JPS6346350B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an air conditioner that is operated while repeatedly starting and stopping, and is capable of continuing heating operation while defrosting an outdoor heat exchanger during heating operation.

In a conventional air conditioner, as shown in FIG. 1, refrigerant returns to the compressor 1 from a compressor 1, a four-way valve 3, an indoor heat exchanger 7, an expansion valve 6, an outdoor heat exchanger 4, and an accumulator 8. It constitutes a circuit. Note that since this case indicates heating operation, the indoor heat exchanger 7 operates as a condenser, and the outdoor heat exchanger 4 operates as an evaporator. Further, in the case of cooling operation, the four-way valve 3 is switched to operate the indoor heat exchanger 7 as an evaporator and the outdoor heat exchanger 4 as a condenser. Here, 9 is a fan for an outdoor heat exchanger, and 10 is a fan for an indoor heat exchanger.

In the above air conditioner, when performing defrost operation on the outdoor heat exchanger 4 during heating operation, the four-way valve 3 is switched to reverse the flow of refrigerant and the outdoor heat exchanger 4 is operated in the same way as during cooling operation. Since the condenser and the indoor heat exchanger 7 are used as an evaporator, it is necessary to stop the operation of the fan 10 or to generate hot air by inputting power to a heater.

Further, when the compressor 1 is stopped, the high pressure side refrigerant and the low pressure side refrigerant are mixed and balanced, and after the compressor 1 is started, the difference between the high pressure and the low pressure gradually increases as the state shifts to a steady operating state. Therefore, when the compressor 1 is restarted, it is necessary to suck and compress the refrigerant liquid accumulated in the evaporator on the low pressure side and carry it to the condenser, resulting in a worse COP than during continuous operation.

In this invention, when defrosting the outdoor heat exchanger during heating operation, the flow of refrigerant in the indoor heat exchanger is stopped and the defrosting operation of the outdoor heat exchanger is performed while the heating operation continues.
When the compressor is stopped, the refrigerant that is distributed separately to the high-pressure side and the low-pressure side is kept separate without mixing, eliminating the energy loss that would occur when restarting the compressor with conventional equipment, and improving efficiency. It is an object of the present invention to provide an air conditioner that can shift to a steady operating state in a short time.

The details of this invention will be explained below based on the illustrated embodiments.

In FIG. 2, 2 is a check valve provided between the discharge side of the compressor 1 and the inlet side of the four-way valve 3, 5 is provided between the outdoor heat exchanger 4 and the expansion valve 6, A first solenoid valve 11 is open when the compressor 1 is running and closed when the compressor 1 is stopped, and a second solenoid valve 12 is connected between the discharge side of the compressor 1 and the outdoor heat exchanger 4 and this solenoid valve 5.
Refrigerant branch pipes (hereinafter referred to as bypass pipes) connected via
Other than the above, this device is the same as the conventional device shown in FIG.

In the air conditioner configured as described above, in order to maintain the indoor temperature at a predetermined value, the compressor 1 is driven by a temperature detection element (not shown) that detects the indoor temperature.
The solenoid valve 5 opens and closes in conjunction with the operation and stop of the refrigeration cycle. Therefore, when the compressor 1 is stopped, the solenoid valve 5 is closed, so the high temperature and high pressure refrigerant liquid in the indoor heat exchanger 7 does not flow into the expansion valve 6, and therefore the outdoor heat exchanger 7 does not flow into the expansion valve 6. No high-temperature, high-pressure refrigerant liquid flows into the container 4. On the other hand, since the check valve 2 is provided on the discharge side of the compressor 1, the refrigerant gas and condensed refrigerant liquid in the indoor heat exchanger 7 do not return to the compressor 1.

Therefore, when the compressor 1 is restarted, the high pressure side refrigerant and the low pressure side refrigerant in the refrigeration cycle remain separated, and the solenoid valve 5 is opened at the time of restart, so that a predetermined pressure difference is achieved in a short time. obtained, and the state shifts to steady operation.

The conventional air conditioner shown in FIG. 1 which does not have high and low pressure separation means consisting of the check valve 2 and the solenoid valve 5, and the air conditioner shown in FIG. 2 from restart to transition to steady operation. While it took about 5 minutes with the conventional device, it took 1 minute and 20 seconds in this example.

The above-mentioned opening/closing element is not limited to the electromagnetic valve 5, but may be any other opening/closing valve, as long as it closes when the compressor 1 is stopped and opens when the compressor 1 is started.

Furthermore, during heating operation, if frost accumulates on the outdoor heat exchanger 4, the heat exchange efficiency of the outdoor heat exchanger 4 deteriorates and the COP decreases, so a defrost operation is performed to remove this frost.

In this case, the solenoid valve 5 closes and the second solenoid valve 12 of the refrigerant bypass passage 11 opens simultaneously with the defrost operation command signal. Therefore, the indoor heat exchanger 7
The high-temperature, high-pressure refrigerant gas inside condenses while releasing heat to the surroundings, becoming a high-temperature, high-pressure refrigerant liquid. On the other hand, the high-temperature, high-pressure refrigerant gas compressed by the compressor 1 passes through the refrigerant bypass pipe 11 and enters the outdoor heat exchanger 4, where it gives heat to the frost and causes the frost to form. is melted, enters the compressor 1 again from the accumulator 8 via the four-way valve 3, is compressed again by the compressor 1, becomes high-temperature and high-pressure refrigerant gas, and passes through the refrigerant bypass pipe 11 to the outdoor heat exchanger 4.
to go into.

In this way, in this embodiment, the heating operation is continued using the high-temperature, high-pressure refrigerant gas stored in the indoor heat exchanger 7, and the heat of the refrigerant in the indoor heat exchanger 7 is more than enough. It can be used for. Further, in this embodiment, defrost operation can be performed without switching the four-way valve 3.

Further, in the embodiment shown in FIG. 2, the compressor 1 is repeatedly driven and stopped in order to adjust the indoor temperature during heating operation, and at that time, the second solenoid valve 12 is activated and stopped.
It closes and opens in conjunction with the stop. Of course, during defrost operation, the same operation as above is performed.

With this configuration, when the compressor 1 is stopped, the second
Since the solenoid valve 12 is opened, the refrigerant on the outlet side of the compressor 1 flows through the refrigerant bypass passage 11 to the outdoor heat exchanger 4, and the pressure on the outlet side of the compressor 1 decreases and balances with the pressure on the inlet side. Therefore, when restarting the compressor 1, since there is no pressure difference between the inlet side and the outlet side, the starting torque can be small, and the power consumption at the time of restarting can be reduced. In addition, since the starting torque is small, the compressor 1 can be made smaller.

Note that the amount of refrigerant between the outlet side of the compressor 1 and the check valve 2 is small, and the solenoid valve 5 is closed, and since the check valve 2 is present, the second solenoid valve 12 is opened and the outlet of the compressor 1 is closed. Even if the side refrigerant flows into the outdoor heat exchanger 4, the pressure in the outdoor heat exchanger 4 does not become high.

Furthermore, during heating operation, the second solenoid valve 12 is configured to open when the compressor 1 is stopped, and to close after a predetermined short period of time when the compressor 1 is started.

In this way, when the compressor 1 is restarted, the compressed refrigerant flows to the low pressure side, so that the starting torque can be further reduced.

Furthermore, in the embodiment shown in FIG. 2, in the defrost operation during the heating operation, the second solenoid valve 12 is first opened at the start of the defrost, and the first solenoid valve 5 is closed after a predetermined short time, Further, the second solenoid valve 12 is closed at the end of defrosting, and the first solenoid valve 5 is opened after a predetermined short time. A control signal for controlling the second electromagnetic valve 12 in this manner is provided by a defrost detector (not shown) provided in the outdoor heat exchanger 4.

With this configuration, high-temperature, high-pressure refrigerant gas quickly flows into the outdoor heat exchanger 4 during defrosting, so the defrosting time becomes shorter.
Since the refrigerant in the outdoor heat exchanger 4 is used and flows out until the solenoid valve 5 is opened, the function of the outdoor heat exchanger 4 as an evaporator is restored when the next heating operation starts. becomes faster and efficiency improves.

As described above, when the present invention shifts from heating operation to defrost operation, the flow of refrigerant in the indoor heat exchanger is stopped and the refrigerant from the compressor is circulated only in the outdoor heat exchanger. The indoor heat exchanger can perform defrost operation while continuing heating operation, and during cooling/heating operation, when the compressor is stopped, the refrigerant can be kept separated and distributed between the high pressure side and the low pressure side. This makes it possible to reduce startup energy loss when restarting the compressor.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a refrigeration cycle of a conventional air conditioner, and FIG. 2 is a block diagram of a refrigeration cycle of an air conditioner showing an embodiment of the present invention. The same symbols in the figures indicate the same or corresponding parts, 1
is a compressor, 2 is a check valve, 3 is a four-way valve, 4 is an outdoor heat exchanger, 5 is a first solenoid valve, 6 is an expansion valve, 7 is an indoor heat exchanger, 8 is an accumulator, 11 is a The bypass passage 12 is a second solenoid valve.

Claims (1)

[Scope of Claims] 1. A compressor, a four-way valve, an indoor heat exchanger, an expansion means, an outdoor heat exchanger, the four-way valve, and the compressor are connected in series, and the inlet of the compressor and the four-way valve are connected in series. In an air conditioner that repeatedly starts and stops the compressor depending on the set indoor temperature with an accumulator provided between the check valve and the indoor heat exchanger, the check valve is provided between the compressor outlet and the four-way valve. The refrigerant is installed between the outlet of the heat exchanger and the inlet of the outdoor heat exchanger, and is closed to prevent mixing of the refrigerant separated into the high-pressure side and the low-pressure side when the compressor is stopped during cooling/heating operation, and is opened when the compressor is running. , and a first solenoid valve that closes during defrosting during heating operation; a refrigerant branch pipe connecting the compressor outlet and the check valve to the outdoor heat exchanger inlet side; It is provided in the middle, and opens so that the compressor outlet and the outdoor heat exchanger inlet side are connected when the compressor is stopped during cooling/heating operation, closes when the compressor is running, and when defrosting during heating operation. and a second solenoid valve that opens to send high-pressure refrigerant from the compressor outlet to the outdoor heat exchanger. 2. The air conditioner according to claim 1, wherein the second solenoid valve is configured to close after a predetermined period of time after starting the compressor during heating operation. 3 The first solenoid valve closes the second solenoid valve when defrosting starts.
The air conditioner according to claim 1, wherein the air conditioner is configured to close a predetermined time after the first solenoid valve opens, and to open after a predetermined time after the second solenoid valve closes when defrosting ends. Device.