Air conditioning system and method for protecting it with pressure start

Abstract

The application provides an air conditioning system and a protection method thereof with pressure starting, the air conditioning system comprising a compressor and a solenoid valve, the solenoid valve being arranged on a pipeline between an exhaust port of the compressor and a suction port of the compressor; a preset module, presetting a corresponding relationship of a saturation pressure corresponding to a condenser temperature and a condensing side environment temperature and an on duration of the solenoid valve; a temperature detection module, used for detecting the condenser temperature and the condensing side environment temperature; a delay starting judgment module, used for judging whether the compressor meets a delay starting condition before starting; and a control module, used for starting the compressor in a delay mode if the compressor meets the delay starting condition, and used for controlling the solenoid valve to operate for the on duration according to the corresponding relationship of the saturation pressure corresponding to the condensing side environment temperature and the condenser temperature in the preset module during the delay period. The application improves the safety and stability of the compressor starting with pressure, and is beneficial to prolonging the service life of the compressor.

Description

Technical Field

[0001] This invention relates to the field of air conditioning, specifically to an air conditioning system and a protection method for pressure-driven start-up. Background Technology

[0002] After an air conditioning system has been running for a period of time, the high and low pressures may not be balanced when the compressor stops. Upon restarting, this can cause difficulty in starting the compressor, bringing it close to a stalled state. The sudden and sharp increase in current can negatively impact the compressor's lifespan. Prolonged exposure to frequent starts can burn out the compressor coils, resulting in economic losses.

[0003] In response to the above situation, some existing technologies use a capillary tube to bypass the compressor's exhaust port and suction port directly, and use a solenoid valve to control the opening and closing of the capillary tube to improve the high and low pressure imbalance. However, due to the lack of corresponding control logic, the pressure balancing effect is poor. Other technologies use copper pipes to directly bypass the exhaust port and suction port, but these also lack other control protections, and the compressor is at risk of liquid slugging. Summary of the Invention

[0004] To address the above problems, this invention provides an air conditioning system and its protection method for pressure-driven start-up. By determining whether to delay start-up before the compressor is started and determining the energization time of the solenoid valve based on the ambient temperature on the condenser side and the condenser temperature during delayed start-up, the safety and stability of the compressor under pressure-driven start-up are improved, which is beneficial to extending the service life of the compressor.

[0005] This invention provides an air conditioning system, including a compressor and a solenoid valve. The solenoid valve is disposed on a pipeline between the compressor's discharge port and its suction port. The air conditioning system further includes:

[0006] The preset module sets the relationship between the saturation pressure corresponding to the ambient temperature on the condenser side and the temperature of the condenser and the power-on time of the solenoid valve.

[0007] Temperature detection module is used to detect condenser temperature and ambient temperature on the condenser side;

[0008] The delayed start judgment module determines whether the compressor meets the delayed start conditions before it is started.

[0009] The control module starts the compressor after a delay if the compressor meets the delayed start conditions; and during the delay period, it controls the solenoid valve to run for the corresponding power-on duration according to the correspondence between the detected ambient temperature on the condenser side, the saturation pressure corresponding to the condenser temperature in the preset module.

[0010] According to this technical solution, by determining whether the compressor needs a delayed start before startup, it is possible to prevent high and low pressure imbalance during compressor startup, which could lead to difficulty in restarting the compressor and a sharp increase in current, thus improving the safety and stability of compressor startup. The solenoid valve is located on the pipeline between the compressor's exhaust and intake ports. By controlling the opening and closing of the solenoid valve, pressure balance in the air conditioning system can be achieved. The duration of solenoid valve energization also affects the compressor's operational safety and stability. A longer energization time may cause more refrigerant to flow into the compressor's receiver tank, reducing the amount of refrigerant in the cooling or heating cycle and affecting the cooling or heating effect of the air conditioning system. A shorter energization time may fail to achieve high and low pressure balance, leading to problems such as difficulty in compressor startup. Furthermore, when the ambient temperature on the condenser side is high, the condenser temperature is relatively high, and the corresponding saturation pressure is high; conversely, when the ambient temperature on the condenser side is low, the corresponding saturation pressure is low. Strictly controlling the solenoid valve energization time based on the ambient temperature on the condenser side and the condenser temperature improves the accuracy of the solenoid valve energization time, which is beneficial for strengthening compressor protection, improving the safety and stability of the compressor during pressurized startup, and preventing liquid slugging in the compressor.

[0011] In an optional technical solution of the present invention, the temperature detection module is also used to detect the compressor exhaust temperature;

[0012] The delayed start condition is: the difference between the compressor discharge temperature and the ambient temperature on the condenser side is greater than a specified threshold.

[0013] According to this technical solution, when the difference between the compressor discharge temperature and the ambient temperature on the condenser side is greater than a specified threshold, it indicates that the discharge temperature has not dropped effectively under this environment, the pressure is high, which is not conducive to the compressor starting. Therefore, it can be used as a criterion for determining the compressor's delayed start.

[0014] The optional technical solutions of the present invention also include:

[0015] Start-up type determination module: Determines whether the compressor is starting for the first time, starting upon receiving a start-up signal, or starting after reaching the temperature and stopping.

[0016] If the compressor is starting for the first time upon power-on or upon receiving a start-up signal, the specified threshold is the first threshold.

[0017] If the compressor is restarted after reaching the set temperature and then stopping, the specified threshold is the second threshold, which is greater than the first threshold.

[0018] According to this technical solution, the threshold for determining whether to delay the start varies depending on the compressor's start-up method, which improves the accuracy of determining the compressor's delayed start and can take into account both the compressor's operational safety and stability as well as user needs, thereby enhancing the user experience.

[0019] The optional technical solutions of the present invention also include:

[0020] A current detection module is used to detect the compressor's current.

[0021] The control module is configured to: after the compressor has been running for a specified time with a delay and there is no current in the compressor, control the compressor to stop for a second specified time and keep the solenoid valve open for a second specified time, and control the compressor to start again after the compressor has stopped for the second specified time and the solenoid valve has been open for the second specified time.

[0022] According to this technical solution, when the compressor has no current value, that is, the compressor current value is too high, it indicates that the high and low pressure difference is large at this time, so it is not suitable to start the compressor. Controlling the compressor to stop and opening the solenoid valve is beneficial to the protection of the compressor. Afterwards, controlling the compressor to start again can avoid misjudgment or affect the user's use by directly starting the compressor, thus improving the user experience.

[0023] In an optional technical solution of the present invention, the control module is further configured as follows:

[0024] After the compressor restarts and runs for a specified time, and the compressor has no current, the compressor is controlled to stop and the power is cut off.

[0025] According to this technical solution, when the compressor has no current value, that is, when the compressor current value is too high, it indicates that the high and low pressure difference is large. Therefore, it is not suitable to start the compressor. Controlling the compressor to stop and disconnecting the power is beneficial to the protection of the compressor, preventing the compressor coil from burning out due to excessive current, and ensuring the service life of the compressor.

[0026] In an optional technical solution of the present invention, in the cooling mode, the ambient temperature on the condenser side is the outdoor ambient temperature;

[0027] If the ambient temperature on the condenser side is greater than the first preset temperature value, and the saturation pressure corresponding to the condenser temperature is not less than the first preset value, the energizing time of the solenoid valve is the first preset time; if the saturation pressure corresponding to the condenser temperature is less than the first preset value, the energizing time of the solenoid valve is the second preset time.

[0028] If the ambient temperature on the condenser side is greater than the second preset temperature value and less than the first preset temperature value, and the saturation pressure corresponding to the condenser temperature is not less than the second preset value, the energizing time of the solenoid valve is the third preset time; if the saturation pressure corresponding to the condenser temperature is less than the second preset value, the energizing time of the solenoid valve is the fourth preset time.

[0029] If the ambient temperature on the condenser side is greater than the third preset temperature value and less than the second preset temperature value, and the saturation pressure corresponding to the condenser temperature is not less than the third preset value, the energizing time of the solenoid valve is the fifth preset time; if the saturation pressure corresponding to the condenser temperature is less than the third preset value, the energizing time of the solenoid valve is the sixth preset time.

[0030] If the ambient temperature on the condenser side is greater than the fourth preset temperature value and less than the third preset temperature value, and the saturation pressure corresponding to the condenser temperature is not less than the fourth preset value, the energizing time of the solenoid valve is the seventh preset time; if the saturation pressure corresponding to the condenser temperature is less than the fourth preset value, the energizing time of the solenoid valve is the eighth preset time.

[0031] If the ambient temperature on the condenser side is less than the fourth preset temperature value, the solenoid valve is normally closed; wherein, the first preset temperature value is greater than the second preset temperature value, the third preset temperature value is greater than the fourth preset temperature value, and the fourth preset temperature value decreases in sequence; the first preset pressure value is greater than the second preset pressure value, the third preset pressure value is greater than the fourth preset pressure value, the fifth preset pressure value is greater than the sixth preset pressure value, and the seventh preset pressure value is greater than the eighth preset pressure value.

[0032] According to this technical solution, when the ambient temperature on the condensing side is low, the saturation pressure corresponding to the condenser temperature is low, so the pressure preset value is relatively reduced; when the saturation pressure corresponding to the condenser temperature is high, the required pressure balance time is long, so the energization time of the solenoid valve is long; when the saturation pressure corresponding to the condenser temperature is low, the required pressure balance time is short. This solution determines the energization time of the solenoid valve based on the saturation temperature corresponding to the condenser temperature under the ambient temperature on the condensing side, which helps to achieve high and low pressure balance of the compressor more quickly, improves the starting safety and stability of the compressor, and helps to extend the service life of the compressor.

[0033] The present invention also provides a protection method for an air conditioning system under pressure start-up. The air conditioning system includes a compressor and a solenoid valve. The solenoid valve is located on the pipeline between the compressor's discharge port and the compressor's suction port. The control method includes the following steps:

[0034] Preset steps: Preset the relationship between the ambient temperature on the condenser side, the saturation pressure corresponding to the condenser temperature, and the energization time of the solenoid valve;

[0035] Testing steps: Test the condenser temperature and the ambient temperature on the condenser side;

[0036] Delayed start judgment steps: Before the compressor is started, determine whether the compressor meets the delayed start conditions;

[0037] Control steps: If the compressor meets the delayed start conditions, the compressor is started after a delay; and during the delay period, the solenoid valve is controlled to run for the corresponding power-on duration according to the correspondence between the detected ambient temperature on the condenser side, the saturation pressure corresponding to the condenser temperature and the preset module.

[0038] In an optional technical solution of the present invention, the temperature detection step further includes detecting the compressor exhaust temperature;

[0039] The delayed start condition is: the difference between the compressor discharge temperature and the ambient temperature on the condenser side is greater than a specified threshold.

[0040] The optional technical solutions of the present invention also include:

[0041] Before the delayed start determination step, a compressor start type determination step is also included:

[0042] Determine whether the compressor is starting for the first time, starting upon receiving a start signal, or starting after reaching the set temperature and stopping; among these...

[0043] If the compressor is starting for the first time upon power-on or upon receiving a start-up signal, the specified threshold is the first threshold.

[0044] If the compressor is restarted after reaching the set temperature and then stopping, the specified threshold is the second threshold, which is greater than the first threshold.

[0045] The optional technical solutions of the present invention also include:

[0046] Detect the compressor's current;

[0047] After the compressor has been running for a specified time with a delayed start, and there is no current in the compressor, the compressor is stopped for a second specified time, the solenoid valve remains open for a second specified time, and the compressor is restarted.

[0048] After the compressor restarts and runs for a specified time, and the compressor has no current, the compressor is controlled to stop and the power is cut off. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the air conditioning system in an embodiment of the present invention.

[0050] Figure 2 This is a schematic diagram of the modular structure of the air conditioning system in an embodiment of the present invention.

[0051] Figure 3 This is a flowchart illustrating a protection method for a pressure-driven start-up of an air conditioning system according to an embodiment of the present invention.

[0052] Figure 4 This is another flowchart illustrating the protection method for pressure-driven start-up of an air conditioning system according to an embodiment of the present invention.

[0053] Figure label:

[0054] Compressor 11; Outdoor heat exchanger 12; Throttling valve 13; Indoor heat exchanger 14; Bypass pipe 15; Solenoid valve 151; Preset module 21; Temperature detection module 22; Delay start judgment module 23; Control module 24; Start type judgment module 25. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] like Figure 1 As shown, this embodiment provides an air conditioning system, including a compressor 11, an outdoor heat exchanger 12, a throttle valve 13, and an indoor heat exchanger 14 connected in sequence to form a refrigerant circulation loop. A bypass pipe 15 is connected between the exhaust port and the suction port of the compressor 11. The bypass pipe 15 is equipped with a solenoid valve 151, and preferably also includes a four-way valve (not shown in the figure) for switching operating modes. A thermal expansion valve 16 and a temperature sensing bulb 17 are respectively provided at both ends of the indoor heat exchanger 14. Figure 1 The arrows indicate the refrigerant flow direction in cooling mode. During cooling, the outdoor heat exchanger 12 acts as a condenser. The indoor unit's thermal expansion valve 16 and throttle valve 13 are closed when the compressor 11 stops. The high-pressure side liquid refrigerant flows directly to the return pipe of the compressor 11. The compressor 11 is at risk of liquid slugging when it starts up again.

[0057] Furthermore, if the high and low pressures are not balanced when the compressor 11 is stopped (i.e., the pressure difference between high and low pressures is large), restarting it may cause the compressor 11 to have difficulty starting, approach a stalled state, and experience a sudden and sharp increase in current, which will adversely affect the lifespan of the compressor 11. If it is in a frequent start-up scenario for a long time, it will burn out the compressor coil. In this embodiment, the high and low pressures refer to the high pressure at the discharge port of the compressor 11 and the low pressure at the suction port of the compressor 11.

[0058] In some implementations, a capillary tube may also be installed on the bypass line 15 to control the refrigerant flow rate. Compared with using copper pipes for direct bypass, this can reduce the risk of the compressor starting under pressure.

[0059] Furthermore, such as Figure 2 As shown, to solve the above problems, the air conditioning system also includes,

[0060] Preset module 21, presets the relationship between the saturation pressure Pt3 corresponding to the ambient temperature T4 on the condenser side and the condenser temperature T3 and the energization time t of the solenoid valve 151;

[0061] Temperature detection module 22 is used to detect condenser temperature T3 and condenser side ambient temperature T4;

[0062] The delayed start judgment module 23 determines whether the compressor 11 meets the delayed start conditions before the compressor 11 is started.

[0063] If the compressor 11 meets the delayed start condition, the control module 24 starts the compressor 11 after a first specified time delay; and during the delay period (i.e., within the first specified time period), the control module 24 controls the solenoid valve 151 to run for the corresponding power-on time t according to the correspondence between the detected condenser ambient temperature T4 and the saturated pressure Pt3 corresponding to the condenser temperature T3 in the preset module 21.

[0064] By determining whether compressor 11 needs a delayed start before startup, the above method can prevent high and low pressure imbalance during compressor 11 startup, which could lead to difficulty in restarting compressor 11 and a sharp increase in current, thus improving the safety and stability of compressor 11 startup. Solenoid valve 151 is located on the pipeline between the exhaust port and intake port of compressor 11. Controlling the opening and closing of solenoid valve 151 can achieve pressure balance in the air conditioning system. The energizing time of solenoid valve 151 also affects the operational safety and stability of compressor 11. A long energizing time may cause more refrigerant to flow into the compressor 11's receiver tank, reducing the amount of refrigerant in the cooling or heating cycle and affecting the cooling or heating effect of the air conditioning system. A short energizing time may prevent high and low pressure balance, leading to problems such as difficulty in starting compressor 11. Furthermore, when the ambient temperature T4 on the condenser side is high, the condenser temperature T3 is relatively high, and the saturation pressure Pt3 corresponding to condenser temperature T3 is large, affecting the condenser side... When the ambient temperature T4 is low, the saturation pressure Pt3 corresponding to the condenser temperature T3 is also low. The energizing time t of the solenoid valve 151 is strictly controlled according to the ambient temperature T4 on the condensing side and the condenser temperature T3, or according to the ambient temperature T4 on the condensing side, the condenser temperature T3, and the refrigerant flow rate in the bypass pipe 15. This improves the accuracy of the energizing time t of the solenoid valve 151, which is beneficial to strengthen the protection of the compressor 11, improve the safety and stability of the compressor 11 when starting under pressure, and prevent liquid slugging of the compressor 11.

[0065] Specifically, the temperature detection module 22 includes a temperature sensor for detecting the condenser temperature T3 and a temperature sensor for detecting the ambient temperature on the condenser side; the preset module 21 can be a read-write memory that stores the above-mentioned preset relationships.

[0066] The control module 24 can be an integrated circuit chip with signal processing capabilities. The control module 24 can be a general-purpose processor, including a central processing unit (CPU), or a microcontroller, microcontroller unit (MCU), complex programmable logic device (CPLD), field-programmable gate array (FPGA), application-specific integrated circuit (ASIC), embedded ARM, etc. The control module 24 can implement or execute the methods, steps, logic diagrams, and data processing disclosed in the embodiments of this invention. The preset module 21 and the delayed start judgment module 23 can be at least partially integrated into the control module 24.

[0067] In a preferred embodiment of the present invention, the temperature detection module 22 is further used to detect the exhaust temperature of the compressor 11;

[0068] The delayed start condition is: the difference ΔTP between the compressor discharge temperature TP and the ambient temperature T4 on the condenser side is greater than the specified threshold.

[0069] If the difference between the compressor discharge temperature TP and the condenser side ambient temperature T4 is greater than the specified threshold, it indicates that the discharge temperature has not decreased effectively under this environment, the pressure is high, which is not conducive to the start-up of compressor 11. Therefore, it can be used as a judgment condition for delayed start-up of compressor 11.

[0070] Furthermore, the control module 24 is configured to start the compressor 11 if the compressor 11 does not meet the delayed start conditions.

[0071] In a preferred embodiment of the present invention, it further includes:

[0072] Start-up type determination module 25: Determines whether compressor 11 is starting for the first time, starting after receiving a start-up signal, or starting after reaching the temperature and stopping;

[0073] If compressor 11 is starting for the first time upon power-on or upon receiving a start-up signal, the specified threshold is the first threshold.

[0074] If compressor 11 is started after reaching the temperature and stopping (in a non-power-off state), the specified threshold is the second threshold, which is greater than the first threshold.

[0075] By using the above methods, the starting methods of compressor 11 are different, and the prescribed threshold for determining whether to delay the start is different, which improves the accuracy of the delayed start judgment of compressor 11, and can take into account the operational safety and stability of compressor 11 as well as user needs, thereby improving the user experience.

[0076] In a preferred embodiment of the present invention, it further includes:

[0077] A current detection module is used to detect the current of compressor 11;

[0078] The control module 24 is configured to: after the compressor 11 has been running for a specified time and there is no current in the compressor 11, control the compressor 11 to stop for a second specified time and the solenoid valve 151 to remain open for a second specified time, and control the compressor 11 to start again after the compressor 11 has stopped for a second specified time and the solenoid valve 151 has remained open for a second specified time.

[0079] In the above manner, when the compressor 11 has no current value, that is, when the current value of the compressor 11 is too large, it indicates that the high and low pressure difference is large at this time. Therefore, it is not suitable to start the compressor 11. Controlling the compressor 11 to stop and opening the solenoid valve 151 is beneficial to the protection of the compressor 11. Afterwards, controlling the compressor 11 to start again can avoid misjudgment or affect the user's use by directly starting the compressor 11, thus improving the user experience.

[0080] In a preferred embodiment of the present invention, the control module 24 is further configured to:

[0081] After the compressor 11 restarts and runs for a specified time, and the compressor 11 has no current value, the compressor 11 is controlled to stop and the power is cut off.

[0082] By using the above method, when the compressor 11 has no current value, that is, when the current value of the compressor 11 is too high, it indicates that the high and low pressure difference is large at this time. Therefore, it is not suitable to start the compressor 11. Controlling the compressor 11 to stop and disconnect the power is beneficial to the protection of the compressor 11, preventing the compressor 11 coil from burning out due to excessive current, and ensuring the service life of the compressor 11.

[0083] In a preferred embodiment of the present invention, in cooling mode, the ambient temperature T4 on the condenser side is the outdoor ambient temperature;

[0084] If the ambient temperature T4 on the condenser side is greater than the first preset temperature value, and the saturation pressure Pt3 corresponding to the condenser temperature T3 is not less than the first preset value, the energizing time t of the solenoid valve 151 is the first preset time; if the saturation pressure Pt3 corresponding to the condenser temperature T3 is less than the first preset value, the energizing time t of the solenoid valve 151 is the second preset time.

[0085] If the ambient temperature T4 on the condenser side is greater than the second preset temperature value and less than the first preset temperature value, and the saturation pressure Pt3 corresponding to the condenser temperature T3 is not less than the second preset value, the energizing time t of the solenoid valve 151 is the third preset time; if the saturation pressure Pt3 corresponding to the condenser temperature T3 is less than the second preset value, the energizing time t of the solenoid valve 151 is the fourth preset time.

[0086] If the ambient temperature T4 on the condenser side is greater than the third preset temperature value and less than the second preset temperature value, and the saturation pressure Pt3 corresponding to the condenser temperature T3 is not less than the third preset value, the energizing time t of the solenoid valve 151 is the fifth preset time; if the saturation pressure Pt3 corresponding to the condenser temperature T3 is less than the third preset value, the energizing time t of the solenoid valve 151 is the sixth preset time.

[0087] If the ambient temperature T4 on the condenser side is greater than the fourth preset temperature value and less than the third preset temperature value, and the saturation pressure Pt3 corresponding to the condenser temperature T3 is not less than the fourth preset value, the energizing time t of the solenoid valve 151 is the seventh preset time; if the saturation pressure Pt3 corresponding to the condenser temperature T3 is less than the fourth preset value, the energizing time t of the solenoid valve 151 is the eighth preset time.

[0088] If the ambient temperature T4 on the condenser side is less than the fourth preset temperature value, the solenoid valve 151 is normally closed; wherein, the first preset temperature value is greater than the second preset temperature value, the third preset temperature value is greater than the fourth preset temperature value, and the fourth preset temperature value decreases in sequence; the first preset pressure value is greater than the second preset pressure value, the third preset pressure value is greater than the fourth preset pressure value, the fifth preset pressure value is greater than the sixth preset pressure value, and the seventh preset pressure value is greater than the eighth preset pressure value.

[0089] Through the above method, when the ambient temperature T4 on the condensing side is low, the saturation pressure Pt3 corresponding to the condenser temperature T3 is low, so the pressure preset value is relatively reduced. When the saturation pressure Pt3 corresponding to the condenser temperature T3 is high, the required pressure balance time is long, so the energizing time t of the solenoid valve 151 is long. When the saturation pressure Pt3 corresponding to the condenser temperature T3 is low, the required pressure balance time is short. This scheme determines the energizing time t of the solenoid valve 151 based on the saturation temperature corresponding to the condenser temperature T3 at the ambient temperature T4 on the condensing side, which is conducive to achieving high and low pressure balance of the compressor 11 more quickly, and improves the starting safety and stability of the compressor 11, which is conducive to extending the service life of the compressor 11.

[0090] In some implementations, when the pressure difference between high and low pressures is less than a certain value, it is not necessary to open the solenoid valve 151.

[0091] like Figure 3 As shown, corresponding to the air conditioning system of this embodiment, this embodiment also provides a protection method for air conditioning system with pressure start. The air conditioning system includes a compressor 11 and a solenoid valve 151. The solenoid valve 151 is disposed on the pipeline between the exhaust port and the intake port of the compressor 11. The control method includes the following steps:

[0092] Preset steps: Preset the relationship between the saturation pressure Pt3 corresponding to the ambient temperature T4 on the condenser side and the condenser temperature T3 and the energization time t of the solenoid valve 151;

[0093] Testing steps: Detect condenser temperature T3 and condenser-side ambient temperature T4;

[0094] Delayed start judgment steps: Before compressor 11 is started, determine whether compressor 11 meets the delayed start conditions;

[0095] Control steps: If the compressor 11 meets the delayed start condition, the compressor 11 is started after a first specified delay; and during the delay period, the solenoid valve 151 is controlled to run for the corresponding energization time t according to the correspondence between the detected ambient temperature T4 on the condenser side and the saturated pressure Pt3 corresponding to the condenser temperature T3 in the preset module 21.

[0096] In a preferred embodiment of the present invention, the temperature detection step further includes detecting the exhaust temperature of the compressor 11;

[0097] The delayed start condition is: the difference between the compressor discharge temperature TP and the ambient temperature T4 on the condenser side is greater than the specified threshold.

[0098] In a preferred embodiment of the present invention, it further includes:

[0099] Before the delayed start determination step, a compressor start type determination step is also included:

[0100] Determine whether compressor 11 is starting for the first time, starting after receiving a start signal, or starting after reaching the temperature and stopping;

[0101] If compressor 11 is starting for the first time upon power-on or upon receiving a start-up signal, the specified threshold is the first threshold.

[0102] If compressor 11 is started after reaching the temperature and then stopping, the specified threshold is the second threshold, which is greater than the first threshold.

[0103] In a preferred embodiment of the present invention, it further includes:

[0104] Detect the current of compressor 11;

[0105] After a predetermined delay of the compressor 11's start-up operation, and with no current in the compressor 11, the compressor 11 is stopped for a second predetermined time, the solenoid valve 151 remains open for a second predetermined time, and the compressor 11 is restarted.

[0106] After the compressor 11 restarts and runs for a specified time, and the compressor 11 has no current value, the compressor 11 is controlled to stop and the power is cut off.

[0107] The present invention also provides a computer-readable storage medium, including a memory storing a computer program that, when executed, implements the steps of the pressure-start protection method for an air conditioning system as described above.

[0108] Example 1

[0109] like Figure 4 As shown, this embodiment provides a specific operating flow of a protection method for pressure-driven start-up of an air conditioning system. In the refrigeration cycle, when the compressor 11 reaches the set temperature and stops without being powered off, the corresponding saturation pressure Pt3 is calculated based on the detected condenser temperature T3, and the energizing duration t of the solenoid valve 151 is determined based on the saturation pressure Pt3 and the detected ambient temperature T4 on the condenser side; specifically,

[0110] When T4 > 40℃, Pt3 ≥ 3.0 MPa, the power-on time t = 3 min; when Pt3 < 3 MPa, the power-on time t = 1.5 min.

[0111] 40℃≥T4>20℃, Pt3≥2.5Mpa, energization time t=3min; Pt3<2.5Mpa, solenoid valve energization time t=1.5min;

[0112] 20℃≥T4>0℃, Pt3≥2.0Mpa, energization time t=3min; Pt3<2.0Mpa, solenoid valve energization time t=1.5min;

[0113] 0℃≥T4>-10℃, Pt3≥1.5Mpa, energization time t=3min; Pt3<1.5Mpa, solenoid valve energization time t=1.5min;

[0114] -10℃≥T4, power-on time t=0min; when the ambient temperature T4 on the condenser side is too low, solenoid valve 151 is closed to avoid the risk of liquid slugging.

[0115] After the compressor stops at the set temperature, before restarting, the temperature difference ΔTP between the compressor discharge temperature TP and the ambient temperature T4 on the condenser side is measured. If ΔTP ≥ 25℃ (defined between 10-40℃, taking the value according to most actual cases), it indicates that the discharge temperature has not dropped effectively and the high pressure is too high, which is not conducive to this start-up. The compressor 11 is started after a 3-minute delay. During the delay, the energization time t of the solenoid valve 151 is executed according to the saturation pressure Pt3 and the detected ambient temperature T4 on the condenser side. After 3 minutes, to avoid misjudgment or affecting user operation, the compressor 11 is started directly.

[0116] If compressor 11 fails to operate normally after 3 minutes of startup and no current is detected, it indicates that compressor 11 has overloaded due to excessive instantaneous current, causing it to stop for 6 minutes, with solenoid valve 151 remaining open for 6 minutes. If compressor 11 fails to operate normally after restarting and running for 3 minutes and no compressor current is detected, it indicates a serious system abnormality. This may be due to blockage of the pressure balancing device (bypass line 15) or other parts of the system, resulting in an imbalance between high and low pressures. The system will then report a fault, shut down, and disconnect power, requiring a power-on reset to restore operation.

[0117] Example 2

[0118] like Figure 4 As shown, this embodiment provides a specific operation flow of a protection method for air conditioning system with pressure start-up. The difference from embodiment 1 is that the compressor start-up type is different and the corresponding specified threshold is different. Specifically, if the compressor 11 is starting for the first time or starting after receiving a start-up signal, the specified threshold is the first threshold, which is less than the second threshold.

[0119] The preset relationships between the condenser side ambient temperature T4, saturation pressure Pt3, and energization time t of solenoid valve 151 in the preset steps are the same as in Example 1, and will not be repeated here.

[0120] In the refrigeration cycle, when the compressor 11 receives a remote control signal to start or is powered on for the first time, before starting, the temperature difference ΔTP between the compressor discharge temperature TP and the ambient temperature T4 on the condensing side is detected. If ΔTP ≥ 15℃, it indicates that the discharge temperature has not dropped effectively and the high pressure is too high, which is not conducive to this start-up. The compressor 11 is started after a 3-minute delay. During the delay, the energization time t of the solenoid valve 151 is executed according to the energization time t determined by the saturation pressure Pt3 and the detected ambient temperature T4 on the condensing side. If ΔTP < 15℃, the compressor can be started directly.

[0121] If compressor 11 fails to operate normally after 3 minutes of startup and no current is detected, it indicates that compressor 11 has triggered overload protection due to excessive instantaneous current, causing it to stop for 6 minutes with the solenoid valve remaining open for 6 minutes. If compressor 11 fails to operate normally after restarting and running for 3 minutes and no compressor current is detected, it indicates a serious system abnormality, possibly due to blockage of the balancing device or other parts of the system, resulting in an imbalance between high and low pressures. This will trigger a fault report, shutdown, and power cut-off, requiring a power-on reset to restore operation.

[0122] It should be noted that the processes and flowcharts described in Examples 1 and 2 do not involve preset steps, temperature detection steps, or data processing steps (such as the conversion of saturation pressure Pt3, the calculation of ΔTP, etc.). Those skilled in the art can supplement these steps by referring to the above descriptions, and they will not be repeated in this embodiment. Furthermore, the data appearing in the above embodiments are merely examples, and those skilled in the art can adjust them according to actual circumstances, and are not limited to the examples given in this embodiment; T3 and T4 are only used to distinguish between condenser temperature and condenser-side ambient temperature, and have no other meaning.

[0123] Example 3

[0124] This embodiment provides a protection method for air conditioning system with pressure start-up. The difference from Embodiments 1 and 2 is that the air conditioning system is running in heating cycle, the ambient temperature T4 on the condenser side is the indoor temperature, the condenser temperature T3 is the indoor heat exchanger temperature, and the solenoid valve 151 is in the normally closed state in heating mode. This is mainly because when heating stops, the four-way valve reverses and the pressure is instantly balanced.

[0125] The above are merely preferred embodiments of the present invention and are 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. An air conditioning system, characterized in that, The air conditioning system includes a compressor and a solenoid valve, wherein the solenoid valve is located on the pipeline between the compressor's discharge port and the compressor's suction port. The air conditioning system also includes: The preset module presets the relationship between the ambient temperature on the condensing side, the saturation pressure corresponding to the condensing side temperature, and the power-on duration of the solenoid valve. The temperature detection module is used to detect the condenser side temperature and the condenser side ambient temperature. The delayed start judgment module determines whether the compressor meets the delayed start conditions before the compressor is started. The control module starts the compressor after a delay if the compressor meets the delayed start condition; and during the delay period, it controls the solenoid valve to run for the corresponding power-on duration according to the correspondence between the detected ambient temperature on the condensing side and the saturation pressure corresponding to the condensing side temperature in the preset module.

2. The air conditioning system according to claim 1, characterized in that, The temperature detection module is also used to detect the compressor exhaust temperature; The delayed start condition is that the difference between the compressor exhaust temperature and the ambient temperature on the condenser side is greater than a specified threshold.

3. The air conditioning system according to claim 2, characterized in that, Also includes: Start-up type determination module: determines whether the compressor is starting for the first time, starting upon receiving a start-up signal, or starting after reaching the temperature and stopping. If the compressor is starting for the first time upon power-on or upon receiving a power-on signal, the specified threshold is the first threshold. If the compressor is started after reaching the set temperature and then stopping, the specified threshold is a second threshold, which is greater than the first threshold.

4. The air conditioning system according to claim 1, characterized in that, Also includes: A current detection module is used to detect the current of the compressor; The control module is configured to: after the compressor has been running for a specified time with a delay and the compressor has no current value, control the compressor to stop for a second specified time and the solenoid valve to remain open for a second specified time, and control the compressor to restart after the compressor has stopped for the second specified time and the solenoid valve has remained open for the second specified time.

5. The air conditioning system according to claim 4, characterized in that, The control module is also configured to: After the compressor restarts and runs for a specified time, and the compressor has no current value, the compressor is controlled to stop and the power is cut off.

6. The air conditioning system according to any one of claims 1 to 5, characterized in that, In cooling mode, the ambient temperature on the condenser side is the outdoor ambient temperature; If the ambient temperature on the condensing side is greater than the first preset temperature value, and the saturation pressure corresponding to the condensing side temperature is not less than the first preset pressure value, the energizing time of the solenoid valve is the first preset time; if the saturation pressure corresponding to the condensing side temperature is less than the first preset pressure value, the energizing time of the solenoid valve is the second preset time. If the ambient temperature on the condensing side is greater than the second preset temperature value and less than the first preset temperature value, and the saturation pressure corresponding to the condensing side temperature is not less than the second preset pressure value, the energizing time of the solenoid valve is the third preset time; if the saturation pressure corresponding to the condensing side temperature is less than the second preset pressure value, the energizing time of the solenoid valve is the fourth preset time. If the ambient temperature on the condensing side is greater than the third preset temperature value and less than the second preset temperature value, and the saturation pressure corresponding to the condensing side temperature is not less than the third preset pressure value, the energizing time of the solenoid valve is the fifth preset time; if the saturation pressure corresponding to the condensing side temperature is less than the third preset pressure value, the energizing time of the solenoid valve is the sixth preset time. If the ambient temperature on the condensing side is greater than the fourth preset temperature value and less than the third preset temperature value, and the saturation pressure corresponding to the condensing side temperature is not less than the fourth preset pressure value, the energizing time of the solenoid valve is the seventh preset time; if the saturation pressure corresponding to the condensing side temperature is less than the fourth preset pressure value, the energizing time of the solenoid valve is the eighth preset time. If the ambient temperature on the condenser side is less than the fourth preset temperature value, the solenoid valve is normally closed; wherein, the first preset temperature value, the second preset temperature value, the third preset temperature value, and the fourth preset temperature value decrease sequentially; the first preset pressure value, the second preset pressure value, the third preset pressure value, and the fourth preset pressure value decrease sequentially; the first preset duration is greater than the second preset duration, the third preset duration is greater than the fourth preset duration, the fifth preset duration is greater than the sixth preset duration, and the seventh preset duration is greater than the eighth preset duration.

7. A protection method for an air conditioning system under pressure start-up, characterized in that, The air conditioning system includes a compressor and a solenoid valve. The solenoid valve is located on the pipeline between the compressor's exhaust port and its intake port. The protection method includes the following steps: Preset steps: Preset the correspondence between the ambient temperature on the condensing side, the saturation pressure corresponding to the condensing side temperature, and the energization time of the solenoid valve; Detection steps: Detect the condenser side temperature and the condenser side ambient temperature; Delayed start judgment step: Before the compressor is started, determine whether the compressor meets the delayed start conditions; Control steps: If the compressor meets the delayed start condition, the compressor is started with a delay; and during the delay period, the solenoid valve is controlled to operate for the corresponding power-on duration according to the correspondence between the detected ambient temperature on the condensing side and the saturation pressure corresponding to the condensing side temperature in the preset steps.

8. The protection method for air conditioning system under pressure start according to claim 7, characterized in that, The detection step also includes detecting the compressor exhaust temperature; The delayed start condition is that the difference between the compressor exhaust temperature and the ambient temperature on the condenser side is greater than a specified threshold.

9. The protection method for air conditioning system under pressure start according to claim 8, characterized in that, Also includes: Before the delayed start determination step, a compressor start type determination step is also included: Determine whether the compressor is starting for the first time, starting upon receiving a start signal, or starting after reaching the set temperature and stopping; wherein, If the compressor is starting for the first time or is started upon receiving a power-on signal, the specified threshold is the first threshold. If the compressor is started after reaching the set temperature and then stopping, the specified threshold is a second threshold, which is greater than the first threshold.

10. The protection method for air conditioning system under pressure start according to claim 7, characterized in that, Also includes: Detect the current of the compressor; After the compressor has been running for a specified time with a delayed start, and the compressor has no current value, the compressor is stopped for a second specified time, the solenoid valve remains open for a second specified time, and the compressor is restarted. as well as After the compressor restarts and runs for a specified time, and the compressor has no current value, the compressor is controlled to stop and the power is cut off.

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