A long-time heat storage and heat preservation system and method based on data center waste heat recovery

Abstract

The application relates to the technical field of heat storage and heat preservation, and discloses a long-time heat storage and heat preservation system and method based on data center waste heat recovery, which comprises the following steps: transferring data center heat to a heat carrier fluid through waste heat exchange; distributing heat of the heat carrier fluid, wherein the heat exchange priority of domestic hot water is higher than that of peripheral heat preservation circulation; judging the demand for domestic hot water according to water taking flow and water storage temperature, performing domestic hot water heat exchange when the demand is established, otherwise, starting the peripheral heat preservation circulation when the waste heat recovery is running; adjusting the circulation flow according to the waste heat supply, the tank temperature and the environment temperature when the heat storage tank is static; and switching to domestic hot water heat exchange or waste heat discharge when the shutdown condition is met. The application actively performs peripheral heat preservation on the heat storage tank through data center waste heat, solves the problem of heat loss accumulation in the static stage, realizes graded utilization of waste heat, and reduces the heat attenuation risk.

Description

Technical Field

[0001] This invention relates to the field of thermal energy storage and insulation technology, and more specifically, to a long-term thermal energy storage and insulation system and method based on waste heat recovery from data centers. Background Technology

[0002] Phase change thermal energy storage (PCE) technology utilizes the absorption or release of latent heat by phase change materials during solid-liquid phase change processes to achieve the storage and reuse of thermal energy. Compared to sensible heat storage, PCE has advantages such as higher heat storage capacity per unit volume, more stable heat storage and release temperature plateaus, and easier modular integration of the system. It has been applied in areas such as building heating and domestic hot water, peak shaving of solar and heat pump systems, and waste heat recovery in industrial processes. To address inter-period demands beyond intraday regulation, long-term PCE devices for weekly, monthly, and even seasonal scales are gradually emerging. These devices typically include a PCE storage unit, a heat exchange unit, a circulation loop, and an insulation structure. After heat storage is completed, the device enters a static storage phase, releasing heat only when heat demand arises.

[0003] The main problem with long-term phase change thermal energy storage devices during the static storage phase is the significant accumulation of heat loss. The static phase is prolonged, and a temperature difference exists between the storage unit and the external environment. Heat is transferred outwards through multiple pathways, including conduction through the tank walls, convective heat transfer on the outer surface, surface radiation, and thermal bridges formed by interfaces, supports, and pipe penetrations. Even with common insulation materials, limitations imposed by the material's thermal conductivity and construction and assembly factors still exist. For example, the insulation layer thickness is constrained by space and cost, making it difficult to increase indefinitely. Gaps, compression deformation, and moisture aging can cause localized degradation of insulation performance, and continuous heat transfer paths can easily appear at the connection between the outer shell and the pipes. These factors may not be noticeable in short-term operation, but they accumulate over long storage periods, causing the phase change material temperature to gradually deviate from the phase change temperature range. Some latent heat is released prematurely, ultimately resulting in a decrease in stored heat capacity, a shortened heat release duration, or an unstable heat output temperature plateau.

[0004] Furthermore, long-term phase change thermal energy storage devices often exhibit a separation of heat storage, resting, and heat release characteristics. During the resting phase, there is a lack of effective heat compensation and heat loss suppression methods, and the system can only rely on passive insulation structures to reduce heat dissipation. When the ambient temperature fluctuates significantly or the resting time increases, the marginal effect of passive insulation further decreases, making it difficult for the device to meet the heat retention requirements of cross-seasonal thermal energy storage. This limits the application effectiveness and economic efficiency of long-term phase change thermal energy storage technology in energy management scenarios on a larger timescale. Summary of the Invention

[0005] In view of this, the present invention proposes a long-term thermal storage and insulation system and method based on waste heat recovery from data centers, aiming to solve the problem that the heat loss of long-term phase change thermal storage devices is significant during the static storage stage after the completion of thermal storage, resulting in the decay of the stored heat.

[0006] In one aspect, the present invention proposes a long-term thermal storage and insulation method based on waste heat recovery from data centers, comprising: The waste heat exchange process is used to exchange heat with the cooling medium of the data center, and the heat obtained from the heat exchange is transferred to the heat transfer fluid. A heat distribution process is implemented for the heat transfer fluid, which includes a domestic hot water heat exchange process and an external insulation circulation process. The domestic hot water heat exchange process has a higher priority than the external insulation circulation process. The system acquires domestic hot water intake flow rate information and domestic hot water storage temperature information. Based on the domestic hot water intake flow rate information, domestic hot water storage temperature information, first threshold, second threshold, first set value, and second set value, the system determines the domestic hot water demand status. The first threshold is greater than the second threshold, and the second set value is greater than the first set value. When the domestic hot water demand is met, the heat distribution process selects the domestic hot water heat exchange process. The heat carrier fluid enters the domestic hot water heat exchange process and exchanges heat with the domestic hot water side fluid. The domestic hot water side fluid is driven to circulate by the domestic hot water circulation process. When the domestic hot water demand is not met and the waste heat recovery loop is in operation, the heat distribution process selects the external insulation circulation process. The heat-carrying fluid enters the external insulation circulation process and circulates in the external insulation structure loop. The external insulation structure loop is arranged around the periphery of the long-term phase change heat storage box and forms a closed loop. When the long-term phase change thermal storage tank is in a static state, the external insulation circulation process is kept in the open state, and the circulation flow rate of the external insulation circulation process is adjusted based on the collected waste heat recovery status information, external insulation temperature information and ambient temperature information. When the waste heat recovery loop meets the shutdown conditions or the external insulation circulation process meets the shutdown conditions, the external insulation circulation process is stopped, and the heat distribution process is switched to the domestic hot water heat exchange process or the waste heat discharge process.

[0007] Furthermore, when exchanging heat with the data center cooling medium through a waste heat exchange process, it includes: Acquire data center cooling medium inlet temperature information, data center cooling medium outlet temperature information, heat transfer fluid inlet temperature information, and heat transfer fluid outlet temperature information; During the start-up phase of the waste heat exchange process, a heat transfer fluid pre-circulation process is performed, which includes starting the heat transfer fluid circulation drive component and keeping the drive component in operation. The data center cooling medium inlet temperature information and data center cooling medium outlet temperature information are used to determine the data center cooling medium side temperature difference information, and the heat transfer fluid inlet temperature information and heat transfer fluid outlet temperature information are used to determine the heat transfer fluid side temperature difference information. The heat transfer fluid circulation volume is switched between several discrete cycle levels based on the temperature difference information. When the fluctuation judgment condition is met, a buffer transition process is executed. The fluctuation judgment condition includes the change of the heat transfer fluid outlet temperature information within a preset time window exceeding a preset change threshold. The buffer transition process includes gradually switching the heat transfer fluid circulation volume and simultaneously adjusting the bypass ratio within a preset transition period.

[0008] Furthermore, when performing a heat distribution process on the heat transfer fluid, it includes: When switching between the establishment of domestic hot water demand status and the non-establishment of domestic hot water demand status, an interlock control action is executed. The interlock control action includes closing the on / off valve group corresponding to the process to be exited and keeping the on / off valve group corresponding to the target process in the closed state. After the interlock control action, the heat transfer fluid is directed into the return path and a pressure balance determination is performed; After the pressure balance condition is met, open the on / off valve group corresponding to the target process and close the on / off valve group corresponding to the return path to enter the target process.

[0009] Furthermore, when assessing the demand for domestic hot water, the following factors are considered: The flow rate of domestic hot water intake is continuously sampled and the moving average value is calculated. The temperature of domestic hot water storage is continuously sampled and the moving average value is calculated. The state of domestic hot water demand is established when the sliding average value meets the criteria for establishing the domestic hot water demand state. If the sliding average value meets the condition that the domestic hot water demand state is not met, output "Domestic hot water demand state is not met". During the transition between the establishment of domestic hot water demand status and the non-establishment of domestic hot water demand status, a hold action is performed, which includes maintaining the original output status for a certain duration before the output status changes.

[0010] Furthermore, when the domestic hot water demand condition is met, the heat distribution process selects the domestic hot water heat exchange process. The heat transfer fluid enters the domestic hot water heat exchange process and exchanges heat with the domestic hot water side fluid. When the domestic hot water side fluid is driven to circulate by the domestic hot water circulation process, it includes: The domestic hot water circulation process is started and enters the acceleration phase, which includes gradually increasing the circulation volume from a low volume to a stable volume. During the stable circulation phase, the domestic hot water circulation volume is adjusted based on the changing trend of the domestic hot water storage temperature information. The adjustment actions include increasing the domestic hot water circulation volume when the temperature drop rate increases and decreasing the domestic hot water circulation volume when the temperature drop rate decreases. When the domestic hot water demand state changes from being established to not being established, the heat transfer fluid maintains a transitional circulation period within the domestic hot water heat exchange process and then exits the domestic hot water heat exchange process and enters the switching path of the heat distribution process. The transitional circulation period is limited by the transition duration parameter.

[0011] Furthermore, when the external insulation structure loop is arranged around the periphery of the long-term phase change thermal storage box and forms a closed loop, it includes: Open each loop of the outer insulation structure circuit in sequence according to the filling order, and vent air at the highest point of the circuit. During the operation of the external insulation circulation process, different loop segments of the external insulation structure circuit are connected sequentially according to time sequence, and the remaining loop segments are disconnected sequentially. When switching between adjacent loop segments in the partitioned circulation process, the circulation direction of the peripheral insulation structure loop is switched between forward and reverse circulation.

[0012] Furthermore, when the long-term phase change thermal storage tank is in a static state, maintaining the external insulation circulation process in an open state includes: The long-term phase change thermal storage tank is in a static state when the operating mode information indicates that it is not in the heat charging mode and not in the heat dissipation mode. The external insulation circulation maintenance process is executed in a static state. The external insulation circulation maintenance process includes continuous circulation mode and intermittent circulation mode. In the intermittent cyclic mode, the timing control process is executed. The timing control process includes starting the external insulation cycle process according to the running period and stopping the external insulation cycle process according to the rest period.

[0013] Furthermore, when adjusting the circulation flow rate of the external insulation circulation process based on the collected waste heat recovery status information, external insulation temperature information, and ambient temperature information, the following steps are taken: The temperature difference is determined based on the external insulation temperature information and the ambient temperature information. The waste heat supply status is determined based on the waste heat recovery status information. The waste heat supply status includes a sufficient waste heat status and a insufficient waste heat status. Under conditions of sufficient residual heat, the circulation flow rate of the external insulation circulation process is switched between multiple circulation flow rate levels based on the temperature difference. The multiple circulation flow rate levels are limited by a set of levels, which includes low, medium and high levels. When the residual heat is insufficient, the load reduction process is executed. The load reduction process includes reducing the circulation flow rate of the external insulation circulation process to a low level or switching the external insulation circulation process to an intermittent circulation mode.

[0014] Furthermore, when the waste heat recovery loop meets the shutdown conditions or the external insulation circulation process meets the shutdown conditions, the external insulation circulation process is stopped, and the heat distribution process is switched to the domestic hot water heat exchange process or the waste heat discharge process, including: The system acquires the outlet temperature and flow rate of the heat transfer fluid, and outputs a judgment result indicating whether the waste heat recovery loop meets the shutdown conditions based on the outlet temperature and flow rate of the heat transfer fluid. Acquire external insulation temperature information and ambient temperature information, and output the judgment result that the external insulation cycle process meets the shutdown conditions based on the external insulation temperature information and ambient temperature information; Before stopping the external insulation circulation process, a load reduction transition process is performed. The load reduction transition process includes reducing the circulation flow rate of the external insulation circulation process in a stepwise manner and stopping the external insulation circulation process after pressure balance is completed. After stopping the external heat preservation circulation process, a process switching action is performed. The process switching action includes switching the heat distribution process to the domestic hot water heat exchange process or switching the heat distribution process to the waste heat discharge process. The waste heat discharge process includes the heat transfer fluid entering the return path for circulation or the heat transfer fluid entering the heat dissipation path for circulation.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: Heat in the data center cooling medium is transferred to the heat transfer fluid through a waste heat exchange process. Priority scheduling is performed between the domestic hot water heat exchange process and the external insulation circulation process through a heat distribution process. This ensures that the heat transfer fluid enters the domestic hot water heat exchange process when domestic hot water demand is met, and enters the external insulation circulation process when domestic hot water demand is not met and the waste heat recovery loop is in operation. This forms a coordinated waste heat utilization path for both immediate heat use and long-term phase change heat storage tank external circulation. Furthermore, the domestic hot water demand status is determined based on domestic hot water intake flow rate information and domestic hot water storage temperature information, and a first threshold greater than a second threshold is set. The parameter relationship where the second set value is greater than the first set value improves the stability of the heat distribution process switching and reduces the risk of frequent switching; by maintaining the external insulation circulation process open when the phase change heat storage tank is in a static state for a long time, and adjusting the circulation flow of the external insulation circulation process based on the waste heat recovery status information, external insulation temperature information and ambient temperature information, the external insulation circulation process can adapt to changes in waste heat supply level and ambient temperature; by stopping the external insulation circulation process and switching to the domestic hot water heat exchange process or waste heat discharge process when the waste heat recovery loop meets the shutdown conditions or the external insulation circulation process meets the shutdown conditions, the operation and switching of the waste heat recovery loop have a controllable exit path.

[0016] On the other hand, this application also provides a long-term thermal storage and insulation system based on data center waste heat recovery, used to implement the above-mentioned long-term thermal storage and insulation method based on data center waste heat recovery, including: The waste heat exchange module is configured to exchange heat with the data center cooling medium through a waste heat exchange process, and transfer the heat obtained from the heat exchange to the heat transfer fluid. The heat distribution module is configured to perform a heat distribution process on the heat transfer fluid. The heat distribution process includes a domestic hot water heat exchange process and an external insulation circulation process. The domestic hot water heat exchange process has a higher priority than the external insulation circulation process. The demand determination module is configured to obtain the domestic hot water intake flow rate information and the domestic hot water storage temperature information, and to determine the domestic hot water demand status based on the domestic hot water intake flow rate information, the domestic hot water storage temperature information, the first threshold, the second threshold, the first set value and the second set value, wherein the first threshold is greater than the second threshold and the second set value is greater than the first set value. The domestic hot water heat exchange module is configured such that when the domestic hot water demand is met, the heat distribution process selects the domestic hot water heat exchange process, the heat carrier fluid enters the domestic hot water heat exchange process and exchanges heat with the domestic hot water side fluid, and the domestic hot water side fluid is driven to circulate by the domestic hot water circulation process. The external insulation circulation module is configured to select the external insulation circulation process when the domestic hot water demand is not met and the waste heat recovery loop is in operation. The heat-carrying fluid enters the external insulation circulation process and circulates in the external insulation structure loop. The external insulation structure loop is arranged around the periphery of the long-term phase change heat storage box and forms a closed loop. The static adjustment module is configured to keep the external insulation circulation process in the open state when the long-term phase change thermal storage box is in a static state, and adjust the circulation flow rate of the external insulation circulation process based on the collected waste heat recovery status information, external insulation temperature information and ambient temperature information. The shutdown switching module is configured to stop the external heat insulation circulation process and switch the heat distribution process to the domestic hot water heat exchange process or the waste heat discharge process when the waste heat recovery loop meets the shutdown conditions or the external heat insulation circulation process meets the shutdown conditions.

[0017] It is understandable that the aforementioned long-term thermal storage and insulation system and method based on data center waste heat recovery has the same beneficial effects, and will not be elaborated further here. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart illustrating a long-term thermal storage and insulation method based on waste heat recovery from a data center, provided as an embodiment of the present invention; Figure 2 This is a functional block diagram of a long-term thermal storage and insulation system based on waste heat recovery from a data center, provided as an embodiment of the present invention. Detailed Implementation

[0019] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] See Figure 1 As shown, this application proposes a long-term thermal storage and insulation method based on waste heat recovery from data centers, including: S1: Heat is exchanged between the cooling medium of the data center through a waste heat exchange process, and the heat obtained from the heat exchange is transferred to the heat transfer fluid. S2: Perform a heat distribution process on the heat transfer fluid. The heat distribution process includes a domestic hot water heat exchange process and an external insulation circulation process. The domestic hot water heat exchange process has a higher priority than the external insulation circulation process. S3: Obtain the domestic hot water intake flow rate and domestic hot water storage temperature information, and determine the domestic hot water demand status based on the domestic hot water intake flow rate, domestic hot water storage temperature information, first threshold, second threshold, first set value and second set value, wherein the first threshold is greater than the second threshold and the second set value is greater than the first set value. S4: When the domestic hot water demand state is established, the heat distribution process selects the domestic hot water heat exchange process. The heat carrier fluid enters the domestic hot water heat exchange process and exchanges heat with the domestic hot water side fluid. The domestic hot water side fluid is driven to circulate by the domestic hot water circulation process. S5: When the domestic hot water demand is not met and the waste heat recovery loop is in operation, the heat distribution process selects the external insulation circulation process. The heat carrier fluid enters the external insulation circulation process and circulates in the external insulation structure loop. The external insulation structure loop is arranged around the periphery of the long-term phase change heat storage box and forms a closed loop. S6: When the long-term phase change thermal storage box is in a static state, the external insulation circulation process is kept in the open state, and the circulation flow rate of the external insulation circulation process is adjusted based on the collected waste heat recovery status information, external insulation temperature information and ambient temperature information. S7: When the waste heat recovery loop meets the shutdown conditions or the external insulation circulation process meets the shutdown conditions, stop the external insulation circulation process and switch the heat distribution process to the domestic hot water heat exchange process or the waste heat discharge process.

[0021] Specifically, the waste heat exchange process is used to realize heat exchange between the data center cooling medium and the heat transfer fluid within the waste heat exchange unit. The data center cooling medium is the circulating medium in the data center cooling loop, and the heat transfer fluid is the circulating medium in the waste heat recovery loop. The waste heat recovery loop being in operation indicates that the heat transfer fluid circulation drive component is in operation, the heat transfer fluid outlet temperature is not lower than the minimum waste heat utilization temperature, and the heat transfer fluid flow rate is not lower than the minimum circulation flow rate. The minimum waste heat utilization temperature limits the minimum usable output temperature of the waste heat recovery loop and can be between 25 and 45°C. The minimum circulation flow rate limits the minimum stable circulation volume of the waste heat recovery loop and can be 0.2 to 0.5 times the rated flow rate of the heat transfer fluid circulation drive component. The heat distribution process is used to select the flow path of the heat transfer fluid between the domestic hot water heat exchange process and the external insulation circulation process. The domestic hot water heat exchange process has a higher priority than the external insulation circulation process, meaning that the domestic hot water flow enters when the domestic hot water demand is met. The heat exchange process is maintained while the external insulation circulation process is not in operation. When the domestic hot water demand is not met and the waste heat recovery loop is in operation, the external insulation circulation process is entered while the domestic hot water heat exchange process is maintained while the domestic hot water demand is not in operation. The domestic hot water demand is determined based on the domestic hot water intake flow rate and the domestic hot water storage temperature. The domestic hot water intake flow rate represents the amount of domestic hot water taken out per unit time, and the domestic hot water storage temperature represents the water temperature level at the domestic hot water storage end. The first threshold and the second threshold are used to limit the intake flow rate judgment range and ensure that the first threshold is greater than the second threshold. The first set value and the second set value are used to limit the storage temperature judgment range and ensure that the second set value is greater than the first set value. The first threshold and the second threshold are adjusted during the system debugging phase based on the maximum designed intake flow rate and the minimum guaranteed intake flow rate of the domestic hot water side. For example, the first threshold is 0.6 to 0.9 times the maximum designed intake flow rate, and the second threshold is 0.2 to 0.Five times the target domestic hot water supply temperature. The first and second setpoints are adjusted during the system commissioning phase based on the target domestic hot water supply temperature and the allowable temperature fluctuation range. For example, the first setpoint is the target domestic hot water supply temperature minus 5-15℃, and the second setpoint is the target domestic hot water supply temperature minus 0-5℃. When the domestic hot water demand is met, the heat transfer fluid and the domestic hot water side fluid exchange heat in the domestic hot water heat exchange unit. The domestic hot water circulation process drives the domestic hot water side fluid to circulate in the heat exchange loop. When the domestic hot water demand is not met and the waste heat recovery loop is in operation, the heat transfer fluid enters... The external insulation structure loop is a closed-loop channel surrounding the periphery of the long-term phase change thermal storage tank, and can be in the form of a sandwiched flow channel or a coiled flow channel. When the long-term phase change thermal storage tank is in a static state, it indicates that the tank is not performing the heat charging or heat release processes. This static state is determined by the operating mode information, which is determined by a combination of heat charging execution signals, heat release execution signals, valve opening / closing status information, or the operating status information of the circulation drive components. In the static state, the external insulation circulation process remains open and operates based on waste heat recovery status information and external insulation temperature information. The circulation flow rate of the external insulation circulation process is adjusted based on ambient temperature information. The circulation flow rate is adjusted using discrete levels: low, medium, and high. These levels correspond to the low, medium, and high speed ranges of the external insulation circulation drive component, respectively. The waste heat recovery loop meets shutdown conditions including: the outlet temperature of the heat transfer fluid is lower than the minimum waste heat utilization temperature and remains there for at least a duration specified by the shutdown confirmation time parameter; or the flow rate of the heat transfer fluid is lower than the minimum circulation flow rate and remains there for at least a duration specified by the shutdown confirmation time parameter. The process meets the shutdown conditions if the temperature difference between the external insulation temperature and the ambient temperature is less than the first temperature difference boundary parameter and remains continuously for a duration not less than the duration defined by the shutdown confirmation time parameter. This shutdown confirmation time parameter is adjusted during system commissioning based on the short-term fluctuations of the heat transfer fluid outlet temperature and flow rate, as well as the fluctuation range of the external insulation temperature, and can be taken as 30–600 seconds. When the shutdown conditions are met, the external insulation circulation process is stopped and a process switch is executed. The waste heat discharge process includes either the heat transfer fluid entering the return path or the heat transfer fluid entering the heat dissipation path.

[0022] In some embodiments of this application, when exchanging heat with the data center cooling medium through a waste heat exchange process, the following steps are included: Acquire data center cooling medium inlet temperature information, data center cooling medium outlet temperature information, heat transfer fluid inlet temperature information, and heat transfer fluid outlet temperature information; During the start-up phase of the waste heat exchange process, a heat transfer fluid pre-circulation process is performed, which includes starting the heat transfer fluid circulation drive component and keeping the drive component in operation. The data center cooling medium inlet temperature information and data center cooling medium outlet temperature information are used to determine the data center cooling medium side temperature difference information, and the heat transfer fluid inlet temperature information and heat transfer fluid outlet temperature information are used to determine the heat transfer fluid side temperature difference information. The heat transfer fluid circulation volume is switched between several discrete cycle levels based on the temperature difference information. When the fluctuation judgment condition is met, a buffer transition process is executed. The fluctuation judgment condition includes the change of the heat transfer fluid outlet temperature information within a preset time window exceeding a preset change threshold. The buffer transition process includes gradually switching the heat transfer fluid circulation volume and simultaneously adjusting the bypass ratio within a preset transition period.

[0023] Specifically, the inlet and outlet temperatures of the data center cooling medium are used to characterize the temperature change of the cooling medium before and after the waste heat exchange unit. Similarly, the inlet and outlet temperatures of the heat transfer fluid are used to characterize the temperature change of the heat transfer fluid before and after the waste heat exchange unit. This temperature information is collected by the temperature acquisition unit at a fixed sampling period and input to the controller. The heat transfer fluid pre-circulation process is used to establish continuous flow of the heat transfer fluid within the waste heat recovery loop during the initial stage of the waste heat exchange process. This pre-circulation process includes starting the heat transfer fluid circulation drive component and maintaining it in operation. The duration of the pre-circulation is limited by the pre-circulation transition time parameter, which is determined during system debugging based on the waste heat recovery loop volume and the heat transfer fluid circulation volume. The pre-circulation transition time parameter is taken as one to three fluid replacement times corresponding to the waste heat recovery loop volume, where the fluid replacement time is the ratio of the waste heat recovery loop volume to the heat transfer fluid circulation volume during the pre-circulation stage. The temperature difference information on the data center cooling medium side is obtained from the inlet and outlet temperatures of the data center cooling medium. The difference in information is obtained by comparing the heat transfer fluid outlet temperature with the heat transfer fluid inlet temperature. The controller switches the heat transfer fluid circulation rate between several discrete cycle levels based on the temperature difference between the data center cooling medium and the heat transfer fluid. The discrete cycle levels are used to divide the heat transfer fluid circulation rate into multiple selectable operating levels. The set of discrete cycle levels can include low, medium, and high levels, which correspond to the low, medium, and high speed ranges of the heat transfer fluid circulation drive component, respectively. The set of levels is determined during the system commissioning phase based on the designed heat exchange capacity of the waste heat exchange unit, the rated flow range of the heat transfer fluid circulation drive component, and the allowable pressure drop on the data center cooling medium side. The fluctuation judgment condition is used to identify rapid changes in the heat transfer fluid outlet temperature. The preset time window is used to limit the statistical range of the fluctuation amplitude, and the preset change amplitude threshold is used to limit the allowable temperature change amplitude. The preset time window is 5 to 30 times the sampling period of the temperature acquisition unit, and the preset change amplitude threshold is 1% of the upper limit of the natural fluctuation amplitude of the heat transfer fluid outlet temperature during steady-state operation.Both the 5-3 times and the 3 times were measured and statistically tuned during the system debugging phase by collecting steady-state temperature sequences. When the change in the outlet temperature of the heat transfer fluid within a preset time window exceeds a preset change threshold, the controller executes a buffer transition process. The preset transition period in the buffer transition process is limited by the buffer transition duration parameter, which takes one to three gear switching cycles. The buffer transition process includes switching the heat transfer fluid circulation rate step by step according to the gear sequence within the time limit of the buffer transition duration parameter and simultaneously adjusting the bypass ratio. The bypass ratio represents the distribution ratio between the bypass flow rate of the heat transfer fluid bypassing the waste heat exchange unit and the main flow rate entering the waste heat exchange unit. The adjustment of the bypass ratio is executed in a step-by-step manner. The controller limits the bypass ratio between the lower limit and the upper limit of the bypass ratio, where the lower limit of the bypass ratio is 0. The bypass ratio is set to a maximum of 40-70%, with a maximum range of ~10%. Within the buffer transition time limit specified by the buffer transition duration parameter, the controller divides the buffer transition time into several adjustment sub-periods based on the number of gear switching cycles. Each adjustment sub-period corresponds to one step adjustment of the bypass ratio and one cycle gear adjustment. When the heat transfer fluid circulation rate is increased sequentially by gear, the bypass ratio is decreased by a step amount of 5-15%. When the heat transfer fluid circulation rate is decreased sequentially by gear, the bypass ratio is increased by a step amount. At the end of each adjustment sub-period, the controller reads the heat transfer fluid outlet temperature information. If the change in the heat transfer fluid outlet temperature information within the preset time window still exceeds the preset change threshold, the next step adjustment continues. If the change does not exceed the preset change threshold, the current bypass ratio is maintained until the buffer transition process ends.

[0024] In some embodiments of this application, the heat distribution process for the heat transfer fluid includes: When switching between the establishment of domestic hot water demand status and the non-establishment of domestic hot water demand status, an interlock control action is executed. The interlock control action includes closing the on / off valve group corresponding to the process to be exited and keeping the on / off valve group corresponding to the target process in the closed state. After the interlock control action, the heat transfer fluid is directed into the return path and a pressure balance determination is performed; After the pressure balance condition is met, open the on / off valve group corresponding to the target process and close the on / off valve group corresponding to the return path to enter the target process.

[0025] Specifically, the heat distribution process switches the flow path of the heat transfer fluid between the domestic hot water heat exchange process and the external insulation circulation process. On / off valve groups control the opening and closing of corresponding process paths, and the return path provides a closed-loop circulation channel for the heat transfer fluid during the transition phase of process switching. When switching occurs between a domestic hot water demand state and a domestic hot water demand state, the controller first executes an interlock control action. This interlock control action prevents two process paths from being simultaneously open during the same period of process switching. The interlock control action includes closing the on / off valve group corresponding to the process to be exited and keeping the on / off valve group corresponding to the target process closed, while simultaneously opening the on / off valve group corresponding to the return path to allow the heat transfer fluid to enter the return path circulation. Pressure balance determination is used to determine whether the pressure difference across the heat distribution node is within the allowable range. The pressure difference is determined by… The upstream pressure information of the heat distribution node and the inlet pressure information of the target process are determined, and the allowable range is limited by the differential pressure allowable value. The differential pressure allowable value is obtained during the system commissioning phase based on the rated pressure head of the heat transfer fluid circulation drive component and the allowable differential pressure of the on / off valve group. The differential pressure allowable value is 0.02 to 0.10 MPa. After the pressure balance judgment meets the conditions, the controller opens the on / off valve group corresponding to the target process and closes the on / off valve group corresponding to the return path, and enters the target process. As an optional method, the interlock control action is executed in conjunction with the pressure balance judgment with time constraints. The time constraints are limited by the interlock transition duration parameter. The interlock transition duration parameter is obtained during the system commissioning phase based on the volume of the heat distribution node and the circulation volume of the heat transfer fluid. The interlock transition duration parameter is 3 to 30 seconds, so that when the pressure balance judgment does not meet the conditions, the heat transfer fluid is kept circulating in the return path and waiting for re-judgment.

[0026] In some embodiments of this application, determining the demand for domestic hot water includes: The flow rate of domestic hot water intake is continuously sampled and the moving average value is calculated. The temperature of domestic hot water storage is continuously sampled and the moving average value is calculated. The state of domestic hot water demand is established when the sliding average value meets the criteria for establishing the domestic hot water demand state. If the sliding average value meets the condition that the domestic hot water demand state is not met, output "Domestic hot water demand state is not met". During the transition between the establishment of domestic hot water demand status and the non-establishment of domestic hot water demand status, a hold action is performed, which includes maintaining the original output status for a certain duration before the output status changes.

[0027] Specifically, the domestic hot water intake flow rate information is output by the flow rate acquisition unit, representing the amount of water taken from the domestic hot water side per unit time. The domestic hot water storage temperature information is output by the temperature acquisition unit, representing the water temperature at the domestic hot water storage end. Continuous sampling means that the controller collects the domestic hot water intake flow rate information and domestic hot water storage temperature information according to a fixed sampling period. The sampling period is limited by a sampling period parameter, which can be 1 to 10 seconds. The moving average value is calculated based on a sliding window, which is limited by a window length parameter, which can be 5 to 60 sampling points. The moving average value is the arithmetic mean of the sampled values ​​within the sliding window. The flow rate moving average value is used to replace the instantaneous water intake flow rate information. The temperature sliding average is used to replace the instantaneous storage water temperature information in the judgment. The judgment conditions for the establishment and non-establishment of domestic hot water demand status are limited by a first threshold, a second threshold, a first set value, and a second set value, wherein the first threshold is greater than the second threshold, and the second set value is greater than the first set value. The controller uses the flow sliding average and the temperature sliding average as inputs to execute the judgment logic, which includes: outputting that the domestic hot water demand status is established when the flow sliding average is greater than or equal to the first threshold or the temperature sliding average is less than the first set value; and outputting that the domestic hot water demand status is not established when the flow sliding average is less than the second threshold and the temperature sliding average is greater than or equal to the second set value. The hold action is used to limit the switching frequency of the output state. The hold duration is limited by the hold duration parameter, which can be 10-300s. When the controller determines that the output state needs to be changed, it first maintains the original output state and holds it continuously for a duration not less than the hold duration parameter, and then allows the output state to switch from the domestic hot water demand state being established to the domestic hot water demand state being invalid, or from the domestic hot water demand state being invalid to the domestic hot water demand state being established. As an optional method, the window length parameter and the hold duration parameter are tuned during the system debugging phase based on the domestic hot water consumption fluctuation cycle and the thermal inertia of the domestic hot water storage end. During the system debugging phase, the domestic hot water intake flow is continuously collected during typical water consumption periods. The data collection time for domestic hot water supply and storage temperature information can be 24–72 hours. The controller performs periodic statistics on the water intake flow rate, using the median or 90th percentile of adjacent peak intervals as the domestic hot water supply fluctuation period. The controller also performs time statistics on the recovery process of domestic hot water storage temperature information at the start and end of water intake, using the time corresponding to the temperature recovery from the lowest point to 63% of the target temperature change as the thermal inertia time of the domestic hot water storage end. The target temperature change is the difference between the target domestic hot water supply temperature and the domestic hot water storage temperature corresponding to the lowest point. The window length parameter is set to 0.05–0.5, which is the ratio of the domestic hot water supply fluctuation period to the sampling period parameter.The window length parameter should be increased by 20 times and limited to 5-60 sampling points. For example, if the sampling period parameter is 2s and the water usage fluctuation period is 60s, the window length parameter should be 5-12 sampling points. The hold time parameter should be 0.10-0.50 times the thermal inertia time of the domestic hot water storage end and limited to 10-300s. For example, if the thermal inertia time is 600s, the hold time parameter should be 60-180s. If frequent fluctuations in the domestic hot water demand status output are observed during the commissioning phase, the window length parameter or the hold time parameter should be increased. If a lag in the response of the domestic hot water demand status output is observed during the commissioning phase, the window length parameter or the hold time parameter should be decreased.

[0028] In some embodiments of this application, when the domestic hot water demand state is established, the heat distribution process selects the domestic hot water heat exchange process. The heat transfer fluid enters the domestic hot water heat exchange process and exchanges heat with the domestic hot water side fluid. When the domestic hot water side fluid is driven to circulate by the domestic hot water circulation process, it includes: The domestic hot water circulation process is started and enters the acceleration phase, which includes gradually increasing the circulation volume from a low volume to a stable volume. During the stable circulation phase, the domestic hot water circulation volume is adjusted based on the changing trend of the domestic hot water storage temperature information. The adjustment actions include increasing the domestic hot water circulation volume when the temperature drop rate increases and decreasing the domestic hot water circulation volume when the temperature drop rate decreases. When the domestic hot water demand state changes from being established to not being established, the heat transfer fluid maintains a transitional circulation period within the domestic hot water heat exchange process and then exits the domestic hot water heat exchange process and enters the switching path of the heat distribution process. The transitional circulation period is limited by the transition duration parameter.

[0029] Specifically, the domestic hot water heat exchange process corresponds to the heat exchange between the heat transfer fluid and the domestic hot water side fluid within the domestic hot water heat exchange unit, while the domestic hot water circulation process corresponds to the circulation drive process of the domestic hot water side fluid within the domestic hot water heat exchange loop. When the domestic hot water demand is met, the controller switches the heat distribution process to the domestic hot water heat exchange process and initiates the domestic hot water circulation process into the acceleration phase. The low circulation volume in the acceleration phase is the starting circulation volume of the domestic hot water circulation drive component, and the stable circulation volume is the target circulation volume after the acceleration phase ends. The acceleration phase adopts a stepped or ramp acceleration method, with 2 to 6 acceleration steps and a single step interval of 1 to 5 seconds. The stable circulation volume is 0.6 to 1.0 times the rated circulation volume of the domestic hot water circulation drive component. In the stable circulation phase, the controller adjusts the domestic hot water circulation volume according to the changing trend of the domestic hot water storage temperature information. The changing trend is determined by the temperature change of the domestic hot water storage temperature information within the trend window and the trend window duration, which is 30 to 300 seconds. An increase in the temperature drop rate indicates an increase in the trend window... A larger decrease in the intra-orifice temperature and a smaller rate of temperature decrease indicate a smaller temperature decrease within the trend window. Based on this, the controller performs a step adjustment of the circulation volume, with the step size ranging from 5% to 15% of the rated circulation volume. The circulation volume is limited to between the minimum and maximum circulation volumes, with the minimum circulation volume being 0.3 to 0.5 times the rated circulation volume and the maximum circulation volume being 1.0 to 1.2 times the rated circulation volume. When the domestic hot water demand status changes from established to unestablished, the controller enters the exit control phase. During the exit control phase, the heat transfer fluid maintains a transitional circulation period within the domestic hot water heat exchange process before exiting the domestic hot water heat exchange process and entering the heat distribution process. The transitional circulation period is limited by the transition duration parameter, which is determined during system debugging based on the internal volume of the domestic hot water heat exchange unit, the circulation volume of the domestic hot water side fluid, and the circulation volume of the heat transfer fluid. The transition duration parameter ranges from 5 to 120 seconds, with the liquid exchange time used as a tuning reference. The liquid exchange time is the ratio of the internal volume of the domestic hot water heat exchange unit to the circulation volume of the domestic hot water side fluid, and the transition duration parameter ranges from one to three liquid exchange times.

[0030] In some embodiments of this application, when the peripheral insulation structure loop is arranged around the periphery of the long-term phase change thermal storage box and forms a closed loop, it includes: Open each loop of the outer insulation structure circuit in sequence according to the filling order, and vent air at the highest point of the circuit. During the operation of the external insulation circulation process, different loop segments of the external insulation structure circuit are connected sequentially according to time sequence, and the remaining loop segments are disconnected sequentially. When switching between adjacent loop segments in the partitioned circulation process, the circulation direction of the peripheral insulation structure loop is switched between forward and reverse circulation.

[0031] Specifically, the external insulation structure loop is a closed-loop channel surrounding the long-term phase change heat storage tank. The external insulation structure loop consists of multiple independently connectable segments, which are connected and disconnected via zoned valve groups. The highest point of the loop is the highest or partially highest position of the external insulation structure loop at its installation height, and an exhaust channel is located at the corresponding position. Before starting the external insulation circulation process, the external insulation structure loop is segmented for liquid filling and venting, following the principle of "from low to high, from near to far." First, the segments closer to the heat transfer fluid supply end and with lower heights are opened, followed by the segments with higher heights or greater distances. Simultaneously, the exhaust channel is opened at the highest point of the loop until the exhaust end signal appears. The exhaust end signal is determined by continuous liquid discharge from the exhaust port or the result of bubble detection at the exhaust port. During the external insulation circulation... During process operation, the controller sequentially connects different segments of the external insulation structure loop in chronological order and disconnects the remaining segments, indicating that the controller uses a zoned cyclic process to alternately supply liquid to each segment. The connection time of each segment is limited by the segment connection duration parameter, which ranges from 1 to 30 minutes. The rotation sequence is arranged according to the circumferential or height position of the segment. When switching between adjacent segments in the zoned cyclic process, the controller performs forward and reverse circulation switching of the external insulation structure loop, indicating that the controller performs reversing control during the transition phase of the segment switching. Forward and reverse circulation are defined based on the reference flow direction set by the external insulation structure loop. Reversing control is triggered at each segment switching or after completing a rotation cycle. The reversing holding time is limited by the reversing holding time parameter, which ranges from 10 to 120 seconds, to ensure that the flow direction stabilizes during the reversing period before entering the connection time of the next segment.

[0032] In some embodiments of this application, when the long-term phase change thermal storage tank is in a static state, maintaining the external insulation circulation process in an open state includes: The long-term phase change thermal storage tank is in a static state when the operating mode information indicates that it is not in the heat charging mode and not in the heat dissipation mode. The external insulation circulation maintenance process is executed in a static state. The external insulation circulation maintenance process includes continuous circulation mode and intermittent circulation mode. In the intermittent cyclic mode, the timing control process is executed. The timing control process includes starting the external insulation cycle process according to the running period and stopping the external insulation cycle process according to the rest period.

[0033] Specifically, the long-term phase change thermal storage tank's operating mode information is generated by the controller and used to characterize the tank's current operating mode. The controller collects charging execution signals, heat release execution signals, charging circuit on / off valve group status information, heat release circuit on / off valve group status information, and charging cycle drive component operating status information associated with the long-term phase change thermal storage tank. The determination principle for operating mode information follows a fixed priority order and includes mutual exclusion verification. The fixed priority order includes execution signals taking precedence over valve group status, and valve group status taking precedence over cycle drive component status: when the charging execution signal... When the signal is set, the operating mode information indicates heat charging mode; when the heat release execution signal is set, the operating mode information indicates heat release mode; when neither the heat charging nor heat release execution signal is set, the controller determines the mode based on the on / off valve group status information. If the heat charging circuit on / off valve group is open, the operating mode information indicates heat charging mode; if the heat release circuit on / off valve group is open, the operating mode information indicates heat release mode; when both the heat charging and heat release circuit on / off valve groups are closed, the controller determines the mode based on the operating status information of the cycle drive component. If either the heat charging cycle drive component or the heat release cycle drive component is in operation... When in operation, the operating mode information indicates standby cycle mode; when both are in a stopped state, the operating mode information indicates static state. Mutual exclusion verification includes ensuring that heat charging mode and heat dissipation mode cannot be simultaneously established. When both heat charging execution signals and heat dissipation execution signals are simultaneously set, or when both heat charging circuit on / off valve groups and heat dissipation circuit on / off valve groups are simultaneously opened, the controller outputs an interlock control command and sets the operating mode information to fault mode. Simultaneously, the fault event is recorded, and the external insulation cycle remains closed until the fault is cleared. Non-heat charging mode indicates that the operating mode information does not indicate heat charging mode; non-heat dissipation mode indicates that the operating mode information does not indicate heat dissipation mode. When the operating mode information simultaneously indicates both non-heat-charging mode and non-heat-releasing mode, the controller determines that the long-term phase change thermal storage tank is in a static state. In the static state, the controller executes the external insulation circulation maintenance process to keep the external insulation circulation process in the open state. The external insulation circulation maintenance process includes a continuous circulation mode and an intermittent circulation mode. The continuous circulation mode means that the external insulation circulation process runs continuously in the static state and the external insulation circulation drive component keeps running. The intermittent circulation mode means that the external insulation circulation process runs alternately according to the start-stop rhythm in the static state and the external insulation circulation drive component runs alternately according to the start-stop command.The selection principle for continuous and intermittent circulation modes is based on the prioritization of waste heat supply status and temperature difference. The controller determines the waste heat supply status based on waste heat recovery status information and the temperature difference based on external insulation temperature and ambient temperature information. Continuous circulation mode is selected when the waste heat supply status is sufficient, and intermittent circulation mode is selected when the waste heat supply status is insufficient. When the waste heat supply status is fixed, an increase in the temperature difference increases the selection priority of continuous circulation mode, and a decrease in the temperature difference increases the selection priority of intermittent circulation mode. In intermittent circulation mode, a timing control process is executed, which includes parameters for running and resting periods. The numerical settings and execution sequence are defined as follows: the running period is limited by the running period parameters, and the rest period is limited by the rest period parameters. The running period parameters are set to 5–60 minutes, and the rest period parameters are set to 5–120 minutes. The controller starts the external insulation cycle according to the running period and stops the external insulation cycle at the end of the running period. The controller keeps the external insulation cycle stopped according to the rest period and restarts the external insulation cycle at the end of the rest period to form a periodic start-stop sequence. The running period parameters and rest period parameters are tuned during the system debugging phase. The tuning process includes recording ambient temperature information and external insulation temperature information under typical static operating conditions. The time series analysis is performed, and the decrease magnitude and rate of decrease of the external insulation temperature information during the pause phase are calculated. From the candidate parameter combinations, the parameter combination that ensures the decrease magnitude of the external insulation temperature information during the pause phase does not exceed the upper limit of the allowable temperature fluctuation range is selected as the initial operating period parameter and the initial pause period parameter. The allowable temperature fluctuation range is limited by the target outer peripheral temperature and the minimum allowable outer peripheral temperature of the long-term phase change thermal storage tank. During operation, the controller updates parameters according to the update cycle parameter, which is taken as 1–24 hours or 1–20 start-stop cycles. When the update cycle parameter is reached, the controller reads the external insulation temperature within the start-stop cycle covered by the update cycle parameter. The system calculates the temperature drop in the last start-stop cycle and the temperature drop in the previous start-stop cycle. It then compares the current cycle's temperature drop with the previous cycle's. If the current cycle's temperature drop is greater than the previous cycle's, the pause period parameter is shortened or the running period parameter is extended. If the current cycle's temperature drop is less than the previous cycle's, the pause period parameter is extended or the running period parameter is shortened. The single adjustment amount of the running period parameter and the pause period parameter is limited by a step parameter, which ranges from 1 to 10 minutes. Furthermore, the running period parameter and the pause period parameter are constrained by their respective minimum and maximum values.

[0034] In some embodiments of this application, when adjusting the circulation flow rate of the external insulation circulation process based on the collected waste heat recovery status information, external insulation temperature information, and ambient temperature information, the following methods are included: The temperature difference is determined based on the external insulation temperature information and the ambient temperature information. The waste heat supply status is determined based on the waste heat recovery status information. The waste heat supply status includes a sufficient waste heat status and a insufficient waste heat status. Under conditions of sufficient residual heat, the circulation flow rate of the external insulation circulation process is switched between multiple circulation flow rate levels based on the temperature difference. The multiple circulation flow rate levels are limited by a set of levels, which includes low, medium and high levels. When the residual heat is insufficient, the load reduction process is executed. The load reduction process includes reducing the circulation flow rate of the external insulation circulation process to a low level or switching the external insulation circulation process to an intermittent circulation mode.

[0035] Specifically, the external insulation temperature information is output by the temperature acquisition unit and used to characterize the temperature level around the external insulation structure loop or the long-term phase change thermal storage box. The ambient temperature information is output by the ambient temperature acquisition unit and used to characterize the temperature level of the environment where the long-term phase change thermal storage box is located. The controller collects the external insulation temperature information and ambient temperature information according to the sampling period parameter and calculates the temperature difference, which is the difference between the external insulation temperature information and the ambient temperature information. The sampling period parameter is 1 to 10 seconds. The waste heat recovery status information is used to characterize the available heat level output by the waste heat exchange process. The information is derived from a combination of heat transfer fluid outlet temperature, heat transfer fluid flow rate, and data center cooling medium side temperature difference. The heat transfer fluid outlet temperature represents the heat level carried by the heat transfer fluid, the heat transfer fluid flow rate represents the circulation intensity of the waste heat recovery loop, and the data center cooling medium side temperature difference represents the intensity of heat released by the data center cooling medium. The controller determines the waste heat supply status based on the waste heat recovery status information. The waste heat supply status includes a sufficient waste heat status and a insufficient waste heat status. A sufficient waste heat status requires that the heat transfer fluid outlet temperature is not lower than the minimum waste heat utilization temperature and that the heat transfer fluid flow rate... The information is not lower than the minimum circulation flow rate. In cases of insufficient waste heat, the heat transfer fluid outlet temperature is lower than the minimum waste heat utilization temperature, or the heat transfer fluid flow rate is lower than the minimum circulation flow rate. The minimum waste heat utilization temperature and minimum circulation flow rate are determined during system commissioning. The minimum waste heat utilization temperature is determined based on the minimum heating temperature at which stable heat exchange can be achieved through the external insulation circulation process and is typically between 25 and 45°C. The minimum circulation flow rate is determined based on the minimum flow rate at which the heat transfer fluid circulation drive component can operate stably and is typically 0.2 to 0.5 times the rated flow rate of the heat transfer fluid circulation drive component. Multiple circulation flow rate settings are determined by a set of settings. The set of speed ranges is limited and includes low, medium, and high speeds. Low, medium, and high speeds correspond to the low-speed, medium-speed, and high-speed ranges of the external insulation circulation drive component, respectively. The speed range set is determined during the system commissioning phase based on the design flow rate of the external insulation structure circuit, the allowable pressure drop of the external insulation structure circuit, and the rated flow range of the external insulation circulation drive component. For example, low speed is 0.3 to 0.5 times the rated flow rate of the external insulation circulation drive component, medium speed is 0.5 to 0.8 times the rated flow rate of the external insulation circulation drive component, and high speed is 0.8 to 1 times the rated flow rate of the external insulation circulation drive component.0 times; Under sufficient residual heat, the controller switches between low, medium, and high settings based on the temperature difference. The temperature difference is categorized using a first temperature difference boundary parameter and a second temperature difference boundary parameter. When the first temperature difference boundary parameter is less than the second temperature difference boundary parameter, the low setting is selected; when the temperature difference is greater than or equal to the first temperature difference boundary parameter but less than the second temperature difference boundary parameter, the medium setting is selected; and when the temperature difference is greater than or equal to the second temperature difference boundary parameter, the high setting is selected. The first and second temperature difference boundary parameters are tuned during the system debugging phase. The tuning process includes collecting ambient temperature and external insulation temperature information under typical static conditions and calculating the temperature difference sequence. The collection duration is 24–72 hours or 1–20 start-stop cycles. The 25th and 75th percentiles of the temperature difference sequence are set as the first and second temperature difference boundary parameters, respectively, and amplitude limiting is applied. The first temperature difference boundary parameter is set to 3℃ and the second temperature difference boundary parameter to 8℃ when the statistical results of the temperature difference sequence are not representative. Under insufficient residual heat conditions, the controller executes a load reduction process. This process includes lowering the circulation flow rate of the external insulation circulation process to a lower level to reduce residual heat demand, or switching the external insulation circulation process to an intermittent circulation mode to reduce continuous operation time. The operating period parameters and rest period parameters of the intermittent circulation mode are adjusted during system debugging based on the decrease in external insulation temperature during the rest period. During operation, the controller updates the operating period parameters and rest period parameters according to the update cycle parameters, which range from 1 to 24 hours or 1 to 20 start-stop cycles. The single adjustment amount of the operating period parameters and rest period parameters is limited by a step parameter, which ranges from 1 to 10 minutes.

[0036] In some embodiments of this application, when the waste heat recovery loop meets the shutdown conditions or the external insulation circulation process meets the shutdown conditions, the external insulation circulation process is stopped, and the heat distribution process is switched to the domestic hot water heat exchange process or the waste heat discharge process, including: The system acquires the outlet temperature and flow rate of the heat transfer fluid, and outputs a judgment result indicating whether the waste heat recovery loop meets the shutdown conditions based on the outlet temperature and flow rate of the heat transfer fluid. Acquire external insulation temperature information and ambient temperature information, and output the judgment result that the external insulation cycle process meets the shutdown conditions based on the external insulation temperature information and ambient temperature information; Before stopping the external insulation circulation process, a load reduction transition process is performed. The load reduction transition process includes reducing the circulation flow rate of the external insulation circulation process in a stepwise manner and stopping the external insulation circulation process after pressure balance is completed. After stopping the external heat preservation circulation process, a process switching action is performed. The process switching action includes switching the heat distribution process to the domestic hot water heat exchange process or switching the heat distribution process to the waste heat discharge process. The waste heat discharge process includes the heat transfer fluid entering the return path for circulation or the heat transfer fluid entering the heat dissipation path for circulation.

[0037] Specifically, the determination that the waste heat recovery loop meets the shutdown conditions is based on the heat transfer fluid outlet temperature information and the heat transfer fluid flow rate information. The heat transfer fluid outlet temperature information characterizes the heat level output from the waste heat exchange process to the heat distribution process, and the heat transfer fluid flow rate information characterizes the circulation intensity of the waste heat recovery loop. The controller generates a waste heat supply capacity determination quantity based on the heat transfer fluid outlet temperature information and the heat transfer fluid flow rate information and outputs the determination result that the waste heat recovery loop meets the shutdown conditions. The waste heat recovery loop meeting the shutdown conditions includes: the heat transfer fluid outlet temperature being lower than the minimum waste heat utilization temperature and continuously maintained for a duration not less than the duration limited by the shutdown confirmation duration parameter, or... The hot fluid flow rate is lower than the minimum circulation flow rate and remains continuously for a duration not less than the time specified by the shutdown confirmation duration parameter. The minimum waste heat utilization temperature and minimum circulation flow rate are determined during system commissioning, with the minimum waste heat utilization temperature set between 25 and 45°C. This temperature range matches the phase change temperature (30-40°C) of common phase change materials, ensuring that waste heat can be effectively used for insulation. The minimum circulation flow rate is 0.2 to 0.5 times the rated flow rate of the heat transfer fluid circulation drive component. The shutdown confirmation duration parameter is determined during system commissioning based on the short-term fluctuations in the heat transfer fluid outlet temperature and flow rate, and is set between 30 and 600 seconds. The external insulation circulation process meets… The shutdown condition determination is based on external insulation temperature information and ambient temperature information. The external insulation temperature information characterizes the temperature level around the external insulation structure loop or the long-term phase change heat storage tank, while the ambient temperature information characterizes the external ambient temperature level. The controller calculates the temperature difference and outputs a determination result indicating that the external insulation cycle process meets the shutdown conditions. Meeting the shutdown conditions includes a temperature difference less than the first temperature difference boundary parameter and continuously maintained for a duration not less than the shutdown confirmation duration parameter. When either the waste heat recovery loop or the external insulation cycle process meets the shutdown conditions, the controller executes a load reduction transition process, which includes a stepped approach. After reducing the circulation flow rate of the external insulation circulation process and completing pressure balance, the external insulation circulation process is stopped. The step reduction method includes gradually lowering the circulation flow rate from the current level to a lower level according to the set of levels. The level switching interval is limited by the load reduction step interval parameter, which is 5 to 60 seconds. Pressure balance is determined by pressure balance judgment. The pressure balance judgment is based on the supply and return pressure information of the external insulation structure loop to obtain the supply and return pressure difference, and compares the supply and return pressure difference with the allowable pressure difference value. The allowable pressure difference value is determined during the system commissioning stage based on the rated pressure head of the external insulation circulation drive component and the allowable pressure drop of the pipeline, and the allowable pressure difference value is 0.02 to 0.10MPa; After the external insulation circulation process stops, the controller executes a process switching action. The process switching action selects the target process path according to the switching rules of the heat distribution process. When the domestic hot water demand is met, the heat distribution process switches to the domestic hot water heat exchange process; when the domestic hot water demand is not met, the heat distribution process switches to the waste heat discharge process. The waste heat discharge process includes two modes: return path circulation and heat dissipation path circulation. Return path circulation means that the heat-carrying fluid bypasses the domestic hot water heat exchange process and the external insulation circulation process and returns to the inlet side of the waste heat exchange process, forming a closed loop. Heat dissipation path circulation means that the heat-carrying fluid exchanges heat through the heat dissipation unit and then returns to the inlet side of the waste heat exchange process, forming a closed loop. The heat dissipation unit uses an air-cooled heat exchanger or a water-cooled heat exchanger. The activation conditions for the heat dissipation path circulation are determined during the system commissioning phase based on the heat dissipation capacity of the heat dissipation unit design and the ambient temperature information.

[0038] In another preferred embodiment based on the above embodiments, see [reference] Figure 2 As shown, this embodiment provides a long-term thermal storage and insulation system based on data center waste heat recovery, including: The waste heat exchange module is configured to exchange heat with the data center cooling medium through a waste heat exchange process, and transfer the heat obtained from the heat exchange to the heat transfer fluid. The heat distribution module is configured to perform a heat distribution process on the heat transfer fluid. The heat distribution process includes a domestic hot water heat exchange process and an external insulation circulation process. The domestic hot water heat exchange process has a higher priority than the external insulation circulation process. The demand determination module is configured to obtain the domestic hot water intake flow rate information and the domestic hot water storage temperature information, and to determine the domestic hot water demand status based on the domestic hot water intake flow rate information, the domestic hot water storage temperature information, the first threshold, the second threshold, the first set value and the second set value, wherein the first threshold is greater than the second threshold and the second set value is greater than the first set value. The domestic hot water heat exchange module is configured such that when the domestic hot water demand is met, the heat distribution process selects the domestic hot water heat exchange process, the heat carrier fluid enters the domestic hot water heat exchange process and exchanges heat with the domestic hot water side fluid, and the domestic hot water side fluid is driven to circulate by the domestic hot water circulation process. The external insulation circulation module is configured to select the external insulation circulation process when the domestic hot water demand is not met and the waste heat recovery loop is in operation. The heat-carrying fluid enters the external insulation circulation process and circulates in the external insulation structure loop. The external insulation structure loop is arranged around the periphery of the long-term phase change heat storage box and forms a closed loop. The static adjustment module is configured to keep the external insulation circulation process in the open state when the long-term phase change thermal storage box is in a static state, and adjust the circulation flow rate of the external insulation circulation process based on the collected waste heat recovery status information, external insulation temperature information and ambient temperature information. The shutdown switching module is configured to stop the external heat insulation circulation process and switch the heat distribution process to the domestic hot water heat exchange process or the waste heat discharge process when the waste heat recovery loop meets the shutdown conditions or the external heat insulation circulation process meets the shutdown conditions.

[0039] Understandably, by forming a stable waste heat recovery loop with the waste heat exchange module and the heat transfer fluid, the heat in the data center's cooling medium can be transferred and output in a controllable manner. The heat distribution module works in conjunction with the demand determination module to achieve a tiered response to the immediate demand on the domestic hot water side and the operational demand on the external insulation side. The domestic hot water heat exchange process has a higher priority, ensuring that the distribution of waste heat among different heating scenarios has a clear control sequence, avoiding uncertainties in flow distribution and fluctuations in heat exchange conditions when multiple processes are simultaneously activated. When the domestic hot water demand is not met and the waste heat recovery loop is in operation, the external insulation circulation module drives the heat transfer fluid into the external insulation structure loop for circulation. The external insulation structure loop forms a closed circulation channel around the periphery of the long-term phase change thermal storage tank. Compared to relying solely on static insulation materials, this circulation can form a continuous circulation channel around the periphery of the long-term phase change thermal storage tank. The temperature maintenance conditions reduce the temperature difference-driven heat dissipation during the long-term static period of the phase change thermal storage tank. The static adjustment module further adjusts the circulation flow of the external insulation circulation process based on the waste heat recovery status information, the external insulation temperature information, and the ambient temperature information, so that the external insulation circulation process can adapt to the waste heat supply level of the data center and the changes in the external ambient temperature, reducing unnecessary circulation load. The shutdown switching module performs load reduction and switching when the shutdown conditions are met, so that the cessation of the external insulation circulation process and the switching of the waste heat path have a controllable transition process, reducing the loop pressure difference impact and maintaining the operational stability of the waste heat recovery loop. Without changing the basic operating mode of the data center cooling medium, this invention forms a synergistic utilization path for domestic hot water and long-term static insulation of the phase change thermal storage tank, improving the continuity and adjustability of waste heat utilization, and reducing the risk of heat decay of the long-term phase change thermal storage tank during the storage stage.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A long-term heat storage and insulation method based on waste heat recovery from data centers, characterized in that, include: The waste heat exchange process is used to exchange heat with the cooling medium of the data center, and the heat obtained from the heat exchange is transferred to the heat transfer fluid. A heat distribution process is implemented for the heat transfer fluid, which includes a domestic hot water heat exchange process and an external insulation circulation process. The domestic hot water heat exchange process has a higher priority than the external insulation circulation process. The system acquires domestic hot water intake flow rate information and domestic hot water storage temperature information. Based on the domestic hot water intake flow rate information, domestic hot water storage temperature information, first threshold, second threshold, first set value, and second set value, the system determines the domestic hot water demand status. The first threshold is greater than the second threshold, and the second set value is greater than the first set value. When the domestic hot water demand is met, the heat distribution process selects the domestic hot water heat exchange process. The heat carrier fluid enters the domestic hot water heat exchange process and exchanges heat with the domestic hot water side fluid. The domestic hot water side fluid is driven to circulate by the domestic hot water circulation process. When the domestic hot water demand is not met and the waste heat recovery loop is in operation, the heat distribution process selects the external insulation circulation process. The heat-carrying fluid enters the external insulation circulation process and circulates in the external insulation structure loop. The external insulation structure loop is arranged around the periphery of the long-term phase change heat storage box and forms a closed loop. When the long-term phase change thermal storage tank is in a static state, the external insulation circulation process is kept in the open state, and the circulation flow rate of the external insulation circulation process is adjusted based on the collected waste heat recovery status information, external insulation temperature information and ambient temperature information. When the waste heat recovery loop meets the shutdown conditions or the external insulation circulation process meets the shutdown conditions, the external insulation circulation process is stopped, and the heat distribution process is switched to the domestic hot water heat exchange process or the waste heat discharge process.

2. The long-term heat storage and insulation method based on waste heat recovery from data centers according to claim 1, characterized in that, When heat is exchanged through waste heat exchange processes for the cooling medium in a data center, the process includes: Acquire data center cooling medium inlet temperature information, data center cooling medium outlet temperature information, heat transfer fluid inlet temperature information, and heat transfer fluid outlet temperature information; During the start-up phase of the waste heat exchange process, a heat transfer fluid pre-circulation process is performed, which includes starting the heat transfer fluid circulation drive component and keeping the drive component in operation. The data center cooling medium inlet temperature information and data center cooling medium outlet temperature information are used to determine the data center cooling medium side temperature difference information, and the heat transfer fluid inlet temperature information and heat transfer fluid outlet temperature information are used to determine the heat transfer fluid side temperature difference information. The heat transfer fluid circulation volume is switched between several discrete cycle levels based on the temperature difference information. When the fluctuation judgment condition is met, a buffer transition process is executed. The fluctuation judgment condition includes the change of the heat transfer fluid outlet temperature information within a preset time window exceeding a preset change threshold. The buffer transition process includes gradually switching the heat transfer fluid circulation volume and simultaneously adjusting the bypass ratio within a preset transition period.

3. The long-term heat storage and insulation method based on waste heat recovery from data centers according to claim 2, characterized in that, When performing a heat distribution process on a heat transfer fluid, the following are included: When switching between the establishment of domestic hot water demand status and the non-establishment of domestic hot water demand status, an interlock control action is executed. The interlock control action includes closing the on / off valve group corresponding to the process to be exited and keeping the on / off valve group corresponding to the target process in the closed state. After the interlock control action, the heat transfer fluid is directed into the return path and a pressure balance determination is performed; After the pressure balance condition is met, open the on / off valve group corresponding to the target process and close the on / off valve group corresponding to the return path to enter the target process.

4. The long-term heat storage and insulation method based on waste heat recovery from data centers according to claim 3, characterized in that, When assessing the demand for domestic hot water, the following should be included: The flow rate of domestic hot water intake is continuously sampled and the moving average value is calculated. The temperature of domestic hot water storage is continuously sampled and the moving average value is calculated. The state of domestic hot water demand is established when the sliding average value meets the criteria for establishing the domestic hot water demand state. If the sliding average value meets the condition that the domestic hot water demand state is not met, output "Domestic hot water demand state is not met". During the transition between the establishment of domestic hot water demand status and the non-establishment of domestic hot water demand status, a hold action is performed, which includes maintaining the original output status for a certain duration before the output status changes.

5. The long-term thermal storage and insulation method based on waste heat recovery from data centers according to claim 4, characterized in that, When the domestic hot water demand is met, the heat distribution process selects the domestic hot water heat exchange process. The heat transfer fluid enters the domestic hot water heat exchange process and exchanges heat with the domestic hot water side fluid. When the domestic hot water side fluid circulates driven by the domestic hot water circulation process, it includes: The domestic hot water circulation process is started and enters the acceleration phase, which includes gradually increasing the circulation volume from a low volume to a stable volume. During the stable circulation phase, the domestic hot water circulation volume is adjusted based on the changing trend of the domestic hot water storage temperature information. The adjustment actions include increasing the domestic hot water circulation volume when the temperature drop rate increases and decreasing the domestic hot water circulation volume when the temperature drop rate decreases. When the demand for domestic hot water changes from being established to not being established, the heat transfer fluid maintains a transitional circulation period within the domestic hot water heat exchange process before exiting the domestic hot water heat exchange process and entering the heat distribution process. The transitional circulation period is limited by the transition duration parameter.

6. The long-term thermal storage and insulation method based on waste heat recovery from data centers according to claim 5, characterized in that, When the external insulation structure loop is arranged around the periphery of the long-term phase change thermal storage box and forms a closed loop, it includes: Open each loop of the outer insulation structure circuit in sequence according to the filling order, and vent air at the highest point of the circuit. During the operation of the external insulation circulation process, different loop segments of the external insulation structure circuit are connected sequentially according to time sequence, and the remaining loop segments are disconnected sequentially. When switching between adjacent loop segments in the partitioned circulation process, the circulation direction of the peripheral insulation structure loop is switched between forward and reverse circulation.

7. The long-term thermal storage and insulation method based on waste heat recovery from data centers according to claim 6, characterized in that, When the long-term phase change thermal storage tank is in a static state, the external insulation circulation process is kept open, including: The long-term phase change thermal storage tank is in a static state when the operating mode information indicates that it is not in the heat charging mode and not in the heat dissipation mode. The external insulation circulation maintenance process is executed in a static state. The external insulation circulation maintenance process includes continuous circulation mode and intermittent circulation mode. In the intermittent cyclic mode, the timing control process is executed. The timing control process includes starting the external insulation cycle process according to the running period and stopping the external insulation cycle process according to the rest period.

8. The long-term thermal storage and insulation method based on waste heat recovery from data centers according to claim 7, characterized in that, When adjusting the circulation flow rate of the external insulation circulation process based on the collected waste heat recovery status information, external insulation temperature information, and ambient temperature information, the following steps are taken: The temperature difference is determined based on the external insulation temperature information and the ambient temperature information. The waste heat supply status is determined based on the waste heat recovery status information. The waste heat supply status includes a sufficient waste heat status and a insufficient waste heat status. Under sufficient residual heat, the circulation flow rate of the external insulation circulation process is switched between multiple circulation flow rate levels based on the temperature difference. The multiple circulation flow rate levels are limited by a set of levels, which includes low, medium and high levels. When the residual heat is insufficient, the load reduction process is executed. The load reduction process includes reducing the circulation flow rate of the external insulation circulation process to a low level or switching the external insulation circulation process to an intermittent circulation mode.

9. The long-term thermal storage and insulation method based on waste heat recovery from data centers according to claim 8, characterized in that, When the waste heat recovery loop meets the shutdown conditions or the external insulation circulation process meets the shutdown conditions, the external insulation circulation process is stopped, and the heat distribution process is switched to the domestic hot water heat exchange process or the waste heat discharge process, including: The system acquires the outlet temperature and flow rate of the heat transfer fluid, and outputs a judgment result indicating whether the waste heat recovery loop meets the shutdown conditions based on the outlet temperature and flow rate of the heat transfer fluid. Acquire external insulation temperature information and ambient temperature information, and output the judgment result that the external insulation cycle process meets the shutdown conditions based on the external insulation temperature information and ambient temperature information; Before stopping the external insulation circulation process, a load reduction transition process is performed. The load reduction transition process includes reducing the circulation flow rate of the external insulation circulation process in a stepwise manner and stopping the external insulation circulation process after pressure balance is completed. After stopping the external heat preservation circulation process, a process switching action is performed. The process switching action includes switching the heat distribution process to the domestic hot water heat exchange process or switching the heat distribution process to the waste heat discharge process. The waste heat discharge process includes the heat transfer fluid entering the return path for circulation or the heat transfer fluid entering the heat dissipation path for circulation.

10. A long-term thermal storage and insulation system based on waste heat recovery from data centers, used to implement the long-term thermal storage and insulation method based on waste heat recovery from data centers as described in any one of claims 1-9, characterized in that, include: The waste heat exchange module is configured to exchange heat with the data center cooling medium through a waste heat exchange process, and transfer the heat obtained from the heat exchange to the heat transfer fluid. The heat distribution module is configured to perform a heat distribution process on the heat transfer fluid. The heat distribution process includes a domestic hot water heat exchange process and an external insulation circulation process. The domestic hot water heat exchange process has a higher priority than the external insulation circulation process. The demand determination module is configured to obtain the domestic hot water intake flow rate information and the domestic hot water storage temperature information, and to determine the domestic hot water demand status based on the domestic hot water intake flow rate information, the domestic hot water storage temperature information, the first threshold, the second threshold, the first set value and the second set value, wherein the first threshold is greater than the second threshold and the second set value is greater than the first set value. The domestic hot water heat exchange module is configured such that when the domestic hot water demand is met, the heat distribution process selects the domestic hot water heat exchange process, the heat carrier fluid enters the domestic hot water heat exchange process and exchanges heat with the domestic hot water side fluid, and the domestic hot water side fluid is driven to circulate by the domestic hot water circulation process. The external insulation circulation module is configured to select the external insulation circulation process when the domestic hot water demand is not met and the waste heat recovery loop is in operation. The heat-carrying fluid enters the external insulation circulation process and circulates in the external insulation structure loop. The external insulation structure loop is arranged around the periphery of the long-term phase change heat storage box and forms a closed loop. The static adjustment module is configured to keep the external insulation circulation process in the open state when the long-term phase change thermal storage box is in a static state, and adjust the circulation flow rate of the external insulation circulation process based on the collected waste heat recovery status information, external insulation temperature information and ambient temperature information. The shutdown switching module is configured to stop the external heat insulation circulation process and switch the heat distribution process to the domestic hot water heat exchange process or the waste heat discharge process when the waste heat recovery loop meets the shutdown conditions or the external heat insulation circulation process meets the shutdown conditions.

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