JP2000355213A - Air conditioning device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely detect a leakage of carbon dioxide from a refrigerator if carbon dioxide leaks from it and make an occupant in a vehicle recognize this information in an air conditioning device for vehicle using carbon dioxide as refrigerant for refrigerating cycle. SOLUTION: In an air conditioning device for vehicle provided with a cooler 3 for cooling air introduced into a casing 1, the cooling device 3 constitutes a part of refrigerating cycle using carbon dioxide as refrigerant, and a gas detection device 19 for detecting the concentration of CO2 gas in air is provided on a rear flow side of air in the cooler 3. When CO2 leaks from the refrigerating cycle 22 due to some reason, for example, the breakage of the cooler 3, the concentration of CO2 gas in the air passing through the cooler 3 is increased, which is detected by the gas detection device 19 to let an occupant in a vehicle know this information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a cooler for cooling air introduced into a casing, and the cooler forms a part of a refrigeration cycle using carbon dioxide as a refrigerant. Related to the device.

[0002]

2. Description of the Related Art FIG. 4 is a configuration diagram showing an example of a conventional vehicle air conditioner. Casing 1 as air conditioner body
The inner space serves as a flow path for air introduced into the vehicle interior, and houses various components as described later. The blower blower 2 introduces air into the casing 1 through the inside air opening 5 or the outside air opening 6, and the introduced air passes through the cooler 3. Reference numeral 7 denotes an inside / outside air switching damper for switching between the inside air port 5 and the outside air port 6. An air mix damper 8 and a heater 4 are provided downstream of the introduced air of the cooler 3. Symbol 12,
Reference numerals 13 and 14 denote a face-side outlet (FACE outlet), a foot-side outlet (FOOT outlet), and a window-side outlet (DEF outlet), respectively. They are opened and closed by 9, 10, and 11 (FACE damper, FOOT damper, and DEF damper, respectively). In addition, each outlet 12,13,
Reference numeral 14 communicates with the vehicle interior via a duct (not shown).
The control device 15 controls the blower 2 and controls each damper 8,
The control of a motor (not shown) for driving 9, 10, 11 and the control of ON / OFF of the compressor 16, which will be described later, are performed. The air introduced from the inside air port 5 or the outside air port 6 is cooled through the cooler 3, and then the amount of air passing through the heater 4 is adjusted by opening and closing the air mix damper 8, and is adjusted to a predetermined temperature. Later, outlet 12,1
It will be introduced into the vehicle cabin from at least one of the vehicles 3 and 14.

Next, in the refrigerating cycle 22, the compressor 16 is driven by obtaining a driving force from a driving source (eg, an engine or the like) not shown, and compresses the refrigerant in a gaseous state. The condenser 17 cools the refrigerant compressed by the compressor 16 by exchanging heat with the outside air or the like. Reference numeral 18 denotes a throttle device which decompresses the refrigerant at the outlet side of the condenser 17 to make a low-temperature low-pressure gas-liquid two-phase state. The cooler 3 is an evaporator (heat absorber) serving as air cooling means in the vehicle interior. When the gas-liquid two-phase refrigerant evaporates (evaporates) in the evaporator, the refrigerant evaporates from the vehicle interior air or the vehicle exterior air. Takes latent heat and cools. The compressor 16, the condenser 17, the expansion device 18, and the cooler 3 are connected in series by a pipe 21 to form a closed circuit as a refrigeration cycle 22. As the refrigerant, an alternative Freon refrigerant such as R134a is used. ing. The R134a evaporates inside the cooler 3, thereby absorbing heat from the air sent from the blower 2 and performing cooling. The compressor 16, the condenser 17, and the expansion device 18 are installed in an engine room or the like.

[0004] In recent years, there has been an increasing interest in preserving the global environment. However, alternative CFCs such as R134a, which has been conventionally used as a refrigerant for air conditioners for vehicles, have a great influence on global warming. It has been found that Therefore, research has been conducted on vehicle air conditioners using so-called natural refrigerants, which are substances originally existing in the natural world as a substitute for the alternative CFC refrigerants. Carbon dioxide has attracted attention as one of the natural refrigerant candidates. Have been. Carbon dioxide contributes significantly less to global warming than alternative Freon refrigerants, is not flammable, and is basically harmless to the human body.

[0005]

By the way, when the concentration of carbon dioxide becomes higher than the concentration in ordinary air (about 0.04%), even if oxygen is sufficiently present, the human body is adversely affected. May be affected. The allowable concentration is, for example, according to the ACGIH (U.S. Government and Occupational Health Council), but it is indicated as 0.5 to 3.0% depending on the exposure time. And, since the vehicle interior is basically a closed space, in a vehicle air conditioner using carbon dioxide as a refrigerant,
If carbon dioxide leaks from the refrigeration cycle due to some factor and enters the vehicle interior, depending on the amount of leaked carbon dioxide and the size of the vehicle interior space, the carbon dioxide concentration in the vehicle interior greatly exceeds the normal concentration, It is expected to affect passengers.

Accordingly, the present invention has been made in view of the above-mentioned problems of the prior art, and is directed to a vehicle air conditioner using carbon dioxide as a refrigerant of a refrigeration cycle.
Should carbon dioxide leak from the refrigeration cycle,
It is an object of the present invention to provide an air conditioner for a vehicle that can surely detect this and allow a passenger of the vehicle to recognize this information.

[0007]

According to the present invention, there is provided an air conditioner for a vehicle having a cooler for cooling air introduced into a casing. Form a part of a refrigeration cycle using carbon, downstream of the air flow of the cooler,
A gas detection device for detecting the concentration of CO ₂ in the air is provided.

According to the present invention, when CO ₂ leaks from the refrigeration cycle due to any cause, for example, breakage of a cooler, the CO ₂ gas concentration in the air passing through the cooler becomes higher than a specified concentration value. The information is detected by a gas detection device, and this information is made known to the occupants of the vehicle.

In this case, when the detection signal from the gas detection device is equal to or more than a prescribed value, the display device is provided so that the occupant of the vehicle can recognize the detection signal. By simply looking at the display device, the leakage of CO ₂ can be recognized, and the vehicle cost does not increase.

The invention according to claim 3 provides a cooler for cooling the air introduced into the casing, an outlet for blowing the air temperature-controlled in the casing to the outside of the casing, and an outlet for the air. In a vehicle air conditioner including a damper for opening and closing a mouth, the cooler forms a part of a refrigeration cycle using carbon dioxide as a refrigerant, and on a downstream side of the air flow of the cooler,
A gas detection device for detecting the CO ₂ concentration in the air is provided, and a control device for controlling the direction of closing the damper when a detection signal from the gas detection device is equal to or more than a specified value is provided. It is characterized by the following.

When carbon dioxide leaks from the cooler,
If the outlet is open, the CO ₂ gas easily enters the vehicle interior, and the CO ₂ gas concentration in the vehicle interior tends to increase accordingly. Therefore, in the invention of claim 3, wherein, upon detection of the leakage of CO _2, by controlling the direction in which the control device closes the blowout dampers, CO ₂
It is possible to reduce the invasion of gas itself into the vehicle interior.

[0012]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a first embodiment of a vehicle air conditioner of the present invention. As shown in FIG.
In a vehicle air conditioner using carbon dioxide as a refrigerant, a known gas detection device for detecting the concentration of CO ₂ gas in the air downstream of a cooler 3 holding carbon dioxide therein in an air flow. 19 (carbon dioxide detector) is provided. The gas detector 19 is located at a position behind the heater 4 and the air mix damper 8 where the increase in the flow resistance of the air is suppressed as much as possible. In the present embodiment, the warm air H passing through the heater 4 and the heater 4 are connected to each other. It is arranged near the position where the cold air R that does not pass through is mixed. Other configurations are shown in FIG.
Therefore, the same reference numerals are given and the description thereof is omitted.

As described above, when the cooler 3 is damaged for some reason, CO ₂ leaks from the refrigeration cycle 22 and the concentration of CO ₂ gas in the air passing through the cooler 3 increases. The leaked CO ₂ passes through the inside of the casing 1, passes through at least one of the outlets 12, 13, 14, and enters the vehicle interior. In the present embodiment, the cooler 3
If the concentration of CO ₂ gas in the air passing through the vehicle increases and the detection signal from the gas detection device 19 becomes higher than a specified concentration value, this is notified by, for example, an alarm (not shown) provided in the vehicle interior. Passengers can be recognized. The gas detection apparatus 19 of the above embodiment is intended to detect the concentration of CO ₂ gas directly, CO ₂ gas and O ₂ gas component other than the gas in the air, the components of such as nitrogen gas or argon gas Since it is almost unchanged, an O ₂ sensor may be used to detect the oxygen gas concentration and then calculate the CO ₂ gas concentration based on the detected oxygen gas concentration.

Next, a second embodiment will be described. As shown in FIG. 2, the signal from the gas detection device 19 is directly
Alternatively, a display device 20 for indirectly exchanging information via the control device 15 is provided in the vehicle interior.
Passengers can easily recognize the information indicated by. That is, a concentration higher than the normal concentration (approximately 0.04%) by the gas detection device 19, for example, 0.5% (specified concentration value that is considered safe when the exposure time per day is 8 hours in the ACGIH) If a higher concentration (detection signal) is detected,
It is determined that O ₂ has leaked, and the display device 20 displays CO ₂
By letting the passengers recognize the leakage of the vehicle, the possibility that the CO ₂ gas concentration in the vehicle compartment increases can be notified in advance.
Other configurations and operations are the same as those of the first embodiment.

Next, a third embodiment will be described. As shown in FIG. 3, when the gas detector 19 detects the CO ₂ gas normal concentration value or more concentration, as long as a state where the face damper 9 and foot side damper 10 is opened, CO ₂ into the compartment The gas is easy to enter, and the CO ₂
The concentration tends to increase. Therefore, in the present embodiment, when the gas detection device 19 detects a concentration higher than the specified concentration value, the signal is input to the control device 15, and the control device 15 transmits the signal to the damper driving motor (not shown).
Is controlled so that the face side damper 9 is closed. As a result, the invasion of CO ₂ gas into the vehicle interior can be reduced, and the possibility that the occupant directly inhales high-concentration CO ₂ can be reduced. In addition, by closing the foot-side damper 10 and the window-side damper 11 in addition to the face-side damper 9, it is possible to more effectively reduce the intrusion of CO ₂ gas into the vehicle interior. Other configurations and operations are the first
This is the same as the embodiment.

[0016]

Since the present invention is configured as described above, it has the following effects. The invention according to claim 1 is characterized in that, when CO ₂ leaks from the refrigeration cycle due to any cause, for example, breakage of the cooler, the concentration of CO ₂ gas in the air passing through the cooler increases,
This can be detected by the gas detection device, and can be recognized by the occupants of the vehicle. Like the invention of claim 2,
If the detection signal by the gas sensing device specified value or greater, by a display device for recognizing this occupant of the vehicle, only the rider see this display device, the leakage of CO ₂ Can be easily recognized, and the vehicle cost does not increase. According to the third aspect of the present invention, when the gas detection device detects the leakage of CO ₂ , the control device controls the damper in a direction in which the outlet is closed, thereby reducing the intrusion of CO ₂ gas itself into the vehicle interior. it can.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of a vehicle air conditioner of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the vehicle air conditioner of the present invention.

FIG. 3 is a configuration diagram of a third embodiment of the vehicle air conditioner of the present invention.

FIG. 4 is a configuration diagram of a conventional vehicle air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing (air conditioner main body) 2 Blower 3 Cooler 4 Heater 5 Inside air port 6 Outside air port 7 Inside / outside air switching damper 8 Air mix damper 9, 10, 11 Damper 12, 13, 14 Outlet 15 Control device 19 Gas detection Device (carbon dioxide detection device) 20 Display device 22 Refrigeration cycle

Claims (3)

[Claims] 1. A vehicle air conditioner having a cooler for cooling air introduced into a casing, wherein the cooler forms a part of a refrigeration cycle using carbon dioxide as a refrigerant, and An air conditioner for a vehicle, characterized in that a gas detector for detecting the concentration of CO ₂ gas in the air is provided on the downstream side of the flow of the air in the vessel. 2. The air conditioner for a vehicle according to claim 1, further comprising a display device for allowing a passenger of the vehicle to recognize when a detection signal from the gas detection device is equal to or greater than a specified value. 3. A cooler for cooling the air introduced into the casing, an outlet for blowing the air temperature-controlled in the casing out of the casing, and a damper for opening and closing the outlet. In the air conditioner for a vehicle, the cooler forms a part of a refrigeration cycle using carbon dioxide as a refrigerant, and a CO ₂ gas concentration in the air is provided downstream of the air flow of the cooler. Air conditioning for a vehicle, further comprising a control device for controlling a direction of closing the damper when a detection signal from the gas detection device is equal to or more than a prescribed value. apparatus.