Molded dispenser

Abstract

The present invention relates to a fluid distributor for heat exchangers, particularly dry expansion evaporators, which can be integrally molded and has a structure configured to achieve improved heat exchange performance.

Description

Technical Field

[0001] This invention relates to the field of aerodynamic systems, and in particular to the field of air conditioning systems.

[0002] More specifically, the present invention relates to a fluid distributor that can be integrally molded and features improved performance and construction, and is particularly suitable for use in dry expansion evaporators. Background Technology

[0003] In heat exchangers used in air conditioning systems, there are several types, particularly those for high cooling capacity, which include a casing—or outer shell—that houses a bundle of tubes. The working fluid flows within the tube bundle to exchange heat with process fluids at different temperatures.

[0004] In some heat exchangers, such as evaporators, the working fluid is typically an evaporative cooling fluid that circulates within the tube bundle and cools the process fluid. The process fluid flows through the heat exchanger from the outside of the tube bundle housed inside the outer casing.

[0005] Typically, refrigerant is supplied to the heat exchanger via supply pipes connected to the end units—or manifolds—of the heat exchanger. To direct the refrigerant into the tube bundle, the heat exchanger is usually equipped with a dedicated distributor.

[0006] Structurally, known distribution devices typically provide multiple supply pipes, each connecting to a corresponding tubular element of the tube bundle. However, this type of solution suffers from structural complexity because the structures used to connect the supply pipes require expensive and precise machining to maintain the desired output conditions while delivering fluid to each bundle of tubes.

[0007] Furthermore, this solution typically cannot guarantee uniform distribution of the refrigerant flow within the tube bundle, thus significantly reducing the performance of heat exchangers equipped with the aforementioned type of distributor.

[0008] Furthermore, in dry expansion evaporators, liquid distribution at the inlet plays a crucial role in the overall performance of the equipment. For example, in flooded evaporators, the outer shell acts as an "equalizer" after the distributor, as the refrigerant can move between areas of the shell and better wet the exchange tubes. In dry expansion evaporators, however, the refrigerant entering the exchange tubes is forced through the tubes to their ends, except for a small amount of recirculation.

[0009] This means that if the amount of refrigerant from the distributor entering the pipes is not well distributed among different areas of the pipe bundle, performance will drop sharply due to either an excess or deficiency of the liquid itself. The difficulty in achieving good liquid distribution lies mainly in the fact that, in most cases, the refrigerant flow reaching the evaporator is in a two-phase state, i.e., a mixture of liquid and gas; this makes the refrigerant flow turbulent and difficult to control in terms of liquid distribution.

[0010] To improve liquid distribution at the inlet of a dry expander evaporator, several technical / constructive measures are known to be provided.

[0011] For example, some solutions propose installing a mechanical component with suitable geometry and size at the inlet of the evaporator supply manifold to achieve a more turbulent refrigerant flow upstream of the tube sheet. This statistically increases the probability of better liquid distribution to the different tubes of the tube bundle, as other negative effects such as gravity and inertia become less relevant. However, a drawback of this solution is that it is nearly impossible to adequately cover all operating conditions and subsequent different flow patterns at the evaporator inlet with a single, fixed geometry / size.

[0012] In other cases, attempts are made to increase the pressure drop of the distributor, which has a positive effect on two-phase applications due to the strong relationship between flow rate and pressure drop, and proper sizing of the distributor elements helps to distribute the liquid between different areas of the tube bundle.

[0013] It is also known to use a distributor with dedicated power elements for each tube bundle, these power elements having a specific shape to control the flow of refrigerant reaching the tube bundle. A common construction of this solution involves an assembly between two capillary tubes and a base metal plate. The disadvantages of these solutions are that they are generally expensive and difficult to adapt to different tube bundle geometries. Summary of the Invention

[0014] Therefore, the technical problem proposed and solved by the present invention is to provide a fluid distributor for an exchanger, particularly for a dry expansion evaporator, which overcomes one or more of the disadvantages mentioned above with reference to the known art.

[0015] The above problem is solved by the distributor according to claim 1.

[0016] Preferred features of the invention are set forth in the dependent claims.

[0017] The present invention relates to a fluid distributor for a dry expander evaporator. This distributor includes a plate-shaped base element comprising a plurality of through-holes, each through-hole having a first inner wall.

[0018] A plurality of protrusions are arranged on one surface of the base element, each protrusion including a second inner wall defining a corresponding cavity of the protrusion.

[0019] Each through-hole is arranged below the corresponding protrusion, such that the first inner wall and the second inner wall are flush and define a fluid ejection chamber between them.

[0020] At least one protrusion includes a distal end opposite the base element, the distal end having an orifice to form a continuous fluid supply channel, the channel comprising, in sequence, a through hole (of the plate element), a cavity, and an orifice (of the protrusion).

[0021] Each of the multiple protrusions is integrally connected to the base element.

[0022] It should be understood that the present invention provides a distributor in which the element that allows the injection of cooling fluid is preferably integrally formed with the distributor itself by a die-casting process.

[0023] Advantageously, a distributor with great versatility can be obtained through a single mold, because the manufacturing process itself makes it suitable for exchangers of various sizes with different numbers of refrigeration loops—that is, tube bundles.

[0024] In particular, the raised distal end has orifices based on the design conditions of the evaporator and the design of the tube sheet, starting from a single basic design of the distributor, which can be applied to all different arrangements of tube sheets with the same evaporator shell diameter and number of refrigeration circuits.

[0025] For example, if the evaporator tube bundle has fifteen rows of exchange tubes, and the maximum number of rows that can be installed in the same evaporator model is twenty, then only fifteen rows of protrusions are perforated and have orifices at the far end, while the remaining five rows remain closed.

[0026] This versatility significantly reduces the complexity of implementing different distributors in the production cycle, thereby substantially reducing production costs. Furthermore, the proposed distributor enables the orifice to be machined in a simple manner with high and standardized quality independent of the operator, unlike known distributors where the capillary is subsequently welded to the base element depending on the application type and the type of tube sheet to which the distributor must be connected.

[0027] According to another aspect, the present invention provides a dispensing assembly comprising the aforementioned dispenser, inlet manifold, and tube sheet. The dispenser is disposed between the inlet manifold and the tube sheet and is hermetically connected to both the inlet manifold and the tube sheet, and one or more protruding orifices face corresponding openings in the tube sheet, the corresponding openings being configured to receive tube bundles.

[0028] Advantageously, when the dispensing components are connected, the extension of the protrusion in the direction perpendicular to the base element of the dispenser is equal to the distance between the tube sheet and the base element itself.

[0029] This construction offers the advantage of further simplifying the assembly of the dispensing components, as it eliminates the need for spacer elements present in known types of dispensers that ensure the correct positioning of the dispenser and prevent its movement toward the tube sheet. In this invention, such elements are integrated into the dispenser itself, which is configured to be directly supported on the tube sheet via orifice-free protrusions.

[0030] More preferably, the overall size of the distal end with the orifice is smaller than the size of the corresponding opening on the tube sheet facing the protrusion. In conjunction with the preferred embodiment, the dispenser includes a support device connecting two or more adjacent protrusions, the support device being designed to contact the tube sheet itself.

[0031] This solution achieves fluid communication between the internal volume of the exchanger tubes and the free volume existing between the distributor and the tube sheet. This feature is extremely advantageous because it defines a balanced chamber for distributing the fluid into the tube bundle, enabling the (refrigerating) fluid to recirculate between different tube bundle regions and improving the operating performance of the exchanger.

[0032] Other advantages, features, and modes of use of the invention will become apparent from the following detailed description of some embodiments, which are shown for illustrative purposes and not for limiting purposes. Attached Figure Description

[0033] Please refer to the diagram in the attached figure, where: Figure 1 An exploded view of a distributor assembly of a dual-loop evaporator including a fluid distributor, according to a preferred embodiment of the present invention, is shown. Figure 2 Show Figure 1 The distributor assembly shown is in a side sectional view with the components connected. Figure 3 A portion of the overall view of the dispenser according to an embodiment of the present invention is shown; Figure 4 yes Figure 3 Enlarged detail of the side sectional view, showing an embodiment of the connection between the protrusions of the dispenser; Figure 5 yes Figure 4 Further enlarged details show a preferred embodiment of the protrusion of the dispenser of the present invention; Figure 6 Show Figure 2 A magnified view of the details, showing the connection area of ​​the dispenser assembly components; Figure 7 Show Figure 1A cross-section of the overall view of the distributor assembly, showing the flow of fluid from the manifold to the tubing bundle; Figure 8 A top cross-section of a distributor assembly connected to a tube bundle with a reduced tube bank configuration is shown. Figure 9 yes Figure 8 The enlarged details show the protrusions of a dispenser modified according to an embodiment of the invention. Detailed Implementation

[0034] The invention will now be described with reference to the accompanying drawings.

[0035] First refer to Figure 1 and Figure 2 An exploded view of a preferred embodiment of a fluid, particularly refrigerant fluid distributor assembly is shown, generally indicated by reference numeral 50, and includes a distributor 100 according to the invention.

[0036] The distributor 100 of the present invention is intended for use in heat exchangers, preferably evaporators, particularly dry expansion evaporators.

[0037] In the illustrated embodiment, the distributor assembly 50 further includes a tube sheet 30 and a manifold 20 for allowing fluid to enter the distributor assembly 50. It can be seen that the distributor 100 is positioned between the manifold 20 and the tube sheet 30 and is hermetically connected to them. In the assembled state, the manifold 20 and the tube sheet 30 define a chamber in which the distributor 100 is disposed.

[0038] Manifold 20 is configured to receive fluid, particularly a two-phase refrigerant fluid, which enters the heat exchanger, and manifold 20 is connected to tube sheet 30 at a connection surface (denoted by reference numeral A). Typically, connection surface A is located in the peripheral region of manifold 20 and tube sheet 30, which are configured to allow for a flanged connection between them. This peripheral region may have a quadrilateral configuration, but different connection geometries are possible.

[0039] In the example shown, manifold 20 includes two inlets 21 for fluid. In variant embodiments, these inlets may have different numbers, such as one or four, depending on the operating mode of the exchanger in which the distributor assembly 50 will be assembled.

[0040] In its assembled state, the manifold 20 is formed as a hollow element through which fluid can flow toward the tube sheet 30. For this purpose, the manifold 20 preferably includes three fluid-sealed regions: a first sealed region with an inlet 21, a second region between the distributor 100 and the manifold 20 itself for defining the fluid supply chamber 22, and a third region in the peripheral region for connection with the tube sheet 30.

[0041] Tube sheet 30 includes a plurality of openings 31 configured to receive tube bundles, which are generally indicated by reference numeral 40. Tube sheet 30 is represented as a plate having a circular geometry, illustrating the tube sheet used in the art under consideration. However, the geometry of the illustrated tube sheet 30 is not limiting for the purposes of this invention.

[0042] Multiple openings 31 in the tube sheet 30 allow the inlet of the manifold 21 to be in fluid communication with the exchange tube of the tube bundle 40.

[0043] That is, each opening 31 of the tube sheet 30 is configured to connect to the end of a corresponding tubular element, in which refrigerant fluid flows during use.

[0044] The openings 31 of the tubes to which the tube bundle 40 is fixed are preferably arranged in vertical rows, staggered and contained within a specific range based on the mechanical and thermal design of the exchanger.

[0045] The overall configuration of the distributor assembly 50, which is assembled with the tube bundle 40, allows the tube bundle 40 to be arranged inside the housing of the exchanger (not shown in the figure).

[0046] Figure 1 and Figure 2 The example shown relates to a distributor assembly 50 for an evaporator with two refrigeration circuits. Therefore, the openings 31 of the plate 30 are grouped into two main outflow regions 30', each corresponding to an inlet of the manifold 21. Thus, two distributors 100 are provided for each outflow region 30'. The construction of the manifold 20 depends primarily on the size of the evaporator (in terms of diameter) and the number of refrigeration circuits.

[0047] However, it should be understood that the manifold 20 may be connected to a tube sheet 30 having a different distribution of openings 31 or a different number of outflow areas 30' than those shown.

[0048] Further reference Figures 3-5 A preferred embodiment of the dispenser 100 according to the present invention will now be described.

[0049] The dispenser 100 includes a base element 101 that is generally plate-shaped and has a plurality of through holes 102, in particular holes.

[0050] Each through-hole 102 includes a first inner wall 103 that defines the through-hole for fluid.

[0051] A plurality of protrusions 104 are also arranged on one surface 101A of the base element 101. Each protrusion 104 is hollow inside 104a and is defined by a corresponding inner wall 105 of the protrusion 104.

[0052] Each through-hole 102 of the base element 101 is arranged below a corresponding protrusion 104, such that the first inner wall 103 and the second inner wall 105 are flush, i.e., without interruption. Each of the plurality of protrusions 104 is integrally connected to the base element 101. The base element 101 and the plurality of protrusions 104 are preferably integrally formed by die casting. The dispenser 100 is preferably made of aluminum or an alloy thereof.

[0053] A set of through holes 102 and corresponding cavities 104a of protrusions 104 define a fluid injection chamber 107. In addition, one or more protrusions 104 include a distal end 104b—opposite to the face 101A of the base element 101 from which the protrusion 104 protrudes—with an orifice 108 to form a fluid supply channel toward the tube bundle 40.

[0054] The supply channel sequentially includes a through hole 102 in the base element 101, a cavity 104a in the protrusion 104, and an orifice 108 in the distal end 104b. In fact, in the assembled state of the dispenser assembly 50, the orifice 108 faces the corresponding opening 31 of the tube sheet 30.

[0055] The fluid entering the manifold then enters the aforementioned supply chamber 22, and subsequently flows through the supply channel into the injection chamber 107 of the distributor 100.

[0056] Preferably, the internal dimensions of the cavity 104a decrease from the base element 101 toward the distal end 104b. This internal dimension refers to the distance between points on the inner wall 105 of the cavity 104a that are opposite each other in the direction of extension of the protrusion 104.

[0057] Cavity 104a may, for example, have rotational symmetry about the extension axis P of the protrusion 104 projecting from base element 101. In embodiments, cavity 104a may be conical or truncated conical.

[0058] More preferably, the internal dimensions of the injection chamber 107 gradually decrease from the through-hole 102 toward the distal end 104b. The fluid injection chamber 107 is preferably a conical chamber converging toward the distal end 104b of the protrusion 104. Advantageously, this specific shape of the injection chamber 107 ensures improved mixing of the two-phase fluids flowing into the heat exchange tubes 40 of the tube sheet 30 and has a positive impact on exchanger performance.

[0059] According to a preferred embodiment of the distributor 100, the size of the orifice 108 is smaller than the size of the corresponding through hole 102 of the base element 101. Each orifice 108 is preferably a hole with a calibrated diameter and can be advantageously implemented using a CNC machine tool. Advantageously, the distributor 100 provides two or more protrusions 104 with orifices 108 of different sizes.

[0060] Therefore, it is possible to obtain different types of distributors with high construction quality but using simple and inexpensive processes, wherein each distributor in principle realizes different operating conditions of the exchanger, because the protrusions can be customized by creating orifices of different widths at the stage of manufacturing the distributor using the same mold.

[0061] It should be noted that, for the purposes of this invention, it is not required that all protrusions 104 of the distributor 100 have orifices 108. According to the advantageous aspects which will be described in more detail below, some protrusions 104 may not have orifices 108, thus preventing fluid communication between the injection chamber 107 and the exchange tubes 40 of the tube sheet 30. This choice of construction, allowing some protrusions 104 to lack their own orifices, makes the distributor 100 more versatile and adaptable to different types of heat exchangers, for example, those with varying numbers of refrigerant flow channels.

[0062] In a preferred embodiment, even the external dimensions of the protrusion 104 decrease from the base element 101 toward the distal end 104b. The external dimension refers to the overall dimension of the protrusion 104 body, that is, the distance between relative points on the outer surface of the protrusion 104 relative to the direction of extension of the protrusion itself.

[0063] According to the embodiment shown, each protrusion 104 protrudes vertically from the base element 101, i.e., protrudes according to an extending axis P orthogonal to the plane including the base element 101.

[0064] In addition, the distributor 100 advantageously includes a support device that connects two or more adjacent protrusions 104 and is intended to contact the tube sheet 30.

[0065] This feature is preferably implemented in conjunction with the following aspect characterizing the dispenser: the amount by which the protrusion 104 extends relative to the plane including the base element 101. This extension is equal to the distance between the tube sheet 30 and the base element 101, and in particular the protrusion 104 from the surface 101A of the base element from which it protrudes.

[0066] Further reference Figures 6-7 The distributor 100—in the state of being assembled in the distributor assembly 50—faces the orifice 108 toward the outflow portion E, which further includes a corresponding opening 31 in the tube sheet 30, thereby establishing fluid communication between the supply chamber 22, the injection chamber 107 and the heat exchange tube 40.

[0067] The support device serves as a spaced element from the tube sheet 30 and ensures the correct positioning of the distributor 100 relative to the tube sheet 30 by contacting the tube sheet 30, while also preventing the distributor 100 from moving further toward the tube sheet 30.

[0068] In one embodiment, the support device takes the form of connecting ribs 109 that connect the distal ends 104b of adjacent protrusions 104. These connecting ribs 109 provide a connection that provides a support surface for the distributor in one direction to achieve spatial contact with the corresponding adjacent openings 31 (staggered heat exchange tubes 40) carried by the tube sheet 30.

[0069] According to a variation of the embodiment, this support device 109 may further include one or more distal ends 104b of a protrusion 104 without an opening 108. Further reference... Figure 8 and Figure 9 For example, the number of openings 31 on the distal end 104b of the protrusion 104 with orifice 108 on the tube sheet 30 is less than the total number of protrusions 104 on the distributor 100. In this case, the extra protrusions 104 do not have orifices 108 at their own distal ends 104b.

[0070] It should be understood that the dispenser 100 of the present invention is constructed as a self-supporting element, wherein the protrusion 104, due to its extension from the height of the base element 101 itself, ensures a secure connection between the dispenser 100 itself and the manifold 20.

[0071] Preferably, this connection is perfected by the presence of a fluid sealing device to ensure a seal between the supply chamber 22 and the balance chamber B, wherein the fluid sealing device... Figure 1 The balancing chamber B is exemplarily shown by using two washers indicated by the same reference numeral 10, which define the spacer 100 between the tube sheet 30.

[0072] Advantageously, the support device 109 is further configured to push the distributor 100 toward the sealing device 10, which is arranged between the distributor 100 and the manifold 20.

[0073] like Figure 7 As is clearly visible, in a particularly advantageous embodiment of the invention, the overall size of the distal end 104b of the protrusion 104 is smaller than the size of the corresponding opening 31 of the tube sheet 30 facing the protrusion.

[0074] In other words, in the assembled state of the dispenser assembly 50, the outflow portion E is not completely occupied by the distal end 104b of the protrusion 104, and the distal end 104b is not inserted into the tube sheet 30.

[0075] The net outflow portion is an annular surface surrounding the outer dimensions of the distal end 104b of the protrusion 104. In this example, the annular surface is represented in the form of a ring.

[0076] Based on the pressure difference existing between the inlet and outlet of tube bundle 40, fluid moving from injection chamber 107 through the supply channel to its associated exchange tube 40—as indicated by arrow F—can flow back through outflow portion E, enter balancing chamber B, and reach outflow portions E associated with different nearby exchange tubes 40—as indicated by arrow F'. The fluid filling balancing chamber B migrates towards the less supplied tube bundle 40 to ensure pressure differential balance across tube bundle 40.

[0077] It should be understood that the balancing chamber B advantageously enables fluid recirculation between the different bundles 40 and helps to homogenize the flow rate. That is, there is a space located between the surface 101A of the distributor 100 facing the tube sheet 30 and the surface A of the tube sheet 30 itself with openings 31 configured to receive (or carry) the exchange tubes 40, which keeps the exchange tubes 40 in fluid communication and can balance any imbalances that may exist in the distribution.

[0078] The present invention has now been described with reference to preferred embodiments. It should be understood that other embodiments of the same inventive core may exist, which fall within the scope of protection defined by the appended claims.

Claims

1. A fluid distributor (100) for a heat exchanger, particularly a dry expansion evaporator, said distributor comprising: The plate-shaped base element (101) includes a plurality of through holes (102), each through hole having a first inner wall (103). Multiple protrusions (104) are arranged on the surface (101A) of the base element (101), each protrusion (104) including a second inner wall (105) defining a cavity (104a) of the protrusion. Each through hole (102) is arranged below the corresponding protrusion (104), such that the first inner wall (103) and the second inner wall (105) are flush, and a jet chamber (107) is defined between the first inner wall (103) and the second inner wall (105). At least one protrusion (104) includes a distal end (104b) opposite the base element (101), the distal end having an orifice (108) to form a fluid supply channel, the fluid supply channel comprising the through hole (102), the cavity (104a) and the orifice (108) in sequence. Each of the plurality of protrusions (104) is integrally connected to the base element (101).

2. The distributor (100) according to claim 1, wherein, The base element (101) and the plurality of protrusions (104) are integrally formed by die casting.

3. The distributor (100) according to claim 1 or 2, wherein, The internal dimensions of the cavity (104a) decrease from the base element (101) toward the distal end (104b).

4. The distributor (100) according to claim 3, wherein, The internal dimensions of the injection chamber (107) decrease from the through-hole (102) toward the distal end (104b).

5. The dispenser (100) according to claim 3 or 4, wherein, The size of the orifice (108) is smaller than the size of the corresponding through hole (102).

6. The dispenser (100) according to one or more of the preceding claims, wherein, The external dimensions of the protrusion (104) decrease from the base element (101) toward the distal end (104b).

7. The dispenser (100) according to one or more of the preceding claims, wherein, Two or more of the protrusions (104) include orifices (108) of different sizes.

8. The distributor (100) according to one or more of the preceding claims further includes a support device (109) that connects two or more adjacent protrusions (104) and is intended to contact the tube sheet (30) of the heat exchanger.

9. The dispenser (100) according to one or more of the preceding claims, wherein, The plurality of protrusions (104) protrude vertically from the base element (101).

10. A fluid dispensing assembly (50), comprising: Inlet manifold (20). The tube sheet (30) includes a plurality of openings (31) configured to receive a bundle of tubes (40). According to one or more of the preceding claims, the distributor (100) is disposed between the inlet manifold (20) and the tube sheet (30) and is hermetically connected to the inlet manifold (20) and the tube sheet (30). One or more protrusions (104) have an orifice (108) at their distal ends (104b) facing the corresponding opening (31) of the tube sheet (30).

11. The dispensing component (50) according to the preceding claim, wherein, The extension of the protrusion (104) relative to the plane including the base element (101) is equal to the distance between the tube sheet (30) and the base element (101).

12. The dispensing component (50) according to claim 10 or 11, wherein, The overall size of the distal end (104b) of at least one protrusion (104) is smaller than the size of the corresponding opening (31) of the tube sheet (30) facing the at least one protrusion.

13. The dispensing component (50) according to any one of claims 10 to 12, wherein, The number of openings (31) on the corresponding distal end (104b) of the tube sheet (30) facing the protrusion (104) with orifice (108) is equal to or less than the total number of protrusions (104) of the distributor (100), wherein the excess protrusions (104) do not have orifices (108) at the distal end (104b).

14. The dispensing component (50) according to any one of claims 10 to 13, comprising the dispenser (100) according to claim 8 or 9, wherein, The support device (109) is configured to push the distributor (100) toward the sealing device (10), which is arranged between the distributor (100) and the manifold (20).

15. A dry expansion evaporator, comprising: shell, The dispensing component (50) according to any one of claims 10 to 14. Tube bundle (40) is arranged inside the housing, wherein the end of each tube of the tube bundle (40) is connected to an opening (31) of the tube sheet (30) of the distribution assembly (50).

Images