A method for determining initial opening degree of an electronic expansion valve of a pool heat pump and a pool heat pump

Abstract

The present application relates to a kind of initial opening degree determination method of pool heat pump electronic expansion valve and pool heat pump, and the determination method is according to compressor frequency, inlet water temperature and ambient temperature and set reference working condition parameter, respectively calculate the frequency correction opening degree, water temperature correction opening degree and ring temperature correction opening degree of corresponding electronic expansion valve, and then calculate the initial opening degree of electronic expansion valve, so that electronic expansion valve can be adapted to adjust initial opening degree according to working condition, so that initial opening degree meets the demand of actual working condition, to ensure that unit can be quickly and stably started under various working conditions, avoid the initial opening degree of electronic expansion valve and working condition mismatch and lead to trigger high pressure or low pressure protection.

Description

Technical Field

[0001] This invention relates to the field of control technology for swimming pool heat pumps, and more particularly to a method for determining the initial opening degree of an electronic expansion valve for a swimming pool heat pump and the swimming pool heat pump itself. Background Technology

[0002] Existing heated swimming pools, such as those in hotels, clubs, swimming pools, water parks, and hot springs, typically operate at water temperatures between 26°C and 35°C, which is lower than the temperature of household heating and hot water. Pool heat pumps, however, can achieve a COP of 5-6, significantly reducing costs compared to electric heating and gas boilers. Therefore, pool heat pumps are widely used for water heating in these applications.

[0003] In variable frequency swimming pool heat pump control technology, especially in heating mode, the opening control of the electronic expansion valve (EEV) is crucial. During unit startup, if the initial opening setting of the EEV is unreasonable, it can lead to significant pressure fluctuations and suction / discharge temperature fluctuations in the system, prolonging the stabilization time of the EEV. Commonly used control methods include:

[0004] Fixed opening method: Regardless of the operating conditions, a fixed opening is used during startup, such as 200 steps. This method does not consider the effects of ambient temperature, water temperature and compressor frequency, which leads to flow mismatch during low temperature or high frequency startup and is very likely to trigger high pressure or low pressure protection. Physical model method: By analyzing the principle of refrigeration system, theoretical calculations are performed based on parameters such as refrigerant density and pressure difference to directly fit the optimal start-up curve for a specific compressor. However, in actual application, due to the influence of factors such as water temperature, ambient temperature, air humidity, wind speed, and performance degradation of the unit after a period of use, the longer the time, the greater the deviation between theoretical calculation and actual use.

[0005] None of the above methods can adaptively adjust the initial opening of the electronic expansion valve according to the compressor frequency and actual temperature conditions, so that the initial opening meets the requirements of the actual operating conditions. Summary of the Invention

[0006] Based on this, the purpose of the present invention is to provide a method for determining the initial opening degree of the electronic expansion valve of a swimming pool heat pump, so as to ensure that the unit can start up quickly and stably under various operating conditions.

[0007] A method for determining the initial opening degree of an electronic expansion valve for a swimming pool heat pump includes: S10: When the unit starts up, the current ambient temperature is collected. Current inlet water temperature and the compressor's target operating frequency ; S20: Based on the current ambient temperature Current inlet water temperature and the compressor's target operating frequency Calculate the initial opening value of the electronic expansion valve. .

[0008] Furthermore, the initial opening value of the electronic expansion valve satisfy: + +

[0009] In the formula, Indicates the reference electronic expansion valve opening value. Indicates the ambient temperature correction opening. Indicates the water temperature correction setting. This indicates the frequency correction setting.

[0010] Furthermore, the ambient temperature correction opening is calculated using the following method: S21A: Based on the current ambient temperature With the set reference ambient temperature Ambient temperature difference, ambient temperature correction factor Calculate the ambient temperature correction opening ; ; In the formula, the reference ambient temperature The baseline operating parameters are defined and determined based on the rated test conditions.

[0011] Furthermore, the water temperature correction opening is calculated using the following method: S21B: Based on the current inlet water temperature With the set reference inlet water temperature Water temperature difference, water temperature correction factor Calculate water temperature correction opening ; ; In the formula, the reference inlet water temperature The baseline operating parameters are defined and determined based on the rated test water temperature.

[0012] Furthermore, the frequency correction opening is calculated using the following method: S21C: Based on the target operating frequency With the set reference operating frequency Frequency difference, frequency correction factor Calculate the frequency correction opening degree ; ; In the formula, the reference operating frequency is... The baseline operating parameters are defined and determined according to different machine models.

[0013] Furthermore, it also includes step S30: The electronic expansion valve is set according to the initial opening value. After running, obtain the current ambient temperature. Determine the current ambient temperature Is it below the low ambient temperature threshold? : If so, for the initial opening value Make a slight upward adjustment to obtain the execution opening value; If not, the initial opening value As the execution opening value.

[0014] Furthermore, the low ambient temperature threshold The adjustment of the electronic expansion valve is determined based on the operating conditions of the pool heat pump; that is, an additional fine-tuning opening is added to the original operating opening value, and the fine-tuning opening is set to (2~4). .

[0015] Furthermore, it also includes step S40: S40: Determine whether the opening value is within the allowable opening range of the electronic expansion valve. If yes, maintain the execution opening value; If not, the upper or lower limit of the allowable opening range of the electronic expansion valve shall be used as the execution opening value; The electronic expansion valve is controlled to enter PID dynamic regulation.

[0016] Furthermore, the permissible opening range of the electronic expansion valve is ( , );in This represents the lower limit of the allowed opening range. This represents the upper limit of the allowed opening range; When the initial opening value ≥ hour, To execute the opening value; When the initial opening value ≤ hour, To execute the opening value.

[0017] Compared to existing technologies, this invention calculates the frequency-corrected opening, water temperature-corrected opening, and ambient temperature-corrected opening of the electronic expansion valve based on the compressor frequency, inlet water temperature, ambient temperature, and set benchmark operating parameters. This calculation then determines the initial opening of the electronic expansion valve, enabling it to adaptively adjust its initial opening according to operating conditions. This ensures the initial opening meets the actual operating requirements, guaranteeing rapid and stable startup of the unit under various conditions and preventing mismatches between the initial opening of the electronic expansion valve and the operating conditions, which could trigger high-pressure or low-pressure protection.

[0018] Meanwhile, the present invention proposes a swimming pool heat pump, including a compressor, a four-way valve, a titanium tube pool water condenser, an electronic expansion valve, an evaporator, and several temperature sensors connected by refrigerant pipelines, and a controller electrically and / or communicatively connected to the compressor, the electronic expansion valve, and the temperature sensors, wherein the controller executes the method for determining the initial opening degree of the electronic expansion valve of the swimming pool heat pump as described above.

[0019] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the swimming pool heat pump structure of the present invention; Figure 2 This is a flowchart of the method for determining the initial opening degree of the electronic expansion valve of the swimming pool heat pump according to the present invention. Detailed Implementation

[0021] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings of the embodiments of the present invention. The described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0022] Please see Figure 1 The swimming pool heat pump of the present invention includes a variable frequency compressor 10, a four-way valve 20, a titanium tube pool water condenser 30, an electronic expansion valve 40, an evaporator 50, and several temperature sensors connected through refrigerant pipelines, and a controller electrically and / or communicatively connected to the compressor, the electronic expansion valve, and the temperature sensors.

[0023] The titanium tube pool water condenser 30 has pool water flowing inside the titanium tube and refrigerant flowing in the outer cavity of the titanium tube. Its water pipes are connected to the pool water pipes to form a circulating water circuit.

[0024] The evaporator 50 is an air source heat exchanger or a water source heat exchanger. When it is an air source heat exchanger, it adopts a finned heat exchanger; when it is a water source heat exchanger, it adopts a tube heat exchanger or a plate heat exchanger to exchange heat with water sources such as geothermal water, industrial waste hot water, and central heating water.

[0025] The plurality of temperature sensors include a first temperature sensor and a second temperature sensor.

[0026] The first temperature sensor is installed at the inlet of the titanium tube pool water condenser and is used to measure the inlet water temperature of the titanium tube pool water condenser. and real-time inlet water temperature Transmitted to the controller The second temperature sensor is installed in the swimming pool to measure the ambient temperature of the pool. And the ambient temperature is displayed in real time. Transmitted to the controller.

[0027] Please see Figure 2 The method for determining the initial opening degree of the electronic expansion valve of the swimming pool heat pump according to the present invention includes the following steps.

[0028] S10: When the unit starts up, the current ambient temperature is collected. Current inlet water temperature and the compressor's target operating frequency ; Furthermore, the average ambient temperature over a set time period is used as the current ambient temperature. The average influent temperature over a set time period will be used as the current influent temperature. .

[0029] S20: Based on the current ambient temperature Current inlet water temperature and the compressor's target operating frequency Calculate the initial opening value of the electronic expansion valve. .

[0030] Specifically, the determination method is as follows: S21A: Based on the current ambient temperature With the set reference ambient temperature Ambient temperature difference, ambient temperature correction factor Calculate the ambient temperature correction opening .

[0031] in, ; Reference ambient temperature The baseline operating parameters are determined based on the rated test conditions. In this embodiment, =15℃.

[0032] S21B: Based on the current inlet water temperature With the set reference inlet water temperature Water temperature difference, water temperature correction factor Calculate water temperature correction opening .

[0033] in, ; Reference inlet water temperature The baseline operating parameters are determined based on the rated test water temperature. In this embodiment, =26℃.

[0034] S21C: Based on the target operating frequency With the set reference operating frequency Frequency difference, frequency correction factor Calculate the frequency correction opening degree .

[0035] in, ; Reference operating frequency The baseline operating parameters are defined and determined based on different machine models. In this embodiment, =85Hz.

[0036] S22: Adjust opening degree according to ambient temperature Water temperature correction opening Frequency correction opening Calculate the initial opening value of the electronic expansion valve. .

[0037] in, + + .

[0038] In the formula, This represents the reference electronic expansion valve opening value, a defined reference operating condition parameter determined based on the rated test valve opening for different models. In this embodiment, .

[0039] S30: Electronic expansion valve according to initial opening value After running, obtain the current ambient temperature. Determine the current ambient temperature Is it below the low ambient temperature threshold? : If so, for the initial opening value Make a slight upward adjustment to obtain the execution opening value; If not, the initial opening value As the execution opening value.

[0040] In specific implementation, the low ambient temperature threshold Based on the operating conditions of the swimming pool heat pump, in this embodiment... Set to -5℃~10℃.

[0041] The initial opening value Make a slight upward adjustment, that is, at the initial opening value. Based on this, a fine-tuning opening is added, and the fine-tuning opening is set to (2~4). .

[0042] Furthermore, it also includes step S40.

[0043] S40: Determine whether the opening value is within the allowable opening range of the electronic expansion valve. If yes, maintain the execution opening value; If not, the upper or lower limit of the allowable opening range of the electronic expansion valve shall be used as the execution opening value; The electronic expansion valve is controlled to enter PID dynamic regulation.

[0044] In practice, the maximum opening of the electronic expansion valve is used. With minimum opening The allowable opening range is set, that is, the allowable opening range of the electronic expansion valve is expressed as ( , ); This represents the lower limit of the allowed opening range. This represents the upper limit of the allowed opening range.

[0045] When the initial opening value is calculated ≥ hour, To execute the opening value; When the initial opening value is calculated ≤ hour, To execute the opening value.

[0046] Maximum opening With minimum opening All are baseline constraints; in this embodiment, the maximum opening is... Minimum opening .

[0047] Compared to existing technologies, this invention calculates the frequency-corrected opening, water temperature-corrected opening, and ambient temperature-corrected opening of the electronic expansion valve based on the compressor frequency, inlet water temperature, ambient temperature, and set benchmark operating parameters. This calculation then determines the initial opening of the electronic expansion valve, enabling it to adaptively adjust its initial opening according to operating conditions. This ensures the initial opening meets the actual operating requirements, guaranteeing rapid and stable startup of the unit under various conditions and preventing mismatches between the initial opening of the electronic expansion valve and the operating conditions, which could trigger high-pressure or low-pressure protection.

[0048] In specific implementation, the controller performs the initial opening degree determination step of the above-mentioned swimming pool heat pump electronic expansion valve. The controller is an electronic device, which includes, but is not limited to: a memory, processor, network interface and 4G / 5G / WIFE module that can be interconnected via a system bus.

[0049] Among them, electronic devices can be computing devices such as rack servers, blade servers, tower servers, or cabinet servers.

[0050] The memory includes at least one type of readable storage medium, including flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. The memory can be an internal storage unit of the electronic device, such as the hard disk or RAM of the electronic device. The memory can also be an external storage device of the electronic device, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc. The memory can also include both internal storage units and external storage devices of the electronic device.

[0051] The processor can be a central processing unit (CPU), microcontroller, microprocessor, or other data processing chip. This processor is typically used to control the overall operation of the electronic device, such as performing control and processing related to data interaction or communication with the electronic device. The processor is used to run program code stored in the memory or process data, such as running the method for determining the initial opening degree of the swimming pool heat pump electronic expansion valve.

[0052] The network interface may include a wireless network interface or a wired network interface, which is typically used to establish communication connections between the electronic device and other electronic devices. For example, the network interface is used to connect the electronic device to an external data platform via a network, establishing a data transmission channel and communication connection between the electronic device and the external data platform. The network may be an intranet, the Internet, Global System for Mobile communication (GSM), Wideband Code Division Multiple Access (WCDMA), 4G network, 5G network, Bluetooth, Wi-Fi, or other wireless or wired networks.

[0053] The 4G / 5G / WIFE module establishes a communication connection with the cloud platform through the network interface.

[0054] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments and claims of this application are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that, unless otherwise stated, “a plurality” and “several” refer to two or more; “and / or” refers to and includes any or all possible combinations of one or more associated listed items; “first,” “second,” “third,” etc., are used only to distinguish and not to describe a particular order or sequence, nor should they be construed as indicating or implying relative importance. When the above description relates to drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of this application, those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0055] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and the present invention also intends to include these modifications and variations.

Claims

1. A method for determining the initial opening degree of an electronic expansion valve for a swimming pool heat pump, characterized in that, include: S10: When the unit starts up, the current ambient temperature is collected. Current inlet water temperature and the compressor's target operating frequency ; S20: Based on the current ambient temperature Current inlet water temperature and the compressor's target operating frequency Calculate the initial opening value of the electronic expansion valve. .

2. The method for determining the initial opening degree of the electronic expansion valve of a swimming pool heat pump according to claim 1, characterized in that, The initial opening value of the electronic expansion valve satisfy: + + In the formula, Indicates the reference electronic expansion valve opening value. Indicates the ambient temperature correction opening. Indicates the water temperature correction setting. This indicates the frequency correction setting.

3. The method for determining the initial opening degree of the electronic expansion valve of a swimming pool heat pump according to claim 2, characterized in that, The ambient temperature correction opening is calculated using the following method: S21A: Based on the current ambient temperature With the set reference ambient temperature Ambient temperature difference, ambient temperature correction factor Calculate the ambient temperature correction opening ; ； In the formula, the reference ambient temperature The baseline operating parameters are defined and determined based on the rated test conditions.

4. The method for determining the initial opening degree of the electronic expansion valve of a swimming pool heat pump according to claim 2 or 3, characterized in that, The water temperature correction opening is calculated using the following method: S21B: Based on the current inlet water temperature With the set reference inlet water temperature Water temperature difference, water temperature correction factor Calculate water temperature correction opening ; ； In the formula, the reference inlet water temperature The baseline operating parameters are defined and determined based on the rated test water temperature.

5. The method for determining the initial opening degree of the electronic expansion valve of a swimming pool heat pump according to claim 4, characterized in that, The frequency correction opening is calculated using the following method: S21C: Based on the target operating frequency With the set reference operating frequency Frequency difference, frequency correction factor Calculate the frequency correction opening degree ; ； In the formula, the reference operating frequency is... The baseline operating parameters are defined and determined according to different machine models.

6. The method for determining the initial opening degree of the electronic expansion valve of a swimming pool heat pump according to claim 1, characterized in that, It also includes step S30: The electronic expansion valve is set according to the initial opening value. After running, obtain the current ambient temperature. Determine the current ambient temperature Is it below the low ambient temperature threshold? : If so, for the initial opening value Make a slight upward adjustment to obtain the execution opening value; If not, the initial opening value As the execution opening value.

7. The method for determining the initial opening degree of the electronic expansion valve of a swimming pool heat pump according to claim 6, characterized in that, The low ambient temperature threshold The adjustment of the electronic expansion valve is determined based on the operating conditions of the pool heat pump; that is, an additional fine-tuning opening is added to the original operating opening value, and the fine-tuning opening is set to (2~4). .

8. The method for determining the initial opening degree of the electronic expansion valve of a swimming pool heat pump according to claim 6, characterized in that, It also includes step S40: S40: Determine whether the opening value is within the allowable opening range of the electronic expansion valve. If yes, maintain the execution opening value; If not, the upper or lower limit of the allowable opening range of the electronic expansion valve shall be used as the execution opening value; The electronic expansion valve is controlled to enter PID dynamic regulation.

9. The method for determining the initial opening degree of the electronic expansion valve of a swimming pool heat pump according to claim 8, characterized in that, The allowable opening range of the electronic expansion valve is ( , );in This represents the lower limit of the allowed opening range. This represents the upper limit of the allowed opening range; When the initial opening value ≥ hour, To execute the opening value; When the initial opening value ≤ hour, To execute the opening value.

10. A swimming pool heat pump, comprising a compressor, a four-way valve, a titanium tube pool water condenser, an electronic expansion valve, an evaporator, and several temperature sensors connected via refrigerant piping, and a controller electrically and / or communicatively connected to the compressor, the electronic expansion valve, and the temperature sensors, characterized in that, The controller performs the method for determining the initial opening degree of the electronic expansion valve of the pool heat pump as described in any one of claims 1-9.

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