CN106643235B - A kind of recuperative heat exchanger and preparation method thereof - Google Patents

Abstract

A partitioned wall heat exchanger, which is composed of a hot fluid flow channel and a cold fluid flow channel with a rectangular cross-section, and is closely arranged in the form of a plurality of non-closed annular heat exchange flow channel units along the axial direction through the conversion bend. Constitute a flow channel layer, a plurality of such flow channel layers are closely fitted and nested in the radial direction, so that the hot fluid flow channel and the cold fluid flow channel are staggered in the axial and radial directions, and the hot fluid and the cold fluid are axially and Radial two-dimensional heat transfer. The heat exchanger has the advantages of large heat transfer area, high heat transfer coefficient, good compactness, high flow turbulence, no fouling and wide application range.

Description

Partitioning wall heat exchanger and manufacturing method thereof

technical field

The invention relates to a heat exchanger, in particular to a partitioned wall heat exchanger composed of multi-layer spiral flow channels and a manufacturing method thereof.

Background technique

Heat exchanger is an effective equipment used in chemical industry, energy, metallurgy, power and other industries to change the temperature condition of fluid working medium. The heat transfer efficiency of a heat exchanger is directly proportional to the heat transfer area and directly related to the degree of turbulence of the flow. In engineering applications, heat exchangers first require a large heat exchange area to improve heat transfer efficiency, and at the same time hope that their structure should be compact and their volume should be minimized. Compactness refers to the size of the heat exchange area contained in the unit volume of the heat exchanger, and the unit is m ² /m ³ .

The increase of heat exchange area is often accompanied by the increase of flow resistance. In the process of heat exchanger design or selection, it is necessary to make a trade-off between heat exchange area and flow resistance according to the actual needs of the project.

Heat exchangers can be divided into three categories: partition type, hybrid type, and heat storage type according to the heat transfer method. The so-called partition type means that there is a solid wall between the hot fluid and the cold fluid, the two fluids are not in direct contact, and the heat is transferred through the wall. Among them, the partition wall heat exchanger includes shell-and-tube type, submerged type, casing type, spiral plate type, plate type, plate-fin type and other structural forms.

Shell-and-tube heat exchangers are currently the most widely used, and their disadvantages are low compactness, large resistance loss, and easy fouling; submerged heat exchangers have poor compactness and low fluid turbulence; tube-and-tube heat exchangers are only It is suitable for heat exchange of high-temperature, high-pressure, and small-flow fluids, and its scope of application is small; plate and plate-fin heat exchangers are compact, with uneven heat exchange surfaces all over the flow channel, and the heat exchange area is relatively large, but there is also a relatively large flow resistance. Big defect; the technical indicators of the spiral plate heat exchanger are relatively moderate, but its heat transfer method is the same as that of the plate type and plate-fin type. It is still one-dimensional heat transfer, and the heat transfer area, heat transfer efficiency and space utilization are still not ideal. .

Contents of the invention

In view of the above-mentioned defects of the prior art, the purpose of the present invention is to provide a partitioned wall heat exchanger with compact structure, large heat transfer area, high heat transfer efficiency and high turbulence and its manufacturing method.

The partitioned wall heat exchanger provided by the present invention is composed of a rectangular hot fluid flow channel and a cold fluid flow channel that are attached to each other; The unit form forms a channel layer by closely arranging the front and back of the conversion curve, and multiple such channel layers are closely fitted and nested in the radial direction, so that the hot fluid channel and the cold fluid channel are interlaced in the axial and radial directions , hot and cold fluids for axial and radial two-dimensional heat transfer.

The manufacture method of partition heat exchanger of the present invention is:

First use a rectangular thin metal plate as the inner wall of the innermost flow channel layer of the dividing wall heat exchanger, roll it into a cylinder, and weld the cylinder closed; The track of the heat exchange flow channel unit is welded on the outside of the cylinder, as the side wall shared by the hot fluid flow channel and the cold fluid flow channel of the innermost flow channel layer, and the hot fluid outlet and the cold fluid outlet of the flow channel layer will be arranged The outlet and the end layer-changing bend are welded and formed at the same time; then a rectangular thin metal plate is used as the outer wall of the flow channel layer, rolled, and welded to the side wall at the same time during the rolling process. After the rolling is completed, the It is welded and closed, and a rectangular opening is cut at the position of the corresponding layer-changing curve as the interface of the end layer-changing curve to complete the production of the innermost runner layer; then the outer wall of the innermost runner layer is used as the inner-outward The inner wall of the second flow channel layer is welded in the same way as the side wall shared by the cold fluid flow channel and the hot fluid flow channel of the second flow channel layer. From the outer wall of the second flow channel layer from the inside to the outside, complete the making of the second flow channel layer from the inside to the outside; so cycle, until the making of the outermost flow channel layer is completed, the hot fluid inlet and the cold fluid inlet are located at the outermost flow channel layer one end.

Compared with prior art, the advantages of the present invention are:

1. In the present invention, due to the two-dimensional heat transfer of cold and hot fluids, its heat transfer area, compactness, heat transfer efficiency and flow turbulence are all greatly improved compared with the spiral plate heat exchanger of the same volume.

2. Compared with the plate heat exchanger, the present invention has the advantages of small flow resistance and less fouling.

3. Compared with shell-and-tube and submerged heat exchangers, the compactness of the present invention is greatly improved.

4. Compared with the casing heat exchanger, the present invention has high compactness, large rated flow rate and wider application range.

Description of drawings

Accompanying drawing is the schematic diagram of the embodiment of the present invention, wherein:

Fig. 1 is an axonometric view of a heat exchanger main body;

Fig. 2 is a schematic diagram of a single heat exchange flow channel unit intercepted;

Fig. 3 is a schematic diagram of conversion from the outermost flow channel layer to the second outer flow channel layer;

Fig. 4 is an axial front view of the head end of the heat exchanger;

Fig. 5 is a sectional view along Fig. 4A-A;

Fig. 6 is a schematic diagram of the outlet section of the cold fluid flow channel and the hot fluid flow channel of the innermost flow channel layer of the heat exchanger.

Detailed ways

The present invention will be further described below in conjunction with drawings and embodiments.

With reference to Figure 1 and Figure 2, the heat exchanger of this embodiment is composed of a hot fluid flow channel 7 and a cold fluid flow channel 8 with a rectangular cross-section (as shown in Figure 2 ), and is shown in Figure 2 along its axial direction. Eight non-closed annular heat exchange flow channel units are closely arranged in front and rear through the double-arc transition bend 5 to form a flow channel layer. The eight heat exchange flow channel units in each flow channel layer include Z1, Z3, and Z5 in sequence. , Z7, Z9, Z11, Z13, Z15 and Z2, Z4, Z6, Z8, Z10, Z12, Z14, Z16 a total of sixteen cold and hot fluid flow channel units (the odd number group and the even number group are in different flow channels The layers correspond to different hot fluid channel units and cold fluid channel units, black in Fig. 1 indicates the side walls shared by the hot fluid channel and the cold fluid channel). The main body of the heat exchanger is formed by ten flow channel layers R1 to R10 of this structure closely fitting and nesting each other in the radial direction. Combining Figure 3, Figure 4 and Figure 5, taking the outermost flow channel layer R1 as an example, the transition mode between adjacent flow channel layers is: the last heat exchange flow channel unit of the flow channel layer R1 turns over at the end of the heat exchanger After about 270 °, return to the head end of the heat exchanger through the layer-changing bend 6 (the length of the heat exchanger layer-changing bend with a diameter of 800mm is about 120mm), in order to make the thermal fluid flow path in the inner and outer flow path layers ( Figure 3 and Figure 5 (shown in sand patterns) and cold fluid flow channels (shown in Figure 3 and Figure 5 in white patterns) can be staggered in the radial direction to achieve radial heat transfer of cold and hot fluids, and the last heat exchange When the runner unit returns, it needs to be connected to the heat exchange runner unit located at Z13 and Z12 through the transition curve from the positions Z16 and Z15, and the runner corresponding to the Z14 position as shown in the black pattern in Figure 3 and Figure 5 is vacated in the middle The empty area 9 then clings to the inner wall of the outermost flow channel layer R1 and goes to the head end of the heat exchanger to form the second outer flow channel layer R2. The flow channel layer R2 returns to the tail end of the heat exchanger in the same manner at the head end of the heat exchanger to form the third flow channel layer R3. Reciprocating in this way, a total of ten flow channel layers from R1 to R10 are formed in the radial direction from outside to inside, so that the hot fluid flow channel and the cold fluid flow channel are interlaced in the axial and radial directions as shown in Figure 5, realizing the flow of hot and cold fluids Axial and radial two-dimensional heat transfer. The hot fluid inlet 1 and the cold fluid inlet 2 of the heat exchanger are arranged at the outermost flow channel layer at the head end of the heat exchanger (as shown in Figure 1 and Figure 4); the hot fluid outlet 3 and the cold fluid outlet 4 are arranged at the head of the heat exchanger. The innermost runner layer at the end (as shown in Figure 1 and Figure 6).

The hot and cold fluids operate in the above heat exchanger as follows:

The hot fluid and the cold fluid flow in respectively from the hot fluid inlet 1 and the cold fluid inlet 2 arranged on the outermost flow channel layer at the head end of the heat exchanger. It is a circumferential operation in the form of a circle. When the operation is close to a circle, it enters the turning area of the runner, and turns to the second circle through the conversion curve to continue the circumferential operation; it runs to the turning area of the runner and then turns through the second conversion curve. Enter the third circle and continue to run in the circumferential direction; such a cycle, until it runs to the end of the heat exchanger and then returns, after entering the second outer channel layer R2, continue to run to the head of the heat exchanger in the same way, and so on 10 times , the hot fluid and the cold fluid respectively flow out from the hot fluid outlet 3 and the cold fluid outlet 4 arranged at the innermost channel layer at the head end of the heat exchanger. The hot fluid and the cold fluid in the heat exchanger present a superposition of circumferential operation, axial operation and radial operation, wherein the direction of the circumferential operation remains unchanged from beginning to end, and the direction of the axial operation changes after changing layers.

The production method of this embodiment is as follows:

First use a rectangular thin metal plate as the inner wall of the flow channel layer R10 to roll into a cylinder. After welding and closing, weld a strip-shaped thin metal plate with a width equal to the radial thickness of the inner hole of the flow channel along the track of the heat exchange flow channel unit. The outer side is used as the side wall shared by the hot fluid flow channel and the cold fluid flow channel of the innermost flow channel layer, and the hot fluid outlet 3, the cold fluid outlet 4 and the end layer changing bend 6 of the flow channel layer are welded and formed at the same time, Then use a rectangular thin metal plate to roll as the outer wall of the flow channel layer. During the rolling process, the welding with the side wall is carried out at the same time. Cut out a rectangular opening as the interface of the end layer changing bend to complete the production of the innermost runner layer R10; then use the outer wall of the runner layer R10 as the inner wall of the runner layer R9 to weld the hot and cold of the runner layer R9 The side wall shared by the fluid flow channel, and the layer-changing flow channels 6 at both ends are welded and formed at the same time, and then rolled with a rectangular thin metal plate as the outer wall of the flow channel layer R9, and the flow channel layer R9 is completed in the same way as the flow channel layer R10 The production; so cycle, until the completion of the outermost flow channel layer R1 production, the hot fluid inlet 1 and the cold fluid inlet 2 are set at one end of the outermost flow channel layer R10.

A heat exchanger with a diameter of 800mm, an axial length of 1600mm, a cross-section of the hot and cold fluid channels of 25mm×15mm, 20 flow channel layers in the radial direction, and 32 heat exchange flow channel units in the axial direction of each layer is For example, the heat exchange effect is calculated, the heat exchange area is about 72.65m ² , the compactness index is 91m ² /m ³ , and the nominal working pressure is below 2.5MPa. Among them, the compactness is much higher than that of the shell-and-tube heat exchanger; the heat exchange area, compactness and flow turbulence are all better than the spiral plate heat exchanger with the same flow resistance and the same volume. Its scope of application is similar to that of the spiral plate heat exchanger, and its compactness is between the spiral plate heat exchanger and the plate heat exchanger.

It should be noted that the heat exchanger of the present invention is not limited to having 10 flow channel layers in the radial direction and 8 heat exchange flow channel units in each layer as described in the embodiment, the number of flow channel layers and the exchange rate of each flow channel layer The number of hot runner units can be increased or decreased; the inlet and outlet of the hot and cold fluids are not limited to be arranged at the same end of the heat exchanger, but can also be arranged at the first and last ends of the heat exchanger; The fluid channels can be interchanged; hot and cold fluids can be heat-exchanged in either forward or counter-current flow. These changes are all within the protection scope of the present invention.

Claims (2)

1. a kind of recuperative heat exchanger is bonded to each other and is constituted by the hot fluid runner and cold fluid runner that section is rectangle；Its It is characterized in that:The heat exchanger is passed through with multiple not closed annular heat exchange runner unit forms close before and after conversion bend in an axial direction It is arranged to make up a flow channel layer, multiple such flow channel layers radially fit closely nesting, make hot fluid runner and cold fluid flow Road is axially and radially mutually interlocking, and hot fluid and cold fluid are axially and radially Two-Dimensional Heat.

2. the production method of recuperative heat exchanger described in claim 1, it is characterised in that：First use rectangle metal sheet between The inner wall of wall type heat exchanger most inner flow passage layer, rolls into a cylinder, and cylinder welding is closed；Then it is runner by width The band-like metal sheet of endoporus radial thickness along heat exchange runner unit Antiinterference in the outside of cylinder, as most inner flow passage layer Hot fluid runner and the shared side wall of cold fluid runner, and hot fluid outlet ports and cold fluid outlet in the flow channel layer will be set And layer bend welding fabrication simultaneously is changed in end；Then rectangle metal sheet is used as the outer wall of the flow channel layer, rolls and is being rolled Make itself and the sidewall weld simultaneously in the process, by its welded closed after the completion of rolling, is cut in corresponding change at layer bend position Go out a rectangular opening, the interface of layer bend is changed as end, completes the making of most inner flow passage layer；Then with the outer wall of most inner flow passage layer As the inner wall of second channel layer from inside to outside, the cold fluid runner and hot fluid runner of second channel layer are welded by same procedure Shared side wall, while a layer bend welding fabrication is changed at both ends, then use rectangle metal sheet as second flow channel from inside to outside The outer wall of layer completes the making of second channel layer from inside to outside；So cycle, until the making of outermost flow channel layer is completed, it will be hot Fluid inlet and cold fluid inlet are located at one end of outermost flow channel layer.