JPS6363829B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a control method during cooling operation of an air conditioner.

<Prior Art> When an air conditioner performs cooling operation in hot and humid conditions, the temperature may drop below the dew point temperature near the cold air outlet of the indoor heat exchanger or in poorly insulated areas, resulting in dew condensation. In order to prevent this, conventional methods have been to maintain a certain air volume without reducing the rotation speed of the indoor fan too much.
It was common practice to prevent a drop in temperature in areas where dew condensation is likely to occur by not lowering the evaporation temperature. However, with such measures, it is difficult to reduce the air volume to such an extent that the airflow is not felt, and there are problems such as the cold air hitting the body directly, which is uncomfortable, and the noise of the blower tends to increase.

<Object of the Invention> The present invention has been made in view of the above-mentioned problems, and has an object to provide a method for controlling an air conditioner that operates with a reduced air volume of a blower during normal operation.

<Structure of the Invention> In order to achieve the above object, the present invention provides an air conditioner equipped with a compressor, an outdoor heat exchanger, an indoor heat exchanger, a variable speed indoor blower, etc.
It is characterized in that the rotation speed of the indoor blower is increased when the continuous operation time of the compressor reaches a preset time during cooling operation.

<Example> The present invention will be specifically described below with reference to an illustrated example.

FIG. 1 is a schematic diagram of a refrigeration cycle of an air conditioner embodying the present invention, in which a compressor 1, an outdoor heat exchanger 2, a pressure reducing device 3, and an indoor heat exchanger 4 are sequentially connected. 2 is provided with an outdoor blower 5, and the indoor heat exchanger 4 is provided with an indoor blower 6.

FIG. 2 is an electrical circuit diagram, in which a control circuit 7 equipped with a microcomputer is connected to a power plug 8, a series circuit of a starting relay 9 and an indoor blower 6 is connected in parallel to the control circuit 7, and a compressor 1 Parallel circuit of and outdoor blower 5 and comprelay 1
A series circuit with 0 is connected in parallel to the indoor blower 6. The indoor fan 6 has a high and low rotation speed 2
A fan relay 11 on the high-speed side and a fan relay 12 on the low-speed side are provided, respectively. In addition, each relay 9, 1
Only contacts 0, 11, and 12 are shown, and these are configured to be opened/closed by a control circuit 7. In addition, the microcomputer of the control circuit 7 includes, for example, a program
A so-called one-chip microcomputer is used, which is equipped with ROM, data RAM, an accumulator, various general registers, ALU, etc.

Next, the third section regarding the control operation by the control circuit 7 will be explained.
This will be explained with reference to the flow cheat shown in the figure.

First, in step S1, the set temperature C is selected using a manual setting device (not shown), and the air volume is set to low speed L.
, and turn on the cooling operation switch. This turns on the starting relay 9 and starts the operation, and the memory timer t built in the control circuit 7 is cleared in step S2. Next, in step S3, the room temperature is checked, and if the room temperature is higher than the set temperature C, the comprelay 10 is turned on and the memory timer t starts counting (steps S4 and S5). T is a check time for continuous operation that is preset to, for example, 0.5 to 1 hour, and in step S6, the memory timer t and the check time T are set in advance.
are compared, and if t>T is not true, the fan relay 12 on the low speed side is turned on (step S7), and the process returns to step S3 to repeat the above operation.
That is, the compressor 1 discharges high-temperature, high-pressure gas, and the outdoor heat exchanger 2 exchanges heat with outdoor air blown by the outdoor blower 5, so that the gas is condensed and liquefied. This condensed liquid is then depressurized by the pressure reducing device 3, and heat exchanges with the indoor air blown by the indoor blower 6 in the indoor heat exchanger 4, and the evaporated gas returns to the compressor 1. Since the indoor blower 6 is operated at a low speed, the evaporation temperature is low, and dew is generally likely to form near the indoor heat exchanger 4.

When this operating state continues and t>T, the high-speed side fan relay 11 is turned on (step S8), and the indoor blower 6 is switched to high-speed operation. For this reason, heat exchange in the indoor heat exchanger 4 improves, the evaporation temperature rises, and the temperature near the indoor heat exchanger 4 such as the air outlet becomes high and exceeds the dew point, making it difficult to operate with dew formation. Continued.

Further, when the room temperature decreases and it is checked in step S3 that the room temperature has reached the set temperature C, the process proceeds to step S9, where the complete relay 10 is turned off and the fan relay 12 is turned on (step S10). The cycle is stopped and the indoor blower 6 is operated at a low speed, and after elapse of, for example, 3 minutes, the process returns from step S11 to S2, the memory timer t is cleared, and the above-described operation is repeated again.

In other words, the load is generally large when the temperature is high and humid.
The compressor 1 is often operated continuously for a long time, and condensation is more likely to occur.
If the compressor 1 continues to operate beyond the preset check time, the indoor fan 6 is switched to high speed and the air volume is increased to prevent condensation. During normal operation when the load is small and the on-off hunting time is short, the indoor blower 6 is operated at low speed.

Although the above embodiment relates to a 2-speed indoor blower, the present invention can also be applied to a 3-speed or higher-speed indoor blower. The speed may be changed to medium speed and then high speed in sequence.

<Effects of the Invention> As described above, according to the control method of the present invention, it is possible to effectively prevent dew condensation by increasing the rotational speed of the indoor fan in conditions where dew condensation is likely to occur, and also to prevent dew condensation during normal operation. Since the air volume of the fan can be designed to be small, the cold air does not hit the body, improving comfort and reducing the operating noise of the fan.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a refrigeration cycle diagram, FIG. 2 is an electric circuit diagram, and FIG. 3 is a control flowchart. 1...Compressor, 2...Outdoor heat exchanger, 4...
Indoor heat exchanger, 5... Outdoor blower, 6... Indoor blower, 7... Control circuit, 11... High speed side fan relay,
12...Low speed side fan relay.

Claims (1)

[Claims] 1 In an air conditioner equipped with a compressor, an outdoor heat exchanger, an indoor heat exchanger, an indoor blower with variable speed, etc., when the continuous operation time of the compressor reaches a preset time during cooling operation, the rotation speed of the indoor blower is changed. A method for controlling an air conditioner, characterized in that: