EP4606606A1

EP4606606A1 - Air conditioning system for railway vehicle

Info

Publication number: EP4606606A1
Application number: EP22962676.7A
Authority: EP
Inventors: Toshiyuki SHINAGAWA
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2022-10-18
Filing date: 2022-10-18
Publication date: 2025-08-27
Also published as: EP4606606A4; JPWO2024084564A1; WO2024084564A1; JP7814534B2

Abstract

In an air conditioning system for a railway vehicle, when a control device determines based on a result of detection by a refrigerant leakage detector (180) that refrigerant is leaked from a refrigerant circuit (150A, 150B), the control device switches an emergency damper (176d) from an inside air circulating state to an inside air non-circulating state while operating an indoor fan (162) and, when the first fresh damper (172d) is in the non-ventilation state, the control device switches the first fresh damper (172d) from the non-ventilation state to the ventilation state. The control device promotes direct ventilation by controlling the exhaust fan and the second fresh damper (220d) more than when the refrigerant is not leaked from the refrigerant circuit, the direct ventilation permitting the outside air to be drawn in the compartment through the direct ventilation chamber and permitting the inside air of the compartment to be discharged to the exterior (EX) through the exhaust chamber.

Description

Technical Field

The present disclosure relates to an air conditioning system for a railway vehicle.

Background Art

An air conditioning device for a railway vehicle, which is installed on the railway vehicle, air conditions a compartment using a refrigerant circuit in which refrigerant circulates. Here, the term "compartment" refers to a defined space in the railway vehicle for passengers to ride therein. The refrigerant circuit forms a refrigeration cycle using the refrigerant to obtain heat or cold necessary for air conditioning the compartment.
An openable and closable damper may be provided in a housing accommodating the refrigerant circuit in order to allow intake of outside air into the airtight compartment. The damper serves to draw the outside air into the housing. The outside air drawn into the housing through the opened damper is sent into the compartment along with temperature-adjusted air using the refrigerant circuit.
As disclosed in Patent Literature 1, there is also known an air conditioning device for a railway vehicle that has both a function to take in the outside air through the damper and a function to detect refrigerant leakage from the refrigerant circuit. This air conditioning device for the railway vehicle includes an exhaust fan that discharges air from the compartment to the exterior, in addition to an indoor fan that circulates air between the compartment and the interior of the housing. When a refrigerant leakage is detected, the exhaust fan is activated with the aforementioned damper opened.

Citation List

Patent Literature

Patent Literature 1: International Publication No. WO 2021/144907

Summary of Invention

Technical Problem

The air conditioning device for a railway vehicle according to Patent Literature 1 can quickly discharge refrigerant leaking from the refrigerant circuit to the exterior. Thus, even if refrigerant leaks from the refrigerant circuit, the concentration of refrigerant in the compartment can be suppressed.
An objective of the present disclosure is to provide an air conditioning system for a railway vehicle with enhanced safety performance to suppress refrigerant concentration in a compartment.

Solution to Problem

An air conditioning system for a railway vehicle according to the present disclosure includes:

an indoor unit chamber definer including a return port and a supply port each connecting to a compartment of the railway vehicle, and a ventilation port connecting to an exterior of the railway vehicle, the indoor unit chamber definer defining an indoor unit chamber;
an indoor fan disposed in the indoor unit chamber and configured to draw, from the return port, inside air that is air in the compartment and discharging the drawn inside air to the supply port to form in the indoor unit chamber a flow of the inside air from the return port toward the supply port;
a refrigerant circuit including an indoor heat exchanger and a group of cooperative devices, the indoor heat exchanger being disposed at a position in the indoor unit chamber in a path of the flow of the inside air and configured to perform heat exchange between refrigerant and the inside air, the group of cooperating devices constituting a refrigeration cycle using the refrigerant together with the indoor heat exchanger;
a first fresh damper disposed at the ventilation port and being switchable between a ventilation state in which the ventilation port is opened to allow outside air that is air of the exterior to be merged with the inside air flowing in the indoor heat exchanger and a non-ventilation state in which the ventilation port is closed;
a refrigerant leakage detector to detect leakage of the refrigerant from the refrigerant circuit;
an exhaust chamber definer defining an exhaust chamber separated from the indoor unit chamber and including an inside air intake port connecting to the compartment and an inside air discharge port connecting to the exterior;
an exhaust fan disposed in the exhaust chamber and configured to draw the inside air in the exhaust chamber from the inside air intake port and discharge the drawn inside air to the exterior through the inside air discharge port; and
a control device to control the first fresh damper and the exhaust fan, wherein
the indoor unit chamber definer further includes a leaked refrigerant discharge port connecting to the exterior, the leaked refrigerant discharge port being located downstream of the indoor heat exchanger with respect to a flow of the inside air in the indoor unit chamber,
the air conditioning system further includes
- an emergency damper disposed in the indoor unit chamber and being switchable between an inside air circulating state in which the leaked refrigerant discharge port is closed and the supply port is opened and an inside air non-circulating state in which the leaked refrigerant discharge port is opened and the supply port is closed,
- a direct ventilation chamber definer defining a direct ventilation chamber separated from the indoor unit chamber and the exhaust chamber and including an outside air intake port connecting to the exterior and an outside air supply port connecting to the compartment, and
- a second fresh damper disposed at the outside air intake port and configured to control an inflow of the outside air from the exterior to the direct ventilation chamber, and
the control device performs
when the control device determines based on a result of detection by the refrigerant leakage detector that the refrigerant is leaked from the refrigerant circuit,
1. (I) indoor unit chamber ventilation control to switch the emergency damper from the inside air circulating state to the inside air non-circulating state while operating the indoor fan, and switch the first fresh damper from the non-ventilation state to the ventilation state when the first fresh damper is in the non-ventilation state, and
2. (II) compartment ventilation control to promote direct ventilation by controlling the exhaust fan and the second fresh damper more than when the refrigerant is not leaked from the refrigerant circuit, the direct ventilation permitting the outside air to be drawn in the compartment through the direct ventilation chamber and permitting the inside air of the compartment to be discharged to the exterior through the exhaust chamber.

Advantageous Effects of Invention

According to the above configuration, when a determination is made that the refrigerant is leaked from the refrigerant circuit, the supply port is closed by the indoor unit chamber ventilation control. This blocks a flow of the inside air, which may contain leaked refrigerant, from the indoor unit chamber to the compartment.
In addition, in the compartment, the direct ventilation through the direct ventilation chamber and the exhaust chamber is promoted by the compartment ventilation control. Thus, even if refrigerant is leaked, a concentration of the refrigerant in the compartment can be sufficiently suppressed.
The indoor unit chamber ventilation control ventilates the indoor unit chamber through the ventilation port and the leaked refrigerant discharge port, with the supply port closed. This can eliminate the cause of the increased concentration of the refrigerant in the compartment.
As above, safety performance to suppress the refrigerant concentration in the compartment can be more enhanced.

Brief Description of Drawings

FIG. 1 is a schematic diagram illustrating a configuration of an air conditioning system for a railway vehicle according to Embodiment 1;
FIG. 2 is a schematic diagram illustrating a configuration of an air conditioning device according to Embodiment 1;
FIG. 3 is a flowchart of air conditioning control according to Embodiment 1;
FIG. 4 is a schematic diagram illustrating a configuration of an air conditioning system for a railway vehicle according to a modified example 1 of Embodiment 1;
FIG. 5 is a schematic diagram illustrating a configuration of air conditioning system for a railway vehicle according to a modified example 2 of Embodiment 1;
FIG. 6 is a schematic diagram illustrating a configuration of an air conditioning device according to a modified example 3 of Embodiment 1;
FIG. 7 is a schematic diagram illustrating a configuration of an air conditioning device according to Embodiment 2;
FIG. 8 is a schematic diagram illustrating a configuration of an air conditioning device according to a modified example 1 of Embodiment 2;
FIG. 9 is a schematic diagram illustrating a configuration of an air conditioning device according to Embodiment 3;
FIG. 10 is a flowchart of air conditioning control according to Embodiment 3;
FIG. 11 is a schematic diagram illustrating a configuration of an air conditioning device according to a modified example 1 of Embodiment 3;
FIG. 12 is a schematic diagram illustrating a configuration of an air conditioning device according to Embodiment 4;
FIG. 13 is a schematic diagram illustrating a configuration of air conditioning device according to a modified example 1 of Embodiment 4;
FIG. 14 is a schematic diagram illustrating a configuration of an air conditioning device according to a modified example 2 of Embodiment 4;
FIG. 15 is a schematic diagram illustrating a configuration of an air conditioning device according to Embodiment 5;
FIG. 16 is a schematic diagram illustrating a configuration of an air conditioning device according to a modified example 1 of Embodiment 5;
FIG. 17 is a schematic diagram illustrating a configuration of an air conditioning device according to a modified example 2 of Embodiment 5;
FIG. 18 is a schematic diagram illustrating a configuration of an air conditioning system for a railway vehicle according to Embodiment 6;
FIG. 19 is a flowchart of air conditioning control according to Embodiment 6;
FIG. 20 is a schematic diagram illustrating a configuration of an air conditioning device according to Embodiment 7;
FIG. 21 is a schematic diagram illustrating a configuration of an air conditioning device according to Embodiment 8;
FIG. 22 is a schematic diagram illustrating a configuration of an air conditioning device according to a modified example 1 of Embodiment 8;
FIG. 23 is a schematic diagram illustrating a configuration of an air conditioning device according to a modified example 2 of Embodiment 8;
FIG. 24 is a schematic diagram illustrating a configuration of an exhaust device according to Embodiment 9;
FIG. 25 is a schematic diagram illustrating a configuration of an exhaust device according to a modified example 1 of Embodiment 9; and
FIG. 26 is a schematic diagram illustrating a configuration of an air conditioning system for a railway vehicle according to Embodiment 10.

Description of Embodiments

An air conditioning system for a railway vehicle according to one or more embodiments is described below with reference to the drawings. In the figures, the same reference signs denote the same or corresponding components.

Embodiment 1

As illustrated in FIG. 1, an air conditioning system 800 for a railway vehicle according to the present embodiment is installed in a railway vehicle 900. For ease of understanding, a right-handed XYZ orthogonal coordinate system is defined with X-axis that is parallel to a length direction of the railway vehicle 900, Y-axis that is parallel to a width direction of the railway vehicle 900, and Z-axis that is parallel to a vertical direction. A vertically upward direction is the positive Z-axis direction. The XYZ orthogonal coordinate system is provided to FIG. 1 and the drawings referenced thereafter.
The air conditioning system 800 for a railway vehicle according to the present embodiment includes an air conditioning device 100 that air conditions a compartment 910 of the railway vehicle 900, a direct ventilation device 200 that draws air of an exterior EX (hereinafter also referred to as outside air) into the compartment 910, an exhaust device 300 that discharges air of the compartment 910 (hereinafter also referred to as inside air) to the exterior EX, and a control device 400 that controls the air conditioning device 100, the direct ventilation device 200, and the exhaust device 300. The compartment 910 is specifically a passenger compartment.
The air conditioning device 100 and the direct ventilation device 200 are installed on a portion of a roof of the railway vehicle 900. The exhaust device 300 is installed under a portion of a floor of the railway vehicle 900.
The air conditioning device 100 has a function of not only air conditioning the compartment 910, but also of feeding fresh outside air into the compartment 910. The direct ventilation device 200 has a function of drawing fresh outside air into the compartment 910, independently of the air conditioning device 100.
Referring to FIG. 2, configurations of the air conditioning device 100 and the direct ventilation device 200 are described in detail.
First, the air conditioning device 100 is described. The air conditioning device 100 includes two refrigerant circuits 150A and 150B. Each of these two refrigerant circuits 150A and 150B encloses refrigerant.
The refrigerant for use is of greater specific gravity than air, specifically, a substance containing at least 95% by mass hydrocarbon, such as propane, or carbon dioxide.
One refrigerant circuit 150A of the two circuits includes a compressor 151 that compresses the refrigerant, an outdoor heat exchanger 152 serving as a condenser that condenses the compressed refrigerant, an expander 153 that expands the condensed refrigerant, an indoor heat exchanger 154 serving as an evaporator that vaporizes the expanded refrigerant, and refrigerant piping 155 connecting the compressor 151, the outdoor heat exchanger 152, the expander 153, and the indoor heat exchanger 154.
Similarly, the other refrigerant circuit 150B includes a compressor 156, an outdoor heat exchanger 157 serving as a condenser, an expander 158, and refrigerant piping 159 connecting the compressor 156, the outdoor heat exchanger 157, and the expander 158.
The indoor heat exchanger 154 is shared by the refrigerant circuit 150A and the other refrigerant circuit 150B. However, a path for the refrigerant enclosed in the refrigerant circuit 150A and a path for the refrigerant contained in the other refrigerant circuit 150B in the interior of the indoor heat exchanger 154 are independent of each other. Thus, the refrigerant enclosed in the refrigerant circuit 150A and the refrigerant enclosed in the other refrigerant circuit 150B do not mix each other.
In the refrigerant circuit 150A, the compressor 151, the outdoor heat exchanger 152, the expander 153, and the refrigerant piping 155 are a group of cooperating devices that provides 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 cooperating devices that provides a refrigeration cycle together with the indoor heat exchanger 154.
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 serve as condensers and the indoor heat exchanger 154 serves as an evaporator and a heating state in which the outdoor heat exchangers 152 and 157 serve as an evaporator and the indoor heat exchanger 154 serves as a condenser. Such switching is accomplished using a four-way valve.
The air conditioning device 100 includes an outdoor fan 161 that facilitates heat exchange between refrigerant inside the outdoor heat exchangers 152 and 157 and the outside air, and an indoor fan 162 that facilitates heat exchange between refrigerant inside the indoor heat exchanger 154 and the inside air.
The air conditioning device 100 also includes a housing 110 installed on the railway vehicle 900. The housing 110 defines an outdoor unit chamber 120r and an indoor unit chamber 130r arranged in an X-axis direction.
Specifically, the housing 110 includes an outdoor unit chamber definer 120 that defines the outdoor unit chamber 120r. The outdoor unit chamber 120r is further divided into a compressor chamber 121r and an outdoor heat exchange chamber 122r arranged in the X-axis direction. The compressor chamber 121r is located at an end in the X-axis direction.
That is, the outdoor unit chamber definer 120 includes a compressor chamber definer 121 that defines the compressor chamber 121r. The compressor chamber 121r is not in communication with the compartment 910. The compressor chamber 121r houses the compressors 151 and 156.
The outdoor unit chamber definer 120 includes an outdoor heat exchange chamber definer 122 that defines the outdoor heat exchange chamber 122r. The outdoor heat exchange chamber 122r is not in communication with the compartment 910 and is in communication with the exterior EX. The outdoor heat exchange chamber 122r houses the outdoor heat exchangers 152 and 157, the expanders 153 and 158, and the outdoor fan 161.
The housing 110 includes an indoor unit chamber definer 130 that defines the indoor unit chamber 130r. The indoor unit chamber 130r is in communication with the compartment 910. The indoor unit chamber 130r is further divided into a return chamber 131r, an indoor heat exchange chamber 132r, and a supply chamber 133r arranged in the X-axis direction. The return chamber 131r is located next to the outdoor heat exchange chamber 122r.
Specifically, the indoor unit chamber definer 130 includes a return chamber definer 131 that defines the return chamber 131r. Refrigerant piping 155 and 159 pass through the return chamber 131r. The return chamber definer 131 includes the return port 171 connecting to the compartment 910 and the ventilation port 172 connecting to the exterior EX. The return chamber 131r is in communication with the compartment 910 through a return port 171 and is in communication with the exterior EX through a ventilation port 172.
The return port 171 is provided with a return damper 171d. The return damper 171d is switchable between a return permitting state in which the return chamber 131r is permitted to be in communication with the compartment 910 and a return preventing state in which the return chamber 131r is prevented from being in communication with the compartment 910.
The ventilation port 172 is provided with a first fresh damper 172d. The first fresh damper 172d is switchable between a ventilation state in which opening of the ventilation port 172 permits the return chamber 131r to be in communication with the exterior EX and a non-ventilation state in which closing of the ventilation port prevents the return chamber 131r from being in communication with the exterior EX.
The indoor unit chamber definer 130 includes an indoor heat exchange chamber definer 132 that defines the indoor heat exchange chamber 132r. The indoor heat exchange chamber 132r houses the indoor heat exchanger 154 and the indoor fan 162. The refrigerant piping 155 and 159 to be connected to the indoor heat exchanger 154 pass through the indoor heat exchange chamber 132r.
The indoor heat exchange chamber 132r is in communication with the return chamber 131r. The indoor heat exchanger 154 is disposed at an opening that allows the indoor heat exchange chamber 132r to be in communication with the return chamber 131r.
The indoor unit chamber definer 130 includes a supply chamber definer 133 that defines the supply chamber 133r. The supply chamber definer 133 includes a communication port 173 that allows the supply chamber 133r to be in communication with the indoor heat exchange chamber 132r and a supply port 174 that connects to the compartment 910.
The action of the indoor fan 162 in air conditioning the compartment 910 is described below. In air conditioning the compartment 910, the return damper 171d is set to the return permitting state described above. The indoor fan 162 forms, in the indoor unit chamber 130r, a flow of the inside air directing from the return port 171 toward the supply port 174.
Specifically, the indoor fan 162 draws the inside air of the compartment 910 into the return chamber 131r through the return port 171. The inside air drawn in the return chamber 131r passes through the indoor heat exchanger 154.
With the compressors 151 and 156 running, the indoor heat exchanger 154 is in a cooled or heated state. Thus the temperature of the inside air is adjusted as the inside air passes through the indoor heat exchanger 154. The inside air having passed through the indoor heat exchanger 154 passes through the communication port 173 and is returned to the compartment 910 through the supply port 174.
The indoor fan 162 is located downstream of the indoor heat exchanger 154 with respect to the flow of the inside air in the indoor unit chamber 130r. That is, the indoor fan 162 draws the inside air from the compartment 910 via the indoor heat exchanger 154 and discharges the drawn inside air toward the supply port 174.
In a case where fresh outside air is to be fed into the compartment 910, the first fresh damper 172d is set to the ventilation state described above. This allows fresh outside air to be drawn into a return chamber 131r through a ventilation port 172 that is open. The drawn outside air merges with the inside air flowing into an indoor heat exchanger 154 and then is sent into the compartment 910 together with the inside air.
Thus, the indoor fan 162 not only serves to circulate the inside air between the compartment 910 and the indoor unit chamber 130r, but also serves to draw fresh outside air into the indoor unit chamber 130r through the open ventilation port 172.
In the present embodiment, "air conditioning" is defined as having a concept including not only adjusting the temperature of the inside air using the indoor heat exchanger 154 by operating the compressors 151 and 156, but also feeding fresh outside air into the compartment 910 through the ventilation port 172 while the compressors 151 and 156 are stopped.
During air conditioning of the compartment 910, the refrigerant can be leaked from at least one of the refrigerant circuit 150A and the refrigerant circuit 150B due to an accidental failure. The refrigerant leaked from any of the refrigerant circuits 150A and 150B may enter the compartment 910, and thus lower an oxygen concentration in the compartment 910.
The air conditioning device 100 according to the present embodiment thus includes a feature for detecting leakage of the refrigerant, and a feature for rapidly discharging the leaked refrigerant to the exterior EX. These features are described below.
The air conditioning device 100 includes a refrigerant leakage detector 180 that detects leakage of the refrigerant from the refrigerant circuits 150A and 150B. The refrigerant leakage detector 180 is disposed in the indoor unit chamber 130r. Specifically, the refrigerant leakage detector 180 is disposed downstream of the indoor heat exchanger 154 and the refrigerant piping 155 and 159 with respect to the flow of the inside air in the indoor fan 162. The control device 400 illustrated in FIG. 1 determines, based on a result of detection by the refrigerant leakage detector 180, whether the refrigerant is leaked.
The indoor unit chamber definer 130, specifically, the supply chamber definer 133 further includes a leaked refrigerant discharge port 175 connecting to the exterior EX.
The leaked refrigerant discharge port 175 is for discharging the leaked refrigerant to the exterior EX in a case where the refrigerant is leaked at least either from the refrigerant piping 155 connected to the indoor heat exchanger 154 or the refrigerant piping 159 connected to the indoor heat exchanger 154. Thus the leaked refrigerant discharge port 175 is disposed downstream of the indoor heat exchanger 154 and the refrigerant piping 155 and 159 with respect to the flow of the inside air in the indoor unit chamber 130r.
The air conditioning device 100 further includes an emergency damper 176d. The emergency damper 176d is disposed in the indoor unit chamber 130r, specifically, in the supply chamber 133r. The emergency damper 176d is switchable between an inside air circulating state for closing the leaked refrigerant discharge port 175 and opening the supply port 174 and an inside air non-circulating state for opening the leaked refrigerant discharge port 175 and the closing the supply port 174.
In a case where the refrigerant is leaked, the emergency damper 176d is switched from the inside air circulating state to the inside air non-circulating state by the control device 400 illustrated in FIG. 1.
Next, a configuration of the direct ventilation device 200 is described in detail.
The direct ventilation device 200 includes a direct ventilation chamber definer 210 that defines a direct ventilation chamber 210r. The direct ventilation chamber 210r is isolated from the interior of the housing 110 including the indoor unit chamber 130r in the air conditioning device 100.
The direct ventilation chamber definer 210 includes an outside air intake port 220 connecting to the exterior EX and an outside air supply port 230 connecting to the compartment 910. The direct ventilation chamber 210r is in communication with the exterior EX through the outside air intake port 220, and in communication with the compartment 910 through the outside air supply port 230.
The direct ventilation device 200 includes a second fresh damper 220d provided at the outside air intake port 220. The second fresh damper 220d serves to control an inflow of the outside air from the exterior EX into the direct ventilation chamber 210r. Specifically, the second fresh damper 220d is switchable between an outside air intake permitting state for opening the outside air intake port 220 and an outside air intake prohibiting state for closing the outside air intake port 220.
Next, referring back to FIG. 1, a configuration of the exhaust device 300 is described in detail.
As illustrated in FIG. 1, the exhaust device 300 includes an exhaust chamber definer 310 that defines an exhaust chamber 310r. The exhaust chamber 310r is isolated from the direct ventilation chamber 210r and the interior of the housing 110 including the indoor unit chamber 130r in the air conditioning device 100.
The exhaust chamber definer 310 includes an inside air intake port 320 connecting to the compartment 910 and an inside air discharge port 330 connecting to the exterior EX. The exhaust chamber 310r is in communication with the compartment 910 through the inside air intake port 320 and in communication with the exterior EX through the inside air discharge port 330.
The exhaust device 300 includes an exhaust fan 340 disposed in the exhaust chamber 310r. The exhaust fan 340 draws the inside air of the compartment 910 in the exhaust chamber 310r through the inside air intake port 320 and discharges the drawn inside air to the exterior EX through the inside air discharge port 330.
The air conditioning control performed by the control device 400 is described below with reference to FIG. 3.
The control device 400 is assumed to set the emergency damper 176d to the inside air circulating state, set the return damper 171d to the return permitting state, set the first fresh damper 172d to the non-ventilation state, set the second fresh damper 220d to the outside air intake prohibiting state, and stop the exhaust fan 340.
In such a state, the control device 400 start air conditioning of the compartment 910 (step S11). Specifically, the control device 400 starts the indoor fan 162, the outdoor fan 161, and the compressors 151 and 156.
Also, the control device 400 switches the first fresh damper 172d to the ventilation state to feed fresh outside air to the compartment 910 as necessary. Specifically, the control device 400 switches the first fresh damper 172d to the ventilation state upon a conductor's operation to the effect that the outside air is to be drawn in or upon fulfillment of a predetermined condition.
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, an operation to feed fresh outside air in the compartment 910 through the first fresh damper 172d in the ventilation state, so-called free cooling, is performed.
Next, the control device 400 determines, based on a result of detection by the refrigerant leakage detector 180, whether the refrigerant is leaked (step S12). When a determination that the refrigerant is not leaked is made (No in step S12), processing returns to step S12 again. Occurrence or non-occurrence of the refrigerant leakage is continuously monitored by the refrigerant leakage detector 180 and the control device 400.
When a determination is made that the refrigerant is leaked (Yes in step S12), the control device 400 performs indoor unit chamber ventilation control for ventilating the indoor unit chamber 130r.
Specifically, the control device 400 stops the compressors 151 and 156 and the outdoor fan 161 while keeping operating the indoor fan 162, switches the emergency damper 176d from the inside air circulating state to the inside air non-circulating state, and switches the return damper 171d from the return permitting state to the return preventing state (step S13).
Even during the free cleaning, leakage of the refrigerant would occur due to an accidental failure. In that case, the compressors 151 and 156 and the outdoor fan 161 are stopped, and thus stoppage of the compressors 151 and 156 and the outdoor fan 161 in step S13 is omitted.
Next, the control device 400 determines whether or not the first fresh damper 172d is in a ventilation state (step S14). When the first fresh damper 172d is in the non-ventilation state (No in step S14), the control device 400 switches the first fresh damper 172d from the non-ventilation state to the ventilation state (step S15). When the first fresh damper 172d is already in the ventilation state (Yes in step S14), the processing proceeds to step S16.
According to the above indoor unit chamber ventilation control, the indoor fan 162 creates in the indoor unit chamber 130r a flow of outside air from the first fresh damper 172d in the ventilation state to the leaked refrigerant discharge port 175. The refrigerant leaked from at least any of the indoor heat exchanger 154, the refrigerant piping 155, and the refrigerant piping 159 is discharged from the leaked refrigerant discharge port 175 to the exterior EX together with a flow of the outside air formed in the indoor unit chamber 130r.
The control device 400 also performs compartment ventilation control for ventilating the compartment 910, independently of the ventilation of the indoor unit chamber 130r.
Specifically, the control device 400 switches the second fresh damper 220d from the outside air intake prohibiting state to the outside air intake permitting state (step S16). The control device 400 also starts the exhaust fan 340 (step S17).
The above compartment ventilation control performs direct ventilation in which the inside air in the compartment 910 is discharged through the exhaust chamber 310r to the exterior EX while the outside air is drawn in the compartment 910 through the direct ventilation chamber 210r. The direct ventilation chamber 210r is isolated from the indoor unit chamber 130r and does not have a source of refrigerant leakage, and thus no refrigerant flows from the direct ventilation chamber 210r to the compartment.
As described above, according to the present embodiment, when a determination is made that refrigerant is leaked from at least one of the refrigerant circuit 150A and the refrigerant circuit 150B, the supply port 174 is closed by the indoor unit chamber ventilation control. This blocks a flow of the inside air, which may contain leaked refrigerant, from the indoor unit chamber 130r to the compartment 910.
In addition, in the compartment 910, the direct ventilation through the direct ventilation chamber 210r and the exhaust chamber 310r is performed by the compartment ventilation control. Thus, even if refrigerant is leaked, a concentration of the refrigerant in the compartment 910 can be sufficiently suppressed.
The indoor unit chamber ventilation control ventilates the indoor unit chamber 130r through the ventilation port 172 and the leaked refrigerant discharge port 175, with the supply port 174 and the return port 171 closed. This can eliminate the cause of the increased concentration of the refrigerant in the compartment 910. As above, safety performance to suppress the refrigerant concentration in the compartment 910 can be more enhanced.
The air conditioning system 800 for the railway vehicle according to the present embodiment can perform direct ventilation of the compartment 910 by the direct ventilation device 200 and the exhaust device 300 even in a case where the railway vehicle 900 is not equipped with a window that is openable and closable. Even in a case where the railway vehicle 900 is equipped with a window that is openable and closable, the air conditioning system 800 can perform the direct ventilation of the compartment 910 sufficiently without a risky action of opening and closing the window while the vehicle runs.
On the other hand, during a period from start of the air conditioning of the compartment 910 in step S11 of FIG. 3 until a determination is made that the refrigerant is leaked in step S12 of FIG. 3, which is hereinafter referred to as a normal air conditioning period, the second fresh damper 220d is set to the outside air intake prohibiting state and the exhaust fan 340 is stopped. This allows the air pressure of the compartment 910 to be maintained at an appropriate value that can provide comfort to passengers.

Modified Example 1 of Embodiment 1

FIG. 1 illustrates an example of a configuration in which the direct ventilation device 200 is installed horizontally separated from the air conditioning device 100. Specifically, in FIG. 1, the direct ventilation chamber definer 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 direct ventilation device 200 may be installed at any other position.
As illustrated 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 chamber definer 210 of the direct ventilation device 200 is mounted on the upper side of the housing 110 of the air conditioning device 100.
The direct ventilation device 200 according to the present modified example includes an air communication passage 240 that permits the outside air supply port 230 illustrated in FIG. 2 to be in communication with the compartment 910. The air communication passage 240 pass through the interior of the housing 110 of the air conditioning device 100.
FIG. 4 illustrates an example of the configuration in which the direct ventilation device 200 is disposed on the upper side of the air conditioning device 100, but the direct ventilation device 200 may be disposed on the lower side of the air conditioning device 100. In that case, the air communication passage 240 is not necessary.

Modified Example 2 of Embodiment 1

As illustrated in FIG. 5, the direct ventilation device 200 may be provided inside a body of the railway vehicle 900. In this case, a non-illustrated duct that permits the outside air supply port 230 illustrated in FIG. 2 to be in communication with the compartment 910 can be shortened.

Modified Example 3 of Embodiment 1

FIG. 2 illustrates an example of a configuration in which the leaked refrigerant discharge port 175 is formed in the supply chamber definer 133, but the leaked refrigerant discharge port 175 may be disposed at any position that is located downstream of the indoor heat exchanger 154.
As illustrated in FIG. 6, the leaked refrigerant discharge port 175 may be formed in the indoor heat exchange chamber definer 132. Also, the emergency damper 176d may be disposed in the indoor heat exchange chamber 132r. The emergency damper 176d according to the present modified example opens and closes the supply port 174 indirectly by opening and closing the communication port 173.
That is, the emergency damper 176d according to the present modified example is switchable between an inside air circulating state in which the supply port 174 is opened indirectly by closing the leaked refrigerant discharge port 175 and opening the communication port 173 and an inside air non-circulating state in which the supply port 174 is closed indirectly by opening the leaked refrigerant discharge port 175 and closing the communication port 173.

Modified Example 4 of Embodiment 1

In Embodiment 1 above, in the normal air conditioning period, the second fresh damper 220d is set to the outside air intake prohibiting state and the exhaust fan 340 is maintained stopped. That is, the aforementioned direct ventilation is not performed during the normal air conditioning period.
However, the direct ventilation may also be performed during the normal air conditioning period and, in a case where a determination is made that refrigerant is leaked, the direct ventilation may be promoted more than when refrigerant is not leaked. Here, "promoting direct ventilation" means increasing a flow rate per unit time of the outside air drawn in the compartment 910 through the direct ventilation chamber 210r and a flow rate per unit time of the inside air discharged to the exterior EX through the exhaust chamber 310r.
The second fresh damper 220d may have a configuration that provides an adjustable degree of opening, that is, an adjustable amount of the outside air flowing from the exterior EX into the direct ventilation chamber 210r. In that case, when determining that the refrigerant is leaked, the control device 400 can promote the direct ventilation by increasing the degree of opening of the second fresh damper 220d, that is, by increasing the amount of the outside air flowing from the exterior EX into the direct ventilation chamber 210r.
The exhaust fan 340 may have a configuration that provides an adjustable rotational speed, specifically, adjustable inverter control. In that case, when determining that the refrigerant is leaked, the control device 400 can promote the direct ventilation by increasing the rotational speed of the exhaust fan 340.

Modified Example 5 of Embodiment 1

The indoor fan 162 may have a configuration that provides an adjustable rotational speed, specifically, adjustable inverter converter. In that case, when determining that the refrigerant is leaked, the control device 400 may increase the rotational speed of the indoor fan 162 more than during the normal air conditioning period. This enables the refrigerant leaked in the indoor unit chamber 130r to be quickly discharged to the exterior EX.

Modified Example 6 of Embodiment 1

FIG. 2 illustrates an example of a configuration in which the indoor unit chamber definer 130 includes a plurality of supply ports 174, specifically two supply ports 174. The indoor unit chamber definer 130 may include only one supply port 174.
As illustrated in FIG. 2, in a case where the supply chamber definer 133 includes a plurality of supply ports 174, the supply chamber 133r serves to distribute the inside air having passed through the indoor heat exchanger 154 to each of the supply ports 174.
Each of the supply ports 174 is in communication through an individual duct with an individual air outlet that is open in the inner surface of the compartment 910. The air outlet in communication with any one supply port 174 selected from the plurality of supply ports 174 is different from the air supply port 174 in communication with another supply port 174. That is, the supply port 174 has a one-to-one correspondence relationship with the air outlet.
As one specific example, in a case where the supply chamber definer 133 includes two supply ports 174 and railway vehicle 900 has a two-story structure, the inside air distributed to one of the supply ports 174 blows out from the air outlet that opens to the first floor portion of the railway vehicle 900 and the inside air distributed to the other supply port 174 blows out from the air outlet that opens to the second floor portion of the railway vehicle 900.

Embodiment 2

As illustrated in FIG. 7, the air conditioning device 100 according to the present embodiment further includes an indoor unit chamber electric heater 190 disposed in the indoor unit chamber 130r. Other than this point, the configuration is the same as that illustrated in FIG. 2.
Specifically, the indoor unit chamber electric heater 190 is installed in the supply chamber 133r. The indoor unit chamber electric heater 190 heats the inside air drawn in by the indoor fan 162 from the return port 171 toward the supply port 174 by Joule heat during the normal air conditioning period.
As previously described, each of the refrigerant circuits 150A and 150B is switchable between a cooling state and a heating state. Even with each of the refrigerant circuits 150A and 150B switchable to the heating state, the inside air can be heated using not only the indoor heat exchanger 154 serving as a condenser but also the indoor unit chamber electric heater 190.
In the present embodiment, the control device 400 checks whether or not power is supplied to the indoor unit chamber electric heater 190 under the indoor unit chamber ventilation control, and when the power is supplied to the indoor unit chamber electric heater 190, the control device 400 stops the power supply to the indoor unit chamber electric heater 190.
The indoor unit chamber electric heater 190 is disposed downstream of the leaked refrigerant discharge port 175 with respect to the flow of the air directing from the first fresh damper 172d toward the leaked refrigerant discharge port 175 and formed in the indoor unit chamber 130r by the indoor unit chamber ventilation control. Specifically, the indoor unit chamber electric heater 190 is disposed between the supply port 174 and the emergency damper 176d.
Thus, while the flow of the air from the first fresh damper 172d toward the leaked refrigerant discharge port 175 is formed by the indoor unit chamber ventilation control, air containing the leaked refrigerant is unlikely to hit the indoor unit chamber electric heater 190.
Thus, even if propane or other flammable substances are used as a refrigerant, the possibility of the leaked refrigerant being heated by the residual heat of the indoor unit chamber electric heater 190 and catching fire when the refrigerant is leaked can be reduced.

Modified Example 1 of Embodiment 2

As illustrated in FIG. 8, in the present modified example, the direct ventilation device 200 includes a plurality of direct ventilation chamber electric heaters 250 disposed in the direct ventilation chamber 210r. Other than this point, the configuration is the same as that illustrated in FIG. 7.
The direct ventilation chamber electric heaters 250 are disposed both over the outside air supply outside air supply port 230 and between the outdoor air intake outside air intake port 220 and the outside air supply port 230. However, the direct ventilation chamber electric heater 250 may be disposed only in one of two positions, a position over the outside air supply port 230 and a position between the outside air intake port 220 and the outside air supply port 230.
In the present embodiment, the control device 400 checks whether or not power is supplied to the direct ventilation chamber electric heater 250 under the compartment ventilation control, and when the power is not supplied to the direct ventilation chamber electric heater 250, the control device 400 starts the power supply to the direct ventilation chamber electric heater 250.
The direct ventilation chamber electric heater 250 heats outside air from the outside air intake port 220 toward the outside air supply port 230. Thus, even in the event of refrigerant leakage in winter or cold climate areas, the outside air to be drawn into the compartment 910 can be heated by the direct ventilation chamber electric heater 250, thereby reducing the temperature drop of the compartment 910.

Embodiment 3

As illustrated in FIG. 9, in the present embodiment, the direct ventilation chamber definer 210 is integrated with the indoor unit chamber definer 130 and outdoor unit chamber definer 120.
That is, the direct ventilation chamber definer 210, the indoor unit chamber definer 130, and the outdoor unit chamber definer 120 constitute an integral casing. This facilitates the ease and efficiency of manufacturing the direct ventilation chamber definer 210, the indoor unit chamber definer 130, and the outdoor unit chamber definer 120, while also reducing the volume occupied by the air conditioning system 800 for the railway vehicle.
The direct ventilation chamber definer 210 is disposed between the indoor unit chamber definer 130 and the outdoor unit chamber definer 120, specifically between the return chamber definer 131 and the outdoor heat exchange chamber definer 122. The arrangement of the direct ventilation chamber 210r separated from the indoor unit chamber 130r and the outdoor unit chamber 120r by a wall that constitutes the direct ventilation chamber definer 210 is the same as in Embodiment 1.
In the present embodiment, the refrigerant piping 155 and 159 penetrate the direct ventilation chamber definer 210, and the refrigerant piping 155 and 159 pass through the direct ventilation chamber 210r. The portion of the direct ventilation chamber definer 210 penetrated by the refrigerant piping 155 and 159 is hermetically closed.
The portion of the refrigerant piping 155 and 159 that is located in the direct ventilation chamber 210r has a continuous structure with no joints. Thus, the probability of refrigerant leakage from the portion of the refrigerant piping 155 and 159 that is located in the direct ventilation chamber 210r can be considered almost zero.
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 the wall shared by the direct ventilation chamber definer 210 and the return chamber definer 131 for division into the direct ventilation chamber 210r and the indoor unit chamber 130r.
An auxiliary return damper 260 is switchable between an auxiliary return permitting state in which the direct ventilation chamber 210r is permitted to be in communication with the indoor unit chamber 130r and an auxiliary return preventing state in which the direct ventilation chamber 210r is prevented from being in communication with the indoor unit chamber 130r.
As illustrated in FIG. 10, in the present embodiment, the control device 400 sets the auxiliary return damper 260 to the auxiliary return permitting state in step S11 described above. This makes the direct ventilation chamber 210r be in communication with the return chamber 131r, and thus the inside air in the compartment 910 is drawn by the indoor fan 162 not only from the return port 171 but also from the outside air supply port 230.
The inside air drawn in the direct ventilation chamber 210r from the outside air supply port 230 by the indoor fan 162 passes through the auxiliary return damper 260. The inside air having passed the auxiliary return damper 260 merges in the return chamber 131r with the inside air drawn in the return chamber 131r from the return port 171 similarly by the indoor fan 162.
In the normal air conditioning period until a determination is made in step S12 that the refrigerant is leaked, not only the first fresh damper 172d is switched to the ventilation state, but also the second fresh damper 220d may be set to the outside air intake permitting state. If the second fresh damper 220d is set to the outside air intake permitting state during the normal air conditioning period, the outside air can be drawn in the indoor unit chamber 130r and the compartment 910 through the second fresh damper 220d.
In the present embodiment, after determining in step S12 that the refrigerant is leaked, the control device 400 switches the auxiliary return damper 260 from the auxiliary return permitting state to the auxiliary return preventing state in step S13. This breaks the communication between the direct ventilation chamber 210r and the return chamber 131r.
Thus, when the exhaust fan is started in step S17, the direct ventilation is performed in which the outside air is drawn in the compartment 910 through the direct ventilation chamber 210r and the outside air supply port 230, while the inside air in the compartment 910 is discharged to the exterior EX through the exhaust chamber 310r. The configuration and the operation other that these points are the similar to those in Embodiment 1.

Modified Example 1 of Embodiment 3

As illustrated in FIG. 11, the configuration may be such that the direct communication between the direct ventilation chamber 210r and the indoor unit chamber 130r is broken. That is, the auxiliary return damper 260 illustrated in FIG. 9 may be omitted. Here, "the direct communication between the direct ventilation chamber 210r and the indoor unit chamber 130r" means communication by a route other than the route via the compartment 910. According to the present modified example, control by the auxiliary return damper 260 illustrated in FIG. 9 is unnecessary.

Embodiment 4

As illustrated in FIG. 12, in the configuration in which the direct ventilation chamber definer 210 is integrated with the housing 110, the direct ventilation chamber definer 210 may be connected to an end of the indoor unit chamber definer 130 that is an end opposite side of the end connected to the outdoor unit chamber definer 120.
Specifically, in the present embodiment, the direct ventilation chamber definer 210 is integrated with the wall surface of the supply chamber definer 133 in which the supply port 174 is formed. The supply port 174 connects the indoor unit chamber 130r to the direct ventilation chamber 210r.
The direct ventilation chamber definer 210 includes auxiliary supply ports 270 that connect the direct ventilation chamber 210r to the compartment 910, in addition to the outside air supply port 230.
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 closing state in which the outside air supply port 230 is closed and an outside air supply port opening state in which the outside air supply port 230 is opened.
During the normal air conditioning period, the control device 400 maintains the outside air supply port damper 230d in the outside air supply port closing state. Thus, the inside air having passed the indoor heat exchanger 154 flows into the direct ventilation chamber 210r via the supply port 174 and then is supplied to the compartment 910 through each of the auxiliary supply ports 270. At this time, the direct ventilation chamber 210r serves to distribute the inside air having passed the indoor heat exchanger 154 to the auxiliary supply ports 270.
During the compartment ventilation control described above, the control device 400 switches the outside air supply port damper 230d from the outside air supply port closing state to the outside air supply port opening state. At this time, the supply port 174 is closed by the emergency damper 176d, as described above.
The outside air drawn in the direct ventilation chamber 210r through the second fresh damper 220d is fed to the compartment 910 through both the auxiliary supply ports 270 and the open outside air supply port 230. The other configurations and operations are similar to those in Embodiment 1.

Modified Example 1 of Embodiment 4

As illustrated in FIG. 13, the emergency damper 176d may be separated and configured as a leaked refrigerant discharge port damper 176d-1 that serves to open and close the leaked refrigerant discharge port 175 and a supply port damper 176d-2 that serves to open and close the supply port 174. The function of the emergency damper 176d according to the present modified example is the same as the function of the emergency damper 176d having a single configuration illustrated in FIG. 12.

Modified Example 2 of Embodiment 4

As illustrated in FIG. 14, the direct ventilation chamber definer 210 may include a plurality of outside air supply ports 230. In the present modified example, the direct ventilation chamber definer 210 does not have the auxiliary supply ports 270 described above.
In the present modified example, during the normal air conditioning period, the inside air having passed the indoor heat exchanger 154 flows into the direct ventilation chamber 210r through the supply port 174 and then is supplied to the compartment 910 via each of the outside air supply ports 230. At this time, the direct ventilation chamber 210r serves to distribute the inside air having passed the indoor heat exchanger 154 to the outside air supply ports 230.
In the compartment ventilation control described above, the supply port 174 is closed by the emergency damper 176d, and thus, the outside air drawn in the direct ventilation chamber 210r through the second fresh damper 220d is fed to the compartment 910 via each of the outside air supply ports 230.
As described above, the outside air supply port 230 according to the present modified example not only serves to feed the outside air into the compartment when the refrigerant is leaked, but also serves to feed the inside air having passed through the indoor heat exchanger 154 into the compartment 910 during the normal air conditioning period.
The present modified example provides an example of a configuration with the plurality of outside air supply ports 230, but a single outside air supply port 230 may be used. The other configurations and operations are similar to those in Embodiment 1.

Embodiment 5

As illustrated in FIG. 15, in the present embodiment, the exhaust chamber definer 310 is integrated with the indoor unit chamber definer 130 and the outdoor unit chamber definer 120. That is, the exhaust chamber definer 310, the indoor unit chamber definer 130, and the outdoor unit chamber definer 120 constitute an integral casing.
This facilitates the ease and efficiency of manufacturing the exhaust chamber definer 310, the indoor unit chamber definer 130, and the outdoor unit chamber definer 120, while also reducing the volume occupied by the air conditioning system 800 for the railway vehicle.

Modified Example 1 of Embodiment 5

As illustrated in FIG. 16, in the present embodiment, the exhaust chamber definer 310 and the direct ventilation chamber definer 210 are integrated with the indoor unit chamber definer 130 and the outdoor unit chamber definer 120. That is, the exhaust chamber definer 310, the direct ventilation chamber definer 210, the indoor unit chamber definer 130, and the outdoor unit chamber definer 120 constitute an integral casing.

Modified Example 2 of Embodiment 5

As illustrated in FIG. 17, in the configuration in which the exhaust chamber definer 310 and the direct ventilation chamber definer 210 are integrated with the housing 110, the leaked refrigerant discharge port 175 is formed in the wall surface shared by the indoor unit chamber definer 130 and the exhaust chamber definer 310. The leaked refrigerant discharge port 175 is provided with a leaked refrigerant discharge port damper 176d-1 described above.
According to the present modified example, since the leaked refrigerant discharge port damper 176d-1 is opened by the indoor unit chamber ventilation control, the air pressure of the exhaust chamber 310r decreases with the startup of the exhaust fan 340, and thus, the leaked refrigerant of the indoor unit chamber 130r can be discharged to the exterior via the open leaked refrigerant discharge port damper 176d-1, the exhaust chamber 310r, and the inside air discharge port 330.

Embodiment 6

As illustrated in FIG. 18, the air conditioning system 800 for a railway vehicle according to the present embodiment includes two air conditioning devices 100A and 100B that air condition the shared compartment 910, and the exhaust device 300.
Each of the air conditioning devices 100A and 100B is the same as the air conditioning device 100 according to any one of Embodiments 1 to 5 described above. Similarly, the exhaust device 300 is the same as any one of Embodiments 1 to 5 described above.
In the present embodiment, the direct ventilation device 200 described above is omitted. However, in a case where refrigerant is leaked in one of the two air conditioning devices 100A and 100B, the other air conditioning device servers as the direct ventilation device 200 described above. The operation of the air conditioning system 800 according to the present embodiment is hereinafter described in detail.
As illustrated in FIG. 19, when a determination is made that refrigerant is leaked in one of the two air conditioning devices 100A and 100B (hereinafter referred to as a first air conditioning device) (Yes in step S12), the control device 400 performs the indoor unit chamber ventilation control described above on the first air conditioning device (steps S13-S15).
This ventilates the indoor unit chamber 130r of the first air conditioning device. That is, the leaked refrigerant in the indoor unit chamber 130r of the first air conditioning device is discharged to the exterior EX.
As for the other air conditioning device (hereinafter referred to as a second air conditioning device) of the two air conditioning devices 100A and 100B in which refrigerant is not leaked, the control device 400 sets the first fresh damper 172d of the second air conditioning device to the ventilation state as the compartment ventilation control described above (step S16). In a case where the first fresh damper 172d of the second air conditioning device is already in the ventilation state, step S16 is omitted. Then, the control device 400 starts the exhaust fan 340 (step S17).
As a result, as the exhaust fan 340 lowers the air pressure in the compartment 910, fresh outside air is drawn in the compartment 910 through the first fresh damper 172d of the second air conditioning device, and the inside air in the compartment 910 is discharged to the exterior EX from the inside air discharge port 330. In this way, the compartment 910 is ventilated.
At this time, the indoor unit chamber 130r of the second air conditioning device serves as the direct ventilation chamber 210r described above. The ventilation port 172 of the second air conditioning device serves as the outside air intake port 220 described above. The first fresh damper 172d of the second air conditioning device serves as the second fresh damper 220d described above.
At least one of the return port 171 and the supply port 174 of the second air conditioning device serves as the outside air supply port 230 described above. In a case where the indoor fan 162 of the second air conditioning device is stopped in the compartment ventilation control, the return port 171 of the second air conditioning device exclusively serves as the outside air supply ports 230 described above.
Also, in the compartment ventilation control, the rotational speed of the indoor fan 162 of the second air conditioning device may be higher than during the normal air conditioning period. In this case, both the return port 171 and the supply port 174 of the second air conditioning device can serve as the outside air supply ports 230 described above.

Embodiment 7

As illustrated in FIG. 20, the refrigerant leakage detector 180 may be disposed near each of the refrigerant piping 155 and 159 separated from each other in the Y-axis direction. The refrigerant leakage detector 180 that is located closer to the refrigerant piping 155 detects leakage of the refrigerant from one refrigerant circuit 150A. The refrigerant leakage detector 180 that is located closer to the refrigerant piping 159 detects leakage of the refrigerant from the other refrigerant circuit 150B.
In this way, the air conditioning device 100 according to the present embodiment has a configuration in which the control device 400 can determine which of the two refrigerant circuits 150A and 150B the refrigerant is leaked from.
When determining that the refrigerant is leaked from one of the refrigerant circuits 150A and 150B (hereinafter referred to as a first refrigerant circuit in the present embodiment), the control device 400 according to the present embodiment restarts operation of the other refrigerant circuit of the refrigerant circuits 150A and 150B (hereinafter referred to as a second refrigerant circuit in the present embodiment), on the condition that no refrigerant leakage from the first refrigerant circuit is detected after the indoor unit chamber ventilation control and the compartment ventilation control described above are performed.
Here, "restarting operation of the second refrigerant circuit" means restarting circulation of the refrigerant in the second refrigerant circuit, specifically restarting operation of the circuit constituting the second refrigerant circuit of the compressors 151 and 156.
Performing blowing operation for a certain period of time is preferable. The blowing operation is to feed the outside air drawn in the compartment 910 from the first fresh damper 172d while stopping circulation of the refrigerant in the first refrigerant circuit and the second refrigerant circuit before restarting the operation of the second refrigerant circuit after no leakage of the refrigerant from the first refrigerant circuit is detected.

Embodiment 8

As illustrated in FIG. 21, the indoor unit chamber definer 130 according to the present embodiment includes a partition 134 that hermetically divides the portion of the indoor unit chamber 130r that is shared by the indoor heat exchange chamber 132r and the supply chamber 133r into a first indoor unit chamber 130r1 and a second indoor unit chamber 130r2. The partition 134 extends in the X-axis direction. The first indoor unit chamber 130r1 and the second indoor unit chamber 130r2 are adjacent to each other in the Y-axis direction through the partition 134.
The indoor heat exchanger 154 described above is separated into a first indoor heat exchanger 154A constituting one refrigerant circuit (hereinafter referred to as a first refrigerant circuit in the present embodiment and modified examples of the present embodiment) 150A and a second indoor heat exchanger 154B constituting the other refrigerant circuit (hereinafter referred to as a second refrigerant circuit in the present embodiment and modified examples of the present embodiment) 150B.
The first indoor heat exchanger 154A is disposed in the first indoor unit chamber 130r1. The second indoor heat exchanger 154B is disposed in the second indoor unit chamber 130r2.
A pair of the supply port 174 and the leaked refrigerant discharge port 175 is formed in each of a first indoor unit chamber defining section 130A that is a portion of the indoor unit chamber definer 130 that defines the first indoor unit chamber 130r1 and a second indoor unit chamber defining section 130B that is a portion defining the second indoor unit chamber 130r2.
The emergency damper 176d and the indoor fan 162 are disposed in each of the first indoor unit chamber 130r1 and the second indoor unit chamber 130r2.
The emergency damper 176d disposed in the first indoor unit chamber 130r1 opens and closes the supply port 174 and the leaked refrigerant discharge port 175 formed in the first indoor unit chamber defining section 130A. The emergency damper 176d disposed in the second indoor unit chamber 130r2 opens and closes the supply port 174 and the leaked refrigerant discharge port 175 formed in the second indoor unit chamber defining section 130B.
According to the configuration of the indoor unit chamber definer 130 according to the present embodiment, even when refrigerant is leaked from one of first refrigerant circuit 150A and the second refrigerant circuit 150B, the other refrigerant circuit can continuously operate.
Specifically, when the refrigerant is leaked in the first refrigerant circuit 150A, the control device 400 stops the compressor 151 while operating the pair of indoor fans 162, switches the emergency damper 176d of the first indoor unit chamber 130r1 from the inside air circulating state to the inside air non-circulating state, sets the first fresh damper 172d to the ventilation state, and performs the compartment ventilation control described above.
At this time, the return damper 171d is maintained in the return permitting state, the compressor 156 and the outdoor fan 161 are kept running, and the emergency damper 176d of the second indoor unit chamber 130r2 is maintained in the inside air circulating state.
This allows the inside air having passed the second indoor heat exchanger 154B to be fed to the compartment 910 through the second indoor unit chamber 130r2, even though the compartment ventilation control is performed in the first indoor unit chamber 130r1. This reduces the loss of comfort in the compartment 910 due to the direct ventilation of the compartment 910.
Specifically, when the refrigerant is leaked in the second refrigerant circuit 150B, the control device 400 stops the compressor 156 while operating the pair of indoor fans 162, switches the emergency damper 176d of the second indoor unit chamber 130r2 from the inside air circulating state to the inside air non-circulating state, sets the first fresh damper 172d to the ventilation state, and performs the compartment ventilation control described above.
At this time, the return damper 171d is maintained in the return permitting state, the compressor 151 and the outdoor fan 161 are kept running, and the emergency damper 176d of the first indoor unit chamber 130r1 is maintained in the inside air circulating state.
This allows the inside air having passed the first indoor heat exchanger 154A to be fed to the compartment 910 through the first indoor unit chamber 130r1, even though the compartment ventilation control is performed in the second indoor unit chamber 130r2. This reduces the loss of comfort in the compartment 910 due to the direct ventilation of the compartment 910.

Modified Example 1 of Embodiment 8

As illustrated in FIG. 22, the partition 134 may extend to the return chamber 131r. That is, in the present modified example, the indoor heat exchange chamber 132r, the supply chamber 133r, and the return chamber 131r are hermetically divided into the first indoor unit chamber 130r1 and the second indoor unit chamber 130r2.
The partition 134 divides the return port 171 into a portion that opens to the first indoor unit chamber 130r1 and a portion that opens to the second indoor unit chamber 130r2. A pair of the ventilation port 172 and the first fresh damper 172d is disposed in each of the first indoor unit chamber defining section 130A and the second indoor unit chamber defining section 130B.
According to the present modified example, when the refrigerant is leaked in one of the first refrigerant circuit 150A and the second refrigerant circuit 150B, the inside air drawn from the return port 171 is unlikely to merge with the leaked refrigerant in the return chamber 131r. Thus, the leaked refrigerant is unlikely to flow in the compartment 910, though the other refrigerant circuit of the first refrigerant circuit 150A and the second refrigerant circuit 150B are kept running.

Modified Example 2 of Embodiment 8

As illustrated in FIG. 23, in the present modified example, the refrigerant piping 155 constituting the first refrigerant circuit 150A and the refrigerant piping 159 constituting the second refrigerant circuit 150B are located far from each other in the return chamber 131r. This is described in detail below.
Here, the direction in which the first refrigerant circuit 150A and the second refrigerant circuit 150B are arranged is referred to as a refrigerant circuit arrangement direction. In the present modified example, the refrigerant circuit arrangement direction is specifically the Y-axis direction.
The return chamber definer 131 has a first end surface and a second end surface that face each other in the refrigerant circuit arrangement direction. The pair of the ventilation port 172 and the first fresh damper 172d is disposed in each of the first end surface and the second end surface. The return port 171 extends in the refrigerant circuit arrangement direction at a central portion of the return chamber 131r in the refrigerant circuit arrangement direction.
In the return chamber 131r, the refrigerant piping 155 constituting the first refrigerant circuit 150A is disposed closer to the first end surface than to the central portion of the return chamber 131r in the refrigerant circuit arrangement direction. Specifically, in the return chamber 131r, the refrigerant piping 155 constituting the first refrigerant circuit 150A is disposed closer to the first end surface than an edge of the return port 171 closer to the first end surface.
Similarly, in the return chamber 131r, the refrigerant piping 159 constituting the second refrigerant circuit 150B is disposed closer to the second end surface than the central portion of the return chamber 131r in the refrigerant circuit arrangement direction. Specifically, in the return chamber 131r, the refrigerant piping 159 constituting the second refrigerant circuit 150B is disposed closer to the second end surface than an edge of the return port 171 closer to the second end surface.
According to the present modified example, when the refrigerant is leaked in one of the first refrigerant circuit 150A and the second refrigerant circuit 150B, the inside air drawn from the return port 171 is unlikely to merge with the leaked refrigerant in the return chamber 131r. Thus, the leaked refrigerant is unlikely to flow in the compartment 910, though the other refrigerant circuit of the first refrigerant circuit 150A and the second refrigerant circuit 150B are kept running.

Embodiment 9

As illustrated in FIG. 24, the exhaust device 300 may be configured to discharge, from above the railway vehicle 900, the inside air drawn from the compartment 910.
In the present embodiment, the inside air discharge port 330 is open in the top surface of the railway vehicle 900 and the exhaust fan 340 is disposed on a roof portion of the railway vehicle 900. The exhaust chamber 310r surrounds the compartment 910 as viewed in a cross section perpendicular to the length direction of the railway vehicle 900, that is, in the YZ cross section.
The exhaust chamber definer 310 of the exhaust device 300 according to the present embodiment may be provided apart from the housing 110 of the air conditioning device 100 or may be integrated with the housing 110 of the air conditioning device 100.
In the compartment ventilation control described above, the inside air in the compartment 910 flows out from the inside air intake port 320 to the exhaust chamber 310r in the positive and negative Y-axis directions. The outflowing inside air is drawn up by the exhaust fan 340 and discharged upward through the inside air discharge port 330.
In the present embodiment, a refrigerant with a greater specific gravity than air is used as the refrigerant. Therefore, the pair of inside air intake ports 320 facing each other in the Y-axis direction is opened in the compartment 910 below the center of compartment 910 in the height direction. This enables the refrigerant that tends to accumulate in the lower part of the compartment 910 to be efficiently discharged to the exterior EX.

Modified example 1 of Embodiment 9

As illustrated in FIG. 25, the pair of inside air intake ports 320 facing each other in the Y-axis direction may be opened in the center or above the center of the compartment 910 in the height direction. Under conditions where airflow is occurring in the compartment 910, the refrigerant could be dispersed into the compartment 910 even if the specific gravity of the refrigerant is greater than that of air. Thus, the refrigerant can be also discharged to the exterior EX by the inside air intake ports 320 according to the present modified example.

Embodiment 10

As illustrated in FIG. 26, the indoor unit chamber definer 130 and the outdoor unit chamber definer 120 may be disposed separated from each other. In the present embodiment, the indoor unit chamber definer 130 is disposed on a portion of the roof of the railway vehicle 900. The outdoor unit chamber definer 120 is disposed under a portion of the floor of the railway vehicle 900.
In addition, in the present embodiment, the indoor unit chamber definer 130 is disposed separated into the first indoor unit chamber defining section 130A and the second indoor unit chamber defining section 130B. One of the first indoor unit chamber defining section 130A and the second indoor unit chamber defining section 130B may accommodate the refrigerant circuit 150A and the other may accommodate the refrigerant circuit 150B. Also, each of the first indoor unit chamber defining section 130A and the second indoor unit chamber defining section 130B may accommodate the refrigerant circuits 150A and 150B.
The more the number of refrigerant circuits 150A and 150B serving to air coordinate the shared compartment 910 can reduce an amount of refrigerant per the refrigerant circuit 150A or 150B compared with when the compartment 910 is air conditioned with an unillustrated single refrigerant circuit. Thus, when the refrigerant is leaked, the amount of the leaked refrigerant can be suppressed.
Embodiments 1 to 10 are described above, but can be modified as described below.
FIG. 2 illustrates an example of a configuration in which the leaked refrigerant leakage detector 180 is disposed in the indoor unit chamber 130r, but the leaked refrigerant leakage detector 180 may be disposed in the exterior of the indoor unit chamber 130r. As a specific example, the refrigerant leakage detector 180 may be disposed in the compartment 910. In a case where the refrigerant with a greater specific gravity than air is used as the refrigerant, the refrigerant leakage detector 180 may be disposed below the center of the compartment 910 in the height direction.
FIG. 2 illustrates an example of the configuration in which the return chamber 131r is in communication with the indoor heat exchange chamber 132r through the indoor heat exchanger 154. The indoor fan 162 may be disposed at a boundary portion between the return chamber 131r and the indoor heat exchange chamber 132r to permit the return chamber 131r to be in communication with the indoor heat exchange chamber 132r via the indoor fan 162. The same applies to the configurations illustrated in FIGS. 21 to 23.
Embodiments 1 to 10 and the modified examples thereof may be combined with one another. The concept of "railway vehicles" in the present specification encompasses not only trains but also bullet trains, monorails, and other vehicles traveling along rails.
The foregoing describes some example embodiments for explanatory purposes. Although the foregoing discussion has presented specific embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the included claims, along with the full range of equivalents to which such claims are entitled.

Reference Signs List

100: Air conditioning device
100A: Air conditioning device
100B: Air conditioning device
110: Housing
120: Outdoor unit chamber definer
120r: Outdoor unit chamber
121: Compressor chamber definer
121r: Compressor chamber
122: Outdoor heat exchange chamber definer
122r: Outdoor heat exchange chamber
130: Indoor unit chamber definer
130A: First indoor unit chamber defining section
130B: Second indoor unit chamber defining section
130r: Indoor unit chamber
130r1: First indoor unit chamber
130r2: Second indoor unit chamber
131: Return chamber definer
131r: Return chamber
132: Indoor heat exchange chamber definer
132r: Indoor heat exchange chamber
133: Supply chamber definer
133r: Supply chamber
134: Partition
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 leakage detector
190: Indoor unit chamber electric heater
200: Direct ventilation device
210: Direct ventilation chamber definer
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: Air communication passage
250: Direct ventilation chamber electric heater
260: Auxiliary return damper
270: Auxiliary supply port
300: Exhaust device
310: Exhaust chamber definer
310r: Exhaust chamber
320: Inside air intake port
330: Inside air discharge port
340: Exhaust fan
400: Control device
800: Air conditioning system for railway vehicle
900: Railway vehicle
910: Compartment
EX: Exterior

Claims

An air conditioning system for a railway vehicle, the air conditioning system comprising:
an indoor unit chamber definer including a return port and a supply port each connecting to a compartment of the railway vehicle, and a ventilation port connecting to an exterior of the railway vehicle, the indoor unit chamber definer defining an indoor unit chamber;

an indoor fan disposed in the indoor unit chamber and configured to draw, from the return port, inside air that is air in the compartment and discharging the drawn inside air to the supply port to form in the indoor unit chamber a flow of the inside air from the return port toward the supply port;

a refrigerant circuit including an indoor heat exchanger and a group of cooperative devices, the indoor heat exchanger being disposed at a position in the indoor unit chamber in a path of the flow of the inside air and configured to perform heat exchange between refrigerant and the inside air, the group of cooperating devices constituting a refrigeration cycle using the refrigerant together with the indoor heat exchanger;

a first fresh damper disposed at the ventilation port and being switchable between a ventilation state in which the ventilation port is opened to allow outside air that is air of the exterior to be merged with the inside air flowing in the indoor heat exchanger and a non-ventilation state in which the ventilation port is closed;

a refrigerant leakage detector to detect leakage of the refrigerant from the refrigerant circuit;

an exhaust chamber definer defining an exhaust chamber separated from the indoor unit chamber and including an inside air intake port connecting to the compartment and an inside air discharge port connecting to the exterior;

an exhaust fan disposed in the exhaust chamber and configured to draw the inside air in the exhaust chamber from the inside air intake port and discharge the drawn inside air to the exterior through the inside air discharge port; and

a control device to control the first fresh damper and the exhaust fan, wherein

the indoor unit chamber definer further includes a leaked refrigerant discharge port connecting to the exterior, the leaked refrigerant discharge port being located downstream of the indoor heat exchanger with respect to a flow of the inside air in the indoor unit chamber,

the air conditioning system further includes
an emergency damper disposed in the indoor unit chamber and being switchable between an inside air circulating state in which the leaked refrigerant discharge port is closed and the supply port is opened and an inside air non-circulating state in which the leaked refrigerant discharge port is opened and the supply port is closed,

a direct ventilation chamber definer defining a direct ventilation chamber separated from the indoor unit chamber and the exhaust chamber and including an outside air intake port connecting to the exterior and an outside air supply port connecting to the compartment, and

a second fresh damper disposed at the outside air intake port and configured to control an inflow of the outside air from the exterior to the direct ventilation chamber, and

the control device performs
when the control device determines based on a result of detection by the refrigerant leakage detector that the refrigerant is leaked from the refrigerant circuit,
(I) indoor unit chamber ventilation control to switch the emergency damper from the inside air circulating state to the inside air non-circulating state while operating the indoor fan, and switch the first fresh damper from the non-ventilation state to the ventilation state when the first fresh damper is in the non-ventilation state, and

(II) compartment ventilation control to promote direct ventilation by controlling the exhaust fan and the second fresh damper more than when the refrigerant is not leaked from the refrigerant circuit, the direct ventilation permitting the outside air to be drawn in the compartment through the direct ventilation chamber and permitting the inside air of the compartment to be discharged to the exterior through the exhaust chamber.
The air conditioning system according to claim 1, wherein
the group of cooperating devices includes a compressor that compresses the refrigerant and an outdoor heat exchanger that performs heat exchange between the refrigerant and air in the exterior,

the air conditioning system further includes an outdoor unit chamber definer that defines an outdoor unit chamber in which the compressor and the outdoor heat exchanger are disposed, and

the direct ventilation chamber definer is installed separated from the indoor unit chamber definer and the outdoor unit chamber definer.
The air conditioning system according to claim 1, wherein
the group of cooperating devices includes a compressor that compresses the refrigerant and an outdoor heat exchanger that performs heat exchange between the refrigerant and air in the exterior,

the air conditioning system further includes an outdoor unit chamber definer that defines an outdoor unit chamber in which the compressor and the outdoor heat exchanger are disposed, and

the direct ventilation chamber definer is integrated with the indoor unit chamber definer and the outdoor unit chamber definer.
The railroad vehicle air conditioning apparatus according to claim 3, wherein
the direct ventilation chamber definer is disposed between the indoor unit chamber definer and the outdoor unit chamber definer,

the air conditioning system further includes an auxiliary return damper that is disposed between the direct ventilation chamber and the indoor unit chamber and switchable between an auxiliary return permitting state in which the direct ventilation chamber is permitted to be in communication with the indoor unit chamber and an auxiliary return preventing state in which the direct ventilation chamber is prevented from being in communication with the indoor unit chamber, and

when the control device determines based on a result of detection by the refrigerant leakage detector that the refrigerant is leaked from the refrigerant circuit, the control device sets the auxiliary return damper to the auxiliary return preventing state.
The railroad vehicle air conditioning apparatus according to claim 3, wherein
the direct ventilation chamber definer is integrated with a wall surface of the indoor unit chamber definer in which the supply port is formed, and

the supply port connects the indoor unit chamber to the direct ventilation chamber.
The air conditioning system according to claim 5, wherein
the direct ventilation chamber definer includes an auxiliary supply port that connects the direct ventilation chamber to the compartment, in addition to the outside air supply port,

the air conditioning system further includes an outside air supply port damper that is disposed at the outside air supply port and switchable between an outside air supply port closing state in which the outside air supply port is closed and an outside air supply port opening state in which the outside air supply port is opened, and

the control device switches the outside air supply port damper from the outside air supply port closing state to the outside air supply port opening state in the compartment ventilation control.
The air conditioning system according to claim 1, further comprising:
an indoor unit chamber electric heater disposed in the indoor unit chamber and configured to heat the inside air drawn from the return port by the indoor fan toward the supply port, wherein

the indoor unit chamber electric heater is disposed downstream of the leaked refrigerant discharge port with respect to a flow of air from the first fresh damper to the leaked refrigerant discharge port, the flow of air being formed in the indoor unit chamber by the indoor unit chamber ventilation control.
The air conditioning system according to claim 1, further comprising:
a direct ventilation chamber electric heater disposed in the direct ventilation chamber and configured to heat air from the outside air intake port to the outside air supply port, wherein

the direct ventilation chamber electric heater is disposed at least at least one of a position over the outside air supply port and a position between the outside air intake port and the outside air supply port.
The air conditioning system according to claim 1, wherein
the group of cooperating devices includes a compressor that compresses the refrigerant and an outdoor heat exchanger that performs heat exchange between the refrigerant and air in the exterior,

the air conditioning system further includes an outdoor unit chamber definer that defines an outdoor unit chamber in which the compressor and the outdoor heat exchanger are disposed, and

the exhaust chamber definer is integrated with the indoor unit chamber definer and the outdoor unit chamber definer.
The air conditioner system according to claim 1, wherein
the air conditioning system includes two refrigerant circuits,

the indoor unit chamber definer includes a partition that hermetically divides at least a portion of the indoor unit chamber into a first indoor unit chamber in which the indoor heat exchanger included in a first refrigerant circuit that is one of the refrigerant circuits is disposed and a second indoor unit chamber in which the indoor heat exchanger included in a second refrigerant circuit that is the other refrigerant circuit,

the supply port and the leaked refrigerant discharge port is formed in each of a first indoor unit chamber defining section that is a portion of the indoor unit chamber definer that defines the first indoor unit chamber and a second indoor unit chamber defining section that is a portion of the indoor unit chamber definer that defines the second indoor unit chamber, and

the emergency damper and the indoor fan are disposed in each of the first indoor unit chamber and the second indoor unit chamber.