JPH1054687A - Shell and tube heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the blocking of a flow passage due to freezing by stabilizing the flow of supercooled water, which flows in a pipe. SOLUTION: A resin rod 82, provided in a heat transfer tube 49 and having spiral projections 83, is formed of a material having water absorbing property and bloating tendency. There is a gap 84 between the spiral projections 83 and the heat transfer tube 49 under a condition that water is not absorbed into the resin rod 82. However, the resin rod 82 is inflated by absorbing a part of water, flowing through a flow passage, whereby the gap 84 between the spiral projections 83 and the heat transfer tube 49 is eliminated. Accordingly, gap stream between the spiral projections 83 and the heat transfer tube 49 will not be generated and the flow of supercooled water, which flows in the tube, is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shell and tube type heat exchanger, and more particularly to an internal structure of a heat transfer tube.

[0002]

2. Description of the Related Art Heretofore, as a shell-and-tube heat exchanger used to generate supercooled water, a heat exchanger having a rod-shaped flow path forming body provided in a heat transfer tube has been used. . For example, in the heat exchanger disclosed in JP-A-4-332391, as shown in FIG. 11, between the outer peripheral surface of the flow path forming body (a2) and the inner peripheral surface of the heat transfer tube (a1), A spiral ridge (a3) is provided to project from the outer peripheral surface of the flow path forming body (a2) toward the inner peripheral surface of the heat transfer tube (a1).

The spiral ridge (a3) flows through the flow path of the heat storage medium by spirally turning the flow path of the heat storage medium in the axial direction around the flow path forming body (a2) over substantially the entire length of the heat transfer tube. The turbulence of the flow is reduced by pressing the heat storage medium against the inner peripheral surface of the heat transfer tube (a1). Further, since the spiral ridge forms a spiral flow path, a flow path that is considerably longer than the axial length of the heat transfer tube (a1) is formed in the heat storage medium heat exchange unit. Therefore, heat exchange between the heat storage medium flowing in the heat transfer tube (a1) and the refrigerant in the refrigerant flow path portion can be effectively performed.

In a heat exchanger of the type in which the flow path forming member is inserted into the heat transfer tube as described above, the flow path is manufactured by inserting the flow path forming member into the heat transfer tube. The outer diameter of the spiral ridge (a3) is
The diameter is set slightly smaller than the inner diameter of (a1). Therefore, in the inserted state of the flow path forming body, a gap (a4) is generated between the inner peripheral surface of the heat transfer tube (a1) and the radial end of the spiral ridge (a3) of the flow path forming body (a2). Will be. Further, such a gap (a4) may be larger than a design value due to a dimensional error, undulation or bending of the heat transfer tube (a1) or the flow path forming body (a2).

Improving the dimensional accuracy of the heat transfer tube (a1) and the flow path forming body (a2) and making the gap (a4) as close to zero as possible significantly lowers the productivity of the heat exchanger. So it is not realistic from a productivity point of view. Therefore, the gap (a
4) was considered to be a necessary element for this type of heat exchanger.

[0006]

However, in the heat exchanger described in the above publication, the following problems caused by the gap (a4) have occurred.

That is, in addition to the swirling flow (M1) as the main flow flowing through the spiral flow path along the flow path forming body (a2), the flow of the heat storage medium flowing in the heat transfer pipe (a1) While above the gap
A gap flow (S1) that flows straight through the heat transfer tube (a1) in the axial direction via (a4) is generated. And this gap flow (S1) is the swirling flow (M1)
(M1) intersects with the main flow, causing a turbulence in the swirl flow (M1).
(M1) did not flow smoothly.

In addition, supercooled water is inherently unstable, and even if it is slightly stimulated due to turbulence in the flow, etc., the supercooled state is easily eliminated and icing is easily started. The turbulence tends to cause an adverse effect of eliminating the supercooled state of the water that has been supercooled by exchanging heat with the refrigerant. For this reason, in the above-mentioned heat exchanger, there was a problem that the heat storage medium was frozen in the heat transfer tube (a1), and the flow path of the heat storage medium was easily blocked.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the object of the present invention is to provide high manufacturability and to provide no gap between the inner peripheral surface of the heat transfer tube and the spiral ridge of the flow path forming body. Another object of the present invention is to provide a heat exchanger capable of performing heat exchange between a heat storage medium and a refrigerant while keeping a supercooled state of the heat storage medium stable.

[0010]

In order to achieve the above object, the present invention provides a flow path forming member formed of a material that absorbs a heat storage medium and swells, thereby forming a gap between the flow path forming member and the heat transfer tube. And the generation of gap flow was suppressed.

[0011] Specifically, the means of the present invention as defined in claim 1 comprises a closed container (48) and a plurality of heat transfer tubes (49, 49b) provided in the closed container (48). And the heat transfer tube
Refrigerant (R) flowing outside of (49,49b) and the heat transfer tube (49,49b)
In the shell-and-tube heat exchanger that performs heat exchange with the heat storage medium (W) flowing inside the
9, 49b) contains a rod (82
a, 82b), and a helical ridge (hence a spiral flow path of a heat storage medium located between the outer peripheral surface of the rod-shaped body (82a, 82b) and the inner peripheral surface of the heat transfer tube (49)). 83, 83b), and at least one of the rods (82a, 82b) and the spiral ridges (83, 83b) is formed of a swellable material that expands by absorbing the heat storage medium (W). This is the configuration that has been performed.

[0012] On the other hand, the means adopted by the invention according to claim 2 is that, in the shell-and-tube heat exchanger according to claim 1, the rod-shaped body (82a) and the spiral ridge (83) swell. The rod-shaped body (82a) and the spiral ridge (83) integrally formed of a conductive material are integrally formed with the heat storage medium.
(W) is not absorbed, the outer diameter of the heat transfer tube (4
The tip of the spiral ridge (83) is in contact with the heat transfer tube (49) in a state of being smaller than the inner diameter of (9) and absorbing the heat storage medium (W).

[0013] In the shell and tube type heat exchanger according to the first aspect, at least one of the rod-like body (82a) and the spiral ridge (83) is provided. One is a configuration made of nylon.

According to the above-described invention, even when the outer diameter of the flow path forming member is smaller than the inner diameter of the heat transfer tube, when the heat storage medium flows into the heat transfer tube, the rod-shaped member (82a, 8
2b) or the spiral ridge (83, 83b) absorbs the heat storage medium and expands, so the spiral ridge (83) and the heat transfer tube (4
9) or the gap (84, 84b) between the spiral ridge (83b) and the rod (82b). Therefore, a gap flow flowing through these gaps (84, 84b) does not occur. Therefore,
Since the heat storage medium flows in a stable state with little turbulence, even if the heat storage medium is in a supercooled state, the supercooled state is difficult to eliminate.

Thus, a heat exchanger is provided which has high productivity, does not generate gap flow, and can perform heat exchange between the heat storage medium and the refrigerant while keeping the supercooled state of the heat storage medium stable. It becomes possible.

[0016]

Embodiment 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, a regenerative air conditioner (10) using the heat exchanger (50) of the present invention will be described.

As shown in FIG. 1, a regenerative air conditioner (1
0) includes a refrigerant circuit (20) for circulating a refrigerant and a water circuit (30) for circulating water. First, the refrigerant circuit (20) and the water circuit (30) will be described in order.

-Refrigerant circuit (20)-The refrigerant circuit (20) comprises a compressor (21) and a four-way switching valve (22).
The outdoor heat exchanger (23), the outdoor electric expansion valve (EV-1) and the indoor electric expansion valve (EV-2), the indoor heat exchanger (24), and the accumulator (25) are connected to the refrigerant pipe ( A main refrigerant circuit (27), which is connected in order by 26) and is capable of reversible operation, is provided. And the indoor heat exchanger (24) and the indoor electric expansion valve (EV-2)
Is provided in the indoor unit, while other component devices such as the compressor (21) are provided in the outdoor unit.

Further, the refrigerant circulation circuit (20) is provided with a heat storage refrigerant circuit (2a), an ice core circuit (2b), and a hot gas passage (2C). The heat storage refrigerant circuit (2a) is a circuit in which the refrigerant circulates during a cold storage operation or a cooling operation using cold storage described below, and has one end having an outdoor heat exchanger (23) and an outdoor electric expansion valve (EV- 1), the other end is connected between the four-way switching valve (22) and the accumulator (25), and the first solenoid valve (SV-
1), a preheater (11), and a heat storage electric expansion valve (E
V-3), a supercooling heat exchanger (50), and a second solenoid valve (SV-2) are sequentially connected. The heat exchanger of the present invention,
It is used as this supercooling heat exchanger (50).

The above-mentioned ice core circuit (2b) is provided with a water circulating circuit to be described later.
A circuit for generating ice nuclei in (30), one end between the heat storage electric expansion valve (EV-3) and the supercooling heat exchanger (50) in the heat storage refrigerant circuit (2a), the other end Is a subcooling heat exchanger (50)
And a second solenoid valve (SV-2), and a capillary tube (CP) and an ice nucleus generator (13) are connected in order.

The hot gas passage (2C) is used to cool the refrigerant discharged from the compressor (21) during a cooling operation utilizing cold storage heat, etc.
A circuit for supplying to the (50), one end of which is connected to the discharge side of the compressor (21), the other end of which is connected to the subcooling heat exchanger (50), and a third solenoid valve (SV-3). I have.

-Water circulation circuit (30)-The water circulation circuit (30) has a heat storage tank (31) as shown in FIG.
, A pump (32), a preheater (11), a mixer (33), a subcooling heat exchanger (50), and a subcooling elimination unit (34) by a water pipe (35) as a heat storage medium. A certain water circulation (see the arrow in FIG. 2) is connected in order as possible.

Further, the supercooling heat exchanger according to the present invention
Reference numeral (50) denotes a vertical shell-and-tube heat exchanger, which is formed by housing a plurality of heat transfer tubes in a container, as described later. The supercooling heat exchanger (50) exchanges heat between the refrigerant flowing from the refrigerant circuit (20) in the container and the water flowing in the heat transfer tube, and cools the water to a supercooled state during the cold storage operation. It is configured to be.

The preheater (11) is a double-pipe heat exchanger, in which a coolant flows outside the inner pipe, water flows inside the inner pipe, and ice water flowing from the heat storage tank (31) is removed. Heating and water plumbing
It is configured to melt ice flowing through (35).

The ice nucleus generator (13) includes a subcooling heat exchanger (5).
0) is attached to the water pipe (35) at the downstream side, and a part of the water flowing through the water pipe (35) is cooled and iced by the refrigerant in the refrigerant circuit (20), and it is supercooled as ice nuclei. It is configured to supply the solution to the cancellation section (34).

The mixer (33) and the supercooling elimination section (34)
Each is constituted by a hollow cylindrical container, and is configured such that water introduced in a tangential direction forms a swirling flow. And
The mixer (33) stirs the water and ice heated by the preheater (11) to promote the melting of the ice, while the supercooling elimination unit (34)
Is the ice nucleus generated by the ice nucleator (13) and the supercooled heat exchanger
The supercooling water generated in (50) is stirred to eliminate supercooling.

-Supercooling heat exchanger (50)-Next, the supercooling heat exchanger (50) will be described.

As shown in FIG. 3, the subcooling heat exchanger (50)
Is provided with a closed cylindrical container (48) having an axis extending vertically. Inside the container (48), an upper water circulation part (48a) defined by the upper end of the container (48) and the upper tube plate (36a) at both upper and lower ends thereof, and a lower part of the container (48). A lower water flow section (48b) defined by the side end and the lower tube sheet (36b) is provided. Further, inside the container (48), an upper water circulation part (48a) and a lower water circulation part (48
b) a plurality of heat transfer tubes (4
9) is provided.

As shown in FIG. 4, the heat transfer tubes (49) are arranged in parallel with each other at a predetermined distance from adjacent heat transfer tubes (49). One end of each heat transfer tube (49) is an upper water flow section
(48a), and the other end is in communication with the lower water circulation part (48c), allowing water to flow between the upper water circulation part (48a) and the lower water circulation part (48b). is there. In addition, heat transfer tubes (4
In the outer space of (9), a refrigerant circulation part (48c) defined and formed between the upper tube sheet (36a) and the lower tube sheet (36b) is formed.

The refrigerant circulating section (48c) communicates with a lower connecting pipe (52) for introducing a refrigerant at a lower portion of the container (48).
The upper part communicates with the upper connection pipe (51) for leading the refrigerant.

-Heat Transfer Tube- Next, the heat transfer tube (49) which is a feature of the present invention will be described in detail.

As shown in FIG. 5, a plurality of fins (86) are formed on the outer wall of the heat transfer tube (49) at regular intervals in the axial direction. The fins (86) increase the outside area of the heat transfer tubes and improve the heat exchange efficiency. The material of the heat transfer tube (49) is copper, but aluminum can also be used.

On the other hand, as shown in FIG. 6, inside the heat transfer tube (49), a water-absorbing swelling property (the property of expanding by absorbing water) is formed as a flow path forming body for forming a water flow path. The resin rod (82) is inserted. As a material of the resin rod (82), for example, nylon such as polyamide 6 (nylon 6) or polyamide 66 (nylon 66), polyacetal, or the like is used. The water absorption of the polyamide 6 and the polyamide 66 is 1.8% and 1.3%, respectively, under the condition of immersion in water at 23 ° C. for 24 hours. The water absorption of the polyacetal is 0.22 to 0.25% under the above conditions.

The length of the resin rod (82) is substantially equal to the length of the heat transfer tube (49) in the axial direction. On the outer peripheral surface of the resin rod (82), a plurality of spiral ridges convex in the radial direction of the heat transfer tube (49) are provided.
(83) is formed integrally with the rod (82a). The spiral ridge (83) is formed so that the flow of water (W) spirals in the axial direction around the resin rod (82). This spiral ridge (83) is also formed of a resin having water-absorbing swelling property, like the rod-shaped body (82a). The spiral ridge (83) of the present embodiment is formed of the same material as the material forming the rod (82a), but the material of the spiral ridge (83) is the material forming the rod (82a). And may be different.

The rod-shaped body (82a) is formed in a cylindrical shape coaxial with the tube axis of the heat transfer tube (49), and is disposed in the upper water flow part (48a) and the lower water flow part (48b). The upper and lower ends of the body (82a) are sealed so that water does not flow into the center (82d) of the rod (82a). With such a configuration, even if the water is frozen in the flow path, the rod-shaped body (82a) is deformed inward, so that the rupture of the heat transfer tube can be prevented.

The inclination angle of the spiral ridge (83) with respect to the shaft is set to be substantially the same so as to keep a constant pitch with respect to the axial direction. However, the spiral ridge (83) may be configured to have a different pitch and a different angle depending on various design conditions. The spiral ridge (83) winds the outer peripheral surface of the rod (82a) so that the flow of water (W) spirals in the axial direction around the rod (82a).

The above-described internal structure of the heat transfer tube includes a spiral ridge (83).
It is manufactured by inserting a resin rod (82) having At the time of insertion, as shown in FIG. 7A, in order to facilitate insertion of the resin rod (82), the maximum length (D-max) in the axial cross section of the resin rod (82) at the time of insertion is determined by It is configured to be slightly smaller than the inner diameter (Di) of the heat tube (49).
Therefore, the radial tip of the spiral ridge (83) and the heat transfer tube (49)
A gap (84) is formed between the pipe and the inner peripheral surface of the pipe.

-Operation- Next, the operation of the above-described regenerative air conditioner (10) will be described. First, a cold storage operation using the supercooling heat exchanger (50) will be described.

-Cold heat storage operation- In this operation mode, as shown in FIG.
2) is switched to the solid line side, and while the heat storage electric expansion valve (EV-3) is adjusted to the predetermined opening, the other electric expansion valves (EV-1, EV-
2) Close. Also, the first and second solenoid valves (SV-1, SV-
2) is open, and the third solenoid valve (SV-3) is closed.

In this state, in the refrigerant circulation circuit (20), the refrigerant discharged from the compressor (21) exchanges heat with the outside air in the outdoor heat exchanger (23) as shown by an arrow in FIG. Condense. After that, this refrigerant is decompressed by the heat storage electric expansion valve (EV-3), and then exchanges heat with water in the supercooling heat exchanger (50) to evaporate.
The water is cooled to a supercooled state (eg -2 ° C). Thereafter, the refrigerant passes through the accumulator (25) and the compressor (21)
Inhaled.

In this operation, part of the refrigerant is
After being diverted from the downstream side of the heat storage electric expansion valve (EV-3) to the ice nucleus circuit (2b), the pressure was reduced by the capillary tube (CP), and then evaporated by the ice nucleus generator (13), and the accumulator (25) was removed. Via compressor
Inhaled in (21). In this ice nucleus generator (13), the refrigerant exchanges heat with the water flowing through the water pipe (35), and the ice blocks are removed from the water pipe (3).
Generated on the inner wall of 5).

On the other hand, in the water circulation circuit (30), water is circulated by driving the pump (32). The water flowing out of the heat storage tank is heated by a preheater (11) via a pump (32), and then stirred by a mixer (33). Thereafter, the water is cooled by a heat exchanger with the refrigerant in the subcooling heat exchanger (50), is cooled to a predetermined supercooled state, and flows out of the supercooling heat exchanger (50). Then, the supercooled water flowing out of the heat exchanger (50) is further cooled in the ice nucleus generator (13), and the ice block is cooled by a water pipe (35).
Generated on the inner wall surface. After that, ice nuclei are generated around the ice block, and the supercooled water containing the ice nuclei
4) supplied to. Then, in the supercooling elimination section (34),
The ice nuclei and the supercooled water are stirred, and slurry-like ice for heat storage is generated and collected and stored in the heat storage tank (31).

At the time of the main operation, a relatively high-temperature refrigerant flows through the preheater (11), and even if ice flows through the water pipe (35), the preheater (1) may be used.
In step (1), the mixture is heated and melted, and ice is prevented from entering the supercooled heat exchanger (50).

Next, the flow of the refrigerant and water in the subcooling heat exchanger (50) will be described.

The refrigerant flows from the lower connecting pipe (52) to the refrigerant flowing section (48).
c) and flows upward through the refrigerant flow section (48c) while forming a gas-liquid interface (G) while absorbing heat from water flowing in the heat transfer tube (49). Then, the refrigerant that has completed heat exchange with water flows out of the upper connection pipe (51).

On the other hand, the water that has flowed in from the lower water circulation part (48b) exchanges heat with the low-temperature refrigerant flowing through the refrigerant circulation part (48c) and flows upward in a spiral shape while being cooled while being cooled. In other words, the water flowing from the lower water circulation part (48b) at a temperature higher than the freezing point gradually decreases in temperature in the downstream direction of the flow path, that is, above the heat transfer tube (49), and eventually becomes a supercooled state. And the upper water outflow section (4
8a).

At this time, the resin rod (82) expands by absorbing a part of the water flowing through the flow path. Then, as shown in FIG. 7 (b), when the resin rod (82) expands outward in the radial direction of the heat transfer tube, the spiral ridge (83) comes into contact with the inner peripheral surface of the heat transfer tube (49). I do. As a result, there is no gap (84). That is, the resin rod (82) expands by absorbing water such that the gap (84) is eliminated. The spiral ridge (83) and the heat transfer tube (4
The contact with 9) is a contact having a sufficient contact area so that water flowing through the flow path does not bypass.

Water flows in a spiral space defined by the inner peripheral surface of the heat transfer tube (49), the outer peripheral surface of the rod-shaped body (82a), and the surface of the spiral ridge (83) without any gap. . Therefore, the main flow of water flows spirally in the axial direction of the heat transfer tube (49) from the lower portion to the upper portion of the heat transfer tube (49).

As described above, the cold storage operation using the supercooling heat exchanger (50) is performed.

Next, another operation of the regenerative air conditioner (10) will be schematically described.

-Normal Cooling Operation- In this operation mode, only the refrigerant circuit (20) is operated, and the water circuit (30) is not operated.

In this operation mode, the four-way switching valve (22) is switched to the solid line side in FIG. 1, the indoor electric expansion valve (EV-2) is superheated, and the outdoor electric expansion valve (EV-1) is turned on. The heat storage electric expansion valve (EV-3) is controlled to a fully closed state and to a fully closed state. On the other hand, each solenoid valve (SV-1, SV-2, SV-3) is closed.

In this state, the refrigerant discharged from the compressor (21) exchanges heat with the outside air in the outdoor heat exchanger (23) and condenses. After that, the refrigerant is decompressed by the indoor electric expansion valve (EV-2), and then evaporates in the indoor heat exchanger (24) to produce an accumulator.
Through (25), it is sucked into the compressor (21). By this circulation operation, the regenerative air conditioner (10) cools the room.

-Cooling operation utilizing cold storage- In this operation mode, as shown in FIG.
2) is switched to the solid line side, the indoor electric expansion valve (EV-2) is controlled to a predetermined opening, and the other electric expansion valves (EV-1, EV-3) are fully opened. Further, the first and third solenoid valves (SV-1 and SV-3) are opened, and the second solenoid valve (SV-2) is closed.

In this state, in the water circulation circuit (30),
The pump (32) is driven to circulate cold water. The cold water in the heat storage tank (31) passes through the pump (32), the preheater (11), and the mixer (33) in this order, and then flows into the supercooling heat exchanger (50). At this time, the cold water is not preheated by the preheater (11), but simply passes through the preheater (11). Then, the cold water flowing into the subcooling heat exchanger (50) exchanges heat with the refrigerant and is heated. Thereafter, the heated water flows out of the subcooling heat exchanger, and returns to the heat storage tank (31) via the subcooling elimination section. Then, the heated water is cooled by exchanging heat with ice stored in the heat storage tank (31), and becomes cold water,
It flows out of the heat storage tank (31) again and circulates in the water circulation circuit.

On the other hand, in the refrigerant circuit (20), a part of the refrigerant discharged from the compressor (21) passes through the four-way switching valve (22) as shown by the arrow in FIG. Heat exchanger (2
It flows to 3) and exchanges heat with the outside air in the outdoor heat exchanger (23) to condense. Further, the other discharged refrigerant flows into the supercooling heat exchanger (50) via the hot gas passage (2C), and exchanges heat with cold water circulating in the water circulation circuit (30) to condense. Then, the refrigerant condensed in the outdoor heat exchanger (23) and the subcooling heat exchanger (50) are merged and decompressed by the indoor electric expansion valve (EV-2), and then the indoor heat exchanger (24) After evaporating and cooling the room air, the air is sucked into the compressor (21) through the accumulator (25).

With the above operation, the indoor cooling operation using the cold heat of the ice stored in the heat storage tank (31) is performed.

-Normal Heating Operation- In this operation mode, the water circulation circuit (30) is not operated, and only the refrigerant circulation circuit (20) is operated.

In this operation mode, the four-way switching valve (22) is switched to the broken line in FIG. 1, the outdoor electric expansion valve (EV-1) is controlled to a predetermined opening, and the indoor electric expansion valve (EV-2) is controlled. Is fully opened, and the heat storage electric expansion valve (EV-3) is controlled to be fully closed. On the other hand, each solenoid valve (SV-1, SV-2, SV-3) is closed.

In this state, the refrigerant discharged from the compressor (21) flows into the indoor heat exchanger (24), exchanges heat with the indoor air, condenses, and heats the indoor air. After that, this refrigerant is decompressed by the outdoor electric expansion valve (EV-1),
In (23), heat exchange with the outside air evaporates. Thereafter, the refrigerant is sucked into the compressor (21) via the accumulator (25). The room is heated by such a circulation operation of the refrigerant.

The operation of the regenerative air conditioner (10) has been described above.

In the present heat exchanger (50), since the resin rod (82) has a property of absorbing water and expanding (water swelling property), the heat storage type air conditioner using the present heat exchanger (50) When (10) is operated, the resin rod (82) expands in the radial direction by absorbing a part of the water flowing through the flow path.

Therefore, at the time of manufacture, as shown in FIG. 7A, the maximum length (D-ma
x) can be made much smaller than the inner diameter (Di) of the heat transfer tube (49). Therefore, a sufficient gap (84) can be formed between the radial end of the spiral ridge (83) and the inner peripheral surface of the heat transfer tube (49), and the resin rod (82) is inserted into the heat transfer tube (49). Becomes easier. Therefore, there is no problem even if the dimensional accuracy of the heat transfer tube (49) and the resin rod (82) is low, and the manufacture of the heat transfer tube (49) is significantly easier than before. Productivity is high.

In operation, as shown in FIG. 7 (b), the tip of the spiral ridge (83) in the radial direction comes into contact with the inner peripheral surface of the heat transfer tube (maximum in the axial section of the resin rod (82)). Length (D'-
max) is equal to the inner diameter (Di) of the heat transfer tube (49)), and a spiral ridge
There is no gap between the radial end of (83) and the inner peripheral surface of the heat transfer tube (49). Accordingly, in the present heat exchanger (50), there is no gap between the radial end of the spiral ridge (83) and the heat transfer tube (49), so that the adjacent flow separated by the spiral ridge (83) There is no gap flow between the roads flowing substantially parallel to the tube axis. Due to this, the flow of water (W) flowing through the flow path is less disturbed,
Smooth flow with stable supercooling.

As described above, the supercooled water is inherently unstable, and the supercooled state is eliminated by a slight stimulus to start ice formation. Conversion is extremely unlikely to occur. Therefore, the risk of blockage of the flow passage due to icing is significantly reduced, and the degree of supercooling of the water flowing through the flow passage can be increased more than before, and the heat exchanger can be reduced in size and improved in efficiency. can do.

[0067]

Embodiment 2 Next, referring to FIG.
Another embodiment will be described.

The heat exchanger according to the second embodiment differs from the heat exchanger (50) of the first embodiment only in the internal structure of the heat transfer tube (49). In the heat exchanger of the second embodiment, a radially extending spiral ridge (83b) is provided on the inner peripheral surface of the heat transfer tube (49b). This spiral ridge (83b) is a spiral ridge of the heat exchanger (50) of the first embodiment.
Like (83), the flow of water as a heat storage medium is configured to be spiral. On the other hand, a resin rod which is a flow path forming body
(82b) has a cylindrical shape. The heat exchanger of the first embodiment
Like the resin rod (82) of (50), both ends of the resin rod (82b) are sealed so that water does not flow into the inside (82e) of the resin rod.

The internal structure of the heat transfer tube (49b) is a spiral ridge.
It is manufactured by inserting a resin rod (82b) into a heat transfer tube (49b) having (83b). At the time of insertion, the outer diameter (Db) of the resin rod (82b) at the time of insertion is orthogonal to the axial direction of the heat transfer tube in order to facilitate insertion of the resin rod (82b) as shown in FIG. It is configured to be considerably smaller than the minimum length (Di ') of the heat transfer tube (49b) in cross section. Therefore, the spiral ridge
A gap (84b) is formed between the radial end of (83b) and the outer peripheral surface of the resin rod (82b).

Similarly to the heat exchanger of the first embodiment, also in the heat exchanger of the second embodiment, during operation, the resin rod (82b) expands by absorbing a part of the water flowing through the flow path. Then, FIG.
As shown in (5), when the resin rod (82b) expands outward in the radial direction of the heat transfer tube (49b), the spiral ridge (83b) comes into contact with the outer peripheral surface of the resin rod (82b). As a result, the gap (84b)
Is gone. That is, the resin rod (82b) expands by absorbing water such that the gap (84b) is eliminated. The contact between the spiral ridge (83b) and the resin rod (82b) is a contact having a sufficient contact area so that water flowing through the flow path does not bypass.

Therefore, also in the heat exchanger of the second embodiment, since the resin rod (82b) has the property of absorbing water and expanding, the transmission during manufacturing is the same as that of the heat exchanger of the first embodiment. Insertion of the resin rod (82b) into the heat tube (49b) is easy. Therefore, the manufacture of the heat transfer tube (49b) is easy, and the productivity of the heat exchanger is high.

In operation, the resin rod (82b) absorbs a part of the water (W) flowing through the flow path, expands in the radial direction, and
0 (b), the radial end of the spiral ridge (83b) comes into contact with the outer peripheral surface of the resin rod (82b) (the outer diameter of the resin rod (82b)).
(Db-max) is equal to the minimum length (Di ') of the heat transfer tube (49b)), and there is no gap between the radial end of the spiral ridge (83b) and the outer peripheral surface of the resin rod (82b). . Therefore, the spiral ridge
Since no gap flow is generated between the pipe (83b) and the resin rod (82b), the flow (W) of water flowing through the flow path has little turbulence and is a smooth flow in which the supercooled state is kept stable.

[0073]

As described above, according to the present invention, the heat transfer tube
(49, 49b) inserted in a rod or spiral ridge (82, 82
b) absorbs the heat storage medium (W) and expands, and without impairing the productivity of the heat exchanger, the spiral ridge (83) and the inner peripheral surface of the heat transfer tube (49) that were generated at the time of manufacture. Or the gap between the spiral ridge (83b) and the outer peripheral surface of the resin rod (82b) can be eliminated. Therefore, the turbulence of the flow of the heat storage medium (W) flowing through the heat transfer tubes (49, 49b) is small, and the heat storage medium (W)
Storage medium (W) and refrigerant while maintaining the supercooled state of
Heat exchange with (R). As a result, blockage of the flow path of the heat storage medium (W) due to icing of the heat storage medium (W) that occurs when the supercooled state is resolved is prevented even if the degree of supercooling of the heat storage medium (W) is considerably large. Can be. And the heat exchanger can be reduced in size and improved in efficiency.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a regenerative air conditioner.

FIG. 2 is a diagram showing a configuration of a water circulation circuit of the regenerative air conditioner.

FIG. 3 is a side view of the subcooling heat exchanger.

FIG. 4 is a sectional view of the subcooling heat exchanger at a position corresponding to line VV in FIG. 3;

FIG. 5 is a view showing a heat transfer tube of the subcooling heat exchanger.

FIG. 6 is a partially enlarged view of a heat transfer tube of the subcooling heat exchanger.

FIG. 7 is a sectional view of a heat transfer tube of the supercooling heat exchanger,
(A) is a diagram showing a state where a resin rod is inserted at the time of manufacture, and (b) is a diagram showing a state where the resin rod has expanded by absorbing water.

FIG. 8 is a circuit diagram of the regenerative air conditioner during the cold regenerative operation.

FIG. 9 is a circuit diagram of the regenerative air conditioner during a cold storage operation.

FIG. 10 is a view corresponding to FIG. 7 according to another embodiment of the present invention.

FIG. 11 is a diagram showing a flow of water in a heat transfer tube of a conventional heat exchanger.

[Explanation of symbols]

 21 Compressor 22 Four-way switching valve 23 Outdoor heat exchanger 24 Indoor heat exchanger 31 Heat storage tank 48 Container 48c Refrigerant circulation section 49 Heat transfer tube 50 Supercooling heat exchanger 82 Resin rod 82a Rod body 83 Spiral ridge 84 Gap W Water R refrigerant

Claims (3)

[Claims] 1. A closed-type container (48), and a plurality of heat transfer tubes (49, 49b) provided in the closed-type container (48).
(49, 49b) and a heat storage medium (W) flowing inside the heat transfer tubes (49, 49b) and a heat storage medium (W). Inside the heat transfer tubes (49, 49b), rods (82a, 82b) inserted into the heat transfer tubes, an outer peripheral surface of the rods (82a, 82b) and an inner peripheral surface of the heat transfer tubes (49) are provided. And a spiral ridge (83, 83b) that forms a spiral flow path of the heat storage medium is provided between the rod-shaped body (82a, 82b) and the spiral ridge (83, 83b). A shell-and-tube heat exchanger, characterized in that at least one of them is formed of a swellable material that expands by absorbing the heat storage medium (W). 2. The shell-and-tube heat exchanger according to claim 1, wherein the rod-shaped body (82a) and the spiral ridge (83) are integrally formed of a swellable material, and the rod-shaped body is integrally formed. Body (82a) and the spiral ridge (83)
Has a smaller outer diameter than the inner diameter of the heat transfer tube (49) in a state where the heat storage medium (W) is not absorbed, and
A shell-and-tube heat exchanger, wherein the tip of the spiral ridge (83) is in contact with the heat transfer tube (49) when (W) is absorbed. 3. The shell and tube heat exchanger according to claim 1, wherein at least one of the rod-shaped body (82a) and the spiral ridge (83) is formed of nylon. Shell and tube heat exchanger.