JPH09280632A - Outdoor unit of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a heat exchanging capability of a heat exchanger to be reduced while a cooling fan in a control box is being cooled by a method wherein a pair of upper and lower fans within a heat exchanging chamber are turned on or off in response to an indoor load and when these fans are turned on or off, a lower fan is preferentially stopped. SOLUTION: An inner side of a casing 1 of an outdoor device is partitioned by a partition plate 2 to define a machine chamber 3 and a heat exchanging chamber 4. Each of the chambers is provided with a control box 6, a heat exchanger 9 and fans 10A, 10B or the like. Solenoid valves are arranged at a liquid side pipe and a gas side pipe of a circuit opposing against the lower fan 10B in refrigerant flow passage of the heat exchanger 9. When operated, in the case that an indoor load is decreased, the fans 10A, 10B are turned on or off, although at this time the lower fan 10B is preferentially stopped and the upper fan 10A is rotated at a set number of rotation. With such an arrangement as above, surrounding air is flowed at a clearance of the cooling fan so as to enable the cooling fins 7 within the control box 6 to be effectively cooled.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an outdoor unit of an air conditioner.

[0002]

2. Description of the Related Art An example of an outdoor unit of a conventional air conditioner is shown in FIG. 2, where (A) is a schematic front view partially broken, and (B) is B- of (A). Longitudinal section along line B, (C)
It is a schematic sectional drawing which follows the CC line | wire of (A).

The inside of the casing 1 of the outdoor unit is divided into left and right by a partition plate 2, and a machine room 3 is formed on one side and a heat exchange chamber 4 is formed on the other side.

In the machine room 3, an inverter-driven compressor 5,
A four-way valve 8, an expansion valve 17, etc. are arranged, and a control box 6 is arranged on the upper part. A cooling fin 7 of a control device such as a power transistor housed in the control box 6 that requires cooling is projected above the heat exchange chamber 4.

An L-shaped heat exchanger 9 and a pair of upper and lower fans 10A and 10B are arranged in the heat exchange chamber 4, and the L-shaped heat exchanger 9 is formed on the rear surface 1a of the casing 1. Air intake 11
And the air intake 12 formed on the left side surface 1b. The fans 10A and 10B are installed so as to face the exhaust ports 13A and 13B formed in the front panel 1c of the casing 1.

When the fans 10A, 10B are driven by the motors 14A, 14B, outside air is sucked into the heat exchange chamber 4 through the air intakes 11 and 12, and heat is exchanged with the refrigerant in the process of passing through the heat exchanger 9. After raising or lowering the temperature by
It is urged by A and 10B and discharged from exhaust ports 13A and 13B. At the same time, the cooling fins 7 are cooled by the outside air flowing through the gap.

A plurality of indoor units are connected to this outdoor unit via refrigerant pipes and signal lines.

[0008]

In the above conventional air conditioner, when only one small capacity indoor unit is operated,
The capacity of the outdoor unit becomes excessive with respect to the indoor load, and as a result, thermo-stops are frequently repeated, abnormal pressure drop of the high-pressure refrigerant during cooling operation, dew or frost formation on the indoor heat exchanger, and heating operation There was a problem that the high-pressure refrigerant pressure abnormally increased.

[0009]

The present invention has been invented to solve the above-mentioned problems, and the gist of the present invention is to divide the inside of the casing by a partition plate to the left and to the right. A heat exchange chamber is formed and a machine room is formed on the other side. An inverter drive compressor, a control box, etc. are installed in this machine room, and a heat exchanger, a pair of upper and lower fans, etc. are installed in the heat exchange room. In the outdoor unit of the air conditioner in which the cooling fins of the control box are projected above the heat exchange room, the pair of upper and lower fans are turned on / off according to the indoor load, and the fans are turned on / off. In an outdoor unit of an air conditioner, a fan controller that preferentially stops the lower fan is provided.

Another feature is that the fan controller sets the rotational speed of the upper fan to the set rotational speed when the lower fan is stopped.

Still another feature is that the refrigerant passage of the heat exchanger is vertically divided into at least two circuits, and the liquid side and gas side pipes of the circuit facing the lower fan are connected to the lower side. There is an electromagnetic valve that is closed in conjunction with the stop of the side fan.

However, a pair of upper and lower fans are turned on and off according to the indoor load, and when these fans are turned on and off,
The lower fan has priority to stop. Then, when the lower fan is stopped, the solenoid valve is closed in conjunction with this, and the upper fan rotates at the set rotation speed.

[0013]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the invention is shown in FIG. The refrigerant passage of the heat exchanger 9 is vertically divided into at least two circuits 9A and 9B, and a solenoid valve 20 is provided in the liquid side pipe 15B of the circuit 9B facing the lower fan 10B, and a gas side pipe. The solenoid valve 21 is installed in 16B.

The solenoid valves 20, 21 and the drive motor 14A for the upper fan 10A and the drive motor 14B for the lower fan 10B are controlled by a fan controller 22. The other configuration is the same as that of the conventional one shown in FIG. 2, and the corresponding members are denoted by the same reference numerals and description thereof will be omitted.

During the cooling operation, when the number of indoor units operating is large and the indoor load is large, the solenoid valves 20 and 21 are opened by a command from the fan controller 22, and the motor 14
Both A and 14B rotate. The refrigerant gas discharged from the compressor 5 is branched through the four-way valve 8, one of which flows into the circuit 9A of the heat exchanger 9 through the gas side pipe 16A, and the other of which flows into the gas side pipe 16B and the solenoid valve 21. Through heat exchanger 9
Flows into circuit 9B.

Then, in the process of passing through the circuits 9A and 9B, heat is radiated to the outside air blown by the pair of upper and lower fans 10A and 10B to be condensed and liquefied. The liquid refrigerant flowing out of the circuit 9B merges with the liquid refrigerant flowing through the liquid side pipe 15A from the circuit 9A at the place where it has passed through the solenoid valve 20 and the liquid side gas pipe 15B.

Then, after entering the expansion valve 17 and being adiabatically expanded by being throttled here, it is sent to a plurality of indoor units A and B, and in the process of passing through the indoor heat exchangers 23A and 23B, the indoor fan is blown. By cooling the indoor air sent by 24A and 24B, it evaporates and vaporizes. This gas refrigerant is a four-way valve 8
And returns to the compressor 5.

During the heating operation, the four-way valve 8 is switched in the opposite manner to the above, so that the refrigerant circulates in the opposite direction.

When the number of operating indoor units decreases or the indoor load decreases, the rotational speeds of the pair of upper and lower fans 10A and 10B decrease according to a command from the fan controller 20.

When the indoor load is greatly reduced, such as when only one small-capacity indoor unit is operated, for example, B, a pair of upper and lower fans 10A and 10B are turned on by a command from the fan controller 22. Turned off, this time the lower side fan 10B
Is preferentially stopped, the upper fan 10A has a preset rotational speed, and the solenoid valves 20 and 21 are closed.

However, since the outside air sent only by the upper fan 10A flows through the heat exchanger 9 and the refrigerant flows only through the circuit 9A, the heat exchange capacity of the heat exchanger 9 is lowered.

As a result, the thermostat of the air conditioner is frequently stopped, the high-pressure refrigerant pressure is abnormally decreased during the cooling operation, the indoor heat exchanger 23B is exposed to dew or frost, and the high-pressure refrigerant pressure is abnormally increased during the heating operation. Can be prevented.

Further, since the upper fan 10A rotates at the set rotational speed, the outside air does not flow through the gap of the cooling fin 7 and the cooling function of the cooling fin 7 is not impaired. Then, since the solenoid valves 20 and 21 are closed, the refrigerant does not liquefy and accumulate in the lower circuit 9B.

[0024]

According to the present invention, when the indoor load is reduced, the pair of upper and lower fans are turned on and off, and when the fans are turned on and off, the lower fan is preferentially stopped.
The heat exchange capacity of the heat exchanger can be reduced while cooling the cooling fins of the control box.

As a result, the thermostat is frequently stopped due to the capacity of the outdoor unit being excessive with respect to the indoor load, the high-pressure refrigerant pressure is abnormally reduced during the cooling operation, and the dew condensation or adhesion to the indoor heat exchanger is caused. It is possible to prevent an abnormal increase in the high-pressure refrigerant pressure during frost and heating operation.

If the rotation speed of the upper fan is set to the set rotation speed when the lower fan is stopped, the cooling fins of the control box can be effectively cooled even when the lower fan is stopped.

The refrigerant passage of the heat exchanger is vertically divided into at least two circuits, and the liquid side and gas side pipes of the circuit facing the lower fan are closed in conjunction with the stop of the lower fan. If the solenoid valve is provided, the heat exchange capacity of the heat exchanger can be more reliably reduced, and the liquid refrigerant can be prevented from accumulating in the lower circuit.

[Brief description of drawings]

FIG. 1 is a schematic system diagram showing an embodiment of the present invention.

FIG. 2 shows a conventional outdoor unit, (A) is a schematic front view showing a partially broken view, (B) is a schematic vertical sectional view taken along the line BB of (A), (C) is a schematic sectional view taken along the line CC of (A).

[Explanation of symbols]

 1 device casing 2 partition plate 3 machine room 5 compressor 6 control box 7 cooling fin 4 heat exchange chamber 9 heat exchanger 9A, 9B circuit 10A, 10B fan 22 fan controller 15A, 15B liquid side pipe 16A, 16B gas side pipe 21 , 21 solenoid valve

Claims (3)

[Claims] 1. A heat exchange chamber is formed on one side and a machine room is formed on the other side by partitioning the inside of the housing by a partition plate to the left and right, and an inverter drive compressor, a control box, etc. are formed in this machine room. An outdoor unit of an air conditioner in which a heat exchanger, a pair of upper and lower fans, and the like are provided in the heat exchange chamber, and the cooling fins of the control box are protruded above the heat exchange chamber. An outdoor unit for an air conditioner, comprising a fan controller for turning on and off the pair of upper and lower fans according to a load and for stopping the lower fan preferentially when the fans are turned on and off. 2. The outdoor unit for an air conditioner according to claim 1, wherein the fan controller sets the rotational speed of the upper fan to a set rotational speed when the lower fan is stopped. 3. The refrigerant flow path of the heat exchanger is vertically divided into at least two circuits, and the liquid side and gas side pipes of the circuit facing the lower fan are interlocked with the stop of the lower fan. The outdoor unit for an air conditioner according to claim 1, further comprising a solenoid valve that is closed.