Control method and device for water machine system and water machine system

Abstract

The invention relates to the technical field of water machine system control, and discloses a control method for a water machine system, and the control method comprises the steps: detecting the exhaust saturation temperature and the suction saturation temperature of a compressor, and determining a first temperature difference value between the exhaust saturation temperature and the suction saturation temperature; under the condition that the first temperature difference value is smaller than the temperature difference threshold value, the operation duration of the compressor is obtained; under the condition that the operation duration of the compressor is smaller than the duration threshold value, the water temperature drop rate of the water machine system is obtained; and the opening degree adjusting action of the electronic expansion valve is determined according to the water temperature decreasing rate. According to the method, the opening degree adjusting scheme of the electronic expansion valve is jointly determined by combining the water temperature falling rate and the air suction and exhaust saturation temperature difference value, the water temperature of the system is controlled, the system can enter a stable state rapidly and stably, and therefore the operation stability of the system is improved. The invention further discloses a control device for the water machine system and the water machine system.

Description

Technical Field

[0001] This application relates to the field of water turbine system control technology, such as a control method and device for a water turbine system, and a water turbine system. Background Technology

[0002] During startup, the pressure difference between the intake and exhaust gases in a water-cooled air conditioning system gradually increases, leading to increased system instability. This instability not only affects the cooling or heating performance of the system but may also negatively impact its overall performance and lifespan.

[0003] In related technologies, to solve this problem, proportional-integral-derivative (PID) control of the suction superheat is often used to regulate the electronic expansion valve. PID control achieves effective control of refrigerant flow through precise calculations, thereby ensuring that the entire unit remains stable within the set temperature range.

[0004] In implementing the embodiments of this disclosure, at least the following problems were found in the related art: For large water chiller systems, during the period when the compressor is running, due to large fluctuations in water temperature, PID control is prone to losing precise control of the system, leading to increased instability in system operation. This uncontrolled state not only affects the performance of the air conditioning system but may also damage the compressor and other critical components, increasing maintenance costs and usage risks.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0007] This disclosure provides a control method and apparatus for a water turbine system, and a water turbine system in order to improve the stability of the water turbine system operation.

[0008] In some embodiments, the control method for the water purifier system includes: detecting the exhaust saturation temperature and the intake saturation temperature of the compressor, and determining a first temperature difference between the exhaust saturation temperature and the intake saturation temperature; if the first temperature difference is less than a temperature difference threshold, obtaining the compressor running time; if the compressor running time is less than a duration threshold, obtaining the water temperature drop rate of the water purifier system; and determining the opening adjustment action of the electronic expansion valve based on the water temperature drop rate.

[0009] In the initial startup phase of the water chiller system, the exhaust saturation temperature and the intake saturation temperature are close. As the compressor starts, the temperature difference gradually increases. When the temperature difference between the exhaust and intake saturation temperatures is greater than or equal to the temperature difference threshold, or after the unit has been running for a certain period, the unit enters a stable phase, and PID control of the intake superheat can be implemented. If the temperature difference is less than the temperature difference threshold, it indicates that the unit is not yet stable. The rate of water temperature drop reflects the intake pressure. Therefore, by obtaining the compressor's running time and the rate of water temperature drop, the corresponding electronic expansion valve opening adjustment action is determined. In this way, a scheme for determining the electronic expansion valve opening adjustment based on the rate of water temperature drop and the difference between the exhaust and intake saturation temperatures is implemented to control the system water temperature. This allows the system to quickly and smoothly enter a stable state, thereby improving the stability of system operation.

[0010] Optionally, determining the opening adjustment action of the electronic expansion valve based on the water temperature drop rate includes: determining the opening adjustment action of the electronic expansion valve as a first valve opening action when the water temperature drop rate is greater than the set rate; determining a second temperature difference between the actual water temperature of the water purifier system and the intake saturation temperature when the water temperature drop rate is less than or equal to the set rate; and determining the opening adjustment action of the electronic expansion valve based on the numerical range of the second temperature difference.

[0011] When the compressor running time is less than the time threshold, electronic expansion valve control is implemented during the initial compressor start-up phase. If the water temperature drop rate is greater than the set rate, it indicates low suction pressure, requiring an increase in the electronic expansion valve opening. If the water temperature drop rate is less than or equal to the set rate, the difference between the actual water temperature and the suction saturation temperature determines whether valve opening or closing is necessary. This combines the second temperature difference between the water temperature and the suction saturation temperature with the water temperature drop rate to control the electronic expansion valve opening, regulate the system water temperature, and improve system stability.

[0012] Optionally, the first valve opening action includes increasing the opening degree of the electronic expansion valve n1 times consecutively, each time increasing by Y% / s; 2≤n1≤5, 1≤Y≤10.

[0013] By performing the first valve opening action, the opening degree of the electronic expansion valve is increased multiple times, and the valve opening degree is controlled within the set range each time. This helps the system to increase the intake pressure while avoiding excessive water temperature fluctuations and maintaining system stability.

[0014] Optionally, determining the opening adjustment action of the electronic expansion valve based on the numerical range of the second temperature difference includes: determining the opening adjustment action of the electronic expansion valve as a valve-closing action when △T2≤T1; determining the opening adjustment action of the electronic expansion valve as a second valve-opening action when △T2≥T2; and determining the opening adjustment action of the electronic expansion valve as a holding action when T1<△T2<T2; wherein △T2 is the second temperature difference, 5℃≤T1<T2≤11℃.

[0015] The temperature difference between the actual water temperature and the suction saturation temperature is obtained to determine the heat exchange effect of the current water chiller system and the impact of water temperature fluctuations on system stability. Specifically, ΔT2 ≤ T1 indicates a small temperature difference and insignificant heat exchange; in this case, controlling the electronic expansion valve to close and lower the suction saturation temperature increases the temperature difference between the actual water temperature and the suction saturation temperature. ΔT2 ≥ T2 indicates a large temperature difference and excessively rapid heat exchange, which can easily lead to overshoot; in this case, controlling the electronic expansion valve to open and raise the suction saturation temperature decreases the temperature difference. T1 < ΔT2 < T2 indicates a moderate temperature difference and good heat exchange; the electronic expansion valve opening remains unchanged. Thus, by determining the adjustment action of the electronic expansion valve opening, the stability of system operation is further improved.

[0016] Optionally, the valve closing action includes decreasing the electronic expansion valve opening degree n2 times consecutively, each time by M% / s; 2≤n2≤5, 1≤M≤10; and / or, the second valve opening action includes increasing the electronic expansion valve opening degree n3 times consecutively, each time by Z% / s; 2≤n3≤5, 1≤Z≤10.

[0017] By performing the valve closing action, the intake saturation temperature can be reduced, increasing the temperature difference between the actual water temperature and the intake saturation temperature. Simultaneously, reducing the electronic expansion valve opening in multiple stages avoids the impact on the system caused by sudden changes in the electronic expansion valve opening, maintaining system stability. Conversely, by performing the second valve opening action, the intake saturation temperature can be increased, reducing the temperature difference between the actual water temperature and the intake saturation temperature. Furthermore, reducing the electronic expansion valve opening in multiple stages enables more stable and precise control, preventing excessive water temperature fluctuations.

[0018] Optionally, after determining the opening adjustment action of the electronic expansion valve, the method further includes: performing the opening adjustment action of the electronic expansion valve; if the opening of the electronic expansion valve does not change, determining the opening adjustment method of the electronic expansion valve based on the current first temperature difference; if the opening of the electronic expansion valve changes, determining the opening adjustment method of the electronic expansion valve based on the current compressor running time.

[0019] After executing the corresponding opening adjustment action, if the electronic expansion valve opening does not change, it indicates that the current water temperature difference is appropriate and the heat exchange effect is good. The opening adjustment method of the electronic expansion valve can be determined based on the first temperature difference between the current exhaust saturation temperature and the intake saturation temperature. If the electronic expansion valve opening has changed, it is determined whether to exit the electronic expansion valve control mode during the compressor start-up phase based on the compressor's operating time. In this way, the corresponding electronic expansion valve opening adjustment method can be determined more accurately based on the current operating status of the system, thereby improving the stability of system operation.

[0020] Optionally, determining the opening adjustment mode of the electronic expansion valve based on the current first temperature difference includes: when the current first temperature difference is greater than the temperature difference threshold, determining the opening adjustment mode of the electronic expansion valve as suction superheat PID control.

[0021] The current first temperature difference is greater than the temperature difference threshold, indicating that the system has basically entered a stable phase and can be subjected to PID control of the intake superheat, thereby ensuring that the system as a whole remains stable within the set temperature range.

[0022] Optionally, determining the opening adjustment mode of the electronic expansion valve based on the current compressor running time includes: when the current compressor running time is greater than or equal to a time threshold, determining the opening adjustment mode of the electronic expansion valve as suction superheat PID control.

[0023] If the compressor's operating time is greater than or equal to the time threshold, it indicates that the system has basically entered a stable phase, and PID control of the suction superheat can be directly implemented to ensure that the overall system remains stable within the set temperature range.

[0024] In some embodiments, the control device for the water purifier system includes: a compressor temperature detection module configured to detect the discharge saturation temperature and the suction saturation temperature of the compressor, and determine a first temperature difference between the discharge saturation temperature and the suction saturation temperature; a duration detection module configured to acquire the compressor running time when the first temperature difference is less than a temperature difference threshold; a water temperature detection module configured to acquire the water temperature drop rate of the water purifier system when the compressor running time is less than the duration threshold; and an execution module configured to determine the opening adjustment action of the electronic expansion valve based on the water temperature drop rate.

[0025] In some embodiments, the control device for the water purifier system includes a processor and a memory storing program instructions, the processor being configured to execute the control method for the water purifier system described above when the program instructions are executed.

[0026] In some embodiments, the water chiller system includes: a unit body; and the aforementioned control device for the water chiller system is installed on the unit body.

[0027] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0028] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0029] Figure 1 This is a schematic flowchart of a control method for a water turbine system provided in an embodiment of this disclosure;

[0030] Figure 2 This is a schematic flowchart of another control method for a water turbine system provided in an embodiment of this disclosure;

[0031] Figure 3 This is a schematic flowchart of another control method for a water turbine system provided in an embodiment of this disclosure;

[0032] Figure 4 This is a schematic flowchart of another control method for a water turbine system provided in an embodiment of this disclosure;

[0033] Figure 5 This is a schematic flowchart of another control method for a water turbine system provided in an embodiment of this disclosure;

[0034] Figure 6 This is a schematic diagram of a control device for a water turbine system provided in an embodiment of this disclosure;

[0035] Figure 7 This is a schematic diagram of another control device for a water turbine system provided in an embodiment of this disclosure. Detailed Implementation

[0036] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0037] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0038] Unless otherwise stated, the term "plurality" means two or more.

[0039] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0040] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0041] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0042] Water-cooled air conditioning systems, also known as residential central air conditioning water systems or water-cooled central air conditioning, are a type of central air conditioning system. The electronic expansion valve is typically located on the refrigerant supply line of the water-cooled air conditioning system. Its main function is to regulate the refrigerant flow rate, controlling the flow by adjusting its opening to ensure the system operates stably within the set temperature range. Precise control of the electronic expansion valve is crucial to the performance and efficiency of the entire water-cooled system.

[0043] Conventional electronic expansion valves use PID control during startup, but for compressors just starting up, water temperature fluctuations are significant, making PID control prone to malfunction. Therefore, this embodiment of the invention regulates water temperature by combining the rate of water temperature drop and the water temperature difference, thereby controlling the opening of the electronic expansion valve and allowing the system to reach a stable state more quickly and smoothly.

[0044] Figure 1This is a flowchart illustrating a control method for a water turbine system provided in this disclosure. In this embodiment, the control device of the water turbine system is used as the executing entity to describe the scheme. Figure 1 As shown, the control method includes:

[0045] In step S100, the control device detects the exhaust saturation temperature and intake saturation temperature of the compressor and determines the first temperature difference between the exhaust saturation temperature and intake saturation temperature.

[0046] In the initial startup phase of the water chiller system, the discharge saturation temperature and suction saturation temperature are close. As the compressor starts, the temperature difference gradually increases. The discharge saturation temperature of the compressor can be measured using a temperature sensor installed at the compressor discharge port or discharge pipe to reflect the refrigerant temperature state during compressor discharge. Similarly, the suction saturation temperature of the compressor can be measured using a temperature sensor installed at the compressor suction port or suction pipe to reflect the refrigerant temperature state during compressor suction. By collecting and recording the temperature sensor readings, the difference between the discharge saturation temperature and the suction saturation temperature is calculated to obtain the first temperature difference value. This difference reflects the temperature rise experienced by the refrigerant in the compressor and can be used to determine the current stable operating state of the system.

[0047] Step S101: When the first temperature difference is less than the temperature difference threshold, the control device obtains the compressor running time.

[0048] The first temperature difference value is used to represent the difference between the exhaust saturation temperature and the intake saturation temperature when the unit enters the stable operation phase. Optionally, the temperature difference threshold ranges from 5°C to 20°C. When the first temperature difference value is greater than the temperature difference threshold, the normal heat exchange phase has been entered. Preferably, the temperature difference threshold ranges from 10°C to 15°C, and more preferably, the temperature difference threshold is 15°C. When the temperature difference between the exhaust saturation temperature and the intake saturation temperature is greater than or equal to the temperature difference threshold, the unit enters the stable phase, and PID control of the intake superheat can be performed. When the temperature difference value is less than the temperature difference threshold, the operating time of the compressor is obtained to determine whether to perform electronic expansion valve control during the initial compressor start-up phase.

[0049] Step S102: When the compressor running time is less than the time threshold, the control device obtains the water temperature drop rate of the water system.

[0050] In step S103, the control device determines the opening adjustment action of the electronic expansion valve based on the rate of water temperature drop.

[0051] The duration threshold is used to represent the time from compressor startup to stable operation. The water temperature drop rate is used to represent the water temperature drop rate per unit time. In this embodiment, the duration threshold is 3 to 7 minutes. Preferably, the duration threshold is 4 to 5 minutes. More preferably, the duration threshold is 5 minutes. When the compressor running time is less than this duration threshold, it indicates that electronic expansion valve control is performed during the initial startup phase of the compressor, and the corresponding electronic expansion valve opening adjustment action is determined by the water temperature drop rate. When the compressor running time is greater than or equal to this duration threshold, it indicates that the system has basically entered a stable phase, and the electronic expansion valve opening adjustment method can be determined as suction superheat PID control.

[0052] Thus, the embodiments of this disclosure realize a scheme for determining the opening adjustment of the electronic expansion valve by combining the rate of water temperature drop and the difference between the intake and exhaust saturation temperatures, thereby controlling the system water temperature and enabling the system to enter a stable state more quickly and smoothly, thereby improving the stability of system operation.

[0053] The following describes, with reference to specific embodiments, how to determine the opening adjustment action of the electronic expansion valve based on the rate of water temperature drop.

[0054] Figure 2 This is a flowchart illustrating a control method for a water turbine system provided in this disclosure. In this embodiment, the control device of the water turbine system is used as the executing entity to describe the scheme. Figure 2 As shown, the control method includes:

[0055] In step S200, the control device detects the exhaust saturation temperature and intake saturation temperature of the compressor and determines the first temperature difference between the exhaust saturation temperature and intake saturation temperature.

[0056] In step S201, when the first temperature difference is greater than or equal to the temperature difference threshold, the control device determines the opening adjustment mode of the electronic expansion valve to be PID control of the suction superheat. If the first temperature difference is greater than the temperature difference threshold, it indicates that the system has basically entered a stable stage, and PID control of the suction superheat can be performed to ensure that the overall system remains stable within the set temperature range.

[0057] In step S202, the control device obtains the compressor running time when the first temperature difference is less than the temperature difference threshold.

[0058] Step S203: When the compressor running time is less than the time threshold, the control device obtains the water temperature drop rate of the water system.

[0059] When the compressor running time is less than the time threshold, electronic expansion valve control is performed during the initial compressor start-up phase, and the water temperature drop rate is acquired to determine the current system operating status. When the compressor running time is greater than or equal to the time threshold, it indicates that the system has basically entered a stable phase, and the opening adjustment method of the electronic expansion valve can be determined as suction superheat PID control.

[0060] In step S204, when the rate of water temperature drop is greater than the set rate, the control device determines that the opening adjustment action of the electronic expansion valve is the first valve opening action.

[0061] If the rate of water temperature drop is greater than the set rate, it indicates that the suction pressure is low, and the opening of the electronic expansion valve needs to be increased.

[0062] Preferably, the first valve opening action includes increasing the opening degree of the electronic expansion valve n1 times consecutively, each time increasing by Y% / s; 2≤n1≤5, 1≤Y≤10. This first valve opening action, by increasing the opening degree of the electronic expansion valve multiple times and controlling the valve opening degree to be within the set range each time, helps the system to increase the intake pressure while avoiding excessive water temperature fluctuations, thus maintaining system stability.

[0063] Step S205: When the water temperature drop rate is less than or equal to the set rate, the control device determines the second temperature difference between the actual water temperature of the water system and the intake saturation temperature.

[0064] The set rate is used to monitor water temperature changes during stable system operation. If the water temperature decrease rate is greater than the set rate, it indicates low suction pressure, requiring an increase in the opening of the electronic expansion valve. If the water temperature decrease rate is less than or equal to the set rate, the valve opening or closing action is determined by the second temperature difference between the actual water temperature and the suction saturation temperature.

[0065] The set rate is 0 to 2℃ / s, preferably 0.1℃ / s to 1℃ / s, and more preferably 0.2℃ / s to 0.5℃ / s. In this embodiment, the set rate is 0.2℃ / s. In other embodiments of this application, the value of the set rate is determined according to the structure of the water system.

[0066] The electronic expansion valve increases the system suction pressure by performing a first opening action. In this embodiment, n1 = 3, Y = 1. In other embodiments of this application, n1 = 3, Y = 2. Optionally, the value of Y is determined based on the structure of the water chiller system and / or the type of refrigerant.

[0067] In step S206, the control device determines the opening adjustment action of the electronic expansion valve based on the numerical range of the second temperature difference. Here, by obtaining the temperature difference between the actual water temperature and the suction saturation temperature, the heat exchange effect of the current water chiller system and the impact of water temperature fluctuations on system stability are determined.

[0068] Thus, in this embodiment, when the temperature difference between the exhaust saturation temperature and the intake saturation temperature is greater than or equal to a temperature difference threshold, the unit enters a stable phase and performs PID control of the intake superheat. When the temperature difference is less than the temperature difference threshold, the corresponding electronic expansion valve opening adjustment action is determined by acquiring the compressor's operating time and the water temperature drop rate. This achieves a scheme for determining the electronic expansion valve opening adjustment by combining the water temperature drop rate and the water temperature difference, controlling the system water temperature, and enabling the system to enter a stable state quickly and smoothly, thereby improving the stability of system operation.

[0069] The following describes, with reference to specific embodiments, how to determine the opening adjustment action of the electronic expansion valve based on the numerical range of the second temperature difference.

[0070] Figure 3 This is a flowchart illustrating a control method for a water turbine system provided in this disclosure. In this embodiment, the control device of the water turbine system is used as the executing entity to describe the scheme. Figure 3 As shown, the control method includes:

[0071] In step S300, the control device detects the exhaust saturation temperature and the intake saturation temperature of the compressor and determines the first temperature difference between the exhaust saturation temperature and the intake saturation temperature.

[0072] In step S301, if the first temperature difference is greater than or equal to the temperature difference threshold, the control device determines the opening adjustment mode of the electronic expansion valve to be PID control of the suction superheat. If the first temperature difference is greater than the temperature difference threshold, it indicates that the system has basically entered a stable stage, and PID control of the suction superheat can be performed to ensure that the system as a whole remains stable within the set temperature range.

[0073] In step S302, the control device obtains the compressor running time when the first temperature difference is less than the temperature difference threshold.

[0074] Step S303: When the compressor running time is less than a time threshold, the control device acquires the water temperature drop rate of the water chiller system. When the compressor running time is greater than or equal to the time threshold, it indicates that the system has basically entered a stable stage, and the opening adjustment method of the electronic expansion valve can be determined as suction superheat PID control.

[0075] In step S304, when the rate of water temperature drop is greater than the set rate, the control device determines that the opening adjustment action of the electronic expansion valve is the first valve opening action.

[0076] Step S305: When the water temperature drop rate is less than or equal to the set rate, the control device determines the second temperature difference △T2 between the actual water temperature of the water system and the air intake saturation temperature.

[0077] Here, the temperature difference between the actual water temperature and the intake saturation temperature is obtained to determine the heat exchange effect of the current water chiller system and the impact of water temperature fluctuations on system stability.

[0078] In step S306, when △T2≤T1, the control device determines that the opening adjustment action of the electronic expansion valve is the valve closing action.

[0079] Where T1 represents the minimum threshold required to achieve the desired heat exchange effect. When ΔT2≤T1, it indicates that the temperature difference is small and the heat exchange effect is not obvious. In this case, controlling the electronic expansion valve to perform a valve-closing action to reduce the suction saturation temperature can increase the temperature difference between the actual water temperature and the suction saturation temperature.

[0080] Furthermore, in this embodiment of the present disclosure, the valve closing action includes reducing the opening degree of the electronic expansion valve n2 times consecutively, each time by M% / s; 2≤n2≤5, 1≤M≤10.

[0081] Specifically, 2 ≤ n² ≤ 5, 1 ≤ M ≤ 10. Preferably, n² = 3, M = 1. In other embodiments of this application, the value of M is determined based on the structure of the water chiller system and / or the type of refrigerant.

[0082] In step S307, when △T2≥T2, the control device determines that the opening adjustment action of the electronic expansion valve is the second valve opening action.

[0083] Where T2 represents the maximum threshold that can meet the required heat exchange effect. When △T2≥T2, it indicates that the temperature difference is large, the heat exchange is too fast, and overshoot is likely to occur. In this case, controlling the electronic expansion valve to open the valve to increase the suction saturation temperature can reduce the temperature difference between the actual water temperature and the suction saturation temperature.

[0084] Furthermore, in this embodiment of the present disclosure, the second valve opening action includes increasing the opening degree of the electronic expansion valve n3 times consecutively, each time increasing by Z% / s; 2≤n3≤5, 1≤Z≤10.

[0085] Specifically, 2 ≤ n3 ≤ 5, 1 ≤ Z ≤ 10. Preferably, n3 = 3, Z = 1. In other embodiments of this application, the Z value is determined based on the structure of the water chiller system and / or the type of refrigerant.

[0086] In step S308, the control device determines that the opening adjustment action of the electronic expansion valve is a maintenance action when T1 < ΔT2 < T2; wherein 5℃ ≤ T1 < T2 ≤ 11℃.

[0087] At this point, it indicates that the current temperature difference is moderate and the heat exchange effect is good, and the opening of the electronic expansion valve remains unchanged.

[0088] Optionally, T1 = 5℃ or 6℃; T2 = 10℃ or 11℃.

[0089] For example, when T1 = 5℃ and T2 = 10℃, 5℃ < ΔT2 < 10℃ indicates that the system has good heat exchange performance and stable operation, with minimal water temperature fluctuations and a low probability of unit failure. When T1 = 6℃ and T2 = 11℃, 6℃ < ΔT2 < 11℃ indicates that the system's heat exchange performance is further improved, and the stability and reliability of the system operation are guaranteed.

[0090] Thus, when determining the opening adjustment scheme of the electronic expansion valve by combining the water temperature drop rate and the water temperature difference, the heat exchange effect of the system is determined by analyzing the current water temperature difference, thereby determining the corresponding electronic expansion valve opening adjustment action, realizing the control of the system water temperature, and enabling the system to enter a stable state more quickly and smoothly, thereby improving the stability of system operation.

[0091] Figure 4 This is a flowchart illustrating a control method for a water turbine system provided in this disclosure. In this embodiment, the control device of the water turbine system is used as the executing entity to describe the scheme. Figure 4 As shown, the control method includes:

[0092] In step S400, the control device detects the exhaust saturation temperature and intake saturation temperature of the compressor and determines the first temperature difference between the exhaust saturation temperature and intake saturation temperature.

[0093] Step S401: When the first temperature difference is less than the temperature difference threshold, the control device obtains the compressor running time.

[0094] Step S402: When the compressor running time is less than the time threshold, the control device obtains the water temperature drop rate of the water system.

[0095] In step S403, the control device determines the opening adjustment action of the electronic expansion valve based on the rate of water temperature drop.

[0096] In step S404, the control device performs the opening adjustment action of the electronic expansion valve.

[0097] In step S405, if the opening degree of the electronic expansion valve does not change, the control device determines the opening degree adjustment method of the electronic expansion valve based on the current first temperature difference.

[0098] If the opening of the electronic expansion valve does not change after the corresponding opening adjustment action is performed, it indicates that the current water temperature difference is appropriate and the heat exchange effect is good. The opening adjustment method of the electronic expansion valve can be determined according to the first temperature difference between the current exhaust saturation temperature and the intake saturation temperature.

[0099] Step S406: If the opening degree of the electronic expansion valve changes, the control device determines the opening degree adjustment method of the electronic expansion valve based on the current compressor running time.

[0100] If the opening of the electronic expansion valve has changed, the system will determine whether to exit the electronic expansion valve control mode during the early stage of compressor startup or continue to enter the electronic expansion valve control mode during the early stage of compressor startup, based on the compressor's operating time. This will combine the water temperature drop rate and the water temperature difference to determine the electronic expansion valve opening adjustment scheme, control the system water temperature, and allow the system to enter a stable state more quickly and smoothly, thereby improving the stability of system operation.

[0101] This embodiment of the invention determines the corresponding control mode by observing the execution of the electronic expansion valve opening adjustment action. It can accurately determine the corresponding electronic expansion valve opening adjustment method based on the current operating state of the system, thereby improving the stability of system operation.

[0102] In practical use, this control method for water turbine systems is as follows: Figure 5 As shown, it includes:

[0103] In step S500, the control device detects the exhaust saturation temperature and intake saturation temperature of the compressor and determines the first temperature difference ΔT1n between the exhaust saturation temperature and intake saturation temperature at the current time n.

[0104] In step S501, the control device determines whether ΔT1n is greater than or equal to the temperature difference threshold Ts. If ΔT1n ≥ Ts, proceed to step S502. If ΔT1n < Ts, proceed to step S503. In this embodiment, Ts = 15℃.

[0105] In step S502, the control device determines the opening adjustment method of the electronic expansion valve to be PID control of the intake superheat.

[0106] Step S503: The compressor running time t is obtained by the control device.

[0107] In step S504, the control device determines whether t is greater than or equal to the time threshold ts. If t ≥ ts, proceed to step S502. If the compressor running time is greater than or equal to this time threshold, it indicates that the system has basically entered a stable stage, and the opening adjustment method of the electronic expansion valve can be determined as suction superheat PID control.

[0108] Step S505: When t < ts, the control device obtains the rate of decrease in water temperature of the water turbine system.

[0109] In step S506, when the water temperature drop rate is greater than the set rate, the control device determines that the opening adjustment action of the electronic expansion valve is the first valve opening action. In this embodiment of the present disclosure, the set rate is 0.2℃ / s; the first valve opening action includes increasing the opening of the electronic expansion valve three times consecutively, each time by 1% / s.

[0110] Step S507: When the water temperature drop rate is less than or equal to the set rate, the control device determines the second temperature difference △T2 between the actual water temperature of the water system and the air intake saturation temperature.

[0111] In step S508, the control device determines that the opening adjustment action of the electronic expansion valve is a valve closing action when △T2≤6℃. In this embodiment of the present disclosure, the valve closing action includes reducing the opening of the electronic expansion valve three times consecutively, each time by 1% / s.

[0112] In step S509, when ΔT2 ≥ 11℃, the control device determines that the opening adjustment action of the electronic expansion valve is the second valve opening action. In this embodiment of the present disclosure, the second valve opening action includes increasing the opening of the electronic expansion valve three times consecutively, each time by 1% / s.

[0113] In step S510, the control device determines that the opening adjustment action of the electronic expansion valve is a maintenance action when 6℃ < ΔT2 < 11℃.

[0114] In step S511, the control device performs the opening adjustment action of the electronic expansion valve.

[0115] Step S512: Determine whether the opening degree of the electronic expansion valve has changed. If the opening degree of the electronic expansion valve has changed, the control device returns to step S503 to determine the opening degree adjustment method of the electronic expansion valve based on the current compressor running time.

[0116] Step S513: If the opening of the electronic expansion valve does not change, the control device obtains the first temperature difference ΔT1n+1 between the exhaust saturation temperature and the intake saturation temperature at the current time n+1.

[0117] In step S514, the control device determines whether ΔT1n+1 is greater than Ts. If ΔT1n+1 ≤ Ts, it returns to step S503 to determine the opening adjustment mode of the electronic expansion valve based on the current compressor running time. If ΔT1n+1 > Ts, the control device proceeds to step S502 to determine the opening adjustment mode of the electronic expansion valve as suction superheat PID control.

[0118] In this embodiment, when the temperature difference between the exhaust saturation temperature and the intake saturation temperature is greater than or equal to a temperature difference threshold, the unit is determined to have entered a stable phase, and PID control of the intake superheat is performed. When the temperature difference is less than the temperature difference threshold, the corresponding electronic expansion valve opening adjustment action is determined by acquiring the compressor's operating time and the water temperature drop rate. In this way, a scheme for determining the electronic expansion valve opening adjustment based on both the water temperature drop rate and the water temperature difference is implemented to control the system water temperature, enabling the system to quickly and smoothly enter a stable state, thereby improving the stability of system operation.

[0119] Figure 6 This is a schematic diagram of a control device for a water turbine system provided in an embodiment of this application. The control device for the water turbine system can be implemented through software, hardware, or a combination of both.

[0120] Combination Figure 6 As shown, this embodiment of the present disclosure provides a control device 60 for a water purifier system, including a compressor temperature detection module 61, a duration detection module 62, a water temperature detection module 63, and an execution module 64. The compressor temperature detection module 61 is configured to detect the exhaust saturation temperature and the intake saturation temperature of the compressor, and determine a first temperature difference between the exhaust saturation temperature and the intake saturation temperature; the duration detection module 62 is configured to acquire the compressor running time when the first temperature difference is less than a temperature difference threshold; the water temperature detection module 63 is configured to acquire the water temperature drop rate of the water purifier system when the compressor running time is less than the duration threshold; the execution module 64 is configured to execute the control method for the water purifier system described in the above embodiment based on the water temperature drop rate.

[0121] In the initial startup phase of a water chiller system, the exhaust saturation temperature and the intake saturation temperature are close. As the compressor starts, the temperature difference gradually increases. The control device for a water chiller system provided in this embodiment obtains the compressor's operating time and the water temperature drop rate when the temperature difference between the exhaust and intake saturation temperatures is less than a temperature difference threshold, and then determines the corresponding electronic expansion valve opening adjustment action. This achieves a scheme for determining the electronic expansion valve opening adjustment by combining the water temperature drop rate and the water temperature difference, controlling the system water temperature, and enabling the system to quickly and smoothly enter a stable state, thereby improving the system's operational stability.

[0122] Combination Figure 7As shown, this embodiment of the disclosure provides a control device 70 for a water purifier system, including a processor 700 and a memory 701. Optionally, the device 70 may further include a communication interface 702 and a bus 703. The processor 700, communication interface 702, and memory 701 can communicate with each other via the bus 703. The communication interface 702 can be used for information transmission. The processor 700 can call logical instructions in the memory 701 to execute the control method for the water purifier system described in the above embodiment.

[0123] Furthermore, the logic instructions in the aforementioned memory 701 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0124] The memory 701, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 700 executes functional applications and data processing by running the program instructions / modules stored in the memory 701, thereby implementing the control method for the water turbine system in the above embodiments.

[0125] The memory 701 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 701 may include high-speed random access memory and may also include non-volatile memory.

[0126] This disclosure provides a water chiller system, including: a unit body, and the aforementioned control device for the water chiller system, wherein the control device is installed on the unit body. The installation relationship described herein is not limited to placement within the unit body, but also includes installation and connection with other components of the water chiller system, including but not limited to physical connections, electrical connections, or signal transmission connections. Those skilled in the art will understand that the control device for the water chiller system can be adapted to any feasible water chiller system unit body, thereby realizing other feasible embodiments.

[0127] This disclosure provides a computer-readable storage medium storing computer-executable instructions configured to execute the above-described control method for a water turbine system.

[0128] This disclosure provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions that, when executed by a computer, cause the computer to perform the method described above.

[0129] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0130] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code; it can also be a transient storage medium.

[0131] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0132] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0133] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed units may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. Furthermore, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0134] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A control method for a water turbine system, characterized in that, include: Detect the exhaust saturation temperature and intake saturation temperature of the compressor, and determine the first temperature difference between the exhaust saturation temperature and intake saturation temperature; If the first temperature difference is less than the temperature difference threshold, obtain the compressor running time; When the compressor running time is less than the time threshold, obtain the water temperature drop rate of the water chiller system; The opening adjustment action of the electronic expansion valve is determined based on the rate of water temperature drop.

2. The control method according to claim 1, characterized in that, The process of determining the opening adjustment action of the electronic expansion valve based on the rate of water temperature drop includes: If the rate of water temperature drop is greater than the set rate, the opening adjustment action of the electronic expansion valve is determined as the first valve opening action. When the rate of water temperature drop is less than or equal to the set rate, determine the second temperature difference between the actual water temperature and the intake saturation temperature of the water purifier system. The opening adjustment action of the electronic expansion valve is determined based on the numerical range of the second temperature difference.

3. The control method according to claim 2, characterized in that, The first valve opening action includes: The opening of the electronic expansion valve is increased n1 times consecutively, with each increase being Y% / s; 2≤n1≤5, 1≤Y≤10.

4. The control method according to claim 2, characterized in that, The step of determining the opening adjustment action of the electronic expansion valve based on the numerical range of the second temperature difference includes: When △T2≤T1, the opening adjustment action of the electronic expansion valve is determined to be the valve closing action; When △T2≥T2, the opening adjustment action of the electronic expansion valve is determined to be the second valve opening action; When T1 < ΔT2 < T2, the opening adjustment action of the electronic expansion valve is determined to be a holding action; Where △T2 is the second temperature difference, 5℃≤T1<T2≤11℃.

5. The control method according to claim 4, characterized in that, The valve closing action includes continuously reducing the opening of the electronic expansion valve n2 times, each time by M% / s; 2≤n2≤5, 1≤M≤10; And / or, The second valve opening action includes increasing the opening degree of the electronic expansion valve n3 times consecutively, each time increasing by Z% / s; 2≤n3≤5, 1≤Z≤10.

6. The control method according to any one of claims 1 to 5, characterized in that, After determining the opening adjustment action of the electronic expansion valve, the following is also included: Perform the opening adjustment action of the electronic expansion valve; If the opening of the electronic expansion valve does not change, the opening adjustment method of the electronic expansion valve is determined based on the current first temperature difference value. If the opening degree of the electronic expansion valve changes, the adjustment method for the opening degree of the electronic expansion valve is determined based on the current compressor running time.

7. The control method according to claim 6, characterized in that, The method for determining the opening adjustment of the electronic expansion valve based on the current first temperature difference includes: When the current first temperature difference is greater than the temperature difference threshold, the opening adjustment method of the electronic expansion valve is determined to be PID control of the intake superheat.

8. The control method according to claim 6, characterized in that, The method for determining the opening adjustment of the electronic expansion valve based on the current compressor running time includes: When the current compressor operating time is greater than or equal to the time threshold, the opening adjustment method of the electronic expansion valve is determined to be suction superheat PID control.

9. A control device for a water turbine system, characterized in that, include: The compressor temperature detection module is configured to detect the compressor's exhaust saturation temperature and intake saturation temperature, and determine the first temperature difference between the exhaust saturation temperature and intake saturation temperature. The duration detection module is configured to acquire the compressor running time when the first temperature difference is less than the temperature difference threshold. The water temperature detection module is configured to obtain the rate of decrease of water temperature in the water purifier system when the compressor running time is less than a time threshold. The execution module is configured to execute the control method for a water turbine system as described in any one of claims 1-8, based on the rate of decrease in water temperature.

10. A water purifier system, characterized in that, include: Unit body; The control device for a water turbine system as described in claim 9 is installed on the unit body.

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