JPH1183353A - Plate fin type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate fin type heat exchanger having a sound absorbing structure for reducing noise. SOLUTION: In a crossflow plate fin type heat exchanger, a resonance type sound absorbing structure having a porous plate 5 and a rear air layer 6 is installed at a sidewall (spacer bar 4) of a refrigerant channel. Since thickness, diameter of pore, rate of hole area of the plate 5 and thickness of the layer 6 are decided so as to resonate particularly with a large frequency of a level of the noise generated from the exchanger, collision sound generated when the refrigerant or atmospheric air passes the exchanger or noise generated due to abrupt enlargement or contraction of the channel at a tube connecting part can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a heat exchanger of a type generally known as a plate-fin heat exchanger.

[0002]

2. Description of the Related Art Various types of plate fin type heat exchangers have been proposed (for example, Japanese Utility Model Publication No. 7-4).
No. 0852). Among them, FIG. 11 shows a core portion of a generally used plate-fin heat exchanger. In the conventional example shown in FIG. 1, a first flow path 1 for flowing a first refrigerant A and a second flow path 2 for flowing a second refrigerant B are alternately stacked in a plurality of stages at right angles. This is a cross-flow type conventional example configured to exchange heat between the refrigerant A and the refrigerant B. Each flow path 1 and 2 is a pair of upper and lower tube plates (plate-shaped partition)
3, a spacer bar 4 disposed at both ends of the space between the tube plates 3, and first or second fins 1 a and 2 a disposed between the pair of spacer bars 4. The laminated channels 1 and 2 are integrally brazed, and both ends (that is, an inlet and an outlet) of each channel 1 and 2 are covered with a header tank (not shown).

[0003] The first refrigerant A is a high-temperature refrigerant, and the second refrigerant B is a low-temperature refrigerant. Each of the refrigerants A and B is taken into each of the flow paths 1 and 2 from the side surface of the adjacent core part at an angle of 90 °, and flows in the direction orthogonal to each other at different levels. At this time, the heat held by the high-temperature refrigerant A is transmitted to the tube plates 3 located above and below the fins 1 a arranged in the flow path 1, and the heat transmitted to the tube plate 3 is Is transmitted to the low-temperature refrigerant B by the fins 2a arranged at the bottom.

[0004] The plate fin type heat exchanger has an advantage that a high heat transfer density can be obtained, so that downsizing and high performance can be easily achieved. Further, since the heat transfer area on the high-temperature side and the low-temperature side, the type of the fin, and the like can be freely selected according to the purpose, there is an advantage that it can be used for any combination of refrigerant fluids.

[0005]

However, the conventional plate-fin type heat exchanger has a problem that noise is generated. The noise includes a collision noise generated when the refrigerant or the outside air passes through the heat exchanger, and a noise generated by a sudden expansion and contraction of the flow path at the pipe connection. These noises are transmitted through the pipes and discharged from the outlets and suction ports of the refrigerant or the outside air, or propagated through the pipes and discharged to the outside. In order to improve the comfort of the system environment using the heat exchanger, it is necessary to reduce these noises.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a plate-fin heat exchanger having a structure for reducing noise.

[0007]

In order to achieve the above object, a plate fin type heat exchanger according to a first aspect of the present invention has a first flow path through which a first refrigerant flows and a second flow path through which a second refrigerant flows. A plurality of flow passages alternately orthogonally stacked in a plurality of stages, and configured to exchange heat between the first refrigerant and the second refrigerant.
Alternatively, a sound absorbing structure is provided on a side wall portion of the second flow path.

A plate fin type heat exchanger according to a second aspect of the present invention is the plate fin type heat exchanger according to the first aspect of the present invention, wherein the sound absorbing structure comprises:
It is characterized by a resonance type sound absorbing structure comprising a guide provided so as to surround the side wall of the other flow path so as to regulate the flow of the refrigerant at the inlet or outlet of one flow path.

A plate fin type heat exchanger according to a third aspect of the present invention is the plate fin type heat exchanger according to the first or second aspect, wherein a sound absorbing material is attached or filled to a part of the sound absorbing structure.

According to a fourth aspect of the present invention, in the plate fin type heat exchanger according to the first or second aspect, the sound absorbing structure is provided in a plurality of stages of the first or second flow path. Each stage has a different resonance frequency.

According to a fifth aspect of the present invention, in the plate fin type heat exchanger, the first flow path through which the first refrigerant flows and the second flow path through which the second refrigerant flows alternately intersect at a plurality of stages. And a plate-fin heat exchanger configured to perform heat exchange between the first refrigerant and the second refrigerant, and to cover an inlet or an outlet of the first or second flow path. The header tank is provided as described above, and a sound absorbing structure is provided in the header tank.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plate fin type heat exchanger embodying the present invention will be described below with reference to the drawings. Note that the same or corresponding portions in the embodiments are denoted by the same reference numerals, and redundant description will be appropriately omitted.

<< First Embodiment (FIGS. 1 and 2) >> FIG.
FIG. 2 shows a schematic configuration of a heat exchanger core unit according to the first embodiment, and FIG. 2 shows an enlarged vertical cross-sectional main structure taken along line XX (FIG. 1). This plate fin type heat exchanger has the first
A first flow path 1 for flowing the refrigerant A and a second flow path 2 for flowing the second refrigerant B are alternately orthogonally stacked in a plurality of stages, and the first refrigerant A and the second refrigerant 7 is a cross-flow embodiment configured to perform heat exchange with B.

Each of the flow paths 1 and 2 has a pair of upper and lower tube plates (plate-like partition walls) 3, spacer bars 4 disposed at both ends of a space between the tube plates 3, and a pair of spacer bars 4. The arranged first or second fin 1a,
2a. The space server 4 has a U-shaped cross section, and constitutes the side walls of the flow paths 1 and 2. Since the perforated plate 5 is provided on the opening side of the U-shape, the cross section of the spacer bar 4 and the perforated plate 5 forms a square shape. That is,
As shown in FIG. 2, a back air layer 6 is formed in a side wall portion of each of the flow paths 1 and 2, which comprises a space surrounded by a pair of upper and lower tube plates 3, a spacer bar 4, and a perforated plate 5. It is. Further, the laminated channels 1 and 2 and the perforated plate 5 are integrally brazed, and both ends (that is, the inlet and the outlet) of each of the channels 1 and 2 are covered with a header tank (not shown). I have.

[0015] The first refrigerant A is a high-temperature refrigerant, and the second refrigerant B is a low-temperature refrigerant. Each of the refrigerants A and B is taken into each of the flow paths 1 and 2 from the side surface of the adjacent core part at an angle of 90 °, and flows in the direction orthogonal to each other at different levels. At this time, the heat held by the high-temperature refrigerant A is transmitted to the tube plates 3 located above and below the fins 1 a arranged in the flow path 1, and the heat transmitted to the tube plate 3 is Is transmitted to the low-temperature refrigerant B by the fins 2a arranged at the bottom.

A major feature of the first embodiment is that a perforated plate 5 and a back air layer 6 (spacer bar 4 in FIG. 2) are provided on the side walls of the first flow path 1 and the second flow path 2. (A space sandwiched by the perforated plate 5). This sound absorbing structure is a resonance type sound absorbing structure that absorbs a sound near a resonance frequency by resonance absorption.
And at all stages of the flow path 2. Each sound absorbing structure is caused by a noise generated from the heat exchanger (for example, a collision noise generated when a refrigerant or outside air passes through the heat exchanger, or a sudden expansion or contraction of a flow path at a pipe connection portion. noise)
Of the frequency components, the frequency having a particularly high level matches the resonance frequency.

The resonance frequency is determined by the thickness of the perforated plate 5, the area of the holes, the number of holes, and the volume of the air layer 6 behind, and is calculated by the following equation (1). Therefore, the optimal value of each of the above elements constituting the sound absorbing structure is
The frequency to be sound reduction as the resonance frequency f ₀ is determined from Equation (1). For example, in the case of designing to reduce the frequency around 1600 Hz, the thickness t of the perforated plate 5 = 2 (mm), the diameter d of the hole, d = 1 (mm), and the volume V of the back air layer 6 = 2.4 × 10 ^-5 (m ³ ), 75 holes.

F ₀ = (c / 2π) · √ (C ₀ / V) (1) where C ₀ = n · S ₀ /[t+0.8(√S ₀ )] f ₀ : resonance frequency (Hz) ), c: velocity of sound in air (m / s), n: number of holes, S _0: area of the hole (m ^2), t: plate thickness of the perforated plate (m), V: volume of the back air layer (m ³ ).

[0019] The above the sound absorbing structure is incident, cause air resonance vibration of air and the back air layer 6 of the portion of the hole provided in the perforated plate 5, the resonance frequency f ₀ near the sound of the sound absorbing structure has Is absorbed. The frequency component of the sound near the resonance frequency f ₀ controls the collision noise generated when the refrigerant or the outside air passes through the heat exchanger and the noise generated due to the sudden expansion and contraction of the flow path at the pipe connection. , And the level of the high-frequency component, the noise is greatly reduced by the resonance absorption. At this time, since the flow path 1 and the flow path 2 are alternately stacked so as to be orthogonal to each other, noise generated at the entrance / exit portion of one of the flow paths 1 or 2 is mainly caused by the other at the upper and lower sides thereof. The noise is reduced by the sound absorbing structure provided on the side wall of the flow path 2 or 1.

Further, when the noise generated from a compressor, a blower or the like for sending refrigerant or air to the heat exchanger and transmitted through the pipeline to the heat exchanger is larger than the above-described noise. The noise can be reduced by providing a sound absorbing structure that resonates with the dominant frequency. In the first embodiment, the sound absorbing structure is provided on both the first and second flow paths 1 and 2. However, the sound absorbing structure is provided on only one of the side walls of the flow path as necessary. Alternatively, the sound absorbing structure provided on the side wall of the flow path 1 and the sound absorbing structure provided on the side wall of the flow path 2 may have different resonance frequencies f ₀ .

As can be seen from equation (1), the resonance frequency f ₀ itself is independent of the material forming the perforated plate 5. However, a material having high rigidity is suitable so that the material does not easily vibrate due to the sound pressure inside the back air layer. For example, iron,
A metal such as aluminum may be used.

In a general plate-fin heat exchanger, the spacer bar hardly transmits heat when performing heat exchange, and functions as a partition for maintaining the mechanical strength of the core. I just do. Therefore, even if the sound absorbing structure including the perforated plate 5 is installed next to the spacer bar 4 as in the first embodiment, the heat transfer performance does not decrease. The sound absorbing structure is compact because it is integrated with the heat exchanger core, and the flow volume is almost the same as that of the conventional example (FIG. 11). There is no adverse effect on

<< Second Embodiment (FIG. 3) >> FIG.
1 shows an external configuration of the embodiment. In the second embodiment, the ratio of the length and the number of the flow path 1 to the flow path 2 is greatly different from that of the first embodiment. Further, the first embodiment is used in a state where a total of four header tanks are provided at the inlet / outlet portions of each of the flow paths 1 and 2, whereas the second embodiment uses the flow path 1 The header tank 7 is provided only at the entrance / exit portion of the
The inlet and outlet are used in an open state. Second
Flow path 2 is forced into a second
Refrigerant (air) B is circulated. Here, the refrigerant A is a high-temperature refrigerant and the refrigerant B is a low-temperature refrigerant.
May be a low-temperature refrigerant and the refrigerant B may be a high-temperature refrigerant.

<< Third Embodiment (FIG. 4) >> FIG.
2 is an enlarged view of a cross-sectional structure of a main part of a heat exchanger core part according to the embodiment. The third embodiment is configured in the same manner as the first embodiment except that a guide 9 is provided instead of the perforated plate 5 in the first embodiment. The guide 9 is provided so as to surround the side wall of the other flow path 2 or 1 (that is, the spacer bar 4) so as to regulate the flow of the refrigerant A or B at the inlet or outlet of one flow path 1 or 2. The guide 9 and the back air layer 6 constitute the above-described resonance type sound absorbing structure. Although the guide 9 has a shape obtained by bending the perforated plate 5 into a dogleg shape, the equation (1) can be applied similarly to the first embodiment. A noise reduction effect by resonance absorption similar to the embodiment can be obtained.

In the structure in which the flow paths 1 and the flow paths 2 are alternately stacked so as to be orthogonal to each other, the refrigerants A and B are retained while maintaining the function as the perforated plate 5 in the first embodiment. Since the function as the guide 9 for adjusting the flow can be realized, the refrigerants A and B can be smoothly guided into the flow paths 1 and 2 along the guide 9. Therefore, the resistance at the inlet portions of the flow paths 1 and 2 and the friction loss at the inlet / outlet portions are reduced, and the collision of the refrigerants A and B with the spacer bar 4 and the guide 9 at the inlet portions of the flow paths 1 and 2. The generation of noise (collision noise) due to this can be suppressed. In addition,
The shape of the guide 9 is not limited to the dogleg shape, and may be a shape curved in a semicircle.

<< Fourth Embodiment (FIG. 5) >> FIG.
2 is an enlarged view of a cross-sectional structure of a main part of a heat exchanger core part according to the embodiment. The fourth embodiment is characterized in that the porous sound absorbing material 10 is attached to a part of the sound absorbing structure, and that the porous sound absorbing material 10 is attached to the back surface of the perforated plate 5. The configuration is the same as that of the first embodiment.
Therefore, the same noise reduction effect by resonance absorption as in the first embodiment can be obtained, and the resonance frequency f ₀ can be obtained by the porous sound absorbing material 10 located immediately behind the perforated plate 5.
And a wide frequency of sound absorption centered on.

The fourth embodiment is similar to the first embodiment.
A part of the back air layer 6 in FIG.
The porous sound absorbing material 10 is filled in the entire internal space of the sound absorbing structure (that is, the entire back air layer 6), so that the sound absorbing structure is formed by the perforated plate 5 and the porous sound absorbing material 10. May be configured. Third Embodiment
A porous sound absorbing material 10 may be used for the sound absorbing structure in FIG. In that case, the porous sound absorbing material 10 may be attached to the back surface of the U-shaped guide 9 or the porous sound absorbing material 10 may be filled in the back air layer 6.

<< Fifth Embodiment (FIG. 6) >> FIG.
2 is an enlarged view of a cross-sectional structure of a main part of a heat exchanger core part according to the embodiment. Fifth embodiment is characterized in that it has a resonance frequency f ₀ of the sound absorbing structure is different for each stage, other are configured similarly to the first embodiment. FIG.
Is a perforated plate 5a provided on the side wall of the flow path 2.
By changing the number n of holes between the hole and the perforated plate 5b provided on the side wall portion of the flow path 2 located therebelow, the resonance frequency f ₀ of the sound absorbing structure at each stage is made different. an example is shown, other elements (perforated plate 5a constituting the sound absorbing structure, 5b of the plate thickness t, the area S ₀ of the hole, back air layer 6
May be changed. According to the fifth embodiment, a noise reduction effect due to resonance absorption similar to that of the first embodiment can be obtained, and a plurality of resonance-type sound absorbing structures having different resonance frequencies f ₀ for each stage can be used. It is possible to reduce frequency noise.

<< Sixth Embodiment (FIG. 7) >> FIG.
2 is an enlarged view of a cross-sectional structure of a main part of a heat exchanger core part according to the embodiment. The sixth embodiment is characterized in that the sound absorbing structure has a different resonance frequency f ₀ along the flow direction of the flow path, and the other configuration is the same as that of the first embodiment. 7, by changing along the area S ₀ of the number n and the bore hole of the perforated plate 5c provided on the side wall of the channel 2 in the flow path 2 flow direction, the resonance of the sound absorbing structure Although an example in which the frequency f ₀ is partially changed is shown, other elements constituting the sound absorbing structure (the thickness t of the perforated plate 5c, the air layer
May be changed. According to the sixth embodiment, a noise reduction effect by resonance absorption similar to that of the first embodiment can be obtained, and a resonance type sound absorbing structure having a different resonance frequency f ₀ along the flow direction of the flow path can be obtained. In addition, it is possible to reduce noise of a plurality of frequencies.

<< Seventh Embodiment (FIGS. 8 to 10) >> FIG.
Next, a vertical sectional structure of the seventh embodiment is shown. The feature of the seventh embodiment is that a header tank 7 is provided so as to cover the inlet and outlet portions of the first flow path 1 and the second flow path 2, and a sound absorbing structure is provided in the header tank 7. It is in. This sound absorbing structure is a resonance type sound absorbing structure that absorbs a sound near a resonance frequency by resonance absorption, and a noise generated from a heat exchanger (for example, a collision sound generated when a refrigerant or outside air passes through the heat exchanger). , Rapid expansion of the flow path at the pipe connection
Among the frequency components of the noise generated by the reduction, the frequency having a particularly high level is configured to coincide with the resonance frequency.

Although the shape of each header tank 7 is a simple box, the internal structure is different between the inlet side and the outlet side. A diffuser 11 made of a perforated plate (may be a sound absorbing material) as shown in FIG. 9 is fitted in the header tank 7 covering the inlet portions of the flow paths 1 and 2.
In the header tank 7 covering the outlets of the flow paths 1 and 2,
A nozzle 12 made of a perforated plate (may be a sound absorbing material) as shown in FIG. 10 is fitted therein. Diffuser 11
Or the nozzle 12 and the diffuser 11 or the nozzle 12
The space surrounded by the inner wall of the header tank 7 constitutes a sound absorbing structure.

The space surrounded by the diffuser 11 or the nozzle 12 and the inner wall of the header tank 7 corresponds to the back air layer 6 in the first embodiment. That is, in the header tank 7 on the inlet side, the space on the right side of the diffuser 11 shown in FIG. 8 corresponds to the back air layer 6, and in the header tank 7 on the outlet side, the space on the left side of the nozzle 12 shown in FIG. Since it corresponds to the layer 6 and the equation (1) can be applied in the same manner as in the first embodiment, the same noise reduction effect by resonance absorption as in the first embodiment can be obtained. In addition, a plurality of frequency noises can be reduced by changing the resonance frequency of each part by partially changing each element (the diameter d of the hole of the diffuser 11, the nozzle 12 and the like) constituting the sound absorbing structure. Furthermore, Paste or porous sound absorbing material in a sound absorbing structure, or by filling, it is possible to reduce the noise of wide frequency range around the resonance frequency f _0.

[0033] The diffuser 11 and the nozzle 12 installed in the header tank 7 allow the flow path 1 and the pipe 1 to pass from the pipe outlet.
Since the flow path to the inlet 2 and the flow path from the outlet of the flow paths 1 and 2 to the pipe inlet can be gently connected, the pressure loss in the header tank 7 can be reduced.
In the header tank 7 on the inlet side, a sound absorbing structure is formed by the diffuser 11 having a shape gradually expanding from the pipe outlet. Since the sound absorbing structure is configured by the nozzle 12 having a shape that gradually narrows to the suction port, it is possible to suppress the generation of noise due to the sudden expansion and contraction of the flow path at the pipe connection.

In the seventh embodiment, since the configuration uses a total of four header tanks 7, the first, third, and third header tanks are used.
It is possible to use the heat exchanger cores used in the fourth, fifth, and sixth embodiments (FIGS. 1, 2, and 4 to 7) and the conventional example (FIG. 11). In the case where one of the flow paths 2 is opened as in the second embodiment (FIG. 3), the diffuser 1 is used only for the other flow path 1.
1, a header tank 7 having a nozzle 12 may be used.

[0035]

As described above, according to the first to fifth aspects of the present invention, since the sound absorbing structure is provided in the side wall portion of the flow passage or in the header tank, the refrigerant and the outside air pass through the heat exchanger. It is possible to reduce the noise generated when the flow path suddenly expands or contracts at the pipe connection part, or the collision noise that sometimes occurs.

According to the second aspect, the resonance type sound absorbing structure is formed by a guide provided so as to surround the side wall of the other flow path so as to regulate the flow of the refrigerant at the inlet or the outlet of one flow path. Because it is configured, it has the effect of reducing the resistance at the inlet of the heat exchanger and the friction loss at the inlet / outlet, and the refrigerant flowing to the side wall and the guide at the inlet of the heat exchanger. The effect of suppressing the generation of noise due to the collision is obtained.

According to the third aspect of the present invention, since the sound absorbing material is affixed or filled to a part of the sound absorbing structure, it is possible to reduce noise in a wide frequency range around the resonance frequency. Further, according to the fourth aspect, since the sound absorbing structure having a different resonance frequency for each stage is provided, noise at a plurality of frequencies can be reduced. According to the fifth aspect, since the sound absorbing structure is provided in the header tank, a pressure loss reducing effect can be obtained in addition to the noise reducing effect.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic structure of a heat exchanger core according to a first embodiment.

FIG. 2 is an enlarged view showing a main structure of a longitudinal section taken along line XX of FIG. 1;

FIG. 3 is a perspective view illustrating an appearance of a second embodiment.

FIG. 4 is an enlarged view showing a cross-sectional structure of a main part of a heat exchanger core according to a third embodiment.

FIG. 5 is an enlarged view showing a main part cross-sectional structure of a heat exchanger core according to a fourth embodiment.

FIG. 6 is an enlarged view showing a cross-sectional structure of a main part of a heat exchanger core according to a fifth embodiment.

FIG. 7 is an enlarged view showing a main part cross-sectional structure of a heat exchanger core part according to a sixth embodiment.

FIG. 8 is a sectional view showing a longitudinal sectional structure according to a seventh embodiment.

FIG. 9 is a perspective view showing a diffuser installed in a header tank in a seventh embodiment.

FIG. 10 is a perspective view showing a nozzle installed in a header tank in a seventh embodiment.

FIG. 11 is a perspective view showing a schematic structure of a core part of a conventional plate-fin heat exchanger.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st flow path 1a 1st fin A 1st refrigerant | coolant (high temperature refrigerant) 2 2nd flow path 2a 2nd fin B 2nd refrigerant | coolant (low temperature refrigerant) 3 Tube plate 4 Spacer (flow path side wall) 5) Perforated plate 5a Perforated plate 5b Perforated plate 5c Perforated plate 6 Behind air layer 7 Header tank 8 Piping 9 Guide 10 Porous sound absorbing material 11 Diffuser 12 Nozzle

Claims (5)

[Claims] 1. A first flow path for flowing a first refrigerant and a second flow path for flowing a second refrigerant are alternately stacked in a plurality of layers at right angles, and the first refrigerant and the second A plate fin type heat exchanger configured to perform heat exchange with a second refrigerant, wherein a sound absorbing structure is provided on a side wall portion of the first or second flow path. Exchanger. 2. The resonance type sound absorbing structure according to claim 1, wherein the sound absorbing structure includes a guide provided so as to surround a side wall of the other flow path so as to regulate a flow of the refrigerant at an inlet or an outlet of one flow path. The plate fin type heat exchanger according to claim 1, wherein 3. The plate fin type heat exchanger according to claim 1, wherein a sound absorbing material is attached or filled to a part of said sound absorbing structure. 4. The sound absorbing structure according to claim 1, wherein the sound absorbing structure is provided in a plurality of stages of the first or second flow path, and each stage has a different resonance frequency.
The described plate-fin heat exchanger. 5. A first flow path for circulating a first refrigerant and a second flow path for circulating a second refrigerant are alternately and orthogonally stacked in a plurality of stages, and the first refrigerant and the second refrigerant are stacked one upon another. In a plate-fin heat exchanger configured to perform heat exchange with a second refrigerant, a header tank is provided so as to cover an inlet or an outlet of the first or second flow path, and the inside of the header tank is provided. A plate fin type heat exchanger characterized by having a sound absorbing structure.