LNG ship isolation void cabin modular heating structure and control method thereof

Abstract

The invention discloses a control method of an LNG (liquefied natural gas) ship isolation void modularized heating structure, which comprises a module frame, a main heater, a standby heater, an auxiliary heater and a heating coil, and is characterized in that the module frame is arranged in a motor chamber which is originally used for placing a compressor motor; the main heater, the standby heater and the auxiliary heater are all fixed on the module frame, the heating coil is fixed in a cabin of the isolation void cabin, and a plurality of temperature sensors are fixed on the front cabin wall and the rear cabin wall of the isolation void cabin. The isolated void modular heating structure is arranged in the compressor motor chamber, the heating coil is arranged in the internal space of the isolated void, and the heating medium conveying pipeline of the isolated void modular heating structure is connected with the heating coil, so that gas in the isolated void can be heated; condensate water is prevented from being formed in the isolation void cabin, material performance reduction caused by low temperature is avoided, and therefore the integrity of the ship structure is guaranteed, and ship navigation safety is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of shipbuilding, and in particular to a control method for a modular heating structure of an isolated empty tank of an LNG ship. Background Art

[0002] LNG carriers are designed to transport liquefied natural gas (LNG) at extremely low temperatures. Their cargo tanks are designed to hold ultra-low-temperature LNG at -163°C. Due to the low ambient temperature surrounding the cargo tanks, condensation forms within the insulated compartments, leading to ice or frost. This can easily lead to brittle fractures in the ship's steel structure, compromising the integrity of the ship's structure and compromising its navigational safety. Summary of the Invention

[0003] In view of this, the present invention provides a control method for a modular heating structure of an isolated air tank of an LNG ship, so as to solve the problems existing in the above-mentioned background technology.

[0004] A modular heating structure for an isolated empty tank of an LNG carrier, comprising a module frame, a main heater, a standby heater, an auxiliary heater and a heating coil.

[0005] The module frame is placed in the motor room originally used to house the compressor motor, and the motor room is located on the dome deck;

[0006] The main heater, standby heater and auxiliary heater are all fixed on the module frame. The heating medium delivery pipelines of the main heater, standby heater and auxiliary heater are fixed on the module frame and laid downward through the dome deck and then extended into the isolation cabin to be connected to the heating coil;

[0007] The heating coil is fixed in the isolation cabin, and a plurality of temperature sensors are fixed on the front and rear walls of the isolation cabin;

[0008] The main heater and the standby heater are both electric heaters and are controlled in conjunction with the fan in the motor room. The auxiliary heater is a steam heater and its steam inlet is connected to the steam pipeline of the ship.

[0009] Preferably, the module frame includes a first frame, a second frame arranged on one side of the first frame, and an inspection platform connected between the first frame and the second frame. An extension frame extends from the top of the first frame toward the second frame, and the extension frame is connected to the second frame through a connecting rod.

[0010] Preferably, the main heater and the backup heater are both fixed on the first frame, and the auxiliary heater is fixed on the second frame.

[0011] Preferably, the height of the second frame is lower than that of the first frame.

[0012] Preferably, a plurality of lifting lugs are fixed to the top of the module frame.

[0013] Preferably, the temperature sensor is located at the center of the bulkhead or around the center of the bulkhead, and the temperature sensors located around the center of the bulkhead are 1 / 4 of the bulkhead height from the bottom or top of the bulkhead and 1 / 3 of the bulkhead width from the center of the bulkhead.

[0014] A control method for a modular heating structure of an isolated empty tank of an LNG ship specifically comprises the following steps:

[0015] Under normal circumstances, the dual-fuel generator in the ship's engine room supplies power to various electrical equipment in the motor room. The main heater or auxiliary heater is activated according to the load energy consumption. The main heater or auxiliary heater uses electrical energy to heat the medium inside it. The heated medium is then transported to the heating coil through the heating medium transmission pipeline to heat the isolation tank.

[0016] When the main heater fails or the fan in the motor room fails, the power supply of the currently running main heater or auxiliary heater is cut off, and the standby heater is started at the same time. The steam in the ship's steam pipeline is passed into the auxiliary heater, and the steam is used to heat the medium inside the standby heater. The heated medium is transported to the heating coil through the heating medium transmission pipeline to heat the isolation tank.

[0017] Preferably, when the dual-fuel generator in the nacelle fails, the emergency generator is immediately switched to supply power to various electrical equipment in the motor room.

[0018] Preferably, when the standby heater is in operation, if it issues an alarm indicating a high condensate level, its power supply must be immediately cut off and the power supply must be restored after the fault is resolved.

[0019] Preferably, the power of the main heater 2 is at least twice that of the auxiliary heater 3. When the load energy consumption is lower than the set value, the auxiliary heater 3 is enabled, and when the load energy consumption is higher than the set value, the main heater 2 is enabled.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention sets an isolation cabin modular heating structure in the compressor motor room, sets a heating coil in the interior space of the isolation cabin, and connects the heating medium delivery pipeline of the isolation cabin modular heating structure with the heating coil. This can heat the cabin gas of the isolation cabin, avoid the formation of condensed water in the isolation cabin, and avoid the degradation of material properties caused by low temperature, thereby ensuring the integrity of the ship structure and ensuring the safety of ship navigation.

[0022] 2. The modular heating structure of the isolation compartment of the present invention is provided with two electric heaters and one steam heater. The electric heater and the steam heater serve as a main and backup heater for each other. When the fan in the motor room is operating normally, the main heater or the auxiliary heater is used according to the ambient temperature of the ship. When the ambient temperature is too low, a high-power main heater needs to be enabled to provide a larger heat exchange capacity. When the ambient temperature is high, the system has a smaller demand for heat exchangers, and a smaller-power auxiliary heater can be enabled to save energy. The steam heater is a backup heater for the electric heater. When the fan in the motor room fails, the power supply of the currently running electric heater is cut off, and the steam heater is started at the same time. Steam is used to heat the ethylene glycol aqueous solution inside the steam heater to ensure uninterrupted heating of the isolation compartment.

[0023] 3. The present invention integrates two electric heaters and one steam heater and their pipelines and valves on a module frame, which greatly improves the structural and system integrity and the pre-outfitting rate of the ship. It can greatly reduce the difficulty and workload of the later construction on the ship, shorten the shipbuilding cycle, and reduce the construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is a schematic diagram of installing the main heater, backup heater, and auxiliary heater on the module frame.

[0026] Figure 2 This is a schematic diagram showing the installation of piping, valves, etc. for the main heater, standby heater, and auxiliary heater.

[0027] Figure 3 This is a schematic diagram of the arrangement of temperature sensors on the bulkhead of the adjacent void compartment.

[0028] The meanings of the numbers in the figure are:

[0029] 1 is the module frame, 11 is the first frame, 12 is the second frame, 13 is the maintenance platform, 14 is the extension frame, 15 is the connecting rod, 16 is the lifting lug,

[0030] 2 is the main heater,

[0031] 3 is an auxiliary heater,

[0032] 4 is a spare heater,

[0033] 5 is a temperature sensor,

[0034] 6 is the isolation bulkhead. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the present invention more clearly apparent, the present invention is described below using specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0036] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0037] It should be understood that although the terms first, second, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms and should not be understood to indicate or imply relative importance. These terms are only used to distinguish information of the same type from each other. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information without departing from the scope of this disclosure. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining."

[0038] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention.

[0039] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0040] In order to better understand the technical solution of the present invention, the present invention is described in detail below with reference to the accompanying drawings.

[0041] The present invention provides a modular heating structure for an isolated empty tank of an LNG ship, comprising a module frame 1, a main heater 2, a standby heater 3, an auxiliary heater 4 and a heating coil.

[0042] The main heater 2, standby heater 3 and auxiliary heater 4 are all fixed on the module frame 1. The module frame 1 is set in the motor room originally used to place the compressor motor, and the motor room is located on the dome deck.

[0043] Specifically, the module frame 1 includes a first frame 11, a second frame 12 disposed on one side of the first frame 11, and an inspection platform 13 connected between the first frame 11 and the second frame 12. An extension frame 14 extends from the top of the first frame 11 toward the second frame 12, and the extension frame 14 is connected to the second frame 12 via a connecting rod 15. The first frame 11 and the second frame 12 are of different heights. In this embodiment, the height of the second frame 12 is lower than that of the first frame 11.

[0044] When manufacturing the module frame 1 , the heater bases of the three heaters are directly integrated on the frame and manufactured as one piece with the frame body of the module frame 1 .

[0045] The main heater 2 and the backup heater 4 are both fixed to the first frame 11, and the auxiliary heater 3 is fixed to the second frame 12. In this embodiment, the main heater 2 and the backup heater 4 are respectively fixed to the left and right sides of the first frame 11, and the fixing heights of the two are equal.

[0046] The heating medium delivery pipelines of the main heater 2, the standby heater 3 and the auxiliary heater 4 are fixed on the module frame 1 and laid downward through the dome deck and then extended into the isolation cabin to be connected to the heating coils, which are fixed in the cabin space of the isolation cabin.

[0047] Among them, the main heater 2 and the auxiliary heater 3 are both electric heaters and are jointly controlled with the fan in the motor room. The electric heater heats the liquid medium flowing through it by converting electrical energy into thermal energy. The heated liquid medium can be transmitted to the heating coil through its heating medium transmission pipeline to heat the air inside the isolation cabin. The liquid medium transmitted to the heating coil then flows back to the electric heater through the heating medium transmission pipeline, and the cycle is repeated.

[0048] The backup heater 4 is a steam heater, and its steam inlet is connected to the ship's steam pipeline. The backup heater 4 uses steam as a heat source to heat the liquid medium flowing through it. The heated liquid medium is then transferred through its heating medium delivery pipeline to the heating coil, which heats the air inside the isolation compartment. The liquid medium transferred to the heating coil then flows back through the heating medium delivery pipeline to the electric heater, and this cycle repeats.

[0049] In this embodiment, the liquid medium in the main heater 2, the standby heater 3 and the auxiliary heater 4 is all ethylene glycol aqueous solution.

[0050] A plurality of temperature sensors 5 for detecting the air temperature within the cofferdam are fixed to the front and rear bulkheads of the cofferdam. These temperature sensors 5 are located at or around the center of the bulkhead. In this embodiment, five temperature sensors are fixed to each of the front and rear bulkheads of the cofferdam. One temperature sensor is fixed to the center of the bulkhead, and the remaining four temperature sensors are symmetrically arranged around the center of the bulkhead. These four temperature sensors are located at a distance of 1 / 4 of the bulkhead height from the bottom or top of the bulkhead and 1 / 3 of the bulkhead width from the center of the bulkhead.

[0051] Preferably, a plurality of lifting lugs 16 are fixed to the top of the module frame 1 .

[0052] The present invention also provides a control method for a modular heating structure of an isolated empty tank of an LNG ship, which specifically includes the following steps:

[0053] Under normal circumstances, the dual-fuel generator in the ship's engine room supplies power to various electrical equipment in the motor room, and starts the main heater 2 or the auxiliary heater 3 according to the load energy consumption. The main heater 2 or the auxiliary heater 3 uses electrical energy to heat the medium (ethylene glycol aqueous solution) inside it, and the heated medium is transported to the heating coil through the heating medium transport pipeline to heat the isolated cabin; in this embodiment, the power of the main heater 2 is at least twice that of the auxiliary heater 3. When the load energy consumption is lower than the set value, the auxiliary heater 3 is enabled, and when the load energy consumption is higher than the set value, the main heater 2 is enabled.

[0054] When the main heater 2 fails or the fan in the motor room fails, the power supply of the currently running main heater 2 or auxiliary heater 3 is cut off, and the standby heater 4 is started at the same time and the steam in the ship's steam pipeline is passed into the auxiliary heater 4. The steam is used to heat the medium (ethylene glycol aqueous solution) inside the auxiliary heater 4, and the heated medium is transported to the heating coil through the heating medium delivery pipeline to heat the isolation compartment.

[0055] If all fans in the motor room fail, the motor room is considered a hazardous area. Since the electric heaters are explosion-proof equipment, the power to the currently running main heater 2 or auxiliary heater 3 must be disconnected. Simultaneously, the backup heater 4 is activated and steam from the ship's steam pipeline is passed through the auxiliary heater 4. This steam heats the medium (ethylene glycol water solution) inside the auxiliary heater 4. The heated medium is then transported via the heating medium delivery pipeline to the heating coil to heat the isolated compartment. While the auxiliary heater 4 is operating, if it issues a high condensate level alarm, its power must be immediately disconnected and restored after the fault is resolved. (If the condensate level in the steam heater is higher than the set value, indicating a blockage in one of its pipelines, the power must be immediately disconnected and stopped. Once the blockage is cleared, power can be restored.)

[0056] When the dual-fuel generator in the engine room fails, the emergency generator is immediately switched to supply power to various electrical equipment in the motor room.

[0057] It should be understood that the embodiments described are only a portion of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

Claims

1. A modular heating structure for an isolated empty tank of an LNG ship, characterized in that: It includes a module frame (1), a main heater (2), an auxiliary heater (3), a standby heater (4) and a heating coil. The module frame (1) is arranged in a motor room originally used for accommodating a compressor motor, and the motor room is located on the dome deck; The main heater (2), auxiliary heater (3) and standby heater (4) are all fixed on the module frame (1); heating medium delivery pipelines of the main heater (2), auxiliary heater (3) and standby heater (4) are fixed on the module frame (1) and laid downward through the dome deck and then extended into the isolation cabin to be connected to the heating coil; The heating coil is fixed in the isolation cabin, and a plurality of temperature sensors (5) are fixed on the front and rear walls of the isolation cabin; The main heater (2) and the auxiliary heater (3) are both electric heaters and are controlled in conjunction with the fan in the motor room; the standby heater (4) is a steam heater and its steam inlet is connected to the ship's steam pipeline.

2. The modular heating structure for the isolated empty tank of an LNG ship according to claim 1 is characterized in that: The module frame (1) comprises a first frame (11), a second frame (12) arranged on one side of the first frame (11), and an inspection platform (13) connected between the first frame (11) and the second frame (12); an extension frame (14) extends from the top of the first frame (11) in a direction toward the second frame (12); and the extension frame (14) is connected to the second frame (12) via a connecting rod (15).

3. The modular heating structure for the isolated empty tank of an LNG ship according to claim 1 is characterized in that: The main heater (2) and the standby heater (4) are both fixed on the first frame (11), and the auxiliary heater (3) is fixed on the second frame (12).

4. The modular heating structure for the isolated empty tank of an LNG ship according to claim 1 is characterized in that: The height of the second frame (12) is lower than that of the first frame (11).

5. The modular heating structure for the isolated empty tank of an LNG ship according to claim 1 is characterized in that: A plurality of lifting lugs (16) are also fixed to the top of the module frame (1).

6. The modular heating structure for the isolated empty tank of an LNG ship according to claim 1 is characterized in that: The temperature sensor (5) is located at the center of the bulkhead or around the center of the bulkhead. The temperature sensors located around the center of the bulkhead are at a distance of 1 / 4 of the bulkhead height from the bottom or top of the bulkhead and at a distance of 1 / 3 of the bulkhead width from the center of the bulkhead.

7. A control method for a modular heating structure of an isolated empty tank of an LNG ship, characterized in that: The specific steps include: Under normal circumstances, the dual-fuel generator in the ship's engine room supplies power to various electrical equipment in the motor room, and starts the main heater (2) or the auxiliary heater (3) according to the load energy consumption. The main heater (2) or the auxiliary heater (3) uses electric energy to heat the medium inside it, and the heated medium is transported to the heating coil through the heating medium transport pipeline to heat the isolation cabin; When the main heater (2) fails or the fan in the motor room fails, the power supply of the main heater (2) or the auxiliary heater (3) currently in operation is cut off, and the standby heater (4) is started at the same time, and the steam in the ship's steam pipeline is passed into the standby heater (4), and the steam is used to heat the medium inside the standby heater (4). The heated medium is transported to the heating coil through the heating medium transport pipeline to heat the isolation compartment.

8. The control method of the modular heating structure of the LNG ship isolation tank according to claim 7 is characterized in that: When the dual-fuel generator in the engine room fails, the emergency generator is immediately switched to supply power to various electrical equipment in the motor room.

9. The control method of the modular heating structure of the LNG ship isolation tank according to claim 7 is characterized in that: When the standby heater (4) is in operation, if it issues an alarm indicating a high condensate level, its power supply must be immediately cut off and the power supply can be restored after the fault is resolved.

10. The control method of the modular heating structure of the LNG ship isolation tank according to claim 7, characterized in that: The power of the main heater (2) is at least twice that of the auxiliary heater (3). When the load energy consumption is lower than a set value, the auxiliary heater (3) is activated, and when the load energy consumption is higher than the set value, the main heater (2) is activated.

Images