JP2000266495A - Plate type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate type heat exchanger the manufacturing and assembling costs of which can be reduced and which does not allow liquid drops to be scattered between heat-exchanging elements and fulfills a high heat- exchanging function. SOLUTION: A plate type heat exchanger which simultaneously performs heat exchange on two sets of fluids is constituted by alternately arranging pluralities of heat-exchanging elements (A) 2, each of which is constituted by putting two facing plates 1 together and uses the internal space formed between the plates 1 as the flow passage of a first fluid and the external surfaces of the plates 1 as the flow passage of a second fluid, and heat-exchanging elements (B) 2' each of which is constituted by putting two facing plates 1 together and uses the internal space formed between the plates 1 as the flow passage of a third fluid and the external surfaces of the plates 1 as the flow passage of a fourth fluid at prescribed intervals and, at the same time, installing scattering preventing means 3 which prevents the scattering of liquid drops in the spaces among the elements 2 and 2'. Each scattering preventing means 3 can be constituted of two boards so as to return scattered liquid drops to the heat transferring surfaces from which the drops are scattered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate heat exchanger in which plates are stacked and two fluids are alternately flowed between the plates to exchange heat. The present invention relates to a play heat exchanger suitable for a case where at least one fluid is low-pressure steam (or a case where a phase changes to vaporize or liquefy from vapor) such as a regenerator and a condenser.

[0002]

2. Description of the Related Art Generally, unless the vapor flow velocity at the outlet of an evaporator or the vapor velocity at the entrance of an absorber is controlled within about 50 m / s, the flow resistance increases and the performance of a refrigerator decreases. Conventionally, as a plate heat exchanger, as shown in FIG. 6, an absorber element 2 and an evaporator element 2 'have been proposed in which the plate faces face each other and are alternately arranged. In this case, the size of the steam passage with respect to the surface of the plate 1 is equal to the plate height × the plate width, and the gap between the plates is not limited by the steam flow rate, and can be made compact.

In a heat exchanger of the type shown in FIG.
It is necessary to manufacture one heat exchange element by combining two plates, and attach them one by one to the cold water header and the cooling water header one by one. The shapes of the vessels are different and the types of parts are also increased. Further, for example, when the absorber element and the evaporator element are alternately arranged, the absorbing solution 11
And the refrigerant liquid 12 flow down at the same time, so that the droplets scatter,
When the absorbing solution enters the refrigerant, the refrigerant is contaminated, raises the boiling point, raises the evaporation temperature, deteriorates the performance as a refrigerator, and reduces the amount of the solution on the heat transfer surface, making it hard to wet. There's a problem. On the other hand, the refrigerant liquid is scattered as droplets from the heat transfer surface of the evaporator, and when the refrigerant liquid enters the absorber side, the solution concentration is reduced, the absorption capacity is reduced, and the performance of the refrigerator is deteriorated. In addition, since the refrigerant liquid does not evaporate and jumps out as it is, the original refrigeration effect is not exhibited, the efficiency is reduced, and the amount of the refrigerant liquid on the heat transfer surface is reduced, and there is also a problem that it is difficult to get wet. is there.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, the present invention reduces the number of parts, reduces the cost of manufacturing and assembling, and does not cause droplets to scatter between heat exchange elements.
An object is to provide a plate heat exchanger having a high heat exchange function.

[0005]

According to the present invention, there is provided a plate heat exchanger for simultaneously exchanging heat between two sets of fluids having different temperatures. A heat exchange element (A) having a pair of inner sealed spaces as a first fluid passage, a plate surface as a heat transfer surface, and a fluid flowing along the outer surface of the plate as a second fluid; A pair of plates facing each other, a sealed space inside the two plates as a third fluid passage, a plate surface as a heat transfer surface, and a fluid flowing along the outer surface of the plate as a fourth fluid. And a plurality of heat exchange elements (A) and (B) are alternately arranged at predetermined intervals with the respective plate faces facing each other. Droplets scatter in gaps It is obtained by a providing a scattering prevention means for preventing.

[0006] In the plate heat exchanger, the inner space of the heat exchange element (A) and the inner space of the heat exchange element (B) are provided on the plate surfaces of the heat exchange elements (A) and (B). It is preferable to provide a communication pipe which communicates with each other separately, and the scatter prevention means can be constituted by two plate members so as to return each scattered liquid to the heat transfer surface of the scatter source. In the plate heat exchanger of the present invention, a communication pipe communicating between the heat exchange elements can be integrally formed as a part of a plate of each heat exchange element, and the two alternately arranged two The heat exchange elements (A) and (B) have the same shape and can be symmetrical in opposite directions, and the outer surface of the plate of each heat exchange element (A) and / or (B) A liquid distributor for the second fluid and / or the fourth fluid can be provided.

[0007]

Next, the present invention will be described in detail.
In the plate used in the present invention, when two plates having uneven portions are overlapped so as to form a space inside, and the communication pipes (fluid ports) of the peripheral portion and the openings at both ends are simply overlapped, the plate is light over the entire station. When a contact is made (line contact) and a force is applied in the overlapping direction, the shape of the contact portion changes to form a surface contact. A shape suitable for sealing the periphery by (phrasing) can be used. That is, in the case of the above-mentioned plate, in the case of brazing, in order to make the plates adhere to each other, brazing is performed while applying a force. Is preferred.

[0008] When the two plates as described above are overlapped with the brazing material placed (painted) on the portions to be contacted, a fluid flow path is formed between the spaces from the openings formed at both ends of the plates. Having a heat exchange element. In the present invention, in addition to brazing (phrasing), a case in which a gasket is inserted therebetween to apply a force from the outside or a case in which the gasket is sealed by welding is also included. The unevenness of the plate of the present invention can be formed as a wavy pattern extending in a predetermined direction, and a complicated flow path that refracts two-dimensionally can be formed with a relatively simple configuration. In addition, in the opening communicating pipes at both ends of the plate, since the heat exchange element of another flow path and the scattering prevention means are inserted between the heat exchange elements of the same flow path, the elements and the prevention means are inserted. The communication pipe can be provided on one side of both ends of the plate, and the communication pipe can be provided on one side of both ends of the plate. Can be soldered all at once by inserting a spacer into the furnace and applying force in the furnace.

Providing a swivel at one end of the communicating pipes at both ends of the plate makes it easy to position the fitting by fitting the openings when overlapping. Thus, the two-dimensional positioning of the plates is naturally performed only by overlapping the plates, thereby simplifying the manufacturing process. Heat exchange elements (A) and (B) of the present invention
The scattering prevention means to be inserted between the first and second fluids may have any structure in which the second fluid and the fourth fluid can separately flow down the heat transfer surfaces on the plate surfaces of both elements to prevent the droplets of both fluids. ,
For example, a baffle plate composed of two plate members can be used to return each scattered liquid to the heat transfer surface of the scatter source. In addition, the inserted baffle plate is brought into contact with the convex portion on the plate surface, and furthermore, the same baffle plate is brought into contact with the baffle plate to transmit a load to the brazing portion as a spacer, thereby brazing the heat exchanger at once. You can also.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an example of the plate heat exchanger of the present invention, which is configured by alternately connecting three heat exchange elements 2, 2 ′. The heat exchange element 2 is formed by laminating the two plates 1 and fixing them by welding or brazing between the contact portion 8 of the uneven pattern 7 and the peripheral portion 6. A baffle plate 3 is disposed between the heat exchange elements 2 and 2 'to prevent the fluid flowing on the plate surface from scattering. A liquid distributor 4 is provided above the heat exchange elements 2 and 2'.
The fluid flows from the hole 5 of the liquid distributor orifice along the heat transfer surface of the plate surface. in this way,
If the baffle is placed in contact with or slightly away from the heat transfer surface of the plate surface, the second fluid 11 or the fourth fluid 12 flowing down from the liquid distributor 4, for example, the absorbing solution 11 or the refrigerant liquid 12, Even if they scatter, they can be prevented from entering the evaporator side or the absorber side, respectively, and by returning the solution to the absorber side, the amount of the absorbing solution and the amount of the refrigerant liquid can be secured, respectively. The collected refrigerant liquid 12 can be circulated and supplied.

In FIG. 1, although not shown, the first
The fluid is supplied by a communication pipe communicating with the heat exchange element 2 ′, and the third fluid is supplied by a communication pipe communicating with the heat exchange element 2. Then, the plate-type absorption / evaporator of the absorption refrigerator can be obtained by using the first fluid as the cooling water and the third fluid as the cold water. When applied to a regenerator / condenser combination of an absorption refrigerator, cooling water is supplied to the inside of the heat exchange element 2 and a heat source fluid is supplied to the inside of the heat exchange element 2 ′ through the communication pipe. Flows through the liquid distributor 4 to the heat transfer surface on the surface of the heat exchange element 2 ′ to evaporate the refrigerant liquid and condense the refrigerant on the heat transfer surface on the plate surface of the heat exchange element 2. Therefore, it is not necessary to flow the liquid from the liquid distributor 4 to the heat exchange element 2.

FIG. 2 is a sectional view showing another essential part of the plate heat exchanger of the present invention. In FIG. 2, the plates are brought into contact with each other at the plate peripheral edge 6 and the plate convex / concave intersection 8, the baffle plate 3 is also brought into contact with the plate 1 and the other baffle plate 9, and the baffle plate 3 is connected to the heat transfer element 2. By using the spacer as a spacer between the 2 ′ and the plate type heat exchanger, the load can be transmitted to the brazing portion of the entire plate 1 at the time of manufacturing and heating, so that the entire heat exchanger can be brazed at once. Become. 3, 4 and 5 show the shape 7 of the heat transfer surface on the plate surface. FIG. 3 (a) is a front view, FIG. 3 (b) is a plan view, and 10 is an opening. The dashed line in FIG. 5 represents the unevenness of the back plate. As shown in FIGS. 3 to 5, the strength is increased by providing irregularities and brazing the contact portions of the plates 1, and when the shape is made to be vertical or nearly vertical with a linear waveform, the unevenness of the flowing liquid is increased. And flows evenly over the plate. Further, it is preferable that the heat transfer surface on the surface of the plate is improved in wettability and spread of the liquid by sandblasting or the like. As described above, it is desirable that the plate surface is subjected to a treatment for increasing hydrophilicity or is subjected to the treatment.

[0013]

As described above, according to the present invention,
A complicated plate-type heat exchanger is provided in which a flow path bent by unevenness is formed inside and outside of a heat exchange element composed of one or two kinds of parts and heat exchanges from two fluids having different temperatures. With a small number of parts and a simple manufacturing process, a heat exchanger having an efficient heat exchange function at low cost can be provided. Further, according to the present invention, since the scattering of droplets can be prevented, the two flowing fluids do not mix, and when used as an absorption / evaporator and a regeneration / condenser of an absorption refrigerator, the refrigerator As a result, an absorption refrigerator having a high heat exchange function can be obtained without deteriorating the performance of the device and without the problem of becoming less wet.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a plate heat exchanger according to the present invention.

FIG. 2 is a cross-sectional configuration view illustrating a main part of an example of a plate heat exchanger according to the present invention.

FIGS. 3A and 3B are configuration diagrams showing a surface shape of a plate of the plate heat exchanger of the present invention, wherein FIG. 3A is a front view and FIG.

FIG. 4 is a configuration diagram showing another plate surface shape of the plate heat exchanger of the present invention.

FIG. 5 is a configuration diagram showing another plate surface shape of the plate heat exchanger of the present invention.

FIG. 6 is a partial configuration diagram in which a conventional plate heat exchanger is applied to an absorber / evaporator.

[Explanation of symbols]

1: plate, 2 ': heat exchange element, 3: baffle plate
4: liquid distributor, 5: orifice hole, 6: peripheral portion, 7: uneven pattern of plate, 8: uneven intersection, 9: baffle plate contact portion, 10: opening, 11: second fluid, 12: second 4 fluids

Claims (5)

[Claims] 1. A plate type heat exchanger for simultaneously exchanging heat of two sets of fluids having different temperatures, wherein two sets of plates facing each other are formed as one set, and a sealed space inside the two sets is defined as a first set. One set of a heat exchange element (A) using a fluid flowing along the outer surface of the plate as a second fluid, and a pair of two plates facing each other as a single fluid passage and a plate surface as a heat transfer surface. The inner sealed space is used as a third fluid passage, and the plate surface is used as a heat transfer surface.
A heat exchange element (B) having a fluid flowing along the outer surface of the plate as a fourth fluid, wherein the heat exchange elements (A) and (B)
A plurality of plates are arranged alternately at predetermined gaps so that the respective plate surfaces face each other, and scatter prevention means for preventing scatter of droplets is provided in the gaps. Plate heat exchanger. 2. On the plate surfaces of the heat exchange elements (A) and (B), separate the inner spaces of the heat exchange element (A) and the inner spaces of the heat exchange element (B) separately. 2. The plate heat exchanger according to claim 1, wherein a communicating pipe is formed to communicate with the plate. 3. The plate heat exchanger according to claim 2, wherein the communication pipe communicating between the heat exchange elements is configured as a part of a plate of each heat exchange element. 4. The apparatus according to claim 1, wherein the scatter prevention means is constituted by two plates so as to return each scattered liquid to the heat transfer surface of the scattered source. Plate heat exchanger. 5. A liquid distributor for a second fluid and / or a fourth fluid is provided on an outer surface of the plate of each of the heat exchange elements (A) and / or (B). ~
5. The plate heat exchanger according to any one of 4.