Variable volume replenishment system and replenishment method

Abstract

This invention discloses a variable-volume coolant replenishment system and method. The variable-volume coolant replenishment system includes: a refrigeration module for supplying coolant; a supply and return module including a supply pump, a supply pipeline, and a return pipeline, wherein the supply pipeline connects to the outlet of the refrigeration module, the return pipeline connects to the inlet of the refrigeration module, and the supply pump is installed on the return pipeline; a replenishment unit including a water tank, a pressure regulating pipeline, a first expansion tank, and a second expansion tank, wherein the pressure regulating pipeline is connected between the outlet of the water tank and the inlet of the supply pump, and the first and second expansion tanks are connected in parallel on the pressure regulating pipeline, and the first and second expansion tanks independently regulate their liquid output; and a heating pipeline for providing heat to the second expansion tank. This invention effectively solves the problem of difficulty in replenishing coolant caused by increased coolant viscosity in low-temperature environments, avoids frequent start-stop of the supply pump and the risk of cavitation, and significantly improves system energy efficiency and the service life of core components.

Description

Technical Field

[0001] This invention relates to the field of liquid cooling technology, and in particular to a variable volume liquid replenishment system and liquid replenishment method thereof. Background Technology

[0002] In temperature control solutions for high heat flux density scenarios such as data centers, 5G communication base stations, and high-performance computing equipment, liquid cooling technology is gradually replacing traditional air cooling due to its superior heat dissipation efficiency, becoming a key means to ensure the stable operation of core electronic equipment. The core of a liquid cooling system lies in using a circulating pump to drive coolant to flow through the pipes, continuously removing heat from the heat-generating components. Maintaining a stable and suitable back pressure at the inlet of the liquid supply pump is a prerequisite for ensuring the continuous, efficient, and safe operation of the entire liquid cooling system.

[0003] However, existing closed-loop liquid cooling systems generally use a single expansion tank as a constant-pressure water supply device. This traditional single-tank constant-pressure mode is showing its limitations in increasingly complex application environments. Because the constant pressure of a single expansion tank is usually fixed, it lacks the ability to dynamically adapt to changes in ambient temperature. In applications with large diurnal temperature differences or extreme cold, it is prone to problems such as excessively high back pressure leading to pipeline pressure risks, or excessively low back pressure causing cavitation and suction problems in the liquid supply pump, making it difficult to maintain a stable back pressure output across the entire operating range.

[0004] Especially under low-temperature conditions, existing systems face even more severe challenges. When the ambient temperature drops sharply, the temperature of the coolant in the expansion tank decreases accordingly, leading to a significant increase in liquid viscosity and a substantial decrease in fluidity. This high-viscosity coolant generates significant flow resistance when flowing through the replenishment pipeline, severely hindering the expansion tank's ability to replenish coolant to the system in a timely manner. Consequently, the system back pressure continues to drop and cannot recover effectively. The existing single-tank architecture is powerless to address this issue and can only passively accept the fact of insufficient back pressure.

[0005] This back pressure instability further exacerbates the vicious cycle of system operation. When back pressure fluctuations exceed the safety threshold, the system is often forced to frequently start and stop in order to prevent the coolant supply pump from dry-running and being damaged. This not only fails to guarantee a continuous supply of coolant to the load side, but the frequent starting inrush currents also significantly increase system energy consumption. More seriously, long-term back pressure fluctuations and low back pressure operation accelerate cavitation wear of the impeller inside the coolant supply pump, significantly shortening the service life of core power components and increasing user maintenance costs and downtime risks.

[0006] Therefore, how to design a replenishment system that can adapt to different ambient temperatures and operate reliably for a long time, and how to develop a replenishment method, are technical problems that the industry urgently needs to solve. Summary of the Invention

[0007] To address the shortcomings of existing technologies that rely solely on a single expansion tank to meet the requirements of low-temperature coolant replenishment and stable coolant supply, this invention proposes a variable-volume coolant replenishment system and its replenishment method. Through the parallel design of two expansion tanks and the coordinated design of heating pipelines, the problem of replenishment difficulties caused by increased coolant viscosity in low-temperature environments is effectively solved, ensuring back pressure stability across the entire temperature range. Furthermore, by adjusting the replenishment volume and rate, frequent start-stop of the supply pump and the risk of cavitation are avoided, significantly improving system energy efficiency and the service life of core components.

[0008] The technical solution adopted in this invention is to design a variable-volume replenishment system, comprising:

[0009] The refrigeration module is used to supply coolant;

[0010] The liquid supply and return module includes a liquid supply pump, a liquid supply pipeline and a liquid return pipeline. The liquid supply pipeline is connected to the outlet of the refrigeration module and the liquid return pipeline is connected to the inlet of the refrigeration module. The liquid supply pump is installed on the liquid return pipeline.

[0011] The replenishment unit includes a water tank, a pressure regulating pipeline, a first expansion tank, and a second expansion tank. The pressure regulating pipeline is connected between the outlet of the water tank and the inlet of the liquid supply pump. The first expansion tank and the second expansion tank are connected in parallel on the pressure regulating pipeline, and the liquid output of the first expansion tank and the second expansion tank can be adjusted independently.

[0012] The heating pipeline is used to provide heat to the second expansion tank. Both ends of the heating pipeline are connected to the return pipeline, and the heating pipeline passes through the second expansion tank.

[0013] This design achieves dynamic adjustment of replenishment volume and rate by independently regulating the liquid output of the two expansion tanks, solving the problem that a single expansion tank cannot adapt to a wide range of temperature changes. In particular, the heating pipeline utilizes the waste heat from the return liquid to specifically heat the second expansion tank, effectively reducing the viscosity of the coolant in low-temperature environments and ensuring stable back pressure replenishment capability even under extremely cold conditions.

[0014] Furthermore, the replenishment unit also includes: a secondary pressurization pump installed on the pressure regulating pipeline, a first expansion tank and a second expansion tank connected in parallel to the inlet of the secondary pressurization pump, and the outlet of the secondary pressurization pump connected to the inlet of the supply pump through the replenishment pipeline.

[0015] This design uses a secondary pressurization pump to repressurize the low-temperature, low-pressure coolant from the expansion tank, ensuring that the inlet of the supply pump always maintains positive pressure. This completely eliminates the problems of cavitation and wear of the supply pump caused by insufficient back pressure, and significantly extends the service life of the core power components.

[0016] Furthermore, the replenishment unit also includes a bypass line and an emergency back pressure pump. The bypass line is connected in parallel with the pressure regulating line, and the emergency back pressure pump is installed on the bypass line.

[0017] This design allows for rapid and direct replenishment of liquid via a bypass pipeline and emergency back pressure pump in the event of severe system leakage or insufficient expansion tank replenishment capacity. This prevents the system from shutting down due to pressure loss and also allows for online maintenance of the main replenishment circuit, greatly improving the operational reliability and maintainability of the liquid cooling system.

[0018] Furthermore, the fluid replenishment system includes: a back pressure sensor and an ambient temperature sensor; the back pressure sensor is used to detect the back pressure P1 at the inlet of the fluid supply pump; the ambient temperature sensor is used to detect the ambient temperature T1.

[0019] This design enables precise sensing of system back pressure and ambient temperature, providing crucial data input for subsequent control logic. This allows the system to automatically match the optimal liquid replenishment strategy based on actual operating conditions (such as extreme cold or normal temperature), improving the intelligence level and response speed of the control.

[0020] Furthermore, the fluid replenishment system also includes a leakage sensor for detecting the amount of leakage, which is located on the supply line and the return line.

[0021] This design uses a leak sensor to monitor the sealing status of the pipeline in real time. Once a leak occurs, an alarm or emergency response is immediately triggered, preventing coolant depletion and system overheating damage caused by leaks, and ensuring the safe operation of the liquid cooling device.

[0022] This invention also proposes a fluid replenishment control method, employing the aforementioned fluid replenishment system, comprising:

[0023] Detect the back pressure P1 at the inlet of the liquid supply pump and calculate the rate of change of the back pressure ΔP.

[0024] If P1 ≤ the set back pressure P 设定1 And ΔP ≤ the set upper limit value of back pressure rate ΔP 上1 Then open the pressure regulating pipeline and adjust the switching status of the heating pipeline, the first expansion tank, and the second expansion tank according to the ambient temperature T1;

[0025] If P1 ≤ the set back pressure P 设定1 And ΔP > the set upper limit value of back pressure rate ΔP 上1 Then open the pressure regulating pipeline, start the first expansion tank liquid supply, and close the heating pipeline and the second expansion tank.

[0026] If P1 > set back pressure P 设定1 If the pressure regulating pipeline is shut off, the liquid supply and heating pipelines of the first expansion tank and the second expansion tank will also be shut off.

[0027] This design introduces the rate of change of back pressure as a control variable, enabling the system to not only sense the current pressure level but also predict pressure change trends. This feedforward control strategy effectively suppresses large fluctuations in back pressure, avoids frequent start-stop of the liquid supply pump, and ensures the stability and continuity of the liquid supply.

[0028] Furthermore, fluid replacement control methods also include:

[0029] If P1 ≤ the set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 Then the pressure regulating valve in the pressure regulating pipeline will open to the set maximum opening degree K1;

[0030] If P1 ≤ the set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate. 下1 ≤ΔP≤ Set upper limit value of back pressure rate ΔP 上1 Then the pressure regulating valve in the pressure regulating pipeline will open to the set high opening degree K2;

[0031] If P1 ≤ the set back pressure P 设定1 And ΔP > the set upper limit value of back pressure rate ΔP 上1 Then the pressure regulating valve in the pressure regulating pipeline opens to the set neutral position K3;

[0032] If P1 > set back pressure P 设定1 If so, the pressure regulating valve in the pressure regulating pipeline will be closed;

[0033] Where K1>K2>K3, the lower limit value of the back pressure rate ΔP is set. 下1 <0< Set the upper limit value of back pressure rate ΔP 上1 .

[0034] This design enables precise adjustment of the replenishment flow rate. When the back pressure drops sharply, a large opening allows for rapid pressure replenishment; when the back pressure stabilizes, a small opening is maintained. This ensures timely pressure recovery while avoiding energy waste and overflow risks caused by excessive replenishment, thus optimizing system energy efficiency.

[0035] Furthermore, adjusting the on / off states of the heating pipes, the first expansion tank, and the second expansion tank according to the ambient temperature T1 includes:

[0036] When T1 ≤ the set lower limit temperature T 设1 At that time, start the liquid supply to the first and second expansion tanks, start the secondary pressurization pump on the pressure regulating pipeline, and open the heating pipeline;

[0037] When the lower limit temperature T is set 设1 <T1≤Set Low Temperature T 设2 At this time, start the liquid supply to the first and second expansion tanks, start the secondary pressurization pump on the pressure regulating pipeline, and shut down the heating pipeline;

[0038] When the low temperature T is set 设2 <T1≤Set upper limit temperature T 设3 When the liquid supply to the first and second expansion tanks is activated, the secondary pressurization pump on the pressure regulating pipeline is turned off, and the heating pipeline is shut off.

[0039] When T1 > the set upper limit temperature T 设3 At this time, open the first expansion tank, close the secondary pressurization pump on the pressure regulating pipeline, and close the second expansion tank and the heating pipeline;

[0040] Among them, T 设1 <T 设2 <0<T 设3 .

[0041] This design solves the challenge of adaptability to replenishment under different ambient temperatures. At low temperatures, both tanks operate simultaneously and are heated, while at high temperatures, only one tank operates and heating stops. This ensures the fluidity of replenishment at low temperatures while avoiding ineffective energy consumption at high temperatures, achieving efficient and energy-saving operation across the entire temperature range.

[0042] Furthermore, adjusting the on / off states of the heating pipes, the first expansion tank, and the second expansion tank according to the ambient temperature T1 also includes:

[0043] If P1 ≤ the set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 The corresponding expansion tank will be opened by continuously supplying electricity.

[0044] If P1 ≤ the set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate. 下1 If the value is less than or equal to ΔP, the corresponding expansion tank will be opened by pulse energizing.

[0045] This design optimizes fluid replenishment accuracy and energy consumption. Continuous power is used for rapid pressure recovery from a fall, while pulsed power is used for precise pressure maintenance. This "fast-slow combination" control method effectively prevents over- or under-replenishment of fluid, improving the stability of system control.

[0046] Furthermore, adjusting the on / off states of the heating pipes, the first expansion tank, and the second expansion tank according to the ambient temperature T1 also includes:

[0047] If P1 ≤ the set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 Then when T1 ≤ the set lower limit temperature T 设1 At that time, fully open the heating pipes;

[0048] If P1 ≤ the set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate. 下1≤ΔP≤ Set upper limit value of back pressure rate ΔP 上1 Then when T1 ≤ the set lower limit temperature T 设1 At that time, the heating pipes were partially open.

[0049] This design achieves a precise match between heating power and dynamic pressure requirements. It provides full heating power during back pressure drops and uses semi-heating for fine adjustment when back pressure is stable. This solves the problems of poor liquid replenishment and "false low pressure" caused by the viscosity of the liquid in extremely cold environments, and avoids system overpressure or energy waste caused by overheating. It further improves the system's survivability and energy efficiency ratio under extreme low temperatures.

[0050] Furthermore, fluid replacement control methods also include:

[0051] Before detecting the back pressure P1 at the inlet of the liquid supply pump and calculating the rate of change of the back pressure ΔP, the leakage rate V1 of the liquid replenishment system is detected first.

[0052] If V1 > set rate V0, then open the bypass line of the pressure regulating line, close the pressure regulating line and the heating line, and turn on the emergency back pressure pump on the bypass line.

[0053] If V1 ≤ set rate V0, then close the bypass line of the pressure regulating line, close the emergency back pressure pump on the bypass line, and then execute the steps of detecting the back pressure P1 at the inlet of the liquid supply pump and calculating the rate of change of the back pressure ΔP.

[0054] In the event of a serious leak such as a burst pipe, this design allows the system to quickly switch to a high-flow emergency mode and alert the user for maintenance, preventing system failure due to insufficient conventional fluid replenishment capacity and enhancing the system's fault tolerance and safety.

[0055] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0056] 1. By setting up the first and second expansion tanks in parallel, independent adjustment of the replenishment volume and rate is achieved. In particular, the introduction of heating pipes to utilize the residual heat from the system's return liquid to specifically heat the second expansion tank effectively solves the problem of replenishment difficulties caused by increased coolant viscosity and decreased fluidity in extremely cold environments, ensuring that the system can maintain stable back pressure across the entire temperature range from -35℃ to high-temperature environments;

[0057] 2. A secondary pressurization pump is added to the replenishment pipeline. This pump can pressurize the coolant from the expansion tank a second time, ensuring that the inlet of the supply pump is always under positive pressure, which fundamentally eliminates cavitation and greatly extends the service life of the supply pump and the system.

[0058] 3. By monitoring the back pressure P1 and its rate of change ΔP, feedforward intelligent control is achieved. The system can predict the trend of back pressure changes and dynamically adjust the fluid replenishment strategy, avoiding frequent start-stop shocks of the fluid supply pump and back pressure pump, significantly reducing system energy consumption, and ensuring long-term stability of the fluid supply pressure. Attached Figure Description

[0059] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0060] Figure 1 This is a schematic diagram of the connection of the fluid replenishment system according to a feasible embodiment of the present invention;

[0061] Figure 2 This is a schematic diagram of the connection of the fluid replenishment system according to a preferred embodiment of the present invention;

[0062] Figure 3 This is a schematic diagram of the flow direction in the first working state of the fluid replenishment system of the present invention;

[0063] Figure 4 This is a schematic diagram of the flow direction in the second working state of the fluid replenishment system of the present invention;

[0064] Figure 5 This is a schematic diagram of the flow direction in the third working state of the fluid replenishment system of the present invention;

[0065] Figure 6 This is a schematic diagram of the control logic of the fluid replenishment control method of the present invention;

[0066] Figure 7 This is a schematic diagram of the opening adjustment of the fluid replenishment control method of the present invention;

[0067] Figure 8 This is a schematic diagram of the temperature control method for fluid replenishment control of the present invention;

[0068] Figure 9 This is a schematic diagram of the continuous power supply control of the fluid replenishment control method of the present invention;

[0069] Figure 10 This is a schematic diagram of the pulse energization control of the fluid replenishment control method of the present invention;

[0070] Figure 11 This is a schematic diagram of the fluid replenishment control logic of a preferred embodiment of the present invention;

[0071] Explanation of reference numerals in the attached diagram: 10, refrigeration module; 20, water tank; 30, first expansion tank; 31, first water valve; 40, second expansion tank; 41, second water valve; 42, heating pipeline; 43, heating valve; 50, secondary pressurization pump; 60, pressure regulating pipeline; 61, pressure regulating valve; 70, bypass pipeline; 71, bypass valve; 80, emergency back pressure pump; 90, replenishment pipeline; 100, supply pump; 110, supply pipeline; 120, return pipeline; 130, ambient temperature sensor; 140, back pressure sensor; 150, leakage sensor. Detailed Implementation

[0072] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0073] like Figures 1 to 3 As shown, this invention proposes a variable-volume liquid replenishment system, including a refrigeration module 10, a liquid supply and return module, and a liquid replenishment unit. The refrigeration module 10 provides a constant-temperature coolant; the liquid supply and return module includes a supply pump 100, a supply pipeline 110, and a return pipeline 120. The supply pipeline 110 connects to the outlet of the refrigeration module 10, and the return pipeline 120 connects to the inlet of the refrigeration module 10. The supply pump 100 is installed on the return pipeline 120. The liquid replenishment unit includes a water tank 20, a pressure regulating pipeline 60, a first expansion tank 30, and a second expansion tank 40. The pressure regulating pipeline 60 connects between the outlet of the water tank 20 and the inlet of the supply pump 100. The first expansion tank 30 and the second expansion tank 40... Tanks 40 are connected in parallel on the pressure regulating pipeline 60. The outlet of the first expansion tank 30 is equipped with a first water valve 31, and the outlet of the second expansion tank 40 is equipped with a second water valve 41. Both of them can independently regulate the liquid output through their water valves. In addition, the system is also equipped with a heating pipeline 42, both ends of which are connected to the return liquid pipeline 120. The heating pipeline 42 passes through the second expansion tank 40, but the liquid in the heating pipeline 42 does not mix with the second expansion tank 40. It is only used to provide heat to the second expansion tank 40. The heating pipeline 42 is equipped with a heating valve 43 to control its on / off state.

[0074] This design achieves dynamic adjustment of replenishment volume and rate by independently regulating the liquid output of the two expansion tanks, solving the problem that a single expansion tank cannot adapt to a wide range of temperature changes. In particular, the heating pipe 42 utilizes the residual heat from the return liquid to specifically heat the second expansion tank 40, effectively reducing the viscosity of the coolant in low-temperature environments and ensuring stable back pressure replenishment capability even under extremely cold conditions.

[0075] In actual operation, the system will preset a specified back pressure value for the first expansion tank 30 – the set back pressure P. 设定1The system monitors the back pressure P1 at the inlet of the liquid supply pump 100 in real time and calculates the rate of change of the back pressure ΔP. When the system is in an extremely low temperature environment and the back pressure drops rapidly, for example, if P1 ≤ the set back pressure P... 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 When T1≤-35℃, the system will introduce high-temperature coolant from the return pipe 120 through the fully open heating valve 43, which will flow through the heating pipe 42 to precisely heat the second expansion tank 40, thereby increasing the pressure inside the tank and reducing the viscosity of the ethylene glycol solution, thus solving the problem of difficulty in replenishing liquid at low temperatures.

[0076] like Figure 1 and Figure 2 As shown, the specific structure of the replenishment unit is further refined to ensure pressure stability under different operating conditions. The replenishment unit also includes a secondary pressurization pump 50 installed on the pressure regulating pipeline 60. The first expansion tank 30 and the second expansion tank 40 are connected in parallel to the inlet of the secondary pressurization pump 50. The outlet of the secondary pressurization pump 50 is connected to the inlet of the supply pump 100 through the replenishment pipeline 90. The pressure regulating pipeline 60 is equipped with a pressure regulating valve 61 to control its on / off state. When the pressure regulating valve 61 is closed, the first expansion tank 30, the second expansion tank 40 and the secondary pressurization pump 50 are not working. When the pressure regulating valve 61 is open, the first expansion tank 30, the second expansion tank 40 and the secondary pressurization pump 50 are selectively working.

[0077] This design uses a secondary pressurization pump 50 to repressurize the low-temperature, low-pressure coolant from the expansion tank, ensuring that the inlet of the liquid supply pump 100 always maintains positive pressure. This completely eliminates the problems of cavitation and wear of the liquid supply pump caused by insufficient back pressure, and significantly extends the service life of the core power components.

[0078] The specific implementation parameters of the secondary booster pump 50 can be adaptively adjusted according to different operating conditions, thereby achieving "pressure supply on demand". The specific logic is as follows:

[0079] If P1 ≤ the set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 This indicates that the back pressure is extremely low and is experiencing a precipitous drop, putting the system in an emergency "rescue" state. Under this critical condition, when the temperature is extremely low (T1≤-35℃), the secondary booster pump 50 will run at full speed at its rated frequency, forcibly overcoming fluid resistance and injecting high-pressure refrigerant into the system. In the low-temperature range (-35℃<T1≤-20℃), although the fluid flow is slightly improved, it is still limited. The secondary booster pump 50 will then adjust to run at 80% of its rated frequency, ensuring rapid pressure stabilization while avoiding unnecessary power consumption caused by full-speed operation, thus precisely balancing energy consumption and refrigerant replenishment requirements under extreme conditions.

[0080] Conversely, if P1 ≤ set back pressure P设定1 And set a lower limit value ΔP for the back pressure rate. 下1 ≤ΔP≤ Set upper limit value of back pressure rate ΔP 上1 This indicates that although the back pressure is low, it has become relatively stable, and the system only needs to maintain fluid replenishment. Under this condition, when the temperature is extremely low (T1≤-35℃), the secondary booster pump 50 will operate at 60% of its rated frequency to prevent pressure overshoot or oscillation due to excessive pressurization; while in the low temperature range (-35℃<T1≤-20℃), it will be adjusted to operate at 50% of its rated frequency.

[0081] This step-down frequency reduction strategy effectively avoids the "overkill" phenomenon under low-demand conditions and significantly optimizes the system's energy efficiency ratio across the entire temperature range.

[0082] like Figure 4 and Figure 5 As shown, to cope with extreme operating conditions, the system is also designed with a highly reliable redundant circuit. The replenishment unit also includes a bypass line 70 and an emergency back pressure pump 80. The bypass line 70 is connected in parallel with the pressure regulating line 60. The emergency back pressure pump 80 is installed on the bypass line 70, which is equipped with a bypass valve 71 to control its on / off state. When the bypass valve 71 is closed, the emergency back pressure pump 80 does not work; when the bypass valve 71 is open, the emergency back pressure pump 80 starts working. This design allows for direct and rapid replenishment of liquid through the bypass line 70 and the emergency back pressure pump 80 in the event of severe leakage or insufficient replenishment capacity of the expansion tank, preventing system shutdown due to pressure loss. It also allows for online maintenance of the main replenishment circuit, greatly improving the operational reliability and maintainability of the liquid cooling system.

[0083] In some application examples, the control logic is as follows: the system calculates the leakage rate V1 in real time, which is derived from the derivatives of n1 and n2 detected by the leakage sensor 150 with respect to time—V1 = d(n1 + n2) / dt, where t is time, n1 is the leakage amount detected by the leakage sensor 150 on the supply line 110 (usually in liters), and n2 is the leakage amount detected by the leakage sensor 150 on the return line 120 (usually in liters), with the rate unit being liters per minute. Once V1 exceeds the set emergency threshold—the set rate V0—the system determines it as a serious leak, immediately fully opens the bypass valve 71 corresponding to the bypass line 70, closes the pressure regulating line 60 and the heating line 42, and starts the emergency back pressure pump 80, which acts as a constant-speed pump, to force liquid replenishment. At the same time, it reports fault information and displays the emergency operating time, reminding the user to locate the leak.

[0084] like Figure 1 and Figure 2As shown, to achieve intelligent and precise control, the system is equipped with multi-dimensional monitoring and sensing devices. The fluid replenishment system includes a back pressure sensor 140 and an ambient temperature sensor 130. The back pressure sensor 140 detects the back pressure P1 at the inlet of the fluid supply pump 100 and calculates the rate of change ΔP of the back pressure. The ambient temperature sensor 130 detects the ambient temperature T1. This design enables precise sensing of the system's back pressure and ambient temperature, providing crucial data input for subsequent control logic. This allows the system to automatically match the optimal fluid replenishment strategy based on actual operating conditions, improving the intelligence level and response speed of the control.

[0085] In some embodiments of the present invention, the rate of change of back pressure ΔP is defined as the difference between the back pressure value at the current sampling point and the sampling point 60 seconds ago (in kPa / minute). This feedforward control based on the rate of change is the key to distinguishing static control and can effectively predict pressure trends.

[0086] Furthermore, the system strengthens its safety protection mechanisms. The replenishment system also includes a leak sensor 150 for detecting leakage. The leak sensor 150 is located in the low-level area of ​​the supply line 110 and the return line 120 (usually at the bottom of the line, but can be selected as the lowest position). This design uses the leak sensor 150 to monitor the sealing status of the lines in real time. Once a leak occurs, an alarm or emergency response is immediately triggered, preventing coolant depletion and system overheating damage caused by leakage, thus ensuring the safe operation of the liquid cooling device. In practical applications, the leakage rate V1 is calculated based on the leakage amount detected by the leak sensor 150. This dynamic rate monitoring reflects the sealing status of the system more promptly than simple level monitoring, providing a basis for decision-making on whether to activate the emergency mode. Only when V1 ≤ the set rate V0 will the system enter the pressure regulation and replenishment process; otherwise, it will directly switch to the emergency replenishment process.

[0087] like Figure 6 As shown, this invention also proposes a fluid replenishment control method, employing the aforementioned fluid replenishment system, the core of which lies in dual-factor regulation based on pressure and temperature. Specifically, the fluid replenishment method includes a pressure-regulating fluid replenishment process, the contents of which are as follows:

[0088] Detect the back pressure P1 at the inlet of the liquid supply pump 100 and calculate the rate of change of the back pressure ΔP.

[0089] If P1 ≤ the set back pressure P 设定1 And ΔP ≤ the set upper limit value of back pressure rate ΔP 上1 If the back pressure is low and there is a risk of it dropping, open the pressure regulating line and adjust the switching status of the heating line 42, the first expansion tank 30 and the second expansion tank 40 according to the ambient temperature T1 to match the current heat load and liquid replenishment requirements. While ensuring the positive pressure at the inlet of the liquid supply pump 100, avoid overflow or energy waste caused by excessive liquid replenishment.

[0090] If P1 ≤ the set back pressure P 设定1 And ΔP > the set upper limit value of back pressure rate ΔP 上1 If the system back pressure is low, it indicates that the pressure is rising rapidly (e.g., after a large flow of liquid replenishment or a sudden reduction in load), which poses a risk of overshoot or oscillation. Open the pressure regulating line, start the first expansion tank 30 to supply liquid, and close the heating line 42 and the second expansion tank 40 to reduce the liquid replenishment volume and slow down the pressure rise rate, prevent pressure overshoot caused by simultaneous liquid replenishment or heating of the two tanks, and ensure that the back pressure converges smoothly to the set value.

[0091] If P1 > set back pressure P 设定1 If the system back pressure is above the safe threshold, no additional liquid is needed. Close the pressure regulating pipeline, and shut down the first expansion tank 30, the heating pipeline 42, and the second expansion tank 40 to avoid ineffective work and system overpressure, maintain the current stable operating state, and achieve optimal energy efficiency.

[0092] This design introduces the rate of change of back pressure as a control variable, enabling the system to not only sense the current pressure level but also predict pressure change trends. This feedforward control strategy effectively suppresses large fluctuations in back pressure, avoids frequent start-stop of the liquid supply pump, and ensures the stability and continuity of the liquid supply.

[0093] like Figure 7 As shown, further refinement of the method regarding the above control logic lies in the precise control of the flow regulating valve. The replenishment control method also includes:

[0094] If P1 ≤ the set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 If the back pressure is low and the rate of back pressure drop is fast, the system is at risk of pressure loss. The pressure regulating valve 61 of the pressure regulating pipeline 60 is opened to the set maximum opening degree K1 to maximize the liquid replenishment flow and quickly inject coolant into the system to curb the rapid drop in back pressure and buy time for the system to recover.

[0095] If P1 ≤ the set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate. 下1 ≤ΔP≤ Set upper limit value of back pressure rate ΔP 上1 If the back pressure is low, but the back pressure value remains basically unchanged, the system is in a dynamic equilibrium state. The pressure regulating valve 61 of the pressure regulating pipeline 60 is opened to the set high opening degree K2 to maintain the current stable liquid replenishment flow, accurately fill the small pressure loss of the system, ensure the back pressure rises, and avoid excessive liquid replenishment causing overflow.

[0096] If P1 ≤ the set back pressure P 设定1 And ΔP > the set upper limit value of back pressure rate ΔP上1 This indicates that although the back pressure is low, the back pressure value is slowly rising and the system is in the pressure recovery period. The pressure regulating valve 61 of the pressure regulating pipeline 60 is opened to the set middle position K3 to reduce the liquid replenishment flow and play the role of "throttling" buffer to prevent a large amount of refrigerant from rushing in and causing the back pressure to rise instantly, and to ensure that the pressure smoothly transitions to the set range.

[0097] If P1 > set back pressure P 设定1 If the system back pressure is not low, then replenishment is not needed for the time being. The pressure regulating valve 61 of the pressure regulating line 60 is closed to cut off the replenishment passage, prevent the system pressure from continuing to rise and causing overpressure protection, and at the same time avoid the replenishment pump from doing useless work, thus saving energy.

[0098] Where K1>K2>K3, the lower limit value of the back pressure rate ΔP is set. 下1 <0< Set the upper limit value of back pressure rate ΔP 上1 .

[0099] This design enables precise adjustment of the replenishment flow rate. When the back pressure drops sharply, a large opening allows for rapid pressure replenishment; when the back pressure stabilizes, a small opening is maintained. This ensures timely pressure recovery while avoiding energy waste and overflow risks caused by excessive replenishment, thus optimizing system energy efficiency.

[0100] like Figure 8 As shown, to meet the differentiated needs under different ambient temperatures, the switching states of the heating pipe 42, the first expansion tank 30, and the second expansion tank 40 are adjusted according to the ambient temperature T1, specifically including a segmented control strategy.

[0101] When T1 ≤ the set lower limit temperature T 设1 (For example, at -35℃) the ambient temperature is extremely low, the viscosity of the ethylene glycol solution increases dramatically and its fluidity is extremely poor. At this time, the first expansion tank 30 and the second expansion tank 40 are turned on to supply liquid, the secondary pressurization pump 50 on the pressure regulating pipeline 60 is turned on, and the heating pipeline 42 is turned on to introduce the residual heat of the return liquid. By connecting the two tanks in parallel, the effective liquid replenishment volume is increased. With the combined effect of secondary pressurization and heating, the resistance of low temperature viscosity is forcibly overcome, ensuring that the inlet of the liquid supply pump 100 maintains positive pressure, thus solving the liquid replenishment problem under extremely cold conditions.

[0102] When the lower limit temperature T is set 设1 <T1≤Set Low Temperature T 设2 (For example, at -20℃), the first expansion tank 30 and the second expansion tank 40 are turned on to supply liquid, the secondary pressurization pump 50 on the pressure regulating pipeline 60 is turned on, and the heating pipeline 42 is turned off. This is because as the temperature rises, the fluidity of the coolant has naturally improved, and the liquid replenishment needs can be met without additional consumption of return liquid heat energy. By maintaining liquid replenishment in both tanks and moderate frequency conversion pressurization, the back pressure is kept stable while avoiding unnecessary energy consumption caused by heating.

[0103] When the low temperature T is set 设2 <T1≤Set upper limit temperature T 设3 When the liquid supply is turned on, the first expansion tank 30 and the second expansion tank 40 are turned on, the secondary pressurization pump 50 on the pressure regulating pipeline 60 is turned off, and the heating pipeline 42 is turned off.

[0104] When T1 > the set upper limit temperature T 设3 At this time, open the first expansion tank 30, close the secondary pressurization pump 50 on the pressure regulating pipeline 60, and close the second expansion tank 40 and the heating pipeline 42;

[0105] Among them, T 设1 <T 设2 <0<T 设3 .

[0106] This design solves the challenge of adaptability to replenishment under different ambient temperatures. At low temperatures, both tanks operate simultaneously and are heated; at high temperatures, only one tank operates and heating is stopped. This ensures fluidity during replenishment at low temperatures while avoiding ineffective energy consumption at high temperatures, achieving efficient and energy-saving operation across the entire temperature range. Specific temperature thresholds can be found in the implementation example; for instance, if P1 ≤ the set back pressure P... 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 If T1 ≤ -35℃, then the heating pipe 42 needs to be fully opened to utilize the residual heat from the return liquid to heat the second expansion tank 40; if P1 ≤ the set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate. 下1 ≤ΔP≤ Set upper limit value of back pressure rate ΔP 上1 If T1≤-35℃, the heating pipe 42 needs to be partially opened to utilize the residual heat from the return liquid to heat the second expansion tank 40.

[0107] The power on / off control method for the expansion tanks has also been optimized based on the rate of pressure change. Adjusting the on / off states of the heating pipe 42, the first expansion tank 30, and the second expansion tank 40 according to the ambient temperature T1 also includes:

[0108] like Figure 9 As shown, if P1 ≤ set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 If the system back pressure is extremely low and is dropping at a dangerous rate, a large flow of medium is urgently needed to quickly curb the decline. At this time, the corresponding expansion tank should be opened by continuously energizing the system, keeping the valve fully open, opening up the maximum flow area of ​​the liquid replenishment channel, allowing the coolant to be injected into the system at the fastest speed, quickly raising the back pressure, and preventing the liquid supply pump from triggering low pressure protection or cavitation due to the low inlet pressure.

[0109] like Figure 10 As shown, if P1 ≤ set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate.下1 If the value is ≤ΔP, it indicates that although the system back pressure is low, it has become stable and only a small amount of replenishment is needed to maintain the balance. The corresponding expansion tank is opened by pulse energizing, and the high-frequency switching valve is used to simulate "drip" replenishment. This avoids pressure oscillation or overflow caused by excessive replenishment due to continuous large valve opening, and achieves micron-level precise stabilization of back pressure.

[0110] This design optimizes fluid replenishment accuracy and energy consumption. Continuous energization is used for rapid pressure recovery from a fall, while pulsed energization is used for precise pressure maintenance. This "fast-slow combination" control method effectively prevents over- or under-replenishment of fluid, improving the stability of system control. Specific pulse parameters can be set according to actual usage requirements. For example, the water valves of both expansion tanks can be pulsed and energized in a manner that opens for t1 seconds and closes for t2 seconds in each operating cycle. The range of t1 and t2 is 0-60 seconds and are independently settable values.

[0111] Furthermore, the control of the heating pipe 42 can also be optimized based on the rate of pressure change. Adjusting the on / off states of the heating pipe 42, the first expansion tank 30, and the second expansion tank 40 according to the ambient temperature T1 also includes:

[0112] If P1 ≤ the set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 This indicates that the system back pressure is extremely low and is decreasing at a dangerous rate, urgently requiring a large flow of medium to quickly curb the decline. Under this condition, when T1 ≤ the set lower limit temperature T 设1 (For example, at -35℃) the ambient temperature is extremely low, the viscosity of the ethylene glycol solution increases dramatically and its fluidity is extremely poor. The heating valve 43 of the fully open heating pipe 42 introduces the residual heat of the return liquid, and rapidly increases the temperature of the coolant in the second expansion tank 40 by maximizing the heat exchange flow, which greatly reduces the viscosity, thereby releasing the liquid volume "locked" by the low temperature and improving the pumping efficiency. In conjunction with the continuously energized expansion tank valve, rapid and powerful pressure replenishment is achieved in extremely cold environments.

[0113] If P1 ≤ the set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate. 下1 ≤ΔP≤ Set upper limit value of back pressure rate ΔP 上1 This indicates that although the system back pressure is low, it has stabilized and only a small amount of replenishment is needed to maintain balance. Under this condition, when T1 ≤ the set lower limit temperature T 设1 At temperatures as low as -35°C, the viscosity of the ethylene glycol solution increases dramatically and its fluidity is extremely poor. The heating valve 43 of the partially open heating pipe 42 introduces residual heat from the return liquid. By precisely controlling the heating power, the fluidity of the liquid in the second expansion tank 40 is maintained while preventing excessive vaporization of the coolant that could lead to air blockage. In conjunction with the pulse-energized expansion tank valve, precise pressure stabilization and energy-saving operation are achieved in low-temperature environments.

[0114] This design achieves a precise match between heating power and dynamic pressure requirements. It provides full heating power during back pressure drops and uses semi-heating for fine adjustment when back pressure is stable. This solves the problems of poor liquid replenishment and "false low pressure" caused by the viscosity of the liquid in extremely cold environments, and avoids system overpressure or energy waste caused by overheating. It further improves the system's survivability and energy efficiency ratio under extreme low temperatures.

[0115] like Figure 11 As shown, the fluid replenishment control method incorporates a safety self-check and leakage prediction mechanism at the initial startup stage, with the specific logic as follows:

[0116] Before detecting the back pressure P1 at the inlet of the liquid supply pump 100 and calculating the rate of change of the back pressure ΔP, the leakage rate V1 of the liquid replenishment system is detected first.

[0117] If V1 > set rate V0, it indicates that the system has experienced a pipe burst or serious leakage, and the conventional replenishment capacity is no longer able to maintain the system pressure. At this time, the emergency replenishment process is initiated. The bypass line 70 is opened, the pressure regulating line 60 and the heating line 42 are closed, and the emergency back pressure pump 80 on the bypass line 70 is turned on to perform forced high-flow replenishment. At the same time, the system reports fault information to the user, reminds them to find the leak, and displays the remaining emergency operating time of the unit, thereby buying time for maintenance personnel to repair in extreme cases and preventing the system from collapsing instantly.

[0118] If V1 ≤ set rate V0, it indicates that the system is well sealed and within the normal leakage range. At this time, the pressure adjustment and liquid replenishment process is initiated. The bypass line 70 is closed, the emergency back pressure pump 80 on the bypass line 70 is closed, and then the steps of detecting the back pressure P1 at the inlet of the liquid supply pump 100 and calculating the rate of change of the back pressure ΔP are executed.

[0119] In the event of a severe leak such as a burst pipe, this design allows the system to quickly switch to a high-flow emergency mode and alert the user for maintenance, preventing system failure due to insufficient conventional fluid replenishment capacity and enhancing the system's fault tolerance and safety. Before formal operation, the system also performs self-checks on the fluid supply pump, back pressure pump, various valves, and sensors to ensure that the components are fault-free and that the detection accuracy meets requirements, thereby further guaranteeing the reliable execution of the entire control process.

[0120] To facilitate understanding, the fluid replenishment control method will be described in detail using application examples of the present invention.

[0121] When the liquid cooling unit is started up, the back pressure P1 at the inlet of the liquid supply pump 100 is detected by real-time monitoring of the system's leakage rate V1.

[0122] Determine if V1 ≤ set rate V0. If yes, close the bypass line 70, close the emergency back pressure pump 80 on the bypass line 70, and execute the pressure regulation and liquid replenishment process. If no, execute the emergency liquid replenishment process, open the bypass line 70, close the pressure regulating line 60 and the heating line 42, and turn on the emergency back pressure pump 80 on the bypass line 70.

[0123] The pressure regulation and fluid replenishment procedure is as follows:

[0124] Determine if P1 ≤ set back pressure P 设定1 If not, it means that the system back pressure is not low and there is no need to add liquid for the time being. The pressure regulating valve 61 of the pressure regulating line 60 and the heating valve 43 of the heating line 42 are both closed. If yes, then operate according to the following logic.

[0125] 1. If P1 ≤ set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 At this time, the back pressure is low and the rate of back pressure decrease is fast. The pressure regulating valve 61 of the pressure regulating pipeline 60 opens to the set maximum opening degree K1, and the ambient temperature T1 of the liquid replenishment system is monitored in real time for segmented control:

[0126] When T1 ≤ the set lower limit temperature T 设1 At this time, the ambient temperature is extremely low, and the pressure of the corresponding ethylene glycol solution in the expansion tank is very low. Simultaneously, ethylene glycol, due to its high viscosity, makes replenishment difficult. To ensure rapid replenishment and increase back pressure, the first water valve 31 of the first expansion tank 30 and the second water valve 41 of the second expansion tank 40 are continuously energized, ensuring that both expansion tanks are connected to the supply pipeline. By fully opening the heating valve 43 of the heating pipeline 42, a portion of the coolant from the return pipeline 120 is drawn to heat the second expansion tank 40, thereby increasing the system pressure of the second expansion tank 40. Then, the secondary replenishment pump 50 is activated at its rated speed to rapidly increase the back pressure, ensuring that the inlet pressure of the supply pump 100 is positive, thus achieving rapid and stable operation. At this time, both expansion tanks participate in system replenishment simultaneously.

[0127] When the lower limit temperature T is set 设1 <T1≤Set Low Temperature T 设2 At this time, the ambient temperature is very low, and the pressure of the ethylene glycol solution in the expansion tank is relatively low. Simultaneously, due to the high viscosity of the low-temperature ethylene glycol solution, the replenishment rate is slow. By continuously energizing and opening the first water valve 31 of the first expansion tank 30 and the second water valve 41 of the second expansion tank 40, the secondary replenishment pump 50 is activated and runs at 80% of its rated frequency to rapidly increase the back pressure. At this time, both expansion tanks participate in system replenishment simultaneously, and the heating valve 43 of the heating pipeline 42 is closed.

[0128] When the low temperature T is set 设2 <T1≤Set upper limit temperature T 设3At this time, the ambient temperature is relatively suitable, and the replenishment rate of the ethylene glycol solution in the expansion tank meets the requirements. By continuously energizing and opening the first water valve 31 of the first expansion tank 30 and the second water valve 41 of the second expansion tank 40, stable replenishment is achieved and the back pressure is steadily increased. At this time, both expansion tanks participate in the system replenishment simultaneously, the heating valve 43 of the heating pipeline 42 is closed, and the secondary pressurization pump 50 is not working.

[0129] When T1 > the set upper limit temperature T 设3 At this time, the ambient temperature is relatively high, and the ethylene glycol pressure inside the expansion tank is high. Stable replenishment is achieved by continuously energizing and opening the first water valve 31 of the first expansion tank 30. At this point, one expansion tank participates in the system replenishment, the heating valve 43 of the heating pipeline 42 is closed, and the secondary pressurization pump 50 is not operating.

[0130] 2. If P1 ≤ set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate. 下1 ≤ΔP≤ Set upper limit value of back pressure rate ΔP 上1 At this point, the back pressure is relatively low, but the back pressure value remains basically unchanged. The pressure regulating valve 61 of the pressure regulating pipeline 60 is opened to the set high opening degree K2, and the ambient temperature T1 of the liquid replenishment system is monitored in real time for segmented control.

[0131] When T1 ≤ the set lower limit temperature T 设1 When the pulse is energized, the first water valve 31 of the first expansion tank 30 and the second water valve 41 of the second expansion tank 40 are opened, ensuring that both expansion tanks are connected to the liquid supply line. The heating valve 43 of the heating line 42 is partially opened, drawing a small amount of coolant from the return line 120 to heat the second expansion tank 40, thereby increasing the system pressure of the second expansion tank 40. Then, the secondary liquid addition pump 50 is turned on and operates at 60% of its rated frequency. At this time, both expansion tanks participate in system liquid replenishment simultaneously.

[0132] When the lower limit temperature T is set 设1 <T1≤Set Low Temperature T 设2 When the pulse is energized, the first water valve 31 of the first expansion tank 30 and the second water valve 41 of the second expansion tank 40 are opened, and the secondary liquid addition pump 50 is started and operates at 50% of its rated frequency. At this time, both expansion tanks participate in system liquid replenishment simultaneously, and the heating valve 43 of the heating pipeline 42 is closed;

[0133] When the low temperature T is set 设2 <T1≤Set upper limit temperature T 设3 When the pulse is energized, the first water valve 31 of the first expansion tank 30 and the second water valve 41 of the second expansion tank 40 are opened to achieve stable liquid replenishment and ensure stable back pressure. At this time, both expansion tanks participate in system liquid replenishment simultaneously, the heating valve 43 of the heating pipeline 42 is closed, and the secondary pressurization pump 50 does not work;

[0134] When T1 > the set upper limit temperature T 设3 At this time, the ethylene glycol pressure in the first expansion tank 30 is relatively high. The first water valve 31 of the first expansion tank 30 is opened via a pulse to ensure stable liquid replenishment. At this point, one expansion tank participates in system liquid replenishment, the heating valve 43 of the heating pipeline 42 is closed, and the secondary pressurization pump 50 is not operating.

[0135] 3. If P1 ≤ set back pressure P 设定1 And ΔP > the set upper limit value of back pressure rate ΔP 上1 This indicates that although the back pressure is low at this time, the back pressure value is slowly rising. The pressure regulating valve 61 of the pressure regulating pipeline 60 is opened to the set mid-position opening degree K3, and the pulse opens the first water valve 31 of the first expansion tank 30 to replenish the liquid at constant pressure, ensuring the stability of the liquid supply system. At this time, one expansion tank participates in the system liquid replenishment, the heating valve 43 of the heating pipeline 42 is closed, and the secondary pressurization pump 50 does not work.

[0136] Among them, the lower limit temperature T is set. 设1 Set the lower limit temperature T 设2 Set the lower limit temperature T 设3 The temperatures are -35℃, -20℃, and 20℃, respectively. The maximum opening K1, the high-position opening K2, and the middle-position opening K3 are set to 100%, 75%, and 50% opening, respectively. These values ​​are for illustrative purposes only, and the settings in this article can be designed according to actual usage requirements.

[0137] It should be noted that the terminology used above is for describing specific embodiments only and is not intended to limit the exemplary embodiments of the present invention. When the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. The order of execution of actions, steps, etc., in the apparatus and methods shown in the specification and drawings may be implemented in any order unless a specific express order is specified, and as long as the output of a previous process is not used in a subsequent process. Similar sequential terms used for ease of description do not imply that such an order must be followed.

[0138] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as constraints. 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.

[0139] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A variable-volume replenishment system, characterized in that, include: The refrigeration module is used to supply coolant; The liquid supply and return module includes a liquid supply pump, a liquid supply pipeline and a liquid return pipeline. The liquid supply pipeline is connected to the outlet of the refrigeration module, and the liquid return pipeline is connected to the inlet of the refrigeration module. The liquid supply pump is installed on the liquid return pipeline. The replenishment unit includes a water tank, a pressure regulating pipeline, a first expansion tank, and a second expansion tank. The pressure regulating pipeline is connected between the outlet of the water tank and the inlet of the liquid supply pump. The first expansion tank and the second expansion tank are connected in parallel on the pressure regulating pipeline, and the liquid output of the first expansion tank and the second expansion tank can be adjusted independently. A heating pipe is used to provide heat to the second expansion tank. Both ends of the heating pipe are connected to the return pipe, and the heating pipe passes through the second expansion tank.

2. The fluid replenishment system according to claim 1, characterized in that, The replenishment unit further includes a secondary pressurization pump installed on the pressure regulating pipeline, the first expansion tank and the second expansion tank being connected in parallel to the inlet of the secondary pressurization pump, and the outlet of the secondary pressurization pump being connected to the inlet of the supply pump through the replenishment pipeline.

3. The fluid replenishment system according to claim 2, characterized in that, The replenishment unit also includes a bypass pipeline and an emergency back pressure pump. The bypass pipeline is connected in parallel with the pressure regulating pipeline, and the emergency back pressure pump is installed on the bypass pipeline.

4. The fluid replacement system according to any one of claims 1 to 3, characterized in that, Also includes: Back pressure sensor and ambient temperature sensor; The back pressure sensor is used to detect the back pressure P1 at the inlet of the liquid supply pump; The ambient temperature sensor is used to detect the ambient temperature T1.

5. The fluid replenishment system according to claim 4, characterized in that, Also includes: A leakage sensor is used to detect the amount of leakage, and the leakage sensor is installed on the liquid supply line and the liquid return line.

6. A fluid rehydration control method, employing the fluid rehydration system according to any one of claims 1 to 5, characterized in that, include: The back pressure P1 at the inlet of the liquid supply pump is detected and the rate of change of the back pressure ΔP is calculated. If P1 ≤ the set back pressure P 设定1 And ΔP ≤ the set upper limit value of back pressure rate ΔP 上1 Then, the pressure regulating pipeline is opened, and the switching status of the heating pipeline, the first expansion tank, and the second expansion tank is adjusted according to the ambient temperature T1. If P1 ≤ the set back pressure P 设定1 And ΔP > the set upper limit value of back pressure rate ΔP 上1 Then, open the pressure regulating pipeline, start the liquid supply to the first expansion tank, and close the heating pipeline and the second expansion tank; If P1 > set back pressure P 设定1 If the pressure regulating pipeline is shut off, the liquid supply to the first expansion tank, the heating pipeline, and the second expansion tank will also be shut off.

7. The fluid replacement control method according to claim 6, characterized in that, Also includes: If P1 ≤ the set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 Then the pressure regulating valve of the pressure regulating pipeline opens to the set maximum opening degree K1; If P1 ≤ the set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate. 下1 ≤ΔP≤ Set upper limit value of back pressure rate ΔP 上1 Then the pressure regulating valve of the pressure regulating pipeline opens to the set high opening degree K2; If P1 ≤ the set back pressure P 设定1 And ΔP > the set upper limit value of back pressure rate ΔP 上1 Then the pressure regulating valve of the pressure regulating pipeline opens to the set mid-position opening degree K3; If P1 > set back pressure P 设定1 If so, the pressure regulating valve of the pressure regulating pipeline will be closed; Where K1>K2>K3, the lower limit value of the back pressure rate ΔP is set. 下1 <0< Set the upper limit of back pressure rate ΔP 上1 .

8. The fluid replacement control method according to claim 6, characterized in that, Adjusting the on / off states of the heating pipeline, the first expansion tank, and the second expansion tank according to the ambient temperature T1 includes: When T1 ≤ the set lower limit temperature T 设1 At that time, the first expansion tank and the second expansion tank are turned on to supply liquid, the secondary pressurization pump on the pressure regulating pipeline is turned on, and the heating pipeline is turned on; When the lower limit temperature T is set 设1 <T1≤Set low temperature T 设2 When the liquid supply to the first expansion tank and the second expansion tank is turned on, the secondary pressurization pump on the pressure regulating pipeline is turned on, and the heating pipeline is turned off; When the low temperature T is set 设2 <T1≤Set upper limit temperature T 设3 When the liquid supply to the first expansion tank and the second expansion tank is turned on, the secondary pressurization pump on the pressure regulating pipeline is turned off, and the heating pipeline is turned off; When T1 > the set upper limit temperature T 设3 When the time comes, open the first expansion tank, close the secondary pressurization pump on the pressure regulating pipeline, and close the second expansion tank and the heating pipeline; Among them, T 设1 <T 设2 <0<T 设3 .

9. The fluid replacement control method according to claim 8, characterized in that, Adjusting the on / off states of the heating pipeline, the first expansion tank, and the second expansion tank according to the ambient temperature T1 also includes: If P1 ≤ the set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 The corresponding expansion tank will be opened by continuously supplying electricity. If P1 ≤ the set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate. 下1 If the value is less than or equal to ΔP, the corresponding expansion tank will be opened by pulse energizing.

10. The fluid replacement control method according to claim 9, characterized in that, Adjusting the on / off states of the heating pipeline, the first expansion tank, and the second expansion tank according to the ambient temperature T1 also includes: If P1 ≤ the set back pressure P 设定1 And ΔP < the set lower limit value of back pressure rate ΔP 下1 Then when T1 ≤ the set lower limit temperature T 设1 At that time, the heating pipes are fully opened; If P1 ≤ the set back pressure P 设定1 And set a lower limit value ΔP for the back pressure rate. 下1 ≤ΔP≤ Set upper limit value of back pressure rate ΔP 上1 Then when T1 ≤ the set lower limit temperature T 设1 At that time, the heating pipe is partially open.

11. The fluid replacement control method according to claim 6, characterized in that, Also includes: Before detecting the back pressure P1 at the inlet of the liquid supply pump and calculating the rate of change of the back pressure ΔP, the leakage rate V1 of the liquid replenishment system is detected first. If V1 > set rate V0, then open the bypass line of the pressure regulating line, close the pressure regulating line and the heating line, and turn on the emergency back pressure pump on the bypass line. If V1 ≤ set rate V0, then close the bypass line of the pressure regulating line, close the emergency back pressure pump on the bypass line, and then perform the steps of detecting the back pressure P1 at the inlet of the liquid supply pump and calculating the rate of change of the back pressure ΔP.

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