DETECTION SYSTEM AND TRANSIENT PRESSURE RESPONSE DETECTION METHOD FOR DETECTING RESIDUAL AIR BUBBLES IN LIQUID-COOLING SYSTEM AND FLOW RATE CONTROL DEVICE FOR USING THE SAME

A detection system adapted for a liquid-cooling system includes a pressurizing device and at least one pressure sensor, the pressurizing device is configured to connect to and to pressure the liquid-cooling system, the pressure sensor is configured to measure a transient pressure response in response to detecting residual air bubbles in the liquid-cooling system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 111107315 filed in Taiwan (R.O.C.) on Mar. 1, 2022, the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

The disclosure relates to a detection system, more particularly to a detection system and a transient pressure response detection method for detecting residual air bubbles in liquid-cooling system and a flow rate control device for using the same.

BACKGROUND

With the advancement and popularization of science and technology and the advent of the era of Internet of Things (IoT), electronic devices, such as notebook computers, desktop computers, and servers, have become an indispensable part of daily life. In order to prevent the heat generated by internal electronic components from affecting the performance and service life, liquid-cooling, which is more effective in heat dissipation than air cooling, has gradually been paid more and more attention.

In general, a liquid-cooling system uses coolant as a medium for heat dissipation and is cooperated with a pump to form a cooling circulation to continuously absorb and take away the heat generated by the heat sources. In some applications, there may be multiple heat sources in the system that need to be cooled, thus a cooling distribution unit (CDU) is widely used to efficiently and controllably distribute the coolant to the cold plates arranged at the heat sources. For example, please seeFIG.1, a conventional liquid-cooling system that adopts a typical cooling distribution unit is provided, as shown, a CDU31is connected to a server33through manifolds32and the CDU31is connected to an external cooling tower34through pipes, in such an arrangement, the CDU31is able to control the flow rate and/or pressure of the coolant and pump the coolant to pass through heat sources (not shown) inside the server33from one of the manifolds32and pump the high-temperature coolant out of the server33to the other manifold32.

It is known that residual air bubbles or air plugs in the passage of a liquid-cooling system will affect the heat dissipation; in particular, some areas of the passage of the liquid-cooling system, such as turns of pipes or fins within cold plates, tend to result in accumulation of residual air bubbles to reduce performance. Thus, removing residual air bubbles from the coolant inside the liquid-cooling system becomes a necessary work before the operation of the liquid-cooling system. However, to avoid unwanted physical or chemical reactions (e.g., corrosion or freezing) due to uncontrollable factors such as vibration or drastic changes in temperature during transportation and to avoid violations of regulations of some countries on the transportation restrictions to liquid substance, the products that adopt CDU or cold plate are filled with low-reactive gas (e.g., nitrogen gas) instead of coolant before shipping in order to keep the passage clean and dry. As a result, uses have to install pipes, add coolant, and remove residual air bubbles by themselves.

Conventionally, the user is needed to spend hours or days on slowly pouring coolant into the CDU to visually observe whether residual air bubbles have been eliminated from exhaust port, but the user is unable to observe the situation inside the cold plate. Thus, the user has to spend longer time on adding coolant to expect that the residual air bubbles can be completely eliminated. This leads to a time-consuming and troublesome works on the determination of the removal of residual air bubbles from the liquid-cooling system. Also, visually observing residual air bubbles with naked eyes cannot effectively allow users to detect whether residual air bubbles appear in the passage or cold plate and thereby making it unable to achieve the required cooling performance of the liquid-cooling system.

SUMMARY

Accordingly, one aspect of the disclosure is to provide a detection system, a transient pressure response detection method, and a flow rate control device, capable of solving the problems raised in the conventional methods.

One embodiment of the disclosure provides a detection system adapted for a liquid-cooling system and including a pressurizing device and at least one pressure sensor, the pressurizing device is configured to connect to and to pressure the liquid-cooling system, the pressure sensor is configured to measure a transient pressure response in response to detecting residual air bubbles in the liquid-cooling system.

One embodiment of the disclosure provides a flow rate control device adapted to have fluid communication with a cold plate of a liquid-cooling system and including a housing and a detection system. The detection system includes a pressurizing device and at least one pressure sensor, the pressurizing device and the at least one pressure sensor are disposed in the housing, the pressurizing device is configured to connect to at least one of an inlet and an outlet of the cold plate, the at least one pressure sensor is configured to measure a transient pressure response in response to detecting residual air bubbles in the liquid-cooling system.

One embodiment of the disclosure provides a transient pressure response detection method adapted for a pressurizing device and at least one pressure sensor being in fluid communication with a liquid-cooling system. The transient pressure response detection method includes: pressurizing the liquid-cooling system by the pressurizing device; and measuring a transient pressure response in the liquid-cooling system by the at least one pressure sensor to detect residual air bubbles in the liquid-cooling system.

According to the detection system, the transient pressure response detection method, and the flow rate control device as discussed in the above embodiments of the disclosure, the detection system is able to pressurize the coolant in the passage of the liquid-cooling system to incur a transient pressure response used to determine whether residual air bubble or air plug exists in the liquid-cooling system.

DETAILED DESCRIPTION

Aspects and advantages of the disclosure will become apparent from the following detailed descriptions with the accompanying drawings. The inclusion of such details provides a thorough understanding of the disclosure sufficient to enable one skilled in the art to practice the described embodiments but it is for the purpose of illustration only and should not be understood to limit the disclosure. On the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects of the disclosure described herein, while still obtaining the beneficial results of the present disclosure. It will also be apparent that some of the desired benefits of the present disclosure can be obtained by selecting some of the features of the present disclosure without utilizing other features.

It is to be understood that the phraseology and terminology used herein are for the purpose of better understanding the descriptions and should not be regarded as limiting. Unless specified or limited otherwise, the terms “end”, “portion”, “area” may be used to, but not limiting, describe specific feature or structure. As used herein, the terms “substantially” or “approximately” may describe a slight deviation from a target value, in particular a deviation within the production accuracy and/or within the necessary accuracy, so that an effect as present with the target value is maintained. Unless specified or limited otherwise, the phrase “at least one” as used herein may mean that the quantity of the described element or component is one or more than one but does not necessarily mean that the quantity is only one. The term “and/or” may be used herein to indicate that either or both of two stated possibilities.

In addition, it is known that devices (e.g., servers) that contain more than one heat sources needed to be cooled adopt a liquid-cooling system involving one or more cooling distribution units (CDU); in specific, a typical CDU has a pump used to transfer coolant to cold plates at the heat sources through pipes, such that the heat generated by the heat sources can be absorbed by the cold plates and taken away by the coolant passing through the cold plates. The coolant can be cooled at other places and then flow back to join the next circulation by the pump of the cooling distribution unit, thereby continuously cooling the heat sources. Ideally, the path of the coolant (including the pipes and the cold plate) within the liquid-cooling system shall be filled with coolant and absent of air bubbles, if residual air bubbles exist, the cooling performance of the coolant will be affected. Thus, detecting whether residual air bubbles exist in the path of the coolant within the liquid-cooling system becomes a necessary step before the operation of the cooling circulation.

To this end, a detection system and a transient pressure response detection method according to embodiments of the disclosure are described in detail with reference toFIGS.2-5. To better understand the following detail descriptions, the terms “pathway”, “passage”, “pipe”, and “tube” and phrase “in fluid communication with” may be used hereinafter; in specific, the terms “pathway”, “passage”, “pipe”, and “tube” may be referred to an assembly of one or more components that transfer coolant to enable coolant to form a circulation over the liquid-cooling system or are able to be in fluid communication with the circulation within the liquid-cooling system, and the phrase “in fluid communication with” means a situation that fluid (liquid and/or gas) is allowed to directly or indirectly flow from one component to another.

Please refer toFIG.2, one embodiment of the disclosure provides a detection system1and a liquid-cooling system2adopts the detection system1. For the purpose of simplicity, the pipes inFIG.1are not numbered, and the pipes are merely provided for illustrating the relationships among other components but not intended to limit the disclosure.

The liquid-cooling system2is applicable to devices (e.g., servers) that contain at least one heat source needed to be cooled. As shown, the liquid-cooling system2may include at least one flow rate control device8, at least one cold plate9, at least one manifold M1, and at least one manifold M2which are in fluid communication with one another and therefore can form a cooling circulation CL (as indicated by arrows).

The flow rate control device8may be served as a cooling distribution unit (CDU) or part thereof. The flow rate control device8is configured to transfer and distribute coolant (not shown) flowing through the liquid-cooling system2so as to ensures adequate circulation of coolant to different heat sources in the liquid-cooling system2. Optionally, the flow rate control device8is able to control flow rate and/or pressure of coolant. The cold plate9is configured to have direct or indirect thermal contact with one or more heat sources, thus the heat generated by the heat source can be absorbed by the cold plate9and taken away by the coolant passing through the cold plate9. The manifolds M1and M2may be any typical manifold and configured to connect to the flow rate control device8and an inlet91and an outlet92of the cold plate9via one or more pipes.

Then, please further refer toFIG.3, a perspective view of an exemplary flow rate control device inFIG.2is provided. As shown, the flow rate control device8may include a housing81, a controller82, a power source83, a heat exchanger84, and a reservoir85. The housing81is configured to accommodate the controller82, the power source83, the heat exchanger84, and the reservoir85. The controller82may be any suitable processor. The power source83may be any suitable pump that can be used to pump coolant to form the cooling circulation CL inside the liquid-cooling system2. The heat exchanger84may act as a radiator to transfer heat from the coolant through its passages so that the coolant can continue traveling through the liquid-cooling system2.

The reservoir85is configured to store a certain amount of coolant to provide or replenish coolant needed by the cooling circulation CL.

Referring toFIGS.2and3, the power source83is in fluid communication with the manifold M1through one or more pipes, the manifold M1is in fluid communication with the inlet91of the cold plate9through one or more pipes, the outlet92of the cold plate9is in fluid communication with the manifold M2through one or more pipes, the manifold M2is in fluid communication with the heat exchanger84through one or more pipes, and the heat exchanger84is in fluid communication with the power source83through one or more pipes. In such an arrangement, the power source83can pump coolant to the cold plate9via the pipes and the manifold M1, and the heat generated by the heat source will be taken away by the coolant passing through the cold plate9, and then the heated coolant is pumped back to the heat exchanger84via the pipes and the manifold M2, the heat exchanger84cools the coolant, and then the cooled coolant flows back to the power source83to continue circulating as indicated by the cooling circulation CL. In other words, the cooling circulation CL is at least formed by the cold plate9, the manifolds M1and M2, the power source83, the heat exchanger84, and the pipes thereamong. The reservoir85is selectively in fluid communication with the power source83to provide or replenish coolant to the cooling circulation CL.

The detection system1is provided to detect whether residual air bubbles existing in the cooling circulation CL of the liquid-cooling system2. In one embodiment, the detection system1may include a pressurizing device11and at least one pressure sensor13.

The pressurizing device11is configured to pressurize the coolant inside the cooling circulation CL of the liquid-cooling system2. In one embodiment, the pressurizing device11may be any suitable pump. The pressurizing device11may be electrically connected to the controller82of the flow rate control device8or another external controller via a Serial Peripheral Interface (SPI) or an Inter-Integrated Circuit (I2C) bus. The pressurizing device11is selectively in fluid communication with the cooling circulation CL but does not participate the cooling circulation CL; in other words, the pressurizing device11is not part of the cooling circulation CL and is considered locating outside the cooling circulation CL. Thus, the pressurizing device11is externally connected to the liquid-cooling system2. For example, the pressurizing device11may be in fluid communication with the pipes between the inlet91and outlet92of the cold plate9and the manifolds M1and M2.

The pressure sensor13is configured to measure the pressure or pressure variation of the coolant inside the cooling circulation CL of the liquid-cooling system2. The pressure sensor13may be electrically connected to the controller82of the flow rate control device8or another external controller via a Serial Peripheral Interface (SPI) or an Inter-Integrated Circuit (I2C) bus, thus the pressure sensor13is able to transmit signal related to the detected pressure to the controller82. The pressure sensor13may be in fluid communication with the cooling circulation CL but does not participate the cooling circulation CL; in other words, the pressure sensor13is not part of the cooling circulation CL and is considered locating outside the cooling circulation CL. For example, the pressure sensor13may be in fluid communication with the pipes between the cold plate9, the manifolds M1and M2, and the pressurizing device11.

In this embodiment, the pressurizing device11and the pressure sensor13may be accommodated within the housing81of the flow rate control device8, in other words, the pressurizing device11and the pressure sensor13may be integrated into the flow rate control device8. In other embodiments, the pressurizing device11and the pressure sensor13may be integrated into another module located outside the flow rate control device8. For example, in one embodiment, the pressurizing device11and the pressure sensor13can be placed within a housing with a required electromagnetic shielding to prevent electromagnetic interference from affecting the measurement or detection.

Alternatively, in another embodiment, the pressurizing device11and the pressure sensor13may be respectively arranged in separated modules or assemblies.

In this embodiment, the detection system1may include at least one multiport valve (e.g., a multiport valve15and a multiport valve17). The multiport valve15may be any suitable mechanical or electrically driven valve having multiple ports. As shown, the multiport valve15may at least include a first port151, a second port152, and a third port153. The first port151may be selectively in fluid communication with the pressurizing device11. For example, the first port151may be selectively in fluid communication with the pressurizing device11via at least one pipe and a connector811of the housing81. The second port152may be selectively in fluid communication with the pressure sensor13.

For example, the second port152may be selectively in fluid communication with the pressure sensor13via at least one pipe and a connector813of the housing81. The third port153may be selectively in fluid communication with the cooling circulation CL. For example, the third port153may be selectively in fluid communication with the pipe connected between the inlet91of the cold plate9and the manifold M1via at least one pipe.

In such an arrangement, the pressurizing device11is in indirect fluid communication with the pressure sensor13through the pipes and the multiport valve15.

The multiport valve17may be any suitable mechanical or electrically driven valve having multiple ports. As shown, the multiport valve17may at least include a first port171, a second port172, and a third port173. The first port171may be selectively in fluid communication with the pressurizing device11. For example, the first port171may be selectively in fluid communication with the pressurizing device11via at least one pipe and a connector812of the housing81. The second port172may be selectively in fluid communication with the pressure sensor13. For example, the second port172may be selectively in fluid communication with the pressure sensor13via at least one pipe and a connector814of the housing81. The third port173may be selectively in fluid communication with the cooling circulation CL. For example, the third port173may be selectively in fluid communication with the pipe connected between the outlet92of the cold plate9and the manifold M2. In such an arrangement, the pressurizing device11is in indirect fluid communication with the pressure sensor13through the pipes and the multiport valve17.

Accordingly, the pressurizing device11is able to selectively pressurize the coolant inside the cooling circulation CL of the liquid-cooling system2, and the pressure sensor13is able to selectively detect the pressure variation or pulse caused by the pressurization that the pressurizing device11acts on the cooling circulation CL. For example, in this embodiment, the pressurizing device11is able to pressurize the coolant near the inlet91or the outlet92of the cold plate9so as to increase the pressure difference between the inlet91and the outlet92of the cold plate9, and the pressure sensor13can detect such sudden difference in pressure and thereby output a result facilitating to determine whether residual air bubbles existing in the cooling circulation CL (e.g., the cold plate9).

The particles in gas are much farther away from each other allowing them for easier movement and more compressibility while the particles in liquid are closer together making them a lost less compressible. Thus, when a certain amount of sudden pressure is applied to a liquid-cooling circulation with residual air bubbles or air plugs therein, pressure waves transmitting through the liquid substance will be partially reflected by the residual air bubbles and thereby causing the pressure wave to oscillate back and forth in liquid. On the other hand, when the same sudden pressure is applied to a liquid-cooling circulation without residual air bubbles or air plugs, the pressure wave in liquid will not be oscillated.

Please seeFIGS.4-5to better understand the above findings behind the transmission of pressure wave through liquid-cooling system, whereFIG.4is a graph showing a pressure variation of the coolant in the liquid-cooling system2when the detection system1pressurizes the liquid-cooling system2and there is no residual air bubbles existing in the liquid-cooling system2, andFIG.5is a graph showing a pressure variation of the coolant in the liquid-cooling system2when the detection system1pressurizes the liquid-cooling system2and there are residual air bubbles existing in the liquid-cooling system2. As can be seen, the pressure variation inFIG.4is mild when responding to the pressure by the detection system1, but the pressure variation inFIG.5appears a short period of significant oscillations when responding to the same pressure. This transient pressure response (i.e., the oscillations) shown inFIG.5is caused by residual air bubbles repeatedly reflecting the pressure wave in the liquid. Accordingly, to observe or detect whether a transient pressure response or similar pressure variation occur after additionally pressurizing the coolant inside the liquid-cooling system can be an approach to determine whether residual air bubbles or air plugs existing in the liquid-cooling system. Based on that, the detection system1employs the pressurizing device11to pressurize the passage of the liquid-cooling system2and employs the pressure sensor13to measure the pressure variation responsive to the pressurization and thereby the detection system1will be able to detect whether residual air bubbles or air plugs existing in the liquid-cooling system2.

An suitable algorithm for determining the pressure signal sent from the pressure sensor13may be pre-stored in the controller (e.g., the controller82) cooperated with the detection system1; in specific, the system pre-stored in the controller may contain standard pressure variations responsive to different pressures (e.g., the graph inFIG.4), transient pressure variations responsive to different pressures (e.g., the transient pressure response inFIG.5), and an algorithm for comparing the transient pressure variations to the standard pressure variations.

The aforementioned pressure oscillation caused by residual air bubbles generally is transmitted at a speed of about 10 m/s- 100 m/s or higher. Thus, when the traveling distance available for the pressure oscillation is short (e.g., the passage between the cold plate9and the detection system1may be less than one or few meters), the transient pressure response caused by the oscillation may appear merely within a short period of time (e.g., 10 to 100 milliseconds). The pressure sensor13may have a response time fast enough to capture such transient pressure response. In one embodiment, the pressure sensor13of the detection system1may have a response time at least shorter than 10 milliseconds. For example, the pressure sensor13may have a response time ranging between 1 and 10 milliseconds. Correspondingly, the controller (e.g., the controller82) cooperated with the detection system1may be able to perform at a speed responsive to the pressure signal sent from the pressure sensor13.

The pressurizing device11of the detection system1not only can pressurize the coolant but also can work as an amplifier to increase the amplitude of the pressure oscillation, making it easier for the pressure sensor13to effectively detect the transient pressure response happening in a short period of time. Optionally, the controller (e.g., the controller82) cooperated with the detection system1may be able to filter noise out of the transient pressure variation using time-series averaging or any suitable method to generate an accurate result.

Then, please seeFIG.2and further seeFIG.6, the transient pressure response detection method that adopts the detection system1to detect the liquid-cooling system2is described in detail hereinafter. As shown, the transient pressure response detection method of one embodiment may include the following steps: a step S01related to connecting a cold plate to the pressurizing device and the pressure sensor, steps S02-S03related to adding coolant, a step S04related to opening one of valves to make the pressurizing device in fluid communication with the cold plate, a step S05related to pressurizing the coolant, a step S06related to measuring pressure of the coolant, and steps S07-08related to sending signal and determining whether the measurement result meets standards.

In detail, in step S01, pipes are provided to make the inlet91and outlet92of the cold plate9in fluid communication with the pressurizing device11and the pressure sensor13. Thus, the pressurizing device11and the pressure sensor13may both be in fluid communication with the inlet91and outlet92of the cold plate9and the manifolds M1and M2via the pipes. More specifically, as discussed above, the pressurizing device11may be in fluid communication with the inlet91and outlet92of the cold plate9and the pressure sensor13through the pipes, the multiport valve15, and the multiport valve17; in other words, the pressure sensor13may be in fluid communication with the inlet91and outlet92of the cold plate9and the pressurizing device11through the pipes, the multiport valve15, and the multiport valve17.

In step S02, a suitable coolant is added into the passage of the liquid-cooling system2, thus the coolant exists in the pipes and the cold plate9. Note that the adding of the coolant is not intended to limit the disclosure and may be omitted if the coolant was pre-filled in the liquid-cooling system2.

Then or meanwhile, in step S03, the multiport valve15and the multiport valve17connected to the pressurizing device11, the pressure sensor13, and the inlet91and outlet92of the cold plate9are closed to facilitate the coolant to be added into the cold plate9.

Then, in step S04, the multiport valve15connected to the inlet91or the multiport valve17connected to the outlet92is opened. Specifically, when the first port151and the third port153of the multiport valve15connected between the pressurizing device11and the inlet91of the cold plate9or the first port171and the third port173of the multiport valve17connected between the pressurizing device11and the outlet92of the cold plate9are opened, the pressurizing device11can be in fluid communication with the cold plate9.

Then or meanwhile, in step S05, the pressurizing device11pressurizes the passage of the liquid-cooling system2. Specifically, the controller (e.g., the controller82) cooperated with the detection system1can instruct the pressurizing device11to apply a specific high pressure to the passage of the liquid-cooling system2. Since the pressurizing device11is in fluid communication with the inlet91or outlet92of the cold plate9, the pressurizing device11at this stage can pressurize at least one of the pipes connected to the inlet91and outlet92of the cold plate9so as to generate a short period time of pressure increase near the inlet91or outlet92of the cold plate9. This causes an additional pressure difference appearing between the inlet91and outlet92of the cold plate9. Note that the actual pressure provided by the pressurizing device11is not limiting as long as it is high enough for the pressure sensor13to be able to detect an effective transient pressure response.

Then or meanwhile, in step S06, the pressure sensor13measures the gauge pressure or pressure variation of the coolant inside the liquid-cooling system2caused by the pressurizing device11. Specifically, the second port152of the multiport valve15or the second port172of the multiport valve17may be opened during the step S04, such that the pressure sensor13can be in fluid communication with the passage or pipes pressurized by the pressurizing device11, thereby the pressure sensor13can measure the gauge pressure or pressure variation of the coolant near the inlet91and/or outlet92of the cold plate9.

Then or meanwhile, in step S07, the pressure sensor13outputs pressure signal according to the pressure or pressure variation and sends it to the controller (e.g., the controller82) cooperated with the detection system1in a wireless or wired manner. As discussed above, when there are no residual air bubbles or air plugs existing in the cold plate9, the graph reflecting the pressure signal responsive to the pressure variation measured by the pressure sensor13will be similar to a standard pressure variation as depicted inFIG.4; however, when there are residual air bubbles or air plugs existing in the cold plate9, the graph reflecting the pressure signal responsive to the pressure variation measured by the pressure sensor13will appear a transient pressure response as depicted inFIG.5.

Then or meanwhile, step S08is performed to determine whether the measurement result meets standards. Specifically, an algorithm or database for determining the relationships between the pressure variation and existence of residual air bubbles under various circumstances may be pre-stored in the controller (e.g., the controller82) cooperated with the detection system1. For example, the standard pressure variation inFIG.4may be used as a standard to be compared with the pressure or pressure variation measured by the pressure sensor13. As such, comparing the stored standard pressure variation with the measure result obtained by the pressure sensor13is able to determine whether residual air bubbles exist in the passage of the liquid-cooling system2.

When the graph reflected by the obtained pressure signal responsive to the pressure variation is similar to or the same as the stored standard pressure variation, the passage (e.g., the cold plate9) of the liquid-cooling system2is determined to have no residual air bubble or air plug therein. On the contrary, when the graph reflected by the obtained pressure signal responsive to the pressure variation appears a transient pressure response similar to that as shown inFIG.5, the passage (e.g., the cold plate9) of the liquid-cooling system2is determined to have residual air bubbles, and then the user can do required action, such as performing step S02again to keep adding coolant to force out the remaining residual air bubbles.

By operating the multiport valve15and the multiport valve17, the pressure sensor13is allowed to measure the pressures or pressure differences of both the inlet91and outlet92of the cold plate9at the same time. Thus, the controller (e.g., the controller82) can obtain two graphs reflected by the pressure variations occurring near the inlet91and the outlet92and therefore are beneficial to improve the accuracy of detection. The number of points that the pressure sensor measures the liquid-cooling system is not limiting, and the number of the valves used in the detection system can be modified as required. In one embodiment, there may be only one valve connected between the pressurizing device, the pressure sensor, and the cold plate.

Optionally, the pipes between the multiport valves and the pressure sensor may have an inside diameter smaller than 1 millimeter to facilitate the pressure sensor to accurately and precisely measure the pressure or the pressure difference near or at the cold plate. Note that the detection system and the transient pressure response detection method may be applied to other areas of the passage of the liquid-cooling system but not limited to be near the inlet and outlet of the cold plate.

According to the detection system, transient pressure response detection method, and the flow rate control device as discussed in the above embodiments of the disclosure, the detection system is able to pressurize the coolant in the passage of the liquid-cooling system to incur a transient pressure response used to determine whether residual air bubble or air plug exists in the liquid-cooling system. This allows the user to efficiently and effectively determine the existence of air bubble during the installation, operation, and maintenance of the liquid-cooling system to prevent the problems that the conventional approach needs to take couple days to verify the existence of air bubbles, thereby ensuring that the cooling circulation performs at a predetermined speed or facilitating to determine whether the system needs maintenance or piece replacement.