LEAK DETECTION SYSTEM

Abstract

A leak detection system for a coolant system includes a coolant reservoir including a coolant holding portion configured to store coolant for the coolant system and a gas holding portion, a reservoir inlet fluidically connected to the gas holding portion, a reservoir outlet fluidically connected to the coolant holding portion, and a pressure relief valve including a coolant inlet portion fluidically connected to the coolant holding portion and a pressure relief outlet. The pressure relief valve is configured to respond to pressure in the gas holding portion to vent coolant from the coolant holding portion through the pressure relief outlet without venting gas from the gas holding portion.

Claims

1. A leak detection system for a coolant system comprising: a coolant reservoir including a coolant holding portion configured to store coolant for the coolant system and a gas holding portion; a reservoir inlet fluidically connected to the gas holding portion; a reservoir outlet fluidically connected to the coolant holding portion; and a pressure relief valve including a coolant inlet portion fluidically connected to the coolant holding portion and a pressure relief outlet, the pressure relief valve being configured to respond to pressure in the gas holding portion to vent coolant from the coolant holding portion through the pressure relief outlet without venting gas from the gas holding portion.

2. The leak detection system according to claim 1, wherein the pressure relief valve includes a spring configured to respond to a selected gas pressure in the gas holding portion to vent coolant from the coolant holding portion.

3. The leak detection system according to claim 2, further comprising a gas sensor arranged in the gas holding portion, the gas sensor being configured to detect refrigerant gas in the coolant reservoir; and a leak alert system operatively connected to the gas sensor, the leak alert system being configured to provide one of an audible alert and a visual alert indicating a presence of refrigerant gas in the coolant holding portion.

4. The leak detection system according to claim 3, wherein the gas sensor is configured to detect hydrocarbon (HC) gas.

5. The leak detection system according to claim 4, wherein the HC gas is propane gas.

6. The leak detection system according to claim 1, wherein the coolant reservoir includes an inlet chamber including the reservoir inlet, an outlet chamber including the reservoir outlet, and a dividing wall separating the inlet chamber from the outlet chamber, the dividing wall including a coolant passage.

7. The leak detection system according to claim 6, wherein the pressure relief valve is arranged in the outlet chamber.

8. The leak detection system according to claim 7, wherein the inlet chamber includes a gas sensor and a bleed valve, the gas sensor being configured to detect refrigerant gas in the inlet chamber and the bleed valve providing a refrigerant gas outlet.

9. The leak detection system according to claim 1, further comprising a bleed valve fluidically connected to the gas holding portion, the bleed valve providing a pathway for removing refrigerant gas from the coolant reservoir.

10. A dual secondary loop cooling system comprising: a primary heat exchanger including a coolant inlet and a coolant outlet; a refrigeration module including a module housing surrounding a first heat exchanger coil fluidically connected to the coolant outlet of the primary heat exchanger and the coolant inlet of the primary heat exchanger, a second heat exchanger coil, and a refrigeration circuit that fluidically connects the first heat exchanger coil with the second heat exchanger coil; and a leak detection system fluidically connected to the primary heat exchanger, the leak detection system including: a coolant reservoir including a coolant holding portion configured to store coolant for the dual secondary loop cooling system and a gas holding portion; a reservoir inlet fluidically connected to the gas holding portion and the coolant inlet of the primary heat exchanger; a reservoir outlet fluidically connected to the coolant holding portion and the coolant outlet of the primary heat exchanger; and a pressure relief valve including a valve inlet fluidically connected to the coolant holding portion and a pressure relief outlet, the pressure relief valve being configured to respond to pressure in the gas holding portion to vent coolant from the coolant holding portion through the pressure relief outlet without venting gas from the gas holding portion.

11. The dual secondary loop cooling system according to claim 10, further comprising a gas sensor arranged in the gas holding portion, the gas sensor being configured to detect refrigerant gas in the coolant reservoir; and a leak alert system operatively connected to the gas sensor, the leak alert system being configured to provide one of an audible alert and a visual alert indicating a presence of refrigerant gas in the coolant holding portion.

12. The dual secondary loop cooling system according to claim 11, wherein the gas sensor is configured to detect hydrocarbon (HC) gas.

13. The dual secondary loop cooling system according to claim 11, wherein the gas holding portion includes an outlet fluidically connected to the module housing.

14. The dual secondary loop cooling system according to claim 10, wherein the coolant reservoir includes an inlet chamber including the reservoir inlet, an outlet chamber including the reservoir outlet, and a dividing wall separating the inlet chamber from the outlet chamber, the dividing wall including a coolant passage.

15. The dual secondary loop cooling system according to claim 14, wherein the pressure relief valve is arranged in the outlet chamber.

16. The dual secondary loop cooling system according to claim 15, wherein the inlet chamber includes a gas sensor and a bleed valve, the gas sensor being configured to detect refrigerant gas in the inlet chamber and the bleed valve providing a refrigerant gas outlet.

17. The dual secondary loop cooling system according to claim 10, further comprising a bleed valve fluidically connected to the gas holding portion, the bleed valve providing a pathway for removing refrigerant gas from the coolant reservoir.

18. The dual secondary loop cooling system according to claim 10, wherein the module housing includes a module coolant outlet including a gas sensor, the pressure relief outlet being fluidically connected to the module coolant outlet.

19. A leak detection system for a cooling system comprising: a coolant reservoir including a coolant holding portion configured to store coolant for the cooling system, the coolant reservoir including a reservoir inlet, a reservoir outlet, and a pressure relief valve having a coolant inlet portion and a pressure relief outlet; and a gas separator bottle including an internal volume, the gas separator bottle including a separator inlet connectable to the cooling system, a separator outlet connected to the reservoir inlet of the coolant reservoir, a gas sensor configured to detect refrigerant gas in the coolant holding portion.

20. The leak detection system according to claim 19, wherein the gas separator bottle includes a bleed valve operable to remove refrigerant gas from the internal volume.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure.

[0029] FIG. 1 illustrates a dual secondary loop cooling system including a coolant reservoir having a leak detection system, in accordance with the present disclosure;

[0030] FIG. 2 depicts a dual chamber coolant reservoir including a leak detection system, in accordance with the present disclosure;

[0031] FIG. 3 depicts a coolant reservoir including a leak detection system, in accordance with an aspect of the present disclosure;

[0032] FIG. 4 depicts the coolant reservoir of FIG. 3 in a leak detection mode, in accordance with the present disclosure;

[0033] FIG. 5 depicts a coolant reservoir including a leak detection system, in accordance with another aspect of the present disclosure;

[0034] FIG. 6 depicts a coolant reservoir including a leak detection system, in accordance with yet another aspect of the present disclosure;

[0035] FIG. 7A depicts a coolant reservoir including a leak detection system in a coolant fill mode, in accordance with an aspect of the present disclosure;

[0036] FIG. 7B depicts the coolant reservoir of FIG. 7A in normal operating mode, in accordance with an aspect of the present disclosure;

[0037] FIG. 7C depicts the coolant reservoir of FIG. 7B in a leak detection mode system, in accordance with an aspect of the present disclosure;

[0038] FIG. 7D depicts the coolant reservoir of FIG. 7C in a refrigerant removal mode, in accordance with an aspect of the present disclosure;

[0039] FIG. 8 depicts a dual secondary loop cooling system including a coolant reservoir having a leak detection system, in accordance with an aspect of the present disclosure;

[0040] FIG. 9 depicts a dual secondary loop cooling system including a coolant reservoir having a leak detection system, in accordance with another aspect of the present disclosure; and

[0041] FIG. 10 depicts a coolant reservoir including a leak detection system including a gas separator bottle, in accordance with an aspect of the present disclosure.

[0042] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0043] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0044] Vehicle refrigerant may come in many forms. Older vehicles employed a hydrofluorocarbon (HFC) refrigerant, such as freon, in various mixtures, as a refrigerant. Given the desire to avoid greenhouse gas producing emissions, HFC refrigerants are being phased out in favor of non-fluorocarbon substances. One such substance that would present as a good substitute for HFC refrigerants is a hydrocarbon (HC) refrigerant such as propane. While known as being a great refrigerant, propane has several drawbacks including a low-flash point. As such, a system for detecting HC leaks would be welcome in the industry.

[0045] A dual secondary loop cooling system, in accordance with the present disclosure, is indicated generally at 10 in FIG. 1. Dual secondary loop cooling system 10 is arranged in a vehicle (not shown) and includes a primary heat exchanger or radiator 12 having a coolant inlet 14 and a coolant outlet 16. A heat exchange portion or coil 18 is fluidically connected between coolant inlet 14 and coolant outlet 16. Dual secondary loop cooling system 10 also includes a secondary heat exchanger that may take the form of a heating, ventilation, and air conditioning (HVAC) unit 20. HVAC unit 20 includes a cabin cooling coil 22 and a cabin heating coil 24 that may provide conditioned air (heated or cooled) to passenger spaces (not shown) of a vehicle (also not shown).

[0046] Dual secondary loop cooling system 10 is also shown to include a refrigerant module 28 through which the coolant passes in a heat exchange relationship with a refrigerant, such as a hydrocarbon refrigerant. For example, the hydrocarbon refrigerant may be propane. Refrigerant module 28 may include a module housing 30 within which is arranged a first refrigeration coil 32 and a second refrigeration coil 34. First refrigeration coil 32 may take the form of a condenser coil and second refrigeration coil 34 may take the form of an evaporator coil. A refrigerant circuit 36 circulates an amount of refrigerant through each refrigeration coil 32, 34.

[0047] As will be detailed more fully herein, supply coolant flowing from primary heat exchanger 12 may flow through first refrigeration coil 32 in a heat exchange relationship with the amount of refrigerant in refrigeration circuit 36. The supply coolant absorbs heat from the amount of refrigerant in first refrigeration coil 32. Return coolant may flow through second refrigeration coil 34 and releases heat to the refrigerant before passing back through, in the non-limiting example shown, primary heat exchanger 12. It should be understood that the particular path taken by the return refrigerant may vary and may be dictated by operating conditions and by system architecture.

[0048] Dual secondary loop cooling system 10 includes a coolant supply circuit 39 and a coolant return circuit 41. Coolant supply circuit 39 passes supply coolant through various devices in the vehicle that may include an inverter 43, an electric motor 45, and a battery heat exchanger 48 that is arranged in a heat exchange with a battery 50 that is operatively coupled to electric motor 45 through inverter 43. At this point it should be understood that while described as being part of an electric vehicle, the cooling system described in the present disclosure may be associated with other vehicle types as well as non-vehicle based systems.

[0049] Coolant supply circuit 39 includes a cooling circuit branch 54 and a heated coolant branch 56. Multiple heating and cooling scenarios can be supported through this sort of secondary loop thermal management system via control of the heated coolant branch 56 and cooled cooling circuit branch 54 through control of the one or more three-way valves such as indicated at 58 in FIG. 1. For example, in a cabin and a battery cooling mode, cooling circuit branch 54 delivers chilled coolant from second refrigeration coil 34 to cabin cooling coil 22 in the HVAC unit 20 to cool passenger spaces (not shown) of the vehicle and through battery heat exchanger 48. Heat removed from the battery 50 by battery heat exchanger 48 and from the air by the cabin cooling coil 22 is transferred from the return side (not separately labeled) of the cooled cooling circuit branch 54 into the refrigeration circuit 36 at second refrigeration coil 34, and transferred into the heated coolant branch 56 at the first refrigeration coil 32 by the refrigerant circulating though refrigeration circuit 36. Heated coolant branch 56 carries heated coolant from first refrigeration coil 32 back to and through primary heat exchanger 12.

[0050] In accordance with the present disclosure, dual secondary loop cooling system 10 includes a leak detection system 60 including a coolant reservoir 64 that may detect the presence of refrigerant in the coolant. The refrigerant may pass into the coolant in refrigeration module 28 if there is damage to refrigeration circuit 36 and first and/or second refrigeration coils 32 and 34.

[0051] A coolant reservoir 64 in accordance with one exemplary aspect of leak detection system 60 is shown in FIG. 2. Coolant reservoir 64 includes an outer surface 66 defining an internal volume 68 including an inlet chamber 70 and an outlet chamber 72. A divider wall 78 partially separates and defines inlet chamber 70 and outlet chamber 72. Divider wall 78 includes a coolant passage 80 that allows coolant to flow between inlet chamber 70 and outlet chamber 72. In accordance with the present disclosure, coolant passage 80 fluidically connects a first coolant holding portion 81 in inlet chamber 70 and a second coolant holding portion 82 in outlet chamber 72. A gas holding portion 84 is formed in inlet chamber 70 above first coolant holding portion 81.

[0052] Outlet chamber 72 includes a pressure relief valve 94 mounted to an upper surface (not separately labeled) of coolant reservoir 64. Pressure relief valve 94 includes a valve inlet 96 and a pressure relief outlet 98. A valve member 100 separates valve inlet 96 and pressure relief outlet 98. A biasing element 102, which may take the form of a spring 104, holds valve member 100 against valve inlet 96. If coolant pressure exceeds a set pressure, spring 104 compresses allowing valve member 100 to unseat opening a pathway between valve inlet 96 and pressure relief outlet 98.

[0053] In accordance with a non-limiting example, pressure relief valve 94 is incorporated into a pressure cap assembly 108. Pressure cap assembly 108, valve member 100 and biasing element 102 may be removed, as an assembly exposing a fill neck 109, which serves as a coolant fill port (not separately labeled) for dual secondary loop cooling system 10.

[0054] In accordance with the present disclosure, inlet chamber 70 includes a gas sensor 110 that is configured for detecting refrigerant. Gas sensor 110 may be configured, for example, to detect a presence of hydrocarbon gas. For example, gas sensor 110 may be configured to detect whether propane is present within coolant flowing through dual secondary loop cooling system 10. Gas sensor 110 may be connected to a leak alert system 112 having an alert output 114. Alert output 114 may provide one or more of a visible alert and an audible alert to indicate that refrigerant has infiltrated into the coolant. Inlet chamber 70 may also include a bleed valve 116 that allows technicians or others to remove refrigerant from inlet chamber 70 of coolant reservoir 64.

[0055] Reference will now follow to FIGS. 3 and 4 in describing a leak detection system 130 in accordance with another example of the present disclosure. Leak detection system 130 includes a coolant reservoir 132 having an outer surface 134 defining an internal volume 136 forming a coolant holding portion 139 and a gas holding portion 141. Gas holding portion 141 is above coolant holding portion 139. Coolant reservoir 132 includes a reservoir inlet 143 fluidically connected to gas holding portion 141 and a reservoir outlet 145 fluidically connected to coolant holding portion 139. A pressure cap assembly 150 containing a pressure relief valve 151 is mounted to outer surface 134 and fluidically connected with coolant holding portion 139.

[0056] Pressure cap assembly 150 includes a valve inlet portion 152 exposed to coolant holding portion 139 and a pressure relief outlet 154. Pressure cap assembly 150 is further shown to include a valve member 156 that is urged against valve inlet portion 152 by a biasing element 158. Biasing element 158 may take the form of a spring 160 configured to force valve member against valve inlet portion 152 with a selected pressure. Valve member 156 and biasing element 158 are connected to a cover 162 that is secured over pressure relief valve 151 of pressure cap assembly 150.

[0057] In accordance with the present disclosure, gas infiltrating into coolant flowing through dual secondary loop cooling system 10 will accumulate in gas holding portion 141. The accumulation of refrigerant in gas holding portion 141 will elevate pressures on coolant in coolant holding portion 139 as shown in FIG. 4. Pressure on the coolant will continue to increase until pressure applied to valve member 156 by biasing element 158 is overcome. At such a time, coolant will pass from pressure relief outlet 154. The coolant will fall onto surfaces below the vehicle to provide a visual indication to operators of the vehicle that a refrigerant leak may exist, prior to allowing any of the leaked refrigerant to escape the coolant circuit.

[0058] In FIG. 5 a gas sensor 168 is shown mounted to outer surface 134 at gas holding portion 141. Gas sensor 168 may be connected to leak alert system 112 to provide additional feedback to operators of the vehicle that a refrigerant leak may exist. The operator may then take remedial action to mitigate and correct the leak. FIG. 6 depicts pressure relief valve 151 mounted to outer surface 134 in gas holding portion 141. In this configuration, gas sensor 168 will provide an alert that gas is present in gas holding portion 141 before pressure relief valve 151 responds.

[0059] Reference will now follow to FIGS. 7A-7D in describing a method of introducing coolant into dual secondary loop cooling system 10 and removing accumulated gas from gas holding portion 141 in accordance with an aspect of the present disclosure. Coolant is introduced dual into secondary loop cooling system 10 through fill neck 109 of coolant reservoir 132, which is exposed by removing pressure cap assembly 150 for initial system coolant fill as shown in FIG. 7A. During normal operation, coolant enters into internal volume 136 via reservoir inlet 143 and passes from coolant reservoir 132 through reservoir outlet 145 as shown in FIG. 7B.

[0060] If a hole or crack forms between refrigerant coils and coolant passes of the first refrigeration coil 32 or second refrigeration coil 34, refrigerant gas may infiltrate into coolant supply system, 39 from refrigerant module 28. The refrigerant gas travels with the coolant to coolant reservoir 132. Once in coolant reservoir 132, the gas separates from the coolant and fills gas holding portion 141 as shown in FIG. 7C. Any gas accumulating in gas holding portion 141 is detected by gas sensor 168 and an alert is presented to the operator through leak alert system 112. At this point, service personnel can access a bleed valve 178, connect a service hose 180 and remove and collect any gas accumulated in gas holding portion 141 as shown in FIG. 7D.

[0061] FIG. 8 depicts an alternative arrangement for leak detection system 130. In the example shown, pressure relief outlet 154 is connected to a conduit 182 fluidically connected to a module outlet 183 of module housing 30. An outlet conduit 188 is connected to module outlet 183. A gas sensor 185 is arranged at module outlet 183. Gas sensor 185 is positioned so as to detect any refrigerant gas that may pass from coolant reservoir 132 via conduit 182 and/or refrigerant that my exist within module housing 30. In FIG. 9, coolant reservoir 132 includes an outlet 192 connected to module housing 30 through an outlet conduit 194. A gas sensor 196 is arranged in module housing 30. Gas sensor is positioned to as to detect any refrigerant gas that may pass from coolant reservoir 132 and/or directly from refrigerant circuit 36.

[0062] FIG. 10 depicts a leak detection system 203 in accordance with another example of the present disclosure. Leak detection system 203 includes a coolant reservoir 206 having an outer surface 208 defining an internal volume 210. Internal volume 210 includes a coolant holding portion 212. Coolant reservoir 206 includes a reservoir inlet 214 ana a reservoir outlet 216.

[0063] Leak detection system 203 also includes a gas separator bottle 220 having an outer surface section 222 defining an internal volume portion 224. Gas separator bottle 220 includes a separator inlet member 226 fluidically connected with coolant return circuit 41 and a separator outlet member 228 fluidically connected to reservoir inlet 214. Internal volume portion 224 defines a gas holding portion 232 that retains any refrigerant gas entrained in the coolant passing into gas separator bottle 220. Gas separator bottle 220 includes a gas sensor 234 that detects the presence of refrigerant in gas holding portion 230 and a bleed valve 236 that accommodate gas removal.

[0064] At this point, it should be appreciated that the leak detection system as described in the present disclosure provides a warning to operators regarding the presence of refrigerant gas in the cooling system. Operators are then able to take steps to remove the gas from the coolant and make any necessary repairs.

[0065] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

[0066] Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0067] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms a, an, and the may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms comprises, comprising, including, and having, are inclusive and therefore 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. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0068] When an element or layer is referred to as being on, engaged to, connected to, or coupled to another element or layer, it may be directly on, engaged, connected, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being directly on, directly engaged to, directly connected to, or directly coupled to another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., between versus directly between, adjacent versus directly adjacent, etc.). As used herein, the term and/or includes any and all combinations of one or more of the associated listed items.

[0069] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer, or section. Terms such as first, second, and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the example embodiments.

[0070] Spatially relative terms, such as inner, outer, beneath, below, lower, above, upper, and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as below, or beneath other elements or features would then be oriented above the other elements or features. Thus, the example term below can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.