Downflow heat exchanger

Abstract

A heat exchanger for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a shell having an inlet configured to receive a refrigerant and an outlet configured to output the refrigerant. The heat exchanger also includes a refrigerant distributor disposed within the shell and a plurality of evaporator tubes disposed within the shell and positioned below the refrigerant distributor. The refrigerant distributor includes a perforated plate having a plurality of holes, each hole extending from a top surface of the perforated plate to a bottom surface of the perforated plate, and a center point of each hole substantially aligned with a centerline of a respective evaporator tube.

Description

[0001] This application is a divisional application of the invention patent application filed on October 20, 2017, with international application number PCT / US2017 / 057680, national application number 201780095892.X, and entitled "Falling Film Heat Exchanger". Background Technology

[0002] This application generally relates to a falling film heat exchanger that can be used in air conditioning and refrigeration applications.

[0003] Vapor compression systems utilize a working fluid, commonly referred to as a refrigerant, which changes phase between vapor, liquid, and combinations thereof in response to varying temperatures and pressures associated with the operation of the vapor compression system. Some vapor compression systems include a falling film heat exchanger (e.g., an evaporator) with a refrigerant distributor configured to distribute the refrigerant to the evaporator tube bundle. For example, some refrigerant distributors include a perforated plate with holes that allow the refrigerant to flow through to the evaporator tubes. Unfortunately, typical perforated plates may not distribute the refrigerant evenly to the evaporator tubes, thus reducing the efficiency of the vapor compression system. Summary of the Invention

[0004] In embodiments of this disclosure, a heat exchanger for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a housing having an inlet configured to receive refrigerant and an outlet configured to discharge the refrigerant. The heat exchanger also includes a refrigerant distributor disposed within the housing; and a plurality of evaporator tubes disposed within the housing and below the refrigerant distributor. The refrigerant distributor includes a perforated plate having a plurality of holes, each hole extending from a top surface of the perforated plate to a bottom surface of the perforated plate, and the center point of each hole being substantially aligned with the centerline of the corresponding evaporator tube.

[0005] In another embodiment of this disclosure, a heat exchanger for an HVAC&R system includes a housing having an inlet configured to receive refrigerant and an outlet configured to discharge the refrigerant. The heat exchanger also includes a refrigerant distributor disposed within the housing; and a plurality of evaporator tubes disposed within the housing and below the refrigerant distributor. The refrigerant distributor includes a perforated plate having a plurality of holes, each extending substantially along a vertical axis, each hole extending from a top surface of the perforated plate to a bottom surface of the perforated plate, and a first portion of the top surface lying above a second portion of the top surface along the vertical axis.

[0006] In another embodiment of this disclosure, a heat exchanger for an HVAC&R system includes a housing having an inlet configured to receive refrigerant and an outlet configured to discharge the refrigerant. The heat exchanger also includes a refrigerant distributor disposed within the housing; and a plurality of evaporator tubes disposed within the housing and below the refrigerant distributor. Each evaporator tube extends along a longitudinal axis. The refrigerant distributor includes a perforated plate having a plurality of holes, each hole extending from a top surface of the perforated plate to a bottom surface of the perforated plate, and the holes are arranged in at least one row. Furthermore, the spacing between adjacent holes in the at least one row varies along the longitudinal axis, and / or the size of adjacent holes in the at least one row varies along the longitudinal axis.

[0007] In another embodiment of this disclosure, a heat exchanger for an HVAC&R system includes a housing having an inlet configured to receive refrigerant and an outlet configured to discharge the refrigerant. The heat exchanger also includes a refrigerant distributor disposed within the housing; and a plurality of evaporator tubes disposed within the housing and below the refrigerant distributor. Each evaporator tube extends along a longitudinal axis. Additionally, the heat exchanger includes a spray manifold disposed within the housing and above the refrigerant distributor. The spray manifold has a plurality of openings configured to discharge the refrigerant toward the refrigerant distributor, and the openings are arranged along a transverse axis substantially perpendicular to the longitudinal axis. Attached Figure Description

[0008] Figure 1 This is a perspective view of an embodiment of a building in a commercial setting that can utilize heating, ventilation, air conditioning and refrigeration (HVAC&R) systems, according to one aspect of this disclosure; Figure 2 It is possible Figure 1 A perspective view of an embodiment of a vapor compression system used in an HVAC&R system; Figure 3 It is possible Figure 1 A schematic diagram of an embodiment of a vapor compression system used in an HVAC&R system; Figure 4 This is a schematic diagram of an embodiment of a falling film evaporator in a vapor compression system, wherein the falling film evaporator includes a refrigerant distributor; Figure 5 It is possible Figure 4 A perspective view of an embodiment of a perforated plate used in a refrigerant distributor; Figure 6 It is possible Figure 4A detailed cross-sectional view of an embodiment of a perforated plate used in a refrigerant distributor; Figure 7 It is possible Figure 4 A top view of an embodiment of a perforated plate used in a refrigerant distributor; Figure 8 It is possible Figure 1 A schematic diagram of a portion of an embodiment of a falling film evaporator used in an HVAC&R system; Figure 9 It is possible Figure 4 A top view of another embodiment of the perforated plate used in a refrigerant distributor; Figure 10 It is possible Figure 4 A top view of yet another embodiment of the perforated plate used in a refrigerant distributor; and Figure 11 It is possible Figure 1 A schematic diagram of a portion of an embodiment of a falling film evaporator used in an HVAC&R system. Detailed Implementation

[0009] Now turn to the attached image. Figure 1 This is a perspective view of an embodiment of a building 12 that can utilize a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system 10 in a commercial setting. The HVAC&R system 10 may include a vapor compression system 14 that supplies a cooling liquid for cooling the building 12. The HVAC&R system 10 may also include a boiler 16 for supplying warm liquid to heat the building 12, and an air distribution system for circulating air through the building 12. The air distribution system may include an air return duct 18, an air supply duct 20, and / or an air handling unit 22. In some embodiments, the air handling unit 22 may include a heat exchanger connected to the boiler 16 and the vapor compression system 14 via a duct 24. The heat exchanger in the air handling unit 22 may receive heated liquid from the boiler 16 or cooled liquid from the vapor compression system 14, depending on the operating mode of the HVAC&R system 10. The HVAC&R system 10 is shown as having separate air handling units on each floor of the building 12; however, in other embodiments, the HVAC&R system 10 may include an air handling unit 22 and / or other components that can be shared between two or more floors.

[0010] Figure 2 It is possible Figure 1 A perspective view of an embodiment of the vapor compression system 14 used in an HVAC&R system, and Figure 3 It is possible Figure 1 A schematic diagram of an embodiment of the vapor compression system 14 used in an HVAC&R system. Figure 2 and Figure 3 The vapor compression system 14 allows refrigerant to circulate through a loop starting from the compressor 32. The loop may also include a condenser 34, (multiple) expansion valves or (multiple) expansion devices 36, and a liquid cooler or evaporator 38. The vapor compression system 14 may further include a control system 40 having an analog-to-digital (A / D) converter 42, a microprocessor 44, a non-volatile memory 46, and / or an interface board 48.

[0011] Some examples of fluids that can be used as refrigerants in the vapor compression system 14 include hydrofluorocarbon (HFC) based refrigerants (e.g., R-410A, R-407, R-134a), hydrofluoroolefins (HFO), “natural” refrigerants (e.g., ammonia (NH3), R-717, carbon dioxide (CO2), R-744, or hydrocarbon-based refrigerants), water vapor, or any other suitable refrigerant. In some embodiments, the vapor compression system 14 may be configured to efficiently utilize a refrigerant having a standard boiling point of about 19 degrees Celsius (66 degrees Fahrenheit) at one atmosphere (as opposed to medium-pressure refrigerants such as R-134a, also known as low-pressure refrigerants). As used herein, “standard boiling point” can refer to the boiling point temperature measured at one atmosphere.

[0012] In some embodiments, the vapor compression system 14 may use one or more of the following: a variable speed drive (VSD) 52, a motor 50, a compressor 32, a condenser 34, an expansion valve or expansion device 36, and / or an evaporator 38. The motor 50 may drive the compressor 32 and may be powered by the VSD 52. The VSD 52 receives AC power with a specific fixed line voltage and fixed line frequency from an alternating current (AC) power source and supplies power with a variable voltage and frequency to the motor 50. In other embodiments, the motor 50 may be directly powered by an AC power source or a direct current (DC) power source. The motor 50 may include any type of electric motor that can be powered by a VSD or directly by an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically rectified permanent magnet motor, or another suitable motor.

[0013] Compressor 32 compresses refrigerant vapor and delivers it to condenser 34 through a discharge passage. In some embodiments, compressor 32 may be a centrifugal compressor. The refrigerant vapor delivered by compressor 32 to condenser 34 can transfer heat to a cooling fluid (e.g., water or air) in condenser 34. Due to heat transfer with the cooling fluid, the refrigerant vapor can condense into liquid refrigerant in condenser 34. The liquid refrigerant from condenser 34 can flow through expansion device 36 to evaporator 38. Figure 3In the illustrated embodiment, the condenser 34 is water-cooled and includes a tube bundle 54 connected to a cooling tower 56, which supplies cooling fluid to the condenser.

[0014] The liquid refrigerant supplied to evaporator 38 can absorb heat from another cooling fluid, which may or may not be the same cooling fluid used in condenser 34. The liquid refrigerant in evaporator 38 may undergo a phase change from liquid refrigerant to refrigerant vapor. For example... Figure 3 As shown in the illustrated embodiment, the evaporator 38 may include a tube bundle 58 having a supply line 60S and a return line 60R connected to the cooling load 62. Cooling fluid (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) enters the evaporator 38 via the return line 60R and exits the evaporator 38 via the supply line 60S. The evaporator 38 may reduce the temperature of the cooling fluid in the tube bundle 58 by heat transfer with the refrigerant. The tube bundle 58 in the evaporator 38 may include multiple tubes and / or multiple tube bundles. In any case, vaporized refrigerant flows out of the evaporator 38 and returns to the compressor 32 via a suction line to complete the cycle.

[0015] Figure 4 This is a schematic diagram of an embodiment of a falling film evaporator 64 (e.g., a falling film heat exchanger) that can be used in a vapor compression system. For example, the falling film evaporator 64 can replace... Figure 2 and Figure 3 The vapor compression system's expansion device and evaporator are used. In the illustrated embodiment, the falling film evaporator 64 includes a housing 66 having an inlet 68 and an outlet 70. The inlet 68 is configured (e.g., via a discharge passage) to be fluidly coupled to the discharge port of the condenser, while the outlet 70 is configured (e.g., via a suction line) to be fluidly coupled to the suction port of the compressor. The inlet 68 is configured to receive refrigerant from the discharge port of the condenser, while the outlet 70 is configured to discharge refrigerant to the suction port of the compressor. In the illustrated embodiment, the housing 66 has a substantially circular cross-section. However, it should be understood that in alternative embodiments, the housing may have other cross-sectional shapes, such as elliptical or polygonal, etc.

[0016] In the illustrated embodiment, the falling film evaporator 64 includes a liquid refrigerant region 74 extending from an inlet 68 to a refrigerant distributor 78 disposed within a housing 66. The liquid refrigerant region 74 is located above the refrigerant distributor 78 along a vertical axis 80, and the evaporator tube 82 is located below the refrigerant distributor 78 along the vertical axis 80. As shown, the evaporator tube 82 is located within the evaporator region 84 of the housing 66. The refrigerant distributor 78 extends along a longitudinal axis 86 and a transverse axis 88. In the illustrated embodiment, the longitudinal axis 86 corresponds to the extension direction of the evaporator tube 82 (e.g., the orientation of the longitudinal axis of the evaporator tube). Therefore, the evaporator tube 82 extends along the longitudinal axis 86.

[0017] During operation of the vapor compression system, liquid refrigerant from the condenser enters the housing 66 through inlet 68. The liquid refrigerant then flows through a refrigerant distributor 78, which distributes liquid refrigerant droplets to the evaporator tubes 82. Contact between the liquid refrigerant droplets and the evaporator tubes 82 causes the droplets to evaporate, thereby absorbing heat from the cooling fluid within the evaporator tubes. This lowers the temperature of the cooling fluid within the evaporator tubes. The vaporized refrigerant flows from the evaporator region 84 to the outlet 70, and then to the compressor's suction port (e.g., via a suction line). The refrigerant distributor 78 also establishes a pressure differential between the liquid refrigerant region 74 and the evaporator region 84 sufficient to promote effective evaporation of the refrigerant in the evaporator region.

[0018] Figure 5 It is possible Figure 4 A perspective view of an embodiment of a perforated plate 90 used in a refrigerant distributor. In the illustrated embodiment, the perforated plate 90 includes a plurality of holes 92. As discussed in detail below, each hole 92 extends from the top surface of the perforated plate 90 to the bottom surface of the perforated plate 90, thereby allowing refrigerant to flow through the perforated plate. The holes can be arranged in any suitable pattern to control the refrigerant flow rate through the perforated plate. Additionally, the size and / or number of holes can be specifically selected to control droplet formation and / or the pressure difference between the liquid refrigerant region and the evaporator region of the falling film evaporator.

[0019] Figure 6 It is possible Figure 4A detailed cross-sectional view of an embodiment of the perforated plate 91 used in the refrigerant distributor 78 is shown. As shown, the perforated plate 91 includes a plurality of holes 92 that facilitate the flow of refrigerant from a liquid refrigerant region to an evaporator region. Each hole 92 extends along a vertical axis 80 from a top surface 94 of the perforated plate 91 to a bottom surface 96 of the perforated plate 91. In the illustrated embodiment, the perforated plate includes a protrusion 98 extending from the bottom surface 96 of the perforated plate 91. As shown, each protrusion 98 is located at the outlet 100 of the corresponding hole 92. The protrusion 98 is configured to cause the refrigerant flowing through the hole 92 to form droplets, which then fall downwards into the evaporator region under the influence of gravity.

[0020] The height 102 of each protrusion 98 can be specifically chosen to establish the target droplet size. Additionally, the profile (e.g., shape) of each protrusion can be specifically configured to establish the target droplet size. For example, in some embodiments, the protrusion may extend around the entire periphery (e.g., circumference) of the orifice outlet. However, in alternative embodiments, the protrusion may extend around a portion of the periphery (e.g., about 5% to about 95%, about 10% to about 91%, about 20% to about 80%, about 30% to about 70%, or about 40% to about 60%, etc.), and / or multiple protrusions may be located at the outlet of at least one orifice. In some embodiments, at least one protrusion may be located at the outlet of each orifice. However, in alternative embodiments, (multiple) protrusions may be located at a portion of the orifice outlet. Furthermore, in some embodiments, the height and / or profile of the protrusions may be substantially the same as each other, or at least a portion of the protrusions may have different heights and / or profiles.

[0021] In some embodiments, holes and protrusions can be formed by a stamping process. For example, during stamping, protrusions of a die can engage a solid plate, thereby displacing material from the solid plate to form a hole. The protrusions can be specifically configured such that the displaced material forms a protrusion on the bottom surface of the plate. For example, the shape and / or configuration of each protrusion can be specifically chosen to form a corresponding protrusion with a target height and / or profile. In some embodiments, among other things, the protrusions can be further shaped by post-stamping processes such as grinding and / or finishing. In other embodiments, the protrusions can be formed separately and attached to the bottom surface of the perforated plate (e.g., by welding, by adhesive bonding, etc.). It should be understood that protrusions may be used in any of the embodiments disclosed herein, or protrusions may be omitted.

[0022] Figure 7 It is possible Figure 4A top view of an embodiment of the perforated plate 93 used in the refrigerant distributor 78. In the illustrated embodiment, holes 92 are arranged in a first row 104 and a second row 106. As shown, the first row 104 is aligned (e.g., substantially aligned) with the corresponding first evaporator tube 108, while the second row 106 is aligned (e.g., substantially aligned) with the corresponding second evaporator tube 108. Additionally, the center point 112 of each hole 92 is aligned (e.g., substantially aligned) with the center line 114 of the corresponding evaporator tube 82. As shown, the center point 112 of each hole 92 in the first row 104 is aligned (e.g., substantially aligned) with the center line 114 of the first evaporator tube 108, while the center point 112 of each hole 92 in the second row 106 is aligned (e.g., substantially aligned) with the center line 114 of the second evaporator tube 110. Because the center point of each hole is aligned (e.g., substantially aligned) with the center line of the corresponding evaporator tube, droplets formed by refrigerant flowing through the holes may impact the center of the tube. Therefore, the amount of liquid refrigerant that bonds with the surface of the corresponding tube can be increased compared to liquid droplets that impact the side of the tube (e.g., off-center), thereby improving the efficiency of the evaporation process.

[0023] As used herein, alignment and substantially alignment refer to alignment within an offset tolerance along the transverse axis 88. For example, the offset tolerance may be between about 0.1 mm and about 5 mm, about 0.2 mm and about 2 mm, or about 0.5 mm and about 1 mm. As a further example, the offset tolerance may be between about 0.5% and about 5%, about 1% and about 4%, or about 2% and about 3% of the transverse extent (e.g., diameter) of the corresponding hole. In the illustrated embodiment, the evaporator tubes and the rows of holes extend along the longitudinal axis 86. However, it should be understood that in alternative embodiments, the evaporator tubes and the rows of holes may be angled relative to the longitudinal axis. Furthermore, although two rows of holes are shown in the illustrated embodiment, it should be understood that the perforated plate may include more or fewer rows of holes (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more). Furthermore, it should be understood that one or more evaporator tubes may be positioned along the transverse axis 88 between adjacent rows of holes. In some embodiments, each row of holes may be aligned with a corresponding evaporator tube in the top row of the evaporator tube bundle (e.g., the row of evaporator tubes closest to the perforated plate positioning). However, it should be understood that in alternative embodiments, one or more rows of holes may be aligned with a corresponding evaporator tube in the lower row of the evaporator tube bundle (e.g., the second row, the third row, etc.). It should be understood that hole / evaporator tube alignment may be used in any of the embodiments disclosed herein, or at least a portion of the holes may not be aligned with the corresponding evaporator tubes.

[0024] Figure 8This is a schematic diagram of a portion of an embodiment of a falling film evaporator 64. In the illustrated embodiment, a plurality of evaporator tubes 82 extend along a longitudinal axis 86. Although three evaporator tubes 82 are shown in the illustrated embodiment, it should be understood that in some embodiments, the falling film evaporator may include more (e.g., significantly more) evaporator tubes. As shown, the evaporator tubes 82 are supported by a pair of tube sheets 116, each tube sheet 116 extending along a vertical axis 80 and a transverse axis 88. Although the illustrated embodiment includes two tube sheets 116, it should be understood that in alternative embodiments, the heat exchanger may include more or fewer tube sheets.

[0025] In the illustrated embodiment, the perforated plate 95 of the refrigerant distributor 78 is positioned above the evaporator tube 82 along a vertical axis 80. The perforated plate 95 includes a plurality of holes 92 configured to facilitate the flow of refrigerant from the liquid refrigerant region 74 to the evaporator region 84. As shown, each hole 92 extends substantially along the vertical axis 80. As used herein, substantially along the vertical axis means an angle of approximately 0 to approximately 45 degrees, approximately 0 to approximately 30 degrees, approximately 0 to approximately 20 degrees, or approximately 0 to approximately 15 degrees relative to the vertical axis 80. In the illustrated embodiment, the perforated plate 95 is curved (e.g., arcuate) to distribute the refrigerant substantially uniformly on the top surface 94 of the perforated plate 95. For example, the refrigerant may be directed to the central region of the perforated plate (e.g., via a refrigerant manifold), and the refrigerant may flow towards the distal ends of the plate under the influence of gravity, thereby distributing the refrigerant substantially uniformly on the perforated plate.

[0026] The perforated plate 95 can be specifically configured to control the flow of refrigerant on the top surface 94. For example, the maximum vertical extent 120 of the perforated plate 95 can be specifically selected at a height 118 along the vertical axis 80 relative to the minimum vertical extent 122 of the perforated plate 95 to control refrigerant distribution. Although the perforated plate 95 forms a single continuous arc in the illustrated embodiment, it should be understood that in alternative embodiments, the perforated plate can be formed into other suitable shapes. For example, in some embodiments, the perforated plate can form a substantially linear segment between the longitudinal center of the perforated plate (e.g., at the maximum vertical extent of the perforated plate) and the distal end of the perforated plate (e.g., at the minimum vertical extent of the perforated plate). Alternatively, the perforated plate can include multiple curved and / or linear segments to establish a desired shape / profile. For example, in embodiments where the refrigerant is guided along the perforated plate to multiple longitudinal locations, the perforated plate can include a peak at each longitudinal location.

[0027] Although the perforated plate 95 shown includes a shaped / formed top surface 94 and a shaped / formed bottom surface 96, it should be understood that in alternative embodiments, the bottom surface of the perforated plate may be substantially flat, and the refrigerant distribution may be controlled by the shape / profile of the top surface. Furthermore, in some embodiments, the shape / profile of the perforated plate (e.g., the shape / profile of the top surface of the perforated plate) may extend along the longitudinal axis and along the transverse axis of the heat exchanger. For example, the perforated plate (e.g., the top surface of the perforated plate) may form an arc along the longitudinal axis and an arc along the transverse axis. Moreover, the shape / profile of the perforated plate along the longitudinal axis (e.g., the shape / profile of the top surface of the perforated plate) may differ from the shape / profile of the perforated plate along the transverse axis (e.g., the shape / profile of the top surface of the perforated plate). For example, the shape / profile of the perforated plate (e.g., the shape / profile of the top surface of the perforated plate) may be substantially constant along one axis (e.g., the transverse axis) and may be arcuate along another axis (e.g., the longitudinal axis). It should be understood that a shaped / formed perforated plate (e.g., a shaped / formed top surface of a perforated plate) may be used in any of the embodiments disclosed herein, or the perforated plate (e.g., a top surface of a perforated plate) may be substantially flat.

[0028] Figure 9 It is possible Figure 4 A top view of another embodiment of the perforated plate 97 used in the refrigerant distributor 78. In the illustrated embodiment, the holes 92 are arranged in five rows, each row extending along a longitudinal axis 86. In some embodiments, each row may be aligned (e.g., substantially aligned) with a corresponding evaporator tube, such that the center point of each hole is aligned (e.g., substantially aligned) with the centerline of the corresponding evaporator tube. Although the holes 92 are arranged in five rows in the illustrated embodiment, it should be understood that in alternative embodiments, the holes may be arranged in more or fewer rows.

[0029] In the illustrated embodiment, the spacing between adjacent holes 92 in each row varies along the longitudinal axis 86. As shown, the spacing between adjacent holes 92 in each row decreases along the longitudinal axis 86 from the central portion 124 of the perforated plate 97 to each distal portion 126. In the illustrated embodiment, each row includes seven holes 92 between the central portion 124 and each distal portion 126. However, it should be understood that in alternative embodiments, each row may include more or fewer holes. As shown, a first spacing 128 along the longitudinal axis 86 between the first hole 130 and the second hole 132 is greater than a second spacing 134 along the longitudinal axis 86 between the second hole 132 and the third hole 136. Additionally, the second spacing 134 is greater than a third spacing 138 along the longitudinal axis 86 between the third hole 136 and the fourth hole 140. Furthermore, the third spacing 138 is greater than a fourth spacing 142 along the longitudinal axis 86 between the fourth hole 140 and the fifth hole 144. The fourth spacing 142 is greater than the fifth spacing 146 along the longitudinal axis 86 between the fifth hole 144 and the sixth hole 148. Furthermore, the fifth spacing 146 is greater than the sixth spacing 150 along the longitudinal axis 86 between the sixth hole 148 and the seventh hole 152. The decreasing spacing along the longitudinal axis between the central portion and each distal portion allows the refrigerant to be distributed substantially uniformly on the top surface of the perforated plate. For example, refrigerant can be directed to the central portion of the perforated plate (e.g., via a refrigerant manifold), and refrigerant can flow to the distal portions of the perforated plate. As the refrigerant flows from the central portion to the distal portions, a portion of the refrigerant can flow through the holes adjacent to the central portion, thereby reducing the amount of refrigerant reaching the distal portions. Therefore, compared to a perforated plate with holes evenly spaced along the longitudinal axis, the wider hole spacing near the central portion causes more refrigerant to flow to the distal portions. Thus, the refrigerant can be distributed substantially uniformly on the perforated plate.

[0030] In the illustrated embodiment, the spacing pattern on the first side 154 of the transverse centerline 156 of the perforated plate 97 is symmetrical to the spacing pattern on the second side 158 of the transverse centerline 156. However, it should be understood that in alternative embodiments, the spacing patterns on both sides of the transverse centerline may be asymmetrical. Furthermore, although the spacing patterns of the rows are substantially identical in the illustrated embodiment, it should be understood that in alternative embodiments, at least one row may have different spacing patterns. Additionally, although the hole spacing decreases along the longitudinal axis between each pair of adjacent holes and between the central portion and each distal portion in the illustrated embodiment, it should be understood that in alternative embodiments, different spacing patterns can be used to control the flow of refrigerant on the perforated plate (e.g., based on guiding the refrigerant to the perforated plate at multiple longitudinal positions). For example, in some embodiments, the hole spacing between certain pairs of adjacent holes in a row may be substantially equal to each other, and / or the hole spacing between certain pairs of adjacent holes in a row may increase along the longitudinal axis between the central portion and at least one distal portion. It should be understood that variations in hole spacing can be utilized in any of the perforated plate embodiments disclosed herein, or at least a portion of the holes within the perforated plate may have substantially equal spacing along the longitudinal axis.

[0031] Figure 10 It is possible Figure 4 A top view of another embodiment of the perforated plate 99 used in the refrigerant distributor 78. In the illustrated embodiment, the holes 92 are arranged in five rows, each row extending along the longitudinal axis 86. In some embodiments, each row may be aligned (e.g., substantially aligned) with a corresponding evaporator tube, such that the center point of each hole is aligned (e.g., substantially aligned) with the centerline of the corresponding evaporator tube. Although the holes 92 are arranged in five rows in the illustrated embodiment, it should be understood that in alternative embodiments, the holes may be arranged in more or fewer rows.

[0032] In the illustrated embodiment, the size of adjacent holes 92 in each row varies along the longitudinal axis 86. As shown, the size of adjacent holes 92 in each row increases along the longitudinal axis 86 from the central portion 124 of the perforated plate 99 to each distal portion 126. In the illustrated embodiment, each row includes six holes 92 between the central portion 124 and each distal portion 126. However, it should be understood that in alternative embodiments, each row may include more or fewer holes. As shown, a first size (e.g., a first diameter 160) of the first hole 162 is smaller than a second size (e.g., a second diameter 164) of the second hole 166. Additionally, a second size (e.g., a second diameter 164) of the second hole 166 is smaller than a third size (e.g., a third diameter 168) of the third hole 170. Furthermore, a third size (e.g., a third diameter 168) of the third hole 170 is smaller than a fourth size (e.g., a fourth diameter 172) of the fourth hole 174. The fourth size (e.g., fourth diameter 172) of the fourth hole 174 is smaller than the fifth size (e.g., fifth diameter 176) of the fifth hole 178. Furthermore, the fifth size (e.g., fifth diameter 176) of the fifth hole 178 is smaller than the sixth size (e.g., sixth diameter 180) of the sixth hole 182. The increasing spacing along the longitudinal axis between the central portion and each distal portion allows the refrigerant to be distributed substantially uniformly on the top surface of the perforated plate. For example, refrigerant can be directed to the central portion of the perforated plate (e.g., via a refrigerant manifold), and refrigerant can flow to the distal portions of the perforated plate. As the refrigerant flows from the central portion to the distal portions, a portion of the refrigerant flows through the holes adjacent to the central portion, thereby reducing the amount of refrigerant reaching the distal portions. Therefore, compared to a perforated plate with holes of equal size along the longitudinal axis, the smaller holes adjacent to the central portion cause more refrigerant to flow to the distal portions. Thus, the refrigerant can be distributed substantially uniformly on the perforated plate.

[0033] In the illustrated embodiment, the hole size pattern on the first side 154 of the transverse centerline 156 of the perforated plate 99 is symmetrical to the hole size pattern on the second side 158 of the transverse centerline 156. However, it should be understood that in alternative embodiments, the hole size patterns on both sides of the transverse centerline may be asymmetrical. Furthermore, although the hole size patterns in the rows are substantially identical to each other in the illustrated embodiment, it should be understood that in alternative embodiments, at least one row may have different hole size patterns. Additionally, although the size of each hole increases along the longitudinal axis between the central portion and each distal portion in the illustrated embodiment, it should be understood that in alternative embodiments, different hole size patterns can be used to control the flow of refrigerant on the perforated plate (e.g., based on the longitudinal positions of the perforated plate to guide the refrigerant). For example, in some embodiments, the sizes of some adjacent holes in a row may be substantially equal to each other, and / or the hole size between some adjacent holes in a row may decrease along the longitudinal axis between the central portion and at least one distal portion. It should be understood that variations in hole size (e.g., variations in hole size can be combined with variations in hole spacing) can be utilized in any of the perforated plate embodiments disclosed herein, or at least a portion of the holes within the perforated plate can have substantially equal hole sizes along the longitudinal axis.

[0034] Figure 11 It is possible Figure 1 This is a schematic diagram of a portion of an embodiment of a falling film evaporator 64 used in an HVAC&R system. In the illustrated embodiment, the falling film evaporator 64 includes a spray manifold 200 located within the housing above a refrigerant distributor 78. The spray manifold 200 is configured to receive refrigerant (e.g., from an inlet in the housing) and direct the refrigerant to the refrigerant distributor 78. In the illustrated embodiment, the spray manifold 200 includes an inlet 202 configured to receive refrigerant, two nozzles 204 configured to output refrigerant toward the refrigerant distributor 78, and a manifold 206 configured to direct refrigerant from the inlet 202 to the nozzles 204. Although the illustrated embodiment includes two spray manifolds, it should be understood that in alternative embodiments, the spray manifold may include more or fewer nozzles (e.g., 1, 2, 3, 4, 5, 6, or more).

[0035] In the illustrated embodiment, the nozzle 204 extends along a transverse axis 88, which is substantially perpendicular to the direction of extension of the evaporator tube 82. As used herein, substantially perpendicular means an angle between the nozzle and the evaporator tube of about 45 degrees to about 135 degrees, about 60 degrees to about 120 degrees, about 75 degrees to about 105 degrees, about 80 degrees to about 100 degrees, or about 90 degrees. Each nozzle includes a plurality of openings distributed along the transverse extent of the nozzle (e.g., such that the openings are arranged along the transverse axis). Each opening is configured to discharge refrigerant toward a refrigerant distributor. Because the openings in the spray manifold are arranged along the transverse axis, the refrigerant can be distributed more uniformly along the transverse axis compared to a heat exchanger having a spray manifold with openings arranged along the longitudinal axis. Furthermore, in some embodiments, the refrigerant distributor may include features configured to distribute refrigerant substantially uniformly along the longitudinal axis, such as a shaped / formed perforated plate, variations in the perforation spacing, variations in the perforation size, or combinations thereof. It should be understood that the above-described spray manifold can be used with any heat exchanger embodiment disclosed herein.

[0036] Although the embodiments disclosed herein are described with reference to falling film evaporators, it should be understood that some of the embodiments disclosed herein (e.g., some embodiments of perforated plates) can be used in other suitable heat exchangers (such as hybrid falling film heat exchangers, e.g., falling film heat exchangers where the condenser tubes are located above the perforated plate)). Furthermore, although the refrigerant distributor disclosed herein comprises a single perforated plate, it should be understood that in alternative embodiments, the refrigerant distributor may comprise multiple perforated plates (e.g., additional perforated plates substantially parallel to the perforated plates disclosed herein). Additionally, although the perforated plates disclosed herein comprise substantially circular holes, it should be understood that in alternative embodiments, the holes in the perforated plates may have other suitable shapes, such as elliptical or polygonal.

[0037] Although only certain features and embodiments have been shown and described, many modifications and variations will occur to those skilled in the art (e.g., variations in the size, shape, and proportion of various elements, values ​​of parameters (e.g., temperature, pressure, etc.), installation arrangements, use of materials, color, orientation, etc.) without substantially departing from the novelty teachings and advantages of the subject matter of the claims. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. Therefore, it should be understood that the appended claims are not intended to cover all such modifications and variations as falling within the true spirit of this disclosure. Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual implementations (i.e., features unrelated to the currently conceived best mode of carrying out this disclosure, or features unrelated to achieving the claimed disclosure) may not be described. It should be understood that in the development of any such actual implementation (as in any engineering or design scheme), numerous implementation-specific decisions must be made. Such development work may be complex and time-consuming, but it remains routine design, production, and manufacturing work for those of ordinary skill who benefit from this disclosure without requiring excessive experimentation.

Claims

1. A heat exchanger for a heating, ventilation, air conditioning and refrigeration (HVAC&R) system, comprising: A housing having an inlet configured to receive refrigerant and an outlet configured to discharge the refrigerant; A refrigerant distributor, wherein the refrigerant distributor is disposed within the housing; A spray manifold, which is disposed within the housing and located above the refrigerant distributor; as well as A plurality of evaporator tubes are disposed within the housing and below the refrigerant distributor, wherein each of the plurality of evaporator tubes extends along a longitudinal axis. The refrigerant distributor includes a perforated plate with a plurality of holes, each of which extends from the top surface of the perforated plate through the thickness of the perforated plate to the bottom surface of the perforated plate. The plurality of holes are arranged in at least one row and configured to drip the refrigerant directly from the bottom surface onto the plurality of evaporator tubes. The spray manifold has multiple openings configured to direct the refrigerant toward the refrigerant distributor. These openings are arranged along a transverse axis substantially perpendicular to the longitudinal axis. The spray manifold includes: A first nozzle, extending along the transverse axis and having a first portion of the plurality of openings, wherein the first portion of the plurality of openings is arranged along the transverse axis and configured to directly spray the refrigerant onto the top surface of the perforated plate; and A second nozzle, extending along the transverse axis and having a second portion of the plurality of openings, wherein the second portion of the plurality of openings is arranged along the transverse axis and configured to spray the refrigerant directly onto the top surface of the perforated plate. Wherein, the first nozzle and the second nozzle are offset from the center portion of the perforated plate along the longitudinal axis, and wherein the first nozzle and the second nozzle are configured to spray the refrigerant toward the center portion of the perforated plate, and Wherein, the spacing between adjacent holes in the at least one row decreases along the longitudinal axis from the center portion of the perforated plate to the distal portion of the perforated plate, and the size of the adjacent holes in the at least one row increases along the longitudinal axis from the center portion of the perforated plate to the distal portion of the perforated plate, or a combination thereof.

2. The heat exchanger according to claim 1, wherein, At least a portion of the plurality of holes are arranged in a first row, the first row being substantially aligned with a corresponding first evaporator tube among the plurality of evaporator tubes, and the center point of each hole in the first row being substantially aligned with the centerline of the corresponding first evaporator tube.

3. The heat exchanger according to claim 2, wherein, Another portion of the plurality of holes is arranged in a second row, the second row being substantially aligned with the corresponding second evaporator tube among the plurality of evaporator tubes, and the center point of each hole in the second row being substantially aligned with the center line of the corresponding second evaporator tube.

4. The heat exchanger according to claim 1, wherein, At the outlet of one of the plurality of holes, a protrusion extends from the bottom surface of the perforated plate toward the plurality of evaporation tubes; and / or Each of the plurality of holes extends from the top surface of the perforated plate to the bottom surface of the perforated plate at an angle of 0 to 45 degrees relative to the vertical axis.

5. The heat exchanger according to claim 1, wherein, Each of the plurality of holes extends substantially along a vertical axis, and a first portion of the perforated plate is located above a second portion of the perforated plate along the vertical axis.

6. The heat exchanger according to claim 5, wherein, The first portion of the perforated plate includes the central portion of the perforated plate, and the second portion of the perforated plate includes the distal portion of the perforated plate.

7. A heat exchanger for a heating, ventilation, air conditioning and refrigeration (HVAC&R) system, comprising: A housing having an inlet configured to receive refrigerant and an outlet configured to discharge the refrigerant; A refrigerant distributor, wherein the refrigerant distributor is disposed within the housing; as well as A plurality of evaporator tubes are disposed within the housing and below the refrigerant distributor, wherein each of the plurality of evaporator tubes extends along a longitudinal axis, and wherein the refrigerant distributor includes a perforated plate configured to drip refrigerant onto the plurality of evaporator tubes; as well as A spray manifold, disposed within the housing and above the refrigerant distributor, wherein the spray manifold has a plurality of openings configured to output the refrigerant toward the refrigerant distributor, the plurality of openings being arranged along a transverse axis substantially perpendicular to the longitudinal axis, and the spray manifold comprising: A first nozzle extends along the transverse axis and has a first portion of the plurality of openings, wherein the first portion of the plurality of openings is arranged along the transverse axis and configured to spray the refrigerant directly onto the top surface of the perforated plate. as well as A second nozzle, extending along the transverse axis and having a second portion of the plurality of openings, wherein the second portion of the plurality of openings is arranged along the transverse axis and configured to spray the refrigerant directly onto the top surface of the perforated plate. The first nozzle and the second nozzle are offset from the center portion of the perforated plate along the longitudinal axis, and the first nozzle and the second nozzle are configured to spray the refrigerant toward the center portion of the perforated plate.

8. The heat exchanger according to claim 7, wherein, The first nozzle and the second nozzle are separated from each other along the longitudinal axis; and / or The perforated plate includes a plurality of holes, and each of the plurality of holes extends from the top surface of the perforated plate to the bottom surface of the perforated plate; The center point of each of the plurality of holes is substantially aligned with the center line of the corresponding evaporator tube in the plurality of evaporator tubes; The plurality of holes are arranged in at least one row, the spacing between adjacent pairs of holes in the at least one row varies along the longitudinal axis, the size of adjacent holes in the at least one row varies along the longitudinal axis, or a combination thereof.

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