JP7411423B2 - Shell and tube heat exchanger and refrigeration cycle equipment - Google Patents

Description

The present disclosure relates to a shell-and-tube heat exchanger and a refrigeration cycle device.

A shell-and-tube heat exchanger is known as a heat exchanger for condensing or evaporating refrigerant. Shell-and-tube heat exchangers may be configured to spray refrigerant toward the heat transfer tubes.

FIG. 8 shows a conventional shell-and-tube type evaporator 2 described in Patent Document 1 (FIG. 21). The evaporator 2 has a shell 11, a plurality of tubes 15 and a plurality of sprays 14. The refrigerant liquid 12 is stored in a liquid reservoir 17 provided at the bottom of the shell 11, pumped up by a refrigerant pump 18, and sprayed toward the tube 15 via a sprayer 14. The refrigerant liquid 12 adheres to the surface of the tube 15 to form a liquid film 16 . As the refrigerant liquid 12 and the cold water flowing through the tubes 15 exchange heat, the refrigerant liquid 12 evaporates and the cold water is cooled.

Japanese Patent Application Publication No. 2000-230760

The conventional shell-and-tube type evaporator 2 shown in FIG. 8 still has room for improvement in terms of heat transfer performance.

The present disclosure provides a shell and tube heat exchanger with excellent heat transfer performance.

The shell and tube heat exchanger of the present disclosure includes:
shell and
a plurality of heat exchanger tube groups arranged inside the shell and connected in series so that the first fluid flows in sequence;
a plurality of spray units disposed inside the shell and spraying a second fluid toward the plurality of heat transfer tube groups;
Equipped with
The plurality of heat transfer tube groups and the plurality of spray units are arranged in a predetermined direction so that the heat transfer tube groups and the spray units appear alternately,
The plurality of spray units are configured to spray the first fluid in a specific direction, which is a direction from a heat transfer tube group located on the downstream side in the flow direction of the first fluid to a heat transfer tube group located on the upstream side in the flow direction of the first fluid. 2. Spray two fluids.

The refrigeration cycle device of the present disclosure includes:
The shell and tube heat exchanger of the present disclosure,
a compressor connected to the shell and tube heat exchanger;
It is equipped with

According to the present disclosure, a shell and tube heat exchanger having excellent heat transfer performance can be provided.

Configuration diagram of a refrigeration cycle device in Embodiment 1 of the present disclosure Longitudinal section of the evaporator along the line II-II Cross-sectional view of the heat exchanger tube used in the evaporator shown in Figure 2 Schematic top view showing the positional relationship of heat exchanger tubes and spray nozzles A graph schematically showing the relationship between the temperature Tw of the heat medium and the temperature Tr of the refrigerant in each of a plurality of heat transfer tube groups. A diagram schematically showing the relationship between the capacity of multiple heat transfer tube groups and the amount of refrigerant sprayed. A cross-sectional view of an evaporator in Embodiment 2 of the present disclosure Cross-sectional view of a conventional shell-and-tube evaporator

(Findings, etc. that formed the basis of this disclosure)
In the conventional evaporator 2 shown in FIG. 8, the temperature of the cold water flowing through the tube 15 is not constant. Therefore, excess or deficiency of refrigerant liquid 12 tends to occur on the surface of each tube 15. In other words, a thick liquid film may be formed on the surface of the tube 15 or dry-out may occur over a wide area. In this case, the heat transfer performance of the evaporator 2 cannot be fully exhibited. Based on such knowledge, the present inventors have come to form the subject matter of the present disclosure.

Therefore, the present disclosure provides a technique for improving the heat transfer performance of a shell-and-tube heat exchanger.

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 well-known matters or redundant explanations of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate understanding by those skilled in the art.

The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

(Embodiment 1)
Embodiment 1 will be described below using FIGS. 1 to 6.

[1-1. Configuration of refrigeration cycle device]
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, and channels 110a to 110d. The outlet of the evaporator 101 is connected to the inlet of the compressor 102 by a flow path 110a. The outlet of the compressor 102 is connected to the inlet of the condenser 103 by a flow path 110b. The outlet of the condenser 103 is connected to the inlet of the flow valve 104 by a flow path 110c. The outlet of the flow valve 104 is connected to the inlet of the evaporator 101 by a flow path 110d. Flow paths 110a and 110b are steam paths. The flow path 110c and the flow path 110d are liquid paths. Each route is composed of, for example, at least one metal pipe.

The evaporator 101 is constituted by a shell and tube heat exchanger, as will be described later.

Compressor 102 may be a velocity type compressor such as a centrifugal compressor, or may be a positive displacement compressor such as a scroll compressor.

The type of condenser 103 is not particularly limited. A heat exchanger such as a plate heat exchanger, a shell and tube heat exchanger, etc. may be used for the condenser 103.

The refrigeration cycle device 100 is, for example, an air conditioner for commercial 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 indoors through the circuit 106 and is used for heating the room. The heat medium is, for example, water. However, the refrigeration cycle device 100 is not limited to an air conditioner, and may be other devices such as a chiller or a heat storage device.

The circuit 105 is a circuit that circulates a heat medium through the evaporator 101. The circuit 106 is a circuit that circulates a heat medium through the condenser 103. Circuit 105 and circuit 106 may be sealed circuits isolated from the outside air.

The heat medium is the first fluid flowing through each of the circuits 105 and 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 in circuit 105 may be different from the composition of the heat medium in circuit 106.

[1-2. Operation of refrigeration cycle equipment]
When the compressor 102 is started, the refrigerant is heated and evaporated in the evaporator 101. As a result, a gas phase refrigerant is generated. The gas phase refrigerant is sucked into the compressor 102 and compressed. The compressed gas phase refrigerant is supplied from the compressor 102 to the condenser 103. The gas phase refrigerant is cooled in the condenser 103 and condensed and liquefied. As a result, liquid phase refrigerant is generated. The liquid phase refrigerant is returned to the evaporator 101 from the condenser 103 via the flow valve 104.

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

The refrigerant may be a refrigerant containing as a main component a substance having a negative saturated vapor pressure at room temperature. Examples of such refrigerants include refrigerants containing water, alcohol, or ether as a main component. "Main component" means the component contained in the largest amount in terms of mass ratio. "Negative pressure" means a pressure below atmospheric pressure in absolute terms. "Normal temperature" means a temperature within the range of 20° C.±15° C. according to Japanese Industrial Standards (JIS Z8703).

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

[1-3. Evaporator configuration]
FIG. 2 is a longitudinal cross-sectional view of the evaporator 101 along the line II-II. As shown in FIG. 2, the evaporator 101 is composed of a shell and tube heat exchanger. The evaporator 101 includes a shell 21, a plurality of heat transfer tube groups 22a to 22c, a plurality of spray units 24a to 24c, a circulation circuit 25, and a circulation pump 26. The plurality of heat exchanger tube groups 22a to 22c and the plurality of spray units 24a to 24c are arranged inside the shell 21. By efficiently evaporating the refrigerant in the evaporator 101, the efficiency of the refrigeration cycle (COP) can be improved.

The plurality of heat exchanger tube groups 22a, 22b, and 22c include a first heat exchanger tube group 22a, a second heat exchanger tube group 22b, and a third heat exchanger tube group 22c. The first heat exchanger tube group 22a, the second heat exchanger tube group 22b, and the third heat exchanger tube group 22c are arranged in a predetermined direction. In FIG. 2, the "predetermined direction" is a direction parallel to the X axis.

Each of the plurality of heat exchanger tube groups 22a, 22b, and 22c includes a plurality of heat exchanger tubes 22 and a pair of headers 23. In each of the plurality of heat exchanger tube groups 22a, 22b, and 22c, the plurality of heat exchanger tubes 22 are arranged in parallel to each other. The plurality of heat exchanger tubes 22 may be bundled by means other than the header 23.

The heat exchanger tube 22 is a multi-hole, flat heat exchanger tube. The heat medium flows from the inlet to the outlet of the heat transfer tube 22. In each of the plurality of heat transfer tube groups 22a, 22b, and 22c, the plurality of heat transfer tubes 22 are arranged between the headers 23 so that the flat heat transfer surfaces are parallel to the vertical direction. In FIG. 2, the direction parallel to the Z-axis is the vertical direction.

When heat exchanger tubes 22 having a flat shape are used in a shell-and-tube heat exchanger, it is possible to increase the mounting density of the heat exchanger tubes 22 inside the shell 21, so that the heat transfer per unit volume of the shell-and-tube heat exchanger can be increased. It is advantageous to increase the thermal area. In other words, using the heat exchanger tubes 22 having a flat shape is advantageous for downsizing the shell-and-tube heat exchanger.

Examples of the material for the heat exchanger tubes 22 include metal materials such as aluminum, aluminum alloy, and stainless steel.

FIG. 3 shows a cross section of the heat exchanger tube 22. The heat transfer tube 22 includes a tubular outer wall 41 and a plurality of partition walls 42 so as to have a pair of flat heat transfer surfaces 22p. A space surrounded by the outer wall 41 and the partition wall 42 is a heat medium flow path 43. The outer wall 41 and the partition wall 43 are each made of a thin plate. The thickness of the thin plate is, for example, in the range from 0.5 mm to 0.8 mm. The flow path 43 has, for example, a rectangular cross-sectional shape. In the cross section of the heat exchanger tube 22, one side of the flow path 43 ranges from 0.5 mm to 3 mm, for example. The flow path 43 may have a cross section of other shapes such as circular or triangular. Fine grooves or fins may be formed on the inner wall surface of the flow path 43 to increase the surface area.

The first heat exchanger tube group 22a, the second heat exchanger tube group 22b, and the third heat exchanger tube group 22c are connected in series so that the heat medium flows in this order. The first heat exchanger tube group 22a is connected to the second heat exchanger tube group 22b by a connecting pipe 29. The second heat exchanger tube group 22b is connected to the third heat exchanger tube group 22c by a connecting pipe 29. One end of the circuit 105 is connected to the header 23 of the first heat exchanger tube group 22a. The header 23 to which one end of the circuit 105 is connected forms the inlet of the plurality of heat exchanger tube groups 22a, 22b, and 22c. The other end of the circuit 105 is connected to the header 23 of the third heat exchanger tube group 22c. The header 23 to which the other end of the circuit 105 is connected forms the outlet of the plurality of heat exchanger tube groups 22a, 22b, and 22c. In the flow direction of the heat medium, the first heat exchanger tube group 22a is located upstream of the second heat exchanger tube group 22b. In the flow direction of the heat medium, the second heat exchanger tube group 22b is located upstream of the third heat exchanger tube group 22c.

The plurality of spray units 24a, 24b, and 24c play the role of spraying liquid phase refrigerant toward the plurality of heat transfer tube groups 22a, 22b, and 22c. The plurality of spray units 24a, 24b, and 24c include a first spray unit 24a, a second spray unit 24b, and a third spray unit 24c. Like the plurality of heat exchanger tube groups 22a, 22b, and 22c, the first spray unit 24a, the second spray unit 24b, and the third spray unit 24c are also arranged in a predetermined direction (direction parallel to the X-axis).

Each of the plurality of spray units 24a, 24b, and 24c includes a plurality of spray nozzles 24. In this embodiment, each of the spray units 24a, 24b, and 24c includes a plurality of spray nozzles 24 arranged in a matrix in a plane parallel to the vertical direction and the arrangement direction of the heat exchanger tubes 22. The arrangement of the plurality of spray nozzles 24 in the first spray unit 24a is equal to the arrangement of the plurality of spray nozzles 24 in the second spray unit 24b. The arrangement of the plurality of spray nozzles 24 in the first spray unit 24a is equal to the arrangement of the plurality of spray nozzles 24 in the third spray unit 24c. That is, in each of the plurality of spray units 24a, 24b, and 24c, the plurality of spray nozzles 24 are arranged in the same pattern. Such a configuration is excellent in cost and productivity of the evaporator 101. The same spray nozzle 24 may be used in each of the plurality of spray units 24a, 24b, and 24c. The phrase "identical" means identical in design structure and design characteristics.

FIG. 4 is a schematic top view showing the positional relationship between the heat exchanger tube 22 and the spray nozzle 24. In FIG. 4, the header 23 is omitted. In this embodiment, in each of the plurality of heat transfer tube groups 22a, 22b, and 22c, the plurality of heat transfer tubes 22 are arranged in the horizontal direction so that the heat transfer surfaces 22p are parallel to the vertical direction. In FIG. 4, the direction parallel to the Y-axis is the direction in which the plurality of heat exchanger tubes 22 are arranged.

In each of the spray units 24a, 24b, and 24c, the spray nozzle 24 is arranged to spray the liquid phase refrigerant toward the heat transfer tube 22 from the side in a horizontal direction. The spray nozzle 24 faces the side surfaces of the plurality of heat exchanger tubes 22 and sprays the liquid phase refrigerant radially toward the plurality of heat exchanger tubes 22. The refrigerant mist enters the space between the heat exchanger tubes 22 and is heated on the surface 22p of the heat exchanger tubes 22.

In this embodiment, the plurality of heat exchanger tube groups 22a, 22b, and 22c have the same structure. Specifically, the arrangement of the plurality of heat exchanger tubes 22 in each of the plurality of heat exchanger tube groups 22a, 22b, and 22c may be the same. The tube pitch in the first heat exchanger tube group 22a is equal to the tube pitch in the second heat exchanger tube group 22b. The tube pitch in the first heat exchanger tube group 22a is equal to the tube pitch in the third heat exchanger tube group 22c. Such a configuration is excellent in cost and productivity of the evaporator 101. "Pipe pitch" means the distance L between the heat transfer surfaces 22p of the heat transfer tubes 22 adjacent to each other.

As shown in FIG. 2, a plurality of heat transfer tube groups 22a to 22c and a plurality of spray units 24a to 24c are arranged in a predetermined direction (direction parallel to the X axis) so that heat transfer tube groups and spray units appear alternately. has been done. In this embodiment, the first heat exchanger tube group 22a, the first spray unit 24a, the second heat exchanger tube group 22b, the second spray unit 24b, the third heat exchanger tube group 22c, and the third spray unit 24c are arranged in this order in a predetermined direction. It is located in The first heat exchanger tube group 22a and the first spray unit 24a form a pair. The second heat exchanger tube group 22b and the second spray unit 24b form a pair. The third heat exchanger tube group 22c and the third spray unit 24c form a pair. The plurality of spray units 24a, 24b, and 24c spray refrigerant in a specific direction. The specific direction is a direction from a group of heat transfer tubes located on the downstream side in the flow direction of the heat medium to a group of heat transfer tubes located on the upstream side in the flow direction of the heat medium. The specific direction is also a direction from the third heat exchanger tube group 22c to the first heat exchanger tube group 22a. In this embodiment, the "specific direction" is the -X-axis direction.

The shell 21 is configured to store liquid phase refrigerant at its bottom. A circulation circuit 25 connects the bottom of the shell 21 and each of the spray 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 at the bottom of the shell 21 is supplied to the spray nozzle 24 through the circulation circuit 25. According to such a configuration, the liquid phase refrigerant can be easily recovered, and energy consumption for supplying the liquid phase refrigerant to the spray nozzle 24 can be suppressed.

In this embodiment, the shell 21 has a rectangular cross-sectional shape, but may have a circular cross-sectional shape. Shell 21 may be a pressure container.

The shell 21 is provided with an inlet pipe 27 and an outlet pipe 28. The inflow pipe 27 is a flow path that guides the refrigerant into the interior of 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 tube groups 22a, 22b, and 22c 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.

In this embodiment, the heat exchanger tube group located most upstream in the flow direction of the heat medium is arranged at the position closest to the discharge pipe 28 among the plurality of heat exchanger tube groups 22a, 22b, and 22c. The first heat exchanger tube group 22a is a heat exchanger tube group located on the most upstream side in the flow direction of the heat medium, and is located closest to the discharge pipe 28 among the plurality of heat exchanger tube groups 22a, 22b, and 22c. has been done. The amount of gas phase refrigerant generated in the first heat exchanger tube group 22a is greater than the amount of gas phase refrigerant generated in the second heat exchanger tube group 22b. The amount of gas phase refrigerant generated in the second heat exchanger tube group 22b is greater than the amount of gas phase refrigerant generated in the third heat exchanger tube group 22c. The amount of gas phase refrigerant generated in the first heat exchanger tube group 22a is the largest among the plurality of heat exchanger tube groups 22a, 22b, and 22c. Therefore, when the first heat transfer tube group 22a is located near the discharge pipe 28, the gaseous refrigerant can be guided to the outside of the evaporator 101 more smoothly. The phrase "amount" means an amount per unit time.

The discharge pipe 28 has an opening located in a specific direction (-X-axis direction) when viewed from the plurality of spray units 24a, 24b, and 24c. In other words, the discharge pipe 28 opens at the wall surface of the shell 21 located in a specific direction. According to such a configuration, the pressure loss of the gaseous refrigerant can be reduced and the gaseous refrigerant can be guided to the outside of the evaporator 101 more smoothly.

[1-4. motion]
The operation and effect of the evaporator 101 configured as above will be explained below.

When the circulation pump 26 is started, liquid phase refrigerant is supplied from the bottom of the shell 21 to the spray units 24a, 24b and 24c. The liquid phase refrigerant is sprayed from each of the spray units 24a, 24b, and 24c in parallel to the flat heat transfer surface 22p of each heat transfer tube 22 of the heat transfer tube groups 22a, 22b, and 22c. The heat medium flows into the first heat exchanger tube group 22a, flows through the first heat exchanger tube group 22a, and then flows into the second heat exchanger tube group 22b through the connecting tube 29. After flowing through the second heat exchanger tube group 22b, the heat medium flows into the third heat exchanger tube group 22c through the connecting tube 29. If the liquid phase refrigerant is sprayed toward the heat exchanger tube groups 22a, 22b, and 22c while flowing the heat medium through the heat exchanger tube groups 22a, 22b, and 22c, the heat medium and the liquid phase refrigerant will be mixed in the heat exchanger tube groups 22a, 22b, and 22c. Heat exchange occurs and the refrigerant evaporates to produce a vapor phase refrigerant.

By using flat heat exchanger tubes as the heat exchanger tubes 22 and spraying the refrigerant in parallel to the heat transfer surface 22p, dead areas in the heat exchanger tube groups 22a, 22b, and 22c can be reduced. Therefore, even when the refrigerant is sprayed in only one direction as in this embodiment, a sufficient heat transfer area can be ensured. The "dead area" refers to a part of the surface of the heat exchanger tube 22, which is a part with which refrigerant mist is difficult to come into contact. The greater the distance from the spray nozzle 24, the more likely a dead zone will be formed on the surface of the heat transfer tube 22.

FIG. 5 is a graph schematically showing the relationship between the temperature Tw of the heat medium and the temperature Tr of the refrigerant in each of the plurality of heat transfer tube groups 22a, 22b, and 22c. The vertical axis represents temperature. The horizontal axis represents the positions of the heat exchanger tube groups 22a, 22b, and 22c. The "Inlet" position corresponds to the header 23 to which one end of the circuit 105 is connected. The "Outlet" position corresponds to the header 23 to which the other end of the circuit 105 is connected.

When the heat medium flows through the heat transfer tube groups 22a, 22b, and 22c, the heat medium is cooled by the refrigerant. Therefore, the temperature Tw of the heat medium gradually decreases. The refrigerant removes heat from the heat medium and changes from a liquid phase to a gas phase. Therefore, the temperature Tr of the refrigerant is constant at the evaporation temperature. The temperature difference (Tw-Tr) between the heat medium and the refrigerant is the largest in the first heat exchanger tube group 22a. The temperature difference (Tw-Tr) in the first heat exchanger tube group 22a is larger than the temperature difference (Tw-Tr) in the second heat exchanger tube group 22b. The temperature difference (Tw-Tr) in the second heat exchanger tube group 22b is larger than the temperature difference (Tw-Tr) in the third heat exchanger tube group 22c. The greater the temperature difference (Tw-Tr), the greater the amount of refrigerant that can be evaporated per unit time. Therefore, the amount of refrigerant that can be evaporated in the first heat exchanger tube group 22a is the largest. The amount of refrigerant that can be evaporated in the second heat exchanger tube group 22b is the second largest. The amount of refrigerant that can evaporate in the third heat transfer tube group 22c is the smallest.

FIG. 6 schematically shows the relationship between the capacity of each of the plurality of heat exchanger tube groups 22a, 22b, and 22c and the amount of refrigerant sprayed. The horizontal axis represents the positions of the heat exchanger tube groups 22a, 22b, and 22c. The area of the region surrounded by the line segment corresponds to the capacity of each of the heat exchanger tube groups 22a, 22b, and 22c. "Capacity" means the ability to evaporate refrigerant.

In the example shown in FIG. 6, the evaporator 101 is designed so that the capacity C2 of the second heat exchanger tube group 22b and the amount of refrigerant sprayed from the second spray unit 24b are balanced. Since the capacity C1 of the first heat exchanger tube group 22a is larger than the capacity C2 of the second heat exchanger tube group 22b, the capacity α is left over in the first heat exchanger tube group 22a. In other words, there is a shortage of refrigerant in an amount corresponding to the capacity α. Since the capacity C3 of the third heat exchanger tube group 22c is smaller than the capacity C2 of the second heat exchanger tube group 22b, the capacity β is insufficient in the third heat exchanger tube group 22c. In other words, there is a surplus of refrigerant in an amount corresponding to the capacity β.

According to this embodiment, the refrigerant is sprayed in a specific direction, which is the direction from the heat transfer tube group located on the upstream side in the flow direction of the heat medium to the heat transfer tube group located on the downstream side in the flow direction of the heat medium. . Therefore, when the refrigerant is sprayed from the third spray unit 24c toward the third heat exchanger tube group 22c, a part of the refrigerant passes through the third heat exchanger tube group 22c as a surplus while remaining in a liquid phase. The surplus is sprayed onto the second heat exchanger tube group 22b together with the refrigerant sprayed from the second spray unit 24b. However, since the capacity C2 of the second heat transfer tube group 22b and the amount of refrigerant sprayed from the second spray unit 24b are balanced, the amount of refrigerant corresponding to the surplus cannot be evaporated in the second heat transfer tube group 22b. First, it passes through the second heat exchanger tube group 22b. Then, the amount of refrigerant corresponding to the surplus is sprayed onto the first heat transfer tube group 22a together with the refrigerant sprayed from the first spray unit 24a. The first heat transfer tube group 22a has the ability to evaporate an amount of refrigerant corresponding to the capacity α in addition to the refrigerant sprayed from the first spray unit 24a. Therefore, the amount of refrigerant corresponding to the surplus evaporates in the first heat transfer tube group 22a together with the refrigerant sprayed from the first spray unit 24a. In this way, by supplying the surplus refrigerant from the heat exchanger tube group located on the downstream side to the heat exchanger tube group located on the upstream side, the amount of refrigerant sprayed can be increased in each of the plurality of heat exchanger tube groups 22a, 22b, and 22c. It is possible to balance the capacity of the heat exchanger tube group. It is possible to avoid forming a thick liquid film on the surface of the heat transfer tube 22 or causing dry-out over a wide area. As a result, the evaporator 101 exhibits excellent heat transfer performance.

The refrigerant is also drawn into the compressor 102 (FIG. 1) through a discharge pipe 28 located in the same direction as the spray direction. Therefore, when the refrigerant is sprayed from each of the spray units 24a, 24b, and 24c, the suction force of the compressor 102 is applied to the refrigerant mist, so that the refrigerant mist is accelerated to the heat transfer tube groups 22a, 22b, and 22c. Inflow. In particular, when a large refrigerating capacity is required, such as under overload conditions, the amount of refrigerant sucked into the compressor 102 increases as the rotational speed of the compressor 102 increases. Therefore, the moving speed of the refrigerant mist sprayed from the spray units 24a, 24b, and 24c also increases. Then, the liquid film of the refrigerant on the surface of the heat exchanger tube 22 becomes thin. As the liquid film becomes thinner, heat is more easily transmitted, and the heat transfer coefficient on the surface of the heat exchanger tube 22 is further improved. This also contributes to improving the performance of the evaporator 101.

[1-5. Effects, etc.]
As described above, in this embodiment, a plurality of heat exchanger tube groups and a plurality of spray units are arranged in a predetermined direction so that the heat exchanger tube groups and the spray units appear alternately. The plurality of spray units spray the refrigerant in a specific direction, which is a direction from a group of heat transfer tubes located on the downstream side in the flow direction of the heat medium to a group of heat transfer tubes located on the upstream side in the flow direction of the heat medium.

According to such a configuration, unevaporated refrigerant passes through the heat transfer tube group located on the downstream side, and is sprayed together with the refrigerant sprayed from the spray unit located on the upstream side to the heat transfer tube group located on the upstream side. . The amount of refrigerant that can evaporate in the heat transfer tube group located on the upstream side is greater than the amount of refrigerant that can evaporate in the heat transfer tube group located on the downstream side. The refrigerant can be evaporated in the heat transfer tube group located upstream together with the refrigerant sprayed from the spray unit located upstream. Therefore, according to the present embodiment, the amount of refrigerant supplied to each heat transfer tube group is optimized without adjusting the amount of refrigerant sprayed from the spray unit. In particular, it is possible to prevent dryout from occurring over a wide range in the heat exchanger tube group located on the upstream side. As a result, the shell-and-tube heat exchanger of this embodiment exhibits excellent heat transfer performance.

In this embodiment, the plurality of spray units may include a first spray unit including a plurality of spray nozzles, and a second spray unit including a plurality of spray nozzles. The array of spray nozzles in the first spray unit may be equal to the array of spray nozzles in the second spray unit. Such a configuration is excellent in cost and productivity of the shell-and-tube heat exchanger.

In this embodiment, the shell-and-tube heat exchanger may further include a discharge pipe provided in the shell and guiding the refrigerant evaporated on the surfaces of the plurality of heat transfer tube groups to the outside of the shell. The heat exchanger tube group located on the most upstream side in the flow direction of the heat medium may be arranged at the position closest to the discharge pipe among the plurality of heat exchanger tube groups. According to such a configuration, the gas phase refrigerant can be guided to the outside of the shell-and-tube heat exchanger more smoothly.

In this embodiment, the discharge pipe may have an opening located in a specific direction when viewed from the plurality of spray units. According to such a configuration, the moving speed of the refrigerant mist sprayed from the spray unit increases. Then, the liquid film of the refrigerant on the surface of the heat exchanger tube becomes thin. As the liquid film becomes thinner, heat transfers more easily and the heat transfer coefficient on the surface of the heat exchanger tube improves.

In this embodiment, each of the plurality of heat exchanger tube groups may include a plurality of flat heat exchanger tubes arranged in parallel to each other. When heat exchanger tubes having a flat shape are used in a shell-and-tube heat exchanger, the packaging density of the heat exchanger tubes inside the shell can be increased.

The refrigeration cycle device of this embodiment includes the shell-and-tube heat exchanger of this embodiment and a compressor connected to the shell-and-tube heat exchanger. Shell and tube heat exchangers may be used for evaporators and condensers. By using the shell-and-tube heat exchanger of this embodiment, the efficiency of the refrigeration cycle device can be improved.

(Embodiment 2)
Embodiment 2 will be described below using FIG. 7. Components that are the same as those in Embodiment 1 are given the same numbers and detailed explanations will be omitted.

[2-1. Evaporator configuration]
FIG. 7 is a cross-sectional view of the evaporator 111 in Embodiment 2 of the present disclosure. In FIG. 7, the direction perpendicular to the page is the vertical direction.

The evaporator 111 of this embodiment includes a plurality of heat exchanger tube groups 202a, 202b, and 202c. The plurality of heat exchanger tube groups 202a, 202b, and 202c have mutually different structures. The plurality of heat exchanger tube groups 202a, 202b, and 202c include a first heat exchanger tube group 202a, a second heat exchanger tube group 202b, and a second heat exchanger tube group 202c. The first heat exchanger tube group 202a is a heat exchanger tube group located on the most upstream side in the flow direction of the heat medium. The first heat exchanger tube group 202a is arranged at the position closest to the discharge pipe 28 among the plurality of heat exchanger tube groups 202a, 202b, and 202c. The third heat exchanger tube group 202c is arranged at the farthest position from the discharge pipe 28 among the plurality of heat exchanger tube groups 202a, 202b, and 202c. The second heat exchanger tube group 202b is arranged between the first heat exchanger tube group 202a and the third heat exchanger tube group 202c.

The number of heat exchanger tubes 22 in the first heat exchanger tube group 202a is the largest among the numbers of heat exchanger tubes 22 in each of the plurality of heat exchanger tube groups 202a, 202b, and 202c. Specifically, the number of heat exchanger tubes 22 included in the first heat exchanger tube group 202a is greater than the number of heat exchanger tubes 22 included in the second heat exchanger tube group 202b. The number of heat exchanger tubes 22 included in the second heat exchanger tube group 202b is greater than the number of heat exchanger tubes 22 included in the third heat exchanger tube group 202c. In other words, the number of heat exchanger tubes 22 included in the heat exchanger tube group located on the upstream side in the flow direction of the heat medium is the number of heat exchanger tubes 22 included in the heat exchanger tube group located on the downstream side in the flow direction of the heat medium. more than

Further, the tube pitch in the second heat exchanger tube group 202b is wider than the tube pitch in the first heat exchanger tube group 202a. The tube pitch in the third heat exchanger tube group 202c is wider than the tube pitch in the second heat exchanger tube group 202b. That is, the tube pitch in the heat exchanger tube group located on the downstream side in the flow direction of the heat medium is wider than the tube pitch in the heat exchanger tube group located on the upstream side in the flow direction of the heat medium. For example, the tube pitch in the first heat exchanger tube group 202a is 8 mm, the tube pitch in the second heat exchanger tube group 202b is 9 mm, and the tube pitch in the third heat exchanger tube group 202c is 10 mm.

[2-2. motion]
As described in the first embodiment, when the refrigerant is sprayed from the spray units 24a, 24b, and 24c toward the heat transfer tube groups 202a, 202b, and 202c, the gas phase refrigerant generated in the first heat transfer tube group 202a is discharged. It quickly flows into tube 28. The gas phase refrigerant generated in the second heat exchanger tube group 202b passes through the first heat exchanger tube group 202a and flows into the discharge pipe 28. The gas phase refrigerant generated in the third heat exchanger tube group 202c passes through the second heat exchanger tube group 202b and the first heat exchanger tube group 202a in this order, and flows into the discharge pipe 28.

Since the first heat exchanger tube group 202a is located near the discharge pipe 28, pressure loss is suppressed even if the volumetric flow rate of the gas phase refrigerant generated in the first heat exchanger tube group 202a is large. The volume flow rate of the gas phase refrigerant generated in the second heat exchanger tube group 202b is lower than the volume flow rate of the gas phase refrigerant generated in the first heat exchanger tube group 202a. Therefore, even if the distance from the second heat exchanger tube group 202b to the discharge pipe 28 exceeds the distance from the first heat exchanger tube group 202a to the discharge tube 28, pressure loss is suppressed. Although the volumetric flow rate of the gas phase refrigerant generated in the third heat transfer tube group 202c is the smallest, the third heat transfer tube group 202c is disposed at the farthest position from the discharge pipe 28, so pressure loss is suppressed. Thus, in this embodiment, the amount of gas phase refrigerant generated and the distance from the discharge pipe 28 to the heat transfer tube group have an inverse relationship. In other words, the shorter the distance from the discharge pipe 28 to the heat transfer tube group, the greater the amount of gas phase refrigerant generated. Thereby, it is possible to minimize the pressure loss accompanying the movement of the gas phase refrigerant inside the shell 21. This also applies to the first embodiment.

Furthermore, when the refrigerant is sprayed from the spray units 24a, 24b, and 24c toward the heat exchanger tube groups 202a, 202b, and 202c, the refrigerant in the gas-liquid two-phase flow containing unevaporated refrigerant flows into the second heat exchanger tube group 202b and the third heat exchanger tube group. It passes through the heat exchanger tube group 202c. Therefore, the pressure loss in the second heat exchanger tube group 202b and the third heat exchanger tube group 202c tends to increase.

However, according to this embodiment, the number of heat exchanger tubes 22 is adjusted to a number suitable for each heat exchanger tube group. Alternatively, the tube pitch is adjusted to a tube pitch suitable for each heat transfer tube group. Therefore, according to the present embodiment, it is possible to reduce the pressure loss when the gas-liquid two-phase refrigerant passes through the heat exchanger tube group located on the downstream side.

[2-3. Effects, etc.]
In this embodiment as well, the same effects as in the first embodiment can be obtained.

In this embodiment, the plurality of heat exchanger tube groups may include a first heat exchanger tube group located on the most upstream side in the flow direction of the heat medium. The number of heat exchanger tubes in the first heat exchanger tube group may be the largest among the numbers of heat exchanger tubes in each of the plurality of heat exchanger tube groups. According to such a configuration, pressure loss when the gas-liquid two-phase refrigerant passes through the heat exchanger tube group located on the downstream side can be reduced.

In this embodiment, the number of heat exchanger tubes included in the heat exchanger tube group located on the upstream side in the flow direction of the heat medium is equal to the number of heat exchanger tubes included in the heat exchanger tube group located on the downstream side in the flow direction of the heat medium. There may be more than . According to such a configuration, pressure loss when the gas-liquid two-phase refrigerant passes through the heat exchanger tube group located on the downstream side can be reduced.

In the present embodiment, the tube pitch in the heat transfer tube group located downstream in the flow direction of the heat medium may be wider than the tube pitch in the heat transfer tube group located upstream in the flow direction of the heat medium. According to such a configuration, pressure loss when the gas-liquid two-phase refrigerant passes through the heat exchanger tube group located on the downstream side can be reduced.

(Other embodiments)
The shell and tube heat exchanger of the present disclosure may have only two heat exchanger tube groups, or may have four or more heat exchanger tube groups.

Each of the plurality of spray units 24a, 24b, and 24c may have only one spray nozzle 24.

The heat exchanger tube is not limited to a flat heat exchanger tube with a large aspect ratio, but may be a heat exchanger tube having a circular or elliptical cross section.

In each of the plurality of heat exchanger tube groups 22a, 22b, and 22c, the heat exchanger tubes 22 may be provided in multiple rows (for example, two rows in the front and rear), or may be provided in only one row.

The shell-and-tube heat exchanger disclosed herein is particularly useful in air conditioners such as commercial air conditioners. A shell-and-tube heat exchanger may be used not only as an evaporator but also as a condenser. The refrigeration cycle device disclosed in this specification is not limited to an air conditioner, and may be other devices such as an absorption refrigerator, a chiller, or a heat storage device.

21 Shell 22 Heat transfer tubes 22a, 202a First heat transfer tube group 22b, 202b Second heat transfer tube group 22c, 202c Third heat transfer tube group 23 Header 24 Spray nozzle 24a First spray unit 24b Second spray unit 24c Third spray unit 25 Circulation circuit 26 Circulation pump 27 Inflow pipe 28 Discharge pipe 29 Connection pipe 100 Refrigeration cycle device 101, 111 Evaporator 102 Compressor 103 Condenser 104 Flow valve 105, 106 Circuit 110a, 110b, 110c, 110d Flow path

Claims (10)

shell and
a plurality of heat exchanger tube groups arranged inside the shell and connected in series so that the first fluid flows in sequence;
a plurality of spray units disposed inside the shell and spraying a second fluid toward the plurality of heat transfer tube groups;
a discharge pipe provided in the shell and guiding the second fluid evaporated on the surface of the plurality of heat transfer tube groups to the outside of the shell;
Equipped with
The plurality of heat transfer tube groups and the plurality of spray units are arranged in a predetermined direction so that the heat transfer tube groups and the spray units appear alternately,
The plurality of spray units are configured to spray the first fluid in a specific direction, which is a direction from a heat transfer tube group located on the downstream side in the flow direction of the first fluid to a heat transfer tube group located on the upstream side in the flow direction of the first fluid. Spray two fluids,
The heat exchanger tube group located most upstream in the flow direction of the first fluid is located closest to the discharge pipe among the plurality of heat exchanger tube groups,
Shell and tube heat exchanger. The plurality of spray units have a first spray unit including a plurality of spray nozzles, and a second spray unit including a plurality of spray nozzles,
The arrangement of the plurality of spray nozzles in the first spray unit is equal to the arrangement of the plurality of spray nozzles in the second spray unit,
A shell and tube heat exchanger according to claim 1. The discharge pipe has an opening located in the specific direction when viewed from the plurality of spray units.
The shell and tube heat exchanger according to claim 1 or 2 . shell and
a plurality of heat exchanger tube groups arranged inside the shell and connected in series so that the first fluid flows in sequence;
a plurality of spray units disposed inside the shell and spraying a second fluid toward the plurality of heat transfer tube groups;
Equipped with
The plurality of heat transfer tube groups and the plurality of spray units are arranged in a predetermined direction so that the heat transfer tube groups and the spray units appear alternately,
The plurality of spray units are configured to spray the first fluid in a specific direction, which is a direction from a heat transfer tube group located on the downstream side in the flow direction of the first fluid to a heat transfer tube group located on the upstream side in the flow direction of the first fluid. Spray two fluids,
The plurality of heat exchanger tube groups include a first heat exchanger tube group located on the most upstream side in the flow direction of the first fluid,
The number of heat exchanger tubes in the first heat exchanger tube group is the largest among the number of heat exchanger tubes in each of the plurality of heat exchanger tube groups,
Shell and tube heat exchanger. shell and
a plurality of heat exchanger tube groups arranged inside the shell and connected in series so that the first fluid flows in sequence;
a plurality of spray units disposed inside the shell and spraying a second fluid toward the plurality of heat transfer tube groups;
Equipped with
The plurality of heat transfer tube groups and the plurality of spray units are arranged in a predetermined direction so that the heat transfer tube groups and the spray units appear alternately,
The plurality of spray units are configured to spray the first fluid in a specific direction, which is a direction from a heat transfer tube group located on the downstream side in the flow direction of the first fluid to a heat transfer tube group located on the upstream side in the flow direction of the first fluid. Spray two fluids,
The number of heat exchanger tubes included in the heat exchanger tube group located on the upstream side in the flow direction of the first fluid is the number of heat exchanger tubes included in the heat exchanger tube group located on the downstream side in the flow direction of the first fluid. more than the number of
Shell and tube heat exchanger. shell and
a plurality of heat exchanger tube groups arranged inside the shell and connected in series so that the first fluid flows in sequence;
a plurality of spray units disposed inside the shell and spraying a second fluid toward the plurality of heat transfer tube groups;
Equipped with
The plurality of heat transfer tube groups and the plurality of spray units are arranged in a predetermined direction so that the heat transfer tube groups and the spray units appear alternately,
The plurality of spray units are configured to spray the first fluid in a specific direction, which is a direction from a heat transfer tube group located on the downstream side in the flow direction of the first fluid to a heat transfer tube group located on the upstream side in the flow direction of the first fluid. Spray two fluids,
A tube pitch in the heat exchanger tube group located downstream in the flow direction of the first fluid is wider than a tube pitch in the heat exchanger tube group located upstream in the flow direction of the first fluid.
Shell and tube heat exchanger. shell and
a plurality of heat exchanger tube groups arranged inside the shell and connected in series so that the first fluid flows in sequence;
a plurality of spray units disposed inside the shell and spraying a second fluid toward the plurality of heat transfer tube groups;
Equipped with
The plurality of heat transfer tube groups and the plurality of spray units are arranged in a predetermined direction so that the heat transfer tube groups and the spray units appear alternately,
The plurality of spray units are configured to spray the first fluid in a specific direction, which is a direction from a heat transfer tube group located on the downstream side in the flow direction of the first fluid to a heat transfer tube group located on the upstream side in the flow direction of the first fluid. Spray two fluids,
The spraying direction of the second fluid to the plurality of heat exchanger tube groups is only one of the specific directions,
Shell and tube heat exchanger. shell and
a plurality of heat exchanger tube groups arranged inside the shell and connected in series so that the first fluid flows in sequence;
a plurality of spray units disposed inside the shell and spraying a second fluid toward the plurality of heat transfer tube groups;
Equipped with
The plurality of heat transfer tube groups and the plurality of spray units are arranged in a predetermined direction so that the heat transfer tube groups and the spray units appear alternately,
Each of the plurality of heat exchanger tube groups includes a plurality of flat heat exchanger tubes arranged in parallel to each other,
In each of the plurality of heat exchanger tube groups, the plurality of heat exchanger tubes are arranged in a horizontal direction so that the heat transfer surfaces of each of the plurality of heat exchanger tubes are parallel to the vertical direction,
The plurality of spray units are configured to spray the first fluid in a specific direction, which is a direction from a heat transfer tube group located on the downstream side in the flow direction of the first fluid to a heat transfer tube group located on the upstream side in the flow direction of the first fluid. Spray two fluids,
The specific direction is a horizontal direction parallel to the heat transfer surface of the heat transfer tube.
Shell and tube heat exchanger. Each of the plurality of heat exchanger tube groups includes a plurality of flat heat exchanger tubes arranged in parallel to each other.
A shell-and-tube heat exchanger according to any one of claims 1 to 7. The shell and tube heat exchanger according to any one of claims 1 to 9 ,
a compressor connected to the shell and tube heat exchanger;
A refrigeration cycle device equipped with

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