JPS5919877Y2 - Open rack type heat exchanger - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an open rack type heat exchanger that satisfactorily vaporizes gas-liquid separated multiphase liquefied gas.

Conventionally, as a method for vaporizing liquefied refrigerant, a large number of finned tubes are arranged vertically in parallel, header tanks are fixed to both the upper and lower ends of the tubes to form a heat exchange section that forms a curtain-like panel, and the liquefied refrigerant is transferred to the bottom of the tube. A heat exchanger is used in which the refrigerant is introduced through a header tank, and the refrigerant is heated by room-temperature air or liquid flowing on the outer surface of the heat exchanger, causing it to evaporate and then being sent out as a room-temperature gas from the upper header tank.

By the way, some of the liquefied refrigerant introduced has vaporized, that is,
There are many cases where the refrigerant is a gas-liquid phase mixture, and if it is vaporized in the heat exchanger mentioned above, it will separate into upper and lower two phases when it is introduced into the lower header tank, and the vaporized refrigerant will be more finned than the liquefied refrigerant. The air or liquid that flows rapidly into the tube and flows on the outer surface of each finned tube causes the temperature to rise as it rises toward the outlet side.

On the other hand, the liquefied refrigerant flows into the finned tube and is vaporized as it rises toward the outlet side due to the amount of heat transferred from the outside.

In other words, the temperature distribution and flow within the finned tube become extremely non-uniform, resulting in various disadvantages such as a reduction in heat exchange performance.

Furthermore, the heat exchanger using the above finned tube,
The manufacturing cost was high and there was a problem with economic efficiency.

This invention proposes an open rack type heat exchanger that aims to eliminate the above-mentioned drawbacks.

As shown in FIG. 1, this invention consists of two flat plates 2 sandwiching a corrugated fin 1 and facing each other, and both ends of the flow path closed with spacer bars 3. A header tank 8 for gas-liquid mixing is provided at the lower end of the heat exchange section 4, to which a header tank 5 is fixed, and a number of connecting pipes 7 protruding from the lower surface in the axial direction to which a lower header tank 6 is fixed. .

On the other hand, a small diameter pipe 10 having a number of nozzles 9 protruding in a comb shape is inserted into the lower header tank 6 to form a double pipe structure, and the nozzles 9 are inserted into each connecting pipe 7 of the gas-liquid mixing header tank 8. The nozzle 9 is inserted into the gas-liquid mixing header tank 8 with a gap therebetween, and the tip of the nozzle 9 is made to protrude into the header tank 8 for integration.

Further, one end of the small diameter pipe 10 is closed by a pipe end plate,
The upper part of an external gas-liquid phase separation drum or the like connected to the gas-liquid phase mixed liquefied gas introduction pipe (not shown) is connected to the open end on both sides of the lower header tank 6, and the lower part is connected to the open end of the small diameter pipe 10, respectively. They are connected via an introduction pipe or the like.

Note that 11 is a water sprinkler pipe, and 12.13 is an annular gap.

In the heat exchanger, for example, seawater is sprinkled from the sprinkler pipe 11, and the seawater is dropped in a film along the heat exchange section 4, and the gas-liquid phase mixed liquefied gas is transferred to a gas-liquid phase separation drum (not shown).
The separated liquefied refrigerant is introduced into the small diameter pipe 10, and the vaporized refrigerant is introduced into the annular gap 12 from both ends of the lower header tank 6.

The liquefied refrigerant flows through the nozzle 9, and the vaporized refrigerant flows into the gas-liquid mixing header tank 8 through the annular gap 13 formed by the connecting pipe 7 and the nozzle 9.

At this time, the temperature difference between the liquefied refrigerant and the vaporized refrigerant can be kept relatively small because the lower header tank 6 has a double pipe structure.
Furthermore, the pressure difference does not pose much of a problem because the resistance to the flow into the gas-liquid mixing header tank 8 through the nozzle 9 and the annular gap 13 on its outer periphery is increased.

Therefore, the liquefied refrigerant and the vaporized refrigerant are always uniformly mixed in the header tank 8 for gas-liquid mixing, and the corrugated fins 1 and the flat plate 2
The gas flows into the flow path formed by the gas, is heated by the seawater flowing on the outer surface of the flat plate 2, becomes completely room temperature gas at the upper end of the heat exchange section 4, and is sent out from the upper header tank 5.

Note that during the above operation, when the speed of the vaporized refrigerant rising in the annular gap 13 becomes small, the liquid accumulated in the gas-liquid mixing header tank 8 drips down through the connecting pipe 7, and the lower header tank 6 As time passes, the liquid level may rise and block the passage for the vaporized refrigerant.

At this time, the vaporized refrigerant passes through the gap above the liquid level into the connecting pipe 7.
However, due to the structure in which the vaporized refrigerant is introduced from both sides of the lower header tank 6, the amount of vaporized refrigerant generated at the liquid level is compared to a case where the vaporized refrigerant is introduced from one end of the lower header tank 6 and the other end is closed with a mirror plate. The ripples are small.

In addition, in the latter case, when the flow velocity of the vaporized refrigerant introduced into the lower header tank 6 is high, a phenomenon occurs in which waves run to the end plate and collide with each other, causing large vibrations, which causes problems in mechanical strength and adversely affects the shunt flow. However, it does not occur in this design.

According to this invention, as mentioned above, by adding a simple structure, the liquefied gas separated into gas and liquid can be constantly mixed uniformly and good vaporization can be achieved, and the heat exchanger uses a finned tube. It is very easy and economical to manufacture.

Further, even if the liquid drips due to the inability to adjust the speed of the vaporized refrigerant rising in the annular gap of the connecting pipe, good vaporization can be performed without causing any operational problems.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing the open rack type heat exchanger of this invention. In the diagram: 1...Corrugated fin, 2...Flat plate, 3...Spacer bar, 4...Heat exchange section, 5...Top Header tank, 6...
・・Lower header tank, 7・・Connecting pipe, 8・
...Header tank for gas-liquid mixing, 9...
Nozzle, 10... Small diameter pipe, 11... Water pipe, 12.13... Annular gap.

Claims (1)

[Scope of utility model registration request] In an open rack type heat exchanger, a gas-liquid mixing header tank with many parallel connecting pipes protruding from the bottom is installed at the lower end of the heat exchanger, and small diameter pipes with many comb-shaped protruding nozzles are inserted. Each nozzle of the lower header tank, which has a double-pipe structure, is inserted into each connecting pipe of the gas-liquid mixing header tank with an annular gap, and the annular gap in the connecting pipe and the annular gap in the lower header tank are separated. A lower header tank is connected to and fixed to the lower end of the connecting pipe, and a liquefied refrigerant is introduced into the small diameter pipe, and a vaporized refrigerant is introduced into the annular gap from both ends of the lower header tank. Rack type heat exchanger.