JP2000274780A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner for shortening a defrosting time by reducing a loss of radiating a heat while heating when an outdoor unit is defrosted. SOLUTION: In the air conditioner comprising an outdoor heat exchanger 5 having a compressor 2, a four-way valve 3 and two passes 5a, 5b, a throttle unit 6, an indoor heat exchanger 11 in such a manner that they are sequentially connected by refrigerant pipings to constitute a refrigerant circuit and the valve 3 is switched to normally defrost an outdoor unit 1, a first solenoid valve 9a and a second solenoid valve 9b are arranged between the passes 5a, 5b of the exchanger 5 and the unit 6, and an outdoor temperature sensor 4z is disposed in the unit 1. In this case, when the detected temperature of the sensor 4z exceeds a set temperature, the valves 9a, 9b are selectively controlled to be closed to defrost while heating, and when the detected temperature does not exceed the set temperature, normal defrosting is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner and, more particularly, to a configuration and control of a refrigerant circuit of an outdoor unit.

[0002]

2. Description of the Related Art FIG. 6 is a refrigerant circuit diagram of an air conditioner showing one example of the prior art, and FIG. 7 is a refrigerant circuit diagram of an air conditioner showing another example of the related art. As shown in the figure, a refrigerant circuit of a conventional air conditioner includes a compressor 2 housed in an outdoor unit 1, a four-way valve 3, an outdoor heat exchanger 5, and a throttle device 6 housed in an indoor unit 10. And an indoor heat exchanger 11, which are sequentially connected to form a refrigerant circuit.

In the above configuration, during the cooling operation, the refrigerant flow in the outdoor unit 1 passes through the compressor 2 and the four-way valve 3 to the two-pass outdoor heat exchanger 5 as indicated by a broken line arrow. The refrigerant flows from the outdoor heat exchanger 3 via the expansion device 6 into the indoor heat exchanger 11 of the indoor unit 10. And
The refrigerant returns to the compressor 2 via the four-way valve 3 of the outdoor unit 1. Further, during the heating operation, the refrigerant flow path returns to the compressor 2 via the expansion device 6 along a path opposite to that during the cooling as indicated by a solid arrow.

In order to defrost the outdoor unit 1 during heating, the four-way valve 3 is switched as shown in FIG.
As shown in FIG. 4, a reverse method performed by using a cooling cycle, and a discharge gas from the compressor 2 is supplied to the outdoor heat exchanger 5 via the bypass pipe 7 and the solenoid valve 8 a on the side of the throttle device 6 of the outdoor heat exchanger 5. There is a hot gas bypass system in which one end 5a is injected. However, in any of the above methods,
High-temperature discharge gas is injected from the same point from the start to the end of the defrost regardless of the degree of frost melting, so the frost immediately melts near the injection point, but the frost has already melted to melt the frost near the outlet There has been a problem that the discharge gas must be continuously injected into the injection port, a continuous heating operation cannot be performed, a loss due to heat dissipation increases, and a defrosting time may be prolonged.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an air conditioner in which the loss of heat radiation is reduced when the outdoor unit is defrosted, and the defrosting time is shortened while performing the heating operation. It is intended to be.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a compressor, a four-way valve, and a compressor.
An outdoor heat exchanger having a path, a throttle device, and an indoor heat exchanger. These are sequentially connected by a refrigerant pipe to form a refrigerant circuit, and the outdoor heat exchanger is switched by switching the four-way valve. In an air conditioner that performs defrosting, each of the first solenoid valve and the second solenoid valve are disposed between each path of the outdoor heat exchanger and the expansion device,
An outdoor temperature sensor is disposed in the outdoor unit, and when the detected temperature of the outdoor temperature sensor exceeds a set temperature, the first solenoid valve or the second solenoid valve is selectively controlled to a closed state to perform a heating operation. Defrosting is performed while performing, and when the set temperature is not exceeded, normal defrosting operation is performed.

[0007] A first temperature sensor and a second temperature sensor are provided near each of the four-way valve-side paths of the outdoor heat exchanger, respectively, when the detected temperature of the outdoor temperature sensor exceeds a set temperature. When the first solenoid valve is closed, the second solenoid valve is opened, and when the difference between the temperature detected by the outdoor temperature sensor and the temperature detected by the first temperature sensor is smaller than a set temperature value, The first solenoid valve is opened, the second solenoid valve is closed, and when the difference between the temperature detected by the outdoor temperature sensor and the temperature detected by the second temperature sensor becomes smaller than a set temperature value, the second electromagnetic valve is closed. The valve is controlled to be open and the first solenoid valve is controlled to be open.

Alternatively, when the temperature detected by the outdoor temperature sensor exceeds a set temperature, the first solenoid valve is closed,
Open the second solenoid valve, after a predetermined time, open the first solenoid valve, close the second solenoid valve, then,
After the predetermined time has passed again, the second solenoid valve is opened and the first solenoid valve is opened. Then, the predetermined time is controlled so as to be shorter when the temperature detected by the outdoor temperature sensor is higher, and to be longer when the temperature detected is lower.

Further, when the temperature detected by the outdoor temperature sensor exceeds a set temperature, the rotation speed of the outdoor fan is increased.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail based on embodiments with reference to the accompanying drawings. FIG.
FIG. 2 is a refrigerant circuit diagram of an air conditioner showing one embodiment of the present invention.
FIG. 3 is an explanatory view of a main part of an air conditioner showing one embodiment of the present invention, and FIG. 3 is a flowchart of the air conditioner showing one embodiment of the present invention. The same numbers are used for the same components. In the figure, 1 is an outdoor unit, 2 is a compressor, 3 is a four-way valve, 4a is a first temperature sensor, 4b is a second temperature sensor, 4z is an outdoor temperature sensor, 5 is an outdoor heat exchanger, 5a and 5b are paths. , 6 is a throttle device, 9a is a first solenoid valve, 9b is a second solenoid valve, 10 is an indoor unit, 11 is an indoor heat exchanger, 20 is an outdoor fan, 21 is an outdoor unit control unit, and 22 is an indoor unit control unit. , 23 are input units, and 24 is a storage unit.

This air conditioner comprises an outdoor unit 1 and an indoor unit 10.
And a compressor 2, a four-way valve 3,
It comprises an outdoor heat exchanger 5 having two paths 5a, 5b, a throttle device 6, and an indoor heat exchanger 11, and these are sequentially connected by refrigerant piping to form a refrigerant circuit. At the same time, the outdoor unit 1 is provided with the outdoor unit control unit 21 and the indoor unit 10 is provided with the indoor unit control unit 11, and the four-way valve 3 is switched to perform normal defrosting of the outdoor heat exchanger 5. here,
The air conditioner of the present invention performs each of the passes 5a and 5b of the outdoor heat exchanger 5 to perform defrosting while performing the continuous heating operation.
A first solenoid valve 9a and a second solenoid valve 9b are arranged between the throttle unit 6 and the outdoor unit 1, respectively, and an outdoor temperature sensor 4z is arranged in the outdoor unit 1. In addition, the outdoor heat exchanger 5
A first temperature sensor 4a and a second temperature sensor 4b are disposed near the respective paths 5a and 5b on the four-way valve 3 side. Further, the indoor unit control unit 22 receives data input such as set values from the input unit 23 and stores it in the storage unit 24, while the outdoor unit control unit 21 communicates with the indoor unit control unit 22 to transmit data. And the operation of the outdoor unit 1 is controlled.

Then, as shown in FIG. 3, it is determined whether or not the detected temperature of the outdoor temperature sensor 4z has exceeded a set temperature (ST1). If Yes, the rotational speed of the outdoor fan 20 is increased (ST2). Closing the first solenoid valve 9a,
The second solenoid valve 9b is opened. (ST3) On the other hand, ST
If No in 1, normal defrost is performed. (ST0) Also, it is determined whether or not the difference between the detected temperature of the outdoor temperature sensor 4z and the detected temperature of the first temperature sensor 4a is smaller than a set temperature value (ST4). The valve 9a is opened and the second solenoid valve 9b is closed. (ST5) On the other hand, if No in ST4, the process returns to ST4.

Next, it is determined whether or not the difference between the temperature detected by the outdoor temperature sensor 4z and the temperature detected by the second temperature sensor 9b is smaller than a set temperature value (ST6). 9b is open, the first solenoid valve 9a
Is controlled to the open state. (ST7) On the other hand, at ST6, N
If it is o, the process returns to ST6.

Next, the operation and effect of the embodiment of the present invention having the above configuration will be described. According to this embodiment,
When the first solenoid valve 9a is closed, the refrigerant does not flow through the path 5a of the outdoor heat exchanger 5 on the four-way valve 3 side,
Since the rotation speed of the outdoor fan 20 is increased, defrosting is performed in a short time. And pass 5 where this defrost is performed
In the other path 5b with respect to a, the refrigerant flows and continuous heating operation is enabled. Further, when the second solenoid valve 9b is closed, the refrigerant does not flow through the path 5b of the outdoor heat exchanger 5 on the side of the four-way valve 3 and the rotation speed of the outdoor fan 20 is increased, so Frost occurs in a short time. Similarly, the path 5b on which the defrosting is performed is different from the path 5a on the other side.
, The refrigerant is flowing and continuous heating operation is possible.

FIG. 4 is an explanatory view of a main part of an air conditioner showing another embodiment of the present invention, and FIG. 5 is a flowchart of the air conditioner showing another embodiment of the present invention. In the case of this embodiment, a predetermined time is set in the outdoor unit control unit 21. Then, it is determined whether or not the detected temperature of the outdoor temperature sensor 4z has exceeded the set temperature (ST1). If Yes, the rotation speed of the outdoor fan 20 is increased (ST2), and the first solenoid valve 9a is closed. Then, the second solenoid valve 9b is opened. (S
T3) On the other hand, if No in ST1, normal defrost is performed. (ST0) Also, it is determined whether the elapsed time from ST3 has passed the predetermined time (ST4), and if Yes, the first solenoid valve 9a is opened and the second solenoid valve 9b is closed. (ST5) On the other hand, if No in ST4,
Return to ST4.

Next, it is again determined whether or not the elapsed time from ST5 has passed the predetermined time (ST6). If Yes, the second solenoid valve 9b is opened and the first solenoid valve 9a is opened.
Is controlled to the open state. (ST7) On the other hand, at ST6, N
If it is o, the process returns to ST6. And, the predetermined time is:
The control is performed such that the detection temperature of the outdoor temperature sensor 4z is short if it is high, and is long if it is low.

Next, the operation and effect of the other embodiment of the present invention will be described. According to this embodiment, similar to the above-described embodiment, when the first solenoid valve 9a is closed, the refrigerant does not flow through the path 5a on the four-way valve 3 side of the outdoor heat exchanger 5, Since the rotation speed of the outdoor fan 20 is increased, defrosting is performed in a short time. Then, the other path 5b is connected to the path 5a where the defrosting is performed.
, The refrigerant is flowing and continuous heating operation is possible.

When the second solenoid valve 9b is closed, the path 5 of the outdoor heat exchanger 5 on the side of the four-way valve 3 is closed.
Since the refrigerant does not flow in b and the rotation speed of the outdoor fan 20 is increased, defrosting is performed in a short time. Similarly, the other path 5a, on which the defrosting is being performed, flows in the other path 5a, so that the continuous heating operation can be performed. Further, since the predetermined time by the outdoor unit controller 21 is controlled to be shorter when the temperature detected by the outdoor temperature sensor 4z is higher and longer when the temperature detected by the outdoor temperature sensor 4z is lower, more appropriate defrosting can be performed in accordance with the outdoor temperature. .

[0019]

As described above, according to the present invention, a compressor, a four-way valve, an outdoor heat exchanger having two passes, a throttling device, and an indoor heat exchanger are connected by refrigerant piping. In the air conditioner performing the defrosting of the outdoor heat exchanger by switching the four-way valve while sequentially connecting pipes to form a refrigerant circuit, each of the paths of the outdoor heat exchanger and the throttle device are respectively provided. A first solenoid valve and a second solenoid valve are disposed, and an outdoor temperature sensor is disposed in the outdoor unit, and when the detected temperature of the outdoor temperature sensor exceeds a set temperature, the first solenoid valve or the second The defrosting is performed while performing the heating operation by selectively controlling the two solenoid valves to the closed state, and the normal defrosting operation is performed when the set temperature is not exceeded.

As a result, it is possible to provide an outdoor unit of an air conditioner in which loss of heat radiation is reduced while continuous heating operation is performed, defrosting time is shortened, and low-temperature heating capacity and comfort are improved.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner showing one embodiment of the present invention.

FIG. 2 is an explanatory view of a main part of an air conditioner showing one embodiment of the present invention.

FIG. 3 is a flowchart of the air conditioner showing one embodiment of the present invention.

FIG. 4 is an explanatory view of a main part of an air conditioner showing another embodiment of the present invention.

FIG. 5 is a flowchart of an air conditioner showing another embodiment of the present invention.

FIG. 6 is a refrigerant circuit diagram of an air conditioner showing an example of the related art.

FIG. 7 is a refrigerant circuit diagram of an air conditioner showing another conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 outdoor unit 2 compressor 3 four-way valve 4a first temperature sensor 4b second temperature sensor 4z outdoor temperature sensor 5 outdoor heat exchanger 5a pass 5b pass 6 expansion device 9a first solenoid valve 9b second solenoid valve 10 indoor unit 11 indoor Heat exchanger 20 Outdoor fan 21 Outdoor unit control unit 22 Indoor unit control unit 23 Input unit 24 Storage unit

Claims (5)

[Claims] 1. An air conditioner comprising a compressor, a four-way valve, an outdoor heat exchanger having two passes, a throttle device, and an indoor heat exchanger.
In an air conditioner that sequentially connects these with a refrigerant pipe to form a refrigerant circuit and switches the four-way valve to defrost the outdoor heat exchanger, each path of the outdoor heat exchanger and the throttle A first solenoid valve and a second solenoid valve are disposed between the devices, and an outdoor temperature sensor is disposed in the outdoor unit. When the detected temperature of the outdoor temperature sensor exceeds a set temperature, the second Defrosting is performed while performing the heating operation by selectively controlling the one solenoid valve or the second solenoid valve to the closed state, and when the set temperature is not exceeded, the normal defrosting operation is performed. Air conditioner. 2. A first temperature sensor and a second temperature sensor are respectively disposed near each of the four-way valve-side paths of the outdoor heat exchanger, and when a temperature detected by the outdoor temperature sensor exceeds a set temperature. When the first solenoid valve is closed and the second solenoid valve is opened, when the difference between the temperature detected by the outdoor temperature sensor and the temperature detected by the first temperature sensor is smaller than a set temperature value,
The first solenoid valve is opened, the second solenoid valve is closed, and when the difference between the detected temperature of the outdoor temperature sensor and the detected temperature of the second temperature sensor is smaller than a set temperature value, the second The air conditioner according to claim 1, wherein the electromagnetic valve is controlled to be in an open state and the first electromagnetic valve is controlled to be in an open state. 3. When the temperature detected by the outdoor temperature sensor exceeds a set temperature, the first solenoid valve is closed and the second solenoid valve is opened, and after a predetermined time, the first solenoid valve is opened. Open state, close the second solenoid valve, and then, after the predetermined time has passed again, the second solenoid valve is opened, the first solenoid valve is controlled to open state, characterized by the following: Item 7. The air conditioner according to Item 1. 4. The air conditioner according to claim 3, wherein the predetermined time is controlled so as to be shorter when the temperature detected by the outdoor temperature sensor is higher, and to be longer when the temperature detected by the outdoor temperature sensor is lower. 5. The air conditioner according to claim 1, wherein when the temperature detected by the outdoor temperature sensor exceeds a set temperature, the rotation speed of the outdoor fan is increased.