HK40001526B - Vehicle air-conditioning device and obstruction detection system for vehicle air-conditioning device - Google Patents

Description

Vehicle air conditioning device and clogging detection system for vehicle air conditioning device

Technical Field

The present invention relates to a vehicle air conditioner mounted on a vehicle and a clogging detection system for the vehicle air conditioner.

Background Art

Patent Document 1 describes an air conditioner equipped with an outdoor heat exchanger. If the outdoor heat exchanger becomes clogged, the air resistance in the outdoor heat exchanger increases, preventing sufficient heat exchange between the outside air and the outdoor heat exchanger. In this air conditioner, the outdoor heat exchanger is determined to be clogged when the difference between the saturation temperature calculated based on the compressor's exhaust pressure and the outside air temperature falls below a predetermined temperature.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application Laid-Open No. 2012-26702

Summary of the Invention

Technical problem to be solved by the invention

In the case of a vehicle air conditioner, air passage resistance varies depending on the vehicle's running state, position, etc. Therefore, unlike a fixed air conditioner such as Patent Document 1, a vehicle air conditioner has a problem in that it is difficult to accurately detect clogging of the heat exchanger.

The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a vehicle air conditioner and a clogging detection system for a vehicle air conditioner that can more accurately detect clogging of a heat exchanger.

Technical solutions used to solve technical problems

The vehicle air conditioning device involved in the present invention includes a refrigerant circuit having a heat exchanger, a blower that supplies air to the heat exchanger, and a control unit that controls the refrigerant circuit and the blower. The vehicle air conditioning device is mounted on a vehicle, and the control unit is configured to: when the position or speed of the vehicle meets specified conditions, obtain a physical quantity correlated with the blockage amount of the heat exchanger, and determine whether the heat exchanger is blocked based on the physical quantity.

The blockage detection system for a vehicle air-conditioning device involved in the present invention includes: a vehicle air-conditioning device, which includes a refrigerant circuit with a heat exchanger, a blower that blows air to the heat exchanger, and a control unit that controls the refrigerant circuit and the blower, and the vehicle air-conditioning device is mounted on a vehicle; and a ground system, which is connected to the control unit via a communication network, and the control unit is configured to: when the position or speed of the vehicle meets specified conditions, obtain a physical quantity correlated with the blockage amount of the heat exchanger, and send information about the physical quantity to the ground system, and the ground system is configured to determine whether the heat exchanger is blocked based on the physical quantity.

Effects of the Invention

According to the present invention, since the influence of the fluctuation of the air passage resistance due to the position and speed of the vehicle can be limited, clogging of the heat exchanger can be detected more accurately.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic side view showing the schematic configuration of a railway vehicle 100 equipped with a vehicle air conditioning apparatus 1 according to Embodiment 1 of the present invention.

FIG2 is a refrigerant circuit diagram showing a schematic configuration of the vehicle air-conditioning apparatus 1 according to Embodiment 1 of the present invention.

FIG3 is a block diagram showing a schematic configuration of the clogging detection system 2 of the vehicle air conditioner 1 according to Embodiment 1 of the present invention.

FIG. 4 is a flowchart showing an example of the flow of a congestion detection process executed by the terminal 30 in the vehicle air conditioning apparatus 1 according to Embodiment 1 of the present invention.

FIG5 is a flowchart showing an example of the flow of a physical quantity acquisition process executed by the terminal 30 in the congestion detection system 2 of the vehicle air conditioner 1 according to Embodiment 2 of the present invention.

FIG6 is a flowchart showing an example of the flow of a congestion detection process executed by the ground system 50 in the congestion detection system 2 of the vehicle air conditioner 1 according to Embodiment 2 of the present invention.

DETAILED DESCRIPTION

Implementation method 1.

A vehicle air conditioning system and a congestion detection system for a vehicle air conditioning system according to Embodiment 1 of the present invention will now be described. FIG1 is a schematic side view showing the general configuration of a railway vehicle 100 equipped with the vehicle air conditioning system 1 according to this embodiment. In the following drawings, including FIG1 , the relative dimensions and shapes of various components may differ from actual configurations.

As shown in Figure 1 , a vehicle air conditioner 1 is mounted on the roof of a railway vehicle 100. An air supply duct 102 is provided on the ceiling of a compartment 101 within the railway vehicle 100. Conditioned air blown out from the vehicle air conditioner 1 is supplied into the compartment 101 via the air supply duct 102. Furthermore, air within the compartment 101 is drawn into the vehicle air conditioner 1 via a return air duct (not shown). While the vehicle air conditioner 1 in this example is mounted on the roof of the railway vehicle 100, the vehicle air conditioner 1 may alternatively be mounted under the floor of the railway vehicle 100.

The railway vehicle 100 constitutes a part or the entirety of one train set. In other words, one train set is constituted by at least one railway vehicle 100. One railway vehicle 100 is equipped with one or more vehicle air conditioners 1.

FIG2 is a refrigerant circuit diagram schematically illustrating the configuration of a vehicle air conditioner 1. As shown in FIG2 , the vehicle air conditioner 1 includes, for example, two refrigerant circuits 10a and 10b. Furthermore, the vehicle air conditioner 1 includes an outdoor chamber 20 and indoor chambers 21a and 21b disposed on either side of the railway vehicle 100 in the longitudinal direction, sandwiching the outdoor chamber 20.

The refrigerant circuit 10a has the following structure: a compressor 11a, a four-way valve 12a, an indoor heat exchanger 13a, a pressure reducing device 14a (e.g., a linear electronic expansion valve), and an outdoor heat exchanger 15a are connected via refrigerant piping. During heating operation, the compressor 11a, indoor heat exchanger 13a, pressure reducing device 14a, and outdoor heat exchanger 15a are sequentially connected in a loop. This causes the indoor heat exchanger 13a to function as a condenser, and the outdoor heat exchanger 15a to function as an evaporator. During cooling operation, the four-way valve 12a switches the refrigerant flow path, and the compressor 11a, outdoor heat exchanger 15a, pressure reducing device 14a, and indoor heat exchanger 13a are sequentially connected in a loop. This causes the indoor heat exchanger 13a to function as an evaporator, and the outdoor heat exchanger 15a to function as a condenser. The compressor 11a, four-way valve 12a, pressure reducing device _14a , and outdoor heat exchanger 15a are located in the outdoor room 20. The indoor heat exchanger 13a is arranged in the indoor chamber 21a.

Similarly, the refrigerant circuit 10b has the following structure: a compressor 11b, a four-way valve 12b, an indoor heat exchanger 13b, a pressure reducing device 14b (e.g., a linear electronic expansion valve), and an outdoor heat exchanger 15b are connected via refrigerant piping. The compressor 11b, four-way valve 12b, pressure reducing device 14b, and outdoor heat exchanger 15b are located in the outdoor room 20. The indoor heat exchanger 13b is located in the indoor room 21b.

The indoor heat exchangers 13a, 13b and the outdoor heat exchangers 15a, 15b may be of any form. For example, various fin forms such as flat fins, corrugated fins, and wave fins may be adopted.

The outdoor chamber 20 is equipped with an outdoor blower 16 that supplies outdoor air to the outdoor heat exchangers 15a and 15b. The indoor chamber 21a is equipped with an indoor blower 17a that supplies indoor air to the indoor heat exchanger 13a. The indoor air that has exchanged heat with the refrigerant in the indoor heat exchanger 13a is supplied to the interior of the vehicle cabin 101, for example, at the front of the vehicle. The indoor chamber 21b is equipped with an indoor blower 17b that supplies indoor air to the indoor heat exchanger 13b. The indoor air that has exchanged heat with the refrigerant in the indoor heat exchanger 13b is supplied to the interior of the vehicle cabin 101, for example, at the rear of the vehicle.

The vehicle air conditioner 1 includes a terminal 30 as a control unit. The terminal 30 includes a microcomputer equipped with a CPU, ROM, RAM, and I/O ports. Based on detection signals from various sensors, the terminal 30 controls the overall operation of the refrigerant circuits 10a and 10b, including the compressors 11a and 11b, the outdoor blower 16, and the indoor blowers 17a and 17b. The terminal 30 functions as the control unit of the vehicle air conditioner 1 and also constitutes part of the blockage detection system 2, described later. In this example, the terminal 30 is installed in each vehicle air conditioner 1, but the terminal 30 may also be installed in each refrigerant circuit 10a and 10b.

FIG3 is a block diagram schematically illustrating the configuration of a congestion detection system 2 for a vehicle air conditioning system 1 according to this embodiment. As shown in FIG3 , the congestion detection system 2 includes at least one onboard system 40 and a ground system 50 connected to the onboard system 40 via a communication network 60. The communication network 60 utilizes wireless communication such as mobile phones, wireless LAN, WiMAX (registered trademark), and millimeter waves.

The onboard system 40 is installed on a single train consisting of multiple railway vehicles 100. Generally, one onboard system 40 is installed on each train. The onboard system 40 includes an onboard communication device 41 that communicates with the ground system 50 via a communication network 60, central devices 42 and 43 installed on the railway vehicles 100 at the front and rear ends of the train, and, for example, multiple terminals 30 installed on each vehicle air conditioner 1. The onboard communication device 41, central devices 42 and 43, and multiple terminals 30 function as a control unit that controls the multiple vehicle air conditioners 1 installed on the train.

The ground system 50 includes a ground communication device 51 for communicating with the onboard system 40 via a communication network 60, a database 52 for storing data received from the onboard system 40, and a control unit (not shown) for controlling the ground communication device 51 and the database 52. The ground system 50 transmits and receives data with at least one onboard system 40 via the communication network 60, thereby remotely monitoring each vehicle air conditioning system 1.

FIG4 is a flowchart illustrating an example of the flow of a blockage detection process executed by terminal 30 in the vehicle air conditioner 1 according to this embodiment. The blockage detection process illustrated in FIG4 detects blockage in at least one of the indoor heat exchangers 13a, 13b and the outdoor heat exchangers 15a, 15b. Unlike stationary air conditioners, in the vehicle air conditioner 1, not only the outdoor heat exchangers 15a, 15b but also the indoor heat exchangers 13a, 13b can be subject to blockage detection. The blockage detection process is repeatedly executed at predetermined time intervals.

First, in step S1 of FIG4 , terminal 30 obtains the train's position information or speed information, including that of railway vehicle 100, from either onboard communication device 41 or central devices 42 or 43. The train's position information may be two-dimensional or three-dimensional position information using GPS, or information indicating the distance to the starting station in kilometers.

Next, in step S2, the terminal 30 determines whether the position or speed of the train meets the specified conditions based on the acquired position information or speed information. Examples of the specified conditions include: the speed of the train is a specific speed greater than 0 km/h (i.e., the train is in the process of traveling at a specific speed), the speed of the train is 0 km/h (i.e., the train is in the process of stopping), the position of the train is not in a tunnel, the position of the train is not in a station, etc. The position of the train can be grasped based on the position information. The speed of the train can be grasped based on the speed information, or the position information acquired this time and the position information acquired last time. In step S2, if it is determined that the position or speed of the train meets the specified conditions, the process proceeds to step S3, and if it is determined that the position or speed of the train does not meet the specified conditions, the process ends.

Here, determining whether the specified conditions are met in step S2 is done so that, in step S4 described later, physical quantities correlated with the amount of heat exchanger blockage can be acquired under conditions that are as consistent as possible each time the physical quantities are acquired. By ensuring that the conditions for acquiring the physical quantities are as consistent as possible, the amount of heat exchanger blockage can be assessed based on the physical quantities. For example, by comparing the physical quantities acquired by the vehicle air conditioner with those acquired by other vehicle air conditioners, the amount of heat exchanger blockage in the vehicle air conditioner can be relatively determined.

Physical quantities correlated with the amount of heat exchanger blockage vary depending on the train's speed. Therefore, by acquiring physical quantities at a specific train speed, the conditions for acquiring the physical quantities can be kept nearly constant. However, if the relationship between a physical quantity when the train is stopped (for example, the current flowing in the blower) and a physical quantity when the train is traveling at a specified speed is known in advance, or if the relationship between how the physical quantity changes with train speed is known, the acquired physical quantity can be corrected according to the train's speed.

Furthermore, the wind resistance of outdoor air, in particular, fluctuates between when the train is in a tunnel and when it is not. Consequently, the physical quantity correlated with the amount of heat exchanger blockage fluctuates between when the train is in a tunnel and when it is not. Therefore, by acquiring the physical quantity when the train is not in a tunnel, the conditions for acquiring the physical quantity can be made nearly identical. Tunnel location information is pre-stored in the ROM of the terminal 30. Furthermore, whether the train is in a tunnel can be determined based on detection signals from illumination sensors provided in the vehicle air conditioner 1 or the railway vehicle 100.

Furthermore, the wind resistance of the outdoor air, in particular, varies between when the train is inside a station and when it is not. Consequently, the physical quantity correlated with the amount of heat exchanger blockage varies between when the train is inside a station and when it is not. Therefore, by acquiring the physical quantity when the train is not inside a station, the conditions for acquiring the physical quantity can be kept nearly constant. The station location information is pre-stored in the ROM of terminal 30. Physical quantities can be acquired when the train is neither inside a tunnel nor inside a station.

In step S3, the terminal 30 activates at least the fan (e.g., outdoor fan 16 or indoor fan 17a, 17b) that is the target of the blockage detection, i.e., the fan that supplies air to the heat exchanger. Specifically, the terminal 30 activates the fan if it is stopped, and continues to operate the fan if it is already running. Furthermore, the terminal 30 may activate the refrigerant circuits 10a, 10b as needed.

Next, in step S4, the terminal 30 obtains physical quantities correlated with the amount of heat exchanger blockage. Examples of physical quantities correlated with the amount of heat exchanger blockage include: the power supplied to the blower, the current flowing through the blower, the blower's rotational speed, the temperature difference between the condensation or evaporation temperature of the refrigerant in the heat exchanger and the temperature of the air supplied to the heat exchanger, and the pressure within the vehicle cabin. These physical quantities are obtained based on detection signals from various sensors. Furthermore, the terminal 30 can calculate the air resistance of the heat exchanger's air path based on the blower's torque calculated using the current and rotational speed, thereby quantifying the amount of heat exchanger blockage. Furthermore, the terminal 30 can also calculate the heat exchange performance of the heat exchanger based on the current and temperature difference, thereby quantifying the amount of heat exchanger blockage.

Next, in step S5, the presence of blockage in the heat exchanger is determined based on the acquired physical quantities. For example, the terminal 30 uses a physical quantity acquired from a vehicle air conditioner installed in another vehicle on the same train as the railway vehicle 100 as a reference physical quantity, compares the physical quantity acquired in step S4 with the reference physical quantity, and determines the presence of blockage in the heat exchanger based on the comparison result. The physical quantity of the vehicle air conditioner installed in the other vehicle can be acquired from, for example, the terminal 30, the central unit 42 or 43, or the onboard communication device 41 of the vehicle air conditioner.

For each vehicle, maintenance of the vehicle air conditioning unit 1 is sometimes performed on different dates. The amount of blockage of the heat exchanger is the smallest immediately after maintenance of the vehicle air conditioning unit 1 is performed, and then slowly increases with the working time of the vehicle air conditioning unit 1 and the travel distance of the railway vehicle 100. Taking this into consideration, it is preferred to use the physical quantity obtained from the vehicle air conditioning unit with the shortest time to maintenance among the multiple vehicle air conditioning units mounted on the train as the reference physical quantity. Alternatively, the past physical quantity obtained from the same vehicle air conditioning unit 1 (for example, the physical quantity initially obtained after maintenance of the vehicle air conditioning unit 1) can also be used as the reference physical quantity. The physical quantities to be compared with each other are preferably obtained when the conditions related to the position or speed of the train are as identical as possible.

For example, when the difference between the physical quantity obtained in step S4 and the reference physical quantity, or the ratio of the physical quantity obtained in step S4 to the reference physical quantity is above a threshold, it is determined that the heat exchanger is clogged; otherwise, it is determined that the heat exchanger is not clogged.

If it is determined that the heat exchanger is clogged (Yes in step S6 ), the process proceeds to step S7 . If it is determined that the heat exchanger is not clogged (No in step S6 ), the process proceeds to step S8 .

In step S7, the terminal 30 notifies the ground system 50 of the blockage in the heat exchanger. For example, the terminal 30 transmits information indicating the blockage in the heat exchanger of the vehicle air conditioner 1 to the central units 42 and 43. The central units 42 and 43 display information indicating which heat exchanger of the vehicle air conditioner 1 is blocked on the display units provided on the central units 42 and 43. Alternatively, the terminal 30 may transmit information indicating the blockage in the heat exchanger of the vehicle air conditioner 1 to the ground system 50 via the on-board communication device 41. The ground system 50 may display information indicating which heat exchanger of the vehicle air conditioner 1 on which train is blocked on the display units provided on the ground system 50.

In step S8, the terminal 30 notifies the ground system 50 that the heat exchanger is not blocked. For example, the terminal 30 transmits information indicating that the heat exchanger in the vehicle air conditioner 1 is not blocked to the central units 42 and 43. The central units 42 and 43 display information indicating which heat exchanger in the vehicle air conditioner 1 is not blocked on a display unit provided on the central units 42 and 43. Alternatively, the terminal 30 may transmit information indicating that the heat exchanger in the vehicle air conditioner 1 is not blocked to the ground system 50 via the on-board communication unit 41. The ground system 50 may display information indicating which heat exchanger in which vehicle air conditioner 1 is not blocked on a display unit provided on the ground system 50.

As described above, the vehicle air conditioner 1 according to this embodiment includes refrigerant circuits 10a and 10b having heat exchangers (e.g., outdoor heat exchangers 15a and 15b, and indoor heat exchangers 13a and 13b); fans (e.g., outdoor fan 16 and indoor fan 17a and 17b) that supply air to the heat exchangers; and a control unit (e.g., terminal 30) that controls the refrigerant circuits 10a and 10b and the fans. The vehicle air conditioner 1 is mounted on a railway vehicle 100. The control unit is configured to acquire a physical quantity correlated with the amount of blockage in the heat exchangers when the position or speed of the railway vehicle 100 satisfies predetermined conditions, and to determine whether the heat exchangers are blocked based on the physical quantity.

In this embodiment, heat exchanger blockage is determined based on physical quantities acquired when the position or speed of the railway vehicle 100 meets specified conditions. This allows for more accurate detection of heat exchanger blockage, as the effects of changes in airflow resistance due to the position or speed of the railway vehicle 100 are limited. Consequently, maintenance of the vehicle air conditioner 1 can be performed at more appropriate times, preventing increased power consumption due to heat exchanger blockage and fan failures caused by increased load. Furthermore, since the heat exchange performance of the heat exchanger is maintained, the comfort level within the vehicle cabin can be improved.

In the vehicle air conditioner 1 according to this embodiment, the control unit may be configured to compare the above physical quantity with a physical quantity acquired from a vehicle air conditioner mounted on a vehicle other than the railway vehicle 100 and determine whether the heat exchanger is clogged based on the comparison result.

In the vehicle air conditioning apparatus 1 according to the present embodiment, the predetermined condition may be that the railway vehicle 100 is not located in a tunnel, or that the speed of the railway vehicle 100 is a specific speed.

In the vehicle air-conditioning device 1 involved in this embodiment, the physical quantity may include any physical quantity among the power supplied to the blower, the current flowing through the blower, the rotational speed of the blower, the temperature difference between the condensation temperature or evaporation temperature of the refrigerant in the heat exchanger and the temperature of the air supplied to the heat exchanger, the pressure in the vehicle cabin, the air resistance of the heat exchanger, and the heat exchange performance of the heat exchanger.

Implementation method 2.

A blockage detection system for a vehicle air conditioner according to a second embodiment of the present invention will be described. While in the first embodiment, heat exchanger blockage detection was performed by terminal 30 of each vehicle air conditioner 1, in this embodiment, heat exchanger blockage detection is performed by ground system 50. The schematic configuration of blockage detection system 2 is the same as that shown in FIG3 .

FIG5 is a flowchart illustrating an example of the flow of physical quantity acquisition processing executed by terminal 30 in congestion detection system 2 of vehicle air conditioner 1 according to this embodiment. The physical quantity acquisition processing is repeatedly executed at predetermined time intervals. Steps S11 through S14 in FIG5 are identical to steps S1 through S4 shown in FIG4 , and therefore their description is omitted.

In step S15 , the terminal 30 transmits the acquired physical quantity information to the ground system 50 via the on-board communication device 41 and the communication network 60 .

FIG6 is a flowchart illustrating an example of the flow of congestion detection processing executed by the ground system 50 in the congestion detection system 2 of the vehicle air conditioner 1 according to this embodiment. The congestion detection processing is repeatedly executed at predetermined time intervals. In step S21 of FIG6 , the ground system 50 receives physical quantity information from the onboard system 40 of a certain train. The ground system 50 stores the received physical quantity information in the database 52. The database 52 stores physical quantity information received from multiple onboard systems 40.

Next, in step S22, the ground system 50 compares the physical quantity acquired from the onboard system 40 of the train in question with the physical quantities acquired from the onboard systems of other trains (e.g., trains traveling before or after the train in question), and determines whether the heat exchanger is clogged based on the comparison results. In this case, the physical quantity acquired from the onboard air conditioner with the shortest time until maintenance is required among the multiple onboard air conditioners installed on the other train is preferably used as the reference physical quantity. Furthermore, the physical quantities being compared are preferably acquired under conditions related to the train's position or speed that are as similar as possible.

If it is determined that the heat exchanger is clogged (Yes in step S23 ), the process proceeds to step S24 . If it is determined that the heat exchanger is not clogged (No in step S23 ), the process proceeds to step S25 .

In step S24, the ground system 50 notifies the user that a blockage has occurred in the heat exchanger. For example, the ground system 50 displays information on a display unit provided within the ground system 50 indicating which vehicle air conditioner 1 on which train has a blockage in its heat exchanger. Alternatively, the ground system 50 may transmit information indicating which vehicle air conditioner 1 has a blockage in its heat exchanger to the onboard system 40 of the train equipped with the vehicle air conditioner 1. In this case, the onboard system 40, upon receiving the information, displays information indicating which vehicle air conditioner 1 has a blockage in its heat exchanger, for example, on a display unit provided within the central unit 42 or 43.

In step S25, the ground system 50 notifies the user that the heat exchanger is not blocked. For example, the ground system 50 displays information on a display unit provided within the ground system 50 indicating which vehicle air conditioner 1 on which train has a heat exchanger that is not blocked. Alternatively, the ground system 50 may transmit information indicating which vehicle air conditioner 1 has a heat exchanger that is not blocked to the onboard system 40 of the train equipped with the vehicle air conditioner 1. In this case, the onboard system 40, upon receiving the information, displays information indicating which vehicle air conditioner 1 has a heat exchanger that is not blocked, for example, on a display unit provided within the central unit 42 or 43.

As described above, the blockage detection system 2 for a vehicle air conditioner 1 according to this embodiment includes refrigerant circuits 10a and 10b having heat exchangers (e.g., outdoor heat exchangers 15a and 15b, and indoor heat exchangers 13a and 13b); blowers (e.g., outdoor blower 16 and indoor blowers 17a and 17b) that supply air to the heat exchangers; a control unit (e.g., onboard communication device 41, central units 42 and 43, and terminal 30) that controls the refrigerant circuits 10a and 10b and the blowers, and the vehicle air conditioner 1 is mounted on a railway vehicle 100; and a ground system 50 connected to the control unit via a communication network 60. The control unit is configured to acquire a physical quantity correlated with the amount of blockage in the heat exchanger when the position or speed of the railway vehicle 100 satisfies a predetermined condition, and transmit the information on the physical quantity to the ground system 50. The ground system 50 is configured to determine whether the heat exchanger is blocked based on the physical quantity.

According to this embodiment, as in the first embodiment, heat exchanger blockage can be detected more accurately. Consequently, vehicle air conditioning system 1 can be maintained at a more appropriate time, preventing increased power consumption due to heat exchanger blockage and blower failure due to increased load. Furthermore, since the heat exchange performance of the heat exchanger is maintained, the comfort level within the vehicle cabin can be improved.

In the blockage detection system 2 for the vehicle air conditioning unit 1 according to this embodiment, the ground system 50 may be configured to compare the above-mentioned physical quantity with a physical quantity obtained from a vehicle air conditioning unit mounted on a vehicle other than the railway vehicle 100, and determine whether the heat exchanger is blocked based on the comparison result.

The above-mentioned embodiments can be implemented in combination with each other.

Description of labels

1 Vehicle air conditioning system, 2 Blockage detection system, 10a, 10b Refrigerant circuit, 11a, 11b Compressor, 12a, 12b Four-way valve, 13a, 13b Indoor heat exchanger, 14a, 14b Pressure reducing device, 15a, 15b Outdoor heat exchanger, 16 Outdoor blower, 17a, 17b Indoor blower, 20 Outdoor room, 21a, 21b Indoor room, 30 Terminal, 40 Onboard system, 41 Onboard communication device, 42, 43 Central unit, 50 Ground system, 51 Ground communication device, 52 Database, 60 Communication network, 100 Railway vehicle, 101 Carriage, 102 Air supply duct

Claims (7)

1. A vehicle air conditioning unit, comprising a refrigerant circuit having a heat exchanger, a blower for supplying air to the heat exchanger, and a control unit for controlling the refrigerant circuit and the blower, the vehicle air conditioning unit being mounted in a vehicle, characterized in that, The control unit is configured as follows: When the vehicle's position meets specified conditions, a physical quantity related to the amount of blockage in the heat exchanger is obtained. The physical quantity is compared with a reference value of the physical quantity obtained when the conditions related to the vehicle's position are the same as those when the physical quantity was obtained. Based on the comparison result, it is determined whether the heat exchanger is blocked. 2. The vehicle air conditioning unit as described in claim 1, characterized in that, The control unit compares the physical quantity with a reference value of the physical quantity obtained from a vehicle air conditioning unit installed in another vehicle different from the vehicle, and determines whether the heat exchanger is blocked based on the comparison result. 3. The vehicle air conditioning unit as described in claim 1 or 2, characterized in that, The specified condition is that the vehicle is not located inside the tunnel. 4. The vehicle air conditioning unit as described in claim 1 or 2, characterized in that, The specified condition is that the vehicle is not located within the station. 5. The vehicle air conditioning unit as described in claim 1 or 2, characterized in that, The physical quantities include any physical quantity among the following: the power supplied to the blower, the current flowing through the blower, the rotational speed of the blower, the temperature difference between the condensation or evaporation temperature of the refrigerant in the heat exchanger and the temperature of the air supplied to the heat exchanger, the pressure inside the carriage, the air resistance of the heat exchanger, and the heat exchange performance of the heat exchanger. 6. A blockage detection system for a vehicle air conditioning unit, characterized in that it comprises: A vehicle air conditioning unit, comprising a refrigerant circuit having a heat exchanger, a blower for supplying air to the heat exchanger, and a control unit for controlling the refrigerant circuit and the blower, the vehicle air conditioning unit being mounted in a vehicle; and A ground system, which is connected to the control unit via a communication network. The control unit is configured as follows: When the vehicle's position meets specified conditions, a physical quantity related to the amount of blockage in the heat exchanger is obtained. The information of the physical quantity is sent to the ground system. The ground system compares the physical quantity with a reference value obtained when the physical quantity is acquired under conditions related to the vehicle's position and when the physical quantity is acquired. Based on the comparison result, it determines whether the heat exchanger is blocked. 7. The blockage detection system for a vehicle air conditioning unit as described in claim 6, characterized in that, The ground system compares the physical quantity with a reference value of the physical quantity obtained from the air conditioning unit of a vehicle on another train that is different from the vehicle, and determines whether the heat exchanger is blocked based on the comparison result.