HEAT EXCHANGER FOR A HEATING, VENTILATION AND AIR CONDITIONING SYSTEM

Abstract

The present invention relates to a heat exchanger for receiving an airflow of uneven intensity distribution through the heat exchanger and for circulating refrigerant within the heat exchanger. The heat exchanger includes microchannel tube sections for conveying the refrigerant through at least one passage within the heat exchanger, wherein the sections are configured to conform to the airflow through the heat exchanger. The heat exchanger can be used in an HVAC system. A method for manufacturing the heat exchanger is also provided.

Description

HEAT EXCHANGER FOR A HEATING, VENTILATION AND AIR CONDITIONING SYSTEM BACKGROUND OF THE INVENTION This section is intended to provide relevant background information to facilitate a better understanding of the various aspects of the methods described. Accordingly, these statements should be read in this light and not as admissions of prior art. In general, heating, ventilation, and air conditioning (“HVAC”) systems circulate indoor air through low-temperature (for cooling) or high-temperature (for heating) sources, thereby adjusting the ambient air temperature. HVAC systems generate these low- and high-temperature sources, among other techniques, by taking advantage of a well-known physical principle: a fluid transitioning from a gas to a liquid releases heat, while a fluid transitioning from a liquid to a gas absorbs heat. Within a typical HVAC system, a refrigerant circulates through a closed-loop piping system using a compressor, which receives DC power from an inverter, and flow control devices to manipulate the refrigerant's flow and pressure, causing it to cycle between liquid and gaseous phases. These phase transitions generally occur within the HVAC system's heat exchangers, which are part of the closed loop and are designed to transfer heat between the circulating refrigerant and the surrounding ambient air. As might be expected, the heat exchanger that provides heating or cooling to the climate-controlled space or structure is described as "indoor," and the heat exchanger that transfers heat to the surrounding outdoor environment is described as "outdoor." The refrigerant circulating between the indoor and outdoor heat exchangers, transitioning between phases along the way, absorbs heat from one place and releases it to the other. Those in the HVAC industry describe this cycle of heat absorption and release as “pumping.” To cool a climate-controlled indoor space, heat is “pumped” from the inside to the outside, and the indoor space is heated by doing the opposite, pumping heat from the outside to the inside. BRIEF DESCRIPTION OF THE FIGURES The HVAC system modes are described with reference to the following figures. The same numbers are used throughout the figures to refer to similar features and components. The features depicted in the figures are not necessarily shown to scale. Certain mode features may be shown in exaggerated scale or somewhat schematically, and some element details may be omitted for the sake of clarity and conciseness. Figure 1 is a block diagram of an HVAC system, in accordance with one or more modalities; Figure 2 is a simplified block diagram of an HVAC 200 system, in accordance with one or more modes; and Figure 3 is a block diagram of a multi-pass fan and heat exchanger, in accordance with one or more modes; Figure 4 is a schematic graph of the intensity of an uneven airflow distribution, according to one or more modalities; Figure 5 is a block diagram of a heat exchanger, in accordance with one or more modalities; Figure 6 is a block diagram of a tube section of a heat exchanger, according to one or more embodiments; and Figure 7 is a block diagram of an alternative modality of a heat exchanger. DETAILED DESCRIPTION OF THE INVENTION This description describes a heat exchanger designed to receive an airflow distribution with uneven airflow intensity and to flow refrigerant within the heat exchanger. The heat exchanger comprises a plurality of tubes, each containing several microchannels for refrigerant flow from one side of the heat exchanger to the other, which is considered a pass through the heat exchanger. The fluid can only make one pass through the heat exchanger and thus only one stage. However, the fluid can make multiple passes through the heat exchanger, with each successive pass constituting a different stage. One or more tubes carrying fluid in a particular direction through the heat exchanger at the same stage of the flow circuit can be grouped into a single section.It is not necessary for all tubes flowing refrigerant in the same direction on the same stage to be adjacent to each other; they can instead be separated into non-adjacent sections. The tubes can also be separated by fins. In a microchannel heat exchanger, the tube sections are designed based on an uneven distribution of airflow through the heat exchanger. In particular, the sections are configured based on the intensity of the uneven airflow distribution through the heat exchanger at different locations, as well as between the tubes. The configuration can involve various aspects of the sections, such as the number of tubes in each section, the heat transfer surface geometries of the tubes in the heat exchanger sections, the total number of tube sections, whether the heat exchanger sections in a stage are adjacent, the total fluid flow volume within a section, and the total number of stages.The configuration of the sections is designed to increase the efficiency of heat exchange between the airflow and the refrigerant flow. Furthermore, the section configuration minimizes the negative effect of cross-conduction, that is, unwanted heat exchange between portions of the heat exchanger instead of with the airflow. Turning now to the figures, Figure 1 is an HVAC 100 system conforming to one modality. As depicted, the HVAC 100 system provides heating and cooling for a residential structure 102. However, the concepts described in this document are applicable to numerous heating and cooling situations, including residential, industrial, and commercial environments. The described HVAC system 100 is divided into two main portions: the outdoor unit 104, which mainly comprises components for transferring heat with the environment outside the structure 102; and the indoor unit 106, which mainly comprises components for transferring heat with the air inside the structure 102. To heat or cool the illustrated structure 102, the indoor unit 106 draws in ambient indoor air through the returns 110, passes that air over one or more heating / cooling systems (i.e., heat or cooling sources), and then directs that conditioned air, whether heated or cooled, back to the various climate-controlled spaces 112 through ducts or conduits 114, which are relatively large pipes that can be either rigid or flexible. A blower 116 provides the driving force for circulating the ambient air through the returns 110 and the ducts 114.Furthermore, although Figure 1 shows a split system, the described modalities can be applied equally to packaged or other system configurations. As shown, the HVAC system 100 is a dual-fuel system with multiple heating elements, such as an electric heating element or a gas furnace 118. The gas furnace 118, located downstream (relative to the airflow) of the fan 116, burns natural gas to produce heat in the furnace tubes (not shown) that are coiled through the gas furnace 118. These furnace tubes act as a heating element for the indoor ambient air that is exhausted from the blower 116, over the furnace tubes, and into the ducts 114. However, the gas furnace 118 is generally operated only when heavy heating is desired. During conventional heating and cooling operations, the air from the blower 116 passes through an indoor heat exchanger 120 and into the ducts 114.The blower 116, gas furnace 118, and indoor heat exchanger 120 can be packaged as an integrated air handling unit, or these components can be modular. In other configurations, the positions of the gas furnace 118, indoor heat exchanger 120, and blower 116 can be reversed or rearranged. In at least one embodiment, the indoor heat exchanger 120 acts as a heating or cooling medium, adding or removing heat from the building, respectively, by manipulating the pressure and flow of refrigerant circulating within and between the indoor and outdoor units through the refrigerant lines 122. In another embodiment, the refrigerant may circulate only to cool (i.e., remove heat from) the building, with heating provided independently by another source, such as, but not limited to, the gas furnace 118. In other embodiments, there may be no heating of any kind. HVAC systems 100 that use refrigerant for both heating and cooling the building 102 are often described as heat pumps, while HVAC systems 100 that use refrigerant only for cooling are commonly described as air conditioners.Whatever the state of the indoor heat exchanger 120 (i.e., absorbing or releasing heat), the outdoor heat exchanger 124 is in the opposite state. More specifically, if heating is desired, the indoor heat exchanger 120 acts as a condenser, facilitating the transition of the refrigerant from a high-pressure gas to a high-pressure liquid and releasing heat in the process. The outdoor heat exchanger 124 acts as an evaporator, facilitating the transition of the refrigerant from a low-pressure liquid to a low-pressure gas, thereby absorbing heat from the outside environment. If cooling is desired, the outdoor unit 104 has flow control devices 126 that reverse the flow of the refrigerant, allowing the outdoor heat exchanger 124 to act as a condenser and the indoor heat exchanger 120 to act as an evaporator.The flow control devices 126 can also act as an expander to reduce the pressure of the refrigerant flowing through them. In other embodiments, the expander may be a separate device located in the outdoor unit 104 or the indoor unit 106. To facilitate heat exchange between the indoor ambient air and the outdoor environment in the described HVAC system 100, the respective heat exchangers 120, 124 have tubes that are wrapped or coiled across heat exchange surfaces to increase the surface area of ​​contact between the tubes and the surrounding air or environment. The illustrated outdoor unit 104 may also include an accumulator 128 that helps prevent liquid refrigerant from reaching the inlet of a compressor 130. The outdoor unit 104 may include a receiver 132 that helps maintain sufficient refrigerant charge distribution in the HVAC system 100. The size of these components is often defined by the amount of refrigerant used by the HVAC system 100. Compressor 130 receives low-pressure refrigerant gas from the indoor heat exchanger 120 if cooling is required, or from the outdoor heat exchanger 124 if heating is required. Compressor 130 then compresses the refrigerant gas to a higher pressure based on a compressor volume ratio, that is, the ratio between the discharge volume (the volume of gas leaving compressor 130 after compression) and the suction volume (the volume of gas entering compressor 130 before compression). In the illustrated configuration, the compressor 130 is a multi-stage compressor that can switch between at least two volume ratios depending on whether heating or cooling is required. In other configurations, the HVAC system 100 may be set up for cooling only or heating only, and the compressor 130 may be a single-stage compressor with only one volume ratio. Compressor 130 receives electrical power from a control system 134 that includes an inverter system, as described in more detail below with reference to Figure 2, which converts the AC power received by the HVAC system 100 into DC power for use by compressor 130. The control system 134 controls the speed of compressor 130, as well as the switching between compressor stages for multi-stage compressors, based on the required heating or cooling to be provided by the HVAC system, i.e., the load on the HVAC system 100. In some embodiments, the control system can also control the speed of a fan 136 that blows air through the heat exchanger 124. With reference to Figure 2, Figure 2 is a simplified block diagram of an HVAC 200 system. The HVAC 200 system includes a first heat exchanger 202, an expansion device 204, a second heat exchanger 206, and a compressor 208. Furthermore, the heat exchangers 202 and 206 can be either indoor or outdoor heat exchangers, depending on the configuration of the HVAC 200 system. The HVAC 200 system may also include the equipment shown in Figure 1, and they operate as discussed earlier with reference to Figure 1. Consequently, the function of the first heat exchanger 202, the expansion device 204, the second heat exchanger 206, and the compressor 208 will not be discussed in detail except as necessary for understanding the HVAC 200 system shown in Figure 2. As shown in Figure 2, the high-pressure refrigerant flows from compressor 208 to the first heat exchanger 202, where it condenses. The high-pressure liquid refrigerant then flows to the expansion device 204, where it expands to low-pressure refrigerant. The low-pressure refrigerant then evaporates in the second heat exchanger 206, and the low-pressure vapor flows back to compressor 208 to begin the cycle again. With reference to Figures 3 and 4, Figure 3 is a block diagram of a fan and a side view of a multi-pass microchannel heat exchanger 124 that can be used in an HVAC system, as described above. Figure 4 is a schematic graph of the AF airflow, which has an uneven intensity distribution that can occur in an HVAC system. The fan 136 operates to generate the AF airflow, which has an uneven intensity distribution 410, through the heat exchanger 124, as shown by the arrows in Figure 3, where the intensity distribution varies along the direction given in Figures 3 and 4. The AF airflow can have an uneven intensity for various reasons. For example, the fan 136 includes a plurality of fan blades, and the uneven intensity distribution may be due to the orientations and / or geometries of the fan blades.It is understood that while fan 136 is shown in a plane parallel to heat exchanger 124, a fan operating to generate an uneven intensity distribution may be in an alternative arrangement to the heat exchanger, for example, in a plane perpendicular to the heat exchanger. Furthermore, it is understood that the uneven intensity of the airflow may be due, alternatively or in combination, to the direction of airflow through the heat exchanger. Moreover, while fan 136 and heat exchanger 124 are shown in Figure 1 where the heat exchanger is a condenser, a heat exchanger receiving an uneven intensity airflow distribution may act as an alternative component of an HVAC system, for example, an evaporator. With reference now to Figures 3 and 5, Figure 5 is a block diagram of a front view of the heat exchanger 124 shown in Figure 3. The heat exchanger 124 includes a plurality of heat exchanger sections 310a, 310b, 310c, 310d, 310e connected at each end to headers 520, 522. As shown in Figure 3, an “x” indicates coolant flow in a direction into the page, toward the negative di direction, and a circle indicates coolant flow out of the page, toward the positive di direction, where di is a direction in the coordinate system shown in Figure 3. As explained above, a coolant pass is a passage of coolant from a header at one end of the heat exchanger 124 to the opposite header at the opposite end of the heat exchanger 124.For each step, the coolant flows through a section of a plurality of tubes that carry the coolant from one end of heat exchanger 124 to an opposite end for a given stage of flow through the heat exchanger. There may be more than one tube section carrying the fluid in the same direction at the same stage, and the sections need not be adjacent. For example, as shown, sections 310a and 310e carry fluid in the same direction at the same stage but are not adjacent. Furthermore, the fluid from non-adjacent sections may mix when transitioning to a new step and thus a new stage. For example, the fluid from sections 310b and 310d mixes in the tubes of section 310c for the last step. However, it will be appreciated that the fluid does not necessarily need to mix before exiting the heat exchanger. Referring to Figure 5, headers 520 and 522 are in fluid communication with sections 310a, 310b, 310c, 31Od, and 31Oe. Header 520 includes inlets 524a and 524b for receiving refrigerant from heat exchanger 124. Header 522 includes outlet 526 for delivering refrigerant from heat exchanger 124. Section 310c receives refrigerant flow from sections 310b and 31Od, which in turn receive refrigerant flow from sections 310a and 31Od. Therefore, the tube sections carry refrigerant from one of the headers 520 and 522 to the other of the headers 520 and 522. Heads 520 and 522 include separators or are otherwise divided to allow the refrigerant flow to change direction to proceed to the next stage as shown by the U-shaped turning arrows in Figure 5.It is understood that although heat exchanger 124 is illustrated in Figures 3 and 5 as a three-pass heat exchanger (the coolant makes three passes from inlet to outlet), alternative numbers of passes are acceptable, for example, two, four, five, six, seven, eight, nine, ten, or more. The number of passes does not need to be the same for each inlet before the coolant exits the heat exchanger. Likewise, any number of sections, inlets, and outlets is also acceptable. With reference now to Figures 3 and 6, Figure 6 is an enlarged block diagram of a cross-sectional view of a section of heat exchanger 310a shown in Figure 3. The heat exchanger section 310a includes a plurality of tubes 612. The tubes 612 may be known as flat tubes, which are wider than they are tall. Each tube 612 includes a plurality of microchannels 614 for carrying refrigerant. In the microchannels 614, for the heat exchanger section 310a, the direction of refrigerant flow is toward the page in the direction di (not shown). The tubes 612 are stacked, thus defining a size or volume of the heat exchanger section 310a along the direction in which the airflow is irregular, as shown in Figures 3-6 as ds.It is understood that while the tubes are shown stacked “horizontally” in Figure 6, a heat exchanger may include tubes that are stacked “vertically”. A plurality of fins 616 are arranged between the tubes 612. The operating heat exchanger section 310a receives airflow AF through the fins between the tubes. The operating heat exchanger exchanges heat between the airflow and the refrigerant flow. Heat exchanger sections 310b, 310c, 310d, and 310e are likewise composed of tubes and fins (not shown). With reference to Figures 3-6, the heat exchanger sections are configured according to the airflow intensity through each section of the heat exchanger 310a, 310b, 310c, 310d, 310e to match the irregular airflow distribution 410. However, it is understood that there may be alternative section arrangements to those shown in Figures 3 and 5. For example, although there are five sections and all the fluid passes through three passes, there may be more or fewer sections and passes in a heat exchanger. Furthermore, all the tubes in a section for a given stage may be adjacent. In addition, sections may contain different numbers of tubes, even within the same stage if the stage is divided into non-adjacent sections.Furthermore, although the number of sections, and therefore passes, shown on either side of section 310c in Figure 5 are symmetrical, there can be more sections on one side—for example, four instead of two—than on the other. Additionally, fluid recombine is not required for the heat exchanger to exist; instead, there can be two outlets similar to two inlets, and thus the separate fluid flows never combine. Moreover, a heat exchanger can have any number of passes, sections, inlets, and outlets. As mentioned, the heat exchanger sections are configured to take advantage of the uneven airflow distribution, maximizing heat exchange in areas with higher airflow. Therefore, since heat exchange can be enhanced by increasing the refrigerant flow volume, the refrigerant volume in each heat exchanger section can be optimized based on the airflow intensity through that section, rather than maintaining a uniform volume. Refrigerant flow is driven by pressure differentials, which are directly related to heat transfer. Optimal heat exchanger design achieves substantially identical refrigerant outlet states, where the outlet state is defined, for example, by temperature and / or pressure, before the sections are combined.Furthermore, a higher airflow rate is suitable for a section where the temperature difference is low and heat transfer benefits from a boost, for example, a subcooling section in a condenser or a superheating section in an evaporator. The number of tubes in each heat exchanger section 310a, 310b, 310c, 310d, 310e can also depend on the intensity of the airflow through each tube. IVIA / a / ZUZZ / UI oozl heat exchanger section. Heat exchange increases with the number of tubes. Changing the number of tubes in a section also changes the total cross-sectional area of ​​the section and the amount of refrigerant flowing through the heat exchanger section. Heat exchanger sections 310a, 310b, 310c, 310d, and 310e may further include different tube geometries 612 and / or fins 616 depending on the airflow intensity through each heat exchanger section. Varying the tube geometry may include varying one or more of the tube density, tube cross-sectional shape, tube width, tube height, number of microchannels, microchannel shape, or similar features. Varying the fin geometry may include varying one or more of the fin density, fin height, number of louvers, louver angle, or similar features. With reference now to Figure 7, Figure 7 is a block diagram of a front view of an alternative embodiment of heat exchanger 724 that includes components similar to those of heat exchanger 124 shown in Figure 3. For example, heat exchanger 724 includes a plurality of heat exchanger sections 71 Oa-e connected at each end to headers 720, 722. For each step, the coolant flows through a section of a plurality of tubes that carry the coolant from one end of heat exchanger 724 to an opposite end for a given stage of flow through the heat exchanger. There may be more than one tube section flowing fluid in the same direction at the same stage, and the sections need not be adjacent. For example, as shown, sections 710a and 71 Oe flow fluid in the same direction at the same stage but are not adjacent.Still with reference to Figure 7, heads 720 and 722 are in fluid communication with sections 71 Oa-e. Header 720 includes inlets 724a and 724b for receiving refrigerant to heat exchanger 724. Header 722 includes outlet 726 for supplying refrigerant from heat exchanger 724. Tube sections carry refrigerant from one of the headers 720 and 722 to the other. Headers 720 and 722 include separators or are otherwise divided to allow the refrigerant flow to change direction to pass to the next stage, as shown by the U-turn arrows in Figure 7. Unlike the three-pass heat exchanger 124 in Figure 5 (where the refrigerant from inlet to outlet makes three passes), heat exchanger 724 includes seven passes with the inclusion of two additional tube sections, 71Of and 71Og.As shown, sections 71 Of and 71 Og are not symmetrical with respect to inlets 724a, 724b and outlet 726, but are located between inlet 724b and outlet 726. Therefore, heat exchanger 724 includes additional individual sections for refrigerant flow in additional steps, one each before the refrigerant flows to the third step section 71 Oc, so that the number of sections and steps from one inlet 724a to outlet 726 is different from that of the other inlet 724b. Section 710c still functions to receive refrigerant flow from multiple sections; however, section 710c receives flow from sections 710b and 71 Of. Alternating numbers of steps are to be expected. Likewise, any number of runs, inlets, and outlets are also to be expected. The sections of heat exchanger 710a-g are configured according to the airflow intensity through each section of heat exchanger 710a-g, based on the uneven airflow distribution through heat exchanger 724 and the airflow intensity through each section. It is understood that alternative section arrangements to those shown in Figure 7 are possible. For example, although there are seven sections and seven passes, a heat exchanger may have more or fewer sections and passes. Furthermore, all the tubes in a section for a given stage may be adjacent. Additionally, sections may contain different numbers of tubes, even within the same stage if the stage is divided into non-adjacent sections.Furthermore, it is not necessary to recombine the fluid for the heat exchanger to exist, and instead there can be two outlets similar to two inlets, and therefore the separate fluid flows never combine. With reference to Figure 7, the heat exchanger sections are configured according to the airflow intensity through each section of heat exchanger 710a-g to match the uneven airflow distribution 410. However, it is understood that there may be alternative section arrangements to those shown in Figure 7. For example, although there are seven sections, there may be more or fewer sections and passes in a heat exchanger. Furthermore, the sections may include different numbers of tubes, even within the same stage if the stage is divided into non-adjacent sections. Additionally, fluid recombine is not required for the heat exchanger to function; instead, there may be two outlets similar to two inlets, and thus the separate fluid flows never combine. Moreover, there may be any number of passes, sections, inlets, and outlets for a heat exchanger.As discussed, the heat exchanger sections are configured to take advantage of the uneven airflow distribution, maximizing heat exchange in areas with higher airflow. Therefore, since heat exchange can be enhanced by increasing the refrigerant flow volume, the refrigerant volume in each heat exchanger section can be optimized based on the airflow intensity through that section, rather than maintaining a uniform volume. Refrigerant flow is driven by pressure differentials, which are directly related to heat transfer. Optimal heat exchanger design achieves substantially identical refrigerant outlet states, where the outlet state is defined, for example, by temperature and / or pressure, before the sections are combined.Furthermore, a higher airflow rate is suitable for sections where the temperature difference is low and heat transfer benefits from enhancement, such as a subcooling section in a condenser or a superheating section in an evaporator. The number of tubes in each section of the 710a-g heat exchanger can also depend on the airflow intensity through that section. Heat exchange increases with the number of tubes. Changing the number of tubes in a section also changes the total cross-sectional area of ​​the section and the amount of refrigerant flowing through it. The sections of the 710a-g heat exchanger can also incorporate different tube and / or fin geometries depending on the airflow intensity through each section.Varying the tube geometry may include varying one or more of the tube density, the shape of the tube cross-section, the tube width, the tube height, the number of microchannels, the shape of the microchannels, or similar features. Varying the fin geometry may include varying one or more of the fin density, the fin height, the number of louvers, the louver angle, or similar features. Additional examples include: Example 1 is a heat exchanger designed to receive an airflow with an uneven intensity distribution and to circulate refrigerant within the heat exchanger. The heat exchanger includes microchannel tube sections for the refrigerant to flow through at least one passage, where the sections are configured according to the airflow pattern. Example 2 is the heat exchanger from Example 1 or any other appropriate example, where the number of tubes in each section depends on the intensity of the airflow through each section. Example 3 is the heat exchanger of Example 1 or any other appropriate example, wherein the sections comprise fins having different geometries according to the intensity of airflow through each section. Example 4 is the heat exchanger of Example 1 or any other appropriate example, wherein the tubes have different geometries according to the intensity of the airflow through each tube. Example 5 is the heat exchanger from Example 1 or any other appropriate example, wherein the non-adjacent sections are configured so that the coolant flows in the same direction. Example 6 is the heat exchanger of Example 1 or any other appropriate example, wherein two inlets are in fluid communication with two non-adjacent sections for flow in a first pass through a first header. Example 7 is the heat exchanger from Example 6 or any other appropriate example, which includes two additional sections located between the first-pass sections to allow the coolant to flow in a second pass through the heat exchanger. Example 8 is the heat exchanger of Example 7 or any other appropriate example, which includes an additional section for a third pass in which the coolant from the second pass sections is combined with the third pass section and further comprises an outlet in fluid communication with the third pass section through a second header. Example 9 is the heat exchanger of Example 8 or any other appropriate example, which further includes additional individual sections for flowing the coolant in additional steps each before flowing the coolant to the third pass section, so that the number of sections and steps from one inlet to the outlet is different from the other. Example 10 is the heat exchanger of Example 7 or any other appropriate example, which further includes an outlet in fluid communication with the second-pass sections through the first header. Example 11 is the heat exchanger from Example 1 or any other appropriate example, where the heat exchanger is a condenser. Example 12 is the heat exchanger of Example 11 or any other appropriate example, wherein one of the sections comprises a subcooling section that is positioned to receive the greatest intensity of airflow in the uneven airflow distribution. Example 13 is the heat exchanger from Example 1 or any other appropriate example, where the heat exchanger is an evaporator. Example 14 is the heat exchanger of Example 13 or any other appropriate example, wherein one of the sections comprises a superheating section that is positioned to receive the greatest intensity of airflow in the uneven airflow distribution. Example 15 is a heating, ventilation, and air conditioning (“HVAC”) system that includes a fan that operates to generate an airflow with an uneven intensity distribution. The HVAC system also includes a heat exchanger that incorporates sections of microchannel tubing to allow refrigerant to flow through at least one passage of the heat exchanger, where the sections are configured to optimize heat exchange in accordance with the airflow through the heat exchanger. Example 16 is the HVAC system of Example 15 or any other appropriate example, where the number of pipes in each section depends on the intensity of the airflow through each section. Example 17 is the HVAC system of Example 15 or any other appropriate example, wherein the sections include fins that have different geometries according to the intensity of airflow through each section. Example 18 is the HVAC system of Example 15 or any other appropriate example, where the pipes have different geometries according to the intensity of airflow through each pipe. Example 19 is the HVAC system from Example 15 or any other appropriate example, where non-adjacent sections are configured to circulate the refrigerant in the same direction. Example 20 is the HVAC system of Example 15 or any other appropriate example, where two inlets are in fluid communication with two non-adjacent sections for flow in a first pass through a first header. Example 21 is the HVAC system from Example 20 or any other appropriate example, which includes two additional sections located between the first-pass sections to allow the refrigerant to flow in a second pass through the heat exchanger. Example 22 is the HVAC system of Example 21 or any other appropriate example, which includes an additional section for a third pass where the refrigerant from the second pass sections is combined in the third pass section and further includes an outlet in fluid communication with the third pass section through a second header. Example 23 is the heat exchanger of Example 22 or any other appropriate example, which further includes additional individual sections for flowing the coolant in additional steps each before flowing the coolant to the third pass section, so that the number of sections and steps from one inlet to the outlet is different from the other. Example 24 is the HVAC system of Example 21 or any other appropriate example, which also includes an output in fluid communication with the second-pass sections through the first header. Example 25 is the HVAC system from Example 15 or any other appropriate example, where the heat exchanger is a condenser. Example 26 is the HVAC system of Example 25 or any other appropriate example, in which case one of the sections comprises a subcooling section that is positioned to receive the greatest intensity of airflow in the uneven airflow distribution. Example 27 is the HVAC system from Example 15 or any other appropriate example, where the heat exchanger is an evaporator. Example 28 is the HVAC system of Example 27 or any other appropriate example, wherein one of the sections comprises a superheat section that is positioned to receive the greatest intensity of airflow in the uneven airflow distribution. Example 29 is the HVAC system from Example 15 or any other appropriate example, where the fan rotates in a plane parallel to the heat exchanger. Example 30 is the HVAC system from Example 15 or any other appropriate example, where the fan rotates in a plane perpendicular to the heat exchanger. Example 31 is a method of manufacturing a heat exchanger for receiving an airflow that has an uneven intensity distribution through the heat exchanger and for flowing refrigerant within the heat exchanger. The method includes constructing a plurality of microchannel tube sections to allow the refrigerant to flow through at least one passage through the heat exchanger and configuring the sections in accordance with the airflow through the heat exchanger. Example 32 is the method of Example 31 or any other appropriate example, wherein the configuration comprises selecting the number of tubes in each section depending on the intensity of airflow through each section. Example 33 is the method of Example 31 or any other appropriate example, wherein the configuration comprises selecting fin geometries for each section according to the intensity of airflow through each section. Example 34 is the method of Example 31 or any other appropriate example, wherein the configuration comprises selecting tube geometries according to the intensity of airflow through each tube. Example 35 is the method of Example 31 or any other appropriate example, wherein the configuration comprises arranging two non-adjacent sections for passage in the same direction. Example 36 is the method of Example 31 or any other appropriate example, wherein the configuration comprises providing two inputs in fluid communication with two non-adjacent sections in a first pass through a first header. Example 37 is the method of Example 36 or any other appropriate example, wherein the configuration comprises arranging two additional sections located between the sections of the first pass to allow the refrigerant to flow in a second pass through the heat exchanger. Example 38 is the method of Example 37 or any other appropriate example, wherein the configuration comprises providing an additional section for a third pass in which the refrigerant from the second pass sections is combined in the third pass section and further provides an outlet in fluid communication with the third pass section through a second header. Example 39 is the method of Example 38 or any other appropriate example, wherein the configuration further comprises providing additional individual sections for the flow of the refrigerant in additional steps, each before the flow of the refrigerant to the third step section, so that the number of sections and steps from one inlet to the outlet is different from the other. Example 40 is the method of Example 37 or any other appropriate example, wherein the configuration further comprises providing an output in fluid communication with the second through-sections through the first header. Example 41 is the method of Example 31 or any other appropriate example, wherein the construction involves configuring the heat exchanger to act as a condenser. Example 42 is the method of Example 41 or any other appropriate example, wherein the configuration comprises configuring a section as a subcooling section and positioning the subcooling section to receive the greatest intensity of airflow in the uneven airflow distribution. Example 43 is the method of Example 31 or any other appropriate example, wherein the construction involves configuring the heat exchanger to act as an evaporator. Example 44 is the method of Example 43 or any other appropriate example, wherein the configuration comprises configuring a section as a superheating section and positioning the superheating section to receive the greatest intensity of airflow in the uneven airflow distribution. Certain terms are used throughout the description and claims to refer to particular features or components. As someone skilled in the art will appreciate, different people may refer to the same feature or component by different names. This document does not purport to distinguish between components or features that differ in name but not in function. References throughout this specification to “in a modality,” “a modality,” “modalities,” “some modalities,” “certain modalities,” or similar language mean that a particular factor, structure, or characteristic described in relation to the modality may be included in at least one modality of this description. Therefore, these phrases or similar language throughout this specification may, but do not necessarily, all refer to the same modality. References to “includes” mean “includes, but are not limited to.” The described methods should not be interpreted or otherwise used as limiting the scope of the description, including the claims. It should be fully recognized that the different teachings of the discussed methods may be employed separately or in any combination suitable for producing the desired results. Furthermore, a person skilled in the art will understand that the description has broad application, and that the discussion of any one method is intended only as an example of that method and is not intended to suggest that the scope of the description, including the claims, is limited to that method. MA / a / zuzz / ui oozr NOVELTY OF THE INVENTION Having described the present invention as above, it is considered novel and, therefore, the contents contained in the following are claimed as property:

Claims

1. A heat exchanger for receiving an airflow having an uneven intensity distribution through the heat exchanger and for flowing refrigerant within the heat exchanger, characterized in that the heat exchanger comprises: microchannel tube sections for flowing refrigerant through at least one passage through the heat exchanger; and wherein the sections are configured in accordance with the airflow through the heat exchanger.

2. The heat exchanger according to claim 1, characterized in that the number of tubes in each section depends on the intensity of the air flow through each section.

3. The heat exchanger according to claim 1, characterized in that the sections comprise fins having different geometries according to the intensity of the airflow through each section.

4. The heat exchanger according to claim 1, characterized in that the tubes have different geometries according to the intensity of the air flow through each tube.

5. The heat exchanger according to claim 1, characterized in that the non-adjacent sections are configured to circulate the coolant in the same direction.

6. The heat exchanger according to claim 1, characterized in that two inlets are in fluid communication with two non-adjacent sections for flow in a first pass through a first manifold.

7. The heat exchanger according to claim 6, characterized in that it comprises two additional sections located between the sections of the first pass to allow the coolant to flow in a second pass through the heat exchanger.

8. The heat exchanger according to claim 7, characterized in that it comprises an additional section for a third pass wherein the coolant from the second pass sections is combined in the third pass section and further comprises an outlet in fluid communication with the third pass section through a second header.

9. The heat exchanger according to claim 8, characterized in that it further comprises additional individual sections for flowing the coolant in additional steps each before flowing the coolant to the third passage section, such that the number of sections and steps from one inlet to the outlet is different from the other.

10. The heat exchanger according to claim 7, characterized in that it further comprises an outlet in fluid communication with the second passage sections through the first collector.

11. The heat exchanger according to claim 1, characterized in that the heat exchanger is a condenser.

12. The heat exchanger according to claim 11, characterized in that one of the sections comprises a subcooling section that is positioned to receive the greatest intensity of airflow in the uneven airflow distribution.

13. The heat exchanger according to claim 1, characterized in that the heat exchanger is an evaporator.

14. The heat exchanger according to claim 13, characterized in that one of the sections comprises a superheating section that is positioned to receive the greatest intensity of airflow in the uneven airflow distribution.

15. A heating, ventilation and air conditioning (“HVAC”) system characterized in that it comprises: an operable fan for generating an airflow with an irregular intensity distribution; and a heat exchanger comprising: microchannel tube sections for flowing refrigerant through at least one passage through the heat exchanger; and wherein the sections are configured to optimize heat exchange in accordance with the airflow through the heat exchanger.

16. The HVAC system according to claim 15, characterized in that the number of tubes in each section depends on the intensity of the airflow through each section.

17. The HVAC system according to claim 15, characterized in that the sections comprise fins having different geometries according to the intensity of the airflow through each section. MA / a / zuzz / ui 18. The HVAC system according to claim 15, characterized in that the tubes have different geometries according to the intensity of the airflow through each tube.

19. The HVAC system according to claim 15, characterized in that the non-adjacent sections are configured to circulate the refrigerant in the same direction.

20. The HVAC system according to claim 15, characterized in that two inlets are in fluid communication with two non-adjacent sections for flow in a first pass through a first header.

21. The HVAC system according to claim 20, characterized in that it comprises two additional sections located between the sections of the first pass to flow the refrigerant in a second pass through the heat exchanger.

22. The HVAC system according to claim 21, characterized in that it comprises an additional section for a third pass in which the refrigerant from the second pass sections is combined in the third pass section and further comprises an outlet in fluid communication with the third pass section through a second manifold.

23. The heat exchanger according to claim 22, characterized in that it further comprises additional individual sections for flowing the coolant in additional steps each before flowing the coolant to the third passage section, such that the number of sections and steps from one inlet to the outlet is different from the other.

24. The HVAC system according to claim 21, characterized in that it further comprises an outlet in fluid communication with the second passage sections through the first header.

25. The HVAC system according to claim 15, characterized in that the heat exchanger is a condenser.

26. The HVAC system according to claim 25, characterized in that one of the sections comprises a subcooling section that is positioned to receive the greatest intensity of airflow in the uneven airflow distribution.

27. The HVAC system according to claim 15, characterized in that the heat exchanger is an evaporator.

28. The HVAC system according to claim 27, characterized in that one of the sections comprises a superheating section that is positioned to receive the greatest intensity of airflow in the uneven distribution of airflow.

29. The HVAC system according to claim 15, characterized in that the fan rotates in a plane parallel to the heat exchanger.

30. The HVAC system according to claim 15, characterized in that the fan rotates in a plane perpendicular to the heat exchanger.

31. A method for manufacturing a heat exchanger to receive an airflow having an uneven intensity distribution through the heat exchanger and to flow refrigerant within the heat exchanger, characterized in that the method comprises: constructing a plurality of microchannel tube sections for flowing refrigerant through at least one passage through the heat exchanger; and configuring the sections in accordance with the airflow through the heat exchanger.

32. The method according to claim 31, characterized in that the configuration comprises selecting the number of tubes in each section depending on the intensity of the airflow through each section.

33. The method according to claim 31, characterized in that the configuration comprises selecting fin geometries for each section according to the intensity of the airflow through each section.

34. The method according to claim 31, characterized in that the configuration comprises selecting tube geometries according to the intensity of the airflow through each tube.

35. The method according to claim 31, characterized in that the configuration comprises arranging two non-adjacent sections for passage in the same direction.

36. The method according to claim 31, characterized in that the configuration comprises providing two inlets in fluid communication with two non-adjacent sections in a first pass through a first head.

37. The method according to claim 36, characterized in that the configuration comprises providing two additional sections located between the sections of the first pass to flow the coolant in a second pass through the heat exchanger.

38. The method according to claim 37, characterized in that the configuration comprises providing an additional section for a third step wherein the coolant from the second step sections is combined in the third step section and further provides an outlet in fluid communication with the third step section through a second header.

39. The method according to claim 38, characterized in that the configuration further comprises providing additional individual sections for flowing the refrigerant in additional passes, each before flowing the refrigerant to the third pass section, so that the number of sections and passes from one inlet to the outlet is different from the other.

40. The method according to claim 37, characterized in that the configuration further comprises providing an outlet in fluid communication with the second through-sections through the first head.

41. The method according to claim 31, characterized in that the construction comprises configuring the heat exchanger to act as a condenser.

42. The method according to claim 41, characterized in that the configuration comprises configuring a section as a subcooling section and positioning the subcooling section to receive the greatest intensity of airflow in the uneven airflow distribution.

43. The method according to claim 31, characterized in that the construction comprises configuring the heat exchanger to act as an evaporator.

44. The method according to claim 43, characterized in that the configuration comprises configuring a section as a superheating section and positioning the superheating section to receive the greatest intensity of airflow in the uneven airflow distribution.

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