JPH0232959Y2 - - Google Patents

Description

[Detailed explanation of the invention] (Industrial application field) This invention uses liquefied natural gas (hereinafter referred to as LNG)
This invention relates to a device that heats and vaporizes liquefied gases such as liquefied petroleum gas, liquid nitrogen, and liquid oxygen using the atmosphere.

(Prior technology) The vaporizers at LNG vaporization terminals include a method in which an aluminum finch tube is installed vertically and makes contact with seawater, a method in which LNG is passed through a coil through hot water heated by underwater combustion, or a method in which LNG is passed through a coil through hot water heated by underwater combustion. There are methods for indirect vaporization using an intermediate medium such as , but these systems require complicated equipment such as melting of ice and the use of a combustion device and an intermediate medium.

As another prior art, Japanese Utility Model Application Publication No. 59-175798 describes a heat recovery device for evaporation of liquefied gas which uses a heat pipe and is heated by an air flow. That is, a heat pipe condensing section is inserted through the peripheral wall into a vaporization tank into which liquefied gas is introduced, and air is circulated toward an evaporation section to vaporize the liquefied gas.

In addition, there is an air temperature vaporization device that exchanges heat with the atmosphere using a vertical finch tube for LNG vaporization terminals in cities far from the coast, and an economical-scale device that suppresses the heat transfer area to a certain extent has been put into practical use. It is served to.

(Problem to be solved by the invention) However, the prior art device as described above,
Due to the reduction in the amount of heat transfer due to the freezing of moisture in the atmosphere, the vaporization operation had to be interrupted and ice melting work was required by water sprinkling, resulting in many problems such as shortening the vaporization operation time and reducing work efficiency. .

(Means for Solving the Problems) In view of the above, the present applicant proposed, in the earlier utility model registration application dated June 5, 1985, that the heat dissipation part of the heat pipe was melted into a finned outer tube by melting the gap. A heat pipe type liquefied gas air temperature vaporization device has been disclosed which heats and vaporizes the liquefied gas introduced into the outer tube from inside and outside by exposing it to the atmosphere. By changing the gap between the finned outer tube and the heat pipe heat dissipation section on the upstream and downstream sides of the liquefied gas introduction, that is, in the part where vaporization is mainly performed by evaporation on the upstream side of the liquefied gas introduction, The flow path area of the gap is widened to allow smooth evaporation to promote gas generation, and in the downstream area where vaporized gas is mainly superheated, the cross-sectional area of the gap is made small to increase the flow rate. The aim is to make the device more compact by increasing heat transfer and improving heat transfer.

(Embodiment) Fig. 1 shows an embodiment of the present invention, in which a heat pipe 1 is arranged, for example, in a vertical shape, and the upper and lower ends are sealed as usual, and there is an active material such as Freon R-22 inside. The heat dissipation section 2, which is filled with liquid and condenses the working fluid, has a bare tubular shape and is covered with an outer tube 3 having a bottom plate 4, and a gap 5 is provided between the outer tube 3 and the heat dissipation section 2. There is. The outer tube 3 has a liquefied gas inlet 6 and an outlet 7, and furthermore, vertical fins 8 are installed on the outside and exposed to the atmosphere. This outer tube 3 is preferably cylindrical so that it has a double tube structure in order to eliminate dead space from the heat pipe 1, and if a large number of grooves are provided on the outer surface of the heat pipe heat dissipation section 2, the heat transfer effect will be increased. .

The heat receiving section 9 of the heat pipe 1 has vertical fins 8 planted therein, and has a length approximately three times that of the heat dissipating section 2.
It is exposed to the atmosphere, and its lower end is fitted and supported in a hole 11 of a mounting base 10, and the upper outer tube 3 is held in place by a spacer 12 to maintain its position.

A heat pipe type heat exchanger 13 is formed by appropriately connecting a plurality of heat pipes in series according to the vaporization capacity.
As a pair, if the connecting pipe 15 is used to connect the outer pipe on the downstream side, the piping becomes simple.Moreover, this curved pipe 1
4 can participate in the vaporization of liquefied gas.

Here, the liquefied gas is mainly evaporated in the upstream heat pipe type heat exchanger shown by a pair of heat pipes 1A and 1a, for example, where the liquefied gas is introduced.
The downstream heat pipes 1B and 1b mainly superheat the vaporized gas, and the outer tube that covers the heat dissipation part of the upstream heat pipes 1A and 1a and is installed by melting the gap is shown in Figure 2. As is clear, the flow path cross-sectional area of the gap 5 is large, and the heat pipe 1 on the downstream side
The flow passage cross-sectional area of the gap 5' in the outer tube 3' of the heat dissipation part of B, 1b is formed small as shown in FIG.
For example, if the outer diameter of the heat pipe is 38 mm, and the large gap on the upstream side is 6 mm wide and the small gap is 3 mm wide, the gas flow velocity in the former width is approximately 3 to 6 m/min.
In the latter case, the gas flow velocity is about 6 to 12 m/s, and the value of the overall heat transfer coefficient increases by about 60% compared to the former case.

FIG. 5 shows another embodiment, in which the heat pipe type liquefied gas air temperature vaporization device is installed horizontally and slightly inclined so that the working fluid inside the pipe can easily flow, and has a configuration in which a plurality of heat pipes are stacked upward. An annular fin 16 is provided.

(Function) In the heat pipe type liquefied gas air temperature vaporizer having the above configuration, for example, LNG enters the outer tube 3 of the upstream heat pipe from the inlet 6, and the vertical fin 8
The heat receiving part 9 exposed to the atmosphere evaporates the working fluid, condenses it in the heat radiating part 2, and exchanges heat with the latent heat of condensation. Part of the LNG vaporizes due to further heating, but here the evaporation occurs smoothly because the cross-sectional area of the flow path is large.

The LNG partially vaporized in this way is transferred to the curved pipe 1.
3, and after exchanging heat with the atmosphere in this curved tube 13, it enters the adjacent outer tube and is vaporized, and further downstream, the same operation occurs one after another, increasing the amount of vaporization.

However, since this vaporized gas is still at a low temperature, even if it is supplied as it is to the customer, there is a risk that moisture from the atmosphere will form on the surface of the pipe. The gas is allowed to flow through the gap 5' with a small flow path cross-sectional area, and the gas flow rate is increased to improve the heat transfer coefficient, and after the temperature is raised to a temperature that does not cause ice formation, it can be sent out from the outlet 17 to the customer.

In the illustration, heat pipes 1A, 1a, 1B,
1b were formed as a pair, but they were accommodated individually or in groups by forming a gap in the outer tube.
The flow path cross-sectional area of the gap between the upstream side and the downstream side may be changed.

Furthermore, the liquefied gas is not limited to LNG, but may also be liquid nitrogen, liquid oxygen, liquefied propane, liquefied butane, or the like.

(Effects) The heat pipe has its heat dissipating part covered by an outer tube with an inlet and an inlet for liquefied gas by melting the gap, and multiple outer tubes are connected together and exposed to the atmosphere together with the heat receiving part. is a heat pipe type heat exchanger in which liquefied gas is passed through, and the upstream side mainly evaporates, and the downstream gap mainly superheats the vaporized gas, and the cross-sectional area of the gap is Since this is a heat pipe type liquefied gas air temperature vaporization device that is large on the side and small on the downstream side, the liquefied gas is vaporized in the outer tube with a wide flow path cross section, making the evaporation smooth. Since the rest of the flow is guided into the outer tube with a small cross-sectional area, the heat transfer coefficient is further promoted by increasing the gas flow rate, making it easier to superheat the vaporized gas, resulting in a compact device with high heat transfer efficiency. It can be done.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which FIG. 1 is a partially cutaway front view with a part omitted, FIG. 2, FIG. 3, and FIG. 4 are the - line, - line, and - line of FIG. FIG. 5 is an enlarged line sectional view, and FIG. 5 is a front view of another embodiment. 1...Heat pipe, 2...Heat radiation section, 3...Outer tube, 4...Bottom plate, 5...Gap, 6...Liquefied gas inlet, 7...Outlet, 8...Vertical fin, 9...Heat receiving Part, 10... Installation stand, 11... Hole, 12... Spacer, 13... Heat pipe type heat exchanger, 14
... Curved pipe, 15 ... Communication pipe, 16 ... Annular fin, 17 ... Exit.

Claims (1)

[Scope of utility model registration request] A heat pipe type heat exchanger consisting of a plurality of heat pipes sequentially connecting outer tubes that cover a heat radiating part and are separated by gaps, and the gaps through which liquefied gas flows are formed to be large on the upstream side and small on the downstream side. A heat pipe type liquefied gas vaporization device.