JPH07139888A - Open rack type vaporizer - Google Patents

Abstract

PURPOSE:To provide an open rack type vaporizer in which problems of building of more heat exchanging panel, complicated piping are eliminated, a structure is simple, a heat exchanging efficiency is high, a temperature rise and vaporization are realized in an LNG vaporizer for regulating heat quantity of city gas, etc. CONSTITUTION:An open rack type vaporizer comprises an introducing nozzle 13 provided at a lower end of an outer tube 11 of a double tube type heat exchanging panel 10 having a heat exchanging tube of a double tube structure to mix liquefied petroleum gas with liquefied natural gas raised at its temperature and vaporized while moving down via a U-shaped flow to raise the temperature and vaporize it thereby to regulate heat quantity of the petroleum gas without separating and precipitating methanol in the petroleum gas. Another heat source, a special purpose heat exchanging panel of a conventional system is eliminated for vaporizing the petroleum gas thereby to reduce total number of the panels. Since the double tube type exchanger having high efficiency to raise a temperature and to vaporize the natural gas is employed, a flow rate hunting can be prevented, and adfreezing can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an open rack type vaporizer for vaporizing liquefied natural gas with a heat medium such as seawater, and a double pipe type heat exchange pipe having a double pipe structure. From the introduction nozzle provided at the lower end of the outer tube of the heat exchange panel,
Calorific value using liquefied petroleum gas with a simple open rack type vaporizer configuration by mixing liquefied petroleum gas with liquefied liquefied natural gas that has been vaporized liquefied natural gas while raising the temperature while lowering in U-type flow The present invention relates to an open rack type vaporizer capable of adjustment.

[0002]

2. Description of the Related Art An open rack type vaporizer, which is often used as a vaporizer for liquefied natural gas (hereinafter referred to as LNG),
For example, fin tubes with a pair of fins protruding in the diametrical direction are arranged in the fin direction to form a single panel, and header tanks are provided at the upper and lower ends of the fin tubes to form a heat exchange panel. The structure is such that seawater, which is a heat medium, flows down to the surface of the heat exchange panel from the sprinkling trough arranged above the heat exchange panel.

Natural gas (hereinafter referred to as NG) which has been vaporized at elevated temperatures by an open rack type vaporizer or the like, for example, when used as city gas, has various types of L having different compositions such as methane.
Since it is necessary to supply a gas having a stable calorific value from the NG, the calorific value is generally adjusted by mixing the liquefied petroleum gas having a high calorific value (hereinafter referred to as LPG) with the LNG having a low calorific value.

The LNG vaporizer for city gas, which requires adjustment of the calorific value of the generated gas, needs to have a structure in which LPG is mixed with LNG having a low calorific value, but LN at an extremely low temperature (-160 ° C.).
When LPG (−45 ° C.) is directly mixed with G, there is a problem that LPG is cooled and methanol in LPG is separated and deposited. Therefore, as shown in FIG. 3, apart from the vaporizer 2 in which a large number of vaporization heat exchange panels 1 are arranged, the LPG is vaporized by a heat exchanger 3 using steam as a heat source, and the NG from the vaporizer 2 is vaporized. The vaporizer is composed of a mixture of vaporized petroleum gas.

Alternatively, in order to prevent precipitation of methanol, a part of LNG, for example, about 10% is taken out, vaporized at elevated temperature (0 ° C. or higher), and then mixed again with the original LNG, whereby the temperature of LNG is reduced. It becomes about −130 ° C., and methanol does not precipitate even if LPG is mixed. That is, as shown in FIG. 4, the conventional LNG vaporizer for city gas is different from the vaporizer 2 in which a large number of the vaporizing heat exchange panels 1 are arranged, and is used for raising and vaporizing a part of LNG in advance. A vaporizer having a configuration in which a plurality of heat exchange panels 4 for warming are installed is used.

[0006]

As described above, the conventional LNG vaporizer for city gas shown in FIG. 3 has a problem that a heat exchanger for LPG vaporization and another dedicated heat source are required. The conventional LNG vaporizer for city gas shown in FIG. 4 requires a heat exchange panel for heating, that is, an independent LNG vaporizer, and the original heat exchange panel for vaporization vaporizes LNG and LPG. Since the ability to raise the temperature is required, for example, in a vaporizer that processes LNG at 100 tons / hour and LPG at 16.5 tons / hour, there are two heating heat exchange panels and vaporization heat exchange. There is a problem that the total number of heat exchange panels is increased to about 16 panels. Further, there is a problem that the total number of heat exchange panels becomes large, and the number of connecting pipes becomes large and the structure becomes complicated.

The present invention solves the problems such as the addition of heat exchange panels and the complication of piping in an LNG vaporizer for heat quantity adjustment for city gas, etc. It aims to provide an open rack type vaporizer that realizes vaporization.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted various studies for the purpose of a vaporizer having a simple structure and capable of heating and vaporizing LNG mixed with LPG with high heat exchange efficiency. From the inlet nozzle provided at the lower end of the outer tube of the double-tube heat exchange panel with a heavy tube structure, the temperature rises while descending in a U-shaped flow, and the liquefied petroleum gas is mixed with the liquefied liquefied natural gas to rise. The present invention has been completed by finding that the provision of the heat quantity adjusting mechanism for heating and vaporizing enables the heat quantity adjustment with a simple structure of the open rack type vaporizer.

That is, according to the present invention, a large number of double-tube heat exchange tubes are connected to form a heat exchange panel, and the LPG inlet header tank and the vaporized gas outlet header tank are arranged on the upper portion of the heat exchange panel. A sprinkling trough is arranged above the exchange panel, LPG is supplied from the upper end of the inner pipe of the double pipe, and it is made to flow into the outer pipe from the other end, in a U-shaped flow,
In a double-tube open rack type vaporizer for LPG vaporization that enables the vaporized gas to be discharged from the upper end of the outer pipe, a liquefied petroleum gas introduction nozzle or header tank is provided at the lower end of the outer pipe, and the inner pipe is placed inside the lower part of the outer pipe. LP heated up while descending
The open rack type vaporizer is characterized in that LNG is mixed with G for vaporization.

[0010]

The operation of the double-tube open rack type vaporizer according to the present invention will be described below with reference to the drawings. 1 is a perspective explanatory view showing the configuration of a double-tube open rack type vaporizer provided with a heat quantity adjusting mechanism according to the present invention.
FIG. 3 is a vertical cross-sectional explanatory view showing details of a double-tube fin tube. Each of the plurality of heat exchange panels 10 constituting the double-tube open rack-type vaporizer has, for example, a double tube composed of a fin tube having a pair of fins protruding in the diameter direction arranged in the fin direction. It is configured in a panel shape, and an LNG inlet header tank 15 and an NG outlet header tank 12 are provided on the upper portion of the panel 10. NG is formed on the outer surface of each outer tube 11 that constitutes the heat exchange panel 10.
Overflow water from the water sprinkling trough 16 that is disposed below and facing the outlet header tank 12 flows down.

Each double pipe has a required length, as shown in FIG.
An open lower end of the inner pipe 14 is inserted into the inner bottom of the outer pipe 11 having an inner diameter and the lower end is closed, and the upper end of the inner pipe 14 is connected to the LNG inlet header tank 15 to connect to the LNG.
Is allowed to flow down, the upper end of the outer pipe 11 is closed, and the NG outlet header tank 12 is provided on the outer periphery of the upper part.
3 is provided. Further, the lower end of the inner pipe 14 may be closed and a small hole having a required inner diameter may be provided in the lower part of the inner pipe 14 by appropriately selecting the installation range, interval, and number.

In the above-mentioned structure, first, the cryogenic (-160 ° C.) LNG supplied from the LNG inlet header tank 15 of the heat exchange panel 10 to the inner pipe 14 is passed through the outer pipe 11 and then the seawater. 0 is vaporized by heat exchange with
A low temperature NG of ℃ or less is reached, and when reaching the inner bottom of the outer pipe 11, a predetermined amount of LPG is introduced from the LPG introduction nozzle 13 and mixed, while rising between the inner pipe 14 inside the outer pipe 11. Furthermore, the temperature is raised by heat exchange with seawater, NG with a calorific value adjusted to 0 ° C. or higher is obtained, and the NG is discharged from the NG outlet header tank 12. In addition, the double tube heat exchange panel 10
By using, it is possible to prevent flow rate hunting and reduce icing.

[0013]

Example: LNG 100 tons / hour, LPG 16.
When vaporizing at a temperature of 5 tons / hour to obtain NG at 0 ° C., in the above-described conventional configuration of FIG.
The total number of heat exchange panels for vaporization is 16 and the number of heat exchange panels for vaporization is 16, which is large, but in the vaporizer according to the present invention shown in FIG. 1, the number of heat exchange panels for temperature rise and vaporization 10 is reduced to 12. I was able to.

[0014]

Industrial Applicability According to the present invention, the temperature is increased and vaporized while descending in a U-shaped flow from the introduction nozzle provided at the lower end of the outer tube of the double tube type heat exchange panel having the double tube structure. By mixing liquefied petroleum gas with the liquefied liquefied natural gas, heating and vaporizing it, liquefied petroleum gas was used in a simple open rack type vaporizer configuration without separating and precipitating methanol in the liquefied petroleum gas. It is possible to adjust the amount of heat, and
A separate heat source and a dedicated heat exchange panel are not required for the vaporization of liquefied petroleum gas as in the past, the total number of heat exchange panels can be reduced, and a double-tube type heat that is efficient for heating and vaporizing liquefied natural gas Uses an exchanger to prevent flow rate hunting,
There is an advantage that it is possible to reduce ice accretion.

[Brief description of drawings]

FIG. 1 is a perspective explanatory view showing a configuration of a double-tube open rack type vaporizer provided with a heat quantity adjusting mechanism according to the present invention.

FIG. 2 is a vertical cross-sectional explanatory view showing details of a double-tube fin tube.

FIG. 3 is a perspective explanatory view showing a configuration example of a conventional open rack type vaporizer for vaporizing liquefied natural gas.

FIG. 4 is a perspective explanatory view showing a configuration example of another conventional open rack type vaporizer for vaporizing liquefied natural gas.

[Explanation of symbols]

 1 heat exchange panel for vaporization 2 vaporizer 3 heat exchanger 4 heat exchange panel for temperature rise 10 heat exchange panel 11 outer tube 12 NG outlet header tank 13 LPG introduction nozzle 14 inner tube 15 LNG inlet header tank 16 water sprinkling trough

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Takahide Yamamoto 1-48-6-1402 Higashiikebukuro, Toshima-ku, Tokyo (72) Inventor Toshiyasu Miura 38-37-402 (72) Shirahatakami-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Inventor Hitotani Shono 1-10 Fuso-cho, Amagasaki-shi, Hyogo Within Sumitomo Precision Industries Ltd. (72) Inventor Isya Sahara 1-10 Fuso-cho, Amagasaki-shi, Hyogo Within Sumitomo Precision Industries Ltd.

Claims (1)

[Claims] 1. A heat exchange panel is formed by arranging a large number of heat exchange tubes having a double-tube structure, and a liquefied natural gas inlet header tank and a vaporized gas outlet header tank are arranged above the heat exchange panel. A trough for sprinkling is arranged above the pipe, and liquefied natural gas is supplied from the upper end of the inner pipe of the double pipe and allowed to flow into the outer pipe from the other end to generate vaporized gas from the upper end of the outer pipe in a U-shaped flow. In the double tube open rack type vaporizer for liquefied natural gas vaporization that can be led out, a liquefied petroleum gas introduction nozzle or header tank is provided at the lower end of the outer pipe, and the inner pipe is lowered while descending inside the outer pipe. An open rack type vaporizer characterized by mixing liquefied petroleum gas with heated liquefied natural gas to vaporize it.