JPH0435732Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a heat exchanger in which substantially plate-shaped elements are laminated.

(Prior Art and its Problems) This type of heat exchanger is known from the prior art, for example, in Japanese Utility Model Publication No. 15641/1983 and Japanese Patent Application Laid-open No. 41946/1983. In this conventional example, a plurality of corrugated elements are laminated to form passages between the elements. Furthermore, a conventional example is known in which needle-like protrusions are formed on a flat element to disrupt the flow of air flowing through a passage and improve heat transfer efficiency.

However, the above conventional examples leave room for improvement in the overall heat transfer coefficient (U value) and are not sufficient in terms of heat exchange efficiency, and there is a need for a heat exchanger with further improved heat exchange efficiency. There is.

(Purpose of the invention) The object of the invention is to provide a heat exchanger in which substantially plate-shaped elements are laminated, which can further improve heat exchange efficiency.

(Structure of the invention) (1) Technical means The present invention consists of a plurality of corrugated plate-like elements 10 having rectangular peaks and valleys press-formed and having irregularities in a lattice pattern, separated by passages 14 and 16, and laminated. In the heat exchanger, the above-mentioned peaks and valleys are formed by four horizontally long rectangular first projecting elements 18a arranged in a staggered manner and protruding to one side, and in the center of which is a vertically extending element 18a that is 90 degrees different from the first protruding elements 18a. the second long rectangle
The first protrusion element 18b is arranged in such a manner that it protrudes toward the other, and the first
The protrusion element 18a has an upstream portion 20 steeply inclined in the protruding direction and a downstream portion 22 gently inclined in the opposite direction, which are smoothly continuous at the top, and the second protrusion element 18b is It has the same shape as the first protrusion element 18a, differing only in the protrusion direction, and in the nine-way passage 14 of each element 10, the first fluid flows into the upstream portion 2 of the first protrusion element 18a.
0 through the downstream portion 22 to the second projection element 18b portion having a substantially trapezoidal cross section, and in the other passage 16, the second fluid flows from the upstream portion to the downstream portion of the second projection element 18b. The heat exchanger is characterized in that the heat exchanger is configured to flow vertically through the first projection element portion having a substantially trapezoidal cross section.

(2) Effect The airflow impinges on the upstream part of the protruding element with a steep inclination angle to disturb the airflow, forming a turbulent heat transfer region with a high heat transfer coefficient, and reducing the airflow in the downstream part of the protruding element. smoothly leads to the next protrusion element, forming a turbulent heat transfer zone again to improve heat exchange efficiency.

(Example) In FIG. 1 showing a heat exchanger employing the present invention, 10 is a substantially plate-shaped element. The planar shape of the element 10 is approximately square. As shown in FIG. 1A, this element 10 is assembled by alternately abutting the upper and lower edges and the left and right edges and welding the welded portions 12 together. Passages 14, 16 are thus formed between mutually adjacent elements 10.

As shown in FIG. 2, for example, high-temperature air flows laterally in the passage 14 along the arrow X, and the passage 16
For example, low-temperature air flows vertically in the direction of arrow Y to exchange heat.

Next, in FIG. 3 showing a more detailed structure of the element 10, 18a and 18b are protruding elements, respectively. The protrusion element 18a corresponds to the airflow flowing in the direction of the arrow X, and the protrusion element 18b corresponds to the airflow flowing in the direction of the arrow Y. In other words, the protrusion element 18b is set to have the same conditions regardless of the directionality of the airflow. There is.

The protruding elements 18a and the protruding elements 18b are arranged adjacent to each other alternately in five rows and columns. As shown in FIG. 3C, which is a view in the direction of arrow C in FIG. As shown in FIG. 3D, the protrusion element 18b protrudes from the lower surface of the element 10 in a substantially chevron shape. Therefore, A-A in FIG.
As shown in FIG. 3A, which is a sectional view, and FIG. 3B, which is a BB sectional view, substantially chevron-shaped cross sections and flat substantially trapezoidal cross sections are alternately adjacent to each other in each row in the vertical and horizontal directions.

For example, as shown in FIG. 4, which is an enlarged cross-sectional view of the passageway 14, the upstream portion 20 of the protrusion element 18a is inclined at a relatively steep angle, and air flows into this upstream portion 20 along the arrow X. collide to form a turbulent flow, and a turbulent heat transfer region with a high heat transfer coefficient is formed within the turbulent heat transfer region T.

A gently sloped downstream portion 22 is formed on the downstream side of the upstream portion 20, and in this downstream portion 22, the turbulent flow state formed in the turbulent heat transfer region T is maintained along a smooth slope. It is designed to guide the airflow while doing so. Therefore, as mentioned above, the protruding element 18b has a substantially trapezoidal cross section.
When the airflow collides with the next protrusion element 18a across the gap, consideration is given so that a turbulent heat transfer region T with a high heat transfer rate is again formed in the upstream portion 20.

Note that in the passage 16 as well, the airflow is caused by the protruding element 18.
b to form a turbulent heat transfer region T for each protrusion element 18b.

As described above, in the passage 14, heat is transferred from the airflow in the direction of arrow X to the element 10, and in the passage 16, heat is transferred from the element 10 to the airflow.

Next, the effect will be explained. First, as shown in FIG. 4, for example, in the passage 14, an airflow in the direction of arrow X collides with the upstream portion 20 of the protrusion element 18a, and turbulent heat transfer with a high heat transfer coefficient occurs in the turbulent heat transfer region T. will be carried out. In the downstream part 22, the turbulent airflow is guided downstream as it is, and the adjacent protrusion element 18
It collides with the next protruding element 18a through the protruding element 18b disposed between a and the upstream portion 20 again.
The airflow becomes turbulent, and turbulent heat transfer occurs in the turbulent heat transfer region T.

Therefore, from the airflow flowing through the passage 14 to the element 10, the upstream portion 20 of the protruding element 18a
A turbulent heat transfer region T is formed nearby, and heat is transferred by turbulent heat transfer with a high heat transfer coefficient.

In general, the overall heat transfer coefficient, which indicates the performance of heat transfer,
That is, the U value is expressed as U=1/1/h1+δ/λ+1/h2...(1) h1, h2: film heat transfer coefficient λ: thermal conductivity of element material δ: plate thickness. Equation (1) shows that the influence of the film heat transfer coefficients h1 and h2 is large;
h1 and h2 can be increased depending on the surface shape of this element. Therefore, as the heat transfer coefficients h1 and h2 increase, the U value naturally increases, and the amount of heat transfer per unit area increases.

The same applies to the passage 16.

(Effect of the invention) As explained above, according to the invention, the protruding elements 18a, 18b are formed on the element 10, and the protruding elements 18a, 18b are formed by the steep upstream part 20 and the gentle downstream part 22. Therefore, for example, in the passage 14, the upstream portion 20 of the protruding element 18a
The airflow in the direction of arrow X collides with the turbulent heat transfer area T.
Heat can be transferred by turbulent heat transfer with a high heat transfer coefficient in the range of protrusion element 18b
The air can be made to collide with the next protruding element 18a through the above process, and the airflow can be made turbulent again in the upstream portion 20, thereby allowing turbulent heat transfer to occur in the turbulent heat transfer region T.

Therefore, by increasing the overall heat transfer coefficient U value in equation (1), the amount of heat transfer per unit area of the element 10 can be increased compared to the conventional one, and the heat transfer efficiency can be greatly improved.

Furthermore, in the present invention, since the downstream part 22 smoothly continues behind the upstream part 22 and has a gentle slope, there is no risk that the turbulent flow in the turbulent heat transfer region T will stay in the downstream part 22 ( (dead zone is not formed),
The fluid flows through the passage 14 in a moderately turbulent state, and the low trapezoidal cross-section formed by the back surface of the protrusion element 18b continues smoothly in the downstream portion 22, increasing the chances of contact between the element 10 and the turbulent fluid. Heat transfer efficiency can be increased without increasing flow path loss. When we compared the heat transfer performance of a rectangular corrugated plate with a combination of rectangular peaks and troughs as in the present invention and an elliptical corrugated plate in the case of cross-counterflow, and at the same time conducted a flow visualization experiment, we found that the heat transfer coefficient was Compared to the elliptical corrugated plate, the product of the present invention had an increase of about 6%, and even though turbulence occurred at each mountain part, no dead area was observed in the valley part.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a heat exchanger adopting the present invention, Fig. 1A is an enlarged view of part A in Fig. 1, Fig. 2 is an enlarged perspective view of the main part of Fig. 1, and Fig. 3 is an enlarged view of the element. Side view, Figure 3A is a sectional view taken along line A-A in Figure 3, Figure 3B
The figure is a sectional view taken along line B-B in Fig. 3, Fig. 3C is a view taken in the direction of arrow C in Fig. 3, Fig. 3D is a view taken in the direction of arrow D in Fig. 3, and Fig. 4 is an enlarged sectional view of the main part of the passage. be. 10...Element, 12...Welding part, 14,
16... Passage, 18a, 18b... Projection element, 2
0... Upstream part, 22... Downstream part.

Claims (1)

[Scope of utility model registration request] The heat exchanger is a heat exchanger in which a plurality of corrugated plate-shaped elements 10 having rectangular peaks and valleys formed by pressing and having irregularities in a lattice pattern are laminated with passages 14 and 16 separated, and the above-mentioned peaks and valleys are arranged horizontally. Four long rectangular first protruding elements 18a are arranged in a staggered manner and protrude to one side, and at the center thereof, a vertically long rectangular second protruding element 18b, which is oriented at 90 degrees and is different from them, protrudes to the other side. The first protrusion element 18a, which forms a mountain, has an upstream portion 20 that is steeply inclined in the protruding direction, and a downstream portion 22 that is gently inclined in the opposite direction. The second protrusion element 18b is smoothly continuous at the top, and the second protrusion element 18b is connected to the first protrusion element 1.
In one passage 14 of each element 10, the first fluid passes from the upstream portion 20 of the first protrusion element 18a to the downstream portion of the first protrusion element 18a, and the second protrusion element 18a has a substantially trapezoidal cross section. Projection element 18
b, and in the other passage 16 the second fluid flows longitudinally from the upstream portion of the second projection element 18b through the downstream portion to the first projection element portion having a substantially trapezoidal cross section. A heat exchanger characterized by having a flowing structure.