JP2007309604A - Evaporator for refrigeration system, and refrigeration system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaporator for a refrigeration system, and a refrigeration system effectively carrying out heat transfer to a heat transfer pipe. <P>SOLUTION: In the evaporator 30 for the refrigeration system, a coolant is supplied from a condenser. A gas-liquid separator 60 carrying out gas-liquid separation of the coolant is provided in a coolant piping 11 supplying the coolant to the evaporator 30. The coolant mainly composed of vapor separated by the gas-liquid separator 60 is introduced to a lower part of the heat transfer pipe 31 of the evaporator, and the coolant mainly composed of liquid separated by the gas-liquid separator 60 is introduced to an upper part of the heat transfer pipe 31 of the evaporator 30. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an evaporator and a refrigeration apparatus of a refrigeration apparatus suitable for application to a full liquid evaporator such as a turbo refrigerator.

  FIG. 1 is a basic configuration diagram of a refrigeration apparatus (compression refrigeration apparatus) 1-1. The refrigeration apparatus 1-1 shown in the figure is configured by a closed system in which a refrigerant is enclosed. Specifically, an evaporator 3 that takes heat from cold water (cooled fluid) and evaporates the refrigerant to exert a refrigeration effect. A compressor 5 that compresses the refrigerant vapor into high-pressure steam, a condenser 7 that cools and condenses the high-pressure steam with cooling water (cooling fluid), and a throttle mechanism that decompresses and expands the condensed refrigerant. The (expansion valve) 9 is connected by a refrigerant pipe 11.

  FIG. 2 is a basic configuration diagram of a refrigeration apparatus (compression refrigeration apparatus) 1-2 with an economizer, and the same reference numerals are given to the same parts as the refrigeration apparatus 1-1. The refrigeration apparatus 1-2 differs from the refrigeration apparatus 1-1 in that the refrigerant pipe 11 from the condenser 7 toward the evaporator 3 has a higher efficiency than the refrigeration apparatus 1-1. An economizer (gas-liquid separator) 13 is installed, and the refrigerant vapor from the economizer 13 is sucked into the middle of the compressor 5. The economizer 13 may be singular or plural.

  The evaporator 3 shown in FIGS. 1 and 2 is provided with a heat transfer tube 17 extending in the horizontal direction in the evaporator can body 15, and the condenser 7 (or the economizer 13) is placed on the bottom surface of the evaporator can body 15. The refrigerant pipe 11 is connected, a refrigerant distribution porous plate 19 is attached between the heat transfer tube 17 and the bottom surface of the evaporator can body 15, and the lower part of the porous plate 19 is configured as a refrigerant passage 21.

  In the evaporator 3 configured as described above, the refrigerant that has passed through the throttle mechanism 9 from the condenser 7 (or the economizer 13) becomes a gas-liquid two-phase state and is supplied to the lower part of the evaporator 3, It is distributed in the longitudinal direction (horizontal direction) by the passage 21. By the way, the refrigerant passing through the throttle mechanism 9 is in a gas-liquid two-phase as described above, and it is important to distribute the two-phase refrigerant equally to each part of the heat transfer tube 17. In particular, the refrigerant vapor having a large volume flow rate exerts an effect of improving the heat transfer to the heat transfer tube 17 by stirring the refrigerant from the lower part of the heat transfer tube 17, so that the refrigerant vapor is equally distributed to each part of the heat transfer tube 17. Is important for improving heat transfer in the entire longitudinal direction of the heat transfer tube 17.

  However, if all of the gas-liquid two-phase refrigerant is supplied to the refrigerant passage 21 below the porous plate 19 of the evaporator 3 and distributed in the longitudinal direction, it is necessary to provide a large passage as the refrigerant passage 21 below the porous plate 19. . For this reason, an invalid area that does not serve as a passage is formed around the refrigerant passage 21, and refrigerant liquid accumulates in the invalid area, and accordingly, the refrigerant to be charged in the refrigeration apparatus 1-1 (1-2). There was a problem that the amount would increase.

  On the other hand, FIG. 3A shows the number of cold water flow paths in which the cold water flowing inside the heat transfer tube 17 flows once and reciprocally in the can body 15 of the evaporator 3 as in the evaporator 3 shown in FIG. FIG. 3B is a diagram showing a temperature distribution in the case of a two-pass structure, and FIG. 3B shows a can of the evaporator 3 ′, such as an evaporator 3 ′ shown in FIG. It is a figure which shows the temperature distribution in case the number of the flow paths of the cold water which flows in the inside of the trunk | drum 15 toward the other end is a 1 pass structure. On the other hand, FIG. 4 (a) is a diagram showing the refrigerant liquid level in the evaporator when the evaporator 3 has the two-pass structure of FIG. 3 (a), and FIG. 4 (b) shows the evaporator 3 'shown in FIG. It is a figure which shows the refrigerant | coolant liquid level in an evaporator in the case of 1 pass structure of (). Further, FIG. 4C is a diagram showing the refrigerant liquid level in the evaporator 3 ″ when the refrigerant passage 21 below the perforated plate 19 is small.

  As shown in FIG. 3 (a), in an evaporator having a heat transfer tube having a two-pass structure, the temperature difference between the cold water and the refrigerant on the cold water inlet side is larger than the temperature difference on the cold water return side. The boiling heat transfer on the side is intense, the bubble content increases, the apparent specific gravity is small, and the liquid level of the refrigerant rises as shown in FIG. On the other hand, as shown in FIG. 3 (b), in the evaporator having a heat transfer tube having a one-pass structure, the temperature difference between the cold water inlet side and the outlet side is large, resulting in a difference in boiling heat transfer on both sides. As shown in FIG. 4B, the difference in the liquid level of the refrigerant becomes very large. Due to the difference in the refrigerant liquid level, a part of the heat transfer tube 17 is exposed from the refrigerant liquid level, and the exposed part hardly contributes to the heat transfer. On the other hand, in order to prevent the exposure, it is conceivable to increase the amount of refrigerant to be filled. However, adverse effects such as an increase in the required amount of refrigerant and a decrease in the liquid surface portion evaporation temperature due to an increase in liquid height will occur.

On the other hand, when the cross-sectional area of the refrigerant passage 21 is small as shown in FIG. 4C, the flow resistance in the longitudinal direction of the gas-liquid two-phase refrigerant is large, and the distribution is not uniform in the longitudinal direction. The liquid level at the upper part of the refrigerant introduction part connected to the liquid rises abnormally. As a result, a part of the heat transfer tube 17 may be exposed from the liquid surface of the refrigerant, and a large amount of liquid droplets may be generated from the rising portion, and the liquid droplets may be sucked into the compressor 5.
JP 2002-340444 A

  This invention is made | formed in view of the above-mentioned point, The objective is to provide the evaporator and freezing apparatus of a freezing apparatus which can transfer the heat to a heat exchanger tube effectively.

  The invention according to claim 1 of the present application is the evaporator of the refrigeration apparatus to which the refrigerant from the condenser is supplied, and the gas-liquid separation means for separating the refrigerant into a system supplying the refrigerant to the evaporator is installed. Introducing the refrigerant mainly composed of vapor separated by the gas-liquid separation means into the lower part of the heat transfer tube of the evaporator, and introducing the refrigerant mainly composed of the separated liquid into the upper part of the heat transfer tube of the evaporator. It is in the evaporator of the freezing apparatus characterized by this.

  The invention according to claim 2 of the present application is provided with a distribution pipe for distributing the refrigerant mainly composed of the vapor separated by the gas-liquid separation means in the longitudinal direction of the heat transfer pipe of the evaporator, The refrigerant of the refrigeration apparatus according to claim 1, wherein a refrigerant mainly composed of steam is introduced into the lower part of the heat transfer tube.

  In the invention according to claim 3 of the present application, the refrigerant mainly composed of the liquid separated by the gas-liquid separation means is supplied to the portion where the liquid level of the refrigerant liquid in the evaporator is lower than the other portions. It exists in the evaporator of the freezing apparatus of Claim 1 or 2 characterized by the above-mentioned.

  In the invention according to claim 4 of the present application, the evaporator is composed of two systems of evaporators respectively used in two systems of refrigeration cycles of the refrigeration apparatus, and these two systems of evaporators are in one can body. And a vapor passage for guiding the refrigerant mainly composed of the vapor separated by the gas-liquid separation means of each refrigeration cycle to the lower part of the heat transfer tube of the evaporator. It is provided in the partition, It exists in the evaporator of the freezing apparatus of Claim 1 or 2 or 3 characterized by the above-mentioned.

  In the invention according to claim 5 of the present invention, the fluid to be cooled that flows inside the heat transfer tube of the evaporator has a one-pass structure, and the amount of refrigerant mainly composed of steam introduced into the lower portion of the heat transfer tube is reduced. The cooling fluid outlet side of the heat transfer tube is increased, or the fluid to be cooled flowing inside the heat transfer tube of the evaporator has a two-pass structure, and steam introduced into the lower portion of the heat transfer tube is mainly used. 5. The evaporator of the refrigeration apparatus according to claim 1, 2, 3, or 4, wherein the amount of refrigerant introduced is increased on a cooled fluid return side of the heat transfer tube.

  According to the sixth aspect of the present invention, in the evaporator of the refrigeration system to which the refrigerant from the condenser is supplied, the fluid to be cooled that flows inside the heat transfer tube of the evaporator has a one-pass structure, and the refrigerant The introduction position to the evaporator is the outlet side of the fluid to be cooled at the lower part of the heat transfer tube, or the fluid to be cooled flowing inside the heat transfer tube of the evaporator has a two-pass structure, and the evaporator of the refrigerant In the evaporator of the refrigeration apparatus, the introduction position is set to the cooling fluid return side of the lower part of the heat transfer tube.

  The invention according to claim 7 of the present application is the evaporator of the refrigeration apparatus to which the refrigerant from the condenser is supplied, and includes the heat transfer tube in the can body of the evaporator and the introduction position of the refrigerant to the lower portion of the heat transfer tube. The space to be cooled is partitioned by a perforated plate so that the fluid to be cooled flowing inside the heat transfer tube of the evaporator has a one-pass structure, and the opening per unit area of the perforated plate in the portion facing the cooled fluid outlet side of the heat transfer tube Make the area larger than the opening area of the other part of the perforated plate, or make the fluid to be cooled flowing inside the heat transfer tube of the evaporator a two-pass structure, The evaporator of the refrigeration apparatus is characterized in that the opening area per unit area of the perforated plate of the facing portion is larger than the opening area of the other portion of the perforated plate.

  The invention described in claim 8 includes at least an evaporator that takes heat from a fluid to be cooled and evaporates the refrigerant to exert a refrigeration effect, a compressor that compresses the refrigerant vapor into high-pressure vapor, and high-pressure vapor A refrigerating apparatus having a condenser that cools and condenses with a cooling fluid, wherein the evaporator according to any one of claims 1 to 7 is used as the evaporator. .

  According to the first aspect of the present invention, the refrigerant mainly composed of the vapor separated by the gas-liquid separation means is introduced into the lower part of the heat transfer tube of the evaporator. Stirring is effective in improving heat transfer to the heat transfer tube. On the other hand, since the refrigerant mainly composed of the liquid separated by the gas-liquid separation means is introduced from the upper part of the heat transfer tube of the evaporator, even if the heat transfer tube has a portion exposed from the liquid surface of the refrigerant liquid. By spraying, the heat transfer effect can be exhibited even in the exposed portion. Furthermore, since only the refrigerant mainly composed of steam is introduced from the lower part of the heat transfer tube, it is not necessary to provide a large passage as a refrigerant passage for the refrigerant introduced into the lower part of the evaporator, and thus a passage that can be formed around the refrigerant passage. As a result, the ineffective area that is not useful is reduced, and the amount of refrigerant to be charged in the refrigeration apparatus can be reduced accordingly.

  According to the second aspect of the present invention, since the refrigerant is distributed in advance before being introduced into the lower portion of the heat transfer tube by the distribution pipe, the sectional area of the refrigerant passage at the lower portion of the heat transfer tube of the evaporator can be reduced.

  According to the third aspect of the present invention, since the refrigerant mainly composed of liquid can be preferentially sprayed on the portion of the heat transfer tube that is easily exposed from the refrigerant liquid surface, a more effective heat transfer effect can be obtained.

  According to the invention described in claim 4, the evaporator can be made compact and the can body can be reinforced.

  According to the fifth aspect of the present invention, it is possible to increase the ratio of the supply amount of the refrigerant vapor to the portion where the refrigerant liquid level in the evaporator is expected to decrease, improve the heat transfer, and improve the liquid level. Can be averaged.

  According to the sixth aspect of the present invention, the amount of refrigerant vapor in the portion where the refrigerant liquid level in the evaporator is expected to decrease and heat transfer is expected to increase, and the liquid level can be averaged and heat transfer improved. .

  According to the seventh aspect of the present invention, the amount of refrigerant vapor ejected from the perforated plate at the portion where the liquid level in the evaporator is expected to decrease and heat transfer is expected to deteriorate, and the liquid level is averaged. And improve heat transfer.

  According to the invention described in claim 8, since the evaporator having a high heat transfer effect is used, the refrigeration performance of the refrigerator can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 5 is a configuration diagram of the evaporator 30 according to the first embodiment of the present invention. The evaporator 30 is used as the evaporator of the refrigeration apparatus 1-1 having the basic configuration shown in FIG. 1, the evaporator of the refrigeration apparatus 1-2 with an economizer shown in FIG. That is, the evaporator 30 is installed in place of the evaporator 3 shown in FIGS. 1 and 2, and the refrigerant from the condenser 7 shown in FIGS. 1 and 2 is supplied directly or via the economizer 13. It is an evaporator. Therefore, the basic configuration of other parts of the refrigeration apparatus to which the evaporator 30 is applied is the same as the basic configuration of the refrigeration apparatuses 1-1 and 1-2 shown in FIGS.

  As shown in FIG. 5, the evaporator 30 gas-liquid separates this refrigerant into a system for supplying the refrigerant to the evaporator 30, that is, in the refrigerant pipe 11 from the condenser 7 (or economizer 13) to the evaporator 30. A gas-liquid separator (gas-liquid separation means) 60 is installed, and a refrigerant mainly composed of vapor separated by the gas-liquid separator 60 is introduced into the lower part of the heat transfer tube 31 of the evaporator 30 and gas-liquid separation is performed. The refrigerant mainly composed of the liquid separated in the evaporator 60 is introduced into the upper part of the heat transfer tube 31 of the evaporator 30.

  The gas-liquid separator 60 mainly includes the refrigerant pipe 11 introduced from the condenser 7 (or the economizer 13), the refrigerant pipe 61 for taking out the refrigerant mainly composed of the separated vapor, and the separated liquid. A refrigerant pipe 63 for taking out the refrigerant is attached. Note that the gas-liquid separation by the gas-liquid separator 60 may not be complete gas-liquid separation.

  In the evaporator 30, a plurality of heat transfer tubes 31 directed in the horizontal direction (front and back in the drawing in FIG. 5) are installed in parallel in the evaporator can body 33, and the heat transfer tube 31 and the bottom surface 33 a of the evaporator can body 33 are arranged. A perforated plate (refrigerant vapor distribution plate) 35 for refrigerant distribution is attached between the bottom of the perforated plate 35, a lower portion of the perforated plate 35 serves as a refrigerant passage 37, the refrigerant pipe 61 is connected to the bottom surface 33 a of the evaporator can body 33, and the refrigerant A pipe 63 is introduced from the side wall 33 b of the evaporator can body 33 into the upper part of the heat transfer tube 31. Further, baffle plates 37 and 37 for preventing refrigerant droplets from being sucked into the refrigerant pipe 11 on the compressor 5 side are installed in the upper vapor space in the evaporator can body 33. The perforated plate 35 is installed so as to partition the heat transfer tube 31 and the bottom surface 33a of the evaporator can body 33 almost horizontally, and a hole 35a is provided over the entire surface.

  In the evaporator 30 with the gas-liquid separator 60 configured as described above, the refrigerant introduced into the gas-liquid separator 60 from the condenser 7 (or economizer 13) side is a refrigerant mainly composed of steam, The refrigerant mainly composed of liquid is separated into the refrigerant mainly composed of vapor, and the refrigerant mainly composed of vapor is introduced into the refrigerant passage 37 below the evaporator 30 through the refrigerant pipe 61, and is almost uniformly distributed by the numerous holes 35 a provided in the perforated plate 35. In this state, the heat transfer tube 31 is supplied. Since most of the supplied refrigerant is steam, the agitation action by bubbles, that is, the refrigerant is agitated from the lower part of the heat transfer tube 31 by the bubbles, and the heat transfer efficiency from the refrigerant to the cold water (cooled fluid) in the heat transfer tube 31 is improved. . On the other hand, the refrigerant mainly composed of liquid is introduced into the vapor space above the heat transfer tube 31 by the refrigerant pipe 63 and is sprayed on the portion exposed from the refrigerant liquid surface of the heat transfer tube 31 by the spray nozzle 63a. That is, the exposed portion of the heat transfer tube 31 from the refrigerant liquid level can also contribute to heat transfer. The refrigerant droplets (mist refrigerant) in the vapor space collide with the baffle plates 37 and 37 and are collected, so that the suction to the compressor 5 is prevented.

  In addition, in the evaporator 30 with the gas-liquid separator 60, only the refrigerant mainly composed of steam is introduced from the lower part of the heat transfer tube 31, so that it is necessary to provide a large passage as the refrigerant passage 37 below the evaporator 30. For this reason, the ineffective area that does not serve as a passage around the refrigerant passage 37 can be reduced, and accordingly, the amount of refrigerant to be charged in the refrigeration apparatus 1-1 or 1-2 can be reduced.

[Second Embodiment]
6A and 6B are configuration diagrams of an evaporator 30-2 according to the second embodiment of the present invention. FIG. 6A is a diagram viewed from the side surface, and FIG. 6B is a diagram viewed from the front side. . In the evaporator 30-2, as in the first embodiment, the evaporator of the refrigeration apparatus 1-1 having the basic configuration shown in FIG. 1, the evaporator of the refrigeration apparatus 1-2 with an economizer shown in FIG. Used. That is, the evaporator 30-2 is installed in place of the evaporator 3 shown in FIGS. 1 and 2, and the refrigerant from the condenser 7 shown in FIGS. 1 and 2 is supplied directly or via the economizer 13. It is an evaporator. Therefore, the basic configuration of other parts of the refrigeration apparatus to which the evaporator 30-2 is applied is the same as the basic configuration of the refrigeration apparatuses 1-1 and 1-2 shown in FIGS. In this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  That is, also in the evaporator 30-2, as shown in FIG. 6, a system for supplying a refrigerant to the evaporator 30-2, that is, a refrigerant pipe 11 from the condenser 7 (or the economizer 13) to the evaporator 30-2. A gas-liquid separator (gas-liquid separation means) 60 for gas-liquid separation of the refrigerant is installed therein, and the refrigerant mainly composed of the vapor separated by the gas-liquid separator 60 is used as a heat transfer tube of the evaporator 30-2. In addition to being introduced into the lower portion of the refrigerant 31, the refrigerant mainly composed of the separated liquid is introduced into the upper portion of the heat transfer tube 31 of the evaporator 30-2.

  The gas-liquid separator 60 is also provided with a refrigerant pipe 61 for taking out the refrigerant mainly composed of the separated vapor and a refrigerant pipe 63 for taking out the refrigerant mainly made of the separated liquid. The difference from the first embodiment in the form is further transmitted to the root portion of the refrigerant pipe 61 immediately after being separated by the gas-liquid separator 60 at the upper part of the evaporator can body 33 (that is, above the refrigerant liquid level). A tubular distributor (steam distributor) 65 extending in the evaporator can body 33 along the longitudinal direction of the heat pipe 31 and extending substantially the same length as the heat transfer pipe 31 is provided. The gas-liquid separator 60 is installed at the center of the distributor 65 as shown in FIG. The distributor 65 is provided with openings 67 at predetermined intervals. The refrigerant pipes 61 extend horizontally from the openings 67, and the tips of the refrigerant pipes 61 are respectively connected to tubular steam passages 69 directed downward. The lower end of the vapor passage 69 is connected to the refrigerant passage 37 below the perforated plate 35.

  In the evaporator 30-2 with the gas-liquid separator 60 configured as described above, the refrigerant introduced into the gas-liquid separator 60 is separated into a refrigerant mainly composed of steam and a refrigerant mainly composed of liquid. Then, the refrigerant mainly composed of steam is distributed in the longitudinal direction of the heat transfer pipe 31 above the refrigerant liquid level in the evaporator can body 33 by the distributor 65 in advance, and then from each steam passage 69 to the lower part of the evaporator 30. The refrigerant is introduced into the refrigerant passage 37 and supplied to the heat transfer tube 31 almost uniformly from a large number of holes 35 a provided in the perforated plate 35. In this embodiment, since the distribution of the refrigerant vapor after the gas-liquid separation is performed above the refrigerant liquid level, the refrigerant liquid pool is located around the distributor 65 as in the case where the distribution is performed below the refrigerant liquid level. Will not occur. The cross-sectional area of the refrigerant passage 37 below the perforated plate 35 can be further reduced because the distribution of the refrigerant vapor in the longitudinal direction of the heat transfer tube 31 has already been completed by the distributor 65.

  In addition, in the evaporator 30-2 shown in FIG. 6, the amount of spraying of the liquid mainly separated from the gas-liquid separator 60 from the spray nozzle 63a is changed in the longitudinal direction of the heat transfer tube 31, so that the evaporator 30- It is preferable to increase the spray amount of the refrigerant liquid in the part where the refrigerant liquid level in 2 (evaporator can body 33) is lower than the other parts. For example, the number of spray nozzles 63a at a portion where the amount of sprayed refrigerant liquid is desired to be increased may be larger than that at other portions, or a spray nozzle 63a having a larger nozzle diameter than other portions may be used. Specifically, in the case of this evaporator 30-2, as shown in FIG. 6B, since it has a one-pass structure, as shown in FIG. 4B, the refrigerant liquid level is on the cold water outlet side of the heat transfer tube 31. Therefore, more refrigerant liquid may be sprayed to the portion of the heat transfer tube 31 on the cold water outlet side than the other portions. Further, when the structure of the evaporator 30-2 is a two-pass structure, more refrigerant liquid may be sprayed on the cold water return side of the heat transfer tube 31 than in other portions.

[Third Embodiment]
7A and 7B are configuration diagrams of an evaporator 30-3 according to the third embodiment of the present invention. FIG. 7A is a diagram viewed from the side surface, and FIG. 7B is a diagram viewed from the top surface side. . FIG. 8 is a configuration diagram showing an example of a refrigeration apparatus (compression refrigeration apparatus) 1-3 of a double refrigeration cycle configured using the evaporator 30-3. First, the configuration of the refrigeration apparatus 1-3 will be described. The refrigeration apparatus 1-3 shown in FIG. 8 includes two refrigeration apparatuses 1a and 1b having the same configuration as the refrigeration apparatus 1-1 shown in FIG. 1, and each of the refrigeration apparatuses 1a and 1b is Is also composed of a closed system filled with refrigerant, and evaporators 30-3a and 30-3b, compressors 5a and 5b, condensers 7a and 7b, and throttle mechanisms 9a and 9b are connected by refrigerant pipes 11a and 11b. Concatenated. In the case of this refrigeration apparatus 1-3, the electric motor M which drives the two compressors 5a and 5b is shared. The evaporator 30-3 partitions each of the evaporators 30-3a and 30-3b of the two refrigeration apparatuses 1a and 1b into a plurality of (two) one evaporator can body 33, and is a partitioned part Each of the heat transfer tubes 17 is installed. Each of the condensers 7a and 7b is also configured by dividing one condenser can body 41 into a plurality (two) and installing heat transfer tubes in the divided parts.

  The evaporator 30-3 shown in FIG. 7 is provided with evaporators 30-3a and 30-3b that are independent from each other on the left and right sides, and the evaporators 30-3a and 30-3b are partitioned (separated) by a double partition wall 45. Yes. The refrigerant is supplied to the evaporators 30-3a and 30-3b, that is, in the refrigerant pipes 11a and 11b from the condensers 7a and 7b to the evaporators 30-3a and 30-3b. Gas-liquid separators (gas-liquid separation means) 60, 60 to be separated are installed, and a refrigerant mainly composed of vapor separated by the gas-liquid separators 60, 60 is used as heat transfer tubes of the evaporators 30-3a, 30-3b. The refrigerant is mainly introduced into the lower part of the heat exchanger tubes 31 and 31 of the evaporators 30-3a and 30-3b. Also in these gas-liquid separators 60, 60, refrigerant pipes 61, 61 for taking out refrigerant mainly composed of separated vapor and refrigerant pipes 63, 63 for taking out refrigerant mainly composed of separated liquid are attached. However, as in the second embodiment, the root portion of the refrigerant pipes 61 and 61 immediately after being separated by the gas-liquid separators 60 and 60 is disposed above the evaporator can body 33 (that is, above the refrigerant liquid level). ), Tubular distributors 65 and 65 are installed in the evaporator can body 33 along the longitudinal direction of the heat transfer tubes 31 and 31 so as to extend approximately the same length as the length of the heat transfer tubes 31 and 31. The gas-liquid separators 60, 60 are installed at the center of the distributors 65, 65 as shown in FIG. 7B, and the distributors 65, 65 are provided with openings 67, 67 at predetermined intervals. Refrigerant piping 61 directed horizontally to the double partition wall 45 is connected to the 67 and 67, respectively, and tubular steam passages 69 and 69 directed downward in the double partition wall 45 are connected to the tip of the refrigerant piping 61. Refrigerant passages 37, 37 below the perforated plates 35, 35 are connected to the lower ends of the passages 69, 69. That is, tubular vapor passages 69, 69 that are refrigerant vapor descending passages are provided in the double partition wall 45, and the refrigerant vapor is introduced below the perforated plates 35, 35 by these. In this embodiment, the steam passages 69 and 69 in the double partition 45 are alternately provided. If the distribution of the refrigerant vapor after gas-liquid separation is performed above the refrigerant liquid surface as in this embodiment, a refrigerant liquid pool is generated around the distributors 65 and 65 as in the second embodiment. Further, the cross-sectional area of the refrigerant passages 37, 37 below the perforated plates 35, 35 can be further reduced because the distribution of the refrigerant vapor in the longitudinal direction of the heat transfer tubes 31, 31 has already been completed.

  In addition, the heat transfer tubes 31 and 31 used in this embodiment have a two-pass structure with respect to the entire evaporators 30-3a and 30-3b, but with respect to the evaporators 30-3a and 30-3b. Has a one-pass structure. Accordingly, in these evaporators 30-3a and 30-3b, the amount of spray from the spray nozzles 63a and 63 of the refrigerant mainly composed of the liquid separated by the gas-liquid separators 60 and 60 is determined in the longitudinal direction of the heat transfer tubes 31 and 31. Is changed by the cold water inlet / outlet and the number of passes for one evaporator 30-3a or 30-3b. In this embodiment, each of the evaporators 30-3a and 30-3b has a one-pass structure. What is necessary is just to spray more refrigerant | coolants liquid to the part by the side of the cold water outlet of the heat exchanger tubes 31 and 31 than another part. Specifically, in FIG. 7B, the upper side of the evaporator 30-3a in the figure increases the amount of refrigerant liquid on the right side, and the lower side of the evaporator 30-3b increases the amount of refrigerant liquid on the left side.

  The evaporators 30-3a and 30-3b are effective for reinforcing the evaporator can body 33 as well as making the entire evaporator compact. That is, in this embodiment, the distributors 65, 65 are installed on the upper inner surface side of the evaporator can body 33, so that the evaporator can body 33 is reinforced. Further, the steam passages 69 and 69 provided in the double partition 45 can be used to reinforce the double partition 45, and the evaporators 30-3a and 30-3b can be made compact as a whole.

  In each of the above embodiments, in order to improve the heat transfer of the portion where the refrigerant liquid level in the evaporators 30, 30-2 and 30-3 is expected to be lowered, when the heat transfer tube 31 has a one-pass structure, The refrigerant mainly composed of steam introduced into the lower part of the heat transfer tube 31 is introduced into the refrigerant outlet side of the heat transfer tube 31 more than the other part, or when the heat transfer tube 31 has a two-pass structure, the heat transfer tube 31 It is preferable that the refrigerant mainly composed of steam introduced into the lower part of the heat transfer pipe 31 is introduced to the cold water return side of the heat transfer tube 31 more than the other parts. If comprised in this way, the refrigerant | coolant liquid level of the part in which the refrigerant | coolant liquid level in evaporator 30,30-2,30-3 is anticipated to fall can be raised with a lot of refrigerant | coolants vapor | steam, and an average of a refrigerant | coolant liquid level As a result, part of the heat transfer tube 31 is not exposed from the coolant level, and heat transfer can be improved.

[Fourth Embodiment]
9 and 10 are configuration diagrams of the refrigeration apparatuses 1-4 and 1-5 configured using the evaporators 30-4 and 30-5 according to the fourth embodiment of the present invention. In these drawings, the basic configuration of each part other than the evaporators 30-4 and 30-5 is the same as the basic configuration of the refrigeration apparatuses 1-1 and 1-2 shown in FIGS. Detailed description thereof will be omitted. That is, the evaporators 30-4 and 30-5 are installed in place of the evaporator 3 shown in FIGS. 1 and 2, and the refrigerant from the condenser 7 shown in FIGS. It is an evaporator supplied via.

  Each of the evaporators 30-4 and 30-5 shown in FIGS. 9 and 10 is an evaporator having no gas-liquid separating means, and both have the heat transfer tubes 31 directed in the horizontal direction in the evaporator can body 33. The refrigerant pipe 11 from the condenser 7 (or the economizer 13) is connected to the bottom surface of the evaporator can body 33, and a perforated plate for refrigerant distribution is provided between the heat transfer tube 31 and the bottom surface of the evaporator can body 33. 35, and the lower part of the perforated plate 35 is configured as a refrigerant passage 37, and each of the evaporators 30-4 and 30-5 has a heat transfer tube 31 of a two-pass structure.

  And the introduction position of the refrigerant | coolant to evaporator 30-4, 30-5 is made into the cold water return side rather than the center of the lower part of the heat exchanger tube 31. FIG.

  In the evaporators 30-4 and 30-5 configured as described above, the refrigerant from the condenser 7 side becomes a gas-liquid two-phase state and is supplied to the lower parts of the evaporators 30-4 and 30-5. Although the refrigerant is distributed in the longitudinal direction (horizontal direction) in the refrigerant passage 37, the refrigerant in the gas-liquid two-phase state is introduced to the cold water return side from the lower center of the heat transfer tube 31. Is pushed up compared to other parts. This pushes up the portion where the coolant level is expected to decrease as described in FIGS. 4 (a) and 4 (b), and the coolant level in the evaporators 30-4 and 30-5 is lowered to transfer heat. As a result, the amount of refrigerant vapor increases in the portion where it is expected to become worse, and the liquid level can be averaged and heat transfer can be improved.

  In particular, when the cross-sectional area of the refrigerant passage 37 below the perforated plate 35 is small, the gas-liquid two-phase refrigerant is supplied to the refrigerant passage 37 in this embodiment. The distribution of the refrigerant in the liquid two-phase state is not uniform in the longitudinal direction, and the amount of refrigerant vapor ejected from the perforated plate 35 increases in the vicinity of the refrigerant introduction part connected to the refrigerant pipe 11, and the liquid level at the upper part thereof greatly increases. To do. In the present embodiment, by actively utilizing this phenomenon on the contrary, the refrigerant liquid level is lowered and the amount of refrigerant introduced into the part where heat transfer is expected to be worsened is actively increased to reduce the refrigerant liquid level. By increasing the temperature, the liquid level of the refrigerant is made uniform to improve heat transfer. In this embodiment, since the heat transfer tube 31 has a two-pass structure, the refrigerant introduction position is the cold water return side. However, in the case of the one-pass structure, the refrigerant introduction position to the evaporator is the cold water outlet at the bottom of the heat transfer pipe. Let it be the side.

[Fifth Embodiment]
11 and 12 are configuration diagrams of refrigeration apparatuses 1-5 and 1-7 configured using evaporators 30-6 and 30-7 according to the fifth embodiment of the present invention. In these drawings, the basic configuration of each part other than the evaporators 30-6 and 30-7 is the same as the basic configuration of the refrigeration apparatuses 1-1 and 1-2 shown in FIGS. Detailed description thereof is omitted.

  Similarly to the evaporators 30-4 and 30-5 shown in the fourth embodiment, the evaporators 30-6 and 30-7 shown in FIGS. 11 and 12 are evaporators that do not have gas-liquid separation means. In each case, a heat transfer tube 31 extending in the horizontal direction is installed in the evaporator can body 33, the refrigerant pipe 11 from the condenser 7 (or economizer 13) is connected to the bottom surface of the evaporator can body 33, and the heat transfer tube 31. A perforated plate 35 for distributing refrigerant is attached between the bottom of the evaporator can body 33 and a lower portion of the perforated plate 35 is configured as a refrigerant passage 37. The heat transfer tubes 31 of the evaporators 30-6 and 30-7 all have a two-pass structure.

  In these evaporators 30-6 and 30-7, the opening area per unit area of the porous plate 35 in the portion facing the refrigerant return side of the heat transfer tube 31 is compared with the opening area of other portions of the porous plate 35. It is getting bigger. Here, the large opening area per unit area means that the hole diameter is the same but the number of holes per unit area is large, or the number of holes per unit area is the same, but the hole diameter itself is the same. Say the big case.

  In the evaporators 30-6 and 30-7 configured as described above, the refrigerant from the condenser 7 side supplied to the lower portions of the evaporators 30-6 and 30-7 is in a gas-liquid two-phase state. The refrigerant passage 37 is distributed in the longitudinal direction (horizontal direction), but the refrigerant in the gas-liquid two-phase state has a large amount of ejection from a portion having a large opening area per unit area of the perforated plate 35, and the cold water return side. The refrigerant liquid level is pushed up. As a result, the portion of the refrigerant liquid level that is expected to be lowered as described in FIG. 4A is pushed up, and the liquid level in the evaporators 30-6 and 30-7 is lowered and heat transfer is expected to deteriorate. The amount of refrigerant vapor in the portion to be increased increases, and the liquid level of the refrigerant can be averaged and the heat transfer can be improved. In this embodiment, similarly to the fourth embodiment, when the heat transfer tube 31 has a one-pass structure, the opening area per unit area of the porous plate in the portion facing the cold water outlet side of the heat transfer tube is set to be equal to that of the porous plate. It is only necessary to make it larger than the opening area of other portions, and the same effect is produced.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. Note that any shape or structure not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are achieved. For example, the configuration of the refrigeration apparatus to which the present invention can be applied is not limited to the refrigeration apparatus having the structure shown in FIGS. 1 and 2. For example, in the refrigerant piping from the condenser to the evaporator, power recovery is performed instead of the expansion valve. Other various structures such as a refrigeration apparatus provided with an expander (which expands the condensate and sends it to the evaporator and collects power by a power recovery machine (generator)) may be used.

It is a basic lineblock diagram of freezing equipment 1-1. It is a basic lineblock diagram of refrigeration equipment 1-2 with an economizer. FIG. 3A is a diagram showing a temperature distribution when the heat transfer tube 17 has a two-pass structure, and FIG. 3B is a diagram showing a temperature distribution when the heat transfer tube 17 has a one-pass structure. 4A shows a refrigerant liquid level when the evaporator 3 has a two-pass structure, FIG. 4B shows a refrigerant liquid level when the evaporator 3 has a one-pass structure, and FIG. ) Is a diagram showing the refrigerant liquid level when the refrigerant passage 21 below the perforated plate 19 is small. 2 is a configuration diagram of an evaporator 30. FIG. It is a block diagram of the evaporator 30-2, Fig.6 (a) is the figure seen from the side surface side, FIG.6 (b) is the figure seen from the front side. It is a block diagram of the evaporator 30-3, Fig.7 (a) is the figure seen from the side surface side, FIG.7 (b) is the figure seen from the upper surface side. It is a block diagram which shows an example of the freezing apparatus 1-3 of the double refrigerating cycle comprised using the evaporator 30-3. It is a block diagram of the evaporator 30-4. It is a block diagram of the evaporator 30-5. It is a block diagram of the evaporator 30-6. It is a block diagram of the evaporator 30-7.

Explanation of symbols

1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7 Refrigeration apparatus 5 Compressor 7 Condenser 9 Throttle mechanism (expansion valve)
11 Refrigerant piping 13 Economizer (gas-liquid separator)
30 Evaporator 31 Heat Transfer Tube 33 Evaporator Can Body 35 Perforated Plate 35a Hole 37 Refrigerant Passage 60 Gas-Liquid Separator (Gas-Liquid Separation Means)
30-2 Evaporator 65 Distributor (Vapor Distributor)
69 Steam passage 30-3 (30-3a, 30-3b) Evaporator 45 Double partition 30-4, 30-5, 30-6, 30-7 Evaporator

Claims (8)

In the evaporator of the refrigeration system to which the refrigerant from the condenser is supplied,
A gas-liquid separation means for separating the refrigerant into a gas and liquid is installed in a system for supplying the refrigerant to the evaporator,
Introducing the refrigerant mainly composed of vapor separated by the gas-liquid separation means into the lower part of the heat transfer tube of the evaporator, and introducing the refrigerant mainly composed of the separated liquid into the upper part of the heat transfer tube of the evaporator. An evaporator for a refrigeration apparatus.   A distribution pipe that distributes the refrigerant mainly composed of the vapor separated by the gas-liquid separation means in the longitudinal direction of the heat transfer pipe of the evaporator is provided, and the refrigerant mainly composed of the vapor after distribution by the distribution pipe is It introduce | transduces into a heat exchanger tube lower part, The evaporator of the freezing apparatus of Claim 1 characterized by the above-mentioned.   The refrigerant mainly composed of the liquid separated by the gas-liquid separation means is supplied to a portion where the liquid level of the refrigerant liquid in the evaporator is lower than the other portions. The evaporator of the refrigeration apparatus described in 1. The evaporator is composed of two systems of evaporators respectively used in two systems of refrigeration cycle of the refrigeration apparatus,
These two systems of evaporators are installed separately in a can body by a double partition wall, and the refrigerant mainly composed of vapor separated by the gas-liquid separation means of each refrigeration cycle is supplied to each evaporator. The evaporator of the refrigerating apparatus according to claim 1, wherein a vapor passage leading to a lower portion of the heat transfer tube is provided in the double partition wall. The cooled fluid flowing inside the heat transfer tube of the evaporator has a one-pass structure, and the amount of refrigerant mainly composed of steam introduced into the lower portion of the heat transfer tube is set to the cooled fluid outlet side of the heat transfer tube. Or more
Alternatively, the fluid to be cooled flowing inside the heat transfer tube of the evaporator has a two-pass structure, and the introduction amount of the refrigerant mainly composed of steam introduced into the lower portion of the heat transfer tube is set back to the fluid to be cooled of the heat transfer tube. The evaporator of the refrigeration apparatus according to claim 1, 2, 3, or 4, wherein the evaporator is increased on the side. In the evaporator of the refrigeration system to which the refrigerant from the condenser is supplied,
The fluid to be cooled that flows inside the heat transfer tube of the evaporator has a one-pass structure, and the introduction position of the refrigerant to the evaporator is the cooling fluid outlet side below the heat transfer tube,
Alternatively, the fluid to be cooled that flows inside the heat transfer tube of the evaporator has a two-pass structure, and the introduction position of the refrigerant to the evaporator is the folded back side of the fluid to be cooled at the bottom of the heat transfer tube. Refrigeration equipment evaporator. In the evaporator of the refrigeration system to which the refrigerant from the condenser is supplied,
Partitioning between a heat transfer tube in the can body of the evaporator and a position where the refrigerant is introduced to the lower portion of the heat transfer tube with a perforated plate;
The fluid to be cooled flowing inside the heat transfer tube of the evaporator has a one-pass structure, and the opening area per unit area of the perforated plate in the portion of the heat transfer tube facing the fluid outlet side of the heat transfer tube Or larger than the opening area of the part,
Alternatively, the fluid to be cooled flowing inside the heat transfer tube of the evaporator has a two-pass structure, and the opening area per unit area of the perforated plate at the portion facing the cooled fluid return side of the heat transfer tube is different from that of the porous plate. An evaporator of a refrigeration apparatus, wherein the evaporator is larger than the opening area of the portion. At least an evaporator that takes heat from the fluid to be cooled and evaporates the refrigerant to exert a refrigeration effect, a compressor that compresses the refrigerant vapor into high-pressure vapor, and a condensation that cools and condenses the high-pressure vapor with the cooling fluid In a refrigeration apparatus having a container,
A refrigerating apparatus using the evaporator according to any one of claims 1 to 7 as the evaporator.

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