Control method, electronic device and storage medium for rail vehicle air conditioning unit

Abstract

The present application relates to a control method, an electronic device and a storage medium for a rail vehicle air conditioning unit, the control method comprising: after receiving a heating request signal, obtaining a first outdoor temperature; after judging that the first temperature is lower than a first preset temperature, determining a matching temperature difference level according to the temperature difference information between the first temperature and the second preset temperature, and determining a corresponding preset low-temperature start mode according to the temperature difference level; after controlling the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature start mode, detecting the high pressure pressure on the exhaust side of the compressor, and judging whether the high pressure pressure on the exhaust side is in a preset high pressure pressure range; according to the judgment result of judging whether the high pressure pressure on the exhaust side is in the preset high pressure pressure range, determining a pressure regulation mode corresponding to the judgment result, and controlling the EC centrifugal fan to operate according to the corresponding pressure regulation mode. Through the present application, the problem that the heating start of the rail vehicle air conditioning unit in a low temperature environment easily causes low pressure protection of the compressor is solved.

Description

Technical Field

[0001] The present application relates to the field of vehicle air-conditioning units, and in particular to a control method, an electronic device and a storage medium for a rail vehicle air-conditioning unit. Background Art

[0002] Heat pump air-conditioning units are popular for their economical, energy-saving, safe and comfortable features, and are widely used in rail vehicle air conditioning.

[0003] The heat pump air-conditioning unit in the related technology is restricted by the outdoor ambient temperature. When the outdoor ambient temperature decreases, the heating capacity and energy efficiency ratio of the heat pump air-conditioning unit will decrease. When it is lower than the limit temperature, a low-voltage protection failure will occur, causing the heat pump unit to fail to work normally.

[0004] In the field of rail air conditioning, in order to ensure the uniformity of the temperature field distribution in rail vehicles, the evaporator adopts cross-row control. When the single heating system of the air-conditioning unit starts heating operation, the two evaporators of the single heating system (actually condensers when heating) are both working. This causes the condensing temperature and condensing pressure to decrease, making the compressor prone to low-pressure protection failure when the air-conditioning unit starts at low-temperature heating.

[0005] With regard to the problem in the related art that the startup of the rail vehicle air-conditioning unit in a low-temperature environment easily causes low-pressure protection of the compressor, no effective solution has been proposed so far. Summary of the invention

[0006] In this embodiment, a control method, an electronic device and a storage medium for a rail vehicle air-conditioning unit are provided to solve the problem in the related art that starting the rail vehicle air-conditioning unit in a low-temperature environment easily causes low-pressure protection of the compressor.

[0007] In a first aspect, a control method for a rail vehicle air-conditioning unit is provided in this embodiment, wherein the rail vehicle air-conditioning unit comprises a control unit, a compressor, a condensing fan and an EC centrifugal fan respectively connected to the control unit, wherein the condensing fan is arranged on a condenser, and the EC centrifugal fan is arranged on an evaporator, wherein the control method comprises: after receiving a heating request signal, the control unit obtains a first outdoor temperature; after determining that the first temperature is lower than a first preset temperature, the control unit determines a matching temperature difference level according to temperature difference information between the first temperature and a second preset temperature, and determines a corresponding preset low-temperature start mode according to the temperature difference level, wherein each preset Assume that the low-temperature starting mode corresponds to setting the starting sequence of the compressor, the condensing fan and the EC centrifugal fan, setting the operating frequency of the compressor and setting the target exhaust side high pressure pressure of the compressor; after the control unit controls the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature starting mode, the control unit detects the exhaust side high pressure pressure of the compressor and determines whether the exhaust side high pressure pressure is in a preset high pressure pressure range; the control unit determines the pressure regulation mode corresponding to the judgment result based on the judgment result of whether the exhaust side high pressure pressure is in the preset high pressure pressure range, and controls the EC centrifugal fan to operate according to the corresponding pressure regulation mode.

[0008] In some of the embodiments, before determining the pressure regulation mode corresponding to the judgment result, the control method further includes: the control unit detects whether the high-pressure pressure on the exhaust side is greater than a preset target high-pressure pressure, wherein the preset target high-pressure pressure represents the high-pressure pressure value of low-temperature startup corresponding to the preset low-temperature startup mode; when the control unit detects that the high-pressure pressure on the exhaust side is greater than the preset target high-pressure pressure, the control unit controls the EC centrifugal fan to start.

[0009] In some of the embodiments, the control unit determines the pressure regulation mode corresponding to the judgment result based on the judgment result of whether the high-pressure pressure on the exhaust side is in the preset high-pressure pressure range, including: after the control unit controls the EC centrifugal fan to start, the control unit detects whether the high-pressure pressure on the exhaust side drops to the preset high-pressure pressure range; the control unit determines the speed adjustment parameter corresponding to the pressure regulation mode based on the result of checking whether the high-pressure pressure on the exhaust side drops to the preset high-pressure pressure range, and adjusts the speed of the EC centrifugal fan according to the speed adjustment parameter to adjust the high-pressure pressure on the exhaust side to the preset high-pressure pressure range, wherein the speed adjustment parameter at least includes the speed adjustment method.

[0010] In some embodiments, the control unit determines the speed adjustment parameter corresponding to the pressure regulation mode according to the result of checking whether the high pressure pressure on the exhaust side drops to the preset high pressure pressure interval, and adjusts the speed of the EC centrifugal fan according to the speed adjustment parameter, including: when the control unit detects that the high pressure pressure on the exhaust side has not dropped to the preset high pressure pressure interval, determining that the speed adjustment method includes increasing the speed, increasing the speed of the EC centrifugal fan according to the preset speed increase value, and controlling the EC centrifugal fan to operate at the increased first speed; when the control unit detects that the speed of the EC centrifugal fan has been increased to the rated maximum speed and the high pressure pressure on the exhaust side has not dropped to the preset high pressure pressure interval, controlling the EC centrifugal fan to operate at the rated maximum speed; when the control unit detects that the high pressure pressure on the exhaust side is in the preset high pressure pressure interval, controlling the EC centrifugal fan to operate at the current third speed; when the control unit detects that the high pressure pressure on the exhaust side is less than the lower limit of the preset high pressure pressure interval, determining that the speed adjustment method includes reducing the speed, reducing the rotation of the EC centrifugal fan according to the preset speed drop value, and controlling the EC centrifugal fan to operate at the reduced second speed.

[0011] In some embodiments, adjusting the speed of the EC centrifugal fan according to the speed adjustment parameter includes: the control unit performing PID control on the speed of the EC centrifugal fan according to the speed adjustment parameter.

[0012] In some embodiments, when the control unit determines that the first temperature is not lower than a first preset temperature, the control unit controls the EC centrifugal fan, the condensing fan and the compressor to start in sequence.

[0013] In some embodiments, after the control unit controls the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature start-up mode, the control method further includes: the control unit detects the running time of the compressor and the condensing fan after they are started in sequence, and when it is detected that the running time is greater than a first preset time, controls the compressor, the condensing fan and the EC centrifugal fan to exit the preset low-temperature start-up mode.

[0014] In some of the embodiments, when the control unit detects that the high pressure on the exhaust side is greater than a preset high pressure protection threshold, the compressor, the condensing fan and the EC centrifugal fan are controlled to exit the preset low temperature start mode.

[0015] In a second aspect, an electronic device is provided in this embodiment, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the control method for the rail vehicle air-conditioning unit described in the first aspect is implemented.

[0016] In a fourth aspect, in this embodiment, a storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the control method of the rail vehicle air-conditioning unit described in the first aspect is implemented.

[0017] Compared with the related art, the control method, electronic device and storage medium of the rail vehicle air-conditioning unit provided in this embodiment obtain the first outdoor temperature through the control unit after receiving the heating request signal; after judging that the first temperature is lower than the first preset temperature, the control unit determines the matching temperature difference level according to the temperature difference information between the first temperature and the second preset temperature, and determines the corresponding preset low-temperature starting mode according to the temperature difference level, wherein each preset low-temperature starting mode corresponds to setting the starting sequence of the compressor, the condensing fan and the EC centrifugal fan, setting the operating frequency of the compressor and setting the target exhaust side high pressure pressure of the compressor; after the control unit controls the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature starting mode, the exhaust side high pressure pressure of the compressor is detected, and it is judged whether the exhaust side high pressure pressure is in the preset high pressure pressure range; the control unit determines the pressure regulation mode corresponding to the judgment result according to the judgment result of judging whether the exhaust side high pressure pressure is in the preset high pressure pressure range, and controls the EC centrifugal fan to operate according to the corresponding pressure regulation mode, so as to solve the problem that the low-temperature environment of the rail vehicle air-conditioning unit is easy to cause the low-pressure protection of the compressor, realize the stable operation of the full air volume in the startup stage of the rail vehicle air-conditioning unit in the low-temperature environment, and prevent the low-pressure protection of the compressor of the rail vehicle air-conditioning unit.

[0018] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0020] Figure 1 This is a structural view of a rail vehicle air conditioning unit according to an embodiment of the present application.

[0021] Figure 2 It is a flow chart of a control method of a rail vehicle air conditioning unit according to an embodiment of the present application.

[0022] Figure 3 The process of the control method of the rail vehicle air conditioning unit according to the preferred embodiment of the present application is as follows Figure 1 .

[0023] Figure 4 The process of the control method of the rail vehicle air conditioning unit according to the preferred embodiment of the present application is as follows Figure 2 . DETAILED DESCRIPTION

[0024] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0025] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the general meaning understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the", "these" and the like in this application do not represent quantitative restrictions, and they can be singular or plural. The terms "include", "comprise", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether directly or indirectly. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. Usually, the character " / " indicates that the objects associated with each other are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0026] Figure 1 1 is a structural view of a rail vehicle air conditioning unit according to an embodiment of the present application. Figure 1As shown, the rail vehicle air-conditioning unit in the embodiment of the present application at least includes a compressor 1, a condensing fan 2 and an EC centrifugal fan 3. The condensing fan 2 is arranged on the condenser 4, and the EC centrifugal fan 3 is arranged on the evaporator 5. Of course, the rail vehicle air-conditioning unit in the embodiment of the present application also includes other components and modules for cooling or heating the vehicle, such as: a frequency converter 6, an air purifier 7, a return air valve 8, a fresh air pressure wave valve 9, a four-way reversing valve 10, a gas-liquid separator 11, a waste exhaust pressure wave valve 12 and a waste exhaust valve 13. The air-conditioning unit in the embodiment of the present application is composed of an EC centrifugal fan 3 in the embodiment of the present application arranged on an existing heat pump unit. Therefore, air-conditioning units that meet the requirements of cooling or heating rail vehicles are suitable for the rail vehicle air-conditioning unit in the embodiment of the present application. At the same time, the control unit that executes the control method in the embodiment of the present application is Figure 1 Not shown, the control unit is electrically connected to the compressor 100, the condensing fan 200 and the EC centrifugal fan 300. The control unit in the embodiment of the present application controls the compressor 100, the condensing fan 200 and the EC centrifugal fan 300 to control the rail vehicle air-conditioning unit in a low temperature environment to establish a stable high and low pressure difference, thereby avoiding low pressure protection during the startup phase of the rail vehicle air-conditioning unit.

[0027] In this embodiment, a control method for a rail vehicle air conditioning unit is provided, which is applied to Figure 1 In the rail vehicle air conditioning unit shown, Figure 2 is a flow chart of a control method for a rail vehicle air conditioning unit according to an embodiment of the present application, such as Figure 2 As shown, the process includes the following steps:

[0028] Step S201: After receiving a heating request signal, the control unit obtains a first outdoor temperature.

[0029] In this embodiment, the ambient temperature of the heating condition adapted by the rail vehicle air-conditioning unit is below zero degrees, therefore, the control unit receives a heating request; at the same time, in this embodiment of the application, the control unit detects the outdoor temperature through a temperature sensor, and detects that the first outdoor temperature is below zero degrees, the rail vehicle air-conditioning unit is operating in a low temperature environment, and at the same time, the control unit controls the execution of the low temperature heating start-up phase.

[0030] Step S202, after determining that the first temperature is lower than the first preset temperature, the control unit determines a matching temperature difference level based on the temperature difference information between the first temperature and the second preset temperature, and determines a corresponding preset low-temperature start-up mode based on the temperature difference level, wherein each preset low-temperature start-up mode corresponds to setting the start-up sequence of the compressor, the condensing fan and the EC centrifugal fan, setting the operating frequency of the compressor and setting the target exhaust side high pressure pressure of the compressor.

[0031] In this embodiment, the first preset temperature is the upper limit threshold of the ambient temperature for judging the low-temperature heating start mode in the embodiment of the present application. When the ambient temperature reaches below the first preset temperature, the rail vehicle air-conditioning unit is started in the low-temperature heating start mode.

[0032] In this embodiment, after determining that the first temperature is lower than the first preset temperature, it is necessary to determine the corresponding temperature difference level based on the temperature difference between the first temperature of the current environment and the preset low-temperature heating start ambient temperature threshold, that is, the temperature difference with the second preset temperature. Each temperature difference level is associated with a corresponding preset low-temperature start mode. For example: when the temperature level determined according to the temperature difference between the first temperature and the second preset temperature is Level I, and the preset low-temperature start mode corresponding to the temperature difference level of Level I is low-temperature start mode A, the rail vehicle air-conditioning unit is started according to low-temperature start mode A.

[0033] In this embodiment, referring to the following table, the correlation between the temperature difference level and the first temperature, the second preset temperature, and the low temperature start mode is as follows:

[0034] Serial number Temperature difference information Temperature difference level Low temperature start mode 1 b<t<a Ⅰ A 2 c<t<b Ⅱ B 3 t<c Ⅲ C

[0035] In some of the optional embodiments, the corresponding preset low-temperature start-up mode can be determined by comparing the first temperature with a plurality of set second preset temperatures, and by judging whether the second temperature is lower than the corresponding second preset temperature, the start-up mode of the rail vehicle air-conditioning unit is determined to be the preset low-temperature start-up mode corresponding to the second preset temperature. For example, the second preset temperatures corresponding to the low-temperature start-up mode B and the low-temperature start-up mode C are set to b and c respectively. When the first temperature is lower than the first preset temperature, and the second temperature is lower than the second preset temperature b but higher than the second preset temperature c, then it is determined that the start-up mode of the rail vehicle air-conditioning unit corresponds to the low-temperature start-up mode B.

[0036] In this embodiment, the compressor is a variable frequency compressor, and the compressor frequency limited by each low-temperature start-up mode is the maximum frequency of the compressor operation set in the corresponding low-temperature start-up mode. Within this maximum frequency, the speed of the compressor will not cause the low pressure on the suction side of the compressor to be too low, and the speed of the corresponding compressor within the maximum frequency adapts to the low-temperature start-up mode, wherein the maximum frequency is determined based on the lowest value of the low pressure in the low-temperature start-up stage, and at the same time, as the second preset temperature corresponding to the low-temperature start-up mode decreases, the maximum frequency value also decreases.

[0037] Step S203, after the control unit controls the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature start mode, it detects the high-pressure pressure on the exhaust side of the compressor and determines whether the high-pressure pressure on the exhaust side is in the preset high-pressure pressure range.

[0038] In this embodiment, when the first temperature matches the second preset temperature defined by the corresponding low-temperature start mode, the condensing fan and the compressor are started in sequence, and the EC centrifugal fan is started with a delay. After the condensing fan and the compressor are started, the high-pressure pressure on the exhaust side of the compressor gradually increases. The control unit checks the high-pressure pressure on the exhaust side of the compressor and compares the high-pressure pressure on the exhaust side with the set high-pressure pressure threshold, and accordingly controls the start-up and speed adjustment of the EC centrifugal fan.

[0039] In step S204, the control unit determines a pressure regulation mode corresponding to the judgment result of whether the high pressure on the exhaust side is in a preset high pressure range, and controls the EC centrifugal fan to operate in the corresponding pressure regulation mode.

[0040] In the embodiment of the present application, the preset high-pressure pressure interval is determined according to the stable high-pressure pressure value during heating operation at different outdoor temperatures, that is, by controlling the high-pressure pressure on the exhaust side to be equal to the high-pressure pressure on the exhaust side at the temperature of the heating operation stage, so that a pressure difference is constructed between the exhaust side of the compressor and the suction side of the compressor during the low-temperature startup stage of the rail vehicle air-conditioning unit, thereby ensuring that the low pressure is at a set safety value, avoiding the pressure drop that occurs when the EC centrifugal fan is turned on and drops to the low-pressure protection value and causing low-pressure protection, that is, before the low pressure reaches the low-pressure protection value, the pressure drop is slowed down and stopped by controlling the EC centrifugal fan.

[0041] In this embodiment, after determining the corresponding judgment result, the speed of the EC centrifugal fan will be controlled accordingly, that is, controlling the EC centrifugal fan to operate in the corresponding pressure regulation mode at least includes controlling the speed of the EC centrifugal fan; in this embodiment of the present application, before making a judgment on the speed control of the EC centrifugal fan, a judgment on the start-up control of the EC centrifugal fan is also made; therefore, controlling the EC centrifugal fan to operate in the corresponding pressure regulation mode includes controlling the start-up of the EC centrifugal fan and controlling the speed of the EC centrifugal fan; in this embodiment, the judgment on the start-up control of the EC centrifugal fan is by comparing the high-pressure pressure on the exhaust side with the preset target high-pressure pressure. When the high-pressure pressure on the exhaust side is greater than the preset target high-pressure pressure, the EC centrifugal fan is controlled to start. Through the above steps S201 to S204, after receiving the heating request signal, the control unit obtains the first outdoor temperature; after judging that the first temperature is lower than the first preset temperature, the control unit determines the matching temperature difference level according to the temperature difference information between the first temperature and the second preset temperature, and determines the corresponding preset low-temperature starting mode according to the temperature difference level, wherein each preset low-temperature starting mode corresponds to setting the starting sequence of the compressor, the condensing fan and the EC centrifugal fan, setting the operating frequency of the compressor and setting the target exhaust side high pressure pressure of the compressor; after the control unit controls the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature starting mode, the exhaust side high pressure pressure of the compressor is detected, and it is judged whether the exhaust side high pressure pressure is in the preset high pressure pressure range; the control unit determines the pressure regulation mode corresponding to the judgment result according to the judgment result of judging whether the exhaust side high pressure pressure is in the preset high pressure pressure range, and controls the EC centrifugal fan to operate according to the corresponding pressure regulation mode, so as to solve the problem that the low-temperature environment of the rail vehicle air-conditioning unit is easy to cause the low-pressure protection of the compressor, realize the stable operation of the full air volume in the startup stage of the rail vehicle air-conditioning unit in the low-temperature environment, and prevent the low-pressure protection of the compressor of the rail vehicle air-conditioning unit.

[0042] In some of the embodiments, before determining the pressure relief mode corresponding to the judgment result, the following steps are further implemented:

[0043] Step 1: The control unit detects whether the high pressure on the exhaust side is greater than a preset target high pressure, wherein the preset target high pressure represents a high pressure value for low temperature startup corresponding to a preset low temperature startup mode.

[0044] In this embodiment, the preset target high pressure is determined according to the high and low pressure curves of heating startup at different indoor and outdoor temperatures, and the preset target high pressure is greater than the upper limit of the preset high pressure range.

[0045] Step 2: When the control unit detects that the high pressure on the exhaust side is greater than the preset target high pressure, the control unit controls the EC centrifugal fan to start.

[0046] The control unit in the above steps detects whether the high pressure pressure on the exhaust side is greater than the preset target high pressure pressure; when the control unit detects that the high pressure pressure on the exhaust side is greater than the preset target high pressure pressure, the control unit controls the EC centrifugal fan to start, thereby controlling the start of the EC centrifugal fan according to the comparison result between the high pressure pressure on the exhaust side and the target high pressure pressure, so that a pressure difference is formed between the exhaust side of the compressor and the suction side of the compressor during the low-temperature startup stage of the rail vehicle air-conditioning unit, thereby ensuring that the low pressure is at a set safety value, and avoiding the pressure drop when the EC centrifugal fan is turned on to drop to the low pressure protection value and cause low pressure protection.

[0047] In some of the embodiments, the control unit determines the pressure regulation mode corresponding to the judgment result of whether the high pressure pressure on the exhaust side is in the preset high pressure range according to the judgment result by:

[0048] Step 1: After the control unit controls the EC centrifugal fan to start, the control unit detects whether the high pressure on the exhaust side drops to a preset high pressure range.

[0049] Step 2: The control unit determines the speed adjustment parameter corresponding to the pressure regulation mode according to the result of checking whether the high pressure pressure on the exhaust side drops to the preset high pressure pressure range, and adjusts the speed of the EC centrifugal fan according to the speed adjustment parameter to adjust the high pressure pressure on the exhaust side to the preset high pressure pressure range, wherein the speed adjustment parameter at least includes the speed adjustment method.

[0050] In this embodiment, the high pressure on the exhaust side is greater than the preset target high pressure, and the EC centrifugal fan has been started. However, the start-up of the EC centrifugal fan will cause the high pressure on the exhaust side to decrease. Therefore, after the EC centrifugal fan is started, the high pressure on the exhaust side will be detected. By detecting whether the high pressure on the exhaust side is in the preset high pressure range, the speed of the EC centrifugal fan is controlled, so that a pressure difference is created between the exhaust side of the compressor and the suction side of the compressor during the low-temperature start-up stage of the rail vehicle air-conditioning unit, thereby ensuring that the low pressure is at a set safety value.

[0051] In the present embodiment, after the EC centrifugal fan is started, although the high-pressure pressure on the exhaust side will decrease, within a period of time after the EC centrifugal fan is started, the high-pressure pressure on the exhaust side will not drop below the preset high-pressure pressure range. Therefore, it is necessary to increase the speed of the EC centrifugal fan so that the high-pressure pressure on the exhaust side can be quickly reduced to the preset high-pressure pressure range. When the high-pressure pressure on the exhaust side drops to the preset high-pressure pressure range, due to the operation of the EC centrifugal fan, the high-pressure pressure on the exhaust side will be reduced to maintain in the preset high-pressure pressure range or below the lower limit of the preset high-pressure pressure range. At this time, it is necessary to control the speed of the EC centrifugal fan to decrease, so that the pressure value of the high-pressure pressure on the exhaust side generated by the operation of the EC centrifugal fan is not greater than the increase value of the high-pressure pressure on the exhaust side generated by the operation of the compressor and the condensing fan. In this way, the high-pressure pressure on the exhaust side is maintained within the preset high-pressure pressure range.

[0052] In this embodiment, since it involves controlling the speed of the EC centrifugal fan and adjusting the high pressure pressure on the exhaust side, in this embodiment, the speed adjustment parameters include a speed adjustment method and a speed adjustment value corresponding to the speed adjustment method, wherein the speed adjustment method includes increasing the speed and reducing the speed, and the corresponding speed adjustment value includes a preset speed increase value and a preset speed drop value.

[0053] After the control unit controls the EC centrifugal fan to start in the above steps, the control unit detects whether the high-pressure pressure on the exhaust side drops to the preset high-pressure pressure range; the control unit determines the speed adjustment parameter corresponding to the pressure regulation mode according to the result of checking whether the high-pressure pressure on the exhaust side drops to the preset high-pressure pressure range, and adjusts the speed of the EC centrifugal fan according to the speed adjustment parameter, and adjusts the high-pressure pressure on the exhaust side to the preset high-pressure pressure range, thereby adjusting the speed of the EC centrifugal fan according to the comparison result between the high-pressure pressure on the exhaust side and the target high-pressure pressure, so that a pressure difference is formed between the exhaust side and the suction side of the compressor during the low-temperature startup stage of the rail vehicle air-conditioning unit, thereby ensuring that the low pressure is at the set safety value, and avoiding the pressure drop when the EC centrifugal fan is turned on to drop to the low-pressure protection value and cause low-pressure protection.

[0054] In some of the embodiments, the control unit determines the speed adjustment parameter corresponding to the pressure regulation mode according to the result of checking whether the high pressure pressure on the exhaust side falls into the preset high pressure pressure range, and adjusts the speed of the EC centrifugal fan according to the speed adjustment parameter by the following steps:

[0055] Step 1: When the control unit detects that the high pressure pressure on the exhaust side has not dropped to the preset high pressure pressure range, it determines that the speed adjustment method includes increasing the speed, and increases the speed of the EC centrifugal fan according to the preset speed increase value, and controls the EC centrifugal fan to operate at the increased first speed.

[0056] In this embodiment, when the high-pressure pressure on the exhaust side is higher than the upper limit of the preset high-pressure pressure range, the speed of the EC centrifugal fan is increased according to the preset speed increase value, so that the high-pressure pressure on the exhaust side is quickly reduced to the preset high-pressure pressure range, and the rail air-conditioning unit can operate stably at full air volume.

[0057] Step 2: When the control unit detects that the speed of the EC centrifugal fan has increased to the rated maximum speed and the high pressure pressure on the exhaust side has not dropped to the preset high pressure pressure range, the control unit controls the EC centrifugal fan to operate at the rated maximum speed.

[0058] In this embodiment, when the EC centrifugal fan increases its speed to the rated maximum speed, it still cannot reduce the high pressure pressure on the exhaust side to the preset high pressure pressure range. In this case, the EC centrifugal fan is controlled to operate at the rated maximum speed, so that the high pressure pressure on the exhaust side can be reduced to the preset high pressure pressure range after running for a preset time.

[0059] Step 3: When the control unit detects that the high pressure on the exhaust side is in the preset high pressure range, the control unit controls the EC centrifugal fan to operate at the current third speed.

[0060] In this embodiment, when the EC centrifugal fan operates at the current third speed, it is the speed at which the EC centrifugal fan operates when the control unit detects whether the high pressure pressure on the exhaust side is in a preset high pressure pressure range. In some optional implementations, the third speed includes one of the first speed and the second speed.

[0061] Step 4: When the control unit detects that the high pressure pressure on the exhaust side is less than the preset high pressure pressure range, it determines that the speed adjustment method includes reducing the speed, reducing the rotation of the EC centrifugal fan according to the preset speed drop value, and controlling the EC centrifugal fan to operate at the reduced second speed.

[0062] In this embodiment, when the high pressure on the exhaust side drops to the preset high pressure pressure range, the operation of the EC centrifugal fan will cause the high pressure on the exhaust side to drop to a low pressure value lower than the safety value, and the rail vehicle air conditioning unit will be protected from low pressure during the startup phase. At this time, it is necessary to control and reduce the speed of the EC centrifugal fan, so that the pressure value of the high pressure on the exhaust side generated by the operation of the EC centrifugal fan is not greater than the increase value of the high pressure on the exhaust side generated by the operation of the compressor and the condensing fan, so that the high pressure on the exhaust side is maintained within the preset high pressure pressure range. In some of the embodiments, adjusting the speed of the EC centrifugal fan according to the speed adjustment parameter is achieved in the following manner: the control unit performs PID control on the speed of the EC centrifugal fan according to the speed adjustment parameter.

[0063] In this embodiment, PID control is adopted to achieve precise control of the rotation speed of the EC centrifugal fan and to perform stepless speed regulation.

[0064] In some of the embodiments, the following steps are further implemented: when the control unit determines that the first temperature is not lower than the first preset temperature, the control unit controls the EC centrifugal fan, the condensing fan and the compressor to start in sequence.

[0065] In this embodiment, when the control unit determines that the first temperature is not lower than the first preset temperature, that is, the ambient temperature is not lower than the first preset temperature, it indicates that the conditions for the preset low-temperature start-up mode are not met. At this time, it is started in normal mode and the EC centrifugal fan, condensing fan and compressor are controlled to start in sequence.

[0066] In some of the embodiments, the rail vehicle air conditioning unit further implements the following process steps: Figure 3 The process of the control method of the rail vehicle air conditioning unit according to the preferred embodiment of the present application is as follows Figure 1 ,like Figure 3 As shown, the process includes the following steps:

[0067] Step S301: After receiving a heating request signal, the control unit obtains a first outdoor temperature.

[0068] Step S302, after determining that the first temperature is lower than the first preset temperature, the control unit determines a matching temperature difference level based on the temperature difference information between the first temperature and the second preset temperature, and determines a corresponding preset low-temperature start-up mode based on the temperature difference level, wherein each preset low-temperature start-up mode corresponds to setting the start-up sequence of the compressor, the condensing fan and the EC centrifugal fan, setting the operating frequency of the compressor and setting the target exhaust side high pressure pressure of the compressor.

[0069] Step S303, after the control unit controls the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature start mode, it detects the high-pressure pressure on the exhaust side of the compressor and determines whether the high-pressure pressure on the exhaust side is in the preset high-pressure pressure range.

[0070] Step S304, the control unit determines a pressure regulation mode corresponding to the judgment result of whether the high pressure on the exhaust side is in a preset high pressure range, and controls the EC centrifugal fan to operate in the corresponding pressure regulation mode.

[0071] Step S305, the control unit detects the running time of the compressor and the condensing fan after they are started in sequence, and when it is detected that the running time is greater than the first preset time, controls the compressor, the condensing fan and the EC centrifugal fan to exit the preset low-temperature start-up mode.

[0072] In this embodiment, by setting the time exit mode, when the low-temperature start mode runs for a preset time threshold, the low-temperature start mode is exited and the heating operation mode is entered. After entering the heating operation mode, the speed of the EC centrifugal fan is controlled according to the target high-pressure pressure corresponding to the current temperature, so that the high-pressure pressure on the exhaust side of the compressor matches the target high-pressure pressure corresponding to the current temperature.

[0073] In some of the embodiments, the rail vehicle air conditioning unit further implements the following process steps: Figure 4 The process of the control method of the rail vehicle air conditioning unit according to the preferred embodiment of the present application is as follows Figure 2 ,like Figure 4 As shown, the process includes the following steps:

[0074] Step S401: After receiving a heating request signal, the control unit obtains a first outdoor temperature.

[0075] Step S402, after determining that the first temperature is lower than the first preset temperature, the control unit determines a matching temperature difference level based on the temperature difference information between the first temperature and the second preset temperature, and determines a corresponding preset low-temperature start-up mode based on the temperature difference level, wherein each preset low-temperature start-up mode corresponds to setting the start-up sequence of the compressor, the condensing fan and the EC centrifugal fan, setting the operating frequency of the compressor and setting the target exhaust side high pressure pressure of the compressor.

[0076] Step S403, after the control unit controls the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature start mode, it detects the high-pressure pressure on the exhaust side of the compressor and determines whether the high-pressure pressure on the exhaust side is in the preset high-pressure pressure range.

[0077] Step S404, the control unit determines a pressure regulation mode corresponding to the judgment result of whether the high pressure on the exhaust side is in a preset high pressure range, and controls the EC centrifugal fan to operate in the corresponding pressure regulation mode.

[0078] Step S405, when the control unit detects that the high pressure on the exhaust side is greater than a preset high pressure protection threshold, the compressor, the condensing fan and the EC centrifugal fan are controlled to exit the preset low temperature start mode.

[0079] In this embodiment, by setting the high-pressure exit mode, when the high-pressure pressure on the exhaust side is greater than the high-pressure exit protection value, the low-temperature start-up mode is exited and the heating operation mode is entered. When the heating operation mode is entered, the speed of the EC centrifugal fan is controlled according to the target high-pressure pressure corresponding to the current temperature, so that the high-pressure pressure on the exhaust side of the compressor matches the target high-pressure pressure corresponding to the current temperature.

[0080] In this embodiment, an electronic device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0081] Optionally, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0082] Optionally, in this embodiment, the processor may be configured to perform the following steps through a computer program:

[0083] S1, after receiving a heating request signal, obtaining a first outdoor temperature.

[0084] S2, after determining that the first temperature is lower than the first preset temperature, determining a matching temperature difference level according to temperature difference information between the first temperature and the second preset temperature, and determining a corresponding preset low-temperature start mode according to the temperature difference level.

[0085] S3, after controlling the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature start mode, detecting the high pressure pressure on the exhaust side of the compressor, and determining whether the high pressure pressure on the exhaust side is in a preset high pressure range.

[0086] S4, according to the judgment result of whether the high pressure on the exhaust side is in the preset high pressure range, determining the pressure regulation mode corresponding to the judgment result, and controlling the EC centrifugal fan to operate according to the corresponding pressure regulation mode.

[0087] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation modes, and will not be repeated in this embodiment.

[0088] In addition, in combination with the control method of the rail vehicle air conditioning unit provided in the above embodiment, a storage medium can also be provided in this embodiment to implement the control method. The storage medium stores a computer program; when the computer program is executed by the processor, any of the control methods of the rail vehicle air conditioning unit in the above embodiment is implemented.

[0089] It should be understood that the specific embodiments described herein are only used to explain the application, rather than to limit it. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of this application.

[0090] Obviously, the drawings are only some examples or embodiments of the present application. For ordinary technicians in the field, the present application can also be applied to other similar situations based on these drawings without creative work. In addition, it is understandable that although the work done in this development process may be complicated and lengthy, for ordinary technicians in the field, certain changes in design, manufacturing or production based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient content disclosed in this application.

[0091] The term "embodiment" in this application refers to a specific feature, structure or characteristic described in conjunction with the embodiment that can be included in at least one embodiment of the present application. The appearance of this phrase in various locations in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. It is clearly or implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict.

[0092] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of patent protection. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

1. A control method for a rail vehicle air conditioning unit, the rail vehicle air conditioning unit comprising a control unit, a compressor, a condensing fan and an EC centrifugal fan respectively connected to the control unit, the condensing fan being arranged on a condenser, and the EC centrifugal fan being arranged on an evaporator, characterized in that: The control method comprises: The control unit acquires a first outdoor temperature after receiving a heating request signal; After determining that the first temperature is lower than the first preset temperature, the control unit determines a matching temperature difference level according to temperature difference information between the first temperature and the second preset temperature, and determines a corresponding preset low-temperature start mode according to the temperature difference level, wherein each preset low-temperature start mode corresponds to setting a start sequence of the compressor, the condensing fan and the EC centrifugal fan, setting an operating frequency of the compressor and setting a target exhaust side high pressure pressure of the compressor; After the control unit controls the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature start-up mode, it detects the high-pressure pressure on the exhaust side of the compressor and determines whether the high-pressure pressure on the exhaust side is in a preset high-pressure pressure range; The control unit determines a pressure regulation mode corresponding to the judgment result of whether the high pressure pressure on the exhaust side is in a preset high pressure pressure range, and controls the EC centrifugal fan to operate in the corresponding pressure regulation mode.

2. The control method of the rail vehicle air conditioning unit according to claim 1, characterized in that: Before determining the voltage regulation mode corresponding to the judgment result, the control method further includes: The control unit detects whether the exhaust side high pressure is greater than a preset target high pressure, wherein the preset target high pressure represents a high pressure value of low temperature startup corresponding to the preset low temperature startup mode; In the case where the control unit detects that the exhaust side high pressure is greater than the preset target high pressure, the control unit controls the EC centrifugal fan to start.

3. The control method of the rail vehicle air conditioning unit according to claim 2, characterized in that: The control unit determines the pressure regulation mode corresponding to the judgment result according to the judgment result of whether the high pressure pressure on the exhaust side is in the preset high pressure pressure range, including: After the control unit controls the EC centrifugal fan to start, the control unit detects whether the high pressure pressure on the exhaust side drops to the preset high pressure pressure range; The control unit determines the speed adjustment parameter corresponding to the pressure regulation mode according to the result of checking whether the high-pressure pressure on the exhaust side drops to the preset high-pressure pressure range, and adjusts the speed of the EC centrifugal fan according to the speed adjustment parameter to adjust the high-pressure pressure on the exhaust side to the preset high-pressure pressure range, wherein the speed adjustment parameter at least includes the speed adjustment method.

4. The control method of the rail vehicle air conditioning unit according to claim 3, characterized in that: The control unit determines the speed adjustment parameter corresponding to the pressure regulation mode according to the result of checking whether the high pressure pressure on the exhaust side drops to the preset high pressure pressure range, and adjusts the speed of the EC centrifugal fan according to the speed adjustment parameter, including: When the control unit detects that the high pressure pressure on the exhaust side has not fallen to the preset high pressure pressure interval, it determines that the speed adjustment method includes increasing the speed, increases the speed of the EC centrifugal fan according to a preset speed increase value, and controls the EC centrifugal fan to operate at the increased first speed; When the control unit detects that the speed of the EC centrifugal fan has increased to the rated maximum speed and the high pressure pressure on the exhaust side has not dropped to the preset high pressure pressure range, the control unit controls the EC centrifugal fan to operate at the rated maximum speed; The control unit controls the EC centrifugal fan to operate at the current third speed when detecting that the high pressure pressure on the exhaust side is in the preset high pressure pressure interval; When the control unit detects that the high pressure pressure on the exhaust side is less than the lower limit of the preset high pressure pressure range, it determines that the speed adjustment method includes reducing the speed, reduces the rotation of the EC centrifugal fan according to the preset speed drop value, and controls the EC centrifugal fan to operate at the reduced second speed.

5. The control method of the rail vehicle air conditioning unit according to claim 3, characterized in that: Adjusting the speed of the EC centrifugal fan according to the speed adjustment parameter includes: the control unit performing PID control on the speed of the EC centrifugal fan according to the speed adjustment parameter.

6. The control method of the rail vehicle air conditioning unit according to claim 1, characterized in that: When the control unit determines that the first temperature is not lower than a first preset temperature, the control unit controls the EC centrifugal fan, the condensing fan and the compressor to start in sequence.

7. The control method of the rail vehicle air conditioning unit according to claim 1, characterized in that: After the control unit controls the compressor and the condensing fan to start in sequence according to the corresponding preset low-temperature starting mode, the control method further includes: The control unit detects the operating time of the compressor and the condensing fan after they are started in sequence, and when it is detected that the operating time is greater than a first preset time, controls the compressor, the condensing fan and the EC centrifugal fan to exit the preset low-temperature start-up mode.

8. The control method of the rail vehicle air conditioning unit according to claim 1, characterized in that: When the control unit detects that the high pressure on the exhaust side is greater than a preset high pressure protection threshold, the compressor, the condensing fan and the EC centrifugal fan are controlled to exit the preset low temperature start mode.

9. An electronic device comprising a memory and a processor, characterized in that: A computer program is stored in the memory, and the processor is configured to run the computer program to execute the control method of the rail vehicle air-conditioning unit according to any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for controlling a rail vehicle air conditioning unit according to any one of claims 1 to 8 are implemented.

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