Improving the efficiency of a thermodynamic machine

Abstract

Device (10) for transporting a refrigerant fluid in which a lubricant is dispersed. The device (10) comprises, in the direction of flow of the refrigerant fluid, a flared inlet chamber (1), a tube bundle (2), a single channel (3) and a narrowed outlet chamber (4), such that a primary flow of the refrigerant fluid passes through the inlet chamber (1) and divides into secondary flows in the tubes (2), the secondary flows opening into and merging in the single channel (3) before reaching the outlet chamber (4).

Description

Improving the efficiency of a thermodynamic machine

[0001] This application relates to the technical field of thermodynamic vapor compression machines. Technological background

[0002] A thermodynamic vapor compression machine typically comprises four elements: a compressor, a condenser, an expansion valve, and an evaporator. These four elements are connected in series in a closed fluid circuit containing a refrigerant. The refrigerant exchanges heat with a cold source and a hot sink via the evaporator and condenser, respectively. The machine extracts heat from the cold source and transfers it to the hot sink. Therefore, the machine can be used as a heat pump or as a refrigeration unit.

[0003] The four components of the fluid circuit are connected by pipes that transport the refrigerant from one component to the next. A pipe is characterized by its internal cross-sectional area, which limits the extent of the fluid flowing through the pipe perpendicular to its direction of flow, and by its length, which is equal to the length of the flow path within the pipe. The volumetric flow rate of the fluid in the pipe is then equal to the area of ​​the pipe's internal cross-sectional area multiplied by the fluid's flow velocity. In the following, the internal cross-sectional area of ​​a pipe, a section of a pipe, or any other component through which a fluid flows, is simply called the "cross-sectional area" and corresponds to the area through which the fluid passes.

[0004] Furthermore, in thermodynamic vapor compression machines, a lubricant is used to lubricate the compressor. For the machine to function correctly, the refrigerant in its gaseous form must be soluble in the lubricant. Lubricant and refrigerant combinations suitable for thermodynamic machines are part of the general knowledge of those skilled in the art. Examples include combinations consisting of a synthetic polyol ester-based lubricant, such as the oil marketed under the name "Emkarate RL32-3 MAF," and a refrigerant based on hydrochlorofluorocarbons (HCFCs), chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), or hydrofluoroolefins (HFOs), such as the fluids known as R407C, R410A, or R454C. Another example is combinations consisting of propane (R290) and alkylbenzene (AB) type oils.

[0005] Patent document EP 3071901 B1 describes devices integrated into a pipe and forming a pipe bulge, that is, an increase in the pipe's cross-section over a limited length, less than the total pipe length. This type of device is called a "bulge" by metonymy and comprises a flared inlet chamber through which the refrigerant enters and a constricted outlet chamber through which the refrigerant exits. An intermediate chamber fluidly connects the inlet and outlet chambers without fluid loss.

[0006] In the prior art, two types of bulges exist: parallel and series. In a parallel bulge, the refrigerant flow in the intermediate chamber is divided into parallel secondary flows through tubes grouped in a bundle. In a series bulge, the intermediate chamber consists of a single tubular channel, and the refrigerant flow is not divided. Configurations of vapor-compression thermodynamic machines incorporating one or two bulges are described in the prior art and are shown below.

[0007] One configuration features a single parallel bulge between the compressor and condenser, operating in the high-pressure gas phase for the refrigerant. The presence of this parallel bulge improves the thermodynamic efficiency of the heat pump.

[0008] A second configuration, improving upon the first, includes, in addition to a first parallel bulge between the compressor and the condenser, a second bulge between the condenser and the expansion valve, operating in a high-pressure liquid phase for the refrigerant. This second bulge is either a series or a parallel bulge. This second configuration offers better thermodynamic efficiency than the first.

[0009] To date, it is estimated that the improvement provided by these two configurations is linked to the transport of the lubricant, in the form of dispersed droplets, within the refrigerant. The bulges tend to regenerate or maintain this dispersion of lubricant droplets in a form conducive to improving heat exchange in the condenser and evaporator of the machine. The first bulge allows for the regeneration or maintenance of a lubricant mist (i.e., lubricant droplets in the gaseous refrigerant) between the compressor and the condenser. The second bulge allows for the formation of a dispersion of lubricant droplets in the liquid refrigerant (i.e., a kind of emulsion) between the condenser and the expansion valve.

[0010] In general, there is a constant need to improve thermodynamic machines. More specifically, an improvement in the thermodynamic efficiency of the second configuration mentioned above would be desirable. General presentation

[0011] According to a first aspect, the invention relates to a device for transporting a refrigerant in which a lubricant is dispersed. The device comprises, in the direction of refrigerant flow, a flared inlet chamber, i.e., of strictly increasing cross-section, a bundle of tubes, and a narrowed outlet chamber, i.e., of strictly decreasing cross-section. The device further comprises a single channel between the tube bundle and the outlet chamber, such that a primary flow of the refrigerant passes through the inlet chamber and divides into secondary flows in the tubes, the secondary flows exiting and reuniting in the single channel before reaching the outlet chamber.

[0012] In this application, a "tube bundle" refers to an assembly of elongated tubes oriented generally in the same direction, the orientation of the tubes corresponding to their longitudinal direction. Furthermore, a "tube" refers to a channel through which the refrigerant circulates. Each tube in the bundle is, by definition, elongated, meaning longer than it is wide. In other words, the length of the tube is greater than the largest dimension of its cross-section (for example, for a tube with a circular cross-section, the length of the tube is greater than its diameter). The tubes are isolated from one another: each tube defines an independent channel, and the refrigerant cannot flow from one tube to another. Moreover, the refrigerant cannot flow between the tubes (for example, the space between the tubes is sealed).The tubes therefore form the only passageway for the refrigerant, which allows the exact division of the primary flow into secondary flows in the tubes.

[0013] Such a device is intended for integration into a thermodynamic vapor compression machine. In some embodiments, the device is located downstream of the compressor and upstream of the machine's expansion valve, with upstream and downstream defined relative to the normal flow direction of the refrigerant in the machine's circuit. In particular, the device is located between the condenser and the machine's expansion valve. In some embodiments, the device is integrated into a two-bulge machine according to the second configuration mentioned above, as the second bulge between the condenser and the machine's expansion valve.

[0014] In some embodiments, the device is oriented vertically so that, from the inlet chamber to the outlet chamber, an upward flow of the refrigerant fluid is carried through it.

[0015] The tube bundle accelerates the refrigerant flow (increasing the flow velocity in the tubes compared to the flow velocity in the inlet chamber) and increases the turbulent kinetic energy in the tubes. To optimize this effect, the cross-sectional area of ​​the tubes is chosen to be sufficiently small compared to the cross-sectional area of ​​the inlet chamber. Thus, in some embodiments, the cross-sectional area of ​​the inlet chamber increases from an initial inlet section to a maximum section, and the cumulative cross-sectional area of ​​the tubes is less than or equal to 40% of the maximum cross-sectional area and / or the cross-sectional area of ​​a single tube is less than or equal to 10% of the maximum cross-sectional area.

[0016] The arrangement of the tube bundle and the single channel creates specific refrigerant flow conditions that affect the behavior of the lubricant droplets dispersed within the fluid. These specific flow conditions have unexpected effects on the operation of the heat exchanger. In particular, the inventors observed improved heat exchange in both heat exchangers (i.e., the evaporator and the condenser) of the machine. This improved heat exchange translates into an increase in the thermodynamic efficiency, or coefficient of performance (COP), of the machine. For example, compared to a machine with a first bulge in parallel and a second bulge in series or parallel, as described in the second configuration mentioned above, the measured improvement in COP is typically between 15 and 30%.

[0017] Certain parameters were chosen and measured to characterize the specific flow conditions created by the succession of the tube bundle and the single channel, namely the refrigerant flow velocity (in m / s), the turbulent kinetic energy (in m 2 / s 2 ) and the residence time (in s) of the lubricant drops in the single channel. These parameters evolve as follows.

[0018] Within the tube bundle, the refrigerant flow accelerates (increasing the flow velocity compared to the flow velocity in the inlet chamber), and turbulent zones appear. These turbulent zones are characterized by a non-zero turbulent kinetic energy, which is maximal within the tubes. As the tube length increases, the larger lubricant droplets are more likely to burst upon contact with the tube walls, breaking into smaller droplets. This results in smaller droplets at the tube outlet than at the inlet. To optimize this effect, the tube length must be sufficiently long. Therefore, in some embodiments, for each tube in the bundle, the ratio "Lt / Dt" of the tube length "Lt" to the largest dimension "Dt" of the tube cross-section is greater than or equal to 3 (i.e., 3 ≤ Lt / Dt).Conversely, excessive tube length can lead to a decrease in the turbulent flow intensity at the tube outlet, thus reducing residence times within the device. Therefore, in some embodiments, the Lt / Dt ratio is less than or equal to 10 (i.e., Lt / Dt ≤ 10), particularly less than or equal to 8. For example, for circular tubes with diameters between 4 mm and 9 mm, the tube length ranges from 12 mm to 72 mm. In the single channel, flow velocities decrease. The greater this deceleration, the longer the residence time of the lubricant droplets in the single channel.

[0019] The turbulence created in the tube bundle is dissipated in the single channel, resulting in a decrease in turbulent kinetic energy. The inventors have observed the influence of this decrease in turbulent kinetic energy on the desired COP improvement. In practice, the single channel must be sufficiently long to achieve a significant reduction in turbulent kinetic energy, ideally reaching a value of zero or near-zero turbulent kinetic energy. Thus, in some embodiments, the length of the single channel is at least twice the length of the tube bundle. In particular, the length of the single channel is at least four times the length of the tube bundle. In this application, lengths are measured along the general direction of fluid flow, and the length of an element corresponds to the maximum length of that element.

[0020] In some embodiments, the single channel has a constant cross-section. In particular, in some embodiments, the cross-section of the outlet chamber decreases between a larger cross-section and an outlet cross-section, while the single channel has a constant cross-section equal to the larger cross-section. This helps, among other things, to avoid creating turbulence in the single channel and the outlet chamber.

[0021] The onset of turbulence (vortices in the flow), and consequently the turbulent kinetic energy, reaches its maximum in the tube bundle. The highest COP gains are obtained at a limiting value for the turbulence kinetic energy. The inventors observed that beyond this limit, the COP gains decreased. Currently, it is believed that this limit is due to a decrease in lubricant droplet concentration resulting from the bursting of smaller droplets against the tube walls. To maintain this limit, the cumulative cross-sectional area of ​​the tubes (i.e., the sum of all the individual areas) must not be too small compared to the maximum cross-sectional area of ​​the inlet chamber.Thus, in some embodiments, the inlet chamber cross-section increases between an inlet cross-section and a maximum cross-section, and the cumulative area of ​​the tube cross-sections is greater than or equal to 17% of the area of ​​the maximum cross-section.

[0022] The aforementioned features and advantages, as well as others, will become apparent upon reading the detailed description that follows. This detailed description refers to the attached drawings.

[0023] The accompanying drawings are schematic and not necessarily to scale; their primary purpose is to illustrate the principles of the invention. In these drawings, identical elements (or parts of elements) are identified by the same reference numerals from one figure (Fig.) to the next. This figure schematically represents an example of a device according to the invention. This figure is a cross-sectional view, along section plane II-II, of the tube bundle forming part of the device. This figure schematically represents an example of a thermodynamic vapor compression machine. Detailed description

[0024] Specific embodiments of a device for transporting a refrigerant fluid in which a lubricant is dispersed are described in detail below, with reference to the example shown in the figures. These embodiments illustrate the features and advantages of the invention. It should be noted, however, that the invention is not limited to these embodiments or to the example shown.

[0025] In certain embodiments, and in the example shown, the device 10 is integrated into a pipe 50 in the sense that the device 10 is connected at its upstream end to an upstream pipe section 50A and at its downstream end to a downstream pipe section 50B. Upstream and downstream are defined with respect to the normal flow direction of the refrigerant. From upstream to downstream, the device extends along a principal axis AX.

[0026] In some embodiments and in the example of the, the upstream 50A and downstream 50B pipe sections are coaxial with axis AX and the main elements of the device 10 have axial symmetry around the axis AX.

[0027] In the direction of fluid flow, the device 10 extends over a length L from an inlet section S1 of an inlet chamber 1 to an outlet section S4 of an outlet chamber 4. The inlet chamber 1 is frustoconical and flared. The outlet chamber 4 is frustoconical and narrowed. The inlet chamber 1 extends over a length L1. Within the inlet chamber 1, the cross-section increases strictly from the upstream inlet section S1 to a maximum cross-section S2. The inlet chamber 1 thus ensures a gradual increase in the cross-sectional area for the refrigerant. The outlet chamber 4 extends over a length L4. Within the outlet chamber 4, the cross-section decreases strictly from a larger cross-section S3 to the downstream outlet section S4. In the example, the inlet section S1 and outlet section S4 are equal and correspond to the section of the pipe 50 upstream and downstream of the device 10.Device 10 forms a bulge in pipe 50.

[0028] The inlet chamber 1 and the outlet chamber 4 are fluidically connected, without fluid loss, by a tube bundle 2 that divides the refrigerant flow, and then by a single channel 3 that reunites the flow. The tube bundle 2 extends over a length L2. The single channel 3 extends over a length L3.

[0029] The tube bundle 2 is formed by placing tubes 2 side by side with a gap between them, it being understood that the refrigerant cannot flow between the tubes 2. In other words, the tubes 2 form the only path for the refrigerant. In the example shown, the tubes 2 are straight, parallel to each other, and radially offset around the main axis AX: a first series of peripheral tubes 22 is arranged in a first circle around the axis AX, and a second series of peripheral tubes 20 is arranged in a second circle (with a larger diameter than the first circle) around the axis AX. This arrangement of peripheral tubes 20 and 22 is completed by the addition of a central tube 24 with axis AX. The tubes 20, 22, and 24 can be radially aligned. Other arrangements and distributions of the tubes 2 can be considered.In the example, the cross-sectional area of ​​each tube 20, 22 and 24 is less than 10% of the cross-sectional area S2 and the cumulative cross-sectional area of ​​all tubes 20, 22 and 24 is less than 40% of the cross-sectional area S2.

[0030] Furthermore, the tube bundle 2 has a flat upstream end and a frustoconical downstream end, in that the upstream ends of the tubes 2 lie in the same plane, generally perpendicular to the AX axis, and the downstream ends of the tubes 2 lie within a frustocone centered on the AX axis. This configuration results in a more homogeneous velocity profile at the outlet of the tube bundle 2. Indeed, the velocity profile at the inlet of the tube bundle 2 (i.e., at the outlet of the inlet chamber 1) is not homogeneous: the velocity is at its maximum at the inlet of the central tube 24 and decreases with distance from the center. To ensure greater homogeneity of the velocity profile at the outlet of the tube bundle 2 (i.e., at the inlet of the single channel 3), the central tube 24 is longer than the peripheral tubes 22, which are themselves longer than the peripheral tubes 20.In other words, the length of tubes 2 decreases as you move away from the AX axis.

[0031] Furthermore, the cumulative area of ​​the cross-sections of tube 2 is at least equal to 17% of the area of ​​the maximum cross-section S2. For example, the cumulative area of ​​the cross-sections of tube 2 is between 17% and 35% of the area of ​​the maximum cross-section S2. In the example given, the cumulative area of ​​the cross-sections of the thirteen tubes 2 is equal to 28.4% of the area of ​​the maximum cross-section S2.

[0032] For example, for an inlet chamber 1 with a circular inlet section S1 of 16 mm diameter and a circular maximum section S2 of 34 mm diameter, the tube bundle 2 may comprise a central tube 24 with a circular cross-section of 8 mm diameter, a first series of four peripheral tubes 22 with a circular cross-section of 4 mm diameter, and a second series of eight peripheral tubes 20 with a circular cross-section of 6 mm diameter. The number and arrangement of the tubes 2 result from a compromise between flow division, the overall size of the tube bundle 2, and its efficiency.

[0033] The tube bundle 2 can be formed by a solid piece 25 traversed through and through by channels forming said tubes 2. For example, the tube bundle 2 can be made by drilling circular holes of constant diameter in a solid metal piece.

[0034] Device 10 can be made of copper, brass, stainless steel or any other material compatible with refrigerants, lubricants associated with these fluids, and the pressure and temperature levels reached in thermodynamic machines.

[0035] In the example shown, for a refrigerant flowing through device 10 (i.e., from left to right in this figure), the fluid exiting the upstream section of pipe 50A first encounters the inlet chamber 1, whose cross-section increases between the inlet cross-section S1 and the maximum cross-section S2, then an intermediate chamber 5 of constant cross-section, and finally the tube bundle 2. Typically, the cross-section of the intermediate chamber 5 is equal to the maximum cross-section S2. The intermediate chamber 5 fluidly connects the inlet chamber 1 and the tube bundle 2 without fluid loss. The intermediate chamber 5 is optional in that the inlet chamber 1 could open directly into the tube bundle 2. The inlet chamber 1 extends over a length L1. The chamber 5 extends over a length L5. The sum of the lengths L1 and L5 can be close to the length L2 of the tube bundle 2.

[0036] The tube bundle 2 divides the refrigerant flow exiting the inlet chamber 1, called the primary flow, into several secondary flows, each of the tubes 2 carrying one secondary flow.

[0037] The tube bundle 2 opens into a single channel 3, combining the secondary flows from the tubes 2 into a single flow. The entire flow thus passes through the single channel 3. The single channel 3 fluidly connects the tube bundle 2 and the outlet chamber 4 without fluid loss. The cross-sectional area of ​​the single channel 3 is equal to the largest cross-sectional area S3 of the outlet chamber 4, ensuring that the fluid passage from the single channel 3 to the outlet chamber 4 is turbulent.

[0038] Furthermore, the single channel 3 is the longest part of the device 10. In particular, the single channel 3 extends over a length L3 at least twice the length L2. This allows for the dissipation of the turbulent kinetic energy created in the tube bundle 2. The ratio of lengths L3 / L2 can be optimized using computational fluid dynamics (CFD) software to simulate fluid flows within a numerically modeled device 10 and to calculate the turbulent kinetic energy in the modeled device 10. The L3 / L2 ratio can be optimized, in particular, based on parameters such as the nature of the fluid or the input parameters (e.g., velocity, pressure, temperature) of the fluid in the device 10.

[0039] For example, for a total length L of device 10 measured between the inlet of the inlet chamber 1 and the outlet of the outlet chamber 4 (i.e., between the inlet sections S1 and outlet S4) of 30.5 cm, the length L1 of the inlet chamber is 0.6 cm, the length L5 of the intermediate chamber 5 is 1.9 cm, the length L2 of the tube bundle 2 is 3.2 cm, the length L3 of the single channel 3 is 22.6 cm, and the length L4 of the outlet chamber 4 is 2.2 cm. In this example, the length L3 of the single channel 3 is therefore slightly greater than 7 times the length L2 of the tube bundle 2. Thus, the device 10 comprises successively, in the direction of flow of the refrigerant, the inlet chamber 1 in which the cross-section is increasing, the intermediate chamber 5, the tube bundle 2 which divides the flow, the single channel 3 which reunites the flow and the outlet chamber 4 of decreasing cross-section.More generally, the device 10 includes inlet chambers 1 and outlet chambers 4 to increase and decrease the fluid passage cross-section respectively and, between these chambers, a part with parallel secondary fluid flows followed by a part with a single fluid flow.

[0040] Figure 100 schematically represents an example of a vapor compression thermodynamic machine. This machine comprises a closed circuit for containing a refrigerant in which a lubricant is dispersed. The closed circuit includes, in the direction of refrigerant flow, a compressor 51 (lubricated by the lubricant), a condenser 52, an expansion valve 53, and an evaporator 54. The refrigerant exchanges heat with a cold source and a hot sink via the evaporator 54 and the condenser 52, respectively. A first pipe 61 connects the compressor 51 to the condenser 52. A second pipe 62 connects the condenser 52 to the expansion valve 53. A third pipe 63 connects the expansion valve 53 to the evaporator 54. A fourth pipe 64 connects the evaporator 54 to the compressor 51. A first device 10 according to the invention is integrated into the second pipe 62. This first device 10 is similar to that described above and shown in Figures 1 and 2.In particular, this device 10 comprises an inlet chamber 1 and an outlet chamber 4 between which are interposed a bundle of tubes 2 and a single channel 3. The inlet chamber 1 is connected to an upstream portion 62A of the second conduit 62 and the outlet chamber 4 is connected to a downstream portion 62B of the second conduit 62.

[0041] The refrigerant circulating in the closed circuit of machine 100 and exiting the condenser 52 passes through the first device 10 before reaching the expansion valve 53. The refrigerant is then in its liquid form, and droplets of lubricant are dispersed within it. The device 10 can be oriented vertically so that the refrigerant flows upward from the inlet chamber 1 to the outlet chamber 4.

[0042] The machine 100 includes a second device 40 for transporting the refrigerant in which the lubricant is dispersed. The second device 40 comprises, in the direction of refrigerant flow, a flared inlet chamber 41, a tube bundle 42, and a constricted outlet chamber 44. The refrigerant flows through the second device 40 as follows: a primary flow of refrigerant passes through the inlet chamber 41 and divides into secondary flows in the tubes 42. The secondary flows exit and rejoin in the outlet chamber 44. The second device 40 is a "parallel bulge" as mentioned in the introduction. The first device 10 differs from the second device 40 at least by the presence of the single channel 3 between the tube bundle and the outlet chamber. Furthermore, the number and arrangement of the tubes 2 may differ from the number and arrangement of the tubes 42.

[0043] The second device 40 is integrated into the first pipe 61, with its inlet chamber 41 connected to an upstream section 61A of the first pipe 61 and its outlet chamber 44 connected to a downstream section 61B of the first pipe 61. Thus, the refrigerant exiting the compressor 51 passes through the second device 40 before reaching the condenser 52. The refrigerant is then in its gaseous form, and droplets of lubricant are dispersed within it. The second device 40 can be oriented vertically so that the refrigerant flows upward from the inlet chamber 41 to the outlet chamber 44.

[0044] The first device 10 improves the thermodynamic efficiency of the machine 100 compared with: (a) a machine 100 without a first device 10, (b) a machine 100 including a series bulge instead of the first device 10, and (c) a machine 100 including a parallel bulge instead of the first device 10. As an example, in case (b), for a thermodynamic machine operating as an air / water heat pump, with a refrigerant R454C, the measured improvement in COP is approximately 25%.

[0045] The embodiments described herein are given by way of illustration and not limitation. A person skilled in the art may readily, upon reading this description, modify these embodiments or examples, or consider others, while remaining within the scope of the invention. In particular, a person skilled in the art may readily consider variations comprising only some of the features of the embodiments described above, if those features alone are sufficient to provide one of the advantages of the invention. Furthermore, the various features of these embodiments or examples may be combined as described above or otherwise; the invention is not limited to the specific combinations described herein.In particular, unless otherwise specified, a feature described in relation to one embodiment can be applied in a similar manner to another embodiment.

Claims

Device for transporting a refrigerant fluid in which a lubricant is dispersed, the device (10) comprising, in the direction of flow of the refrigerant fluid, a flared inlet chamber (1), a tube bundle (2) and a narrowed outlet chamber (4), characterized in that it further comprises a single channel (3) between the tube bundle (2) and the outlet chamber (4), such that a primary flow of the refrigerant fluid passes through the inlet chamber (1) and divides into secondary flows in the tubes (2), the secondary flows exiting and joining in the single channel (3) before reaching the outlet chamber (4). Device according to claim 1, wherein, for each tube (2), the ratio of the length of the tube to the largest dimension of the cross-section of the tube is between 3 and 10. Device according to claim 1 or 2, wherein the tube bundle (2) extends over a first length (L2), wherein the single channel (3) extends over a second length (L3), and wherein the second length (L3) is at least equal to 2 times the first length (L2). Device according to any one of claims 1 to 3, wherein the cross-section of the inlet chamber (1) is increasing between an inlet cross-section (S1) and a maximum cross-section (S2), and wherein the cumulative area of ​​the cross-sections of the tubes (2) is greater than or equal to 17% of the area of ​​the maximum cross-section (S2) of the inlet chamber (1). Device according to any one of claims 1 to 4, wherein the cross-section of the inlet chamber (1) is increasing between an inlet cross-section (S1) and a maximum cross-section (S2), and wherein the cumulative area of ​​the cross-sections of the tubes (2) is less than or equal to 40% of the area of ​​the maximum cross-section (S2) of the inlet chamber (1). Device according to any one of claims 1 to 5, wherein the cross-section of the inlet chamber (1) is increasing between an inlet cross-section (S1) and a maximum cross-section (S2), and wherein the cross-sectional area of ​​each tube (2) is less than or equal to 10% of the area of ​​the maximum cross-section (S2). Device according to any one of claims 1 to 6, wherein the single channel (3) has a constant cross-section. Device according to claim 7, wherein the section of the outlet chamber (4) is decreasing between a larger section (S3) and an outlet section (S4), and wherein the single channel (3) has a constant section, equal to the larger section (S3). Device according to any one of claims 1 to 8, comprising an intermediate chamber (5) of constant cross-section between the inlet chamber (1) and the tube bundle (2). Device according to any one of claims 1 to 9, wherein the tube bundle (2) has a flat upstream end and a frustoconical downstream end. Thermodynamic vapor compression machine comprising: a closed circuit for containing a refrigerant fluid in which a lubricant is dispersed, and a first device (10) according to any one of claims 1 to 10. A thermodynamic vapor compression machine according to claim 11 comprising: a second device (40) for transporting the refrigerant in which the lubricant is dispersed, wherein the second device (40) comprises, in the direction of refrigerant flow, a second flared inlet chamber (41), a bundle of second tubes (42) and a second constricted outlet chamber (44), such that a primary flow of the refrigerant passes through the second inlet chamber (41) and divides into secondary flows in the second tubes (42), the secondary flows exiting and joining in the second outlet chamber (44), wherein the closed circuit comprises, in the direction of refrigerant flow, a compressor (51), a condenser (52), an expansion valve (53) and an evaporator (54), a first pipe (61) connecting the compressor (51) to the condenser (52),a second pipe (62) connecting the condenser (52) to the expansion valve (53), a third pipe (63) connecting the expansion valve (53) to the evaporator (54), and a fourth pipe (64) connecting the evaporator (54) to the compressor (51), wherein the first device (10) is integrated into the second pipe (62), the inlet chamber (1) being connected to an upstream portion (62A) of the second pipe (62) and the outlet chamber (4) being connected to a downstream portion (62B) of the second pipe (62), and wherein the second device (40) is integrated into the first pipe (61), the second inlet chamber (41) being connected to an upstream portion (61A) of the first pipe (61) and the second outlet chamber (44) being connected to a downstream portion (61B) of the first pipe (61). Thermodynamic vapor compression machine according to claim 11 or 12, wherein the first device (10) is oriented vertically so as to be traversed, from the inlet chamber (1) to the outlet chamber (4), by an upward flow of the refrigerant.

Images