Closed fluid system

Abstract

Among other things, a closed system (10) containing a circulating fluid (20) is described. A partially inflated barrier bag (30) is located inside the closure system (5) to control expansion and / or contraction of the fluid caused by temperature changes.

Description

Technical Field

[0001] This disclosure relates to closed systems containing fluids. In particular, this disclosure relates to a closed system for a fluid with varying temperature, wherein the fluid circulates. This disclosure also extends to thermal management systems and expansion devices. Background Technology

[0002] Many applications utilize closed systems containing fluids. In such systems, if the temperature rises, the fluid volume expands, posing a risk of explosion or damage to components within the system. Conversely, if the temperature drops, a vacuum bag or an undefined phase of fluid, gas, or the like can form, which can degrade performance. This is particularly true for circulating fluid systems (such as thermal management systems), where the system is designed to move heat from one location to another.

[0003] For example, in thermal control systems (such as the closed-loop systems described in WO 2017 / 127017), the temperature can rise and fall during the operation of the loop system. Typically, the need to manage the expansion / contraction of the circulating fluid is addressed by some form of expansion device connected to the closed-loop system (e.g., as described in US 6,119,951 and US 5,456,409).

[0004] There is a constant desire to improve the operation of closed-loop systems that contain / hold fluids. Therefore, there is a need for improved closed-loop systems that contain fluids. Summary of the Invention

[0005] The purpose of this invention is to provide an improved closed-loop circulation system for containing fluid.

[0006] This objective and / or other objectives are achieved, at least in part, by a closed-loop system containing fluid as set forth in the appended claims.

[0007] As the inventors have recognized, existing solutions for compensating for volume changes in fluids filling closed-loop systems typically require some external device (e.g., an external expansion device) to mitigate the volume changes of the fluid.

[0008] By placing at least one partially inflated barrier bag in a closed-loop system containing fluid, the barrier bag can act as an internal expansion device and be responsible for handling the expansion / contraction of the fluid, as the barrier bag will change its volume in response to changes in the volume of the fluid in the closed system.

[0009] According to one embodiment, a closed system for containing fluid is provided. The system is configured to circulate the fluid, and a partially inflated barrier bag is located inside the closed system to compensate for the expansion and / or contraction of the fluid caused by temperature changes. The barrier bag comprises at least two layers. Thus, when the fluid expands / contracts due to temperature changes within the fluid, the barrier bag can absorb volume differences in the fluid and ensure that the barrier bag does not leak gas over time.

[0010] According to one embodiment, multiple barrier bags are located in the closure system. This enables additional design possibilities for the closure system.

[0011] According to one embodiment, the closed system is configured to circulate fluid within a closed pathway. The closed system may include at least two chambers. At least one barrier bag may then be provided in each chamber, thereby enabling effective compensation for fluid volume changes when multiple chambers are provided in the circulation system.

[0012] Using barrier bags to control fluid volume changes is particularly useful in circulation systems that use flow units such as electrohydrodynamic (EHD) pumps, where the circulating fluid is a dielectric fluid.

[0013] According to some embodiments, the barrier bag includes at least two layers, one of which is a metal layer. This allows the barrier bag to have a long service life. In particular, the barrier bag may include at least three layers, including an inner polymer layer, an intermediate metal layer, and an outer polymer layer. This allows for a very robust structure of the barrier bag, suitable for many applications, especially pumped circulation systems for thermal management.

[0014] According to an advantageous embodiment, the barrier bag includes a layered structure comprising an outer layer of polyethylene terephthalate (PET), an intermediate layer of aluminum (Al), and an inner layer of polyethylene (PE) or low-density polyethylene (LDPE).

[0015] According to one embodiment, the barrier bag is formed as a bag having four welded sides. This provides a robust yet easy-to-manufacture barrier bag.

[0016] According to one embodiment, the barrier bag is provided with anchors. Therefore, the barrier bag can be easily secured within a closed system.

[0017] According to one embodiment, a cage is disposed within a closed system, and one or more barrier bags are located inside the cage. This provides an alternative mechanism for holding the barrier bags in place. The cage can be located outside the flow path of the circulating fluid in the closed system, so that the barrier bags will not negatively affect the circulation.

[0018] According to another aspect of the present invention, a thermal management system comprising the closed system described above is provided. The thermal management system may include a radiator and / or a heating device. Thus, when the heat of the radiator and / or the heating device changes, the expansion / contraction of the fluid in the system containing the fluid can be easily controlled.

[0019] In another aspect, a barrier bag suitable for use as an expansion device according to the above is provided. Attached Figure Description

[0020] The invention will now be described in more detail by way of non-limiting example and with reference to the accompanying drawings, in which:

[0021] - Figure 1 It is a view of a thermal management system that includes a closed system containing fluids.

[0022] - Figure 2 It is a view of a closed system containing a circulating fluid.

[0023] - Figure 3 It is a view of a closed system containing fluid circulating in a closed loop within the closed system.

[0024] - Figure 4 This is a view of a closed system containing circulating fluid, wherein the closed system has multiple chambers.

[0025] - Figure 5 An exemplary structure for a barrier bag is shown, and

[0026] - Figure 6 The barrier bag is shown. Detailed Implementation

[0027] The invention will now be described more fully with reference to the accompanying drawings, in which certain embodiments of the invention are illustrated. However, the invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that the disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. For example, the same or similar components in different embodiments may be interchanged between different embodiments. Some components may be omitted in different embodiments. Throughout the specification, the same numbers refer to the same elements.

[0028] The following description describes a system filled with fluid. This system is a closed system. The fluid can typically be a liquid, but other fluids are also conceivable. The system can be a closed-loop system in which the flow of a circulating fluid (e.g., a thermal management fluid) is circulated. According to some embodiments, the flow can be regulated by controlling a flow unit. In some embodiments, the closed system can be designed to allow the circulation of fluid without providing a dedicated flow unit (self-propelled system) to propel the flow within the closed system.

[0029] It should be understood that features in different embodiments may be used in combination, and that no feature in an embodiment is required unless explicitly stated otherwise. Therefore, those skilled in the art may choose features and dimensions that they deem advantageous for a particular implementation.

[0030] exist Figure 1 The diagram shows an overall view of the thermal management system 1. The thermal management system 1 includes a closed system 10, which includes a fluid 20. The closed system 10 is completely sealed, ensuring that no gas or fluid can enter or leave the closed system 10 in an uncontrolled manner. The closed system 10 can withstand varying temperature changes. For example, the system can be heated (or cooled) by some external device 120 (e.g., a radiator or heat-generating device). Figure 1 In this embodiment, the external device is exemplified by a heat sink 120 having a flange 122. Therefore, the enclosed system 10 can be used in certain types of thermal regulation applications (e.g., thermal management system 1), where the enclosed system is used as a control mechanism for controlling heat and heat dissipation. According to some other embodiments, fluctuations in the ambient temperature of the enclosed system 10 cause changes in the temperature of the fluid within the enclosed system 10.

[0031] Regardless of the application type, if the closed system 10 is completely filled with fluid at a specific temperature, an increase in the temperature of the fluid 20 will increase the pressure inside the closed system 10, and there is a risk of damage to the components inside the closed system. Similarly, a decrease in temperature will cause the fluid to contract, and may form undesirable vacuum bags and the like.

[0032] The closed system 10, filled with fluid 20, further comprises a barrier bag 30, at least partially inflated therein. The barrier bag 30 is a bag formed of an elastic material, capable of varying its volume. The barrier bag can be formed in various ways; for example, according to one embodiment, three sides of the bag can be pulse-welded to form an open bag container. Next, in-situ gas filling of the bag is performed, and finally, a fourth open side of the bag is welded to close the gas-filled bag. Typically, but not required, the bag is partially filled with a known pure gas (e.g., air, nitrogen, or argon). The amount of gas to be filled into the closed volume of the bag is determined by the overall fluid system parameters and the bag dimensions. Typically, the fluid volume expansion and contraction within the operating temperature range of the fluid system are determined. Based on this determined fluid volume expansion and contraction, the specifications of the barrier bag and the amount of gas to be filled in the bag are determined. This can be performed, for example, by observing permissible overpressure and underpressure in the fluid system; for example, the barrier bag may be filled to 5-95% of its unpressurized initial volume. The barrier bag is then sealed. Typically, the barrier bag can be immediately sealed using, for example, a pulse welding machine, thereby sealing the bag. At least one barrier bag 30 has the function of compensating for temperature changes that cause volume changes in the fluid 20 within the closed system 10. Therefore, the partially inflated barrier bag 30 serves as an internal expansion device to compensate for temperature changes that cause volume changes in the fluid 20.

[0033] Advantageously, the barrier bag 30 is designed to contain gas for extended periods, typically at least for the system's expected lifespan. When the circulating fluid expands, the gas in the barrier bag 30, which is in contact with the fluid, is pressurized, and vice versa. This allows for cost-effective mitigation of temperature variations as the barrier bag absorbs changes in the volume of fluid 20 within the closed system 10.

[0034] exist Figure 2 Another example of a closed system 10 including fluid 20 is depicted in the image. Figure 2 The closed system 10 includes a flow unit 40 that drives a flow to circulate fluid 20 within the closed system 10. This flow is... Figure 2 The arrow in the text indicates this.

[0035] According to one embodiment, the closed system is formed by or includes a closed passage suitable for transporting circulating fluid. The closed passage may, for example, define a closed loop in which fluid 20 can circulate. Figure 3 This configuration is illustrated, in which flow unit 40 drives flow to circulate in closed passage 50. In some embodiments, more than one flow unit 40 is provided. It is also conceivable that the flow in closed passage 50 can be driven without flow unit 40 (e.g., by temperature change).

[0036] The flow unit 40 can be any type of device that facilitates fluid circulation. According to one embodiment, the flow unit is a mechanical pump. According to another embodiment, the flow unit is an electrohydrodynamic (EHD) pump. An EHD pump drives a flow by having a dielectric fluid (typically ionized particles or molecules of fluid 20) interact with an electric field. The EHD pump may include a first electrode and a second electrode, wherein the second electrode is biased from the first electrode in a downstream direction of the flow of the circulating fluid. The first and second electrodes may be connected to a voltage source. According to one embodiment, the first electrode is formed as a mesh structure that allows the circulating fluid to flow through it. Further, as... Figure 3 As shown, multiple barrier bags 30 can be provided in the closed system 10.

[0037] exist Figure 4 Another embodiment with circulating fluid 20 is depicted. According to... Figure 4 In the embodiment depicted, the closed passage 50 is defined by at least a first chamber 52 and a second chamber 54 separated from each other. For example, a partition wall 56 or a diaphragm may be used to separate the at least two chambers 52, 54. The partition wall 56 may include a gap or partial passage connecting the first chamber 52 and the second chamber 54 to each other, thereby defining a closed loop in which fluid can circulate. Fluid can circulate through the first chamber 52, enter the second chamber 54 via one of the gaps in the partition wall 56, pass through the second chamber 54, and re-enter the first chamber 52 via a second gap in the wall 56. The circulating fluid... Figure 4 The arrow indicates the middle.

[0038] At least one of the chambers 52, 54 (e.g., the first chamber 52) may include the flow unit 40 as described above. The flow unit 40 may be configured to induce flow in the fluid when operating in an active state and to impede or reduce flow in the fluid when operating in a deactivated state. For example, when the flow unit 40 is an EHD pump, the voltage difference may be reduced compared to the active state. Therefore, the flow unit 40 may be used to influence or control the circulation of fluid between the first chamber 52 and the second chamber 54. According to some embodiments, when multiple chambers 52, 54 are provided, multiple barrier bags 30 may be provided. According to one embodiment, each of the chambers 52, 54 has at least one barrier bag.

[0039] Furthermore, such as Figure 4As shown, the barrier bag 30 can be secured within the closed system 10. Furthermore, in some applications or configurations including all the configurations described herein, the barrier bag 30 can be held in a suitable position within the closed system. According to some embodiments, the barrier bag can be placed in a cage 37 inside the closed system. The cage 37 can be located at any suitable location within the closed system. According to one embodiment, the cage is located outside the circulating flow of the closed system. Therefore, the flow is not affected by the cage 37 or the barrier bag 30. The cage can be formed in some suitable manner and has at least one port serving as an inlet / outlet through which the fluid of the closed system can enter or exit the cage.

[0040] Other securing methods can also be used to hold the barrier bag 30 in place (e.g., anchoring the barrier bag or providing a retainer). The retainer can be made of plastic or metal. For example, the retainer can be shaped like a hook and secured within the closure system to hold the barrier bag in place. According to some embodiments, a cavity is formed within the closure system where the barrier bag 30 can be placed. However, it is also conceivable that in some applications, the barrier bag does not need to be secured by any special securing device and can float freely within the closure system 10.

[0041] The barrier bag 30 can be any suitable barrier bag that meets the requirement of securely holding a gas for the required time under given conditions. The barrier bag 30 typically has multiple layers (at least two layers) to ensure that the gas is held within the barrier bag 30 for an extended period, and the bag is mechanically rigid and compatible with the chosen sealing method, typically (but not limited to) pulse-welded heat sealing. The different layers of the barrier bag serve different purposes, and a suitable barrier bag for an application typically (but not limited to) consists of three layers. This three-layer structure can be formed by an inner polymer layer, an intermediate metal layer, and an outer polymer layer. Depending on the application, additional or fewer layers may be used. At least one of the layers is advantageously a metal layer.

[0042] According to one embodiment, the barrier bag 30 is formed of a layered structure comprising an outer layer of polyethylene terephthalate (PET), an intermediate layer of aluminum (Al), and an inner layer of polyethylene (PE) or low-density polyethylene (LDPE). This layered structure... Figure 5The outer layer 32 is a fluid-facing layer and serves as a barrier layer, but it also protects the second intermediate layer 34. The intermediate layer 34 acts as a gas and fluid sealant and has anti-diffusion properties. The third layer 36 (i.e., the inner layer) is weldable and can be used to create seam welds. The inner layer 36 also protects the intermediate layers and increases the rigidity of the barrier bag wall. According to one embodiment, the barrier bag 30 is formed from a thin PET layer (approximately 5-20 or 12 micrometers), a thin Al layer (approximately 10-30 or 18 micrometers), and a thicker PE or LDPE layer (approximately 20-200 micrometers or 100 micrometers). Figure 5 The exemplary structure of the barrier bag 30 shown has multiple layers and is presented in the form of a side cross-sectional view. Figure 5 In an exemplary embodiment, an outer layer 32 of PET 12 is provided. Additionally, an intermediate layer 34 of Al 18 and an inner layer 36 of PE 100 are provided.

[0043] exist Figure 6 The diagram depicts a barrier bag 30. The barrier bag 30 is provided with an anchor 39. The anchor 39 is used to secure the barrier bag within a closed system. For example, the anchor 39 can be attached to a connector (e.g., a retainer) within the closed system. The anchor 39 can be formed as a hole punched in the barrier bag on the outside of its sealing periphery. For example, the hole 39 can be located outside the weld of the barrier bag 30. The barrier bag 30 can then be secured within the closed system 10 by providing a hook or similar device inside the closed system to which it can be attached. Such a hook can be located outside the flow in the circulating closed system so as not to affect the flow itself.

[0044] The use of inflatable barrier bags in closed fluid systems is advantageous in many types of products. For example, they are used in high-volume production due to their inherent ease of use and low manufacturing costs. Furthermore, because barrier bags can be formed in a variety of different ways, they are advantageous for use in fluid systems with irregular shapes or other size constraints, or as part of known solutions to the problem of fluid expansion in closed fluid systems. They can be formed into very small, thin, round, square, etc. Barrier bags in closed fluid systems can be used, for example, in heat-generating electronic devices, such as battery modules for automobiles, heavy equipment, peak shaving, and energy storage. They can also be used in applications such as electronic devices connected to heat sinks, finned heat sinks with forced or natural air convection cooling, etc. In addition, they can be used in telecommunications equipment, information and communication technologies, and similar applications.

Claims

1. A closed system (10) for containing a fluid (20), said system being configured to circulate the fluid, wherein, A partially inflated barrier bag (30) is located inside the closed system to compensate for the expansion and / or contraction of the fluid caused by temperature changes, wherein the barrier bag comprises at least two layers (32, 34, 36).

2. The closed system according to claim 1, wherein, Multiple barrier bags (30) are located in the closed system.

3. The closed system according to claim 1 or 2, wherein the closed system is configured to circulate the fluid in a closed passage (50).

4. The closed system according to any one of claims 1 to 3, wherein, The enclosed system includes at least two chambers (52, 54).

5. The closed system according to claim 4, wherein, Each chamber (52, 54) contains at least one barrier bag (30).

6. The closed system according to any one of claims 1 to 5, wherein, The fluid is circulated using a flow unit (40).

7. The closed system according to claim 6, wherein, The flow unit (40) is an electrohydrodynamic (EHD) pump.

8. The closed system according to claim 7, wherein, The circulating fluid is a dielectric fluid.

9. The closed system according to any one of claims 1 to 8, wherein, The barrier bag includes at least one metal layer (34).

10. The closed system according to claim 9, wherein, The barrier bag comprises at least three layers (32, 34, 36), the at least three layers comprising an inner polymer layer (36), an intermediate metal layer (34), and an outer polymer layer (32).

11. The closed system according to claim 10, wherein, The barrier bag comprises a layered structure including an outer layer of polyethylene terephthalate (PET), an intermediate layer of aluminum (Al), and an inner layer of polyethylene (PE) or low-density polyethylene (LDPE).

12. The closed system according to any one of claims 1 to 11, wherein, The barrier bag is filled with gas corresponding to 5-95% of its unpressurized initial volume.

13. The closed system according to any one of claims 1 to 12, wherein, The barrier bag is formed as a bag with four welded sides.

14. The closed system according to any one of claims 1 to 13, wherein, The barrier bag is provided with anchors (39).

15. The closure system according to any one of claims 1 to 14, further comprising a cage (37), wherein the barrier bag is located within the cage.

16. The closed system according to claim 15, wherein, The cage (37) is located outside the flow path of the circulating fluid.

17. A thermal management system (1) comprising a closed system according to any one of claims 1 to 16.

18. The thermal management system according to claim 17, further comprising a radiator (120) and / or a heating device (120).

19. A partially inflatable barrier bag (30), comprising at least two layers (32, 34, 36), used as an expansion device in a closed system containing circulating fluid, wherein, The barrier bag is formed as a bag with four welded sides, and the partially inflated barrier bag (30) is sealed and filled with gas corresponding to 5-95% of its unpressurized initial volume.

20. The partially inflatable barrier bag (30) according to claim 19, wherein, The barrier bag is provided with anchors (39).

21. The partially inflatable barrier bag (30) according to claim 20, wherein, The anchor (39) includes a hole punched in the barrier bag on the outside of the sealing periphery of the barrier bag (30).

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