WO2022130986A1

WO2022130986A1 - Shell-and-tube heat exchanger, refrigeration cycle device, and heat exchange method

Info

Publication number: WO2022130986A1
Application number: PCT/JP2021/044142
Authority: WO
Inventors: 道美日下
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2020-12-17
Filing date: 2021-12-01
Publication date: 2022-06-23
Also published as: EP4265982A1

Abstract

In the present invention, an evaporator 101 is constituted by a shell-and-tube heat exchanger. The evaporator 101 includes: a plurality of heat transfer tubes 22 through which a first fluid flows; and a plurality of nozzles 24 that spray a second fluid toward the plurality of heat transfer tubes 22. When a direction parallel to the longitudinal direction of the plurality of heat transfer tubes 22 is defined as an X direction, a direction vertical to the X direction is defined as a Y direction, and a direction perpendicular to the X direction and the Y direction is defined as a Z direction, the plurality of nozzles 24 include a plurality of first nozzles 24a that spray the second fluid from a first side toward a second side in the Z direction, and a plurality of second nozzles 24b that spray the second fluid from the first side toward the second side in the Z direction. In a projected image obtained by projecting the plurality of first nozzles 24a and the plurality of second nozzles 24b in the Z direction, the plurality of first nozzles 24a and the plurality of second nozzles 24b exhibit a staggered arrangement pattern.

Description

Shell-and-tube heat exchanger, refrigeration cycle device, and heat exchange method

The present disclosure relates to shell and tube heat exchangers, refrigeration cycle devices, and heat exchange methods.

A technique for cooling the refrigerant inside the heat transfer tube by spraying cooling water toward the heat transfer tube is known. FIG. 19 shows a conventional evaporative condenser described in Patent Document 1 (FIG. 9). The watering unit 330 of the evaporative condenser 300 has a plurality of watering nozzles 334 that sprinkle the cooling water CW toward the condensing coil 326. By exchanging heat between the cooling water CW and the refrigerant R flowing through the condensing coil 326, the cooling water CW evaporates, and the refrigerant R is cooled and condensed.

International Publication No. 2017/073367

The present disclosure provides a shell-and-tube heat exchanger that is advantageous from the viewpoint of suppressing dryout on the outer surface of a plurality of heat transfer tubes.

The shell-and-tube heat exchangers of the present disclosure are:
With the shell
A plurality of heat transfer tubes arranged inside the shell,
Equipped with a nozzle,
The following conditions (Ia), (Ib), (Ic), and (Id), or the following conditions (IIa), (IIb), (IIc), and (IId) are satisfied.
(Ia) The plurality of heat transfer tubes are arranged parallel to each other inside the shell, and the first fluid flows through the plurality of heat transfer tubes.
(Ib) The nozzle is arranged inside the shell and includes a plurality of nozzles that spray a second fluid toward the plurality of heat transfer tubes.
(Ic) The direction parallel to the longitudinal direction of the plurality of heat transfer tubes is defined as the X direction, the direction perpendicular to the X direction is defined as the Y direction, and the X direction and the direction perpendicular to the Y direction are the Z direction. When defined as
The plurality of nozzles include a plurality of first nozzles that spray the second fluid from the first side to the second side in the Z direction, and the first side to the second side in the Z direction. It includes a plurality of second nozzles for spraying the second fluid.
(Id) In a projection image obtained by projecting the plurality of first nozzles and the plurality of second nozzles in the Z direction, the plurality of first nozzles and the plurality of second nozzles are arranged in a staggered pattern. Show the pattern.
(IIa) The plurality of heat transfer tubes form a heat transfer tube group.
(IIb) The nozzle sprays a liquid toward the heat transfer tube group.
(IIc) The heat transfer tube group has a first stage having a plurality of heat transfer tubes arranged along the first plane and a plurality of heat transfer tubes arranged along a second plane parallel to the first plane. And includes a second stage adjacent to the first stage in a direction perpendicular to the first plane.
(IId) The nozzle has a first end portion of the plurality of heat transfer tubes in the first stage near the second stage in a direction perpendicular to the first plane, and the first stage in a direction perpendicular to the first plane. A flat spray pattern that has a spray shaft that passes between the two-stage heat transfer tubes and the second end near the first stage, and that passes between the first stage and the second stage. The liquid is sprayed with.

Further, the heat exchange method of the present disclosure is described.
It has a first stage having a plurality of heat transfer tubes arranged along the first plane, and a plurality of heat transfer tubes arranged along a second plane parallel to the first plane, and is perpendicular to the first plane. Passing the heat medium inside the heat transfer tube group including the first stage and the second stage adjacent to the first stage in the above direction.
The first end portion of the plurality of heat transfer tubes in the first stage near the second stage in the direction perpendicular to the first plane, and the plurality of heat transfer tubes in the second stage in the direction perpendicular to the first plane. It has a spray shaft that passes between the second end of the heat tube near the first stage, and has a flat spray pattern that passes between the first stage and the second stage toward the heat transfer tube group. The liquid is sprayed to exchange heat between the heat medium and the liquid.

According to the shell-and-tube heat exchanger of the present disclosure, when the conditions (Ia), (Ib), (Ic), and (Id) are satisfied, the particles are sprayed from the plurality of first nozzles to the fourth nozzle. The surface of the plurality of heat transfer tubes can be uniformly wetted by the second fluid. As a result, dryout can be suppressed. Further, when the conditions of (IIa), (IIb), (IIc), and (IId) are satisfied, the first end of the plurality of heat transfer tubes in the first stage and the first of the plurality of heat transfer tubes in the second stage. A flat spray pattern with a spray shaft passing between the two ends can spray the liquid towards the heat transfer tube group. The spray pattern passes between the first and second stages. According to the heat exchange method of the present disclosure, the liquid can be sprayed toward the heat transfer tube group by such a spray pattern. As a result, dryout can be suppressed.

Configuration diagram of the refrigeration cycle device according to the first embodiment of the present disclosure. Longitudinal section of the evaporator along line II-II in FIG. Cross-sectional view of the evaporator along lines III-III in FIG. Side view of the evaporator along the IVA-IVA line in FIG. Side view of the evaporator along the IVB-IVB line in FIG. Cross-sectional view of the evaporator along the VA-VA line in FIG. Sectional drawing of the evaporator along the VB-VB line in FIG. The figure which shows the moving direction and the dropping state of the refrigerant sprayed from the 1st nozzle and the 3rd nozzle to a plurality of heat transfer tubes. The figure which shows the positional relationship between the nozzle surface defined by the 1st nozzle and the 3rd nozzle, and the nozzle surface defined by the 2nd nozzle and the 4th nozzle. The figure which shows the state of the refrigerant on each nozzle surface after spraying the refrigerant. Cross-sectional view of the evaporator according to the second embodiment of the present disclosure. Side view of the evaporator along the IX-IX line in FIG. Sectional drawing of the evaporator along the XA-XA line in FIG. Sectional drawing of the evaporator along the XB-XB line in FIG. The figure which shows the structure of the refrigerating cycle apparatus in Embodiment 3 of this disclosure. Longitudinal cross-sectional view of the evaporator with the line II-II as the cutting line in FIG. The figure which shows the spraying pattern of the liquid phase refrigerant sprayed from a nozzle The figure which shows the spraying pattern of the liquid phase refrigerant sprayed from a nozzle Longitudinal cross-sectional view of the evaporator with the IV-IV line in FIG. 11 as the cutting line. The figure which shows the region where the liquid phase refrigerant is sprayed. The figure which shows the state of spraying and flow of a liquid phase refrigerant. The figure which shows the region where the liquid phase refrigerant is sprayed in Embodiment 4 of this disclosure. The figure which shows the state of spraying and flow | flow of a liquid phase refrigerant in Embodiment 5 of this disclosure. Sectional view of a conventional evaporative condenser

(Knowledge, etc. that became the basis of this disclosure)
When the conventional nozzle configuration is applied to shell and tube heat exchangers, dryouts tend to occur at specific locations. Heat exchange does not occur on the surface where dryout occurs, and the performance of the shell-and-tube heat exchanger is not fully exhibited. If the occurrence of dryout can be prevented, the performance of the shell-and-tube heat exchanger can be fully exhibited. Based on such findings, the inventor has come to constitute the subject matter of the present disclosure. The “dry-out surface” means a surface on which the liquid film of the refrigerant does not exist.

At the time when the present inventor came up with the present disclosure, it was attempted to spray a liquid such as cooling water toward a heat transfer tube using a nozzle in a shell-and-tube heat exchanger. Under such circumstances, the present inventor has come up with the idea that the performance of the shell-and-tube heat exchanger can be improved by using the flow of the liquid sprayed from the nozzle as a hint. Then, in order to realize the idea, for example, when the spray pattern of the liquid phase refrigerant is conical, the atomized liquid phase refrigerant reaches the outer surface of the heat transfer tube far from the nozzle. I discovered that there is a problem that it is difficult to do and dryout is likely to occur. The present inventor has come to construct the subject matter of the present disclosure in order to solve the problem.

Therefore, the present disclosure provides a shell-and-tube heat exchanger that is advantageous from the viewpoint of suppressing dryout on the outer surface of a plurality of heat transfer tubes.

Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of already well-known matters or duplicate explanations for substantially the same configuration may be omitted. This is to prevent the following explanation from becoming unnecessarily redundant and to facilitate the understanding of those skilled in the art.

It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 7B.

[1-1. Constitution]
FIG. 1 shows the configuration of a refrigeration cycle device using a shell-and-tube heat exchanger. The refrigeration cycle device 100 includes an evaporator 101, a compressor 102, a condenser 103, a flow valve 104, a flow path 110a, a flow path 110b, a flow path 110c, and a flow path 110d. The outlet of the evaporator 101 is connected to the inlet of the compressor 102 by the flow path 110a. The outlet of the compressor 102 is connected to the inlet of the condenser 103 by the flow path 110b. The outlet of the condenser 103 is connected to the inlet of the flow valve 104 by the flow path 110c. The outlet of the flow valve 104 is connected to the inlet of the evaporator 101 by the flow path 110d. The

flow paths

110a and 110b are steam paths. The flow path 110c and the flow path 110d are liquid paths. Each path is composed of, for example, at least one metal pipe.

The evaporator 101 is composed of a shell-and-tube heat exchanger, as will be described later.

The compressor 102 may be a speed compressor such as a centrifugal compressor or a positive displacement compressor such as a scroll compressor.

The model of the condenser 103 is not particularly limited. Heat exchangers such as plate heat exchangers and shell and tube heat exchangers can be used in the condenser 103.

The refrigeration cycle device 100 is, for example, an air conditioner for business use or home use. The heat medium cooled by the evaporator 101 is supplied into the room through the circuit 105 and used for cooling the room. Alternatively, the heat medium heated by the condenser 103 is supplied into the room through the circuit 106 and used for heating the room. The heat medium is, for example, water. However, the refrigeration cycle device 100 is not limited to the air conditioner, and may be another device such as a chiller or a heat storage device. The refrigeration cycle device 100 may be an absorption chiller equipped with an evaporator, an absorber, a regenerator and a condenser.

The circuit 105 is a circuit that circulates a heat medium in the evaporator 101. The circuit 106 is a circuit for circulating a heat medium in the condenser 103. The circuit 105 and the circuit 106 may be a closed circuit isolated from the outside air.

The heat medium is the first fluid flowing through each of the circuit 105 and the circuit 106. The heat medium is not limited to water, and may be a liquid such as oil or brine, or a gas such as air. The composition of the heat medium of the circuit 105 may be different from the composition of the heat medium of the circuit 106.

When the compressor 102 is started, the refrigerant is heated and evaporated in the evaporator 101. This produces a gas phase refrigerant. The vapor phase refrigerant is sucked into the compressor 102 and compressed. The compressed vapor phase refrigerant is supplied from the compressor 102 to the condenser 103. The vapor phase refrigerant is cooled by the condenser 103 to condense and liquefy. This produces a liquid phase refrigerant. The liquid phase refrigerant is returned from the condenser 103 to the evaporator 101 via the flow valve 104.

The type of refrigerant is not particularly limited. Examples of the refrigerant include chlorofluorocarbon refrigerants, low GWP (Global Warming Potential) refrigerants, and natural refrigerants. Examples of chlorofluorocarbon refrigerants include HCFC (hydrochlorofluorocarbon) and HFC (hydrofluorocarbon). Examples of the low GWP refrigerant include HFO-1234yf and water. Examples of the natural refrigerant include carbon dioxide and water.

The refrigerant may be a refrigerant containing a substance having a negative saturated vapor pressure at room temperature as a main component. Examples of such a refrigerant include a refrigerant containing water, alcohol or ether as a main component. The "main component" means the component contained most in the mass ratio. "Negative pressure" means pressure that is absolute and lower than atmospheric pressure. "Room temperature" means a temperature within the range of 20 ° C ± 15 ° C according to the Japanese Industrial Standards (JIS Z8703).

The refrigerant is an example of a second fluid that should exchange heat with a heat medium that is the first fluid.

FIG. 2 is a vertical sectional view of the evaporator 101 along the line II-II. FIG. 3 is a cross-sectional view of the evaporator 101 along the line III-III. As shown in FIGS. 2 and 3, the evaporator 101 is configured as a shell-and-tube heat exchanger. The evaporator 101 includes a shell 21, a plurality of heat transfer tubes 22, a plurality of nozzles 24, a circulation circuit 25, and a circulation pump 26. The plurality of heat transfer tubes 22 and the plurality of nozzles 24 are arranged inside the shell 21. The plurality of nozzles 24 include a plurality of first nozzles 24a, a plurality of second nozzles 24b, a plurality of third nozzles 24c, and a plurality of fourth nozzles 24d. A plurality of heat transfer tubes 22 are arranged between a nozzle group including a plurality of first nozzles 24a and a plurality of second nozzles 24b and a nozzle group including a plurality of third nozzles 24c and a plurality of fourth nozzles 24d. .. The coefficient of performance (COP) of the refrigeration cycle can be improved by efficiently evaporating the refrigerant in the evaporator 101.

The plurality of heat transfer tubes 22 include a circular tube having a circular cross section. In FIGS. 2 and 3, all of the plurality of heat transfer tubes 22 are circular tubes having a circular cross section. A heat medium, which is the first fluid, flows from the inlet to the outlet of the heat transfer tube 22. Each of the plurality of heat transfer tubes 22 penetrates the facing surfaces of the shell 21.

The plurality of heat transfer tubes 22 are arranged parallel to each other inside the shell 21. Specifically, the plurality of heat transfer tubes 22 are regularly arranged in a plurality of rows and a plurality of stages inside the shell 21. The regular arrangement is advantageous for uniform thinning of the liquid film on the surface of the heat transfer tube 22.

In this embodiment, the direction parallel to the longitudinal direction of the heat transfer tube 22 is defined as the X direction. The direction vertical to the X direction is defined as the Y direction. The direction perpendicular to the X and Y directions is defined as the Z direction. The Y direction and the Z direction are the step direction and the column direction, respectively. The Y direction can be parallel to the direction of gravity. The X and Z directions can be parallel to the horizontal direction.

As shown in FIG. 3, in a cross section perpendicular to the X direction and parallel to the Y and Z directions, the plurality of heat transfer tubes 22 are located on the grid points of the square lattice. Specifically, the center of each heat transfer tube 22 is located at a grid point in a square grid. However, the arrangement of the heat transfer tubes 22 is not particularly limited. The plurality of heat transfer tubes 22 may be arranged so that the center of each heat transfer tube 22 is located at a grid point in a rectangular lattice, for example. In FIGS. 2 and 3, the plurality of heat transfer tubes 22 are arranged in 8 stages and 12 rows. The number of stages and the number of columns are also not limited to specific values.

The pipe constituting the heat transfer pipe 22 may be a machined pipe in which the inside of the pipe, the outside of the pipe, or both of them are grooved.

A heat medium that exchanges heat with the refrigerant flows inside the heat transfer tube 22. The heat medium is a fluid such as water, ethylene glycol, or propylene glycol. The heat medium absorbs heat in the atmosphere through a heat exchanger such as a fin-and-tube heat exchanger and flows into each heat transfer tube 22 of the evaporator 101. In each heat transfer tube 22, the heat medium is cooled by the refrigerant.

Examples of the material of the heat transfer tube 22 include metal materials such as aluminum, aluminum alloy, stainless steel, and copper.

As shown in FIGS. 2 and 3, the refrigerant is sprayed from each of the first nozzle 24a to the fourth nozzle 24d toward the plurality of heat transfer tubes 22. The plurality of first nozzles 24a and the plurality of second nozzles 24b spray the refrigerant from the first side to the second side in the Z direction. The plurality of third nozzles 24c and the plurality of fourth nozzles 24d spray the refrigerant from the second side to the first side in the Z direction. The "first side" is, for example, one side in the width direction of the heat transfer tube 22. The "second side" is the other side in the width direction of the heat transfer tube 22. The width direction of the heat transfer tube 22 may be the width direction with respect to the horizontal direction.

The nozzle 24 is, for example, a pressure injection type spray nozzle. The pressure injection type spray nozzle is configured to receive the pressurized refrigerant from the inlet, apply a swirling force to the refrigerant by a swirling mechanism inside the nozzle, and inject it into the space. As a result, the injected refrigerant spreads in a conical shape due to the centrifugal force due to the swirling speed, is thinned and liquefied, and then splits into a group of droplets.

The same spray nozzle can be used for each of the first nozzle 24a to the fourth nozzle 24d. The phrase "identical" means that the design structure and design characteristics are identical. However, the structures and dimensions of the first nozzle 24a to the fourth nozzle 24d may be different from each other.

In the present embodiment, the plurality of first nozzles 24a and the plurality of second nozzles 24b are present at the same position in the Z direction. The plurality of third nozzles 24c and the plurality of fourth nozzles 24d are present at the same position in the Z direction. Further, the plurality of first nozzles 24a and the plurality of third nozzles 24c are present at the same position in the Y direction. The plurality of second nozzles 24b and the plurality of fourth nozzles 24d are present at the same position in the Y direction. In FIGS. 2 and 3, the first nozzle 24a and the second nozzle 24b are each provided in one stage. The third nozzle 24c and the fourth nozzle 24d are each provided in one stage. The plurality of first nozzles 24a and the plurality of second nozzles 24b may be arranged in a matrix in the X direction and the Y direction. The plurality of third nozzles 24c and the plurality of fourth nozzles 24d may be arranged in a matrix in the X direction and the Y direction.

FIG. 4A is a side view of the evaporator 101 along the IVA-IVA line. In FIG. 4A, elements other than the heat transfer tube 22 and the nozzle 24 are omitted. As shown in FIG. 4A, in the projection image obtained by projecting the plurality of first nozzles 24a and the plurality of second nozzles 24b in the Z direction, the plurality of first nozzles 24a and the plurality of second nozzles 24b are staggered. The arrangement pattern of is shown. The projected image is, in detail, an image obtained by orthographically projecting a plurality of first nozzles 24a and a plurality of second nozzles 24b onto an arbitrary projection surface perpendicular to the Z direction.

FIG. 4B is a side view of the evaporator 101 along the IVB-IVB line. In FIG. 4B, elements other than the heat transfer tube 22 and the nozzle 24 are omitted. As shown in FIG. 4B, in the projection image obtained by projecting the plurality of third nozzles 24c and the plurality of fourth nozzles 24d in the Z direction, the plurality of third nozzles 24c and the plurality of fourth nozzles 24d are staggered. The arrangement pattern of is shown. The projected image is, in detail, an image obtained by orthographically projecting a plurality of third nozzles 24c and a plurality of fourth nozzles 24d onto an arbitrary projection surface perpendicular to the Z direction.

As shown in FIG. 4A, the plurality of first nozzles 24a are arranged in the X direction. The plurality of second nozzles 24b are arranged in the X direction. The position of the first nozzle 24a in the Y direction is different from the position of the second nozzle 24b in the Y direction. The plurality of first nozzles 24a and the plurality of second nozzles 24b are located on the same plane perpendicular to the Z direction.

As shown in FIG. 4B, the plurality of third nozzles 24c are arranged in the X direction. The plurality of fourth nozzles 24d are arranged in the X direction. The position of the third nozzle 24c in the Y direction is different from the position of the fourth nozzle 24d in the Y direction. The plurality of third nozzles 24c and the plurality of fourth nozzles 24d are located on the same plane perpendicular to the Z direction.

FIG. 5A is a cross-sectional view of the evaporator 101 along the VA-VA line, and FIG. 5B is a cross-sectional view of the evaporator 101 along the IVB-IVB line. In FIGS. 5A and 5B, elements other than the heat transfer tube 22 and the nozzle 24 are omitted.

The spray shaft O1 of the first nozzle 24a and the spray shaft O2 of the second nozzle 24b are parallel to each other in the X direction and the Z direction. The spray shaft O1 is the central shaft of the spray flow of the refrigerant produced by the first nozzle 24a. The spray shaft O2 is the central shaft of the spray flow of the refrigerant produced by the second nozzle 24b. The spray shaft O1 and the spray shaft O2 are each inclined with respect to the row direction (Z direction). According to such a configuration, the refrigerant can be sprayed over a wide range by the first nozzle 24a and the second nozzle 24b. This also contributes to a uniform thinning of the liquid film on the surface of the heat transfer tube 22.

The spray shaft O3 of the third nozzle 24c and the spray shaft O4 of the fourth nozzle 24d are parallel to the inclined direction with respect to both the X direction and the Z direction. The spray shaft O3 is the central shaft of the spray flow of the refrigerant produced by the third nozzle 24c. The spray shaft O4 is the central shaft of the spray flow of the refrigerant produced by the fourth nozzle 24d. The spray shaft O3 and the spray shaft O4 are each inclined with respect to the row direction (Z direction). According to such a configuration, the refrigerant can be sprayed over a wide range by the third nozzle 24c and the fourth nozzle 24d.

The "spray axis O1" can also be regarded as the central axis of the first nozzle 24a. The spray shaft O1 may be a shaft that passes through the center of the opening of the first nozzle 24a. The "spray axis O2" can also be regarded as the central axis of the second nozzle 24b. The spray shaft O2 may be a shaft that passes through the center of the opening of the second nozzle 24b. The "spray axis O3" can also be regarded as the central axis of the third nozzle 24c. The spray shaft O3 may be a shaft that passes through the center of the opening of the third nozzle 24c. The "spray axis O4" can also be regarded as the central axis of the fourth nozzle 24d. The spray shaft O4 may be a shaft that passes through the center of the opening of the fourth nozzle 24d.

When viewed in a plan view from the Y direction, the spray axis O1 of the first nozzle 24a is inclined in the clockwise direction with respect to the first reference line L1 which passes through the center of the opening of the first nozzle 24a and is parallel to the Z direction. The spray shaft O2 of the second nozzle 24b is inclined counterclockwise with respect to the second reference line L2 which passes through the center of the opening of the second nozzle 24b and is parallel to the Z direction. According to such a configuration, the refrigerant can be sprayed over a wide range by the minimum necessary number of the first nozzles 24a and the second nozzles 24b.

When viewed in a plan view from the Y direction, the spray axis O3 of the third nozzle 24c is inclined in the clockwise direction with respect to the third reference line L3 which passes through the center of the opening of the third nozzle 24c and is parallel to the Z direction. The spray shaft O4 of the fourth nozzle 24d is inclined in the counterclockwise direction with respect to the fourth reference line L4 which passes through the center of the opening of the fourth nozzle 24d and is parallel to the Z direction. According to such a configuration, the refrigerant can be sprayed over a wide range by the minimum necessary number of the first nozzles 24a and the second nozzles 24b.

When viewed in a plan view from the Y direction, the angle θ1 formed by the spray shaft O1 of the first nozzle 24a and the first reference line L1 is equal to the angle θ2 formed by the spray shaft O2 of the second nozzle 24b and the second reference line L2. ..

When viewed in a plan view from the Y direction, the angle θ3 formed by the spray axis O3 of the third nozzle 24c and the third reference line L3 is equal to the angle θ4 formed by the spray axis O4 of the fourth nozzle 24d and the fourth reference line L4. ..

The angle θ1, the angle θ2, the angle θ3, and the angle θ4 may be equal to or different from each other. The angle θ1, the angle θ2, the angle θ3, and the angle θ4 may be such that at least one of the outer edges of the spray stream of the refrigerant is non-parallel to the longitudinal direction (X direction) of the heat transfer tube 22. The angle θ1, the angle θ2, the angle θ3, and the angle θ4 are, for example, 30 to 40 degrees, typically 30 degrees. In FIGS. 5A and 5B, the broken line indicates the spread angle α of the spray flow of the refrigerant. The spread angle α of the spray flow shows a spread symmetrical with respect to each of the spray axes O1, O2, O3 and O4. The spread angle α of the spray flow may be an acute angle, for example, 60 degrees. The angle θ1, the angle θ2, the angle θ3, and the angle θ4 can be half of the spread angle α of the spray flow. According to such a configuration, one of the outer edges of the spray stream of the refrigerant is substantially parallel to the reference lines L1, L2, L3 and L4. As a result, the generation of the component of the flow of the refrigerant that goes against the moving direction of the refrigerant that moves along the surface of the heat transfer tube 22 is suppressed. Since the movement of the refrigerant on the surface of the heat transfer tube 22 is promoted, it can be expected that the heat transfer coefficient will be improved by improving the movement speed. The angle θ1, the angle θ2, the angle θ3, and the angle θ4 are determined according to conditions such as the number of nozzles 24 and the distance between adjacent nozzles 24.

The plurality of first nozzles 24a are arranged at predetermined intervals in the X direction. The distance between the first nozzles 24a adjacent to each other in the X direction is the distance W. The plurality of second nozzles 24b are arranged at predetermined intervals in the X direction. The distance between the second nozzles 24b adjacent to each other in the X direction is the distance W. The plurality of third nozzles 24c are arranged at predetermined intervals in the X direction. The distance between the third nozzles 24c adjacent to each other in the X direction is the distance W. The plurality of fourth nozzles 24d are arranged at predetermined intervals in the X direction. The distance between the fourth nozzles 24d adjacent to each other in the X direction is the distance W. That is, the distance between the first nozzles 24a adjacent to each other in the X direction, the distance between the second nozzles 24b, the distance between the third nozzles 24c, and the distance between the fourth nozzles 24d are equal to each other. The interval W is appropriately determined according to the angle θ of the nozzle 24 and the distance from the nozzle 24 to the heat transfer tube 22. The distance between the nozzles 24 adjacent to each other in the X direction is defined as the distance between the centers of the openings of the adjacent nozzles 24.

The distance between the first nozzle 24a and the second nozzle 24b in the X direction is 1/2 of the distance between the first nozzles 24a adjacent to each other in the X direction. The distance between the third nozzle 24c and the fourth nozzle 24d in the X direction is ½ of the distance between the third nozzles 24c adjacent to each other in the X direction. That is, the distance between the first nozzle 24a and the second nozzle 24b in the X direction is W / 2. The distance between the third nozzle 24c and the fourth nozzle 2 in the X direction is W / 2.

In a plan view from the Y direction, the positions of the plurality of third nozzles 24c are offset in the X direction with respect to the positions of the plurality of first nozzles 24a. Further, in a plan view from the Y direction, the positions of the plurality of fourth nozzles 24d are offset in the X direction with respect to the positions of the plurality of second nozzles 24b. Such a configuration is advantageous in avoiding overlapping refrigerant flows in the Z direction.

The spray shafts O1 of the plurality of first nozzles 24a pass between the heat transfer tubes 22 and the heat transfer tubes 22 that are adjacent to each other in the Y direction. In other words, the positions of the plurality of first nozzles 24a are set so that the spray shaft O1 passes through the space between the heat transfer tubes 22 adjacent to each other in the Y direction. The spray shafts O2 of the plurality of second nozzles 24b pass between the heat transfer tubes 22 and the heat transfer tubes 22 that are adjacent to each other in the Y direction. In other words, the positions of the plurality of second nozzles 24b are set so that the spray shaft O2 passes through the space between the heat transfer tubes 22 adjacent to each other in the Y direction. According to such a configuration, the reach of the spray flow in the row direction (Z direction) is extended. This not only contributes to the miniaturization of the evaporator 101, but also contributes to the uniform thinning of the liquid film on the surface of the heat transfer tube 22.

The spray shafts O3 of the plurality of third nozzles 24c pass between the heat transfer tubes 22 and the heat transfer tubes 22 that are adjacent to each other in the Y direction. In other words, the position of the third nozzle 24c in the Y direction is determined so that the spray shaft O3 passes through the space between the heat transfer tubes 22 and the heat transfer tubes 22 adjacent to each other in the Y direction. The spray shafts O4 of the plurality of fourth nozzles 24d pass between the heat transfer tubes 22 and the heat transfer tubes 22 that are adjacent to each other in the Y direction. In other words, the position of the fourth nozzle 24d in the Y direction is determined so that the spray shaft O4 passes through the space between the heat transfer tubes 22 and the heat transfer tubes 22 adjacent to each other in the Y direction. According to such a configuration, the reach of the spray flow in the row direction (Z direction) is extended.

As shown in FIG. 4A, there are at least one or more heat transfer tubes 22 between the plurality of first nozzles 24a and the plurality of second nozzles 24b in the Y direction. As shown in FIG. 4B, there is at least one or more heat transfer tubes 22 between the plurality of third nozzles 24c and the plurality of fourth nozzles 24d in the Y direction. In the present embodiment, there are three stages of heat transfer tubes 22 between the plurality of first nozzles 24a and the plurality of second nozzles 24b in the Y direction. In the Y direction, there are three stages of heat transfer tubes 22 between the plurality of third nozzles 24c and the plurality of fourth nozzles 24d.

As shown in FIG. 2, the shell 21 is configured to store a liquid phase refrigerant at the bottom thereof. The circulation circuit 25 connects the bottom of the shell 21 to each of the plurality of nozzles 24. A circulation pump 26 is arranged in the circulation circuit 25. By the action of the circulation pump 26, the liquid phase refrigerant stored in the bottom of the shell 21 is supplied to the plurality of nozzles 24 through the circulation circuit 25. According to such a configuration, the liquid phase refrigerant can be easily recovered, and the energy consumption for supplying the liquid phase refrigerant to the plurality of nozzles 24 can be suppressed.

The shell 21 is provided with an inflow pipe 27 and a discharge pipe 28. The inflow pipe 27 is a flow path for guiding the refrigerant into the shell 21. The discharge pipe 28 is a flow path that guides the refrigerant evaporated on the surfaces of the plurality of heat transfer pipes 22 to the outside of the shell 21. A flow path 110d and a flow path 110a may be connected to the inflow pipe 27 and the discharge pipe 28, respectively.

The plurality of nozzles 24 are connected to the circulation circuit 25 via the header 23.

A flow path cover 29a is attached to the shell 21 so as to cover one end of a plurality of heat transfer tubes 22. A flow path cover 29b is attached to the shell 21 so as to cover the other ends of the plurality of heat transfer tubes 22. The flow path cover 29a has two partition plates 31 inside. The flow path cover 29b has one partition plate 31 inside. The flow path cover 29a has a secondary side inflow port 32 and a secondary side outflow port 33. The secondary side inflow port 32 may be provided on the flow path cover 29b. The secondary side outlet 33 may be provided on the flow path cover 29b. The number of passes in the evaporator 101 of the present embodiment increases by "1" each time the flow direction of the refrigerant is reversed at the flow path cover 29a or 29b. In the present embodiment, the secondary side inflow port 32 and the secondary side outflow port 33 are arranged on the flow path cover 29a so that the number of passes is “4”.

In the present embodiment, the shell 21 has a rectangular cross-sectional shape. However, the shape of the shell 21 is not limited. The shell 21 may have a circular cross-sectional shape. The shell 21 may be a pressure resistant container.

[1-2. motion]
The operation and operation of the evaporator 101 configured as described above will be described below.

When the circulation pump 26 is started, the liquid phase refrigerant is supplied from the bottom of the shell 21 to the plurality of nozzles 24 via the header 23. The liquid phase refrigerant is sprayed from each of the plurality of first nozzles 24a and the plurality of second nozzles 24b onto the plurality of heat transfer tubes 22. Further, the liquid phase refrigerant is sprayed from each of the plurality of third nozzles 24c and the plurality of fourth nozzles 24d onto the plurality of heat transfer tubes 22. The heat medium flows into the flow path cover 29a from the secondary side inflow port 32 and flows through the heat transfer tube 22. Next, the heat medium reverses the flow direction at the flow path cover 29b and flows through the heat transfer tube 22. Next, the heat medium reverses the flow direction again at the flow path cover 29a and flows through the heat transfer tube 22. The heat medium again reverses the flow direction at the flow path cover 29b and flows through the heat transfer tube 22. After that, the heat medium flows out from the secondary side outlet 33 and is discharged to the outside of the evaporator 101. If the liquid phase refrigerant is sprayed toward the heat transfer tube 22 while flowing the heat medium through the heat transfer tube 22, heat exchange between the heat medium and the liquid phase refrigerant is performed in the heat transfer tube 22, and the refrigerant evaporates to produce the gas phase refrigerant. Generated.

Here, the components of the refrigerant sprayed from each nozzle 24 will be described with reference to FIGS. 5A and 5B. In FIGS. 5A and 5B, the arrows on the heat transfer tube 22 indicate the main directions of movement of the sprayed refrigerant.

The spray flow of the refrigerant sprayed from the first nozzle 24a has a flow component C1 along the spray shaft O1 and a flow component C2 along the surface of the heat transfer tube 22. The component C1 is a component of the flow of the refrigerant sprayed and spread from the first nozzle 24a. The component C1 is a component of the flow of the refrigerant that moves in the space between the heat transfer tubes 22 and the heat transfer tubes 22 that are adjacent to each other in the Y direction along the spray shaft O1. The component C2 is a component of the flow of the refrigerant that moves on the surface of the heat transfer tube 22 with a velocity component in the X direction. The spray flow of the refrigerant sprayed from the second nozzle 24b has a flow component C3 along the spray shaft O2 and a flow component C4 along the surface of the heat transfer tube 22. The spray flow of the refrigerant sprayed from the third nozzle 24c has a flow component C5 along the spray shaft O3 and a flow component C6 along the surface of the heat transfer tube 22. The spray stream of the refrigerant sprayed from the fourth nozzle 24d has a flow component C7 along the spray shaft O4 and a flow component C8 along the surface of the heat transfer tube 22.

The flow of the refrigerant having the component C1, the component C3, the component C5 and the component C7 travels in the space between the heat transfer tubes 22 and the heat transfer tubes 22 adjacent to each other in the Y direction, respectively. At that time, the refrigerant moves while contacting the lower surface of the heat transfer tube 22 located on the upper side and the upper surface of the heat transfer tube 22 located on the lower side. The flow of the refrigerant having the component C2 and the component C8 moves on the surface of the heat transfer tube 22 along the X direction, respectively. The flow of the refrigerant having the component C4 and the component C6 moves on the surface of the heat transfer tube 22 in the direction opposite to the direction of the flow of the refrigerant having the component C2 and the component C8, respectively. The refrigerant having these components exchanges heat with the heat medium circulating inside the heat transfer tube 22 on the surface of the heat transfer tube 22 and evaporates. The unevaporated refrigerant drops toward the heat transfer tube 22 located below.

FIG. 6 is a diagram showing a moving direction and a dropping state of the refrigerant sprayed from the first nozzle 24a and the third nozzle 24c onto the plurality of heat transfer tubes 22. FIG. 6 shows a part of a portion viewed from the Z direction, which is visible from the surface including the frontmost heat transfer tube 22 with respect to the front, and a part visible from the surface including the innermost heat transfer tube 22. There is. In FIG. 6, the arrow on the heat transfer tube 22 indicates the main moving direction of the sprayed refrigerant.

The spray stream of the refrigerant sprayed from the first nozzle 24a forms a space between the heat transfer tubes 22 and the heat transfer tubes 22 adjacent to each other in the Y direction from the first side to the second side in the Z direction and the X direction. Proceed in the direction between and. The spray shaft O1 is located between the heat transfer tube 22 and the heat transfer tube 22 in the Y direction. The spray stream of the refrigerant sprayed from the third nozzle 24c forms a space between the heat transfer tubes 22 and the heat transfer tubes 22 adjacent to each other in the Y direction from the second side to the first side in the Z direction and the X direction. Proceed in the direction between and. The spray shaft O3 is located between the heat transfer tube 22 and the heat transfer tube 22 in the Y direction.

At this time, a part of the refrigerant (component C2) sprayed from the first nozzle 24a moves on the surface of the heat transfer tube 22 along the X direction. A part of the refrigerant sprayed from the third nozzle 24c (component C6) moves on the surface of the heat transfer tube 22 along the X direction. The refrigerant flow component C2 is a component in the opposite direction to the refrigerant flow component C6. When the moving speed in the X direction decreases, the refrigerant starts to drip toward the heat transfer tube 22 located below. On the other hand, the components (components C1 and C5) of the flow of the refrigerant sprayed from the first nozzle 24a and the third nozzle 24c hardly reach the heat transfer tube 22 located below the heat transfer tube 22. Therefore, heat exchange is performed by dropping the unevaporated refrigerant in the heat transfer tube 22 located above. The same description can be applied to the second nozzle 24b and the fourth nozzle 24d.

FIG. 7A is a diagram showing the positional relationship between the nozzle surface defined by the first nozzle 24a and the third nozzle 24c and the nozzle surface defined by the second nozzle 24b and the fourth nozzle 24d. In FIG. 7A, for ease of understanding, only one first nozzle 24a, one second nozzle 24b, one third nozzle 24c, and one fourth nozzle 24d are shown. The third nozzle 24c is on the same nozzle surface as the second nozzle 24b. In the Y direction, there is a three-stage heat transfer tube 22 between the first nozzle 24a and the second nozzle 24b. Similarly, in the Y direction, there is a three-stage heat transfer tube 22 between the third nozzle 24c and the fourth nozzle 24d.

The n-th nozzle surface is defined as an XZ surface defined by the spray shaft O1 of the first nozzle 24a (not shown in FIG. 7A) and the spray shaft O3 of the third nozzle 24c (not shown in FIG. 7A). The heat transfer tube 22 located above the spray shaft O1 of the first nozzle 24a is defined as the heat transfer tube 22a. The heat transfer tube 22 located below the spray shaft O1 of the first nozzle 24a is defined as the heat transfer tube 22b. The heat transfer tube 22a and the heat transfer tube 22b are adjacent to each other in the Y direction. The n-th nozzle surface includes a lower surface of the heat transfer tube 22a and an upper surface of the heat transfer tube 22b. The first (n + 1) nozzle surface is defined as an XZ surface defined by the spray shaft O2 of the second nozzle 24b (not shown in FIG. 7A) and the spray shaft O4 of the fourth nozzle 24d (not shown in FIG. 7A). The heat transfer tube 22 located above the spray shaft O2 of the second nozzle 24b is defined as the heat transfer tube 22c. The heat transfer tube 22 located below the spray shaft O2 of the second nozzle 24b is defined as the heat transfer tube 22d. The heat transfer tube 22c and the heat transfer tube 22d are adjacent to each other in the Y direction. The first (n + 1) nozzle surface includes a lower surface of the heat transfer tube 22c and an upper surface of the heat transfer tube 22d.

A predetermined number of heat transfer tubes 22 exist between the nth nozzle surface and the (n + 1) th nozzle surface.

FIG. 7B is a diagram showing the state of the refrigerant on the nth nozzle surface and the (n + 1) th nozzle surface after spraying the refrigerant. In FIG. 7B, the arrow indicates the direction in which the refrigerant is dropped. When the refrigerant is sprayed from each of the first nozzle 24a, the second nozzle 24b, the third nozzle 24c, and the fourth nozzle 24d, the refrigerant as shown in FIG. 7B is on the nth nozzle surface and the (n + 1) nozzle surface. A coarse and dense state occurs. Specifically, on the nth nozzle surface and the (n + 1) th nozzle surface, dense regions and coarse regions of the refrigerant are generated in a staggered manner.

Specifically, on the n-th nozzle surface, the refrigerant sufficiently reaches the region including the heat transfer tube 22 in the vicinity of the first nozzle 24a and the third nozzle 24c by the components of the flow of the refrigerant (components C1 and C5). .. The components of the flow of the refrigerant (components C2 and C6) allow the refrigerant to sufficiently move on the surface of the heat transfer tube 22. As a result, as shown in FIG. 7B, a dense region of the refrigerant is formed on the n-th nozzle surface, and a liquid film of the refrigerant is formed. Similarly, on the first (n + 1) nozzle surface, the refrigerant sufficiently reaches the region including the heat transfer tube 22 in the vicinity of the second nozzle 24b and the fourth nozzle 24d by the components of the flow of the refrigerant (components C3 and C7). do. The components of the flow of the refrigerant (components C4 and C8) allow the refrigerant to sufficiently move on the surface of the heat transfer tube 22. As a result, as shown in FIG. 7B, a dense region of the refrigerant is formed on the (n + 1) th nozzle surface, and a liquid film of the refrigerant is formed.

On the other hand, on the nth nozzle surface, the amount of the refrigerant that reaches is not sufficient or the refrigerant does not reach the region including the heat transfer tube 22 that is located away from the first nozzle 24a and the third nozzle 24c. Therefore, as shown in FIG. 7B, a rough region of the refrigerant is generated. Similarly, on the first (n + 1) nozzle surface, the amount of the refrigerant that reaches is not sufficient or the refrigerant does not reach the region including the heat transfer tube 22 that is located away from the second nozzle 24b and the fourth nozzle 24d. Therefore, as shown in FIG. 7B, a rough region of the refrigerant is generated. However, the unevaporated refrigerant drops from the dense region of the n-th nozzle surface to the rough region of the (n + 1) th nozzle surface, so that the wet state of the rough region is improved.

[1-3. Effect, etc.]
As described above, in the projection image obtained by projecting the plurality of first nozzles 24a and the plurality of second nozzles 24b in the Z direction in the present embodiment, the plurality of first nozzles 24a and the plurality of second nozzles are present. Reference numeral 24b shows a staggered arrangement pattern. Further, in the projection image obtained by projecting the plurality of third nozzles 24c and the plurality of fourth nozzles 24d in the Z direction, the plurality of third nozzles 24c and the plurality of fourth nozzles 24d show a staggered arrangement pattern. ..

According to such a configuration, the surface of the plurality of heat transfer tubes 22 can be uniformly wetted by the refrigerant sprayed from the plurality of first nozzles 24a to the fourth nozzle 24d. This makes it possible to prevent the generation of a dry-out surface that the refrigerant does not reach. Therefore, the heat transfer performance of the evaporator 101 can be improved.

This embodiment is particularly effective when there is a heat transfer tube 22 having a large number of rows of heat transfer tubes 22 and a small amount of refrigerant reaching from the nozzle 24. According to the present embodiment, the difference in wet state on each nozzle surface is determined by the superimposing action of the refrigerant supply action by the spray type and the refrigerant supply action by the flowing liquid film type from both sides of the plurality of heat transfer tubes 22. Can be improved. This makes it possible to prevent the formation of a dry-out surface. Further, in the region including the heat transfer tube 22 where the spray stream of the refrigerant directly reaches and the refrigerant moves on the surface, the heat transfer coefficient is improved by the forced convection, so that the heat exchange efficiency can be further improved.

In the present embodiment, the first nozzle 24a may be provided in a plurality of stages. The second nozzle 24b may be provided in a plurality of stages. The number of stages of the first nozzle 22a may or may not match the number of stages of the second nozzle 24b. The third nozzle 24a may be provided in a plurality of stages. The second nozzle 24b may be provided in a plurality of stages. The number of stages of the third nozzle 22c may or may not match the number of stages of the fourth nozzle 24d. According to such a configuration, even when the number of stages of the plurality of heat transfer tubes 22 is large, it is possible to more sufficiently suppress the generation of a region where the refrigerant does not reach due to the dropping of the refrigerant on the nozzle surface located below.

When a plurality of first nozzles 24a having three or more stages are provided along the Y direction, the distances between the first nozzles 24a adjacent to each other in the Y direction may be equal to or different from each other. Such a configuration also applies to the second nozzle 24b, the third nozzle 24c and the fourth nozzle 24d. The distance between the first nozzle 24a and the second nozzle 24b in the Y direction may be ½ of the distance between the first nozzles 24a adjacent to each other in the Y direction. The distance between the third nozzle 24c and the fourth nozzle 24d in the Y direction may be ½ of the distance between the third nozzles 24c adjacent to each other in the Y direction.

When viewed in a plan view from the Z direction, a plurality of first nozzles 24a and second nozzles 24b may be arranged in a matrix. When four first nozzles 24a forming the four vertices of the quadrangle having the smallest area are selected in a plan view from the Z direction, the second nozzle 24b may be located at the center of the quadrangle formed by the four first nozzles 24a. .. Similarly, when four second nozzles 24b are selected so as to form the four vertices of the quadrangle having the smallest area in a plan view from the Z direction, the first nozzle is located in the center of the quadrangle formed by the four second nozzles 24b. 24a can be located.

When viewed in a plan view from the Z direction, the plurality of third nozzles 24c and the fourth nozzle 24d may be arranged in a matrix. When four third nozzles 24c forming the four vertices of the quadrangle having the smallest area are selected in a plan view from the Z direction, the fourth nozzle 24d may be located in the center of the quadrangle formed by the four third nozzles 24c. .. Similarly, when the four fourth nozzles 24d are selected so as to form the four vertices of the quadrangle having the smallest area when viewed in a plan view from the Z direction, the third nozzle is located in the center of the quadrangle formed by the four fourth nozzles 24d. 24c can be located.

A plurality of first nozzles 24a having two or more stages and a plurality of second nozzles 24b having two or more stages may be provided along the Y direction. In this case, the distance between the first nozzles 24a adjacent to each other in the Y direction may be wider than the distance W between the first nozzles 24a adjacent to each other in the X direction. The distance between the second nozzles 24b adjacent to each other in the Y direction may be wider than the distance W between the second nozzles 24b adjacent to each other in the X direction. Such a configuration is advantageous in avoiding overlapping refrigerant flows in the Y direction.

A plurality of third nozzles 24c having two or more stages and a plurality of fourth nozzles 24d having two or more stages may be provided along the Y direction. In this case, the distance between the third nozzles 24c adjacent to each other in the Y direction may be wider than the distance W between the third nozzles 24c adjacent to each other in the X direction. The distance between the fourth nozzles 24d adjacent to each other in the Y direction may be wider than the distance W between the fourth nozzles 24d adjacent to each other in the X direction. Such a configuration is advantageous in avoiding overlapping refrigerant flows in the Y direction.

A plurality of first nozzles 24a having two or more stages and a plurality of second nozzles 24b having two or more stages may be provided along the Y direction. In this case, the distance between the first nozzles 24a adjacent to each other in the Y direction may be equal to the distance between the second nozzles 24b adjacent to each other in the Y direction. The distance between the first nozzle 24a and the second nozzle 24b in the Y direction may be ½ of the distance between the first nozzles 24a adjacent to each other in the Y direction. With such a configuration, the above-mentioned effect can be more sufficiently obtained.

A plurality of third nozzles 24c having two or more stages and a plurality of fourth nozzles 24d having two or more stages may be provided along the Y direction. In this case, the distance between the third nozzles 24c adjacent to each other in the Y direction may be equal to the distance between the fourth nozzles 24d adjacent to each other in the Y direction. The distance between the third nozzle 24c and the fourth nozzle 24d in the Y direction may be ½ of the distance between the third nozzles 24c adjacent to each other in the Y direction. With such a configuration, the above-mentioned effect can be more sufficiently obtained.

The refrigeration cycle apparatus 100 of the present embodiment includes the shell-and-tube heat exchanger of the present embodiment. The shell-and-tube heat exchanger may be used in the evaporator 101 or in the condenser 103. By using the shell-and-tube heat exchanger of the present embodiment, the efficiency of the refrigeration cycle apparatus 100 can be improved.

(Embodiment 2)
Hereinafter, the second embodiment will be described with reference to FIGS. 8 to 10. The same components as those in the first embodiment are designated by the same numbers, and detailed description thereof will be omitted.

[2-1. Evaporator configuration]
FIG. 8 is a cross-sectional view of the evaporator 111 according to the second embodiment of the present disclosure. FIG. 8 corresponds to FIG. 3 of the first embodiment. The evaporator 111 of the present embodiment does not include the plurality of third nozzles 24c and the plurality of fourth nozzles 24d, and the number of rows of the plurality of heat transfer tubes 22 is six. It has the same configuration as the evaporator 101 of 1.

FIG. 9 is a side view of the evaporator 111 along the IX-IX line. In FIG. 9, elements other than the heat transfer tube 22 and the nozzle 24 are omitted. As shown in FIG. 9, in the projection image obtained by projecting the plurality of first nozzles 24a and the plurality of second nozzles 24b in the Z direction, the plurality of first nozzles 24a and the plurality of second nozzles 24b are staggered. The arrangement pattern of is shown.

FIG. 10A is a cross-sectional view of the evaporator 111 along the line XA-XA, and FIG. 10B is a cross-sectional view of the evaporator 111 along the line XB-XB. In FIGS. 10A and 10B, elements other than the heat transfer tube 22 and the nozzle 24 are omitted.

[2-2. motion]
As described in the first embodiment, when the circulation pump 26 is started, the liquid phase refrigerant is supplied from the bottom of the shell 21 to the plurality of first nozzles 24a and the plurality of second nozzles 24b via the header 23. The liquid phase refrigerant is sprayed from each of the plurality of first nozzles 24a and the plurality of second nozzles 24b onto the plurality of heat transfer tubes 22.

The moving direction and the dropping state of the refrigerant sprayed from each of the plurality of first nozzles 24a and the plurality of second nozzles 24b are as described in the first embodiment.

[2-3. Effect, etc.]
This embodiment is also effective when the number of rows of the heat transfer tubes 22 is small. According to the present embodiment, it is possible to improve the difference in the density of the wet state on each nozzle surface by the superimposing action between the supply action of the refrigerant by the spray type and the supply action of the refrigerant by the flowing liquid film type. This makes it possible to prevent the formation of a dry-out surface.

In the present embodiment, the first nozzle 24a may be provided in a plurality of stages. The second nozzle 24b may be provided in a plurality of stages. The number of stages of the first nozzle 22a may or may not match the number of stages of the second nozzle 24b. The same description as in the first embodiment may be applied to such a configuration.

(Other embodiments)
In the first embodiment described above, the plurality of first nozzles 24a and the plurality of third nozzles 24c are arranged so as to define the same nozzle surface. Further, a plurality of second nozzles 24b and a plurality of fourth nozzles 24d are arranged so as to define the same nozzle surface. The plurality of first nozzles 24a and the plurality of third nozzles 24c may be arranged on different nozzle surfaces. Further, the plurality of second nozzles 24b and the plurality of fourth nozzles 24d may be arranged on different nozzle surfaces. That is, the position of the first nozzle 24a in the Y direction may be different from the position of the third nozzle 24c in the Y direction. Further, the position of the second nozzle 24b in the Y direction may be different from the position of the fourth nozzle 24d in the Y direction. A plurality of first nozzles 24a, a plurality of first nozzles 24a, in a projection image obtained by projecting a plurality of first nozzles 24a, a plurality of third nozzles 24c, a plurality of second nozzles 24b, and a plurality of fourth nozzles 24d in the Z direction. The third nozzle 24c, the plurality of second nozzles 24b, and the plurality of fourth nozzles 24d may exhibit a staggered arrangement pattern.

(Embodiment 3)
Hereinafter, the third embodiment will be described with reference to FIGS. 11 to 16.

[3-1. Constitution]
FIG. 11 shows the configuration of a refrigeration cycle device 200 equipped with a shell-and-tube heat exchanger. As shown in FIG. 11, the refrigerating cycle device 200 includes an evaporator 201, a compressor 202, a condenser 203, a flow valve 204, a flow path 210a, a flow path 210b, a flow path 210c, and a flow path 210d. The outlet of the evaporator 201 is connected to the inlet of the compressor 202 by the flow path 210a. The outlet of the compressor 202 is connected to the inlet of the condenser 203 by the flow path 210b. The outlet of the condenser 203 is connected to the inlet of the flow valve 204 by the flow path 210c. The outlet of the flow valve 204 is connected to the inlet of the evaporator 201 by the flow path 210d. The

flow paths

210a and 210b are paths through which the gas phase refrigerant passes. The flow path 210c and the flow path 210d are paths through which the liquid phase refrigerant passes. Each path is composed of, for example, at least one metal pipe.

The liquid phase refrigerant is heated and evaporated in the evaporator 201 to generate a vapor phase refrigerant. The gas phase refrigerant is sucked into the compressor 202 and compressed. The compressed vapor phase refrigerant is supplied from the compressor 202 to the condenser 203. The vapor phase refrigerant is cooled by the condenser 203 to condense and liquefy. This produces a liquid phase refrigerant. The liquid phase refrigerant is returned from the condenser 203 to the evaporator 201 via the flow valve 204.

The refrigerant in the refrigeration cycle device 200 is not limited to a specific refrigerant. Examples of the refrigerant include chlorofluorocarbon refrigerants, low GWP (Global Warming Potential) refrigerants, and natural refrigerants. Examples of chlorofluorocarbon refrigerants include hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). Examples of the low GWP refrigerant include HFO-1234yf and water. Examples of the natural refrigerant include carbon dioxide and water.

The refrigerant may be a refrigerant containing a substance having a negative saturated vapor pressure at room temperature as a main component. Examples of such a refrigerant include a refrigerant containing water, alcohol, or ether as a main component. The "main component" means the component contained most in the mass ratio. "Negative pressure" means pressure that is absolute and lower than atmospheric pressure. "Room temperature" means a temperature within the range of 20 ° C ± 15 ° C according to the Japanese Industrial Standards (JIS Z8703).

The evaporator 201 is composed of a shell-and-tube heat exchanger as described later.

The compressor 202 may be a speed compressor such as a centrifugal compressor or a positive displacement compressor such as a scroll compressor.

The model of the condenser 203 is not limited to a specific type. Heat exchangers such as plate heat exchangers and shell and tube heat exchangers can be used in the condenser 203.

The refrigeration cycle device 200 is, for example, an air conditioner for business use or home use. The heat medium cooled by the evaporator 201 is supplied into the room through the circuit 205 and used for cooling the room. Alternatively, the heat medium heated by the condenser 203 is supplied into the room through the circuit 206 and used for heating the room. The heat medium is, for example, water. The refrigeration cycle device 200 is not limited to the air conditioner, but may be another device such as a chiller or a heat storage device. The refrigeration cycle device 200 may be an absorption chiller including an evaporator, an absorber, a regenerator, and a condenser.

Circuit 205 is a circuit that circulates a heat medium in the evaporator 201. The circuit 206 is a circuit for circulating a heat medium in the condenser 203. The circuit 205 and the circuit 206 may be a closed circuit isolated from the outside air.

The heat medium is a fluid flowing through each of the circuit 205 and the circuit 206. The heat medium is not limited to water, and may be a liquid such as oil or brine, or a gas such as air. The composition of the heat medium of the circuit 205 may be different from the composition of the heat medium of the circuit 206.

FIG. 12 is a vertical cross-sectional view of the evaporator 201 having the line II-II in FIG. 11 as a cutting line. As shown in FIG. 12, the evaporator 201 is configured as a shell-and-tube heat exchanger. The evaporator 201 includes a shell 221, a heat transfer tube group 222, and a nozzle 224. The heat transfer tube group 222 is arranged inside the shell 221. The nozzle 224 sprays the liquid phase refrigerant toward the heat transfer tube group 222. The heat transfer tube group 222 is composed of, for example, a plurality of heat transfer tubes 222p arranged in parallel. For example, the heat transfer tube 222p has a circular cross section perpendicular to the longitudinal direction. Grooves may be applied to the inner surface of the heat transfer tube 222p, the outer surface of the heat transfer tube 222p, or both.

As shown in FIG. 12, the shell 221 has, for example, a rectangular cross-sectional shape. The shell 221 may have a circular cross-sectional shape. The shell 221 may be a pressure resistant container.

The evaporator 201 further includes, for example, a header 223, a circulation circuit 225, a pump 226, an inflow pipe 227a, an outflow pipe 227b, a first cover 229a, and a second cover 229b.

The nozzle 224 is connected to the circulation circuit 225 by the header 223. The pump 226 is arranged in the circulation circuit 225. A liquid phase refrigerant is stored in the bottom of the shell 221. By the action of the pump 226, the liquid phase refrigerant stored in the bottom of the shell 221 is supplied to the nozzle 224 through the circulation circuit 225 and the header 223.

The inflow pipe 227a and the outflow pipe 227b are attached to the shell 221. The inflow pipe 227a forms a flow path for guiding the refrigerant inside the shell 221. The discharge pipe 227b forms a flow path that guides the vapor phase refrigerant generated inside the evaporator 201 to the outside of the shell 221. A flow path 210d and a flow path 210a can be connected to the flow path formed by the inflow pipe 227a and the discharge pipe 227b, respectively.

The first cover 229a is attached to the shell 221 and covers one end of the heat transfer tube group 222 in the longitudinal direction (X-axis direction) of the heat transfer tube 222p. The second cover 229b is attached to the shell 221 and covers the other end of the heat transfer tube group 222 in the longitudinal direction of the heat transfer tube 222p. The first cover 229a has two partition plates 229c inside thereof. The second cover 229b has one partition plate 229d inside. The first cover 229a has, for example, a secondary side inlet 228a and a secondary side outlet 228b. Each of the secondary side inlet 228a and the secondary side outlet 228b may be formed on the second cover 229b. The number of passes in the evaporator 201 increases by "1" each time the flow direction of the heat medium inside the heat transfer tube 222p is reversed at the flow path cover 229a or 229b. In the present embodiment, the flow path cover 229a has a secondary side inflow port 228a and a secondary side outflow port 228b so that the number of passes is “4”.

As shown in FIG. 12, the evaporator 201 includes a plurality of nozzles 224. The plurality of nozzles 224 are arranged at predetermined intervals in the longitudinal direction (X-axis direction) of the heat transfer tube 222p. Further, the plurality of nozzles 224 are alternately arranged on a pair of straight lines parallel to the Y-axis direction in the longitudinal direction of the heat transfer tube 222p. Further, each nozzle 224 is arranged so as to spray the liquid phase refrigerant toward, for example, between the adjacent heat transfer tubes 222p in the Y-axis direction.

13A and 13B show the spray pattern of the liquid phase refrigerant sprayed from the nozzle 224. As shown in FIGS. 13A and 13B, the nozzle 224 sprays the liquid phase refrigerant in a flat spray pattern having a spray axis Am. The spray axis Am can also be regarded as the central axis of the nozzle 224. The spray axis Am can be an axis that passes through the center of the opening of the nozzle 224. As shown in FIG. 13A, the liquid phase refrigerant sprayed from the nozzle 224 forms a fan-shaped spray area M. Further, the shape of the spray region S that appears when this spray pattern is projected onto the plane H perpendicular to the spray axis Am is flat. The liquid phase refrigerant sprayed in such a spray pattern passes between the heat transfer tubes 222p.

FIG. 14 is a vertical cross-sectional view of the evaporator 201 having the IV-IV line in FIG. 11 as a cutting line. In the heat transfer tube group 222, the number of heat transfer tubes 222p arranged in the Z-axis direction is not limited to a specific value. In the heat transfer tube group 222, for example, 12 heat transfer tubes 222p are arranged in the Z-axis direction. In the nozzle 224, the spray shaft Am passes between the pair of heat transfer tubes 222p closest to the nozzle 224 in the direction perpendicular to the longitudinal direction of the heat transfer tube 222p (Z-axis direction), and the spray region S is a pair of transfer tubes. The liquid phase refrigerant is sprayed so as to pass between the hot tubes 222p. The spray axis Am extends horizontally, for example.

As shown in FIG. 14, the nozzle 224 is arranged only at one end of the heat transfer tube group 222 in the Z-axis direction, and is not arranged at the other end of the heat transfer tube group 222 in the Z-axis direction, for example. Therefore, the nozzle 224 sprays the liquid phase refrigerant in the positive direction of the Z axis, for example, on the plane (YZ plane) perpendicular to the longitudinal direction of the heat transfer tube 222p.

FIG. 15 shows a region where the liquid phase refrigerant is sprayed from the nozzle 224. In FIG. 15, the spray area M of the liquid phase refrigerant sprayed from the heat transfer tube group 222 and the nozzle 224 is seen along the Y-axis direction. The nozzle 224 is arranged, for example, at a distance L from the heat transfer tube 222p closest to the Z-axis direction in the heat transfer tube group 222. Further, the spray area M has a first contour line W1 and a second contour line W2 formed so as to form a central angle α. The central angle α is not limited to a specific size. The central angle α is, for example, 90 ° or more and 120 ° or less.

FIG. 16 is a diagram showing a state of spraying and flow of the liquid phase refrigerant sprayed from the nozzle 224 toward the heat transfer tube group 222. As shown in FIG. 16, the heat transfer tube group 222 includes a first stage 222a and a second stage 222b. The first stage 222a has a plurality of heat transfer tubes 222p arranged along the first plane. The second stage 222b has a plurality of heat transfer tubes 222p arranged along the second plane parallel to the first plane, and has the first stage 222a in the direction perpendicular to the first plane (Y-axis direction). Next to each other. The first plane and the second plane are planes parallel to the ZX plane.

As shown in FIG. 16, for example, between the first stage 222a and the second stage 222b, the first stage 222a intersects a tangible object from one end to the other end in the arrangement direction of the plurality of heat transfer tubes 222p of the first stage 222a. There is a virtual plane that does not.

As shown in FIG. 16, for example, the plurality of heat transfer tubes 222p in the first stage 222a and the plurality of heat transfer tubes 222p in the second stage 222b are rectangular in a third plane perpendicular to the longitudinal direction (X-axis direction) of the heat transfer tube 222p. It forms a grid, a square grid, or a parallelogram grid. The third plane is a plane parallel to the YZ plane.

As shown in FIG. 16, the spray axis Am of the spray pattern of the liquid phase refrigerant sprayed from the nozzle 224 is the first end portion 222j of the plurality of heat transfer tubes 222p of the first stage 222a and the plurality of transmissions of the second stage 222b. It passes between the hot tube 222p and the second end 222k. The first end portion 222j is an end portion close to the second stage 222b in the direction perpendicular to the first plane (Y-axis direction). The second end portion 222k is an end portion close to the first stage 222a in the direction perpendicular to the first plane (Y-axis direction). The spray pattern of the liquid phase refrigerant sprayed from the nozzle 224 passes between the first stage 222a and the second stage 222b.

The second stage 222b is arranged below the first stage 222a in the direction of gravity, for example. The heat transfer tube group 222 includes, for example, the lower heat transfer tube group 222c. The lower heat transfer tube group 222c has a plurality of heat transfer tubes 222p and is arranged below the second stage 222b in the direction of gravity. Each of the plurality of heat transfer tubes 222p of the lower heat transfer tube group 222c is arranged directly under any one of the plurality of heat transfer tubes 222p of the second stage 222b, for example.

As shown in FIG. 16, the plurality of heat transfer tubes 222p of the lower heat transfer tube group 222c form a rectangular lattice or a square lattice in the third plane together with, for example, the plurality of heat transfer tubes 222p of the second stage 222b.

[3-2. motion]
As described above, the operation and operation of the evaporator 201 configured as the shell-and-tube heat exchanger will be described below.

In the steady operation of the refrigeration cycle device 200, in the evaporator 201, the pump 226 operates and the liquid phase refrigerant is supplied to the nozzle 224 through the circulation circuit 225 and the header 223. As a result, the liquid phase refrigerant is sprayed from the nozzle 224 toward the heat transfer tube group 222. On the other hand, the heat medium is guided from the outside of the evaporator 201 to the inside of the first cover 229a through the secondary side inflow port 228a. Next, the heat medium passes through the inside of the heat transfer tube 222p in the positive direction of the X-axis and is guided to the space below the partition plate 229d inside the second cover 229b. The direction of the flow of the heat medium is reversed inside the second cover 229b, and the heat medium passes through the inside of the heat transfer tube 222p in the negative direction of the X-axis and is between the two partition plates 229c inside the first cover 229a. Guided to space. Next, the direction of the flow of the heat medium is reversed inside the first cover 229a, and the heat medium passes through the inside of the heat transfer tube 222p in the positive direction of the X axis and is above the partition plate 229d inside the second cover 229b. Guided to the space of. The direction of the flow of the heat medium is reversed inside the second cover 229b, and the heat medium passes through the inside of the heat transfer tube 222p in the negative direction of the X-axis and is guided to the inside of the first cover 229a. After that, the heat medium is guided to the outside of the evaporator 201 through the secondary side outlet 228b.

As shown in FIG. 14, the nozzle 224 sprays the liquid phase refrigerant toward the space between the two adjacent stages of heat transfer tubes in the Y-axis direction. The liquid phase refrigerant is sprayed in a spray pattern in which the spray axis Am extends between the two stages. The mist-like liquid-phase refrigerant generated by spraying the liquid-phase refrigerant adheres to the outer surface of the heat transfer tube 222p. By heat exchange between the heat medium inside the heat transfer tube 222p and the liquid phase refrigerant adhering to the outer surface of the heat transfer tube 222p, the liquid phase refrigerant evaporates to generate a gas phase refrigerant. The liquid-phase refrigerant that has not evaporated flows along the outer surface of the heat transfer tube 222p and is dropped toward the lower heat transfer tube 222p.

As shown in FIG. 15, for example, when the first stage 222a is viewed from the direction perpendicular to the first plane (Y-axis direction), the spray axis Am is perpendicular to the central axis Ax of the heat transfer tube 222p of the first stage 222a. A spray pattern of the liquid phase refrigerant is formed so as to extend. In the heat transfer tube group 222, the distance L between the heat transfer tube 222p closest to the nozzle 224 in the Z-axis direction and the nozzle 224 has a predetermined size. Therefore, the spray area M of the liquid phase refrigerant gradually expands from the front row heat transfer tube 222p in the first stage 222a toward the last row heat transfer tube 222p, and the outer surface of the last row heat transfer tube 222p in the first stage 222a. A sufficient range of is wet with the liquid phase refrigerant.

As shown in FIG. 16, the liquid phase refrigerant sprayed from the nozzle 224 is transmitted in the first stage 222a and the second stage 222b arranged so as to form a rectangular grid, a square grid, or a parallelogram grid in the third plane. It passes between the hot tubes 222p. Between the first stage 222a and the second stage 222b, there is no member such as a heat transfer tube that directly hinders the progress of the liquid phase refrigerant sprayed from the nozzle 224. Therefore, the liquid phase refrigerant sprayed from the nozzle 224 easily travels straight between the first stage 222a and the second stage 222b. On the other hand, a part of the liquid phase refrigerant sprayed from the nozzle 224 comes into contact with the first end portion 222j of the heat transfer tube 222p of the first stage 222a and the second end portion 222k of the heat transfer tube 222p of the second stage 222b. A part of the liquid phase refrigerant in contact with the heat transfer tube 222p of the first stage 222a flows in the positive direction of the Y axis along the leading edge of the heat transfer tube 222p with respect to the flow of the liquid phase refrigerant. On the other hand, a part of the liquid phase refrigerant in contact with the heat transfer tube 222p of the second stage 222b flows in the negative direction on the Y axis along the leading edge of the heat transfer tube 222p. In addition, another portion of the liquid phase refrigerant flows in the negative Y-axis direction along the trailing edge of the heat transfer tube 222p of the second stage 222b. Such a flow of the liquid phase refrigerant occurs around the heat transfer tubes 222p in each row of the first stage 222a and the second stage 222b.

As shown in FIG. 16, in the upper heat transfer tube group 222m composed of the first stage 222a and the second stage 222b, the liquid phase refrigerant comes into direct contact with the outer surface of the heat transfer tube 222p to cause heat transfer accompanied by forced convection, and the liquid phase refrigerant occurs. Heat exchange between and the heat medium is promoted.

The liquid phase refrigerant forms a liquid film while flowing in the negative direction of the Y axis on the outer surface of the heat transfer tube 222p of the second stage 222b, and a part of the liquid phase refrigerant forming the liquid film evaporates. The unevaporated liquid-phase refrigerant that could not be completely evaporated in the upper heat transfer tube group 222m is dropped from the lowermost portion of the heat transfer tube 222p of the second stage 222b toward the heat transfer tube 222p of the lower heat transfer tube group 222c. The dropped liquid phase refrigerant flows downward while forming a liquid film on the outer surface of the heat transfer tube 222p, some of the liquid phase refrigerant evaporates, and another part of the liquid phase refrigerant is further below the heat transfer tube 222p. It is dropped toward. Such flow and dripping of the liquid phase refrigerant occurs around the heat transfer tubes 22p in each row of the lower heat transfer tube group 222c. In this way, the liquid phase refrigerant sprayed from the nozzle 224 is dropped from the heat transfer tube 222p of the upper heat transfer tube group 222m and indirectly supplied around the heat transfer tube 222p of the lower heat transfer tube group 222c. The liquid phase refrigerant remaining after the dropping is stored in the bottom of the shell 221.

Around the heat transfer tube 222p of the upper heat transfer tube group 222m, the liquid phase refrigerant sprayed from the nozzle 224 is directly supplied to generate forced convection. Since the nozzle 224 sprays the liquid phase refrigerant in a flat spray pattern having a spray shaft Am, the liquid phase refrigerant easily travels straight between the first stage 222a and the second stage 222b. As a result, in the upper heat transfer tube group 222 m, forced convection of the liquid phase refrigerant is likely to occur even around the heat transfer tube 222p far from the nozzle 224. Therefore, the outer surface of the heat transfer tube 222p distant from the nozzle 224 is easily wetted with the liquid phase refrigerant, and dryout is less likely to occur on the outer surface of the heat transfer tube 222p distant from the nozzle 224.

In addition, since the liquid phase refrigerant is dropped from the heat transfer tube 222p of the upper heat transfer tube group 222m toward the lower heat transfer tube group 22c, even on the outer surface of the heat transfer tube 222p far from the nozzle 224 in the lower heat transfer tube group 222c. A liquid film of a liquid phase refrigerant is likely to be formed. Therefore, the outer surface of the heat transfer tube 22p located far from the nozzle 224 is easily wetted with the liquid phase refrigerant, and dryout is unlikely to occur on the outer surface of the heat transfer tube 222p far away.

[3-3. Effect, etc.]
As described above, in the present embodiment, the evaporator 201 configured as a shell-and-tube heat exchanger includes a shell 221, a heat transfer tube group 222, and a nozzle 224. The heat transfer tube group 222 is arranged inside the shell 221. The nozzle 224 sprays the liquid phase refrigerant toward the heat transfer tube group 222. The heat transfer tube group 222 includes a first stage 222a and a second stage 222b. The first stage 222a has a plurality of heat transfer tubes 222p arranged along the first plane. The second stage 222b has a plurality of heat transfer tubes 222p arranged along the second plane parallel to the first plane, and is adjacent to the first stage 222a in the direction perpendicular to the first plane. The nozzle 224 has a spray axis Am and sprays the liquid phase refrigerant in a flat spray pattern passing between the first stage 222a and the second stage 222b. The spray shaft Am passes between the first end portion 222j of the plurality of heat transfer tubes 222p of the first stage 222a and the second end portion 222k of the plurality of heat transfer tubes 222p of the second stage 222b. The first end portion 222j is an end portion close to the second stage 222b of the plurality of heat transfer tubes 222p of the first stage 222a in the direction perpendicular to the first plane. The second end portion 222k is an end portion close to the first stage 222a of the plurality of heat transfer tubes 222p of the second stage 222b in the direction perpendicular to the first plane.

As a result, the nozzle 224 sprays the liquid phase refrigerant in a flat spray pattern having a spray shaft Am, so that the liquid phase refrigerant easily travels straight between the first stage 222a and the second stage 222b. Therefore, in the first stage 222a and the second stage 222b, forced convection of the liquid phase refrigerant is likely to occur even around the heat transfer tube 222p far from the nozzle 224. As a result, the outer surface of the heat transfer tube 222p distant from the nozzle 224 is easily wetted with the liquid phase refrigerant, and dryout is less likely to occur on the outer surface of the heat transfer tube 222p distant from the nozzle 224.

As in the present embodiment, between the first stage 222a and the second stage 222b, the first stage 222a does not intersect the tangible object from one end to the other end in the arrangement direction of the plurality of heat transfer tubes 222p of the first stage 222a. A virtual plane may exist. As a result, between the first stage 222a and the second stage 222b, the liquid phase refrigerant easily travels straight from one end to the other end of the first stage 222a, and dryout occurs more reliably on the outer surface of the distant heat transfer tube 222p. It's hard to do.

As in the present embodiment, the plurality of heat transfer tubes 222p of the first stage 222a and the plurality of heat transfer tubes 222p of the second stage 222b are rectangular grids, square grids, in a third plane perpendicular to the longitudinal direction of the heat transfer tubes 222p. Alternatively, it may form a parallelogram lattice. As a result, the flow of the liquid phase refrigerant between the first stage 222a and the second stage 222b is likely to be stable and straight. As a result, dryout is less likely to occur more reliably on the outer surface of the distant heat transfer tube 222p.

As in the present embodiment, the second stage 222b may be arranged below the first stage 222a in the direction of gravity. In addition, the heat transfer tube group 222 may include a lower heat transfer tube group 222c having a plurality of heat transfer tubes 222p and arranged below the second stage 222b in the direction of gravity. As a result, the liquid phase refrigerant is dropped from the second stage 222b toward the lower heat transfer tube group 222c, and the outer surface of the heat transfer tube 222p distant from the nozzle 224 in the lower heat transfer tube group 222c is also easily wetted by the liquid phase refrigerant. As a result, dryout is unlikely to occur on the outer surface of the distant heat transfer tube 222p of the lower heat transfer tube group 222c. In this case, even if the plurality of heat transfer tubes 222p of the first stage 222a and the plurality of heat transfer tubes 222p of the second stage 222b form a rectangular grid or a square grid in a third plane perpendicular to the longitudinal direction of the heat transfer tube 222p. good. As a result, the liquid phase refrigerant is more likely to drip toward the lower heat transfer tube group 222c more reliably.

As in the present embodiment, the plurality of heat transfer tubes 222p of the lower heat transfer tube group 222c, together with the plurality of heat transfer tubes 222p of the second stage 222b, form a rectangular lattice or a square lattice in the third plane. As a result, the liquid phase refrigerant dropped from the plurality of heat transfer tubes 222p of the second stage 222b more reliably forms a liquid film on the outer surface of each heat transfer tube 222p of the lower heat transfer tube group 222c, and it is easy to wet the outer surface thereof. As a result, dryout is less likely to occur more reliably on the outer surface of the distant heat transfer tube 222p of the lower heat transfer tube group 222c.

As in the present embodiment, it is possible to provide a refrigeration cycle apparatus 200 provided with an evaporator 201 configured as a shell-and-tube heat exchanger. Since dryout is unlikely to occur on the outer surface of the heat transfer tube 222p far from the nozzle 224, the refrigeration cycle apparatus 200 tends to exhibit a high coefficient of performance (COP).

According to this embodiment, it is possible to provide a heat exchange method including the following items (I) and (II).
(I) A heat medium is passed inside the heat transfer tube group 222 including the first stage 222a and the second stage 222b. The first stage 222a has a plurality of heat transfer tubes arranged along the first plane. The second stage 222b has a plurality of heat transfer tubes 222p arranged along the second plane parallel to the first plane, and is adjacent to the first stage 222a in the direction perpendicular to the first plane.
(II) A liquid phase refrigerant is sprayed toward the heat transfer tube group 222 with a flat spray pattern having a spray shaft Am and passing between the first stage 222a and the second stage 222b, and the heat medium and the liquid are sprayed. Heat exchanges with the phase refrigerant. The spray shaft Am has a first end portion 222j close to the second stage 222b of the plurality of heat transfer tubes 222p of the first stage 222a and a second end portion close to the first stage 222a of the plurality of heat transfer tubes 222p of the second stage 222b. Pass between 222k.

(Embodiment 4)
Hereinafter, the fourth embodiment will be described with reference to FIG. The fourth embodiment is configured in the same manner as the third embodiment except for a part to be described in particular. The same components as those of the third embodiment or the corresponding components of the fourth embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The description of Embodiment 3 also applies to Embodiment 4, as long as it is not technically inconsistent.

[4-1. Constitution]
FIG. 17 shows a region where the liquid phase refrigerant is sprayed from the nozzle 224 in the fourth embodiment. In FIG. 17, the spray area M of the liquid phase refrigerant sprayed from the heat transfer tube group 222 and the nozzle 224 is seen along the Y-axis direction. As shown in FIG. 17, when the first stage 222a is viewed along the direction perpendicular to the first plane (Y-axis direction), the spray axis Am of the spray pattern of the liquid phase refrigerant sprayed from the nozzle 224 is a straight line. It forms an acute angle θ of a predetermined size with respect to P. The straight line P extends perpendicularly to the longitudinal direction (X-axis direction) of the heat transfer tube 222p of the first stage 222a.

The acute angle θ is not limited to a specific value. The acute angle θ is, for example, α / 2. α is the central angle of the spray area M. For example, the central angle α is 80 ° and the acute angle θ is 40 °.

[4-2. motion]
The operation and operation of the second embodiment configured as described above will be described below.

As shown in FIG. 17, the liquid phase refrigerant is sprayed from the nozzle 224 so that the spray axis Am forms an acute angle θ with respect to the straight line P. Even when the nozzle 224 is arranged near the heat transfer tube group 222, the range of the heat transfer tube group 222 that overlaps with the spray area M on the XZ plane tends to be large. For example, the first contour line W1 of the spray area M tends to extend along the straight line P, and the second contour line W2 of the spray area M tends to extend along the central axis Ax of the heat transfer tube 22p.

When the nozzle 224 is arranged so that the spray axis Am is parallel to the straight line P, in other words, the nozzle 224 is arranged so that the spray axis Am is perpendicular to the central axis Ax of the heat transfer tube 222p. think. In this case, when the distance L is small and the nozzle 224 is arranged near the heat transfer tube group 222, the range in which the heat transfer tube 222p near the nozzle 224 of the heat transfer tube group 222 and the spray area M overlap on the XZ plane is small. Become. In particular, the portion of the heat transfer tube 222p away from the nozzle 224 in the longitudinal direction is unlikely to overlap with the spray area M. As a result, on the outer surface of the heat transfer tube 222p of the heat transfer tube group 222, a portion where the liquid phase refrigerant sprayed from the nozzle 224 is difficult to reach is likely to occur. On the other hand, according to the present embodiment, it is possible to suppress the occurrence of such a state. Therefore, a wide range of the outer surface of the heat transfer tube 222p of the heat transfer tube group 222 can be wetted with the liquid phase refrigerant, and dryout is less likely to occur on the outer surface of the heat transfer tube 222p.

As shown in FIG. 17, when the liquid phase refrigerant is sprayed so that the spray axis Am forms an acute angle θ with respect to the straight line P, the liquid phase refrigerant sprayed from the nozzle 224 causes a flow C1 and a flow C2. The flow C1 is a flow of the liquid phase refrigerant passing between the heat transfer tubes 222p in the first stage 222a and the second stage 222b. The flow C2 is a flow of the liquid phase refrigerant that collides with the leading edge of the outer surface of the heat transfer tube 222p and moves along the longitudinal direction (X-axis direction) of the heat transfer tube 222p. Since a part of the liquid phase refrigerant sprayed from the nozzle 224 collides with the front edge of the outer surface of the heat transfer tube 222p in a state of having a velocity component in the X-axis direction, such a flow of the liquid phase refrigerant occurs. ..

The flow C1 is a flow of the liquid phase refrigerant spread so as to form the spray area M at the central angle α sprayed from the nozzle 224. The liquid phase refrigerant in this flow C1 is in contact with the first end portion 222j of the plurality of heat transfer tubes 222p of the first stage 222a or the second end portion 222k of the plurality of heat transfer tubes 222p of the second stage 222b, while being in contact with the first stage. It passes between 222a and the second stage 222b.

Due to the generation of the flow C1 and the flow C2, in addition to the movement of the liquid phase refrigerant in the arrangement direction (Z-axis direction) of the plurality of heat transfer tubes 222p in the first stage 222a, in addition to the movement of the liquid phase refrigerant in the longitudinal direction (X-axis direction) of the heat transfer tubes 22p. The movement of the liquid phase refrigerant also occurs. Therefore, heat transfer accompanied by forced convection is promoted. In addition, as described above, a wide range of the outer surface of the heat transfer tube 222p of the heat transfer tube group 222, including the heat transfer tube 222p close to the nozzle 224, is wetted with the liquid phase refrigerant.

[4-3. Effect, etc.]
As described above, in the present embodiment, when the first stage 222a is viewed along the direction perpendicular to the first plane (Y-axis direction), the spray axis Am has a predetermined size with respect to the straight line P. Makes an acute angle θ.

As a result, even if the nozzle 224 is arranged near the heat transfer tube group 222, a wide range of the outer surface of the heat transfer tube 222p of the heat transfer tube group 222 can be wetted with the liquid phase refrigerant, and the dry out on the outer surface of the heat transfer tube 222p. Is unlikely to occur.

For example, in order to support the operation of the refrigeration cycle device 200 under a light load condition, it is conceivable to reduce the supply pressure of the liquid phase refrigerant to the nozzle 224. In this case, the central angle in the spray pattern of the liquid phase refrigerant sprayed from the nozzle 224 becomes small, and the spray area M may become narrow. Further, the flow rate of the liquid phase refrigerant sprayed from the nozzle 224 may decrease. However, according to the present embodiment, even in such a case, the desired range of the outer surface of the heat transfer tube 222p of the heat transfer tube group 222 can be wetted with the liquid phase refrigerant, and the outer surface of the heat transfer tube 222p is dried out. Is unlikely to occur.

(Embodiment 5)
Hereinafter, the fifth embodiment will be described with reference to FIG. The fifth embodiment is configured in the same manner as the third embodiment except for a part to be described in particular. The same components as those of the third embodiment or the corresponding components of the fifth embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The description of Embodiment 3 also applies to Embodiment 5, as long as it is not technically inconsistent.

[5-1. Constitution]
FIG. 18 shows the state of spraying and flow of the liquid phase refrigerant in the evaporator 201 according to the fifth embodiment. As shown in FIG. 18, the heat transfer tube group 222 has a distal heat transfer tube 222d. The distal heat transfer tube 222d is arranged at a position intersecting the spray axis Am. For example, the distal heat transfer tube 222d intersects the central axis of the nozzle 224. The first stage 222a is arranged between the nozzle 224 and the distal heat transfer tube 222d in the arrangement direction (Z-axis direction) of the plurality of heat transfer tubes 222p of the first stage 222a.

As shown in FIG. 18, the heat transfer tube group 222 has, for example, a lower heat transfer tube 222e. The lower heat transfer tube 222e is arranged directly below the distal heat transfer tube 222d in the direction of gravity.

The distal heat transfer tube 222d and the lower heat transfer tube 222e have, for example, the same shape and dimensions as the heat transfer tube 222p in the first stage 222a, the second stage 222b, or the lower heat transfer tube group 222c.

[5-2. motion]
The operation and operation of the fifth embodiment configured as described above will be described below.

The liquid phase refrigerant that has passed between the first stage 222a and the second stage 222b collides with the distal heat transfer tube 222d and is captured. Therefore, the heat transfer associated with forced convection around the distal heat transfer tube 222d is significantly promoted as compared with the heat transfer associated with forced convection around the heat transfer tube 222p in the first stage 222a and the second stage 222b. .. In addition, the outer surface of the distal heat transfer tube 222d located distant from the nozzle 224 can be wetted with the liquid phase refrigerant, and dryout can be suppressed on the outer surface of the heat transfer tube distant from the nozzle 224.

The liquid phase refrigerant that has collided with the distal heat transfer tube 222d flows along the outer surface of the distal heat transfer tube 222d and is dropped toward the lower heat transfer tube 222e. As a result, the outer surface of the lower heat transfer tube 222e located far from the nozzle 224 can be wetted with the liquid phase refrigerant, and dryout can be suppressed on the outer surface of the heat transfer tube far from the nozzle 224.

[5-3. Effect, etc.]
As described above, in the present embodiment, the heat transfer tube group 222 has the distal heat transfer tube 222d, and the distal heat transfer tube 222d is arranged at a position where the distal heat transfer tube 222d intersects the spray axis Am. In addition, the first stage 222a is arranged between the nozzle 224 and the distal heat transfer tube 222d in the arrangement direction of the plurality of heat transfer tubes 222p of the first stage 222a.

As a result, heat transfer associated with forced convection around the distal heat transfer tube 222d is greatly promoted, and dryout can be suppressed on the outer surface of the distal heat transfer tube 222d located far from the nozzle 224.

For example, even when a sudden load fluctuation occurs in the refrigerating cycle device 200 and the supply pressure of the liquid phase refrigerant to the nozzle 224 changes, the heat transfer tube group is stable regardless of the supply pressure of the liquid phase refrigerant to the nozzle 224. The outer surface of the heat transfer tube 222p of 222 can be wetted. Therefore, the outer surface of the heat transfer tube 222p of the heat transfer tube group 222 can be wetted with a liquid phase refrigerant in a desired state under a wide range of operating conditions including light load conditions and overload conditions.

For example, when the refrigeration cycle device 200 is an absorption chiller, the vapor phase refrigerant generated in the evaporator 201 can be supplied toward the absorber. At this time, from the viewpoint of increasing the COP of the absorption chiller, it is desirable to prevent the liquid phase refrigerant from being guided to the absorber by riding on the flow of the gas phase refrigerant supplied from the evaporator 201. According to the present embodiment, the liquid phase refrigerant that has passed between the first stage 222a and the second stage 222b collides with the distal heat transfer tube 222d and is captured. Therefore, it is easy to prevent the liquid phase refrigerant from being guided from the evaporator 201 toward the absorber.

As in the present embodiment, the heat transfer tube group 222 may have a lower heat transfer tube 222e arranged directly under the distal heat transfer tube 222d in the direction of gravity. As a result, the outer surface of the lower heat transfer tube 222e can be wetted with the liquid phase refrigerant dropped from the distal heat transfer tube 222d.

(Other embodiments)
As described above, embodiments 3, 4, and 5 have been described as examples of the techniques disclosed in the present application. However, the technique in the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, etc. have been made. Further, it is also possible to combine the constituent elements described in the above-described embodiments 3, 4, and 5 to form a new embodiment. Therefore, other embodiments will be exemplified below.

In the third embodiment, as an example of the shell-and-tube heat exchanger, the evaporator 201 provided with the nozzle 224 for spraying the liquid phase refrigerant is shown. In the shell-and-tube heat exchanger, the nozzle 224 may be any one that sprays a liquid. Therefore, the liquid sprayed from the nozzle 224 is not limited to the liquid phase refrigerant. Therefore, the liquid sprayed from the nozzle 224 may be a cooling liquid used for condensing the gas phase refrigerant in the condenser of the refrigerating cycle device, or may be another liquid. However, if the liquid sprayed from the nozzle 224 is a liquid phase refrigerant, the shell-and-tube heat exchanger can be used as an evaporator in the refrigeration cycle apparatus.

In the third embodiment, as an example of the shell-and-tube heat exchanger, the evaporator 201 in which the spray shaft Am extends horizontally is shown. The spray shaft Am has a first end portion 222j close to the second stage 222b of the plurality of heat transfer tubes 222p of the first stage 222a and a second end portion close to the first stage 222a of the plurality of heat transfer tubes 222p of the second stage 222b. Anything that passes between 222k and 22k may be used. Therefore, the spray axis Am may be inclined with respect to the horizontal plane. However, when the spray shaft Am extends horizontally, it is easy to arrange the plurality of heat transfer tubes 222p in the first stage 222a and the second stage 222b.

In the third embodiment, between the first stage 222a and the second stage 222b, a virtual object that does not intersect the tangible object from one end to the other end of the first stage 222a in the arrangement direction of the plurality of heat transfer tubes 222p of the first stage 222a. Explained that a plane may exist. In the shell-and-tube heat exchanger, the spray shaft Am is between the first end portion 222j of the plurality of heat transfer tubes 222p of the first stage 222a and the second end portion 222k of the plurality of heat transfer tubes 222p of the second stage 222b. Should have passed. Therefore, between the first stage 222a and the second stage 222b, a member such as a wire rod or a rod that has almost no effect on the flow of the liquid sprayed from the nozzle 224 and does not affect the formation of the spray shaft Am. May be arranged.

In the fifth embodiment, an example in which the distal heat transfer tube 222d has the same shape and dimensions as the heat transfer tube 222p has been described. In the shell-and-tube heat exchanger, the distal heat transfer tube 222d may be arranged at a position intersecting the spray axis Am. Therefore, the shape and dimensions of the distal heat transfer tube 222d are not limited to the same as the shape and dimensions of the heat transfer tube 222p. However, if the distal heat transfer tube 222d has the same shape and dimensions as the heat transfer tube 222p, it is not necessary to prepare the distal heat transfer tube 222d separately from the heat transfer tube 222p, and production control is easy. Further, as the distal heat transfer tube 222d, a tube having an outer diameter larger than the outer diameter of the heat transfer tube 222p may be used. In this case, the liquid phase refrigerant can be more reliably captured by the distal heat transfer tube 222d.

The shell-and-tube heat exchangers disclosed herein are particularly useful for air conditioners such as commercial air conditioners. The shell-and-tube heat exchanger may be used as a condenser as well as an evaporator. The refrigerating cycle device disclosed in the present specification is not limited to the air conditioner, and may be another device such as an absorption chiller, a chiller, or a heat storage device.

Claims

With the shell
A plurality of heat transfer tubes arranged inside the shell,
Equipped with a nozzle,
The following conditions (Ia), (Ib), (Ic), and (Id), or the following conditions (IIa), (IIb), (IIc), and (IId),
Shell and tube heat exchanger.
(Ia) The plurality of heat transfer tubes are arranged parallel to each other inside the shell, and the first fluid flows through the plurality of heat transfer tubes.
(Ib) The nozzle is arranged inside the shell and includes a plurality of nozzles that spray a second fluid toward the plurality of heat transfer tubes.
(Ic) The direction parallel to the longitudinal direction of the plurality of heat transfer tubes is defined as the X direction, the direction perpendicular to the X direction is defined as the Y direction, and the X direction and the direction perpendicular to the Y direction are the Z direction. When defined as
The plurality of nozzles include a plurality of first nozzles that spray the second fluid from the first side to the second side in the Z direction, and the first side to the second side in the Z direction. It includes a plurality of second nozzles for spraying the second fluid.
(Id) In a projection image obtained by projecting the plurality of first nozzles and the plurality of second nozzles in the Z direction, the plurality of first nozzles and the plurality of second nozzles are arranged in a staggered pattern. Show the pattern.
(IIa) The plurality of heat transfer tubes form a heat transfer tube group.
(IIb) The nozzle sprays a liquid toward the heat transfer tube group.
(IIc) The heat transfer tube group has a first stage having a plurality of heat transfer tubes arranged along the first plane and a plurality of heat transfer tubes arranged along a second plane parallel to the first plane. And includes a second stage adjacent to the first stage in a direction perpendicular to the first plane.
(IId) The nozzle has a first end portion of the plurality of heat transfer tubes in the first stage near the second stage in a direction perpendicular to the first plane, and the first stage in a direction perpendicular to the first plane. A flat spray pattern that has a spray shaft that passes between the two-stage heat transfer tubes and the second end near the first stage, and that passes between the first stage and the second stage. The liquid is sprayed with.
The shell-and-tube heat exchanger according to claim 1, which satisfies the conditions of (Ia), (Ib), (Ic), and (Id).
The spray axis of the first nozzle and the spray axis of the second nozzle are parallel to the inclined direction with respect to both the X direction and the Z direction.
The shell-and-tube heat exchanger according to claim 2.
When viewed in a plan view from the Y direction, the spray axis of the first nozzle passes through the center of the opening of the first nozzle and is inclined clockwise with respect to the first reference line parallel to the Z direction. ,
When viewed in a plan view from the Y direction, the spray axis of the second nozzle passes through the center of the opening of the second nozzle and is inclined counterclockwise with respect to the second reference line parallel to the Z direction. Yes,
The shell-and-tube heat exchanger according to claim 3.
When viewed in a plan view from the Y direction, the angle formed by the spray axis of the first nozzle and the first reference line is equal to the angle formed by the spray axis of the second nozzle and the second reference line.
The shell-and-tube heat exchanger according to claim 4.
The plurality of nozzles are a plurality of third nozzles that spray the second fluid from the second side to the first side in the Z direction, and from the second side to the first side in the Z direction. Includes a plurality of fourth nozzles that spray the second fluid towards.
In the projection image obtained by projecting the plurality of third nozzles and the plurality of fourth nozzles in the Z direction, the plurality of third nozzles and the plurality of fourth nozzles show a staggered arrangement pattern. ,
The shell-and-tube heat exchanger according to any one of claims 2 to 5.
The spray axis of the third nozzle and the spray axis of the fourth nozzle are parallel to the inclined direction with respect to both the X direction and the Z direction.
The shell and tube heat exchanger according to claim 6.
When viewed in a plan view from the Y direction, the spray axis of the third nozzle passes through the center of the opening of the third nozzle and is inclined clockwise with respect to the third reference line parallel to the Z direction. ,
When viewed in a plan view from the Y direction, the spray axis of the fourth nozzle passes through the center of the opening of the fourth nozzle and is inclined counterclockwise with respect to the fourth reference line parallel to the Z direction. Yes,
The shell-and-tube heat exchanger according to claim 7.
When viewed in a plan view from the Y direction, the angle formed by the spray axis of the third nozzle and the third reference line is equal to the angle formed by the spray axis of the fourth nozzle and the fourth reference line.
The shell-and-tube heat exchanger according to claim 7 or 8.
In a plan view from the Y direction, the positions of the plurality of third nozzles are offset in the X direction with respect to the positions of the plurality of first nozzles.
In a plan view from the Y direction, the positions of the plurality of fourth nozzles are offset in the X direction with respect to the positions of the plurality of second nozzles.
The shell-and-tube heat exchanger according to any one of claims 6 to 9.
In the Y direction, the spray shafts of the plurality of first nozzles pass between the heat transfer tubes adjacent to each other and the heat transfer tubes.
In the Y direction, the spray shafts of the plurality of second nozzles pass between the heat transfer tubes adjacent to each other and the heat transfer tubes.
The shell-and-tube heat exchanger according to any one of claims 2 to 10.
In the Y direction, the spray shafts of the plurality of third nozzles pass between the heat transfer tubes adjacent to each other and the heat transfer tubes.
In the Y direction, the spray shafts of the plurality of fourth nozzles pass between the heat transfer tubes adjacent to each other and the heat transfer tubes.
The shell-and-tube heat exchanger according to any one of claims 6 to 10.
In a cross section perpendicular to the X direction and parallel to the Y direction and the Z direction, the plurality of heat transfer tubes are located on grid points of a square lattice.
The shell-and-tube heat exchanger according to any one of claims 2 to 12.
The plurality of heat transfer tubes include a circular tube having a circular cross section.
The shell-and-tube heat exchanger according to any one of claims 2 to 13.
A refrigeration cycle apparatus provided with the shell-and-tube heat exchanger according to any one of claims 2 to 14.
The shell-and-tube heat exchanger according to claim 1, which satisfies the conditions of (IIa), (IIb), (IIc), and (IId).
Between the first stage and the second stage, there is a virtual plane that does not intersect the tangible object from one end to the other end of the first stage in the arrangement direction of the plurality of heat transfer tubes of the first stage.
The shell-and-tube heat exchanger according to claim 16.
The plurality of heat transfer tubes in the first stage and the plurality of heat transfer tubes in the second stage form a rectangular grid, a square grid, or a parallelogram grid in a third plane perpendicular to the longitudinal direction of the heat transfer tubes. ing,
The shell-and-tube heat exchanger according to claim 16 or 17.
The second stage is arranged below the first stage in the direction of gravity.
The heat transfer tube group includes a lower heat transfer tube group having a plurality of heat transfer tubes and arranged below the second stage in the direction of gravity.
The shell-and-tube heat exchanger according to any one of claims 16 to 18.
The plurality of heat transfer tubes of the lower heat transfer tube group, together with the plurality of heat transfer tubes of the second stage, form a rectangular lattice or a square lattice in a third plane perpendicular to the longitudinal direction of the heat transfer tubes.
The shell-and-tube heat exchanger according to claim 19.
When the first stage is viewed along a direction perpendicular to the first plane, the spray axis has a predetermined size with respect to a straight line extending perpendicular to the longitudinal direction of the heat transfer tube of the first stage. Make a sharp angle,
The shell-and-tube heat exchanger according to any one of claims 16 to 20.
The heat transfer tube group has a distal heat transfer tube arranged at a position intersecting the spray axis.
The first stage is arranged between the nozzle and the distal heat transfer tube in the arrangement direction of the plurality of heat transfer tubes of the first stage.
The shell-and-tube heat exchanger according to any one of claims 16 to 21.
The group of heat transfer tubes has a lower heat transfer tube arranged directly below the distal heat transfer tube in the direction of gravity.
22. The shell and tube heat exchanger according to claim 22.
A refrigeration cycle apparatus provided with the shell-and-tube heat exchanger according to any one of claims 16 to 23.
It has a first stage having a plurality of heat transfer tubes arranged along the first plane, and a plurality of heat transfer tubes arranged along a second plane parallel to the first plane, and is perpendicular to the first plane. Passing the heat medium inside the heat transfer tube group including the first stage and the second stage adjacent to the first stage in the above direction.
The first end portion of the plurality of heat transfer tubes in the first stage near the second stage in the direction perpendicular to the first plane, and the plurality of heat transfer tubes in the second stage in the direction perpendicular to the first plane. It has a spray shaft that passes between the second end of the heat tube near the first stage, and has a flat spray pattern that passes between the first stage and the second stage toward the heat transfer tube group. A heat exchange method comprising spraying a liquid and exchanging heat between the heat medium and the liquid.