Active air pressure for coolant system

Abstract

A coolant expansion tank for a vehicle cooling system includes a coolant side having coolant. The tank further includes a first gas port on the coolant side for receiving first gas comprising gas bubbles separated from coolant in a first coolant circuit by a first gas separator, the first gas contributing to air pressure on the coolant in the coolant side. The tank further includes at least one second gas port on the coolant side for receiving second gas comprising gas bubbles separated from coolant in at least one second coolant circuit by at least one second gas separator, the second gas contributing to air pressure on the coolant in the coolant side. The tank further includes a pressurized air side having pressurized air to pressurize the coolant in the coolant side to a set pressure and has a port for receiving pressurized air from a pressure regulator.

Description

ACTIVE AIR PRESSURE FOR COOLANT SYSTEMTECHNICAL FIELD

[0001] The disclosure relates generally to vehicle cooling systems. In particular aspects, the disclosure relates to an active air pressure for a coolant system. The disclosure can be applied in heavy-duty vehicles, such as trucks, buses, and construction equipment. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle.BACKGROUND

[0002] Fuel cell stack (FCS) vehicles are different compared with internal combustion engine (ICE) vehicles. The FCS vehicles require a strict control of coolant system pressure. Therefore, an active pressure system is used on FCS vehicles.

[0003] One drawback of active pressure control is that pressurized air is used to create the required pressure. Adding fresh air continuously will increase ageing of the coolant fluid. When coolant ages, its pH decreases, making it less efficient to prevent corrosion inside the coolant system.

[0004] Some vehicles have multiple coolant systems. For example, there could be one or more cold coolant circuits 100 having a pump 102 and components 104 and its own cooling system 106 where coolant enters the coolant expansion tank 108 and one or more hot coolant circuits 110 have a pump 112 and components 114 with its own cooling system 116 where the deairation line is connected to the coolant expansion tank that will create a flow of coolant through the coolant expansion tank 118, each cooling circuit separated from each other as illustrated in Figure 1. In a closed loop cooling system, air and other gasses are undesirable and may reduce system performance. Excess gas is typically removed after filling the system with cooling fluid, but air and other gasses can still build up over time, due to seepage or dissolved gasses in the cooling fluid forming air bubbles for example. In some conventional systems, each coolant circuit flows coolant through an expansion tank at the highest position of the cooling system, where gas bubbles in the fluid can be separated due togravity and removed from the cooling system as illustrated in Figure 1. However, if multiple deairation lines from different circuits are connected to the coolant expansion tank, it will have an effect on the coolant temperature in the coolant systems. For instance, a coolant circuit that needs to keep cool gets hotter because of deairation flow from a hot running circuit mixing in the coolant expansion tank.. Thus, there is a need for an improved degassing system with fewer constraints on positioning within the cooling system.SUMMARY

[0005] According to a first aspect of the disclosure, a coolant expansion tank for a vehicle cooling system includes a coolant side having coolant. The coolant expansion tank further includes a first gas port on the coolant side for receiving first gas comprising gas bubbles separated from coolant in a first coolant circuit by a first gas separator, the first gas contributing to air pressure on the coolant in the coolant side. The coolant expansion tank further includes at least one second gas port on the coolant side for receiving second gas comprising gas bubbles separated from coolant in at least one second coolant circuit by at least one second gas separator, the second gas contributing to air pressure on the coolant in the coolant side. The coolant expansion tank further includes a pressurized air side having pressurized air to pressurize the coolant in the coolant side to a set pressure; the pressurized air side have a port for receiving pressurized air from a pressure regulator. The first aspect of the disclosure may seek to prevent injected air from oxidizing coolant in the coolant circuits. A technical benefit may include using one coolant expansion tank for multiple coolant circuits of a vehicle where coolant exposed to air inside the coolant expansion tank is not shared with any of the coolant circuits.

[0006] In some examples, the first gap separator is connected to the first gas port and the at least one second gas separator is connected to the second gas port. A technical benefit may include using a single coolant expansion tank for multiple coolant circuits.

[0007] In some examples, the first gas separator and the second gas separator are integrated to the coolant side of the coolant expansion tank. A technical benefit may include using a single coolant expansion tank for multiple coolant circuits.

[0008] In some examples, the first gas separator receives from components of the first coolant circuit coolant requiring deairation at a first gas separator input port, separates first gas from the coolant requiring deairation and outputs deairated coolant to the first coolant circuit at a first gas separator out port while outputting the first gas without any coolant therein at a first gas separator gas port towards the coolant expansion tank and the at least one second gas separator receives from components of the second coolant circuit coolant requiring deairation at a second gas separator input port and outputs deairated coolant to the second coolant circuit at a second gas separator out port while outputting the second gas without any coolant therein at a second gas separator gas port to the coolant expansion tank. A technical benefit may be the coolant expansion tank never receives coolant from the first coolant circuit and the at least one second coolant circuit.

[0009] In some examples, the coolant side has a first coolant chamber for a first coolant circuit and at least one second coolant chamber for at least one second coolant fluid circuit where the coolant expansion tank has a divider separating coolant in the first coolant chamber from coolant in the at least one second coolant chamber. A technical benefit may include isolating the first coolant circuit from the at least one second coolant circuit for when the coolant circuits have to be isolated from each other.

[0010] In some examples, the coolant expansion tank has a wall between the pressurized air side and the coolant side, the wall having a transfer channel for transferring air from the pressurized air side to the coolant side to pressurize the coolant. A technical benefit may include using a single coolant expansion tank for multiple coolant circuits and eliminating any need for bellows.

[0011] In some examples, the transfer channel has a first opening proximate a bottom of pressurized air side and a second opening proximate a top of the coolant side. A technical benefit may include enabling pressurized air from the air side to flow to the coolant side to pressurize the coolant.

[0012] In some examples, the pressure regulator is integrated to the coolant expansion tank. A technical benefit may include reducing the number of air lines in the vehicle cooling system.

[0013] In some examples, a Teflon membrane is between the pressurized air side and the pressure regulator. A technical benefit may include letting air / hydrogen be released while preventing water vapor from entering the air side.

[0014] According to a second aspect of the disclosure, a coolant system for a vehicle cooling system includes a coolant expansion tank. The coolant expansion tank includes a coolant side that includes a first gas port for receiving first gas comprising gas bubbles separated from coolant in a first coolant circuit by a first gas separator, the first gas contributing to air pressure on the coolant in the coolant side; at least one second gas separation port for receiving second gas comprising gas bubbles separated from coolant in a second coolant circuit by a second gas separator, the second gas contributing to air pressure on the coolant in the coolant side; and a pressurized air side configured to pressurize the coolant in the coolant side. The coolant system further includes a pressure regulator configured to provide pressurized air to the pressurized air side. The coolant system further includes the first gas separator configured to receive first cooling fluid from the first coolant circuit requiring deairation and provide the gas bubbles separated from the first cooling fluid to the first gas separation port of the coolant expansion tank. The coolant system further includes the at least one second gas separator configured to receive from the at least one second coolant circuit second coolant requiring deairation and provide the gas bubbles separated from the second coolant to the at least one second gas separation port of the coolant expansion tank. The second aspect of the disclosure may seek to seek to prevent injected air from oxidizing coolant in the coolant circuits. A technical benefit may include using one coolant expansion tank for multiple coolant circuits of a vehicle where coolant exposed to air inside the coolant expansion tank is not shared with any of the coolant circuits.

[0015] In some examples, the coolant system further includes a first coolant chamber for the first coolant circuit; a second coolant chamber for the second coolant fluid circuit; and a divider separating coolant in the first coolant chamber from coolant in the second coolant chamber. A technical benefit may include isolating the first coolant circuit from the at least one second coolant circuit for when the coolant circuits have to be isolated from each other.

[0016] In some examples, the first gas separator and the at least one second gas separator are integrated into the coolant side such that the gas separated from coolant in thefirst coolant circuit and the at least one second coolant circuit enters the coolant side and contributes to air pressure pressurizing the coolant on the coolant side. A technical benefit may include using a single coolant expansion tank for multiple coolant circuits.

[0017] In some examples, the pressure regulator is further configured to: release air to lower air pressure in the coolant system when air pressure rises above a first threshold; and add air to increase air pressure in the coolant system when air pressure falls below a second threshold. A technical benefit may include keeping the air pressure on the coolant on the coolant side at a set point.

[0018] In some examples, the coolant system further includes a wall in the coolant expansion tank separating the coolant side from the pressurized air side in the coolant expansion tank, the wall having a transfer channel that transfers air from the pressurized air side to the coolant side. A technical benefit may include using a single coolant expansion tank for multiple coolant circuits and eliminating any need for bellows.

[0019] In some examples, the transfer channel has a first opening proximate a bottom of the pressurized air side and a second opening proximate a top of the coolant side, wherein pressurized air flows through the transfer channel to provide pressurized air to coolant in the coolant side. A technical benefit may include using a single coolant expansion tank for multiple coolant circuits and eliminating any need for bellows.

[0020] In some examples, one of the first coolant circuit and the at least one second coolant circuit is a hot coolant circuit and an other of the first coolant circuit and the at least one second coolant circuit is a cold coolant circuit. A technical benefit may be the coolant expansion tank does not receive coolant from either of the hot coolant circuit and the cold coolant circuit thereby allowing one coolant expansion tank to be used for a hot coolant circuit and a cold coolant circuit.

[0021] In some examples, a Teflon membrane is between the pressurized air side and the pressure regulator. A technical benefit may include letting air / hydrogen be released while preventing water vapor from entering the air side.

[0022] According to a third aspect of the disclosure, a method of degassing coolant in a vehicle cooling system having a first cooling circuit and a second cooling circuit includes receiving pressurized air at a pressurized air side of a coolant expansion tank from a pressureregulator. The method includes pressurizing coolant in a coolant side of the coolant expansion tank using the pressurized air. The method includes receiving, on the coolant side, first gas comprising gas bubbles separated from first coolant in the first coolant circuit by a first gas separator, the first gas contributing to air pressure on the coolant in the coolant side. The method includes receiving, on the coolant side, second gas comprising gas bubbles separated from second coolant in the at least one second coolant circuit by at least one second gas separator, the second gas contributing to air pressure on the coolant in the coolant side, the first coolant circuit and the at least one second coolant circuit isolated from each other. The second aspect of the disclosure may seek to seek to prevent injected air from oxidizing coolant in the coolant circuits. A technical benefit may include using one coolant expansion tank for multiple coolant circuits of a vehicle where coolant exposed to air inside the coolant expansion tank is not shared with any of the coolant circuits.

[0023] In some examples, the method further includes releasing air to lower air pressure in the coolant system when air pressure rises above a first threshold and adding pressurized air to increase air pressure in the coolant system when air pressure falls below a second threshold. A technical benefit may include keeping the air pressure on the coolant on the coolant side at a set point.

[0024] In some examples, the method further includes providing first coolant fluid having first gas within the first coolant fluid requiring deairation to the first gas separator, the first gas separator having a first round interior wall, wherein providing the first cooling fluid comprises directing the first coolant fluid having gas toward the first round interior wall such that inertia of the first cooling fluid having gas causes the first cooling fluid to move around the first round interior wall in a vortex to press the first cooling fluid against the first round interior wall, wherein pressure of the first cooling fluid against the first round interior wall causes the first gas to move toward a center of the first gas separator and be vented out a top of the first swirl pot into the coolant side; and providing second coolant fluid having second gas within the second coolant fluid requiring deairation to the at least one second separator, the at least one second separator having a second round interior wall, wherein providing the second cooling fluid comprises directing the second coolant fluid having gas toward the second round interior wall such that inertia of the second cooling fluid having gas causes thesecond cooling fluid to move around the second round interior wall in a vortex to press the second cooling fluid against the second round interior wall, wherein pressure of the second cooling fluid against the second round interior wall causes the second gas to move toward a center of the at least one second gas separator and be vented out a top of the at least one second separator into the coolant side. A technical benefit may be the coolant expansion tank never receives coolant from the first coolant circuit and the at least one second coolant circuit.

[0025] The above aspects, accompanying claims, and / or examples disclosed herein above and later below may be suitably combined with each other as would be apparent to anyone of ordinary skill in the art.

[0026] Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be readily apparent therefrom to those skilled in the art or recognized by practicing the disclosure as described herein. There are also disclosed herein control units, computer readable media, and computer program products associated with the above discussed technical benefits.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate certain non-limiting embodiments of the disclosure.

[0028] Figure 1 is an illustration of an example of a conventional cooling system where cooling circuits are completely isolated and coolant enters the expansion tanks according to one example.

[0029] Figure 2 is an illustration of a cooling system where gas separators for multiple coolant circuits are integrated into a single coolant expansion tank form multiple coolant circuits according to an example.

[0030] Figure 3 is an illustration of a coolant expansion tank of a cooling system according to one example.

[0031] Figure 4 is an illustration of a coolant expansion tank according to another example.

[0032] Figure 5 is an illustration of a coolant expansion tank according to a further example.

[0033] Figures 6-8 are flowcharts illustrating operations of a colling system according to examples.

[0034] Figure 9 is another view of a coolant system according to an example.DETAILED DESCRIPTION

[0035] Aspects set forth below represent the necessary information to enable those skilled in the art to practice the disclosure.

[0036] Referring now to Figures 2-5, examples of a cooling system 200 for a vehicle having multiple coolant circuits according to examples is illustrated. The cooling system 200 has a coolant expansion tank 202 having a coolant side 204 having coolant and a pressurized air side 206. The pressurized air side 206 has pressurize air to pressurize the coolant in the coolant side 204 to a set pressure. The pressurized air side 206 has a port 226 for receiving pressurized air from a pressure regulator 228, which is configured to provide pressurized air to the pressurized air side 206. Note that in some instances, a pressure cap can be used instead of a pressure regulator 228 where control of the system pressure can be relaxed.

[0037] The coolant expansion tank 202 also includes a first gas port on the coolant side 204 for receiving first gas 212, typically in the form of gas bubbles 214, separated from coolant in a first coolant circuit 216 by a first gas separator 218, the first gas 212 contributing to air pressure on the coolant in the coolant side 204. The first gas separator 218 is configured to receive from the first coolant circuit 216 first coolant requiring deairation, deairate the first coolant requiring deairation, and provide the gas bubbles separated from the first coolant to the first gas port 208 of the coolant expansion tank 202.

[0038] The coolant expansion tank also includes at least one second gas port 210 on the coolant side for receiving second gas 220, typically in the form of gas bubbles 214 separated from coolant in at least one second coolant circuit 222 by at least one second gas separator 224, the second gas contributing to air pressure on the coolant in the coolant side. The at least one second gas separator 224 is configured to receive from the at least one second coolant circuit 222 second coolant requiring deairation, deairate the second coolant requiringdeairation, and provide the gas bubbles 214 separated from the second coolant to the at least one second gas port 210 of the coolant expansion tank 202.

[0039] In some aspects, the first gas separator 218 is connected to the first gas port 208 and the at least one second gas separator 224 is connected to the at least one second gas port 210. In one example, the first gas separator 218 and the at least one second gas separator 224 are integrated to the coolant side 204 of the coolant expansion tank 202 such that the first gas 212 separated from coolant in the first coolant circuit 216 and the second gas 220 separated from coolant in the at least one second coolant circuit 222 enters the coolant side 204 of the coolant expansion tank 202 and contributes to air pressure pressurizing the coolant on the coolant side 204 of the coolant expansion tank 202.

[0040] While only one first coolant circuit 216 and one second coolant circuit 222 is shown, there may be multiple coolant circuits with each coolant circuit having a gas separator. In some examples where the gas separators are not integrated into the coolant expansion tank 202, there can be multiple gas separator gas ports associated with multiple gas separators connected to a same gas port of the coolant expansion tank 202. This can be done because no coolant of any of the coolant circuits flows through the coolant expansion tank 202. For example, if there is a coolant circuit that is used as a back-up coolant circuit or is only used in specific situations, then it may not make sense to have a separate gas port on the coolant expansion tank for this coolant circuit. The gas separator for such a coolant circuit can separate the gas from coolant in the coolant circuit and the gas can be routed to a gas port on the coolant expansion tank that is shared with one or more other coolant circuits.

[0041] The first gas separator 218 receives from components 230 of the first coolant circuit 216 coolant requiring deairation at a first gas separator input port 232, separates first gas from the coolant requiring deairation and outputs deairated coolant to the first coolant circuit 216 at a first gas separator out port 234 while outputting the first gas 212 without any coolant therein at a first gas separator gas port 236 towards the coolant expansion tank 202. The at least one second gas separator 224 receives from components 238 of the at least one second coolant circuit 222 coolant requiring deairation at a second gas separator input port 240 and outputs deairated coolant to the at least one second coolant circuit 222 at a second gas separator out port 242 while outputting the second gas 220 without any coolant therein ata second gas separator gas port 244 to the coolant expansion tank 202. Pump 246 and pump 248 pump coolant through the first coolant circuit 216 and the at least one second coolant circuit, respectively. Note that the cooling line from a gas separator to a coolant circuit can be angled downward to further prevent circulation of coolant through the coolant expansion tank.

[0042] In some aspects, a Teflon membrane 250 is between the pressurized air side 206 and the pressure regulator 228. The Teflon membrane 250 allows air / hydrogen to be released or added while preventing water vapor from entering the pressurized air side 206.

[0043] The pressure regulator 228 in some aspects may receive air from the braking system 252 of the vehicle. In fuel cell stack (FCS) vehicles, the air may come from compressors in the FCS cooling system of the FCS vehicle. The pressure regulator 228 is configured to release air to lower air pressure in the coolant system when air pressure rises above a first threshold and add pressurized air to increase air pressure in the coolant system when air pressure falls below a second threshold.

[0044] In some scenarios, even though no coolant from the coolant circuits flows into the coolant expansion tank, there may be requirements to separate the coolant circuits from each other. Figure 4 illustrates an example where the coolant circuits are separated from each other. In Figure 4, the coolant side 204 of the coolant expansion tank 202 has a first coolant chamber 400 for the first coolant circuit 216 and at least one second coolant chamber 402 for the at least one second coolant circuit 222. A divider 404 separates coolant in the first coolant chamber 400 from coolant in the at least one second coolant chamber 402.

[0045] Figure 5 illustrates another example where the coolant circuits can be separated from each other. The example of Figure 5 does not need any bellows or other membranes between air and the coolant to operate. In Figure 5, a wall 500 is between the pressurized air side 206 and the coolant side 204, where the wall 500 has a transfer channel 502 for transferring air from the pressurized air side 206 to the coolant side 204 to pressurize the coolant. The transfer channel has a first opening 504 proximate a bottom 506 of the pressurized air side 206 of the coolant expansion tank 202 and a second opening 508 proximate a top 510 of the coolant side 204 of the coolant expansion tank 202.

[0046] In Figures 2-5, one of the first coolant circuit 216 and the at least one second coolant circuit 222 is a hot coolant circuit and an other of the first coolant circuit 216 and the at least one second coolant circuit 222 is a cold coolant circuit. For example, the first coolant circuit 216 may be a cold coolant circuit and the at least one second coolant circuit 222 may be a hot coolant circuit.

[0047] Figure 6 is a flowchart of operations 600 for degassing coolant in a vehicle cooling system having a first cooling circuit and at least one second cooling circuit according to some aspects. The operations 600 include receiving pressurized air at a pressurized air side 206 of a coolant expansion tank 202 from a pressure regulator 228 (Block 601).

[0048] The operations 600 further include pressurizing coolant in a coolant side 204 of the coolant expansion tank 202 using the pressurized air (Block 603)

[0049] The operations 600 further include receiving, on the coolant side 204, first gas 212 comprising gas bubbles 214 separated from first coolant in the first coolant circuit 216 by a first gas separator 218, the gas bubbles 214 contributing to air pressure on the coolant in the coolant side 204 (Block 605).

[0050] The operations 600 further include receiving, on the coolant side 204, second gas 220 comprising gas bubbles 214 separated from second coolant in the at least one second coolant circuit 222 by at least one second gas separator 224, the second gas 220 contributing to air pressure on the coolant in the coolant side 204, the first coolant circuit 216 and the at least one second coolant circuit 222 isolated from each other (Block 607).

[0051] Figure 7 is a flowchart of operations 700 for degassing coolant in a vehicle cooling system having the first cooling circuit and the at least one second cooling circuit according to some aspects. The operations 700 include reducing air pressure on the coolant side 204 responsive to air pressure rising above a threshold level by releasing air via the pressure regulator 228 (Block 701).

[0052] The operations 700 include adding pressurized air via the pressure regulator 228 to increase air pressure on the coolant side 204 when air pressure falls below a second threshold (Block 703).

[0053] Figure 8 is a flowchart of operations 800 for receiving the first gas and receiving the second gas according to some aspects. The operations 800 include providing first coolantfluid having first gas 212 within the first coolant fluid requiring deair ation to the first gas separator 218, the first gas separator 218 having a first round interior wall 254, wherein providing the first cooling fluid comprises directing the first coolant fluid having gas toward the first round interior wall 254 such that inertia of the first cooling fluid having gas causes the first cooling fluid to move around the first round interior wall 254 in a vortex to press the first cooling fluid against the first round interior wall 254, wherein pressure of the first cooling fluid against the first round interior wall 254 causes the first gas to move toward a center of the first gas separator and be vented out a top of the first gas separator 218 into the coolant side 204 of the coolant expansion tank 202 (Block 801).

[0054] The operations 800 further include providing second coolant fluid having second gas within the second coolant fluid requiring deairation to the at least one second gas separator (224), the at least one second gas separator 224 having a second round interior wall 256, wherein providing the second cooling fluid comprises directing the second coolant fluid having gas toward the second round interior wall 256 such that inertia of the second cooling fluid having gas causes the second cooling fluid to move around the second round interior wall 256 in a vortex to press the second cooling fluid against the second round interior wall 256, wherein pressure of the second cooling fluid against the second round interior wall 256 causes the second gas to move toward a center of the at least one second gas separator 224 and be vented out a top of the at least one second gas separator 224 into the coolant side 204 of the coolant expansion tank 202.

[0055] Figure 9 is another view of a coolant system, according to another example. Figure 9 illustrates a coolant expansion tank 202 for a vehicle cooling system. The coolant expansion tank 202 includes a coolant side 204 having coolant. The coolant expansion tank 202 further includes a first gas port 208 on the coolant side 204 for receiving first gas 212 comprising gas bubbles 214 separated from coolant in a first coolant circuit 216 by a first gas separator 218, the first gas 212 contributing to air pressure on the coolant in the coolant side 204;

[0056] The coolant expansion tank 202 further includes at least one second gas port 210 on the coolant side for receiving second gas 220 comprising gas bubbles 214 separated fromcoolant in at least one second coolant circuit 222 by at least one second gas separator 224, the second gas contributing to air pressure on the coolant in the coolant side 204; and

[0057] The coolant expansion tank 202 further includes a pressurized air side 206 having pressurized air to pressurize the coolant in the coolant side 204 to a set pressure; the pressurized air side having a port 226 for receiving pressurized air from a pressure regulator 228.

[0058] The gas separators described herein make it possible to decrease the draw down volume and to use a pressure regulator to inject air when needed to control system pressure. The injected air does not oxidize (age) the coolant to glycolate besides a very small fraction that stays inside the coolant expansion tank 202.

[0059] The concepts described herein have the benefit of not having coolant exchange between the coolant expansion tank 202 and the rest of the coolant system. Thus, potentially oxidized coolant will not mix with the fresh coolant inside the coolant system.

[0060] The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises," "comprising," "includes," and / or "including" when used herein specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0061] It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.

[0062] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe a relationship of one element to another element as illustrated in the Figures. It will be understood that these terms and those discussed aboveare intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

[0001] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0002] It is to be understood that the present disclosure is not limited to the aspects described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and appended claims. In the drawings and specification, there have been disclosed aspects for purposes of illustration only and not for purposes of limitation, the scope of the inventive concepts being set forth in the following claims.

Claims

AMENDED CLAIMS received by the International Bureau on 27 February 2024 (27.02.2024)1. A coolant expansion tank (202) for a vehicle cooling system (200), the coolant expansion tank comprising: a coolant side (204) having expansion tank coolant; a first gas port (208) on the coolant side (204) for receiving first gas (212) comprising gas bubbles (214) separated from first coolant in a first coolant circuit (216) by a first gas separator (218) without any first coolant with the first gas (212), the first gas (212) contributing to air pressure on the coolant in the coolant side (204); at least one second gas port (210) on the coolant side for receiving second gas (220) comprising gas bubbles (214) separated from second coolant in at least one second coolant circuit (222) by at least one second gas separator (224) without any second coolant with the second gas (214), the second gas contributing to air pressure on the coolant in the coolant side; and a pressurized air side (206) having pressurized air to pressurize the expansion tank coolant in the coolant side (204) to a set pressure; the pressurized air side having a port (226) for receiving pressurized air from a pressure regulator (228).

2. The coolant expansion tank (202) of claim 1, further comprising: the first gas separator (218) connected to the first gas port (208); and the at least one second gas separator (224) connected to the at least one second gas port (210).

3. The coolant expansion tank (202) of claim 2, wherein the first gas separator (218) and the second gas separator (224) are integrated to the coolant side (204) of the coolant expansion tank (202).

4. The coolant expansion tank (202) of any of claims 1-3, wherein the first gas separator (218) receives from components (230) of the first coolant circuit (214) first coolant requiring deairation at a first gas separator input port (232), separates first gas from the first coolant requiring deairation and outputs deairated first coolant to the first coolant circuit (216) at a first gas separator out port (234) while outputting the first gas (212) without any first coolant therein at a first gas separator gas port (236) towards the coolant expansion tank (212) and the at least one second gas separator (224) receives from components (238) of the second coolant circuitAMENDED SHEET (ARTICLE 19)(222) second coolant requiring deairation at a second gas separator input port (240) and outputs deairated second coolant to the second coolant circuit (222) at a second gas separator out port (242) while outputting the second gas (220) without any second coolant therein at a second gas separator gas port (244) to the coolant expansion tank (212).

5. The coolant expansion tank of any of claims 1-4, wherein the pressure regulator (228) is integrated to the coolant expansion tank (212).

6. The coolant expansion tank of any of claims 1-5, further comprising: a Teflon membrane (250) between the pressurized air side (206) and the pressure regulator (228).

7. The coolant expansion tank (202) of any of claims 1-6, wherein the coolant side (204) has a first coolant chamber (400) for the first coolant circuit (216) and at least one second coolant chamber (402) for the at least one second coolant circuit (222), the coolant expansion tank further comprising: a divider (404) separating expansion tank coolant in the first coolant chamber (400) from expansion tank coolant in the at least one second coolant chamber (402).

8. The coolant expansion tank (202) of any of claims 1-6, further comprising: a wall (500) between the pressurized air side (206) and the coolant side (204), the wall (500) having a transfer channel (502) for transferring air from the pressurized air side (206) to the coolant side (204) to pressurize the expansion tank coolant and thereby pressurize the first coolant and the second coolant.

9. The coolant expansion tank of claim 8, wherein the transfer channel has a first opening (504) proximate a bottom (506) of the pressurized air side (206) of the coolant expansion tank (202) and a second opening (508) proximate a top (510) of the coolant side (204) of the coolant expansion tank (202).

10. A coolant system for a vehicle cooling system, the coolant system comprising: a coolant expansion tank (202) comprising: a coolant side (204) comprising:AMENDED SHEET (ARTICLE 19)a first gas port (208) for receiving first gas (212) comprising gas bubbles (214) separated from first coolant in a first coolant circuit (216) by a first gas separator (218) without any first coolant with the first gas (212), the first gas (212) contributing to air pressure on-the second coolant in the coolant side (204); at least one second gas port (210) for receiving second gas (220) comprising gas bubbles (214) separated from second coolant in at least one second coolant circuit (222) by at least one second gas separator (224) without any second coolant with the second gas (214), the second gas (220) contributing to air pressure on the expansion tank coolant in the coolant side (204); and a pressurized air side (206) configured to pressurize the coolant in the coolant side (204); a pressure regulator (228) configured to provide pressurized air to the pressurized air side (206); the first gas separator (218) configured to receive from the first coolant circuit (216) first coolant requiring deairation, deairate the first coolant requiring deairation, and provide the gas bubbles separated from the first coolant to the first gas port (208) of the coolant expansion tank (202); and the at least one second gas separator (224) configured to receive from the at least one second coolant circuit (222) second coolant requiring deairation, deairate the second coolant requiring deairation, and provide the gas bubbles (214) separated from the second coolant to the at least one second gas port (210) of the coolant expansion tank (202).

11. The coolant system of claim 10, wherein the first gas separator (218) and the at least one second gas separator (224) are integrated into the coolant side (204) such that the gas (212) separated from first coolant in the first coolant circuit (216) and gas (220) separated from second coolant in the at least one second coolant circuit (222) enters the coolant side (204) of the coolant expansion tank (202) and contributes to air pressure pressurizing the expansion tank coolant on the coolant side (204) of the coolant expansion tank (202).

12. The coolant system of any of claims 10-11, further comprising: a Teflon membrane (250) between the pressurized air side (206) and the pressure regulator (228).AMENDED SHEET (ARTICLE 19)13. The coolant system of any of claims 10-12 wherein the pressure regulator (228) is further configured to: release air to lower air pressure in the coolant system when air pressure rises above a first threshold; and add pressurized air to increase air pressure in the coolant system when air pressure falls below a second threshold.

14. The coolant system of any of claims 10-13, wherein the coolant side further comprises: a first coolant chamber (400) for the first coolant circuit (216); at least one second coolant chamber (402) for the at least one second coolant circuit (222); and a divider (404) separating expansion tank coolant in the first coolant chamber (400) from expansion tank coolant in the at least one second coolant chamber (402).

15. The coolant system of any of claims 10-14 further comprising: a wall (500) in the coolant expansion tank (202) separating the coolant side (204) from the pressurized air side (206) in the coolant expansion tank (202), the wall (500) having a transfer channel (502) that transfers air from the pressurized air side to the coolant side.

16. The coolant system of claim 15 wherein the transfer channel (502) has a first opening (504) proximate a bottom (506) of the pressurized air side (206) and a second opening (508) proximate a top (510) of the coolant side (302), wherein pressurized air flows through the transfer channel (502) to provide pressurized air to coolant in the coolant side.

17. The coolant system of any of claims 10-16, wherein one of the first coolant circuit (216) and the at least one second coolant circuit (222) is a hot coolant circuit and an other of the first coolant circuit (216) and the at least one second coolant circuit (222) is a cold coolant circuit.

18. A method of degassing coolant in a vehicle cooling system having a first cooling circuit and at least one second cooling circuit, the method comprising: receiving (601) pressurized air at a pressurized air side (206) of a coolant expansion tank (202) from a pressure regulator (228);AMENDED SHEET (ARTICLE 19)pressurizing (603) expansion tank coolant in a coolant side (204) of the coolant expansion tank (202) using the pressurized air; receiving (605), on the coolant side (204), first gas (212) comprising gas bubbles (214) separated from first coolant in the first coolant circuit (216) by a first gas separator (218) without any first coolant with the first gas (212), the gas bubbles (214) contributing to air pressure on the coolant in the coolant side (204); and receiving (607), on the coolant side (204), second gas (220) comprising gas bubbles (214) separated from second coolant in the at least one second coolant circuit (222) by at least one second gas separator (224) without any second coolant with the second gas (220), the second gas (220) contributing to air pressure on the coolant in the coolant side (204), the first coolant circuit (216) and the at least one second coolant circuit (222) isolated from each other.

19. The method of claim 18, further comprising: reducing (701) air pressure on the coolant side (204) responsive to air pressure rising above a threshold level by releasing air via the pressure regulator (228); and adding (703) pressurized air via the pressure regulator (228) to increase air pressure in the coolant side (204) when air pressure falls below a second threshold.

20. The method of any of claims 18-19, wherein receiving the first gas and receiving the second gas comprises: providing (801) first coolant fluid having first gas (212) within the first coolant fluid requiring deairation to the first gas separator (218), the first gas separator (218) having a first round interior wall (254), wherein providing the first cooling fluid comprises directing the first coolant fluid having gas toward the first round interior wall (254) such that inertia of the first cooling fluid having gas causes the first cooling fluid to move around the first round interior wall (254) in a vortex to press the first cooling fluid against the first round interior wall (254), wherein pressure of the first cooling fluid against the first round interior wall (254) causes the first gas to move toward a center of the first gas separator and be vented out a top of the first gas separator (218) into the coolant side (204); and providing (803) second coolant fluid having second gas within the second coolant fluid requiring deairation to the at least one second gas separator (224), the at least one second gas separator (224) having a second round interior wall (256), wherein providing the second coolingAMENDED SHEET (ARTICLE 19)fluid comprises directing the second coolant fluid having gas toward the second round interior wall (256) such that inertia of the second cooling fluid having gas causes the second cooling fluid to move around the second round interior wall (256) in a vortex to press the second cooling fluid against the second round interior wall (256), wherein pressure of the second cooling fluid against the second round interior wall (256) causes the second gas to move toward a center of the at least one second gas separator (224) and be vented out a top of the at least one second gas separator (224) into the coolant side (204) of the coolant expansion tank (202).AMENDED SHEET (ARTICLE 19)

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