JPS5938598A - Plate type heat exchanger - Google Patents

Abstract

PURPOSE:To intend to improve performance of exchanging heat, by providing a heat transmitting promotor to the part of a flow path of a heat exchanger other than a cross flow part, in a heat exchanger having a cross flow part so as to be designed to flow fluids having different temperatures, directly crossed to each other, at the outlet of the fluid. CONSTITUTION:Turbulent flow promotors in order to disturb the flow of fluid, twisted strips 3, for example, are inserted into the flow path of the fluid only on the high temperature side and the low temperature side of the counter-flow path 2, along the longitudinal direction of the flow paths. The said twisted strips 3 are fixed to plates or partition walls of a heat exchanger. When the fluids on the high temperature side and the low temperature side flow into the counter-flow part respectively, the flow of these fluids are disturbed because of the existence of the twisted strips 3. By these turbulences, the temperature boundary layer which is the resistance to transfer heat is decreased, and the heat transfer rate between the fluid and the solid surface inside of the flow path can be increased, accordingly, the heat transfer rate of a heat exchanger can be increased. By promoting heat transfer in such a manner, 1/50-1/20 out of total heat exchanged calorific value is absorbed into the cross flow part 1 in the above- mentioned form of a heat exchanger and under the temperature condition, so that the difference in temperature at the outlet of fluid can be suppressed down to the range at 5-15 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger used in power plants, chemical plants, etc., and is a heat exchanger for use in gas-gas, liquid-liquid, and even liquid-gas indirect heat exchangers. Kata play 1
This relates to a flattened heat exchanger.

For example, among the play one-fin type heat exchangers in which the heat transfer surface is formed into rectangular fins, there is one having an oblique flow section a and a counterflow section 11, as shown in FIG.

In the diagonal flow section a, the flow path C for flowing the high temperature side fluid and the flow path d for flowing the low temperature side fluid are obliquely intersecting, and in the counter flow section [), the flow path C for the high temperature side fluid and the flow path d for the low temperature side fluid cross each other obliquely. The flow channels d and the like are arranged in parallel.

Introducing the high-temperature side fluid in the direction of the white arrow to the above-mentioned conventional plate-fin heat exchanger having the oblique flow section a and the counterflow section A,
The temperature distribution of the heat exchanger when the low-temperature fluid is guided in the direction of the black arrow is shown in FIG. When the high-temperature side fluid and the low-temperature side fluid flow into the heat exchanger at constant temperatures Tl1l and TO+, the temperature distribution changes as shown in the figure, and the temperature distribution of both fluids is not uniform at the exit of the heat exchanger, resulting in a high temperature. side, low temperature side (A Tll 2 , IJ 'l'c respectively)
2 temperature difference occurs, which causes uneven thermal stress,
This has caused disadvantages such as the generation of natural convection due to temperature differences and an increase in exergy loss. The above A l-1+ 2 ,
The value of IJ -1-02 is - for example, Ul'l+1=50
0°C and rc+=150°C are continuous to about 100°C in the case of a sous gas heat exchanger.

To explain further, in the conventional technology, even when heat transfer is promoted in a conventional heat exchanger (not shown in FIG. 1), heat transfer is promoted in both the diagonal flow section a and the counter flow section a. The ratio of the amount of heat absorbed by the opposing flow section A is mainly proportional to the heat transfer area, and once the shape of the heat exchanger is determined, the ratio of the amount of heat absorbed is determined, and if the shape is J34J
Le Wi/L-0,8~1.2-r full cross 1%t4
17) Approximately 115 to 1/3 of the fluid is collected in the oblique flow section, and the temperature in the opposite flow section becomes uneven, which causes the outlet temperature to become uneven, and the fluid flow [1] When the temperature difference is about 200°C, the difference in temperature of lj D is 80 to 1
When the temperature reached 20'C, problems such as generation of non-uniform thermal stress, generation of natural convection due to temperature difference, and increase in exergy loss occurred as described above.

The present invention aims to eliminate such problems and improve the performance of the heat exchanger.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in Figures 3 and 4, the planar shape is hexagonal,
A diagonal flow section 1 in which the flow paths of the inlet and outlet portions of the fluid on the high temperature side and the flow paths of the outlet and inlet portions of the fluid on the low temperature side obliquely intersect, and the flow path of the high temperature side fluid and the flow path of the low temperature side fluid. In a single-fin type heat exchanger in which the flow paths extend in parallel to each other in the counterflow section 2, the fluid flow is limited only to the high temperature side fluid flow path and the low temperature side fluid flow path in the counterflow section 2. A turbulence promoter, for example, a torsion plate 3, is inserted along the longitudinal direction of the flow path, and the torsion plate 3 is fixed to a plate, a partition wall, or the like.

With both of the above configurations, when the high-temperature side fluid and the low-mixing side iL body flow into the opposing flow sections, the flow of the fluids is disturbed due to the torsion. By reducing the number of layers, it is possible to increase the heat transfer coefficient between the fluid and the surface of the body placed in the flow path, and the amount of heat transfer in the heat exchanger can be increased.By promoting heat transfer in this way, the above-mentioned With the heat exchanger shape and temperature conditions, 1/50 to 1/20 of the total heat exchanged will be collected in the oblique flow section 1, making it possible to keep the temperature difference at the fluid outlet to 5 to 15 degrees Celsius. can.

In the above explanation, the inflow and outflow of one flow on the high temperature side and the low temperature side intersects diagonally at the 1'' portion, and at the intermediate portion, the ゛ is a counterflow. j; In the Unishida heat exchanger, a method for promoting heat transfer is shown. Even if other heat transfer promotion methods such as inserting holes in the fins or forming holes in the fins,
Further, the present invention provides parallel flow type plays 1 to 1 in which the opposing flow sections become parallel flows.
It can be used for fin-type heat exchangers, and in addition, similar effects can be expected by promoting heat transfer only in the parallel flow section (in the case of play type heat exchangers without fins, the counter-flow section). There are, of course, C's.

As described above, by using the heat exchanger of the present invention, it is possible to equalize the fluid outlet temperature of the heat exchanger, thereby preventing the occurrence of uneven thermal stress, and reducing the temperature difference of the fluid. This prevents natural convection and equalizes the temperature, reducing the secondary energy loss of the fluid, improving the durability of the heat exchanger, improving heat exchange performance, and helping to save energy. It can have excellent effects.

[Brief explanation of the drawing]

Figure 1 is an explanatory perspective view of a conventional diagonal flow section to play 1 fin type heat exchanger, and Figure 2 is an explanatory perspective view of the heat exchanger shown in Figure 1.
FIG. 3 is a perspective view showing an example of the heat exchanger of the present invention, and FIG. 4 is a perspective view showing the configuration of the heat exchanger of the present invention. 1... Oblique flow section, 2... Counterflow section, 3... Torsion plate. Patent application: Person Ishikawajima Harima Heavy Duty] - Ministry of Industry and Stock Exchange, Figure 3, Figure 2

Claims (1)

[Claims] 1) A heat transfer accelerator is applied to the fluid flow path at a location other than the diagonal flow section of a heat exchanger that has a diagonal flow section in which fluids with different humidity flow orthogonally at the fluid inlet and outlet sections. Features: - Type heat exchanger.