JPH0755267A - Air conditioner - Google Patents

Abstract

PURPOSE:To prevent ignition and explosion of flammable refrigerant used in a refrigerating cycle from occurring when a gas leakage occurs. CONSTITUTION:An air conditioner has a compressor motor 1, a fan motor 2 and a controller 3. The controller 3 includes an output side 9 of a COMP solid-state relay (hereinafter abbreviated to COMPSSR) that controls power supply to the compressor motor 1, an output side 10 of a fan solid-state relay (hereinafter abbreviated to fan SSR) that controls power supply to the fan motor 2, an input side 11 of the COMPSSR, an input side 12 of the fan relay, and a CPU 8 that controls power supply to the input side 11 of the COMPSSR and the input side 12 of the fan SSR.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having a refrigeration cycle using a flammable refrigerant.

[0002]

2. Description of the Related Art Conventionally, in air conditioners, compressor motors,
As a relay for controlling energization of a fan motor, a contact type relay has been used in which a coil and a coil are energized to attract a contact by a coil magnetic field to turn on and off.

FIG. 3 shows an electric circuit diagram of a conventional air conditioner. Reference numeral 1 is a compressor motor, 2 is a fan motor, 3 is a control device, and the control device 3 has a contact 4 of a COMP relay for controlling energization of the compressor motor 1 and a fan relay for controlling energization of the fan motor 2. Contact point 5, COM
Coil 6 for P relay, Coil 7 for fan relay, COM
A CPU 8 for controlling energization of the P relay coil 6 and the fan relay coil 7 is included.

The operation of the conventional air conditioner configured as described above will be described below. When the CPU 8 determines that the compressor 1 and the fan motor 2 are to be operated while the air conditioner is in operation, the COMP relay coil 6 and the fan relay coil 7 are energized, and relay contacts 4 and 5, respectively.
Is closed and the compressor 1 and the fan motor 2 are energized to perform air conditioning. For example, when the CPU 8 judges that the thermostat is off and tries to stop the compressor 1, the power supply to the relay coil 6 is stopped. When the power supply to the relay coil 6 is stopped, the relay contact 4 is opened and the power supply to the compressor 1 is stopped. Relay contact 4
When is opened, an induced current tries to flow and a spark is generated at the contact point. For example, when the CPU 8 judges that the defrosting operation should be performed and tries to stop the fan 2, the power supply to the relay coil 7 is stopped. When the power supply to the relay coil 7 is stopped, the relay contact 5 is opened and the power supply to the fan 2 is stopped. When the relay contact 5 is opened, an induced current tends to flow and a spark is generated at the contact portion.

[0005]

However, if the refrigerant is inflammable but the refrigerant is flammable, if refrigerant leaks and refrigerant fills around the refrigeration cycle, the contact at the ON / OFF of the relay There was a risk of fire or explosion due to the spark.

In view of the above problems, the present invention prevents ignition due to sparks at the time of turning on and off even when a flammable refrigerant leaks and is filled.

[0007]

To solve the above problems, the present invention provides a refrigeration cycle using a flammable refrigerant,
A contactless relay that controls the operation and stop of the compressor, a contactless relay that controls the operation and stop of the air circulation fan motor, and a control device that drives each relay are provided.

A refrigeration cycle using a flammable refrigerant, a non-contact relay for controlling the operation and stop of the compressor, a non-contact relay for controlling the operation and stop of the air circulation fan motor, and the compressor Current detection means for detecting current,
Temperature detection means for detecting the discharge gas temperature of the compressor, comparison means for comparing the current value detected by the current detection means with the temperature detected by the temperature detection means, and drive control of the relay or the like based on the result of the comparison means. It is equipped with a control device.

[0009]

The operation of the above means is as follows.

According to the present invention, since the relay for controlling the operation and stop of the compressor and the relay for controlling the operation and stop of the air circulation fan motor are non-contact relays, the energization of the compressor motor and the fan motor is turned on, Even if the relay is turned off, no spark occurs in the relay and no ignition occurs.

Further, the relay for controlling the operation and stop of the compressor and the relay for controlling the operation and stop of the fan motor for air circulation are non-contact relays, and current, temperature detection and judgment for overload protection of the compressor are performed. Since the processing is performed by the same control device as the operation control and the operation and stop control of the compressor for overload protection are also performed by the non-contact relay, spark does not occur and no ignition occurs even in the protection control.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 1 is an electric circuit diagram of an air conditioner according to one embodiment of the present invention. Reference numeral 1 is a compressor motor, 2 is a fan motor, 3 is a control device, and the control device 3 has an output side 9 of a COMP solid state relay (hereinafter abbreviated as COMPSSR) for controlling energization of the compressor motor 1 and a fan motor 2 Output 10 of a fan solid-state relay (hereinafter abbreviated as fan SSR) that controls energization to
SSR input side 11, fan relay input side 12, CO
A CPU 8 for controlling energization of the MPSSR input side 11 and the fan SSR input side 12 is included.

The operation of the air conditioner configured as above will be described below. When the CPU 8 determines that the compressor 1 and the fan motor 2 are to be driven while the air conditioner is in operation, the COMPSSR input side 11 and the fan SS
When the R input side 12 is energized, the SSR output side 9 and 1, respectively
When 0 is conducted, the compressor 1 and the fan motor 2 are energized to perform air conditioning. For example, when the CPU 8 judges that the thermostat is OFF and tries to stop the compressor 1, the energization to the COMPSSR input side 11 is stopped. When the energization to the COMPSSR input side 11 is stopped, the COMPSSR output side 9 becomes non-conductive, and the energization to the compressor 1 is stopped. When the COMPSSR output side 9 becomes non-conductive, an induced current tries to flow, but no spark occurs. Further, for example, when the CPU 8 determines to perform the defrosting operation and tries to stop the fan 2, the power supply to the fan SSR input side 12 is stopped. When the power supply to the fan SSR input side 12 is stopped, the fan SSR output side 10 becomes non-conductive and the power supply to the fan 2 is stopped. When the fan SSR output side 10 is opened, an induced current tries to flow, but no spark occurs. If the solid state relay (SSR) is used to control the ON / OFF control of the energization of the compressor and the fan, the spark does not occur, and even if the flammable refrigerant leaks, it does not ignite or explode.

FIG. 2 is an electric circuit diagram of another embodiment of the present invention in which a CT 13 for measuring the current of the compressor 1 and a thermistor 14 for measuring the discharge gas temperature of the compressor 1 are installed.
To explain the operation of this embodiment, the operating current of the compressor 1 is changed to C
The temperature is measured at T13, rectified by a diode and taken into the CPU8, the temperature of the gas discharged from the compressor 1 is detected by the thermistor 14, and taken into the CPU8. In order to protect the compressor 1 in the CPU 8, it is judged that the compressor 1 is stopped when the operating current and the discharge gas surface temperature exceed preset ranges. CPU8
Determines that the compressor 1 has stopped, the COMPSSR input side 1
The energization to the compressor 1 is stopped, the COMPSSR output side 9 is made non-conductive, and the energization to the compressor 1 is stopped. COMPSSR output side 9
When becomes non-conductive, an induced current tries to flow but no spark occurs. In this way, even in the case of compressor protection control, even if the flammable refrigerant leaks, it will not ignite or explode.

Although the discharge gas temperature of the compressor is detected in this embodiment, the same effect can be obtained by detecting the surface temperature of the compressor.

[0017]

As is apparent from the above embodiments, in the air conditioner of the present invention, the relay for controlling the operation and stop of the compressor is a contactless relay, and the relay for controlling the operation and stop of the fan motor for air circulation. Since it is a non-contact relay, no spark is generated even if ON / OFF control of energization of the compressor and fan is performed, and even if the flammable refrigerant leaks, it does not ignite or explode.

Further, the relay for controlling the operation and stop of the compressor is a non-contact relay, the relay for controlling the operation and stop of the air circulation fan motor is a non-contact relay, and the current of the compressor and the temperature of the gas discharged from the compressor are set. Is detected and the overload state of the compressor is determined from the detected current value and temperature to drive and control the compressor relay and the like, so spark does not occur even in overload control, and even if flammable refrigerant Even if it leaks, it will not catch fire or explode.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is an electric circuit diagram of the present invention.

FIG. 3 is an electric circuit diagram of a conventional example.

[Explanation of symbols]

 1 Compressor 2 Fan motor 8 Control CPU 9 and 10 Solid state relay

Claims (2)

[Claims] 1. A refrigeration cycle having a compressor, an evaporator, a condenser, and a throttle device and using a flammable refrigerant,
An air conditioner comprising a non-contact relay that controls the operation and stop of the compressor, a non-contact relay that controls the operation and stop of an air circulation fan motor, and a control device that drives each of the relays. 2. A refrigeration cycle having a compressor, an evaporator, a condenser, and a throttle device, and using a flammable refrigerant,
A non-contact relay that controls the operation and stop of the compressor, a non-contact relay that controls the operation and stop of the air circulation fan motor, and a current detection unit that detects the current of the compressor,
A temperature detecting means for detecting the discharge gas temperature of the compressor,
An air conditioner comprising: comparing means for comparing the current value detected by the current detecting means with the temperature detected by the temperature detecting means; and a control device for driving and controlling each relay based on the result of the comparing means.