage-side discharge gas which is detected by the
temperature sensor 27 reaches a third preset temperature T3 (lower than the second preset temperature T2), thecontrol unit 25 controls the operation of the low pressure stagecapacity adjusting device 21 and that of the high pressure stagecapacity adjusting device 22 so as to make the load ratio R to be the same as that in a steady operation. For example, thecontrol unit 25 sets both the low pressure stage-side load and the high pressure stage-side load to 25%. As a result, the temperature of low pressure stage-side discharge gas rises temporarily, but does not reach Th1. Thereafter, the low pressure stage-side suction gas temperature and the low pressure stage-side discharge gas temperature drop gradually and reach a stable state where each of them is maintained within a certain range. - Thus, according to the method for controlling the operation of a BOG multistage displacement compressor according to a third embodiment of the present invention, the discharge gas temperature of the low pressure
stage compression section 9 of the BOG multistage displacement compressor 8 is made detectable, and a predetermined condition is a condition from judgment that the detected temperature of the discharge temperature is not lower than the second preset temperature T2 until judgment that the detected temperature has reached the third preset temperature T3 lower than the second preset temperature T2. Therefore, even if the temperature of low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the temperature of low pressure stage-side discharge gas from exceeding the temperature allowable for the operation. - As described above, according to the present invention, the method for controlling the operation of a BOG multistage displacement compressor, includes: in case of a predetermined condition, making a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section in the BOG multistage displacement compressor (load ratio) R smaller than load ratios in case of conditions other than the predetermined condition. Since the operation is consequently performed at a low load ratio R, that is, the compression ratio of the low pressure stage compression section is made smaller, the temperature of low pressure stage-side discharge gas consequently drops. Thus, even when the temperature of low pressure stage-side suction gas is higher than that in a steady operation, it is possible to prevent the low pressure stage-side discharge gas temperature from exceeding the temperature allowable for the operation.
- In the above embodiments, the methods for controlling the operation of a BOG multistage displacement compressor according to the present invention have been described by exemplifying a reciprocating compressor and a screw type compressor, and the capacity adjusting devices are described by exemplifying suction valve unloaders, head end unloaders and slide valves. The present invention is, however, not limited thereto, but the method for controlling the operation of a BOG multistage displacement compressor according to the present invention is also applicable to various types of displacement compressors and BOG displacement compressors having capacity adjusting devices of various structures.
-
1: Liquefied natural gas (LNG), 2: LNG storage tank, 3: LNG conducting line, 4: LNG pump, 5: Evaporator, 6: Gas conveying line, 7: BOG delivery line, 8: BOG multistage (displacement) compressor (Reciprocating compressor), 9: Low pressure stage compression section (First stage-side compression section), 9a: Suction valve unloader, 9b: Head end unloader, 10: High pressure stage compression section (Second stage-side compression section), 10a: Suction valve unloader, 10b: Head end unloader, 11: Drive motor, 12: Intermediate line, 17: Discharge line, 18: BOG multistage (displacement) compressor (Screw type compressor), 19: Low pressure stage compression section, 19a: Slide valve, 20: High pressure stage compression section, 20a: Slide valve, 21: Low pressure stage capacity adjusting device, 22: High pressure stage capacity adjusting device, 23: Confluence section, 24: Pressure sensor, 25: Control unit, 26, 27: Temperature sensor - It is an object of the present invention to provide a method for Controlling the operation of a BOG multistage displacement compressor, capable of preventing the temperature of low pressure stage-side discharge gas from exceeding a temperature allowable for the operation, even when the temperature of low pressure stage-side suction gas is higher than that in a steady operation.
- A method for controlling the operation of a BOG multistage displacement compressor including plural stages of displacement compression sections, which are connected with each other, for compressing BOG generated from liquefied natural gas, includes: in case of a predetermined condition, making a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section in the BOG multistage displacement compressor (load ratio) smaller than load ratios in case of conditions other than the predetermined condition. In other words, suction temperature of the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and the predetermined condition is a condition where a detected temperature of the suction temperature is not lower than a first preset temperature.
Claims (3)
- A method for controlling the operation of a BOG multistage displacement compressor including plural stages of displacement compression sections, which are connected with each other, for compressing BOG generated from liquefied natural gas, comprising:in case of a predetermined condition, making a ratio of a load on a low pressure stage compression section to a load on a high pressure stage compression section in the BOG multistage displacement compressor (load ratio) smaller than load ratios in case of conditions other than the predetermined condition.
- The method for controlling the operation of a BOG multistage displacement compressor according to claim 1, wherein
suction temperature of the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and
the predetermined condition is a condition where a detected temperature of the suction temperature is not lower than a first preset temperature. - The method for controlling the operation of a BOG multistage displacement compressor according to claim 1, wherein
discharge temperature from the low pressure stage compression section of the BOG multistage displacement compressor is made detectable, and
the predetermined condition is a condition from judgment that a detected temperature of the discharge temperature is not lower than a second preset temperature until judgment that the detected temperature has reached a third preset temperature lower than the second preset temperature.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2010129956A JP5391154B2 (en) | 2010-06-07 | 2010-06-07 | Operation control method for BOG multistage positive displacement compressor |
Publications (3)
Publication Number | Publication Date |
---|---|
EP2392825A2 true EP2392825A2 (en) | 2011-12-07 |
EP2392825A3 EP2392825A3 (en) | 2011-12-21 |
EP2392825B1 EP2392825B1 (en) | 2019-01-16 |
Family
ID=44675977
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP11166316.7A Active EP2392825B1 (en) | 2010-06-07 | 2011-05-17 | Method for controlling the operation of a multistage boil-off gas (BOG) compressor |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP2392825B1 (en) |
JP (1) | JP5391154B2 (en) |
CN (1) | CN102269154B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015175488A (en) * | 2014-03-17 | 2015-10-05 | 大阪瓦斯株式会社 | Compressor operation plan formation system |
US11346348B2 (en) * | 2019-09-04 | 2022-05-31 | Advanced Flow Solutions, Inc. | Liquefied gas unloading and deep evacuation system |
US12031541B2 (en) | 2022-04-26 | 2024-07-09 | Advanced Flow Solutions, Inc. | Liquefied gas unloading and deep evacuation system |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2016070218A (en) * | 2014-09-30 | 2016-05-09 | Jfeスチール株式会社 | Gas turbine power generation device and method of controlling gas turbine power generation device |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002213366A (en) | 2001-01-16 | 2002-07-31 | Kobe Steel Ltd | Operation control method in starting bog compressor |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63110687U (en) * | 1987-01-12 | 1988-07-15 | ||
JP3045243B2 (en) * | 1990-05-01 | 2000-05-29 | 石川島播磨重工業株式会社 | Operation control method of low-temperature gas compressor |
JPH08284839A (en) * | 1995-04-12 | 1996-10-29 | Kobe Steel Ltd | Operating method and controller for low temperature gas compressor |
GB0400986D0 (en) * | 2004-01-16 | 2004-02-18 | Cryostar France Sa | Compressor |
FR2875784B1 (en) * | 2004-09-30 | 2008-03-14 | Alstom Sa | GAS FUEL SUPPLY INSTALLATION AND STARTING SEQUENCE OF SUCH A FACILITY |
US8820096B2 (en) * | 2007-02-12 | 2014-09-02 | Daewoo Shipbuilding & Marine Engineering Co., Ltd. | LNG tank and operation of the same |
KR20080097141A (en) * | 2007-04-30 | 2008-11-04 | 대우조선해양 주식회사 | Floating marine structure having in-tank re-condenser and method for treating boil-off gas on the floating marine structure |
JP4852003B2 (en) * | 2007-07-24 | 2012-01-11 | 株式会社神戸製鋼所 | Reciprocating compressor capacity adjustment method |
-
2010
- 2010-06-07 JP JP2010129956A patent/JP5391154B2/en active Active
-
2011
- 2011-05-17 EP EP11166316.7A patent/EP2392825B1/en active Active
- 2011-06-03 CN CN201110149003.8A patent/CN102269154B/en active Active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002213366A (en) | 2001-01-16 | 2002-07-31 | Kobe Steel Ltd | Operation control method in starting bog compressor |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015175488A (en) * | 2014-03-17 | 2015-10-05 | 大阪瓦斯株式会社 | Compressor operation plan formation system |
US11346348B2 (en) * | 2019-09-04 | 2022-05-31 | Advanced Flow Solutions, Inc. | Liquefied gas unloading and deep evacuation system |
US12031541B2 (en) | 2022-04-26 | 2024-07-09 | Advanced Flow Solutions, Inc. | Liquefied gas unloading and deep evacuation system |
Also Published As
Publication number | Publication date |
---|---|
CN102269154B (en) | 2014-12-03 |
EP2392825A3 (en) | 2011-12-21 |
CN102269154A (en) | 2011-12-07 |
JP5391154B2 (en) | 2014-01-15 |
JP2011256735A (en) | 2011-12-22 |
EP2392825B1 (en) | 2019-01-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2461038B1 (en) | Operation control method for BOG multistage displacement compressor | |
US10704736B2 (en) | LNG boiloff gas recondensation configurations and methods | |
US11300355B2 (en) | Boil-off gas supply device | |
KR101167556B1 (en) | Number-of-compressors controlling system | |
JP2008019746A (en) | Compressed-air production facility | |
KR20100046274A (en) | Cryopump system | |
EP2392825A2 (en) | Method for controlling the operation of a multistage boil-off gas (BOG) compressor | |
CN113302439B (en) | Starting method of cryogenic refrigerator and cryogenic refrigerator | |
JP2017122481A5 (en) | ||
CN102465867A (en) | Compression device and operation control method thereof | |
JP4962853B2 (en) | BOG compression equipment and method | |
JP4009426B2 (en) | Operation control method at startup of BOG compressor | |
JP2008291836A (en) | Multi-stage gas compressing apparatus | |
KR101867024B1 (en) | System for supplying fuel gas of floating marine structure and method for supplying fuel gag of the same | |
JP6256815B2 (en) | BOG compression equipment and reciprocating compressor control method | |
JPH0412178A (en) | Operation control method for low temperature gas compressor | |
KR102481790B1 (en) | Fuel gas supply system | |
JP2008064126A (en) | Operating method for boiloff gas delivery facility | |
CN116075638A (en) | Air compressor | |
JPH0942598A (en) | Processing system and processing method for vaporized gas of liquefied gas | |
KR20170050920A (en) | Fuel sypply system and method for controlling boil-off gas pressure of the same | |
JP2008057366A (en) | Method and device for pressurizing and feeding inert gas |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
17P | Request for examination filed |
Effective date: 20110517 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: F04B 49/10 20060101ALI20111116BHEP Ipc: F04B 25/00 20060101ALI20111116BHEP Ipc: F04B 49/06 20060101ALI20111116BHEP Ipc: F04B 49/00 20060101AFI20111116BHEP Ipc: F17C 9/02 20060101ALI20111116BHEP |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: EXAMINATION IS IN PROGRESS |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: F04B 49/10 20060101ALI20170217BHEP Ipc: F17C 9/02 20060101ALI20170217BHEP Ipc: F04B 49/00 20060101AFI20170217BHEP Ipc: F04B 25/00 20060101ALI20170217BHEP Ipc: F04B 49/06 20060101ALI20170217BHEP |
|
17Q | First examination report despatched |
Effective date: 20170316 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: GRANT OF PATENT IS INTENDED |
|
INTG | Intention to grant announced |
Effective date: 20180731 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE PATENT HAS BEEN GRANTED |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 602011055703 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: REF Ref document number: 1089896 Country of ref document: AT Kind code of ref document: T Effective date: 20190215 |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MP Effective date: 20190116 |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG4D |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MK05 Ref document number: 1089896 Country of ref document: AT Kind code of ref document: T Effective date: 20190116 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190416 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190516 Ref country code: ES Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190416 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190417 Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190516 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 602011055703 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 |
|
26N | No opposition filed |
Effective date: 20191017 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20190517 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190531 Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190531 |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20190531 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190517 Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190517 Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190517 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190531 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 Ref country code: HU Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO Effective date: 20110517 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190116 |
|
P01 | Opt-out of the competence of the unified patent court (upc) registered |
Effective date: 20230523 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: IT Payment date: 20230412 Year of fee payment: 13 Ref country code: DE Payment date: 20230321 Year of fee payment: 13 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20240308 Year of fee payment: 14 |