JP2626158B2 - Operation control device for air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a small air conditioner provided with a refrigeration cycle and a defrost circuit using a hot gas bypass.

2. Description of the Related Art Conventionally, in a small-sized air conditioner of this type, the defrost control is a method in which the operation of a compressor is stopped and frost is melted by heat of suction air by a blowing operation.

FIG. 4 shows a conventional small air conditioner.
1 is an air conditioner unit, 2 is an evaporator, 3 is a condenser,
4 is a compressor, 5 is an electric motor, 6 is a duct connecting the evaporator air blower circuit 7 and the condenser air blower circuit 8, and 9 is a damper for switching the blower air from the condenser side to the condenser side air outlet 8 a and the duct 6. It is. Reference numeral 10 denotes a fan for an evaporator, 11 denotes a fan for a condenser, and 14 denotes a piping sensor fixed to a pipe of the condenser 2 for temperature detection.

About the conventional air conditioner configured as above,
The operation will be described below. When this air conditioner is used in the cold air operation, the damper 9 is rotated to the position indicated by the solid line in FIG. 4, and the cool air that has passed through the evaporator air blower circuit 7 is discharged from the cool air side outlet 7a and is supplied to the user by the cool air. Brings a feeling. The air blown out of the condenser is discharged to the outlet 8a on the back surface. Also,
During the dehumidifying operation, the damper 9 is located at the position shown by the broken line in FIG. 4, and the condenser outlet air is mixed with the cool air that has passed through the duct 6 and the evaporator blower circuit 7 and is discharged from the cool air side outlet 7a. Dehumidification is performed. In both cases of the cold air operation and the dehumidification operation, when the room temperature falls and the temperature of the evaporator 2 drops due to frost on the evaporator 2, the temperature of the evaporator 2 is detected by the pipe sensor 12 and the compressor 4 stops and only the air is blown. In operation, frost is melted by suction air.

However, in the above-described configuration, the defrosting time is long, and the frost on the evaporator is melted during the defrosting operation, evaporates into the blast air, and is contained in the blast air and discharged again into the room. This has the disadvantage that the dehumidifying effect is significantly impaired.

In view of the above problems, the present invention reduces the defrosting time by flowing hot gas to the evaporator during the defrosting operation, stops the ventilation during the dehumidifying operation, prevents the condensed water from being released again into the room, and during the cold air operation. The air is continuously blown, and a cool breeze is maintained by the latent heat of evaporation and the blowing.

Means for Solving the Problems In order to solve the above problems (attain the object), the present invention provides
A refrigeration cycle having an evaporation-side heat exchanger, a condensation-side heat exchanger, a compressor, and a switching valve for sending hot gas to the evaporation-side heat exchanger during defrosting operation; and an evaporation-side ventilation circuit passing through the evaporation-side heat exchanger. A condensation side ventilation circuit passing through the condensation side heat exchanger;
A fan provided in each ventilation circuit, a fan motor, and a temperature detecting means fixed to a refrigerant pipe of the evaporating-side heat exchanger,
An air conditioner including a control circuit having a comparing means for comparing a temperature detected by the temperature detecting means with a control means for controlling energization of the switching valve and the fan motor based on a result of the comparing means. In the defrosting control, the switching valve is opened during the dehumidifying operation to stop the fan motor, and the operation valve during cooling operation is opened while the operation of the fan motor is continued.

Operation The operation of the above means is as follows.

The present invention reduces the defrosting time by flowing hot gas to the evaporator during the defrosting operation, stops the air blowing during the dehumidifying operation, prevents the condensed water from being released again into the room, and continues the air blowing during the cold air operation. It keeps a cool breeze by evaporating latent heat and air blowing.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

First, an embodiment of the present invention will be described with reference to FIGS. Since the schematic configuration of this embodiment is the same as the conventional example shown in FIG. 4, the schematic configuration will be described with reference to FIG.

FIG. 1 is a refrigeration cycle diagram of a small air conditioner having a defrosting circuit by hot gas bypass. FIG. 1 shows a pipe connecting the compressor 4 and the condenser 3 and a capillary tube 14.
The solenoid valve is provided in a bypass circuit that connects a pipe connecting the evaporator 2 and the evaporator 2.

FIG. 2 shows a block diagram of the small air conditioner of the present invention. Reference numeral 15 denotes a microcomputer including a comparison unit (hereinafter referred to as a microcomputer). Drive circuit 18, fan motor 5
A fan motor control unit 20, such as a relay circuit 19, which controls the energization of the solenoid valve, a relay drive circuit 21, and an electromagnetic valve control unit 23, such as a relay circuit 22, which controls the energization of the electromagnetic valve coil 13a, are coupled.

The control operation in the above configuration will be described with reference to the flowchart of FIG.

When power is turned on, initial settings are performed. Next is the operation switch "ON"? Is determined and if "NO", stop processing is performed and the process returns to A. If "YES", is the mode switch set to dehumidify operation? Is determined. Dehumidification operation? Is "YE
In the case of "S", the damper 9 is set at the position indicated by the broken line in FIG. 4 so as to open the passage to the duct 6. Next, the fan motor 5 is operated to blow air, and then the compressor 4 is operated to perform a dehumidification operation.

Next, the temperature is measured by the piping sensor 12 of the temperature detecting unit 15 and compared with a preset temperature T1 by a comparing unit inside the microcomputer 13. At this time, the set temperature T1 is set to a temperature slightly higher than the freezing point (for example, 3 ° C.). Where piping temperature ≧ T1
? Is "NO", the flow returns to A and the dehumidifying operation is continued. Is the piping temperature ≥ T1? Is "YES", the solenoid valve 13 is opened and the hot gas discharged from the compressor 4 is sent to the evaporator 2,
Next, the fan motor 5 is stopped to perform the defrosting operation. Next, the temperature is measured by the piping sensor 12 of the temperature detection unit 15, and the microcomputer
13 The temperature is compared with a preset temperature T2 in a comparison unit inside. At this time, the set temperature T2 is set to a higher temperature (for example, 13 ° C.) than the set temperature T1. Is the pipe temperature ≧ T2 here?
Is "NO", the defrosting operation is continued. Is the pipe temperature ≧ T2? Is "YES", the flow returns to A and the dehumidifying operation is restarted.

Is it the dehumidifying operation? Is "NO", the damper 9 is set to the position indicated by the solid line in FIG. 4 so as to close the passage to the duct 6. Next, the fan motor 5 is operated to blow air, and then the compressor 4 is operated to perform cool air operation.

Next, the temperature is measured by the piping sensor 12 of the temperature detecting unit 15 and compared with a preset temperature T1 by a comparing unit inside the microcomputer 13. Is the piping temperature ≥ T1? Is "NO", the process returns to A and the cold air operation is continued. Is the piping temperature ≥ T1? Is "YES", the solenoid valve 13 is opened, the hot gas discharged from the compressor 4 is sent to the evaporator 2, and the defrosting operation is performed. At this time, the fan motor 5 is operating. Next, the temperature is measured by the piping sensor 12 of the temperature detecting section 15 and compared with a preset temperature T2 by a comparing section inside the microcomputer 13. Is the pipe temperature ≧ T2?
Is "NO", the defrosting operation is continued. Is the pipe temperature ≧ T2? Is "YES", the process returns to A and restarts the cold air operation.

As described above, in the present embodiment, the hot gas is supplied to the evaporator during the defrosting operation to shorten the defrosting time, and the ventilation is stopped during the dehumidifying operation to prevent the condensed water from being released again into the room.
At the time of the cold air operation, the air blowing is continued, and the cool air feeling can be maintained by the latent heat of evaporation and the air blowing.

Advantageous Effects of the Invention As is clear from the above embodiment, the small air conditioner of the present invention has a switching valve for sending hot gas to the evaporation side heat exchanger during the defrosting operation, the evaporation side heat exchanger, the condensation side heat exchanger, the compressor. A refrigeration cycle having the same, an evaporation side ventilation circuit passing through the evaporation side heat exchanger, a condensation side ventilation circuit passing through the condensation side heat exchanger, a fan provided in each ventilation circuit, a fan motor, Temperature detecting means fixed to the refrigerant pipe of the side heat exchanger, comparing means for comparing the temperature detected by the temperature detecting means, and controlling the energization of the switching valve and the fan motor based on the result of the comparing means. In a defrost control in an air conditioner having a control circuit having a control means for performing a dehumidifying operation, a switching valve is opened to stop a fan motor during a dehumidifying operation, and a switching is performed while a fan motor is being operated during a cooling operation. Open valve Operation switching means.

Because it is configured as described above, during the defrosting operation, the hot gas is caused to flow to the evaporator to shorten the defrosting time, and during the dehumidifying operation, the blowing is stopped to prevent the condensed water from being discharged again into the room, Further, during the cool air operation, the air is continued to be blown and the effect of maintaining the cool breeze by the latent heat of evaporation and the blowing is provided.

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram of one embodiment of the present invention, FIG. 2 is a block diagram thereof, FIG.
FIG. 4 is a sectional view of a conventional example. DESCRIPTION OF SYMBOLS 1 ... Air conditioning unit, 2 ... Evaporator, 3 ... Condenser, 4 ... Compressor, 7 ... Blower circuit for evaporator, 8 ... Blower circuit for condenser, 9 ... Damper, 12 ... Piping Sensor, 13
……solenoid valve.

Claims (1)

(57) [Claims] 1. A refrigeration cycle having an evaporation-side heat exchanger, a condensation-side heat exchanger, a compressor, a switching valve for sending hot gas to the evaporation-side heat exchanger during defrosting operation, and passing through the evaporation-side heat exchanger. An evaporation-side ventilation circuit, a condensation-side ventilation circuit passing through the condensation-side heat exchanger, fans provided in each of the evaporation-side ventilation circuit and the condensation-side ventilation circuit, a fan motor, and a refrigerant pipe of the evaporation-side heat exchanger Temperature detection means fixed to the control means, a comparison means for comparing the temperature detected by the temperature detection means, and a control means for controlling energization of the switching valve and the fan motor based on a result of the comparison means. In the defrost control in the air conditioner including the control circuit, the switching valve is opened during the dehumidifying operation and the fan motor is stopped, and the switching valve is opened while the operation of the fan motor is continued during the cold air operation. Operation control device for air conditioner, characterized in that provided operation changeover means.