JPS60133253A - Rotating speed controller for exterior blower in air conditioner - Google Patents

Abstract

PURPOSE:To reduce noise of an exterior unit while performing an efficient refrigerating cycle, by using a defrosting thermistor also for controlling the rotating speed of an exterior blower. CONSTITUTION:The temperature (analog signal) detected by the defrosting thermistor 7 is converted into a digital signal by an A/D converter 8, and the digital signal is compared with a previously stored value by a comparing and calculating part 9. When the detected temperature is higher than the previously stored value, it is discriminated that the quantity of heat exchanged by an exterior heat exchanger 3 is small, and a signal is transmitted to a driving unit part 10 so as to increase the quantity of air blown by the exterior blower 12, whereby a high-voltage high-frequency power source is supplied to the blower 12 through an inverter part 11. On the other hand, when the temperature detected by the thermistor 7 is lower than the stored value, it means that the rotating speed of the blower 12 may be reduced, and as a result, the noise generation of the exterior unit can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotation speed control device for an outdoor blower of an air conditioner using a refrigeration cycle.

Conventional configuration and its problems Noise from air conditioners has been a social problem for some time. In particular, the noise of outdoor units can be a nuisance to neighboring households, so it has been desired to reduce the noise level of outdoor units.

Conventionally, noise reduction from outdoor units has been achieved by lowering the rotational speed of the blower using a signal from an outside temperature sensor when the outside temperature is low during cooling, for example, in order to reduce the wind noise from the blower, which is the main cause of noise. It was In addition, in variable capacity air conditioners that control the rotation speed of the refrigerant compressor using an inverter, etc., the input power to the compressor is connected to the blower in parallel with the compressor, so that the rotation speed of the compressor is low. Sometimes, the number of revolutions of the blower was also lowered to reduce noise.

However, with the former method using an outside temperature sensor, for example, when the outside temperature is low during cooling and the rotation speed of the outdoor fan is lowered, the indoor temperature is high and the low pressure of the refrigeration cycle increases, resulting in a high high pressure. It goes off and consumes more power than necessary. On the other hand, it has the disadvantage that an outside temperature sensor must be installed solely for the purpose of controlling the outdoor blower.

In addition, in the latter method that utilizes changes in the input power to the refrigerant compressor, the method of controlling the rotation speed of the refrigerant compressor itself is affected by the deviation between the indoor temperature measurement value of the indoor temperature sensor and the room temperature set value. When the deviation is large, the rotational speed of the refrigerant compressor is increased, and as the deviation becomes smaller, the rotational speed is lowered.The control of the outdoor blower does not include the influence of the outside temperature, and the rotational speed of the outdoor blower is normally low. Sometimes the refrigerant compressor operates at high rotation speeds, making more noise than necessary, and even when the refrigerant compressor rotation speed is low, the outside temperature is high, and as an outdoor blower, there are times when high rotation speeds are required. There was a problem with the refrigeration cycle that the change in the rotation speed of the outdoor blower could not be matched with the change in the rotation speed of the compressor.

OBJECTS OF THE INVENTION In view of the above-mentioned drawbacks, it is an object of the present invention to reduce the noise of the outdoor unit while operating the refrigeration cycle efficiently without adding any sensors.

Structure of the Invention In order to achieve this object, the present invention is configured with a defrosting thermistor, an electric circuit, and an outdoor fan with variable rotation speed as the main components, thereby replacing the conventional defrosting thermistor. It can also be used to control the rotation speed of an outdoor blower, without the need for an additional sensor, and can also be used to control the indoor temperature.
This system operates the outdoor unit at a rotation speed that matches the operating conditions of the refrigeration cycle, which vary depending on the outside temperature and the rotation speed of the refrigerant compressor, thereby reducing noise from the outdoor unit without straining or wasting the refrigeration cycle. .

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

The figure is a block diagram of an air conditioner in one embodiment of the present invention. In the figure, 1 is a refrigerant compressor, 2 is a four-way switching valve, 3 is an outdoor heat exchanger, 4 is a pressure reducer, 5 is an indoor heat exchanger,
6 is an indoor blower, and 7 is a defrosting thermistor, which is a temperature signal detection section used for controlling the rotational speed of the outdoor blower according to the present invention. 8
1O is a comparison calculation unit that digitally converts and compares the analog signal obtained by the defrosting thermistor 7 to determine the rotation speed of the outdoor blower 12. 1O is a comparison calculation unit for the inverter unit 11 that changes the voltage and frequency of the AC power supply 13. This is a driving unit that provides 9 calculation results.

Further, symbols - and -1 in the figure indicate the flow directions of refrigerant during cooling and heating, respectively, and -1 and -→ indicate electrical signals, power lines, and their directions.

The operation of the air conditioner configured as above will be described below. First, in the refrigeration cycle, as is generally known, the refrigerant flow follows - during cooling and -→ during heating to perform cooling and heating. The defrosting thermistor 7, which is a requirement of the present invention, is usually installed near the inlet of the outdoor heat exchanger 3 during heating, and when the temperature becomes lower than a certain value, the defrosting thermistor 7 stops the operation of the refrigerant compressor 1.
It is configured to start defrosting operation upon heating.

The present invention uses the defrosting thermistor 7 not only for defrosting operation, but also for defrosting operation.
It is also used to control the rotational speed of an outdoor blower, and will be explained separately for cooling and heating.

First, during cooling, when the outside temperature is high, the indoor temperature is high, and the low pressure is high, the high pressure becomes high, the outlet temperature of the outdoor heat exchanger also becomes high, and the defrosting thermistor 7 reaches a high temperature. Detect. The temperature (analog signal) detected by the defrosting thermistor 7 is converted into a digital signal by the A/D converter 8, and compared with a pre-stored value in the comparison calculation section 9.
If it is high, it is determined that the amount of heat exchanged by the outdoor heat exchanger 3 is small, and a signal is transmitted to the driving unit section 10 to increase the air volume of the outdoor blower 12. Power is supplied to the outdoor blower 12.

When the defrosting thermistor 7 detects a low temperature, this means that the rotation speed of the outdoor fan 12 may be reduced, and as a result, the noise of the outdoor unit can be reduced.

During heating, if the defrosting thermistor 7 detects a low temperature,
If the rotation speed of the outdoor fan 7 is increased and high temperature is detected,
Just lower the rotation speed.

Note that it is necessary for the comparison calculation unit 9 to change the value used as the comparison standard during cooling and heating.

Defrosting thermistor 7 still indicates the temperature at which normal defrosting operation should be performed.
When detected, defrosting operation starts.

As described above, according to this embodiment, by using the defrosting thermistor 7 to control the outdoor blower 120 rotation speed, the temperature inside the refrigeration cycle as a result of all conditions can be adjusted to the temperature outside the room without increasing the number of thermistors. Since the rotation speed of the blower 12 is controlled, the refrigeration cycle can be operated efficiently.
It has the effect of reducing noise from the outdoor unit.

In this embodiment, the inverter section 11 is used to control the rotation speed of the outdoor blower 12, but a relay or the like may be used to switch the notch of the outdoor blower 12.

Effects of the Invention As described above, the present invention utilizes a defrosting thermistor as a sensor for controlling the rotation speed of an outdoor fan, thereby maintaining the refrigeration cycle in an efficient operating state without increasing the number of sensors. Since it is possible to reduce the noise of the outdoor unit by controlling the rotation speed of the blower, the practical effects are significant.

[Brief explanation of the drawing]

The figure is a block diagram of an air conditioner in one embodiment of the present invention. 3... Outdoor heat exchanger, 7... Defrosting thermistor, 12... Outdoor blower.

Claims (1)

[Claims] An outdoor blower and an outdoor heat exchanger, a defrosting thermistor installed in piping near the outdoor heat exchanger, and a comparison calculation section and an inverter section that control the rotation speed of the outdoor blower based on the temperature signal of the defrosting thermistor. An outdoor blower rotation speed control device for an air conditioner, comprising a control unit comprising: