JP2003240454A - Plate heat exchanger and absorption refrigerator using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plate heat exchanger which assures an effective heat transfer area and has a simplified structure, and also to provide a compact and high performance absorption refrigerator using the plate heat exchanger. <P>SOLUTION: In this plate heat exchanger 52, two sheets 51 are connected to each other, first fluid is allowed to flow on the inside thereof, and second fluid is allowed to flow on the outside for a heat exchange. An inlet 53 and an outlet 54 for the first fluid are provided at one end part of a plate separately from each other, and a flow passage 60 allowing the first fluid flowing from the inlet at one end part to return to the opposite side of the plate and to flow out of the outlet at one end part is formed in the plate, and a plurality of pipes 65 and 66 connected to a tube sheet 2 are fitted to the inlet and outlet. The flow passage 60 is formed as the plurality of flow passages returned on the opposite side, and desirably formed by connecting projected parts on the surface of the plate to each other. The plate heat exchanger 52 can be used for equipment forming the absorption refrigerator. <P>COPYRIGHT: (C)2003,JPO

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, and more particularly to a compact and high performance falling liquid film plate heat exchanger and an absorption refrigerator using the same.

[0002]

2. Description of the Related Art Conventional heat exchangers for absorption refrigerators, particularly evaporators, absorbers, regenerators and condensers, have mainly been shell-and-tube type as falling-film heat exchangers. . Although this heat exchanger has become considerably compact due to the development of various high-performance heat transfer tubes, a plate heat exchanger has been proposed in recent years for further compactification and higher performance. FIG. 8 and FIG. 9 show sectional structural views of a conventional plate heat exchanger, (a) is a front view and (b) is a plan view. In FIG. 8, the inlets / outlets 53, 54 for the internal fluid are arranged on the left and right on the plate surface, and in FIG. 9, the inlets / outlets 53, 54 for the internal fluid are arranged above and below the plate surface. In FIG. 8 and FIG. 9, the fluid inlet 53 and the fluid outlet 54
Is a wasted space unrelated to heat transfer. Further, in FIG. 9, there is a dry area 57 below the inlets / outlets 53 and 54, to which the liquid flowing outside the plate cannot be supplied. On the plate surface, there are joint points D where a large number of concavo-convex portions are joined.

Such a conventional plate heat exchanger has the following problems. Since the inlet / outlet passage of the internal fluid is arranged on the plate surface, the effective heat transfer area is reduced (the inlet / outlet area of the internal fluid does not contribute as a heat exchanger). When increasing the heat exchange capacity of the plate heat exchanger, the number of stacked layers is usually increased, and the inlet / outlet dimensions are determined from the flow rate considering the maximum capacity. Therefore, the ratio of this entrance / exit area to the plate area is quite large, and this useless space hinders compactness. If the inlet and outlet passages for the internal fluid are arranged vertically on the plate surface, when the liquid is made to flow down from the upper part of the plate heat exchanger to the plate surface, the flowing liquid does not flow below the inlet and outlet passages. , A dryout area is created,
Reduce the effective heat transfer area.

A large number of irregularities provided around the thin plate and in the internal flow path are joined by brazing, welding or the like. However, if there is an incomplete part in the joint, poor airtightness and strength. There is a shortage and there is a difficulty in securing reliability. It is difficult to form a thin and uniform falling film over the wide heat transfer surface. Inside the absorption refrigerator, the flow velocity of the refrigerant vapor is considerably high,
Since there is a decrease in performance due to this pressure loss, it was necessary to enlarge the steam passage. For this, it is preferable to stagger the evaporators and absorbers, but in this case,
There was a problem that the structure of the cold water header and the structure of the cooling water header became complicated.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, can secure an effective heat transfer area, and has a simplified structure, and a plate heat exchanger using the same. An object is to provide a compact and high-performance absorption refrigerator.

[0006]

In order to solve the above problems, according to the present invention, two thin plates are joined together, a first fluid is flown inside, and a second fluid is flown outside to exchange heat with each other. In the plate heat exchanger, an inlet and an outlet of the first fluid are separately provided at one end portion of the plate, and the inside of the plate flows from the inlet of the one end portion. The first fluid is folded back at the opposite end of the plate and a flow path is formed so as to flow out from the one end outlet, and a plurality of pipes for joining with the tube sheet are provided at the inlet and the outlet. It is supposed to have a pipe. In the plate heat exchanger,
The fluid flow path is formed as a plurality of independent flow paths that are folded back at the opposite end, and the flow path is formed by a space formed by joining the convex portions of the concavo-convex portion continuously formed on the plate surface. The plate surface has a concave shape of a semicircle or a substantially triangular shape, and the shape of the flow path formed between the concave portions is a substantially circular shape or a substantially rectangular shape, and the plate outer surface is wet. A hydrophilic treatment for improving the properties may be applied.

Further, according to the present invention, the plate heat exchanger is used for at least one of the evaporator, the absorber, the regenerator, the condenser and the solution heat exchanger constituting the absorption refrigerator. The absorption refrigerator is characterized by the following.
The absorption refrigerator has a plurality of plate heat exchangers arranged in a horizontal direction, a refrigerant spraying device and an absorbing solution spraying device are alternately provided on an upper part, and a refrigerant and / or an absorbing solution is separated and collected on a lower part. A collector is provided so that they function alternately as an evaporator and an absorber.The plate heat exchanger for the evaporator is joined to the tube plate on one side, and the plate heat exchanger for the absorber is connected to the tube on the opposite side. It can be used by being joined to a plate, and a plurality of plate heat exchangers are arranged in the horizontal direction, an absorbing solution spraying device is provided in every other row in the upper part, and a refrigerant and / or absorbing solution is separated and collected in the lower part. A recovery device for the regenerator and condenser so that they act alternately as a regenerator and a condenser.The plate heat exchanger for the regenerator is joined to the tube plate on one side, and the plate heat exchanger for the condenser is on the other side. For joining to the tube sheet of Rukoto can also.

Further, the plate heat exchanger acting as the evaporator and the absorber and the plate heat exchanger acting as the regenerator and the condenser are used together, and the plate heat exchanger for the evaporator and the plate heat exchanger for the regenerator are respectively provided on one side. It can be joined to a tube plate, and a plate heat exchanger for an absorber and a plate heat exchanger for a condenser can be joined to the tube plates on the opposite side to be used as a refrigerator / cooler.
The plate heat exchanger for the absorber and the plate heat exchanger for the condenser are joined to the tube plate on one side of the two tube plates arranged at both ends, or the tube plate for the absorber and the tube plate for the condenser. Can be composed of a single tube sheet.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides an effective heat transfer area by providing an inlet / outlet of a fluid flowing inside a plate heat exchanger at one end of the plate heat exchanger and joining it to a tube sheet. This is to secure and also to bond the plates of the evaporator and the absorber to the tube plates on the opposite sides, respectively, to simplify the bonding. Furthermore, the structure of the cold water header and the cooling water header is simplified. Further, the reliability of the joining is enhanced by forming the fluid passages flowing inside the plate as independent and continuous joining.

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional configuration diagram showing an example of a plate heat exchanger of the present invention, which is (a) a front view, (b) a plan view, and (c) a side view. In FIG. 1, reference numeral 51 designates a plate 2
Reference numeral 52 is a thin plate, 52 is a plate heat exchanger in which two plates 51 are joined, and 56 is a joining portion at the end portions of the plates. In FIG. 1, the tube sheet 2 is provided on the side surface of the inlet header 53 provided at one plate end of the plate heat exchanger 52.
A plurality of pipes 65 are provided for joining with.
Similarly, the outlet header 5 provided at the end of one plate
4 also has a plurality of pipes 6 for joining with the tube sheet 2
6 is provided. The diameter and the number of the pipes can be arbitrarily determined according to the plate shape. Pipe 6
The internal fluid that has entered from 5 passes through the header portion 53, passes through the continuous passage 60 where the convex portions 59 are joined together, turns back at the other end, and flows out of the pipe 66 through the outlet header 54. The inlet header 53 and the outlet header 54 have an oval shape so as to collect the passages 60, and a plate material for sealing the opening is provided at this end, and a plurality of holes formed in the plate material are used to form the above-mentioned holes. A plurality of pipes 65, 66 are joined together. The tube sheet is provided with holes for joining the plurality of pipes. By doing so, the joining to the tube sheet 2 can be facilitated. For example, it is possible to join the tubes by expanding the tubes that are used in ordinary heat exchangers. Other methods such as welding and brazing may be used for joining to the tube sheet. As is clear from FIG. 1, there are no passages for internal fluid on the plate surface, and they all act as effective heat transfer surfaces. Also, the tube sheet and the plate can be easily joined. It is also possible to reverse the positions of the entrance and the exit.

2 and 3 show the upper half of FIG.
FIG. Continuous passage 60 joined by the convex portions 59
The cross-sectional shape of is shown. The joint portion of 59 is a continuous joint, the joint reliability is high, and a lateral groove is formed in the joint portion of 59, and the liquid flowing down the outside of the plate is spread in the lateral direction in this groove portion. It is possible to improve the heat transfer performance by forming a good thin film on the entire plate surface. Further, in order to enhance wettability and spreadability, it is preferable to apply hydrophilic treatment to the outer surface of the plate. The hydrophilic treatment can be achieved by forming irregularities on the plate surface by an oxide film, shot blasting, metal spraying, or the like. Further, the strength can be increased by forming the recess 58 of the plate forming the passage 60 into a semicircular shape or a triangular shape.

FIG. 4 is a cross sectional view showing an example of an absorption refrigerator using the plate heat exchanger of the present invention. In FIG. 4, the evaporator plate 4 is placed in a container surrounded by the shell 1.
E and the absorber plate 4A are arranged on the left and right. In the evaporator plate, cold water flows inside the plate, the refrigerant liquid flows down to the outside of the plate, and heat exchanges with the cold water during the flow to partially evaporate the refrigerant liquid. In the absorber plate,
Cooling water flows inside the plate, and the absorbing solution flows outside the plate. The refrigerant vapor from the evaporator is absorbed during the flow. An eliminator 6 is arranged between the evaporator and the absorber to prevent droplets from scattering.

Further, in order to prevent heat loss between the refrigerant reservoir in the lower portion of the evaporator and the absorbent solution reservoir in the lower portion of the absorber, an inverted U-shaped heat insulating space is provided. It is also possible to replace the evaporator part with a regenerator and further replace the absorber part with a condenser. In this case, the liquid spraying device 5A is unnecessary in the condenser section. In the regenerator plate, a heating fluid (steam, warm water, etc.) flows inside the plate, and an absorbing solution flows down outside the plate. Refrigerant vapor is generated from the absorbing solution on the way down. In the condenser plate, the cooling water flows inside the plate, the refrigerant vapor from the regenerator condenses outside the plate, and the condensed refrigerant liquid flows down.

FIG. 5 is a plan sectional view showing another example of an absorption refrigerator using the plate heat exchanger of the present invention.
In FIG. 5, three tube plates 4E for an evaporator are joined to the tube sheet 2 on the right side, and a header 13 for cold water is provided. To the tube plate 2 on the left side, three absorber plates 4A are joined and a cooling water header 11 is provided. Inside the shell 1, evaporator plates 4E and absorber plates 4A are alternately arranged. Thus, by alternately joining the tube sheets, it is possible to make sufficient space for joining and to simplify the structure of the cold water header and the cooling water header even if the arrangement interval of 4E and 4A is narrowed. There are advantages.

FIG. 6 is a sectional view of the side surface of the example of FIG. 5 as viewed from the right side. In FIG. 6, three evaporator plates 4E and three absorber plates 4A are alternately arranged in a container surrounded by the shell 1. With this arrangement, since the refrigerant vapor evaporated in the evaporator flows toward the adjacent absorber plate, the vapor flow velocity is extremely low, so that the pressure loss is small and the performance of the absorption refrigerator can be improved. In the evaporator plate, cold water flows inside the plate, the refrigerant liquid flows down to the outside of the plate, and heat exchanges with the cold water during the flow to partially evaporate the refrigerant liquid. In the absorber plate, cooling water flows inside the plate, and the absorbing solution flows down outside the plate. The refrigerant vapor from the evaporator is absorbed during the flow. A refrigerant spraying device 5E is arranged above the evaporator plate 4E, and an absorbing solution spraying device 5A is arranged above the absorber plate 4A. This spraying device 5
E and 5A may be formed integrally with each plate or may be installed independently. Also in this spraying device,
It is preferable that the surface in contact with the liquid is subjected to hydrophilic treatment.
This hydrophilic treatment makes it possible to obtain a good spraying state.

At the lower part of the evaporator plate 4E or the lower part of the absorber plate 4A, a collector 7 for separating and collecting the refrigerant and the absorbing solution is provided. In the example of this figure, the example provided in the lower part of the evaporator plate is illustrated. The refrigerant liquid recovered by this collector can be guided to a refrigerant liquid reservoir (not shown) to prevent mixing with the absorbing solution. It is also possible to replace the evaporator part with a regenerator and further replace the absorber part with a condenser. In this case, the liquid spraying device 5A is unnecessary in the condenser section. In the regenerator plate, a heating fluid (steam, warm water, etc.) flows inside the plate, and an absorbing solution flows down outside the plate. Refrigerant vapor is generated from the absorbing solution on the way down. In the condenser plate, the cooling water flows inside the plate, the refrigerant vapor from the regenerator condenses outside the plate, and the condensed refrigerant liquid flows down.

FIG. 7 is a sectional view showing an example in which the absorber plate end portion and the condenser plate end portion of the present invention are installed in the same direction. In FIG. 7, an absorber plate 4A and a condenser plate 4C are joined to the left tube plate 2. On the other hand, an evaporator plate 4E and a regenerator plate 4G are joined to the right tube plate 2. With this arrangement, the cooling water flowing through the absorber and the condenser can be constituted by the common header 11. The illustrated example is not limited to a single-effect absorption refrigerator, but can naturally be applied to a multiple-effect absorption refrigerator or absorption cold / hot water machine. Further, the evaporator, the absorber, the regenerator, and the condenser can be housed in an integral shell or in a twin shell shell.

[0018]

According to the plate heat exchanger of the present invention, there is no obstacle on the heat transfer surface, an effective heat transfer area can be secured, and continuous bonding can easily and firmly strengthen the bonding. . Further, the absorption refrigerator using this plate heat exchanger can simplify the structure of the header and provide a compact and high-performance absorption refrigerator.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram showing an example of a plate heat exchanger of the present invention, (a) front view, (b) plan view, (c) side view.

FIG. 2 is an enlarged cross-sectional view showing an example of the XX cross section of FIG.

FIG. 3 is an enlarged cross-sectional view showing another example of the XX cross section of FIG. 1.

FIG. 4 is a cross-sectional configuration diagram showing an example of an absorption refrigerator using the plate heat exchanger of the present invention.

FIG. 5 is a cross-sectional configuration diagram showing another example of the absorption refrigerator using the plate heat exchanger of the present invention.

FIG. 6 is a cross-sectional configuration diagram of a side surface viewed from the right direction in FIG.

FIG. 7 is a cross-sectional configuration diagram in which the absorber plate end portion and the condenser plate end portion of the present invention are installed in the same direction.

FIG. 8 is a cross-sectional configuration diagram showing an example of a conventional plate heat exchanger, including (a) a front view and (b) a plan view.

FIG. 9 is a cross-sectional configuration diagram showing another example of the conventional plate heat exchanger, including (a) a front view and (b) a plan view.

[Explanation of symbols]

1: shell, 2: tube plate, 4A: absorber plate, 4
C: condenser plate, 4E: evaporator plate, 4
G: Regenerator plate, 5A: Absorbing solution spraying device, 5
E: Refrigerant spraying device, 6: Eliminator, 7: Recovery device, 1
0: internal fluid header, 11: cooling water header, 12: heating fluid header, 13: cold water header, 51: plate thin plate, 52: plate heat exchanger, 53: fluid inlet, 5
4: Fluid outlet, 56: Joining portion of plate end portion, 58: Plate surface concave portion, 59: Plate surface convex portion, 60: Continuous passage, 65: Inlet pipe, 66: Outlet pipe

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F25B 39/04 F25B 39/04 Q F28D 3/02 F28D 3/02 F28F 3/12 F28F 3/12 Z 13 / 18 13/18 B (72) Inventor Ken Ishiyama 11-11 Haneda Asahi-cho, Ota-ku, Tokyo Inside the EBARA CORPORATION (72) Inventor Toshio Matsubara 11-11 Haneda-Asahi-cho, Ota-ku, Tokyo EBARA CORPORATION In-house (72) Inventor Osamu Ito 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo Inside EBARA CORPORATION (72) Inventor Kikuichi Mori 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo Inside EBARA CORPORATION ( 72) Inventor Koichi Kunimasa 11-1 Haneda Asahi-cho, Ota-ku, Tokyo (72) Inventor Hiroshi Ishii 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo (72) Inventor Yumoto Imoto 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo F-term in Ebara Corporation (reference) 3L093 BB00 BB29 BB31 BB32 MM02 3L103 AA01 AA05 AA35 AA36 AA37 BB33 CC02 CC12 CC18 CC30 DD06 DD08 DD42 DD44 DD57 DD62 DD95

Claims (9)

[Claims] 1. A plate heat exchanger in which two thin plates are joined together, a first fluid is made to flow inside, a second fluid is made to flow outside, and heat is exchanged with each other. An outlet is separately provided at one end of the plate, and the first fluid flowing from the inlet of the one end is provided inside the plate at the opposite end of the plate. A plate heat exchanger, characterized in that a flow path is formed so as to be folded back and flow out from an outlet at the end on the one side, and pipes for joining with a tube plate are provided at the inlet and the outlet. 2. A first fluid flow path that flows through the inside is formed as a plurality of independent flow paths that are folded back at opposite ends, and the flow paths are continuously formed on a plate surface. The plate heat exchanger according to claim 1, wherein the plate heat exchanger is configured by a space in which convex portions of the portions are joined together. 3. The plate according to claim 2, wherein the plate surface has a concave shape of a semicircle or a substantially triangular shape, and a flow path formed by the concave portions has a substantially circular shape or a substantially rectangular shape. Heat exchanger. 4. The plate heat exchanger according to claim 1, wherein the outer surface of the plate is subjected to a hydrophilic treatment for improving wettability. 5. An evaporator, an absorber, which constitutes an absorption refrigerator,
An absorption refrigerator, wherein the plate heat exchanger according to any one of claims 1 to 4 is used for at least one of a regenerator, a condenser, and a solution heat exchanger. 6. The absorption refrigerator according to claim 5, wherein a plurality of the plate heat exchangers are arranged in a horizontal direction, a refrigerant spraying device and an absorbing solution spraying device are alternately provided on an upper part, and a refrigerant and / or a lower part are provided. A collector for separating and collecting the absorbing solution is provided, and the collector and the plate are arranged so as to alternately act as an evaporator and an absorber, and the evaporator plate heat exchanger is joined to the tube plate on one side to form an absorber plate. An absorption refrigerator having a heat exchanger joined to a tube plate on the opposite side. 7. The absorption refrigerator according to claim 5, wherein a plurality of the plate heat exchangers are arranged in a horizontal direction, an absorption solution spraying device is provided in every other row in an upper part, and a refrigerant and / or an absorption solution is in a lower part. A collector for separating and recovering is provided and arranged so as to alternately act as a regenerator and a condenser, and a plate heat exchanger for a regenerator is joined to a tube plate on one side to form a plate heat exchanger for a condenser. An absorption refrigerating machine, characterized in that the tube is joined to the tube plate on the opposite side. 8. The absorption refrigerator according to claim 5, wherein a plurality of the plate heat exchangers are arranged in a horizontal direction, a refrigerant spraying device and an absorbing solution spraying device are alternately provided on an upper part, and a refrigerant and / or a lower part are provided. A collecting device for separating and collecting the absorbing solution is provided, and the collecting solution is arranged so as to alternately act as an evaporator and an absorbing device. Further, an absorbing solution spraying device is provided in every other row in the upper part, and a refrigerant and / or a lower part is provided. A recovery device for separating and recovering the absorption solution is provided and arranged so as to alternately act as a regenerator and a condenser, and a plate heat exchanger for the evaporator and a plate heat exchanger for the regenerator are provided on one side each. An absorption chiller characterized by being joined to a plate, and an absorber plate heat exchanger and a condenser plate heat exchanger being joined to opposite tube plates. 9. The absorber according to claim 8, wherein the plate heat exchanger for the absorber and the plate heat exchanger for the condenser are configured by a single tube plate for the absorber tube plate and the condenser tube plate. refrigerator.