CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from and the benefit of U.S. Provisional Application No. 63/351,711, entitled “PRE-SUBCOOLER FOR A CONDENSER,” filed June 13, 2022, which is herein incorporated by reference in its entirety for all purposes.

BACKGROUND

[0002] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0003] Chiller systems, or vapor compression systems, utilize a working fluid (e.g., a refrigerant) that changes phases between vapor, liquid, and combinations thereof, in response to exposure to different temperatures and pressures within components of the chiller system. A chiller system may place the working fluid in a heat exchange relationship with a conditioning fluid (e.g., water) and may deliver the conditioning fluid to conditioning equipment and/or to a conditioned environment serviced by the chiller system. In such applications, the conditioning fluid may be passed through downstream equipment, such as air handlers, to condition other fluids, such as air in a building.

[0004] Traditional chiller systems include a refrigerant circuit having, for example, a compressor, a condenser, and an evaporator. In some condensers, one or more tube bundles may be positioned in a shell or housing of the condenser. Refrigerant vapor may be directed into the shell, and a cooling fluid may be circulated through tubes of the tube bundle to enable heat transfer from the refrigerant to the cooling fluid. The transfer or exchange of heat between the refrigerant vapor and the cooling fluid may cause the refrigerant vapor to condense or change into a liquid phase. Before the refrigerant liquid is discharged from the condenser, the refrigerant liquid may be further cooled (e.g., subcooled) by cooling fluid circulated through an additional tube bundle, which may be referred to as a subcooler, positioned within the shell of the condenser to transfer additional heat from the condensed refrigerant liquid to the cooling fluid. Unfortunately, heat transfer efficiencies of existing condenser designs may be limited.

SUMMARY

[0005] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a bnef summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

[0006] In one embodiment, a condenser of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a shell configured to receive vapor heat transfer fluid and a condensing section. A first plurality of heat exchange tubes is configured to place the vapor heat transfer fluid in a heat exchange relationship with cooling fluid to produce liquid heat transfer fluid. The condenser includes a subcooling section having a second plurality of heat exchange tubes extending within the shell, where the second plurality of heat exchange tubes is configured to place the liquid heat transfer fluid in a heat exchange relationship with cooling fluid to subcool the liquid heat transfer fluid. The condenser includes a pre-subcooler disposed in the condensing section, where the pre-subcooler includes a trough configured to collect a portion of the liquid heat transfer fluid and direct the portion of the liquid heat transfer fluid to the subcooling section.

[0007] In another embodiment, a method includes directing vapor heat transfer fluid across a first plurality of heat exchange tubes of a condensing section of a condenser to place the vapor heat transfer fluid in a heat exchange relationship with cooling fluid directed through the first plurality of heat exchange tubes. The first plurality of heat exchange tubes is configured to condense the vapor heat transfer fluid to produce liquid heat transfer fluid. The method includes directing the liquid heat transfer fluid across a second plurality of heat exchange tubes of a subcooling section of the condenser to place the liquid heat transfer fluid in a heat exchange relationship with cooling fluid directed through the second plurality of heat exchange tubes, where the second plurality of heat exchange tubes is configured to subcool the liquid heat transfer fluid. The method includes collecting, via a pre-subcooler disposed in the condensing section, a portion of the liquid heat transfer fluid condensed by a first tube bundle of the first plurality of heat exchange tubes. The method includes directing the portion of the liquid heat transfer fluid from the pre-subcooler toward longitudinal ends of a second tube bundle of the first plurality of heat exchange tubes.

[0008] In another embodiment, a condenser of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a shell configured to receive vapor heat transfer fluid. The condenser includes a condensing section having a first tube bundle and a second tube bundle extending within the shell, where the first tube bundle and the second tube bundle are configured to place the vapor heat transfer fluid in a heat exchange relationship with cooling fluid to produce liquid heat transfer fluid from the vapor heat transfer fluid. The condenser includes a pre-subcooler disposed between the first tube bundle and the second tube bundle, where the pre-subcooler includes a trough configured to collect a portion of the liquid heat transfer fluid produced by the first tube bundle. The condenser includes a subcooling section having a plurality of heat exchange tubes extending within the shell, where the pre-subcooler is configured to direct the portion of the liquid heat transfer fluid to the subcooling section. The plurality of heat exchange tubes is configured to place the portion of the liquid heat transfer fluid in a heat exchange relationship with cooling fluid directed through the plurality of heat exchange tubes to subcool the portion of the liquid heat transfer fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:

[0010] FIG. 1 is a perspective view of a building that may utilize an embodiment of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system in a commercial setting, in accordance with an aspect of the present disclosure;

[0011] FIG. 2 is a perspective view of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure; [0012] FIG. 3 is a schematic diagram of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure;

[0013] FIG. 4 is a schematic diagram of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure;

[0014] FIG. 5 is a schematic cross-sectional side view of an embodiment of a condenser including a pre-subcooler, in accordance with an aspect of the present disclosure;

[0015] FIG. 6 is a cross-sectional axial view of an embodiment of a condenser including a pre-subcooler, in accordance with an aspect of the present disclosure;

[0016] FIG. 7 is a cross-sectional axial view of an embodiment of a condenser including a pre-subcooler, in accordance with an aspect of the present disclosure; and

[0017] FIG. 8 is a schematic cross-sectional side view of an embodiment of a condenser including a pre-subcooler, in accordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

[0018] One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0019] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0020] As used herein, the terms “approximately,” “generally,” “substantially,” and so forth, are intended to convey that the property value being described may be within a relatively small range of the property value, as those of ordinary skill would understand. For example, when a property value is described as being “approximately” equal to (or, for example, “substantially similar” to) a given value, this is intended to convey that the property value may be within +/- 5%, within +/- 4%, within +/- 3%, within +/- 2%, within +/- 1%, or even closer, of the given value. Similarly, when a given feature is described as being “substantially parallel” to another feature, “generally perpendicular” to another feature, and so forth, this is intended to convey that the given feature is within +/- 5%, within +/- 4%, within +/- 3%, within +/- 2%, within +/- 1%, or even closer, to having the described nature, such as being parallel to another feature, being perpendicular to another feature, and so forth. Mathematical terms, such as “parallel” and “perpendicular,” should not be rigidly interpreted in a strict mathematical sense, but should instead be interpreted as one of ordinary skill in the art would interpret such terms. For example, one of ordinary skill in the art would understand that two lines that are substantially parallel to each other are parallel to a substantial degree, but may have minor deviation from exactly parallel.

[0021] Embodiments of the present disclosure relate to a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, such as a chiller system. The HVAC&R system may include a vapor compression system (e.g., vapor compression circuit) through which a heat transfer fluid (e.g., a working fluid), such as a refrigerant, is directed in order to heat and/or cool a conditioning fluid. As an example, the vapor compression system may include a compressor configured to pressurize the heat transfer fluid and to direct the pressurized heat transfer fluid to a condenser configured to cool and condense the pressurized heat transfer fluid. An evaporator of the vapor compression system may receive the cooled, condensed heat transfer fluid and may place the cooled, condensed heat transfer fluid in a heat exchange relationship with the conditioning fluid to absorb thermal energy or heat from the conditioning fluid, thereby cooling the conditioning fluid. The cooled conditioning fluid may then be directed to conditioning equipment, such as air handlers and/or terminal units, for use in conditioning air supplied to a building or other conditioned space.

[0022] In general, the condenser is configured to cool the pressurized heat transfer fluid by placing the pressurized heat transfer fluid in a heat exchange relationship with a cooling fluid, such as air, water, brine, or other fluid. For example, the condenser may have a shell or housing defining an inner volume configured to receive the pressurized heat transfer fluid from the compressor, and the condenser may include a plurality of tubes (e.g., one or more tube bundles, condensing tubes) disposed within the inner volume of the shell. The plurality of tubes is configured to circulate the cooling fluid (e.g., water or brine) through the plurality of tubes to enable heat transfer from the pressurized heat transfer fluid to the cooling fluid.

[0023] In some embodiments, the condenser may include a subcooler configured to further cool (e.g., subcool) the heat transfer fluid once it has condensed within the condenser (e g., via heat exchange with the cooling fluid directed through the plurality of tubes). For example, the condenser may include an additional plurality of tubes (e.g., an additional tube bundle, subcooling tubes) disposed within the shell and configured to circulate cooling fluid to further cool the heat transfer fluid. Unfortunately, existing condenser designs may be susceptible to inefficiencies. For example, as vapor heat transfer fluid flows across the condensing tubes within the condenser, the vapor heat transfer fluid may condense into liquid heat transfer fluid, and a film of the liquid heat transfer fluid may form on one or more of the condensing tubes. As liquid film (e.g., heat transfer fluid liquid film, refrigerant liquid film) forms on the tubes and/or resides on the tubes, a heat transfer efficiency of the condenser may be reduced. That is, a heat transfer rate between the cooling fluid within the tubes of the condenser and the heat transfer fluid within the condenser may be reduced.

[0024] Accordingly, present embodiments are directed to a system and method configured to reduce formation of liquid film on condensing tubes of a condenser, which may improve a heat transfer rate and/or heat transfer efficiency of the condenser. In particular, the present embodiments include a pre-subcooler positioned within a condensing section of the condenser. The pre-subcooler is configured to collect heat transfer fluid liquid that forms from heat transfer fluid vapor within the condensing section and is configured to direct the liquid heat transfer fluid to a subcooler of the condenser. In this way, the pre-subcooler may block flow of liquid heat transfer fluid to one or more condensing tubes in the condensing section (e.g., downstream of the presubcooler, relative to a direction of heat transfer fluid flow; beneath the pre-subcooler, relative to a direction of gravity), thereby blocking formation or collection of a liquid heat transfer fluid film on the condensing section. As a result, the condensing tubes downstream of the pre-subcooler may benefit from improved heat transfer with vapor heat transfer fluid directed thereacross.

[0025] The pre-subcooler may include a trough extending longitudinally along the condenser and within the condensing section. The trough may include a sheet or panel and flanges extending from lateral sides (e.g., edges) of the sheet. The trough may define a basin configured to collect liquid heat transfer fluid that is formed as vapor heat transfer fluid condenses within the condensing section. Further, one or more tubes within the condensing section, which may be referred to as pre-subcooler tubes, may extend within the basin of the trough. Thus, liquid heat transfer fluid collected within the basin may be further cooled or subcooled via cooling fluid directed through the presubcooler tubes. The liquid heat transfer fluid collected within the basin of the trough may flow toward longitudinal ends of the trough (e.g., via gravity) and may flow out of the trough towards the subcooler of the condenser. The flanges of the trough (e.g., a first flange and a second flange of the trough) may retain the condensed heat transfer fluid and direct the condensed heat transfer fluid toward longitudinal ends of the presubcooler. As described in detail below, tubes of the condensing section disposed beneath the pre-subcooler (e.g., relative to gravity) may receive a reduced amount of condensed (e.g., liquid) heat transfer fluid from the condensing tubes disposed above the pre-subcooler. Accordingly, contact between remaining heat transfer fluid vapor within the condenser and the condensing tubes disposed beneath the pre-subcooler may be improved (e.g., due to reduced liquid film formed or residing on the condensing tubes), thereby improving heat transfer efficiency of the condenser. In this way, the pre-subcooler of the present disclosure improves efficiency of the condenser and the HVAC&R system. [0026] Turning now to the drawings, FIG. 1 is a perspective view of an embodiment of an environment for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system 10 in a building 12 for a typical commercial setting. The HVAC&R system 10 may include a vapor compression system 14 that supplies a chilled liquid, which may be used to cool the building 12. The HVAC&R system 10 may also include a boiler 16 to supply warm liquid to heat the building 12 and an air distribution system which circulates air through the building 12. The air distribution system can also include an air return duct 18, an air supply duct 20, and/or an air handler 22. In some embodiments, the air handler 22 may include a heat exchanger that is connected to the boiler 16 and the vapor compression system 14 by conduits 24. The heat exchanger in the air handler 22 may receive either heated liquid from the boiler 16 or chilled liquid from the vapor compression system 14, depending on the mode of operation of the HVAC&R system 10. The HVAC&R system 10 is shown with a separate air handler on each floor of building 12, but in other embodiments, the HVAC&R system 10 may include air handlers 22 and/or other components that may be shared between or among floors.

[0027] FIGS. 2 and 3 illustrate embodiments of the vapor compression system 14 that can be used in the HVAC&R system 10. The vapor compression system 14 may circulate a heat transfer fluid (e.g., a refrigerant) through a circuit starting with a compressor 32. The circuit may also include a condenser 34, an expansion valve(s) or device(s) 36, and a liquid chiller or an evaporator 38. The vapor compression system 14 may further include a control panel 40 (e g., controller) that has an analog to digital (A/D) converter 42, a microprocessor 44, a non-volatile memory 46, and/or an interface board 48.

[0028] In some embodiments, the vapor compression system 14 may use one or more of a variable speed drive (VSDs) 52, a motor 50, the compressor 32, the condenser 34, the expansion valve or device 36, and/or the evaporator 38. The motor 50 may drive the compressor 32 and may be powered by a variable speed drive (VSD) 52. The VSD 52 receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor 50. In other embodiments, the motor 50 may be powered directly from an AC or direct current (DC) power source. The motor 50 may include any type of electric motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.

[0029] The compressor 32 compresses a heat transfer fluid vapor and delivers the vapor to the condenser 34 through a discharge passage. In some embodiments, the compressor 32 may be a centrifugal compressor. The heat transfer fluid vapor delivered by the compressor 32 to the condenser 34 may transfer heat to a cooling fluid (e.g., water or air) in the condenser 34. The heat transfer fluid vapor may condense to a heat transfer fluid liquid in the condenser 34 as a result of thermal heat transfer with the cooling fluid. The heat transfer fluid liquid from the condenser 34 may flow through the expansion device 36 to the evaporator 38. In the illustrated embodiment of FIG. 3, the condenser 34 is water cooled and includes a tube bundle 54 connected to a cooling tower 56, which supplies the cooling fluid to the condenser.

[0030] The heat transfer fluid liquid delivered to the evaporator 38 may absorb heat from another cooling fluid, which may or may not be the same cooling fluid used in the condenser 34. The heat transfer fluid liquid in the evaporator 38 may undergo a phase change from the heat transfer fluid liquid to a heat transfer fluid vapor. As shown in the illustrated embodiment of FIG. 3, the evaporator 38 may include a tube bundle 58 having a supply line 60S and a return line 60R connected to a cooling load 62. The cooling fluid of the evaporator 38 (e g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) enters the evaporator 38 via return line 60R and exits the evaporator 38 via supply line 60S. The evaporator 38 may reduce the temperature of the cooling fluid in the tube bundle 58 via thermal heat transfer with the heat transfer fluid. The tube bundle 58 in the evaporator 38 can include a plurality of tubes and/or a plurality of tube bundles. In any case, the heat transfer fluid vapor exits the evaporator 38 and returns to the compressor 32 by a suction line to complete the cycle.

[0031] FIG. 4 is a schematic of the vapor compression system 14 with an intermediate circuit 64 incorporated between condenser 34 and the expansion device 36. The intermediate circuit 64 may have an inlet line 68 that is directly fluidly connected to the condenser 34. In other embodiments, the inlet line 68 may be indirectly fluidly coupled to the condenser 34. As shown in the illustrated embodiment of FIG. 4, the inlet line 68 includes a first expansion device 66 positioned upstream of an intermediate vessel 70. In some embodiments, the intermediate vessel 70 may be a flash tank (e.g., a flash intercooler). In other embodiments, the intermediate vessel 70 may be configured as a heat exchanger or a “surface economizer.” In the illustrated embodiment of FIG. 4, the intermediate vessel 70 is used as a flash tank, and the first expansion device 66 is configured to lower the pressure of (e.g., expand) the liquid heat transfer fluid received from the condenser 34. During the expansion process, a portion of the liquid may vaporize, and thus, the intermediate vessel 70 may be used to separate the vapor from the liquid received from the first expansion device 66.

[0032] Additionally, the intermediate vessel 70 may provide for further expansion of the liquid heat transfer fluid because of a pressure drop experienced by the liquid heat transfer fluid when entering the intermediate vessel 70 (e.g., due to a rapid increase in volume experienced when entering the intermediate vessel 70). The vapor in the intermediate vessel 70 may be drawn by the compressor 32 through a suction line 74 of the compressor 32. In other embodiments, the vapor in the intermediate vessel may be drawn to an intermediate stage of the compressor 32 (e.g., not the suction stage). The liquid that collects in the intermediate vessel 70 may be at a lower enthalpy than the liquid heat transfer fluid exiting the condenser 34 due to expansion in the expansion device 66 and/or the intermediate vessel 70. The liquid from intermediate vessel 70 may then flow in line 72 through a second expansion device 36 to the evaporator 38.

[0033] It should be appreciated that any of the features described herein may be incorporated with the vapor compression system 14 or any other suitable HVAC&R system. As mentioned above, embodiments of the present disclosure are directed to a pre-subcooler that may be utilized with the condenser 34 of the vapor compression system 14. The pre-subcooler may be disposed within a condensing section of the condenser 34 that is configured to condense vapor heat transfer fluid received by the condenser 34. As described in further detail below, the pre-subcooler may be configured to collect liquid heat transfer fluid that forms within the condensing section and direct the liquid heat transfer fluid toward a subcooler of the condenser 34. In some embodiments, the pre-subcooler may also subcool the collected liquid heat transfer fluid. The pre-subcooler enables improved heat transfer between tubes in the condensing section and vapor heat transfer fluid by enabling reduced formation of liquid film (e.g., liquid heat transfer fluid film) on the tubes.

[0034] FIG. 5 is a schematic cross-sectional side view of an embodiment of a condenser 100 in accordance with aspects of the present disclosure. The condenser 100 may be an embodiment of the condenser 34 of the vapor compression system 14 described above. The condenser 100 includes a shell 102 that defines an inner volume 104 and separates the inner volume 104 from an exterior environment 106. In some embodiments, the shell 102 may be formed from a metal and may have a generally cylindrical shape. As indicated by arrow 108, the condenser 100 (e.g., the shell 102) is configured to receive a heat transfer fluid (e.g., vapor heat transfer fluid, refrigerant vapor) circulated through the vapor compression system 14. The condenser 100 may place the heat transfer fluid in a heat exchange relationship with a cooling fluid (e.g., water, brine). For example, the condenser 100 may include a plurality of heat exchange tubes 110 configured to direct the cooling fluid therethrough, and the heat transfer fluid within the condenser 100 may flow across the heat exchange tubes 110 and transfer heat to the cooling fluid. As discussed further below, the heat exchange tubes 110 may be grouped in one or more tube bundles and/or one or more sections. For example, the condenser 100 may define a condensing section having corresponding heat exchange tubes 110 configured to condense vapor heat transfer fluid received by the condenser 100 to form liquid heat transfer fluid. The condenser 100 may also define a subcooling section (e.g., a subcooler) having corresponding heat exchange tubes 110 configured to further cool or subcool the liquid heat transfer fluid formed in the condenser 100.

[0035] As mentioned above, the heat exchange tubes 110 are configured to direct a cooling fluid through the condenser 100. In the illustrated embodiment, the condenser 100 is a multi-pass heat exchanger and is configured to direct the cooling fluid therethrough along multiple passes (e.g., arranged in series with one another). In particular, the condenser 100 defines a first pass 112, which may include a first subset of the heat exchange tubes 110, and a second pass 114, which may include a second subset of the heat exchange tubes 110. Thus, at least a portion of the heat transfer fluid may be directed across the heat exchanges tubes 110 of the second pass 114 and then be directed across the heat exchange tubes 110 of the first pass 112 before the heat transfer fluid is discharged from the condenser 100 as indicated by arrow 116. [0036] In operation, the condenser 100 may receive a flow of the cooling fluid, as indicated by arrow 118. The cooling fluid may enter the condenser 100 via a first cooling fluid section 120 (e.g., cooling fluid box, water box). The first cooling fluid section 120 is divided into an inlet section 122 and an outlet section 124 that are separated (e.g., fluidly separated) by a divider plate 126. The cooling fluid may be directed into the inlet section 122 and may then be directed into the heat exchange tubes 110 of the first pass 112, as indicated by arrow 128. The heat exchange tubes 110 of the first pass 112 may include condensing tubes and subcooling tubes, as described further below. The cooling fluid may travel through the heat exchange tubes 110 of the first pass 112 (e.g., along a length 130 of the condenser 100) and may be discharged into a second cooling fluid section 132 disposed at an end of the condenser 100 opposite the first cooling fluid section 120. The second cooling fluid section 132 may direct the cooling fluid (e.g., a first flow of cooling fluid) into the heat exchange tubes 110 associated with the second pass 114, as indicated by arrow 134. At least a portion of the heat exchange tubes 110 associated with the second pass 114 may be condensing tubes. The cooling fluid may flow into the heat exchange tubes 110 of the second pass 114 and into the outlet section 124 of the first cooling fluid section 120, as indicated by arrow 136, and may then be discharged from the first cooling fluid section 120 and the condenser 100, as indicated by arrow 138. As such, the cooling fluid may flow sequentially through the first pass 112 and the second pass 114.

[0037] As mentioned above, vapor heat transfer fluid (e.g., gaseous heat transfer fluid) may be directed into the shell 102 of the condenser 100. The vapor heat transfer fluid first flows across heat exchange tubes 110 of the second pass 114. As the vapor heat transfer fluid contacts heat exchange tubes 110 of the second pass 114, heat is transferred from the cooling fluid within the heat exchange tubes 110 to the vapor heat transfer fluid, which causes the vapor heat transfer fluid to condense and form liquid heat transfer fluid. In some instances, as the heat transfer fluid continues to flow across the heat exchange tubes 110 of the second pass 114, and thereafter flow across the heat exchange tubes 110 of the first pass 112, condensed liquid heat transfer fluid may form a liquid film on one or more of the heat exchange tubes 110 (e.g., of the second pass 114, the first pass 112, or both). Unfortunately, formation and/or accumulation of liquid film (e.g., liquid heat transfer fluid film) on the heat exchange tubes 110 may reduce heat transfer efficiency between the heat exchange tubes 110 and the heat transfer fluid. [0038] Accordingly, present embodiments of the condenser 100 include a presubcooler 140 configured to enable a reduction in liquid film (e.g., condensed, liquid heat transfer fluid) formed on heat exchange tubes 110 within the condenser 100. In the illustrated embodiment, the pre-subcooler 140 is positioned at least partially within the second pass 114 and/or at least partially within a region 142 (e.g., gap, space) extending between (e.g., vertically between) the first pass 112 and the second pass 114 (e.g., a region without heat exchange tubes 110). The pre-subcooler 140 includes a trough 144 configured to collect condensed, liquid heat transfer fluid formed via heat exchange with the heat exchange tubes 110 of the second pass 114. As described further below, the trough 144 may include a sheet or panel (e.g., horizontal sheet) extending along the length 130 of the condenser 100 (e.g., along the second pass 114) and lateral sides or segments (e.g., vertical segments) extending from edges of the panel and along the length of the condenser 100. In some embodiments, the trough 144 may be formed from a solid (e.g., non-perforated) piece of material. The trough 144 may extend substantially horizontally (e.g., with respect to gravity) along the length 130 of the condenser 100 and/or along a width (e.g., a dimension extending cross-wise to the length 130) of the condenser 100. That is, a plane formed by a panel (e.g., a lower panel, with respect to a direction of gravity) of the trough 144 may include a slope (e.g., with respect to gravity) that is substantially negligible (e.g., less than 5 degrees, less than 1 degree) along the length 130 of the condenser 100 and/or along the width of the condenser 100.

[0039] Liquid heat transfer fluid collected within the trough 144 may flow (e.g., via force of gravity) towards longitudinal ends 146 of the pre-subcooler 140, as indicated by arrows 148. That is, as liquid heat transfer fluid accumulates within the relatively horizontal basin formed by the trough 144, gravity may naturally force the heat transfer fluid toward the longitudinal ends 146 of the trough 144. The longitudinal ends 146 may enable the heat transfer fluid to flow therethrough (e.g., via one or more openings formed in the longitudinal ends 146). As such, at the longitudinal ends 146, the liquid heat transfer fluid may flow out of the trough 144 (e.g., in a vertically downward direction) toward the first pass 112 (e.g., toward a subcooler of the condenser 100). In this way, the liquid heat transfer fluid collected within the trough 144 may not flow across one or more heat exchange tubes 110 of the first pass 112 and/or may not flow across a substantial portion of the heat exchange tubes 110 of the first pass 112. Thus, liquid film may not form on heat exchange tubes 1 10 of the first pass 1 12, which may improve heat transfer efficiency of the heat exchange tubes 110 of the first pass 112 and the condenser 100 generally.

[0040] In some embodiments, the longitudinal ends 146 may be configured to retain a threshold level of heat transfer fluid within the trough 144 during operation of the condenser 100. For example, the longitudinal ends 146 may be configured to block flow of heat transfer fluid from a basin of the trough 144 toward the first pass 112 until a threshold quantity (e.g., a threshold level) of heat transfer fluid has accumulated within the trough 144. The longitudinal ends 146 may be configured (e.g., via openings formed therein, by having a designed height) to allow heat transfer fluid (e.g., liquid heat transfer fluid) to flow out of the trough 144 (e.g., from the trough 144 to the first pass 112) once the level of heat transfer fluid within the trough 144 exceeds the threshold quantity. As such, the longitudinal ends 146 may ensure that tubes (e.g., presubcooler tubes) within the trough 144 remain submerged (e.g., partially submerged, fully submerged) in heat transfer fluid within the trough 144 during operation of the condenser 100 to facilitate heat exchange with and subcooling of the heat transfer fluid within the trough 144.

[0041] It should be understood that, in certain embodiments, the trough 144 may include a slope configured to direct heat transfer fluid that may be accumulated within the trough 144 toward one of the longitudinal ends 146. In other embodiments, a first portion of the trough 144 may include a first slope configured to direct heat transfer fluid accumulated within the first portion of the trough 144 toward one of the longitudinal ends 146, while a second portion (e.g., a remaining portion) of the trough 144 may include a second slope configured to direct heat transfer fluid accumulated within the second portion of the trough 144 toward an opposing one of the longitudinal ends 146.

[0042] As described further below, one or more heat exchange tubes 110 of the second pass 114 may extend within the trough 144 (e g., within a basin of the trough 144). Thus, liquid heat transfer fluid collected within the trough 144 may be placed in a heat exchange relationship with the heat exchange tubes 110 extending within the trough 144. To enable subcooling of the liquid heat transfer fluid within the trough 144, the heat exchange tubes 110 extending within the trough 144 may not receive the cooling fluid directed through remaining heat exchange tubes 1 10 of the second pass 114. Instead, cooling fluid from the inlet section 122 of the first cooling fluid section 120 may be directed to the heat exchange tubes 110 extending within the trough 144 (e.g., without first being directed through the first pass 112 or the second pass 114).

[0043] For example, the condenser 100 may include a conduit 150 (e.g., pipe, manifold, nozzle, etc.) extending between and fluidly coupling the inlet section 122 of the first cooling fluid section 120 and the heat exchange tubes 110 extending within the trough 144, which may be longer than the heat exchange tubes 110 of second pass 114 (e.g., condensing heat exchange tubes). For example, the conduit 150 may extend through the divider plate 126. The divider plate 126 and the conduit 150 may be coupled to one another in a sealing engagement to block flow of cooling fluid directly from the inlet section 122 to the outlet section 124 of the first cooling fluid section 120. As will be appreciated, the cooling fluid within the inlet section 122 of the first cooling fluid section 120 may be colder than the cooling fluid directed from the second cooling fluid section 132 into heat exchange tubes 110 of the second pass 114. Thus, the cooling fluid directed from the inlet section 122 of the first cooling fluid section 120 and through the heat exchange tubes 110 extending within the trough 144 may enable further cooling and/or subcooling of the liquid heat transfer fluid collected within the trough 144. Cooling fluid directed through the heat exchange tubes 110 extending within the trough 144 may be discharged into the second cooling fluid section 132, and the second cooling fluid section 132 may then direct the cooling fluid (e.g., a second flow of cooling fluid) into the heat exchange tubes 110 of the second pass 114, as indicated by arrow 152. As such, the flow of cooling fluid (e.g., indicated by arrow 152) discharged from the heat exchange tubes 110 extending within the trough 144 may mix (e.g., in the second cooling fluid section 132) with cooling fluid (e.g., indicated by arrow 134) received from the first pass 112. Arrangements of the heat exchange tubes 110 within the condenser 100 and embodiments of the pre-subcooler 140 are described in further detail below.

[0044] FIG. 6 is a cross-sectional axial view of an embodiment of the condenser 100 including the pre-subcooler 140. In the illustrated embodiment, the heat exchange tubes 110 are arranged in a first tube bundle 170, a second tube bundle 172, and a third tube bundle 174. The first tube bundle 170 generally defines the second pass 114 configured to direct cooling fluid through the condenser 100 However, as described below, one or more of the heat exchange tubes 110 of the first tube bundle 170 may not be associated with the second pass 114. The second tube bundle 172 and third tube bundle 174 define the first pass 112 configured to direct cooling fluid through the condenser 100.

[0045] In the illustrated embodiment, the first tube bundle 170 and the second tube bundle 172 may generally define a condensing section 176 of the condenser 100. That is, heat transfer fluid directed across the heat exchange tubes 110 of the first tube bundle 170 and the second tube bundle 172 (e.g., along a vertical axis 178) may be vapor heat transfer fluid that condenses to form liquid heat transfer fluid. Thus, heat transfer fluid that flows to the third tube bundle 174 may be substantially in a liquid phase. Accordingly, the third tube bundle 174 may generally define a subcoohng section 180 (e g., subcooler) of the condenser 100. Liquid heat transfer fluid flowing along and/or across the heat exchange tubes 110 of the third tube bundle 174 may be further cooled and/or subcooled before the heat transfer fluid is discharged from the condenser 100. The subcooling section 180 may have any suitable configuration. For example, in some embodiments, the subcooling section 180 may define multiple passes (e.g., heat transfer fluid passes) whereby heat transfer fluid may flow sequentially across and/or along different groups of heat exchanger tubes 110 in the subcooling section 180.

[0046] The condenser 100 also includes the pre-subcooler 140 having the trough 144. The trough 144 is disposed within the condensing section 176 and is at least partially disposed within the region 142 extending between (e.g., extending vertically between, relative to vertical axis 178) the first tube bundle 170 and the second tube bundle 172. In some embodiments, the trough 144 may be completely disposed within the region 142. In particular, a sheet 182 (e.g., horizontal sheet relative to gravity) of the trough 144 extends within the region 142 (e.g., along a lateral axis 184 or horizontal axis). The trough 144 also includes lateral segments 186 (e.g., vertical segments, flanges) extending from lateral edges or sides of the sheet 182. That is, the lateral segments 186 may extend cross-wise from lateral edges or sides of the sheet 182. In some embodiments, a single piece of material (e.g., sheet metal) may be utilized (e.g., bent) to form the trough 144 having the sheet 182 and the lateral segments 186. In other embodiments, the sheet 182 and the lateral segments 186 may be separate components mechanically fastened to one another (e.g., via welding, bolts, rivets, etc ). The sheet 182, the lateral segments 186, or both, may be solid (e.g., non-porous, non-perforated) pieces of material. That is, the sheet 182, the lateral segments 186, or both, may not include perforations (e.g., apertures) formed therein, such that fluid flow through a thickness of the sheet 182, through thicknesses of the lateral segments 186, or both, may be blocked.

[0047] The sheet 182 and the lateral segments 186 cooperatively define a basin 188 (e.g., reservoir, volume) of the trough 144. As vapor heat transfer fluid is directed across the heat exchange tubes 110 of the first tube bundle 170, some of the vapor heat transfer fluid may condense to form liquid heat transfer fluid, and the liquid heat transfer fluid may be captured within the basin 188 of the trough 144. That is, liquid heat transfer fluid that may be formed on at least a portion 189 of the first tube bundle 170 may flow (e g., drip) from the portion 189 of the first tube bundle 170 into the basin 188. The portion 189 may include some of or all of the tubes included in the first tube bundle 170.

[0048] The liquid heat transfer fluid within the basin 188 may be directed (e g., via force of gravity) to the longitudinal ends 146 of the trough 144. From the longitudinal ends 146, the liquid heat transfer fluid may flow downward (e.g., along vertical axis 178) across longitudinal ends of the heat exchange tubes 110 of the second tube bundle 172. In some embodiments, the longitudinal ends of the heat exchange tubes 110 of the second tube bundle 172 may include designated portions of a length of the heat exchange tubes 110 of the second tube bundle 172. For example, the designated portions may be a percentage of a length of the heat exchange tubes 110 of the second tube bundle 172 (e.g., 5 percent, 10 percent) extending from corresponding distal ends of the heat exchange tubes 110 of the second tube bundle 172. Additionally or alternatively, the liquid heat transfer fluid may be directed to the subcooling section 180 (e.g., after contacting the longitudinal ends of the tubes of the second tube bundle 172, without contacting tubes of the second tube bundle 172) where the liquid heat transfer fluid may be further cooled and/or subcooled prior to discharge of the liquid heat transfer fluid from the condenser 100. In this way, the liquid heat transfer fluid collected within the trough 144 does not contact a substantial portion of the heat exchange tubes 110 of the second tube bundle 172, which reduces formation of liquid film on a substantial portion of the heat exchange tubes 1 10 of the second tube bundle 172 and therefore improves heat transfer of remaining vapor heat transfer fluid via the second tube bundle 172. That is, vapor heat transfer fluid that does not condense and collect within the trough 144 as liquid heat transfer fluid may continue flowing across the first tube bundle 170 and subsequently flow across the second tube bundle 172 and undergo more efficient heat transfer via the heat exchange tubes 110 of the first tube bundle 170 and second tube bundle 172 disposed beneath (e.g., relative to the vertical axis 178) the trough 144.

[0049] As mentioned above, one or more heat exchange tubes 110 may be disposed within the basin 188 defined by the trough 144. For example, heat exchange tubes 110 disposed within the basin 188 may be referred to as pre-subcooler tubes 190. In some embodiments, the lateral segments 186 may protrude vertically beyond (e.g., along the axis 178) the pre-subcooler tubes 190, such that the pre-subcooler tubes 190 may be disposed completely within the basin 188 with respect to the vertical axis 178. In other embodiments, a portion of the pre-subcooler tubes 190 may protrude beyond (e.g., above, with respect to a direction of gravity) the basin 188.

[0050] While the pre-subcooler tubes 190 may be arranged with and/ or adj acent the heat exchange tubes 110 of the first tube bundle 170, the pre-subcooler tubes 190 may not receive the same flow of cooling fluid that is received by the heat exchange tubes 110 of the first tube bundle 170, in some embodiments. For example, as described above, cooling fluid from the inlet section 122 of the first cooling fluid section 120 may be directed into (e.g., directly into) the pre-subcooler tubes 190 via the conduit 150. Thus, the pre-subcooler tubes 190 may define a pre-subcooler pass of the condenser 100, and cooling fluid directed through the pre-subcooler tubes 190 may bypass the heat exchange tubes 110 of the first pass 112. However, in other embodiments, the presubcooler tubes 190 may receive the cooling fluid from the second cooling fluid section 132, similar to the heat exchange tubes 110 of the first tube bundle 170.

[0051] As liquid heat transfer fluid flows within the basin 188 toward the longitudinal ends 146 of the pre-subcooler 140, the liquid heat transfer fluid may be further cooled (e.g., pre-subcooled) and/or subcooled via heat exchange with the presubcooler tubes 190. Indeed, in some embodiments, the pre-subcooler tubes 190 may be at least partially immersed in liquid heat transfer fluid collected within the trough 144. Thus, the pre-subcooler tubes 190 may effectively further cool the liquid heat transfer fluid prior to discharge of the liquid heat transfer fluid from the trough 144.

[0052] As shown in the illustrated embodiment, the pre-subcooler 140 includes a width 192, which may be a dimension extending between the lateral segments 186 of the trough 144. In other words, the width 192 may be a dimension of the sheet 182 extending along the lateral axis 184. A magnitude of the width 192 may be different for different embodiments of the pre-subcooler 140. As will be appreciated, the width 192 of the pre-subcooler 140 (e.g., the trough 144) may affect with a pressure drop of vapor heat transfer fluid flowing through the condenser 100. Accordingly, a magnitude of the width 192 may be selected to achieve a desired pressure drop of vapor heat transfer fluid. In some embodiments, the magnitude of the width 192 may be determined or selected based on a position of the pre-subcooler 140 within the shell 102 (e g., a vertical position, along the vertical axis 178, of the trough 144 within the condenser 100). Indeed, an amount of remaining vapor heat transfer fluid (e.g., vapor heat transfer fluid that does condense to liquid heat transfer fluid collected within the trough 144) that flows across heat exchange tubes 110 disposed beneath the trough 144 may be dependent on a vertical position of the pre-subcooler 140 within the shell 102. In some embodiments, a higher position of the pre-subcooler 140 within the shell 102 (e.g., along vertical axis 178, relative to gravity) may correspond to a reduced magnitude of the width 192.

[0053] As mentioned above, the trough 144 (e.g., the sheet 182) may be positioned within the region 142 between the first tube bundle 170 and the second tube bundle 172 (e.g., vertically between the first pass 112 and the second pass 114) where heat exchange tubes 110 are not located. Thus, in some embodiments, the pre-subcooler 140 may be incorporated with the condenser 100 and without modifying a number of the heat exchange tubes 110 (e.g., relative to an embodiment of the condenser 100 without the pre-subcooler 140), which may further contribute to improved heat transfer efficiency of the condenser 100 with the pre-subcooler 140. However, it should be appreciated that the pre-subcooler 140 may be disposed in any suitable location within the condenser 100 based on operating condition considerations, including but not limited to heat transfer fluid pressure drop, number of total heat exchange tubes 110, number of pre-subcooler tubes 190, number of passes (e.g., cooling fluid passes), and so forth.

[0054] FIG. 7 is a cross-sectional axial view of an embodiment of the condenser 100 including the pre-subcooler 140. In the illustrated embodiment, the pre-subcooler 140 includes two separate troughs 144. Thus, the condenser 100 may be described as including two pre-subcoolers 140 (e.g., a first pre-subcooler 200 and a second presubcooler 202). Each trough 144 includes the sheet 182 and the lateral segments 186 discussed above. As in the embodiment described above with reference to FIG. 6, the troughs 144 may be disposed within the region 142 between the first tube bundle 170 and the second tube bundle 172. The respective sheets 182 of the first pre-subcooler 200 and the second pre-subcooler 202 may be aligned with one another along the lateral axis 184 or may be vertically offset from one another along the vertical axis 178. Each trough 144 is configured to receive and collect liquid heat transfer fluid that is condensed via heat exchange tubes 110 of the second pass 114 (e.g., the first tube bundle 170). However, in other embodiments, the troughs 144 may be vertically offset from one another and may receive liquid heat transfer fluid condensed via different heat exchange tubes 110 and/or different tube bundles within the condenser 100.

[0055] The respective pre-subcooler tubes 190 disposed within the respective troughs 144 may each receive cooling fluid from the inlet section 122 of the first cooling fluid section 120, or the respective pre-subcooler tubes 190 may receive cooling fluid from different portions of the condenser 100. Further, the pre-subcoolers 140 each include the width 192, which may be the same or different from one another and may be selected based on the factors discussed above. In some embodiments, the condenser 100 having the first pre-subcooler 200 and the second pre-subcooler 202 may enable a reduced pressure drop of vapor heat transfer fluid within the condenser 100 (e.g., as compared to an embodiment of the condenser 100 having one pre-subcooler 140). The first pre-subcooler 200 and the second pre-subcooler 202 are also configured to operate in a similar manner as that described above. In other embodiments, the pre-subcooler 202 may include 1, 2, 3, 4, 5, or more than 5 separate troughs 144 disposed along various locations and/or at various orientations within the condenser 100.

[0056] FIG. 8 is a schematic cross-sectional side view of an embodiment of the condenser 100 including the pre-subcooler 140 and flow of liquid heat transfer fluid through the condenser 100. As described above, the pre-subcooler 140 includes the trough 144, which may be positioned at least partially between the first tube bundle 170 and the second tube bundle 172 that cooperatively define the condensing section 176 of the condenser 100. The condenser also includes the subcooling section 180 having the third tube bundle 174.

[0057] In the illustrated embodiment, the subcooling section 180 (e.g., subcooler) is a two pass subcooler. That is, the subcooling section 180 defines two passes (e.g., a first pass 220 and a second pass 222) that cooperatively define a heat transfer fluid flow path through the subcooling section 180. The heat exchange tubes 110 of the third tube bundle 174 may be divided into a first group of heat exchange tubes 110 associated with the first pass 220 (e.g., a first subcooler pass) and a second group of heat exchange tubes 110 associated with the second pass 222 (e.g., a second subcooler pass). The subcooling section 180 also includes a separation plate 224 extending between (e g., relative to vertical axis 178) the heat exchange tubes 110 of the first pass 220 and the heat exchange tubes 110 of the second pass 222. The separation plate 224 generally extends along a longitudinal axis 226 of the condenser 100. In some embodiments, the separation plate 224 may be a solid piece of material (e.g., a non-perforated piece of material) that does not include apertures formed therein.

[0058] The first pass 220 of the subcooling section 180 may be described as an open pass (e.g., an open subcooler section) that is, for example, configured to receive heat transfer fluid directly from the second tube bundle 172 (e.g., the condensing section 176). That is, heat transfer fluid (e.g., liquid heat transfer fluid) may flow from the second tube bundle 172 directly to heat exchange tubes 110 of the third tube bundle 174 associated with the first pass 220 of the subcooling section 180, as indicated by arrows 228. The heat transfer fluid may then be directed by the separation plate 224 (e.g., via gravity) to flow along the heat exchange tubes 110 of the first pass 220 towards longitudinal ends 230 of the separation plate 224, as indicated by arrows 232. At the longitudinal ends 230, the heat transfer fluid may flow from the first pass 220 to the second pass 222 of the subcooling section 180 and be directed along the heat exchange tubes 110 of the second pass 222, as indicated by arrows 234, to flow toward an outlet 236 of the condenser 100. The second pass 222 may be described as a closed pass of the subcooling section 180. As the heat transfer fluid (e.g., liquid heat transfer fluid) flows along the first pass 220 and the second pass 222, the heat transfer fluid may be further cooled and/or subcooled via heat transfer with the cooling fluid directed through the heat exchange tubes 110 of the subcooling section 180.

[0059] As discussed above, the trough 144 of the pre-subcooler 140 is configured to collect liquid condensate that forms via heat exchange with the first tube bundle 170. The liquid condensate may be captured within the basin 188 of the trough 144 defined by the sheet 182 and lateral segments 186. The trough 144 is configured to direct the liquid condensate to the longitudinal ends 146 of the trough 144. At the longitudinal ends 146, the liquid condensate may flow out of the trough 144 and downward (e.g., along vertical axis 178), as indicated by arrows 238. As mentioned above, the liquid heat transfer fluid discharged from the trough 144 may flow across longitudinal ends 223 of the heat exchange tubes 110 in the second tube bundle 172. Thus, formation and/or accumulation of liquid heat transfer fluid film on a substantial portion (e g., central portion 225) of the heat exchange tubes 110 in the second tube bundle 172 is avoided, which improves heat transfer between the second tube bundle 172 and vapor heat transfer fluid that flows from the first tube bundle 170 to the second tube bundle 172. That is, the trough 144 may be configured to direct liquid heat transfer fluid onto the longitudinal ends 223 of the second tube bundle 172 and to block flow of liquid heat transfer fluid from the trough 144 (e.g., from the first tube bundle 170) onto the central portion 225 of the second tube bundle 172. In some embodiments, the central portion 225 may correspond to a majority of a length of the second tube bundle 172 (e.g., 50 percent of the length of the second tube bundle 172, 60 percent of the length of the second tube bundle 172, 70 percent of the length of the second tube bundle 172) and the longitudinal ends 223 may correspond to remaining portions of the length of the second tube bundle 172.

[0060] In some embodiments, the liquid heat transfer fluid discharged from the trough 144 may flow across longitudinal ends 227 of the heat exchange tubes 110 in the first pass 220 of the subcooling section 180, thereby bypassing contact with a substantial portion (e.g., central portion 229) of the heat exchange tubes 110 in first pass 220. That is, the trough 144 may be configured to direct liquid heat transfer fluid toward the longitudinal ends 227 of the first pass 220 (e.g., the first subcooler pass) and to block flow of liquid heat transfer fluid from the trough 144 toward the central portion difference between heat transfer fluid directed along the first pass 220 (e.g., received from the second tube bundle 172) and the cooling fluid directed through the heat exchange tubes 110 in first pass 220 may be greater, which may improve heat transfer efficiency within the condenser 100.

[0061] The liquid heat transfer fluid discharged from the trough 144 may flow from the longitudinal ends of the heat exchange tubes 110 in the first pass 220 to the second pass 222 and may be directed along the second pass 222 (e.g., thereby being further cooled and/or subcooled) toward the outlet 236 of the condenser 100. To this end, the trough 144 (e.g., the sheet 182) may have a length 240 extending along the longitudinal axis 226 that is greater than a length 242 of the separation plate 224 that extends along the longitudinal axis 226. In this way, contact between the liquid heat transfer fluid discharged from the trough 144 and the heat exchange tubes 110 in the first pass 220 is limited. In some embodiments, the trough 144 (e.g., sheet 182, lateral segments 186) may include one or more openings formed therein (e.g., at the longitudinal ends 146) to enable desired discharge of the liquid heat transfer fluid from the trough 144.

[0062] In some embodiments, the condenser 100 may include additional or alternative features that facilitate incorporation of the pre-subcooler 140. For example, one or more baffles or sheets may be utilized to support the pre-subcooler tubes 190 extending through the trough 144. In some embodiments, tube sheets 244 implemented to support the first tube bundle 170, the second tube bundle 172, and/or the third tube bundle 174 may also be configured to support the pre-subcooler tubes 190. The tube sheets 244 may also support the trough 144 within the shell 102. For example, the trough 144 may be welded, fastened, or otherwise secured to the tube sheets 244. The tube sheets 244 implemented to support the first tube bundle 170, the second tube bundle 172, and/or the third tube bundle 174 may additionally or alternatively be configured to function as baffles that enable desired flow of liquid heat transfer fluid within the basin 188 (e.g., toward the longitudinal ends 146). In some embodiments, additional tube sheets 244 may be incorporated in the condenser 100 to support the presubcooler tubes 190 and/or to facilitate liquid heat transfer fluid flow through the trough 144. In some embodiments, additional baffles 246 may be included with the presubcooler 140 to support the pre-subcooler tubes 190 and/or to facilitate liquid heat transfer fluid flow through the trough 144. For example, the additional baffles 246 may be disposed within the basin 188 and may be secured to the trough 144 (e.g., the sheet 182).

[0063] Embodiments of the pre-subcooler 140 may also be incorporated with other embodiments of the condenser 100, such as an embodiment of the condenser 100 having three passes (e.g., first pass 112, second pass 114, and an additional pass). In such an embodiment, the pre-subcooler 140 may be disposed vertically between the second pass 114 and the additional (e.g., third) pass disposed vertically above the second pass 114 within the shell 102. In another embodiment, the pre-subcooler 140 may be implemented with the condenser 100 having one cooling fluid pass.

[0064] In accordance with the present techniques, the pre-subcooler 140 enables improved heat transfer between the cooling fluid and the heat transfer fluid directed through the condenser 100 by reducing formation and/or accumulation of liquid heat transfer fluid fdm on heat exchange tubes 110 of the condenser 100. In some embodiments, incorporation of the pre-subcooler 140 may enable a reduction in size of the subcooling section 180 (e.g., fewer heat exchange tubes 110 in the subcooling section 180), which may increase an available pressure drop for the subcooling section 180. Further, the pre-subcooler 140 may be incorporated in a cost-effective manner, may reduce costs associated with the subcooling section 180, and may be implemented without reducing a number of heat exchange tubes 110 otherwise included in the condenser 100.

[0065] While only certain features and embodiments have been illustrated and described, many modifications and changes may occur to those skilled in the art, such as variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, such as temperatures and pressures, mounting arrangements, use of materials, colors, orientations, and so forth, without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or resequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. [0066] Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described, such as those unrelated to the presently contemplated best mode, or those unrelated to enablement. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.

[0067] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] ... ” or “step for [perform] ing [a function]... ”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).