JP2001248996A - Plate type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact shell-and-plate type heat exchanger in which a heat transferring performance is improved. SOLUTION: There is provided a heat exchanger in which heat transferring plates 12 having holes 13 acting as fluid inlets and fluid outlets at their corner portions are overlapped to each other and stored in a container 11 and fluid is made to flow in flow passages formed between the heat transferring plates to perform a heat exchanging operation between fluids, wherein a pair of flow passages are formed by orthogonal flow passages in the flow passages formed by connecting the holes 13 at the corners between the laminated layers, one pair of flow passages and the other pair of flow passages formed between the heat transfer plates are communicated to each other to form a first flow passage where the first fluid flows, the other pair of flow passages and the other flow passages between the laminated heat transferring plates are communicated to each other to form the second flow passage where the second fluid flows and there is provided a means for closing the flow passages at the midway of each of the flow passages formed by the holes 13 in these first and second flow passages.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plate heat exchanger, and more particularly to a plate heat exchanger used as a solution heat exchanger of an absorption refrigerator.

[0002]

2. Description of the Related Art Conventionally, a plate-type heat exchanger (hereinafter referred to as a shell-and-plate type) constructed by housing stacked heat transfer plates in a container (shell) as described in JP-A-7-229687. Plate heat exchanger). This will be described with reference to FIG.

FIG. 1 is a sectional view of a fluid inlet / outlet pipe of a plate heat exchanger. A plurality of heat transfer plates 2 having irregularities are stacked in the container 1, and a gap formed therebetween forms a flow path so that fluid flows, and is adjacent to the heat transfer plate 2. Two types of fluids that exchange heat at different temperatures flow through the layer. The heat transfer plate 2 has a hole 3 for guiding or discharging a fluid to the flow path, and is connected to a pipe 4 serving as an inlet or an outlet. Inner circumference 5 of hole 3, heat transfer plate 2
Is welded to the outer periphery 6, the joint 7 between the hole 3 and the pipe 4, and two kinds of passages are formed so that two kinds of fluids having different temperatures are not mixed. The welding here uses plasma welding, so that the welded portion can be made of the same metal.

[0004] As plate heat exchangers other than the shell and plate method, heat transfer plates are stacked one by one with packing, and the whole is fastened with bolts, or all the stacked heat transfer plates are brazed. There is a sealing method. Since the method of sealing the fluid with packing or brazing material does not have a container, the sealing of the fluid to the outside is performed by the packing or brazing material and the heat transfer plate, so that the fluid is reliably sealed for a long time. Not considered.

[0005] In particular, in the solution heat exchanger of the absorption refrigerator, since the machine must be kept in a vacuum state, there must be no intrusion of air, and the solution of the absorption refrigerator generally has an odor. Lithium chloride aqueous solution is used, and this solution is highly corrosive, and is used at a high temperature of 160 ° C., and requires hermeticity under severe conditions. In the method using packing, it is necessary to consider heat resistance and durability of the packing, and cannot be used for heat exchange of a high-temperature fluid. In the method using a brazing material, since the brazing material and the heat transfer plate are dissimilar metals, a potential difference is generated, so that corrosion easily proceeds.

As a countermeasure, there is a method of using a high corrosion-resistant material for the heat transfer plate and the brazing material, but this increases the cost. For this reason, it is difficult to use a brazing material in a heat exchanger for a highly corrosive fluid. In the shell and plate method, the same metal is joined by using plasma welding for joining the heat transfer plates, so that corrosion due to a potential difference does not occur. In addition, since the container seals the fluid to the outside and a thick plate is used for the container, highly reliable sealing can be achieved even with inexpensive materials.

Further, since the heat transfer plate does not need to be sealed to the outside, no stress is applied due to a pressure difference between the fluid and the outside, and the heat transfer plate is made of a thin plate made of an inexpensive material. Can be. When the heat transfer plate can be made thinner,
Not only the manufacturing cost is reduced, but also the thermal resistance in performing heat exchange via the heat transfer plate is reduced, resulting in an efficient heat exchanger. For this reason, the shell-and-plate method is used when a high-temperature corrosive fluid is used as in an absorption refrigerator, and is also used in a plate heat exchanger requiring hermeticity.

[0008]

In the conventional plate heat exchanger of the shell-and-plate type, the fluid flows through the container in only one pass, and the fluid does not flow back. For this reason, in order to increase the heat exchange capacity, the number of stacked heat transfer plates has been increased. The heat exchange capacity of the heat exchanger is determined by the product of the heat transfer coefficient and the heat transfer area.
Since the heat transfer area is proportional to the number of heat transfer plates, the heat exchange capacity can be improved by increasing the number of heat transfer plates. When the number of heat transfer plates is increased, the flow rate to one flow path interposed between the heat transfer plates decreases, and the flow velocity of the fluid decreases. The heat transfer coefficient of a fluid depends on the flow rate, and the heat transfer rate increases as the flow rate increases. However, when the number of heat transfer plates is increased, the heat transfer rate is reduced due to a decrease in the flow velocity, so that the heat exchange capacity does not improve as the heat transfer area increases.
For this reason, the plate-type heat exchanger of the shell-and-plate type having only one pass cannot improve the heat exchange capacity using the heat transfer plate effectively.

In a plate heat exchanger of a type in which a fluid is sealed with a packing or a brazing material, since the heat transfer coefficient is improved by forming the flow in the heat exchanger into a multi-stage path, a plate having no holes is used. A method of sandwiching in the middle is used.

[0010] However, in the plate heat exchanger of the shell and plate type, since the bag-shaped heat transfer plates are welded while being laminated, if there is a plate with no holes, the flow path below the plate is not formed. The hole became invisible and welding of the hole could not be performed.

For this reason, the plate heat exchanger of the shell-and-plate type has been able to form only one pass.

An object of the present invention is to improve the heat exchange capacity by flowing a fluid in a multi-stage path, and to provide a compact plate heat exchanger.

[0013]

Means for Solving the Problems In order to solve the above problems, the configuration of the invention of the plate heat exchanger according to the present invention is as follows.
A heat transfer plate having a hole serving as a fluid inlet or outlet at the corner is overlapped, the periphery is joined to form a bag, the bag-shaped heat transfer plates are stacked and stored in a container, and the heat transfer plate In a plate-type heat exchanger in which a fluid flows through a flow path formed to exchange heat between the fluids, among the flow paths formed by connecting the holes at the corners between the laminations, a diagonal flow path is formed. A pair of flow paths is formed, and one of the pair of flow paths and one of the flow paths formed between the heat transfer plates are communicated with each other to form a first flow path of the first fluid. Forming a flow path, and communicating the other pair of flow paths with the other flow path between the stacked heat transfer plates to form a second flow path through which a second fluid flows; A means for closing the flow path is provided in the middle of each flow path formed by the hole of the second flow path,
By changing the direction of the flow, the flow path is configured in multiple stages.

[0014] Preferably, the means for closing the flow path is performed by closing the first flow path with a heat transfer plate.
In this case, a closing plate for closing the hole of the heat transfer plate is attached to the bag-like heat transfer plate.

Preferably, the closing plate has a notch and is fixed to a hole of the heat transfer plate with a plate smaller than the hole interposed between plates larger than the hole.

In another aspect of the plate heat exchanger according to the present invention, a heat transfer plate having a hole serving as a fluid inlet or outlet at a corner portion is overlapped, and the periphery thereof is joined to form a bag. In the plate heat exchanger in which the bag-shaped heat transfer plates are stacked and stored in a container, and a fluid flows through a flow path formed between the heat transfer plates to perform heat exchange between the fluids, Of the flow paths formed by connecting the holes between the laminations, a pair of flow paths is formed at diagonal flow paths, and one of the pair of flow paths, and between the heat transfer plates. A first flow path through which a first fluid flows is formed by communicating with one of the formed flow paths, and the other pair of flow paths and the other flow path between the stacked heat transfer plates are communicated with each other. This forms a second flow path through which the second fluid flows, and is formed by the holes of the first and second flow paths. A means for closing the flow path is provided in the middle of each flow path, the flow direction is changed and the flow path is configured in multiple stages, and between any of the heat transfer plates before and after the means for closing the flow path. The flow path is provided with a means for narrowing the flow path to restrict the flow rate.

[0017] Preferably, the means for restricting the flow rate is such that a flow rate adjusting ring is fitted into a hole serving as a fluid inlet or outlet at a corner.

In still another embodiment of the plate heat exchanger according to the present invention, a heat transfer plate having a hole serving as a fluid inlet or outlet at a corner is overlapped, and the periphery is joined to form a bag. In the plate heat exchanger in which the bag-shaped heat transfer plates are stacked and stored in a container, and a fluid flows through a flow path formed between the heat transfer plates to perform heat exchange between the fluids, Of the flow paths formed by connecting the holes between the laminations, a pair of flow paths is formed at diagonal flow paths, and one of the pair of flow paths, and between the heat transfer plates. A first flow path through which a first fluid flows is formed by communicating with one of the formed flow paths, and the other pair of flow paths and the other flow path between the stacked heat transfer plates are communicated with each other. To form a second flow path through which the second fluid flows, formed by the holes of the first and second flow paths. In the middle of each flow path, a means for closing the flow path is provided to change the direction of flow to form a multi-stage flow path, and at the corner of the outermost heat transfer plate of the heat transfer plate, a fluid inlet is provided. Or a hole that becomes an exit, and
A hole is provided at a position higher than the diagonal corner, and a flow path for discharging gas accumulated in the container is provided.

Preferably, the flow path for discharging the gas is connected to an outlet of a fluid from a heat exchanger.

Preferably, the heat transfer plate is formed by laminating plates each having an inclined corrugated surface so that the corrugations cross each other.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are sectional views of a first embodiment of a plate heat exchanger according to the present invention. FIG.
FIG. 4 is a plan view of a heat transfer plate veneer, and FIG. 4 is a view showing a state in which heat transfer plate veneers are superposed. FIG. 5 is a schematic diagram showing the flow of the fluid in the plate heat exchanger. FIG. 1 is a cross-sectional view at section (1), and FIG. 2 is a cross-sectional view at section (2). FIG.
FIG. 4 is a diagram showing an example in which a plate heat exchanger is configured with three heat exchange stages (three-pass system), and showing the flow of fluid in each heat exchange stage.

First, an outline of the flow of the fluid will be described with reference to FIGS. FIG. 5 shows T-plate heat exchanger.
This shows a state where two types of fluids (first fluid and second fluid) indicated by i and To enter and exit.

FIG. 6 shows the flow of fluid in a plate heat exchanger composed of three heat exchange stages. The first fluid (indicated by a solid line) enters the heat exchanger at a temperature Ti1 and has one stage. When passing through the second heat exchange stage P1, the temperature becomes Ti2, when passing through the second heat exchange stage P2, the temperature becomes Ti3, and after passing through the third heat exchange stage P3, the temperature becomes Ti4, Effluent from the heat exchanger.

The second fluid (indicated by a broken line) flows in the opposite direction (counterflow) to the first fluid, enters the heat exchanger from the first heat exchange stage P1 at the temperature To1, and enters each heat exchange stage. P2, P3
, And flows out of the heat exchanger at temperatures To2, To3, and To4. Each fluid flows from one hole provided at the four corners to the other hole located diagonally.

A specific configuration for realizing the flow of the fluid shown in FIG. 6 will be described with reference to FIGS.
The container 11 contains the heat transfer plates 12 stacked in multiple layers. On this heat transfer plate 12, two types of plates 12 (1) and 12 (2) shown in FIG. 3 are joined and alternately laminated on a bag as shown in FIG. Holes 13 are provided at the four corners of the heat transfer plate 12, and corrugated irregularities 14 are formed in the center at an angle in different directions,
A flange 15 is formed on the outer periphery. The holes 13 have a difference in height. One diagonal hole 13A is formed high, and the other diagonal hole 13B is formed low. When these heat transfer plates 12 are overlapped, the cross section (3) and the cross section (4) are as shown in FIG. The outer periphery of the two superposed heat transfer plates 12 and the inner periphery of the hole 13 that contacts when the heat transfer plates 12 are stacked are joined by plasma welding or the like to form a bag.

The stacked heat transfer plates 12 are housed in a container 11. The closing plate 16 is configured as shown in FIG. 8 described later, and is attached to two locations 16 </ b> A of one diagonal hole 13 to close the hole 13. At two places (16B) of the other diagonal hole 13, the hole 13 is closed without using a closing plate by using the heat transfer plate 12 that does not open. The reason for providing two locations is to configure three heat exchange stages.

Flow control rings (flow control members) 17 to 24 for controlling the fluid flow are fitted in the holes 13i and 13o at the positions 16A and 16B on the inflow side or the outflow side. Hereinafter, the flow state will be described with the flow path formed by the hole 13 through which the first fluid Ti flows as the hole 13i and the flow path formed by the hole 13 through which the second fluid To flows as the hole 13o.

The fluid Ti flowing inside the bag-shaped heat transfer plate 12 flows into the heat exchanger at a temperature Ti1 (shown by a solid line). The fluid Ti that has flowed through the holes 13i (1) of the heat transfer plate 12 has its flow path closed by the closing plate 16A, changes its direction, and flows obliquely from the near side through the first heat exchange stage P1. The fluid Ti flowing diagonally through the holes 13 of the heat transfer plate 12 changes from the temperature Ti1 to the temperature Ti2 by heat exchange. The fluid Ti that has reached the temperature Ti2 is the hole 1
Although flowing through 3i (2), the flow path is closed by the closing plate 16A, the flow direction is changed, and flows from the side facing the second heat exchange stage P2 to the front. The fluid Ti that has changed from the temperature Ti2 to the temperature Ti3 by flowing through the second heat exchange stage P2 flows into the third heat exchange stage P3 through the hole 13i (3). The temperature of the fluid Ti changes from Ti3 to Ti4 by flowing through the third heat exchange stage P3, and flows out of the heat exchanger through the holes 13i (4).

Similarly, the fluid To flowing outside the bag-shaped heat transfer plate 12 flows into the heat exchanger at the temperature To1 (shown by a broken line). The flow of the fluid To flowing through the hole 13o (1) of the heat transfer plate 12 is closed by the closing plate 16B, the flow direction is changed, and the first heat exchange stage P1 (fluid T
(In i, it is the third stage). The fluid To that has changed from the temperature To1 to the temperature To2 by passing through the first heat exchange stage P1 for the fluid To flowing outside the bag flows into the second heat exchange stage P2 through the hole 13o. . The flow path of the fluid To is closed by the closing plate 16B, the flow direction is changed from the near side to the obliquely opposite side, and flows through the second heat exchange stage P2. The fluid To that has changed from the temperature To2 to the temperature To3 by flowing through the second heat exchange stage P2 flows into the third heat exchange stage P3 through the hole 13o (3). The temperature of the fluid To changes from To3 to To4 by flowing through the third heat exchange stage P3,
o (4) exits the heat exchanger.

The second heat exchange stage P2 for the fluid Ti flowing inside the bag and the third heat exchange stage P3 for the fluid To flowing outside the bag,
It flows in parallel inside and outside the bag with (3) in between. It is preferable to reduce the flow rate of the fluids flowing in parallel because the temperature difference is reversed and internal heat loss occurs.

Therefore, in the present embodiment, the fluid T inside the bag is
As means for reducing the flow rate of i, a flow rate adjusting ring 17 is fitted at the inlet and a flow rate adjusting ring 18 is fitted at the outlet.
As means for reducing the flow rate of the fluid To outside the bag,
A flow rate adjusting ring 19 is fitted into the inlet and a flow rate adjusting ring 20 is fitted into the outlet.

Similarly, the third heat exchange stage P3 for the fluid Ti flowing inside the bag and the fluid T flowing outside the bag
The second heat exchange stage P2 for o flows in parallel inside and outside the bag with the heat transfer plate 12 (4) interposed therebetween. As means for reducing the flow rate of the fluid Ti inside the bag in the portion flowing in parallel, a flow rate adjusting ring 21 is fitted at the inlet and a flow rate adjusting ring 22 is fitted at the outlet. As a means for reducing the flow rate of the fluid To outside the bag, a flow rate adjusting ring 23 is fitted at the inlet and a flow rate adjusting ring 24 is fitted at the outlet.

FIG. 7 is a schematic diagram showing the temperature distribution in each heat exchange stage. In the case where the temperature of the fluid Ti flowing inside the bag is higher than the temperature of the fluid To flowing outside the bag, the internal temperature is taken as an example. The cause of the heat loss will be described.

When the fluid Ti flowing inside the bag passes through the second heat exchange stage P2, the temperature changes from Ti2 to Ti3,
When the fluid To flowing outside the bag passes through the third heat exchange stage P3, the temperature changes from the temperature To3 to To4. However, at the boundary between the heat exchange stages P2 and P3, the temperature from Ti2 to Ti3
And the flow from temperature To3 to To4 is parallel and flows in contact with one heat transfer plate 12 (3). The relationship between temperature Ti2 and temperature To3 is normal, but the relationship between temperature Ti3 and To4 is reversed from the direction in which heat exchange is desired. For a heat exchanger with low temperature efficiency, T
Since the temperature difference between o4 and Ti1 widens, To4 becomes Ti3
Although the temperature becomes lower and the reversal of the temperatures Ti3 and To4 does not occur, this reversal of the temperature becomes remarkable when the temperature efficiency becomes higher.

As shown in the temperature distribution of FIG. 7, when heat is exchanged with high temperature efficiency, heat flows from the temperature of To4 to the temperature of Ti3, and the heat transfer plate 12 (at the boundary between the heat exchange stages P2 and P3). Fluids Ti and To flowing in contact with 4) have temperatures Ti3 'and To4', respectively. As a result, the internal heat loss is caused by the inverted temperature relationship between the temperature To4 'and the temperature Ti3' as the driving force.

Similarly, when the fluid Ti flowing inside the bag changes from the temperature Ti3 to Ti4 and the fluid To flows outside the bag changes from the temperature To2 to To3, one heat transfer plate 12 (4) at the boundary portion. Flows in parallel in contact with. The relationship between the temperature Ti4 and the temperature To3 is opposite to the direction in which heat exchange is desired. Therefore, heat flows from the temperature of To3 toward the temperature of Ti4, and the fluid flowing in contact with the heat transfer plate 12 (4) at the boundary between the heat exchange stages P3 and P2 has a temperature of Ti4 '.
And the temperature To3 '. As a result, an inverted temperature relationship between the temperature To3 'and the temperature Ti4' becomes a driving force, and an internal heat loss occurs.

The position 16B in FIG. 1 and the position 16B in FIG. 2 are locations for closing the flow path of the fluid To flowing outside the bag, and are closed by using the heat transfer plate 12 that does not open. Further, the position 16A and the position 16A in FIG. 2 are locations where the flow path of the fluid Ti flowing inside the bag is closed, and after the bag-shaped heat transfer plate 12 is laminated, the closing plate 16 is attached to the heat transfer plate 12. Attach.

FIGS. 8A and 8B are diagrams showing the construction of the closing means for closing the hole, wherein FIG. 8A is an assembled view and FIG. 8B is a developed view. Closure plate 16
(1) and 16 (2) are disks having a diameter larger than the hole 13 of the heat transfer plate 12, and are provided with a hole 26 for passing the bolt 25 at the center and a notch 27 in the radial direction.
The closing plate 16 (3) is a disk having a diameter slightly smaller than the hole 13 of the heat transfer plate 12, and has only a hole 26 for passing the bolt 25 at the center.

FIG. 3 shows a portion where the flow path of the fluid Ti flowing inside the bag is formed by laminating the heat transfer plates 12, and the inner periphery 5 of these holes 13 is subjected to plasma welding. Thus, the fluids Ti and To inside and outside the bag are not mixed. Since the sealing of the fluids Ti and To cannot be maintained only by attaching the closing plate 16, the attaching of the closing plate 16 is performed after the inner periphery 5 is joined. The notch 27 of the closing plates 16 (1) and 16 (2) is for passing a plate having a diameter larger than the hole 13 of the heat transfer plate 12. Due to the presence of the notch 27, a plate having a larger diameter than the hole 13 can be fitted after the heat transfer plate 12 is laminated, and the hole 12 is closed by the closing plates 16 (1), 16 (16).
It can be closed by sandwiching it in (2). Closure plate 16
(3) positioning with respect to the hole 13 and the fluid Ti, To
It is installed to reduce the leakage. These closing plates 16 (1) to 16 (3) are fastened and fixed by bolts 25 and nuts 28.

Further, by joining the nut 28 to the closing plate 16 (1), it is not necessary to hold the nut 28 by hand, and the bolt and nut can be easily fastened only by working from the bolt 25 side. I can do it.

The flow channel 29 in FIG. 1 is for extracting gas contained in the fluid Ti flowing inside the bag, and as shown in FIG.
, The gas is always exhausted. Also,
The flow path 31 is for extracting gas contained in the fluid To flowing outside the bag, and as shown in FIG. 5, the gas is constantly discharged by being connected to the outlet fluid To by a pipe 32.

In FIG. 2, position 16B is where the fluid To flowing outside the bag enters the heat exchanger and first changes the direction of the flow, and directly regulates the discharge pressure of the pump for flowing the fluid. It is a place to receive. Therefore, position 1
Although the member for closing the hole 13 in 6B requires some strength, the position 16B can maintain the strength against the pump pressure because the two heat transfer plates 12 having no holes are overlapped.

The position 16A is a place where the fluid Ti flowing inside the bag flows into the heat exchanger and changes the direction of the flow first. Like the position 16B, the discharge of the pump for flowing the fluid is performed. It is a place that receives pressure directly. For this reason, a certain degree of strength is required to close the hole 13 at the position 16A, but the closing means shown in FIG.
6 (1) and 16 (2) have strength, and the closing plates 16 (1) and 16 (2) can be thicker than the heat transfer plate 12. , Sufficient strength against the pump pressure can be maintained.

According to the present embodiment described above, in a shell-and-plate type plate heat exchanger in which a heat transfer plate is housed in a container, the heat transfer plate is configured in a multi-stage path to achieve The flow rate can be increased and the heat transfer coefficient can be improved as compared with the case of the pass, and the heat exchange capacity can be improved by effectively using the heat transfer plate.

When the fluid outside the bag-shaped heat transfer plate is not sealed, it may flow to the heat exchanger outlet after passing through the first heat exchange stage, or may flow from the heat exchanger inlet. Although the flow directly enters the third heat exchange stage, a flow that shortcuts the heat exchange stage is generated. In the present embodiment, the periphery of the bag-shaped heat transfer plate is stacked in contact. Therefore, the fluid outside the bag is also sealed, so that the flow that short-circuits the heat exchange stage can be suppressed. Therefore, each heat exchange stage works effectively, and the heat exchange capacity is improved.

Further, in the case of a plate-type heat exchanger having a high temperature efficiency by using a multi-stage path configuration, the temperature difference is reversed at the boundary of the heat exchange stage, causing an internal heat loss. By reducing the flow velocity of the fluid flowing through the boundary, the heat transfer coefficient of the fluid is reduced, and heat loss that is lost can be suppressed. Although the internal heat loss causes a decrease in heat exchange capacity, the heat loss is reduced and the heat exchange capacity is improved by lowering the heat transfer coefficient of the portion that is lost due to the reduction in the flow rate.

In the flow path at the boundary of the heat exchange stage, the corrosion inhibitor cannot be flowed unless a fluid is flowed at all, so that the corrosion easily proceeds and the heat transfer plate is not effectively used. Therefore, by flowing a reduced flow rate to the flow path at the boundary of the heat exchange stage, corrosion can be suppressed and the heat transfer plate can be used effectively.

FIGS. 9 and 10 are sectional views of a second embodiment of the plate heat exchanger according to the present invention. FIG. 9 is a sectional view (1) of the plate heat exchanger shown in FIG. (2) is shown in FIG. In this embodiment, a case where no gas vent channel is provided is shown.

This embodiment is different from the first embodiment in the way the fluid flows at the boundary of the heat exchange stage. That is,
In the first embodiment, the flow rates of both fluids flowing in contact with the heat transfer plate at the boundary of the heat exchange stage are reduced. In the present embodiment, the flow rate of only one fluid is reduced.

In the figure, a bag-like heat transfer plate 1 is shown.
2 flows into the heat exchanger at the temperature Ti1, passes through the first heat exchange stage P1, and passes through the hole 13i (2).
And flows through the second heat exchange stage P2. In the first embodiment, the flow rate of the fluid Ti inside the bag that flows in contact with the heat transfer plate 12 (3) is reduced, but this is not performed in the present embodiment.

However, for the fluid To outside the bag, which flows in contact with the heat transfer plate 12 (3), the flow rate is sufficiently reduced by using the flow rate adjusting ring 34. On the other hand, when the fluid To flowing inside the bag flows through the third heat exchange stage P3, the heat transfer plate 12 (4) becomes a boundary of the heat exchange stage. In this case, the heat transfer plate 12 (4) The flow Ti of the fluid Ti inside the bag flowing in contact with the heat transfer plate 12 (4) is sufficiently reduced using the flow rate adjusting ring 34, and the flow rate of the fluid To outside the bag flowing in contact with the heat transfer plate 12 (4) is not adjusted. By reducing the number of flow paths for reducing the flow rate, the number of heat transfer plates to be used can be reduced, the manufacturing can be performed at low cost, and the heat exchanger can be made compact.

According to the present embodiment, it is possible to provide a low-cost and compact plate heat exchanger while improving the heat exchange capacity.

FIGS. 11 and 12 are sectional views of a third embodiment of the plate heat exchanger according to the present invention. FIG. 11 is a sectional view (1) of the plate heat exchanger shown in FIG. (2)
Is shown in FIG. This embodiment also shows a case where no gas vent channel is provided.

This embodiment differs from the first and second embodiments in the means for closing the flow path of the fluid Ti flowing inside the bag. In the present embodiment, in order to close the flow path of the fluid in the bag, the closing plates 35 and 36 are interposed between the bag-shaped heat transfer plates 12.
And the heat transfer plate 12 is bonded thereto. Further, since the closing plates 35 and 36 are placed between the bag-shaped heat transfer plates 12, the closing plates 35 and 3 are placed between the bag-shaped heat transfer plates 12.
An extra gap is created by the thickness of 6. Heat transfer plate 12
If the gap between the heat transfer plates 39 and 4 is not larger than the others, efficient heat exchange cannot be performed.
0 is set, and the flow is divided into a heat transfer passage having a normal gap and a passage having a gap corresponding to the plate thickness of the closing plates 35 and 36.

The closing plate 35 separates the first heat exchange stage P1 and the second heat exchange stage P2 for the fluid Ti inside the bag, and separates the upper and lower bag-like heat transfer plates 12 from each other. The hole 13 and the closing plate 35 are joined to prevent fluid in the bag from leaking out of the bag.

Similarly, the closure plate 36 provides the fluid T inside the bag.
The second heat exchange stage P2 and the third heat exchange stage P for i
The hole 13 of the upper and lower bag-shaped heat transfer plates 12 and the closing plate 36 are joined.

The fluid To outside the bag enters the heat exchanger at the temperature To1, and changes the direction of the flow because no hole is formed in the heat transfer plate 12 at the position 16B, and the first heat exchange stage P
1 and through the hole 13o (2) to enter the second heat exchange stage P2. Here, the boundary of the heat exchange stage is the heat transfer plate 12 (4), and in order to suppress the heat loss there, the fluid To outside the bag flowing in contact with the heat transfer plate 12 (4). The flow rate is reduced by the flow rate adjusting plate 41.

Similarly, when the fluid To outside the bag flows through the third heat exchange stage P3, the heat transfer plate 12 (3) becomes a boundary of the heat exchange stage, and the flow flowing in contact with the heat exchange plate 12 (3) is adjusted. It is reduced by the plate 42. According to this embodiment, the same effect as that of the second embodiment can be obtained.

[0059]

As described above, according to the present invention,
Since the fluid flows in the container in a multi-stage path, the flow rate increases, and heat exchange can be performed in a state where the heat transfer rate is high, a plate heat exchanger with improved heat exchange capacity can be provided.

Further, according to the present invention, it is possible to provide a low-cost and compact plate heat exchanger while improving the heat exchange capacity.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of a plate heat exchanger according to the present invention (section 1 in FIG. 5).

FIG. 2 is a cross-sectional view of the first embodiment of the plate heat exchanger according to the present invention (cross-section 2 in FIG. 5).

FIG. 3 is a plan view of the single heat transfer plate of FIGS. 1 and 2;

FIG. 4 is a diagram showing a state in which single heat transfer plates are superposed.

FIG. 5 is a schematic diagram showing a flow of a fluid in the plate heat exchanger.

FIG. 6 is a diagram illustrating an example in which a plate heat exchanger is configured with three heat exchange stages (three-pass system), and illustrates a flow of a fluid in each heat exchange stage.

FIG. 7 is a schematic diagram of a temperature distribution in each heat exchange stage, and is an explanatory diagram of a cause of internal heat loss.

8A and 8B are configuration diagrams of the closing means, in which FIG. 8A is an assembled view and FIG. 8B is an expanded view.

FIG. 9 is a sectional view of a second embodiment of the plate heat exchanger according to the present invention (section 1 in FIG. 5).

FIG. 10 is a sectional view of a plate-type heat exchanger according to a second embodiment of the present invention (section 2 in FIG. 5).

FIG. 11 is a sectional view of a third embodiment of the plate heat exchanger according to the present invention (section 1 in FIG. 5).

FIG. 12 is a sectional view of a plate-type heat exchanger according to a third embodiment of the present invention (section 2 in FIG. 5).

FIG. 13 is a sectional view of a conventional plate heat exchanger.

[Explanation of symbols]

1,11: Container 2, 12, 39, 40 ... Heat transfer plate 3, 13 ... Hole 4, 30, 32 ... Piping 5 ... Inner circumference 6 ... Outer circumference 14 ... Irregularity 15 ... Flange 16, 35, 36.37, 38 … Closed plates 17, 18, 19, 20, 21, 22, 23, 24, 3
3, 34 flow rate adjusting ring 25 bolt 26 hole 27 notch 28 nut 29, 31 flow path 34 bolt 41, 42 flow rate adjusting plate

 ──────────────────────────────────────────────────続 き Continuation of the front page (71) Applicant 000221834 Toho Gas Co., Ltd. 19-18, Sakuradacho, Atsuta-ku, Nagoya-shi, Aichi (72) Inventor Akira Nishioka 603, Kandamachi, Tsuchiura-shi, Ibaraki Prefecture Tsuchiura Corporation In-house (72) Inventor Tomihisa Ouchi 603, Kandachi-cho, Tsuchiura-shi, Ibaraki Pref.Hitsuchi Works, Tsuchiura Works (72) Inventor Michihiko Aizawa 603, Tsuchiura-shi, Tsuchiura-shi, Ibaraki Pref. 72) Inventor Atsushi Shitara 1-10-3-810, Akabane-Minami, Kita-ku, Tokyo (72) Inventor Toshikuni Ohashi 1-3-1 Shirotsu, Hokuko, Konohana-ku, Osaka, Japan (72) Inventor Koji Matsubara Tokai, Aichi 507 Shinfukucho, 2F term (reference) 3L093 MM02 3L103 AA05 AA37 DD15 DD57

Claims (8)

[Claims] 1. A heat transfer plate having a hole serving as an inlet or an outlet for a fluid at a corner portion is overlapped, the periphery is joined to form a bag, and the bag-shaped heat transfer plates are stacked and stored in a container. In a plate heat exchanger in which a fluid flows through a flow path formed between heat transfer plates and performs heat exchange between the fluids, a pair of flow paths formed by connecting the holes at the corners between the laminations Forming a pair of flow paths with the angular flow path, and connecting the flow path of one of the pair of flow paths with the one of the flow paths formed between the heat transfer plates to form a first fluid; Forming a first flow path through which the other pair of flow paths and the other flow path between the stacked heat transfer plates are communicated to form a second flow path through which a second fluid flows. A means for closing the flow path is provided in the middle of each of the first and second flow paths formed by the holes. ,
A plate-type heat exchanger characterized in that the flow direction is changed and the flow path is configured in multiple stages. 2. The means for closing the flow path uses a non-opening heat transfer plate for closing the first flow path, and transfers heat to the bag-shaped heat transfer plate when closing the second flow path. The plate-type heat exchanger according to claim 1, further comprising a closing plate for closing a hole of the plate. 3. The heat-transfer plate according to claim 2, wherein the closing plate has a notch and is fixed to a hole of the heat transfer plate with a plate smaller than the hole interposed between plates larger than the hole. Plate heat exchanger. 4. A heat transfer plate having a hole serving as an inlet or an outlet for a fluid at a corner portion is overlapped, the periphery is joined to form a bag, and the bag-shaped heat transfer plates are stacked and stored in a container. In a plate heat exchanger in which a fluid flows through a flow path formed between heat transfer plates and performs heat exchange between the fluids, a pair of flow paths formed by connecting the holes at the corners between the laminations Forming a pair of flow paths with the angular flow path, and connecting the flow path of one of the pair of flow paths with the one of the flow paths formed between the heat transfer plates to form a first fluid; Forming a first flow path through which the other pair of flow paths and the other flow path between the stacked heat transfer plates are communicated to form a second flow path through which a second fluid flows. A means for closing the flow path is provided in the middle of each of the first and second flow paths formed by the holes. A flow path is formed in multiple stages by changing the flow direction, and a means for restricting the flow rate by narrowing the flow path is provided in the flow path between any of the heat transfer plates before and after the means for closing the flow path. Characterized plate heat exchanger. 5. The plate-type heat exchanger according to claim 4, wherein the means for restricting the flow rate includes fitting a flow rate adjusting member into a hole serving as a fluid inlet or outlet at a corner. 6. A heat transfer plate having a hole serving as an inlet or an outlet for a fluid at a corner is overlapped, and the periphery is joined to form a bag, and the bag-shaped heat transfer plates are stacked and stored in a container. In a plate heat exchanger in which a fluid flows through a flow path formed between heat transfer plates and performs heat exchange between the fluids, a pair of flow paths formed by connecting the holes at the corners between the laminations Forming a pair of flow paths with the angular flow path, and connecting the flow path of one of the pair of flow paths with the one of the flow paths formed between the heat transfer plates to form a first fluid; Forming a first flow path through which the other pair of flow paths and the other flow path between the stacked heat transfer plates are communicated to form a second flow path through which a second fluid flows. A means for closing the flow path is provided in the middle of each of the first and second flow paths formed by the holes. The direction of the flow is changed to form a multi-stage flow path, at the corner of the outermost heat transfer plate of the heat transfer plate, a hole serving as a fluid inlet or outlet, and higher than the diagonal corner. A plate type heat exchanger, wherein a hole is provided at a predetermined position, and a flow path for discharging gas accumulated in a container is provided. 7. A flow passage for discharging the gas is connected to an outlet of a fluid coming out of a heat exchanger.
4. The plate heat exchanger according to 1. 8. The plate according to claim 1, wherein the heat transfer plate is formed by laminating plates having inclined corrugations formed so as to intersect with each other. Type heat exchanger.