JPH04251175A - Air conditioner - Google Patents

Abstract

PURPOSE:To provide an air conditioner which is capable of detecting abnormal low pressure gaseous refrigerant, preventing a compressor from absorbing liquid refrigerant and announcing the phase transition state of said refrigerant whenever it is required. CONSTITUTION:A detection sensor 70 which comprises a light emitting section and a light receiving section is installed between a low pressure pipeline installed between a vaporizer 5 and a compressor 3, detecting the abnormality (phase transition state) of low pressure gaseous phase refrigerant based on a detection signal generated from the detection sensor 70. When the low pressure gaseous phase refrigerant is under a phase transition state, the compressor 3 is halted by a compressor shutdown type control section 11 which has received the detection signal while the operation is alarmed by blinking a lighting section R.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner mainly used for cooling vehicles.

0002

2. Description of the Related Art Conventionally, as shown in FIG. 5, this type of air conditioner includes a compressor 3 that compresses a low-pressure gas-phase refrigerant according to a flow direction M and discharges the high-pressure gas-phase refrigerant as a high-pressure gas-phase refrigerant; A condenser 4 condenses and discharges the high-pressure liquid refrigerant as a high-pressure liquid refrigerant, and a compressor 3 that absorbs heat from the high-pressure liquid refrigerant and converts it into a low-pressure gas refrigerant.
A refrigerant flow path 1 includes an evaporator 5 for discharging air to
It consists of A high-pressure pipe between the condenser 4 and the evaporator 5 among the various pipes is connected to the evaporator 5, and is connected to the high-pressure liquid phase refrigerant sucked into the evaporator 5 for adjusting the amount. An expansion valve 8 is inserted.

Recently, a viewing window 6A has been provided on the high-pressure pipe, and a pressure sensor or the like has been installed to detect the flow rate of the high-pressure liquid refrigerant by generating a detection signal corresponding to the flow rate. In addition to providing a receiver tank 6 equipped with a sensor 7, a control unit (not shown) connected to the detection sensor 7 and configured to control the compressor 3 in response to a detection signal from the detection sensor 7 is provided. There is.

0004

However, in the case of the above-mentioned conventional air conditioner, since the detection sensor is provided in the high-pressure piping, it is not possible to detect abnormalities in the low-pressure gas phase refrigerant.

In particular, when a conventional air conditioner is applied to detect abnormalities in the flow rate of low-pressure gas phase refrigerant, the expansion valve, evaporator, or blower for refrigerant to the evaporator may malfunction. However, there is a drawback in that accurate detection cannot be performed unless the overfilling of the liquid refrigerant reaches an extremely abnormal state. Furthermore, if the air conditioner in such a state is continued to be used and liquid refrigerant continues to be sucked into the compressor from the evaporator, there is a risk that the compressor will be damaged.

Furthermore, in such an air conditioner, the low-pressure gas phase refrigerant may turn into liquid refrigerant even when the temperature inside the room in which it is used drops, and in such a case, when the power supply voltage is applied, the liquid refrigerant turns into liquid refrigerant. It may be inhaled into the compressor and damage the compressor.

[0007] Therefore, the technical problem of the present invention was to avoid the above-mentioned problems, and to detect abnormalities in low-pressure gas phase refrigerant and prevent liquid refrigerant from being sucked into the compressor. In addition, it is an object of the present invention to provide an air conditioner that can warn of a phase transition state of a low-pressure gas-phase refrigerant.

[0008]

[Means for Solving the Problems] According to the present invention, there is provided a compressor that compresses a low pressure gas phase refrigerant and discharges it as a high pressure gas phase refrigerant, and a high pressure liquid phase refrigerant that absorbs heat after the high pressure gas phase refrigerant is condensed. In an air conditioner equipped with an evaporator that discharges the refrigerant as a low-pressure gas-phase refrigerant, and a low-pressure piping installed between the compressor and the evaporator, the low-pressure piping is equipped with an air conditioner that irradiates the low-pressure gas-phase refrigerant with light. A detection sensor that receives reflected light from the low-pressure gas-phase refrigerant and generates a detection signal corresponding to the state of the low-pressure gas-phase refrigerant in the low-pressure piping based on the amount of the reflected light, and a detection sensor that receives the detection signal. , an air conditioner equipped with a compression stop type control unit that generates a stop signal to stop the compressor when the low pressure gas phase refrigerant is in a phase transition state, or a low pressure gas phase refrigerant installed in this low pressure piping. A detection sensor that irradiates the refrigerant with light, receives reflected light from the low-pressure gas-phase refrigerant, and generates a detection signal corresponding to the state of the low-pressure gas-phase refrigerant in the low-pressure piping based on the amount of reflected light; a heater for heating the piping;
An air conditioner can be obtained that includes a heater drive type control section that generates a drive signal for driving the heater when the low pressure gas phase refrigerant is in a phase transition state.

[0009] In addition, as an embodiment, each of the above-mentioned air conditioners is provided with an alarm means that issues an alarm when the low-pressure gas phase refrigerant is in a phase transition state, and the heater is configured with a radiator. be able to.

0010

[Example] The air conditioner of the present invention will be explained in detail with reference to Examples below. FIG. 1 shows the main parts of an air conditioner that is an embodiment of the present invention.

In the main part of the air conditioner shown in FIG. 1, a compressor 3 compresses a low-pressure phase refrigerant and discharges it as a high-pressure gas phase refrigerant.
and an evaporator 5 that absorbs heat from the high-pressure liquid-phase refrigerant after the high-pressure gas-phase refrigerant has been condensed and discharges it to the compressor 3 as a low-pressure gas-phase refrigerant. Low pressure piping is provided.

[0012] Also, the high-pressure pipe on the side where the high-pressure liquid phase refrigerant of the evaporator 5 is sucked is connected to an air conditioner inserted in the low-pressure pipe between the evaporator 5 and the compressor 3, and the evaporator An expansion valve 8 is inserted to adjust the amount of high-pressure liquid refrigerant discharged into the refrigerant 5. An air blower 9 is provided near the evaporator 5 to cool the evaporator 5, and the compressor 3 is provided with a blower 9 for cooling the evaporator 5. When the low-pressure gas refrigerant is compressed into high-pressure gas refrigerant, a portion of the refrigerant is liquefied. A discharge pipe is provided for discharging the refrigerant.

Among these, the low-pressure piping includes an irradiation section for irradiating the refrigerant with irradiation light, and a irradiation section that receives the reflected light from the refrigerant in response to the irradiation light irradiated by the irradiation section. A detection sensor 70 is provided which integrally includes a light receiving section that generates a detection signal corresponding to the state of the refrigerant.

Furthermore, the detection sensor 70 has a sensor amplifier 15 interposed therebetween, which receives a detection signal from the detection sensor 70 and stops the compressor 3 through a relay 16 when the low-pressure gas phase refrigerant is in a phase transition state. A compression stop type control section 11 that generates a stop signal is connected. For this reason, each part of the sensor amplifier 15, the compression stop type control section 11, and the relay 16 is connected to the power supply terminal A. In addition to the compressor 3, the relay 16 is connected to a lighting section R that blinks in response to an alarm signal generated from the compression stop type control section 11 when the low-pressure gas phase refrigerant is in a phase transition state. And the detection sensor 70
and the lighting section R are each grounded.

Although it is schematically illustrated, in the case of the air conditioner of the present invention, the high-pressure gas phase refrigerant is condensed between the evaporator 5 and the compressor 3 in the direction opposite to that shown in the figure, in order to form a refrigerant flow path. In addition to providing a condenser for discharging high-pressure liquid-phase refrigerant to the evaporator 5, high-pressure piping is also provided between the condenser and the compressor 3, and between the condenser and the evaporator 5.

0016
] The air conditioner having such a configuration is located in the pipe provided between the evaporator 5 and the compressor 3, and detects an abnormality (phase transition state) of the low-pressure gas phase refrigerant in the flow direction M by a sensor 7.
Since the light receiving unit 0 generates a detection signal for detection, the compression stop type control unit 11 can determine when the low pressure gas phase refrigerant in the low pressure pipe enters a phase transition state. Then, the compression stop type control unit 11 controls the relay 1
6, a stop signal is transmitted to the compressor 3, and an alarm signal for blinking the stop signal is transmitted to the lighting section R. Therefore, the compressor 3 is alerted to the phase transition state of the low-pressure gas phase refrigerant.
can be stopped to prevent liquid refrigerant from being sucked into the compressor 3.

Specifically, when the low-pressure gas-phase refrigerant enters a phase transition state and gas-liquid is mixed, the amount of light reflected from the gas-liquid mixed refrigerant increases compared to before mixing. The stop-type control unit 11 can accurately determine the gas-liquid mixing state of the low-pressure gas-phase refrigerant and stop the compression operation of the compressor 3. Figure 2 explains the phase transition state of such a low-pressure gas-phase refrigerant. In contrast to the normal low-pressure gas-phase refrigerant in Figure (A), the figure (B) shows a gas-liquid mixed refrigerant in which gas and liquid are mixed. It shows. That is, when the low-pressure gas-phase refrigerant becomes a gas-liquid mixed refrigerant, the density of the entire refrigerant increases and becomes gaseous.
This indicates that the amount of reflected light increases.

FIG. 3 shows the basic configuration of an air conditioner according to another embodiment of the present invention. Here, refrigerant flow path 1
In addition to the compressor 3, condenser 4, and evaporator 5 that make up the system, high-pressure and low-pressure pipes are installed between these parts. The low-pressure piping provided between the evaporator 5 and the compressor 3 is provided with the detection sensor 70 described in the previous embodiment, and a portion that avoids the detection sensor 70 is provided with a low-pressure gas phase refrigerant. A heater 1 such as a heater for heating the gas-liquid mixed refrigerant in the low-pressure pipe to bring it into a gas phase when the refrigerant is in a phase transition state
9 is provided. Note that this heater 19 is grounded together with the detection sensor 70.

For this reason, here, a heater drive type control section 12 is provided which generates a drive signal for driving the heater 19. This heater drive type control section 12 is connected to a sensor amplifier 15 along with a relay 17 connected to a heater 19 and a compressor 3 . Further, a power supply section 14 is connected to the heater drive type control section 12 and the sensor amplifier 15. The heater drive type control unit 12 receives a detection signal from the detection sensor 70, and when the low-pressure gas phase refrigerant is in a phase transition state, the heater drive type control unit 12 drives the heater 1 without stopping the compressor 3.
A drive signal for driving the heater 9 is generated and transmitted to the heater 19 .

The air conditioner having such a configuration detects an abnormality (phase transition state) in the low pressure gas phase refrigerant in the flow direction M by the light receiving section of the detection sensor 70 generating a detection signal. When the gas phase refrigerant enters a phase transition state, the heater drive control unit 12 transmits drive signals to the compressor 3 and the heater 19 through the relay 17, and drives the heater 19 without stopping the compressor 3. let me,
The heater 19 can heat the gas-liquid mixed refrigerant in the low-pressure pipe to bring it into a gaseous state (restore it to the low-pressure gaseous refrigerant).

Furthermore, FIG. 4 shows the basic configuration of an air conditioner according to another embodiment of the present invention. Here, when the above-mentioned air conditioner is installed in the vehicle, the above-mentioned heater 19 is configured with a radiator 20, and the gas-liquid mixed refrigerant is heated to a gas phase by hot water flowing into the radiator 20. It is.

That is, the air conditioner shown in FIG. 4 also includes a compressor 3, a condenser 4, and an evaporator 5 constituting the refrigerant flow path 1, as well as high-pressure and low-pressure pipes arranged between these parts. The low-pressure piping provided between the evaporator 5 and the compressor 3 is provided with the detection sensor 70 described in the previous embodiment, and a portion that avoids the detection sensor 70 is provided with a low-pressure gas phase refrigerant. A radiator 20 is provided for heating the gas-liquid mixed refrigerant in the piping to bring it into a gas phase when the refrigerant is in a phase transition state. This radiator 20 has a solenoid valve 10 in the middle.
is connected to the engine 21, and hot water is supplied through the engine 21.

For this reason, here, a solenoid valve drive type control section 13 is provided which generates a drive signal for driving the solenoid valve 10. This electromagnetic valve drive type control section 13 is connected to a sensor amplifier 15 along with a relay 18 connected to the electromagnetic valve 10 and the electromagnetic clutch 22. Further, a power supply section 140 such as a battery is connected to the electromagnetic valve drive type control section 13 and the sensor amplifier 15. Then, when the low-pressure gas phase refrigerant is in a phase transition state in response to a detection signal from the detection sensor 70, the solenoid valve drive type control unit 13 generates drive signals for driving the compressor 3 and the solenoid valve 10, respectively. and transmits it to the compressor 3 and the solenoid valve 10. Note that this solenoid valve 10 is grounded together with the detection sensor 70.

The air conditioner having such a configuration also detects an abnormality (phase transition state) in the low pressure gas phase refrigerant following the flow direction M by the light receiving section of the detection sensor 70 generating a detection signal. When the gas phase refrigerant is in a phase transition state, the solenoid valve drive type control unit 13 transmits drive signals to the solenoid clutch 22 and the solenoid valve 10 through the relay 18, and drives the solenoid valve 10 without stopping the compressor 3. When the low-pressure gas-phase refrigerant is in a phase transition state, the gas-liquid mixed refrigerant can be heated to a gas-phase state by the hot water flowing in the radiator 20.

[0025] Regardless of whether the heater drive type control section 12 or the electromagnetic valve drive type control section 13 is used, as in the compression stop control section 11 shown in Fig. 1, the phase transition state of the low pressure gas phase refrigerant can be controlled. It may be possible to issue a warning. Furthermore, any of the air conditioners shown in FIGS. 1 and 3 can be installed in a vehicle. However, when these air conditioners are installed in a vehicle, an electromagnetic clutch is required for either the compression stop type control unit 11 or the heater drive type control unit 12, and the electromagnetic clutch 22 is interlocked by the engine 21. Sometimes it is necessary to drive the compressor 3. Furthermore, although the lighting section R is disclosed as the alarm means, this may also be used as a sounding section.

[0026]

As described above, according to the air conditioner of the present invention, it is possible to accurately detect the phase transition state of low-pressure gas phase refrigerant, prevent liquid refrigerant from being sucked into the compressor, and An air conditioner is provided that can warn of a phase transition state of a low-pressure gas-phase refrigerant. That is, since liquid refrigerant is not sucked into the compressor of the air conditioner, most of the causes of compressor failure are avoided, and the reliability of the air conditioner itself can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing essential parts of an air conditioner that is an embodiment of the present invention.

FIG. 2 is a diagram shown to explain a phase transition state of a low-pressure gas-phase refrigerant that occurs during use of the air conditioner.

FIG. 3 is a diagram showing the basic configuration of an air conditioner according to another embodiment of the present invention.

FIG. 4 is a diagram showing the basic configuration of an air conditioner that is another embodiment of the present invention.

FIG. 5 is a diagram showing the basic configuration of a conventional air conditioner.

[Explanation of symbols]

1 Refrigerant flow path 2 Piping 3 Compressor 4 Condenser 5 Evaporator 6 Receiver tank 7,70 Detection sensor 8 Expansion valve 9 Air blower 10 Solenoid valve 11 Compression stop control section 12 Heater drive type control section 13 Solenoid valve driven control unit 14,140 Power supply section 15 Sensor amplifier 16, 17, 18 Relay 19 Heater 20 Radiator 21 Engine 22 Electromagnetic clutch

Claims (4)

[Claims] 1. A compressor that compresses a low-pressure gas-phase refrigerant and discharges it as a high-pressure gas-phase refrigerant; and a compressor that absorbs heat from the high-pressure liquid-phase refrigerant after the high-pressure gas-phase refrigerant is condensed and discharges it as the low-pressure gas-phase refrigerant. In the air conditioner, the air conditioner is provided with an evaporator that performs the refrigerant, and a low-pressure pipe that is arranged between the compressor and the evaporator. a detection sensor that receives reflected light from the phase refrigerant and generates a detection signal corresponding to the state of the low pressure gas phase refrigerant in the low pressure piping based on the amount of the reflected light; An air conditioner comprising: a compression stop type control section that generates a stop signal for stopping the compressor when the gas phase refrigerant is in a phase transition state. 2. A compressor that compresses a low-pressure gas-phase refrigerant and discharges it as a high-pressure gas-phase refrigerant, and a compressor that absorbs heat from the high-pressure liquid-phase refrigerant after the high-pressure gas-phase refrigerant is condensed and discharges it as the low-pressure gas-phase refrigerant. In the air conditioner, the air conditioner is provided with an evaporator that performs the refrigerant, and a low-pressure pipe that is arranged between the compressor and the evaporator. a detection sensor that receives reflected light from the phase refrigerant and generates a detection signal corresponding to the state of the low pressure gas phase refrigerant in the low pressure piping based on the amount of the reflected light; a heater for heating the piping;
An air conditioner comprising: a heater drive type control section that generates a drive signal for driving the heater when the low pressure gas phase refrigerant is in a phase transition state. 3. The air conditioner according to claim 1, further comprising an alarm means for issuing an alarm when the low pressure gas phase refrigerant is in a phase transition state. 4. The heater according to claim 2 comprises:
An air conditioner comprising the radiator.