Defrosting control methods, devices, equipment and media for roof-mounted air conditioners in electric buses

Abstract

This invention discloses a defrosting control method, device, computer equipment, and storage medium for a roof-mounted air conditioner in an electric bus. The method includes: if a forced defrosting command is received within a preset power-on time, closing the four-way valve in the air conditioner, controlling the compressor in the air conditioner to enter the start-up operation phase, and controlling the evaporator fan in the air conditioner to operate at the highest fan speed; if a preset first condition is met after the compressor enters the start-up operation phase, controlling the compressor to enter a frequency-increasing operation phase; if a preset second condition is met after the compressor enters the frequency-increasing operation phase, controlling the compressor to enter a high-frequency defrosting operation phase; if a defrosting exit condition is met, controlling the compressor to enter a frequency-reducing operation phase, and ending forced defrosting when a preset third condition is met. This invention can automatically clear snow accumulation on the vehicle roof or frost from the condenser before the vehicle travels, improving efficiency and ensuring safety.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to a defrosting control method, device, computer equipment, and storage medium for a roof-mounted air conditioner in an electric bus. Background Technology

[0002] With government subsidies for new energy vehicles, a large number of pure electric buses have appeared on the market. Electric buses used in northern regions typically have roof-mounted heat pump air conditioners for winter heating. However, under heat pump operation, the condenser on the roof, because its temperature is below the freezing point, will accumulate a lot of frost after running for a period of time, thus affecting the heating efficiency of the air conditioner. Even worse, after snowfall in winter, the roofs of vehicles parked outdoors will be covered with a large amount of snow. To restore the heating capacity of the air conditioner, the snow on the roof or the frost on the condenser needs to be cleaned. However, cleaning the snow on the roof or the frost on the condenser requires manual labor, which is time-consuming, laborious, and unsafe. Summary of the Invention

[0003] This invention provides a defrosting control method, device, computer equipment, and storage medium for a roof-mounted air conditioner in an electric bus. It aims to solve the problem in the prior art where the heating effect of the roof-mounted air conditioner in an electric bus deteriorates due to snow accumulation on the roof or frost on the condenser. It can automatically clear snow accumulation on the roof or frost on the condenser before the vehicle is driven, thereby improving efficiency and ensuring safety.

[0004] In a first aspect, embodiments of the present invention provide a defrosting control method for a roof-mounted air conditioner in an electric bus, comprising:

[0005] If a forced defrosting command is received within the preset power-on time, the four-way valve in the air conditioner will be closed, the compressor in the air conditioner will be controlled to enter the start-up and operation phase, and the evaporator fan in the air conditioner will be controlled to run at the highest fan speed.

[0006] If a preset first condition is met after the compressor enters the start-up and operation phase, the compressor is controlled to enter the frequency-increasing operation phase.

[0007] If the preset second condition is met after the compressor enters the frequency-increasing operation stage, the compressor is controlled to enter the high-frequency defrosting stage.

[0008] If the defrosting exit condition is met, the compressor is controlled to enter the frequency reduction operation stage, and the forced defrosting ends when the preset third condition is met.

[0009] Secondly, embodiments of the present invention provide a defrosting control device for a roof-mounted air conditioner in an electric bus, comprising:

[0010] The defrost command receiving unit is used to close the four-way valve in the air conditioner, control the compressor in the air conditioner to enter the start-up and operation stage, and control the evaporator fan in the air conditioner to run at the highest fan speed if a forced defrost command is received within a preset power-on time.

[0011] The compressor frequency boosting unit is used to control the compressor to enter the frequency boosting operation stage if a preset first condition is met after the compressor enters the start-up operation stage.

[0012] A high-frequency defrosting unit is used to control the compressor to enter a high-frequency defrosting stage if a preset second condition is met after the compressor enters the frequency-increasing operation stage.

[0013] The defrost exit unit is used to control the compressor to enter the frequency reduction operation stage if the defrost exit condition is met, and to end the forced defrost when the preset third condition is met.

[0014] Thirdly, embodiments of the present invention provide a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the defrosting control method for the roof-mounted air conditioner of the electric bus described in the first aspect.

[0015] Fourthly, embodiments of the present invention also provide a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, which, when executed by a processor, causes the processor to perform the defrosting control method for the roof-mounted air conditioner of the electric bus described in the first aspect.

[0016] This invention provides a defrosting control method, device, computer equipment, and storage medium for a roof-mounted air conditioner in an electric bus. The method includes: if a forced defrosting command is received within a preset power-on time, closing the four-way valve in the air conditioner, controlling the compressor in the air conditioner to enter the start-up operation phase, and controlling the evaporator fan in the air conditioner to operate at the highest fan speed; if a preset first condition is met after the compressor enters the start-up operation phase, controlling the compressor to enter a frequency-increasing operation phase; if a preset second condition is met after the compressor enters the frequency-increasing operation phase, controlling the compressor to enter a high-frequency defrosting operation phase; if a defrosting exit condition is met, controlling the compressor to enter a frequency-reducing operation phase, and ending the forced defrosting when a preset third condition is met. This invention can automatically clear snow accumulation on the vehicle roof or frost on the condenser before the vehicle travels, improving efficiency and ensuring safety. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic flowchart of the defrosting control method for a roof-mounted air conditioner in an electric bus provided in an embodiment of the present invention;

[0019] Figure 2 This is a schematic block diagram of a defrosting control device for a roof-mounted air conditioner in an electric bus, provided in an embodiment of the present invention.

[0020] Figure 3 A schematic block diagram of a computer device provided for an embodiment of the present invention. Detailed Implementation

[0021] 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, not all, of the embodiments of the present invention. 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.

[0022] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0023] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0024] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0025] Please see Figure 1 , Figure 1This is a flowchart illustrating the defrosting control method for a roof-mounted air conditioner in an electric bus according to an embodiment of the present invention. The defrosting control method for a roof-mounted air conditioner in an electric bus according to an embodiment of the present invention includes steps S101 to S104.

[0026] S101. If a forced defrosting command is received within the preset power-on time, the four-way valve in the air conditioner is closed, the compressor in the air conditioner is controlled to enter the start-up and operation stage, and the evaporator fan in the air conditioner is controlled to run at the highest fan speed.

[0027] In this embodiment, when the roof-mounted air conditioner of the electric bus uses heat pump heating in winter, the heating effect will be reduced due to snow or frost accumulation on the roof. Therefore, before the vehicle is ready to drive, defrosting and snow removal are required to ensure the stability of the air conditioner's heating function. Specifically, before the vehicle is ready to drive, the air conditioner, after being powered on, will detect in real time whether it has received a forced defrosting command issued by the driver through the air conditioner control panel. If a forced defrosting command is received within a preset power-on time, a forced defrosting action will be performed to automatically complete the defrosting and snow removal tasks. The preset power-on time can be adjusted according to customer needs and usage scenarios. Preferably, the preset power-on time in this embodiment can be set to 40 seconds. After receiving the forced defrosting command, the four-way valve in the air conditioner is closed, causing the air conditioner to operate in cooling mode. At this time, the evaporator located inside the vehicle will become cold, and the condenser located on the roof will become hot, thereby melting the frost or snow on the condenser into water, and the melted water will flow down the drain pipe to the bottom of the vehicle. Furthermore, controlling the compressor in the air conditioner to enter the start-up phase and operate at a lower frequency ensures stable operation of the air conditioner, which helps improve the reliability and stability of the system. At the same time, controlling the evaporator fan in the air conditioner to operate at the highest fan speed increases the speed of the evaporator fan inside the vehicle, since the temperature of the evaporator inside the vehicle is lower at this time. This allows the refrigerant to absorb heat from inside the vehicle and then release heat in the condenser to melt frost or snow.

[0028] S102. If a preset first condition is met after the compressor enters the start-up operation stage, the compressor is controlled to enter the frequency-increasing operation stage.

[0029] In this embodiment, upon receiving a forced defrost command, the compressor enters the start-up phase, operating at a lower frequency. When a preset first condition is met, indicating that the compressor can enter the next operating phase, the compressor is controlled to enter the frequency-increasing phase, increasing its operating frequency. This allows the air conditioner to more efficiently complete the defrosting and snow removal tasks, avoiding direct high-frequency operation and extending the compressor's lifespan.

[0030] In one embodiment, the first condition includes:

[0031] The compressor's operating frequency reaches a preset first target frequency, or the compressor's operating time in the start-up phase reaches a first maximum operating time.

[0032] In this embodiment, after the compressor enters the start-up phase, the air conditioning system adjusts the compressor's operating frequency in real time according to system parameters. When the compressor's operating frequency reaches a preset first target frequency, or when the compressor's operating time in the start-up phase reaches a first maximum operating time, it indicates that the compressor's start-up phase is complete, and the compressor can enter the next operating phase (i.e., the frequency ramp-up phase). The first target frequency is the target frequency for the compressor's start-up phase, which can be determined based on different compressor displacements. Preferably, 30% of the compressor's highest operating frequency is selected as the first target frequency, meaning the operating phase from compressor start-up to frequency adjustment to the first target frequency is defined as the start-up phase. Furthermore, under normal circumstances, the compressor's operating frequency will quickly reach the first target frequency. However, in actual operation, limitations may arise (such as excessively high system pressure), preventing the compressor's operating frequency from reaching the first target frequency. In this case, the maximum operating time is used to determine whether the compressor should enter the next operating phase. If the compressor's operating time in the start-up phase reaches the first maximum operating time, the compressor can be controlled to enter the next operating phase. The first maximum operating time can be adjusted according to actual conditions. Preferably, in this embodiment, the first maximum operating time can be set to 40 seconds.

[0033] S103. If the preset second condition is met after the compressor enters the frequency-increasing operation stage, the compressor is controlled to enter the high-frequency defrosting stage.

[0034] In this embodiment, after the compressor enters the frequency-increasing operation stage, the operating frequency of the compressor is continuously increased, thereby improving the effect and efficiency of air conditioning defrosting and snow removal. When the preset second condition is met, the compressor is controlled to enter the high-frequency operation defrosting stage, so that the compressor operates at a higher frequency. The high-frequency operation of the compressor can increase the system high pressure. At this time, the high-pressure refrigerant enters the condenser on the roof, thereby increasing the temperature of the roof condenser. The higher the temperature of the roof condenser, the easier it is for the frost or snow attached to the surface of the condenser to melt, so that the air conditioner reaches the optimal defrosting and snow removal state, improving the defrosting and snow removal efficiency of the air conditioner. The target frequency of the compressor high-frequency operation defrosting stage can be determined according to different compressor displacements. Preferably, 90% of the compressor's highest operating frequency is selected, that is, when the compressor enters the high-frequency operation defrosting stage, the compressor's operating frequency is adjusted to 90% of its highest operating frequency.

[0035] In one embodiment, the second condition includes:

[0036] The compressor's operating frequency reaches the preset second target frequency, or the compressor's operating time in the frequency-increasing operation phase reaches the second longest operating time.

[0037] In this embodiment, after the compressor enters the frequency-increasing operation phase, its operating frequency is continuously increased. When the compressor's operating frequency reaches a preset second target frequency, or when the compressor's operating time in the frequency-increasing operation phase reaches a second maximum operating time, the compressor is controlled to enter the high-frequency defrosting operation phase. The second target frequency is the target frequency for the compressor's frequency-increasing operation phase, which can be determined based on different compressor displacements. Preferably, 70% of the compressor's highest operating frequency is selected as the second target frequency; that is, after the compressor enters the frequency-increasing operation phase, its operating frequency is adjusted to 70% of its highest operating frequency. Furthermore, if the compressor's operating frequency cannot reach the second target frequency, the decision to enter the high-frequency defrosting operation phase is made by checking whether the compressor's operating time in the frequency-increasing operation phase reaches the second maximum operating time. The second maximum operating time can be adjusted according to actual conditions; preferably, in this embodiment, the second maximum operating time can be set to 180 seconds.

[0038] S104. If the defrosting exit condition is met, the compressor is controlled to enter the frequency reduction operation stage, and the forced defrosting ends when the preset third condition is met.

[0039] In this embodiment, when the air conditioner detects that the defrost exit condition has been met, meaning the defrost exit condition has been met and the air conditioner no longer needs to defrost, the compressor is controlled to enter the frequency reduction operation phase, causing the compressor to begin reducing its operating frequency. Controlling the compressor to enter the frequency reduction operation phase can avoid direct shutdown under high power, which is beneficial to extending the service life of the unit. Furthermore, after the compressor enters the frequency reduction operation phase, when a preset third condition is met, the forced defrosting can be terminated, that is, the action corresponding to the forced defrosting command is terminated. After defrosting is completed, all loads are shut down, that is, the four-way valve remains closed, and the compressor and evaporator fan stop running, waiting for the user or operator to perform the next operation.

[0040] In one embodiment, the defrosting exit condition includes:

[0041] The refrigerant pressure value in the air conditioner is greater than the preset pressure threshold.

[0042] In this embodiment, a pressure sensor is installed in the air conditioner to obtain the refrigerant high-pressure value in real time. The completion of defrosting and snow removal is determined based on this pressure value. When the refrigerant high-pressure value in the air conditioner exceeds a preset pressure threshold, it indicates that the frost or snow on the condenser has been cleared, and the air conditioner has met the defrosting exit condition. The specific pressure threshold value needs to be determined based on the characteristics of different refrigerants. For example, if R401a refrigerant is used in this embodiment, the pressure threshold can be set to 3.5 MPa. That is, when the refrigerant high-pressure value in the air conditioner exceeds 3.5 MPa, the defrosting exit condition is met.

[0043] In one embodiment, the defrosting exit condition further includes:

[0044] The temperature of the roof heat exchanger tube in the air conditioner is greater than a preset temperature threshold and the duration exceeds a preset time.

[0045] In this embodiment, the completion of defrosting and snow removal tasks can also be determined based on the temperature of the roof heat exchanger tubes. A temperature sensor is installed on the roof heat exchanger tubes in the air conditioner. The temperature of the roof heat exchanger tubes is acquired in real time by the temperature sensor. Changes in the roof heat exchanger tube temperature reflect the presence or absence of frost or snow on the roof heat exchanger (i.e., the roof condenser). When the roof heat exchanger tube temperature exceeds a preset temperature threshold and remains above a preset time, it indicates that the frost or snow on the roof condenser has been cleared, and the air conditioner has met the defrosting exit condition. The specific values ​​of the temperature threshold and preset time need to be determined based on the characteristics of different refrigerants. For example, if R401a refrigerant is used in this embodiment, the temperature threshold can be set to 50°C, and the preset time can be set to 5 seconds. That is, if the roof heat exchanger tube temperature remains above 50°C for 5 seconds, the defrosting exit condition is met.

[0046] In one embodiment, the third condition includes:

[0047] The compressor's operating frequency reaches the preset third target frequency, or the compressor's operating time in the frequency reduction operation phase reaches the third longest operating time.

[0048] In this embodiment, when the defrosting exit condition is met, the compressor is controlled to enter a frequency reduction operation phase, causing the compressor to begin reducing its operating frequency. When the compressor's operating frequency reaches a preset third target frequency, or when the compressor's operating time in the frequency reduction operation phase reaches a third maximum operating time, defrosting is considered complete, and forced defrosting ends. The third target frequency is the target frequency for the compressor's frequency reduction operation phase, which can be determined based on different compressor displacements. Preferably, 30% of the compressor's highest operating frequency is selected as the third target frequency; that is, after the compressor enters the frequency reduction operation phase, the compressor's operating frequency is adjusted to 30% of its highest operating frequency. Furthermore, if the compressor's operating frequency cannot reach the third target frequency, the forced defrosting is terminated by determining whether the compressor's operating time in the frequency reduction operation phase reaches the third maximum operating time. The third maximum operating time can be adjusted according to actual conditions; preferably, in this embodiment, the third maximum operating time can be set to 40 seconds.

[0049] In one embodiment, after step S102, the method further includes:

[0050] If the defrosting exit condition is met after the compressor enters the frequency-increasing operation phase, the compressor is controlled to enter the frequency-reducing operation phase, and the forced defrosting ends when the third condition is met.

[0051] In this embodiment, if the frost or snow on the roof condenser is only a small amount, defrosting and snow removal can be completed once the compressor enters the frequency-increasing operation phase. That is, once the defrosting exit condition is met after the compressor enters the frequency-increasing operation phase, there is no need to further increase the compressor's operating frequency for defrosting and snow removal. The compressor is then controlled to enter the frequency-reducing operation phase, starting to decrease its operating frequency, and the forced defrosting ends when the third condition is met. By controlling the compressor to enter the frequency-reducing operation phase, direct shutdown under high power can be avoided, which helps extend the unit's service life.

[0052] In another embodiment, if the defrosting exit condition is met after the compressor enters the start-up phase, the forced defrosting can be terminated directly. This is because the compressor operates at a lower frequency at this time, allowing it to stop operating directly.

[0053] The present invention provides a defrosting control method for a roof-mounted air conditioner in an electric bus. By adjusting the operating frequency of the compressor in real time, the temperature of the roof heat exchanger is increased, thereby melting the frost or snow and enabling the air conditioner to automatically clean the frost and snow in the most efficient way.

[0054] This invention also provides a defrosting control device for a roof-mounted air conditioner in an electric bus. This defrosting control device is used to execute any embodiment of the aforementioned defrosting control method for a roof-mounted air conditioner in an electric bus. Specifically, please refer to... Figure 2 , Figure 2 This is a schematic block diagram of a defrosting control device for a roof-mounted air conditioner in an electric bus provided in an embodiment of the present invention. The defrosting control device for a roof-mounted air conditioner in an electric bus includes a defrosting command receiving unit 101, a compressor frequency boosting unit 102, a high-frequency defrosting unit 103, and a defrosting exit unit 104.

[0055] The defrost command receiving unit 101 is used to close the four-way valve in the air conditioner, control the compressor in the air conditioner to enter the start-up and operation stage, and control the evaporator fan in the air conditioner to run at the highest fan speed if a forced defrost command is received within a preset power-on time.

[0056] In this embodiment, when the roof-mounted air conditioner of the electric bus uses heat pump heating in winter, the heating effect will be reduced due to snow or frost accumulation on the roof. Therefore, before the vehicle is ready to drive, defrosting and snow removal are required to ensure the stability of the air conditioner's heating function. Specifically, before the vehicle is ready to drive, the air conditioner, after being powered on, will detect in real time whether it has received a forced defrosting command issued by the driver through the air conditioner control panel. If a forced defrosting command is received within a preset power-on time, a forced defrosting action will be performed to automatically complete the defrosting and snow removal tasks. The preset power-on time can be adjusted according to customer needs and usage scenarios. Preferably, the preset power-on time in this embodiment can be set to 40 seconds. After receiving the forced defrosting command, the four-way valve in the air conditioner is closed, causing the air conditioner to operate in cooling mode. At this time, the evaporator located inside the vehicle will become cold, and the condenser located on the roof will become hot, thereby melting the frost or snow on the condenser into water, and the melted water will flow down the drain pipe to the bottom of the vehicle. Furthermore, controlling the compressor in the air conditioner to enter the start-up phase and operate at a lower frequency ensures stable operation of the air conditioner, which helps improve the reliability and stability of the system. At the same time, controlling the evaporator fan in the air conditioner to operate at the highest fan speed increases the speed of the evaporator fan inside the vehicle, since the temperature of the evaporator inside the vehicle is lower at this time. This allows the refrigerant to absorb heat from inside the vehicle and then release heat in the condenser to melt frost or snow.

[0057] The compressor frequency boosting unit 102 is used to control the compressor to enter the frequency boosting operation stage if a preset first condition is met after the compressor enters the start-up operation stage.

[0058] In this embodiment, upon receiving a forced defrost command, the compressor enters the start-up phase, operating at a lower frequency. When a preset first condition is met, indicating that the compressor can enter the next operating phase, the compressor is controlled to enter the frequency-increasing phase, increasing its operating frequency. This allows the air conditioner to more efficiently complete the defrosting and snow removal tasks, avoiding direct high-frequency operation and extending the compressor's lifespan.

[0059] In one embodiment, the first condition includes:

[0060] The compressor's operating frequency reaches a preset first target frequency, or the compressor's operating time in the start-up phase reaches a first maximum operating time.

[0061] In this embodiment, after the compressor enters the start-up phase, the air conditioning system adjusts the compressor's operating frequency in real time according to system parameters. When the compressor's operating frequency reaches a preset first target frequency, or when the compressor's operating time in the start-up phase reaches a first maximum operating time, it indicates that the compressor's start-up phase is complete, and the compressor can enter the next operating phase (i.e., the frequency ramp-up phase). The first target frequency is the target frequency for the compressor's start-up phase, which can be determined based on different compressor displacements. Preferably, 30% of the compressor's highest operating frequency is selected as the first target frequency, meaning the operating phase from compressor start-up to frequency adjustment to the first target frequency is defined as the start-up phase. Furthermore, under normal circumstances, the compressor's operating frequency will quickly reach the first target frequency. However, in actual operation, limitations may arise (such as excessively high system pressure), preventing the compressor's operating frequency from reaching the first target frequency. In this case, the maximum operating time is used to determine whether the compressor should enter the next operating phase. If the compressor's operating time in the start-up phase reaches the first maximum operating time, the compressor can be controlled to enter the next operating phase. The first maximum operating time can be adjusted according to actual conditions. Preferably, in this embodiment, the first maximum operating time can be set to 40 seconds.

[0062] The high-frequency defrosting unit 103 is used to control the compressor to enter the high-frequency defrosting stage if a preset second condition is met after the compressor enters the frequency-increasing operation stage.

[0063] In this embodiment, after the compressor enters the frequency-increasing operation stage, the operating frequency of the compressor is continuously increased, thereby improving the effect and efficiency of air conditioning defrosting and snow removal. When the preset second condition is met, the compressor is controlled to enter the high-frequency operation defrosting stage, so that the compressor operates at a higher frequency. The high-frequency operation of the compressor can increase the system high pressure. At this time, the high-pressure refrigerant enters the condenser on the roof, thereby increasing the temperature of the roof condenser. The higher the temperature of the roof condenser, the easier it is for the frost or snow attached to the surface of the condenser to melt, so that the air conditioner reaches the optimal defrosting and snow removal state, improving the defrosting and snow removal efficiency of the air conditioner. The target frequency of the compressor high-frequency operation defrosting stage can be determined according to different compressor displacements. Preferably, 90% of the compressor's highest operating frequency is selected, that is, when the compressor enters the high-frequency operation defrosting stage, the compressor's operating frequency is adjusted to 90% of its highest operating frequency.

[0064] In one embodiment, the second condition includes:

[0065] The compressor's operating frequency reaches the preset second target frequency, or the compressor's operating time in the frequency-increasing operation phase reaches the second longest operating time.

[0066] In this embodiment, after the compressor enters the frequency-increasing operation phase, its operating frequency is continuously increased. When the compressor's operating frequency reaches a preset second target frequency, or when the compressor's operating time in the frequency-increasing operation phase reaches a second maximum operating time, the compressor is controlled to enter the high-frequency defrosting operation phase. The second target frequency is the target frequency for the compressor's frequency-increasing operation phase, which can be determined based on different compressor displacements. Preferably, 70% of the compressor's highest operating frequency is selected as the second target frequency; that is, after the compressor enters the frequency-increasing operation phase, its operating frequency is adjusted to 70% of its highest operating frequency. Furthermore, if the compressor's operating frequency cannot reach the second target frequency, the decision to enter the high-frequency defrosting operation phase is made by checking whether the compressor's operating time in the frequency-increasing operation phase reaches the second maximum operating time. The second maximum operating time can be adjusted according to actual conditions; preferably, in this embodiment, the second maximum operating time can be set to 180 seconds.

[0067] The defrost exit unit 104 is used to control the compressor to enter the frequency reduction operation stage if the defrost exit condition is met, and to end the forced defrost when the preset third condition is met.

[0068] In this embodiment, when the air conditioner detects that the defrost exit condition has been met, meaning the defrost exit condition has been met and the air conditioner no longer needs to defrost, the compressor is controlled to enter the frequency reduction operation phase, causing the compressor to begin reducing its operating frequency. Controlling the compressor to enter the frequency reduction operation phase can avoid direct shutdown under high power, which is beneficial to extending the service life of the unit. Furthermore, after the compressor enters the frequency reduction operation phase, when a preset third condition is met, the forced defrosting can be terminated, that is, the action corresponding to the forced defrosting command is terminated. After defrosting is completed, all loads are shut down, that is, the four-way valve remains closed, and the compressor and evaporator fan stop running, waiting for the user or operator to perform the next operation.

[0069] In one embodiment, the defrosting exit condition includes:

[0070] The refrigerant pressure value in the air conditioner is greater than the preset pressure threshold.

[0071] In this embodiment, a pressure sensor is installed in the air conditioner to obtain the refrigerant high-pressure value in real time. The completion of defrosting and snow removal is determined based on this pressure value. When the refrigerant high-pressure value in the air conditioner exceeds a preset pressure threshold, it indicates that the frost or snow on the condenser has been cleared, and the air conditioner has met the defrosting exit condition. The specific pressure threshold value needs to be determined based on the characteristics of different refrigerants. For example, if R401a refrigerant is used in this embodiment, the pressure threshold can be set to 3.5 MPa. That is, when the refrigerant high-pressure value in the air conditioner exceeds 3.5 MPa, the defrosting exit condition is met.

[0072] In one embodiment, the defrosting exit condition further includes:

[0073] The temperature of the roof heat exchanger tube in the air conditioner is greater than a preset temperature threshold and the duration exceeds a preset time.

[0074] In this embodiment, the completion of defrosting and snow removal tasks can also be determined based on the temperature of the roof heat exchanger tubes. A temperature sensor is installed on the roof heat exchanger tubes in the air conditioner. The temperature of the roof heat exchanger tubes is acquired in real time by the temperature sensor. Changes in the roof heat exchanger tube temperature reflect the presence or absence of frost or snow on the roof heat exchanger (i.e., the roof condenser). When the roof heat exchanger tube temperature exceeds a preset temperature threshold and remains above a preset time, it indicates that the frost or snow on the roof condenser has been cleared, and the air conditioner has met the defrosting exit condition. The specific values ​​of the temperature threshold and preset time need to be determined based on the characteristics of different refrigerants. For example, if R401a refrigerant is used in this embodiment, the temperature threshold can be set to 50°C, and the preset time can be set to 5 seconds. That is, if the roof heat exchanger tube temperature remains above 50°C for 5 seconds, the defrosting exit condition is met.

[0075] In one embodiment, the third condition includes:

[0076] The compressor's operating frequency reaches the preset third target frequency, or the compressor's operating time in the frequency reduction operation phase reaches the third longest operating time.

[0077] In this embodiment, when the defrosting exit condition is met, the compressor is controlled to enter a frequency reduction operation phase, causing the compressor to begin reducing its operating frequency. When the compressor's operating frequency reaches a preset third target frequency, or when the compressor's operating time in the frequency reduction operation phase reaches a third maximum operating time, defrosting is considered complete, and forced defrosting ends. The third target frequency is the target frequency for the compressor's frequency reduction operation phase, which can be determined based on different compressor displacements. Preferably, 30% of the compressor's highest operating frequency is selected as the third target frequency; that is, after the compressor enters the frequency reduction operation phase, the compressor's operating frequency is adjusted to 30% of its highest operating frequency. Furthermore, if the compressor's operating frequency cannot reach the third target frequency, the forced defrosting is terminated by determining whether the compressor's operating time in the frequency reduction operation phase reaches the third maximum operating time. The third maximum operating time can be adjusted according to actual conditions; preferably, in this embodiment, the third maximum operating time can be set to 40 seconds.

[0078] In one embodiment, the defrosting control device for a roof-mounted air conditioner in an electric bus provided by the present invention further includes:

[0079] The frequency-increasing defrosting termination unit is used to control the compressor to enter the frequency-reducing operation phase if the defrosting exit condition is met after the compressor enters the frequency-increasing operation phase, and to end the forced defrosting when the third condition is met.

[0080] In this embodiment, if the frost or snow on the roof condenser is only a small amount, defrosting and snow removal can be completed once the compressor enters the frequency-increasing operation phase. That is, once the defrosting exit condition is met after the compressor enters the frequency-increasing operation phase, there is no need to further increase the compressor's operating frequency for defrosting and snow removal. The compressor is then controlled to enter the frequency-reducing operation phase, starting to decrease its operating frequency, and the forced defrosting ends when the third condition is met. By controlling the compressor to enter the frequency-reducing operation phase, direct shutdown under high power can be avoided, which helps extend the unit's service life.

[0081] In another embodiment, if the defrosting exit condition is met after the compressor enters the start-up phase, the forced defrosting can be terminated directly. This is because the compressor operates at a lower frequency at this time, allowing it to stop operating directly.

[0082] The present invention provides a defrosting control device for a roof-mounted air conditioner in an electric bus. By adjusting the operating frequency of the compressor in real time, the temperature of the roof heat exchanger is increased, thereby melting the frost or snow and enabling the air conditioner to automatically clean the frost and snow in the most efficient way.

[0083] The defrosting control method for the roof-mounted air conditioner in the above-mentioned electric bus can be implemented as a computer program, which can be used in, for example... Figure 3It runs on the computer device shown.

[0084] Please see Figure 3 , Figure 3 This is a schematic block diagram of a computer device provided in an embodiment of the present invention. The computer device 500 includes a processor 502, a memory, and a network interface 505 connected via a device bus 501, wherein the memory may include a storage medium 503 and internal memory 504.

[0085] The storage medium 503 may store the operating device 5031 and the computer program 5032. When the computer program 5032 is executed, it causes the processor 502 to execute the defrosting control method of the roof-mounted air conditioner of the electric bus.

[0086] The processor 502 provides computing and control capabilities to support the operation of the entire computer device 500.

[0087] The internal memory 504 provides an environment for the operation of the computer program 5032 in the storage medium 503. When the computer program 5032 is executed by the processor 502, the processor 502 can execute the defrosting control method of the roof-mounted air conditioner of the electric bus.

[0088] This network interface 505 is used for network communication, such as providing data transmission. Those skilled in the art will understand that... Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present invention and does not constitute a limitation on the computer device 500 to which the present invention is applied. The specific computer device 500 may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0089] The processor 502 is used to run a computer program 5032 stored in a memory to implement the defrosting control method for the roof-mounted air conditioner of an electric bus disclosed in this embodiment of the invention.

[0090] Those skilled in the art will understand that Figure 3 The embodiments of the computer device shown do not constitute a limitation on the specific configuration of the computer device. In other embodiments, the computer device may include more or fewer components than illustrated, or combine certain components, or have different component arrangements. For example, in some embodiments, the computer device may include only memory and a processor. In such embodiments, the structure and function of the memory and processor are different from those shown. Figure 3 The embodiments shown are consistent and will not be repeated here.

[0091] It should be understood that, in this embodiment of the invention, the processor 502 may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0092] In another embodiment of the present invention, a computer-readable storage medium is provided. This computer-readable storage medium may be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium. The computer-readable storage medium stores a computer program, wherein when executed by a processor, the computer program implements the defrosting control method for a roof-mounted air conditioner in an electric bus disclosed in this embodiment of the present invention.

[0093] Those skilled in the art will readily understand that, for the sake of convenience and brevity, the specific working processes of the devices, apparatuses, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0094] In the embodiments provided by this invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Units with the same function may be grouped into one unit. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, or may be electrical, mechanical, or other forms of connection.

[0095] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0096] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0097] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a backend server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), magnetic disks, or optical disks.

[0098] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A defrosting control method for a roof-mounted air conditioner in an electric bus, characterized in that, include: If a forced defrosting command is received within the preset power-on time, the four-way valve in the air conditioner will be closed, the compressor in the air conditioner will be controlled to enter the start-up and operation phase, and the evaporator fan in the air conditioner will be controlled to run at the highest fan speed. If a preset first condition is met after the compressor enters the start-up and operation phase, the compressor is controlled to enter the frequency-increasing operation phase. If the preset second condition is met after the compressor enters the frequency-increasing operation stage, the compressor is controlled to enter the high-frequency defrosting stage. If the defrosting exit condition is met, the compressor is controlled to enter the frequency reduction operation stage, and the forced defrosting ends when the preset third condition is met; The first condition includes: the operating frequency of the compressor reaches a preset first target frequency, or the operating time of the compressor in the start-up operation phase reaches a first maximum operating time. The second condition includes: the operating frequency of the compressor reaches the preset second target frequency, or the operating time of the compressor in the frequency-increasing operation phase reaches the second longest operating time; The defrosting exit condition includes: the high pressure value of the refrigerant in the air conditioner is greater than a preset pressure threshold; The third condition includes: the operating frequency of the compressor reaches the preset third target frequency, or the operating time of the compressor in the frequency reduction operation stage reaches the third longest operating time.

2. The defrosting control method for a roof-mounted air conditioner in an electric bus according to claim 1, characterized in that, The defrosting exit conditions also include: The temperature of the roof heat exchanger tube in the air conditioner is greater than a preset temperature threshold and the duration exceeds a preset time.

3. The defrosting control method for a roof-mounted air conditioner in an electric bus according to claim 1, characterized in that, If a preset first condition is met after the compressor enters the start-up operation phase, and then the compressor is controlled to enter the frequency-increase operation phase, the method further includes: If the defrosting exit condition is met after the compressor enters the frequency-increasing operation phase, the compressor is controlled to enter the frequency-reducing operation phase, and the forced defrosting ends when the third condition is met.

4. A defrosting control device for a roof-mounted air conditioner in an electric bus, characterized in that, include: The defrost command receiving unit is used to close the four-way valve in the air conditioner, control the compressor in the air conditioner to enter the start-up and operation stage, and control the evaporator fan in the air conditioner to run at the highest fan speed if a forced defrost command is received within a preset power-on time. The compressor frequency boosting unit is used to control the compressor to enter the frequency boosting operation stage if a preset first condition is met after the compressor enters the start-up operation stage. A high-frequency defrosting unit is used to control the compressor to enter a high-frequency defrosting stage if a preset second condition is met after the compressor enters the frequency-increasing operation stage. The defrost exit unit is used to control the compressor to enter the frequency reduction operation stage if the defrost exit condition is met, and to end the forced defrost when the preset third condition is met. The first condition includes: the operating frequency of the compressor reaches a preset first target frequency, or the operating time of the compressor in the start-up operation phase reaches a first maximum operating time. The second condition includes: the operating frequency of the compressor reaches the preset second target frequency, or the operating time of the compressor in the frequency-increasing operation phase reaches the second longest operating time; The defrosting exit condition includes: the high pressure value of the refrigerant in the air conditioner is greater than a preset pressure threshold; The third condition includes: the operating frequency of the compressor reaches the preset third target frequency, or the operating time of the compressor in the frequency reduction operation stage reaches the third longest operating time.

5. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the defrosting control method for the roof-mounted air conditioner of an electric bus as described in any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, causes the processor to perform the defrosting control method for a roof-mounted air conditioner in an electric bus as described in any one of claims 1 to 3.

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