WO2017187048A1

WO2017187048A1 - Insulation device for thermal system

Info

Publication number: WO2017187048A1
Application number: PCT/FR2017/050928
Authority: WO
Inventors: Julien Tissot; Patrick Boisselle; Kamel Azzouz
Original assignee: Valeo Systemes Thermiques
Priority date: 2016-04-28
Filing date: 2017-04-19
Publication date: 2017-11-02
Also published as: EP3449199A1; FR3050813B1; FR3050813A1; CN109863361A

Abstract

The invention relates to a thermal insulation device (1) for a thermal accumulation system (2) or a heat exchanger, the insulation device (1) comprising a duct (3) and a sealing element (10) which, in a closed position, can seal the duct (3) and, in an open position, allows a fluid to flow inside the duct (3).

Description

INSULATION DEVICE FOR THERMAL SYSTEM

The invention relates to an insulation device, in particular for a thermal system, such as a thermal storage device or a heat exchanger of a motor vehicle.

It will be noted that by thermal storage device is meant any device comprising dedicated elements, for example made of phase-change material, which are capable of storing or destocking calories, such as a thermal storage battery or a heat exchanger. heat comprising phase change materials.

A storage thermal battery operates using a fluid, such as a heat transfer fluid, adapted to flow between an input and a battery output. During its circulation, thermal energy initially stored in the battery is transferred to the fluid. The fluid thus heated can circulate thereafter inside the heating radiator of a vehicle, which transfers the heat of the fluid to the interior of the passenger compartment.

This type of battery can also be used to preheat a liquid, such as engine oil or automatic transmission oil, and before the cold start of the motor vehicle.

In order to limit thermal losses and conserve energy as heat in the battery, it is known to use an insulation wall surrounding the battery.

However, such an insulation wall does not limit the heat loss via the fluid by thermosiphon or by thermal conduction at the inlet line and / or output of the battery.

In the same way, a heat exchanger works with the help of a fluid adapted to flow between an inlet and an outlet of the exchanger. The fluid circulating in the exchanger can transfer heat to another external element, such as a flow of air, through an exchange surface.

Such a heat exchanger is for example used as an evaporator or as a condenser for a thermodynamic loop of the motor vehicle.

When stopping the circulation of the fluid, it is preferable that the fluid contained in the exchanger can continue to transmit a maximum of heat through the exchange surface.

It is then necessary to limit the heat losses via the fluid by thermosiphon or by thermal conduction at the inlet and / or outlet pipe of the exchanger,

The object of the invention is to overcome these disadvantages.

In particular, the invention aims at providing an economical and reliable device for limiting the heat loss of a thermal system, in particular a thermal storage device or a heat exchanger of a motor vehicle, at its level. fluid inlet and outlet.

For this purpose, the subject of the invention is a thermal insulation device for a thermal storage device or a heat exchanger, the isolation device comprising a channel and a shutter element, the shutter element being suitable, in a closed position, to close the channel and, in an open position, to allow a fluid to flow in the channel.

The isolation device, once placed at an inlet and / or outlet opening of a thermal storage system, isolates the fluid included in the system from the fluid located outside the system. This reduces the heat loss via the fluid by conduction or thermosiphon.

Experiments carried out on a thermal storage battery show that the use of such isolation devices at the input and at the output The battery reduces heat losses by approximately 80%, and thus increases the heat storage time in the battery by 40%.

According to one characteristic, the shutter element is thermally insulating.

According to another characteristic, the isolation device comprises a rod, the shutter element being fixed to the rod.

According to another characteristic, the isolation device comprises a guide, the rod being slidably mounted in the guide between the closed position and the open position.

According to another characteristic of the invention, the isolation device comprises a return element adapted to urge the shutter element towards the closed position (that is to say that the return element exerts a restoring force on the shutter element so as to bring it back to the closed position).

The return element makes it possible to ensure good sealing, in particular thermal, of the isolation device when there is no circulation of fluid in the channel. In addition, because of the presence of the return element, the channel is closed in the closed position regardless of the orientation of the isolation device.

According to another characteristic of the invention, the return element is a spring, for example helical.

According to another characteristic of the invention, the coil spring is arranged around the rod.

The arrangement of the spring around the rod makes it possible to minimize the space occupied by the spring, and thus to minimize the pressure drop during the circulation of fluid in the channel.

According to another characteristic of the invention, the shutter element has a trapezoidal shape or a circular shape according to a passing section plane. by a flow direction of the fluid in the channel.

The trapezoidal or circular shape of the shutter element makes it possible to obtain a satisfactory fluid passage in the channel when the rod is in the open position. The passage of fluid between the opening of the channel and the shutter member in the open position is adapted to minimize the pressure drop during the fluid circulation.

According to another characteristic of the invention, the shutter element comprises an envelope surrounding a cavity.

The envelope is preferably made of a weakly thermally conductive material, for example a plastic material, to prevent any loss of heat at the shutter member of the isolation device.

According to another characteristic of the invention, the cavity is empty or filled with a gas.

The presence of gas in the cavity also limits the heat loss by conduction at the shutter member, so as to isolate the fluid on each side of the shutter member in the closed position.

According to another characteristic of the invention, the shutter element is disposed at a fluid inlet opening in the channel.

In this embodiment, the shutter member is moved inwardly of the channel in the open position, which limits the space occupied by the isolation device.

According to another characteristic of the invention, the shutter element is disposed at an outlet opening of the fluid in the channel.

According to another characteristic of the invention, the shutter element and the opening have a shape adapted so that the shutter element is in surface contact with the opening in the closed position.

Surface contact between the opening of the channel and the shutter element is preferable to a single point contact that may facilitate thermal leakage at the opening.

According to another characteristic of the invention, the return element is disposed between the guide and the shutter member, the biasing element being biased in compression when the shutter member is in an open position.

According to another characteristic of the invention, the return element is disposed between a fixing element fixed to the rod and the guide, the biasing element being biased in compression when the shutter element is in an open position.

The invention also relates to an assembly comprising a thermal system and at least one isolation device according to the invention, wherein the isolation device is disposed at an inlet and / or a fluid outlet of the system. thermal.

According to one characteristic, said thermal system is a thermal storage battery or a heat exchanger.

According to another characteristic, the thermal system is surrounded by an insulating wall, the isolation device being integrated in the insulating wall.

According to another characteristic, the thermal system is surrounded by an insulating wall, the insulating device extending between the insulating wall and the outside of the thermal system.

Other features and advantages of the invention will become apparent on reading the description which follows. This is purely illustrative and should be read in conjunction with the attached drawings in which:

FIG. 1 illustrates a perspective view of a motor vehicle storage thermal battery comprising insulating devices according to the invention respectively at the input and at the output of the battery; FIG. 2 illustrates a side view of an isolation device of FIG. 1;

FIGS. 3A and 3B illustrate sectional views of the isolation device along a sectional plane P of FIG. 2 according to a first embodiment;

- Figure 4 illustrates a perspective view of the isolation device of Figure 3A, wherein the first and second parts of the isolation device are shown in section along the sectional plane P of Figure 2;

FIGS. 5A and 5B illustrate sectional views of the isolation device along section plane P of FIG. 2 according to a second embodiment;

FIG. 6 illustrates a perspective view of the isolation device of FIG. 5A, in which the first and second parts of the isolation device are shown in section along the section plane P of FIG. 2; and

- Figures 7A and 7B illustrate schematic side views of a battery comprising an isolation device disposed respectively in the battery isolating wall and at the boundary of the insulation wall with the outside.

Insulation device

As illustrated in FIG. 1, the subject of the invention is a thermal insulation device 1, in particular for a thermal system 2 such as a thermal battery or a heat exchanger of a motor vehicle.

The isolation device 1 comprises a channel 3.

According to the embodiments shown in the figures, and in particular illustrated in FIG. 2, the isolation device 1 consists of a first piece 17 and a second piece 18 to form the channel 3.

The first piece 17 and the second piece 18 have a shape complementary to each other so as to be assembled by screwing, welding or by any other means. The use of two pieces to form the isolation device 1 facilitates the mounting of elements in the channel 3, such as a guide and a rod as will be described below.

However, alternatively, the channel 3 of the isolation device 1 can be made in one piece, or even more than two pieces.

The channel 3 extends through the insulating device 1 between a first opening 4 and a second opening 5.

The channel 3 preferably has a cylindrical shape and is delimited by an inner wall 6 of the isolation device 1. The channel 3 advantageously extends rectilinearly in a flow direction D between the first and second openings 4, 5. The channel 3 is adapted to allow the circulation of a fluid through the isolation device 1.

The channel 3 may have a constant section in a plane perpendicular to the flow direction D between the first and second openings 4, 5. Alternatively, the section of the channel 3 in a plane perpendicular to the flow direction D may be variable in order to limit the pressure drop during the circulation of the fluid in the isolation device 1.

The isolation device 1 comprises a rod 7. The rod 7 is disposed at the center of the channel 3 in the direction of flow D.

The rod 7 is further slidably mounted in a guide 8.

As illustrated in Figures 4 and 6, the guide 8 comprises a cylindrical portion 21 in which the rod 7 is slidably mounted.

The guide 8 also comprises ribs 9 and an annular wall 22. The ribs 9, advantageously distributed at 120 ° around the direction D flow, connect the cylindrical portion 21 to the annular wall 22 of the guide 8. Each of the ribs 9 thus extends between the center of the channel 3 and the annular wall 22. The annular wall 22 of the guide 8 is held so that fixed against the inner wall 6 of the channel 3. The annular wall 22 and the ribs 9 serve to maintain the cylindrical portion 21 of the guide 8 without blocking the flow of fluid in the channel 3.

An end 7a of the rod 7 comprises a shutter element 10, such as a valve, adapted to alternatively open or close the first opening 4 of the channel 3.

The shutter element 10 is a thermally insulating element.

In one embodiment, the shutter member 10 comprises an insulating material. The shutter member 10 is further preferably made of an insulating material.

As illustrated in FIGS. 3A, 3B, 5A and 5B, the shutter element 10 comprises a casing 11.

The envelope 1 1 of the shutter element 10 is advantageously in a material with low thermal conductivity or a material which is a heat insulator in order to limit the loss by heat conduction at the shutter element 10. The envelope 1 is for example a plastic material.

The shutter element 10 also comprises a cavity 12. The envelope 1 1 of the shutter element 10 surrounds the cavity 12. The interior of the cavity 12 may also comprise a low-conductive material, air or a gas, especially an inert gas. According to another alternative, the cavity 12 is empty of any material or any gas.

The shutter element 10 may have a shape of revolution around the direction of flow D. As illustrated in FIGS. 3A, 3B, 5A and 5B, the shutter element 10 has for example a triangular, trapezoidal or circular shape according to a plane of section P passing through the direction The shutter element 10 may also have any other shape.

The first opening 4 further has a shape complementary to that of the shutter member 10. The first opening 4 may in particular have an outwardly or inwardly flared shape of the insulating device 1 as illustrated respectively in the figures. 3B and 5B. The shape of the shutter member 10 and the first opening 4 are advantageously adapted to limit the pressure drop during the passage of the fluid through the channel 3.

The isolation device 1 also comprises a return element 13.

The return element 13 is adapted to urge the shutter element 10 towards a closed position, of rest. In the closed position, the shutter element 10 closes the first opening 4 of the isolation device 1, so that a fluid can not flow through the first opening 4. The shutter element 10 and the first opening 4 are advantageously in surface contact with each other in the closed position.

The shutter element 10 can also be in an open position in which the shutter element 10 does not close the first opening 4 of the isolation device 1, so that a fluid can flow through the channel 3 More specifically, the fluid flows in the open position through the first opening 4 around the shutter element 10.

The return element 13 is advantageously arranged around the rod 7. According to the embodiments illustrated in the figures, the return element 13 is a helical spring disposed around the rod 7. The return element 13 is in particularly arranged in the channel 3 so as to minimize the pressure drop during the flow of the fluid in the isolation device 1. The coefficient of stiffness of the return element 13 is also chosen to limit the pressure drop during the flow of the fluid in the isolation device 1. First embodiment

In a first embodiment illustrated by FIGS. 3A, 3B and 4, the isolation device 1 is more particularly intended to be disposed at a fluid inlet line 23 of a thermal system 2. However, it may also be envisaged to use the isolation device 1 described by the first embodiment at a fluid outlet line 24 of a thermal system 2.

According to this first embodiment, the fluid can flow in the isolation device 1 in a direction of circulation 19 illustrated in Figure 3B. More particularly, the fluid flows in the channel 3 from the second opening 5 to the first opening 4 of the isolation device 1. The first opening 4 and the second opening 5 of the isolation device 1 then respectively constitute an outlet opening and a fluid inlet opening in the isolation device 1.

According to this first embodiment, the guide 8 is located in the vicinity of the first opening 4. The return element 13 is disposed between a fixing member 14 and the guide 8. The fixing member 14 is more particularly fixed at the rod 7, in particular at the end 7b of the rod 7 opposite the end 7a comprising the shutter element 10.

In the absence of fluid circulation in the isolation device 1, the rod 7 and the shutter member 10 is in the closed position (more particularly visible in Figure 1A). In this closed position, the shutter member 10 seals the first opening 4 of the insulating device 1.

When the fluid is put in circulation, the fluid exerts a force on the shutter element 10 in the direction of circulation 19, so that the shutter element 10 is displaced towards the outside of the isolation device 1 in the position opened. The isolation device 1 allows a flow of fluid through the first opening 4. The return element 13 is stressed in compression between the fixing member 14 and the guide 8 during the fluid circulation. When the flow of fluid ceases, the return element 13 urges the rod 7 and the shutter element 10 in the closed position, so as to isolate the fluid which is on either side of the first opening 4.

Second embodiment

In a second embodiment illustrated by FIGS. 5A, 5B and 6, the isolation device 1 is more particularly intended to be disposed at a fluid outlet line 24 of a thermal system 2. it can also be envisaged to use the isolation device 1 described by the second embodiment at a fluid inlet pipe 23 of a thermal system 2.

According to this first embodiment, the fluid can flow in the isolation device 1 in a direction of circulation 20 illustrated in Figure 5B. More particularly, the fluid flows from the first opening 4 to the second opening 5 of the isolation device 1. The first opening 4 and the second opening 5 of the isolation device then respectively constitute an inlet opening and an outlet opening of the fluid in the isolation device 1.

According to this first embodiment, the return element 13 is arranged between the guide 8 and the shutter element 10.

In the absence of fluid circulation in the isolation device 1, the rod 7 and the shutter member 10 is in the closed position. In this closed position, the shutter element 10 closes the first opening 4 of the isolation device 1.

During the circulation of the fluid, the fluid exerts from the outside a force on the shutter member 10, so that the shutter member 10 is moved in the direction of circulation 20 in the open position. The shutter element 10 is more particularly moved towards the interior of the insulation device 1. The isolation device 1 allows a flow of fluid through the first opening 4.

The return element 13 is stressed in compression between the shutter element 10 and the guide 8 during the fluid circulation. When the flow of fluid ceases, the return element 13 urges the rod 7 and the shutter element 10 in the closed position, so as to isolate the fluid which is on either side of the first opening 4.

Assembly comprising a thermal system and an isolation device

The isolation device 1 is preferably a connector, in particular intended to be disposed at an inlet pipe 23 or an outlet pipe 24 of a thermal storage system 2.

The invention thus relates to an assembly 15 comprising a thermal system 2 and at least one isolation device 1.

As illustrated in FIG. 1, insulating devices 1 according to the invention can be arranged both at the inlet 23 and at the outlet 24 of the thermal system 2.

According to one embodiment, the thermal system 2 is a thermal storage device, in particular a thermal battery of a motor vehicle.

As illustrated in FIGS. 7A and 7B, the storage thermal battery 2 is surrounded by an insulating wall 16, in particular a thermal one. The insulation wall 16 is for example a foam, an airgel, a fibrous material such as glass wool, or vacuum.

According to an embodiment illustrated in FIG. 7A, the insulating device 1 is disposed in the insulating wall 16 of the storage thermal battery 2. More precisely, the insulating wall 16 completely surrounds the insulating device 1.

According to another embodiment illustrated in FIG. 7B, the insulating device 1 extends on either side of the insulation wall 16. More Specifically, the isolation device 1 is located at the boundary between the insulation wall 16 and the outside of the thermal storage system 2.

In another embodiment, the thermal system 2 is a motor vehicle heat exchanger. Of course, the invention is not limited to a particular use, and the insulation device 1 according to the invention can also be used to isolate other thermal systems for which it is necessary to limit the heat loss at fluid inlet / outlet level.

Claims

1. Thermal insulation device (1) for a thermal storage device (2) or a heat exchanger, the isolation device (1) comprising a channel (3) and a shutter element (10), the shutter element ( 10) being able, in a closed position, to close the channel (3) and, in an open position, to allow a fluid to flow in the channel (3).

2. Isolation device (1) according to claim 1, wherein the shutter member (10) is thermally insulating.

3. Isolation device (1) according to any one of the preceding claims, comprising a rod (7), the shutter member (10) being fixed to the rod (7).

4. Isolation device (1) according to any one of the preceding claims, comprising a guide (8), the rod (7) being slidably mounted in the guide (8) between the closed position and the open position.

5. Isolation device (1) according to any one of the preceding claims, comprising a return element (13) adapted to bias the shutter member (10) to the closed position.

6. Insulating device (1) according to claim 5, wherein the biasing element (13) is a spring.

An isolation device (1) according to any one of the preceding claims, wherein the shutter member (10) is trapezoidal in shape or circular in shape of a sectional plane (P) passing through a flow direction. (D) fluid in the channel (3).

8. Insulation device (1) according to any one of the preceding claims, wherein the shutter member (10) comprises a casing (1 1) surrounding a cavity (12).

An isolation device (1) according to claim 8, wherein the cavity (12) is empty or filled with a gas.

10. Isolation device (1) according to any one of the preceding claims, wherein the shutter member (10) is disposed at an opening (4) inlet and / or outlet of the channel fluid. (3).

1 1. An isolation device (1) according to claim 10, wherein the shutter member (10) and the aperture (4) are shaped to fit with each other so that the shutter member (10) is in surface contact with the opening (4) in the closed position.

12. Assembly (15) comprising a thermal system (2) and at least one isolation device (1) according to any preceding claim, wherein the isolation device (1) is disposed at a input (23) and / or fluid outlet (24) of said thermal system (2).

13. Assembly (15) according to claim 12, wherein the thermal system (2) is a thermal storage battery or a heat exchanger.

14. Assembly (15) according to claim 12 or 13, wherein the thermal system (2) is surrounded by an insulating wall (16), the isolation device (1) being integrated in the insulation wall (16).

15. Assembly (15) according to claim 12 or 13, wherein the thermal system (2) is surrounded by an insulating wall (16), the isolation device (1) extending between the wall of insulation (16) and the outside of the thermal system (2).