EP2174075B1 - Thermodynamic system employing a device for producing heat by passing a fluid at pressure through a plurality of tubes - Google Patents

Abstract

The present invention provides a secondary heat production device (5) for fitting to a closed circuit thermodynamic system associating main heat production means (1) operating by compressing a fluid and a heat exchanger (2) that are interconnected by a fluid flow channel (3). The device (5) is mainly constituted by a plurality of individual channels (8, 9) interposed between an inlet chamber (11) and an outlet chamber (13), each of the chambers (11, 13) including a respective inlet or outlet pipe (10, 12) on a common axis and presenting respective identical main sections corresponding to the total section of the individual channels (8, 9).

Description

The present invention is in the field of thermodynamics, and more particularly in the field of heat generating apparatus from the operation of a fluid under pressure. It relates to a device for producing heat from a flow through a fluid under pressure.

In the field of thermodynamics, it is known systems associating means for producing heat by compression of a first fluid, in particular gas, which use a compressor, and means for exploiting the heat produced which implement A heat exchanger apparatus is used between the first fluid maintained under pressure and a second fluid. Such systems include more particularly the compressor, to put the first fluid under high pressure such as of the order of 30 bar for example, a channel for conveying the first compressed fluid between the compressor and the exchanger, and the latter. The system is in particular organized in closed circuit inside which circulates the first pressurized fluid, this closed circuit comprising the compressor and the exchanger, which are interconnected by said channel. It will be understood that this channel comprises a supply line, interposed in the direction of flow of the fluid between the compressor and the exchanger, and a return pipe interposed always in the direction of flow of the fluid between the exchanger and the compressor. In general, the temperature of the first fluid at the outlet of the compressor is dependent on its nature and the pressure to which it is subjected. Such systems may be placed downstream of a refrigeration unit, using a heat pump in particular, or a geothermal group for example. The document FR 2,850,738 describes a device of the prior art.

The object of the present invention is to propose a thermodynamic system comprising a device associating main means for producing heat by compression of a fluid, and a heat exchanger, which are interconnected by a fluid channel. The device of the present invention is in particular a secondary device for producing heat, intended to increase the temperature of the compressed fluid upstream of the exchanger in the direction of circulation of the fluid inside the system. More particularly, the device of the present invention aims to increase the heat generated by the first fluid at the outlet of the compressor and upstream of the exchanger, without substantially modifying the set pressure of the fluid inside the major part of the system, this setpoint pressure corresponding to that obtained under the effect of the compressor.

The inventive step of the present invention was in its entirety to organize at least in part the channel carrying the compressed fluid between the compressor and the exchanger in the fluid flow direction, in a plurality of elementary channels. In order to avoid a significant change in the pressure and / or the target flow rate of the fluid conveyed inside the system, on the one hand the main section of the outlet channel of the compressor and on the inlet side of the exchanger is identical, and on the other hand, the cumulative sections of the elementary channels are of the order nearest to said main section.

It surprisingly appeared that such an organization of the routing channel caused a significant increase in the heat of the fluid, compared in input and output of the secondary channels. Depending on the nature and the pressure of the fluid circulating inside the system, this measured increase can reach 50% of the initial fluid temperature. compressor output. By way of example, the fluid being freon maintained at a pressure of the order of 30 bar, the temperature of the fluid at the inlet of the elementary channels is of the order of 100 ° C. while the temperature of the fluid at the outlet of the elementary channels and of the order of 150 ° C.

There then arises an additional difficulty to be overcome which lies in maintaining the pressure of the fluid at the set pressure, despite the geometric structural organization of the transformation of the channel between a main section manifold and a plurality of elementary section manifolds. and vice versa. More particularly, it is necessary to avoid the consequences of a possible change in fluid pressure due to its passage through the secondary channels relative to the set pressure of the fluid flowing in the remainder of the system. Such a change in pressure is likely to result from the formation of a throttling and / or expansion chamber in the passage areas of the channel between its main section and its elementary sections, and vice versa. For this, the present invention secondarily proposes to organize the geometric structure of these passage zones to avoid the consequences of such a possible modification of fluid pressure.

Firstly, the input passage area of the elementary channels from a main section input conduit in relation to the main channel to the plurality of elementary sections is organized into an input chamber. This inlet chamber on the one hand provides a progressive increase in the main section of the inlet pipe, in particular from a widening of its outlet facing the elementary channels, and on the other hand by a reverse inclination outlets of the elementary channels facing the outlet of the entry pipe. Preferably, the slope of this inverse inclination is to be considered in a globalized manner for all the corresponding outlets of the elementary channels juxtaposed. However, according to another variant embodiment, the inclination of the outlets of the elementary channels is individualized, nevertheless following for each of the elementary channels a inverse slope to the flare of the corresponding outlet of the inlet pipe. The juxtaposition of the elementary channels is notably composed of a juxtaposition of peripheral elementary channels, which are radially offset around the axis of the input pipe. This juxtaposition of peripheral elementary channels is preferably completed by the addition of a median elementary channel coaxial with the input pipe. In this case and more particularly, the flaring of the outlet of the inlet pipe is of the order of between 45 ° and 75 °, and is arranged in the overall view of all the outlets of the peripheral elementary channels, or even if necessary, the median elementary channel. The inverse inclination slope of the peripheral elementary channels, preferably considered global in relation to an overall angle with respect to the axis of the inlet duct, is of the order of between 90 ° and 160 °. Appropriate values appear to be 60 ° for flaring out of the inlet duct and 120 ° for the angle corresponding to the inverse inclination slope of the peripheral elementary channels.

Secondly, the exit zone of the elementary channels towards a main section outlet pipe is organized in an outlet chamber generally arranged as a Venturi device. More particularly, the outlets of the peripheral elementary channels facing the outflow outlet outlet are inclined in a slope oriented in a direction similar to the slope of a flare that includes the outlet outlet outlet. Preferably, the slope of the inclination of the outlets of the peripheral elementary channels is to be considered in a globalized manner for all the outlets of the peripheral elementary channels. However, according to another variant embodiment, the inclination of the outlets of the peripheral elementary channels is individualized, nevertheless according to each of the elementary channels a slope oriented in a direction similar to the slope of the flare of the corresponding outlet of the outlet pipe. . More particularly, the flare of the outflow of the outlet pipe is of the order of between 30 ° and 50 °, and is arranged in the overall view of all the outlets of the peripheral elementary channels, or even the case of the middle elemental channel. The inclination slope of the peripheral elementary channels, preferably considered global in relation to an overall angle with respect to the axis of the outlet duct, is of the order between 180 ° and 270 °. Suitable values are 40 ° for flaring out of the outlet duct and 240 ° for the angle corresponding to the inclination slope of the peripheral elementary channels.

In general, the present invention relates to a closed circuit thermodynamic system associating main means for producing heat by compressing a fluid and a heat exchanger, comprising a secondary heat production device. The heat generating means and the exchanger are in particular interconnected by a channel for conveying the fluid under pressure.

According to the present invention, such a device is recognizable in that it consists mainly of a plurality of elementary channels interposed between an inlet chamber and an outlet chamber. Each of these chambers has an inlet and outlet duct, respectively, which are coaxial, and which are respectively identical in main section and corresponding to the cumulative section of the elementary ducts.

The elementary channels are preferably arranged side by side, leaving a gap between them. These elementary channels comprise in particular peripheral elementary channels which are radially offset around the common axis of the inlet and outlet ducts, or even a median elementary duct coaxial with the inlet and outlet ducts.

The inlet chamber more particularly forms a flare of the outlet of the inlet pipe generally on the elementary channels. In addition, the inlet chamber more particularly forms an inclination of outlets of the peripheral elementary channels on the inlet duct following an orientation slope opposite to the slope of the flare of the outlet of the duct. input. As referred to above, the inclination of the outlets of the elementary channels is likely to be individualized for each of the elementary channels, with in particular respective slopes according to their own position with respect to the axis of the inlet duct, or to be globalized for all the outlets of the peripheral elementary channels. For example, in the latter case, the inlet chamber forms a second flare on which the peripheral elementary channels open, this second flare being of inversely oriented slope to the slope of the flare of the outlet of the inlet duct.

Preferably, the outlet chamber is generally organized into Venturi effect device. The outlet chamber more particularly forms a flare of the outlet outlet outlet generally on the elementary channels. In addition, the outlet chamber more particularly forms an inclination of outlets of the peripheral elementary channels on the outlet duct along an orientation slope similar to the orientation of the slope of the flare of the outflow of the outlet duct. As referred to above, the inclination of the outlets of the elementary channels is likely to be individualized for each of the elementary channels, including respective slopes according to their own position relative to the axis of the outlet pipe, or to be globalized for all outlets for peripheral elementary channels. For example in the latter case, the outlet chamber forms a second flare on which the peripheral elementary channels open, this second flare being of slope of an orientation similar to the slope of the flare of the outflow of the outlet pipe.

The device is indifferently monobloc and / or composed of elements assembled together reversibly. Such elements may be assembled together by screwing or by means of reported and / or integrated assembly members. In the case of a one-piece connection of the elements to each other, such a connection can be made by gluing, welding or the like.

According to an exemplary embodiment of the invention, the device comprises a pair of bodies respectively input and output. The inlet pipe extended by the inlet chamber is formed inside the inlet body. The outlet pipe extended by the outlet chamber is formed inside the output body. Such internal arrangements of the bodies may be made by machining or molding, for example, or similar techniques. The bodies are connected to each other by the elementary channels. These are advantageously constituted by conduits made by stretching material or similar techniques. The constituent material of the conduits at least, if not also of the bodies, is a metal whose thermal coefficient is high, such as copper and / or brass. The bodies are provided with assembly means on respective outlets of a channel for conveying a fluid under pressure. These assembly means are indifferently reversible assembly means, such as by screwing or similar technique, and / or irreversible assembly means such as by gluing, welding or similar techniques. Preferably, the assembly means comprise thermally insulating junction members which are intended to be interposed between the bodies and the outlets of the corresponding routing channel.

Preferably, the elementary channels are jointly surrounded by a thermally insulating sheath, which advantageously prevents heat radiation from the elementary channels, for a part to secure the device vis-à-vis the outside, and on the other hand to avoid an untimely loss of heat and to promote heat exchange between the elementary channels and the fluid.

• La fig.1 est un schéma illustrant un système thermodynamique équipé d'un dispositif de la présente invention.
• La fig.2 est un schéma en coupe axiale illustrant un dispositif de la présente invention selon un exemple préféré de réalisation.
• La fig.3 est un détail représentant une chambre d'entrée que comporte le dispositif illustré sur la fig.2.
• La fig.4 est un détail représentant une chambre de sortie que comporte le dispositif illustré sur la fig.2.

The present invention will be better understood, and details will arise from the description which will be made of a preferred embodiment, in connection with the figures of the attached plates, wherein:

• The fig.1 is a diagram illustrating a thermodynamic system equipped with a device of the present invention.
• The fig.2 is an axial sectional diagram illustrating a device of the present invention according to a preferred embodiment.
• The fig.3 is a detail representing an entrance chamber that includes the device shown on the fig.2 .
• The fig.4 is a detail representing an exit chamber that includes the device illustrated on the fig.2 .

On the fig.1 a thermodynamic system associates mainly main means of heat production 1 and a heat exchanger 2. A main closed circuit conveys under high pressure a first coolant, such as Freon or similar fluid, between the main means of heat production 1 and the exchanger 2, which are interconnected by a routing channel 3 of the first fluid. The first fluid flows through the exchanger 2 for heating a second fluid, which is used for a heating installation for example. The heat generating means 1 use a compressor 4 or similar device of the heat pump type in particular, for compressing the first fluid at high pressure, such as of the order of 30 bar.

To increase the heat production of the first fluid, a device of the invention 5 is placed on the delivery channel 3 interposed between the compressor 4 and the exchanger 2 in the fluid flow direction. This device 5 is a secondary heat production device, intended to increase the heat of the first fluid as it passes through it.

On the fig.2 , the device 5 of the invention mainly comprises two bodies 6 and 7 intended to be connected to respective outlets of the conveying channel 3. These bodies, respectively inlet 6 and outlet 7 with respect to the direction of circulation of the fluid , are interconnected by elementary channels 8, 9, the accumulated sections of which are of the order of the main one of the routing channel 3. Inside these bodies 6, 7, are provided respectively for the body of inlet 6 an inlet pipe 10 and an inlet chamber 11, and for the outlet body 7 an outlet pipe 12 and an outlet chamber 13. The inlet pipe 10 and outlet pipe 13 are coaxial, and are a respective section of the order of the main channel of the routing channel 3. The input bodies 6 and output 7 are provided with respective connecting means at the corresponding outlet of the routing channel 3, comprising organs junction 14 thermally insulating. These joining members 14 consist of intermediate rings of thermally insulating material, such as bakelite or similar material. Preferably, these assembly means are reversible assembly means, to allow installation of the device 5 on a pre-existing thermodynamic system.

Elementary channels 8, 9 are in plurality. Peripheral peripheral channels 8 are radially distributed around the general axis A of the input and output conduits 6 7. These peripheral elementary channels 8 are in number chosen according to a compromise between the main section of the routing channel 3 to be subdivided. in a plurality of elementary sections relating to the elementary channels 8, 9, the size of the device 5 and its effectiveness. It appeared that such a compromise led to a number of peripheral elementary channels 8 of between three and twelve, this number being ideally of the order of eight. Preferably, the elementary channels also comprise a central elementary channel 9 coaxial with the input and output lines 12.

A thermally insulating sheath 15 envelopes at least the elementary channels 8, 9, being in engagement with the input 6 and output 7 bodies. Such a sheath 15 can be put in place by threading the sleeve 15 over the body 6, 7, to which it is preferably fixed, indifferently permanently and / or removably to possibly allow access to the elementary channels 8, 9 and the input 6 and output 7 bodies.

The input 6 and output 7 bodies are each composed of at least two elementary bodies 16, 17 and 18, 19 assembled to each other, to facilitate the formation of the inlet and outlet chambers. The elementary bodies 16,17; 18,19 are assembled to one another by means of fixing indifferently reversibly, such as by screwing or similar technique, and / or irreversibly such as by gluing and / or welding or other similar techniques.

The elementary channels 8, 9 are connected at their respective ends to the input 6 and output 7 bodies by means of connecting means, in an undifferentially reversible manner, such as by interlocking or similar technique, and / or irreversible, the aforementioned interlocking being completed by gluing and / or welding operations or other similar techniques.

On the fig.3 , the inlet chamber 11 is organized to limit the hydraulic head losses during the passage of the fluid from the inlet pipe 10 to the elementary channels 8, 9. In the first place, the outlet of the inlet duct 10 facing the elementary channels 8, 9 comprises a first flaring 20 of an angle B1 of the order of 60 °. This first flare 20 is in particular formed in a first elementary body 16 of the input body 6. In the second place, the outlets of the elementary channels, and more particularly the peripheral elementary channels 8, facing the inlet duct 10 exhibit inclination 21 of opposite orientation to that of the slope of the first flaring 20 that comprises the outlet of the inlet duct 10. This inclination 21 is formed from a second flare that comprises a second elementary body 17 of the input body 6. The first and second flares 20,21 of the input body 6 are in particular coaxial with the common axis A of the input and output ducts 12. The inclination 21 of the outlets of the peripheral elementary channels 8 is to be considered globally for these outlets. The slope of the inclination 21, corresponding to the slope of the second flaring that comprises the input body 6, forms an overall angle B2 of the order of 120 ° with respect to the axis of the inlet pipe. An appropriate proportion of the angle B2 with respect to the angle B1 is of the order of twice.

On the fig.4 the outlet chamber 13 is arranged as a Venturi device. More particularly and firstly, the outlet of the outlet duct 12 facing the elementary channels 8, 9 comprises a first flaring 22 of an angle B3 of the order of 40 °. This first flare 22 is formed in particular inside a first elementary body 18 of the output body 7. In the second place, the outlets of the elementary channels, and more particularly the peripheral elementary channels 8, facing the outlet duct 12 have an inclination 23 of the same orientation as that of the slope of the first flaring 20 that comprises the outlet outlet outlet 12. This inclination 23 is formed from a second flaring that comprises a second elementary body 19 of the body of 7. The first and second flares 22, 23 of the output body 7 are in particular coaxial with the common axis A of the inlet and outlet ducts 12. In this, the inclination 23 of the outlets of the peripheral elementary channels 8 is to be considered globally for these outlets. The slope of the inclination 23, corresponding to the slope of the second flaring that comprises the output body 7, forms an overall angle B4 of the order of 240 ° with respect to the axis A of the outlet duct 12. The appropriate proportion of the angle B4 with respect to the angle B3 is of the order of six times greater.

Claims (10)

1. A closed circuit thermodynamic system associating main heat production means (1) operating by compressing a fluid and a heat exchanger (2) that are interconnected by a flow channel (3) for fluid under pressure, the system being characterized in that it includes at least one secondary heat production device (5) comprising a plurality of individual channels (8, 9) interposed between an inlet chamber (11) and an outlet chamber (13), each of the chambers (11, 13) having a respective inlet or outlet pipe (10 or 12) of identical respective main sections corresponding to the total section of the individual channels (8, 9), the individual channels comprising peripheral individual channels (8) that are radially offset around a common axis (A) shared by the inlet and outlet pipes (10 and 12), which lie on a common axis, said device (5) being placed in the flow channel (3) interposed in the fluid flow direction between the main heat production means (1) and the heat exchanger (2).
2. A system according to claim 1, characterized in that the individual channels further comprise a middle individual channel (9) lying on the same axis as the inlet and outlet pipes (10 and 12).
3. A system according to either preceding claim, characterized in that the inlet chamber (11) forms a flare (20) at the outlet of the inlet pipe (10) leading generally to the individual channels (8, 9).
4. A system according to claim 3, characterized in that the inlet chamber (11) forms an angle of inclination (21) made up of the inlets to the peripheral individual channels (8) facing the inlet pipe (10) with a slope of orientation that is opposite to the slope of the flare (20) at the outlet from the inlet pipe (10).
5. A system according to any preceding claim, characterized in that the outlet chamber (13) is generally organized as a Venturi effect device.
6. A system according to claim 5, characterized in that the outlet chamber (13) forms a flare (22) constituting the inlet to the outlet pipe (12) facing the individual channels (8, 9).
7. A system according to claim 6, characterized in that the outlet chamber (12) forms an angle of inclination (23) made up of the outlets from the peripheral individual channels (8) facing the outlet pipe (12) with a slope of orientation analogous to the orientation of the slope of the flare (22) at the inlet of the outlet pipe (12).
8. A system according to any preceding claim, characterized in that it may equally well be a single piece and/or made up of elements assembled to one another.
9. A system according to any preceding claim, characterized in that it comprises two bodies (6, 7), respectively an inlet body (6) and an outlet body (7), having arranged respectively therein, for the inlet body (6) the inlet pipe (10) extended by the chamber (11), and for the outlet body (7) the outlet pipe (12) extended by the outlet chamber (13), these bodies (6, 7) being interconnected by the individual channels (8, 9) and being provided with assembly means for assembling with respective junctions of a flow channel (3) for a fluid under pressure.
10. A system according to claim 9, characterized in that the assembly means may equally well be releasable and/or permanent assembly means, comprising thermally insulating junction members (14) for interposing between the bodies (6, 7) and the corresponding junctions of the flow channel (3).

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