JPH0429193Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heat-insulating structure for an independent low-temperature liquefied gas tank.

[Conventional technology]

Insulating materials for low-temperature liquefied gas tanks include:
Some are known to use foamed plastic, perlite, etc., and others are to use vacuum multilayer insulation.

However, when such a heat insulating material is used for the heat insulation structure of a low-temperature liquefied gas tank, there are the following drawbacks.

(1) When using foamed plastic, etc., the thickness of the heat insulation layer increases, and in marine applications, the length and width of the ship increase, which increases the weight of the ship and is uneconomical.

(2) When using a vacuum multilayer insulation (a) In the case where the multilayer insulation is installed directly on the surface of the tank, the voids in the multilayer insulation are evacuated using a vacuum pump, making it difficult to detect gas leaks at all times. , gas will gush out if the tank is damaged.

(b) Since a multilayer insulation body maintains a high vacuum, if its inner and outer surfaces are each covered with thick metal plates, the weight is large and the heat insulation properties of the metal plates themselves are low.

(c) Since the thermal conductivity of the mounting part of the multilayer insulation is extremely high, the effectiveness of the vacuum multilayer insulation is reduced.

(d) To prevent the effectiveness of vacuum multilayer insulation from decreasing,
If the number of multilayer insulation mounting parts is reduced, the load per multilayer insulation mounting part increases, and the multilayer insulation is likely to fall off from the tank when the ship shakes in a marine vessel or during an earthquake on land.

[Problem that the invention attempts to solve]

The present invention was proposed in view of these circumstances, and is safe, economical, and capable of detecting leaks of liquefied gas. The purpose of this invention is to provide a heat-insulating structure for low-temperature liquefied gas tanks using vacuum multilayer insulation.

[Means for solving problems]

To this end, the present invention provides a heat-insulating structure for a low-temperature liquefied gas tank in which the surface of the tank housing the low-temperature liquefied gas tank is covered with a heat insulating material. a first honeycomb structure heat insulating plate fixed to the upper part of each of the stud bolts via a nut, surrounding the entire surface of the tank with a void of a constant thickness, and having a ventilation hole bored in the vertical partition; a spacer fixed on the first honeycomb structure heat insulating board and having an appropriate height; a second honeycomb structure heat insulating board fixed on the top of the spacer and having a ventilation hole in the vertical partition; A multilayer heat insulating body sandwiched between a honeycomb structure heat insulating board and the second honeycomb structure heat insulating board, and a space inside the first honeycomb structure heat insulating board, the second honeycomb structure heat insulating board, and the multilayer heat insulating body. It is characterized by being equipped with vacuum pump equipment for evacuation.

[Effect]

(1) A plurality of stud bolts protruding from the surface of the tank at suitable intervals in the vertical and horizontal directions, and a void of a constant thickness is fixed to the top of each of the stud bolts through a nut, covering the entire surface of the tank. Since the first honeycomb structure heat insulating board surrounding the first honeycomb structure and having ventilation holes formed in the vertical partitions is provided, the heat insulating properties of the first honeycomb structure heat insulating board are greatly improved.

(2) A plurality of spacers each having an appropriate height and fixed on the first honeycomb structure heat insulation board, and a second honeycomb structure heat insulation plate fixed on the top of each spacer and having ventilation holes in the vertical partitions. Since the spacer is provided with a plate, the heat insulation properties of each spacer are improved.

(3) Since the multilayer insulation is sandwiched between the first honeycomb structure insulation board and the second honeycomb structure insulation board, the weight of the multilayer insulation is reduced and the insulation properties are improved. do.

(4) Vacuum pump equipment is installed to evacuate the space inside each of the first honeycomb structure insulation board, the second honeycomb structure insulation board, and the multilayer insulation body, so gas leakage can be detected at all times. At the same time, there will be no gas blowout when the tank is damaged.

〔Example〕

An embodiment of the present invention will be explained with reference to the drawings.
FIG. 1 is a partial cross-sectional plan view thereof, and FIG. 2 is a vertical sectional view taken along the line - in FIG. 1.

In the above figure, reference numerals 1 and 1 are a pair of perforated honeycomb structural plates facing each other, and holes 2 are bored in each of the vertical partitions of the honeycomb structural plate 1, and a vacuum is drawn through the holes 2 by a vacuum pump equipment (not shown). It is possible that

Reference numeral 3 denotes a heat insulating spacer for fixing the perforated honeycomb structure plates 1, 1 at an appropriate distance from each other, and a doubling plate 4 is attached to the lower surface of the spacer 3.

Reference numeral 5 denotes a multilayer heat insulator sandwiched between a pair of perforated honeycomb structure plates 1, 1, and the voids in the multilayer heat insulator 5 can be evacuated by a vacuum pump (not shown).

Reference numeral 6 denotes stud bolts protruding from the surface of the tank 7 at appropriate intervals vertically and horizontally in order to fix the inner perforated honeycomb structure plate 1 on the surface of the low-temperature liquefied gas tank (hereinafter referred to as tank) 7 with appropriate gaps. ，
8 is a nut for setting the inner perforated honeycomb structure plate 1 onto the stud bolt 6 with an appropriate gap while adjusting the distortion of the tank 2; 9 is a filler for sealing the gap between the stud bolt 6 and the nut 8; 10
is a void formed between the tank 7 and the inner perforated honeycomb structure plate 1.

In such a structure, the following effects can be obtained.

(1) The void 10 is provided on the outside of the tank 7, so gas leakage can be detected at all times.
There is no gas ejection in the event of tank damage.

(2) Since both sides of the multilayer heat insulating body 5 are covered with the perforated honeycomb structure plates 1, the overall weight is reduced and the heat insulation properties are improved.

(3) Since the spacers 3 for mounting the multilayer heat insulating body 5 can be made of a heat insulating material, the effectiveness of the multilayer heat insulating body 5 does not decrease, and therefore there is no need to limit the number of spacers 3 for mounting. Therefore, the multilayer insulation body 5 will not fall off in the event of ship shaking or an earthquake.

According to such a structure, the following effects can be achieved.

(1) Gas leakage can be detected at all times, there is no gas ejection when the tank is damaged, and the multilayer insulation will not fall off even in the event of ship shaking or earthquakes, improving safety.

(2) Since the multi-layer insulation is supported by insulating spacers and covered with perforated honeycomb structure plates, the insulation is lighter and has higher insulation properties, thus improving economic efficiency.

[Effect of idea]

In short, according to the present invention, in a heat-insulating structure for a low-temperature liquefied gas tank in which the surface of the tank for storing low-temperature liquefied gas is covered with a heat insulating material, a plurality of stud bolts protruding from the tank surface at appropriate intervals vertically and horizontally. , a first honeycomb structure heat insulating plate fixed to the upper part of each of the stud bolts via a nut, surrounding the entire surface of the tank with a void of a constant thickness, and having a ventilation hole bored in the vertical partition; , a spacer fixed on the first honeycomb structure heat insulating board and having an appropriate height; a second honeycomb structure heat insulating board fixed on the top of the spacer and having a ventilation hole in the vertical partition; a multilayer heat insulating body sandwiched between the honeycomb structure heat insulating board and the second honeycomb structure heat insulating board, the first honeycomb structure heat insulating board, the second honeycomb structure heat insulating board, and the space within the multilayer heat insulating body. This is a safe and economical vacuum multi-layer insulation that is small in thickness, lightweight, has a large insulation effect, and will not fall off, making it possible to detect leaks of liquefied gas. The present invention is industrially very useful because it provides a heat-insulating structure for low-temperature liquefied gas tanks.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional plan view showing an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view taken along the line - in FIG. 1. DESCRIPTION OF SYMBOLS 1... Honeycomb structural plate, 2... Hole, 3... Spacer, 4... Doubling plate, 5... Multilayer insulation, 6... Stud bolt, 7... Low temperature liquefied gas tank (tank), 8... Nut , 9... filler, 10... void.

Claims (1)

[Scope of utility model registration request] A heat-insulating structure for a low-temperature liquefied gas tank in which the surface of the tank storing low-temperature liquefied gas is covered with a heat insulating material includes a plurality of stud bolts protruding from the tank surface at appropriate intervals in the vertical and horizontal directions, and the upper part of each of the stud bolts. a first honeycomb structure heat insulating plate fixed to each via a nut and surrounding the entire surface of the tank with a void of a constant thickness and having a ventilation hole bored in the vertical partition, and the first honeycomb structure a spacer fixed on the heat insulating board and having an appropriate height; a second honeycomb structure heat insulating board fixed to the top of the spacer and having ventilation holes in the vertical partitions; the first honeycomb structure heat insulating board; and the above. A multilayer heat insulating body sandwiched between a second honeycomb heat insulating board, the first honeycomb heat insulating board, the second honeycomb heat insulating board, and a vacuum pump equipment for evacuating the space inside the multilayer heat insulating body. A heat-insulating structure for a low-temperature liquefied gas tank, characterized by comprising: