Liquid injection rod and tank with at least one such rod

Abstract

The invention relates to a liquid injection lance (1) intended to be mounted through the wall of a reservoir and to extend partially into the internal volume of said reservoir, said lance (1) comprising a tubular body (3) which is open at one end (4) and closed at its opposite end (4'), and which has at least one lateral opening (5, 5') in an invasive portion of the tubular body (3) intended to be located within the reservoir. The lance (1) is characterized in that the tubular body (3) has two openings (5 and 5') in the form of two slits extending over a fraction of the length of the invasive portion of the tubular body (3) and along the longitudinal axis of this invasive portion, and where applicable, of the tubular body (3).

Description

[0001] The present invention relates to the field of liquid storage equipment, in particular hot water storage tanks or so-called "buffer" tanks, and has as its object a liquid injection lance and a tank comprising at least one such lance.

[0002] Many injection cane designs are already known, for example from documents FR 2976348, DE 10 2009 002 712 and EP 0 881 438.

[0003] In the context of a domestic hot water storage tank or buffer tank, it is desirable to provide and maintain water temperature stratification for optimal user comfort. Since water is drawn for user needs from the upper part of the tank, such stratification allows for the preservation of a significant reserve (relative to the tank's volume) of the hottest water in this section, for domestic hot water and / or heating needs.

[0004] However, in the case of a tank of this type supplied by an external hot water source, the injection of heated water tends to disrupt this stratification, and therefore reduce the associated user comfort. Furthermore, maintaining this stratification increases the performance and efficiency of the entire hot water supply system.

[0005] This problem is particularly acute when the external hot water source is a heat pump, which typically has a high injection flow rate combined with a small temperature differential in the injected water. It is therefore important and desirable to be able to reduce the hot water injection velocity, break the inertial force of the flow along its injection direction, and distribute the injected flow as evenly as possible within the tank, avoiding significant turbulence and mixing, all while not substantially limiting the maximum permissible injection flow rate.

[0006] However, the known injection lances mentioned above do not allow for a satisfactory response to this complex problem, with a concern for achieving and preserving thermal stratification of the liquid in the tank concerned.

[0007] Thus, the main objective of the present invention is to overcome the limitations of these known achievements and to meet the demand expressed, in particular in an application context related to a hot water storage tank or a so-called "buffer" tank, and in particular in relation to the implementation of a heat pump or a similar heat generator with high flow rate and low temperature delta.

[0008] To this end, the invention relates to a liquid injection pipe for a tank, in particular an injection pipe for a domestic hot water tank or buffer tank, intended to be mounted through the wall of said tank and to extend partially into the internal volume of said tank, said pipe comprising a tubular body which is open at one end and closed at its opposite end, and which has at least one lateral opening in an invasive part of the tubular body intended to be located in the tank, characterized in that the tubular body has two openings in the form of two slits extending over a fraction of the length of the invasive part of the tubular body and along the longitudinal axis of this invasive part, and where appropriate of the tubular body.

[0009] The invention will be better understood from the following description, which relates to a preferred embodiment, given by way of non-limiting example, and explained with reference to the accompanying schematic drawings, in which: [ Fig. 1 ] is a perspective view of an injection cannula according to the invention; [ Fig. 2A] et [Fig. 2B ] are respectively side elevation and top elevation views of the cane shown figure 1 ; Fig. 3 ] is a cross-sectional view along AA (and therefore along plane PP) of the cane shown figure 2A ; Fig. 4A] et [Fig. 4B ] are views at a different scale of details B and C of the figure 3 ; Fig. 5 ] is a cross-sectional view along DD of the cane shown figure 2A ; Fig. 6 ] is a partial (upper part only) cross-sectional view along a vertical plane of a reservoir comprising an injection lance according to the invention; [ Fig. 7 ] is a view at a different scale of detail E of the figure 6 .

[0010] THE figures 1 à 5 illustrate by way of example in accordance with the invention, a liquid injection lance (1) for a tank (2), in particular an injection lance for a domestic hot water tank or buffer tank, intended to be mounted through the wall (2') of said tank (2) and to extend partially into the internal volume of said tank (2), said lance (1) comprising a tubular body (3) which is open at one end (4) and closed at its opposite end (4'), and which has at least one lateral opening (5, 5') in an invasive part (3') of the tubular body (3) intended to be located in the tank (2).

[0011] According to the invention, this cane (1) is characterized in that the tubular body (3) has two openings (5 and 5') in the form of two slits extending over a fraction of the length of the invasive part (3') of the tubular body (3) and along the longitudinal axis (AL) of this invasive part (3'), and where appropriate of the tubular body (3).

[0012] The two slits (5 and 5') are preferably identical in terms of dimensions and shapes, and advantageously both located in the same position of the invasive part (3') of the cane (3) in the longitudinal direction along the axis (AL).

[0013] Thanks to these provisions, the invention provides an injection lance (1) that achieves the intended objective. Indeed, the inventors observed that implementing an injection lance (1) specifically featuring two continuous slots (5 and 5') as injection openings resulted in a reduction of the inertial forces of the injected flows and their structuring into two laminar / stratified flows, delivered in bands or layers, which integrate relatively continuously into the thermally stratified fluidic structure of the reservoir (2) in question. Thus, the solution proposed by the invention does not significantly disrupt the stratified distribution of the liquid along a vertical thermal gradient in a reservoir (2) equipped with such an injection lance (1).

[0014] Advantageously, and as shown in the aforementioned figures, the tubular body (3) has a straight structure along its entire length and a circular or elliptical section.

[0015] In order to direct the flows downwards in the tank, while simultaneously breaking the kinetic energy of the two liquid flows injected into the internal volume of the tank (by causing them to impact the tank wall before reaching the lowest part of the tank), it can advantageously be provided that the two slots (5 and 5') are both located i) on either side and at the same distance from a plane of symmetry (PS) of the tubular body (3) containing its longitudinal axis (AL), and ii) on the same side and at the same distance from a plane (PP) perpendicular to said plane of symmetry (PS) and also containing the longitudinal axis (AL) (see figure 4 notably).

[0016] In accordance with a highly favorable design variant, the normals (N5, N5') to the planes (PLS) of the passage sections of the two slots (5 and 5') both form an identical angle (A) with a plane of symmetry (PS) of the tubular body (3) containing its longitudinal axis (AL), the value of said angle being less than 90°, in particular between 75° and 55°, advantageously between 70° and 65°, preferably on the order of approximately 70°. Most preferably, the two slots (5 and 5') are located on the same side and at the same distance from a plane (PP) perpendicular to said plane of symmetry (PS).

[0017] In particular, and as illustrated by the figures 5 et 6 , when the rod (1) is mounted in a tank (2) with thermal stratification along a vertical direction (coinciding with the axis of revolution AR on the figure 5 ), and that the plane (PP) then coincides with the horizontal plane (PH), the two slits (5 and 5') are located below said plane (PP, PH) and the two aforementioned normals (N5 and N5') are inclined at an angle of (90°-A) with respect to said plane (PP, PH). Consequently, the liquid layer located above the pipe (1), and more generally the entire resident static (thermally stratified) fluidic structure, are not significantly disturbed, or at least only to a much lesser extent than with existing solutions.

[0018] To allow easy identification of the orientation around the axis (AL) of the rod (1) during its assembly, and as marked on the figure 2B , the tubular body (3) advantageously includes at its open end (4), located opposite its invasive part (3'), a visual index (6) for locating the position in rotation around the longitudinal axis (AL) of said tubular body (3).

[0019] As an example, the visual index (6) may consist of a local modification of the wall of the tubular body (3), for example a deformation or a cut of this wall, such as a hole or a lug, or even a simple marking.

[0020] To facilitate its assembly and locking in position, the tubular body (3) may also include, at its open end (4), a mounting collar or flange (7), for example in the form of a washer fixed by welding, and is closed at its opposite end (4') by an added plate (7'), and for example secured by welding, the mounting collar or flange (7) possibly including a visual index (6) for locating the position in rotation around the longitudinal axis (AL).

[0021] In accordance with a first variant of the embodiment not shown, the two slots (5 and 5') have a constant width over their entire length.

[0022] In accordance with a second preferred embodiment variant and shown in the attached figures, the two slots (5 and 5') have a width which decreases continuously and progressively towards the closed end of the tubular body (3), preferably in a straight line.

[0023] This characteristic allows the inertia of the injected fluid to be distributed proportionally over the entire longitudinal extension length of the slots, between the portions of the slots close to the open end (4) of the tubular body (3) and the portions of the slots (5,5') close to the closed end (4').

[0024] To promote ejection at a reduced velocity but with a still substantial flow rate, the combined cross-sectional area of ​​the two openings (5 and 5') is between 3 and 9 times, advantageously between 4 and 7 times, and preferably between 5 and 6 times, the cross-sectional area of ​​the tubular body (3). This cross-sectional area ratio prevents an excessively small cross-section at the point where the nozzle passes through the internal volume of the reservoir from causing an increase in the injection velocity and therefore the kinetic energy of the liquid upon its entry into the resident liquid mass.

[0025] Additionally, and still with the aim of limiting the disturbances and destratifications that could be caused by the injection, it can be provided that the two continuous slit-shaped openings (5 and 5') each extend over approximately 85% to 99%, preferably approximately 90% to 95%, of the length of the invasive portion (3') of the tubular body (3). Such a distribution of the two flows over a large outlet width (or outlet length along the AL axis) further facilitates a smooth introduction of the injected fluid into the stratified distribution of the resident fluid volume.

[0026] As a practical implementation, and for an injection cannula (1) having an internal diameter of approximately 42 mm and an invasive portion length (3') of approximately 570 mm, each of the slits (5, 5') has a length of approximately 550 mm and a width that decreases continuously and straight down from 5 mm at its widest end to 1.5 mm at its narrowest end (preferably, and as shown in particular by the figures 1 et 2A (The slots are pointed cutouts with a symmetrical structure and rounded ends).

[0027] The invention also relates, as shown partially and by way of example, to figures 6 And 7, a tank (2), in particular a domestic hot water tank or buffer tank, which includes at least one liquid injection pipe (1), this pipe (1) being mounted through the wall (2') of said tank (2) and extending partially into the internal volume of said tank (2), with its longitudinal axis (AL) located in a horizontal plane (PH) and directed towards the center of said internal volume.

[0028] According to the invention, this reservoir is characterized in that said at least one injection lance is an injection lance (1) as described above. Preferably, said or each lance (1) is advantageously arranged such that the plane of symmetry (PS) of the tubular body (3), containing the longitudinal axis (AL) and equidistant from the two slots (5 and 5') of the lance (1) considered, is perpendicular to the horizontal plane (PH) and that the two slots (5 and 5') are directed towards the bottom of the reservoir (2).

[0029] The longitudinal axis (AL) of the injection lance(s) (1) advantageously passes through the center of the reservoir (2), and intersects the vertical axis of symmetry of the latter (particularly when it has a cylindrical shape with a circular axis of revolution AR, see figure 6 Advantageously, the slots (5 and 5') extend substantially from the wall (2') of the tank to at least the center of the tank (2).

[0030] In accordance with a constructive variant of the invention, illustrated more precisely on the figure 7 , the or each injection lance (1) is mounted, preferably in a substantially adjusted manner and with shimming, in a tubular nozzle or sleeve (8) forming a sealed passage through the wall (2') of said reservoir (2) and integral with this wall and integral with this wall.

[0031] The invasive portion (3') in contact with the internal volume is defined by this sleeve (8), which advantageously receives the tubular body with minimal play and over a sufficient length to ensure rigid retention. This invasive portion (3') may or may not extend to the center of the reservoir, or even beyond.

[0032] According to an optional feature in this variant, the nozzle or sleeve (8) is provided at its outer end (8') with a means (9) for blocking the translation of the injection lance (1) along the longitudinal axis (AL), this means (9) simultaneously achieving a leak-proof coupling of said lance (1), at its open end (4) provided with a mounting collar or flange (7), with, on the one hand, the nozzle or sleeve (8), advantageously also provided with a collar or flange, and, on the other hand, with an external conduit (9') (only a portion of whose end is shown in the figure 7 ).

[0033] The locking and coupling means (9) may, for example, include, as shown in the figure 7 , a nut mounted on the end of the conduit (9') to be connected and intended to cooperate with an external thread of the end (8') of the fitting or sleeve (8). The seal at the two connection interfaces of the pipe (1) / fitting (8) / conduit (9') can, for example, be achieved by flat gaskets compressed by tightening the nut.

[0034] According to a first embodiment, the reservoir (2) is provided to have a single injection lance (1) disposed at a variable height in the reservoir (2) according to the desired fractionation of the internal volume of said reservoir (2), for example substantially at mid-height.

[0035] According to a second embodiment, the reservoir (2) is provided to have at least two injection rods (1) arranged at different heights in said reservoir (2), the longitudinal axes (AL) of these rods being preferably located in the same vertical plane.

[0036] Of course, the invention is not limited to the embodiment described and shown in the accompanying drawings. Modifications remain possible, particularly with regard to the composition of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

1. Liquid injection pipe (1) for a tank (2), in particular an injection pipe for a domestic hot water tank or buffer tank, intended to be mounted through the wall (2') of said tank (2) and to extend partially into the internal volume of said tank (2), said pipe (1) comprising a tubular body (3) which is open at one end (4) and closed at its opposite end (4'), and which has at least one lateral opening (5, 5') in an invasive portion (3') of the tubular body (3) intended to be located in the tank (2), pipe (1) characterized in that the tubular body (3) has two openings (5 and 5') in the form of two slits extending over a fraction of the length of the invasive part (3') of the tubular body (3) and along the longitudinal axis (AL) of this invasive part (3'), and where applicable of the tubular body (3).

2. Cane (1) according to claim 1, characterized in thatthe tubular body (3) has a straight structure along its entire length and a circular or elliptical section.

3. Cane (1) according to claim 1 or 2, characterized in that the two slots (5 and 5') are both located i) on either side and at the same distance from a plane of symmetry (PS) of the tubular body (3) containing the longitudinal axis (AL) of the latter and ii) on the same side and at the same distance from a plane (PP) perpendicular to said plane of symmetry (PS) and also containing the longitudinal axis (AL).

4. Cane according to any one of claims 1 to 3, characterized in thatthe normals (N5, N5') respectively to the planes (PLS) of the passage sections of the two slots (5 and 5') both form an identical angle (A) with a plane of symmetry (PS) of the tubular body (3) containing the longitudinal axis (AL) of the latter, the value of said angle being between 75° and 55°, advantageously between 70° and 65°, preferably of the order of about 70°, the two slots (5 and 5') being located on the same side and at the same distance from a plane (PP) perpendicular to said plane of symmetry (PS).

5. Cane according to any one of claims 1 to 4, characterized in that the tubular body (3) has, at its open end (4), located opposite its invasive part (3'), a visual index (6) for locating the position in rotation around the longitudinal axis (AL) of said tubular body (3).

6. Cane (1) according to claim 5, characterized in thatthe visual index (6) consists of a local modification of the wall of the tubular body (3), for example a deformation or a cut of this wall, such as a hole or a lug.

7. Cane according to any one of claims 1 to 6, characterized in that the tubular body (3) has, at its open end (4), a mounting flange or flange (7), for example in the form of a washer fixed by welding, and is closed at its opposite end (4') by an added plate (7'), and for example secured by welding, the mounting flange or flange (7) possibly having a visual index (6) for locating the position in rotation around the longitudinal axis (AL).

8. Cane according to any one of claims 1 to 7, characterized in that that the two slots (5 and 5') have a constant width along their entire length.

9. Cane according to any one of claims 1 to 7, characterized in thatthe two slots (5 and 5') have a width which decreases continuously and progressively towards the closed end of the tubular body (3).

10. Cane according to any one of claims 1 to 9, characterized in that the value of the cumulative passage section of the two openings (5 and 5') represents between 3 and 9 times, advantageously between 4 and 7 times, preferably between 5 and 6 times, the value of the passage section of the tubular body (3).

11. Cane according to any one of claims 1 to 10, characterized in that the two slit-shaped openings (5 and 5') extend over approximately 85% to 99%, preferentially over approximately 90% to 95% of the length of the invasive part (3') of the tubular body (3).

12. Tank (2), in particular domestic hot water tank or buffer tank, which includes at least one liquid injection pipe (1), this pipe (1) being mounted through the wall (2') of said tank (2) and extending partially into the internal volume of said tank (2), with its longitudinal axis (AL) situated in a horizontal plane (PH) and directed towards the center of said internal volume, tank (12) characterized in that said at least one injection lance (1) is an injection lance according to any one of claims 1 to 11, said or each lance (1) being advantageously arranged such that the plane of symmetry (PS) of the tubular body (3), containing the longitudinal axis (AL) and equidistant from the two slots (5 and 5') of the lance (1) considered, is perpendicular to the horizontal plane (PH) and that the two slots (5 and 5') are directed towards the bottom of the reservoir (2).

13. Reservoir (2) according to claim 12, characterized in thatthe or each injection lance (1) is mounted, preferably in a substantially adjusted manner and with shimming, in a tubular nozzle or sleeve (8) forming a sealed passage through the wall (2') of said reservoir (2) and integral with this wall.

14. Reservoir (2) according to claim 13, characterized in that the nozzle or sleeve (8) is provided at its outer end (8') with a means (9) for blocking the translation of the injection lance (1) along the longitudinal axis (AL), this means (9) simultaneously achieving a tight coupling of said lance (1), at its open end (4) provided with a mounting collar or flange (7), with, on the one hand, the nozzle or sleeve (8), advantageously also provided with a collar or flange, and, on the other hand, with an external conduit (9').

15. Reservoir (2) according to any one of claims 12 to 14, characterized in thatIt comprises a single injection lance (1) disposed at a variable height in the reservoir (2) according to the desired fractionation of the internal volume of said reservoir (2), for example substantially at mid-height.

16. Reservoir (2) according to any one of claims 12 to 14, characterized in that it comprises at least two injection rods (1) arranged at different heights in said reservoir (2), the longitudinal axes (AL) of these rods being preferably located in the same vertical plane.

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