Dual-compressor air source heat pump valve coordination control method, system and storage medium

Abstract

The present application relates to the field of district heating system, and particularly relates to a kind of double-compressor air source heat pump valve coordination control method, system and storage medium.The control method includes: fin heat exchanger enters defrosting mode, interval time acquisition compressor low pressure, high pressure, ambient temperature, defrosting time and fin liquid pipe temperature;According to the low pressure value and safety limit value of real-time acquisition, the control value of the first calculation main electronic expansion valve opening degree and defrosting electronic expansion valve opening degree;According to the condensing temperature and minimum limit value of real-time acquisition, the control value of the second calculation main electronic expansion valve opening degree and defrosting electronic expansion valve opening degree;According to the real-time liquid pipe temperature and guide value, the control value of the third calculation main electronic expansion valve opening degree and defrosting electronic expansion valve opening degree.The present application is adjusted intelligently, in district heating system, ensure that compressor is always in safe working condition, effectively reduce the failure rate of heat pump unit, improve the defrosting speed and operating efficiency of heat pump unit.

Description

Technical Field

[0001] This invention relates to the field of district heating systems, and in particular to a method, system, and storage medium for coordinated control of valve components in a dual-compressor air source heat pump. Background Technology

[0002] During the operational testing of the dual-compressor air source heat pump system, it was found that when the electronic expansion valve opening was too large during defrosting, the compressor high pressure was too low, resulting in a slow defrosting speed; when the electronic expansion valve opening was too small, it easily caused the compressor low pressure to be too low, exceeding the compressor's safe operating range. In addition, the two fins in a V-shaped finned heat exchanger belong to different heat pump systems, resulting in asynchronous defrosting speeds and wasting energy. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method, system and storage medium for coordinated control of valve components in a dual-compressor air source heat pump.

[0004] In a first aspect, the present invention provides a method for coordinated control of valve components in a dual-compressor air source heat pump, wherein the dual-compressor air source heat pump comprises:

[0005] The first heat pump system includes a first compressor, a shell-and-tube heat exchanger, a first main electronic expansion valve, a first one-way valve and a second one-way valve, a first defrost electronic expansion valve, a first finned heat exchanger and a third finned heat exchanger, a first three-way valve and a second three-way valve, wherein the first finned heat exchanger is connected in series with the first three-way valve, and the third finned heat exchanger is connected in series with the second three-way valve.

[0006] It also includes a first pressure sensor, a third pressure sensor, a first temperature sensor, and a third temperature sensor. The first pressure sensor monitors the low pressure value of the first compressor. The third pressure sensor monitors the high pressure value of the first compressor. The first temperature sensor monitors the liquid tube temperature of the first finned heat exchanger. The third temperature sensor monitors the liquid tube temperature of the third finned heat exchanger. ;

[0007] The second heat pump system includes a second compressor, a shell-and-tube heat exchanger, a second main electronic expansion valve, a third and a fourth one-way valve, a second defrost electronic expansion valve, a second and a fourth finned heat exchanger, a third and a fourth three-way valve, wherein the second finned heat exchanger is connected in series with the fourth three-way valve, and the fourth finned heat exchanger is connected in series with the third three-way valve.

[0008] It also includes a second pressure sensor, a fourth pressure sensor, a second temperature sensor, and a fourth temperature sensor. The second pressure sensor monitors the low pressure value of the second compressor. The fourth pressure sensor monitors the high pressure value of the second compressor. The second temperature sensor monitors the liquid tube temperature of the second finned heat exchanger. The fourth temperature sensor monitors the liquid tube temperature of the fourth finned heat exchanger. ;

[0009] The control method includes the following steps:

[0010] S1: Determine if the defrosting conditions are met. If they are met, execute S2; otherwise, continue to maintain the heating mode.

[0011] S2: The first finned heat exchanger and the second finned heat exchanger enter defrost mode, initialize the defrost timer, and start timing;

[0012] S3: Open the first defrost electronic expansion valve and the second defrost electronic expansion valve, set the opening degree of the first defrost electronic expansion valve and the second defrost electronic expansion valve to be equal, and set the opening degree of the first main electronic expansion valve and the second main electronic expansion valve to be equal.

[0013] S4: Every interval Time, collecting compressor low pressure, high pressure, ambient temperature, defrost time, and finned liquid tube temperature;

[0014] S5: Based on the real-time collected low pressure value and safety limit, calculate the control values ​​of the main electronic expansion valve opening and the defrost electronic expansion valve opening for the first time;

[0015] Determine if the compressor's low pressure is higher than the safety limit. If it is higher, execute S6 directly; otherwise, increase the opening degree of the main electronic expansion valve and the defrost electronic expansion valve.

[0016] S6: Based on the real-time collected condensation temperature and minimum limit value The second calculation involves the control values ​​for the opening of the main electronic expansion valve and the opening of the defrosting electronic expansion valve.

[0017] Determine if the condensation temperature is greater than the minimum limit. If so, execute S7 directly; otherwise, reduce the opening of the system's main electronic expansion valve and defrost electronic expansion valve.

[0018] S7: Based on real-time tubing temperature and guide value The control values ​​for the opening of the main electronic expansion valve and the opening of the defrosting electronic expansion valve are calculated for the third time.

[0019] Determine if the real-time liquid tubing temperature is higher than the guide value. If so, execute S8 directly; otherwise, increase the opening of the defrost electronic expansion valve and decrease the opening of the main electronic expansion valve to ensure that the total opening remains unchanged.

[0020] S8: Calculate and adjust the opening degree of each electronic expansion valve so that... and Between R1 and R2 and Between R3 and R4, R1, R2, R3, and R4 are all preset values. The opening degree of the first main electronic expansion valve. This refers to the opening degree of the second main electronic expansion valve. For the opening degree of the first defrosting electronic expansion valve, This refers to the opening degree of the second defrosting electronic expansion valve;

[0021] S9: Determine whether the first finned heat exchanger and the second finned heat exchanger have met the defrosting exit conditions or the defrosting time has reached the set value. If the conditions are met, the fins will exit defrosting. If the conditions are not met, S4-S9 will be executed again until both the first finned heat exchanger and the second finned heat exchanger have exited defrosting.

[0022] S10: After both the first and second finned heat exchangers have exited defrosting mode, they are switched to heating mode.

[0023] S11: After a certain time, the third and fourth finned heat exchangers enter defrosting mode, and the defrosting timer is initialized. And start timing;

[0024] S12: Execute S3-S8;

[0025] S13: Determine whether the third finned heat exchanger and the fourth finned heat exchanger have met the defrosting exit conditions or the defrosting time has reached the set value. If the conditions are met, the fins will exit defrosting. If the conditions are not met, repeat S3-S8 and S13 until the third finned heat exchanger and the fourth finned heat exchanger have exited defrosting.

[0026] S14: The third and fourth finned heat exchangers exit defrosting mode and enter heating mode.

[0027] Preferably, in step S5, the opening degrees of the main electronic expansion valve and the defrost electronic expansion valve are calculated as follows:

[0028] When the first finned heat exchanger or the third finned heat exchanger is defrosted

[0029] ;

[0030] When the second or fourth finned heat exchanger is defrosted

[0031] ;

[0032] In the formula, It is the first coefficient.

[0033] Preferably, in step S6, the opening degrees of the main electronic expansion valve and the defrost electronic expansion valve are calculated as follows:

[0034] When the first finned heat exchanger or the third finned heat exchanger is defrosted

[0035] ;

[0036] When the second or fourth finned heat exchanger is defrosted

[0037] ;

[0038] In the formula, For the high pressure of the first compressor Converted to temperature, This is the minimum defrosting condensation temperature. For the high pressure of the second compressor Converted to temperature, This is the second coefficient.

[0039] Preferably, in step S7, the opening degrees of the main electronic expansion valve and the defrost electronic expansion valve are calculated as follows:

[0040] When the first fin heat exchanger defrosts

[0041]

[0042] When the second fin heat exchanger defrosts

[0043]

[0044] When the third fin heat exchanger defrosts

[0045]

[0046] When the fourth fin heat exchanger defrosts

[0047]

[0048] In the formula, The temperature of the finned liquid tube during defrosting varies with defrosting time. and ambient temperature Changes in guidance values, It is the third coefficient.

[0049] Preferably, in S8,

[0050] First main electronic expansion valve opening ,

[0051] Second main electronic expansion valve opening ,

[0052] First defrosting electronic expansion valve opening ,

[0053] Second defrosting electronic expansion valve opening .

[0054] Preferably, in step S9, it is determined whether the first finned heat exchanger and the second finned heat exchanger have reached the defrost exit condition or the defrost duration has reached the set value. If the condition is met, the fins exit defrost, the opening of the main electronic expansion valve of the system is adjusted, and the defrost electronic expansion valve of the system is closed.

[0055] In step S13, it is determined whether the third finned heat exchanger and the fourth finned heat exchanger have met the defrosting exit conditions or the defrosting time has reached the set value. If the conditions are met, the fins will exit defrosting, the opening of the main electronic expansion valve of the system will be adjusted, and the defrosting electronic expansion valve of the system will be closed.

[0056] Preferably, in step S2, the first finned heat exchanger and the second finned heat exchanger enter the defrost mode, the defrost timer is initialized and starts timing, and the first three-way valve and the fourth three-way valve are switched to the b and c interfaces for connection.

[0057] In S10, after the first finned heat exchanger and the second finned heat exchanger have both exited defrosting mode, the first three-way valve and the fourth three-way valve are switched to the connection of interfaces a and c, and the mode is changed to heating mode.

[0058] In step S11, the second three-way valve and the third three-way valve switch to the b and c interfaces, while the first three-way valve and the fourth three-way valve remain connected at the a and c interfaces.

[0059] Preferably, in step S14, the third finned heat exchanger and the fourth finned heat exchanger exit defrosting mode, and the second three-way valve and the third three-way valve switch to connect interfaces a and c, entering the heating mode.

[0060] In a second aspect, the present invention provides a dual-compressor air source heat pump valve collaborative control system, employing any of the dual-compressor air source heat pump valve collaborative control methods described above.

[0061] In a third aspect, the present invention provides a computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device in which the computer-readable storage medium is located to perform any of the described dual-compressor air-source heat pump valve coordinated control methods.

[0062] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0063] The dual-compressor air-source heat pump valve collaborative control system described in this invention ensures that the compressor is always in a safe operating condition by intelligently adjusting valves such as the main electronic expansion valve, defrost electronic expansion valve, and three-way valve. This effectively reduces the failure rate of the heat pump unit while improving its defrosting speed and operational efficiency. Especially in district heating systems, it can improve system energy efficiency, reduce overall energy consumption, and provide an innovative solution for efficient heat pump control. Attached Figure Description

[0064] Figure 1 This is a flowchart of the dual-compressor air source heat pump valve coordinated control method described in this invention.

[0065] Figure 2 This is a schematic diagram of the structure of the dual-compressor air source heat pump described in this invention.

[0066] Figure 3 This is a refrigerant circulation diagram for the dual-compressor air source heat pump heating mode described in this invention.

[0067] Figure 4 This is a refrigerant circulation diagram during defrosting of the first and second finned heat exchangers of the dual-compressor air source heat pump described in this invention.

[0068] Figure 5 This is a control flowchart of the main electronic expansion valve and the defrost electronic expansion valve of the dual-compressor air source heat pump described in this invention.

[0069] Figure 6 This is a refrigerant circulation diagram for the dual-compressor air source heat pump of the present invention when the first finned heat exchanger is out of defrost and the second finned heat exchanger is still defrosting.

[0070] Figure 7 This is a refrigerant circulation diagram for the dual-compressor air source heat pump of the present invention when the second finned heat exchanger is out of defrost and the first finned heat exchanger is still defrosting.

[0071] Figure 8 This is a refrigerant circulation diagram during defrosting of the third and fourth finned heat exchangers of the dual-compressor air source heat pump described in this invention.

[0072] Figure 9 This is a refrigerant circulation diagram for the dual-compressor air source heat pump of the present invention when the third finned heat exchanger is out of defrost and the fourth finned heat exchanger is still defrosting.

[0073] Figure 10 This is a refrigerant circulation diagram for the dual-compressor air source heat pump of the present invention when the fourth finned heat exchanger is out of defrost and the third finned heat exchanger is still defrosting.

[0074] Figure 11This is a temperature curve of the liquid pipe during defrosting of the second finned heat exchanger of the dual-compressor air source heat pump described in this invention.

[0075] Marked in the image:

[0076] 1-1: First compressor; 1-2: Second compressor.

[0077] 2: Shell and tube heat exchangers

[0078] 3-1: First main electronic expansion valve; 3-2: Second main electronic expansion valve.

[0079] 4-1: First check valve; 4-2: Second check valve; 4-3: Third check valve; 4-4: Fourth check valve.

[0080] 5-1: First defrost electronic expansion valve; 5-2: Second defrost electronic expansion valve.

[0081] 6-1: First finned heat exchanger; 6-2: Second finned heat exchanger; 6-3: Third finned heat exchanger; 6-4: Fourth finned heat exchanger.

[0082] 7-1: First three-way valve, 7-2: Second three-way valve, 7-3: Third three-way valve, 7-4: Fourth three-way valve.

[0083] 8-1: First pressure sensor; 8-2: Second pressure sensor; 8-3: Third pressure sensor; 8-4: Fourth pressure sensor.

[0084] 9-1: First temperature sensor, 9-2: Second temperature sensor, 9-3: Third temperature sensor, 9-4: Fourth temperature sensor. Detailed Implementation

[0085] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0086] Unless otherwise specified, the terms "upper," "lower," "left," "right," "center," "inner," and "outer," etc., used in the description of specific embodiments of the present invention to indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is usually placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, and for enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0087] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are arranged as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when arranged in "horizontal," "vertical," "suspended," "parallel," or "coaxial" directions, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0088] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0089] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0090] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to connection methods commonly used in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0091] Example 1

[0092] like Figure 1 As shown, a method for coordinated control of valve components in a dual-compressor air source heat pump is provided for controlling the valve components of a dual-compressor air source heat pump.

[0093] like Figure 2 As shown, the dual-compressor air source heat pump includes a first heat pump system and a second heat pump system.

[0094] The first heat pump system includes a first compressor 1-1, a shell-and-tube heat exchanger 2, a first main electronic expansion valve 3-1, a first one-way valve 4-1 and a second one-way valve 4-2, a first defrost electronic expansion valve 5-1, a first finned heat exchanger 6-1 and a third finned heat exchanger 6-3, a first three-way valve 7-1 and a second three-way valve 7-2. The first finned heat exchanger 6-1 is connected in series with the first three-way valve 7-1, and the third finned heat exchanger 6-3 is connected in series with the second three-way valve 7-2. It also includes a first pressure sensor 8-1, a third pressure sensor 8-3, a first temperature sensor 9-1, and a third temperature sensor 9-3. The first pressure sensor 8-1 monitors the low pressure value of the first compressor 1-1. The third pressure sensor 8-3 monitors the high pressure value of the first compressor 1-1. The first temperature sensor 9-1 monitors the temperature of the liquid tube in the first finned heat exchanger 6-1. The third temperature sensor 9-3 monitors the liquid tube temperature of the third finned heat exchanger 6-3. .

[0095] The second heat pump system includes a second compressor 1-2, a shell-and-tube heat exchanger 2, a second main electronic expansion valve 3-2, a third check valve 4-3 and a fourth check valve 4-4, a second defrost electronic expansion valve 5-2, a second finned heat exchanger 6-2 and a fourth finned heat exchanger 6-4, a third three-way valve 7-3 and a fourth three-way valve 7-4. The second finned heat exchanger 6-2 is connected in series with the fourth three-way valve 7-4, and the fourth finned heat exchanger 6-4 is connected in series with the third three-way valve 7-3. It also includes a second pressure sensor 8-2, a fourth pressure sensor 8-4, a second temperature sensor 9-2, and a fourth temperature sensor 9-4. The second pressure sensor 8-2 monitors the low pressure value of the second compressor 1-2. The fourth pressure sensor 8-4 monitors the high pressure value of the second compressor 1-2. The second temperature sensor 9-2 monitors the liquid tube temperature of the second finned heat exchanger 6-2. The fourth temperature sensor 9-4 monitors the liquid tube temperature of the fourth finned heat exchanger 6-4. .

[0096] The structure of the dual-compressor air source heat pump can be referenced in the published patent documents: CN117073261A A method for constructing a cross-type uninterrupted defrosting air source heat pump unit, and CN222417774U An air source heat pump unit and air conditioning system with multi-system collaborative defrosting.

[0097] The method for coordinated control of valve components in a dual-compressor air-source heat pump includes the following steps:

[0098] S1: Determine if defrosting conditions are met. If met, execute S2; otherwise, continue in heating mode. Connect ports a and c of the first three-way valve 7-1, the second three-way valve 7-2, the third three-way valve 7-3, and the fourth three-way valve 7-4. Close the first defrost electronic expansion valve 5-1 and the second defrost electronic expansion valve 5-2. Open the first main electronic expansion valve 3-1 and the second main electronic expansion valve 3-2, adjusting the opening degree according to the return gas superheat. Refrigerant circulation proceeds as follows... Figure 3 As shown.

[0099] S2: The first finned heat exchanger 6-1 and the second finned heat exchanger 6-2 enter defrost mode, initialize the defrost timer, and start timing. The first three-way valve 7-1 and the fourth three-way valve 7-4 switch to connect ports b and c, respectively, and the refrigerant circulation proceeds as follows. Figure 4 As shown.

[0100] S3: Open the first defrost electronic expansion valve 5-1 and the second defrost electronic expansion valve 5-2, set the opening degrees of the first defrost electronic expansion valve 5-1 and the second defrost electronic expansion valve 5-2 to be equal, and set the opening degrees of the first main electronic expansion valve 3-1 and the second main electronic expansion valve 3-2 to be equal. For example , In the formula, For the opening degree of the first main electronic expansion valve 3-1, For the second main electronic expansion valve 3-2 opening degree, The opening degree of the first defrosting electronic expansion valve 5-1 is as follows: The opening degree of the second defrosting electronic expansion valve 5-2.

[0101] S4: Every interval The time frame includes collecting data on compressor low pressure, high pressure, ambient temperature, defrosting time, and finned liquid tube temperature. This is the default value.

[0102] S5: To ensure stable unit operation, based on the real-time collected low-pressure value and safety limit, the control values ​​for the opening of the main electronic expansion valve and the defrost electronic expansion valve are calculated for the first time to determine whether the compressor's low pressure is higher than the safety limit. If the pressure is higher, there is no need to adjust the opening of the electronic expansion valve based on the low pressure value; simply execute S6 directly. Otherwise, the opening of the main electronic expansion valve and the defrost electronic expansion valve needs to be increased.

[0103] The calculation method for the opening degree of the main electronic expansion valve and the defrost electronic expansion valve is as follows:

[0104] When the first finned heat exchanger 6-1 or the third finned heat exchanger 6-3 is defrosted

[0105] ;

[0106] When the second finned heat exchanger 6-2 or the fourth finned heat exchanger 6-4 is defrosted

[0107] ;

[0108] In the formula, The low-pressure limit for safe operation of the compressor. For the low pressure of the first compressor 1-1, For the low pressure of the first compressor 1-2, The first coefficient can be determined based on experience or experimentation.

[0109] S6: To ensure that the refrigerant temperature (condensation temperature) in the fins meets the defrosting requirements, based on the real-time collected condensation temperature and the minimum limit... The second calculation involves setting the control values ​​for the opening of the main electronic expansion valve and the defrost electronic expansion valve to determine if the condensing temperature exceeds the minimum limit. If so, there is no need to adjust the opening of the electronic expansion valve based on the condensing temperature; simply execute S7. Otherwise, the opening of the main electronic expansion valve and the defrost electronic expansion valve of the system must be reduced.

[0110] The calculation method for the opening degree of the main electronic expansion valve and the defrost electronic expansion valve is as follows:

[0111] When the first finned heat exchanger 6-1 or the third finned heat exchanger 6-3 is defrosted

[0112] ;

[0113] When the second finned heat exchanger 6-2 or the fourth finned heat exchanger 6-4 is defrosted

[0114] ;

[0115] In the formula, For the high pressure of the first compressor 1-1 Converted to temperature, This is the minimum defrosting condensation temperature. For the high pressure of the second compressor 1-2 Converted to temperature, This is the second coefficient, which can be determined based on experience or experimentation.

[0116] S7: To ensure the defrosting speed of the fins, a preset temperature for the finned liquid pipe is provided based on the defrosting duration. and ambient temperature Change guidance value Based on real-time liquid tube temperature and guide value The control values ​​for the opening of the main electronic expansion valve and the defrost electronic expansion valve are calculated for the third time to determine whether the real-time liquid pipe temperature is higher than the guide value. If so, it means that the defrosting speed meets expectations, and S8 can be executed directly; otherwise, it is necessary to increase the opening of the defrosting electronic expansion valve and decrease the opening of the main electronic expansion valve to ensure that the total opening remains unchanged.

[0117] The calculation method for the opening degree of the main electronic expansion valve and the defrost electronic expansion valve is as follows:

[0118] When the first finned heat exchanger 6-1 is defrosted

[0119]

[0120] When the second finned heat exchanger 6-2 is defrosted

[0121]

[0122] When the third finned heat exchanger 6-3 is defrosted

[0123]

[0124] When the fourth fin heat exchanger 6-4 is defrosted

[0125]

[0126] In the formula, the liquid tube temperatures of the first finned heat exchanger 6-1, the second finned heat exchanger 6-2, the third finned heat exchanger 6-3, and the fourth finned heat exchanger 6-4 are respectively represented by... , , and express, The temperature of the finned liquid tube during defrosting varies with defrosting time. and ambient temperature Changes in guidance values, This is the third coefficient, which can be determined based on experience or experimentation.

[0127] S8: Calculate and adjust the opening degree of each electronic expansion valve so that... and Between R1 and R2 and Between R3 and R4, R1, R2, R3, and R4 are all preset values.

[0128] Main electronic expansion valve or

[0129] Defrosting electronic expansion valve or .

[0130] In a preferred embodiment, the opening degree of each electronic expansion valve is calculated and adjusted to ensure... and Between 0 and 480, and Between 150 and 300.

[0131] Steps S4-S8 are the control algorithms for the main electronic expansion valve and the defrosting electronic expansion valve, such as... Figure 5 As shown.

[0132] S9: Determine whether the first finned heat exchanger 6-1 and the second finned heat exchanger 6-2 have met the defrosting exit conditions or the defrosting time has reached the set value. If the conditions are met, the fins will exit defrosting, the opening of the main electronic expansion valve of the system will be adjusted, and the defrosting electronic expansion valve of the system will be closed. If the conditions are not met, S4-S9 will be executed again until the first finned heat exchanger 6-1 and the second finned heat exchanger 6-2 have both exited defrosting.

[0133] When the first finned heat exchanger 6-1 stops defrosting while the second finned heat exchanger 6-2 is still defrosting, the refrigerant circulation is as follows: Figure 6 At this time, no refrigerant flows into the first finned heat exchanger 6-1.

[0134] When the second finned heat exchanger 6-2 stops defrosting while the first finned heat exchanger 6-1 is still defrosting, the refrigerant circulation is as follows: Figure 7 At this time, no refrigerant flows into the second finned heat exchanger 6-2.

[0135] S10: After both the first finned heat exchanger 6-1 and the second finned heat exchanger 6-2 have exited defrosting mode, the first three-way valve 7-1 and the fourth three-way valve 7-4 switch to connect interfaces a and c, changing to heating mode, and the refrigerant circulation proceeds as follows. Figure 3 .

[0136] S11: After a certain time, the third finned heat exchanger 6-3 and the fourth finned heat exchanger 6-4 enter the defrosting process, as follows: Figure 8 As shown, initialize the defrost timer. , t Start the defrosting timer; switch the second three-way valve 7-2 and the third three-way valve 7-3 to the b and c ports, while the first three-way valve 7-1 and the fourth three-way valve 7-4 remain connected at the a and c ports.

[0137] S12: Similar to the defrosting of the first finned heat exchanger 6-1 and the second finned heat exchanger 6-2, execute S3-S8.

[0138] S13: Determine whether the third finned heat exchanger 6-3 and the fourth finned heat exchanger 6-4 have met the defrosting exit conditions or the defrosting time has reached the set value. If the conditions are met, the fins will exit defrosting, the opening of the main electronic expansion valve of the system will be adjusted, and the defrosting electronic expansion valve of the system will be closed. If the conditions are not met, S3-S8 and S13 will be executed again until the third finned heat exchanger 6-3 and the fourth finned heat exchanger 6-4 have exited defrosting.

[0139] When the third finned heat exchanger 6-3 stops defrosting while the fourth finned heat exchanger 6-4 is still defrosting, the refrigerant circulation is as follows: Figure 9 At this time, no refrigerant flows into the third finned heat exchanger 6-3.

[0140] When the third finned heat exchanger 6-3 is still defrosting, while the fourth finned heat exchanger 6-4 has stopped defrosting, the refrigerant circulation is as follows: Figure 10 At this time, no refrigerant flows into the fourth finned heat exchanger 6-4.

[0141] S14: The third finned heat exchanger 6-3 and the fourth finned heat exchanger 6-4 exit defrosting mode, and the second three-way valve 7-2 and the third three-way valve 7-3 switch to the a and c interfaces to be connected, entering the heating mode.

[0142] This invention optimizes four aspects: compressor low pressure, high pressure, defrosting speed, and system energy efficiency. Specifically, for a dual-compressor high-efficiency defrosting air source heat pump system, it proposes a coordinated control method for valves such as the main electronic expansion valve, the defrosting electronic expansion valve, and the three-way valve, aiming to improve the defrosting performance and stability of the new heat pump system.

[0143] Example 2

[0144] Based on Example 1, taking a dual-compressor air source heat pump with a rated heating capacity of 270kW as an example, such as... Figure 2 As shown, two scroll compressors are configured, and the compressors are designed for safe operation at low pressure limits. The refrigerant used is R410A; the finned liquid line temperature during defrosting varies with defrosting time. and ambient temperature The guidance value for the change ,in and The unit is ℃. The unit is seconds (s). Minimum defrost condensation temperature. Control coefficient , , .

[0145] The first step is to determine whether the defrosting conditions are met. If the defrosting conditions are met, proceed to the second step.

[0146] In the second step, the first finned heat exchanger 6-1 and the second finned heat exchanger 6-2 first enter the defrost mode and initialize the defrost timer. And start timing. Switch the first three-way valve 7-1 and the fourth three-way valve 7-4 to their respective ports (b and c) for refrigerant circulation. Figure 4 .

[0147] The third step is to open the first defrost electronic expansion valve 5-1 and the second defrost electronic expansion valve 5-2, with the opening degree... The opening degrees of the first main electronic expansion valve 3-1 and the second main electronic expansion valve 3-2 are set to... .

[0148] Next is each interval The process repeats from step four to step nine. Only a few key moments are described here.

[0149] when hour, , .

[0150] The fourth step is to collect the low-pressure data from the compressor. , ,high pressure , Ambient temperature finned liquid tube temperature , .

[0151] Fifth, the low pressure of both system compressors is higher than the safety limit. Proceed directly to the next step.

[0152] Step 6, condensing temperature of the first heat pump system If the temperature is below 25℃, then

[0153] Main electronic expansion valve opening ;

[0154] Defrosting electronic expansion valve opening .

[0155] Second heat pump system condensation temperature For temperatures above 25℃, no calculation or adjustment is required.

[0156] Step 7: The liquid tube temperatures of both the first finned heat exchanger 6-1 and the second finned heat exchanger 6-2 are higher than the guide values. Proceed directly to the next step.

[0157] Step 8 , Between 0 and 480 steps, , The range is between 150 and 300 steps, therefore the opening of the electronic expansion valve is adjusted to the new value.

[0158] Step 9: If the defrosting exit conditions are not met, repeat steps 4 through 9.

[0159] when hour, , , , .

[0160] The fourth step is to collect the low-pressure data from the compressor. , ,high pressure , Ambient temperature finned liquid tube temperature , .

[0161] Fifth, the low pressure of both system compressors is higher than the safety limit. Proceed directly to the next step.

[0162] Step 6, condensing temperature of the first heat pump system Second heat pump system condensation temperature If all temperatures are above 25°C, proceed directly to the next step.

[0163] Step 7: The liquid tube temperatures of both the first finned heat exchanger 6-1 and the second finned heat exchanger 6-2 are lower than the guideline values. Then calculate and adjust the opening degree of the electronic expansion valve.

[0164]

[0165] Step 8 , Between 0 and 480 steps, , The range is between 150 and 300 steps, therefore the opening of the electronic expansion valve is adjusted to the new value.

[0166] Step 9: If the defrosting exit conditions are not met, repeat steps 4 through 9.

[0167] when hour, , ,

[0168] The fourth step is to collect the low-pressure data from the compressor. , ,high pressure , Ambient temperature finned liquid tube temperature , .

[0169] Fifth, the low pressure of both system compressors is higher than the safety limit. Proceed directly to the next step.

[0170] Step 6, condensing temperature of the first heat pump system Second heat pump system condensation temperature If all temperatures are above 25°C, proceed directly to the next step.

[0171] Step 7: The liquid tube temperatures of both the first finned heat exchanger 6-1 and the second finned heat exchanger 6-2 are lower than the guide values. Then calculate and adjust the opening degree of the electronic expansion valve.

[0172]

[0173] Step 8 , It needs to be between 0 and 480 steps. , The number of steps needs to be between 150 and 300, therefore the opening of the electronic expansion valve needs to be adjusted. , , and

[0174] Step 9: The first finned heat exchanger 6-1 reaches the defrost exit condition and exits defrost. Set the opening of the main electronic expansion valve 3-1. Close the defrosting electronic expansion valve. The second finned heat exchanger 6-2 has not met the defrosting exit conditions; repeat steps four through nine.

[0175] After the second finned heat exchanger 6-2 has also completed defrosting, close the defrosting electronic expansion valve 5-2 and set the opening of the main electronic expansion valve 3-2. The first three-way valve 7-1 and the fourth three-way valve 7-4 are switched to connect interfaces a and c.

[0176] Afterwards, the third finned heat exchanger 6-3 and the fourth finned heat exchanger 6-4 enter the defrosting process, and the defrosting timer is initialized. The timing begins. The second three-way valve 7-2 and the third three-way valve 7-3 are switched to connect ports b and c. The remaining steps are similar to those for defrosting the first finned heat exchanger 6-1 and the second finned heat exchanger 6-2.

[0177] The original control method fixed the opening of the main electronic expansion valve to 100°C and the opening of the defrost electronic expansion valve to 250°C during defrosting. Under the same operating conditions, when using the original control method, the liquid pipe temperature of the second finned heat exchanger 6-2 remained at 18°C, meeting the defrost exit condition, even after the defrost duration reached the set value of 300 seconds. The control method described in this invention achieves the defrost exit condition at 250 seconds, as... Figure 11 As shown, the defrosting speed of the control method described in this invention is increased by about 20%.

[0178] Example 3

[0179] A dual-compressor air source heat pump valve collaborative control system is provided, employing the dual-compressor air source heat pump valve collaborative control method as described in any of Examples 1-2.

[0180] Example 4

[0181] A computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device on which the computer-readable storage medium is located to perform a dual-compressor air-source heat pump valve cooperative control method as described in any of Examples 1-2.

[0182] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for coordinated control of valve components in a dual-compressor air source heat pump, characterized in that, The dual-compressor air source heat pump includes: The first heat pump system includes a first compressor (1-1), a shell-and-tube heat exchanger (2), a first main electronic expansion valve (3-1), a first check valve (4-1) and a second check valve (4-2), a first defrost electronic expansion valve (5-1), a first finned heat exchanger (6-1) and a third finned heat exchanger (6-3), a first three-way valve (7-1) and a second three-way valve (7-2), wherein the first finned heat exchanger (6-1) is connected in series with the first three-way valve (7-1), and the third finned heat exchanger (6-3) is connected in series with the second three-way valve (7-2). It also includes a first pressure sensor (8-1), a third pressure sensor (8-3), a first temperature sensor (9-1), and a third temperature sensor (9-3). The first pressure sensor (8-1) monitors the low pressure value of the first compressor (1-1). The third pressure sensor (8-3) monitors the high pressure value of the first compressor (1-1). The first temperature sensor (9-1) monitors the liquid tube temperature of the first finned heat exchanger (6-1). The third temperature sensor (9-3) monitors the liquid tube temperature of the third finned heat exchanger (6-3). ; The second heat pump system includes a second compressor (1-2), a shell-and-tube heat exchanger (2), a second main electronic expansion valve (3-2), a third check valve (4-3) and a fourth check valve (4-4), a second defrost electronic expansion valve (5-2), a second finned heat exchanger (6-2) and a fourth finned heat exchanger (6-4), a third three-way valve (7-3) and a fourth three-way valve (7-4), wherein the second finned heat exchanger (6-2) is connected in series with the fourth three-way valve (7-4), and the fourth finned heat exchanger (6-4) is connected in series with the third three-way valve (7-3). It also includes a second pressure sensor (8-2), a fourth pressure sensor (8-4), a second temperature sensor (9-2), and a fourth temperature sensor (9-4). The second pressure sensor (8-2) monitors the low pressure value of the second compressor (1-2). The fourth pressure sensor (8-4) monitors the high pressure value of the second compressor (1-2). The second temperature sensor (9-2) monitors the liquid tube temperature of the second finned heat exchanger (6-2). The fourth temperature sensor (9-4) monitors the liquid tube temperature of the fourth finned heat exchanger (6-4). ; The control method includes the following steps: S1: Determine if the defrosting conditions are met. If they are met, execute S2; otherwise, continue to maintain the heating mode. S2: The first finned heat exchanger (6-1) and the second finned heat exchanger (6-2) enter the defrost mode, initialize the defrost timer, and start timing; S3: Open the first defrost electronic expansion valve (5-1) and the second defrost electronic expansion valve (5-2), set the opening degree of the first defrost electronic expansion valve (5-1) and the second defrost electronic expansion valve (5-2) to be equal, and set the opening degree of the first main electronic expansion valve (3-1) and the second main electronic expansion valve (3-2) to be equal; S4: Every interval Time, collecting compressor low pressure, high pressure, ambient temperature, defrost time, and finned liquid tube temperature; S5: Based on the real-time collected low pressure value and safety limit, calculate the control values ​​of the main electronic expansion valve opening and the defrost electronic expansion valve opening for the first time; Determine if the compressor's low pressure is higher than the safety limit. If it is higher, execute S6 directly; otherwise, increase the opening degree of the main electronic expansion valve and the defrost electronic expansion valve. S6: Based on the real-time collected condensation temperature and minimum limit value The second calculation involves the control values ​​for the opening of the main electronic expansion valve and the opening of the defrosting electronic expansion valve. Determine if the condensation temperature is greater than the minimum limit. If so, execute S7 directly; otherwise, reduce the opening degree of the system's main electronic expansion valve and defrost electronic expansion valve. This is the minimum defrosting condensation temperature. S7: Based on real-time tubing temperature and guide value The control values ​​for the opening of the main electronic expansion valve and the opening of the defrosting electronic expansion valve are calculated for the third time. Determine if the real-time liquid tubing temperature is higher than the guide value. If so, execute S8 directly; otherwise, increase the opening of the defrosting electronic expansion valve and decrease the opening of the main electronic expansion valve to ensure the total opening remains unchanged. The temperature of the finned liquid tube during defrosting varies with defrosting time. and ambient temperature Changes in guidance values; S8: Calculate and adjust the opening degree of each electronic expansion valve so that... and Between R1 and R2 and Between R3 and R4, R1, R2, R3, and R4 are all preset values. For the opening degree of the first main electronic expansion valve (3-1), For the opening degree of the second main electronic expansion valve (3-2), For the opening degree of the first defrosting electronic expansion valve (5-1), The opening degree of the second defrosting electronic expansion valve (5-2); S9: Determine whether the first finned heat exchanger (6-1) and the second finned heat exchanger (6-2) have met the defrosting exit conditions or the defrosting time has reached the set value. If the conditions are met, the fins will exit defrosting. If the conditions are not met, S4-S9 will be executed again until both the first finned heat exchanger (6-1) and the second finned heat exchanger (6-2) have exited defrosting. S10: After both the first finned heat exchanger (6-1) and the second finned heat exchanger (6-2) have exited defrosting mode, they are switched to heating mode. S11: After a certain time, the third finned heat exchanger (6-3) and the fourth finned heat exchanger (6-4) enter the defrosting phase, and the defrosting timer is initialized. And start timing; S12: Execute S3-S8; S13: Determine whether the third finned heat exchanger (6-3) and the fourth finned heat exchanger (6-4) have met the defrosting exit conditions or the defrosting time has reached the set value. If the conditions are met, the fins will exit defrosting. If the conditions are not met, S3-S8 and S13 will be executed again until the third finned heat exchanger (6-3) and the fourth finned heat exchanger (6-4) have both exited defrosting. S14: The third finned heat exchanger (6-3) and the fourth finned heat exchanger (6-4) exit defrosting mode and enter heating mode.

2. The method for coordinated control of valve components in a dual-compressor air source heat pump according to claim 1, characterized in that, In S5, The calculation method for the opening degree of the main electronic expansion valve and the defrost electronic expansion valve is as follows: When the first finned heat exchanger (6-1) or the third finned heat exchanger (6-3) is defrosted, ； When the second finned heat exchanger (6-2) or the fourth finned heat exchanger (6-4) is defrosted, ； In the formula, It is the first coefficient.

3. The method for coordinated control of valve components in a dual-compressor air source heat pump according to claim 2, characterized in that, In S6, The calculation method for the opening degree of the main electronic expansion valve and the defrost electronic expansion valve is as follows: When the first finned heat exchanger (6-1) or the third finned heat exchanger (6-3) is defrosted, ； When the second finned heat exchanger (6-2) or the fourth finned heat exchanger (6-4) is defrosted, ； In the formula, For the high pressure of the first compressor (1-1) Converted to temperature, For the high pressure of the second compressor (1-2) Converted to temperature, This is the second coefficient.

4. The method for coordinated control of valve components in a dual-compressor air-source heat pump according to claim 3, characterized in that, In S7 The calculation method for the opening degree of the main electronic expansion valve and the defrost electronic expansion valve is as follows: When the first finned heat exchanger (6-1) defrosts, When the second finned heat exchanger (6-2) defrosts, When the third finned heat exchanger (6-3) defrosts, When the fourth fin heat exchanger (6-4) defrosts, In the formula, It is the third coefficient.

5. The method for coordinated control of valve components in a dual-compressor air source heat pump according to claim 1, characterized in that, In S8, First main electronic expansion valve opening , Second main electronic expansion valve opening , First defrosting electronic expansion valve opening , Second defrosting electronic expansion valve opening .

6. The method for coordinated control of valve components in a dual-compressor air source heat pump according to claim 1, characterized in that, In S9, it is determined whether the first finned heat exchanger (6-1) and the second finned heat exchanger (6-2) have met the defrosting exit conditions or the defrosting time has reached the set value. If the conditions are met, the fins will exit defrosting, the opening of the main electronic expansion valve of the system will be adjusted, and the defrosting electronic expansion valve of the system will be closed. In step S13, it is determined whether the third finned heat exchanger (6-3) and the fourth finned heat exchanger (6-4) have met the defrosting exit conditions or the defrosting time has reached the set value. If the conditions are met, the fins will exit defrosting, the opening of the main electronic expansion valve of the system will be adjusted, and the defrosting electronic expansion valve of the system will be closed.

7. The method for coordinated control of valve components in a dual-compressor air-source heat pump according to any one of claims 1-6, characterized in that, In S2, the first finned heat exchanger (6-1) and the second finned heat exchanger (6-2) enter the defrost mode, initialize the defrost timer and start timing, and the first three-way valve (7-1) and the fourth three-way valve (7-4) switch to the b and c interfaces to be connected. In S10, after the first finned heat exchanger (6-1) and the second finned heat exchanger (6-2) have both stopped defrosting, the first three-way valve (7-1) and the fourth three-way valve (7-4) are switched to the a and c interfaces connected, and the heating mode is changed. In S11, the second three-way valve (7-2) and the third three-way valve (7-3) are switched to the b and c interfaces, while the first three-way valve (7-1) and the fourth three-way valve (7-4) remain connected at the a and c interfaces.

8. The method for coordinated control of valve components in a dual-compressor air source heat pump according to claim 7, characterized in that, In step S14, the third finned heat exchanger (6-3) and the fourth finned heat exchanger (6-4) exit defrosting mode, and the second three-way valve (7-2) and the third three-way valve (7-3) switch to the a and c interfaces to be connected, entering the heating mode.

9. A dual-compressor air source heat pump valve collaborative control system, characterized in that, The method of coordinated control of dual-compressor air source heat pump valves as described in any one of claims 1-8 is adopted.

10. A computer-readable storage medium, characterized in that, The system includes a stored computer program, wherein, when the computer program is executed, it controls the device containing the computer-readable storage medium to perform the dual-compressor air-source heat pump valve coordinated control method as described in any one of claims 1-8.

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