An adaptive cooperative control method and system for a direct-fired heat pump hot water unit

Abstract

The application provides a self-adaptive cooperative control method and system of a direct heating type heat pump hot water unit, the method obtains operation parameters to generate a temperature control demand mark and a direct heating control state quantity; calculates a plate heat exchanger safety margin value according to the direct heating control state quantity and determines a plate heat exchanger safety state; generates an action permission relationship containing the action permission strength of a compressor and a water pump and a window mutual exclusion lock mark according to the plate heat exchanger safety state; and generates a compressor frequency adjustment action and a water pump speed adjustment action according to the temperature control demand mark and the action permission relationship. The application makes a unified decision on the temperature control demand and the plate heat exchanger safety state, avoids the simultaneous effect of the compressor frequency increase and the water pump speed reduction through the window mutual exclusion constraint, effectively prevents the heat load concentration, reduces the temperature overshoot probability, and improves the unit operation stability.

Description

Technical Field

[0001] This invention belongs to the field of heat pump water heating equipment control technology, and particularly relates to an adaptive collaborative control method and system for direct-heating heat pump water heating units. Background Technology

[0002] Direct-heating heat pump water heaters are a type of hot water preparation equipment that transfers heat from air sources, waste heat sources, or other low-grade heat sources to the water side through refrigerant circulation. The chilled water is then heated to a set temperature in a single pass through a plate heat exchanger before being sent to a water tank or the user's end. Compared to circulating water heaters, direct-heating units have shorter water-side residence times, larger single-pass temperature rises, and more concentrated plate heat exchange loads. The stability of the outlet water temperature depends not only on the compressor's heating capacity but also on the water-side heat carrying capacity provided by the pump and the system's stable state after the three-way valve switching. Existing direct-heating heat pump water heaters typically employ outlet water temperature threshold control, zone control, or closed-loop control methods where the compressor and pump are relatively independent. This means that the unit should be loaded, maintained, or unloaded based on the deviation between the plate heat exchanger outlet water temperature and the set hot water temperature, and further adjustments are made to the compressor frequency and pump speed. When the outlet water temperature is too low, the controller may increase the heating capacity by increasing the compressor frequency or increase the temperature rise per unit volume of water by decreasing the water pump speed. When the outlet water temperature is too high, the controller may decrease the compressor frequency or increase the water pump speed to lower the outlet water temperature. From the perspective of the effect of a single actuator, the above actions can improve the outlet water temperature deviation. However, under the direct heating and high temperature rise conditions, the adjustment results of the compressor and water pump ultimately affect the plate heat exchanger simultaneously. The two are not independent actuators. If the compressor frequency increase and the water pump speed decrease occur simultaneously within the same control window, on the one hand, the heating intensity on the refrigerant side increases, and on the other hand, the heat removal capacity of the water side decreases. This can easily cause the heat load on the plate heat exchanger per unit volume of water to rise rapidly, resulting in problems such as outlet water temperature overshoot, high-pressure side fluctuations, increased exhaust temperature, or insufficient heat exchange at low flow rates. On the other hand, existing minimum water flow protection systems typically only stop the pump from further reducing its speed after the water flow reaches the lower limit. This is end-point protection and makes it difficult to promptly identify risks where the heat exchanger is already under pressure or strain even though the water flow has not yet exceeded the limit. Furthermore, the pressure and heat exchange status of the three-way valve are not yet stable after switching. If a fixed temperature difference threshold is still applied rapidly at this time, it may amplify system fluctuations. Therefore, the main deficiency of existing technologies lies in the fact that while outlet water temperature threshold control can provide a direction for temperature adjustment, it lacks a heat exchanger safety judgment mechanism that unifies this temperature control requirement with water flow, compressor frequency, pump speed, and valve stability. It also lacks a collaborative constraint mechanism that further transforms the heat exchanger safety level into a permissible relationship between the compressor and pump actions. This results in correct temperature adjustment direction but unreasonable action combinations, making it difficult to balance heating rate, outlet water stability, and heat exchanger safety boundaries in engineering scenarios involving direct heating, large temperature rise heat exchange, and dual-actuator coupled regulation. Summary of the Invention

[0003] This invention discloses an adaptive collaborative control method and system for a direct-heating heat pump water heater unit to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, a first aspect of the present invention provides an adaptive cooperative control method for a direct-heating heat pump water heater unit, the method comprising: The operating parameters of the direct-heating heat pump water heater are obtained, and a temperature control requirement mark is generated based on the plate heat exchanger outlet water temperature and the hot water set temperature. The direct-heating control status quantity is generated based on the operating parameters and the temperature control requirement mark. The plate heat exchanger safety margin value is calculated based on the direct heating control state quantity, and the plate heat exchanger safety state is determined based on the plate heat exchanger safety margin value and the water flow rate in the operating parameters. Based on the aforementioned safety status of the power supply, an action permission relationship is generated. The action permission relationship includes compressor frequency increase permission strength, compressor frequency decrease permission strength, water pump speed increase permission strength, water pump speed decrease permission strength, and a window mutual exclusion lock flag. Based on the temperature control requirement flag and the action permission relationship, compressor frequency adjustment action and water pump speed adjustment action are generated to control the compressor and water pump.

[0005] Furthermore, the operating parameters include the heat exchanger outlet water temperature, the hot water set temperature, water flow rate, compressor frequency, water pump speed, and the time elapsed after the three-way valve is switched. The process of generating a temperature control requirement flag based on the heat exchanger outlet water temperature and the set hot water temperature includes: Based on the heat exchanger outlet water temperature, the hot water set temperature, and the temperature buffer boundary, the temperature control requirement is marked and determined as a loading requirement, a holding requirement, a fine-tuning requirement, or an unloading requirement.

[0006] Furthermore, the direct heating control status parameters include the temperature control demand flag, the water flow rate, the compressor frequency, the water pump speed, and the elapsed time after the three-way valve switches.

[0007] Further, the calculation of the plate heat exchanger safety margin value based on the direct heating control state includes: Calculate the flow margin based on the water flow rate, the minimum allowable flow boundary, and the safe flow reference boundary; Calculate the compressor frequency margin based on the compressor frequency, medium heating reference frequency, and high heating reference frequency; Calculate the pump speed margin based on the pump speed, minimum allowable pump speed, and safe pump speed reference value; The stability margin of the three-way valve is calculated based on the elapsed time after the three-way valve switching and the three-way valve stabilization reference time. The minimum value among the water flow margin, the compressor frequency margin, the water pump speed margin, and the three-way valve stability margin is taken as the basic margin; When the temperature control requirement is marked as the loading requirement, a correction term for the superposition of low water flow and high compressor frequency is calculated based on the water flow and the compressor frequency, and a correction term for the superposition of three-way valve instability and high compressor frequency is calculated based on the elapsed time after the three-way valve switching and the compressor frequency. The plate heat exchanger safety margin value is calculated based on the basic margin, the low water flow rate and high compressor frequency superposition correction term, and the three-way valve instability and high compressor frequency superposition correction term.

[0008] Further, determining the heat exchanger safety status based on the heat exchanger safety margin value and the water flow rate in the operating parameters includes: When the water flow rate is less than or equal to the minimum allowable water flow boundary, the safe state of the plate heat exchanger is determined to be a dangerous state. When the water flow rate is greater than the minimum allowable water flow boundary, the safety status of the transformer is determined as a safe status, a restricted status, a tense status, or a dangerous status based on the transformer safety margin value, the first level boundary, the second level boundary, and the third level boundary. Wherein, the first level boundary is smaller than the second level boundary, and the second level boundary is smaller than the third level boundary.

[0009] Further, the step of generating an action permission relationship based on the board switch safety status includes: When the plate heat exchanger is in the safe state, the compressor frequency increase permit strength, the compressor frequency decrease permit strength, the water pump speed increase permit strength, and the water pump speed decrease permit strength are all set to the normal amplitude permit value; When the plate heat exchanger safety state is the restricted state, the compressor frequency increase permit intensity is set to the restricted amplitude permit value, the water pump speed reduction permit intensity is set to the prohibited permit value, and the compressor frequency reduction permit intensity and the water pump speed increase permit intensity are set to the normal amplitude permit value. When the plate heat exchanger safety state is the tense state, the compressor frequency increase permit strength and the water pump speed decrease permit strength are set to the prohibited permit value, and the compressor frequency decrease permit strength and the water pump speed increase permit strength are set to the normal amplitude permit value; When the safe state of the plate heat exchanger is the dangerous state, the frequency reduction permit strength of the compressor and the speed increase permit strength of the water pump are both set to the priority amplitude permit value.

[0010] Furthermore, the window-to-window mutual exclusion lock flag is used to indicate that the compressor frequency increase action and the water pump speed decrease action are prohibited from being selected simultaneously within the same control window; The step of generating compressor frequency adjustment actions and water pump speed adjustment actions based on the temperature control requirement marker and the action permission relationship includes: Based on the temperature control requirement flag, the compressor frequency increase permission strength, the compressor frequency decrease permission strength, the water pump speed increase permission strength, the water pump speed decrease permission strength, and the window mutual exclusion lock flag, determine the compressor frequency increase action selection flag, the compressor frequency decrease action selection flag, the water pump speed increase action selection flag, and the water pump speed decrease action selection flag.

[0011] Further, determining the compressor frequency increase action selection flag, compressor frequency decrease action selection flag, water pump speed increase permission flag, and water pump speed decrease action selection flag based on the temperature control requirement flag, the compressor frequency increase permission strength, the compressor frequency decrease permission strength, the water pump speed increase permission strength, the water pump speed decrease permission strength, and the window mutual exclusion lock flag includes: When the safe state of the plate heat exchanger is the dangerous state, the compressor frequency reduction action selection flag and the water pump speed increase action selection flag are set to valid values, and the compressor frequency increase action selection flag and the water pump speed reduction action selection flag are set to invalid values. When the temperature control requirement is marked as the loading requirement and the compressor frequency increase permit strength is valid, the compressor frequency increase action selection flag is set to a valid value, and the water pump speed reduction action selection flag is set to an invalid value according to the window mutual exclusion lock flag. When the temperature control requirement is marked as the fine-tuning requirement and the water pump speed increase permit strength is valid, the water pump speed increase action selection flag is set to a valid value; When the temperature control requirement is marked as the unloading requirement, the compressor frequency reduction action selection flag and the water pump speed increase action selection flag are set to valid values.

[0012] Furthermore, the step of generating compressor frequency adjustment actions and water pump speed adjustment actions based on the temperature control requirement marker and the action permission relationship also includes: The compressor frequency adjustment amount is calculated based on the compressor frequency increase action selection flag, the compressor frequency decrease action selection flag, the compressor frequency increase allowable strength, the compressor frequency decrease allowable strength, the compressor basic frequency increase step size, and the compressor basic frequency decrease step size. The pump speed adjustment amount is calculated based on the pump speed increase action selection mark, the pump speed decrease action selection mark, the pump speed increase allowable intensity, the pump speed decrease allowable intensity, the pump speed increase ratio, the pump speed decrease ratio, and the current pump speed. The compressor frequency adjustment action is generated based on the compressor frequency adjustment amount, and the water pump speed adjustment action is generated based on the water pump speed adjustment amount.

[0013] A second aspect of the present invention provides an adaptive cooperative control system for a direct-heating heat pump water heater, the system comprising: The data acquisition module is used to obtain the operating parameters of the direct-heating heat pump water heater unit; The temperature control demand generation module is used to generate a temperature control demand flag based on the plate heat exchanger outlet water temperature and the hot water set temperature, and to generate a direct heating control status quantity based on the operating parameters and the temperature control demand flag. The plate heat exchanger safety status determination module is used to calculate the plate heat exchanger safety margin value based on the direct heating control status quantity, and determine the plate heat exchanger safety status based on the plate heat exchanger safety margin value and the water flow rate in the operating parameters. The action permission relationship generation module is used to generate action permission relationships based on the board switch safety status. The action permission relationships include compressor frequency increase permission strength, compressor frequency decrease permission strength, water pump speed increase permission strength, water pump speed decrease permission strength, and window mutual exclusion lock flag. The collaborative execution module is used to generate compressor frequency adjustment actions and water pump speed adjustment actions based on the temperature control requirement marker and the action permission relationship, so as to control the compressor and water pump.

[0014] The beneficial technical effects of the present invention are at least as follows: To address the aforementioned issues, this invention provides an adaptive collaborative control method and system for direct-heating heat pump water heaters. It improves upon the traditional method of directly driving actuator action based on outlet water temperature deviation by incorporating a continuous control chain that includes temperature control demand formation, plate heat exchanger safety status determination, action permission relationship generation, and collaborative execution by two actuators. By comprehensively considering water flow rate, compressor frequency, pump speed, and three-way valve stabilization time, the plate heat exchanger safety margin is calculated. Risk corrections are implemented for the superposition of low water flow rate and high compressor frequency, and the superposition of three-way valve instability and high compressor frequency, accurately identifying heat exchange risks under direct-heating high-temperature-rise conditions. By introducing a window-based mutual exclusion lock, the simultaneous effectiveness of compressor frequency increase and pump speed decrease within the same control window is strictly limited, effectively avoiding the problem of concentrated heat load caused by the superposition of increased refrigerant-side heating and decreased water-side heat carrying capacity. This solution can preemptively limit low-flow risks, reduce the probability of temperature overshoot and protective shutdown, and significantly improve the unit's operational stability and overall energy efficiency under complex conditions such as direct-heating primary heating, high-temperature-rise heat exchange, and loading after valve switching. Attached Figure Description

[0015] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0016] Figure 1This is a flowchart of the adaptive cooperative control method for the direct-heating heat pump water heater of the present invention.

[0017] Figure 2 This is a framework diagram of the adaptive cooperative control system for the direct-heating heat pump water heater unit of the present invention.

[0018] Figure 3 This is a schematic diagram of the computer equipment framework for adaptive cooperative control of a direct-heating heat pump water heater unit according to the present invention. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] like Figure 1 As shown in the figure, this application provides an adaptive cooperative control method for a direct-heating heat pump water heater unit. This method is executed by the main control board of the unit and specifically includes the following steps: Step S101: Obtain the operating parameters of the direct-heating heat pump water heater unit, generate a temperature control requirement flag based on the plate heat exchanger outlet water temperature and the hot water set temperature, and generate a direct-heating control state quantity based on the operating parameters and the temperature control requirement flag.

[0021] Specifically, step S101 is used to generate direct-heating control state variables at the beginning of each control cycle. This step is based on the commonly used outlet water temperature threshold control of existing heat pump water heaters. It determines the current temperature adjustment direction of the unit by analyzing the relationship between the heat exchanger outlet water temperature and the set hot water temperature. This temperature adjustment direction, along with relevant heat exchanger operating information, is then combined into a unified state variable used in subsequent steps. The heat exchanger in a direct-heating heat pump water heater undertakes a one-time large temperature rise task. A low outlet water temperature reflects the temperature rise demand, while specific actions such as compressor frequency increase and water pump speed decrease need to be determined comprehensively based on the water-side heat carrying capacity, refrigerant-side heating intensity, water pump operating position, and the stability of the three-way valve. Therefore, this step unifies the temperature demand with the operating conditions of the direct-heating heat exchanger, enabling subsequent steps to continue determining the heat exchanger's safety status based on the same underlying conditions.

[0022] This step involves the unit's local controller reading six types of equipment operating information: plate heat exchanger outlet water temperature. Hot water setting temperature Water flow compressor frequency Pump speed After switching to the three-way valve, time elapsed .in, Temperature data is collected by a temperature sensing element installed on the heat exchanger outlet pipe and read through the temperature acquisition port of the main control board. The parameters are written to the main control board parameter area by the unit control panel, wired controller, or upper controller. Provided by a continuous water flow detection element, in models equipped with a water flow switch, the equivalent water flow state can be obtained by combining the effective signal of the water flow switch with the corresponding relationship of the current operating gear or speed of the water pump. Continuous detection values ​​should be given priority in engineering implementation. The compressor inverter driver returns the current actual operating frequency of the compressor to the main control board. The pump speed command returned by the pump driver can be used as the equivalent operating value in models where the pump driver does not return the actual speed. Generated by an internal timer on the main control board, the timer is reset and restarted whenever a three-way valve switching command is issued. All of the above information comes from the unit's local control components and reflects the temperature requirements and plate heat exchanger-related operating conditions of the direct-heating heat pump water heater within the current control cycle.

[0023] The above-mentioned data collection quantities are processed using standardized engineering units and the same control cycle before being incorporated into control calculations. and Using Celsius, Use liters per minute or cubic meters per hour, consistent with the units for the water flow boundaries in the parameter table. Using Hertz, Use rotation per minute or pump driver percentage commands, consistent with the pump parameter table. The system operates on a second-by-second basis. Within a control cycle, the main control board prioritizes data from the same sampling time or the same buffer window. If a sensor refresh times out, driver feedback is invalid, the three-way valve timing status is lost, or the water flow detection value clearly contradicts the water flow switch status, the controller does not directly enter loading or pump deceleration direction control. Instead, it maintains the current frequency and pump speed, enters a safety hold state, or handles the situation according to a fault protection strategy. This prevents abnormal sampling from being mistaken for true board replacement safety margins.

[0024] The controller first based on and Generate temperature control requirement tags The original basis for this marking is the dead-zone threshold control commonly used in control engineering, which sets a hold zone near the target value to reduce frequent switching caused by small fluctuations. Based on this, this application divides the outlet water temperature of the direct-heating heat pump water heater unit into four demand states, so that the outlet water temperature is significantly insufficient, close to the target, slightly higher than the target, and significantly higher, respectively, corresponding to different temperature control requirements. Specifically, it can be determined by the following formula: ; in, Temperature control requirements are marked and generated by the main control board within the current control cycle; This indicates a loading requirement, suggesting that the current outlet water temperature is significantly insufficient. This indicates that demand will continue, meaning the current outlet water temperature is within the allowable stable range. This indicates a need for fine-tuning, meaning the current water temperature is slightly high but still suitable for gentle adjustment; This indicates an unloading requirement, suggesting that the current outlet water temperature is too high and the plate heat exchanger load should be reduced. The outlet water temperature of the plate heat exchanger is determined by the temperature detection element in the outlet water pipeline. Set the temperature for hot water from the control panel, wired controller, or host controller; , , The temperature buffer boundary is pre-written into the main control board parameter area. These three areas are used to form the boundaries between the loading area, holding area, fine-tuning area, and unloading area, and are usually set to... Greater than This establishes a clear sequence between the fine-tuning area and the unloading area. The aforementioned segmented judgment converts the traditional temperature deviation into a temperature control requirement marker, enabling subsequent steps to make action permission judgments based on this marker and the circuit breaker's safety status.

[0025] , and and , Using the same temperature unit, the values ​​can be derived from the required accuracy of the outlet water temperature control, the allowable error of the temperature sensor, the allowable fluctuation range of the hot water temperature on the user side, and the unit's commissioning parameters, and generally meet the following requirements. , , To avoid fluctuations in water temperature near the boundary, which could lead to... With frequent switching, the main control board can require the segmented results to remain continuously for several control cycles before updating. Alternatively, the hysteresis values ​​for load exit and unload exit can be set in the parameter area. This process gives the temperature control requirement marker a defined generation method and stability constraints.

[0026] In one engineering setup, the hot water set temperature Take 55, buffer boundary Take 1, Take 1, Select 3. When the controller reads the outlet water temperature of the plate heat exchanger. When the value is 52, since 52 is less than 55 minus 1, the temperature control requirement is marked. Pick This indicates that there is currently a loading requirement. If the controller reads... If the value is 56.5, then it is greater than 55 plus 1 and not greater than 55 plus 3, indicating the temperature control requirement. Pick This indicates that a fine-tuning requirement is currently in place. This segmented approach is suitable for the operating characteristics of direct-heating units: when the outlet water temperature is lower than the target, a loading requirement is generated first; when the outlet water temperature is slightly higher, a fine-tuning requirement is generated first. Whether the compressor or the water pump is activated is further determined by the subsequent circuit breaker safety status and action permission relationship.

[0027] In obtaining Then, the controller continued reading. , , and and with them Synthesized into direct-heat control state variables This state variable adopts the state vector representation method in control engineering, concentrating the key states required for subsequent judgment of the heat exchanger's safety status into the state input for the current cycle. The state content selected in this application is directly related to the safe heat exchange of the direct-heating plate heat exchanger and the coordinated relationship between the compressor and water pump: Indicates the direction of temperature adjustment. Indicates the water-side heat carrying capacity. Indicates the heating intensity on the refrigerant side. Indicates the current adjustment position of the water pump. This represents the stable phase after valve switching. Its structure can be represented as: ; in, This is a direct heating control state variable, generated by the main control board within the current control cycle; Mark the aforementioned temperature control requirements; This is the water flow rate, used to subsequently determine the water's ability to carry away heat. This is the compressor frequency, used to subsequently determine the refrigerant-side heating intensity. This is the water pump speed, used to subsequently determine the water-side adjustment position; This represents the elapsed time after the three-way valve switching, used to determine whether the system is in the load-sensitive phase following the valve switching. This formula is a state combination expression, indicating that the controller writes multiple operating states into the current cycle state value in a fixed order for the next step to read.

[0028] For example, within a certain control cycle, the controller reads... It is 55. The value is 52, preset. For 1, For 1, If the value is 3, then according to the aforementioned segmentation rules, we get... Subsequently, the main control board reads the water flow detection element to obtain... The value is 18, obtained by reading the compressor inverter driver. The value is 72, obtained from reading the water pump driver. The value is 1400, obtained from reading the three-way valve timer. If the value is 12, then the direct-heating control state variable formed in this cycle can be expressed as: This state variable indicates that the unit currently has a loading demand, and also records the current water-side heat carrying capacity, compressor heating intensity, water pump operating position, and three-way valve stability. For example, when... For 55, 56.5 For 1, When the value is 3, the controller receives If at this time higher In the medium operating range It still has adjustment margin and If the valve's settling time has been exceeded, subsequent steps can be based on this to determine that the heat exchanger is operating under conditions suitable for fine-tuning. Therefore, By placing temperature control requirements and direct heat exchanger operating conditions into the same control entry point, it is easier to process them continuously in subsequent steps.

[0029] This step outputs the direct heating control status quantity. This variable is generated by the main control board within the current control cycle and serves as the input for determining the board's safety status in the next step. The next step directly uses... In , , , and Based on the unified temperature control requirements and related operating conditions of the heat exchanger, the safety status of the heat exchanger is further determined. Through this step, the existing outlet water temperature threshold control is used to form a temperature control requirement marker, which, together with water flow rate, compressor frequency, water pump speed, and three-way valve stability information, is used in subsequent judgments, thereby providing a unified state basis for the coordinated control of subsequent compressor and water pump operations. The state values ​​are simply stored in a fixed field order and do not represent the direct addition or comparison of quantities in different physical units; subsequent formulas only convert the running values ​​and corresponding boundaries of the same type of unit.

[0030] Step S102: Calculate the plate heat exchanger safety margin value based on the direct heating control state quantity, and determine the plate heat exchanger safety state based on the plate heat exchanger safety margin value and the water flow rate in the operating parameters.

[0031] Specifically, step S102 is based on the direct heating control state quantity output in step S101. Determine the safety status of the plate heat exchanger Step S101 has been completed. ,in This indicates the current demand for direct heating temperature control. This indicates the current water-side heat carrying capacity. This indicates the current heating intensity of the compressor. Indicates the current operating position of the water pump. This indicates the stabilization process after the three-way valve switches. This step directly reads... The entire content of the process is transformed into a safe state for the heat exchanger that can be used in subsequent action permission relationships. The engineering basis of this step comes from the safety margin evaluation method in control engineering, which transforms the position of the operating quantity relative to the safety boundary into a normalized margin, and then classifies the operating state according to the size of the margin. This application makes improvements based on this, combined with the special operating conditions of direct-heating heat pump water heaters: direct-heating plate heat exchangers are simultaneously affected by the heating intensity on the refrigerant side and the heat carrying capacity on the water side during a one-time large temperature rise. Therefore, in addition to considering the worst-case value of each margin, risk corrections for "low water flow rate superimposed with high compressor frequency" and "three-way valve instability superimposed with high compressor frequency" are further introduced, so that the safe state of the heat exchanger can reflect the heat load concentration problem that is prone to occur during direct-heating loading.

[0032] controller from Read from , , , and Then, first according to Determine the focus of the current security assessment. When At this time, there is a current loading demand, and subsequent actions may involve increasing the compressor frequency or maintaining a high heating intensity. This step focuses on determining whether the heat exchanger has the capacity to continue loading; when At this point, the current requirement is for fine-tuning. This step focuses on determining whether the water flow rate and pump location are still suitable for pump adjustment; when At this time, the current requirement is to maintain operations; this step focuses on determining whether the current operating state is suitable for maintenance. At this time, the current situation is under unloading demand. This step guides the plate heat exchanger's safe state towards a direction that facilitates subsequent reduction of heat load. Therefore, step S101 generates... This step is used for explanation , , and The safety implications, for example, the same ,exist Under the loading conditions, stronger constraints will be placed on the frequency increase and pump decrease operations, while In the context of unloading, it is mainly used to support the operation of pump boosting and frequency reduction.

[0033] The core calculation in this step is to determine the safety margin value for the heat exchanger. The initial source of this formula is the classical safety margin method and the normalized threshold evaluation method. Its basic idea is to compare the current operating value with a preset boundary using similar quantities to obtain a proportional value representing the degree of approach to the safety boundary. The derivation process of this application is as follows: First, construct the water flow margin, compressor frequency margin, water pump speed margin, and three-way valve stability margin respectively. Then, take the minimum value among the four to represent the plate heat exchanger safety being limited by the most unfavorable factor. Subsequently, two coupled correction terms are added for the direct-heat loading scenario. The low water flow and high compressor frequency superposition term is used to reflect the risk when the water-side heat carrying capacity is insufficient while the refrigerant-side heating intensity is high. The three-way valve instability and high compressor frequency superposition term is used to reflect the risk when the system is not yet stable after valve switching while the compressor is already in a high heating state. Specifically, it can be calculated using the following formula: ; in, The safety margin value for board replacement is generated by the main control board within the current control cycle; For water flow margin, by Relative to the minimum permissible flow boundary and safe flow reference boundary The conversion method is to convert the original text into a more coherent sentence or paragraph. Limited to the range of 0 to 1; Derived from the output of step S101 , and Pre-written into the main control board parameter area, and Higher than ; For compressor frequency margin, by Compared to the medium heating reference frequency and high heating reference frequency The conversion method is to convert the original text into a more coherent sentence or paragraph. Limited to the range of 0 to 1; Source , and Pre-written into the main control board parameter area, and Higher than ; For the pump speed margin, by Relative to the minimum permissible pump speed and safe water pump speed reference value The conversion method is to convert the original text into a more coherent sentence or paragraph. Limited to the range of 0 to 1; Source , and Pre-written into the main control board parameter area, and Higher than ; To ensure the stability margin of the three-way valve, by relative to the stabilization reference time of the three-way valve The conversion method is to convert the original text into a more coherent sentence or paragraph. Limited to the range of 0 to 1; Source , Pre-write parameters to the main control board's parameter area; To load the requirement tag, when When, take 1, when for , or Take 0 at time, Source ; A risk correction factor for the superposition of low water flow and high compressor frequency is written into the parameter area of ​​the main control board. This is a risk correction factor for the superposition of three-way valve instability and high compressor frequency, written into the main control board parameter area. Each margin in the formula is obtained by dividing the similar operating value by the similar boundary value. , , , , , and All are used for ratio evaluation. This is also a proportional evaluation value; the minimum margin term and the two correction terms on the right belong to the same evaluation scale and can be added or subtracted. During actual controller execution, each margin conversion result is limited: less than 0 is treated as 0, and greater than 1 is treated as 1; after completing risk correction, if... If it is less than 0, it will be used as 0 in subsequent level judgments. If the value is greater than 1, it will be used as 1 in subsequent level judgments to ensure the stability of subsequent level judgments.

[0034] The above boundary parameters all have corresponding engineering sources: The minimum allowable water flow rate of the plate heat exchanger, the pump anti-dry running requirements, or the unit's water flow protection value are all taken into account. Reference value for safe water flow that can stably remove heat under direct heating and high temperature rise conditions; and This information comes from the compressor's permissible operating frequency, rated thermal capacity range, and high-pressure side protection boundary. and These factors are derived from the minimum permissible speed of the water pump, the minimum circulation capacity required for plate heat exchange, and the stable operating range of the driver. These parameters are derived from the three-way valve's actuation time, the downstream pressure stabilization time, and the heat exchange stabilization time. Each denominator should meet the following requirements before being written into the parameter area. , , , To avoid division by zero or incorrect direction; and The dimensionless correction coefficient can be limited to... to Within the specified range, and determined by prototype debugging, historical protection shutdown records, or factory parameter sheets. If , , or If any key input is invalid, the controller will not use the high margin result from the previous cycle to continue loading, but will instead load the current cycle's result. Direct traffic to the stressed or dangerous side, and prioritize maintaining the frequency reduction and pump boost actions.

[0035] In the above formula, This indicates that the safe operating condition of the plate heat pump is determined by the weakest operating condition. For example, when the water flow rate is close to the minimum boundary, even if the compressor frequency is not high, the plate heat pump is not suitable for continuing to increase the outlet water temperature by reducing the pump speed; immediately after the three-way valve switches, even if there is still room for the pump speed, it is not suitable to quickly increase the compressor's heating intensity. The two corrections following the first item reflect the scenario improvement for direct-heating heat pump water heaters: when hour, If 1 is selected, the loading requirement triggers a correction for the risk of direct hot loading; if lower and Lower, then An increase indicates a greater risk associated with the combined effects of low water flow and high compressor frequency; if lower and Lower, then An increase indicates a greater risk arising from the combination of an unstable three-way valve and a higher heating intensity. for , or hour, Taking 0, the safety margin for board replacement is mainly determined by the most unfavorable term among the four basic margins, suitable for state judgment under the background of maintenance, fine-tuning, or unloading. Thus, The temperature control requirement flag output from step S101 is fully incorporated into the safety margin calculation of this step. , , and These are also entered into the corresponding margin and correction terms, respectively.

[0036] In one engineering setup, the main control board parameter area is set... For 15, For 25, For 90, For 60, For 900, For 1500, The risk adjustment factor is 30. Take 0.25, Take 0.20. If the direct heating control state quantity output in step S101 is... ,but , Water flow margin Compressor frequency margin Pump speed margin Three-way valve stability margin The minimum of the four margins is 0.30. The combined effect of low water flow and high compressor frequency is corrected to... The instability of the three-way valve combined with the high compressor frequency was corrected to... ,therefore This result indicates that although there is a current loading demand, the water flow margin is low and the three-way valve stability margin is insufficient, placing the heat exchanger in a state unsuitable for strong loading or pump reduction. If in another cycle... In for ,but The two loading fixes are not included. Determined by the minimum of the four basic margins, it is more in line with the control logic under the background of fine-tuning.

[0037] The controller gets Then, it is converted to a safe state for the plate switch. This classification is derived from the threshold segmentation method commonly used in relay protection and graded control, which determines the corresponding control level based on the interval in which the evaluation value falls. This application applies this method to the safety state classification of direct-heating plate heat exchangers, setting the lowest water flow boundary as the condition for directly entering a dangerous state, so that subsequent action permission relationships can prioritize handling low water flow risks. Specifically, it can be determined by the following formula: ; in, To ensure a safe switching condition, the main control board determines the switching safety margin value. and water flow Sure; This indicates a safe state, and normal loading or fine-tuning is allowed subsequently. This indicates a restricted state; the pump speed should be limited and the load amplitude controlled accordingly. This indicates a tense situation, and subsequent actions that increase the plate heat exchanger load, such as increasing the compressor frequency and reducing the water pump speed, should be cancelled. This indicates a dangerous situation; in the subsequent steps, the water pump speed should be increased and the compressor frequency should be reduced. This is the safety margin value for plate heat exchange obtained from the previous formula; , , The preset level boundaries are written into the main control board parameter area and arranged from low to high. The output of step S101 Water flow rate in; This is the minimum allowable water flow boundary preset in the main control board parameter area. In the formula... , , and They belong to the same proportional evaluation scale. and When comparing the boundaries of similar water flows, the comparative relationships for segmented judgments are clear.

[0038] , and All are dimensionless level boundaries, preferably satisfying Its value can be determined jointly by the allowable temperature rise of the plate heat exchanger, the allowable overshoot value of the outlet water temperature, the high pressure protection margin, the exhaust temperature limit, the water flow protection boundary, and the results of commissioning tests. The main control board can also... Set the minimum hold period or recovery hysteresis, for example from Restore to or Time requirements The continuous period above the corresponding boundary prevents frequent jumps in the safety state of the heat exchanger near the boundary. This classification result directly determines the action permission relationship in step S103. It is not just an alarm status for display purposes, but the upstream constraint status of the actual control action.

[0039] Continuing with the above engineering settings, if the level boundary... , , If we set them to 0.20, 0.45, and 0.70 respectively, then the previously calculated... satisfy The controller will Determined as At this point, step S103 will be based on Generate a biased protection switch action permission relationship, such as allowing the water pump to increase speed and the compressor to decrease frequency, and revoking the water pump speed reduction permission. If calculated in another cycle... ,and Higher than ,but The controller will Determined as Subsequently, it may enter a restricted adjustment state. If And if the water flow rate is higher than the minimum allowable limit, then Determined as This indicates that the plate heat exchanger has a good safety margin in the current cycle. Through this classification, the safety status of the plate heat exchanger can reflect not only whether a single parameter has exceeded the limit, but also the direct heat exchange risk resulting from the superposition of multiple operating factors.

[0040] This step outputs a variable, namely the safety status of the plate switch. . The direct heating control status quantity output by the main control board in step S101 Generate, and In , , , and All of them have entered the calculation or judgment process in this step. This will be used as the input for generating the action permission relationship in step S103, which will be directly based on... Determine whether actions such as compressor frequency increase, water pump speed decrease, water pump speed increase, and compressor frequency decrease are permissible. Through this step, the temperature control requirements and equipment operating conditions formed in step S101 are transformed into the safe state of the plate heat exchanger, so that the subsequent coordinated actions of the compressor and water pump can be constrained by the current safe heat exchange boundary of the direct-heating plate heat exchanger.

[0041] Step S103: Generate an action permission relationship based on the board replacement safety status. The action permission relationship includes compressor frequency increase permission strength, compressor frequency decrease permission strength, water pump speed increase permission strength, water pump speed decrease permission strength, and window mutual exclusion lock mark.

[0042] Specifically, step S103 is based on the board replacement safety status output in step S102. Generate the permission relationship between the compressor and the water pump. Step S102 has already changed the direct heating control state. Transform into ,in This comprehensively reflects the safety level of the heat exchanger after considering the combined effects of current temperature control requirements, water flow margin, compressor heating intensity, water pump operating position, and the stabilization process of the three-way valve. This step is based on... As input, the current tolerable adjustment level of the heat exchanger is converted into the permissible action boundaries of the compressor and water pump within the current control window. This step is based on the state machine action mapping concept commonly used in industrial control, that is, determining the actuator action range according to the equipment safety state. On this basis, considering the characteristic of the compressor and water pump simultaneously acting on the heat exchanger in the heat pump unit of direct-heating heat pump, the ordinary single actuator action permission is extended to a dual actuator action permission relationship, and a mutual exclusion constraint of compressor frequency increase and water pump speed decrease within the same window is added. This improvement addresses the actual engineering risks of direct-heating plate heat exchangers: compressor frequency increase will increase the heating intensity on the refrigerant side, and water pump speed decrease will reduce the water side heat carrying capacity. When both occur simultaneously, the heat load on a unit volume of water will increase significantly, which can easily cause outlet water temperature overshoot, high-pressure side fluctuations, or low flow risks.

[0043] Controller Read Then, action permission relationships are generated according to the board replacement safety level. . This indicates that the heat exchanger is in a safe state and the current operating conditions allow for relatively complete adjustments, but the combination of compressor frequency increase and water pump speed decrease still needs to be constrained. This indicates that the plate heat exchanger is in a restricted state. Mild adjustments can still be made at present, but the pump speed reduction will weaken the water-side heat carrying capacity. Therefore, restricted frequency increase, frequency decrease and pump increase actions are retained in the action permission relationship. This indicates that the plate heat exchanger is under stress, and it is currently appropriate to reduce the heat load or enhance the water-side heat carrying capacity. Therefore, the frequency reduction and pump boosting actions are retained in the action permission relationship. This indicates that the heat exchanger is in a dangerous state. The current priority is to reduce the refrigerant-side heating intensity and increase the water-side heat carrying capacity. Therefore, in the action permission relationship, frequency reduction and pump boosting are set as priority actions. This process makes the heat exchanger safety status obtained in step S102 the sole basis for action permission in step S103. Step S103 no longer recalculates the heat exchanger margin, but instead... Step S104 can be transformed into the selection of action boundaries that can be directly executed.

[0044] Action licensing relationship Using a permit strength vector representation, the controller writes together the compressor frequency increase permit strength, compressor frequency decrease permit strength, water pump speed increase permit strength, water pump speed decrease permit strength, and the window mutual exclusion lock flag. The permissible strength value is taken as the controller's internal action level, where... This indicates that the corresponding action will not be included in subsequent selections. This indicates that the corresponding action can only be used to enter subsequent selections within a limited range. This indicates that the corresponding action will proceed to the next selection according to the normal range. This indicates that the corresponding action is prioritized and enters the subsequent selection. This permissive strength design originates from the action level mapping in hierarchical state machine control. The derivation process in this application is as follows: First, the four types of plate heat exchange safety levels output in step S102 are used as state machine states. Then, the compressor and water pump actions corresponding to each state are broken down into four basic directions. Finally, the action directions are classified according to the direct heat exchanger heat load risk, forming the following action permissive relationship: ; in, For the action permission relationship, the main control board outputs the board switching safety status based on step S102. generate; The compressor frequency ramp-up permit strength is used to indicate whether the compressor frequency inverter drive can receive frequency ramp-up direction control in step S104 and whether the frequency ramp-up is restricted. The compressor frequency reduction permit strength is used to indicate whether the compressor frequency inverter drive can receive frequency reduction direction control in step S104 and whether the frequency reduction is prioritized. The pump speed increase permit strength is used to indicate whether the pump driver can receive speed increase direction control in step S104 and whether the speed increase is prioritized. The pump deceleration permit strength is used to indicate whether the pump driver can receive deceleration direction control in step S104. The window-to-window mutual exclusion lock mark is used to indicate that step S104 performs combined constraints on compressor frequency increase and water pump speed decrease within the same control window; For the board replacement safety status output in step S102, take... , , or The left and right sides of this formula represent the action permission level relationship within the controller. The components on the right side are permission levels or lock markers, which together form the left side. The formula does not involve direct addition or subtraction between different physical operating quantities; the main control board only needs to perform calculations based on... Select the corresponding row for the level and write the action permission relationship for the current control cycle.

[0045] , , and It is a dimensionless motion level, not the frequency or rotation speed itself; its specific magnitude is multiplied by the basic step size or rotation speed ratio in step S104 and then converted into the actuator target change. This is a binary locking flag, which is used under each board replacement security level in this embodiment. This indicates that this application always prohibits the compressor frequency increase and water pump speed decrease from being effective simultaneously within the same control window; if certain models allow the mutual exclusion constraint to be turned off under special low-load scenarios, the applicable conditions should be clearly defined through the model parameter table. In this way, the action permission relationship only expresses "whether it can be executed and at what level," and the specific issued value is still calculated by step S104 in combination with the current frequency and speed.

[0046] The aforementioned action licensing relationship has a clear engineering meaning. When hour, This indicates that the plate changer is in a safe state, and all four types of actions can proceed to step S104 for selection, but... This allows the compressor to increase its frequency and the water pump to decrease its speed, creating a mutually exclusive working window. At this point, the unit has relatively complete adjustment capabilities. For example, when adjusting the temperature based on load requirements, the compressor can increase its frequency while the water pump maintains or increases its speed; conversely, when fine-tuning the temperature to lower a slightly higher outlet water temperature, the water pump can increase its speed to enhance the water-side heat carrying capacity. hour, This indicates that the heat exchanger is in a restricted state. The compressor frequency increase is only permitted under limited conditions, the water pump speed reduction is disabled, and both frequency reduction and pump increase remain available. This state is suitable for operating conditions where there is still a need to increase the outlet water temperature but the heat exchanger margin has been tightened. Step S104 can use a smaller frequency increase step to achieve gentle loading while maintaining or improving the water-side heat carrying capacity. When hour, This indicates that the circuit breaker is under stress, and neither frequency increase nor pump decrease will be selected for subsequent actions. Step S104 can only generate actual control actions from the directions of frequency decrease and pump increase. When hour, This indicates that the heat exchanger is in a dangerous state. Frequency reduction and pump boosting are set as priority actions. Step S104 will prioritize reducing the compressor's heating intensity and increasing the water-side heat carrying capacity.

[0047] Classmate Mutual Exclusion Lock This further restricts the combination of compressor frequency increase and water pump speed decrease within the same control window. This constraint originates from the mutual exclusion condition in Boolean logic, the basic form of which states that two mutually exclusive events cannot be valid simultaneously. This application applies it to the dual-actuator control of a direct-heating heat pump water heater unit, specifically constraining two actions that have a unidirectional heating effect on the outlet water temperature but pose a risk of superposition on the plate heat exchange load. The mutual exclusion constraint can be expressed as: ; in, Action licensing relationship The mutex lock flag in the window is obtained from the aforementioned state mapping; This indicates whether the compressor frequency increase action is actually selected in the current control window in step S104. If selected, a valid value is used; otherwise, an invalid value is used. This indicates whether step S104 actually selects the water pump speed reduction action within the current control window. If selected, a valid value is used; otherwise, an invalid value is used. and These are all action selection markers. The product on the right is a Boolean logic product, and the result indicates whether two actions are valid simultaneously. This expression indicates that when... When the action takes effect, the compressor frequency increase action and the water pump speed decrease action cannot be selected simultaneously in step S104 within the same control window. The previous formula is first based on... generate And give The next formula is based on The actual action combination of step S104 is limited, and the two formulas form a logical chain from "safety level to permission relationship, permission relationship to action combination constraint".

[0048] In practice and All are processed as binary quantities; when selecting the corresponding action, take... If no selection is made, take Therefore, the product result is still a Boolean decision result and does not involve multiplying different physical quantities. The mutual exclusion lock check occurs before the action in step S104 is issued. If the action selection rule or external upper-level command simultaneously specifies the direction of frequency increase and pump decrease, the main control board prioritizes retaining the board-side safety action, cancels the water pump speed reduction or cancels the compressor frequency increase, and records the mutual exclusion trigger state. This process can prevent the controller from forming an unfavorable combination of "increased refrigerant-side heating and decreased water-side heat carrying capacity" within the same window.

[0049] In one engineering operation scenario, step S102 obtains the plate heat exchanger safety status based on the direct heating control status parameters. The controller generates the first formula in this step. In this result, This indicates that compressor frequency increase will not be selected in subsequent options. This indicates that the water pump speed has been reduced and will not be selected in subsequent steps. This indicates that the compressor frequency reduction is the priority action. This indicates that increasing the pump speed is the priority action. This indicates that the mutex is in a valid state. Step S104 reads this... Subsequently, priority will be given to controlling the compressor to reduce its frequency and the water pump to increase its speed, thereby reducing the plate heat exchanger load. This situation corresponds to the handling method when the plate heat exchanger safety margin is too low under load demand in direct-heating units, that is, first restore the plate heat exchanger heat exchange conditions, and then enter the next control cycle to continue the judgment.

[0050] In another engineering operation scenario, step S102 outputs... Controller generation At this point, the compressor frequency increase is restricted, while the water pump speed reduction is disabled. If step S104 requires further temperature increase based on direct heating temperature control needs, only restricted frequency increase can be used; water pump speed reduction cannot be used to increase the outlet water temperature. If step S104 requires a reduction in heat load based on direct heating temperature control needs, either compressor frequency reduction or water pump speed increase can be used. This action permission relationship is suitable when the heat exchanger is in a restricted but still adjustable state, allowing the unit to maintain its outlet water temperature regulation capability while preserving its water-side heat carrying capacity.

[0051] In the safe state of the plate-switching In the operating scenario, the controller generates If step S104 selects compressor frequency increase based on loading requirements, then Take the effective value, mutual exclusion constraint requirements If an invalid value is used, the water pump will not slow down within the same control window; if step S104 selects to increase the water pump speed according to fine-tuning requirements, then... The effective value is taken, and the slightly higher outlet water temperature is reduced by increasing the water-side heat carrying capacity. This process reflects the scenario improvement of direct-heating plate heat exchangers: maintaining control flexibility under safe conditions, while avoiding the heat load concentration caused by the superposition of frequency increase and pump decrease at the action combination level.

[0052] This step outputs a variable, namely the action permission relationship. . The main control board outputs the board switching safety status based on step S102. Generates, including compressor upscaling permit strength Compressor frequency reduction permissible strength Permissible strength for water pump speed increase Permissible strength of water pump speed reduction and the classmate mutual exclusion lock mark Step S104 will directly read... and based on The permitted strength and mutual exclusion lock flags in the code select the actual compressor frequency adjustment action and water pump speed adjustment action. Through this step, the heat exchanger safety state obtained in step S102 is transformed into an executable dual actuator action boundary, enabling the subsequent control of the compressor and water pump to form a cooperative relationship under the constraints of the direct-heated heat exchanger safety state.

[0053] Step S104: Generate compressor frequency adjustment action and water pump speed adjustment action according to the temperature control requirement mark and the action permission relationship to control the compressor and water pump.

[0054] Specifically, step S104 involves the formation of the direct-heating temperature control requirement marker in step S101 and its retention within the current control cycle. And the action permission relationship output in step S103 This generates and executes coordinated control actions between the compressor and water pump. The first three steps have sequentially completed the formation of direct-heating temperature control requirements, the determination of the heat exchanger's safety status, and the generation of action permission relationships. This indicates that the current direct-heating heat pump water heater unit is in a loading, holding, fine-tuning, or unloading state. This indicates the permissible strength for compressor frequency increase, compressor frequency decrease, water pump speed increase, and water pump speed decrease under the current board replacement safety state, as well as the window-to-window mutual exclusion lock between compressor frequency increase and water pump speed decrease. This step is located at the actual execution layer, and the main control board will... The indicated temperature adjustment direction is... The represented action boundaries are merged to form the actual control actions issued to the compressor inverter driver and water pump driver within the current control window. The control basis for this step comes from state machine action selection and variable frequency incremental control in industrial control: first, the action direction is determined based on the state and permissible conditions, and then an adjustment amount is superimposed on the current operating value. This application improves upon this by incorporating the plate heat exchanger coupling characteristics of direct-heating heat pump water heaters, ensuring that the actual actions respond to temperature control requirements while also conforming to the action permissible relationships derived from the plate heat exchanger's safety state transformation.

[0055] When the controller enters this step, it reads the output of step S103. All components in, i.e. , , , and And read the temperature control requirement mark generated in step S101. .in, Indicates the compressor's permissible frequency increase intensity. Indicates the allowable frequency reduction strength of the compressor. Indicates the permissible intensity of the water pump's speed increase. Indicates the permissible speed reduction intensity of the water pump. This represents a window-to-window mutual exclusion lock between compressor frequency increase and water pump speed decrease; Indicates loading requirements. This indicates that demand will remain. This indicates a need for fine-tuning. This indicates an unloading requirement. The controller also reads the current compressor frequency. and current water pump speed Both originate from the direct heating control state quantity formed in step S101. This is used to convert the action selection result into the actual frequency adjustment and speed adjustment. In this way, step S104 simultaneously inherits the temperature control direction of step S101 and the action boundary of step S103, forming a continuous chain from state judgment to control execution.

[0056] This step first determines the action selection flag within the current control window. The initial source of this rule is the "state-action" mapping in state machine control, that is, selecting the corresponding action based on the current state; the derivation process of this application is as follows: First, by Determine the current control direction. For loading requirements, prioritize actions that increase temperature; for fine-tuning requirements, prioritize actions that enhance the water-side heat transfer capacity; for unloading requirements, prioritize actions that reduce heat load; for maintenance requirements, maintain the current actions or switch to safe recovery actions when the heat exchanger is under strain; subsequently... The strength of the permission determines whether the corresponding action qualifies for execution; finally, it is determined by... The compressor's frequency increase and the water pump's speed decrease cannot be effective simultaneously within the same control window. This leads to the following action selection rule: ; in, Indicates whether the compressor frequency increase action is selected in the current control window; Indicates whether the compressor frequency reduction action is selected in the current control window; Indicates whether the water pump speed-up action is selected in the current control window; This indicates whether the water pump speed reduction action is selected in the current control window; all four variables above are action selection markers. The temperature control requirement marker formed in step S101 comes from the direct heating control state quantity. ; , , , and Action permission relationship output from step S103 The first line corresponds to the priority unloading permission relationship formed by the dangerous state of the plate changer in step S103. When both frequency reduction and pump increase are priority actions, the controller directly selects compressor frequency reduction and water pump speed increase. The second line corresponds to the situation where there is a loading demand and the compressor frequency increase permission is valid. In this case, the controller selects compressor frequency increase and... The first line corresponds to situations where pump speed reduction is not selected within the same control window; the second line corresponds to situations where there is a loading requirement but frequency increase permission is closed while frequency reduction and pump increase permission are valid, in which the controller selects to reduce the plate heat exchanger load to restore heat exchange conditions; the third line corresponds to fine-tuning requirements, in which the controller selects to increase the pump speed to enhance the water-side heat carrying capacity, thereby reducing the slightly higher outlet water temperature; the fourth line corresponds to unloading requirements, in which the controller selects to reduce the compressor frequency and increase the pump speed; the fifth line corresponds to situations where there is a maintenance requirement but the plate heat exchanger is under stress, in which the controller selects to reduce the compressor frequency and increase the pump speed to prioritize restoring the plate heat exchanger to a safe state; the last line corresponds to other maintenance or no valid permission situations, in which the controller maintains the current compressor frequency and pump speed. Both sides of this formula are combinations of action selection markers, and each row on the right represents the result of selecting the same type of action, with consistent logic.

[0057] The action selection rules reflect the scenario characteristics of direct-heating heat pump water heaters. For To meet the loading requirements, the controller prioritizes increasing the compressor's frequency to enhance heating capacity, while maintaining the water pump's current speed or increasing it as permitted later, ensuring that the water-side heat-carrying capacity is not actively weakened; for To meet the fine-tuning requirements, the controller selects when the pump speed is allowed to increase in step S103. Suitable for slightly higher outlet water temperatures and where the heat exchanger allows for slight cooling; for or In cases where frequency reduction and pump boosting are prioritized actions, the controller selects actions that reduce the compressor's heating intensity and increase the water-side heat carrying capacity. Through this action selection rule, temperature control requirements and action permission relationships are synthesized into the actual execution direction.

[0058] After receiving the action selection flag, the controller converts it into a compressor frequency adjustment amount. and water pump speed adjustment amount The initial source of this formula is the incremental control method in frequency conversion control and speed regulation control, that is, adding or subtracting a control increment based on the current operating value; the derivation process of this application is as follows: first from , , and The direction of the action is determined, and then the permissible intensity is output from step S103. , , and Adjust the amplitude of the movement so that the frequency increase under restricted conditions is less than the normal frequency increase, and the frequency decrease and pump boost under dangerous conditions have higher execution intensity. Specifically, this can be determined by the following formula: ; in, The compressor frequency adjustment amount within the current control window is sent from the main control board to the compressor inverter driver. The adjustment amount of the water pump speed within the current control window is sent from the main control board to the water pump driver. , , and From the action licensing relationship ; , , and This is derived from the aforementioned action selection rules; The preset compressor base frequency ramp step size in the main control board parameter area; The preset compressor base frequency reduction step size in the main control board parameter area; The preset pump speed ratio in the main control board parameter area; The preset water pump speed reduction ratio in the main control board parameter area; The current water pump speed is derived from the direct-heat control state quantity generated in step S101. In the formula, The two components are the frequency increase increment and the frequency decrease increment, both of which correspond to the compressor frequency adjustment amount; The two components are the speed increase increment and the speed decrease increment, both of which correspond to the water pump speed adjustment. and As a proportional parameter, and The multiplication yields the water pump speed adjustment. The main control board then obtains... and Then, set the current compressor frequency. and The current water pump speed is synthesized into the compressor target frequency. and The target speed of the water pump is synthesized and then executed after boundary constraints are imposed according to the allowable operating range of the compressor and water pump driver.

[0059] and The unit is Hertz, which is derived from the allowable frequency change rate of the compressor inverter driver, the heating capacity response speed, and the high-pressure side protection boundary. and This is a dimensionless ratio, derived from the allowable speed change rate of the pump driver, the pressure drop on the plate heat exchanger side, and the response speed of the outlet water temperature. The main control board will... Limiting the compressor to between its minimum and maximum permissible frequencies, The speed is limited to between the minimum and maximum allowable speeds of the water pump, and a slope limit can be set for the change in speed between adjacent control cycles. If the actuator feedback does not reach the target value, the next control cycle uses the drive feedback value instead of the previous target value as the new value. or This avoids the accumulation of target values ​​that could cause deviations in actual actions.

[0060] In one engineering operation scenario, step S103 outputs... The temperature control requirement formed in step S101 is marked as This indicates a loading requirement at the temperature level, while the action permission relationship suggests that the current board switch is in a state requiring priority unloading. Based on the action selection rules, the controller obtains... If the main control board parameter area is set... , And currently The compressor frequency adjustment amount is The water pump speed adjustment amount is Based on this, the controller sends a frequency reduction action to the compressor inverter driver and a speed increase action to the water pump driver. This corresponds to the engineering handling when the direct-heat plate heat exchanger is in a dangerous state: even if the outlet water temperature still corresponds to the load demand, the controller first reduces the heat load of the plate heat exchanger and increases the water-side heat carrying capacity.

[0061] In another control cycle, step S103 outputs... The step S101 forms This indicates that there is a loading requirement and the board switch is in a restricted state. Based on the action selection rules, the controller obtains... .like ,but , The main control board sends a restricted frequency increase action to the compressor inverter driver while maintaining the water pump speed. This process enables the unit to increase its heating capacity while limiting the load range through the permitted action strength. For example, when step S103 outputs... and At that time, the action selection rule is obtained ;like ,current ,but The controller issues a slight speed increase to the water pump while maintaining the compressor frequency. This action reduces the slightly higher outlet water temperature by increasing the water-side heat carrying capacity and avoids the compressor frequency increase and water pump speed decrease overlapping within the same control window.

[0062] This step outputs two actual execution results: the compressor frequency adjustment action and the water pump speed adjustment action. The compressor frequency adjustment action is determined by the main control board based on... The data is generated and sent to the compressor inverter driver; the water pump speed adjustment action is determined by the main control board based on... The data is generated and sent to the water pump driver. After the driver executes the command, the unit enters the next control cycle, and a new direct-heating control state variable is generated again in step S101. Through this step, the direct heating temperature control requirement in step S101, the plate heat exchanger safety status in step S102, and the action permission relationship in step S103 are ultimately realized as the actual coordinated action of the compressor and the water pump, so that the direct heating heat pump water heater unit can maintain the safe heat exchange boundary of the plate heat exchanger while adjusting the outlet water temperature.

[0063] like Figure 2As shown in the illustration, this application also provides an adaptive cooperative control system for a direct-heating heat pump water heater, comprising: a data acquisition module for acquiring operating parameters of the direct-heating heat pump water heater; a temperature control demand generation module for generating a temperature control demand flag based on the heat exchanger outlet water temperature and the set hot water temperature, and generating a direct-heating control state quantity based on the operating parameters and the temperature control demand flag; a heat exchanger safety status determination module for calculating a heat exchanger safety margin value based on the direct-heating control state quantity, and determining a heat exchanger safety status based on the heat exchanger safety margin value and the water flow rate in the operating parameters; an action permission relationship generation module for generating an action permission relationship based on the heat exchanger safety status; and a cooperative execution module for generating compressor frequency adjustment actions and water pump speed adjustment actions based on the temperature control demand flag and the action permission relationship, to control the compressor and water pump.

[0064] It is worth noting that the specific workflow of the adaptive collaborative control system for a direct-heating heat pump water heater provided in this embodiment of the invention is the same as that of the adaptive collaborative control method for a direct-heating heat pump water heater described in the above embodiment, and will not be repeated here.

[0065] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the above-described method. Figure 3 As shown in the figure, this application embodiment also provides a computer device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the above method when it calls the computer program in the memory.

[0066] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An adaptive cooperative control method for a direct-heating heat pump water heater unit, characterized in that, include: The operating parameters of the direct-heating heat pump water heater are obtained, and a temperature control requirement mark is generated based on the plate heat exchanger outlet water temperature and the hot water set temperature. The direct-heating control status quantity is generated based on the operating parameters and the temperature control requirement mark. The plate heat exchanger safety margin value is calculated based on the direct heating control state quantity, and the plate heat exchanger safety state is determined based on the plate heat exchanger safety margin value and the water flow rate in the operating parameters. Based on the aforementioned safety status of the power supply, an action permission relationship is generated. The action permission relationship includes compressor frequency increase permission strength, compressor frequency decrease permission strength, water pump speed increase permission strength, water pump speed decrease permission strength, and a window mutual exclusion lock flag. Based on the temperature control requirement flag and the action permission relationship, compressor frequency adjustment action and water pump speed adjustment action are generated to control the compressor and water pump.

2. The adaptive cooperative control method for a direct-heating heat pump water heater unit according to claim 1, characterized in that, The operating parameters include the heat exchanger outlet water temperature, the hot water set temperature, the water flow rate, the compressor frequency, the water pump speed, and the time elapsed after the three-way valve is switched. The process of generating a temperature control requirement flag based on the heat exchanger outlet water temperature and the set hot water temperature includes: Based on the heat exchanger outlet water temperature, the hot water set temperature, and the temperature buffer boundary, the temperature control requirement is marked and determined as a loading requirement, a holding requirement, a fine-tuning requirement, or an unloading requirement.

3. The adaptive cooperative control method for a direct-heating heat pump water heater unit according to claim 2, characterized in that, The direct heating control status parameters include the temperature control demand flag, the water flow rate, the compressor frequency, the water pump speed, and the elapsed time after the three-way valve is switched.

4. The adaptive cooperative control method for a direct-heating heat pump water heater unit according to claim 3, characterized in that, The calculation of the plate heat exchanger safety margin value based on the direct heating control state includes: Calculate the flow margin based on the water flow rate, the minimum allowable flow boundary, and the safe flow reference boundary; Calculate the compressor frequency margin based on the compressor frequency, medium heating reference frequency, and high heating reference frequency; Calculate the pump speed margin based on the pump speed, minimum allowable pump speed, and safe pump speed reference value; The stability margin of the three-way valve is calculated based on the elapsed time after the three-way valve switching and the three-way valve stabilization reference time. The minimum value among the water flow margin, the compressor frequency margin, the water pump speed margin, and the three-way valve stability margin is taken as the basic margin; When the temperature control requirement is marked as the loading requirement, a correction term for the superposition of low water flow and high compressor frequency is calculated based on the water flow and the compressor frequency, and a correction term for the superposition of three-way valve instability and high compressor frequency is calculated based on the elapsed time after the three-way valve switching and the compressor frequency. The plate heat exchanger safety margin value is calculated based on the basic margin, the low water flow rate and high compressor frequency superposition correction term, and the three-way valve instability and high compressor frequency superposition correction term.

5. The adaptive cooperative control method for a direct-heating heat pump water heater unit according to claim 4, characterized in that, Determining the heat exchanger's safety status based on the heat exchanger's safety margin value and the water flow rate in the operating parameters includes: When the water flow rate is less than or equal to the minimum allowable water flow boundary, the safe state of the plate heat exchanger is determined to be a dangerous state. When the water flow rate is greater than the minimum allowable water flow boundary, the safety status of the transformer is determined as a safe status, a restricted status, a tense status, or a dangerous status based on the transformer safety margin value, the first level boundary, the second level boundary, and the third level boundary. Wherein, the first level boundary is smaller than the second level boundary, and the second level boundary is smaller than the third level boundary.

6. The adaptive cooperative control method for a direct-heating heat pump water heater unit according to claim 5, characterized in that, The step of generating an action permission relationship based on the switch safety status includes: When the plate heat exchanger is in the safe state, the compressor frequency increase permit strength, the compressor frequency decrease permit strength, the water pump speed increase permit strength, and the water pump speed decrease permit strength are all set to the normal amplitude permit value; When the plate heat exchanger safety state is the restricted state, the compressor frequency increase permit intensity is set to the restricted amplitude permit value, the water pump speed reduction permit intensity is set to the prohibited permit value, and the compressor frequency reduction permit intensity and the water pump speed increase permit intensity are set to the normal amplitude permit value. When the plate heat exchanger safety state is the tense state, the compressor frequency increase permit strength and the water pump speed decrease permit strength are set to the prohibited permit value, and the compressor frequency decrease permit strength and the water pump speed increase permit strength are set to the normal amplitude permit value; When the safe state of the plate heat exchanger is the dangerous state, the frequency reduction permit strength of the compressor and the speed increase permit strength of the water pump are both set to the priority amplitude permit value.

7. The adaptive cooperative control method for a direct-heating heat pump water heater unit according to claim 6, characterized in that, The window-to-window mutual exclusion lock mark is used to indicate that the compressor frequency increase action and the water pump speed decrease action are prohibited from being selected simultaneously in the same control window; The step of generating compressor frequency adjustment actions and water pump speed adjustment actions based on the temperature control requirement marker and the action permission relationship includes: Based on the temperature control requirement flag, the compressor frequency increase permission strength, the compressor frequency decrease permission strength, the water pump speed increase permission strength, the water pump speed decrease permission strength, and the window mutual exclusion lock flag, determine the compressor frequency increase action selection flag, the compressor frequency decrease action selection flag, the water pump speed increase action selection flag, and the water pump speed decrease action selection flag.

8. The adaptive cooperative control method for a direct-heating heat pump water heater unit according to claim 7, characterized in that, The step of determining the compressor frequency increase action selection flag, compressor frequency decrease action selection flag, water pump speed increase permission flag, and water pump speed decrease action selection flag based on the temperature control requirement flag, the compressor frequency increase permission strength, the compressor frequency decrease permission strength, the water pump speed decrease permission strength, and the window mutual exclusion lock flag includes: When the safe state of the plate heat exchanger is the dangerous state, the compressor frequency reduction action selection flag and the water pump speed increase action selection flag are set to valid values, and the compressor frequency increase action selection flag and the water pump speed reduction action selection flag are set to invalid values. When the temperature control requirement is marked as the loading requirement and the compressor frequency increase permit strength is valid, the compressor frequency increase action selection flag is set to a valid value, and the water pump speed reduction action selection flag is set to an invalid value according to the window mutual exclusion lock flag. When the temperature control requirement is marked as the fine-tuning requirement and the water pump speed increase permit strength is valid, the water pump speed increase action selection flag is set to a valid value; When the temperature control requirement is marked as the unloading requirement, the compressor frequency reduction action selection flag and the water pump speed increase action selection flag are set to valid values.

9. The adaptive cooperative control method for a direct-heating heat pump water heater unit according to claim 8, characterized in that, The step of generating compressor frequency adjustment actions and water pump speed adjustment actions based on the temperature control requirement marker and the action permission relationship also includes: The compressor frequency adjustment amount is calculated based on the compressor frequency increase action selection flag, the compressor frequency decrease action selection flag, the compressor frequency increase allowable strength, the compressor frequency decrease allowable strength, the compressor basic frequency increase step size, and the compressor basic frequency decrease step size. The pump speed adjustment amount is calculated based on the pump speed increase action selection mark, the pump speed decrease action selection mark, the pump speed increase allowable intensity, the pump speed decrease allowable intensity, the pump speed increase ratio, the pump speed decrease ratio, and the current pump speed. The compressor frequency adjustment action is generated based on the compressor frequency adjustment amount, and the water pump speed adjustment action is generated based on the water pump speed adjustment amount.

10. An adaptive cooperative control system for a direct-heating heat pump water heater unit, characterized in that, include: The data acquisition module is used to obtain the operating parameters of the direct-heating heat pump water heater unit; The temperature control demand generation module is used to generate a temperature control demand flag based on the plate heat exchanger outlet water temperature and the hot water set temperature, and to generate a direct heating control status quantity based on the operating parameters and the temperature control demand flag. The plate heat exchanger safety status determination module is used to calculate the plate heat exchanger safety margin value based on the direct heating control status quantity, and determine the plate heat exchanger safety status based on the plate heat exchanger safety margin value and the water flow rate in the operating parameters. The action permission relationship generation module is used to generate action permission relationships based on the board switch safety status. The action permission relationships include compressor frequency increase permission strength, compressor frequency decrease permission strength, water pump speed increase permission strength, water pump speed decrease permission strength, and window mutual exclusion lock flag. The collaborative execution module is used to generate compressor frequency adjustment actions and water pump speed adjustment actions based on the temperature control requirement marker and the action permission relationship, so as to control the compressor and water pump.

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