JP2005104200A - Energy system of liquefied gas carrier - Google Patents

Abstract

A highly efficient energy system for a liquefied gas carrier is provided.
In an energy system of a liquefied gas carrier ship equipped with a liquefied gas tank for storing liquefied gas and a generator for generating ship power, a duct for guiding the evaporated gas vaporized in the liquefied gas tank to the inside of the generator; The generator seal structure that does not leak the evaporated gas introduced into the generator to the outside, and a discharge duct that discharges the evaporated gas that has passed through the generator and has been heat-exchanged. Evaporated gas vaporized in the gas tank can be effectively heat-exchanged in the generator to provide a highly efficient energy system as a whole.
[Selection] Figure 1

Description

  The present invention relates to an energy system for a liquefied gas carrier ship equipped with a tank for storing liquefied gas such as liquefied natural gas (LNG) and a generator for generating electric power on board.

A conventional liquefied gas carrier energy system will be described with reference to FIG.
As shown in FIG. 4A, the conventional energy system of the liquefied gas carrier ship discards the evaporated gas evaporated in the tank 1 to the outside through the disposal duct 14 as it is. Further, as described in Patent Document 1 of FIG. 5B, the evaporated gas evaporated in the tank 1 is sent to the liquefied gas carrier ship propulsion power engine 11 through the duct 15 and burned as fuel for propulsion. The propulsion screw 13 is rotated by the power engine shaft 12. Further, as described in Patent Document 2 of FIG. 2C, the evaporated gas evaporated in the tank 1 is sent to the generator drive power engine 8 through the duct 16 as fuel for the generator drive power engine. Supply. 3 is a generator, and the generator shaft 6 and the generator drive power engine shaft 9 are connected.
JP 2000-142563 A JP-A-9-125976

  However, in the energy system of the conventional liquefied gas carrier described above, the cryogenic evaporative gas is discarded as it is, and the cold heat source is wasted. Also, since the cryogenic evaporative gas is burned as it is as fuel for propulsion power of the liquefied gas carrier ship, or is supplied as fuel for the generator drive power engine, it is necessary to raise the temperature to an effective temperature for combustion. In addition, for this reason, the cold heat source is consumed wastefully, which is a problem from the viewpoint of energy saving.

  The present invention (corresponding to claims 1 to 3) has been made in view of the above circumstances, and an object thereof is to provide a highly efficient energy system for a liquefied gas carrier ship.

  In order to solve the above-mentioned problem, the invention described in claim 1 is directed to an energy system for a liquefied gas carrier ship equipped with a liquefied gas tank for storing liquefied gas and a generator for generating electric power on board. A duct that guides the evaporated gas into the generator, a generator seal structure that does not leak the evaporated gas introduced into the generator to the outside, and discharges the evaporated gas that has passed through the generator and has undergone heat exchange And a discharge duct.

  According to a second aspect of the present invention, there is provided an energy system for a liquefied gas carrier ship according to the first aspect, wherein an exhaust duct for discharging the evaporated gas that has passed through the generator and exchanged heat is provided for the generator drive power engine. It is characterized by being introduced into the fuel inlet.

  The invention according to claim 3 is the energy system of the liquefied gas carrier ship according to claim 1, wherein the discharge duct for discharging the evaporated gas that has passed through the generator and exchanged heat is connected to the propulsion power engine of the liquefied gas carrier ship. It is characterized by being introduced into the fuel inlet.

  According to the present invention, since the evaporated gas vaporized in the liquefied gas tank is heat-exchanged in the generator, a high-efficiency energy system of the liquefied gas carrier can be provided as a total.

  In the energy system of a liquefied gas carrier ship equipped with a liquefied gas tank for storing liquefied gas and a generator for generating ship power, the best mode of the present invention is the generator configured to convert evaporated gas vaporized in the liquefied gas tank to the generator. A structure comprising a duct leading to the inside, a generator seal structure that does not leak the evaporated gas introduced into the generator to the outside, and a discharge duct that discharges the evaporated gas that has passed through the generator and has undergone heat exchange It is what.

FIG. 1 is a configuration diagram of an energy system of a liquefied gas carrier ship that is Embodiment 1 (corresponding to claim 1) of the present invention.
As shown in the figure, in this embodiment, evaporative gas vaporized in the liquefied gas tank 1 is sent into the generator 3 through the evaporative gas introduction duct 2, and the evaporative gas heat-exchanged in the generator 3 is supplied to the generator seal structure. 4 is configured to discharge from the evaporative gas discharge duct 5 without leaking to the outside.

Next, the operation of this embodiment will be described.
There are various evaporative gases vaporized in the liquefied gas tank 1 from −196 ° C. of liquid nitrogen to −25 ° C. of LPG, etc., all of which are extremely low temperature compared to normal temperature. By sending the cryogenic evaporating gas into the generator 3 and exchanging heat, the inside of the generator 3 is cooled to a temperature close to the cryogenic temperature. On the other hand, the generator loss mainly includes fixed loss (iron loss, mechanical loss) and copper loss, and copper loss varies greatly with temperature. For example, comparing the case where the reference temperature of the F-type insulation is 115 ° C. and the case where it is cooled to −60 ° C.,
{−60 − (− 235)} / {115 − (− 235)} = 0.5
(Because copper resistance becomes 0 at -235 ° C)
Thus, copper loss of 50% can be reduced.
Therefore, the power generation efficiency can be improved, and a highly efficient energy system can be provided as a total.

FIG. 2 is a configuration diagram of an energy system for a liquefied gas carrier ship according to a second embodiment (corresponding to claim 2) of the present invention.
As shown in the drawing, in this embodiment, the evaporated gas exchanged in the generator 3 is supplied as a fuel to the fuel inlet of the generator drive power engine 8 through the duct 7. Further, the generator shaft 6 and the generator drive power engine shaft 9 are connected. Other than that, the configuration is the same as in the first embodiment.

Next, the operation of this embodiment will be described.
The liquefied gas includes an inert gas such as liquid nitrogen, but this embodiment uses a liquefied gas that is active and can be used as a fuel, such as LPG and LNG. The liquefied gas is vaporized in the liquefied gas tank 1 to become an evaporated gas. The evaporated gas is heat-exchanged in the generator 3 and is heated to a temperature effective for ignition and combustion. That is, it is not necessary to raise the temperature of the evaporated gas to a temperature effective for combustion by another heat source. Therefore, it is possible to provide a high-efficiency energy system as a whole without requiring energy for raising the temperature of the evaporated gas.

FIG. 3 is a configuration diagram of an energy system of a liquefied gas carrier ship according to a third embodiment (corresponding to claim 3) of the present invention.
As shown in the drawing, in this embodiment, the evaporated gas heat-exchanged in the generator 3 is supplied as fuel to the fuel inlet of the liquefied gas carrier ship propulsion power engine 11 through the duct 10, and the liquefied gas carrier ship propulsion power engine shaft 12 is supplied. Thus, the propulsion screw 13 is rotated. Other than that, the configuration is the same as in the first embodiment.

Next, the operation of this embodiment will be described.
In this embodiment, liquefied gas that can be used as fuel is used as in the second embodiment. The liquefied gas is vaporized in the liquefied gas tank 1 to become an evaporated gas. The evaporated gas is heat-exchanged in the generator 3 and is heated to a temperature effective for ignition and combustion. That is, it is not necessary to raise the temperature of the evaporated gas to a temperature effective for combustion by another heat source. Therefore, as in the second embodiment, energy for raising the temperature of the evaporative gas is not required, and a highly efficient energy system as a whole can be provided.

The block diagram of the energy system of the liquefied gas carrier ship of Example 1 of this invention. The block diagram of the energy system of the liquefied gas carrier ship of Example 2 of this invention. The block diagram of the energy system of the liquefied gas carrier ship of Example 3 of this invention. The same figure (a)-(c) is a block diagram of the energy system of the conventional liquefied gas carrier ship, respectively.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquefied gas tank, 2 ... Evaporative gas introduction duct, 3 ... Generator, 4 ... Generator seal structure, 5 ... Evaporative gas discharge duct, 6 ... Generator shaft, 7 ... Generator-generator drive power engine duct, 8 ... Generator drive power engine, 9 ... Generator drive power engine shaft, 10 ... Generator-liquefied gas carrier propulsion power engine duct, 11 ... Liquefied gas carrier propulsion power engine, 12 ... Liquefied gas carrier propulsion power engine shaft, 13 ... Propulsion Screw, 14 ... evaporative gas waste duct, 15, 16 ... duct.

Claims (3)

  In an energy system of a liquefied gas carrier ship equipped with a liquefied gas tank for storing liquefied gas and a generator for generating ship power, a duct for guiding the evaporated gas evaporated in the liquefied gas tank to the inside of the generator, and the generator Energy of a liquefied gas carrier characterized by comprising a generator seal structure that does not leak evaporative gas introduced into the outside and a discharge duct that discharges evaporative gas that has passed through the generator and has undergone heat exchange system.   2. The energy system for a liquefied gas carrier according to claim 1, wherein an exhaust duct for discharging the evaporated gas that has passed through the generator and exchanged heat is introduced into a fuel inlet of the generator drive power engine. Energy system for liquefied gas carrier. 2. An energy system for a liquefied gas carrier according to claim 1, wherein an exhaust duct for discharging the evaporated gas that has passed through the generator and exchanged heat is introduced into a fuel inlet of a propulsion power engine of the liquefied gas carrier. Characterized energy system for liquefied gas carriers.

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