Absorption type cooling device

Abstract

The invention relates to an absorption type cooling device. The absorption cooling device of the present invention may comprise: an evaporator for evaporating a refrigerant; an absorber that mixes the refrigerant evaporated in the evaporator with an absorbent to generate an absorption liquid; a regenerator that heats the absorption liquid supplied from the absorber; a condenser to which the refrigerant generated in the regenerator is supplied; and a heat transfer tube disposed on at least one of the evaporator and the absorber and extending lengthwise, the heat transfer tube including a plurality of protrusions protruding from a surface of the heat transfer tube and arranged in a longitudinal direction and a circumferential direction of the heat transfer tube, the interval between the plurality of protrusions arranged in the circumferential direction of the heat transfer tube is smaller than the interval between the plurality of protrusions arranged in the length direction of the heat transfer tube.

Description

Technical Field

[0001] The present invention relates to an absorption type chiller, and more particularly, to an absorption type chiller having heat transfer tubes. Background Art

[0002] A cooling device supplies cold water to a cold water demand site, and can perform heat exchange between a refrigerant circulating in a refrigerant cycle and cold water circulating at the demand site, thereby cooling the cold water. Such a cooling device, as a large-capacity device, can be installed in a large-scale building or the like.

[0003] An absorption type chiller is a device that can perform refrigeration or heating by causing a refrigerant to perform heat exchange with cold water through the cyclic operation of an absorbent and a refrigerant.

[0004] An absorption type chiller can perform refrigeration or heating using the following principle: a refrigerant evaporated in an evaporator is absorbed by an absorbent in an absorber, the absorbent liquid that has absorbed the refrigerant passes through a regenerator to evaporate the refrigerant, and the evaporated refrigerant is condensed through a condenser.

[0005] An absorption type chiller may include heat transfer tubes for an absorber and an evaporator. In the evaporator, the refrigerant outside the heat transfer tubes cools the water flowing inside the heat transfer tubes. In the absorber, the absorbent flows along the outer side surface of the heat transfer tubes while absorbing water particles in the air.

[0006] The "heat transfer tubes for an absorption type chiller" disclosed in Korean Registered Patent No. 10-1786858 includes: a plurality of protrusions formed independently of each other on an outer surface; a first groove portion formed circumferentially between the plurality of protrusions; a second groove portion formed axially of the tube between the plurality of protrusions and formed deeper than the first groove portion; and a third groove portion formed axially of the tube between the plurality of protrusions and formed to have a depth corresponding to the depth of the first groove portion.

[0007] In the conventional heat transfer tubes, due to the second groove portion and the third groove portion formed axially of the tube, there is a problem in that the thickness of the liquid refrigerant flowing along the outer side surface of the heat transfer tubes becomes thick due to an increase in the height difference between the protrusions and the groove portions.

[0008] In addition, there is a problem in that the heat transfer performance between the liquid refrigerant flowing along the outer side surface of the heat transfer tubes and the substance flowing inside the heat transfer tubes is reduced due to the thickening of the thickness of the liquid refrigerant flowing along the outer side surface of the heat transfer tubes.

[0009] In addition, there is a problem that the mass transfer performance between the absorbent flowing along the outer side of the heat transfer tube and the moisture in the air decreases due to the thickening of the thickness of the liquid refrigerant flowing along the outer side of the heat transfer tube.

[0010] In addition, due to the protrusions and grooves repeatedly formed on the outer side of the heat transfer tube, the shape of the outer side of the heat transfer tube becomes complicated. Therefore, there is a problem that the viscous absorbent may adhere to or stagnate in the gaps formed between the groove portions and the protrusion portions. This may cause problems of deterioration of heat transfer and mass transfer due to the reduction of the drainage performance of the heat transfer tube.

[0011] Existing literature:

[0012] Patent literature

[0013] Korean Registered Patent Bulletin No. 10-1786858 (Publication date: October 18, 2017) Summary of the Invention

[0014] An object of the present invention may be to provide an absorption cooling device with improved refrigeration and heating performance.

[0015] Another object of the present invention may be to provide an absorption cooling device with improved absorption performance of an absorber.

[0016] Another object of the present invention may be to provide an absorption cooling device with improved evaporation performance of an evaporator.

[0017] Another object of the present invention may be to provide an absorption cooling device with improved absorption efficiency of an absorbent for absorbing water particles.

[0018] Another object of the present invention may be to provide an absorption cooling device with a uniform film thickness formed on the outer side of a heat transfer tube.

[0019] Another object of the present invention may be to provide an absorption cooling device with a reduced film thickness formed on the outer side of a heat transfer tube.

[0020] Another object of the present invention may be to provide an absorption cooling device with improved fluidity and drainage performance on the outer side of a heat transfer tube.

[0021] Another object of the present invention may be to provide an absorption cooling device with improved pressure resistance of a heat transfer tube.

[0022] Another object of the present invention may be to provide an absorption cooling device with improved heat transfer performance of a heat transfer tube.

[0023] Another object of the present invention may be to provide an absorption cooling device with improved mass transfer performance of a heat transfer tube.

[0024] Another object of the present invention may be to provide an absorption cooling device with an increased heat transfer area of a heat transfer tube.

[0025] Another object of the present invention may be to provide an absorption cooling device with reduced manufacturing costs.

[0026] Another object of the present invention may be to provide an absorption cooling device with improved maintenance management performance.

[0027] The problems of the present invention are not limited to the problems mentioned above, and those skilled in the art can clearly understand other problems not mentioned from the following description.

[0028] To achieve the above object, according to one aspect of the present invention, an absorption cooling device may include: an evaporator that evaporates a refrigerant; an absorber that mixes the refrigerant evaporated in the evaporator with an absorbent to generate an absorbent liquid; a regenerator that heats the absorbent liquid supplied from the absorber; a condenser to which the refrigerant generated in the regenerator is supplied; and a heat transfer tube disposed in at least one of the evaporator and the absorber and extending longitudinally, the heat transfer tube including a plurality of protrusions that protrude from the surface of the heat transfer tube and are arranged along the longitudinal direction and the circumferential direction of the heat transfer tube, and the interval between the plurality of protrusions arranged along the circumferential direction of the heat transfer tube is smaller than the interval between the plurality of protrusions arranged along the longitudinal direction of the heat transfer tube, thereby improving the circumferential fluidity of the absorbent flowing along the outer side surface of the heat transfer tube.

[0029] The heat transfer tube may include: a first flow path formed between a plurality of protrusions spaced apart from each other along the longitudinal direction of the heat transfer tube and extending along the circumferential direction of the heat transfer tube; and a second flow path formed between the plurality of protrusions arranged along the circumferential direction of the heat transfer tube and extending along the longitudinal direction of the heat transfer tube, so that the absorbent can flow along the first flow path and the second flow path.

[0030] The width formed by the first flow path in the longitudinal direction of the heat transfer tube may be formed to be greater than the width formed by the second flow path in the circumferential direction of the heat transfer tube, so that the absorbent can flow through the first flow path as compared with the second flow path.

[0031] The first flow path may extend along the flow direction of the liquid flowing on the surface of the heat transfer tube.

[0032] The plurality of protrusions arranged along the circumferential direction of the heat transfer tube may be directly connected to each other, so that the outer side surface structure of the heat transfer tube becomes simple.

[0033] The heat transfer tube may include a base tube, with a plurality of protrusions formed on the surface of the base tube, and fluid flowing inside the base tube. The plurality of protrusions include a first inclined surface that extends obliquely from the protruding surface towards the base tube along the circumferential direction of the heat transfer tube, thereby enhancing the fluidity of the absorbent flowing circumferentially along the heat transfer tube.

[0034] The heat transfer tube may include slits formed between the first inclined surfaces of the plurality of protrusions, thereby ensuring the diffusivity of the absorbent in the longitudinal direction of the heat transfer tube.

[0035] The plurality of protrusions may include a second inclined surface that extends obliquely from the protruding surface towards the first flow path, thereby enhancing the diffusivity of the absorbent in the longitudinal direction of the heat transfer tube.

[0036] The distance between the first inclined surfaces formed in the circumferential direction of the heat transfer tube may be shorter than the distance between the second inclined surfaces formed in the longitudinal direction of the heat transfer tube.

[0037] The thickness of the heat transfer tube may be in the range of 0.9 times to 1.5 times the width of the plurality of protrusions formed in the circumferential direction of the heat transfer tube.

[0038] The interval between the plurality of protrusions arranged in the longitudinal direction of the heat transfer tube may be smaller than the length of the plurality of protrusions formed in the longitudinal direction of the heat transfer tube.

[0039] The length of the plurality of protrusions formed in the longitudinal direction of the heat transfer tube may be greater than the width of the plurality of protrusions formed in the circumferential direction of the heat transfer tube.

[0040] The height by which the plurality of protrusions protrude from the surface of the heat transfer tube may be greater than the interval between the plurality of protrusions arranged in the circumferential direction of the heat transfer tube.

[0041] The height by which the plurality of protrusions protrude from the surface of the heat transfer tube may be greater than the width of the plurality of protrusions formed in the circumferential direction of the heat transfer tube.

[0042] The heat transfer tubes may be uniformly arranged in the evaporator and the absorber, thereby simplifying the shape of the heat transfer tubes.

[0043] In addition, an absorption cooling device according to another embodiment of the present invention includes: an evaporator that evaporates a refrigerant; an absorber that mixes the refrigerant evaporated in the evaporator with an absorbent to generate an absorption liquid; a regenerator that heats the absorption liquid supplied from the absorber; a condenser to which the refrigerant generated in the regenerator is supplied; and a heat transfer tube disposed in at least one of the evaporator and the absorber, the heat transfer tube including: a base tube through which a fluid flows and that extends in a first direction; and a plurality of protrusions that protrude from a surface of the base tube and that are arranged on the surface of the base tube in the first direction and in a second direction orthogonal to the first direction, and a distance between the plurality of protrusions arranged in the second direction is less than a distance between the plurality of protrusions arranged in the first direction.

[0044] The heat transfer tube may include: a first flow path that is formed between the plurality of protrusions spaced apart from each other in the first direction and that extends in the second direction; and a second flow path that is formed between the plurality of protrusions arranged in the second direction and that extends in the first direction.

[0045] A width of the first flow path may be greater than a width of the second flow path.

[0046] The first flow path may extend along a flow direction of a liquid flowing on a surface of the heat transfer tube.

[0047] The plurality of protrusions adjacent to each other in the second direction may be directly connected to each other.

[0048] Specific details of other embodiments are included in the detailed description and the drawings. Description of the Drawings

[0049] Figure 1 is a conceptual diagram of an absorption cooling device according to an embodiment of the present invention.

[0050] Figure 2 is a perspective view of a heat transfer tube according to an embodiment of the present invention.

[0051] Figure 3 is an enlarged view of an outer side surface of a heat transfer tube according to another embodiment of the present invention.

[0052] Figure 4 is an enlarged view of an outer side surface of a heat transfer tube according to an embodiment of the present invention.

[0053] Figure 5 is Figure 2 an enlarged view of a part in

[0054] Figure 6 A and Figure 6 B are graphs showing experimental results of film thickness based on a residual angle according to an embodiment of the present invention.

[0055] Figure 7 It is a graph of experimental results comparing the heat transfer area according to an embodiment of the present invention.

[0056] Figure 8 It is a graph of experimental results comparing the overall heat transfer coefficient according to an embodiment of the present invention.

[0057] Figure 9 It is a perspective view of a heat transfer tube according to another embodiment of the present invention.

[0058] Figure 10 It is an enlarged view of the inner side of a heat transfer tube according to another embodiment of the present invention.

[0059] Figure 11 It is a view showing a longitudinal section of a heat transfer tube according to another embodiment of the present invention.

[0060] Figure 12 It is an enlarged view of a cross section of a heat transfer tube according to another embodiment of the present invention. Detailed implementation manners

[0061] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. Regardless of the reference numerals, the same or similar components are given the same reference numerals and the repeated description thereof is omitted.

[0062] In the following description, the suffixes "module" and "section" for components are given or mixed only for the ease of writing the specification, and they do not have meanings or functions that distinguish each other.

[0063] In addition, during the process of describing the embodiments disclosed in this specification, if it is considered that the detailed description of the related well-known technologies will obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easily understanding the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the accompanying drawings, and should be understood to include all changes, equivalents, and substitutes included in the concept and technical scope of the present invention.

[0064] Ordinal terms such as first, second, etc. may be used to describe various components, but the components are not limited by the terms. The terms are only for the purpose of distinguishing one component from another.

[0065] When it is mentioned that a certain component is "connected" or "linked" to another component, it should be understood that it may be directly connected or linked to the other component, but there may also be other components in between. On the contrary, when it is mentioned that a certain component is "directly connected" or "directly linked" to another component, it should be understood that there are no other components in between.

[0066] Unless otherwise clearly specified in the context, singular expressions include plural expressions.

[0067] The directional marks of up (U), down (D), left (Le), right (Ri), front (F), and rear (R) shown in the drawings are only for convenience of description, and the technical concept disclosed in this specification is not limited by this.

[0068] Refer to Figure 1 , the structure and principle of the absorption cooling device 1 will be described.

[0069] <<Structure of the absorption cooling device 1>>

[0070] The absorption cooling device 1 may include a regenerator 11, a condenser 12, an absorber 14, and an evaporator 13. The refrigerant may circulate in the regenerator 11, the condenser 12, the absorber 14, and the evaporator 13 in sequence for heat exchange.

[0071] <Regenerator 11>

[0072] The absorption cooling device 1 may include a regenerator 11. The regenerator 11 may heat the absorption liquid. The absorption liquid may be a solution formed by mixing an absorbent and a refrigerant. The absorption liquid may be referred to as a dilute solution or a thin solution. For example, the absorption liquid may be an aqueous lithium bromide solution.

[0073] The absorbent may absorb the refrigerant. The absorbent that has absorbed the refrigerant may become the absorption liquid. When the regenerator 11 heats the absorption liquid, the absorbent and the refrigerant may be separated from each other. For example, the heated refrigerant may turn into a vapor state and separate from the liquid absorption liquid. The liquid from which the refrigerant has been separated from the absorption liquid may be referred to as a concentrated solution or a concentrated liquor. For example, the absorbent may be lithium bromide and the refrigerant may be water.

[0074] The absorption cooling device 1 may include a first pipe 110 connecting the regenerator 11 and the condenser 12. The refrigerant vapor separated from the absorption liquid may move along the first pipe 110 to the condenser 12. For example, water vapor as the refrigerant vapor may move through the first pipe 110 to the condenser 12.

[0075] The absorption cooling device 1 may include a fifth pipe 150 connecting the regenerator 11 and the absorber 14. The concentrated solution from which the refrigerant vapor has been separated may move through the fifth pipe 150 to the absorber 14. The concentrated solution that has moved to the absorber 14 may absorb the refrigerant vapor in the absorber 14.

[0076] <Condenser 12>

[0077] The condenser 12 can condense the refrigerant. The regenerator 11 can supply the refrigerant to the condenser 12. For example, the water vapor generated in the regenerator 11 can be supplied to the condenser 12.

[0078] The absorption cooling device 1 can include a cooling tower 16 that cools the cooling water. The condenser 12 can be connected to the cooling tower 16. The cooling tower 16 and the condenser 12 can be connected through a sixth pipe 160. The cooling water can circulate in the cooling tower 16 and the condenser 12 through the sixth pipe 160. The cooling water can absorb heat energy when passing through the condenser 12 and release heat energy when passing through the cooling tower 16.

[0079] The refrigerant vapor supplied to the condenser 12 can be condensed by the cooling water. The cooling water can absorb heat energy from the refrigerant vapor to condense the refrigerant vapor. The refrigerant vapor can be phase-changed into a refrigerant solution in the condenser 12. The refrigerant solution generated in the condenser 12 can be supplied to the evaporator 13.

[0080] The absorption cooling device 1 can include a second pipe 120 that connects the condenser 12 and the evaporator 13. The refrigerant solution can be supplied to the evaporator 13 through the second pipe 120.

[0081] <Evaporator 13>

[0082] The evaporator 13 can be connected to a cooler 17. The cooler 17 can cool the indoor space or supply cold water to the indoor space. Additionally, if the flow path is changed, the cooler 17 can also heat the indoor space or supply hot water to the indoor space. For ease of explanation, in the present invention, the cooler 17 for refrigeration is mainly described.

[0083] The absorption cooling device 1 can include a first heat transfer pipe 20a disposed in the evaporator 13. The first heat transfer pipe 20a can connect the evaporator 13 and the cooler 17. The water supplied to the indoor space can flow inside the first heat transfer pipe 20a. The water flowing inside the first heat transfer pipe 20a may have its temperature reduced when passing through the evaporator 13. The water can also circulate in the evaporator 13 and the cooler 17 through the first heat transfer pipe 20a.

[0084] The refrigerant solution supplied to the evaporator 13 can be evaporated. The refrigerant solution can exchange heat with the water inside the heat transfer pipe 20. The refrigerant solution can exchange heat with the water inside the heat transfer pipe 20 and be phase-changed into refrigerant vapor. For example, the refrigerant solution can absorb heat energy from the water inside the heat transfer pipe 20 and evaporate, and the water inside the heat transfer pipe 20 may have its heat energy taken away by the refrigerant and its temperature reduced.

[0085] The absorption cooling device 1 may include a third pipe 130 connecting the evaporator 13 and the absorber 14. The refrigerant vapor evaporated in the evaporator 13 may be supplied to the absorber 14 through the third pipe 130.

[0086] <absorber 14>

[0087] The refrigerant evaporated in the evaporator 13 may move to the absorber 14. The concentrated solution generated in the regenerator 11 may be supplied to the absorber 14 through the fifth pipe 150.

[0088] The absorption cooling device 1 may include a second heat transfer pipe 20b disposed in the absorber 14. The second heat transfer pipe may be connected to the cooling tower 16. The cooling water supplied from the cooling tower 16 may flow in the second heat transfer pipe. The cooling water may circulate between the cooling tower 16 and the absorber 14 through the second heat transfer pipe.

[0089] The concentrated solution supplied through the fifth pipe 150 may flow toward the second heat transfer pipe 20b. The concentrated solution may flow downward along the outer side surface of the second heat transfer pipe 20b. The refrigerant vapor generated in the evaporator 13 may be supplied to the absorber 14 through the third pipe 130, and the concentrated solution may absorb the refrigerant vapor. The refrigerant vapor and the concentrated solution may meet in the absorber 14 and become a dilute solution.

[0090] The absorption cooling device 1 may include a fourth pipe 140 connecting the absorber 14 and the regenerator 11. The absorption liquid generated in the absorber 14 may move again to the regenerator 11 through the fourth pipe 140. The absorption liquid supplied to the regenerator 11 may be reheated and separated into a concentrated solution and refrigerant vapor.

[0091] Refer to Figure 2 to describe the outer shape of the heat transfer pipe 20.

[0092] <heat transfer pipe 20>

[0093] The heat transfer pipes 20 may be respectively disposed in the evaporator 13 and the absorber 14. The shape of the heat transfer pipe 20 disposed in the evaporator 13 may correspond to the shape of the heat transfer pipe 20 disposed in the absorber 14. For example, a single heat transfer pipe 20 may be applicable to both the evaporator 13 and the absorber 14.

[0094] Water may flow inside the heat transfer pipe 20. Cold water or cooling water may flow inside the heat transfer pipe 20. The heat transfer pipe 20 may include a first heat transfer pipe 20a disposed in the evaporator 13. Cold water may flow inside the first heat transfer pipe 20a. The heat transfer pipe 20 may include a second heat transfer pipe 20b disposed in the absorber 14. Cooling water may flow inside the second heat transfer pipe 20b.

[0095] <Direction definitions - DR1, DR2>

[0096] The heat transfer tube 20 can extend relatively long. The first direction DR1 can be a direction parallel to the length direction of the heat transfer tube 20. The length direction of the heat transfer tube 20 can correspond to the tube axis direction of the heat transfer tube 20.

[0097] The second direction DR2 can represent the circumferential direction of the heat transfer tube 20. The second direction DR2 can intersect the first direction DR1. Regardless of the cross-sectional shape of the heat transfer tube 20, the circumferential direction can be the same. For example, if the cross-sectional shape of the heat transfer tube 20 is circular, the circumferential direction can be the circumferential direction of the circle. For example, if the cross-sectional shape of the heat transfer tube 20 is quadrilateral, the circumferential direction can be the circumferential direction of the circle concentric with the quadrilateral.

[0098] <Base tube 21>

[0099] The heat transfer tube 20 can include a base tube 21 that forms a framework. The base tube 21 can include an outer side surface and an inner side surface. The base tube 21 can include an internal space 200 for fluid to flow through. The internal space 200 of the base tube 21 can be surrounded by the inner side surface.

[0100] <Protrusions 22>

[0101] The heat transfer tube 20 can include a plurality of protrusions 22 protruding from the surface 220. The plurality of protrusions 22 can protrude from the outer side surface of the base tube 21. The plurality of protrusions 22 can be formed on the outer side surface of the base tube 21. The plurality of protrusions 22 can be arranged in a grid pattern on the outer side surface of the base tube 21. The plurality of protrusions 22 can be adjacent to each other or spaced apart from each other. The plurality of protrusions 22 can be connected to each other.

[0102] Thus, the heat transfer area of the heat transfer tube can be increased.

[0103] Refer to Figure 3 and Figure 4 , a structure in which a plurality of protrusions 22 are arranged on the outer side surface of the heat transfer tube 20 will be described.

[0104] <Arrangement of a plurality of protrusions 22>

[0105] The plurality of protrusions 22 can be arranged along the length direction of the heat transfer tube 20. The plurality of protrusions 22 can be arranged along the circumferential direction of the heat transfer tube 20. For example, the plurality of protrusions 22 can be spaced apart from each other at a predetermined interval along the first direction and the second direction and arranged in a grid pattern.

[0106] <First flow path 242>

[0107] The heat transfer tube 20 may include a first flow path 242 extending circumferentially along the heat transfer tube 20. The first flow path 242 may be formed between a plurality of protrusions 22 spaced apart from each other in the longitudinal direction of the heat transfer tube 20. That is, the first flow path 242 may be the space between a plurality of protrusions 22 arranged in a first direction. The first flow path 242 and the plurality of protrusions 22 arranged circumferentially along the heat transfer tube 20 may be alternately arranged with each other in the longitudinal direction of the heat transfer tube 20.

[0108] The first flow path 242 may include a plurality of first flow paths 242 arranged in the longitudinal direction of the heat transfer tube 20. The plurality of first flow paths 242 may be spaced apart from each other in the longitudinal direction of the heat transfer tube 20. The plurality of protrusions 22 may be located between the plurality of first flow paths 242 spaced apart from each other.

[0109] The first flow path 242 may extend along the flow direction of the liquid flowing on the surface 220 of the heat transfer tube 20. The concentrated solution distributed through the fifth pipe 150 may move in a second direction. The second direction may be parallel to the up and down direction. The concentrated solution may flow downward along the periphery of the heat transfer tube 20.

[0110] <Second flow path 244>

[0111] The heat transfer tube 20 may include a second flow path 244 extending in the longitudinal direction of the heat transfer tube 20. The second flow path 244 may be formed between a plurality of protrusions 22 spaced apart from each other in the circumferential direction of the heat transfer tube 20. That is, the second flow path 244 may be the space between a plurality of protrusions 22 arranged in a second direction. The second flow path 244 and the plurality of protrusions 22 arranged in the longitudinal direction of the heat transfer tube 20 may be alternately arranged with each other in the circumferential direction of the heat transfer tube 20.

[0112] The second flow path 244 may include a plurality of second flow paths 244 arranged in the circumferential direction of the heat transfer tube 20. The plurality of second flow paths 244 may be spaced apart from each other in the circumferential direction of the heat transfer tube 20. The plurality of protrusions 22 may be located between the plurality of second flow paths 244 spaced apart from each other.

[0113] The second flow path 244 may extend in a direction intersecting the flow direction of the liquid flowing on the surface 220 of the heat transfer tube 20. The concentrated solution distributed through the fifth pipe 150 may move in a first direction DR1. The first direction DR1 may intersect the up and down direction. The concentrated solution may diffuse in the longitudinal direction of the heat transfer tube 20.

[0114] <Relationship between the first flow path 242 and the second flow path 244>

[0115] The width of the first flow path 242 may be greater than the width of the second flow path 244. The width of the first flow path 242 may be formed in the length direction of the heat transfer tube 20. The width of the second flow path 244 may be formed in the circumferential direction of the heat transfer tube 20. The width of the second flow path 244 may be smaller than the width of the first flow path 242.

[0116] This can improve the fluidity of the concentrated solution flowing in the circumferential direction along the outer surface of the heat transfer tube.

[0117] <Specific shape of each protrusion 22 - surface, inclined surface, slit>

[0118] The plurality of protrusions 22 may include a surface 220 protruding from the base pipe 21. The surface 220 of the plurality of protrusions 22 may be spaced apart from the surface 220 of the base pipe 21. For example, the surface 220 of the plurality of protrusions 22 may be spaced apart from the surface 220 of the base pipe 21 in the radial direction.

[0119] The plurality of protrusions 22 may include a first inclined surface 221 extending obliquely along the circumferential direction of the heat transfer tube 20. The first inclined surface 221 may extend from the surface 220 of the plurality of protrusions 22 toward the base tube 21.

[0120] The first inclined surface 221 can connect the circumference of the surface 220 ( Figure 3 The upper end and the lower end) of the heat transfer tube 20 are connected to the base tube 21 and are inclined relative to the radial direction of the heat transfer tube 20. The radial direction of the heat transfer tube 20 is a direction orthogonal to the axial direction (length direction) of the heat transfer tube 20.

[0121] The first inclined surface 221 may include an upstream first inclined surface 221a extending from the surface 220 of the protrusion 22 to the upstream side of the heat transfer tube 20 in the circumferential direction ( Figure 3 The first inclined surface 221 may include a downstream first inclined surface 221b, which extends from the surface 220 of the protrusion 22 to the downstream of the circumference of the heat transfer tube 20. The upstream first inclined surface 221a and the downstream first inclined surface 221b may be opposite to each other. A second flow path 244 may be formed between the upstream first inclined surface 221a and the downstream first inclined surface 221b.

[0122] The plurality of protrusions 22 may include a second inclined surface 222 extending obliquely in the length direction of the heat transfer tube 20. The second inclined surface 222 may extend from the surface 220 of the plurality of protrusions 22 toward the base tube 21. The second inclined surface 222 may extend from the surface 220 of the plurality of protrusions 22 toward the first flow path 242.

[0123] The second inclined surface 222 may include a first-side second inclined surface 222a that extends from the surface 220 of the protrusion 22 toward one side in the longitudinal direction of the heat transfer tube 20. The second inclined surface 222 may include a second-side second inclined surface 222b that extends from the surface 220 of the protrusion 22 toward the other side in the longitudinal direction of the heat transfer tube 20. The first-side second inclined surface 222a and the second-side second inclined surface 222b may face each other. A first flow path 242 may be formed between the first-side second inclined surface 222a and the second-side second inclined surface 222b.

[0124] The distance between the first inclined surfaces 221 may be shorter than the distance between the second inclined surfaces 222. The distance between the first inclined surfaces 221 may be formed in the circumferential direction of the heat transfer tube 20. The distance between the second inclined surfaces 222 may be formed in the longitudinal direction of the heat transfer tube 20.

[0125] The plurality of protrusions 22 may include a slit 226 formed between the first inclined surfaces 221. The slit 226 may be located between the upstream-side first inclined surface 221a and the downstream-side first inclined surface 221b.

[0126] <Arrangement interval of the plurality of protrusions 22 - longitudinal direction and circumferential direction, g1 > g2>

[0127] The interval between the plurality of protrusions 22 arranged along the circumferential direction of the heat transfer tube 20 may be smaller than the interval between the plurality of protrusions 22 arranged along the longitudinal direction of the heat transfer tube 20. A second flow path 244 may be formed between the plurality of protrusions 22 arranged along the circumferential direction of the heat transfer tube 20. The first flow path 242 may be formed between the plurality of protrusions 22 arranged along the longitudinal direction of the heat transfer tube 20. For example, the interval g2 between the plurality of protrusions 22 arranged along the circumferential direction of the heat transfer tube 20 may be about 0.1 mm or less. For example, the interval g1 between the plurality of protrusions 22 arranged along the longitudinal direction of the heat transfer tube 20 may be in the range of about 0.2 mm to 0.4 mm.

[0128] <Relationship between the width and length of each protrusion 22>

[0129] The protrusion 22 may extend longer in the longitudinal direction of the heat transfer tube 20. The protrusion 22 may extend in the circumferential direction of the heat transfer tube 20. The length of the protrusion 22 may be formed in the longitudinal direction of the heat transfer tube 20. The width of the protrusion 22 may be formed in the circumferential direction of the heat transfer tube 20. The protrusion 22 may be formed in a quadrilateral shape.

[0130] <a1 > b1>

[0131] The length of a plurality of protrusions 22 extending in the longitudinal direction of the heat transfer tube 20 may be greater than the width of the plurality of protrusions 22 extending in the circumferential direction of the heat transfer tube 20. For example, the protrusion 22 may be formed in a rectangular shape with one side longer than the other. For example, the length of the protrusion 22 may be formed to be about 0.45 mm or less. For example, the width of the protrusion 22 may be formed to be about 0.35 mm or less. However, it is not limited thereto, and the protrusion 22 may be formed in various shapes such as a triangle, a square, or a circle.

[0132] <a1>g1>

[0133] The interval between a plurality of protrusions 22 arranged in the longitudinal direction of the heat transfer tube 20 may be smaller than the length of the plurality of protrusions 22 extending in the longitudinal direction of the heat transfer tube 20. The width of the first flow path 242 may be smaller than the length of the protrusion 22. For example, the width of the first flow path 242 may be in the range of about 0.15 mm to 0.45 mm.

[0134] <b1>g2>

[0135] The interval between a plurality of protrusions 22 arranged in the circumferential direction of the heat transfer tube 20 may be smaller than the width of the plurality of protrusions 22 extending in the circumferential direction of the heat transfer tube 20. The width of the second flow path 244 may be smaller than the width of the protrusion 22. For example, the width of the second flow path 244 may be formed to be about 0.15 mm or less.

[0136] <Arrangement interval of a plurality of protrusions 22 - Direct connection>

[0137] A plurality of protrusions 22 arranged in the circumferential direction of the heat transfer tube 20 may be connected to each other. That is, a plurality of protrusions 22 arranged in the circumferential direction of the heat transfer tube 20 may not be spaced apart from each other. For example, the interval between a plurality of protrusions 22 arranged in the circumferential direction of the heat transfer tube 20 may be 0. The width of the second flow path 244 may be 0.

[0138] Thus, the external shape of the heat transfer tube can be simplified.

[0139] In addition, the drainage and fluidity of the heat transfer tube can be improved.

[0140] In addition, the thickness of the liquid flowing along the outer side surface of the heat transfer tube, that is, the thickness of the thin film, can be thinned.

[0141] In addition, the thickness of the thin film can be made uniform.

[0142] Refer to Figure 5 , and the structure of the cross section of the heat transfer tube 20 will be described.

[0143] <h1>h2>

[0144] The thickness of the heat transfer tube 20 can be greater than the height by which the plurality of protrusions 22 protrude. The thickness of the heat transfer tube 20 can be the thickness of the base tube 21. The thickness of the heat transfer tube 20 can be the thickness of the tube excluding the plurality of protrusions 22. For example, the thickness h1 of the heat transfer tube 20 can be in the range of about 0.28 mm to 0.45 mm. For example, the height h2 by which the plurality of protrusions 22 protrude can be formed to be about 0.28 mm or more.

[0145] Thereby, the pressure resistance performance of the heat transfer tube can be improved.

[0146] <h2 > g2>

[0147] The height by which the plurality of protrusions 22 protrude can be greater than the interval between the plurality of protrusions 22 arranged along the circumferential direction of the heat transfer tube 20. For example, the plurality of protrusions 22 can protrude about 0.28 mm or more, and the interval g2 between the plurality of protrusions 22 arranged along the circumferential direction of the heat transfer tube 20 can be formed to be about 0.12 mm or less.

[0148] <h2 > b1>

[0149] The height by which the plurality of protrusions 22 protrude can be less than the width of the plurality of protrusions 22 extending along the circumferential direction of the heat transfer tube 20. For example, the plurality of protrusions 22 can protrude about 0.28 mm or more, and the width b1 of the plurality of protrusions 22 extending along the circumferential direction of the heat transfer tube 20 can be formed to be about 0.32 mm or less.

[0150] Refer to Figure 6 A and Figure 6 B to describe the thickness of the film formed according to an embodiment of the present invention.

[0151] Refer to Figure 6 A to describe an embodiment according to the present invention.

[0152] <Comparison between X1 and X2 - Number, size, interval of protrusions, size relative to the thickness of the heat transfer tube 20>

[0153] It can be represented by X1 Figure 6 The embodiment on the left side of A. It can be represented by X2 Figure 6Embodiment on the right side of A. The size of the protrusion 22 in X2 can be smaller than the size of the protrusion 22 in X1. For example, the length of the protrusion 22 in X2 can be shorter than the length of the protrusion 22 in X1. For example, the width of the protrusion 22 in X2 can be shorter than the width of the protrusion 22 in X1. The number of the plurality of protrusions 22 in X2 can be more than the number of the plurality of protrusions 22 in X1. The width of the first flow path 242 in X2 can be narrower than the width of the first flow path 242 in X1. The number of the first flow paths 242 in X2 can be more than the number of the first flow paths 242 in X1. The width of the second flow path 244 in X1 and X2 can be 0. The protruding height of the protrusion 22 in X2 can be lower than the protruding height of the protrusion 22 in X1.

[0154] In X1, the thickness of the heat transfer tube 20 relative to the width of the plurality of protrusions 22 can be in the range of about 0.2 times to 0.8 times. The width of the plurality of protrusions 22 can be formed in the circumferential direction of the heat transfer tube 20. For example, in X1, the thickness of the heat transfer tube 20 relative to the width of the plurality of protrusions 22 can be in the range of about 0.4 times to 0.65 times.

[0155] In X2, the thickness of the heat transfer tube 20 relative to the width of the plurality of protrusions 22 can be in the range of about 0.8 times to 1.6 times. The width of the plurality of protrusions 22 can be formed in the circumferential direction of the heat transfer tube 20. For example, in X2, the thickness of the heat transfer tube 20 relative to the width of the protrusion 22 can be in the range of about 0.95 times to 1.45 times.

[0156] <Residual angle>

[0157] Figure 6 B is a diagram showing the thickness of the thin film based on the residual angle with reference to the cross section of the heat transfer tube 20.

[0158] The concentrated solution or absorbent supplied to the absorber 14 can move from the upper end to the lower end of the heat transfer tube 20. The absorbent distributed at the upper end of the heat transfer tube 20 with a circular cross section can flow circumferentially along the outer side surface of the heat transfer tube 20 and move to the lower end of the heat transfer tube 20. At this time, if the residual angle at the upper end, which is the uppermost side of the heat transfer tube 20, is set to 0 degrees, the residual angle at the lower end, which is the lowermost side of the heat transfer tube 20, can be regarded as 180 degrees. When the absorbent flows circumferentially along the outer side surface of the heat transfer tube 20, the residual angle can gradually increase from 0 degrees to 180 degrees.

[0159] The thinner the thickness of the thin film formed on the outer side surface of the heat transfer tube 20, the more excellent the heat transfer performance of the heat transfer tube 20 may be. The more uniform the thickness of the thin film formed on the outer side surface of the heat transfer tube 20, the more excellent the heat transfer performance of the heat transfer tube 20 may be.

[0160] Explanation is given to X1 based on the experimental result graph. The film thickness formed on the outer side surface of the heat transfer tube 20 may be the highest at the residual angles near 0 degrees and 180 degrees. The film thickness can be formed to be the thinnest within the residual angle range between 0 degrees and 30 degrees. The film thickness can gradually increase within the residual angle range between 30 degrees and 60 degrees. That is, when the absorbent flows, it may stagnate on the outer side surface of the heat transfer tube 20, and the film thickness may become thicker.

[0161] Explanation is given to X2 based on the experimental result graph. The film thickness formed on the outer side surface of the heat transfer tube 20 can be the highest at the residual angles near 0 degrees and 180 degrees. The film thickness can be formed to be uniform within the residual angle range between 0 degrees and 150 degrees.

[0162] The film thickness formed in X2 can be overall thinner than the film thickness formed in X1. In addition, the film thickness formed in X2 can be more uniform than the film thickness formed in X1.

[0163] Thus, the heat transfer performance of the heat transfer tube can be improved.

[0164] In addition, the mass transfer performance and heat transfer performance in the absorber can be improved, thereby improving the absorption efficiency.

[0165] In addition, the heat transfer performance in the evaporator can be improved, thereby improving the evaporation efficiency.

[0166] Refer to Figure 7 , and the heat transfer area according to the embodiment of the present invention is explained.

[0167] According to the experimental result graph, the heat transfer area in X2 can be increased compared to the heat transfer area in X1. For example, the heat transfer area in X2 can be increased by about 1.4 times compared to the heat transfer area in X1. That is, the larger the number of the plurality of protrusions 22, the more the heat transfer area can be increased. In addition, the smaller the size of the plurality of protrusions 22, the more the heat transfer area can be increased. In addition, the smaller the ratio of the width of the protrusion 22 to the thickness of the heat transfer tube 20, the more the heat transfer area can be increased.

[0168] Thus, the heat transfer performance of the heat transfer tube 20 can be improved.

[0169] In addition, the heat transfer performance can be improved, thereby improving the evaporation efficiency in the evaporator 13.

[0170] Refer to Figure 8 , and the overall heat transfer coefficient according to the embodiment of the present invention is explained.

[0171] According to the experimental result graph, the overall heat transfer coefficient in X2 (hereinafter referred to as "heat transfer coefficient") can be increased compared to the heat transfer coefficient in X1. For example, the heat transfer coefficient in X2 can be increased by about 1.5 times compared to the heat transfer coefficient in X1. That is, the larger the number of the plurality of protrusions 22, the more the heat transfer coefficient can be increased. In addition, the smaller the size of the plurality of protrusions 22, the more the heat transfer coefficient can be increased. In addition, the smaller the ratio of the width of the protrusion 22 to the thickness of the heat transfer tube 20, the more the heat transfer coefficient can be increased.

[0172] Refer to Figure 9 , the inner shape of the heat transfer tube 20 will be described.

[0173]

[0174] The heat transfer tube 20 may include ribs 26 protruding from the inner surface. The ribs 26 may protrude from the inner surface of the heat transfer tube 20 toward the central axis of the heat transfer tube 20. For example, the ribs 26 may protrude from the inner surface of the base tube 21 in a direction opposite to the radial direction.

[0175] The ribs 26 may extend for a long distance. The ribs 26 may extend helically in the length direction DR1 of the heat transfer tube 20. The ribs 26 may rotate along the circumferential direction DR2 of the heat transfer tube 20 and extend for a long distance in the length direction DR1. For example, the ribs 26 may extend for a long distance in the length direction DR1 of the heat transfer tube 20 and extend helically along the inner surface of the base tube 21.

[0176] The ribs 26 may include a plurality of ribs 26 that extend for a long distance in the length direction DR1 along the inner surface of the heat transfer tube 20. The plurality of ribs 26 may be spaced apart from each other along the circumferential direction DR2 of the heat transfer tube 20. The plurality of ribs 26 may protrude from the inner surface of the heat transfer tube 20 toward the center of the heat transfer tube 20 and be arranged on the inner surface along the circumferential direction DR2 of the heat transfer tube 20. The plurality of ribs 26 arranged along the circumferential direction DR2 on the inner surface of the heat transfer tube 20 may extend helically in the length direction DR1 of the heat transfer tube 20. For example, the heat transfer tube 20 may include 7 to 13 ribs 26, which are spaced apart from each other along the circumferential direction DR2 on the inner surface and extend for a long distance in the length direction DR1.

[0177] Refer to Figure 10 , the angle of formation of the plurality of ribs 26 will be described.

[0178] <The angle of the plurality of ribs 26>

[0179] A plurality of ribs 26 may extend obliquely on the inner side surface of the heat transfer tube 20. The plurality of obliquely extending ribs 26 may be spaced apart from each other in the length direction DR1 of the heat transfer tube 20. The ribs 26 spirally extending along the inner side surface of the heat transfer tube 20 may form an angle with the length direction DR1 of the heat transfer tube 20. The angle at which the plurality of ribs 26 extend may be inclined with respect to the length direction DR1 of the heat transfer tube 20. The angle at which the plurality of ribs 26 extend may be inclined with respect to the flow direction LF of the liquid. For example, the plurality of ribs 26 may form a first angle (theta1) with the flow direction LF of the liquid. For example, the plurality of ribs 26 may form a first angle (theta1) with the length direction DR1 of the heat transfer tube 20. For example, the first angle (theta1) may be in the range of 35 degrees to 50 degrees.

[0180] Refer to Figure 11 , the structure of the longitudinal section of the heat transfer tube 20 will be described.

[0181] <Shape of rib 26>

[0182] The width of the rib 26 may be smaller the closer it is to the protruding direction. The width of the rib 26 may be smaller the closer it is to the center of the heat transfer tube 20. The width of the rib 26 may extend in the length direction DR1 of the heat transfer tube 20. The width of the rib 26 may extend in the flow direction LF of the liquid. For example, the width of the rib 26 formed in the length direction DR1 of the heat transfer tube 20 may be smaller the closer it is to the protruding direction.

[0183] <Inclined surface>

[0184] The rib 26 may include a first inclined surface 261 protruding from the heat transfer tube 20. The first inclined surface 261 may be one surface of the rib 26 protruding from the inner side surface of the heat transfer tube 20. The first inclined surface 261 may protrude from the inner side surface of the heat transfer tube 20. The first inclined surface 261 may extend obliquely from the protruding surface 260 in a direction opposite to the flow direction LF of the liquid. The first inclined surface 261 may extend obliquely with respect to the flow direction LF of the liquid. The first inclined surface 261 may form an angle with the length direction DR1 of the heat transfer tube 20. The first inclined surface 261 may form an angle with the flow direction LF of the liquid. For example, the first inclined surface 261 may form a second angle (theta2) with the length direction DR1 of the heat transfer tube 20.

[0185] The rib 26 may include a second inclined surface 262 protruding from the heat transfer tube 20. The second inclined surface 262 may be another surface of the rib 26 protruding from the inner side surface of the heat transfer tube 20. The second inclined surface 262 may protrude from the inner side surface of the heat transfer tube 20. The second inclined surface 262 may extend obliquely from the protruding surface 260 in the liquid flow direction LF. The second inclined surface 262 may extend from the protruding surface 260 toward the inner side surface of the heat transfer tube 20. The second inclined surface 262 may form an angle with the longitudinal direction DR1 of the heat transfer tube 20. The second inclined surface 262 may form an angle with the liquid flow direction LF. The angle formed by the second inclined surface 262 and the longitudinal direction DR1 of the heat transfer tube 20 may correspond to the angle formed by the first inclined surface 261 and the longitudinal direction D1R of the heat transfer tube 20.

[0186] <Surface 260>

[0187] The rib 26 may include a surface 260 connecting the first inclined surface 261 and the second inclined surface 262. The surface 260 may connect the first inclined surface 261 and the second inclined surface 262 in a curved manner. The surface 260 may bulge toward the center of the heat transfer tube 20.

[0188] The length of the surface 260 may be shorter than the length of the first inclined surface 261 and / or the second inclined surface 262. The length that the surface 260 extends may be shorter than the length that the first inclined surface 261 extends. The length that the surface 260 extends may be shorter than the length that the second inclined surface 262 extends. For example, the length of the surface 260 extending along the longitudinal direction DR1 of the heat transfer tube 20 may be shorter than the length of the first inclined surface 261 and / or the second inclined surface 262 extending along the longitudinal direction DR1 of the heat transfer tube 20.

[0189] <Relationship between the height of rib 26 and the tube thickness>

[0190] The rib 26 may protrude from the inner side surface of the heat transfer tube 20. The height by which the rib 26 protrudes from the heat transfer tube 20 may be in the range of 0.1 mm to 0.3 mm. For example, the height by which the rib 26 protrudes from the inner side surface of the heat transfer tube 20 may be in the range of 0.15 mm to 0.3 mm.

[0191] <Relationship between rib 26 and the protrusion - position, height>

[0192] The rib 26 may be located between a plurality of protrusions 22. The plurality of protrusions 22 may be arranged to be spaced apart from each other along the longitudinal direction DR1 of the heat transfer tube 20, and the plurality of ribs 26 may be located at positions corresponding to the intervals at which the plurality of protrusions 22 are spaced apart from each other with respect to the longitudinal direction DR1 of the heat transfer tube 20.

[0193] The height by which a plurality of protrusions 22 protrude from the heat transfer tube 20 may be higher than the height by which a plurality of ribs 26 protrude from the heat transfer tube 20. The plurality of protrusions 22 may protrude radially from the heat transfer tube 20, and the plurality of ribs 26 may protrude in an inward direction from the heat transfer tube 20. That is, the plurality of protrusions 22 and the plurality of ribs 26 may protrude from the heat transfer tube 20 in directions opposite to each other.

[0194] <The inclined surfaces 261, 262 of the rib 26 and the inclined surface 222 of the protrusion>

[0195] The angle by which the inclined surface 222 of the plurality of protrusions 22 is inclined with respect to the longitudinal direction DR1 of the heat transfer tube 20 may be greater than the angle by which the inclined surfaces 261, 262 of the ribs 26 are inclined with respect to the longitudinal direction DR1 of the heat transfer tube 20. For example, a first inclined surface 222 of the protrusion 22 formed on the outer side surface of the heat transfer tube 20 may form a third angle (theta3) with the longitudinal direction DR1 of the heat transfer tube 20. For example, a first inclined surface 261 of the rib 26 formed on the inner side surface of the heat transfer tube 20 may form a second angle (theta2) with the longitudinal direction DR1 of the heat transfer tube 20. The third angle (thata3) formed by the first inclined surface 222 of the protrusion 22 and the longitudinal direction DR1 of the heat transfer tube 20 may be greater than the second angle (theta2) formed by the first inclined surface 261 of the rib 26 and the longitudinal direction DR1 of the heat transfer tube 20.

[0196] Refer to Figure 12 , and the structure of the cross-section of the heat transfer tube 20 will be described.

[0197] <The cross-sectional shape of the rib 26>

[0198] The width of the rib 26 may be smaller the closer it is to the protruding direction. The rib 26 on the cross-section of the heat transfer tube 20 may have a trapezoidal cross-section. For example, the width W of the rib 26 formed along the circumferential direction DR2 of the heat transfer tube 20 may be smaller the closer it is to the protruding direction.

[0199] <The connecting surface 264>

[0200] The rib 26 may include a connecting surface 264 connected to the heat transfer tube 20. The connecting surface 264 may be connected to the inner side surface of the heat transfer tube 20.

[0201] The surface 260 may be spaced apart from the connecting surface 264. The surface 260 may be spaced apart from the connecting surface 264 in the central direction of the heat transfer tube 20. The surface 260 and the connecting surface 264 may be spaced apart from each other along the radial direction of the heat transfer tube 20. The inclined surfaces 261, 262 may connect the surface 260 and the connecting surface 264. The first inclined surface 261 and the second inclined surface 262 may connect the surface 260 and the connecting surface 264 in an inclined manner.

[0202] The connecting surface 264 of the rib 26 may be one end of the rib 26 closest to the base tube 21, and the surface 260 of the rib 26 may be the other end of the rib 26 farthest from the base tube 21.

[0203] <Length ratio of the rib 26>

[0204] The width of the connecting surface 264 may be greater than the width of the surface 260. The width of the connecting surface 264 may extend along the circumferential direction DR2 of the heat transfer tube 20. The width of the surface 260 may extend along the circumferential direction DR2 of the heat transfer tube 20. For example, the width W1 of the connecting surface 264 formed on the circumferential direction DR2 of the heat transfer tube 20 may be greater than the width W2 of the surface 260 formed on the circumferential direction DR2 of the heat transfer tube 20. The width of the connecting surface 264 may be more than 1.5 times the width of the surface 260. For example, the width of the connecting surface 264 relative to the width of the surface 260 may be in the range of 2.0 to 2.5 times.

[0205] Referring to Figures 1 to 12 , an absorption cooling device according to an aspect of the present invention may include: an evaporator that evaporates a refrigerant; an absorber in which the refrigerant evaporated in the evaporator is mixed with an absorbent to generate an absorption liquid; a regenerator that heats the absorption liquid supplied from the absorber; a condenser to which the refrigerant generated in the regenerator is supplied; and a heat transfer tube disposed in at least one of the evaporator and the absorber and extending longitudinally.

[0206] According to another aspect of the present invention, the heat transfer tube may include a plurality of protrusions that protrude from the surface of the heat transfer tube and are arranged along the length direction and the circumferential direction of the heat transfer tube.

[0207] According to another aspect of the present invention, the interval between the plurality of protrusions arranged along the circumferential direction of the heat transfer tube may be smaller than the interval between the plurality of protrusions arranged along the length direction of the heat transfer tube.

[0208] According to another aspect of the present invention, the heat transfer tube may include a first flow path that is formed between a plurality of protrusions spaced apart from each other along the length direction of the heat transfer tube and extends along the circumferential direction of the heat transfer tube.

[0209] According to another aspect of the present invention, the heat transfer tube may include a second flow path that is formed between a plurality of protrusions arranged along the circumferential direction of the heat transfer tube and extends along the length direction of the heat transfer tube.

[0210] According to another aspect of the present invention, the width formed by the first flow path in the length direction of the heat transfer tube may be greater than the width formed by the second flow path in the circumferential direction of the heat transfer tube.

[0211] According to another aspect of the present invention, the first flow path may extend along the flow direction of the liquid flowing on the surface of the heat transfer tube.

[0212] According to another aspect of the present invention, a plurality of protrusions arranged circumferentially along the heat transfer tube may be directly connected to each other.

[0213] According to another aspect of the present invention, the heat transfer tube may include a base tube, on the surface of which the plurality of protrusions are formed, and through which fluid flows inside.

[0214] According to another aspect of the present invention, the plurality of protrusions may include a first inclined surface that extends obliquely from the protruding surface toward the base tube along the circumferential direction of the heat transfer tube.

[0215] According to another aspect of the present invention, the heat transfer tube may include slits formed between the first inclined surfaces of the plurality of protrusions.

[0216] According to another aspect of the present invention, the plurality of protrusions may include a second inclined surface that extends obliquely from the protruding surface toward the first flow path.

[0217] According to another aspect of the present invention, the distance between the first inclined surfaces formed in the circumferential direction of the heat transfer tube may be shorter than the distance between the second inclined surfaces formed in the length direction of the heat transfer tube.

[0218] According to another aspect of the present invention, the thickness of the heat transfer tube may be in the range of 0.9 times to 1.5 times the width of the plurality of protrusions formed in the circumferential direction of the heat transfer tube.

[0219] According to another aspect of the present invention, the interval between the plurality of protrusions arranged in the length direction of the heat transfer tube may be smaller than the length of the plurality of protrusions formed in the length direction of the heat transfer tube.

[0220] According to another aspect of the present invention, the length of the plurality of protrusions formed in the length direction of the heat transfer tube may be greater than the width of the plurality of protrusions formed in the circumferential direction of the heat transfer tube.

[0221] According to another aspect of the present invention, the height by which the plurality of protrusions protrude from the surface of the heat transfer tube may be greater than the interval between the plurality of protrusions arranged in the circumferential direction of the heat transfer tube.

[0222] According to another aspect of the present invention, the height by which the plurality of protrusions protrude from the surface of the heat transfer tube may be greater than the width of the plurality of protrusions formed in the circumferential direction of the heat transfer tube.

[0223] According to another aspect of the present invention, the heat transfer tubes may be disposed in both the evaporator and the absorber.

[0224] According to at least one embodiment of the embodiments of the present invention, the heat transfer tubes may include a plurality of protrusions protruding from the surface, thereby increasing the heat transfer area of the heat transfer tubes. Thus, the heat transfer performance of the heat transfer tubes can be improved.

[0225] According to at least one embodiment of the embodiments of the present invention, it may be configured such that the interval between a plurality of protrusions arranged in the circumferential direction of the heat transfer tube is smaller than the interval between a plurality of protrusions arranged in the length direction of the heat transfer tube, thereby improving the fluidity in the circumferential direction of the heat transfer tube.

[0226] According to at least one embodiment of the embodiments of the present invention, it may be configured such that the width of the first flow path formed in the circumferential direction of the heat transfer tube is greater than the width of the second flow path formed in the length direction of the heat transfer tube, thereby improving the drainage property of the heat transfer tube. Thus, the phenomenon of the absorbent stagnating while flowing along the outer side surface of the heat transfer tube can be reduced.

[0227] According to at least one embodiment of the embodiments of the present invention, a plurality of protrusions arranged in the circumferential direction of the heat transfer tube may be directly connected to each other, thereby minimizing the area of the groove portion formed on the outer side surface of the heat transfer tube. Thus, the film thickness formed on the outer side surface of the heat transfer tube can be made uniform. In addition, the film thickness can be made thinner.

[0228] According to at least one embodiment of the embodiments of the present invention, the plurality of protrusions may include a first inclined surface extending obliquely in the circumferential direction of the heat transfer tube, thereby further improving the fluidity in the circumferential direction of the heat transfer tube.

[0229] According to at least one embodiment of the embodiments of the present invention, the heat transfer tube may include a slit formed between the first inclined surfaces, thereby ensuring the diffusivity in the length direction of the heat transfer tube.

[0230] According to at least one embodiment of the embodiments of the present invention, the plurality of protrusions may include a second inclined surface extending obliquely in the length direction of the heat transfer tube, thereby improving the diffusivity in the length direction of the heat transfer tube.

[0231] According to at least one embodiment of the embodiments of the present invention, the thickness of the heat transfer tube may be in the range of 0.9 times to 1.5 times the width of a plurality of protrusions formed in the circumferential direction of the heat transfer tube, thereby increasing the heat transfer area of the heat transfer tube. In addition, the thickness of the film formed on the outer side surface of the heat transfer tube can be made thinner. Thus, the heat transfer performance of the heat transfer tube can be improved.

[0232] According to at least one embodiment among the embodiments of the present invention, the heat transfer tubes can be applicable to both the evaporator and the absorber, enabling the shape of the heat transfer tubes to be unified, thereby reducing the manufacturing cost. Additionally, an absorption cooling device with improved maintenance management performance can be provided.

[0233] The effects of the present invention are not limited to the effects mentioned above, and those skilled in the art can clearly understand other effects not mentioned based on the description of the scope of the claims.

[0234] Certain embodiments or other embodiments of the present invention described above are not mutually exclusive or different from each other. Any or all of the elements in the embodiments of the present invention described above can be combined with each other or combined in terms of structure or function.

[0235] This means that, for example, component A described in a certain embodiment and / or in the drawings and component B described in another embodiment and / or in the drawings can be combined with each other. That is to say, it means that they can be combined even without directly stating the combination between the components, unless it is stated that they cannot be combined.

[0236] The above detailed description should not be construed restrictively in all aspects and should be regarded as exemplary. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included within the scope of the present invention.

Claims

1. An absorption cooling device, wherein: include: Evaporator, evaporates the refrigerant; an absorber for mixing the refrigerant evaporated in the evaporator with an absorbent to generate an absorption liquid; a regenerator for heating the absorption liquid supplied from the absorber; a condenser to which the refrigerant generated in the regenerator is supplied; as well as The heat transfer tube is arranged in at least one of the evaporator and the absorber and extends long. The heat transfer tube includes a plurality of protrusions, which protrude from the surface of the heat transfer tube and are arranged along the length direction and the circumference direction of the heat transfer tube. The intervals between the plurality of protrusions arranged along the circumferential direction of the heat transfer tube are smaller than the intervals between the plurality of protrusions arranged along the longitudinal direction of the heat transfer tube.

2. The absorption cooling device according to claim 1, wherein: The heat transfer tube comprises: a first flow path formed between a plurality of protrusions spaced apart from each other along a length direction of the heat transfer tube and extending along a circumferential direction of the heat transfer tube; and The second flow path is formed between a plurality of protrusions arranged along the circumferential direction of the heat transfer tube and extends along the longitudinal direction of the heat transfer tube.

3. The absorption cooling device according to claim 2, wherein: The width of the first flow path formed in the longitudinal direction of the heat transfer tube is greater than the width of the second flow path formed in the circumferential direction of the heat transfer tube.

4. The absorption cooling device according to claim 2, wherein: The first flow path extends along a flow direction of liquid flowing on the surface of the heat transfer tube.

5. The absorption cooling device according to claim 2, wherein: A plurality of protrusions adjacent to each other in the circumferential direction of the heat transfer tube are directly connected to each other.

6. The absorption cooling device according to claim 5, wherein: The heat transfer tube further comprises a base tube, the surface of the base tube is formed with the plurality of protrusions, and a fluid flows inside the base tube. The plurality of protrusions include a surface protruding from the base pipe and a first inclined surface connecting one circumferential end of the protruding surface and the base pipe and inclined relative to a radial direction of the heat transfer tube.

7. The absorption cooling device according to claim 6, wherein: The heat transfer pipe includes a slit formed between the first inclined surfaces of the plurality of protrusions adjacent to each other.

8. The absorption cooling device according to claim 6, wherein: The plurality of protrusions include a second inclined surface extending obliquely from the protruding surface toward the first flow path.

9. The absorption cooling device according to claim 8, wherein: A distance between the first inclined surfaces formed in a circumferential direction of the heat transfer tube is shorter than a distance between the second inclined surfaces formed in a longitudinal direction of the heat transfer tube.

10. The absorption cooling device according to claim 1, wherein: The thickness of the heat transfer tube is in a range of 0.9 to 1.5 times the width of the plurality of protrusions formed in the circumferential direction of the heat transfer tube.

Images