WO2021221105A1

WO2021221105A1 - Evaporator

Info

Publication number: WO2021221105A1
Application number: PCT/JP2021/016988
Authority: WO
Inventors: 将之左海; 文平呉; 良枝栂野; 明正横山; 達男石黒; 大智吉井; 泰高青木; 和仁吉田
Original assignee: 三菱重工サーマルシステムズ株式会社
Priority date: 2020-05-01
Filing date: 2021-04-28
Publication date: 2021-11-04
Also published as: KR20220159448A; JP2021175922A; CN115485517A; CN115485517B; JP6880280B1

Abstract

The purpose of the present invention is to improve heat exchange efficiency and improve the performance of an evaporator. The present invention is provided with: a pressure vessel that forms an outer shell; a liquid-film-type heat transfer pipe group that is housed in the pressure vessel and immersed in a liquid-phase refrigerant stored in a storage part provided to a lower part of the pressure vessel and that includes a plurality of first heat transfer pipes in which water to be cooled flows; a liquid-film-type heat transfer pipe group that is housed in the pressure vessel and located upward of the liquid level of the liquid-phase refrigerant stored in the lower part of the pressure vessel and that includes a plurality of second heat transfer pipes which extend in a predetermined direction and in which water to be cooled flows; and a refrigerant supply pipe (13) that is for supplying the refrigerant from above to the liquid-film-type heat transfer pipe groups, that is housed in the pressure vessel, that extends in a predetermined direction, and in which a refrigerant in a state of being in two phases, i.e., gas and liquid phases, flows. The refrigerant supply pipe (13) has: a closure part (20) that closes at least a lower end portion of an end surface in an X-axis direction; and an opening part (21) that is formed, above the closure part (20), at an end portion in the X-axis direction and that connects the internal space of the refrigerant supply pipe (13) and the external space of the refrigerant supply pipe (13).

Description

Evaporator

This disclosure relates to an evaporator.

As an evaporator used in a refrigerator, a liquid film type evaporator that supplies a liquid phase refrigerant from above to a group of heat transfer tubes through which a cooling medium flows inside is known. Such a liquid film type evaporator is provided with a pipe for supplying a refrigerant to a heat transfer tube group (for example, Patent Document 1).

Patent Document 1 describes a liquid film type evaporator in which the entire end surface of a refrigerant supply pipe extending in the longitudinal direction is closed. This pipe supplies the refrigerant to the heat transfer pipe group by blowing out the refrigerant from a plurality of slits formed at the bottom of the pipe.

Chinese Patent No. 10548703

However, as in Patent Document 1, in the refrigerant supply pipe in which the entire entire end surface is closed, the flow velocity of the refrigerant flowing in the pipe decreases remarkably toward the end in the longitudinal direction. Since the refrigerant flowing in the refrigerant supply pipe is in a gas-liquid mixed state, gas-liquid separation is performed by the influence of gravity when the flow velocity decreases. As a result, the liquid-phase refrigerant accumulates at the bottom of the pipe, and the liquid-phase refrigerant easily flows out from the slit. Therefore, there is a possibility that the amount of refrigerant in the liquid phase reaching the end in the longitudinal direction may be reduced.
When the amount of refrigerant in the liquid phase reaching the end in the longitudinal direction is reduced, the amount of refrigerant supplied to the heat transfer tube group is distributed. As a result, the heat exchange efficiency in the heat transfer tube group may decrease, and the performance of the evaporator may decrease.

The present disclosure has been made in view of such circumstances, and an object of the present disclosure is to provide an evaporator capable of improving heat exchange efficiency and improving the performance of the evaporator.

In order to solve the above problems, the evaporator of the present disclosure employs the following means.
The evaporator according to one aspect of the present disclosure is immersed in a housing forming an outer shell and a liquid-phase refrigerant housed in the housing and stored in a storage portion provided in the lower part of the housing. A group of first heat transfer tubes having a plurality of first heat transfer tubes through which a medium to be cooled flows, and a liquid phase refrigerant housed in the housing and stored in the lower part of the housing above the liquid level of the refrigerant. A group of second heat transfer tubes having a plurality of second heat transfer tubes, which are provided in the above and have a plurality of second heat transfer tubes in which a medium to be cooled flows and extend in a predetermined direction, and a group of second heat transfer tubes housed in the housing, which extend in the predetermined direction and extend inside. A refrigerant supply pipe in which a gas-liquid two-phase state refrigerant flows and supplies the refrigerant to the second heat transfer tube group from above is provided, and the refrigerant supply pipe closes at least the lower end portion of the end face in the predetermined direction. It has a closed portion and an opening which is an end portion in the predetermined direction and is formed above the closed portion and connects the inner space of the refrigerant supply pipe and the outer space of the refrigerant supply pipe.

According to the present disclosure, the heat exchange efficiency can be improved and the performance of the evaporator can be improved.

It is a schematic vertical sectional view of the evaporator which concerns on this disclosure. FIG. 1 is a cross-sectional view taken along the line II-II of FIG. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. It is a front view which shows the refrigerant supply pipe provided in the evaporator of FIG. It is a side view which shows the refrigerant supply pipe of FIG. It is a graph which shows the relationship between the position of the refrigerant supply pipe in a predetermined direction, and the flow velocity of the refrigerant at the position. It is a graph which shows the relationship between the position of the refrigerant supply pipe in a predetermined direction, and the supply amount of the refrigerant at the said position. It is a schematic perspective view of the refrigerant supply pipe which concerns on a modification. It is a schematic vertical sectional view of the refrigerant supply pipe which concerns on the modification of this disclosure. It is a schematic vertical sectional view of the refrigerant supply pipe which concerns on the modification of this disclosure. It is a schematic vertical sectional view of the refrigerant supply pipe which concerns on the modification of this disclosure. It is a schematic vertical sectional view of the refrigerant supply pipe which concerns on the modification of this disclosure.

Hereinafter, an embodiment of the evaporator according to the present disclosure will be described with reference to FIGS. 1 to 12. In the following description and drawings, the vertical vertical direction will be the Z-axis direction, the extending direction of the heat transfer tube will be the X-axis direction, and the Z-axis direction and the direction orthogonal to the X-axis direction will be described as the Y-axis direction.

The evaporator 10 according to this embodiment is applied to a turbo refrigerating apparatus. The turbo refrigeration system includes a turbo compressor that compresses the refrigerant (not shown), a condenser that condenses the refrigerant compressed by the turbo compressor (not shown), and an expansion valve that expands the refrigerant condensed by the condenser (not shown). It is configured in a unit shape with an evaporator (not shown) and an evaporator that evaporates the refrigerant expanded by the expansion valve. Each device is connected by a pipe through which a refrigerant flows. As the refrigerant, for example, a low-pressure refrigerant such as R1233zd used at a maximum pressure of less than 0.2 MPaG is used.

As shown in FIG. 1, the evaporator 10 is provided below the pressure vessel (housing) 11 forming the outer shell, the refrigerant inlet pipe 12 for introducing the refrigerant into the pressure vessel 11, and the refrigerant inlet pipe 12. The refrigerant supply pipe 13, the full-liquid heat transfer tube group (first heat transfer tube group) 14 immersed in the liquid phase refrigerant stored in the lower part of the pressure vessel 11, and the liquid stored in the lower part of the pressure vessel 11. A liquid film type heat transfer tube group (second heat transfer tube group) 15 provided above the liquid level S (see FIGS. 2 and 3) of the phase refrigerant, and a refrigerant outlet tube for discharging the evaporated refrigerant from the pressure vessel 11. (Refrigerant outlet) 16.

As shown in FIGS. 1 to 3, in the pressure vessel 11, the cylindrical portion 11a whose central axis extends along the X-axis direction and both ends of the cylindrical portion 11a in the direction along the central axis (X-axis direction). It integrally has two tube plates 11b for closing the. The cylindrical portion 11a is arranged so that the central axis is substantially horizontal. Each tube plate 11b is a disk-shaped plate material. Further, a liquid phase refrigerant is stored in the lower part of the pressure vessel 11. Hereinafter, the region in which the liquid phase refrigerant is stored is referred to as a storage unit 11c.

The refrigerant inlet pipe 12 is a cylindrical member extending in the vertical direction, and is formed in a substantially linear shape. The refrigerant inlet pipe 12 is provided so as to penetrate the upper portion of the cylindrical portion 11a in the vertical direction. The refrigerant inlet pipe 12 is provided at substantially the center of the cylindrical portion 11a in the X-axis direction. The refrigerant inlet pipe 12 is connected to a pipe (not shown) that connects the evaporator 10 and the expansion valve. That is, the refrigerant expanded by the expansion valve is guided to the inside of the pressure vessel 11 via the refrigerant inlet pipe 12.

The refrigerant supply pipe 13 is housed in the pressure vessel 11. The refrigerant supply pipe 13 is provided above the liquid film type heat transfer pipe group 15. The refrigerant supply pipe 13 extends in the X-axis direction. The lower end of the refrigerant inlet pipe 12 is connected to the upper part of the refrigerant supply pipe 13 substantially in the center in the X-axis direction. Inside the refrigerant supply pipe 13, a gas-liquid two-phase state refrigerant introduced from the refrigerant inlet pipe 12 is circulated. A plurality of slits 13a are formed at the lower end of the refrigerant supply pipe 13. Each slit 13a is formed so that the Y-axis direction is the longitudinal direction. The plurality of slits 13a are arranged side by side at equal intervals in the X-axis direction. The refrigerant flowing in the refrigerant supply pipe 13 is blown out from each slit 13a. The refrigerant supply pipe 13 supplies the refrigerant blown out from each slit 13a to the liquid film type heat transfer pipe group 15 from above.

The full-liquid heat transfer tube group 14 is housed in the pressure vessel 11. Further, the full-liquid heat transfer tube group 14 is immersed in the refrigerant stored in the storage unit 11c. That is, it is arranged below the liquid level S of the stored refrigerant. The full-liquid heat transfer tube group 14 has a plurality of first heat transfer tubes extending along the X-axis direction. The plurality of first heat transfer tubes are arranged substantially in parallel. The plurality of first heat transfer tubes are arranged side by side at predetermined intervals in the vertical direction and the Y-axis direction. Specifically, the plurality of first heat transfer tubes are arranged in a plurality of stages in the vertical direction and in a plurality of rows in the Y-axis direction. Water as a cooling medium (hereinafter referred to as "cooled water") is circulated inside each first heat transfer tube. Further, each first heat transfer tube is formed in a straight line. Further, each first heat transfer tube extends from one end (left end in FIG. 1) to the other end (right end in FIG. 1) of the pressure vessel 11 in the X-axis direction and penetrates each tube plate 11b. The length of the full-liquid heat transfer tube group 14 in the X-axis direction is longer than the length of the refrigerant supply tube 13 in the X-axis direction. In addition, in FIGS. 1 to 3, due to the illustration, the first heat transfer tubes are not shown one by one, but are collectively shown as a full-liquid heat transfer tube group 14.

The liquid film type heat transfer tube group 15 is housed in the pressure vessel 11. The liquid film type heat transfer tube group 15 is arranged above the liquid level S of the stored refrigerant. The liquid film type heat transfer tube group 15 has a plurality of second heat transfer tubes extending along the X-axis direction. The plurality of second heat transfer tubes are arranged substantially in parallel. The plurality of second heat transfer tubes are arranged side by side at predetermined intervals in the vertical direction and the Y-axis direction. Specifically, the plurality of second heat transfer tubes are arranged in a plurality of stages in the vertical direction and in a plurality of rows in the Y-axis direction. Water as a cooling medium circulates inside each second heat transfer tube. Further, each second heat transfer tube is formed in a straight line. Further, each second heat transfer tube extends from one end (left end in FIG. 1) to the other end (right end in FIG. 1) of the pressure vessel 11 in the X-axis direction and penetrates each tube plate 11b. The length of the liquid film type heat transfer tube group 15 in the X-axis direction is longer than the length of the refrigerant supply tube 13 in the X-axis direction. In addition, in FIGS. 1 to 3, the second heat transfer tubes are not shown one by one because of the illustration, but are collectively shown as a liquid film type heat transfer tube group 15.

The liquid film type heat transfer tube group 15 includes a lower liquid film type heat transfer tube group 15b provided above the liquid level S, an upper liquid film type heat transfer tube group 15c provided above the lower liquid film type heat transfer tube group 15b, and the upper liquid film type heat transfer tube group 15c. have. The lower liquid film type heat transfer tube group 15b and the lower liquid film type heat transfer tube group 15b are separated from each other in the vertical direction.

One end (the left end in FIG. 1) of the full-liquid heat transfer tube group 14 and the lower liquid film type heat transfer tube group 15b is arranged in the introduction portion 17 into which the water to be cooled is introduced. The introduction portion 17 is arranged outside the pressure vessel 11. Water to be cooled is supplied to the introduction unit 17 from a water to be cooled water supply device (not shown) (see arrow A5). Cooled water flows into the inside of the full-liquid heat transfer tube group 14 and the lower liquid film heat transfer tube group 15b from one end (see arrow A6).

Further, the other end (right end in FIG. 1) of the full-liquid type heat transfer tube group 14 and the lower liquid film type heat transfer tube group 15b is arranged in the return portion 18. Further, the other end (right end in FIG. 1) of the upper liquid film type heat transfer tube group 15c is also arranged in the return portion 18. The return portion 18 is arranged outside the pressure vessel 11. The liquid to be cooled that has flowed through the full-filled heat transfer tube group 14 and the lower liquid film type heat transfer tube group 15b enters the return portion 18 from the other end of the full-liquid type heat transfer tube group 14 and the lower liquid film type heat transfer tube group 15b. It is discharged (see arrow A7). The liquid to be cooled discharged to the return portion 18 flows into the upper liquid film type heat transfer tube group 15c from the other end of the upper liquid film type heat transfer tube group 15c (see arrow A8).

One end (the left end in FIG. 1) of the upper liquid film type heat transfer tube group 15c is arranged in the discharge unit 19 for discharging the cooled water. The discharge unit 19 is arranged outside the pressure vessel 11. The water to be cooled is discharged to the discharge unit 19 from one end of the upper liquid film type heat transfer tube group 15c (see arrow A9). The refrigerant flowing into the discharge unit 19 is cooled to become cold water by exchanging heat with the water in each heat transfer tube group. This cold water is discharged from the discharge unit 19 (see arrow A10) and is used as a cold heat medium for air conditioning, industrial cooling water, and the like.

The refrigerant outlet pipe 16 is a cylindrical member extending in the vertical direction. The refrigerant outlet pipe 16 is provided so as to communicate with an opening formed in the upper part of the cylindrical portion 11a. The refrigerant outlet pipe 16 is provided on the end side of the cylindrical portion 11a in the X-axis direction. That is, the refrigerant outlet pipe 16 is provided in the vicinity of the pipe plate 11b of the pressure vessel 11. The refrigerant vaporized in the evaporator 10 is discharged to the outside of the pressure vessel 11 via the refrigerant outlet pipe 16.

Next, the details of the refrigerant supply pipe 13 will be described in detail with reference to FIGS. 4 and 5.
As shown in FIG. 4, the refrigerant supply pipe 13 is a tubular member extending along the X-axis direction. As shown in FIG. 5, the refrigerant supply pipe 13 is formed in a substantially rectangular shape in a side view. Further, the refrigerant supply pipe 13 is curved so that the lower end portion protrudes downward in a side view. In each slit 13a, the slit 13a is formed in substantially the entire area of the curved portion 13b in the Y-axis direction.

Further, closing portions 20 are provided at both ends of the refrigerant supply pipe 13 in the X-axis direction. Each closing portion 20 closes each end face of the refrigerant supply pipe 13 in the X-axis direction. An opening 21 is formed in each closing portion 20. The opening 21 is formed at a substantially central portion of the closing portion 20 in the Z-axis direction. That is, the closing portion 20 includes a lower closing portion 20b that closes below the opening 21 of the refrigerant supply pipe 13 (including the lower end portion) and an upper closing portion that closes above the opening 21 of the refrigerant supply pipe 13. It has 20a and. Further, the positions and shapes of the openings 21 formed in the closed portions 20 are substantially the same.

The opening 21 is formed above the lower closing portion 20b. The opening 21 is formed so as to penetrate the closing portion 20. That is, the opening 21 connects the inner space of the refrigerant supply pipe 13 and the outer space of the refrigerant supply pipe 13. The opening area of the opening 21 is set to be equal to or larger than the opening area of the slit 13a formed at the end portion in the X-axis direction. The opening 21 is formed over substantially the entire area of the refrigerant supply pipe 13 in the Y-axis direction. Further, the length of the opening 21 in the Z-axis direction is shorter than half the length of the refrigerant supply pipe 13 in the Z-axis direction. The length of the opening 21 in the Z-axis direction may be about one-third of the length of the refrigerant supply pipe 13 in the Z-axis direction. The present disclosure is not limited to this. The length of the opening 21 in the Z-axis direction may be longer than half the length of the refrigerant supply pipe 13 in the Z-axis direction.

The refrigerant supply pipe 13 is supported by the pressure vessel 11 by the support plate (second shielding plate portion) 22. The support plate 22 is arranged so that the plate surface faces the vertical plane. The support plate 22 is fixed to the upper portion and the side portion of the inner peripheral surface of the pressure vessel 11. Further, an opening is formed in the support plate 22, and the refrigerant supply pipe 13 is inserted into the opening. The refrigerant supply pipe 13 inserted into the opening is arranged so as not to protrude from the support plate 22. The support plate 22 is located above and to the side of the upper liquid film type heat transfer tube group 15c. The height of the lower end of the support plate 22 is substantially the same as the height of the upper end of the lower liquid film type heat transfer tube group 15b. In this way, the support plate 22 is provided between the opening 21 and the refrigerant outlet pipe 16.
The support plate 22 may also serve as the end surface of the refrigerant supply pipe 13. That is, the refrigerant supply pipe 13 may be formed by attaching a tubular member extending along the X-axis direction to the support plate 22.
The refrigerant supply pipe 13 may be supported by the pressure vessel 11 by other means without providing the support plate 22.

In the evaporator 10 configured as described above, the refrigerant and the like circulate as follows.
As shown in FIG. 1, in the evaporator 10, the refrigerant flows into the pressure vessel 11 from the refrigerant inlet pipe 12 (see arrow A1). The refrigerant that has flowed into the pressure vessel 11 flows in the refrigerant supply pipe 13 in the X-axis direction (see arrow A2). The refrigerant flowing in the refrigerant supply pipe 13 is in a gas-liquid two-phase state. The liquid-phase refrigerant flowing in the refrigerant supply pipe 13 is blown downward through a large number of slits 13a formed at the lower end of the refrigerant supply pipe 13 (see arrow A3). The liquid-phase refrigerant blown out from the refrigerant supply pipe 13 comes into contact with the second heat transfer tube arranged at the uppermost stage of the liquid film type heat transfer tube group 15 (upper liquid film type heat transfer tube group 15c), and the liquid phase refrigerant of the second heat transfer tube Cover the outer peripheral surface like a film. The refrigerant that covers the outer peripheral surface of the second heat transfer tube in a film shape exchanges heat with the water to be cooled inside the second heat transfer tube. A part of the refrigerant evaporates due to heat exchange, and the non-evaporated refrigerant falls further down to the second heat transfer tube. Such heat exchange is continuously repeated. The refrigerant that has not evaporated even by heat exchange with the water in the second heat transfer tube arranged at the lowermost part is stored in the storage portion 11c provided at the lower part of the pressure vessel 11. In this way, a pool of liquid phase refrigerant is formed inside the pressure vessel 11. The level of the liquid level in this refrigerant pool is automatically adjusted to a predetermined height. The first heat transfer tube of the full-liquid heat transfer tube group 14 is in a state of being immersed in the refrigerant of the liquid phase stored in the storage section 11c. The water to be cooled flowing in the first heat transfer tube exchanges heat with the refrigerant stored in the storage unit 11c. The refrigerant that has exchanged heat with the first heat transfer tube evaporates and is guided upward from the liquid level S. The refrigerant evaporated in the liquid film type heat transfer tube group 15 and the full liquid type heat transfer tube group 14 is guided to the refrigerant outlet pipe 16. The refrigerant guided to the refrigerant outlet pipe 16 is discharged to the outside of the pressure vessel 11 (see arrow A4). The refrigerant discharged from the refrigerant outlet pipe 16 is sucked and compressed by the turbo compressor.

According to this embodiment, the following effects are exhibited.
In the present embodiment, the opening 21 is formed at the end of the refrigerant supply pipe 13. Of the gas-liquid two-phase state refrigerants flowing in the refrigerant supply pipe 13, a part of the gas-phase refrigerant flows to the end of the refrigerant supply pipe 13 and is discharged to the outside from the opening 21. As a result, the flow velocity of the gas-phase refrigerant flowing in the refrigerant supply pipe 13 is unlikely to decrease even at the end. In the refrigerant supply pipe 13, the liquid phase refrigerant is accompanied by the gas phase refrigerant. Therefore, the liquid phase refrigerant can be easily guided to the end. Therefore, since the liquid phase refrigerant can be suitably supplied to the end portion, the amount of the refrigerant supplied to the liquid film type heat transfer tube group 15 can be made uniform in the X-axis direction. Therefore, since the heat exchange efficiency can be improved, the performance of the evaporator 10 can be improved.

The effect of suppressing the reduction in the amount of refrigerant at the end portion will be described with reference to FIGS. 6 and 7. 6 and 7 are simulation results of the refrigerant supply pipe 13 according to the present embodiment.
The horizontal axes of FIGS. 6 and 7 indicate the positions of the refrigerant supply pipe 13 in the X-axis direction. In detail, the position from the center to one end (or the other end) in the X-axis direction is shown. 0 on the horizontal axis indicates the center of the refrigerant supply pipe 13 in the X-axis direction, and 1 on the horizontal axis indicates one end (or the other end) of the refrigerant supply pipe 13 in the X-axis direction. The vertical axis of FIG. 6 shows the flow velocity of the refrigerant flowing inside the refrigerant supply pipe 13 in the X-axis direction. In detail, the ratio when the flow velocity in the center of the refrigerant supply pipe 13 in the X-axis direction is 1. The vertical axis of FIG. 7 shows the amount of refrigerant in the liquid phase blown out from the slit 13a. In detail, the ratio when the amount of the refrigerant blown out is 1 when the refrigerant is blown out evenly from each slit 13a is shown.

As shown in FIG. 6, when the opening is not formed, the flow velocity of the refrigerant decreases from the center to the end in the X-axis direction, and the flow velocity becomes zero at the end in the X-axis direction. As a result, as shown in FIG. 7, the amount of refrigerant blown out at the end becomes zero.
On the other hand, when the opening 21 is formed, as shown in FIG. 6, the flow velocity of the refrigerant decreases from the center to the end in the X-axis direction, as in the case where the opening is not formed. , The reduction of the flow velocity is suppressed as compared with the case where the opening is not formed. As a result, the flow velocity is not zero at the end in the X-axis direction. Therefore, as shown in FIG. 7, the amount of the refrigerant blown out at the end portion is not zero, and the refrigerant is also blown out at the end portion. As described above, in the present embodiment, the liquid phase refrigerant can be suitably supplied to the end in the X-axis direction.

Further, in the present embodiment, a closing portion 20 for closing the lower end portion of the end surface of the refrigerant supply pipe 13 and the like is provided, and the opening portion 21 is formed above the closing portion 20. In the refrigerant supply pipe 13, the liquid phase refrigerant accompanying the gas phase refrigerant easily flows through the lower part of the refrigerant supply pipe 13 due to gravity (see also the refrigerant R in FIG. 8). As a result, the liquid-phase refrigerant accompanying the gas-phase refrigerant collides with the closing portion 20 when it moves to the end face of the refrigerant supply pipe 13. Therefore, it is possible to prevent the liquid phase refrigerant from being discharged from the opening 21 of the refrigerant supply pipe 13. Therefore, it is possible to suppress a reduction in the amount of refrigerant supplied to the liquid film type heat transfer tube group 15 through the slit 13a.

Further, in the present embodiment, the opening 21 is formed substantially in the center of the refrigerant supply pipe 13 in the height direction. As described above, in the refrigerant supply pipe 13, the liquid phase refrigerant easily flows through the lower part in the refrigerant supply pipe 13. Therefore, by forming the opening 21 substantially in the center, it is possible to make it more difficult for the liquid phase refrigerant to be discharged from the opening 21. Therefore, it is possible to further suppress the reduction in the amount of the refrigerant supplied to the liquid film type heat transfer tube group 15.

Further, in the present embodiment, a support plate 22 is provided between the opening 21 and the refrigerant outlet pipe 16. As a result, the gas phase refrigerant discharged from the opening 21 (see arrow A11 in FIG. 1) is once guided downward (see arrow A12 in FIG. 1), and then the refrigerant provided in the upper part of the pressure vessel 11 is provided. It is guided upward with the outlet pipe 16. Therefore, when the gas phase refrigerant discharged from the opening 21 is accompanied by the liquid phase refrigerant, the liquid phase refrigerant can be separated from the gas phase refrigerant by gravity. Therefore, it is possible to make it difficult for the gas phase refrigerant discharged from the refrigerant outlet pipe 16 to the outside of the pressure vessel 11 to accompany the liquid phase refrigerant (so-called carryover).

Further, the separated liquid phase refrigerant falls downward. In the present embodiment, the length of the liquid film type heat transfer tube group 15 in the X-axis direction is longer than the length of the refrigerant supply tube 13 in the X-axis direction. That is, when viewed in a plan view, the end portion of the liquid film type heat transfer tube group 15 protrudes from the end portion of the refrigerant supply pipe 13. As a result, the separated and dropped liquid phase refrigerant comes into contact with the protruding portion of the liquid film type heat transfer tube group 15. Therefore, even when the gas phase refrigerant discharged from the opening 21 is accompanied by the liquid phase refrigerant, the accompanying liquid phase refrigerant can be evaporated.
Further, although it is usually difficult to supply the refrigerant to the protruding portion of the liquid film type heat transfer tube group 15, it can be used for heat exchange by coming into contact with the liquid phase refrigerant discharged from the opening 21. Therefore, the performance of the evaporator 10 can be improved.

[Modification 1]
The position where the opening is provided is not limited to the example described above. It is preferable that the opening is formed in the upper part of the closing portion 20. The upper part may be substantially the center in the Z-axis direction or above the substantially center. Further, for example, as shown in FIG. 8, it is more suitable when the opening 41 is formed above the position of a quarter from the upper end with respect to the entire height of the refrigerant supply pipe 13. .. In the example shown in FIG. 8, the opening 41 is provided near the upper end of the closing portion 20.
Further, the opening may be formed in addition to the closing portion 20 of the refrigerant supply pipe 13. For example, it may be formed above the end of the refrigerant supply pipe 13 (see FIG. 11). Further, it may be formed on the side portion of the end portion of the refrigerant supply pipe 13.

[Modification 2]
Further, as shown in FIGS. 9 to 11, a gas-liquid separation structure 50 may be provided inside the refrigerant supply pipe 13. The gas-liquid separation structure 50 is arranged inside the refrigerant supply pipe 13 and in the vicinity of the opening 41. As shown in FIG. 9, for example, the gas-liquid separation structure is arranged on the central portion side in the X-axis direction with respect to the opening 41, and is a baffle plate (first) extending downward from the upper part of the inner peripheral surface of the refrigerant supply pipe 13. A shielding plate portion) 51, a horizontal surface portion 52 extending from the lower end of the opening 41 to the inside of the refrigerant supply pipe 13, and a vertical portion 53 extending upward from the tip of the horizontal surface portion 52. The baffle plate 51 and the vertical portion 53 are opposed to each other and are arranged apart from each other. The lower end of the baffle plate 51 is located below the lower end of the opening 41.
As a result, a first flow path 54 in which the refrigerant flows from the lower side to the upper side is formed between the baffle plate 51 and the vertical portion 53. Further, the inner peripheral surface of the refrigerant supply pipe 13, the vertical portion 53, and the horizontal surface portion 52 form a second flow path 55 in which the refrigerant flows from above to below.

According to this modification, the following effects are obtained.
As shown in FIG. 9, the liquid phase refrigerant R adheres to the upper part of the inner peripheral surface of the refrigerant supply pipe 13. The refrigerant adhering to the upper part moves toward the end by accommodating the refrigerant in the gas phase that circulates. In this modification, the baffle plate 51 is provided on the central portion side in the X-axis direction with respect to the opening 41. As a result, the liquid phase refrigerant moving toward the end is blocked by the baffle plate 51, so that the refrigerant does not reach the opening 41. Therefore, it is possible to make it more difficult for the liquid phase refrigerant to be discharged from the opening 41.
Further, in this modification, the gas phase refrigerant flowing in the refrigerant supply pipe 13 is guided to the opening 41 by bypassing the obstruction plate 51. As a result, the liquid phase refrigerant accompanied by the gas phase refrigerant can be centrifuged by the centrifugal force when bypassing the baffle plate 51. Therefore, it is possible to make it more difficult for the liquid phase refrigerant to be discharged from the opening 41. Further, in this modification, the refrigerant can be centrifuged even when the refrigerant is guided from the first flow path 54 to the second flow path 55.

The gas-liquid separation structure is not limited to the example described above. For example, as shown in FIG. 10, the horizontal surface portion 52 and the vertical portion 53 may not be provided, and only the baffle plate 51 may be formed. Further, as shown in FIG. 11, an opening 57 may be formed in the upper part of the end portion of the refrigerant supply pipe 13. Even with the configurations shown in FIGS. 10 and 11, the liquid phase refrigerant can be made difficult to be discharged from the opening.

[Modification 3]
Further, as shown in FIG. 12, the pipe (cylinder body) 60 may be inserted into the opening 21 formed in the closed portion 20. The pipe 60 is inserted so as to protrude inside the refrigerant supply pipe 13. With this configuration, the refrigerant R adhering to the upper part of the inner peripheral surface of the refrigerant supply pipe 13 is blocked by the upper part of the pipe 60. Therefore, it is possible to make it more difficult for the liquid phase refrigerant to be discharged from the opening 41.

The present disclosure is not limited to the above embodiment, and can be appropriately modified as long as it does not deviate from the gist thereof.
For example, the opening area of the opening formed in the closing portion 20 on one end side of the refrigerant supply pipe 13 may be different from the opening area of the opening formed in the closing portion 20 on the other end side. With this configuration, the amount of refrigerant in the gas phase discharged from the opening differs between the opening formed at one end and the opening formed at the other end. Therefore, the flow velocity of the gas phase refrigerant flowing toward one end in the refrigerant supply pipe 13 and the flow velocity of the gas phase refrigerant flowing toward the other end are also different. Therefore, since the amount of the liquid phase refrigerant accompanying the gas phase refrigerant is also different, the amount of the liquid phase refrigerant leading to the one end side and the amount of the liquid phase refrigerant leading to the other end side should be different. Can be done. Therefore, the amount of refrigerant leading to each end can be adjusted. Thereby, the amount of the refrigerant supplied to the liquid film type heat transfer tube group 15 can be adjusted along the X-axis direction. Therefore, since the heat exchange efficiency can be improved in the liquid film type heat transfer tube group 15, the performance of the evaporator 10 can be improved. For example, the opening on the side where the heat load of the liquid film type heat transfer tube group 15 is high may be formed larger than the opening on the side where the heat load of the liquid film type heat transfer tube group 15 is low.

The evaporator described in the present embodiment described above is grasped as follows, for example.
The evaporator according to one aspect of the present disclosure includes a housing (11) forming an outer shell and a liquid phase housed in the housing and stored in a storage portion (11c) provided in the lower part of the housing. A first heat transfer tube group (14) having a plurality of first heat transfer tubes immersed in a refrigerant and having a plurality of first heat transfer tubes through which a medium to be cooled flows, and a liquid housed in the housing and stored in the lower part of the housing. A second heat transfer tube group (15) provided above the liquid level (S) of the phase refrigerant and having a plurality of second heat transfer tubes extending in a predetermined direction through which a medium to be cooled flows, and the casing. It is provided with a refrigerant supply pipe (13) that is housed in the body, extends in the predetermined direction, a refrigerant in a gas-liquid two-phase state flows inside, and supplies the refrigerant from above to the second heat transfer tube group. The refrigerant supply pipe is formed at a closing portion (20) that closes at least the lower end of the end face in the predetermined direction and an end portion in the predetermined direction (X-axis direction) above the closing portion. It has an opening (21) that connects the inner space of the supply pipe and the outer space of the refrigerant supply pipe.

In the above configuration, an opening is formed at the end of the refrigerant supply pipe. Of the gas-liquid two-phase state refrigerants flowing in the refrigerant supply pipe, the gas-phase refrigerant is discharged from the opening to the outside when it flows to the end of the refrigerant supply pipe. As a result, the flow velocity of the gas-phase refrigerant flowing in the refrigerant supply pipe is unlikely to decrease even at the end. In the refrigerant supply pipe, the liquid phase refrigerant is accompanied by the gas phase refrigerant. Therefore, the liquid phase refrigerant can be easily guided to the end. Therefore, since the liquid phase refrigerant can be suitably supplied to the end portion, the amount of the refrigerant supplied to the second heat transfer tube group can be made uniform in a predetermined direction. Therefore, the heat exchange efficiency can be improved, and the performance of the evaporator can be improved.
Further, a closing portion for closing the lower end of the end surface of the refrigerant supply pipe is provided, and the opening is formed above the closed portion. In the refrigerant supply pipe, the liquid phase refrigerant accompanying the gas phase refrigerant tends to circulate in the lower part of the refrigerant supply pipe due to gravity. As a result, the liquid-phase refrigerant accompanying the gas-phase refrigerant collides with the closed portion when it moves to the end face of the refrigerant supply pipe. Therefore, it is possible to prevent the liquid phase refrigerant from being discharged from the opening of the liquid supply pipe. Therefore, it is possible to suppress a reduction in the amount of refrigerant supplied to the second heat transfer tube group.

Further, in the evaporator according to one aspect of the present disclosure, the opening is formed in the upper part of the refrigerant supply pipe.

In the above configuration, the opening is formed in the upper part of the refrigerant supply pipe. As described above, in the refrigerant supply pipe, the liquid phase refrigerant easily flows through the lower part in the refrigerant supply pipe. Therefore, by forming the opening at the upper part, it is possible to make it more difficult for the liquid phase refrigerant to be discharged from the opening. Therefore, it is possible to further suppress the reduction in the amount of refrigerant supplied to the second heat transfer tube group.
The upper part of the refrigerant supply pipe may be above the center in the height direction of the refrigerant supply pipe. Further, more preferably, it may be above the position of a quarter from the upper end with respect to the entire height of the refrigerant supply pipe.

Further, the evaporator according to one aspect of the present disclosure is arranged in the refrigerant supply pipe on the central portion side in a predetermined direction from the opening, and extends downward from the upper part of the inner peripheral surface of the refrigerant supply pipe. 1 A shielding plate portion (51) is provided.

Liquid-phase refrigerant adheres to the upper part of the inner peripheral surface of the refrigerant supply pipe. The refrigerant adhering to the upper part moves toward the end by accommodating the refrigerant in the gas phase that circulates. In the above configuration, the first shielding plate portion is provided on the central portion side in the predetermined direction with respect to the opening. As a result, the liquid phase refrigerant moving toward the end is blocked by the first shielding plate portion, so that it does not reach the opening. Therefore, it is possible to make it more difficult for the liquid phase refrigerant to be discharged from the opening. Therefore, it is possible to further suppress the reduction in the amount of refrigerant supplied to the second heat transfer tube group.
Further, in the above configuration, the gas phase refrigerant flowing in the refrigerant supply pipe is guided to the opening by bypassing the first shielding plate portion. As a result, the liquid phase refrigerant accompanied by the gas phase refrigerant can be centrifuged by the centrifugal force when bypassing the first shielding plate portion. Therefore, it is possible to make it more difficult for the liquid phase refrigerant to be discharged from the opening. Therefore, it is possible to further suppress the reduction in the amount of refrigerant supplied to the second heat transfer tube group.
The lower end of the first shielding plate portion may be located below the lower end of the opening.

Further, in the evaporator according to one aspect of the present disclosure, a tubular body (60) is inserted in the opening.

In the above configuration, a cylinder is inserted in the opening. As a result, the refrigerant adhering to the upper part of the inner peripheral surface of the refrigerant supply pipe is blocked by the upper part of the cylinder. Therefore, it is possible to make it more difficult for the liquid phase refrigerant to be discharged from the opening. Therefore, it is possible to further suppress the reduction in the amount of refrigerant supplied to the second heat transfer tube group.

Further, in the evaporator according to one aspect of the present disclosure, the housing is provided with a refrigerant outlet (16) for discharging the evaporated refrigerant to the outside at the upper part, and the second heat transfer tube group is provided in the predetermined direction. The length of the refrigerant supply pipe is longer than the length of the refrigerant supply pipe in the predetermined direction, and is above the refrigerant supply pipe, and between the opening and the refrigerant outlet, a second shielding plate portion (22) Is provided.

In the above configuration, a second shielding plate portion is provided between the opening and the outlet pipe. As a result, the gas phase refrigerant discharged from the opening is once guided downward, and then is guided upward with a refrigerant outlet provided in the upper part of the housing. Therefore, when the gas phase refrigerant discharged from the opening is accompanied by the liquid phase refrigerant, the liquid phase refrigerant can be separated from the gas phase refrigerant by gravity. Therefore, it is possible to prevent the phenomenon that the gas phase refrigerant discharged from the refrigerant outlet to the outside of the housing accompanies the liquid phase refrigerant (so-called carryover).
Further, the separated liquid phase refrigerant falls downward. In the above configuration, the length of the second heat transfer tube group in the predetermined direction is longer than the length of the refrigerant supply tube in the predetermined direction. That is, when viewed in a plan view, the end portion of the second heat transfer tube group protrudes from the end portion of the refrigerant supply pipe. As a result, the separated and dropped liquid phase refrigerant comes into contact with the protruding portion of the second heat transfer tube group. Therefore, even when the gas phase refrigerant discharged from the opening is accompanied by the liquid phase refrigerant, the accompanying liquid phase refrigerant can be evaporated.
Further, although it is usually difficult to supply the refrigerant to the protruding portion of the second heat transfer tube group, it can be used for heat exchange by coming into contact with the liquid phase refrigerant discharged from the opening. Therefore, the performance of the evaporator can be improved.

Further, in the evaporator according to one aspect of the present disclosure, in the refrigerant supply pipe, the openings are formed at both ends in the predetermined direction, and the openings are formed at one end in the predetermined direction. The area is different from the opening area of the opening formed at the other end in the predetermined direction.

In the above configuration, the opening area of the opening formed at one end in a predetermined direction and the opening area of the opening formed at the other end are different. As a result, the amount of the gas phase refrigerant discharged from the opening differs between the opening formed at one end and the opening formed at the other end. Therefore, the flow velocity of the gas phase refrigerant flowing toward one end in the refrigerant supply pipe and the flow velocity of the gas phase refrigerant flowing toward the other end are also different. Therefore, since the amount of the liquid phase refrigerant accompanying the gas phase refrigerant is also different, the amount of the liquid phase refrigerant leading to the one end side and the amount of the liquid phase refrigerant leading to the other end side should be different. Can be done. Therefore, since the amount of the refrigerant leading to each end can be adjusted, the amount of the refrigerant supplied to the second heat transfer tube group can be adjusted along a predetermined direction. Therefore, since the heat exchange efficiency can be improved in the second heat transfer tube group, the performance of the evaporator can be improved.
For example, the opening on the side where the heat load of the second heat transfer tube group is high may be formed larger than the opening on the side where the heat load of the second heat transfer tube group is low.

10: Evaporator 11: Pressure vessel (housing)
11a: Cylindrical part 11b: Pipe plate 11c: Storage part 12: Refrigerant inlet pipe (refrigerant inlet)
13: Refrigerant supply pipe 13a: Slit 13b: Curved part 14: Full-liquid heat transfer tube group (first heat transfer tube group)
15: Liquid film type heat transfer tube group (second heat transfer tube group)
15b: Lower liquid film type heat transfer tube group 15c: Upper liquid film type heat transfer tube group 16: Refrigerant outlet pipe (refrigerant outlet)
17: Introductory part 18: Return part 19: Discharge part 20: Closed part 20a: Upper closed part 20b: Lower closed part 21: Opening part 22: Support plate (second shielding plate part)
41: Opening 50: Gas-liquid separation structure 51: Interfering plate (first shielding plate)
52: Horizontal part 53: Vertical part 54: First flow path 55: Second flow path 57: Opening 60: Piping (cylinder body)
R: Refrigerant S: Liquid level

Claims

The housing that forms the outer shell and
A first heat transfer tube having a plurality of first heat transfer tubes housed in the housing, immersed in a liquid phase refrigerant stored in a storage portion provided in the lower part of the housing, and having a plurality of first heat transfer tubes through which a cooling medium flows. Heat transfer tube group and
A plurality of second heat transfer tubes housed in the housing and provided above the liquid level of the liquid phase refrigerant stored in the lower part of the housing, and a medium to be cooled flows inside and extends in a predetermined direction. 2nd heat transfer tube group with
A refrigerant supply pipe housed in the housing, extending in the predetermined direction, flowing a refrigerant in a gas-liquid two-phase state inside, and supplying the refrigerant from above to the second heat transfer tube group is provided.
The refrigerant supply pipe has a closed portion that closes at least the lower end of the end face in the predetermined direction, an end portion in the predetermined direction that is formed above the closed portion, and an inner space of the refrigerant supply pipe and the refrigerant. An evaporator having an opening that connects to the outer space of the supply pipe.
The evaporator according to claim 1, wherein the opening is formed in the upper part of the refrigerant supply pipe.
1. The refrigerant supply pipe is provided with a first shielding plate portion which is arranged on the central portion side in the predetermined direction with respect to the opening and extends downward from the upper part of the inner peripheral surface of the refrigerant supply pipe. Alternatively, the evaporator according to claim 2.
The evaporator according to any one of claims 1 to 3, wherein a cylinder is inserted into the opening.
The housing is provided with a refrigerant outlet at the top, which discharges the evaporated refrigerant to the outside.
The length of the second heat transfer tube group in the predetermined direction is longer than the length of the refrigerant supply pipe in the predetermined direction.
The evaporator according to any one of claims 1 to 4, wherein a second shielding plate portion is provided above the refrigerant supply pipe and between the opening and the refrigerant outlet.
The refrigerant supply pipe has the openings formed at both ends in the predetermined direction.
Any one of claims 1 to 5, wherein the opening area of the opening formed at one end in the predetermined direction and the opening area of the opening formed at the other end in the predetermined direction are different. Evaporator described in.