JPS6199096A - Heat exchanger - Google Patents

Abstract

PURPOSE:To permit to clean heat transfer tubes easily by a method wherein heat medium fluid is sealed into the trunk of the shell-and-tube type heat exchanger and high-temperature fluid is flowed through the lower part of the group of heat transfer tubes while low- temperature fluid is flowed through the upper part of the group of the same. CONSTITUTION:The heat medium fluid A is sealed into a sealed chamber 16. The sealing amount of the heat medium fluid is in a degree that the interface between gas and liquid upon operating arrives at an intermediate position between the group 14 of upper heat transfer tube and the group 14' of lower heat transfer tubes. The high-temperature fluid B is flowed through the group 14' of lower heat transfer tubes while the low-temperature fluid C is flowed through the group 14 of upper heat transfer tubes. The heat of the high-temperature fluid passes through the wall surface of the lower heat transfer tubes 13 and is transmitted to the heat medium fluid A. Then, the heat medium is boiled and evaporated immediately and the vapor ascends through the sealed chamber 16 to transmit the heat to the low-temperature fluid flowing through the upper heat transfer tubes 13, simultaneously, the vapor is condensed and becomes liquid drops thereby dropping through the sealed chamber 16. According to such cycle of the heat medium fluid, heat may be transmitted from the high-temperature fluid, flowing through the lower heat transfer tube group 14', to the low-temperature fluid, flowing through the group 14 of upper heat transfer tubes.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a heat exchanger.

BACKGROUND OF THE INVENTION Conventionally, a shell-and-tube heat exchanger, as shown in FIG. Fluid (a) flows inside the heat transfer tube (2), while the other fluid (b) flows outside the heat transfer tube (2) and flows through the tube bundle consisting of many tubes, changing its direction by the partition plate (3) in a complicated manner. flows in a pattern.

Problems to be Solved by the Invention According to the above conventional configuration, if the heat transfer surface becomes dirty due to long-term operation, the inside of the heat transfer tube can be easily cleaned by stopping the operation and cleaning by jet cleaning or brushing. There was a problem in that the outside of the heat exchanger tube could not be easily cleaned.

Means for Solving the Problems In order to solve the above problems, the heat exchanger of the present invention is a shell and tube type heat exchanger in which a heating medium fluid is sealed in the body, and 111 tubes are arranged in the body. The heat exchanger tube group is designed so that high temperature fluid flows in the lower part and low temperature fluid flows in the upper part.

When a high-temperature fluid is made to flow in the lower part of the working heat transfer tube 711 and a low-temperature fluid is made to flow in the two sides, the heat of the high-temperature fluid is transferred to the low-temperature fluid through the heat transfer fluid sealed in the body.

EXAMPLE Hereinafter, an example of the present invention will be explained based on FIGS. 1 to 6. The time is the body of the shell and tube heat exchanger,
Both tube plates (2) (12') form a closed groove structure.

There are many heat transfer tubes (
13 are inserted through both tube plates Q'4 (12'), and the interior of the body 0υ is partitioned by partition plates aυ provided at regular intervals to form a plurality of sealed chambers ue. There is. A heat transfer fluid (4) is sealed in each of these sealed chambers 4. This heat transfer fluid is chemically and thermally stable within the range of its usage conditions, and has a body part αυ, a heat transfer tube (1;
9 or react with components to form non-condensable gases, and within the operating temperature range 11aHgabs to 200
Use a material that has a vapor pressure of approximately kq/cd abs and also has a good heat transfer coefficient during boiling and condensation. The amount of heat transfer fluid sealed is such that the gas-liquid interface is the upper heat transfer tube group (1
41 and the lower heat exchanger tube group (14'),
At the time of sealing or initial operation, non-condensable gas is expelled from the closed chamber to prevent the non-condensable gas from inhibiting condensation heat transfer. αη is a cover attached to both ends of the body part aυ, and the inside of this cover α is the upper heat exchanger tube group t.
Corresponding to J4 and the lower heat transfer t# (14'), it is divided into upper and lower halves by a partition plate 0, and a fluid inlet/outlet On is provided respectively. A high-temperature fluid (Q) is flowed in the lower heat exchanger tube group (141) and a low-temperature fluid (Q) is flowed in the upper heat exchanger tube group (141) in opposite directions.

Next, the effect will be explained.

When a high-temperature fluid is passed through the lower heat exchanger tube group (14') and a low-temperature fluid (Q) is passed through the upper heat exchanger tube group αΦ, the heat of the high-temperature fluid passes through the wall surface of the lower heat exchanger tube u1 and is transferred to the heat medium. Fluid (b)
It is transmitted to Then, the heat transfer fluid immediately boils and evaporates into vapor, which rises in the closed chamber conduit and gives heat to the low-temperature fluid flowing in the upper heat transfer tube 03, and at the same time condenses on its outer surface and forms droplets. , and falls inside the closed room QQ. Through this cycle of evaporation → rise → condensation → descent of the heat transfer fluid, heat is transferred from the high temperature fluid flowing in the lower heat exchanger tube group (14') to the low temperature fluid flowing in the upper heat exchanger tube group (14). However, in this case, the heat transfer path from the high temperature fluid to the low temperature fluid becomes complicated. In particular, regarding the evaporation and condensation processes of the heat transfer fluid, when the heat transfer fluid is a fluid with poor heat transfer properties such as fluorocarbon, the heat transfer resistance becomes impossible to ignore. In this case, the lower heat transfer tube may be a special heat transfer tube that promotes boiling and evaporation on the outer surface of the tube, such as a loaf-in tube, a tube with a fine particle sintered layer, or a tube with a porous surface.
°The use of surface-roughened tubes is advantageous. Further, as the upper heat transfer tube, it is advantageous to use a special heat transfer tube that promotes condensation heat transfer on the outer surface of the tube, such as a loaf-in tube, a grooved tube, and various other condensation heat transfer promoting tubes.

Incidentally, the temperature distribution in each sealed room is shown in FIG.

Next, another example will be explained based on FIGS. 5 and 6. This method deals with the case where a plurality of fluids that cannot be mixed are used, for example, as high-temperature fluids. That is,
The lower heat exchanger tube group (14') is divided into left and right first and second lower heat exchanger tube groups (14'A) (14'B), and the lower part inside the cover 7) is separated by an auxiliary partition plate (7). Divided into left and right, each heat exchanger tube 1 (14'A) (14'
A fluid inlet/outlet 01 is provided corresponding to B). In addition, if the low temperature fluid is a fluid that cannot be mixed, the upper heat exchanger tube group may be divided into two, contrary to the above, and furthermore, if the low temperature fluid and the high temperature fluid are both fluids that cannot be mixed,
Each heat exchanger tube group may be divided and shifted according to each fluid.

Effects of the Invention According to the above configuration of the present invention, both high-temperature and low-temperature fluids are made to flow inside the heat exchanger tube, so that only the inner surface of the heat exchanger tube is contaminated by these high-temperature fluids. It is possible to easily carry out cleaning by washing, cleaning by brushing, etc.), and it is also possible to perform on-dream cleaning (cleaning while driving) by circulating sponge balls, which is very advantageous in terms of performance and maintenance.

[Brief explanation of the drawing]

Figures 1 to 4 show one embodiment of the present invention.
The figure is an overall vertical cross-sectional view, Figure 2 is a view taken along the l-■ arrow in Figure 1, Figure 8 is a view taken along the nn arrow in Figure 1, and Figure 4 is a diagram showing the temperature distribution inside the closed room. 5 and 6 show other embodiments, and are views corresponding to 1-1 and nm arrows in FIG. 1, respectively;
FIG. 7 is a longitudinal sectional view of a conventional example.

Claims (1)

[Claims] 1. A heat transfer fluid is sealed in the body of the shell-and-tube heat exchanger, and the high-temperature fluid flows in the lower part of the heat transfer tube group inserted into the body, and the low-temperature fluid flows in the upper part. A heat exchanger characterized by: