Method and device for determining initial opening of expansion valve, and heat pump water heater

Abstract

The application relates to the technical field of home appliance control, and discloses a method for determining the initial opening degree of an expansion valve, which comprises the following steps: obtaining the ambient temperature of the compressor side of a refrigeration system, the coil temperature of the refrigeration system and the water tank water temperature of a heat pump water heater; determining the reference opening degree of the expansion valve according to the ambient temperature; determining the water temperature correction opening degree of the expansion valve according to the water tank water temperature; determining the coil correction opening degree of the expansion valve according to the ambient temperature and the coil temperature; and determining the initial opening degree of the expansion valve according to the reference opening degree, the water temperature correction opening degree and the coil correction opening degree. According to the scheme, the initial opening degree of the expansion valve is effectively corrected, the initial opening degree of the expansion valve is more reasonably determined, the starting success probability of the compressor is improved, and a more accurate determination mode of the initial opening degree of the expansion valve is provided. The application further discloses a device for determining the initial opening degree of the expansion valve and a heat pump water heater.

Description

Technical Field

[0001] This application relates to the field of home appliance control technology, such as a method, apparatus, and heat pump water heater for determining the initial opening degree of an expansion valve. Background Technology

[0002] In existing technologies, heat pump water heaters often use expansion valves to throttle and reduce the pressure in their cooling systems. The effectiveness of this throttling and pressure reduction is controlled by adjusting the opening of the expansion valve. Therefore, the appropriate expansion valve opening needs to be adjusted before the cooling system starts operating to ensure stable operation. Currently, the initial opening of existing expansion valves is usually fixed. For example, a commonly used 600-step expansion valve in a cooling system has an effective range of 50-500 steps. Its initial opening is often preset to 300 steps, the midpoint of the step range, thus setting the initial opening to 300 steps to ensure stable operation of the cooling system.

[0003] While existing expansion valve initial opening settings are suitable for most normal operating conditions, they perform poorly under special operating conditions or when the system has just been shut down and the pressure within the refrigeration system is still high. This is because under special conditions or when the system pressure is high, the heat pump compressor starts under load, which can easily lead to compressor start-up failure. Furthermore, to ensure initial stability during startup, almost all control schemes require maintaining a fixed expansion valve opening and a fixed compressor frequency after startup. However, if there is still significant pressure within the refrigeration system and the heat pump compressor continues to operate at the aforementioned fixed frequency, the system pressure will rise very rapidly. Since the opening of the throttling and pressure-reducing expansion valve is set to a fixed value and cannot be adjusted for the current situation, it can easily cause a sharp accumulation and increase in discharge pressure, triggering discharge overheat protection or compressor frequency reduction. Summary of the Invention

[0004] 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.

[0005] This disclosure provides a method, apparatus, and heat pump water heater for determining the initial opening degree of an expansion valve, thereby providing a method for determining the initial opening degree of an expansion valve.

[0006] In some embodiments, the method includes: acquiring the ambient temperature around the compressor of the refrigeration system, the coil temperature of the refrigeration system, and the water temperature of the water tank of the heat pump water heater; determining a reference opening of the expansion valve based on the ambient temperature; determining a water temperature correction opening of the expansion valve based on the water temperature of the water tank; determining a coil correction opening of the expansion valve based on the ambient temperature and the coil temperature; and determining an initial opening of the expansion valve based on the reference opening, the water temperature correction opening, and the coil correction opening.

[0007] In some embodiments, the method includes: determining the water temperature setting of the water tank based on the water temperature in the tank; determining the water temperature correction coefficient and initial opening offset of the water temperature setting based on the water temperature setting; and determining the water temperature correction opening of the expansion valve based on the water temperature correction coefficient and the initial opening offset.

[0008] In some embodiments, the method includes: equipping the inlet and outlet of the heat pump water heater with temperature sensors; acquiring a first temperature collected by the inlet temperature sensor and a second temperature collected by the outlet temperature sensor; determining the average value of the first temperature and the second temperature; and determining the water temperature setting of the water tank based on the average value of the first temperature and the second temperature.

[0009] In some embodiments, the method includes: determining a temperature correction factor for the coil based on the ambient temperature; and determining a coil correction opening of the expansion valve based on the temperature of the coil and the coil temperature correction factor.

[0010] In some embodiments, the method includes: obtaining the opening increment of the expansion valve of the heat pump water heater at the current start-up and the interval between the last shutdown and the current start-up of the heat pump water heater; determining the cooling correction opening of the expansion valve based on the opening increment and the interval; and correcting the initial opening based on the cooling correction opening of the expansion valve.

[0011] In some embodiments, the method includes: when the interval is less than a preset time, correcting the initial opening based on the cooling correction opening of the expansion valve.

[0012] In some embodiments, the method includes: controlling the expansion valve to operate at an initial opening and starting the compressor.

[0013] In some embodiments, the apparatus includes: an acquisition module configured to acquire the ambient temperature around the compressor of the refrigeration system, the coil temperature of the refrigeration system, and the water temperature of the water tank of the heat pump water heater; a reference opening determination module configured to determine a reference opening of the expansion valve based on the ambient temperature; a water temperature correction opening determination module configured to determine a water temperature correction opening of the expansion valve based on the water temperature of the water tank; a coil correction opening determination module configured to determine a coil correction opening of the expansion valve based on the ambient temperature and the coil temperature; and an initial opening determination module configured to determine the initial opening of the expansion valve based on the reference opening, the water temperature correction opening, and the coil correction opening.

[0014] In some embodiments, the apparatus includes a processor and a memory storing program instructions, the processor being configured to execute the aforementioned method for determining the initial opening of the expansion valve when the program instructions are executed.

[0015] In some embodiments, the heat pump water heater includes: a means for determining the initial opening degree of the expansion valve.

[0016] The method, apparatus, and heat pump water heater for determining the initial opening of the expansion valve provided in this disclosure can achieve the following technical effects: by acquiring the ambient temperature around the compressor of the refrigeration system, the coil temperature, and the water temperature of the water tank of the heat pump water heater, the reference opening of the expansion valve, the water temperature-corrected opening of the expansion valve, and the coil-corrected opening of the expansion valve can be determined. With this scheme, the initial opening of the expansion valve is effectively corrected, and the initial opening of the expansion valve is determined more reasonably, which is conducive to improving the success rate of compressor start-up and provides a more accurate way to determine the initial opening of the expansion valve.

[0017] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0018] 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:

[0019] Figure 1 This is a schematic diagram of a method for determining the initial opening degree of an expansion valve provided in an embodiment of this disclosure;

[0020] Figure 2 This is a schematic diagram of a device for determining the initial opening degree of an expansion valve provided in an embodiment of this disclosure;

[0021] Figure 3 This is a schematic diagram of another device for determining the initial opening degree of an expansion valve provided in an embodiment of this disclosure. Detailed Implementation

[0022] 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.

[0023] 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.

[0024] Unless otherwise stated, the term "multiple" means two or more.

[0025] 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.

[0026] 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.

[0027] In practical applications, after the heat pump water heater is turned off, the compressor operates at zero frequency. When the heat pump water heater is turned on again, the interval between the previous compressor shutdown time and the current compressor start-up time is obtained to determine the compressor's cooling correction opening. The ambient temperature around the compressor, the coil temperature of the refrigeration system, and the water temperature in the heat pump water heater's tank are also obtained. Based on the ambient temperature, the reference opening of the expansion valve is determined. Based on the water temperature in the tank, the water temperature correction opening of the expansion valve is determined. If the interval between the previous compressor shutdown time and the current compressor start-up time is less than a preset interval, the initial opening of the expansion valve is determined based on the reference opening, the water temperature correction opening, the coil correction opening, and the cooling correction opening.

[0028] Figure 1 This is a schematic diagram of a method for determining the initial opening degree of an expansion valve provided in an embodiment of this disclosure, combined with... Figure 1 As shown, this disclosure provides a method for determining the initial opening degree of an expansion valve, including:

[0029] S11, obtain the ambient temperature around the compressor of the refrigeration system, the coil temperature of the refrigeration system, and the water temperature of the water tank of the heat pump water heater.

[0030] S12, determine the reference opening degree of the expansion valve based on the ambient temperature.

[0031] S13, determine the water temperature correction opening of the expansion valve based on the water temperature in the water tank.

[0032] S14. Determine the corrected opening of the expansion valve coil based on the ambient temperature and coil temperature.

[0033] S15, determine the initial opening of the expansion valve based on the reference opening, water temperature correction opening, and coil correction opening.

[0034] In existing technologies, the water temperature in the hot water tank of heat pump water heaters is often above 50℃. The compressor starts heating when the water temperature is below 50℃ and shuts off when it's above 55℃. Therefore, in summer, when users use water continuously, the heat pump compressor will frequently start and stop due to user habits. If only ambient temperature is considered, without considering system pressure and cooling, each start-up will result in significant system pressure, reducing the start-up success rate and overall system efficiency. Therefore, it's necessary to consider ambient temperature, tank temperature, and coil temperature to reduce system pressure. This solution effectively determines the initial opening of the expansion valve through a base opening, a water temperature-corrected opening, and a coil-corrected opening. This reduces system pressure and improves the compressor start-up success rate and overall system efficiency.

[0035] In step 11, the ambient temperature around the compressor of the refrigeration system, the coil temperature of the refrigeration system, and the water temperature of the water tank of the heat pump water heater can be obtained.

[0036] In this solution, an ambient temperature sensor can be installed on the heat pump water heater to obtain the ambient temperature around the compressor. A temperature sensor can also be installed on the heat pump water heater to obtain the water temperature in the tank. Furthermore, a coil temperature sensor can be installed on the heat pump water heater to obtain the coil temperature of the refrigeration system. This solution enables the acquisition of accurate temperature data through sensors, providing precise temperature data for adjusting the initial opening of the expansion valve.

[0037] In step 12, the reference opening degree of the expansion valve is determined based on the ambient temperature.

[0038] In this solution, as shown in Table 1, the ambient temperature is obtained from an ambient temperature sensor, and the corresponding temperature range is determined. The reference opening degree of the expansion valve is then determined based on this temperature range. For example, if the ambient temperature Ta is 38℃, the temperature range corresponding to 38℃ is determined to be 45℃ ≥ Ta > 37℃, and the reference opening degree of the expansion valve is determined to be 300 steps. This solution can obtain an accurate reference opening degree for the expansion valve, meeting user requirements.

[0039] Ta > 45℃ 340 45℃≥Ta>37℃ 300 37℃≥Ta>26℃ 280 26℃≥Ta>17℃ 250 17℃≥Ta>10℃ 220 10℃≥Ta>4℃ 190 4℃≥Ta>-4℃ 140 -4℃≥Ta 120

[0040] Table 1

[0041] In step 13, the water temperature correction opening of the expansion valve is determined based on the water temperature in the water tank.

[0042] In this solution, the water temperature in the heat pump water heater's tank can be obtained using a water temperature sensor, and the water temperature correction parameters for the expansion valve can be determined based on this tank temperature. This solution enables the acquisition of accurate water temperature correction parameters based on the tank water temperature, thereby reducing the impact of the tank water temperature on the refrigeration system's pressure.

[0043] In step 14, the corrected opening of the expansion valve coil can be determined based on the ambient temperature and the coil temperature.

[0044] In this solution, the corrected opening degree of the expansion valve can be determined based on the coil temperature collected by the coil temperature sensor and the ambient temperature obtained by the ambient temperature sensor. This solution allows for the accurate determination of coil temperature correction parameters using both ambient and coil temperatures, thereby reducing the impact of coil temperature on system pressure.

[0045] In step 15, the initial opening of the expansion valve can be determined based on the reference opening, the water temperature-corrected opening, and the coil-corrected opening.

[0046] In this scheme, the initial opening of the expansion valve can be determined based on the baseline opening, the water temperature-corrected opening, and the coil-corrected opening. Specifically, the initial opening P of the expansion valve can be determined in the following way:

[0047] P = P 基 +P 水温 +P 盘管

[0048] In this solution, by acquiring the ambient temperature around the compressor of the refrigeration system, the coil temperature, and the water temperature of the heat pump water heater tank, the reference opening degree of the expansion valve, the water temperature-corrected opening degree of the expansion valve, and the coil-corrected opening degree of the expansion valve can be determined. This solution effectively corrects the initial opening degree of the expansion valve, more reasonably determines the initial opening degree of the expansion valve, and helps to improve the success rate of compressor start-up, providing a more accurate method for determining the initial opening degree of the expansion valve.

[0049] Optionally, in order to determine the water temperature correction parameters of the expansion valve, in this scheme, the water temperature range of the water tank can be determined according to the water temperature of the water tank; and the water temperature correction coefficient and initial opening offset of the range can be determined according to the water temperature range; thereby, the water temperature correction opening of the expansion valve can be determined according to the water temperature correction coefficient and the initial opening offset.

[0050] In this scheme, as shown in Table 2, if the obtained water temperature of the water tank is 42℃, then the water temperature setting corresponding to the water tank temperature is determined to be 45℃≥Tc>30℃. Then, the water temperature correction coefficient Kc=0.8 and the initial opening offset 8 can be determined for this setting.

[0051] Tc > 45℃ Kc = 2.0Kb = 20 45℃≥Tc>30℃ Kc = 0.8Kb = 8 30℃≥Tc>10℃ Kc = 0.4Kb = 0 10℃≥Tc Kc = 0 Kb = 0

[0052] Table 2

[0053] In this scheme, after determining the water temperature correction coefficient and the initial opening offset, the specific details can be determined according to P. 水温 =K C *(T C -T C0 )+K b Determine the water temperature correction opening degree in this scheme. C0 This is the lowest value for the water tank temperature setting. For example, if the obtained water temperature is 51℃, the corresponding water temperature setting is T. C >45℃, and determine the water temperature correction factor Kc = 2, initial opening offset K b =20, and the lowest value T of the water tank temperature setting. C0 =45, and determine the water temperature correction opening P. 水温 =2.0*(51-45)+20=32. With this scheme, accurate water temperature correction parameters can be obtained based on the water temperature in the tank, thereby reducing the impact of the water temperature on the pressure of the refrigeration system.

[0054] Optionally, to make the obtained water tank temperature more accurate, in this solution, if both the inlet and outlet of the heat pump water heater are equipped with temperature sensors, the first temperature collected by the inlet temperature sensor and the second temperature collected by the outlet temperature sensor are obtained; the average value of the first temperature and the second temperature is determined; and the water temperature setting of the water tank is determined based on the average value of the first temperature and the second temperature.

[0055] In this solution, if temperature sensors are installed at both the inlet and outlet of the heat pump water heater, the first temperature at the inlet and the second temperature at the outlet can be obtained respectively. The average of the first and second temperatures is then determined as the water temperature in the tank. Furthermore, based on this average value, the water temperature setting in the tank is determined, thereby determining the water temperature correction opening of the expansion valve. This solution enables the acquisition of accurate temperature data, improving the accuracy of the water temperature correction opening of the expansion valve.

[0056] Optionally, in order to determine the coil correction opening, in this scheme, the temperature correction coefficient of the coil can be determined according to the ambient temperature; and the coil correction opening of the expansion valve can be determined according to the coil temperature and the coil temperature correction coefficient.

[0057] In this scheme, it can be done through P 盘管 =K e *((T e -T e0 )+K a *(T a -20)) Obtain the corrected opening of the expansion valve coil. Wherein, K e T is the coil temperature correction factor. e T represents the coil temperature. e0 The standard operating condition is a coil temperature of 6℃, where the ambient temperature is 20℃. K a The correction parameter for the coil temperature based on ambient temperature is 0.2-0.3. (T) a The ambient temperature.

[0058] In one example, K e The coil temperature correction factor is 2.41 under maximum operating conditions, where the maximum operating condition is an ambient temperature of 43℃. Correspondingly, the corrected coil opening is 2.41*((T) e -6)+0.2*(T a -20)), and then obtain the coil temperature T e and ambient temperature T a Determine the correct opening degree of the coil.

[0059] This approach allows for the determination of accurate coil temperature correction parameters based on ambient temperature and coil temperature, thus avoiding the impact of reduced coil temperature on system pressure.

[0060] Optionally, to avoid pressure impact during system restart after shutdown, this solution sets the opening increment of the expansion valve of the heat pump water heater during startup and calculates the interval between the last shutdown and the current startup of the heat pump water heater; the cooling correction opening of the expansion valve is determined based on the opening increment and the interval; and the initial opening is corrected based on the cooling correction opening of the expansion valve.

[0061] In this solution, to prevent excessive exhaust pressure from causing startup failure after the compressor is shut down and restarted, the opening increment of the expansion valve of the heat pump water heater can be set during restart. Generally, this increment is ≥100, and can be determined according to P. 冷却 =P0*(0.75) t The cooling correction opening of the expansion valve is determined by [the method described in the original text]. Here, P0 represents the increment of the expansion valve opening after the compressor has just stopped and restarted, and t represents the time interval between the last shutdown and restart of the heat pump water heater, in minutes. In the technical solution provided in this disclosure embodiment, 0.75 represents a base value positively correlated with the system capacity; that is, when the system capacity is 200L, the corresponding base value is 0.75. In this solution, the larger the system capacity, the slower its pressure drop rate, and correspondingly, the higher the base value. Furthermore, when the t value reaches 8 minutes, the pressure impact of system shutdown and restart does not need to be considered. With this solution, the correction opening required for system cooling can be obtained, thereby reducing the pressure impact during system shutdown and restart.

[0062] Optionally, if the interval is less than a preset time, the initial opening is corrected based on the cooling correction opening of the expansion valve.

[0063] In this scheme, if the interval is longer than the preset duration, the system will not experience pressure issues upon restarting after a shutdown. However, if the interval is shorter than the preset duration, the cooling correction opening of the system needs to be considered and determined. Specifically, the preset duration can be set in advance based on the ambient temperature and system capacity. For example, the preset duration can be set to 5 minutes. This scheme allows for the determination of the triggering conditions for correcting the initial opening based on the cooling correction opening. This approach effectively simplifies the correction process and improves the accuracy of determining the initial opening of the expansion valve.

[0064] Optionally, after determining the initial opening degree of the expansion valve, the expansion valve is controlled to operate at the initial opening degree and the compressor is started.

[0065] This solution enables the expansion valve to operate at its initial opening after the initial opening is determined, and the compressor to be started, ensuring stable system operation.

[0066] Combination Figure 2As shown, this embodiment of the present disclosure provides a device for determining the initial opening degree of an expansion valve, including an acquisition module 21, a reference opening degree determination module 22, a water temperature correction opening degree determination module 23, a coil correction opening degree determination module 24, and an initial opening degree determination module 25. The acquisition module 21 is configured to acquire the ambient temperature around the compressor of the refrigeration system, the coil temperature of the refrigeration system, and the water temperature of the heat pump water heater's tank; the reference opening degree determination module 22 is configured to determine the reference opening degree of the expansion valve based on the ambient temperature; the water temperature correction opening degree determination module 23 is configured to determine the water temperature correction opening degree of the expansion valve based on the water temperature of the tank; the coil correction opening degree determination module 24 is configured to determine the coil correction opening degree of the expansion valve based on the ambient temperature and the coil temperature; and the initial opening degree determination module 25 is configured to determine the initial opening degree of the expansion valve based on the reference opening degree, the water temperature correction opening degree, and the coil correction opening degree.

[0067] The device for determining the initial opening degree of the expansion valve provided in this embodiment acquires the ambient temperature around the compressor of the refrigeration system, the coil temperature, and the water temperature of the water tank of the heat pump water heater. It can determine the reference opening degree of the expansion valve, the water temperature-corrected opening degree of the expansion valve, and the coil-corrected opening degree of the expansion valve. This scheme effectively corrects the initial opening degree of the expansion valve, determines the initial opening degree of the expansion valve more reasonably, and helps to improve the success rate of compressor start-up. It provides a more accurate method for determining the initial opening degree of the expansion valve.

[0068] Combination Figure 3 As shown, this disclosure provides an apparatus for determining the initial opening degree of an expansion valve, including a processor 100 and a memory 101. Optionally, the apparatus may further include a communication interface 102 and a bus 103. The processor 100, communication interface 102, and memory 101 can communicate with each other via the bus 103. The communication interface 102 can be used for information transmission. The processor 100 can call logical instructions in the memory 101 to execute the method for determining the initial opening degree of the expansion valve described in the above embodiment.

[0069] Furthermore, the logic instructions in the aforementioned memory 101 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0070] The memory 101, 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 100 executes functional applications and data processing by running the program instructions / modules stored in the memory 101, that is, it implements the method for determining the initial opening degree of the expansion valve in the above embodiments.

[0071] The memory 101 may include a program storage area and a data storage area. The program storage area may store the operating system and applications 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 101 may include high-speed random access memory and may also include non-volatile memory.

[0072] This disclosure provides a heat pump water heater that includes the aforementioned device for determining the initial opening degree of the expansion valve.

[0073] This disclosure provides a computer-readable storage medium storing computer-executable instructions configured to perform the above-described method for determining the initial opening degree of an expansion valve.

[0074] 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 above-described method for determining the initial opening degree of an expansion valve.

[0075] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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 method for determining the initial opening degree of an expansion valve, characterized in that, The method, applied to a refrigeration system for a heat pump water heater, includes: The ambient temperature around the compressor of the refrigeration system, the coil temperature of the refrigeration system, and the water temperature in the tank of the heat pump water heater are obtained. The reference opening degree of the expansion valve is determined based on the ambient temperature. The water temperature correction opening of the expansion valve is determined based on the water temperature in the water tank. The corrected opening of the expansion valve coil is determined based on the ambient temperature and the coil temperature. The initial opening of the expansion valve is determined based on the reference opening, the water temperature correction opening, and the coil correction opening. The opening increment of the expansion valve of the heat pump water heater during this start-up and the interval between the last shutdown and the current start-up of the heat pump water heater are obtained. The cooling correction opening of the expansion valve is determined based on the opening increment and the interval duration; When the interval is less than the preset time, the initial opening is corrected according to the cooling correction opening of the expansion valve.

2. The method according to claim 1, characterized in that, The step of determining the water temperature correction opening of the expansion valve based on the water temperature in the water tank includes: Based on the water temperature in the water tank, determine the water temperature setting where the water tank is located; Based on the water temperature setting, determine the water temperature correction coefficient and the initial opening offset for that setting; The water temperature correction opening of the expansion valve is determined based on the water temperature correction coefficient and the initial opening offset.

3. The method according to claim 2, characterized in that, If both the inlet and outlet of the heat pump water heater are equipped with temperature sensors, the method further includes: Obtain the first temperature collected by the inlet temperature sensor and the second temperature collected by the outlet temperature sensor; Determine the average value of the first temperature and the second temperature; The step of determining the water temperature setting of the water tank based on the water temperature includes: The water temperature setting of the water tank is determined based on the average of the first temperature and the second temperature.

4. The method according to claim 1, characterized in that, The step of determining the coil correction opening of the expansion valve based on the ambient temperature and the coil temperature includes: Based on the ambient temperature, determine the temperature correction factor for the coil; The corrected opening degree of the expansion valve is determined based on the temperature of the coil and the temperature correction coefficient of the coil.

5. The method according to claim 1, characterized in that, After determining the initial opening degree of the expansion valve, the method further includes: Control the expansion valve to operate at its initial opening and start the compressor.

6. A device for determining the initial opening degree of an expansion valve, characterized in that, A refrigeration system applied to a heat pump water heater, the device comprising: The acquisition module is configured to acquire the ambient temperature around the compressor of the refrigeration system, the coil temperature of the refrigeration system, and the water temperature of the water tank of the heat pump water heater. The reference opening determination module is configured to determine the reference opening of the expansion valve based on the ambient temperature. The water temperature correction opening determination module is configured to determine the water temperature correction opening of the expansion valve based on the water temperature in the water tank. The coil correction opening determination module is configured to determine the coil correction opening of the expansion valve based on the ambient temperature and the coil temperature. The initial opening determination module is configured to determine the initial opening of the expansion valve based on the reference opening, the water temperature correction opening, and the coil correction opening. The power-on acquisition module is configured to acquire the opening increment of the expansion valve of the heat pump water heater during this power-on and the interval between the last shutdown and the current power-on of the heat pump water heater. The cooling correction opening determination module is configured to determine the cooling correction opening of the expansion valve based on the opening increment and the interval duration. The initial opening correction module is configured to correct the initial opening based on the cooling correction opening of the expansion valve when the interval is less than a preset time.

7. A device for determining the initial opening degree of an expansion valve, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to, when executing the program instructions, perform the method for determining the initial opening of the expansion valve as described in any one of claims 1 to 5.

8. A heat pump water heater, characterized in that, Includes the device for determining the initial opening degree of an expansion valve as described in claim 6 or 7.

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