JPH09303892A - Outdoor machine of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling efficiency upon cooling load by operating an outdoor air fan with higher revolutions than that upon ordinary operation when detected temperature rises to a predetermined temperature or higher, and continuously operating the same until the temperature is lowered from the predetermined high temperature to a lower temperature by a predetermined value. SOLUTION: When temperature of an outdoor heat exchanger becomes a predetermined temperature or higher, the number of revolutions of an outdor fan 15 is raised, and provided the temperature is lowered by a predetermined value, the number of revolutions is returned to the ordinary number of revolutions and there is performed control where deterioration of cooling capability upon cooling load is suppressed. For this, since the temperature of an outdoor heat exchanger following fresh air temperature is detected even upon cooling load, provided air temperature sucked from the outside becomes high, the temperature of the outdoor heat exchanger 6 is also raised, but stable control following a load state is ensured. Thus, satisfactory cooling is achieved without reaching the load state, and quiet operation is ensured without causing the changeover of the number of revolutions of the indoor air fan in a short time interval.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to operation control of an outdoor unit of an air conditioner that performs inverter control.

[0002]

2. Description of the Related Art An outdoor unit of a conventional air conditioner is constructed as shown in FIG. Referring to FIG. 5, the internal structure of the outdoor unit 2 of the air conditioner will be described.
a is a discharge pipe of the compressor 4, 6 is an outdoor heat exchanger for exchanging heat with the refrigerant compressed by the compressor 4, 7 is an outdoor heat exchanger 6
An outdoor blower that blows air to the compressor 11, and a thermistor 11 that is disposed on the discharge pipe 4a and detects the temperature of the refrigerant flowing out from the compressor 4.

A refrigeration cycle of a conventional air conditioner is constructed as shown in FIG. In FIG. 6, the refrigeration cycle is configured by connecting a compressor 4, a four-way valve 5, an outdoor heat exchanger 6, a pressure reducing device 8, and an indoor heat exchanger 9 in this order by a pipe 1. Then, during operation of the air conditioner, the four-way valve 5 is connected in the direction indicated by the solid line, and the refrigerant is caused to flow in the direction indicated by the solid line in the figure to perform the cooling operation. The indoor unit 3 has an indoor heat exchanger 9 and an indoor heat exchanger 9
And an indoor blower 10 that blows air into the room.

At this time, under the condition that the outside air temperature is high during the cooling operation, the refrigeration cycle becomes overloaded, and the discharge capacity rises and the cooling capacity decreases. As a method of preventing this, as disclosed in Japanese Utility Model Laid-Open No. 7-26635, when the temperature of the discharge pipe 4a becomes a certain temperature or more by the temperature detecting thermistor 11 attached to the discharge pipe 4a, the temperature of the outdoor blower 7 is increased. Outdoor heat exchanger 6 by increasing the rotation speed
The condensing pressure was controlled to be reduced by promoting the heat exchange of, and the cooling capacity was operated so as not to drop as much as possible.

[0005]

However, in the outdoor unit of the air conditioner configured as described above, the rotation speed of the outdoor blower 7 is increased by detecting the temperature of the discharge pipe 4a during cooling overload. However, the discharge temperature from the outdoor heat exchanger 6 does not decrease rapidly, and the temperature of the discharge pipe 4a frequently rises and falls when the rotation speed of the outdoor blower 7 is significantly increased. Then, there is a drawback that noise is frequently generated due to the shift of the outdoor blower 7.

Further, the thermistor 11 is attached to the discharge pipe 4a.
Since the temperature of the compressor 4 cannot be directly detected when the compressor is attached, a thermistor or thermostat for heating protection of the compressor 4 is required. Therefore, if the thermistor 11 attached to the discharge pipe 4a is attached to the upper portion of the compressor 4 and the temperature of the compressor 4 and the temperature of the discharge pipe 4a are detected, one thermistor can cover, but the followability of detection of the temperature of the discharge gas Therefore, the control at the time of cooling overload by detecting the discharge temperature by the thermistor attached to the upper part of the compressor 4 becomes unstable, and there is a drawback that noise is frequently generated by the shifting of the outdoor blower 7.

An outdoor unit for an air conditioner according to the present invention solves the above-mentioned problems, and an object thereof is to improve the cooling efficiency when the outdoor unit of the air conditioner has a cooling load.

[0008]

In order to achieve the above object, the outdoor unit of an air conditioner according to the present invention is, in the invention described in claim 1, a compressor for compressing a refrigerant, and is connected to the compressor. An outdoor unit of an air conditioner comprising an outdoor heat exchanger and an outdoor blower that blows air to the outdoor heat exchanger, comprising a temperature detecting means for the refrigerant discharged from the outdoor heat exchanger, and a temperature detected by the temperature detecting means. When the temperature rises above a predetermined high temperature, the outdoor fan is operated at a higher rotational speed than during normal operation, and the outdoor fan is operated at a higher rotational speed when the temperature detected by the temperature detecting means is the predetermined temperature. It is operated continuously until the temperature decreases by a certain value from the high temperature of.

According to the second aspect of the invention, an air conditioner comprising a compressor for compressing the refrigerant, an outdoor heat exchanger connected to the compressor, and an outdoor blower for blowing air to the outdoor heat exchanger. In the outdoor unit of, the temperature detection means of the refrigerant discharged from the outdoor heat exchanger is provided, and when the temperature detected by the temperature detection means rises above a predetermined high temperature, the outdoor blower rotates at a higher speed than in normal operation. The state in which the outdoor blower is operated at a high rotation speed is a continuous operation for a fixed time.

Further, in the invention according to claim 3, an air conditioner comprising a compressor for compressing a refrigerant, an outdoor heat exchanger connected to the compressor, and an outdoor blower for blowing air to the outdoor heat exchanger. In the outdoor unit of, the temperature detection means of the refrigerant discharged from the outdoor heat exchanger is provided, and when the temperature detected by the temperature detection means rises above a predetermined high temperature, the outdoor blower rotates at a higher speed than in normal operation. When the temperature detected by the temperature detecting means falls below a predetermined low temperature, the outdoor blower is operated at a rotational speed lower than the rotational speed during normal operation.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to FIGS. The same parts as those in the conventional example are designated by the same reference numerals.

[First Embodiment] A first embodiment of the outdoor unit for an air conditioner of the present invention is constructed as shown in FIG. In FIG. 1, the internal configuration of the outdoor unit 2 of the air conditioner will be described. 4 is a compressor, 4a is a discharge pipe of the compressor 4, and 6 is an outdoor heat exchange for exchanging heat of the refrigerant compressed by the compressor 4. 6a is a discharge pipe for discharging the refrigerant heat-exchanged in the outdoor heat exchanger 6, 15 is an outdoor blower for blowing air to the outdoor heat exchanger 6, 16 is a refrigerant disposed in the discharge pipe 6a and flowing through the discharge pipe 6a It is a thermistor that detects the temperature of. A thermistor 17 for protecting the compressor 4 from overheating is attached to the upper surface of the compressor 4.

The refrigerating cycle of this embodiment will be described with reference to FIG. In FIG. 2, 2 is an outdoor unit and 3 is an indoor unit. In the indoor unit 2, the refrigerant compressed by the compressor 4 is sent to the outdoor heat exchanger 6 through the refrigerant pipe 1. The outdoor heat exchanger 6 is cooled by the blower 15. Then, the cooled refrigerant is sent to the indoor heat exchanger 9 through the decompressor 8, and the indoor heat exchanger 9 is heat-exchanged by the blowing of the indoor blower 10 to blow cold air to the outside.

Here, the temperature detected by the thermistor 16 arranged in the discharge pipe on the discharge side of the outdoor heat exchanger 6 is sent to the control means 18, which changes the rotation speed of the outdoor blower 15 according to the detected temperature. And change the heat exchange efficiency.

Therefore, the control operation of the first embodiment will be described with reference to FIG.
It will be described based on the flowchart shown in FIG. In FIG. 3, the temperature of the outdoor heat exchanger 6 is detected by the thermistor 16. In step S1, the control means 18 determines whether the temperature of the outdoor heat exchanger 6 is T ₁ or lower, and the temperature is T ₁
If the temperature is below, the process proceeds to step S2. If the temperature of the outdoor heat exchanger 6 is not lower than T ₁ , the process proceeds to step S3. In step S2, the rotation speed of the outdoor blower 15 is returned to the steady rotation speed, and the process returns to step S1.

Then, in step S3, the outdoor blower 15
The number of rotations of is set to a high rotation and the process proceeds to step S4. In step S4, the step in the case where the temperature of the outdoor heat exchanger is determined whether reaches T _1-.alpha., reached T _1-.alpha. S
Returning to step 2, if the temperature has not reached T ₁ -α, the process proceeds to step S5. In step S5, it is determined whether the outdoor heat exchanger temperature T ₁ or less, the temperature is shifted to step S6 if T ₁ or less, the temperature of the outdoor heat exchanger 6 is T ₁
If not, the process proceeds to step S7. In step 6, the number of rotations of the outdoor blower 15 is kept up,
It returns to step S4.

Furthermore, in step S7, step if the outdoor heat exchanger temperature is determined whether T ₀ or less, the process returns to step S5 if the temperature T ₀ or less, the temperature of the outdoor heat exchanger 6 is not T ₀ or less The process moves to S8. In step S8, since the temperature of the outdoor heat exchanger is sufficiently low, the frequency of the compressor is DOWN, and the process proceeds to step S9.
In step 9, it is determined whether the outdoor heat exchanger temperature is T ₁ or lower, and if the temperature is T ₁ or lower, the process proceeds to step S10.
If the temperature of the outdoor heat exchanger 6 is not lower than T ₁ , step S
Go to 11. In step S10, the frequency of the compressor is increased and the process returns to step S5. Further, step S1
1, the compressor frequency is A (1/2 of the cooling rated frequency
Value) or more. If the frequency of the compressor is A or more, the process returns to step S5, and if the frequency of the compressor is not A or more, the compressor is stopped. Note that T ₁ −α <T ₁ <T ₀ .

By controlling as described above, when the temperature of the outdoor heat exchanger reaches a certain temperature T ₁ ° C or higher, the rotational speed of the outdoor blower 15 is set to a high rotational speed, and (T ₁ -α) ° C.
If it becomes the following, it will be returned to the normal number of revolutions and control will be performed to suppress the decrease in the cooling capacity at the time of cooling overload. Therefore, even when the cooling load is applied, in order to detect the temperature of the outdoor heat exchanger that follows the outdoor air temperature, the temperature of the outdoor heat exchanger 6 also rises if the air temperature of the outdoor suction rises, but the load state is reached. It can follow and perform stable control.

[Second Embodiment] A second embodiment of the outdoor unit for an air conditioner of the present invention will be described with reference to the flow chart shown in FIG. In step S1, if the control unit 18 determines whether or not the temperature of the outdoor heat exchanger 6 is T ₁ or less, the process returns to step S1 if the temperature is T ₁ or less, the temperature of the outdoor heat exchanger 6 is not T ₁ or less Control goes to step S3.

Then, in step S3, the outdoor blower 15
The number of rotations of is set to a high rotation and the process proceeds to step S4. In step S4, it is determined whether or not t ₁ time has elapsed from the temperature detection of the outdoor heat exchanger. If t ₁ time has elapsed, the process proceeds to step S4, and if t ₁ time has not elapsed. Returns to step S4. In step S5, it is determined whether the temperature of the outdoor heat exchanger is T ₁ or lower, and the temperature is T ₁
If it is below, the process returns to step S2, and if the temperature of the outdoor heat exchanger 6 is not lower than T ₁ , the process proceeds to step S6. In step S6, the temperature of the outdoor heat exchanger is determined whether T ₀ or less, the process returns to step S5 if the temperature T ₀ or less, the temperature of the outdoor heat exchanger 6 moves to step S7 if not T ₀ or less .

Further, in step S7, since the temperature of the outdoor heat exchanger is sufficiently low, the frequency of the compressor is set to D
OWN, and shifts to step S8. In step S8, the temperature of the outdoor heat exchanger is determined whether T ₁ or less, the temperature is shifted to step S9 if T ₁ below, proceeds to step S10 if the temperature of the outdoor heat exchanger 6 is not T ₁ or less To do. In step S9, the frequency of the compressor is increased and the process returns to step S5. Further, in step S10, it is determined whether or not the frequency of the compressor is A (1/2 of the rated cooling frequency) or more, and if the frequency of the compressor is A or more, step S5.
If the frequency of the compressor is not higher than A, the compressor is stopped. Note that T ₁ <T ₀ .

By controlling as described above, when the temperature of the outdoor heat exchanger reaches a certain temperature T ₁ ° C or higher, the rotation speed of the outdoor blower 15 is set to a high rotation speed, and the temperature is increased for a predetermined time. When the temperature drops to T ₁ or less, the normal rotation speed is restored, and control is performed to suppress the decrease in the cooling capacity during cooling overload. Therefore, even when the cooling load is applied, in order to detect the temperature of the outdoor heat exchanger that follows the outdoor air temperature, the temperature of the outdoor heat exchanger 6 also rises if the air temperature of the outdoor suction rises, but the load state is reached. It can follow and perform stable control.

As described above, the outdoor unit of the air conditioner of this embodiment has a stable cooling capacity in the control of the cooling load of the air conditioner in which the thermistor for detecting the discharge temperature is arranged above the compressor. In order to obtain the temperature, the outdoor heat exchanger temperature detection thermistor switches the rotation speed of the outdoor blower 15 to a high rotation speed to increase the condensation capacity when the temperature exceeds a certain temperature. Therefore, it is possible to change gears by detecting the temperature of the outdoor heat exchanger that follows changes in the outside air temperature.
Since the number of rotations of the outdoor blower 15 can be changed stably when the cooling overload occurs, the shift noise does not occur frequently and the operation can be performed with low noise.

[Third Embodiment] If the temperature of the outdoor heat exchanger becomes a certain temperature T ₂ ° C or lower, the rotational speed of the outdoor blower 15 is set to a low rotational speed, and if T ₂ + α ° C or higher, it is necessary. In order to obtain a sufficient cooling capacity, control is performed to return the rotation speed of the outdoor blower 15 to the normal rotation speed.

That is, when the temperature of the detection thermistor 16 of the outdoor heat exchanger is low, the outdoor heat exchanger 6 has a low condensing capacity, so that the outdoor fan 15 has a low rotational speed to provide an appropriate cooling capacity. It is possible to perform operation control capable of reducing noise and input on the outdoor unit side while ensuring the above.

[0026]

Since the outdoor unit of the air conditioner of the present invention is constructed as described above, the invention according to claim 1 is provided with a temperature detecting means for the refrigerant discharged from the outdoor heat exchanger, When the temperature detected by the temperature detecting means rises above a predetermined high temperature, the outdoor blower is operated at a higher rotation speed than during normal operation, so sufficient cooling can be performed without reaching an overload state. . Further, since the high rotation speed of the compressor is continuously operated until the temperature decreases to a temperature lower than the predetermined high temperature by a constant value, the rotation speed of the indoor blower is not changed at short time intervals. Can do quiet driving.

According to a second aspect of the present invention, there is provided temperature detecting means for the refrigerant discharged from the outdoor heat exchanger, and when the temperature detected by the temperature detecting means rises above a predetermined high temperature, When the outdoor blower is operated at a higher rotation speed than during normal operation, and the outdoor blower operates at a higher rotation speed, the rotation speed of the indoor blower should be changed at short time intervals because it operates continuously for a certain period of time. Without it, you can drive quietly.

Further, according to the invention of claim 3, there is provided temperature detecting means for the refrigerant discharged from the outdoor heat exchanger, and when the temperature detected by the temperature detecting means rises above a predetermined high temperature, When the outdoor blower is operated at a higher rotation speed than during normal operation, and when the temperature detected by the temperature detecting means falls below a predetermined low temperature, the outdoor blower is operated at a lower rotation speed than during normal operation. Therefore, sufficient cooling can be performed without reaching the overload state, and silent operation can be performed when the load is small.

[Brief description of drawings]

FIG. 1 is a perspective view of the inside showing a first embodiment of an outdoor unit of an air conditioner of the present invention.

FIG. 2 is a refrigeration cycle diagram of FIG.

FIG. 3 is a flowchart of FIG.

FIG. 4 is a flowchart showing a second embodiment of the outdoor unit of the air conditioner of the present invention.

FIG. 5 is a perspective view of the inside of an outdoor unit of a conventional air conditioner.

FIG. 6 is a refrigeration cycle diagram of FIG.

[Explanation of symbols]

 4 Compressor 6 Outdoor heat exchanger 6a Discharge pipe 15 Outdoor blower 16 Thermistor

Claims (3)

[Claims] 1. An outdoor unit of an air conditioner comprising a compressor for compressing a refrigerant, an outdoor heat exchanger connected to the compressor, and an outdoor blower for blowing air to the outdoor heat exchanger. A temperature detector for the refrigerant discharged from the exchanger is provided, and when the temperature detected by the temperature detector rises above a predetermined high temperature, the outdoor blower is operated at a higher rotational speed than during normal operation, and the outdoor blower is used. The outdoor unit of the air conditioner, which is continuously operated until the temperature detected by the temperature detecting means decreases to a temperature lower than the predetermined high temperature by a constant value. 2. An outdoor unit of an air conditioner comprising a compressor for compressing a refrigerant, an outdoor heat exchanger connected to the compressor, and an outdoor blower for blowing air to the outdoor heat exchanger, wherein A temperature detecting means for the refrigerant discharged from the exchanger is provided, and when the temperature detected by the temperature detecting means rises above a predetermined high temperature, the outdoor blower is operated at a higher rotation speed than during normal operation, and the outdoor blower is used. The outdoor unit of the air conditioner, which is operated at a high rotation speed for a certain period of time. 3. An outdoor unit of an air conditioner comprising a compressor for compressing a refrigerant, an outdoor heat exchanger connected to the compressor, and an outdoor blower for blowing air to the outdoor heat exchanger, wherein the outdoor heat A temperature detecting means for the refrigerant discharged from the exchanger is provided, and when the temperature detected by the temperature detecting means rises above a predetermined high temperature, the outdoor blower is operated at a higher rotation speed than during normal operation, and the temperature detection is performed. An outdoor unit for an air conditioner, wherein the outdoor blower is operated at a rotational speed lower than the rotational speed during normal operation when the temperature detected by the means is lowered to a predetermined low temperature or lower.