JPS6268912A - Freezing-proof method for tank ballast water in frozen sea - Google Patents

Abstract

PURPOSE:To reduce heat quantity, by operating remote control valves for ballast water service and drainage set on the respective tanks successively, to circulate the ballast water, and by working a ballast water heating device when water temperature comes near the freezing point of the sea water. CONSTITUTION:The temperature of ballast water in ballast tanks 2a-2n is detected by detectors 5a-5n. After that, when the water temperature comes to a specified temperature or made lower, then the water supply valve 4a of the tank 2a and the drain valve 4n of the tank 2n are opened by a remote control means 21, and a pump 6 is driven to feed ballast water in the tank 2n into the tank 2a. At the same time, the service and drain valves 4b-4m of the tanks 2a-2n are opened, and the ballast water of the respective tanks 2a-2m is moved to the respective downstream tanks, and the ballast water in the tanks 2a-2n is circulated from the upper section to the lower section, during which formed convection is applied to the ballast water. As a result, the temperature of the ballast water is uniformed, and so the used fuel of a freezing-proof boiler can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for preventing freezing of tank ballast water of marine structures in icy sea waters, and in particular to a method for reducing the amount of heat required for freezing prevention.

[Conventional technology]

Figure 3 shows an example of marine structures in icy seawater, and in the figure, 611'i residential area 62. De+J IJ Song Knit 33 is an artificial island, 34 is an icy ocean, and 35 is an ocean floor on which an artificial island 61 is installed.

As mentioned above, on the artificial island 61 installed in the icy sea area, the outside air temperature drops to around -50 degrees Celsius, so water and oil stored in the tanks of the artificial island 31 and used for 9 ballast operations may freeze. It may become unusable.

In order to prevent water, etc. in this tank from freezing, conventionally the fourth
As shown in the figure, six heat-insulating vibes 3a=3n are installed independently in each tank 2a to 2n of the artificial island 31, and antifreeze heated by a boiler 41 is sent to the heat-insulating pipe 3=3m,
The water or oil in each tank 2a to 2n is kept warm.

[The problem that the invention is trying to solve]

In the conventional freeze prevention method as described above, the temperature inside each tank 2a to 2n is detected by a temperature detector (not shown),
Each heat-retaining vibro a~
However, for large structures such as the artificial island 31 in icy ocean waters, the amount of heat required to prevent freezing is enormous, requiring a large-capacity boiler and a large amount of equipment. There was an opening point in that fuel consumption was also required.

This invention was made to solve this problem, and aims to propose a complete method for preventing freezing of tank ballast water, which reduces the amount of heat required for freezing prevention.

[Means to resolve inter-JA]

The method for preventing tank ballast water from freezing in an icy sea according to the present invention is to provide a remote control valve for supplying and discharging ballast water to each ballast tank of a marine structure installed in an icy sea area and having a plurality of ballast tanks inside. By operating the valves in sequence, the ballast water in each ballast tank is circulated, and when the temperature of the ballast water drops to near the freezing point of seawater, the ballast water heating device is activated.
Prevent ballast water from freezing.

[For production]

In this invention, the temperature of the ballast water in each ballast tank is made uniform by circulating the ballast water in the ballast tanks and forcibly applying convection to the ballast water.
Prevents local temperature dropping of ballast water and slows the ice production speed.
1 is a partial cross-sectional view of the artificial island 61, in which 1 is the outer plate in contact with the outside air or the icy sea, 2a to 2n are ballast tanks that store ballast water, and 3a to 3c are piped inside the ballast tanks (not shown). Insulated pipes to which heated antifreeze solution is sent to prevent freezing; 4 & ~4n are valves operated by remote control to supply and drain ballast water from each ballast tank 2 &~2nK; 5 is a temperature detector; 6
is a palast pump that circulates the ballast water in each of the ballast tanks 28 to 2n, and the suction port of the ballast pump 6 is connected to the drainage valve 4n of the ballast tank 2n provided at the bottom of the artificial island 31, and the The outlet is connected to a water supply valve 4aK of a ballast tank 2a provided at the top of the artificial island 31.

The second method of keeping the ballast tank configured as described above
The explanation will be based on the control block diagram shown in the figure.

The temperature of the ballast water in the ballast tanks 2a to 2n is constantly detected by the temperature detectors 5a to 5n, and when the water temperature reaches a predetermined temperature, e.g. The water supply valve 4a and the drainage valve 4n of the ballast tank 2n provided at the bottom are opened, the ballast pump 6 is driven, and the ballast water in the ballast tank 2n is sent into the ballast tank 2a. Water supply and drainage valves 41 provided in each ballast tank 2a to 2n on the same surface
By opening the ballast tanks 2a to 2m by 3 to 4 m and moving the ballast water in each ballast tank 2a to 2m to the downstream ballast tanks, the ballast water in each ballast tank 2a to 2n is circulated sequentially from the upper position to the lower position. Forced convection is applied to the Therefore each ballast tank 2&~22
The temperature of the ballast water within 1 can be made uniform and local temperature drops can be prevented.

The temperature of this equalized ballast water is detected by temperature detectors 5a to 5a.
5n, the detected water temperature is compared with a preset temperature 26 by comparison means 22. When the comparison means 22 detects that the temperature of the ballast water has fallen close to the freezing point of seawater, the detection signal operates the boiler control means 24 to drive the boiler and send the heated antifreeze to the heat-insulating vibros a to 6c to the ballast. Keep water warm.

〔Effect of the invention〕

This invention has been described above. In this way, the ballast water in the ballast tank is circulated vertically, and the relatively high-temperature ballast water is constantly sent from below to the lower temperature area above, making the temperature of the ballast water uniform and reducing the local ballast water temperature. Temperature drop can be prevented. Furthermore, since the ice formation rate can be slowed down by forced convection, it is possible to reduce the amount of heat required to prevent ballast water from freezing.

Therefore, the capacity of the boiler used to prevent freezing of ballast water can be reduced, which has the effect of reducing the amount of fuel used.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of an artificial island showing an embodiment of the present invention;
FIG. 2 is a control block diagram of the above embodiment, FIG. 6 is a side view of an artificial island installed in icy sea water, and FIG. 4 is an explanatory diagram showing a conventional freezing prevention method. 101. Outer plate, 2a-2n...Ballast tank, 3a
~5c... Heat retention vibrator, 4a~4n... Valve 15
a. ~5n...Temperature detector, 6...(last pump. Patent attorney Masaru Sato Figure 1)

Claims (1)

[Claims] In a marine structure installed in an icy sea area and having multiple ballast tanks inside, each ballast tank is equipped with a remote control valve for supplying and draining ballast water, and by sequentially operating each valve, the ballast water in each ballast tank can be drained. A method for preventing freezing of tank ballast water in an icy sea, characterized by sequentially circulating the ballast water and operating a ballast water heating device when the temperature of the ballast water drops close to the freezing point of seawater.