JPS6239664B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to LNG cryogenic power generation equipment, and in particular,
Suitable for LNG direct expansion type LNG cold thermal power generation equipment
This relates to LNG cryogenic power generation equipment.

A conventional LNG cryogenic power generation facility will be explained with reference to FIG.

Figure 1 is a system diagram of an LNG direct expansion type LNG cryothermal power generation facility, in which liquefied natural gas (hereinafter abbreviated as LNG) once stored in LNG tank 1 is pumped by liquid transfer pump 2 up to 15 kg/cm ² G. Pressurized pipes 11 and 12
is sent to boost pump 3, where an additional 50
After being pressurized to Kg/cm ²・G, it passes through conduit 13.
The LNG is fed to a vaporizer (hereinafter abbreviated as LNG vaporizer) 4 that vaporizes LNG. The LNG fed to the LNG vaporizer 4 is vaporized by the seawater flowing through the conduit 14 and becomes natural gas (hereinafter abbreviated as NG) and heated to room temperature. NG at room temperature is sent to the expansion turbine 5 through the conduit 15, and the pressure increases from 50Kg/cm ² G to 8
Kg/ ^cm2・G Expands the temperature from room temperature to approximately -60℃
After the temperature has decreased to 100.degree. C., it is sent to the warmer 6 through the conduit 16. The NG fed to the warmer 6 is brought back to room temperature by seawater flowing through the conduit 17, and then passes through the conduit 18 at a pressure of approximately 8 kg/cm ² G to be used as boiler fuel at a power plant (not shown). will be sent as.

In general, an extremely important purpose of LNG cold power generation equipment is not only to use the cold energy of LNG to generate electricity, but also to vaporize LNG to provide pump fuel for power plants. However, in such conventional LNG cold power generation equipment, the reliability of the boost pump is low, so although a separate standby unit is installed, it is still not sufficient.
Even if the boost pump breaks down and stops, it doesn't matter.
In order to secure boiler fuel for power plants by vaporizing LNG, a separate LNG vaporizer had to be installed as a standby machine, which had the disadvantage of increasing the cost of the equipment.

The present invention aims to eliminate the above-mentioned drawbacks, and includes a booster pump that boosts the pressure of liquefied natural gas supplied, a vaporizer that vaporizes the liquefied natural gas supplied from the booster pump, and a vaporizer that vaporizes the liquefied natural gas supplied from the booster pump. an expansion means for expanding the natural gas supplied from the system and sent to the natural gas consumption means outside the system; a generator driven by the expansion means; and another bypass means for supplying natural gas vaporized from liquefied natural gas in the vaporizer to the natural gas consumption means by bypassing the expansion means. It provides cold power generation equipment.

An embodiment of the present invention will be explained with reference to FIG.

Figure 2 shows the LNG direct expansion method according to the present invention.
This is a system diagram of an LNG cryogenic power generation facility, and the same equipment as in FIG. In FIG. 2, it consists of a bypass valve 7 and a bypass pipe 19,
It consists of a bypass means for supplying the LNG fed from the LNG tank 1 by the feed pump 2 to the LNG vaporizer 4 by bypassing the boost pump 3, a bypass valve 8, and a bypass pipe 20. The NG vaporized from the LNG fed by the feed pump 2 bypasses the expansion turbine 5, which is an expansion means, and is sent to the boiler (not shown) of a power plant (not shown), which is an NG consumption means outside the system. Other bypass means are provided. In other words, on the outlet side of the liquid pump 2, for example, the conduit 12 and the LNG vaporizer 4.
A bypass pipe 19 which bypasses the boost pump 3 and is provided with a bypass valve 7 is connected to the inlet side of the LNG vaporizer 4, for example, the conduit 13, and the outlet side of the LNG vaporizer 4, for example, the conduit 15 and the inlet side of the warmer 6, e.g. A bypass pipe 20 that bypasses the expansion turbine 5 and is provided with a bypass valve 8 is connected to the conduit 16 . In this case, the bypass valve 8 has the function of expanding and lowering the pressure of NG that has entered the bypass pipe 20 from the LNG vaporizer 14 via the conduit 15 to a pressure required as boiler fuel.

If the boost pump 3 fails, the bypass valve 7,
Open valves 8 and 15Kg/cm ²・G with liquid feed pump 2.
The pressure was increased to
Pass LNG through bypass pipe 19 and conduit 13
It is fed to the vaporizer 4. Here, LNG is transferred to conduit 14
is vaporized by the flowing seawater and becomes NG, heated to room temperature, passes through conduit 15, and is expanded by bypass valve 8, which is open, from 15Kg/cm ² G to approximately 8
Bypass pipe 20, conduit 1 with pressure reduced to Kg/cm ²・G
6 and is fed to the warmer 6. In this case, since the degree of pressure drop at the bypass valve 8 is small, there is almost no drop in temperature, and the NG is sent through the conduit 18 without being heated by the heater 6 as boiler fuel to the power plant (not shown). be done. In addition, temperature rising pump 3
Even though the expansion turbine 5 is operating normally, if the expansion turbine 5 fails or is stopped due to inspection, the pressure will be increased to 50 kg/cm ² G by the boost pump 3.
LNG is supplied to the LNG vaporizer 4 through the conduit 13, where it is vaporized by the seawater flowing through the conduit 14 to become NG with a pressure of 50 Kg/cm ² · G and heated to room temperature, and then the bypass valve is opened. It is expanded in valve 8 and the pressure is lowered from 50 kg/cm ² G to approximately 8 kg/cm ² G, but in this case, the pressure drop is large, so the temperature of the NG after leaving bypass valve 8 is approximately -20 kg/cm 2 G. ℃, the temperature is restored to room temperature by the seawater flowing through the conduit 17 in the warmer 6, and then the temperature is returned to normal temperature through the conduit 18 and supplied as boiler fuel to the power plant.

In this example, even if the boost pump fails and stops, continuous supply of NG to the boiler of the power plant can be ensured without installing a separate LNG vaporizer as a standby device, so LNG cooling and heating can be ensured. It is possible to suppress the increase in equipment costs of power generation equipment. Further, even if the expansion turbine is stopped due to failure or inspection, continuous supply to the boiler of the power plant can be ensured.

According to the present invention, even if the boost pump stops due to failure etc., continuous supply of NG to the NG consumption means can be ensured without installing a separate LNG vaporizer as a standby device. This has the effect of suppressing increases in equipment costs for cold power generation equipment.

[Brief explanation of the drawing]

Fig. 1 illustrates a conventional LNG cryogenic power generation facility, which is a system diagram of an LNG direct expansion type LNG cryogenic power generation facility, and Fig. 2 illustrates an embodiment of the present invention. LNG direct expansion method
It is a system diagram of LNG cold power generation equipment. 2... Liquid sending pump, 4... LNG vaporizer, 6... Warmer, 7, 8... Bypass valve, 19, 20... Bypass pipe.

Claims (1)

[Claims] 1 A booster pump that boosts the pressure of the liquefied natural gas that has been supplied, a vaporizer that vaporizes the liquefied natural gas that is supplied from the booster pump, and a vaporizer that vaporizes the liquefied natural gas that is supplied from the vaporizer and is sent to the natural gas consumption means outside the system. an expansion means for expanding the natural gas; a generator driven by the expansion means; a bypass means for supplying the supplied liquefied natural gas to the vaporizer by bypassing the boost pump; and the vaporizer. and another bypass means for supplying natural gas vaporized from liquefied natural gas to the natural gas consumption means by bypassing the expansion means.