Not applicable.
Not applicable.
Not applicable.
This disclosure relates generally to heating and cooling systems, and more particularly to a distributor assembly positioned between an expansion valve and a multi-circuit evaporator in a heating or cooling system. In a heat pump and refrigeration cycle, refrigerant alternately absorbs and gives up thermal energy as it circulates through the system and is compressed, condensed, expanded, and evaporated. In particular, a liquid refrigerant flows from a condenser, through an expansion device (e.g., expansion valve) and into an evaporator. As the refrigerant flows through the expansion device and evaporator, the pressure of the refrigerant decreases, the refrigerant phase changes into a gas, and the refrigerant absorbs thermal energy. From the evaporator, the gaseous refrigerant proceeds to a compressor, and then back to the condenser. As the refrigerant flows through the compressor and condenser, the pressure of the refrigerant increases, the refrigerant phase changes back into a liquid, and the refrigerant gives up thermal energy. The process is repeated to emit thermal energy into a space (e.g., heat a house) or remove thermal energy from a space (e.g., air condition a house).
Some conventional evaporators have a plurality of refrigerant flow paths or circuits, each flowing through a different portion of the evaporator. Such evaporators, referred to as multi-circuit evaporators, utilize a distributor device or assembly positioned upstream of the evaporator to divide and direct the flow of refrigerant from the expansion device into the plurality of circuits in the evaporator. The distributor assembly also functions to provide substantially equal distribution of gaseous and liquid refrigerant from the expansion device to each circuit of the evaporator and further to provide substantially even distribution of refrigerant to each of the evaporator circuits. Still further, the distributor assembly is configured to generate a pressure drop in the refrigerant flowing therethrough in route to the evaporator so that the pressure of the refrigerant continues to decrease and the refrigerant absorbs thermal energy, expands, and phase changes into a gas.
In some embodiments of the disclosure, a distributor assembly is provided that comprises a distributor extending along a central axis between a first end and a second end opposite the first end. The distributor may comprise a flow passage extending from the first end of the distributor and a plurality of feeder ports extending from the second end of the distributor to the flow passage, each feeder port being in fluid communication with the flow passage. Each feeder port may extend along a central axis from a first end at the flow passage to a second end at the second end of the distributor and each feeder port may comprises a first axial segment and a second axial segment, the first axial segment being connected between the flow passage and the second axial segment and the second axial segment being connected between the first axial segment and the second end of the distributor.
In other embodiments of the disclosure, a distributor assembly is provided that comprises a distributor extending along a central axis between a first end and a second end opposite the first end, the distributor comprising. The distributor may comprise a flow passage extending from the first end of the distributor and a plurality of feeder ports extending from the second end of the distributor to the flow passage, each feeder port being in fluid communication with the flow passage. Each feeder port may comprises a first axial segment and a second axial segment, the first axial segment being connected between the flow passage and the second axial segment and the second axial segment being connected between the first axial segment and the second end of the distributor, and at least two of the first axial segments may comprise different first axial segment diameters.
In still other embodiments of the disclosure, a method of modifying refrigerant distribution through a distributor assembly is disclosed that comprises at least one of (1) increasing a feeder port diameter and increasing a length of an associated feeder conduit and (2) decreasing a feeder port diameter and decreasing a length of an associated feeder conduit.
For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.
Distributor assemblies sometimes comprise a distributor and a plurality of elongate feeder tubes extending from the distributor to the evaporator. In some applications, the distributor may divide the flow of refrigerant into multiple flow paths, and each feeder tube may direct refrigerant from one of the divided flow paths to one of the evaporator circuits. To achieve a desired pressure drop across the distributor assembly, some conventional feeder tubes are relatively long—about 30 in. (˜0.76 m) long. Such relatively long feeder tubes may present design and servicing limitations since their size may limit the potential locations of certain components of the refrigeration system such as the distributor, the evaporator, etc. In addition, long feeder tubes may negatively impact access to other components of the system during servicing. Accordingly, the present disclosure provides more compact distributor assemblies that enable a sufficient refrigerant pressure drop, provide a lower cost alternative to conventional distributor assemblies, and allow easier servicing of a refrigeration system comprising the more compact distributor assemblies.
Referring now to
During each cycle, at least a portion of fluid refrigerant 60 may phase change from liquid to gas, or from gas to liquid. For example, in compressor 20, a substantially gaseous refrigerant 60 is compressed and pumped to condenser 30 where refrigerant 60 gives up thermal energy and condenses into a substantially liquid refrigerant 60. Thus, thermal energy is transferred from refrigerant 60 to the surrounding environment at condenser 30, thereby providing a heating effect at condenser 30. Liquid refrigerant 60 then flows from condenser 30 through expansion device 40 (e.g., an expansion valve) and distributor assembly 100 where it is expanded, undergoes a pressure reduction, and transitions into a mixed gaseous/liquid refrigerant 60. From distributor assembly 100, the mixed gaseous/liquid refrigerant 60 flows through evaporator 50 where refrigerant 60 absorbs thermal energy, and expands into a substantially gaseous refrigerant 60. Thus, thermal energy is transferred from the surrounding environment at evaporator 50 into refrigerant 60, thereby providing a cooling effect at evaporator 50. From evaporator 50, the substantially gaseous refrigerant 60 returns to the compressor 20 and the cycle repeats. It should be appreciated that system 10 is a closed-loop system, and thus, the mass flow rate of refrigerant 60 through any particular region of system 10 is substantially the same.
As described above, thermal energy is transferred from refrigerant 60 to the surrounding environment at condenser 30, and thermal energy is transferred from the surrounding environment to refrigerant 60 at evaporator 50. Depending on the location of evaporator 50 and condenser 30, system 10 may generally be used to provide heating or cooling. For example, system 10 may be arranged such that evaporator 50 absorbs heat from inside a house and gives up this absorbed heat outside through condenser 30, thereby providing air conditioning to the house. Alternatively, system 10 may be configured such that condenser 30 emits heat inside the house through condenser 30 and absorbs heat from outside the house through evaporator 50, thereby providing heat to the house. By inclusion of a reversing valve, the system shown in
Referring now to
During operation of system 10, refrigerant 60 from distributor assembly 100 enters one of the plurality of circuits 51 at its corresponding inlet 51a, flows downstream through the circuit 51 to its outlet 51b, where it then flows into discharge header 52 through its corresponding header inlet 52a. Refrigerant 60 enters header 52 from all of the circuits 51, recombines, and flows downstream through header outlet 52b to compressor 20. Thus, refrigerant 60 flowing through each circuit 51 comes together and recombines in header 52, and then flows to compressor 20 via outlet 52b.
As best shown in
Without being limited by this or any particular theory, an efficiency of the system (e.g., system 10) may be improved by (a) substantially evenly distributing the refrigerant across the plurality of feeder conduits of the distributor assembly (e.g., feeder conduits 150); (b) moving substantially the same mass flow rate of refrigerant through each feeder conduit; and (c) generating substantially the same pressure drop across each feeder conduit. Configuring and sizing each feeder conduit of the distributor assembly (e.g., each feeder conduit 150) substantially the same offers the potential to desirably achieve even distribution of refrigerant across the plurality of feeder conduits, uniform mass flow rate of refrigerant through each feeder conduit, and equal pressure drop across each feeder conduit. Accordingly, in some embodiments described herein, each feeder conduit of the distributor assembly (e.g., each feeder conduit 150) may be sized and configured substantially the same.
Referring still to
In general, the feeder conduits (e.g., conduits 150) may comprise any suitable materials including, without limitation, metals and metal alloys (e.g., stainless steel, brass, copper, aluminum, etc.), non-metal (e.g., ceramic), or composite (e.g., carbon fiber substrate and epoxy matrix composite). However, in some embodiments, the feeder conduits 150 may comprise corrosion resistant material(s) suitable for use with compressed refrigerants such as brass, copper, or aluminum. Although feeder conduits 150 shown in
Referring now to
Referring still to
Each feeder port 130 has a central or longitudinal axis 135, a first end 130a at its intersection with inlet flow passage 120, and a second end 130b at second end 110b of distributor 110. When refrigerant 60 flows through distributor 110 from first end 110a to second end 110b as shown in
First ends 130a of all the feeder ports 130 converge at second end 120b of inlet flow passage 120, and central axis 135 of each outlet feeder port 130 intersects at a common point 131 disposed on axes 115, 125. Further, as best shown in
Without being limited by this or any particular theory, an efficiency of the system (e.g., system 10) may be improved by (a) substantially evenly distributing the refrigerant across the plurality of feeder ports of the distributor (e.g., feeder ports 130 of distributor 110); (b) moving refrigerant at substantially the same mass flow rate through each feeder port; and (c) generating substantially the same pressure drop across each feeder port. Configuring, orienting, and sizing each feeder port of the distributor substantially the same offers the potential to achieve these performance characteristics. Accordingly, in some embodiments, each feeder port 130 may be configured and sized substantially the same.
Referring specifically to
Referring still to
Each feeder port 130 has a length L130 measured parallel to its axis 135 from its first end 130a at the intersection of axis 135 and axes 115, 125 to its second end 130b. In other words, length L130 of each feeder port 130 is measured parallel to its axis 135 from point 131 to its second end 130b. As noted above, in this embodiment, each feeder port 130 is configured and sized substantially the same, and thus, each feeder port 130 has substantially the same length L130. In some embodiments, the length of each feeder port of the distributor (e.g., the length L130 of each feeder port 130) may be between about ⅛ in. to about ½ in., and alternatively between about 0.2 in. to about 0.3 in.
In the embodiment shown in
Referring still to
In this embodiment, flow restrictor 140 is coupled to distributor 110 via an interference fit. However, in general, flow restrictor 140 may be coupled to distributor 110 within second counterbore 122 in any suitable manner including, without limitation, press fit, adhesive, brazing, welding, threaded, machined, and/or or combinations thereof. Due to the reduced diameter of orifice 141, and substantially constant mass flow rate through system 10, as refrigerant 60 flows through flow restrictor 140, refrigerant velocity generally increases and refrigerant pressure generally decreases as compared to the velocity and pressure of refrigerant immediately upstream of the orifice 141.
Due to the differences in diameters D121 and D122 and diameters D121 and D141, an annular shoulder 124 is formed in inlet flow passage 120 at the intersection of counterbores 121, 122. The abrupt change in the internal diameter of inlet flow passage 120 at shoulder 124 and flow restrictor 140 offers the potential to increase the turbulence of refrigerant flow through inlet flow passage 120, in some cases, increasing mixing of the liquid and gaseous phases of refrigerant 60 passing through inlet flow passage 120 and eventually into feeder ports 130. Without being limited by this or any particular theory, increased turbulence and mixing of refrigerant 60 flowing through inlet flow passage 120 may provide for more even distribution of refrigerant 60 among feeder ports 130.
Referring now to
Second axial segment 133 of each feeder port 130 has a substantially constant or substantially uniform diameter D133 that is greater than diameter D132. Consequently, the second axial segment 133 and second end 130b may also be referred to as forming a “counterbore” extending axially from distributor end 110b. As noted above, in this embodiment, each feeder port 130 is configured and sized substantially the same, and thus, diameter D133 of second axial segment 133 of each feeder port 130 is substantially the same. Second axial segment 133 of each feeder port 130 is adapted to receive end 150a of one of the feeder conduits 150. As best shown in
In general, each feeder conduit 150 may be coupled to its corresponding second axial segment 133 in any suitable manner including, without limitation, welding, brazing, mating threads, machining, etc. The connection between each second axial segment 133 and feeder conduit 150 may form a generally annular substantially fluid tight seal, thereby preventing refrigerant leaks and/or loss of refrigerant 60 flowing through distributor assembly 100.
Referring again to
In general, the distributor (e.g., distributor 110) may comprise any suitable material(s) including, without limitation, metals and metal alloys (e.g., stainless steel, aluminum, etc.), non-metal (e.g., ceramic), and/or composite (e.g., carbon fiber substrate and epoxy matrix composite). In some embodiments, the distributor 110 may comprise corrosion resistant material(s) suitable for use with compressed refrigerants such as aluminum and/or stainless steel.
In some embodiments, the feeder conduits 150 of the distributor assembly 100 may be significantly shorter than some conventional feeder conduits. In particular, some conventional feeder conduits have a length of about 30 in. In comparison, the length of some feeder conduits 150 of some embodiments of this disclosure may comprise a length L150 of each feeder conduit 150 that may be between about 10 in. to about 20 in., and alternatively between about 12 in. to about 15 in. However, it will be appreciated that if a feeder conduit of a conventional distributor assembly 100 were simply shortened, an overall pressure drop across the distributor assembly 100 would decrease. This disclosure provides systems and methods for maintaining an overall pressure drop across a distributor assembly 100 having shortened feeder conduits 150 as compared to conventional feeder conduits. In some embodiments, an overall pressure drop across the entire distributor assembly 100 is achieved and/or maintained in spite of having substantially shorter feeder conduits 150 (as compared to conventional feeder conduits) by selectively reducing a diameter of a feeder port 130.
Referring again to
Referring now to
Referring now to
More specifically, the method 600 may begin at block 602 by first analyzing an existing distributor assembly 100 configuration (either experimentally or through simulation) to gather data related to a functional relationship between diameters D132 and lengths L150 for a particular distributor assembly 100. In some embodiments, the data may be gathered as the result of noting system performance differences caused by at least one of selectively altering a diameter D132 and/or a length L150. In some embodiments, each of the lengths L150 may be altered by a same amount while keeping diameters D132 constant. Alternatively, in some embodiments, the lengths L150 may be altered by different amounts while keeping diameters D132 constant. Still further, in other embodiments, each of the diameters D132 may be altered by a same amount while keeping lengths L150 constant. Alternatively, in some embodiments, the diameters D132 may be altered by different amounts while keeping constant lengths L150.
Regardless of how the functional relationship between diameters D132 and lengths L150 are determined, at block 604, mathematical regression techniques may be used to produce a second-order polynomial equation that defines a relationship between diameters D132 and lengths L150. In some embodiments, an equation may take the form of: D132=a+b*L150, where the variables “a” and “b” are determined as a result of the above-described regression applied to the simulation and/or experimentation test results. In alternative embodiments, other regression techniques and/or methods may be used to generate relationships and/or equations of lesser or greater order (i.e., first degree polynomial equations, third degree polynomial equations, fourth degree polynomial equations, etc.).
Once the above-described equation has been generated, at block 606, a particular desired length L150 may be used in the above-described equation to determine an appropriate diameter D132 for use in designing a customized distributor assembly 100. It will be appreciated that a distributor assembly 100 comprising the particular desired length L150 and the appropriate diameter D132 would result in a distributor assembly 100 that generates substantially the same total pressure differential across the conventional distributor assembly studied above in block 602. Accordingly, by altering the conventional distributor assembly studied above in block 602 and mathematically modeled in block 604 to have the particular desired length L150 and the associated calculated appropriate diameter D132, a conventional distributor assembly that is normally restricted to operation with lengths L150 may customized to have any desired lengths L150 without incurring substantial detriments to operation.
While the above-described diameter D132 may be the preferred diameter D132, there is a high likelihood that the diameter determined above is not one that is easily implemented in a manufacturing environment. Accordingly, at block 608, the two nearest standardized drill bit sizes may be determined, regardless of systems of measurement (i.e., ANSI drill bit sizes, ISO metric drill sizes, and/or other).
Next, at block 610, the above-described desired length L150 in a first one of the two nearest standardized drill bit sizes may be used in the above-described simulation and/or experimental test setup to determine system performance results. Also block 610, a second one of the two nearest standard size drill bit sizes may be used in the above-described simulation and/or experimental test setup to determine another set of system performance results.
At block 612, a customized distributor assembly 100 may reliably be produced by selecting the one of the two nearest standardized drill bit sizes described above it has resulted in most desirable performance results.
In a first example of implementing blocks 606-612, a functional relationship between diameter D132 and length L150 may have been determined as: D132=0.0958+0.000997*L150 from performance of blocks 602-604. Accordingly, at block 606, where a desired length L150 is 15 in., the 15 in. value may be used in the above equation to determine that D132=0.110755 in. Next at block 608, because 0.110755 in. is not a standardized drill bit size, the two nearest drill bit sizes may be determined by determining the two nearest drill bit ANSI and ISO size. Particularly, with D132=0.110755 in., the value is bracketed by ANSI drill bit sizes #35 and #34, having sizes of 0.11 in. and 0.111 in., respectively. Similarly, with D132=0.110755 in., the value is bracketed by ISO drill bit sizes 2.8 mm and 2.9 mm, equating to sizes of 0.1102 in. and 0.1142 in., respectively. Accordingly, D132=0.110755 in. is most closely bracketed from below by the ISO drill bit size of 2.8 mm (with a difference of 0.000555 in.) and from above by the ANSI drill bit size #34 (with a difference of 0.000245 in.). Next, the 0.1102 in. and 0.111 in. values are substituted for the previously determined D132=0.110755 in. in the system performance evaluations of block 610. After comparing the performance results obtained at block 610, at block 612, D132 may be finally selected as the drill bit size yielding the most desirable performance results. The following table further demonstrates the relationship between diameter D132 and length L150 according to the equation of this example.
In other embodiments, alternative equations may be produced in blocks 602 and 604. For example, the relationship between diameter D132 and length L150 may be determined to be D132=−0.0630+0.000946*L150, or alternatively, D132=0.0816+0.00158*L150, among others. In determining the above equations, in some embodiments, some parameters of operation and/or simulation may generally be held constant amongst various experimental and/or simulation scenarios. For example, a mass flow rate of refrigerant may be held substantially constant at 100 lb/hr per each refrigerant circuit 51. Also, an internal diameter of feeder conduits may be held constant.
This disclosure contemplates providing distributor assemblies comprising different numbers and sizes of feeder ports and/or feeder conduits. Further this disclosure demonstrates that, in some embodiments, an overall pressure drop across a distributor assembly may be maintained in spite of the use of shorter feeder conduits and that overall pressure drop may be maintained by generating an internal pressure drop within the distributor to compensate for the loss in pressure drop attributable to the use of shorter feeder conduits. The use of feeder ports having reduced diameters in conjunction with feeder conduits having decreased lengths may provide a distributor assembly that may allow a reduced size and/or cost of manufacturing the distributor assembly. In some embodiments, reducing the length of the feeder conduits may reduce material costs to manufacture the distributor assembly while also providing a smaller distributor assembly. Further, one or more of the features and/or components of the distributor assemblies disclosed herein may comprise a so-called venturi profile, such as, but not limited to orifice 141 of flow restrictor 140. For example, in some alternative embodiments, the distributor may comprise a venturi profile comprising an initially large but decreasing diameter mouth. In some cases, a large chamfered interior wall of the distributor may transition to a curved or “bell-mouthed” wall and the walls may be formed integrally with a body of the distributor. Other alternative embodiments may comprise a sharp edged orifice. In some cases, a sharp edged orifice may comprise a thin plate with a small clean hole drilled through the thin plate. The sharp edged orifice may restrict flow regardless of fluid viscosity so that fluids of varying temperature and viscosity are restricted in substantially the same manner.
In some embodiments, a conventional distributor assembly may be retrofitted in accordance with the method of
Although climate control system 10 has been shown and described primarily from the perspective of an air conditioning system (i.e., to provide cooling to a space), embodiments of the distributor assembly (e.g., distributor assembly 100) and the distributor (e.g., distributor 110) described herein may be used in any suitable refrigerant based heating and/or cooling climate control systems. For example, the components shown in
At least one embodiment is disclosed and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, Rl, and an upper limit, Ru, is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=Rl+k*(Ru−Rl), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . 50 percent, 51 percent, 52 percent, . . . 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Use of the term “optionally” with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention.