Heat storage control method of phase change heat storage device, controller and phase change water heater

Abstract

The invention discloses a heat storage control method of a phase change heat storage device, a controller and a phase change water heater. Heat storage is conducted on a phase change material by heating water under a heat storage working condition, firstly, a front heater is started to heat water flowing through a water inlet pipe, and a heating gear of the front heater is lifted according to a first time interval; if the water inlet temperature of the water inlet pipe is still smaller than the first preset temperature when the heating gear of the front heater reaches the maximum heating gear, it is indicated that the heating power is insufficient, at the moment, the rear heater is started to heat water flowing through the water outlet pipe, and the heating gear of the rear heater is lifted according to a second time interval; according to the embodiment of the invention, the heating power of the heat storage working condition is gradually increased in a manner of firstly starting the front heater and then starting the rear heater, and different heating gear combinations can be utilized to match the current heat storage value of the phase change material, so that the heat storage process is smooth, the problem that the heating power is too large or too small can be avoided, and the energy consumption of the heat storage working condition is optimized.

Description

Technical Field

[0001] This application relates to the field of water heater technology, and in particular to a heat storage control method, controller and phase change water heater for a phase change heat storage device. Background Technology

[0002] Phase change water heaters use phase change materials to store heat, replacing the water heat storage of traditional electric water heaters. Phase change materials have a higher energy storage density, which can solve the problem of traditional electric water heaters having large water tanks that affect the aesthetics of the indoor environment.

[0003] Phase change water heaters fill the space between heat exchangers with phase change materials. Under heat storage conditions, water exchanges heat with the phase change materials as it flows through the heat exchangers. Therefore, the water needs to be heated before entering the heat exchangers to ensure it reaches a certain temperature. In related technologies, a heater is installed near the inlet pipe of the phase change water heater's heat exchangers, and the heater's maximum power is used for heating to achieve rapid heat storage. However, this simple heating method is prone to excessively high water temperatures, resulting in energy waste and is not conducive to the smooth heat storage of the phase change materials. Summary of the Invention

[0004] This application provides a heat storage control method, controller, and phase change water heater for a phase change heat storage device, which can achieve smooth heat storage in the phase change heat storage device.

[0005] In a first aspect, embodiments of this application provide a thermal storage control method for a phase change thermal storage device, the phase change thermal storage device comprising a heat exchanger, a preheater, and a postheater, wherein the preheater is used to heat water flowing through the inlet pipe of the heat exchanger, and the postheater is used to heat water flowing through the outlet pipe of the heat exchanger; the method includes: In response to the phase change thermal storage device entering thermal storage mode, the preheater is started; The heating level of the preheater is increased according to the first time interval; If the heating level of the preheater reaches the maximum heating level of the preheater and the inlet water temperature of the inlet pipe is detected to be lower than the first preset temperature, the rear heater is activated. The heating level of the rear heater is increased according to the second time interval.

[0006] In some embodiments, increasing the heating level of the preheater according to the first time interval includes: Obtain the inlet water temperature and the first water flow rate of the inlet water pipe; In response to detecting that the inlet water temperature is lower than the first preset temperature, a first power increase value is determined for the preheater to increase from the current heating level to the next heating level, and a first target temperature is determined based on the inlet water temperature, the first water flow rate and the first power increase value; If the first target temperature is less than or equal to the second preset temperature, the preheater is controlled to increase the heating level according to the first time interval, and the second preset temperature is less than the first preset temperature. If the first target temperature is greater than the second preset temperature, the preheater is controlled to maintain the current heating level.

[0007] In some embodiments, controlling the preheater to increase its heating level according to the first time interval includes: Determine the first time the preheater previously increased its heating level; In response to a time interval greater than or equal to a first time interval between the current moment and the first time of gear increase, the preheater is controlled to increase the heating level.

[0008] In some embodiments, increasing the heating level of the rear heater according to the second time interval includes: Obtain the inlet water temperature and the second water flow rate of the inlet water pipe; In response to detecting that the inlet water temperature is lower than the first preset temperature, a second power increase value is determined for the post heater to be upgraded from the current heating level to the next heating level, and a second target temperature is determined based on the inlet water temperature, the second water flow rate, and the second power increase value; If the second target temperature is less than or equal to the third preset temperature, the rear heater is controlled to increase the heating level according to the second time interval, and the third preset temperature is less than the first preset temperature; If the second target temperature is greater than the third preset temperature, the rear heater is controlled to maintain the current heating level.

[0009] In some embodiments, controlling the rear heater to increase its heating level according to the second time interval includes: Determine the second boosting moment of the rear heater before the previous boosting of the heating level; In response to the duration between the current moment and the second up-level moment being greater than or equal to the second time interval, the rear heater is controlled to increase the heating level.

[0010] In some embodiments, the method further includes: In response to detecting that the inlet water temperature is greater than or equal to the first preset temperature, the operating status of the post-heater is determined; If the post-heater is in operation, control the post-heater to reduce the heating level; If the rear heater is in the off state, control the front heater to reduce the heating level.

[0011] In some embodiments, the step of activating the preheater in response to the phase change thermal storage device entering thermal storage mode includes: The water valves of the phase change thermal storage device are controlled to form an internal circulation loop connecting the heat exchanger; Obtain the inlet water temperature of the inlet pipe, and determine the initial heating level to control the preheater to start based on the inlet water temperature.

[0012] In some embodiments, after activating the preheater, the method further includes: The cumulative heat storage value is determined based on the duration of the heat storage condition, the heating level of the preheater, and the heating level of the postheater. When the duration of the thermal storage condition exceeds a preset time threshold, the cumulative thermal storage value is greater than a preset value, or the heating level of the preheater drops to 0, the phase change thermal storage device is controlled to exit the thermal storage condition.

[0013] In a second aspect, embodiments of this application provide a controller, including at least one processor and a memory for communicatively connecting to the at least one processor; the memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enable the at least one processor to perform the thermal storage control method as described in the first aspect.

[0014] Thirdly, embodiments of this application provide a phase change water heater, including the controller described in the second aspect.

[0015] The heat storage control method, controller, and phase change water heater of the phase change heat storage device according to the embodiments of this application have at least the following beneficial effects: When the phase change heat storage device heats the phase change material by heating water under heat storage conditions, the preheater is first started to heat the water flowing through the inlet pipe, and the heating level of the preheater is increased according to a first time interval. If the inlet water temperature of the inlet pipe is still lower than the first preset temperature when the heating level of the preheater reaches the maximum heating level, it indicates that the heating power is insufficient. At this time, the postheater is started to heat the water flowing through the outlet pipe, and the heating level of the postheater is increased according to a second time interval. The embodiments of this application gradually increase the heating power of the heat storage condition by starting the preheater first and then the postheater. Different heating level combinations can be used to match the current heat storage value of the phase change material, so that the heat storage process is smooth and the problem of excessive or insufficient heating power can be avoided, thus optimizing the energy consumption of the heat storage condition.

[0016] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description and the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a phase change thermal energy storage device provided in one embodiment of this application; Figure 2 This is an overall flowchart of a thermal storage control method provided in one embodiment of this application; Figure 3 This is a flowchart of adjusting the heating level of the preheater according to one embodiment of this application; Figure 4 This is a flowchart of adjusting the heating level of the preheater according to a first time interval, provided in one embodiment of this application; Figure 5 This is a flowchart illustrating the adjustment of the heating level of the rear heater according to one embodiment of this application; Figure 6 This is a flowchart of adjusting the heating level of the rear heater according to a second time interval, provided in one embodiment of this application; Figure 7 This is a flowchart of reducing the heating level according to one embodiment of this application; Figure 8 This is a flowchart of determining the initial start-up position of the preheater according to one embodiment of this application; Figure 9 This is an overall flowchart of a thermal storage control method provided in one example of this application; Figure 10 This is a schematic diagram of the connection structure of a controller provided in one embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various implementations. Simultaneously, the steps or actions described in the method description can be rearranged or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various orders in the specification and drawings are merely for the clear description of a particular embodiment and do not imply a mandatory order, unless otherwise stated that a particular order must be followed.

[0019] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0020] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0021] Phase change water heaters use phase change materials with high latent heat of phase change, which store much more heat per unit volume than water. This reduces the size of the storage tank and solves the problem of excessively large water tanks in traditional electric water heaters for homes. In addition, since the temperature changes very little during the heat storage and release process of the phase change material within the phase change range, it is conducive to system stability. Therefore, phase change water heaters are very suitable for home use.

[0022] The heat storage process of a phase change water heater is achieved through internal water circulation and heating of the water in the circuit. The water heated by the heater passes through a heat exchanger and exchanges heat with the phase change material between the heat exchanger and the phase change material, which then stores energy. In this process, the power control of the heater is crucial, affecting the heat exchange efficiency between the heated water and the phase change material. Currently, phase change water heaters typically operate at maximum heating power to improve the heat storage speed. While heating at maximum power during the initial heat storage phase is feasible, large temperature fluctuations in the early stages of heat storage can easily trigger alarms. Furthermore, in the later stages of heat storage, when a higher water temperature is not necessary, the water temperature may remain high after heat storage is complete, resulting in energy waste.

[0023] This application provides a heat storage control method, controller, and phase change water heater for a phase change thermal storage device. In the heat storage condition, the phase change thermal storage device heats the phase change material by heating water. First, a preheater is activated to heat the water flowing through the inlet pipe, and the heating level of the preheater is increased according to a first time interval. If the inlet water temperature is still lower than a first preset temperature when the preheater reaches its maximum heating level, it indicates insufficient heating power. At this time, a postheater is activated to heat the water flowing through the outlet pipe, and the heating level of the postheater is increased according to a second time interval. This application embodiment gradually increases the heating power of the heat storage condition by activating the preheater first and then the postheater. Different combinations of heating levels can be used to match the current heat storage value of the phase change material, making the heat storage process smooth and avoiding problems of excessive or insufficient heating power, thus optimizing energy consumption in the heat storage condition.

[0024] The following description, in conjunction with the accompanying drawings, explains the heat storage control method, controller, and phase change water heater of the phase change heat storage device.

[0025] Reference Figure 1 As shown, Figure 1 This is a schematic diagram of the phase change thermal energy storage device provided in this application embodiment. The energy storage tank includes a shell, a heat exchanger, and a phase change material. The heat exchanger is located inside the shell, and the gaps inside the shell are filled with the phase change material. The phase change material is in contact with the surface of the heat exchanger to facilitate heat exchange between the hot water inside the heat exchanger and the phase change material. The inlet pipe of the heat exchanger is equipped with a pre-heater (hereinafter referred to as the pre-heater), and the outlet pipe of the heat exchanger is equipped with a post-heater (hereinafter referred to as the post-heater). In the internal circulation mode (hereinafter referred to as the thermal energy storage mode), the phase change material stores heat. The outlet pipe and the inlet pipe of the heat exchanger are connected to a water pump through a thermostatic valve. The water is heated by the pre-heater under the drive of the water pump, and then enters the heat exchanger to exchange heat with the phase change material. The water is then output from the heat exchanger, passes through the post-heater and the thermostatic valve, and returns to the water pump. Figure 1 The thermostatic valve is also equipped with a parallel bypass pipeline. In the heat storage mode, part of the water output from the post-heater enters the thermostatic valve, and the other part enters the bypass pipeline through the bypass check valve and returns to the water pump. The bypass pipeline can increase the flow area of ​​the thermostatic valve, ensure the water flow of the internal circulation loop, and improve the heat exchange efficiency of the phase change heat storage device.

[0026] based on Figure 1 The architecture of the phase change thermal energy storage device and the overall flowchart of the thermal energy storage control method in this application embodiment can be referred to. Figure 2 As shown, the thermal energy storage control method includes, but is not limited to, the following steps: Step S110: In response to the phase change thermal storage device entering thermal storage mode, the preheater is started; Step S120: Increase the heating level of the preheater according to the first time interval; Step S130: If the heating level of the preheater reaches the maximum heating level of the preheater and the inlet water temperature of the inlet pipe is detected to be lower than the first preset temperature, start the postheater. Step S140: Increase the heating level of the rear heater according to the second time interval.

[0027] Phase change thermal energy storage devices can be triggered to enter thermal storage mode by user settings or by specific conditions (such as initial power-on, after a certain period of time, or when the user stops using hot water). When the device enters thermal storage mode, the thermostatic valve switches internal valves to connect the inlet and outlet pipes of the heat exchanger, and then the water pump and preheater are started. Initially, the preheater is started first, without activating the postheater, to heat the water in the internal circulation loop. Since the thermal storage value of the phase change material cannot usually be directly measured, the required heat storage capacity cannot be accurately determined after entering thermal storage mode. Therefore, multiple exit conditions for thermal storage mode are typically set. If thermal storage has already occurred shortly before entering this mode, directly activating the heater's maximum heating power according to relevant technologies can easily lead to energy waste. Therefore, this embodiment does not directly activate the preheater and postheater to their maximum heating power. Instead, it first activates the preheater and then gradually increases its heating level. If the preheater has already reached its maximum heating level, and the inlet water temperature is lower than the first preset temperature, indicating that the phase change thermal storage device still has a thermal storage requirement, then the postheater is activated, and its heating level is gradually increased. Increasing the heating power in this way makes the heating and thermal storage processes smoother and also helps to avoid energy waste to some extent.

[0028] Understandably, the first and second time intervals can be set according to actual needs. The purpose of the first and second time intervals is to allow the water temperature to rise and stabilize for a period of time after each increase in the heating level. This can prevent water temperature fluctuations from affecting the temperature judgment logic and also prevent the preheater and postheater from being quickly increased to the maximum heating level, which is not much different from directly turning on the maximum heating level.

[0029] It is worth noting that although steps S120 and S140 both involve increasing the heating level, the actual control logic needs to determine whether to increase the heating level by judging the temperature. Therefore, it is possible that the heating level of the preheater or the postheater needs to be reduced due to excessively high water temperature, or the heat storage may be completed even if the preheater is not increased to the maximum heating level. The heating level control of the preheater and the postheater will be explained in detail below.

[0030] Reference Figure 3 As shown, in some embodiments, step S120 above, which involves increasing the heating level of the preheater according to a first time interval, includes: Step S210: Obtain the inlet water temperature and the first water flow rate of the inlet pipe; Step S220: In response to detecting that the inlet water temperature is lower than the first preset temperature, determine the first power increase value of the preheater from the current heating level to the next heating level, and determine the first target temperature based on the inlet water temperature, the first water flow rate and the first power increase value; Step S230: If the first target temperature is less than or equal to the second preset temperature, control the preheater to increase the heating level according to the first time interval, and the second preset temperature is less than the first preset temperature. Step S240: If the first target temperature is greater than the second preset temperature, control the preheater to maintain the current heating level.

[0031] Depend on Figure 1 As shown in the architecture diagram of the phase change thermal energy storage device, a temperature sensor is installed at the inlet pipe from the preheater to the energy storage tank to collect the inlet water temperature. A water flow sensor is also installed to collect the initial water flow rate entering the currently heated water. Since the water circulates in an internal loop during thermal storage, the initial water flow rate detected at the pump is equal to the water flow rate at the inlet pipe. If the detected inlet water temperature is lower than the first preset temperature, it indicates that the preheater's heating power is insufficient and the water temperature has not reached the first preset temperature. However, instead of directly increasing the preheater's heating level, the system further determines how much power the preheater needs to increase from the current heating level to the next level—the first power increase value. Then, based on the inlet water temperature, the first water flow rate, and the first power increase value, a first target temperature is determined. This first target temperature reflects the potential temperature change that increasing the preheater's heating level might result in given the current water flow rate and inlet water temperature. Therefore, the system further determines whether to increase the preheater's heating level to the next level based on the relationship between the first target temperature and the second preset temperature. If the first target temperature is less than or equal to the second preset temperature, the heating level is increased according to the first time interval. If the first target temperature is greater than the second preset temperature, it indicates that increasing the heating level under the current water flow or current inlet water temperature will cause problems such as excessively high water temperature. In this case, the preheater maintains the current heating level and does not increase the level.

[0032] The first and second preset temperatures are set according to actual needs. In some possible embodiments, the first preset temperature is 78°C and the second preset temperature is 73°C. The formula for calculating the first target temperature can be found in the following formula: Ttarg1=(THI+(14.3×△P1)÷QIN)≤73 Wherein, the first target temperature is Ttarg1, the inlet water temperature of the inlet pipe is THI, the inlet water flow rate of the inlet pipe is QIN, and the first power increase value is △P1.

[0033] Additionally, if the detected inlet water temperature is greater than or equal to the first preset temperature, it indicates that the water temperature is too high, and the preheater needs to be reduced in heating mode. If the preheater's heating mode is reduced to 0, the phase change thermal storage device will exit thermal storage mode.

[0034] Reference Figure 4 As shown, in some embodiments, step S120 above, which controls the preheater to increase its heating level according to a first time interval, includes: Step S310: Determine the first time the preheater previously increased its heating level. In step S320, in response to the duration between the current moment and the first upshift moment being greater than or equal to the first time interval, the preheater is controlled to increase the heating level.

[0035] Each time the preheater is upgraded, that heating level is maintained for at least a first time interval. During this first time interval, the preheater's heating level remains unchanged (including both increasing and decreasing the heating level) to ensure the water temperature stabilizes at that level. Therefore, when the aforementioned steps determine that the preheater needs to be upgraded, it is also necessary to determine whether the time between the current moment and the first moment of the previous upgrade has reached the first time interval. If the first time interval has not been reached, the upgrade is not performed. It is understandable that, to avoid frequent temperature checks during the first time interval, no temperature checks can be performed during the first time interval after the preheater is upgraded.

[0036] Reference Figure 5 As shown, in some embodiments, step S140 above, which involves increasing the heating level of the rear heater according to a second time interval, includes: Step S410: Obtain the inlet water temperature and the second water flow rate of the inlet water pipe; Step S420: In response to detecting that the inlet water temperature is lower than the first preset temperature, determine the second power increase value of the post heater from the current heating level to the next heating level, and determine the second target temperature based on the inlet water temperature, the second water flow rate and the second power increase value; Step S430: If the second target temperature is less than or equal to the third preset temperature, control the rear heater to increase the heating level according to the second time interval, and the third preset temperature is less than the first preset temperature. Step S440: If the second target temperature is greater than the third preset temperature, control the rear heater to maintain the current heating level.

[0037] With the preheater already at its maximum heating setting, the postheater can be activated to further increase the water temperature in the internal circulation loop. The method for increasing the heating setting of the postheater is similar to that of the preheater. If the inlet water temperature is detected to be lower than the first preset temperature, it indicates that the heating power of the postheater is insufficient and the water temperature has not reached the first preset temperature. However, the heating setting of the postheater is not directly increased at this time. Instead, the power increase required for the postheater to increase from the current heating setting to the next heating setting is determined, i.e., the second power increase value. Then, based on the inlet water temperature, the second water flow rate, and the second power increase value, the second target temperature is determined. The second target temperature reflects the temperature change that the increase in the postheater setting may result in under the current water flow rate and inlet water temperature. Therefore, the relationship between the second target temperature and the third preset temperature is used to determine whether to increase the postheater to the next heating setting. If the second target temperature is less than or equal to the third preset temperature, the heating level will be increased according to the second time interval. If the second target temperature is greater than the third preset temperature, it indicates that increasing the heating level under the current water flow or current inlet water temperature will cause problems such as excessively high water temperature. In this case, the post-heater will maintain the current heating level and will not increase the level.

[0038] The first and third preset temperatures are set according to actual needs. In some possible embodiments, the first preset temperature is 78°C and the third preset temperature is 73°C. The formula for calculating the second target temperature can be found in the following formula: Ttarg2=(THI+(14.3×△P2)÷QIN)≤73 Wherein, the second target temperature is Ttarg1, the inlet water temperature of the inlet pipe is THI, the inlet water flow rate of the inlet pipe is QIN, and the second power increase value is △P1.

[0039] Additionally, if the detected inlet water temperature is greater than or equal to the first preset temperature, it indicates that the water temperature is too high, and the post-heater needs to be reduced in heating mode. If the post-heater's heating mode is reduced to 0, the pre-heater's heating mode will be reduced in heating mode.

[0040] Reference Figure 6 As shown, in some embodiments, step S140 above, which controls the rear heater to increase its heating level according to a second time interval, includes: Step S510: Determine the second boosting moment before the previous boosting of the rear heater; In step S520, in response to the duration between the current moment and the second up-level moment being greater than or equal to the second time interval, the rear heater is controlled to increase the heating level.

[0041] Each time the post-heater is upgraded, that heating level is maintained for at least a second time interval. During this second time interval, the heating level of the post-heater remains unchanged (including both increasing and decreasing the heating level) to ensure that the water temperature tends to stabilize at that heating level. Therefore, when the aforementioned steps determine that the post-heater needs to be upgraded, it is also necessary to determine whether the time between the current moment and the second time of the previous upgrade has reached the second time interval. If the second time interval has not been reached, the upgrade is not performed. It is understandable that, to avoid frequent temperature checks during the second time interval, no temperature checks can be performed during the second time interval after the post-heater is upgraded.

[0042] It is worth noting that the maximum heating power and heating level division of the preheater and the postheater can be different. By using the above method of starting the preheater first and then starting the postheater, the phase change thermal storage device can achieve multiple heating power combinations, optimize the thermal storage process, achieve smooth thermal storage, and avoid energy waste.

[0043] Reference Figure 7 As shown, in some embodiments, the thermal storage control method of this application further includes: Step S610: In response to detecting that the inlet water temperature is greater than or equal to the first preset temperature, determine the operating status of the post-heater; Step S620: If the post-heater is in operation, control the post-heater to reduce the heating level; Step S630: If the rear heater is in the off state, control the front heater to reduce the heating level.

[0044] When the detected inlet water temperature is greater than or equal to the first preset temperature, it indicates that the current water temperature is too high, and the phase change thermal storage device needs to reduce its heating power. Depending on the current operating status of the preheater and postheater, two processing methods are used. One method is that if both the preheater and postheater are running, the heating level of the postheater is reduced first; if the postheater's heating level is subsequently reduced to 0, then the heating level of the preheater is reduced. The other method is that if only the preheater is running, its heating level is reduced directly.

[0045] The above method, which involves turning off the post-heater before turning off the pre-heater, is also suitable for scenarios where thermal storage is nearing completion. For example, when it is determined that the cumulative thermal storage value of this thermal storage condition is close to the preset thermal value (e.g., reaching 80% of the preset thermal value), or when it is determined that the duration of this thermal storage condition is close to the preset duration threshold (e.g., reaching 75% of the preset duration threshold), step S620 or step S630 can be executed to reduce the heating power of the phase change thermal storage device, thereby avoiding a situation where the water temperature is still relatively high after thermal storage is completed.

[0046] Reference Figure 8 As shown, in some embodiments, step S110 above, in response to the phase change thermal storage device entering thermal storage mode, involves starting the preheater, including: Step S710: Control the operation of the water valve of the phase change thermal storage device to form an internal circulation loop connecting the heat exchanger; Step S720: Obtain the inlet water temperature of the inlet pipe, and determine the initial heating level to start the preheater based on the inlet water temperature.

[0047] After entering the thermal storage mode, the thermostatic valve switches its internal valves to connect the inlet and outlet pipes of the heat exchanger, and then starts the water pump and preheater. The initial heating level of the preheater can be determined based on the current inlet water temperature. If the current inlet water temperature is relatively high, it indicates that thermal storage has already been carried out for a period of time before this thermal storage mode, and the preheater starts at a lower heating level. If the current inlet water temperature is relatively low, the preheater starts at a higher heating level, which shortens the water heating time to some extent.

[0048] In some embodiments, after activating the preheater, the method further includes: Step S810: Determine the cumulative heat storage value based on the duration of the heat storage condition, the heating level of the preheater, and the heating level of the postheater. In step S820, in response to the duration of the thermal storage condition being greater than a preset duration threshold and the cumulative thermal storage value being greater than a preset calorific value, the phase change thermal storage device is controlled to exit the thermal storage condition, and / or, in response to the heating level of the preheater dropping to 0, the phase change thermal storage device is controlled to exit the thermal storage condition.

[0049] There are three conditions for exiting the thermal storage mode: first, the duration of thermal storage mode reaches a preset threshold; second, the calculated cumulative thermal storage calorific value reaches a preset value; and third, the heating level of the preheater drops to 0. The first two conditions are used in combination and are generally suitable for situations where thermal storage has not been performed for a long time, ensuring that the thermal storage calorific value of the phase change material is sufficient. The third condition is triggered by the inlet water temperature being greater than or equal to a first preset temperature, causing the phase change thermal storage device to reduce its heating power. Ultimately, after both the preheater and the postheater are shut down, the phase change thermal storage device exits the thermal storage mode.

[0050] In summary, the phase change thermal storage device heats the phase change material by heating water during thermal storage. First, the preheater is activated to heat the water flowing through the inlet pipe, and the heating level of the preheater is increased according to a first time interval. If the inlet water temperature is still lower than the first preset temperature when the preheater reaches its maximum heating level, it indicates insufficient heating power. At this time, the postheater is activated to heat the water flowing through the outlet pipe, and the heating level of the postheater is increased according to a second time interval. The embodiment of this application gradually increases the heating power of the thermal storage condition by activating the preheater first and then the postheater. Different combinations of heating levels can be used to match the current thermal storage value of the phase change material, making the thermal storage process smooth and avoiding the problem of excessive or insufficient heating power, thus optimizing the energy consumption of the thermal storage condition.

[0051] The following is a detailed explanation of the thermal storage control method of this application through a specific example.

[0052] Reference Figure 1 and Figure 9 As shown, when the phase change water heater is triggered to enter the heat storage mode, the thermostatic valve switches the internal valve to connect the inlet and outlet pipes of the heat exchanger, turns on the water pump and starts the preheater.

[0053] a. Determine whether the cumulative heat storage value of this heat storage condition is greater than or equal to 10,000 and the duration of the heat storage condition is greater than or equal to 1 hour; b. If the conditions of step a are not met, determine whether the preset time interval has been completed. If the conditions of step a are met, exit the thermal storage mode. c. After the preset time interval is completed, determine whether the inlet water temperature THI of the inlet pipe is greater than or equal to 78℃. If yes, control the heating power of the phase change water heater to decrease by one level. If no, determine whether the current heating power has reached the maximum heating level N. d. After reducing the heating power of the phase change water heater by one level, determine whether the heating power of the phase change water heater is 0. If yes, exit the heat storage mode; otherwise, proceed to step g. e. If the maximum heating level N has been reached, return to step a and repeat the judgment. If the maximum heating level N has not been reached, determine whether the condition for increasing the heating power level by one level has been met. f. If the condition for increasing the heating power level by one level is met, control the phase change water heater to increase the heating power by one level; otherwise, return to step a and repeat the judgment. g. Recalculate the preset interval time. In this example, the preset interval time is 60 seconds. After the preset interval time is completed, return to step a and repeat the judgment.

[0054] The condition for the above heating power +1 is as follows: Ttarg=(THI+(14.3×△P)÷QIN)≤73 Wherein, the target temperature is Ttarg, the inlet water temperature of the inlet pipe is THI, the inlet water flow rate of the inlet pipe is QIN, and the power increase value is △P, which is the power increase value of the preheater or postheater when it increases from the current heating level to the next heating level.

[0055] like Figure 10 As shown, Figure 10 This is a schematic diagram of a controller 1000 provided in one embodiment of this application.

[0056] The controller 1000 in this embodiment includes one or more processors 1001 and a memory 1002. Figure 10 The example uses a processor 1001 and a memory 1002.

[0057] Processor 1001 and memory 1002 can be connected via a bus or other means. Figure 10 Taking the example of a connection between China and Israel via a bus.

[0058] Memory 1002, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory 1002 may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory 1002 may optionally include memory 1002 remotely located relative to processor 1001, and these remote memories can be connected to controller 1000 via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0059] Those skilled in the art will understand that Figure 10 The device structure shown does not constitute a limitation on the controller 1000 and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0060] This application also provides a phase change water heater, including the aforementioned controller 1000.

[0061] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network nodes. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0062] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0063] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0064] In the several embodiments provided in this application, it should be understood that the disclosed systems, instruments, and methods can be implemented in other ways. For example, the instrument embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between instruments or units may be electrical, mechanical, or other forms. Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0065] It should also be understood that the various implementation methods provided in this application can be combined arbitrarily to achieve different technical effects.

[0066] The above is a detailed description of the preferred embodiments of this application. However, this application is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for controlling the thermal storage of a phase change thermal storage device, characterized in that, The phase change thermal storage device includes a heat exchanger, a preheater, and a postheater. The preheater is used to heat water flowing through the inlet pipe of the heat exchanger, and the postheater is used to heat water flowing through the outlet pipe of the heat exchanger. The method includes: In response to the phase change thermal storage device entering thermal storage mode, the preheater is started; The heating level of the preheater is increased according to the first time interval; If the heating level of the preheater reaches the maximum heating level of the preheater and the inlet water temperature of the inlet pipe is detected to be lower than the first preset temperature, the rear heater is activated. The heating level of the rear heater is increased according to the second time interval.

2. The method according to claim 1, characterized in that, The step of increasing the heating level of the preheater according to the first time interval includes: Obtain the inlet water temperature and the first water flow rate of the inlet water pipe; In response to detecting that the inlet water temperature is lower than the first preset temperature, a first power increase value is determined for the preheater to increase from the current heating level to the next heating level, and a first target temperature is determined based on the inlet water temperature, the first water flow rate, and the first power increase value; If the first target temperature is less than or equal to the second preset temperature, the preheater is controlled to increase the heating level according to the first time interval, and the second preset temperature is less than the first preset temperature. If the first target temperature is greater than the second preset temperature, the preheater is controlled to maintain the current heating level.

3. The method according to claim 2, characterized in that, The step of controlling the preheater to increase its heating level according to the first time interval includes: Determine the first time the preheater previously increased its heating level; In response to a time interval greater than or equal to a first time interval between the current moment and the first time of gear increase, the preheater is controlled to increase the heating level.

4. The method according to claim 1, characterized in that, The step of increasing the heating level of the rear heater according to the second time interval includes: Obtain the inlet water temperature and the second water flow rate of the inlet water pipe; In response to detecting that the inlet water temperature is lower than the first preset temperature, a second power increase value is determined for the post heater to be upgraded from the current heating level to the next heating level, and a second target temperature is determined based on the inlet water temperature, the second water flow rate, and the second power increase value; If the second target temperature is less than or equal to the third preset temperature, the rear heater is controlled to increase the heating level according to the second time interval, and the third preset temperature is less than the first preset temperature; If the second target temperature is greater than the third preset temperature, the rear heater is controlled to maintain the current heating level.

5. The method according to claim 4, characterized in that, The step of controlling the rear heater to increase the heating level according to the second time interval includes: Determine the second boosting moment of the rear heater before the previous boosting of the heating level; In response to the duration between the current moment and the second up-level moment being greater than or equal to the second time interval, the rear heater is controlled to increase the heating level.

6. The method according to claim 1, characterized in that, The method further includes: In response to detecting that the inlet water temperature is greater than or equal to the first preset temperature, the operating status of the post-heater is determined; If the post-heater is in operation, control the post-heater to reduce the heating level; If the rear heater is in the off state, control the front heater to reduce the heating level.

7. The method according to claim 1, characterized in that, The step of activating the preheater in response to the phase change thermal storage device entering thermal storage mode includes: The water valves of the phase change thermal storage device are controlled to form an internal circulation loop connecting the heat exchanger; Obtain the inlet water temperature of the inlet pipe, and determine the initial heating level to control the preheater to start based on the inlet water temperature.

8. The method according to claim 1, characterized in that, After activating the preheater, the method further includes: The cumulative heat storage value is determined based on the duration of the heat storage condition, the heating level of the preheater, and the heating level of the postheater. In response to the duration of the thermal storage condition exceeding a preset duration threshold and the cumulative thermal storage calorific value exceeding a preset calorific value, the phase change thermal storage device is controlled to exit the thermal storage condition, and / or, in response to the heating level of the preheater dropping to 0, the phase change thermal storage device is controlled to exit the thermal storage condition.

9. A controller, characterized in that, It includes at least one processor and a memory for communicatively connecting with said at least one processor; The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the thermal storage control method as described in any one of claims 1 to 8.

10. A phase change water heater, comprising the controller as described in claim 9.

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