JPS60253747A - Defrosting controller for air conditioner - Google Patents

Abstract

PURPOSE:To eliminate uncomfortable feeling due to the noise generated when stopping an operation, by operating an exterior-side blower prior to switching a four-way valve, when stopping a defrosting operation. CONSTITUTION:Where the exterior-side blower 7 is controlled by a pressure switch 9 under an overload of heating, the defrosting operation is performed only after a compressor 1 is operated for a period of time equal to or longer than a period of time set on a timer 14. When the temperature of an exterior- side heat exchanger is higher than a temperature set by a deforsting temperature setting part for the heat exchanger, a defrosting operation judging part operates the blower 7 through an exterior-side blower controlling part, prior to switching the four-way valve 2 by a four-way valve controlling part. A timer 15 is started at the moment the blower 7 is started, and when the period of time counted by the timer 15 reaches a preset period of time, the valve 2 is switched by the four-way valve controlling part, thereby stopping the defrosting operation. Simultaneously with starting and stopping the defrosting operation, a room-side blower 4 is operated by a room-side blower controlling part. Accordingly, the refrigerant noise and vibrations generated when switching the four-way valve for the defrosting operation are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a defrosting operation control device for an air conditioner that operates an outdoor blower before switching the four-way valve when canceling the defrosting operation. It is.

Conventional Structure and Problems Conventionally, defrosting was performed by switching the four-way valve and then operating the indoor blower and the outdoor blower.

The configuration and the release method after defrosting operation will be explained with reference to FIGS. 1 and 4.

In the same figure, a compressor 1, a four-way valve 2, an indoor heat exchanger 3
, the pressure reducer 4, and the outdoor heat exchanger 6 are connected in series in an annular manner to form a refrigeration cycle.

In general, when the four-way valve switches during outdoor fan operation control during heating overload, where the difference between high and low pressure becomes large when dew protection operation is canceled, a loud cooling noise and vibration occur, causing discomfort to the user. There are many things. Therefore, it is necessary to perform a noise reduction operation when canceling the defrosting operation.

As an example of defrosting operation, in conventional defrosting operation when controlling an outdoor fan at a heating overload temperature, as shown in FIG. 2, the temperature Ta of the outdoor heat exchanger 6 reaches the set temperature Tα. When the temperature reaches the set temperature TB, the four-way valve 2 is switched to stop the indoor fan 4 and the outdoor fan 7 at the same time for defrosting. When the outdoor heat exchanger 3 reaches the set temperature TB, the four-way valve 2 is switched to stop the indoor fan 4 and the indoor fan 7. 4. Operate the outdoor fan 7 to start heating operation.

In this method of canceling the defrosting operation, the defrosting operation is performed even though the amount of frost formation is small, the response of the thermistor 8 to the rise of the outdoor heat exchanger cannot keep up, and the high pressure suddenly rises. By switching the four-way valve in this state,
There are problems with loud refrigerant noise and vibration.

Purpose of the Invention The purpose of the present invention is to eliminate the above-mentioned conventional drawbacks, and to eliminate the refrigerant noise and vibration generated when dew protection operation is canceled by operating the outdoor blower before switching the four-way valve. That is.

Structure of the Invention In order to achieve this object, the present invention detects the temperature of the outside heat exchanger with an outdoor heat exchanger temperature detection section, as shown in FIG. The outdoor heat exchanger defrost temperature setting section or the outdoor heat exchanger defrost temperature setting section that is determined at the beginning is compared with the outdoor heat exchanger comparison section, and the defrosting operation is started. When the defrosting operation is started, the determination section switches the four-way valve using the four-way valve control section, and the indoor blower control section and the outdoor blower control section stop the indoor blower and the outdoor blower. To cancel the trench defrosting operation, the outdoor blower control section operates the outdoor blower, then the four-way valve control section switches the four-way valve, and the indoor blower control section operates the indoor blower. It is.

This controls the refrigerant noise and vibration after the four-way valve operates to be reduced.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 4 to 6 of the accompanying drawings.

In FIG. 4, the control circuit is equipped with a microcomputer 13, a well-known AC-DC exchanger 10 is provided on the input side, and a signal from a thermistor 8 is input to detect and extract the temperature of the outdoor heat exchanger. .

On the output side of this control circuit, relay coils 16, 17, 18, and 19 for controlling energization of the compressor 1, the four-way valve 2, the indoor blower 4, and the outdoor blower 7 are provided.
, the four-way valve 2, the indoor blower 4, and the outdoor blower 7 are controlled in operation via relay contacts 16a, 17a, 18a, and 19a. This circuit includes a timer 14 that operates after the compressor is started, a timer 15 that operates when it is determined that the defrosting operation has been canceled and the outdoor fan 7 is operated, and a pressure switch 9.
is equipped. Further, a power supply circuit for a power supply 11 and an operation switch 12 is configured.

Next, the structure and operation of the control circuit having the above structure will be explained with reference to FIGS. 3 to 6.

The outdoor heat exchanger temperature detection section is provided with a thermistor 8 or the like, detects the outdoor heat exchanger temperature Ta, and converts the signal into a voltage. The outdoor heat exchanger temperature Ta detected there
The Q value is stored, and the value T1 determined by the outdoor heat exchanger frosting temperature setting section and the value T2 determined by the outdoor heat exchanger defrosting temperature setting section are stored.
The outdoor heat exchanger temperature Ta in the operating state is compared with the outdoor heat exchanger temperature comparison section. Here, in the defrosting operation judgment section, if the outdoor heat exchanger temperature Ta is lower than the value TI determined by the outdoor heat exchange frosting temperature setting section, the outdoor heat exchanger 6 is frosted and the outdoor heat exchanger 6 is heated. Judging that the exchanger capacity has decreased,
The four-way valve control unit switches the four-way valve and performs defrosting operation. As one method of this defrosting operation, when the outdoor fan 7 is controlled by the pressure switch 9 during heating overload, the compressor 1 starts operating and the timer 14 sets the time t.
1, it is assumed that the operation is performed only when the operating time t2 is equal to or exceeds the operating time t2. In addition, in the defrosting operation judgment section, if the outdoor heat exchanger temperature Ta is higher than the value T2 determined by the outdoor heat exchanger defrosting temperature setting section, before switching the four-way valve 2 in the four-way valve control section, The outdoor side blower is operated by the outdoor side blower control section, and when the fan 15 starts operating from this time and reaches a certain predetermined time t3, the four-way valve control section starts the operation of the four-way valve 2.
Defrost operation is canceled by switching to . At the same time as starting and canceling this defrosting operation, the indoor blower 7 is operated by the indoor blower control section.

By performing the control explained in FIGS. 3 to 6 and performing the defrosting operation, the refrigerant noise and vibration caused by switching the four-way valve in the defrosting operation are significantly reduced. As a result,
The user no longer feels uncomfortable with the sound during dew protection operation.

Effects of the Invention As is clear from the above embodiments, the present invention operates the outdoor blower before switching the four-way valve when canceling the defrosting operation, thereby dissipating heat from the outdoor blower and lowering the high pressure. By switching the four-way valve, refrigerant noise and vibration are significantly reduced.

By performing such control, there is an advantage that the user is not made to feel uncomfortable by the sound when the defrosting operation is canceled.

[Brief explanation of drawings]

FIG. 1 is a general refrigeration cycle diagram, FIG. 2 is a time chart diagram for conventional defrosting operation, and FIG. 3 is a block circuit diagram of a defrosting operation control device for an air conditioner according to an embodiment of the present invention. Fig. 4 is a schematic configuration diagram of a control circuit in the air conditioner, Fig. 5 is a flowchart of defrosting operation control in the air conditioner, and Fig. 6 is a time chart in defrosting operation of the air conditioner. . 1 Compressor, 2 Four-way valve, 3 Indoor heat exchanger, 4 Indoor blower, 5 Pressure reducer, 6 Heat outside heat exchanger, Outdoor blower, 8 Outdoor thermistor, 9 Pressure switch. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure, 5 D: Summary diagram Figure 3 Figure 4 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A compressor, a condenser, a pressure reducer, and an evaporator are connected in a ring to form a refrigeration cycle, and the outdoor heat exchanger temperature detection section detects the temperature of the outdoor heat exchanger, and the detected outdoor heat exchanger. an outdoor heat exchanger temperature storage unit that stores the temperature of the outdoor heat exchanger; an outdoor heat exchanger frosting temperature setting unit that determines the temperature of the outdoor heat exchanger when frost is formed on the outdoor heat exchanger; An outdoor heat exchanger defrosting temperature setting section that determines the temperature of the outdoor heat exchanger when the frosted state of the outer heat exchanger is melted by the defrosting operation; The outdoor heat exchanger temperature comparison section compares the temperature determined by the setting section or the temperature at the outdoor heat exchanger defrosting temperature setting section with the outdoor heat exchanger temperature, and the outdoor heat exchanger temperature comparison section compares the temperature. By doing so, the defrosting operation judgment unit determines whether or not to stop the defrosting operation, and when performing the defrosting operation, the indoor fan is operated at the same time as the four-way valve operation, and when canceling the defrosting operation, An outdoor side blower control unit that operates the side blower before switching the four-way valve, a four-way valve control unit that opens and closes the four-way valve according to the operation of defrosting operation, and a four-way valve control unit that operates the four-way valve simultaneously when starting and stopping defrosting operation. Defrosting I of an air conditioner consisting of a guide-side blower control unit that operates an indoor blower
≠Control device.