Air conditioning system for railway vehicle

Abstract

In an air conditioning system for a railway vehicle, when it is determined that refrigerant has leaked from refrigerant circuits (150A, 150B) on the basis of a detection result from a refrigerant leak detector (180), a control device switches an emergency damper (176d) from an inside air circulation state to an inside air non-circulation state while keeping an indoor fan (162) operating, and when a first fresh damper (172d) is in a non-ventilation state, the control device switches the first fresh damper (172d) from the non-ventilation state to a ventilation state. By controlling an exhaust fan and a second fresh damper (220d), the control device facilitates direct ventilation to a greater extent than when refrigerant is not leaking from the refrigerant circuits (150A, 150B). In direct ventilation, outside air is directly taken into the passenger cabin through a ventilation chamber (210r), while inside air in the passenger cabin is exhausted to the outside (EX) through an exhaust chamber.

Description

Railway vehicle air conditioning systems

[0001] The present disclosure relates to an air conditioning system for a rail vehicle.

[0002] A railway vehicle air conditioner installed in a railway vehicle uses a refrigerant circuit through which a refrigerant circulates to condition the passenger compartment. Here, "cabin" refers to the space in a railway vehicle designated for passengers. The refrigerant circuit generates the heat or cold required to condition the passenger compartment by forming a refrigeration cycle using the refrigerant.

[0003] In some cases, a closable damper is provided in the housing that houses the refrigerant circuit to allow outside air to be drawn into the airtight passenger compartment. The damper serves to draw outside air into the housing. When the damper is open, the outside air drawn into the housing through the damper is sent into the passenger compartment together with air whose temperature has been adjusted using the refrigerant circuit.

[0004] As disclosed in Patent Document 1, a railroad vehicle air conditioner is known that not only takes in outside air through a damper but also detects refrigerant leaks from the refrigerant circuit. This railroad vehicle air conditioner includes an exhaust fan that exhausts air from the passenger compartment to the outside, in addition to an interior fan that circulates air between the passenger compartment and the interior of the housing. When a refrigerant leak is detected, the exhaust fan is activated with the damper open.

[0005] International Publication No. 2021 / 144907

[0006] The railway vehicle air conditioning system disclosed in Patent Document 1 can quickly discharge refrigerant leaking from the refrigerant circuit to the outside, thereby suppressing the concentration of refrigerant in the passenger compartment even if refrigerant leaks from the refrigerant circuit.

[0007] An object of the present disclosure is to provide an air conditioning system for railway vehicles that has improved safety performance in suppressing the concentration of refrigerant in the passenger compartment.

[0008] The railway vehicle air conditioning system according to the present disclosure includes: an indoor unit room defining section defining an indoor unit room, the indoor unit room being formed with a return port and a supply port, each of which communicates with the passenger compartment of the railway vehicle, and a ventilation port communicating with the outside; an indoor fan disposed in the indoor unit room, which draws in internal air, which is the air in the passenger compartment, from the return port and discharges the drawn internal air toward the supply port, thereby forming a flow of internal air in the indoor unit room from the return port toward the supply port; a refrigerant circuit disposed in a position through which the flow of internal air passes in the indoor unit room, the refrigerant circuit having an indoor heat exchanger which exchanges heat between a refrigerant and the internal air, and a group of cooperating devices which use the refrigerant to form a refrigeration cycle together with the indoor heat exchanger; a first fresh damper disposed at the ventilation port, which is switchable between a ventilation state in which the external air, which is the external air, is mixed with the internal air flowing into the indoor heat exchanger by opening the ventilation port, and a non-ventilation state in which the ventilation port is closed; and a refrigerant leakage detector which detects leakage of the refrigerant from the refrigerant circuit. an exhaust chamber defining section that defines an exhaust chamber isolated from the indoor unit chamber and that has an inside air intake port that communicates with the vehicle cabin and an inside air exhaust port that communicates with the outside; an exhaust fan that is disposed in the exhaust chamber and that draws inside air from the inside air intake port into the exhaust chamber and exhausts the drawn inside air to the outside through the inside air exhaust port; and a control device that controls the first fresh damper and the exhaust fan, wherein the indoor unit chamber defining section is further formed with a leaked refrigerant discharge port that communicates with the outside, at a position downstream of the indoor heat exchanger with respect to the flow of the inside air in the indoor unit chamber, and the railway vehicle air conditioning system comprises: an emergency damper that is disposed in the indoor unit chamber and that can be switched between an inside air circulation state in which the leaked refrigerant discharge port is closed and the supply port is open, and an inside air non-circulation state in which the leaked refrigerant discharge port is opened and the supply port is closed; a direct ventilation chamber defining section defining a direct ventilation chamber isolated from the indoor unit chamber and the exhaust chamber, the direct ventilation chamber defining section including an outside air intake port communicating with the outside and an outside air supply port communicating with the vehicle compartment; and a second fresh damper provided at the outside air intake port for controlling the inflow of the outside air from the outside into the direct ventilation chamber.When it is determined that the refrigerant has leaked from the refrigerant circuit based on the detection result of the refrigerant leak detector, the control device performs: (I) indoor unit compartment ventilation control that switches the emergency damper from the inside air circulation state to the inside air non-circulation state while keeping the indoor fan operating, and, if the first fresh damper is in the non-ventilation state, switches the first fresh damper from the non-ventilation state to the ventilation state; and (II) passenger compartment ventilation control that controls the exhaust fan and the second fresh damper to promote direct ventilation, in which the outside air is taken into the passenger compartment through the direct ventilation chamber while the inside air in the passenger compartment is discharged to the outside through the exhaust chamber, more than when the refrigerant is not leaking from the refrigerant circuit.

[0009] According to the above configuration, when it is determined that refrigerant has leaked from the refrigerant circuit, the supply port is closed by the indoor unit compartment ventilation control, thereby preventing the flow of inside air that may contain the leaked refrigerant from the indoor unit compartment into the vehicle interior.

[0010] Furthermore, in the passenger compartment, direct ventilation through the direct ventilation chamber and the exhaust chamber is promoted by the passenger compartment ventilation control, so that even if a refrigerant leak occurs, the concentration of the refrigerant in the passenger compartment is sufficiently suppressed.

[0011] Furthermore, with the indoor unit compartment ventilation control, the indoor unit compartment is also ventilated through the ventilation opening and the leaked refrigerant discharge opening while the supply opening is closed, thereby eliminating the cause of an increase in the refrigerant concentration in the vehicle cabin.

[0012] As a result, the safety performance of suppressing the concentration of refrigerant in the passenger compartment is further improved.

[0013] Conceptual diagram showing the configuration of an air conditioning system for railway vehicles according to embodiment 1. Conceptual diagram showing the configuration of an air conditioner according to embodiment 1. Flowchart of air conditioning control according to embodiment 1. Conceptual diagram showing the configuration of an air conditioning system for railway vehicles according to modified example 1 of embodiment 1. Conceptual diagram showing the configuration of an air conditioning system for railway vehicles according to modified example 2 of embodiment 1. Conceptual diagram showing the configuration of an air conditioner according to modified example 3 of embodiment 1. Conceptual diagram showing the configuration of an air conditioner according to embodiment 2. Conceptual diagram showing the configuration of an air conditioner according to modified example 1 of embodiment 2. Conceptual diagram showing the configuration of an air conditioner according to embodiment 3. Flowchart of air conditioning control according to embodiment 3. Conceptual diagram showing the configuration of an air conditioner according to modified example 1 of embodiment 3. Conceptual diagram showing the configuration of an air conditioner according to embodiment 4. Conceptual diagram: Conceptual diagram showing the configuration of an air conditioner according to Modification 2 of Embodiment 4. Conceptual diagram showing the configuration of an air conditioner according to Embodiment 5. Conceptual diagram showing the configuration of an air conditioner according to Modification 1 of Embodiment 5. Conceptual diagram showing the configuration of an air conditioner according to Modification 2 of Embodiment 5. Conceptual diagram showing the configuration of an air conditioning system for railway vehicles according to Embodiment 6. Flowchart of air conditioning control according to Embodiment 6. Conceptual diagram showing the configuration of an air conditioner according to Embodiment 7. Conceptual diagram showing the configuration of an air conditioner according to Embodiment 8. Conceptual diagram showing the configuration of an air conditioner according to Modification 1 of Embodiment 8. Conceptual diagram showing the configuration of an air conditioner according to Modification 2 of Embodiment 8. Conceptual diagram showing the configuration of an exhaust device according to Embodiment 9. Conceptual diagram showing the configuration of an exhaust device according to Modification 1 of Embodiment 9. Conceptual diagram showing the configuration of an air conditioning system for railway vehicles according to Embodiment 10.

[0014] Hereinafter, a railway vehicle air conditioning system according to an embodiment will be described with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0015] [Embodiment 1] As shown in Fig. 1, a railway vehicle air conditioning system 800 according to this embodiment is installed in a railway vehicle 900. For ease of understanding, a right-handed XYZ Cartesian coordinate system is defined, having an X axis parallel to the longitudinal direction of the railway vehicle 900, a Y axis parallel to the width direction of the railway vehicle 900, and a Z axis parallel to the vertical direction. The direction pointing vertically upward is the positive direction of the Z axis. The XYZ Cartesian coordinate system is shown in Fig. 1 and in drawings referred to later.

[0016] The railway vehicle air conditioning system 800 according to this embodiment includes an air conditioner 100 that conditions the cabin 910 of the railway vehicle 900, a direct ventilation device 200 that takes in outside EX air (hereinafter also referred to as outside air) into the cabin 910, an exhaust device 300 that exhausts air from the cabin 910 (hereinafter also referred to as inside air) to the outside EX, and a control device 400 that controls the air conditioner 100, the direct ventilation device 200, and the exhaust device 300. The cabin 910 is specifically a passenger compartment.

[0017] The air conditioning device 100 and the direct ventilation device 200 are installed on the roof of the railway vehicle 900. The exhaust device 300 is installed under the floor of the railway vehicle 900.

[0018] The air conditioner 100 not only has the function of conditioning the vehicle interior 910, but also has the function of sending fresh outside air into the vehicle interior 910. The direct ventilation device 200 has the function of taking in fresh outside air into the vehicle interior 910 independently of the air conditioner 100.

[0019] The configurations of the air conditioner 100 and the direct ventilation device 200 will be specifically described with reference to FIG.

[0020] First, a description will be given of the air conditioner 100. The air conditioner 100 includes two refrigerant circuits 150A and 150B. A refrigerant is sealed in each of the two refrigerant circuits 150A and 150B.

[0021] The refrigerant used is one having a higher specific gravity than air, specifically one containing 95% by mass or more of propane or other hydrocarbons or carbon dioxide.

[0022] One refrigerant circuit 150A has a compressor 151 that compresses the refrigerant, an outdoor heat exchanger 152 that functions as a condenser that condenses the compressed refrigerant, an expander 153 that expands the condensed refrigerant, an indoor heat exchanger 154 that functions as an evaporator that evaporates the expanded refrigerant, and refrigerant piping 155 that connects the compressor 151, the outdoor heat exchanger 152, the expander 153, and the indoor heat exchanger 154.

[0023] The other refrigerant circuit 150B similarly includes a compressor 156, an outdoor heat exchanger 157 that functions as a condenser, an expander 158, and refrigerant piping 159 that connects the compressor 156, the outdoor heat exchanger 157, and the expander 158.

[0024] The indoor heat exchanger 154 is shared by both the refrigerant circuit 150A and the refrigerant circuit 150B. However, inside the indoor heat exchanger 154, the path through which the refrigerant sealed in the refrigerant circuit 150A flows and the path through which the refrigerant sealed in the refrigerant circuit 150B flows are independent of each other. Therefore, the refrigerant sealed in the refrigerant circuit 150A and the refrigerant sealed in the refrigerant circuit 150B do not mix with each other.

[0025] In one refrigerant circuit 150A, the compressor 151, the outdoor heat exchanger 152, the expander 153, and the refrigerant piping 155 are a group of cooperative equipment that configures a refrigeration cycle together with the indoor heat exchanger 154. Similarly, in the other refrigerant circuit 150B, the compressor 156, the outdoor heat exchanger 157, the expander 158, and the refrigerant piping 159 are a group of cooperative equipment that configures a refrigeration cycle together with the indoor heat exchanger 154.

[0026] Each of the refrigerant circuits 150A and 150B may be configured to be switchable between a cooling state in which the outdoor heat exchangers 152 and 157 function as condensers and the indoor heat exchanger 154 functions as an evaporator, and a heating state in which the outdoor heat exchangers 152 and 157 function as evaporators and the indoor heat exchanger 154 functions as a condenser. Such switching is achieved using a four-way valve.

[0027] The air conditioning system 100 also includes an outdoor fan 161 that promotes heat exchange between the refrigerant inside the outdoor heat exchangers 152 and 157 and the outside air, and an indoor fan 162 that promotes heat exchange between the refrigerant inside the indoor heat exchanger 154 and the inside air.

[0028] The air conditioner 100 also includes a housing 110 that is installed in the railway vehicle 900. The housing 110 defines an outdoor unit room 120r and an indoor unit room 130r that are aligned in the X-axis direction.

[0029] Specifically, the housing 110 has an outdoor unit room defining portion 120 that defines an outdoor unit room 120r. The outdoor unit room 120r is further divided into a compressor room 121r and an outdoor heat exchange room 122r that are aligned in the X-axis direction. The compressor room 121r is located at the end in the X-axis direction.

[0030] That is, the outdoor unit room defining portion 120 has a compressor room defining portion 121 that defines a compressor room 121r. The compressor room 121r is disconnected from the vehicle interior 910. Compressors 151 and 156 are housed in the compressor room 121r.

[0031] The outdoor unit room defining portion 120 also has an outdoor heat exchange room defining portion 122 that defines an outdoor heat exchange room 122r. The outdoor heat exchange room 122r is disconnected from the vehicle interior 910 and is connected to the outside EX. The outdoor heat exchange room 122r houses outdoor heat exchangers 152 and 157, expanders 153 and 158, and an outdoor fan 161.

[0032] The housing 110 also has an indoor unit compartment defining portion 130 that defines an indoor unit compartment 130r. The indoor unit compartment 130r is connected to the vehicle interior 910. The indoor unit compartment 130r is further divided into a return chamber 131r, an indoor heat exchange chamber 132r, and a supply chamber 133r, which are aligned in the X-axis direction. The return chamber 131r is located next to the outdoor heat exchange chamber 122r.

[0033] Specifically, the indoor unit compartment defining portion 130 has a return compartment defining portion 131 that defines a return compartment 131r. Refrigerant pipes 155 and 159 pass through the return compartment 131r. The return compartment defining portion 131 also has a return port 171 that communicates with the passenger compartment 910 and a ventilation port 172 that communicates with the outside EX. The return compartment 131r communicates with the passenger compartment 910 via the return port 171 and with the outside EX via the ventilation port 172.

[0034] A return damper 171d is provided at the return port 171. The return damper 171d can be switched between a return permitting state in which the return chamber 131r communicates with the casing 910 and a return blocking state in which the communication between the return chamber 131r and the casing 910 is cut off.

[0035] A first fresh damper 172d is provided in the ventilation port 172. The first fresh damper 172d can be switched between a ventilation state in which the return chamber 131r is connected to the outside EX by opening the ventilation port 172, and a non-ventilation state in which the communication between the return chamber 131r and the outside EX is cut off by closing the ventilation port.

[0036] The indoor unit room defining portion 130 has an indoor heat exchange room defining portion 132 that defines an indoor heat exchange room 132r. The indoor heat exchange room 132r houses an indoor heat exchanger 154 and an indoor fan 162. Refrigerant pipes 155 and 159 connected to the indoor heat exchanger 154 also pass through the indoor heat exchange room 132r.

[0037] The indoor heat exchange chamber 132r is in communication with the return chamber 131r. The indoor heat exchanger 154 is disposed in an opening that connects the indoor heat exchange chamber 132r and the return chamber 131r.

[0038] The indoor unit chamber defining portion 130 also has a supply chamber defining portion 133 that defines a supply chamber 133r. The supply chamber defining portion 133 is provided with a communication port 173 that connects the supply chamber 133r to the indoor heat exchange chamber 132r, and a supply port 174 that leads to the vehicle interior 910.

[0039] The following describes the operation of the indoor fan 162 when air-conditioning the vehicle compartment 910. When air-conditioning the vehicle compartment 910, the return damper 171d is set to the previously described return permitting state. The indoor fan 162 generates a flow of inside air from the return port 171 toward the supply port 174 in the indoor unit compartment 130r.

[0040] Specifically, the indoor fan 162 draws the inside air of the vehicle interior 910 into the return chamber 131r through the return port 171. The inside air drawn into the return chamber 131r passes through the indoor heat exchanger 154.

[0041] Due to the operation of the compressors 151 and 156, the indoor heat exchanger 154 is in a cooled or heated state. Therefore, the temperature of the indoor air is adjusted by passing through the indoor heat exchanger 154. The indoor air that has passed through the indoor heat exchanger 154 passes through the communication port 173 and is returned to the passenger compartment 910 through the supply port 174.

[0042] The indoor fan 162 is disposed downstream of the indoor heat exchanger 154 in terms of the flow of internal air in the indoor unit room 130r. That is, the indoor fan 162 draws internal air from the vehicle interior 910 via the indoor heat exchanger 154 and discharges the drawn internal air toward the supply port 174.

[0043] When fresh outside air is to be sent into the passenger compartment 910, the first fresh damper 172d is set to the ventilation state described above. As a result, fresh outside air is taken into the return chamber 131r through the opened ventilation port 172. The taken-in outside air merges with the inside air flowing into the indoor heat exchanger 154 and is then sent into the passenger compartment 910 together with the inside air.

[0044] In this way, the indoor fan 162 not only serves to circulate the indoor air between the passenger compartment 910 and the indoor unit room 130r, but also serves to draw fresh outside air into the indoor unit room 130r through the open ventilation opening 172.

[0045] In this embodiment, "air conditioning" is a concept that includes not only adjusting the temperature of the inside air using the indoor heat exchanger 154 by operating the compressors 151 and 156, but also sending fresh outside air into the passenger compartment 910 through the ventilation opening 172 while the compressors 151 and 156 are stopped.

[0046] Incidentally, an accidental malfunction may occur, causing refrigerant to leak from at least one of the refrigerant circuits 150A and 150B while the vehicle interior 910 is being air-conditioned. If refrigerant leaks from the refrigerant circuits 150A and 150B, the leaked refrigerant may flow into the vehicle interior 910, which may reduce the oxygen concentration in the vehicle interior 910.

[0047] Therefore, the air conditioner 100 according to this embodiment is provided with a configuration for detecting refrigerant leakage and a configuration for quickly discharging leaking refrigerant to the outside EX. These configurations will be described below.

[0048] The air conditioning system 100 includes a refrigerant leak detector 180 that detects refrigerant leakage from the refrigerant circuits 150A and 150B. The refrigerant leak detector 180 is disposed in the indoor unit room 130r. Specifically, the refrigerant leak detector 180 is disposed downstream of the indoor heat exchanger 154 and the refrigerant pipes 155 and 159 with respect to the flow of indoor air formed by the indoor fan 162. The control device 400 shown in FIG. 1 determines whether a refrigerant leak has occurred based on the detection result of the refrigerant leak detector 180.

[0049] Furthermore, the indoor unit room defining portion 130, specifically the supply room defining portion 133, is further formed with a leaked refrigerant discharge port 175 that communicates with the outside EX.

[0050] The leaked refrigerant discharge port 175 is for discharging the leaked refrigerant to the outside EX when a refrigerant leak occurs from at least one of the indoor heat exchanger 154 and the refrigerant pipes 155 and 159 connected to the indoor heat exchanger 154. For this reason, the leaked refrigerant discharge port 175 is disposed downstream of the indoor heat exchanger 154 and the refrigerant pipes 155 and 159 with respect to the flow of indoor air in the indoor unit room 130r.

[0051] The air conditioner 100 further includes an emergency damper 176d. The emergency damper 176d is disposed in the indoor unit room 130r, specifically, in the supply room 133r. The emergency damper 176d is switchable between an inside air circulation state in which the leaked refrigerant discharge port 175 is closed and the supply port 174 is open, and an inside air non-circulation state in which the leaked refrigerant discharge port 175 is open and the supply port 174 is closed.

[0052] When a refrigerant leak occurs, the emergency damper 176d is switched from the inside air recirculation state to the inside air non-circulation state by the control device 400 shown in FIG.

[0053] Next, the configuration of the direct ventilation device 200 will be specifically described.

[0054] The direct ventilation device 200 has a direct ventilation chamber defining portion 210 that defines a direct ventilation chamber 210r. The direct ventilation chamber 210r is isolated from the interior of the housing 110, which includes the indoor unit chamber 130r of the air conditioning device 100.

[0055] The direct ventilation chamber defining portion 210 is formed with an outside air intake port 220 that communicates with the outside EX and an outside air supply port 230 that communicates with the passenger compartment 910. The direct ventilation chamber 210r is in communication with the outside EX through the outside air intake port 220, and is in communication with the passenger compartment 910 through the outside air supply port 230.

[0056] The direct ventilation device 200 also has a second fresh damper 220d provided in the outdoor air intake port 220. The second fresh damper 220d serves to control the inflow of outdoor air from the outside EX into the direct ventilation chamber 210r. Specifically, the second fresh damper 220d can be switched between an outdoor air intake permitting state in which the outdoor air intake port 220 is open and an outdoor air intake prohibiting state in which the outdoor air intake port 220 is closed.

[0057] Next, returning to FIG. 1, the configuration of the exhaust device 300 will be specifically described.

[0058] 1, the exhaust device 300 has an exhaust chamber defining portion 310 that defines an exhaust chamber 310r. The exhaust chamber 310r is isolated from the interior of the housing 110, including the indoor unit chamber 130r of the air conditioner 100, and from the direct ventilation chamber 210r.

[0059] An inside air intake port 320 that communicates with the vehicle interior 910 and an inside air exhaust port 330 that communicates with the outside EX are formed in the exhaust chamber defining portion 310. The exhaust chamber 310r is in communication with the vehicle interior 910 through the inside air intake port 320, and is in communication with the outside EX through the inside air exhaust port 330.

[0060] The exhaust device 300 also has an exhaust fan 340 disposed in the exhaust chamber 310r. The exhaust fan 340 draws the inside air of the vehicle interior 910 into the exhaust chamber 310r through the inside air inlet 320, and exhausts the drawn inside air to the outside EX through the inside air exhaust port 330.

[0061] Hereinafter, the air conditioning control performed by the control device 400 will be described with reference to FIG.

[0062] As a premise, the control device 400 sets the emergency damper 176d to an internal air circulation state, the return damper 171d to a return-permitting state, the first fresh damper 172d to a non-ventilation state, the second fresh damper 220d to a state prohibiting outside air intake, and stops the exhaust fan 340.

[0063] In this state, the control device 400 starts air conditioning of the vehicle interior 910 (step S11). Specifically, the control device 400 starts the indoor fan 162, the outdoor fan 161, and the compressors 151 and 156.

[0064] Furthermore, the control device 400 switches the first fresh damper 172d to a ventilation state as necessary in order to send fresh outside air into the passenger compartment 910. Specifically, the control device 400 switches the first fresh damper 172d to the ventilation state when the conductor operates the device to take in outside air or when a predetermined condition is met.

[0065] The control device 400 may operate the indoor fan 162 while stopping the outdoor fan 161 and the compressors 151 and 156. In this case, so-called free cooling is performed in which fresh outside air is sent into the passenger compartment 910 through the first fresh damper 172d in a ventilation state.

[0066] Next, the control device 400 determines whether or not a refrigerant leak has occurred based on the detection result of the refrigerant leak detector 180 (step S12). If it is determined that a refrigerant leak has not occurred (step S12; NO), the process returns to step S12. In this way, the refrigerant leak detector 180 and the control device 400 constantly monitor for the presence or absence of a refrigerant leak.

[0067] When the control device 400 determines that the refrigerant has leaked (step S12; YES), it performs indoor unit room ventilation control to ventilate the indoor unit room 130r.

[0068] Specifically, the control device 400 stops the compressors 151 and 156 and the outdoor fan 161 while keeping the indoor fan 162 running, switches the emergency damper 176d from an internal air circulation state to an internal air non-circulation state, and switches the return damper 171d from a return-permitting state to a return-blocking state (step S13).

[0069] It should be noted that even during free cooling, refrigerant leakage may occur due to an accidental malfunction. In this case, the compressors 151 and 156 and the outdoor fan 161 are already stopped, so stopping the compressors 151 and 156 and the outdoor fan 161 in step S13 is omitted.

[0070] Next, the control device 400 determines whether the first fresh damper 172d is in a ventilation state (step S14). If the first fresh damper 172d is in a non-ventilation state (step S14; NO), the control device 400 switches the first fresh damper 172d from a non-ventilation state to a ventilation state (step S15). If the first fresh damper 172d is already in a ventilation state (step S14; YES), the process proceeds to step S16, which will be described later.

[0071] According to the above-described indoor unit room ventilation control, the indoor fan 162 creates a flow of outside air in the indoor unit room 130r from the first fresh damper 172d in a ventilated state to the leaked refrigerant discharge port 175. Refrigerant leaking from at least one of the indoor heat exchanger 154, the refrigerant pipe 155, and the refrigerant pipe 159 is discharged to the outside EX from the leaked refrigerant discharge port 175 together with the flow of outside air created in the indoor unit room 130r.

[0072] The control device 400 also performs cabin ventilation control to ventilate the cabin 910 independently of the ventilation of the indoor unit room 130r.

[0073] Specifically, the control device 400 switches the second fresh damper 220d from the outside air intake prohibition state to the outside air intake permission state (step S16).The control device 400 also starts the exhaust fan 340 (step S17).

[0074] According to the above-described vehicle cabin ventilation control, direct ventilation is performed in which outside air is taken into the vehicle cabin 910 through the direct ventilation chamber 210r, while the inside air in the vehicle cabin 910 is exhausted to the outside EX through the exhaust chamber 310r. Note that, because the direct ventilation chamber 210r is isolated from the indoor unit compartment 130r and there is no source of refrigerant leakage in the direct ventilation chamber 210r, refrigerant will not flow from the direct ventilation chamber 210r into the vehicle cabin.

[0075] As described above, according to this embodiment, when it is determined that refrigerant has leaked from at least one of the refrigerant circuits 150A and 150B, the indoor unit compartment ventilation control closes the supply port 174. This blocks the flow of inside air, which may contain the leaked refrigerant, from the indoor unit compartment 130r to the passenger compartment 910.

[0076] Furthermore, in the passenger compartment 910, direct ventilation is performed through the direct ventilation chamber 210r and the exhaust chamber 310r by the passenger compartment ventilation control. Therefore, even if a refrigerant leak occurs, the concentration of the refrigerant in the passenger compartment 910 is sufficiently suppressed.

[0077] Furthermore, according to the indoor unit room ventilation control, with the supply port 174 and the return port 171 closed, the indoor unit room 130r is also ventilated through the ventilation port 172 and the leaked refrigerant discharge port 175. This eliminates the cause of an increase in the refrigerant concentration in the passenger compartment 910. As a result, the safety performance of suppressing the refrigerant concentration in the passenger compartment 910 is improved compared to conventional methods.

[0078] Furthermore, according to the railway vehicle air conditioning system 800 of this embodiment, even if the railway vehicle 900 is not provided with openable / closable windows, the direct ventilation device 200 and the exhaust device 300 can directly ventilate the passenger compartment 910. Furthermore, even if the railway vehicle 900 is provided with openable / closable windows, the passenger compartment 910 can be sufficiently directly ventilated without the need to perform dangerous actions such as opening and closing windows while traveling at high speed.

[0079] On the other hand, during the period from when air conditioning of the passenger compartment 910 is started in step S11 in Fig. 3 until it is determined in step S12 in Fig. 3 that a refrigerant leak has occurred (hereinafter referred to as the normal air conditioning period), the second fresh damper 220d is set to the outside air intake prohibition state and the exhaust fan 340 is stopped. Therefore, the air pressure in the passenger compartment 910 can be maintained at an appropriate value that provides comfort to passengers.

[0080] 1 illustrates a configuration in which the direct ventilation device 200 is installed at a position horizontally separated from the air conditioning device 100. Specifically, in FIG. 1, the direct ventilation chamber defining portion 210 of the direct ventilation device 200 is separated from the housing 110 of the air conditioning device 100 in the X-axis direction. However, the position at which the direct ventilation device 200 is installed is not particularly limited.

[0081] As shown in Fig. 4, the direct ventilation device 200 may be in contact with the air conditioning device 100. Specifically, in Fig. 4, the direct ventilation room defining portion 210 of the direct ventilation device 200 is placed on top of the housing 110 of the air conditioning device 100.

[0082] The direct ventilation device 200 according to this modification has a communication air duct 240 that connects the outside air supply port 230 shown in FIG. 2 with the vehicle interior 910. The communication air duct 240 passes through the inside of the housing 110 of the air conditioner 100.

[0083] 4 illustrates a configuration in which the direct ventilation device 200 is disposed above the air conditioning device 100, the direct ventilation device 200 may also be disposed below the air conditioning device 100. In this case, the communication air duct 240 is not necessary.

[0084] [Second Modification of First Embodiment] As shown in Fig. 5, the direct ventilation device 200 may be provided inside the body of a railway vehicle 900. In this case, the length of the duct (not shown) that connects the outside air supply port 230 shown in Fig. 2 with the vehicle interior 910 can be shortened.

[0085] [Variation 3 of Embodiment 1] Figure 2 illustrates a configuration in which the leaked refrigerant discharge port 175 is formed in the supply chamber defining portion 133, but the position of the leaked refrigerant discharge port 175 is not particularly limited as long as it is located downstream of the indoor heat exchanger 154.

[0086] 6, the leaked refrigerant discharge port 175 may be formed in the indoor heat exchange chamber defining portion 132. Also, an emergency damper 176d may be disposed in the indoor heat exchange chamber 132r. The emergency damper 176d according to this modification opens and closes the supply port 174 indirectly by opening and closing the communication port 173.

[0087] In other words, the emergency damper 176d of this modified example can be switched between an internal air circulation state in which the leaked refrigerant discharge port 175 is blocked and the communication port 173 is opened, thereby indirectly opening the supply port 174, and an internal air non-circulation state in which the leaked refrigerant discharge port 175 is opened and the communication port 173 is blocked, thereby indirectly blocking the supply port 174.

[0088] In the first embodiment, the second fresh damper 220d is set to the outside air intake prohibition state and the exhaust fan 340 is kept stopped during the normal air conditioning period. In other words, the direct ventilation described above is not performed during the normal air conditioning period.

[0089] However, direct ventilation may also be performed during the normal air conditioning period, and when it is determined that a refrigerant leak has occurred, direct ventilation may be promoted more than when there is no refrigerant leak. Here, "promoting direct ventilation" means increasing the flow rate per unit time of outside air taken into the passenger compartment 910 through the direct ventilation chamber 210r and the flow rate per unit time of inside air discharged to the outside EX through the exhaust chamber 310r.

[0090] The second fresh damper 220d may have an adjustable opening, i.e., an adjustable amount of outside air flowing from the outside EX into the direct ventilation chamber 210r. In this case, when the control device 400 determines that a refrigerant leak has occurred, it can increase the opening of the second fresh damper 220d, i.e., increase the amount of outside air flowing from the outside EX into the direct ventilation chamber 210r, thereby promoting direct ventilation.

[0091] The exhaust fan 340 may have a configuration that allows for adjustment of the rotation speed, specifically, a configuration that allows for inverter control. In this case, when the control device 400 determines that a refrigerant leak has occurred, it can promote direct ventilation by increasing the rotation speed of the exhaust fan 340.

[0092] [Fifth Modification of First Embodiment] The indoor fan 162 may have a configuration that allows adjustment of the rotation speed, specifically, a configuration that allows inverter control. In this case, when the control device 400 determines that a refrigerant leak has occurred, it may increase the rotation speed of the indoor fan 162 compared to that during normal air conditioning. This allows the refrigerant leaking in the indoor unit room 130r to be quickly discharged to the outside EX.

[0093] 2 illustrates a configuration in which a plurality of supply ports 174, specifically two supply ports 174, are formed in the indoor unit room defining portion 130. However, only one supply port 174 may be formed in the indoor unit room defining portion 130.

[0094] As shown in Figure 2, when multiple supply ports 174 are formed in the supply chamber defining portion 133, the supply chamber 133r serves to distribute the indoor air that has passed through the indoor heat exchanger 154 to each of the multiple supply ports 174.

[0095] Each of the plurality of supply ports 174 is connected, via a separate duct, to a separate air outlet that opens to the inner surface of the vehicle interior 910. The air outlet that is connected to any one supply port 174 selected from the plurality of supply ports 174 is different from the air outlets that are connected to the other supply ports 174. In other words, there is a one-to-one correspondence between the supply ports 174 and the air outlets.

[0096] As a specific example, if two supply ports 174 are formed in the supply chamber defining portion 133 and the railway vehicle 900 has a two-story structure, the internal air distributed to one of the supply ports 174 is blown out from an outlet opening on the first floor of the railway vehicle 900, and the internal air distributed to the other supply port 174 is blown out from an outlet opening on the second floor of the railway vehicle 900.

[0097] [Embodiment 2] As shown in Fig. 7, the air conditioning device 100 according to this embodiment further includes an indoor unit room electric heater 190 arranged in the indoor unit room 130r. Other configurations are the same as those shown in Fig. 2.

[0098] Specifically, the indoor unit room electric heater 190 is installed in the supply room 133r. During the normal air conditioning period, the indoor unit room electric heater 190 heats the indoor air that is drawn in from the return port 171 by the indoor fan 162 and directed toward the supply port 174 by Joule heat.

[0099] As described above, each of the refrigerant circuits 150A and 150B may be switchable between a cooling state and a heating state. Even if each of the refrigerant circuits 150A and 150B is switchable to a heating state, the inside air can be heated not only by the indoor heat exchanger 154 as a condenser but also by the indoor unit room electric heater 190.

[0100] In this embodiment, the control device 400 checks whether power is being supplied to the indoor unit room electric heater 190 during indoor unit room ventilation control, and if power is being supplied to the indoor unit room electric heater 190, cuts off the power supply to the indoor unit room electric heater 190.

[0101] The indoor unit room electric heater 190 is disposed downstream of the leaked refrigerant discharge port 175 with respect to the air flow from the first fresh damper 172d toward the leaked refrigerant discharge port 175, which is formed in the indoor unit room 130r by indoor unit room ventilation control. Specifically, the indoor unit room electric heater 190 is disposed between the supply port 174 and the emergency damper 176d.

[0102] Therefore, while the indoor unit room ventilation control is creating an air flow from the first fresh damper 172d toward the leaked refrigerant discharge port 175, the air containing the leaked refrigerant is unlikely to hit the indoor unit room electric heater 190.

[0103] Therefore, even if propane or other flammable refrigerant is used as the refrigerant, if a refrigerant leak occurs, the possibility of the leaked refrigerant being heated by the residual heat of the indoor unit room electric heater 190 and catching fire can be reduced.

[0104] [First Modification of Second Embodiment] As shown in Fig. 8, in this modification, the direct ventilation device 200 includes a plurality of direct ventilation chamber electric heaters 250 arranged in the direct ventilation chamber 210r. Other configurations are the same as those shown in Fig. 7.

[0105] The electric heater 250 for the direct ventilation room is disposed both in a position covering the outside air supply port 230 and in a position between the outside air intake port 220 and the outside air supply port 230. However, the electric heater 250 for the direct ventilation room may be disposed only in one of the positions covering the outside air supply port 230 and the positions between the outside air intake port 220 and the outside air supply port 230.

[0106] In this embodiment, the control device 400 checks whether power is being supplied to the electric heater 250 for the direct ventilation room during vehicle cabin ventilation control, and if power is not being supplied to the electric heater 250 for the direct ventilation room, starts supplying power to the electric heater 250 for the direct ventilation room.

[0107] The direct ventilation chamber electric heater 250 heats the outside air flowing from the outside air intake port 220 to the outside air supply port 230. Therefore, even if a refrigerant leak occurs in winter or in a cold region, the outside air taken into the passenger compartment 910 can be heated by the direct ventilation chamber electric heater 250, and a drop in the temperature of the passenger compartment 910 can be suppressed.

[0108] Third Embodiment As shown in FIG. 9 , in this embodiment, a direct ventilation room defining section 210 is integrally formed with the indoor unit room defining section 130 and the outdoor unit room defining section 120 .

[0109] In other words, the direct ventilation room defining portion 210, the indoor unit room defining portion 130, and the outdoor unit room defining portion 120 form an integrated casing. This facilitates and improves the efficiency of manufacturing the direct ventilation room defining portion 210, the indoor unit room defining portion 130, and the outdoor unit room defining portion 120, and also reduces the volume occupied by the railway vehicle air conditioning system 800.

[0110] The direct ventilation room defining section 210 is disposed between the indoor unit room defining section 130 and the outdoor unit room defining section 120, specifically between the return room defining section 131 and the outdoor heat exchange room defining section 122. As in the first embodiment, the direct ventilation room 210r is isolated from the indoor unit room 130r and the outdoor unit room 120r by the wall surfaces that constitute the direct ventilation room defining section 210.

[0111] In this embodiment, the refrigerant pipes 155 and 159 pass through the direct ventilation chamber defining portion 210, and the refrigerant pipes 155 and 159 pass through the direct ventilation chamber 210r. The portion of the direct ventilation chamber defining portion 210 through which the refrigerant pipes 155 and 159 pass is airtightly closed.

[0112] Furthermore, the portions of the refrigerant pipes 155 and 159 that are arranged in the direct ventilation chamber 210r have a seamless continuous structure, so the probability of refrigerant leakage from the portions of the refrigerant pipes 155 and 159 that are arranged in the direct ventilation chamber 210r can be considered to be almost zero.

[0113] The direct ventilation device 200 further includes an auxiliary return damper 260 disposed between the direct ventilation chamber 210r and the indoor unit chamber 130r. The auxiliary return damper 260 is provided on a wall surface that is shared by the direct ventilation chamber defining section 210 and the return chamber defining section 131 and that separates the direct ventilation chamber 210r from the indoor unit chamber 130r.

[0114] The auxiliary return damper 260 can be switched between an auxiliary return permitting state in which the direct ventilation chamber 210r communicates with the indoor unit chamber 130r, and an auxiliary return blocking state in which the communication between the direct ventilation chamber 210r and the indoor unit chamber 130r is cut off.

[0115] 10 , in this embodiment, the control device 400 sets the auxiliary return damper 260 to the auxiliary return permitting state in step S11. This allows the direct ventilation chamber 210r and the return chamber 131r to communicate with each other, so that the indoor fan 162 draws in the inside air from the passenger compartment 910 not only through the return port 171 but also through the outside air supply port 230.

[0116] The indoor air drawn directly into the ventilation chamber 210r from the outdoor air supply port 230 by the indoor fan 162 passes through the auxiliary return damper 260. The indoor air that has passed through the auxiliary return damper 260 merges in the return chamber 131r with the indoor air that has also been drawn into the return chamber 131r from the return port 171 by the indoor fan 162.

[0117] During the normal air conditioning period until it is determined in step S12 that a refrigerant leak has occurred, the first fresh damper 172d may be switched to the ventilation state, and the second fresh damper 220d may be set to the outside air intake permitting state, as necessary. If the second fresh damper 220d is set to the outside air intake permitting state during the normal air conditioning period, outside air can be taken into the indoor unit compartment 130r and the vehicle compartment 910 through the second fresh damper 220d.

[0118] In this embodiment, after determining in step S12 that a refrigerant leak has occurred, the control device 400 switches the auxiliary return damper 260 from the auxiliary return permitting state to the auxiliary return blocking state in step S13, thereby cutting off communication between the direct ventilation chamber 210r and the return chamber 131r.

[0119] Therefore, when the exhaust fan is started in step S17, direct ventilation is performed in which outside air is taken into the passenger compartment 910 through the direct ventilation chamber 210r and the outside air supply port 230, while the inside air of the passenger compartment 910 is exhausted to the outside EX through the exhaust chamber 310r. Other configurations and operations are the same as those in the first embodiment.

[0120] [Variation 1 of Embodiment 3] As shown in Fig. 11 , a configuration may be adopted in which direct communication between the direct ventilation chamber 210r and the indoor unit chamber 130r is cut off. In other words, the auxiliary return damper 260 shown in Fig. 9 may be omitted. Here, "direct communication between the direct ventilation chamber 210r and the indoor unit chamber 130r" means communication via a route other than the route via the vehicle interior 910. According to this variation, control of the auxiliary return damper 260 shown in Fig. 9 is not necessary.

[0121] [Embodiment 4] As shown in Figure 12, in a configuration in which the direct ventilation chamber defining portion 210 is integrated with the housing 110, the direct ventilation chamber defining portion 210 may be connected to the end of the indoor unit chamber defining portion 130 opposite to the end to which the outdoor unit chamber defining portion 120 is connected.

[0122] Specifically, in this embodiment, the direct ventilation chamber defining portion 210 is configured integrally with the wall surface of the supply chamber defining portion 133 on which the supply port 174 is formed. The supply port 174 connects the indoor unit chamber 130r to the direct ventilation chamber 210r.

[0123] In addition to the outside air supply port 230, the direct ventilation chamber defining portion 210 is formed with a plurality of auxiliary supply ports 270 that connect the direct ventilation chamber 210r to the vehicle interior 910.

[0124] The direct ventilation device 200 further includes an outside air supply port damper 230d provided at the outside air supply port 230. The outside air supply port damper 230d is switchable between an outside air supply port closed state in which the outside air supply port 230 is closed and an outside air supply port open state in which the outside air supply port 230 is opened.

[0125] During the normal air conditioning period, the control device 400 keeps the outside air supply port damper 230d in an outside air supply port closed state. Therefore, the inside air that has passed through the indoor heat exchanger 154 flows into the direct ventilation chamber 210r via the supply port 174 and is then supplied to the passenger compartment 910 via each of the multiple auxiliary supply ports 270. At this time, the direct ventilation chamber 210r serves to distribute the inside air that has passed through the indoor heat exchanger 154 to the multiple auxiliary supply ports 270.

[0126] In addition, in the vehicle compartment ventilation control described above, the control device 400 switches the outside air supply port damper 230d from the outside air supply port closed state to the outside air supply port open state. At this time, the supply port 174 is closed by the emergency damper 176d as described above.

[0127] As a result, the outside air taken into the direct ventilation chamber 210r through the second fresh damper 220d is sent into the passenger compartment 910 via both the auxiliary supply port 270 and the open outside air supply port 230. Other configurations and operations are the same as those in the first embodiment.

[0128] 13, the emergency damper 176d may be configured separately as a leaked refrigerant discharge port damper 176d-1 that opens and closes the leaked refrigerant discharge port 175, and a supply port damper 176d-2 that opens and closes the supply port 174. The function of the emergency damper 176d according to this modification is the same as the function of the single-port emergency damper 176d shown in FIG.

[0129] 14 , a plurality of outside air supply ports 230 may be formed in the direct ventilation chamber defining portion 210. In this modification, the auxiliary supply port 270 described above is not formed in the direct ventilation chamber defining portion 210.

[0130] In this modification, during the normal air conditioning period, the inside air that has passed through the indoor heat exchanger 154 flows into the direct ventilation chamber 210r through the supply port 174, and is then supplied to the vehicle interior 910 through each of the plurality of outside air supply ports 230. At this time, the direct ventilation chamber 210r serves to distribute the inside air that has passed through the indoor heat exchanger 154 to the plurality of outside air supply ports 230.

[0131] In addition, in the vehicle cabin ventilation control described above, the supply port 174 is blocked by the emergency damper 176d, so that the outside air taken into the ventilation chamber 210r directly through the second fresh damper 220d is sent into the vehicle cabin 910 through each of the multiple outside air supply ports 230.

[0132] As described above, the outside air supply port 230 in this modified example not only serves to send outside air into the vehicle cabin when a refrigerant leak occurs, but also serves to send inside air that has passed through the indoor heat exchanger 154 into the vehicle cabin 910 during normal air conditioning periods.

[0133] Although the present modified example illustrates a configuration in which a plurality of outside air supply ports 230 are formed, the number of outside air supply ports 230 may be one. The other configurations and operations are the same as those in the first embodiment.

[0134] 15 , in this embodiment, the exhaust chamber defining portion 310 is integrally formed with the indoor unit room defining portion 130 and the outdoor unit room defining portion 120. In other words, the exhaust chamber defining portion 310, the indoor unit room defining portion 130, and the outdoor unit room defining portion 120 form an integrated casing.

[0135] This simplifies and improves the efficiency of manufacturing the exhaust chamber defining portion 310, the indoor unit room defining portion 130, and the outdoor unit room defining portion 120, and also reduces the volume occupied by the railway vehicle air conditioning system 800.

[0136] 16 , in this embodiment, the exhaust chamber defining portion 310 and the direct ventilation chamber defining portion 210 are configured integrally with the indoor unit chamber defining portion 130 and the outdoor unit chamber defining portion 120. In other words, the exhaust chamber defining portion 310, the direct ventilation chamber defining portion 210, the indoor unit chamber defining portion 130, and the outdoor unit chamber defining portion 120 configure an integrated casing.

[0137] 17 , in a configuration in which the exhaust chamber defining portion 310 and the direct ventilation chamber defining portion 210 are integrated with the housing 110, a leaked refrigerant discharge port 175 may be formed in a wall surface shared by the indoor unit chamber defining portion 130 and the exhaust chamber defining portion 310. The leaked refrigerant discharge port 175 is provided with the leaked refrigerant discharge port damper 176d-1 described above.

[0138] According to this modified example, the leaked refrigerant discharge port damper 176d-1 is opened by the indoor unit room ventilation control described above, and as the air pressure in the exhaust chamber 310r decreases as the exhaust fan 340 is started, the leaked refrigerant in the indoor unit room 130r can be discharged to the outside through the opened leaked refrigerant discharge port damper 176d-1, the exhaust chamber 310r, and the inside air exhaust port 330.

[0139] Sixth Embodiment As shown in FIG. 18, a railway vehicle air conditioning system 800 according to this embodiment includes two air conditioners 100A and 100B that air-condition a common passenger compartment 910, and an exhaust device 300.

[0140] Each of the air conditioners 100A and 100B is the same as the air conditioner 100 according to any one of the above-described embodiments 1 to 5. Similarly, the exhaust device 300 is the same as the air conditioner 100 according to any one of the above-described embodiments 1 to 5.

[0141] In this embodiment, the previously described direct ventilation device 200 is omitted. However, if a refrigerant leak occurs in one of the two air conditioners 100A and 100B, the other will function as the previously described direct ventilation device 200. The operation of the railway vehicle air conditioning system 800 according to this embodiment will now be described in detail.

[0142] As shown in FIG. 19, if it is determined in step S12 that a refrigerant leak has occurred in one of the two air conditioning units 100A and 100B (hereinafter referred to as the first air conditioning unit) (step S12; YES), the control unit 400 performs the indoor unit room ventilation control described above for that first air conditioning unit (steps S13-S15).

[0143] This ventilates the indoor unit room 130r of the first air conditioner, that is, the leaked refrigerant in the indoor unit room 130r of the first air conditioner is discharged to the outside EX.

[0144] Meanwhile, the control device 400 sets the first fresh damper 172d of the air conditioner 100A or 100B that is not leaking refrigerant (hereinafter referred to as the second air conditioner) to the ventilation state (step S16). Note that if the first fresh damper 172d of the second air conditioner is already in the ventilation state, step S16 is omitted. Then, the control device 400 starts the exhaust fan 340 (step S17).

[0145] As a result, with the action of the exhaust fan 340 lowering the air pressure in the passenger compartment 910, fresh outside air is taken into the passenger compartment 910 through the first fresh damper 172d of the second air conditioner, and the inside air in the passenger compartment 910 is exhausted to the outside EX through the inside air exhaust port 330. In this way, the passenger compartment 910 is ventilated.

[0146] In this case, the indoor unit room 130r of the second air conditioner plays the role of the above-mentioned direct ventilation room 210r. The ventilation port 172 of the second air conditioner plays the role of the above-mentioned outside air intake port 220. The first fresh damper 172d of the second air conditioner plays the role of the above-mentioned second fresh damper 220d.

[0147] Furthermore, at least one of the return port 171 and the supply port 174 of the second air conditioner serves as the aforementioned outside air supply port 230. When the indoor fan 162 of the second air conditioner is stopped during vehicle cabin ventilation control, the return port 171 of the second air conditioner serves exclusively as the aforementioned outside air supply port 230.

[0148] In addition, in the vehicle compartment ventilation control, the rotation speed of the indoor fan 162 of the second air conditioner may be increased compared to the normal air conditioning period. In this case, both the return port 171 and the supply port 174 of the second air conditioner can function as the outside air supply port 230 described above.

[0149] 20 , refrigerant leak detectors 180 may be disposed near each of refrigerant pipes 155 and 159 that are spaced apart from each other in the Y-axis direction. The refrigerant leak detector 180 disposed closer to the refrigerant pipe 155 detects refrigerant leaks from one refrigerant circuit 150A. The refrigerant leak detector 180 disposed closer to the refrigerant pipe 159 detects refrigerant leaks from the other refrigerant circuit 150B.

[0150] In this way, the air conditioning device 100 according to this embodiment has a configuration in which the control device 400 can determine from which of the two refrigerant circuits 150A and 150B the refrigerant has leaked.

[0151] When the control device 400 of this embodiment determines that a refrigerant leak has occurred from one of the refrigerant circuits 150A and 150B (hereinafter referred to as the first refrigerant circuit in this embodiment), it performs the indoor unit room ventilation control and vehicle interior ventilation control described above, and then resumes operation of the other of the refrigerant circuits 150A and 150B (hereinafter referred to as the second refrigerant circuit in this embodiment) on the condition that refrigerant leakage from the first refrigerant circuit is no longer detected.

[0152] Here, "resuming operation of the second refrigerant circuit" means resuming the circulation of refrigerant in the second refrigerant circuit, specifically, resuming operation of either compressor 151 or 156 that constitutes the second refrigerant circuit.

[0153] After refrigerant leakage from the first refrigerant circuit is no longer detected, it is preferable to perform a blowing operation for a certain period of time before resuming operation of the second refrigerant circuit, while stopping the circulation of refrigerant in the first refrigerant circuit and the second refrigerant circuit, and sending outside air taken in from the first fresh damper 172d into the passenger compartment 910.

[0154] 21 , the indoor unit compartment defining portion 130 according to this embodiment has a partition wall 134 that airtightly divides the portion of the indoor unit compartment 130r occupied by the indoor heat exchange chamber 132r and the supply chamber 133r into a first indoor unit compartment 130r1 and a second indoor unit compartment 130r2. The partition wall 134 extends in the X-axis direction. The first indoor unit compartment 130r1 and the second indoor unit compartment 130r2 are adjacent to each other in the Y-axis direction via the partition wall 134.

[0155] The indoor heat exchanger 154 described above is separated into a first indoor heat exchanger 154A that constitutes one refrigerant circuit (hereinafter referred to as the first refrigerant circuit in this embodiment and the modified example of this embodiment) 150A, and a second indoor heat exchanger 154B that constitutes the other refrigerant circuit (hereinafter referred to as the second refrigerant circuit in this embodiment and the modified example of this embodiment) 150B.

[0156] The first indoor heat exchanger 154A is disposed in the first indoor unit room 130r1, and the second indoor heat exchanger 154B is disposed in the second indoor unit room 130r2.

[0157] A pair of supply port 174 and leakage refrigerant discharge port 175 is formed in each of the first indoor unit room defining portion 130A, which is the portion of the indoor unit room defining portion 130 that defines the first indoor unit room 130r1, and the second indoor unit room defining portion 130B, which is the portion that defines the second indoor unit room 130r2.

[0158] Furthermore, the emergency damper 176d and the indoor fan 162 are disposed in the first indoor unit room 130r1 and the second indoor unit room 130r2, respectively.

[0159] The emergency damper 176d arranged in the first indoor unit room 130r1 opens and closes the supply port 174 and the leaked refrigerant discharge port 175 formed in the first indoor unit room defining portion 130A. The emergency damper 176d arranged in the second indoor unit room 130r2 opens and closes the supply port 174 and the leaked refrigerant discharge port 175 formed in the second indoor unit room defining portion 130B.

[0160] According to the configuration of the indoor unit room definition unit 130 in this embodiment, even if a refrigerant leak occurs in either the first refrigerant circuit 150A or the second refrigerant circuit 150B, it is possible to continue operation of the other refrigerant circuit.

[0161] Specifically, when a refrigerant leak occurs in the first refrigerant circuit 150A, the control device 400 stops the compressor 151 while keeping the pair of indoor fans 162 running, switches the emergency damper 176d in the first indoor unit room 130r1 from an internal air circulation state to an internal air non-circulation state, sets the first fresh damper 172d to a ventilation state, and performs the above-mentioned passenger compartment ventilation control.

[0162] Meanwhile, at this time, the return damper 171d is maintained in the return permitting state, the compressor 156 and the outdoor fan 161 are kept operating, and the emergency damper 176d in the second indoor unit room 130r2 is maintained in the internal air recirculation state.

[0163] As a result, even though cabin ventilation control is being performed in the first indoor unit room 130r1, the inside air that has passed through the second indoor heat exchanger 154B can be sent into the cabin 910 through the second indoor unit room 130r2. This prevents a decrease in the comfort of the cabin 910 that would otherwise be caused by direct ventilation of the cabin 910.

[0164] Similarly, if a refrigerant leak occurs in the second refrigerant circuit 150B, the control device 400 stops the compressor 156 while keeping the pair of indoor fans 162 running, switches the emergency damper 176d in the second indoor unit room 130r2 from an internal air circulation state to an internal air non-circulation state, sets the first fresh damper 172d to a ventilation state, and performs the above-mentioned passenger compartment ventilation control.

[0165] Meanwhile, at this time, the return damper 171d is maintained in the return permitting state, the compressor 151 and the outdoor fan 161 are kept operating, and the emergency damper 176d in the first indoor unit room 130r1 is maintained in the internal air recirculation state.

[0166] As a result, even though cabin ventilation control is being performed in the second indoor unit room 130r2, the inside air that has passed through the first indoor heat exchanger 154A can be sent into the cabin 910 through the first indoor unit room 130r1. This prevents a decrease in comfort in the cabin 910 that would otherwise be caused by direct ventilation of the cabin 910.

[0167] 22, the partition wall 134 may extend to the return chamber 131r. That is, in this modification, the indoor heat exchange chamber 132r, the supply chamber 133r, and the return chamber 131r are airtightly divided into a first indoor unit chamber 130r1 and a second indoor unit chamber 130r2.

[0168] The partition wall 134 divides the return port 171 into a portion that opens to the first indoor unit room 130r1 and a portion that opens to the second indoor unit room 130r2. A pair of a ventilation port 172 and a first fresh damper 172d is disposed in each of the first indoor unit room defining portion 130A and the second indoor unit room defining portion 130B.

[0169] According to this modification, when a refrigerant leak occurs in one of the first refrigerant circuit 150A and the second refrigerant circuit 150B, the leaked refrigerant is less likely to mix with the inside air taken in through the return port 171 in the return chamber 131r. Therefore, even if the other of the first refrigerant circuit 150A and the second refrigerant circuit 150B is kept operating, the leaked refrigerant is less likely to flow into the passenger compartment 910.

[0170] 23 , in this modification, the refrigerant pipe 155 constituting the first refrigerant circuit 150A and the refrigerant pipe 159 constituting the second refrigerant circuit 150B are configured to be spaced apart from each other in the return chamber 131r. This will be described in detail below.

[0171] Hereinafter, the direction in which the first refrigerant circuit 150A and the second refrigerant circuit 150B are arranged will be referred to as the “refrigerant circuit arrangement direction.” In this modification, the refrigerant circuit arrangement direction is specifically the Y-axis direction.

[0172] The return chamber defining portion 131 has a first end face and a second end face facing in the refrigerant circuit arrangement direction. A pair of a ventilation port 172 and a first fresh damper 172d is disposed on each of the first and second end faces. The return port 171 extends in the refrigerant circuit arrangement direction at the center of the return chamber 131r in the refrigerant circuit arrangement direction.

[0173] In the return chamber 131r, the refrigerant pipes 155 constituting the first refrigerant circuit 150A are arranged closer to the first end face than the central portion of the return chamber 131r in the arrangement direction of the refrigerant circuits. Specifically, in the return chamber 131r, the refrigerant pipes 155 constituting the first refrigerant circuit 150A are arranged closer to the first end face than the edge of the return port 171 that is closer to the first end face.

[0174] Similarly, in the return chamber 131r, the refrigerant pipes 159 constituting the second refrigerant circuit 150B are arranged closer to the second end face than the central portion of the return chamber 131r in the arrangement direction of the refrigerant circuits. Specifically, in the return chamber 131r, the refrigerant pipes 159 constituting the second refrigerant circuit 150B are arranged closer to the second end face than the edge of the return port 171 that is closer to the second end face.

[0175] According to this modification, when a refrigerant leak occurs in one of the first refrigerant circuit 150A and the second refrigerant circuit 150B, the leaked refrigerant is less likely to mix with the inside air taken in through the return port 171 in the return chamber 131r. Therefore, even if the other of the first refrigerant circuit 150A and the second refrigerant circuit 150B is kept operating, the leaked refrigerant is less likely to flow into the passenger compartment 910.

[0176] Ninth Embodiment As shown in FIG. 24 , an exhaust device 300 may be configured to draw in inside air from a passenger compartment 910 and exhaust it from above a railway vehicle 900 .

[0177] In this embodiment, inside air exhaust port 330 opens on the top surface of railway vehicle 900, and exhaust fan 340 is disposed on the roof portion of railway vehicle 900. Exhaust chamber 310r surrounds passenger compartment 910 in a cross section perpendicular to the longitudinal direction of railway vehicle 900, i.e., in a YZ cross section.

[0178] The exhaust chamber defining portion 310 of the exhaust device 300 according to this embodiment may be provided at a position separated from the housing 110 of the air conditioning device 100, or may be configured integrally with the housing 110 of the air conditioning device 100.

[0179] In the above-described vehicle interior ventilation control, the inside air in the vehicle interior 910 flows out from the inside air intake port 320 to the exhaust chamber 310r in the positive and negative directions of the Y axis. The outflowing inside air is sucked upward by the exhaust fan 340 and exhausted upward from the inside air exhaust port 330.

[0180] In this embodiment, a refrigerant with a higher specific gravity than air is used. Therefore, the pair of interior air intakes 320 facing each other in the Y-axis direction are positioned below the center of the vehicle interior 910 in the height direction. This allows the refrigerant, which tends to accumulate in the lower part of the vehicle interior 910, to be efficiently discharged to the outside EX.

[0181] 25 , a pair of interior air intake ports 320 facing each other in the Y-axis direction may be opened at the center of the vehicle interior 910 in the vertical direction or at a position above the center. When airflow is generated in the vehicle interior 910, the refrigerant may be dispersed in the vehicle interior 910 even if the specific gravity of the refrigerant is greater than that of air. Therefore, the interior air intake ports 320 according to this modification also allow the refrigerant to be discharged to the outside EX.

[0182] 26 , the indoor unit room defining section 130 and the outdoor unit room defining section 120 may be arranged separately from each other. In this embodiment, the indoor unit room defining section 130 is arranged on the roof of the railcar 900. The outdoor unit room defining section 120 is arranged under the floor of the railcar 900.

[0183] Furthermore, in this embodiment, the indoor unit room defining section 130 is separated into a first indoor unit room defining portion 130A and a second indoor unit room defining portion 130B. The refrigerant circuit 150A may be housed in one of the first indoor unit room defining portion 130A and the second indoor unit room defining portion 130B, and the refrigerant circuit 150B may be housed in the other. Alternatively, the refrigerant circuits 150A and 150B may be housed in each of the first indoor unit room defining portion 130A and the second indoor unit room defining portion 130B.

[0184] The greater the number of systems of the refrigerant circuits 150A, 150B that are responsible for air conditioning of the common passenger compartment 910, the more the amount of refrigerant per refrigerant circuit 150A or 150B can be reduced compared to when a single refrigerant circuit (not shown) is used to air condition the passenger compartment 910. Therefore, when a refrigerant leak occurs, the amount of leaked refrigerant can be kept small.

[0185] The above describes the first to tenth embodiments. The following modifications are also possible.

[0186] 2 illustrates a configuration in which the refrigerant leak detector 180 is disposed in the indoor unit room 130r, but the refrigerant leak detector 180 may be disposed outside the indoor unit room 130r. As a specific example, the refrigerant leak detector 180 may be disposed in the vehicle compartment 910. When a refrigerant having a higher specific gravity than air is used as the refrigerant, the refrigerant leak detector 180 may be disposed in a position below the center of the vehicle compartment 910 in the height direction.

[0187] 2 illustrates a configuration in which the return chamber 131r and the indoor heat exchange chamber 132r are in communication with each other via the indoor heat exchanger 154. An indoor fan 162 may be disposed at the boundary between the return chamber 131r and the indoor heat exchange chamber 132r, and the return chamber 131r and the indoor heat exchange chamber 132r may be in communication with each other via the indoor fan 162. The same applies to the configurations shown in FIGS. 21 to 23.

[0188] The above-described first to tenth embodiments and their modifications may be combined with each other. In this specification, the term "railroad vehicle" is not limited to electric trains, but also includes bullet trains, monorails, and other vehicles that travel along tracks.

[0189] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. The above-described embodiments are intended to explain the present disclosure and do not limit the scope of the present disclosure. The scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of the disclosure equivalent thereto are considered to be within the scope of the present disclosure.

[0190] 100 Air conditioner, 100A Air conditioner, 100B Air conditioner, 110 Housing, 120 Outdoor unit room defining portion, 120r Outdoor unit room, 121 Compressor room defining portion, 121r Compressor room, 122 Outdoor heat exchange room defining portion, 122r Outdoor heat exchange room, 130 Indoor unit room defining portion, 130A First indoor unit room defining portion, 130B Second indoor unit room defining portion, 130r Indoor unit room, 130r1 First indoor unit room, 130r2 Second indoor unit room, 131 Return room defining portion, 131r Return room, 132 Indoor heat exchange room defining portion, 132r Indoor heat exchange room, 133 Supply room defining portion, 133r Supply room, 134 Partition wall, 150A Refrigerant circuit, 150B Refrigerant circuit, 151 compressor, 152 outdoor heat exchanger, 153 expander, 154 indoor heat exchanger, 154A first indoor heat exchanger, 154B second indoor heat exchanger, 155 refrigerant piping, 156 compressor, 157 outdoor heat exchanger, 158 expander, 159 refrigerant piping, 161 outdoor fan, 162 indoor fan, 171 return port, 171d return damper, 172 ventilation port, 172d first fresh damper, 173 communication port, 174 supply port, 175 leaked refrigerant discharge port, 176d emergency damper, 176d-1 leaked refrigerant discharge port damper, 176d-2 supply port damper, 180 refrigerant leak detector, 190 indoor unit room electric heater, 200 direct ventilation device, 210 Direct ventilation chamber defining portion, 210r direct ventilation chamber, 220 outside air intake port, 220d second fresh damper, 230 outside air supply port, 230d outside air supply port damper, 240 communicating air duct, 250 electric heater for direct ventilation chamber, 260 auxiliary return damper, 270 auxiliary supply port, 300 exhaust device, 310 exhaust chamber defining portion, 310r exhaust chamber, 320 inside air intake port, 330 inside air exhaust port, 340 exhaust fan, 400 control device, 800 railway vehicle air conditioning system, 900 railway vehicle, 910 passenger compartment, EX outside.

Claims

1. an indoor unit room defining portion defining an indoor unit room, the indoor unit room being defined by a return port and a supply port each communicating with a vehicle compartment of the railway vehicle and a ventilation port communicating with the outside; an indoor fan that is disposed in the indoor unit room, draws in internal air, which is the air in the vehicle cabin, through the return port and discharges the drawn in internal air toward the supply port, thereby forming a flow of the internal air from the return port toward the supply port in the indoor unit room; a refrigerant circuit including an indoor heat exchanger that is disposed at a position in the indoor unit room through which the flow of the indoor air passes and exchanges heat between a refrigerant and the indoor air, and a group of cooperating devices that configure a refrigeration cycle together with the indoor heat exchanger using the refrigerant; a first fresh damper that is provided at the ventilation port and that is switchable between a ventilation state in which the indoor air flowing into the indoor heat exchanger is mixed with outside air, which is the outside air, by opening the ventilation port, and a non-ventilation state in which the ventilation port is closed; a refrigerant leakage detector that detects leakage of the refrigerant from the refrigerant circuit; A control device for controlling the first fresh damper; A railway vehicle air conditioning system comprising: The indoor unit room defining portion is further provided with a leakage refrigerant discharge port that is connected to the outside at a position downstream of the indoor heat exchanger with respect to the flow of the indoor air in the indoor unit room, The railcar air conditioning system comprises: an emergency damper that is disposed in the indoor unit room and is switchable between an indoor air circulation state in which the leaking refrigerant discharge port is closed and the supply port is opened, and an indoor air non-circulation state in which the leaking refrigerant discharge port is opened and the supply port is closed; Further equipped with The control device includes: When it is determined that the refrigerant has leaked from the refrigerant circuit based on the detection result of the refrigerant leakage detector, (I) an indoor unit room ventilation control in which the emergency damper is switched from the indoor air circulation state to the indoor air non-circulation state while the indoor fan is kept operating, and, when the first fresh damper is in the non-ventilation state, the first fresh damper is switched from the non-ventilation state to the ventilation state; This is an air conditioning system for railway vehicles.

2. An exhaust chamber defining section that defines an exhaust chamber isolated from the indoor unit chamber, the exhaust chamber defining section having an inside air intake port that leads to the vehicle cabin and an inside air exhaust port that leads to the outside; an exhaust fan that is disposed in the exhaust chamber, draws the inside air into the exhaust chamber through the inside air intake port, and exhausts the drawn inside air to the outside through the inside air exhaust port; Further equipped with The control device includes: When it is determined that the refrigerant has leaked from the refrigerant circuit based on the detection result of the refrigerant leakage detector, not only the indoor unit room ventilation control, (II) A vehicle compartment ventilation control that promotes direct ventilation in which the inside air in the vehicle compartment is exhausted to the outside through the exhaust chamber by controlling the exhaust fan, more than in a case in which the refrigerant is not leaking from the refrigerant circuit; The railcar air conditioning system according to claim 1 , further comprising:

3. A direct ventilation chamber defining section that defines a direct ventilation chamber isolated from the indoor unit chamber and the exhaust chamber, and that has an outside air intake port leading to the outside and an outside air supply port leading to the vehicle cabin; a second fresh damper provided at the outside air intake port to control the inflow of the outside air from the outside to the direct ventilation chamber; Further equipped with In the vehicle compartment ventilation control, the control device controls the second fresh damper to take in the outside air into the vehicle compartment through the direct ventilation chamber.

3. A railcar air conditioning system according to claim 2.

4. The group of cooperating devices includes a compressor that compresses the refrigerant and an outdoor heat exchanger that exchanges heat between the refrigerant and the outside air, The railcar air conditioning system comprises: an outdoor unit room defining portion defining an outdoor unit room in which the compressor and the outdoor heat exchanger are disposed; and 4. The air conditioning system for a railway vehicle according to claim 3, wherein the direct ventilation room defining portion is installed at a position separated from the indoor unit room defining portion and the outdoor unit room defining portion.

5. The group of cooperating devices includes a compressor that compresses the refrigerant and an outdoor heat exchanger that exchanges heat between the refrigerant and the outside air, The railcar air conditioning system comprises: an outdoor unit room defining portion defining an outdoor unit room in which the compressor and the outdoor heat exchanger are disposed; and The railway vehicle air conditioning system according to claim 3 , wherein the direct ventilation room defining portion is integral with the indoor unit room defining portion and the outdoor unit room defining portion.

6. The direct ventilation room defining portion is disposed between the indoor unit room defining portion and the outdoor unit room defining portion, The railcar air conditioning system comprises: an auxiliary return damper that is arranged between the direct ventilation chamber and the indoor unit chamber and is switchable between an auxiliary return permissive state that communicates the direct ventilation chamber with the indoor unit chamber and an auxiliary return blocking state that cuts off communication between the direct ventilation chamber and the indoor unit chamber; Further equipped with 6. The air conditioning system for a railway vehicle according to claim 5, wherein the control device sets the auxiliary return damper to the auxiliary return blocking state when it determines that the refrigerant has leaked from the refrigerant circuit based on a detection result of the refrigerant leakage detector.

7. The direct ventilation room defining portion is integrally formed with a wall surface of the indoor unit room defining portion on which the supply port is formed, The railcar air conditioning system according to claim 5 , wherein the supply port connects the indoor unit room with the direct ventilation room.

8. The direct ventilation chamber defining portion is provided with an auxiliary supply port that communicates the direct ventilation chamber with the vehicle cabin in addition to the outside air supply port, The railcar air conditioning system comprises: an outside air supply port damper that is provided in the outside air supply port and that is switchable between an outside air supply port closed state in which the outside air supply port is closed and an outside air supply port open state in which the outside air supply port is opened; Further equipped with 8. The railway vehicle air conditioning system according to claim 7, wherein the control device switches the outside air supply port damper from a state in which the outside air supply port is closed to a state in which the outside air supply port is open in the vehicle cabin ventilation control.

9. an electric heater for the indoor unit room, which is disposed in the indoor unit room and heats the indoor air that is sucked in from the return port by the indoor fan and directed toward the supply port; Further equipped with 2. The air conditioning system for a railway vehicle as described in claim 1, wherein the electric heater for the indoor unit room is arranged at a position downstream of the leaking refrigerant discharge port with respect to the air flow from the first fresh damper toward the leaking refrigerant discharge port, which is formed in the indoor unit room by the indoor unit room ventilation control.

10. an electric heater for the direct ventilation chamber, disposed in the direct ventilation chamber and configured to heat air flowing from the outside air intake port to the outside air supply port; Further equipped with 4. The air conditioning system for a railway vehicle according to claim 3, wherein the electric heater for the direct ventilation room is arranged at least one of a position covering the outside air supply port and a position between the outside air intake port and the outside air supply port.

11. The group of cooperating devices includes a compressor that compresses the refrigerant and an outdoor heat exchanger that exchanges heat between the refrigerant and the outside air, The railcar air conditioning system comprises: an outdoor unit room defining portion defining an outdoor unit room in which the compressor and the outdoor heat exchanger are disposed; and The railway vehicle air conditioning system according to claim 2 , wherein the exhaust chamber defining portion is integral with the indoor unit chamber defining portion and the outdoor unit chamber defining portion.

12. The railway vehicle air conditioning system includes two refrigerant circuits, The indoor unit room defining portion is a partition wall that airtightly divides at least a part of the indoor unit room into a first indoor unit room in which the indoor heat exchanger constituting the first refrigerant circuit, which is one of the refrigerant circuits, is arranged, and a second indoor unit room in which the indoor heat exchanger constituting the second refrigerant circuit, which is the other of the refrigerant circuits, is arranged; having the supply port and the leaking refrigerant discharge port are formed in a first indoor unit room defining portion that is a portion defining the first indoor unit room of the indoor unit room defining portion, and a second indoor unit room defining portion that is a portion defining the second indoor unit room, 2. The railcar air conditioning system according to claim 1, wherein the emergency damper and the indoor fan are arranged in the first indoor unit room and the second indoor unit room, respectively.