Defrosting control method of liquid cooling terminal and liquid cooling system

Abstract

The invention provides a defrosting control method of a liquid cooling terminal and a liquid cooling system, and relates to the technical field of refrigeration equipment, the liquid cooling terminal comprises a first heat exchange area and a second heat exchange area, and the defrosting control method of the liquid cooling terminal comprises the following steps: obtaining a target control temperature of the liquid cooling terminal; based on the target control temperature, a corresponding heating strategy is selected, and the output power of the heating strategy and the high-low level of the target control temperature are in a reverse corresponding relation; and the first heat exchange area is heated according to the heating strategy, supply of the cooling liquid to the first heat exchange area is stopped, and return air flow of the liquid cooling tail end is guided to the second heat exchange area. When the supply of the cooling liquid to the defrosting area is stopped and the defrosting area is heated, all the return air flows are intensively guided to the refrigeration area for enhanced refrigeration, so that the problem that the refrigeration function of the whole tail end needs to be interrupted due to defrosting in the prior art, and consequently the internal temperature of the cooled space fluctuates greatly is solved.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment technology, and in particular to a defrosting control method and liquid cooling system for a liquid cooling terminal. Background Technology

[0002] In liquid cooling systems, especially at the cooling terminals used in low-temperature environments (such as commercial cold chain and airborne equipment storage), the surface temperature of the heat exchanger is typically below 0°C. When humid air flows over the low-temperature heat exchanger surface, the moisture in the air condenses and forms a frost layer. The continuous accumulation of frost layers blocks airflow channels, increases thermal resistance, leads to a significant decrease in heat exchange efficiency, weakens the cooling capacity of the terminal, and ultimately affects the temperature stability of the cooled space.

[0003] Therefore, regular defrosting of heat exchangers is essential for ensuring the normal operation of liquid-cooled terminals. A common defrosting method involves stopping the supply of cryogenic coolant to the entire terminal heat exchanger and activating electric heating elements to melt the frost. The drawback of this method is that the cooling terminal completely loses its cooling capacity during the entire defrosting cycle. This interruption in cooling inevitably leads to a significant rise in the internal temperature of the cooled space (e.g., a refrigerated display case storing goods), resulting in large temperature fluctuations. For applications highly sensitive to temperature changes, such as pharmaceuticals, precision electronic components, or high-value foods, these temperature fluctuations can have unacceptable impacts on their quality, performance, or safety.

[0004] Therefore, it is necessary to improve the existing liquid cooling system terminal defrosting technology to overcome the shortcomings of the existing technology. Summary of the Invention

[0005] To overcome the problems existing in related technologies, one of the objectives of this invention is to provide a defrosting control method for liquid cooling terminals. This defrosting control method divides the heat exchanger of the liquid cooling terminal into at least one defrosting area and a continuously operating refrigeration area. While stopping the supply of coolant to the defrosting area and heating it, all return airflow is concentrated and guided to the refrigeration area for enhanced refrigeration. This overcomes the problem in the prior art where the refrigeration function of the entire terminal needs to be interrupted for defrosting, resulting in large fluctuations in the internal temperature of the cooled space.

[0006] A defrosting control method for a liquid cooling terminal, the liquid cooling terminal including a first heat exchange region and a second heat exchange region, the defrosting control method for the liquid cooling terminal including: Obtain the target control temperature of the liquid cooling terminal; Based on the target control temperature, a corresponding heating strategy is selected, wherein the output power of the heating strategy is inversely related to the level of the target control temperature. The first heat exchange area is heated according to the heating strategy, and the supply of coolant to the first heat exchange area is stopped. The return airflow from the liquid cooling terminal is then guided to the second heat exchange area.

[0007] Furthermore, when the return airflow from the liquid-cooled terminal is guided to the second heat exchange area, the cooling capacity of the second heat exchange area is enhanced.

[0008] Although the second heat exchange zone continues to operate, it bears the entire heat load previously handled by both zones. If operated at normal capacity, its cooling capacity may be insufficient to fully compensate for the first zone's loss, resulting in a continued temperature rise in the cooled space. This solution actively enhances the cooling capacity of the second heat exchange zone (e.g., by putting it into "overclocking" or "powerful" mode), enabling it to generate significantly more cooling than under normal operating conditions. This "compensatory cooling" more effectively offsets the cooling loss due to the first zone's shutdown, thus more significantly suppressing the temperature rise in the cooled space. Therefore, this solution achieves more stable temperature control, further reducing temperature fluctuations during defrosting, making it particularly suitable for applications with extremely high temperature stability requirements.

[0009] Furthermore, enhancing the cooling capacity of the second heat exchange region includes at least one of the following methods: Increase the flow rate of coolant supplied to the second heat exchange zone; Increase the speed of the fan associated with the second heat exchange zone.

[0010] Increasing the coolant flow rate directly provides more cooling capacity to the heat exchanger; increasing the fan speed significantly increases the air mass flow rate through the heat exchanger, thereby enhancing convective heat transfer. By clearly defining these specific control actions, the path to achieving the enhanced cooling capacity becomes clear, reliable, and easy to control, improving the practicality and stability of the technical solution and ensuring that the compensatory cooling effect can be achieved accurately and efficiently.

[0011] Furthermore, the liquid cooling terminal is one of multiple terminals of a liquid cooling system, which includes a central circulation pump; The method further includes: Determine the ratio of the load of the liquid cooling terminal that is defrosting to the total load of the liquid cooling system. When the ratio exceeds a preset threshold, increase the speed of the central circulation pump.

[0012] In a multi-terminal liquid cooling system, all terminals share a central circulating pump supplying coolant. When a terminal (e.g., terminal 1) performs defrosting, its internal valve states change (e.g., one valve closes, another increases flow), altering its fluid resistance and thus affecting the pressure and flow distribution across the entire network. This effect is particularly pronounced if the terminal performing defrosting has a high load, potentially leading to insufficient flow and performance degradation for other normally operating terminals. This solution introduces system-level coordinated control, proactively increasing the central circulating pump speed when a high load is detected at the terminal performing defrosting. This increases the overall system flow and pressure, ensuring that the second heat exchange zone undergoing compensating cooling receives the required increased flow while maintaining the normal cooling performance of other terminals. Therefore, this solution improves the operational stability and robustness of the entire liquid cooling system, preventing localized operations from adversely affecting the overall system.

[0013] Furthermore, increasing the rotational speed of the central circulation pump specifically includes: The rotational speed is increased in a stepwise or linear manner depending on the load ratio.

[0014] Compared to a coarse control method that simply increases the pump speed by a fixed value when a threshold is exceeded, this solution offers a more refined and efficient adjustment strategy. By making the increment of pump speed proportional to the load percentage (stepwise or linear), the system can precisely adjust the total flow rate according to actual needs. When the load percentage at the defrosting end is low, only a small increase in pump speed is needed, avoiding unnecessary energy consumption; when the load percentage is high, the speed is increased significantly accordingly to ensure system performance. This refined control not only ensures system stability but also achieves optimized management of pump power consumption, improving the energy efficiency and operational economy of the entire liquid cooling system.

[0015] Furthermore, after heating the first heat exchange region according to the heating strategy, the method further includes: Start the fan associated with the first heat exchange area and run it at low speed to dry the residual condensate; Restore the coolant supply to the first heat exchange zone and normal fan control.

[0016] After defrosting, a large amount of condensate formed from melting frost adheres to the surface of the heat exchanger. If high-volume cooling is resumed immediately, these water droplets may be blown out, damaging items or equipment (such as the fan motor itself) within the cooled space. More seriously, when the cryogenic coolant flows back into the heat exchanger, this residual moisture quickly refreezes, forming a thin layer of ice. This not only reduces heat exchange efficiency but also causes the heat exchanger to refreeze more quickly, shortening the next defrosting cycle. This solution adds a low-speed drying step, using a gentle airflow to evaporate and dry the residual moisture, ensuring the heat exchanger surface is dry before resuming cooling. This effectively avoids secondary icing, extends the effective operating time of the terminal unit, protects related components, and improves the reliability and thoroughness of equipment operation and defrosting.

[0017] Furthermore, the method also includes: When the coolant outlet temperature of the first heat exchange zone is detected to be lower than the first preset temperature threshold, defrosting control of the first heat exchange zone is initiated.

[0018] Accurately determining when a heat exchanger needs defrosting is crucial for efficient control. Using a fixed defrosting time cycle cannot adapt to changes in environmental humidity and equipment operating conditions, potentially leading to premature defrosting (wasting energy) or delayed defrosting (severely reducing efficiency). This solution utilizes the "coolant outlet temperature" as a criterion. When severe frost buildup on the heat exchanger surface, the frost layer acts as insulation, hindering heat exchange between the air and the pipe wall. This reduces the heat absorbed by the coolant, causing an abnormally low outlet temperature. Therefore, this temperature serves as a reliable indicator of frost severity. Using this indicator as a trigger condition enables on-demand defrosting, ensuring the defrosting process is only initiated when truly necessary. This avoids unnecessary energy consumption and cooling interruptions, making the entire control system more intelligent and efficient.

[0019] Furthermore, when heating the first heat exchange area according to the heating strategy, if the coolant outlet temperature of the first heat exchange area is detected to rise above the second preset temperature threshold, heating of the first heat exchange area is stopped.

[0020] Similar to initiating defrosting, accurately determining when defrosting is complete is crucial for energy saving and efficiency. Using a fixed heating time may result in insufficient or excessive heating due to variations in frost thickness. This solution also utilizes the coolant outlet temperature as a feedback signal. During heating, as the frost melts, the heat from the heating element is more effectively transferred to the heat exchanger tubes and the coolant inside, causing their temperature to gradually rise. When this temperature reaches a preset value (e.g., 5-10°C, well above the freezing point), it can be reliably determined that the frost has completely melted. Stopping heating based on this feedback signal ensures thorough defrosting, avoids energy waste from continuing heating after the frost has melted, and prevents the heat exchanger from overheating. This constitutes a complete closed-loop control, significantly improving the accuracy and economy of the defrosting process.

[0021] Furthermore, the output power of the heating strategy is inversely related to the target controlled temperature level, specifically as follows: When the target control temperature is greater than or equal to the first temperature setpoint, the output power ratio of the heating strategy is the first power range; When the target control temperature is less than the first temperature setting value, the output power ratio of the heating strategy is a second power range, wherein the upper limit of the first power range is lower than the lower limit of the second power range.

[0022] When the target control temperature requirement is not high (e.g., greater than or equal to 1-3℃), the system has a high tolerance for short-term temperature fluctuations. In this case, a low power range (e.g., <30%) can be used for gentle and energy-saving defrosting. However, when the target control temperature requirement is very stringent (e.g., less than 1-3℃), maintaining a low temperature is the highest priority. In this case, a high power range (e.g., 70-100%) must be used for rapid defrosting to minimize the "offline" time of the heat exchange zone on one side and restore its cooling capacity as quickly as possible. This differentiated strategy makes this method highly adaptable, enabling intelligent switching between the two goals of "energy saving and economy" and "ultimate performance" according to actual application needs, thereby optimizing the overall performance of the system under different operating conditions.

[0023] A second objective of this invention is to provide a liquid cooling system for implementing the defrosting control method for liquid cooling terminals as described above, the liquid cooling system comprising: The liquid cooling terminal includes a first heat exchange area, a second heat exchange area, and an air valve; A controller, connected to the liquid cooling terminal and the air valve, is used for: When it is determined that the first heat exchange area needs to be defrosted, the liquid cooling terminal is controlled to stop supplying coolant to the first heat exchange area, and the first heat exchange area is heated according to the heating strategy. The control valve directs the return airflow from the liquid cooling terminal to the second heat exchange zone.

[0024] Traditional systems, due to structural limitations, cannot achieve the function of "defrosting while cooling". The combination of this system's structural design (zoned heat exchangers and dampers) and control logic provides the necessary hardware foundation for realizing this method. When the controller executes a defrost command, the zoning structure allows one zone to stop cooling while another continues operating; the damper, a key component, ensures that all heat load (return airflow) is precisely and without loss guided to the operating second heat exchange zone, thereby maximizing the effect of compensatory cooling. Through its unique hardware construction and accompanying control functions, it solves the technical problem of complete cooling interruption caused by defrosting in existing systems.

[0025] The beneficial effects of this invention are as follows: This invention provides a defrosting control method for a liquid-cooled terminal, which structurally includes a first heat exchange area and a second heat exchange area. When defrosting is required on the frosted first heat exchange area, this method only stops supplying coolant to the first heat exchange area and implements a heating strategy thereon. Simultaneously, it guides all the return airflow from the liquid-cooled terminal to the second heat exchange area, allowing the second heat exchange area to continue its cooling operation. Since the second heat exchange area does not stop working while the first heat exchange area is being defrosted, but continues to perform its cooling task, the liquid-cooled terminal maintains a constant cooling output throughout the entire defrosting cycle. More importantly, by guiding all the return airflow to the second heat exchange area, this area can centrally handle the heat exchange load of the entire terminal, thereby maximizing the efficiency of compensating for cooling. This method of defrosting while simultaneously compensating for cooling fundamentally avoids a significant temperature rebound caused by a complete interruption of cooling, greatly reduces temperature fluctuations in the cooled space, and improves the stability of temperature control. It can select different heating strategies based on the target control temperature of the liquid cooling terminal. Its output power is inversely related to the target control temperature. Under conditions where temperature requirements are not high, low power can be used for energy-saving and gentle defrosting; while under conditions with stringent temperature requirements and low temperatures, high power is used for rapid and powerful defrosting to restore the full cooling capacity of the terminal as quickly as possible. This intelligent adjustment method balances defrosting efficiency and operating economy, improving the overall performance of the system. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the defrosting control method for the liquid cooling terminal provided in this application; Figure 2 This is a schematic diagram of the liquid cooling system provided in Embodiment 6 of this application.

[0027] Figure label: 1. First heat exchanger; 2. Second heat exchanger; 3. Third heat exchanger; 4. Fourth heat exchanger; 5. Fifth heat exchanger; 6. Sixth heat exchanger; 7. Seventh heat exchanger; 8. First fan; 9. Second fan; 10. Air valve; 11. First valve; 12. Second valve; 13. Heating diaphragm; 14. Central circulation pump. Detailed Implementation

[0028] Preferred embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0029] Example 1 like Figure 1 and Figure 2 As shown, this embodiment provides a defrosting control method for a liquid-cooled terminal. This method is applied to a special liquid-cooled terminal that is structurally or functionally divided into at least two independently controllable regions, referred to in this embodiment as a first heat exchange region and a second heat exchange region. These two regions jointly serve the same cooled space. The purpose of this method is to solve the problem of how to prevent the entire terminal from stopping its cooling service when defrosting one region (e.g., the first heat exchange region that requires maintenance due to frost), thereby preventing drastic temperature fluctuations within the cooled space. In this embodiment, the defrosting control method for the liquid-cooled terminal includes: Obtain the target control temperature of the liquid cooling terminal; Based on the target control temperature, a corresponding heating strategy is selected, wherein the output power of the heating strategy is inversely related to the level of the target control temperature. The first heat exchange area is heated according to the heating strategy, and the supply of coolant to the first heat exchange area is stopped. The return airflow from the liquid cooling terminal is then guided to the second heat exchange area.

[0030] The core method of this embodiment is that when it is determined that the first heat exchange area of ​​the liquid cooling terminal needs to be defrosted, the system will execute a set of coordinated control actions: first, obtain the target control temperature currently set for the cooled space; then, based on the target temperature, intelligently select a matching heating strategy to melt the frost layer in the first heat exchange area; while performing heating, precisely stop supplying low-temperature coolant to the first heat exchange area, and cleverly use airflow organization components to concentrate and guide all the return airflow that should have flowed through the entire terminal to the second heat exchange area that is still working normally.

[0031] The purpose of this design is to achieve a continuous working mode of "defrosting and cooling simultaneously".

[0032] Obtaining the target control temperature is crucial for achieving intelligent and differentiated defrosting. The target temperature of the cooled space directly reflects its stringent requirements for temperature stability. If the target temperature requirement is very low (e.g., -8 degrees Celsius), it means the system has a high heat load and extremely low tolerance for cooling interruptions. Therefore, a high-power, high-efficiency heating strategy is needed to complete defrosting as quickly as possible, allowing the terminal units to rapidly restore full cooling capacity. Conversely, if the target temperature is relatively high (e.g., 3 degrees Celsius), the system has a certain temperature margin. In this case, a low-power, more energy-efficient heating strategy can be used for gentle defrosting to reduce energy consumption. Therefore, ensuring that the output power of the heating strategy corresponds inversely to the level of the target control temperature is key to achieving a balance between defrosting efficiency and operational economy.

[0033] Stopping the supply of coolant to the first heat exchange zone while heating it is fundamental to ensuring defrosting energy efficiency. If the coolant supply is not cut off, the heat generated by the heating elements will be largely absorbed by the low-temperature coolant flowing through it, rather than acting on the frost layer. This will greatly prolong the defrosting time, or even prevent defrosting altogether, resulting in serious energy waste.

[0034] In traditional defrosting, the entire terminal stops working, inevitably causing the temperature of the cooled space to rise again. However, in this method, the second heat exchange zone continues to operate, functioning as the cooler. By forcing all return air—the air carrying heat from the cooled space—through this still-operating zone, the second heat exchange zone effectively handles the entire cooling load of the terminal within a given unit of time. This not only ensures continued cooling output from the terminal during defrosting but also enhances the heat exchange effect of the second heat exchange zone through concentrated airflow, thereby maximizing compensation for the cooling capacity lost due to the shutdown of the first heat exchange zone and ultimately effectively suppressing temperature fluctuations in the cooled space.

[0035] In a specific application scenario, the execution steps of this method are as follows: S1. Startup Judgment and Information Acquisition: The controller at the liquid cooling terminal continuously monitors the system status. When it determines, through sensors (such as temperature sensors or frost sensors), that a frost layer has formed in the first heat exchange area and needs to be removed, the defrosting control program is triggered. The program first reads the current target control temperature value set by the user or the upstream system.

[0036] S2. Heating strategy selection: The controller has a pre-set set of judgment logic. For example, a temperature threshold 'a' (such as 1 degree Celsius) can be set.

[0037] If the target control temperature read is less than a, the controller determines that the current condition is a low-temperature harsh operating condition and selects the "high-power rapid defrost" strategy, setting the output power of the heating element to a higher range, such as 70% to 100% of its rated power.

[0038] If the target control temperature read is greater than or equal to a, the controller determines that the current operating condition is medium to low temperature or relatively relaxed, and selects the "low power economic defrosting" strategy, setting the output power of the heating element to a lower range, such as below 30% of its rated power.

[0039] S3, Cooperative Action Execution: After selecting the heating strategy, the controller issues three sets of commands almost simultaneously: Command 1 (Stop cooling): Send a closing command to the solenoid valve or electric valve on the coolant supply line controlling the first heat exchange zone to cut off the cold source.

[0040] Command 2 (Start heating): A drive signal (e.g., PWM pulse width modulation signal) that conforms to the selected power strategy is output to the heating element such as the heating film or heating wire that is attached to the first heat exchange area.

[0041] Command 3 (Guiding Airflow): A command is sent to the drive motor of the air valve or baffle installed inside the end to activate it, closing the airflow passage to the first heat exchange zone while fully opening the airflow passage to the second heat exchange zone, ensuring that all return air from the cooled space can only flow through the second heat exchange zone.

[0042] Through the above steps, the system enters a stable working state of defrosting in the first zone and compensating for cooling in the second zone, until the controller determines that defrosting in the first heat exchange zone is complete, and then executes the subsequent recovery process.

[0043] In addition to the implementation methods mentioned above, this embodiment can also be implemented in the following ways: The physical implementation of the first and second heat exchange zones can be varied. For example, they can be two completely independent heat exchanger cores installed in parallel within the same end housing; they can also be a large heat exchanger, but whose internal coils are designed as two or more independent flow paths, each controlled by an independent valve; or they can be two zones arranged horizontally or vertically in space.

[0044] In addition to offering two or more stepped power options based on the target control temperature, heating power can also form a continuous functional relationship with the target control temperature. For example, output power can be calculated in real time using a linear formula, enabling more precise and smooth adjustment. Furthermore, besides the target temperature, other parameters such as detected ambient humidity and the time interval since the last defrost can be considered when selecting a heating strategy, forming a multi-dimensional decision model.

[0045] Achieving complete guidance of return airflow does not necessarily require a single-piece damper. It can be achieved by a set of linked, controlled louvered blades; or, in some designs, if the first and second heat exchange zones each have completely independent fans and ducts, then guiding the airflow can be simplified to: stopping the fan in the first heat exchange zone and allowing the fan in the second heat exchange zone to continue running, or even increasing its speed to increase the circulating air volume.

[0046] Example 2 like Figure 1 and Figure 2 As shown, this embodiment provides a defrosting control method for a liquid-cooled terminal. Based on Embodiment 1, this embodiment further elaborates on the compensating cooling process during defrosting. The aim is to illustrate that when the first heat exchange zone is defrosted, it is not merely a passive process of guiding all return airflow to the second heat exchange zone, but rather an active and targeted enhancement of the second heat exchange zone's own cooling capacity. This achieves a more efficient and stable compensating cooling effect, maximizing the maintenance of a constant temperature within the cooled space. Furthermore, in the defrosting control method of this embodiment, when guiding the return airflow from the liquid-cooled terminal to the second heat exchange zone, the cooling capacity of the second heat exchange zone is enhanced.

[0047] Enhancing the cooling capacity of the second heat exchange region includes at least one of the following methods: Increase the flow rate of coolant supplied to the second heat exchange zone; Increase the speed of the fan associated with the second heat exchange zone.

[0048] The method described in this embodiment adds a key enhancement and compensation step to the core action of asynchronous defrosting in Embodiment 1 (i.e., stopping cooling and heating the first heat exchange zone and guiding all airflow to the second heat exchange zone). Specifically, at the start of defrosting, the controller sends instructions to the corresponding execution components in the second heat exchange zone to significantly increase its instantaneous cooling power in at least one or more ways. These methods mainly include: increasing the flow rate of the low-temperature coolant supplied to the second heat exchange zone; and increasing the speed of the fan associated with the second heat exchange zone, putting it into an ultra-high speed operation mode.

[0049] The fundamental purpose of this move is to enable a single second heat exchange zone to handle, or even more, the cooling load that was originally shared by the two zones in a short period of time.

[0050] In conventional designs, the cooling capacity of each heat exchange zone (first and second) is configured according to a portion of the total load, for example, each bearing 50%. When the first heat exchange zone stops working, if the second heat exchange zone operates only with its normal parameters, even if it handles 100% of the airflow, its total output cooling capacity may not be sufficient to completely offset the real-time heat load of the entire space. This may still cause a slow but not negligible increase in the temperature of the cooled space.

[0051] Therefore, it is essential to proactively enhance the workload of the second heat exchange zone. By increasing the coolant flow rate, more low-temperature coolant can flow through the heat exchange coil per unit time. This not only brings more cooling capacity but also maintains a larger average temperature difference between the coil surface and the air, thereby strengthening the heat transfer effect. Simultaneously, increasing the fan speed to ultra-high levels can significantly increase the circulating air volume, allowing more air molecules to exchange heat with the heat exchanger surface per unit time, thus significantly improving the convective heat transfer coefficient.

[0052] By combining these two enhancement methods, the cooling capacity of the second heat exchange zone can be overclocked, and its instantaneous output cooling capacity can approach or even exceed the total cooling capacity of the two zones when they are working normally. This achieves a leap from partial compensation to full compensation, providing a nearly uninterrupted and stable cooling supply to the cooled space, which is the key to achieving high-precision temperature control.

[0053] In a specific control flow, after the controller determines to initiate defrosting for the first heat exchange zone, the enhanced compensation steps it performs are as follows: S1. Issuance of collaborative instructions: While the controller sends "close" and "start" commands to the valves and heating diaphragms in the first heat exchange zone, and controls the air valve to redirect the airflow to the second heat exchange zone, it also sends enhanced commands to the control elements in the second heat exchange zone.

[0054] S2, Flow Enhancement Execution: The controller sends an adjustment signal to the valve controlling the coolant supply to the second heat exchange zone. This valve is an adjustable electric valve, which may be 60% open during normal cooling. Upon receiving the enhancement command, the controller will adjust its opening to a larger value, such as 90% or 100% (fully open), to ensure that the maximum flow rate of coolant is supplied to the second heat exchange zone.

[0055] S3, Increased Airflow Execution: The controller simultaneously sends a speed control signal to the driver of the fan associated with the second heat exchange zone. This signal instructs the fan speed to increase from the normal operating speed (e.g., 70% of the rated maximum speed) to an ultra-high speed mode, which can be the fan's rated maximum speed or even a special enhanced mode that allows short-term operation at speeds exceeding the rated maximum speed.

[0056] S4. State Maintenance and Recovery: The second heat exchange zone will continue to operate under this enhanced flow and air volume until the defrosting process of the first heat exchange zone is completed. Once defrosting is complete, the controller will restore the first heat exchange zone to normal operation and simultaneously adjust the valve opening and fan speed of the second heat exchange zone back to the normal set values ​​determined by the temperature control logic.

[0057] In addition to the implementation methods mentioned above, this embodiment can also be implemented in the following ways: In certain applications, only one enhancement method may be used. For example, in situations where operating noise is strictly limited, the system may prioritize increasing the coolant flow rate while only slightly or not increasing the fan speed, in order to control the noise level while ensuring the compensation effect. Conversely, if the system's circulating pump has limited margin, increasing the fan speed may be the preferred method.

[0058] The enhancement level is not necessarily a "one-step" maximum. The controller can dynamically adjust the enhancement magnitude based on changes in return air temperature. For example, if the return air temperature begins to rise, the controller can gradually increase the fan speed or valve opening, forming a closed-loop feedback control that ensures the compensated cooling capacity matches the actual heat load, achieving more precise temperature control and better energy efficiency.

[0059] The valve used to regulate flow can be either a proportional-integral valve capable of continuous adjustment from 0-100% or a multi-position valve with only a few preset opening positions (such as normal and enhanced). Similarly, the fan can be a continuously variable DC brushless fan or an AC fan with only a few fixed speeds (such as low speed, medium speed, high speed, and ultra-high speed). Different hardware configurations can all realize the core idea of ​​this invention.

[0060] Example 3 like Figure 1 and Figure 2As shown, this embodiment provides a defrosting control method for a liquid cooling terminal. Based on the previous embodiments, this embodiment extends the control scope to the entire multi-terminal liquid cooling system, focusing on a system-level collaborative control strategy. It aims to address how to maintain the stability of the entire liquid cooling system's fluid network and ensure that the performance of other normally operating terminals is not affected when one or more terminals with a large load proportion enter defrosting mode. Furthermore, in the defrosting control method of this embodiment, the liquid cooling terminal is one of multiple terminals in a liquid cooling system, and the liquid cooling system includes a central circulation pump. The method further includes: Determine the ratio of the load of the liquid cooling terminal that is defrosting to the total load of the liquid cooling system. When the ratio exceeds a preset threshold, increase the speed of the central circulation pump.

[0061] Increasing the rotational speed of the central circulation pump specifically includes: The rotational speed is increased in a stepwise or linear manner depending on the load ratio.

[0062] The method described in this embodiment is a dynamic central circulation pump speed regulation mechanism that is linked to the defrosting control program of a single terminal. When a liquid cooling terminal (one of multiple terminals in the system) initiates its defrosting program, the system main controller first determines the proportion of the cooling load of the terminal undergoing defrosting to the total load of the entire liquid cooling system. If the calculated load proportion exceeds a preset threshold, the controller will actively issue a command to increase the speed of the central circulation pump in the system. The speed increase can be made in a stepped, incremental manner or a linear, continuous adjustment, depending on the load proportion.

[0063] In a multi-terminal parallel liquid cooling system, all terminals share a fluid piping network driven by a central circulating pump, forming a precise dynamic fluid balance. When one terminal performs a defrost operation, its internal fluid pathways undergo drastic changes: the valves in the defrost zone close, effectively creating a significant local resistance in that branch; conversely, the valves in the compensating refrigeration zone open, effectively reducing the local resistance in that branch. This dramatic change in resistance within a single branch immediately disrupts the pressure and flow distribution balance of the entire piping network.

[0064] Without any system-level compensation measures, this disturbance will propagate throughout the entire system. The consequences are: other normally operating terminals may experience sudden increases or decreases in coolant flow due to fluctuations in the total network pressure, leading to unnecessary fluctuations in their own temperature control. Simultaneously, the area currently undergoing compensatory cooling may fail to receive the expected increased coolant flow due to changes in the total system pressure, significantly reducing the compensation effect.

[0065] Therefore, the introduction of coordinated control of the central circulation pump is crucial. By proactively increasing the pump speed when significant load changes are detected, the system can instantly increase the liquid supply pressure and total flow rate of the main pipeline. This proactive pressurization effectively offsets the negative impact of changes in local branch resistance. It powerfully ensures that the compensation cooling zone obtains the required ultra-high flow rate, while stabilizing the inlet pressure and flow rate of all other normally operating terminals, thereby ensuring the operational stability and overall performance of the entire system.

[0066] In a system comprising a central circulating pump and multiple liquid-cooled terminals, the specific execution steps of this coordinated control method are as follows: S1. Determining the load ratio: When a defrost procedure is initiated at any terminal, the main controller immediately calculates the load percentage of that terminal. This percentage can be determined in several ways; for example, it can be calculated based on the design cooling capacity of each terminal (a static value preset in the system) to determine its proportion of the total power currently in operation.

[0067] S2, Threshold determination: The controller compares the calculated load percentage with a preset threshold (e.g., 30%). This threshold represents the upper limit of disturbances that the system can absorb on its own. Flooding of the end units below this threshold is considered to have a small impact on the overall system and does not require adjustment of the main pump.

[0068] S3, Pump speed adjustment command: If the load ratio exceeds this threshold, the controller will immediately send a speed control command to the inverter of the central circulating pump. The specific speed control method can be preset to one of the following two: 1. Stepped adjustment: The controller selects a fixed speed increment based on the load ratio range. For example, the system can be preset with the following rules: When the load percentage is between 30% and 50%, the pump speed should be increased by 10-20%. When the load ratio is between 50% and 60%, the pump speed should be increased by 20-30%. When the load ratio is greater than 60%, the pump speed is increased by 30-40%.

[0069] 2. Adjustment of linear relationship: The controller calculates the speed increase based on a preset linear relationship to achieve smoother regulation. For example, the percentage increase in pump speed can be proportional to the amount by which the load exceeds a preset threshold. Specifically, the controller calculates the difference between the current load ratio and the threshold, then multiplies this difference by a preset proportionality coefficient K to obtain the specific percentage increase in pump speed.

[0070] S4 control recovery: When the defrosting cycle of the terminal ends and its internal valves and fans return to normal control, the main controller will cancel the speed increase command to the central circulation pump, restoring its speed to the normal operating level determined by the overall cooling demand of the system.

[0071] In addition to the implementation methods mentioned above, this embodiment can also be implemented in the following ways: In addition to using static design power, load ratios can also be calculated more accurately dynamically using real-time operating parameters. For example, it can be determined by the proportion of coolant flow or valve opening at that terminal to the total system flow or the sum of all terminal openings just before defrosting.

[0072] A more advanced control method employs closed-loop control. Pressure sensors can be installed on the main supply and return lines. The controller's goal is no longer simply to increase the pump speed based on the load ratio, but rather to maintain a constant differential pressure in the main pipeline in real time by adjusting the pump speed. When defrosting at one end causes differential pressure fluctuations, the PID controller automatically adjusts the pump speed to quickly eliminate the deviation. This method offers a faster response and more precise control.

[0073] The system can be configured with multiple thresholds, corresponding to different system response levels. For example, a load percentage exceeding 30% may only trigger the pump to increase its speed, while an extremely high load percentage exceeding 70% may trigger a temporary instruction, in addition to increasing the pump speed, to slightly reduce the cooling intensity of other non-critical terminals to ensure the absolute stability of critical terminals.

[0074] Example 4 like Figure 1 and Figure 2 As shown, this embodiment provides a defrosting control method for a liquid-cooled terminal. Based on the previous embodiments, this embodiment elaborates on a complete, closed-loop defrosting control cycle, focusing on precisely defining the start and end conditions of the defrosting process, as well as the safety recovery procedure after defrosting. Furthermore, in the defrosting control method of this embodiment, after heating the first heat exchange area according to the heating strategy, the method further includes: Start the fan associated with the first heat exchange area and run it at low speed to dry the residual condensate; Restore the coolant supply to the first heat exchange zone and normal fan control.

[0075] The method further includes: When the coolant outlet temperature of the first heat exchange zone is detected to be lower than the first preset temperature threshold, defrosting control of the first heat exchange zone is initiated.

[0076] When heating the first heat exchange area according to the heating strategy, if the coolant outlet temperature of the first heat exchange area is detected to rise above the second preset temperature threshold, heating of the first heat exchange area is stopped.

[0077] This embodiment describes a full-cycle defrosting control method. The complete process of this method includes: First, by continuously monitoring the coolant outlet temperature of the first heat exchange zone, when the temperature drops below a preset start threshold due to frost formation, the defrosting program is automatically triggered; then, the core defrosting and compensating cooling actions described in Embodiment 1 are executed; during the heating process, the outlet temperature continues to be monitored, and when it rises above a preset completion threshold due to the melting of the frost layer, heating is stopped; finally, before restoring normal cooling, a specific post-processing step is performed, namely, the associated fan is run at low speed for a period of time to dry the residual condensate on the surface of the heat exchanger, and then the coolant supply and normal fan control of the area are fully restored.

[0078] This complete closed-loop control cycle is designed based on a comprehensive consideration of defrosting efficiency, equipment reliability, and system performance.

[0079] Using the coolant outlet temperature as the basis for initiating defrosting is an accurate and reliable method for determining frost formation. Frost is essentially an insulating layer covering the surface of the heat exchanger, hindering the transfer of heat from the air to the coolant. As the frost layer thickens, heat exchange efficiency deteriorates, and the flowing coolant cannot absorb enough heat, naturally causing its outlet temperature to decrease. Compared to fixed-time defrosting (which may waste energy when defrosting is unnecessary or only initiate when frost is severe), determining defrosting based on outlet temperature more accurately identifies when defrosting is needed, achieving on-demand defrosting while balancing energy efficiency and performance.

[0080] Using the recovery of the outlet temperature as the basis for stopping heating ensures thorough defrosting and avoids energy waste. In the initial heating phase, energy is primarily used to melt frost (a phase change process), during which the heat exchanger surface temperature remains near 0°C, and the outlet temperature rises slowly. Once the frost has completely melted, the heat generated by the heater directly heats the heat exchanger metal body and the stagnant coolant inside the tubes, causing their temperature to rise rapidly. Therefore, when the outlet temperature is monitored to have steadily recovered to a threshold significantly above the freezing point (e.g., 5°C-10°C), defrosting can be considered complete. This avoids frost residue due to insufficient heating time and also avoids the waste of continuously supplying energy to an already clean heat exchanger due to excessive heating time.

[0081] A low-speed air-drying recovery procedure is designed after defrosting to protect the equipment and ensure subsequent cooling performance. After defrosting, a large amount of condensate will adhere to the surface of the heat exchanger. If strong cooling is immediately resumed at this time (i.e., introducing cryogenic coolant and turning on the high-speed fan), two major risks will arise: first, the high-speed airflow may blow water droplets into the fan motor or circuitry, causing short circuits or damage; second, the cryogenic coolant will cause these water droplets to refreeze instantly on the heat exchanger surface, forming a thin layer of ice, rendering the defrosting work ineffective. Through a brief low-speed air-drying phase, a gentle airflow can evaporate or blow away most of the residual moisture, creating safe and clean conditions for a smooth and efficient restoration of cooling.

[0082] In a specific application, a complete defrosting cycle is performed according to the following steps: S1, Status Monitoring: During normal system operation, the controller continuously monitors the coolant outlet temperature (T1) of the first heat exchange zone via a temperature sensor.

[0083] S2, Trigger defrost: The controller has a first preset temperature threshold (e.g., b = -4℃). When T1 is detected to be below -4℃ and remains in this state for a preset period of time (e.g., 5-30 seconds, to prevent false judgments caused by instantaneous fluctuations in the sensor), the controller determines that the first heat exchange area is severely frosted and officially starts the defrosting control process.

[0084] S3, Perform core defrosting: The controller performs the core actions described in Example 1, including closing the valves in the first heat exchange zone, activating the heating diaphragm with the corresponding power according to the target temperature, and guiding all return air to the second heat exchange zone through the air valve. Simultaneously, it can be used in conjunction with the enhanced compensation measures described in Example 2.

[0085] S4. Monitor the defrosting process: During the heating process, the controller continues to monitor the temperature change of T1 continuously.

[0086] S5. Determine that defrosting is complete and stop heating: The controller has a second preset temperature threshold (e.g., c = 5℃). When the temperature of T1 rises from the low temperature zone to above 5℃ and remains in this state for a preset period of time (e.g., 10-60 seconds to confirm a stable temperature rise rather than a brief jump), the controller determines that the frost layer has completely melted. At this point, the controller immediately sends a power-off command to the heating diaphragm in the first heat exchange area to stop heating.

[0087] S6. Perform the air-drying procedure: After heating stops, the recovery program is initiated. The controller first sends a command to the fan associated with the first heat exchange zone, causing it to start operating at a low to medium speed (e.g., 30%-50% of the rated speed). This drying process lasts for a preset duration (e.g., 30-90 seconds).

[0088] S7. Fully restore normal control: After the drying period ends, the controller sends an opening command to the coolant supply valve of the first heat exchange zone, restoring the coolant supply. Simultaneously, control of the fan in that zone is returned to the regular temperature regulation logic, allowing it to enter normal automatic operation. This completes one defrosting cycle.

[0089] In addition to the implementation methods mentioned above, this embodiment can also be implemented in the following ways: The start and stop conditions for defrosting can be more complex and intelligent. For example, the start condition can be an AND logic combination of two conditions: "outlet temperature is below the threshold" and "the time since the last defrost exceeds the minimum interval". The stop condition can be a combination of "outlet temperature is above the threshold" and "the heating time has reached the minimum guaranteed duration" to handle certain special cases.

[0090] The duration of the drying process is not necessarily fixed. A humidity sensor can be added to the system and placed downstream of the airflow in the heat exchange area. The drying process can continue until the relative humidity detected by the humidity sensor drops to a level close to the environmental reference value, at which point the drying process ends, achieving a more efficient and thorough drying effect.

[0091] The first and second preset temperature thresholds can also be dynamically changed. For example, the controller can fine-tune these two thresholds by looking up tables or formulas based on the current ambient temperature and humidity or the system's target control temperature, so that defrosting control can achieve optimal results under different operating conditions.

[0092] Example 5 like Figure 1 and Figure 2 As shown, this embodiment provides a defrosting control method for a liquid-cooled terminal. Based on the previous embodiments, this embodiment integrates the key technical points of the foregoing embodiments, including automatic defrosting triggering, intelligent heating strategy selection based on operating conditions, active enhanced cooling compensation, system-level dynamic collaborative control, and a safe and reliable recovery procedure, into a complete, closed-loop, and highly automated control process. The defrosting control method for the liquid-cooled terminal in this embodiment includes: Obtain the target control temperature of the liquid cooling terminal; Based on the target control temperature, a corresponding heating strategy is selected, wherein the output power of the heating strategy is inversely related to the level of the target control temperature. The first heat exchange area is heated according to the heating strategy, and the supply of coolant to the first heat exchange area is stopped. The return airflow from the liquid cooling terminal is then guided to the second heat exchange area.

[0093] When the return airflow from the liquid-cooled terminal is guided to the second heat exchange area, the cooling capacity of the second heat exchange area is enhanced.

[0094] Enhancing the cooling capacity of the second heat exchange region includes at least one of the following methods: Increase the flow rate of coolant supplied to the second heat exchange zone; Increase the speed of the fan associated with the second heat exchange zone.

[0095] The liquid cooling terminal is one of multiple terminals of a liquid cooling system, which includes a central circulation pump. The method further includes: Determine the ratio of the load of the liquid cooling terminal that is defrosting to the total load of the liquid cooling system. When the ratio exceeds a preset threshold, increase the speed of the central circulation pump.

[0096] Increasing the rotational speed of the central circulation pump specifically includes: The rotational speed is increased in a stepwise or linear manner depending on the load ratio.

[0097] After heating the first heat exchange region according to the heating strategy, the method further includes: Start the fan associated with the first heat exchange area and run it at low speed to dry the residual condensate; Restore the coolant supply to the first heat exchange zone and normal fan control.

[0098] The method further includes: When the coolant outlet temperature of the first heat exchange zone is detected to be lower than the first preset temperature threshold, defrosting control of the first heat exchange zone is initiated.

[0099] When heating the first heat exchange area according to the heating strategy, if the coolant outlet temperature of the first heat exchange area is detected to rise above the second preset temperature threshold, heating of the first heat exchange area is stopped.

[0100] The output power of the heating strategy is inversely related to the target controlled temperature level, specifically as follows: When the target control temperature is greater than or equal to the first temperature setpoint, the output power ratio of the heating strategy is the first power range; When the target control temperature is less than the first temperature set value, the output power ratio of the heating strategy is within the second power range, where the upper limit of the first power range is lower than the lower limit of the second power range.

[0101] This embodiment describes a full-process and multi-level collaborative control method. It begins with the accurate and automatic monitoring and judgment of the frosting state of the heat exchanger; after confirming that defrosting is required, the system immediately selects the most efficient heating strategy according to the extremely harsh low-temperature target; then, the system not only performs the core "zone asynchronous" operation (that is, isolating and heating the frosted area while guiding all the airflows to the working area), but also performs the maximum-intensity enhanced compensation refrigeration on the working area; while performing these fine operations at the end, the system controller will also evaluate the impact of this defrosting on the entire liquid cooling system and dynamically improve the performance of the central circulation pump to maintain system stability; finally, after accurately judging that the defrosting is completed, a safety recovery procedure including a drying step is executed to smoothly restore the end to the full-capacity working state.

[0102] In a low-temperature storage scenario with zero tolerance for temperature fluctuations (for example, storing biological agents at -8°C), any oversight in any link may lead to catastrophic consequences. Automatically triggering defrosting by monitoring the outlet temperature can intervene before the frost layer seriously affects the heat exchange efficiency, preventing problems before they occur and avoiding temperature runaway caused by severely attenuated performance. Under the working condition of -8°C, any lack of refrigeration capacity will be quickly amplified. Adopting a high-power heating strategy corresponding inversely to the low-temperature target is to complete defrosting at the fastest speed and minimize the offline time of a single zone. Relying solely on the compensation of conventional refrigeration capacity is far from enough. It is necessary to maximize the refrigeration potential of the working area by increasing the flow rate and wind speed to truly achieve seamless cold quantity relay and ensure the flatness of the temperature curve.剧烈调节 within a single end (one valve is fully closed and the other is fully open) will cause pressure and flow disturbances in the liquid cooling pipe network. Without system-level active intervention, it may affect the normal operation of other parallel ends. Increasing the speed of the central circulation pump is the prerequisite for ensuring the stability of the system parent body and thus supporting the extreme operation of the sub-units. Accurately judging the defrosting end point can avoid energy waste or incomplete defrosting; and the drying step after defrosting can effectively prevent residual moisture from freezing again or invading the motor, significantly improving the long-term operation reliability of the equipment.

[0103] Taking an airborne liquid cooling system with multiple ends as an example, one of the low-temperature ends is responsible for maintaining the target temperature of the equipment cabin at -8°C. Its complete defrosting control process is as follows: S1. Automatic triggering: The system controller continuously monitors the coolant outlet temperature T1 of the heat exchange area on one side of the terminal. When T1 is detected to be lower than the preset frost threshold c (e.g., -8℃) and this condition persists for a set time (e.g., 60 seconds), the controller determines that the frost on one side of the heat exchange area is severe and automatically starts the defrosting program.

[0104] S2. Strategy Selection and System Collaboration: The controller reads that the current target temperature is -8℃, which is less than the preset operating condition judgment threshold a (e.g., 1℃). Therefore, it selects a high-power fast defrosting strategy and prepares to output 80% of the rated power to one side of the heating diaphragm.

[0105] Meanwhile, the controller calculates that the cooling load at the terminal accounts for 40% of the total load of the liquid cooling system, which exceeds the preset linkage threshold (30%). Therefore, based on the internally set linear relationship, the controller instructs the central circulation pump to increase its speed by 20%.

[0106] S3, the controller sends a series of commands to the terminal almost simultaneously: Isolate the defrosting area and completely close the valves leading to one side of the heat exchange area; stop the operation of the fan on one side.

[0107] To initiate heating, activate one side of the heating diaphragm and output power at 80%.

[0108] Strengthen the compensation zone, drive the air valve, and completely switch all return airflow channels to the other side; adjust the valve controlling the heat exchange area on the other side to the 100% fully open position; instruct the fan on the other side to run at its highest rated speed.

[0109] S4. Process monitoring and termination judgment: Under the above conditions, the controller continuously monitors the outlet temperature T1 on one side. When T1 rises from a low temperature to above the second preset temperature threshold (e.g., 5°C) and remains stable for 15 seconds, the controller determines that the frost layer has completely melted.

[0110] S4. Security Recovery Process: The controller immediately stops supplying power to one side of the heating diaphragm.

[0111] Then, start one of the fans and run it at a low to medium speed (e.g., 40% of the rated speed) for 60 seconds to dry the condensate remaining on the heat exchanger fins.

[0112] After the drying process is completed, the controller will restore the terminal to the normal cooling control mode: open the valve, restore the air valve to its normal position, and return the control of the valve and fan to the conventional temperature PID regulation algorithm.

[0113] Simultaneously, the controller sends a command to the central circulating pump, causing its speed to smoothly return to the normal operating level before defrosting. This completes a full, intelligent defrosting cycle.

[0114] In addition to the implementation methods mentioned above, this embodiment can also be implemented in the following ways: The controller can learn by recording various parameters (such as trigger temperature, heating time, power, temperature rise rate, etc.) and effects (such as the impact on temperature fluctuations inside the chamber) of each defrost, and continuously optimize the internal thresholds (such as the values ​​of a and c), duration, and the proportion of pump speed increase, so that the system can achieve the best control effect under different environments and aging conditions.

[0115] By analyzing historical data, the controller can be upgraded from passive triggering to predictive triggering. For example, the model can predict the time when severe frost will occur based on factors such as running time, ambient humidity, and heat load trends, and then perform a gentle preventative defrost during a window of opportunity when the system load is low, thereby further improving the system's availability and stability.

[0116] Example 6 like Figure 1 and Figure 2 As shown, this embodiment provides a liquid cooling system capable of implementing the defrosting control method described in any of the foregoing embodiments. The liquid cooling system includes: The liquid cooling terminal includes a first heat exchange area, a second heat exchange area, and an air valve; A controller, connected to the liquid cooling terminal and the air valve, is used for: When it is determined that the first heat exchange area needs to be defrosted, the liquid cooling terminal is controlled to stop supplying coolant to the first heat exchange area, and the first heat exchange area is heated according to the heating strategy. The control valve directs the return airflow from the liquid cooling terminal to the second heat exchange zone.

[0117] Reference Figure 2 The liquid cooling system described in this embodiment is a closed-loop system, the core purpose of which is to provide precise cryogenic control for multiple user terminals (such as first terminal, second terminal, etc.). The system mainly consists of a central cooling unit, one or more liquid cooling terminals, and a controller (not shown in the figure, but a necessary component of the system) responsible for scheduling and executing control logic.

[0118] More specifically, the system includes: The central cooling unit consists of a first heat exchanger 1 and a central circulation pump 14. The first heat exchanger 1 is the cold source for the entire system, cooling the coolant (such as an aqueous ethylene glycol solution) to a lower temperature T0. The central circulation pump 14 is the power source for the entire system, responsible for driving the coolant to circulate between the main pipeline and each terminal, and finally the coolant returns to the first heat exchanger 1 at a temperature T4.

[0119] The liquid-cooled terminal, taking the first terminal shown in detail in the diagram as an example, is a precision terminal device capable of achieving "zoned asynchronous defrosting." Its internal structure is clearly divided into two independently controllable areas: The first heat exchange zone (left side zone) includes a set of heat exchangers connected in parallel, such as the second heat exchanger 2, the third heat exchanger 3, and the fourth heat exchanger 4 shown in the figure. The coolant supply to this zone is independently controlled by the first valve 11, and the airflow above it is driven by the first fan 8.

[0120] The second heat exchange zone (right side zone), symmetrical to the left side zone, includes the fifth heat exchanger 5, the sixth heat exchanger 6, and the seventh heat exchanger 7. Its coolant supply is independently controlled by the second valve 12, and airflow is driven by the second fan 9.

[0121] The damper 10, located between the first fan 8 and the second fan 9, is a baffle or valve that can be driven by a motor. Its core function is to select the airflow path, which can close the passage to one side of the heat exchange area and guide all return air (whose temperature is measured by sensor T3) to the other side.

[0122] Heating diaphragms 13, these electric heating elements are closely attached to the surface of each heat exchanger (2 to 7) and can generate heat to melt the frost layer upon instruction.

[0123] The sensors include an outlet temperature sensor T1 for monitoring the frosting status of the left heat exchange area, an outlet temperature sensor T2 for monitoring the right outlet temperature, and a return air temperature sensor T3 for monitoring the cooling space.

[0124] The controller is a microprocessor or PLC (Programmable Logic Controller) that connects to all actuators (first valve 11, second valve 12, first fan 8, second fan 9, air valve 10, heating diaphragm 13, central circulation pump 14) and sensors (T1, T2, T3, etc.) in the system via electrical signals. The controller receives real-time data from the sensors and outputs control commands according to its internally preset program logic (i.e., the method in the aforementioned embodiments) to precisely coordinate the actions of each component.

[0125] By equipping each zone with independent heat exchanger units, independent valves (11 and 12), and independent fans (8 and 9), the system gains the ability to operate the two zones completely differently (one for cooling, one for defrosting). Without this physical isolation and independent control, simultaneous defrosting and cooling would be impossible.

[0126] During defrosting, without the damper 10, even if the first fan 8 is stopped, some return air will still "leak" or short-circuit through the first heat exchange zone that is being defrosted due to pressure differences or other reasons. This part of the airflow is not only not effectively cooled, but may also carry away the heat generated by the heating diaphragm 13, reducing defrosting efficiency. The damper 10, through physical blocking, forces 100% of the return air to be directed to the second heat exchange zone that is in operation, thereby ensuring the maximization of compensatory cooling efficiency.

[0127] Taking defrosting the first heat exchange zone (left side) as an example, the system's workflow is as follows: S1. Monitoring and Triggering: The controller continuously monitors the temperature signal from sensor T1. When the reading of T1 is below a preset frost threshold (e.g., -4°C) for a period of time, the controller determines that the left area needs defrosting.

[0128] S2. Execute defrost and compensation commands: The controller immediately sends coordinated commands to multiple components: A complete closure command is issued to the first valve 11 to cut off the coolant supply to heat exchangers 2, 3, and 4.

[0129] A start command is sent to the heating diaphragm 13 installed on heat exchangers 2, 3, and 4, and its output power is set according to the target temperature.

[0130] A stop command is sent to the first fan 8.

[0131] The air valve 10 is given a command to deflect to the right, completely sealing off the left airflow passage.

[0132] At the same time, a command is sent to the second valve 12 to increase its opening to 100%, and a command is sent to the second fan 9 to increase its speed to an ultra-high speed, so as to enhance the cooling capacity of the right side area.

[0133] S3, Stable Operation: In this state, the left-side area is quietly heated and defrosted, while all the return air from the cooled space is forcefully drawn in by fan 9 and guided by air valve 10, passing through the right-side heat exchange area (heat exchangers 5, 6, and 7) which is working hard to cool, thus continuously providing cooling to the space.

[0134] S4, End and Resume: The controller continuously monitors the temperature of T1. When it rises back to the defrosting completion threshold (e.g., 5°C), the controller stops supplying power to the left heating diaphragm 13 and executes the subsequent drying and recovery procedures, ultimately restoring the entire terminal to the normal state of dual-zone coordinated cooling.

[0135] In addition to the implementation methods mentioned above, this embodiment can also be implemented in the following ways: In addition to being a central single-baffle type, the air valve 10 can also be designed as two independent louvered valves, installed at the inlet or outlet of the first fan 8 and the second fan 9 respectively. During defrosting, the controller closes the left louver and fully opens the right one.

[0136] Besides a symmetrical layout, the first and second heat exchange zones can also be arranged vertically. For example, the lower heat exchanger is used for defrosting, and the air valve guides the airflow to pass entirely through the upper heat exchanger.

[0137] In addition to using the heating diaphragm 13, a hot gas bypass method can also be used. In this case, an additional set of pipes and valves will be added to the system to introduce hot gas (instead of cryogenic coolant) from the high-pressure side of the refrigeration system into the heat exchanger coil that needs to be defrosted during defrosting, so as to heat it from the inside.

[0138] The controller can be an embedded microcontroller integrated inside the liquid-cooled terminal, an external independent PLC control cabinet, or even software running on a remote server, controlling the terminal via a network.

[0139] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this application. Any specific values ​​in all examples shown and discussed herein should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0140] Furthermore, it should be noted that the use of terms such as "first" and "second" is merely for ease of distinction, and unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application.

[0141] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A defrosting control method for a liquid cooling terminal, characterized in that, The liquid cooling terminal includes a first heat exchange region and a second heat exchange region, and the defrosting control method for the liquid cooling terminal includes: Obtain the target control temperature of the liquid cooling terminal; Based on the target control temperature, a corresponding heating strategy is selected, wherein the output power of the heating strategy is inversely related to the level of the target control temperature. The first heat exchange area is heated according to the heating strategy, and the supply of coolant to the first heat exchange area is stopped. The return airflow from the liquid cooling terminal is then guided to the second heat exchange area.

2. The defrosting control method for liquid-cooled terminals according to claim 1, characterized in that: When the return airflow from the liquid-cooled terminal is guided to the second heat exchange area, the cooling capacity of the second heat exchange area is enhanced.

3. The defrosting control method for liquid-cooled terminals according to claim 2, characterized in that: Enhancing the cooling capacity of the second heat exchange region includes at least one of the following methods: Increase the flow rate of coolant supplied to the second heat exchange zone; Increase the speed of the fan associated with the second heat exchange zone.

4. The defrosting control method for liquid-cooled terminals according to claim 1, characterized in that: The liquid cooling terminal is one of multiple terminals of a liquid cooling system, which includes a central circulation pump. The method further includes: Determine the ratio of the load of the liquid cooling terminal that is defrosting to the total load of the liquid cooling system. When the ratio exceeds a preset threshold, increase the speed of the central circulation pump.

5. The defrosting control method for liquid-cooled terminals according to claim 4, characterized in that: Increasing the rotational speed of the central circulation pump specifically includes: The rotational speed is increased in a stepwise or linear manner depending on the load ratio.

6. The defrosting control method for liquid-cooled terminals according to claim 1, characterized in that: After heating the first heat exchange region according to the heating strategy, the method further includes: Start the fan associated with the first heat exchange area and run it at low speed to dry the residual condensate; Restore the coolant supply to the first heat exchange zone and normal fan control.

7. The defrosting control method for liquid-cooled terminals according to claim 1, characterized in that: The method further includes: When the coolant outlet temperature of the first heat exchange zone is detected to be lower than the first preset temperature threshold, defrosting control of the first heat exchange zone is initiated.

8. The defrosting control method for liquid-cooled terminals according to claim 7, characterized in that: When heating the first heat exchange area according to the heating strategy, if the coolant outlet temperature of the first heat exchange area is detected to rise above the second preset temperature threshold, heating of the first heat exchange area is stopped.

9. The defrosting control method for liquid-cooled terminals according to claim 1, characterized in that: The output power of the heating strategy is inversely related to the target controlled temperature level, specifically as follows: When the target control temperature is greater than or equal to the first temperature setpoint, the output power ratio of the heating strategy is the first power range; When the target control temperature is less than the first temperature setting value, the output power ratio of the heating strategy is a second power range, wherein the upper limit of the first power range is lower than the lower limit of the second power range.

10. A liquid cooling system, characterized in that, For implementing the defrosting control method for a liquid-cooled terminal as described in any one of claims 1-9, the liquid-cooling system comprises: The liquid cooling terminal includes a first heat exchange area, a second heat exchange area, and an air valve; A controller, connected to the liquid cooling terminal and the air valve, is used for: When it is determined that the first heat exchange area needs to be defrosted, the liquid cooling terminal is controlled to stop supplying coolant to the first heat exchange area, and the first heat exchange area is heated according to the heating strategy. The control valve directs the return airflow from the liquid cooling terminal to the second heat exchange zone.

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