RU2799003C1 - Plant module, plant including the module and plant operation method - Google Patents

Abstract

FIELD: gas equipment.

SUBSTANCE: invention relates to a plant module having a group of devices used in a natural gas liquefaction plant, to a plant including a plant module. Invention is aimed at the provision of a plant module, which includes a local electrical room and a local hardware room located in the zone of combustible gas presence, and safely starts and ensures the operation of devices without explosion-proof properties, even if these devices are located in the local electrical room and local hardware room. The technical result is achieved by the fact that the plant module includes: a group of plant equipment constituting a plant, a local electrical room located in a hazardous area determined by the presence of combustible gas, and accommodating a power device that supplies electricity to a group of plant equipment, a structure supporting a group of plant equipment and the local electrical room, and an outdoor air supply device with explosion-proof properties located in the local electrical room to supply outdoor air to its interior. At the same time, the plant module is configured to supply electricity to the outdoor air supply device from a non-hazardous area.

EFFECT: provision of a plant module, which includes a local electrical room and a local hardware room located in the zone of combustible gas presence, and safely starts and ensures the operation of devices without explosion-proof properties, even if these devices are located in the local electrical room and local hardware room.

12 cl, 6 dwg

Description

The field of technology to which the invention belongs

[0001] The present invention relates to a factory module having a group of devices used in a factory, to a factory including a factory module, and to a method of operating the factory.

State of the art

[0002] Conventionally, for example, when a natural gas liquefaction plant (hereinafter referred to as "LNG plant") is built, necessary installations such as an acid gas removal plant, a moisture removal plant, and a compression plant are assembled at the construction site. The acid gas removal plant is a plant that removes the acid gas contained in the feed gas to be liquefied. The dehumidifier is a device that removes the moisture contained in the feed gas. The compression plant is a plant that compresses the refrigerant used to cool and liquefy the feed gas.

[0003] On the other hand, the technology for improving work efficiency at such a construction site is distributed in places. In this technology, the plants constituting such an LNG plant and the equipment, devices, etc. included in these plants are assembled in advance at a remote location as a plurality of modular plants (hereinafter simply referred to as "modules"), and then these modules are transported to the construction site.

[0004] Further, the known module includes a frame that constitutes the module, and a building that houses at least one of a power supply device configured to supply power to the power consumption device and a control information output device configured to the ability to output information regarding the functional control of the controlled device (for example, see Fig. 4 of patent document 1).

Prior Art Documents

Patent Documents

[0005] Patent Document 1. WO2019/008725A1

The essence of the invention

Problem to be solved by invention

[0006] Incidentally, the hazardous area is set at the plant that handles combustible gas. A hazardous area is an area in which explosion precautions are required for each device used in it. The area in which the module constituting the plant is located can be defined as a hazardous area.

[0007] Accordingly, in the conventional module disclosed in Patent Document 1, all electrical devices and control devices that are placed in a building in a hazardous area and can be an ignition source must have explosion-proof properties. As a result, plant installation costs may undesirably increase.

[0008] In view of the above problem of the prior art, the main purpose of the present invention is to provide a factory module that includes a local electrical room located in a hazardous area and can safely start and operate devices without explosion-proof properties, even if these devices are located in the local electrical room. In addition, the main object of the present invention is to provide a factory including a factory module and a method for operating the factory.

Means for solving the problem

[0009] The first aspect of the present invention provides a method for operating a factory (1) including a factory module (2), the factory module comprising: a factory equipment group (6) that constitutes the factory; a local electrical room (5) located in a hazardous area (31) defined by the presence of a combustible gas, and the local electrical room has a power device configured to supply electricity to a group of plant equipment; a structure (21) supporting a plant equipment group and a local electrical room; and an outdoor air supply device (64) having explosion-proof properties and located in the local electrical room, so as to supply outdoor air to its interior, while the method of operating the plant includes supplying electricity to the outdoor air supply device from a non-hazardous area.

[0010] According to this aspect, it is possible to safely start and operate devices by supplying outside air to the local electrical room and purging combustible gas or explosive gas from it.

[0011] A second aspect of the present invention provides a method for operating a factory (1) including a factory module (2), the factory module comprising: a factory equipment group (6) that constitutes the factory; a local equipment room (105) located in a hazardous area defined by the presence of combustible gas, and the local equipment room has a control device configured to transmit a control signal to a plant equipment group; a structure (21) supporting a plant equipment group and a local equipment room; and an outside air supply device (64) having explosion-proof properties and configured to supply outside air to the interior of the local equipment room, wherein the method of operating the plant comprises supplying electricity to the outside air supply device from a non-hazardous area.

[0012] According to this aspect, it is possible to safely start and operate the devices by supplying outside air to the local equipment room and purging combustible gas or explosive gas from it.

[0013] According to the third aspect of the present invention, the method of operation further comprises: after starting the supply of electricity to the outdoor air supply device, changing the gas in the local electrical room to outside air through the outside air supply device; and starting to supply electricity to at least one device included in the plant equipment group.

[0014] According to this aspect, it is possible to safely start and operate the device included in the factory equipment group through a simple procedure.

[0015] A fourth aspect of the present invention provides a factory module (2) comprising: a factory equipment group (6) that constitutes a factory (1); a local electrical room (5) located in a hazardous area (31) defined by the presence of a combustible gas, and the local electrical room has a power device configured to supply electricity to a group of plant equipment; a structure (21) supporting a plant equipment group and a local electrical room; an outdoor air supply device (64) having explosion-proof properties and located in the local electrical room so as to supply outdoor air to its interior; and a power cable (C14, C15) configured to supply power to the outdoor air supply device from a non-hazardous area.

[0016] According to this aspect, it is possible to safely start and maintain the devices by introducing outside air into the local electrical room from outside the hazardous area and purging combustible gas or explosive gas from it.

[0017] A fifth aspect of the present invention provides a factory module (2) comprising: a factory equipment group (106) that constitutes a factory (1); a local equipment room (105) located in a hazardous area (31) defined by the presence of combustible gas, and the local equipment room has a control device configured to transmit a control signal to a plant equipment group; a structure (21) supporting a plant equipment group and a local equipment room; an outdoor air supply device (64) having explosion-proof properties and placed in a local equipment room so as to supply outdoor air to its interior; and a power cable (C14, C15) configured to supply power to the outdoor air supply device from a non-hazardous area.

[0018] According to this aspect, it is possible to safely start and operate the devices by introducing outside air into the local equipment room from outside the hazardous area and purging combustible gas or explosive gas from it.

[0019] According to the sixth aspect of the present invention, the outdoor air supply device includes an air intake pipe (71) configured to supply outdoor air to the interior of the local electrical room, and the air intake pipe includes an outdoor air inlet (71A) disposed outside the danger zone.

[0020] According to this aspect, by using a simple configuration, the factory module can reliably supply outside air to the local electrical room from outside the hazardous area.

[0021] According to the seventh aspect of the present invention, the outside air supply device is configured to supply outside air to the inside of the local electrical room so as to set the inside of the local electrical room to a positive pressure.

[0022] According to this aspect, by using a simple configuration, the factory module can prevent gas near the local electrical room (a gas that may contain combustible gas) from entering the local electrical room and thereby stably operate devices that can become a source of ignition.

[0023] An eighth aspect of the present invention provides a factory (1) comprising a factory module (2), wherein the factory module includes: a factory equipment group (6) that constitutes the factory; a local electrical room (5) located in a hazardous area (31) defined by the presence of a combustible gas, and the local electrical room has a power device configured to supply electricity to a group of plant equipment; a structure (21) supporting a plant equipment group and a local electrical room; an outdoor air supply device (64) having explosion-proof properties and located in the local electrical room so as to supply outdoor air to its interior; and a power cable (C14, C15) configured to supply power to the outdoor air supply device from a non-hazardous area.

[0024] According to this aspect, it is possible to safely start and operate devices by introducing outside air into the local electrical room from outside the hazardous area and purging combustible gas or explosive gas from it.

[0025] According to the ninth aspect of the present invention, the plant further comprises a main electrical room (3) located outside the hazardous area and having one or more out-of-zone switchboards (43, 44) configured to supply electricity to the local electrical room, while a power cable connects at least one of the out-of-zone switchboards and the outdoor air supply device, and the out-of-zone switchboards include a normal switchboard (43) configured to distribute electricity from a normal power supply source, and an emergency switchboard (44 ) configured to distribute electricity from an emergency power source.

[0026] According to this aspect, the plant can supply power to the devices from the emergency power supply even if the normal power supply is lost.

[0027] According to the tenth aspect of the present invention, the plant further comprises: a switchboard (65) located in the local electrical room; an indoor switchboard (61) located in the local electrical room and configured to supply power to the plant equipment group; and a power supply device (47, 48) located in the main electrical room and configured to supply control power to the switchboard, wherein the switchboard is configured to supply control power supplied from the power supply device to an indoor switchboard.

[0028] According to this aspect, even if a power outage occurs, the plant can supply electric power, which is supplied from the power supply device, from the indoor switchboard to the devices.

[0029] According to an eleventh aspect of the present invention, each of a normal switchboard and an emergency switchboard includes a high voltage switchgear (41, 42) and a low voltage switchgear (43, 44), and the factory module further includes: a first a dry transformer located in the local electrical room and configured to convert high voltage power to low voltage power, wherein the high voltage power converted by the first dry transformer (62) is supplied from the high voltage switchgear as a normal switchboard to the power device, and a second dry transformer (63) located in the local electrical room and configured to convert high voltage power to low voltage power, wherein the high voltage power converted by the second dry transformer is supplied from the high voltage switchgear as an emergency switchboard to the power device.

[0030] According to this aspect, by using a simple configuration, the plant can stably supply electric power from the emergency power supply as low voltage power even if the normal power supply is lost.

[0031] According to the twelfth aspect of the present invention, a power cable is connected to each of the low voltage switchgear as a normal switchboard and the low voltage switchgear as an emergency switchboard.

[0032] According to this aspect, by using a simple configuration, the plant can safely start and operate devices that are located in the local electrical room and can become a source of ignition.

[0033] According to the thirteenth aspect of the present invention, the factory module further includes a high voltage electrical load (80) to which the high voltage power from the high voltage switchgear as a normal switchboard is supplied without passing through the power device.

[0034] According to this aspect, by using a simple configuration, the plant can safely supply high voltage power to the high voltage electrical load of the plant module.

[0035] According to a fourteenth aspect of the present invention, the plant further comprises a generator (51) connected to an emergency switchboard.

[0036] According to this aspect, even if a power outage occurs, the plant can supply power from the generator to devices that require power.

[0037] According to a fifteenth aspect of the present invention, the plant further comprises a local equipment room (105) having a control device configured to transmit a control signal to the plant equipment group.

[0038] According to this aspect, even if the local equipment room of the plant module has a control device that may be an ignition source, the plant can safely start and operate the control device.

The advantage of the invention

[0039] Thus, according to the above aspects of the present invention, devices without explosion-proof properties can be safely started and operated even if the local electrical room is located in a hazardous area and the above devices are located in the local electrical room.

Brief description of the drawings

[0040] FIG. 1 is a general block diagram showing a brief representation of an LNG plant according to the first embodiment;

Fig. 2 is a circuit diagram showing the configuration of the module shown in FIG. 1.

Fig. 3 is an explanatory diagram showing a configuration for supplying power from the MER shown in FIG. 1, into the module.

Fig. 4 is a flowchart showing the procedure at the time of startup of the local electrical room;

Fig. 5 is an overall block diagram showing a brief representation of an LNG plant according to the second embodiment; And

Fig. 6 is an explanatory diagram showing a configuration for transmission between CCRs shown in FIG. 5, and LCR.

Detailed description of the invention

[0041] The following describes an embodiment of the present invention with reference to the drawings.

[0042] First Embodiment

Fig. 1 is a general block diagram showing a brief representation of the LNG plant 1 according to the first embodiment. Fig. 2 is a circuit diagram showing the configuration of the module 2 shown in FIG. 1.

[0043] As shown in FIG. 1, the LNG plant 1 is a plant for generating LNG (liquefied natural gas) by performing a process of liquefying natural gas produced from gas fields, and the like. The LNG plant 1 includes several devices that make up various installations. In LNG plant 1, devices, pipes, etc. are appropriately combined and modularized and therefore installed as a plurality of modules 2A-2F (factory modules). Additionally, the LNG plant 1 includes a main electrical room 3 (hereinafter referred to as "MER"), which has a primary electrical device for supplying electricity (hereinafter referred to simply as "power") to each module 2.

[0044] Each module 2A-2F is assembled in advance at a remote location to reduce construction costs. Thereafter, each module 2A-2F is transported to the construction site of the LNG Plant 1 shown in FIG. 1. For example, the remote location is a country such as China and a Southeast Asian country in which each module 2A-2F can be assembled in advance at low cost and with a certain quality. After each module 2A-2F is installed, pipes, cables (such as primary power cables 11), etc. devices are interconnected, and because of this, the modules 2A-2F constitute the technological LNG line as one continuous unit.

[0045] Various installations used in the LNG plant 1 include, for example, an acid gas removal plant, a moisture removal plant, a refrigerant compression plant, and a liquefaction process installation. As a refrigerant, mixed refrigerant, propane refrigerant, etc. are used. Each module 2A-2F is modularized according to each application and function. The acid gas removal plant is a plant that removes the acid gas contained in the feed gas to be liquefied. The dehumidifier is a device that removes the moisture contained in the feed gas. The compression plant is a plant that compresses the refrigerant used to cool and liquefy the feed gas. The plant for carrying out the liquefaction process is a plant that liquefies the raw gas through heat exchange between the raw gas and the refrigerant.

[0046] Each module 2A-2E contains a local electrical room 5A-5E (hereinafter referred to as "LER"), which has an auxiliary electrical device. The auxiliary electrical device is supplied with power from the primary electrical device in MER 3 through each primary power cable 11. Accordingly, each LER 5A-5E can supply power to each group 6A-6E of the plant equipment through each secondary power cable 12. Each group 6A-6E of the factory The equipment includes a plurality of power consuming devices that make up each module 2A-2E in which the LER 5A-5E is located.

[0047] In this regard, at least a portion of each secondary power cable 12 is set in advance when each module 2A-2F is assembled at a remote location. Additionally, a cable having a small diameter can be used as each secondary power cable 12, as compared to the case in which the LER 5A-5E is not located in each module 2A-2E, and the cable is placed directly from the MER 3 to each group 6A-6E factory equipment. The distance from each LER 5A-5E to the corresponding factory equipment group 6A-6E is less than the distance from the MER 3 to each factory equipment group 6A-6E. Accordingly, the voltage drop is small, and thus the cable diameter can be set small. Thus, in the LNG plant 1, the cost of power cables is reduced.

[0048] On the other hand, module 2F does not contain LER. However, power is supplied to plant group 6F from the LER 5B of module 2B adjacent to module 2F. In other words, in the event that an LER is not present in one module, an LER located in a module adjacent to one module can supply power to a plant equipment group in one module.

[0049] Hereinafter, in case it is not necessary to distinguish each module 2A-2F by application or function, each module 2A-2F is collectively referred to as "module 2". Additionally, in case it is not necessary to distinguish each LER 5A-5E, each LER 5A-5E is collectively referred to as "LER 5". In addition, in case it is not necessary to distinguish each factory equipment group 6A-6F, each factory equipment group 6A-6F is collectively referred to as "factory equipment group 6".

[0050] As shown in FIG. 2, module 2 includes LER 5, factory equipment group 6, and structure 21 supporting LER 5 and factory equipment group 6. In this regard, similar to module 2F, power can be supplied to LER 5 from adjacent module 2.

[0051] LER 5 is formed in a building having a substantially cubic outer shape and is an enclosed space defined by a top wall, a side wall, and a bottom wall.

[0052] Factory equipment group 6 includes an electric motor or the like driven by relatively high voltage power (eg, 6 kV) or relatively low voltage power (eg, 400 V). For example, such an electric motor is used for a pump, a compressor, an air-cooled fan, and the like. For example, an electric motor driven by high voltage power is an electric motor used for a high-capacity compressor, and the like. On the other hand, the electric motor driven by the low voltage power is an electric motor used for a pump configured to convey LNG or a coolant.

[0053] Structure 21 is a support structure including a metal base 24, posts 25, and beams 26. The posts 25 and beams 26 are made from a plurality of steel frames provided on base 24. Additionally, in module 2, not only LER 5 and group 6 plant equipment, but also pipes 27 for LNG and refrigerant, various cables (power cables, signal cables, etc.), containers (not shown), etc. supported by design 21.

[0054] Structure 21 may contain multiple floors. In an embodiment, LER 5 and plant group 6 are located on base 24, which is the lowest floor in structure 21. The present invention is not limited to this embodiment, and LER 5 and plant group 6 may be placed on any floor. By placing the LER 5 and plant group 6 on multiple floors, the installation area of module 2 can be reduced.

[0055] With reference to FIG. 1, in the LNG plant 1, combustible gas such as natural gas or propane for refrigerant flows through the devices and pipes provided in each module 2. Accordingly, the area within the prescribed distance from the plant equipment group 6 that treats the combustible gas in each module 2 is defined as a hazardous area 31. In the present embodiment, for example, the common area of each module 2 and its peripheral area is defined as a hazardous area 31. In a multi-storey module 2, the hazardous area 31 is defined as a three-dimensional space.

[0056] In the present embodiment, a "dangerous area" is an area in which combustible gas is present or expected to be present, and because of this, precautions (e.g., cleaning to ensure explosion-proof properties for equipment and devices) against explosion are required for construction , installation and use of equipment and devices. Such a hazardous area and precautions for it are usually prescribed by the laws of the country or region in which the plant that handles combustible gas is being built, international standards, etc.

[0057] Hereinafter, an area separated from the danger area 31 by a prescribed distance or more is referred to as a "non-dangerous area". A non-hazardous area is an area in which combustible gas is not present in such an amount that anti-explosion precautions are required for the construction, installation and use of equipment and devices.

[0058] In the present embodiment, the present invention is applied to an LNG plant, for example. However, the present invention is not limited to this embodiment and can be applied to any plant that handles combustible gas. For example, the present invention can also be applied to an LNG gasification plant that gasifies LNG, an oil refinery, a petrochemical plant that makes chemicals such as ethylene and propylene, and a general chemical plant.

[0059] FIG. 3 is an explanatory diagram showing a configuration for supplying power from the MER 3 shown in FIG. 1 to module 2.

[0060] MER 3 includes normal high voltage switching equipment 41, emergency high voltage switching equipment 42, normal low voltage switching equipment 43, emergency low voltage switching equipment 44, normal transformer 45, emergency transformer 46, uninterruptible power supply 47 ( hereinafter referred to as "UPS") and a DC power source 48 . MER 3 is located in a non-hazardous area.

[0061] Each switchgear 41-44 constitutes a normal or emergency switchboard (out-of-zone switchboard) configured such that a switch (opening/closing device) for opening and closing an electric line, a meter for voltage and current, a control circuit, and etc. placed in a metal casing.

[0062] The normal high voltage switchgear 41 is configured to receive high voltage AC power as normal power from a power company (not shown) or a normal generator located in the LNG plant 1.

[0063] Additionally, high voltage emergency switchgear 42 is connected to an emergency generator 51 located in a non-hazardous area near MER 3 and configured to receive AC power from the emergency generator 51. The emergency generator 51 starts if the normal power supplied from a power company, a normal generator, etc., is lost due to the occurrence of a power failure, etc. The emergency generator 51 is configured to supply power to the emergency high voltage switchgear 42. For example, a diesel generator is used as emergency generator 51.

[0064] High voltage normal switchgear 41 is connected to low voltage normal switchgear 43 via power cable C1 through normal transformer 45. Additionally, high voltage emergency switchgear 42 is connected to low voltage emergency switchgear 44 via power cable C2 through emergency transformer 46 The normal transformer 45 and emergency transformer 46 each consist of an oil-filled transformer whose windings are cooled by insulating oil. In this regard, the normal transformer 45 and the emergency transformer 46 may be provided integrally with the normal high voltage switchgear 41 and the emergency high voltage switchgear 42, respectively.

[0065] The high voltage power from the normal high voltage switchgear 41 is supplied to the normal low voltage switchgear 43 as lower voltage power converted by the normal transformer 45. Similarly, the high voltage power from the emergency high voltage switchgear 42 is supplied to the emergency switchgear 44 low voltage as lower voltage power converted by emergency transformer 46.

[0066] The UPS 47 is an emergency power supply to continue supplying AC power to module 2 in an emergency. For example, "emergency" means a situation where power is cut off due to a power failure or the like. The UPS 47 is connected to the normal low voltage switchgear 43 and the emergency low voltage switchgear 44 via power cable C3 and power cable C4, respectively. The UPS 47 is configured to receive power from this switchgear 43, 44.

[0067] Additionally, the DC power source 48 is an emergency power supply device for continuing to supply DC power to the module 2 in an emergency. Like UPS 47, DC power source 48 is connected to normal low voltage switchgear 43 and emergency low voltage switchgear 44 via power cable C5 and power cable C6, respectively.

[0068] In this regard, MER 3 is located in a non-hazardous area. Accordingly, the power devices (every switchgear, every transformer, etc.) housed in MER 3 need not necessarily be intrinsically safe.

[0069] The LER 5 has a normal indoor switchboard 61, a normal first dry transformer 62, an emergency second dry transformer 63, a heating, ventilation and air conditioning (HVAC) unit 64, and a switchboard 65. An indoor switchboard 61 , the first and second dry-type transformers 62, 63 and switchboard 65 are power devices housed in LER 5. Although LER 5 is located in the hazardous area 31, devices without explosion-proof properties are used as an indoor switchboard 61, the first dry-type transformer 62 and the second dry transformer 63.

[0070] On the other hand, the HVAC device 64 and switchboard 65 are devices that can become a source of ignition. Accordingly, the HVAC device 64 and switchboard 65 have explosion-proof properties.

[0071] Additionally, the LER 5 includes an indoor environment sensor 66 (hereinafter simply referred to as "sensor 66") and a ventilation device 67 that provides ventilation between the interior and exterior of the LER 5 by opening and closing an opening provided in the wall. defining the internal part of the LER 5. For example, the ventilation device 67 consists of a damper of the pressure relief system. The ventilation device 67 is configured to control the flow of gas between the inside and the outside of the LER 5 based on the opening/closing degree of the hole. Additionally, the ventilation device 67 may include a fan configured to exhaust gas from the LER 5.

[0072] Additionally, module 2 includes a plant equipment group 6 (see FIG. 1) outside of LER 5. In the example shown in FIG. 3, the high voltage electrical load 80 and at least a portion of the first to third low voltage electrical loads 81 to 83 constitute plant equipment group 6.

[0073] The indoor switchboard 61 has a configuration identical to that of each switchgear 41-44 in MER 3. The indoor switchboard 61 has a configuration in which a switch (opening/closing device) for opening and closing the electrical line, measuring device for voltage and current, control circuit, etc. placed in a metal casing.

[0074] The indoor switchboard 61 is connected to the normal high voltage switchgear 41 in MER 3 via the power cable C11 through the first dry transformer 62. Accordingly, the high voltage power from the normal high voltage switchgear 41 is supplied to the indoor switchboard 61 as the low voltage power converted by the first dry transformer 62.

[0075] Additionally, the indoor switchboard 61 is connected to the high voltage emergency switchgear 42 in MER 3 via the power cable C12 through the second dry-type transformer 63. Accordingly, the high voltage power from the high voltage emergency switchgear 42 is supplied to the indoor switchgear. board 61 as low voltage power converted by the second dry transformer 63.

[0076] Additionally, an indoor switchboard 61 is connected to a switchboard 65 via a power cable C13. For example, the indoor switchboard 61 is configured to receive DC power for the switch from the switchboard 65 in an emergency.

[0077] The HVAC device 64 is an example of an outdoor air supply device, and is an explosion-proof device configured to cool, heat, ventilate, and air-condition the interior of the LER 5. The air intake pipe 71 for introducing outdoor air into the LER 5 is connected to the HVAC device 64. The outside air inlet 71A as the inlet end of the air sampling pipe 71 is located in a non-hazardous area. Accordingly, the combustible gas is prevented from mixing with the outside air supplied to the LER 5 by the HVAC device 64.

[0078] In this regard, in the case where a non-hazardous area is present in the area in module 2, the inlet end 71A of the air sampling pipe 71 may be located in the non-hazardous area in module 2.

[0079] The HVAC device 64 is configured to continuously supply outside air to the interior of the LER 5 so as to apply positive pressure to the interior of the LER 5. When outdoor air is supplied by the HVAC device 64, the ventilation device 67 controls the gas flow between the inside and the outside of the LER 5 based on the opening/closing degree of the hole.

[0080] In this regard, the interior of the LER 5 need not be completely sealed. For example, the LER 5 may have a gap (for example, a small gap between the door of the doorway and the opening of the door frame), through which the gas inside the LER 5 (gas, the amount of which corresponds to the outside air supplied by the HVAC device 64) can be vented to the outside, provided that that a positive pressure can be maintained in the interior of the LER 5.

[0081] The HVAC device 64 is connected to the normal low voltage switchgear 43 and the emergency low voltage switchgear 44 in MER 3 via a C14 power cable and a C15 power cable, respectively. Accordingly, the HVAC device 64 is typically supplied with low voltage AC power from the normal low voltage switchgear 43. On the other hand, in an emergency, the HVAC device 64 is supplied with low voltage AC power from the emergency low voltage switchgear 44. Power is supplied to the HVAC device 64 via the power cables C14 and C15 without passing through the power devices in the LER 5.

[0082] In this regard, the LER 5 may include another device that has at least the above function of introducing outside air into the LER 5, in addition to or instead of the HVAC device 64.

[0083] The switchboard 65 includes an automatic circuit breaker for current leakage, an automatic circuit breaker for wiring, and the like. Switchboard 65 can distribute AC power and DC power. Switchboard 65 is connected to UPS 47 and DC power source 48 in MER 3 via power cable C16 and power cable C17, respectively. Accordingly, in an emergency, AC power and DC power (control electrical power) are supplied from UPS 47 and DC power source 48 to switchboard 65, respectively.

[0084] The sensor 66 consists of, for example, a gas detection sensor configured to detect combustible gas present in the LER 5, a pressure sensor configured to measure the pressure in the LER 5, and a temperature sensor configured to measure the temperature in the LER 5 The sensor 66 is connected to the switchboard 65 via the C20 power cable. Additionally, although not shown, the sensor 66 is connected to an indoor switchboard 61 in the LER 5 via a power cable. Accordingly, low voltage AC power is typically supplied to the sensor 66 from the indoor switchboard 61. On the other hand, in an emergency situation, the sensor 66 is supplied with low voltage AC power from the switchboard 65.

[0085] The high voltage electrical load 80 consists of, for example, an electric motor used for a high performance compressor and the like. The high voltage electrical load 80 is connected to the normal high voltage switchgear 41 in the MER 3 via the power cable C21. Accordingly, the high voltage power is supplied from the normal high voltage switchgear 41 to the high voltage electrical load 80 without passing through the power devices housed in the LER 5.

[0086] The first low voltage electrical loads 81 include, for example, an electric motor used for a pump configured to convey LNG or a refrigerant. The first low voltage electrical loads 81 are connected to the indoor switchboard 61 in LER 5 via C22 power cables. Accordingly, the low voltage power is typically supplied from the indoor switchboard 61 to the first low voltage electrical loads 81. On the other hand, in an emergency, the power supply to the first low voltage electrical loads 81 is stopped.

[0087] The second low voltage electrical load 82 consists, for example, of an electric motor used for a pump configured to supply lubricating oil to the high voltage electrical load 80. The second low voltage electrical load 82 is connected to the low voltage emergency switchgear 44 in the MER 3 via power cable C23. Additionally, although not shown, the normal high voltage switchgear 41 and the emergency high voltage switchgear 42 are configured to receive high voltage AC power as normal power. Accordingly, the AC power that is converted to low voltage by the low voltage emergency switching apparatus 44 in the MER 3 is supplied from the high voltage emergency switching apparatus 42 to the second low voltage electrical load 82 during normal times and in an emergency.

[0088] In this regard, in an emergency, the power supply from the emergency low voltage switchgear 44 takes time to regenerate (for example, to start the emergency generator 51 after a power failure occurs). Accordingly, a device that does not cause major problems for module 2 and LNG plant 1 due to such a temporary power failure is used as the second low voltage electrical load 82.

[0089] The third low voltage electrical load 83 is a device used for communication and the like. in LNG plant 1. For example, the third low voltage electrical load 83 is composed of a network device, a telephone, a speaker, and the like. The third low voltage electrical load 83 is connected to the switchboard 65 via a power cable C24. During normal times and in an emergency, low voltage AC power is supplied from the switchboard 65 to the third low voltage electrical load 83.

[0090] Switchboard 65 can distribute power even in an emergency. Accordingly, if it is not preferable to cut off the power supply to the device, this device is used as the third low voltage electrical load 83.

[0091] In this regard, in FIG. 3, the primary power cables 11 (FIG. 1) connecting MER 3 and LER 5 are power cables C11, C12 and C14-C17. Additionally, the secondary power cables 12 (FIG. 1) are power cables C20, C22 and C24.

[0092] FIG. 4 is a flowchart showing the procedure during startup of the LER 5.

[0093] In the LNG plant 1, almost all electrical devices in the LER 5 stop at the start of operation or in an emergency, such as a power failure. Accordingly, as shown in FIG. 4, the operator or controller starts or restarts the LER 5 based on the likelihood that combustible gas is present in the LER 5.

[0094] First, in the normal low voltage switchgear 43 and the low voltage emergency switchgear 44 in MER 3, the switch for distributing power to the HVAC device 64 is turned on (ST101). Accordingly, the HVAC power supply device 64 starts to operate, and outside air is supplied from the air intake pipe 71, and thereby LER 5 is ventilated and the gas in LER 5 is changed to outside air (ST102).

[0095] Then, based on the determination result of the sensor 66, it is determined whether or not combustible gas is present in the LER 5 (ST103). At this time, in case combustible gas is detected in the LER 5 (ST103: "Yes"), ventilation of the LER 5 by the HVAC device 64 is continued (ST102). On the other hand, if the combustible gas is not determined in the LER 5 (ST103: "No"), the HVAC device 64 sets the inside of the LER 5 to a positive pressure (ST104).

[0096] Thereafter, UPS 47 and DC power source 48 in MER 3 start supplying power to switchboard 65 in LER 5 (ST105). In this regard, in case the LER 5 starts up in an emergency such as a power failure, the UPS 47 and the DC power source 48 start to supply power to the switchboard 65 in the LER 5 when the power failure or the like. arises.

[0097] Then, the control power source of the indoor switchboard 61 in the LER 5 is turned on (ST106). Then, in the normal high voltage switchgear 41 and the emergency high voltage switchgear 42 in the MER 3, the power distribution switch to the first dry transformer 62 in the LER 5 and the power distribution switch to the second dry transformer 63 in the LER 5 are turned on, respectively (ST107 ). Accordingly, the indoor switchboard 61 in the LER 5 is supplied with power from at least one of the normal high voltage switchgear 41 and the emergency high voltage switchgear 42 in the MER 3.

[0098] Next, in the indoor switchboard 61 in the LER 5, the switch for distributing power to the first low voltage electrical loads 81 is turned on (ST108). Accordingly, power is supplied to the first low voltage electrical loads 81, and thereby the first low voltage electrical loads 81 start to operate.

[0099] In this regard, the sequence of steps described above may be at least partially performed by an operator of LNG plant 1. Alternatively, the sequence of steps described above may be at least partially performed by a controller located in MER 3 , and so on.

[0100] Second Embodiment

Fig. 5 is a general block diagram showing a brief representation of the LNG plant 1 according to the second embodiment. In FIG. 5, components identical to those of the above first embodiment are designated by identical reference numbers. Further, in connection with the LNG plant 1 according to the second embodiment, matters not specifically mentioned below are the same as those of the LNG plant 1 according to the first embodiment.

[0101] As shown in FIG. 5, a central equipment room 103 (hereinafter referred to as "CCR"), which has a primary control device for transmitting control signals to each module 2, is provided in the LNG plant 1. Additionally, each module 2A-2E contains a local equipment room 105A-105E (hereinafter referred to as "LCR"), which has an auxiliary control device. The auxiliary control device is configured to transmit/receive control signals to the primary control device in the CCR 103 via each primary signal cable 111. Additionally, the auxiliary control device of each LCR 105A-105E is configured to transmit/receive signals to/from the factory group 106A-106E. equipment through each secondary signal cable 112 based on the transmission/reception of control signals to/from the primary control device in the CCR 103. Factory equipment group 106A-106E consists of a plurality of controlled devices that make up each module 2A-2E in which the auxiliary control device is located .

[0102] On the other hand, the 2F module does not contain an LCR. However, the factory equipment group 106F is configured to transmit/receive control signals to an auxiliary control device in the LCR 105B of module 2B adjacent to module 2F. In other words, in the LNG plant 1, the control device of the LCR provided in one module is configured to transmit/receive control signals to/from the factory equipment group of the module adjacent to one module, in case the LCR is not provided in the module adjacent to one module, or for the convenience of laying a secondary signal cable, etc. in case the LCR is provided in a module adjacent to one module.

[0103] In this regard, at least a portion of each secondary signal cable 112 is set in advance when each module 2A-2F is assembled at a remote location. Further, for each secondary signal cable 112, a cable having a diameter smaller than the diameter of each primary signal cable 111 is used. Accordingly, in the LNG plant 1, the cost of signal cables can be reduced.

[0104] Although not shown in FIG. 5, the above LER 5 shown in FIG. 1 may be provided in the LNG plant 1 according to the second embodiment.

[0105] Below, if it is not necessary to distinguish each LCR 105A-105E, each LCR 105A-105E is collectively referred to as "LCR 105". Additionally, in case it is not necessary to distinguish each factory equipment group 106A-106F, each factory equipment group 106A-106F is collectively referred to as "factory equipment group 106".

[0106] FIG. 6 is an explanatory diagram showing a configuration for transmission between CCRs 103 shown in FIG. 5, and LCR 105.

[0107] The CCR 103 has a control panel 141 as a control device. The control panel 141 is configured to comprehensively control the control target included in the factory equipment group 106 of the LNG plant 1 based on the operator's operation.

[0108] Each module 2 includes an LER 5, which has an electrical device, and an LCR 105, which has a control device. In the present embodiment, LER 5 and LCR 105 share the top wall, side wall and bottom wall of the same building, and the interior of LER 5 and the interior of LCR 105 are separated from each other by a partition 110. Although MER 3 and some components in LER 5 descend in Fig. 6, their configurations are identical to those shown in FIG. 3.

[0109] Factory equipment group 106 includes various sensors, a solenoid valve, a control valve, and the like. as managed devices.

[0110] The LCR 105 has a control device 161 including a controller, an I/O module, and the like. Although the LCR 105 is located in hazardous area 31, the control device 161 does not have explosion-proof properties.

[0111] The control device 161 is connected to each controlled device (factory equipment group 106) through each junction box 162 via each secondary signal cable 112. In the present embodiment, each junction box 162 and factory equipment group 106 are located outside the LCR 105.

[0112] The interior of the LCR 105 communicates with the interior of the LER 5 through a conduit 170 penetrating through the baffle 110. Additionally, a ventilation device 167 is provided on the side wall of the LCR 105. The ventilation device 167 has a function identical to that of the ventilation device 67 of the LER 5. For example, the ventilation device 167 consists of a damper of the pressure relief system.

[0113] According to such a configuration, outdoor air that is supplied to the LER 5 by the HVAC device 64 is supplied to the LCR 105 through the conduit 170. Accordingly, a positive pressure is generally maintained in the interior of the LCR 105. When outdoor air is supplied to the LER 5 by the HVAC device 64, the ventilation device 167 can control the gas flow between the inside and the outside of the LCR 105 (namely, the amount of gas emitted from the LCR 105) based on the opening/closing degree of the hole.

[0114] Additionally, at the start of operation or in an emergency, such as a power failure, the gas in the LCR 105 may be replaced with outside air in a procedure identical to that shown in FIG. 4.

[0115] In this regard, the above HVAC device 64 can be independently located in the LCR 105. In such a case, the conduit 170 that penetrates through the baffle 110 is not required. Additionally, in the present embodiment, the LCR 105, for example, is placed together with the LER 5. However, the LCR 105 and LER 5 may be placed separately. In such a case, the LCR 105 may include a device (outside air supply device) configured to receive power from a switchgear (switchboard) in a non-hazardous area, similar to the HVAC device 64 above.

[0116] The present invention has been described above based on specific embodiments, but these embodiments are merely examples, and the present invention is not limited to these embodiments. Not all of the components of the plant module, the plant incorporating it, and the method of operating the plant according to the present invention shown in the above-described embodiments are mandatory, and at least those skilled in the art can appropriately select the components within the scope of the present invention.

[0117] In case the combustible gas is heavier than air, the LER 5 may be composed of a side wall and a bottom wall while its top wall is lowered. In such a case, the side wall has a cylindrical shape with no entry/exit for the operator. Additionally, the side wall can be made of concrete. In such a case, the interior of the LER 5 is not an enclosed space, but allows the ingress of combustible gas, which is heavier than air, to be prevented. Accordingly, in the LER 5, the HVAC device 64 may be omitted. In this regard, the operator can enter and exit the LER 5 from the opening above the side wall through a ladder or the like.

[0118] Additionally, in LER 5, a known explosion-proof switching rack can be used instead of the indoor switchboard 61 shown in FIG. 3. Accordingly, in the LER 5, the HVAC device 64 may be lowered.

Glossary of terms

[0119] 1 - LNG plant

2 - module

3 - MER (main electrical room)

5 - LER (local electrical room)

6 - group of factory equipment

11 - primary power cable

12 - secondary power cable

21 - design

31 - danger zone

41 - normal high voltage switchgear (normal switchboard)

42 - high voltage emergency switching equipment (emergency switchboard)

43 - normal low voltage switchgear (non-zonal switchboard and normal switchboard)

44 - low voltage emergency switching equipment (out-of-zone switchboard and emergency switchboard)

45 - normal transformer

46 - emergency transformer

47 - UPS (uninterruptible power supply)

48 - DC power source

51 - emergency generator

61 - indoor switchboard (power device)

62 - the first dry transformer

63 - second dry transformer

64 - HVAC device (outside air supply device)

65 - switching board

66 - indoor environment sensor

67 - ventilation device

71 - air intake pipe

71A - outside air inlet

80 - high voltage electrical load

81 - first low voltage electrical load

82 - second low voltage electrical load

83 - third low voltage electrical load

103 - CCR (central equipment room)

105 - LCR (local equipment room)

106 - factory equipment group

110 - partition

111 - primary signal cable

112 - secondary signal cable

141 - control panel

161 - control device

162 - junction box

167 - ventilation device

170 - pipeline

C14 - power cable

C15 - power cable

Claims (42)

1. Factory module containing: - the plant equipment group that makes up the plant, - a local electrical room located in a hazardous area defined by the presence of combustible gas, and the local electrical room has a power device configured to supply electricity to a group of plant equipment, - the structure supporting the plant equipment group and the local electrical room, - an outside air supply device, having explosion-proof properties and located in the local electrical room, in order to supply outside air to its interior, - power cables configured to supply electricity to the outdoor air supply device from a non-hazardous area, defined by an area outside the area where combustible gas is present, and - the main electrical room, located in a non-hazardous area and having one or more out-of-zone switchboards, made with the possibility of supplying electricity to the local electrical room, - moreover, at least one of the power cables connects at least one of the out-of-zone switchboards and the outdoor air supply device. 2. Factory module containing: - the plant equipment group that makes up the plant, - a local equipment room located in a hazardous area defined by the presence of combustible gas, and the local equipment room has a control device configured to transmit a control signal to a plant equipment group, — the structure supporting the plant equipment group and the local equipment room, - an outside air supply device having explosion-proof properties and located in the local equipment room so as to supply outside air to its interior, and - power cables configured to supply electricity to the outdoor air supply device from a non-hazardous area, defined by an area outside the area where combustible gas is present, and - the main electrical room, located in a non-hazardous area and having one or more out-of-zone switchboards, made with the possibility of supplying electricity to the local equipment room, moreover, at least one of the power cables connects at least one of the out-of-zone switchboards and the outdoor air supply device. 3. The factory module according to claim 1, wherein the outdoor air supply device includes an air intake pipe configured to supply outdoor air to the interior of the local electrical room, and the air intake pipe includes an inlet for outside air located outside the hazardous area. 4. The factory module according to claim 1, wherein the outdoor air supply device is configured to supply outdoor air to the interior of the local electrical room so as to set positive pressure in the interior of the local electrical room. 5. Factory containing factory module, while the factory module includes: - the plant equipment group that makes up the plant, - a local electrical room located in a hazardous area defined by the presence of combustible gas, and the local electrical room has a power device configured to supply electricity to a group of plant equipment, - the structure supporting the plant equipment group and the local electrical room, - an outside air supply device having explosion-proof properties and located in the local electrical room so as to supply outside air to its interior, and - power cables configured to supply electricity to the outdoor air supply device from a non-hazardous area, defined by an area outside the area where combustible gas is present, and - the main electrical room, located in a non-hazardous area and having one or more out-of-zone switchboards, made with the possibility of supplying electricity to the local electrical room, moreover, at least one of the power cables connects at least one of the out-of-zone switchboards and the outdoor air supply device. 6. The plant of claim 5, wherein the off-site switchboards include a normal switchboard configured to distribute electricity from a normal power supply and an emergency switchboard configured to distribute electricity from an emergency power supply. 7. Plant according to claim 5 or 6, additionally containing: - switchboard located in the local electrical room, - an indoor switchboard located in the local electrical room and configured to supply electricity to a group of plant equipment, and - a power supply device located in the main electrical room and configured to supply control power to the switchboard, wherein the switching board is configured to supply control electricity supplied from the power supply device to an indoor switchboard. 8. The plant according to claim 6, wherein each of the normal switchboard and the emergency switchboard includes a high voltage switchgear and a low voltage switchgear, and The factory module additionally includes: - a first dry transformer located in the local electrical room and configured to convert high voltage power to low voltage power, wherein the high voltage power converted by the first dry transformer is supplied from the high voltage switchgear as a normal switchboard to the power device, and - a second dry transformer located in the local electrical room and configured to convert high voltage power to low voltage power, wherein the high voltage power converted by the second dry transformer is supplied from the high voltage switchgear as an emergency switchboard to the power device. 9. Plant according to claim 8, wherein the power cable is connected to each of the low voltage switchgear as a normal switchboard and the low voltage switchgear as an emergency switchboard. 10. The plant of claim 8, wherein the plant module further includes a high voltage electrical load to which the high voltage power from the high voltage switchgear as a normal distribution board is supplied without passing through the power device. 11. Plant according to claim 6, further comprising a generator connected to an emergency switchboard. 12. The plant according to claim 5, further comprising a local equipment room having a control device configured to transmit a control signal to a group of plant equipment.

Images