JP2020159594A - Heat exchange unit and absorption type refrigerating machine - Google Patents

Abstract

To appropriately separate a gas-phase cooling medium and a liquid-phase cooling medium in a region where the gas-phase cooling medium flows at a high flow velocity from an evaporator toward an absorber.SOLUTION: A heat exchange unit (1a) includes an evaporator (2a), an absorber (3) and an eliminator (4a). The evaporator (2a) has a plurality of heat transfer tubes (7) arranged in parallel with each other. The eliminator (4a) separates a gas-phase cooling medium and a liquid-phase cooling medium from each other in the cooling medium flowing from the evaporator (2a) toward the absorber (3). The eliminator 4a has a plurality of first plates (10) and a friction member (13a). The plurality of first plates (10) are disposed separately from each other in a gravity direction, and forms a plurality of stages of inflow passages (15). At least a part of the friction member (13a) is disposed in at least one of: a space between the plurality of heat transfer tubes (7) and the plurality of stages of inflow passages (15); an inlet (15a) of at least one of inflow passages (15); and the inside of the inflow passages (15).SELECTED DRAWING: Figure 1

Description

The present disclosure relates to heat exchange units and absorption chillers.

Conventionally, in an absorption chiller, a technique of combining an absorber and an evaporator into one unit is known.

For example, Patent Document 1 describes an absorption chiller equipped with a low temperature cylinder 350, as shown in FIG. 10A. The low temperature cylinder 350 has an absorber 352 and an evaporator 353. The absorber 352 is arranged at the bottom of the box-shaped main body 351. The evaporator 353 is arranged above the absorber 352. Further, the eliminator 366 is diagonally arranged on the side of the evaporator 353.

As shown in FIG. 10B, the eliminator 366 is provided at a large number of inclined plates 367 and at the upper ends of the inclined plates 367, and is provided at an upwardly bent folding portion 368 and at the upper ends of the inclined plates 367 and is curved downward. It is composed of the rectifying unit 365. The refrigerant vapor vaporized in contact with the heat transfer tube of the evaporator 353 flows in the direction of the arrow shown in FIG. 10B, and the droplets are stopped by the folded-back portion 368 and flow down along the inclined plate 367. Refrigerant vapor is smoothly flowed downward (toward the absorber 352) by the rectifying unit 365.

Japanese Unexamined Patent Publication No. 5-215431

The technique described in Patent Document 1 has room for reexamination from the viewpoint of appropriately separating the gas phase refrigerant and the liquid phase refrigerant in the region where the vapor phase refrigerant flows from the evaporator to the absorber at a high flow velocity.

Therefore, the present disclosure provides a heat exchange unit that is advantageous for appropriately separating the gas phase refrigerant and the liquid phase refrigerant in a region where the gas phase refrigerant flows from the evaporator to the absorber at a high flow velocity.

This disclosure is
An evaporator that has a plurality of first heat transfer tubes arranged parallel to each other and produces a gas phase refrigerant,
An absorber that absorbs the vapor-phase refrigerant generated by the evaporator, and
An eliminator, which is arranged between the evaporator and the absorber and separates the gas phase refrigerant and the liquid phase refrigerant in the refrigerant flowing from the evaporator toward the absorber, is provided.
The eliminator has a plurality of first plates and friction members, and has a plurality of first plates and friction members.
The plurality of first plates are arranged apart from each other in the direction of gravity to form a plurality of stages of inflow paths, each having an inlet opening toward the evaporator.
At least a part of the friction member is a space between the plurality of first heat transfer tubes and the plurality of inflow passages, an inlet of at least one inflow passage of the plurality of stages of inflow passages, and an inside of the inflow passages. Located in at least one of
Provide a heat exchange unit.

The heat exchange unit of the present disclosure is advantageous for appropriately separating the gas phase refrigerant and the liquid phase refrigerant in a region where the gas phase refrigerant flows from the evaporator to the absorber at a high flow velocity.

FIG. 1 is a cross-sectional view showing an example of the heat exchange unit of the present disclosure. FIG. 2 is a cross-sectional view of the eliminator shown in FIG. FIG. 3 is a cross-sectional view showing another example of the heat exchange unit of the present disclosure. FIG. 4 is a cross-sectional view of the eliminator shown in FIG. FIG. 5 is a cross-sectional view showing still another example of the heat exchange unit of the present disclosure. FIG. 6 is a cross-sectional view of the eliminator shown in FIG. FIG. 7 is a cross-sectional view showing the arrangement of the friction members shown in FIG. FIG. 8 is a cross-sectional view showing still another example of the heat exchange unit of the present disclosure. FIG. 9 is a configuration diagram showing an example of the absorption chiller of the present disclosure. FIG. 10A is a cross-sectional view showing a low temperature cylinder of a conventional absorption chiller. FIG. 10B is a diagram showing an eliminator in FIG. 10A.

(Knowledge on which this disclosure is based)
In the absorption chiller, it is conceivable to use a heat exchange unit equipped with an evaporator and an absorber. In such a heat exchange unit, it is conceivable to arrange an eliminator between the evaporator and the absorber in order to separate the gas phase refrigerant and the liquid phase refrigerant. The amount of vapor-phase refrigerant generated by the evaporator or the amount of vapor-phase refrigerant absorbed by the absorber is determined according to the local logarithmic mean temperature difference (LMTD) of the evaporator or absorber. Since LMTD is not uniform on a plurality of heat transfer surfaces, the flow velocity of the gas phase refrigerant passing through the eliminator varies. According to the studies by the present inventors, it has been newly found that in the region where the gas phase refrigerant flows at a high flow velocity in the conventional eliminator, the vapor phase refrigerant and the liquid phase refrigerant may not be properly separated. It was.

Therefore, the present inventors have made extensive studies to develop an eliminator capable of appropriately separating the gas phase refrigerant and the liquid phase refrigerant in the region where the gas phase refrigerant flows from the evaporator to the absorber at a high flow velocity, and the present disclosure has been made. I devised a heat exchange unit for.

(Summary of one aspect relating to this disclosure)
The heat exchange unit according to the first aspect of the present disclosure is
An evaporator that has a plurality of first heat transfer tubes arranged parallel to each other and produces a gas phase refrigerant,
An absorber that absorbs the vapor-phase refrigerant generated by the evaporator, and
An eliminator, which is arranged between the evaporator and the absorber and separates the gas phase refrigerant and the liquid phase refrigerant in the refrigerant flowing from the evaporator toward the absorber, is provided.
The eliminator has a plurality of first plates and friction members, and has a plurality of first plates and friction members.
The plurality of first plates are arranged apart from each other in the direction of gravity to form a plurality of stages of inflow paths, each having an inlet opening toward the evaporator.
At least a part of the friction member is a space between the plurality of first heat transfer tubes and the plurality of inflow passages, an inlet of at least one inflow passage of the plurality of stages of inflow passages, and an inside of the inflow passages. It is located in at least one of.

According to the first aspect, the friction member creates resistance to the flow of refrigerant from the evaporator to the absorber. As a result, the flow velocity of the gas phase refrigerant flowing into the inflow path of the eliminator decreases, and the relative velocity between the liquid phase refrigerant and the gas phase refrigerant decreases. For this reason, the force with which the gas phase refrigerant accompanies the floating droplets in the evaporator or the liquid phase refrigerant around the heat transfer tube of the evaporator becomes small, and the amount of the liquid phase refrigerant passing through the eliminator tends to decrease. As a result, it is easy to appropriately separate the gas phase refrigerant and the liquid phase refrigerant in the region where the gas phase refrigerant flows from the evaporator to the absorber at a high flow velocity.

In the second aspect of the present disclosure, for example, in the heat exchange unit according to the first aspect, the size of the friction member in the direction of gravity may be smaller than the size of the inlet in the direction of gravity. According to the second aspect, the magnitude of the resistance generated by the friction member in the flow of the refrigerant from the evaporator to the absorber tends to be a desired magnitude.

In the third aspect of the present disclosure, for example, in the heat exchange unit according to the first or second aspect, at least a part of the friction member is in the inflow path located at the lowest stage in the inflow path of the plurality of stages. It may be arranged in at least one of a first inflow path and a second inflow path which is the inflow path located one step above the lowest step. A liquid phase refrigerant may be stored at the bottom of the evaporator. When the liquid level of the stored liquid phase refrigerant is high, in addition to the droplets floating inside the evaporator or the liquid phase refrigerant around the heat transfer tube of the evaporator, the liquid phase refrigerant stored in the evaporator The possibility of being accompanied by a vapor phase refrigerant increases. However, according to the third aspect, since the friction member is arranged in at least one of the first inflow path and the second inflow path, the force of the gas phase refrigerant to accompany the liquid phase refrigerant stored in the evaporator. Is small, and the amount of liquid phase refrigerant passing through the eliminator tends to be small.

In the fourth aspect of the present disclosure, for example, in the heat exchange unit according to the first to third aspects, at least a part of the friction member is in the inflow path located at the lowest stage in the inflow path of the plurality of stages. The space between the first inflow path and the plurality of first heat transfer tubes, and the second inflow path, which is the inflow path located one step above the lowest stage, and the plurality of first heat transfer tubes. It may be located in at least one of the spaces between them. According to the fourth aspect, as in the second aspect, the force with which the gas phase refrigerant accompanies the liquid phase refrigerant stored in the evaporator becomes small, and the amount of the liquid phase refrigerant passing through the eliminator tends to decrease.

In the fifth aspect of the present disclosure, for example, in the heat exchange unit according to any one of the first to fourth aspects, even if the first plate has a first plane forming the inflow path. Often, the friction member may have a second plane at a predetermined angle with a plane parallel to the first plane. According to the fifth aspect, in addition to the friction member creating resistance to the flow of refrigerant from the evaporator to the absorber, the flow of refrigerant flowing along a plane parallel to the first plane is the second of the friction member. Collide with a plane. As a result, the liquid-phase refrigerant is separated from the flow of the refrigerant, and the amount of the liquid-phase refrigerant passing through the eliminator tends to decrease.

In the sixth aspect of the present disclosure, for example, in the heat exchange unit according to the fifth aspect, the second plane may have the largest area in the plane included in the surface of the friction member. According to the sixth aspect, the resistance to the flow of the refrigerant from the evaporator to the absorber generated by the friction member tends to increase. In addition, the flow of the refrigerant collides with the second plane of the friction member, and the liquid phase refrigerant is likely to be separated from the flow of the refrigerant.

The absorption chiller according to the seventh aspect of the present disclosure includes a heat exchange unit according to any one of the first to sixth aspects. According to the seventh aspect, it is easy to appropriately separate the gas phase refrigerant and the liquid phase refrigerant in the region where the gas phase refrigerant flows from the evaporator to the absorber at a high flow velocity, and it is difficult to supply the liquid phase refrigerant to the absorber. .. As a result, the vapor-phase refrigerant is easily absorbed appropriately in the absorber. Therefore, the absorption chiller tends to exhibit a high coefficient of performance (COP).

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments. In the attached drawing, the negative direction of the Z axis is the direction of gravity, and the XY plane is horizontal. The X-axis and Y-axis are orthogonal to each other.

FIG. 1 is a cross-sectional view of a heat exchange unit 1a according to an example of the embodiment of the present disclosure. The heat exchange unit 1a is, for example, a heat exchange unit that realizes an evaporation process and an absorption process in an absorption chiller. The heat exchange unit 1a includes an evaporator 2a, an absorber 3, and an eliminator 4a. The evaporator 2a has a plurality of first heat transfer tubes 7 arranged in parallel with each other. The evaporator 2a produces a vapor phase refrigerant. In the absorber 3, the vapor-phase refrigerant generated in the evaporator 2a is absorbed. The eliminator 4a is arranged between the evaporator 2a and the absorber 3. The eliminator 4a separates the gas phase refrigerant and the liquid phase refrigerant in the refrigerant flowing from the evaporator 2a toward the absorber 3.

FIG. 2 is a cross-sectional view of the eliminator 4a. The eliminator 4a has a plurality of first plates 10 and a friction member 13a. The plurality of first plates 10 are arranged apart from each other in the direction of gravity to form a plurality of stages of inflow paths 15. Each of the plurality of inflow passages 15 has an inlet 15a that opens toward the evaporator 2a. At least a part of the friction member 13a is (i) a space between the plurality of first heat transfer tubes 7 and the plurality of inflow passages 15, and (ii) an inlet of at least one inflow passage 15 of the plurality of stages of the inflow passages 15. 15a and (iii) are located at least one inside the inflow path 15.

A vapor phase refrigerant and a liquid phase refrigerant are present inside the evaporator 2a. On the other hand, a heat medium that has absorbed heat outside the evaporator 2a flows inside the first heat transfer tube 7 of the evaporator 2a. The pressure of the absorber 3 decreases due to the absorption of the vapor-phase refrigerant in the absorber 3, and the vapor-phase refrigerant existing in the evaporator 2a is supplied to the absorber 3. As a result, the pressure inside the evaporator 2a decreases, and the liquid-phase refrigerant existing inside the evaporator 2a evaporates to generate a vapor-phase refrigerant. The vapor-phase refrigerant is guided from the evaporator 2a to the absorber 3 through the eliminator 4a. When the vapor phase refrigerant flows from the evaporator to the absorber at a high flow velocity, the force of the vapor phase refrigerant to accompany the droplets floating in the evaporator or the liquid phase refrigerant around the heat transfer tube of the evaporator increases. Cheap. However, according to the heat exchange unit 1a, the friction member 13a creates resistance in the flow of the refrigerant from the evaporator 2a to the absorber 3. As a result, the flow velocity of the vapor-phase refrigerant flowing into the inflow path 15 of the eliminator 4a decreases, and the relative velocity between the liquid-phase refrigerant and the vapor-phase refrigerant decreases. Therefore, the force with which the vapor-phase refrigerant accompanies the droplets floating in the evaporator 2a or the liquid-phase refrigerant around the first heat transfer tube 7 of the evaporator 2a becomes small, and the liquid-phase refrigerant passing through the eliminator 4a becomes small. The amount tends to be small. As described above, according to the heat exchange unit 1a, the vapor phase refrigerant and the liquid phase refrigerant are likely to be appropriately separated in the region where the vapor phase refrigerant flows from the evaporator 2a toward the absorber 3 at a high flow velocity.

The shape of the friction member 13a is not limited to a specific shape as long as it can generate resistance to the flow of the refrigerant from the evaporator 2a to the absorber 3. The shape of the friction member 13a is, for example, a rod shape having a circular or rectangular cross section. The friction member 13a may be solid or hollow. It is advantageous from the viewpoint of weight reduction that the friction member 13a is hollow. The shape of the friction member 13a may be a flat plate shape, a curved plate shape, or a net shape.

In the heat exchange unit 1a, the material of the friction member 13a is not limited to a specific material. The material of the friction member 13a is, for example, an iron-based material.

The size of the friction member 13a in the direction of gravity is smaller than the size of the inlet 15a in the direction of gravity. In this case, the magnitude of the resistance generated by the friction member 13a in the flow of the refrigerant from the evaporator 2a to the absorber 3 tends to be a desired magnitude.

The friction member 13a is arranged so as to correspond to at least a part of the inflow passage 15 in a plurality of stages. The friction member 13a is arranged, for example, corresponding to the inflow path 15 located in the region where the vapor-phase refrigerant flows at a high flow velocity among the inflow paths 15 in a plurality of stages.

As shown in FIG. 2, the eliminator 4a further includes, for example, a plurality of second plates 12. The plurality of second plates 12 are arranged apart from each other in the direction of gravity to form an outflow path 17. The outflow passage 17 has an outlet 17a that opens toward the absorber 3. The plurality of second plates 12 form, for example, a plurality of stages of outflow passages 17.

In the eliminator 4a, for example, an inflow path 15 and an outflow path 17 are connected to form a mountainous curved flow path. When the flow of the refrigerant flowing through the eliminator 4a contains droplets, the centrifugal force caused by the change of the flow direction of the vapor-phase refrigerant along the mountainous curved flow path causes the droplets to flow from the vapor-phase refrigerant. Is separated. As a result, the droplets are less likely to be guided to the absorber 3.

The refrigerant existing inside the evaporator 2a is not limited to a specific refrigerant. The refrigerant is, for example, a refrigerant containing water as a main component. In the present specification, the "main component" is the component contained most in terms of mass.

The plurality of first heat transfer tubes 7 form, for example, a group of first heat transfer tubes 7g having a plurality of stages and a plurality of rows. In the first heat transfer tube group 7g, a plurality of stages are formed in the direction of gravity, and a plurality of rows are formed in a direction (X-axis direction) perpendicular to the direction of gravity and the longitudinal direction (Y-axis direction) of the first heat transfer tube 7. There is. When the first heat transfer tube group 7g is viewed along the longitudinal direction of the first heat transfer tube 7, the plurality of first heat transfer tubes 7 are arranged in a grid pattern. In other words, a plurality of first heat transfer tubes 7 are arranged on the same horizontal plane in a plurality of rows of the first heat transfer tube group 7 g. When the first heat transfer tube group 7g is viewed along the longitudinal direction of the first heat transfer tube 7, the plurality of first heat transfer tubes 7 may be arranged in a staggered pattern. In other words, the horizontal plane containing the central axis of one of the first heat transfer tubes 7 in two adjacent rows of the first heat transfer tube group 7g is the horizontal plane containing the central axis of the other first heat transfer tube 7 in the two rows. It is offset in the direction of gravity. In this case, the number of stages in the first heat transfer tube group 7 g may be an odd number.

Grooves may be formed on at least one of the inner surface and the outer surface of the first heat transfer tube 7.

Inside the absorber 3, there is a solution capable of absorbing the vapor phase refrigerant. The solution is not limited to a particular solution as long as it can absorb the gas phase refrigerant. The solution is, for example, a solution containing an aqueous solution of lithium bromide as a main component. A trace amount of octyl alcohol may be added to the solution.

The absorber 3 has, for example, a plurality of second heat transfer tubes 9 arranged parallel to each other. Typically, in the absorber 3, the gas phase refrigerant is absorbed by the solution. At this time, heat absorption is generated. For example, a heat medium radiated to the outside of the evaporator 2a flows inside the plurality of heat transfer tubes 9. The heat absorbed by the gas phase refrigerant absorbed into the solution is dissipated to the heat medium flowing inside the plurality of heat transfer tubes 9.

The plurality of second heat transfer tubes 9 form, for example, a group of second heat transfer tubes 9g having a plurality of stages and a plurality of rows. In the second heat transfer tube group 9g, a plurality of stages are formed in the direction of gravity, and a plurality of rows are formed in a direction (X-axis direction) perpendicular to the direction of gravity and the longitudinal direction (Y-axis direction) of the second heat transfer tube 9. There is. When the second heat transfer tube group 9g is viewed along the longitudinal direction of the second heat transfer tube 9, the plurality of second heat transfer tubes 9 are arranged in a grid pattern. In other words, a plurality of second heat transfer tubes 9 are arranged on the same horizontal plane in a plurality of rows of the second heat transfer tube group 9 g. When the second heat transfer tube group 9g is viewed along the longitudinal direction of the second heat transfer tube 9, the plurality of second heat transfer tubes 9 may be arranged in a staggered pattern. In other words, the horizontal plane containing the central axis of the second heat transfer tube 9 in one of the two adjacent rows of the second heat transfer tube group 9g is the horizontal plane containing the central axis of the other second heat transfer tube 9 in the two rows. It is offset in the direction of gravity. In this case, the number of stages in the second heat transfer tube group 9 g may be an odd number.

Grooves may be formed on at least one of the inner surface and the outer surface of the second heat transfer tube 9.

As shown in FIG. 1, the heat exchange unit 1a further includes, for example, a shell 5, a first spray tray 6, and a second spray tray 8.

The shell 5 has, for example, heat insulating properties and pressure resistance. The shell 5 stores the liquid phase refrigerant, the solution, or both of them, and separates the liquid phase refrigerant, the solution, and the vapor phase refrigerant from the outside air (air in the atmosphere). The evaporator 2a is typically configured as a shell-and-tube heat exchanger by a shell 5 and a plurality of first heat transfer tubes 7. The absorber 3 is typically configured as a shell-and-tube heat exchanger by a shell 5 and a plurality of second heat transfer tubes 9.

The first spray tray 6 is made of, for example, a thin plate made of stainless steel. The first spray tray 6 is arranged above the first heat transfer tube group 7 g. The liquid phase refrigerant is stored in the first spray tray 6. A hole is formed in the lower part of the first spray tray 6. The liquid-phase refrigerant stored in the first spray tray 6 passes through the hole in the lower part of the first spray tray 6 by the action of gravity and is dropped toward the first heat transfer tube group 7 g.

The second spray tray 8 is made of, for example, a thin plate made of stainless steel. The second spray tray 8 is arranged above the second heat transfer tube group 9 g. The solution is stored in the second spray tray 8. A hole is formed in the lower part of the second spray tray 8. The solution stored in the second spray tray 8 passes through the hole in the lower part of the second spray tray 8 by the action of gravity and is dropped toward the second heat transfer tube group 9 g.

Each of the first plate 10 and the second plate 12 is composed of, for example, a thin plate made of stainless steel. The flow of the refrigerant that has reached the inlet 15a of the inflow path 15 from the evaporator 2a collides with the first plate 10 and is guided along the first plate 10 in a direction corresponding to the inclination angle of the first plate 10 with respect to the horizontal plane. .. At this time, if the flow of the refrigerant contains the liquid-phase refrigerant, the liquid-phase refrigerant adheres to the surface of the first plate 10. As a result, the liquid-phase refrigerant is less likely to be guided to the absorber 3.

As shown in FIG. 2, the eliminator 4a further includes, for example, a weir member 11. The weir member 11 is made of, for example, a thin plate made of stainless steel. The weir member 11 is joined to, for example, the first plate 10. The weir member 11 is arranged, for example, between the inflow path 15 and the outflow path 17. The weir member 11 dams the liquid-phase refrigerant adhering to the surface of the first plate 10. As a result, the liquid-phase refrigerant is less likely to be guided to the absorber 3. The liquid-phase refrigerant blocked by the weir member 11 flows down along the first plate 10 toward the evaporator 2a by the action of gravity.

An example of the operation of the heat exchange unit 1a will be described. When the heat exchange unit 1a is left unattended for a predetermined period such as at night, the inside of the heat exchange unit 1a is substantially maintained at the temperature and pressure of the environment in which the heat exchange unit 1a is placed. For example, when the temperature of the environment in which the heat exchange unit 1a is placed is 25 ° C., the temperature inside the heat exchange unit 1a is maintained at about 25 ° C.

When the operation of the heat exchange unit 1a is started, the heat medium absorbed from the outside of the evaporator 2 flows inside the plurality of first heat transfer tubes 7. For example, a heat medium at about 12 ° C. flows into the first heat transfer tube 7. On the other hand, a liquid phase refrigerant at about 25 ° C. is supplied from the first spray tray 6 around the outer surface of the first heat transfer tube 7.

In addition, in the absorber 3, the heat medium radiated outside the absorber 3 flows inside the second heat transfer tube 9. For example, a heat medium at about 32 ° C. flows into the second heat transfer tube 9. A high-concentration solution is supplied from the second spray tray 8 around the outer surface of the second heat transfer tube 9. The concentration of lithium bromide in the supplied solution is, for example, 63% by weight.

In the absorber 3, the gas phase refrigerant is absorbed by the high-concentration solution, so that the pressure of the absorber 3 decreases, and the vapor phase refrigerant existing in the evaporator 2a passes through the eliminator 4a and becomes the absorber 3. Be guided. As a result, the pressure inside the evaporator 2a decreases, the liquid-phase refrigerant at about 25 ° C. evaporates, and the temperature inside the evaporator 2a decreases. As these processes proceed continuously, the temperature of the liquid-phase refrigerant supplied around the outer surface of the first heat transfer tube 7 drops to about 6 ° C. Therefore, the heat medium flowing inside the first heat transfer tube 7 is cooled. In steady state. The temperature of the outlet of the heat medium flowing inside the first heat transfer tube 7 is about 7 ° C. This heat medium at about 7 ° C. can be used, for example, for air conditioning or cooling in industrial processes.

As described above, the friction member 13a creates resistance in the flow of the refrigerant from the evaporator 2a to the absorber 3. As a result, the flow velocity of the vapor-phase refrigerant flowing into the inflow path 15 of the eliminator 4a decreases, and the relative velocity between the liquid-phase refrigerant and the vapor-phase refrigerant decreases. Therefore, the force with which the vapor-phase refrigerant accompanies the droplets floating in the evaporator 2a or the liquid-phase refrigerant around the first heat transfer tube 7 of the evaporator 2a becomes small, and the liquid-phase refrigerant passing through the eliminator 4a becomes small. The amount tends to be small.

The heat exchange unit 1a can be changed from various viewpoints. For example, the heat exchange unit 1a may be modified as the heat exchange unit 1b shown in FIG. 3, the heat exchange unit 1c shown in FIG. 5, or the heat exchange unit 1d shown in FIG. The heat exchange units 1b, 1c, and 1d are configured in the same manner as the heat exchange unit 1a, except for a portion to be particularly described. The components of the heat exchange units 1b, 1c, and 1d that are the same as or correspond to the components of the heat exchange unit 1a are designated by the same reference numerals, and detailed description thereof will be omitted. The description of the heat exchange unit 1a also applies to the heat exchange units 1b, 1c, and 1d, unless technically inconsistent.

FIG. 3 is a cross-sectional view of the heat exchange unit 1b. The heat exchange unit 1b includes an eliminator 4b instead of the eliminator 4a. FIG. 4 is a cross-sectional view of the eliminator 4b. In the eliminator 4b, at least a part of the friction member 13a is a space between the first inflow path 15f and the plurality of first heat transfer tubes 7 and a space between the second inflow path 15s and the plurality of first heat transfer tubes 7. It is located in at least one of. The first inflow path 15f is an inflow path 15 located at the lowest stage in the plurality of inflow paths 15. The second inflow path 15s is an inflow path 15 located one step above the lowest step.

A liquid phase refrigerant may be stored in the bottom of the evaporator 2a. When the liquid level of the stored liquid phase refrigerant is high, the liquid stored in the evaporator 2a is added to the droplets floating inside the evaporator 2a or the liquid phase refrigerant around the first heat transfer tube 7. The possibility that the gas phase refrigerant accompanies the phase refrigerant increases. However, according to the heat exchange unit 1b, since the friction member 13a is arranged as described above, the force with which the gas phase refrigerant accompanies the liquid phase refrigerant stored in the evaporator 2a becomes small, and the eliminator 4b is used. The amount of liquid phase refrigerant that passes through tends to decrease. The eliminator 4b of the heat exchange unit 1b appropriately removes droplets flowing from the evaporator 2a together with the vapor phase refrigerant even under a high rating condition or a high load condition of the liquid phase refrigerant stored in the evaporator 2a. Can be separated into. Such a condition can be satisfied, for example, when a high-concentration solution is stored in the absorber 3 and a large amount of liquid phase refrigerant is stored in the evaporator 2a.

When the evaporator 2a in the heat exchange unit 1b is a spray type evaporator, the liquid film in the first heat transfer tube 7 on the lower side in the direction of gravity is typically thinned, and the heat transfer coefficient of evaporation tends to be high. In this case, the amount of refrigerant flowing into the lower region of the eliminator 4b tends to increase. According to the eliminator 4b, when the evaporator 2a is a spray type evaporator, the droplets flowing in from the evaporator 2a together with the vapor phase refrigerant can be appropriately separated.

In the heat exchange unit 1b, for example, at least a part of the friction member 13a includes a space between the first inflow path 15f and the plurality of first heat transfer tubes 7, a second inflow path 15s, and the plurality of first heat transfer tubes 7. It is placed in the space between. At least a part of the friction member 13a may be arranged only in the space between the first inflow passage 15f and the plurality of first heat transfer tubes 7, or may be arranged only in the space between the first inflow passage 15s and the plurality of first heat transfer tubes 7. It may be arranged only in the space between and.

In the heat exchange unit 1b, at least a part of the friction member 13a may be arranged in at least one of the first inflow path 15f and the second inflow path 15s. Also in this case, even under the condition that the liquid level of the liquid phase refrigerant stored in the evaporator 2a is high, the droplets flowing from the evaporator 2a together with the vapor phase refrigerant can be appropriately separated. At least a part of the friction member 13a may be arranged in the first inflow passage 15f and the second inflow passage 15s, may be arranged only in the first inflow passage 15f, or may be arranged only in the second inflow passage 15s. It may be arranged in.

FIG. 5 is a cross-sectional view of the heat exchange unit 1c. The heat exchange unit 1c includes an eliminator 4c instead of the eliminator 4a. FIG. 6 is a cross-sectional view of the eliminator 4c. The eliminator 4c includes a friction member 13b. The friction member 13b is configured in the same manner as the friction member 13a, except for a portion to be described in particular. In the eliminator 4c, the first plate 10 has a first plane 10a forming an inflow path 15. FIG. 7 is a cross-sectional view showing the arrangement of the friction member 13b. The friction member 13b has a second plane 13f forming a predetermined angle θ with a plane Pr parallel to the first plane 10a.

According to the heat exchange unit 1c, the friction member 13b creates resistance in the flow of the refrigerant from the evaporator 2a to the absorber 3, and in addition, the flow of the refrigerant flowing along the plane Pr parallel to the first plane 10a. Collides with the second plane 13f of the friction member 13b. As a result, the liquid-phase refrigerant is separated from the flow of the refrigerant, and the amount of the liquid-phase refrigerant that passes through the eliminator 4c tends to decrease.

For example, under the start-up transient condition, a low-concentration solution is stored in the absorber 3, a small amount of the liquid-phase refrigerant is stored in the evaporator 2a, and the liquid level of the liquid-phase refrigerant stored in the evaporator 2a becomes low. .. Therefore, under the start-up transient condition, the amount of the refrigerant passing through the space under the evaporator 2a increases, and the vapor-phase refrigerant containing a large amount of droplets of the liquid-phase refrigerant floating inside the evaporator 2a is the eliminator 3c. It easily flows into the lower area. According to the heat exchange unit 1c, the eliminator 4c can appropriately separate the droplets flowing in from the evaporator 2a together with the vapor phase refrigerant even under the start-up transient condition.

The angle θ can be, for example, less than 90 °.

The second plane 13f has, for example, the largest area in the plane included in the surface of the friction member 13b. In this case, the resistance to the flow of the refrigerant from the evaporator 2a to the absorber 3 generated by the friction member 13b tends to increase. In addition, the flow of the refrigerant collides with the second plane 13f of the friction member 13b, and the liquid phase refrigerant is likely to be separated from the flow of the refrigerant.

As shown in FIG. 7, the second plane 13f has a first end 13h and a second end 13m in the X-axis direction. The first end 13h is closer to the evaporator 2a than the second end 13m. The second plane 13f approaches, for example, the lower first plate 10 of the pair of first plates 10 forming the inflow path 15 corresponding to the friction member 13b from the first end 13h to the second end 13m. It is extending. In this case, the flow of the refrigerant collides with the second plane 13f of the friction member 13b, so that the liquid-phase refrigerant can be more reliably separated from the flow of the refrigerant.

The friction member 13b is not limited to a specific shape as long as it has the second plane 13f. The cross section of the friction member 13b perpendicular to the Y axis has, for example, a rectangular cross section. The cross section of the friction member 13b perpendicular to the Y axis may be formed only by a straight line, or a part of the cross section of the friction member 13b perpendicular to the Y axis may be formed by a curved line.

FIG. 8 is a cross-sectional view of the heat exchange unit 1d. The heat exchange unit 1d has the same configuration as the heat exchange unit 1c, except for a portion to be described in particular. The heat exchange unit 1d includes an evaporator 2b. The evaporator 2b is configured in the same manner as the evaporator 2a, except for a portion to be described in particular. As shown in FIG. 8, the evaporator 2b includes a spray nozzle 14 instead of the first spray tray 6.

The spray nozzle 14 is, for example, a pressure injection type spray nozzle. In this case, the liquid phase refrigerant pressurized to the nozzle inlet of the spray nozzle 14 is given a swirling force by the swirling mechanism inside the nozzle, and the liquid phase refrigerant is injected into the space of the gas phase refrigerant. As a result, the injected liquid-phase refrigerant spreads in a conical shape by centrifugal force due to the swirling speed, and after thinning and liquefying, it splits into a group of droplets. For example, in the evaporator 2b, a plurality of spray nozzles 14 are arranged along the longitudinal direction of the first heat transfer tube 7 and the direction of gravity. The liquid phase refrigerant is injected from the spray nozzle 14 toward the first heat transfer tube group 7 g.

According to the heat exchange unit 1d, the friction member 13b creates resistance in the flow of the refrigerant from the evaporator 2b to the absorber 3. In addition, the friction member 13b causes the flow of the refrigerant flowing along the plane Pr parallel to the first plane 10a to collide with the second plane 13f of the friction member 13b. As a result, the liquid-phase refrigerant is separated, and the amount of the liquid-phase refrigerant that passes through the eliminator 4c tends to decrease. Therefore, since the liquid-phase refrigerant is injected from the spray nozzle 14, a large amount of liquid-phase refrigerant droplets are suspended inside the evaporator 2b. As described above, even when the heat exchange unit 1d includes the spray type evaporator 2b, the droplets flowing in from the evaporator 2b together with the vapor phase refrigerant can be appropriately separated.

The heat exchange units 1a, 1b, 1c, or 1d can be used to provide, for example, an absorption chiller. FIG. 9 is a configuration diagram showing an absorption chiller 100 provided with a heat exchange unit 1a. The absorption chiller 100 includes, for example, a regenerator 60 and a condenser 70 in addition to the heat exchange unit 1a. Since the absorption chiller 100 includes the heat exchange unit 1a, it is difficult to supply the liquid phase refrigerant to the absorber 3. As a result, the vapor-phase refrigerant is easily absorbed appropriately in the absorber 3. Therefore, the absorption chiller 100 tends to exhibit a high coefficient of performance (COP).

The absorption chiller 100 is, for example, an absorption chiller with a single utility cycle. The absorption chiller 100 may be changed to a double-effect cycle or triple-effect cycle absorption chiller. When a gas burner is used as the heat source of the regenerator 60, the absorption chiller 100 can be a gas chiller.

The heat exchange unit of the present disclosure is provided in an absorption chiller, and can be applied to applications such as a central air conditioning system of a building and a chiller for process cooling.

1a, 1b, 1c, 1d Heat exchange unit 2a, 2b Evaporator 3 Absorber 4a, 4b, 4c Eliminator 7 First heat transfer tube 10 First plate 13a, 13b Friction member 15 Inflow path 15a Inlet 15f First inflow path 15s (Ii) Inflow path 100 Absorption chiller

Claims (7)

An evaporator that has a plurality of first heat transfer tubes arranged parallel to each other and produces a gas phase refrigerant,
An absorber that absorbs the vapor-phase refrigerant generated by the evaporator, and
An eliminator, which is arranged between the evaporator and the absorber and separates the gas phase refrigerant and the liquid phase refrigerant in the refrigerant flowing from the evaporator toward the absorber, is provided.
The eliminator has a plurality of first plates and friction members, and has a plurality of first plates and friction members.
The plurality of first plates are arranged apart from each other in the direction of gravity to form a plurality of stages of inflow paths, each having an inlet opening toward the evaporator.
At least a part of the friction member is a space between the plurality of first heat transfer tubes and the plurality of inflow passages, an inlet of at least one inflow passage of the plurality of stages of inflow passages, and an inside of the inflow passages. Located in at least one of
Heat exchange unit. The heat exchange unit according to claim 1, wherein the size of the friction member in the direction of gravity is smaller than the size of the inlet in the direction of gravity. At least a part of the friction member is a first inflow path, which is the inflow path located at the lowest stage in the inflow path of the plurality of stages, and the inflow path located one step above the lowermost stage. (Ii) The heat exchange unit according to claim 1 or 2, which is arranged in at least one of the inflow paths. At least a part of the friction member is a space between the first inflow passage, which is the inflow passage located at the lowest stage in the plurality of stages of the inflow passage, and the plurality of first heat transfer tubes, and one of the lowermost stages. The item according to any one of claims 1 to 3, which is arranged in at least one of the spaces between the second inflow path, which is the inflow path located at the upper stage, and the plurality of first heat transfer tubes. The heat exchange unit described. The first plate has a first plane forming the inflow path.
The friction member has a second plane at a predetermined angle with a plane parallel to the first plane.
The heat exchange unit according to any one of claims 1 to 4. The heat exchange unit according to claim 5, wherein the second plane has the largest area in the plane included in the surface of the friction member. An absorption chiller comprising the heat exchange unit according to any one of claims 1 to 6.

Images