JP2528352Y2 - Liquefied natural gas vaporizer - Google Patents

Description

[Detailed description of the invention]

[0001]

This invention relates to the improvement of liquefied natural gas vaporizers such as underwater combustion type vaporizers and open rack type vaporizers, and liquefaction in which the calorific value of vaporized gas is adjusted by mixing liquefied petroleum gas. The present invention relates to a liquefied natural gas vaporizer configured to maintain a good mixed state of natural gas and liquefied petroleum gas and minimize fluctuations in calorie when operation is restarted due to residual liquid when operation is stopped.

[0002]

2. Description of the Related Art An open rack type vaporizer often used as a liquefied natural gas vaporizer is, for example, a fin tube having a pair of fins projecting in a diameter direction arranged in the fin direction to form a single panel. A heat exchange panel is formed by providing a header tank at the upper and lower ends thereof, a plurality of the panels are arranged in parallel, and seawater of the heat medium flows down to the heat exchange panel surface from a sprinkler arranged above the heat exchange panel. Structure.

[0003] Usually, an open-rack type vaporizer is provided with a submerged vaporizer (submerged vaporizer) for the case where the demand for city gas or the like is satisfied but insufficient, or for emergency use. This submerged combustion type vaporizer is shown in FIG.
As shown in the figure, the combustion gas generated in the burner 11 and the combustion chamber 14 is jetted out of the sparge pipe 15 into the water tank 1, and the water 2 is used as an intermediate heat medium in the heat exchanger 5 disposed submerged in the water tank 1. This is a vaporizer configured to heat the liquefied natural gas flowing through the apparatus. In order to keep the calorific value of the vaporized gas constant, liquefied natural gas and liquefied petroleum gas are mixed in a liquid state and vaporized.

In the open rack type vaporizer, it is necessary to pump seawater as a heat medium flowing down to the surface of the heat exchange panel to the sprinkler. In order to reduce the height of the pumping as much as possible, the installation level of the heat exchange panel is set to a normal level. In some cases, a semi-underground structure that is several meters lower than the level is used.

Similarly, as shown in FIG. 2, the submerged combustion type vaporizer also has a semi-underground structure in which about half of the water tank 1 is buried underground. In this case, a pipe 7 for supplying liquefied natural gas to the vaporizer is provided. The mixer 8 for liquefied petroleum gas and the shut-off valves 9 and 10 for liquefied natural gas and liquefied petroleum gas for shutting down the operation are also arranged at the same level near the ground and near the water tank 1. And then connected to the header pipe 6 of the vaporizer that enters the water tank 1.

[Problems to be solved by the invention]

In the case of an underwater combustion type vaporizer, when the shut-off valves for liquefied natural gas and liquefied petroleum gas are closed and the operation is stopped, liquid remains in the pipe from the mixer to the vaporizer. Become. This is the same in the case of an open rack type vaporizer, and the remaining liquid mixture evaporates gradually due to the heat of the atmosphere around the piping, but liquefied natural gas mixed with liquefied petroleum gas is composed of multiple components. Then, evaporation starts from the light components, and the residual liquid becomes heavier with time.

Next, when the shut-off valve is opened and the operation is restarted, the heavy residual liquid first enters the vaporizer and is vaporized, so that the heavy component having a high calorific value fluctuates the set calorific value of the vaporized gas.

In general, if the calorific value of the gas fluctuates, the flame may become large or incomplete combustion may occur, which is not preferable. In particular, city gas is required to have a constant calorific value without fluctuation.

This invention is intended to maintain a good mixture state of liquefied natural gas and liquefied petroleum gas such as an open rack type, submerged combustion type vaporizer, etc., and to reduce the amount of heat fluctuation when the operation is stopped and the operation is restarted due to the residual liquid. It is an object of the present invention to provide a liquefied natural gas vaporizer configured to be as small as possible.

[00010]

According to the present invention, liquefied petroleum gas is mixed with liquefied natural gas to adjust the calorific value of the vaporized gas.
In a liquefied natural gas vaporizer for vaporizing this, a supply pipe for supplying the liquefied gas to the heat exchanger in the apparatus is arranged at a height at least equal to or higher than the header tank height of the heat exchanger, The liquefied natural gas is characterized by being arranged at least as high as the supply pipe diameter just before connecting to the header pipe, and connecting a drain pipe having a smaller diameter than the supply pipe that bypasses the supply pipe section that is arranged to the header pipe to the header pipe. It is a vaporizer.

The present invention can be applied to any liquefied natural gas vaporizer such as an open rack type vaporizer and a submerged combustion type vaporizer. For example, the combustion gas generated by a burner is blown into a water tank, When applied to an underwater combustion type vaporizer that heats liquefied natural gas and liquefied petroleum gas flowing in a heat exchanger that is submerged in water, (a) a supply pipe that supplies the liquefied gas to the heat exchanger in the device (B) at least as high as the supply pipe diameter immediately before connecting to the header pipe of the heat exchanger; An underwater combustion type vaporizer for liquefied natural gas, characterized in that a drain pipe having a smaller diameter than a supply pipe bypassing a section is connected to a header pipe.

[0012]

The submerged combustion type vaporizer according to the present invention can fill the liquefied gas in the piping near the mixer by means of the configuration (a) and (b), obtain a good mixing state, and obtain the calorific value of the mixing station. , Temperature and the like can be accurately measured, and the height of the structure (b) can be minimized, so that the amount of residual liquid can be reduced as much as possible.

Further, the residual liquid in the supply pipe after the shutoff valve is closed by the drain pipe having the configuration (c) flows into the header pipe of the vaporizer by gravity due to gravity, and the residual liquid flowing down to the header pipe is removed from the water tank. Is vaporized with the lapse of time due to the retained heat.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of an underwater combustion type vaporizer according to the present invention will be described in detail with reference to the drawings. The vaporizer such as the water tank 1 is the same as the configuration example of FIG. 2 described above. In FIG. 1,
3 is an upper surface plate, 4 is an exhaust pipe, 12 is a fuel supply pipe, 13 is an air pipe, 16 is a cooler of a combustion chamber 14 using a pumping pipe 17,
Reference numeral 25 denotes a liquefied petroleum gas supply pipe.

In the example shown in FIG. 1, the reference height of the liquefied gas supply pipe 20 is higher than the top plate 3 of the vaporizer and is located at a required height (H) above the ground. The liquefied gas supply pipe 20 is provided with a mixer 21 for liquefied petroleum gas (LPG) downstream of a shutoff valve 22 for liquefied natural gas (LNG),
Between the header pipe 6 of the heat exchanger 5 and the downstream side of the mixer 21, there is provided an ascending portion 23 which is arranged to be higher than the reference height (H) by a height (h) which is equal to or more than the supply pipe diameter height. .

Immediately before connection to the header pipe 6, the supply pipe is raised at least by the height of the diameter of the supply pipe. If the same section remains at the reference height (H), liquefaction occurs in the lower half of the supply pipe of the mixer 21. This is because a mixed liquid in a state where natural gas flows and liquefied petroleum gas falls thereon is supplied to the header pipe as it is, and the two liquids cannot be mixed uniformly. In addition, the rising height (h) needs to be minimized so that the liquefied natural gas and the liquefied petroleum gas can be maintained in a good mixed state so that the residual liquid amount can be reduced as much as possible.

Further, the liquefied gas supply pipe 20 has a rising portion 2
3, a drain pipe 24 having a smaller diameter than the supply pipe is connected to the header pipe 6.

In the above configuration, when the shut-off valves 22 and 26 for liquefied natural gas and liquefied petroleum gas are closed to stop the operation, the rising portion 23 of the supply pipe 20 has the minimum necessary height, so And the provision of the drain pipe 24 causes the residual liquid after the stop to flow naturally to the header pipe of the vaporizer due to gravity, thereby eliminating the residual liquid in the supply pipe 20 and the rising part 23. The residual liquid that has flowed down to the header pipe 6 is vaporized over time by the heat retained in the water tank 1 in the heat exchanger 5.

[0019]

[Effect of the invention] The underwater combustion type vaporizer according to the invention is:
As is clear from the example, since there is almost no residual liquid in the supply pipe after the operation is stopped, the calorific value of the vaporized gas does not fluctuate when the operation is restarted, and the liquefied gas supply pipe is arranged at a predetermined height and the supply pipe diameter is reduced. The provision of the rising portion having a height of about the height makes it possible to maintain a constant mixed state of liquefied natural gas and liquefied petroleum gas during operation. In addition, the present invention can be applied to any liquefied natural gas vaporizer such as an open rack type vaporizer other than the underwater combustion type vaporizer.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a water tank showing a configuration of an underwater combustion type vaporizer according to the present invention.

FIG. 2 is a vertical sectional view of a water tank showing a configuration of a conventional underwater combustion type vaporizer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water tank 2 Water 3 Top plate 4 Exhaust pipe 5 Heat exchanger 6 Header pipe 7 Pipe 8 Mixer 9,10 Shut-off valve 11 Burner 12 Fuel supply pipe 13 Air pipe 14 Combustion chamber 15 Sparge pipe 16 Cooler 17 Pumping pipe 20 Liquefied gas Supply pipe 21 Mixer 22, 26 Shut-off valve 23 Ascending part 24 Drain pipe

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Kazuya Sahara 1-10 Fuso-cho, Amagasaki-shi, Hyogo Sumitomo Precision Industries, Ltd.

Claims (1)

(57) [Scope of request for utility model registration] 1. A liquefied natural gas vaporizer that mixes liquefied petroleum gas into liquefied natural gas to adjust the calorific value of the vaporized gas and supplies the liquefied gas to a heat exchanger in the device in a liquefied natural gas vaporizer. Arrange the pipe at least as high as the header tank height of the heat exchanger, raise it at least by the supply pipe diameter height just before connecting it to the header pipe of the heat exchanger, and remove the raised supply pipe section. A liquefied natural gas vaporizer wherein a drain pipe having a smaller diameter than a supply pipe to be bypassed is connected to a header pipe.