JP2605614B2 - Operation control device for air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for an air conditioner. Specifically, the present invention relates to an improvement in an air conditioner that detects frost generated in an outdoor heat exchanger during a heating operation and performs a frost removal operation.

[0002]

2. Description of the Related Art An air conditioner having a defrost operation function of detecting and removing frost is disclosed in, for example,
There is one disclosed in Japanese Patent Publication No. 122848. FIG. 7 is a block diagram showing a configuration of a frost detection section 101 in a conventional air conditioner, and includes a room temperature detecting means 102 for detecting a room temperature TR and a temperature (condensation temperature) of an indoor heat exchanger.
An indoor heat exchanger temperature detecting means 103 for detecting TH, and a discriminating means 104 for comparing the room temperature TR with the indoor heat exchanger temperature TH to output a frost detection signal when detecting a frost state.
And a control means 10 for outputting a defrost operation command signal when the frost detection signal of the determination means 104 has been maintained for a predetermined time.
And 5.

[0003] When a compressor of an air conditioner is started to start a heating operation, the temperature of the indoor heat exchanger gradually increases, and after a certain period of time, the temperature of the indoor heat exchanger reaches an equilibrium state. Thereafter, the temperature of the outdoor heat exchanger decreases, and frost begins to form. As the frost grows on the surface, the heat exchange efficiency of the outdoor heat exchanger decreases. As a result, the temperature of the indoor heat exchanger decreases. On the other hand, the room temperature gradually increases at first after the start of the heating operation, but reaches a substantially equilibrium state after a certain period of time.

In the air conditioner, the room temperature TR is detected by the room temperature detecting means 102, and the indoor heat exchanger temperature TH is detected by the indoor heat exchanger temperature detecting means 103.
The maximum temperature difference ΔTHR between the indoor heat exchanger temperature TH and the room temperature TR (hereinafter, referred to as “TH-TR” [hereinafter referred to as an initial maximum value]) ΔTmax = (ΔTHR) max is obtained by the determination means 104 in the initial stage of operation. I remember. The discriminating means 104 constantly monitors the temperature difference ΔTHR between the indoor heat exchanger temperature TH and the room temperature TR. The indoor heat exchanger temperature TH decreases as the capacity decreases due to frosting, and the temperature difference ΔTHR becomes the initial maximum value Δ.
When the temperature becomes lower than Tmax by a certain temperature β (for example, 4 ° C.) or more (that is, ΔTHR ≦ ΔTmax−β), it is determined that frost formation is detected, and a frost formation detection signal is output. Then, when the frost detection signal from the determination means 104 continues for a predetermined time (for example, 15 minutes) or more, the control means 105 outputs a defrost operation command. When the defrost operation command is output, the air conditioner determines that frost has occurred, switches the refrigerant circulation path to a cycle opposite to the heating cycle, that is, switches to the cooling cycle, performs defrost operation, and performs outdoor heat After removing the frost on the exchanger, the operation returns to the normal heating operation again.

[0005]

In the conventional air conditioner, the indoor heat exchanger temperature TH and the room temperature TR are set as described above.
ΔTHR = TH−TR, and the temperature difference ΔTHR is the initial maximum value (the maximum value at the time of the initial operation) ΔTmax.
When the temperature becomes lower than the predetermined temperature β by more than a predetermined time, it is determined that frost is formed, and the defrost operation is performed.

However, in an air conditioner employing such a frost detection method, when the room is opened after the start of the heating operation and the heating operation is continued, the room temperature is higher than in a normal use environment. Therefore, the temperature difference ΔTHR between the room temperature and the indoor heat exchanger temperature is large, and even if the temperature of the indoor heat exchanger decreases due to frost on the outdoor heat exchanger and the temperature difference ΔTHR,
THR does not become smaller than ΔTmax−β, and frost formation is not detected. In addition, when other heating devices such as a fan heater and a stove are used together after the operation of the air conditioner, the room temperature increases, so that the temperature difference between the room temperature and the indoor heat exchanger is smaller than that in the normal single operation. The defrost operation is performed in a state in which the frost is smaller than in the case and there is not much frost. Therefore, in the conventional example, when the room temperature changes suddenly due to a disturbance such as a window opening operation or a combination with another heating device, the temperature difference between the room temperature and the indoor heat exchanger is affected, which may cause erroneous detection of frost formation. The nature was high.

Further, the conventional frost detection method in an air conditioner only prevents the defrost operation from being started by mistake due to internal disturbance. The function of correcting the problem of the initial maximum value due to internal disturbance is not provided. If there is any internal disturbance such as a change in the set wind speed of the indoor fan provided in the blower of the indoor heat exchanger or a change in the wind speed due to the cold air prevention control, the temperature of the indoor heat exchanger may be affected. In some cases, the detection of frost was adversely affected.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art, and has as its object the purpose of the present invention when, when internal disturbance or disturbance occurs, the change of the frost detection condition due to the internal disturbance or disturbance. It is an object of the present invention to provide an operation control device for an air conditioner that can correct frost and accurately detect frost formation.

[0009]

A first operation control apparatus for an air conditioner according to the present invention comprises a room temperature detecting means for detecting an indoor temperature and an indoor heat exchanger for detecting an indoor heat exchanger temperature during a heating operation. A temperature detecting means for detecting a frost formed in the outdoor heat exchanger by determining that a temperature difference between the detected indoor heat exchanger temperature and the indoor temperature has decreased by at least a predetermined value from the initial maximum value; a frost detecting means, in the air conditioner so as to remove the defrost operation the detected frosted, time variation of the room temperature detecting means room temperature detected is
Disturbance recognition means for judging the occurrence of disturbance by comparing the conversion rate with a predetermined value, and a temperature difference between the room temperature and the indoor heat exchanger temperature immediately before the occurrence of the disturbance and the room temperature and the indoor heat exchanger temperature after the disturbance is stabilized. An initial maximum value correcting means for correcting the initial maximum value from the temperature difference.

A second operation control device for an air conditioner according to the present invention comprises: a room temperature detecting means for detecting an indoor temperature; an indoor heat exchanger temperature detecting means for detecting an indoor heat exchanger temperature during a heating operation; Frost detection means for detecting frost generated in the outdoor heat exchanger by determining that the temperature difference between the determined indoor heat exchanger temperature and the indoor temperature has decreased by a predetermined value or more from the initial maximum value. , in the air conditioner so as to remove the defrost operation the detected frosted, the room temperature
Disturbance recognizing means for determining the occurrence of disturbance based on the time change rate of the room temperature detected by the detecting means, and disturbance recognizing means.
Separately and independently detected by the indoor heat exchanger temperature detecting means
A disturbance recognition means for judging the occurrence of a disturbance based on the time change rate of the indoor heat exchanger temperature, and a temperature difference between the room temperature and the indoor heat exchanger temperature immediately before the occurrence of the disturbance or the disturbance, and a temperature difference after the disturbance and the disturbance are stabilized. An initial maximum value correcting means for correcting the initial maximum value based on the temperature difference between the indoor temperature and the indoor heat exchanger temperature.

[0011]

According to the first air conditioner operation control device of the present invention, the time change rate of the room temperature is compared with a predetermined value.
Monitoring the disturbance by monitoring the indoor fan
If the set wind speed changes or the wind speed changes due to the cold wind prevention control, etc.
Also does not affect the disturbance recognition means, recognizes the occurrence of disturbance due to window opening operation, combined use with other heating equipment, etc., and corrects the initial maximum value used for frost detection to a value that allows for changes due to disturbance be able to. Therefore, even when disturbance occurs, erroneous detection of frost formation can be prevented.

Further, even when the disturbance has disappeared, it can be detected, and the initial maximum value can be corrected to a value anticipating a change due to the elimination of the disturbance. Detection can be prevented.

In the second operation control apparatus for an air conditioner of the present invention, the occurrence of disturbance due to window opening operation, combined use with other heating equipment, and the like is recognized by constantly monitoring changes in the room temperature, The initial maximum value used for frost detection can be corrected to a value that allows for changes due to disturbance. At the same time, by constantly monitoring the temperature change of the indoor heat exchanger, it is possible to recognize an internal disturbance such as a change in the wind speed or a change in the wind direction of the blower fan, and to correct the initial maximum value to a value that allows the change due to the internal disturbance. Moreover, the function of disturbance recognition means and internal disturbance recognition
Since the function of sensing means is independent and independent,
So that changes in the temperature difference between the
Even if disturbance and internal disturbance occur at the same time,
Correct the initial maximum value appropriately to distinguish the effects of disturbance.
Erroneous detection of frost formation and signal of frost formation detection
Reliability can be improved .

Further, even when the disturbance or the disturbance has disappeared, the disturbance can be detected and the initial maximum value can be corrected to a value anticipating the change due to the elimination of the disturbance or the disturbance. This can also prevent erroneous detection of frost formation.

[0015]

1 shows an air conditioner A according to an embodiment of the present invention.
FIG. The air conditioner A includes an indoor unit 1 and an outdoor unit 2. Inside the outdoor unit 2, a four-way valve 3, an outdoor heat exchanger 4, a capillary tube 5
And a check valve 6 and a capillary tube 7 connected in parallel to form a refrigerant circulation circuit 8. A sub-circuit 11 including an accumulator 9 and a compressor 10 is connected to another inlet and outlet of the four-way valve 3. Reference numeral 12 denotes a blower fan. The indoor unit 1 has a suction port 1
An indoor heat exchanger 14 is provided so as to face the air conditioner 6, and the indoor heat exchanger 14 is connected to the refrigerant circulation circuit 8 of the outdoor unit 2. Reference numeral 15 denotes a blower fan for forcibly blowing out air from the suction port 16 and heat exchanged with the indoor heat exchanger 14 from the air outlet 17, and reference numeral 18 denotes an indoor heat exchanger 14.
This is a drain pan for receiving and discharging the water droplets falling from.

During the cooling operation, the flow direction of the four-way valve 3 is switched to the direction shown by the broken line in FIG. 1, and the indoor cooling is performed by the same operation as a general cooling device. That is, during the cooling operation, the refrigerant circulates in the direction indicated by the dashed arrow in FIG. 1, the refrigerant in the section between the compressor 10 and the capillary tube 5 on the side of the outdoor heat exchanger 4 is condensed by the compressor 10 and the refrigerant is condensed. The heat is discharged from the outdoor heat exchanger 4 to the outside by the blower fan 12. The condensed refrigerant was passed through the capillary tube 5 and the check valve 6, circulated to the indoor heat exchanger 14, and vaporized on the indoor heat exchanger 14 side. The refrigerant expands and vaporizes on the indoor heat exchanger 14 side, and when the refrigerant vaporizes, takes away the surrounding heat as heat of vaporization. Therefore, the air sucked into the indoor unit 1 from the inlet 16 of the indoor unit 1 exchanges heat with the indoor heat exchanger 14 and is cooled, and cool air is blown into the room from the outlet 17 of the indoor unit 1 by the blower fan 12. The room is cooled down.

In the heating operation, the flow direction of the four-way valve 3 is switched to the direction shown by the solid line in FIG. 1, and the functions of the indoor heat exchanger 14 and the outdoor heat exchanger 4 are reversed from those in the cooling operation. That is, during the heating operation, the refrigerant circulates in the direction of the solid line arrow in FIG. 1, and the refrigerant in the section on the indoor heat exchanger 14 side between the compressor 10 and the capillary tube 7 is condensed by the compressor 10 to generate heat of condensation. . Suction port 1 of indoor unit 1
The air sucked from 6 is heated by exchanging heat with the refrigerant by the indoor heat exchanger 14, warm air is blown out from the outlet 17 by the blower fan 12, and the room is heated.
On the other hand, the condensed refrigerant flows into two capillary tubes 5,
7, circulates to the outdoor heat exchanger 4 side, and expands and vaporizes on the outdoor heat exchanger 4 side. The vaporized refrigerant exchanges heat with the outside air in the outdoor heat exchanger 4, absorbs heat, and returns to the compressor 10 again.

Further, in the case of performing a defrost operation for removing frost generated in the outdoor heat exchanger 4 during the heating operation, the refrigerant flows in the same manner as in the cooling operation and the condensation heat is generated in the outdoor heat exchanger 4. At the same time, the outdoor and indoor blowers 12, 15 are stopped.

FIG. 2 is a diagram showing a configuration of a control device 21 for detecting and removing frost in the air conditioner A of the above. 2
Reference numeral 2 denotes a room temperature detector such as a thermistor for detecting the room temperature TR, and reference numeral 23 denotes an indoor heat exchanger temperature detector for detecting an indoor heat exchanger temperature (refrigerant condensation temperature) TH. The microcomputer 24 is mainly a central processing unit (CPU)
25, a memory 26, a timer 27, an input circuit 28, and an output circuit 29. The outputs of the room temperature detector 22 and the indoor heat exchanger temperature detector 23 are transmitted through an analog / digital (A / D) converter 30. The digital signal is input to the input circuit 28 of the microcomputer 24. An output from the remote controller 31 for switching between cooling and heating, setting an on / off timer, and the like is also connected to the input circuit 28. On the other hand, the output circuit 29
Is connected to a load 32 such as a four-way valve 3, a compressor 10, a blower fan 15, and the like, and outputs from the microcomputer 24 according to a cooling operation, a heating operation, a defrost operation, and the like. Is controlled to perform a predetermined operation.

FIG. 3 is a flow chart showing a processing procedure for detecting and removing frost on the outdoor heat exchanger 4 by the control device 21. FIG. 4 shows a room temperature TR detected by the room temperature detector 22. FIG. 4 is a diagram showing a change in the indoor heat exchanger temperature TH detected by the indoor heat exchanger temperature detector 23. Hereinafter, a method for detecting and removing frost according to the present invention will be described with reference to FIGS. First, when the heating operation is started by the setting from the remote controller 31 (S41), the four-way valve 3 is switched to the heating operation side by the output from the microcomputer 24, and the compressor 1
0 starts operation. When the heating operation is started, as shown in FIG. 4, the indoor heat exchanger temperature TH rises, and accordingly, the room temperature TR also rises. Then, after the start of the operation, a predetermined time ta sufficient for the room temperature TR and the indoor heat exchanger temperature TH to reach a stable state by the balance between the heat radiation from the indoor heat exchanger 14 and the heat radiation from the room to the outside has been reached. Is obtained by the timer 27 (S42), the temperature difference ΔTHR = TH−TR between the room temperature TR and the indoor heat exchanger temperature TH is calculated by the central processing unit 25, and the maximum value (initial maximum value) ΔTmax of the temperature difference ΔTHR is calculated. Is calculated, and the initial maximum value ΔTmax is stored in the memory 26 (S43). That is, the initial maximum value ΔTmax is stored as a state where frost formation has not yet occurred on the outdoor heat exchanger 4 and heat exchange is being performed with high efficiency.

The detection of disturbance is performed in step S44 of FIG. That is, the microprocessor 24 samples the room temperature TR at a certain time interval Δt1, and changes the room temperature | ΔT equal to or more than a certain level αΔt1 during the certain time Δt1.
It is monitored whether or not R | has occurred, and abrupt room temperature change | ΔTR | over a certain level αΔt1 during a certain time Δt1
When (≧ αΔt1) occurs, it is determined that disturbance has occurred, and the room temperature change | ΔTR | smaller than the fixed level αΔt1
In the case of (<αΔt1), it is determined that no disturbance has occurred. Note that the value of α is | ΔT in a normal heating operation state.
The value is set so that the value of R | / Δt1 does not reach.

When it is determined that no disturbance has occurred, the temperature difference ΔTHR between the room temperature TR and the room temperature heat exchanger temperature TH is calculated by the central processing unit 25 in real time as in the prior art, and stored in the memory. Initial maximum value ΔTmax
It is determined whether the temperature has decreased by more than the constant temperature β (S49). If the decrease is not large, it is determined that frost has not occurred and the heating operation is continued as it is. However, if the temperature difference ΔTHR is equal to or less than ΔTmax−β, the heat exchange efficiency of the outdoor heat exchanger 4 is reduced due to frost. Is determined, the four-way valve 3 is switched, and the blowing fans 12 and 15 are switched.
Is stopped and the defrost operation is performed (S50), and after a predetermined time td elapses, the operation is returned to the heating operation again (S51,
52).

If it is determined in step S44 that a disturbance has occurred, the disturbance is corrected for the initial maximum value ΔTmax. For example, consider a case where the window is opened at time t1 in FIG. 4 and the room temperature drops rapidly. Here, t2 is the time t
Time after a lapse of a fixed time Δt1 from TR1, TR1 and TR2
Is the room temperature TR, TH1 and TH at times t1 and t2.
2 is the indoor heat exchanger temperature TH at times t1 and t2. When the change in room temperature ΔTR = TR1−TR2 measured after a predetermined time Δt1 has a sudden change equal to or more than the predetermined value αΔt1, it is determined that a disturbance has occurred (S44). When it is determined that a disturbance has occurred, the indoor heat exchanger temperature TH1 and the room temperature TR1 immediately before the occurrence of the disturbance are determined.
From the temperature difference ΔTHR1 = TH1-TR1 (S4
5) Then, a temperature difference ΔTHR3 = TH3-TR3 between the indoor heat exchanger temperature TH3 and the room temperature TR3 after a time Δt2 (S46) sufficient to stabilize the fluctuation of the room temperature TR caused by disturbance is further calculated. (S47), the variation ΔTHR3 of the temperature difference from the temperature difference ΔTHR1 immediately before the occurrence of the disturbance and the temperature difference ΔTHR3 in the stable state after the occurrence of the disturbance.
-ΔTHR1 is obtained and added to the initial maximum value ΔTmax stored and held, and this value ΔTmax + ΔTHR3-ΔT
HR1 is used as the corrected initial maximum value ΔTmax in the memory 2
6 is updated (S48). That is, this correction method
All the temperature changes between times t1 and t3 are ignored so that the capacity reduction from the initial maximum value ΔTmax at time t1 and the capacity reduction from the initial maximum value ΔTmax at time t3 have the same value. If the defrost operation is performed using the corrected initial setting value ΔTmax in the same procedure as the normal frost detection and removal processing (S49 to S52), the defrost operation in consideration of the influence of disturbance becomes possible. In addition, malfunction of the defrost operation can be prevented.

In the above description, the case where the room temperature is lowered due to the disturbance has been described. However, when the disturbance occurs due to the combined use with other heating appliances, or when the disturbance is eliminated by closing the window, the room temperature rises. I do. In this case as well, the disturbance or the cancellation of the disturbance is detected in step S44, and the initial maximum value (or the corrected initial maximum value) ΔTmax is corrected accordingly.

FIG. 5 is a flow chart showing a processing procedure for detecting and removing frost according to another embodiment of the present invention, which can also correct internal disturbance due to a change in the wind speed of the blower fan 15 or the like. It was done. FIG. 6A is a diagram showing a change in the wind speed of the blower fan 15 on the indoor side, and FIG.
Is the room temperature TR when the disturbance and the disturbance occur at the same time
And FIG. 6 (c) showing the change of the indoor heat exchanger temperature TH.
FIG. 7 is a diagram showing changes in the room temperature TR and the indoor heat exchanger temperature TH when only internal disturbance occurs. Hereinafter, a method for detecting and removing frost according to the present embodiment will be described with reference to FIGS. 5 and 6A, 6B, and 6C.

When the heating operation is started (S61) and a predetermined time ta has elapsed (S62), when the room temperature TR and the indoor heat exchanger temperature TH reach a stable state, the temperature between the room temperature TR and the indoor heat exchanger temperature TH is increased. The difference ΔTHR is detected, and the maximum value (initial maximum value) ΔTmax is stored in the memory 26 (S6).
3).

The room temperature TR is sampled at regular intervals of time Δt1, and the occurrence of disturbance is monitored by determining whether or not a room temperature change | ΔTR | of a certain level αΔt1 or more has occurred during the constant time Δt1. (S6
4). Considering the case where only disturbance occurs, in this case, processing is performed in the same procedure as in the first embodiment (FIGS. 3 and 4). That is, assuming that a disturbance occurs at time to1, a predetermined time Δt2 sufficient to stabilize the room temperature fluctuation | ΔTR |
(S65) and immediately before the occurrence of disturbance [time to
1], the temperature difference THo1-TRo1 between the indoor heat exchanger temperature THo1 and the room temperature TRo1 is calculated and stored in the memory 26 as the value of ΔTHRs (S67), and the timer (A)
27 is started (S68). Timer (A) 27
Timer (A) 27 without causing disturbance during the operation of
Is counted up (S74), the temperature difference T between the indoor heat exchanger temperature THup = THo3 and the room temperature TRup = TRo3 at that time [time tup = to3 = to1 + Δt1 + Δt2].
Ho3-TRo3 is calculated as the value of ΔTHRf (S7
6) A variation ΔTHRf−ΔTHRs of the temperature difference is obtained from the temperature difference ΔTHRs immediately before the occurrence of the disturbance and the temperature difference ΔTHRf in a stable state after the occurrence of the disturbance, and this is calculated as an initial maximum value ΔTma.
x as a corrected initial maximum value ΔTmax
6 and updates the value of the initial maximum value ΔTmax (S7).
7). Then, the defrost operation is performed using the corrected initial setting value ΔTmax in the same procedure as the normal frost formation detection and removal processing (S78 to S81). Therefore, in this case, similarly to the first embodiment, the defrost operation in consideration of the influence of the disturbance can be performed, and the malfunction of the defrost operation can be prevented.

If it is determined in step S64 that no disturbance has occurred, then it is determined whether or not internal disturbance has occurred (S69). That is, the microprocessor 24 sets the indoor heat exchanger temperature TH at regular time intervals Δt1.
Is also sampled, and the temperature change | ΔT of the heat exchanger temperature TH over a certain level γΔt1 during a certain time Δt1
H | is generated, and when an abrupt temperature change | ΔTH | (≧ γΔt1) equal to or more than a certain level γΔt1, it is determined that an internal disturbance has occurred, and a room temperature change ΔTH (<γΔt1) smaller than the certain level is determined. In the case of), it is determined that no civil war has occurred. The value of γ is set to a value that does not reach the value of | ΔTH | / Δt1 in the normal heating operation state.

Now, as shown in FIG. 6 (a), at time ti1, the blower fan 15 switches from "high" to "medium".
Consider a case where only internal disturbance occurs as shown in FIG.
In this case, the indoor heat exchanger temperature T
A time Δt3 sufficient to stabilize the fluctuation | ΔTH | of H is set in the timer (B) 27 (S70), and the indoor heat exchanger temperature THi1 immediately before the occurrence of internal disturbance [time ti1].
Is calculated by calculating the temperature difference THi1−TRi1 between
The value of HRs is stored in the memory 26 (S72), and the timer (B) 27 is started (S73). If the timer (B) 27 has counted up without any disturbance during the operation of the timer (B) 27 (S75),
At that time, the temperature difference TH3−TRi3 between the indoor heat exchanger temperature THup = THi3 and the room temperature TRup = TRi3 at [time tup = ti3 = ti1 + Δt1 + Δt3] is calculated as the value of ΔTHRf (S76), and the temperature difference ΔTHRs and the disturbance immediately before the occurrence of the disturbance are calculated. From the temperature difference ΔTHRf in the stable state after the occurrence, a variation ΔTHRf−ΔTHRs of the temperature difference is obtained, added to the initial maximum value ΔTmax, and stored in the memory 26 as a corrected initial maximum value ΔTmax (S77). Then, the defrost operation is performed using the corrected initial setting value ΔTmax in the same procedure as the normal frost formation detection and removal processing (S
78-S81). Then, the corrected initial setting value Δ
If the defrost operation is performed in the same procedure as the normal frost detection and removal processing using Tmax, the defrost operation can be performed in consideration of the influence of the internal disturbance, and the malfunction of the defrost operation can be prevented.

Further, as shown in FIG. 6 (b), a case is considered in which an internal disturbance occurs during the stability confirmation time Δt1 + Δt2 after the occurrence of the disturbance. In this case, when the disturbance is recognized in step 64 (time to1 to to2), the timer (A) 2
7 is set to Δt2 (S65), the temperature difference THo1-TRo1 between the indoor heat exchanger temperature THo1 and the room temperature TRo1 immediately before the occurrence of disturbance (time to1) is calculated, and stored in the memory 26 as ΔTHRs (S67). (A) 27 is started (S67). Assuming that a disturbance has occurred at [time ti1] before the timer (A) 27 has counted up (S69), the timer (B) 27 is set to Δt3 (S70), and the timer (B) 27 is started (S73). ). At this time, since the timer (A) 27 has already started, the value of ΔTHRs is not rewritten,
It is held at the value at the time of disturbance recognition (S71).

Next, when both timers (A) and (B) 27 count up [time ti3] (S74, S74).
75) Indoor heat exchanger temperature THup = THi3 and room temperature TRup
= TRi3 and the temperature difference ΔTHRf = THi3−TRi3 is calculated and stored in the memory 26. The temperature difference ΔTHRs immediately before the occurrence of the disturbance and the internal disturbance (time to1) and the temperature difference ΔT in a state where the disturbance and the internal disturbance are stabilized (time ti3).
The amount of change ΔTHRf−ΔTHRs of the temperature difference is obtained from HRf (S76), added to the initial maximum value ΔTmax, and stored in the memory 27 as a corrected initial maximum value ΔTmax (S77). Then, the corrected initial set value ΔTma
The defrost operation is performed by the same procedure as the normal frost detection and removal processing using x (S78 to S81). As described above, when the disturbance and the disturbance occur simultaneously, the initial maximum value ΔTmax is corrected and corrected by the temperature difference ΔTHRs immediately before the occurrence of the disturbance or the disturbance and the temperature difference ΔTHRf after the disturbance and the disturbance are stabilized. Frost formation can be detected using the maximum value ΔTmax, and erroneous detection of frost formation due to disturbance or internal disturbance can be prevented.

Although FIG. 6B shows a case where an internal disturbance occurs after the occurrence of a disturbance, the initial maximum value ΔTmax is similarly corrected when a disturbance occurs after the occurrence of the disturbance.

If neither internal disturbance nor external disturbance has occurred, the initial maximum value ΔTmax stored in the memory 26 is used without correction, and frost formation is detected to perform defrost operation.

As described above, in this embodiment, when disturbance or internal disturbance is detected, the room temperature T due to each cause is detected.
The initial maximum value ΔTmax is corrected in consideration of the change of R and the change of the indoor heat exchanger temperature TH, and frost formation can be detected using the corrected initial maximum value ΔTmax. Can be prevented.

[0035]

According to the present invention, it is possible to recognize the occurrence of disturbance due to a window opening operation, a combined use with other heating equipment, or the like. Erroneous detection can be prevented even when disturbance occurs. Similarly, even when the disturbance has disappeared, the initial maximum value can be corrected to a value anticipating a change due to the elimination of the disturbance, so that even when the disturbance has disappeared, erroneous detection of frost formation can be prevented. .

Further, since it is possible to recognize internal disturbances such as a change in wind speed and a change in wind direction of the blower fan, the initial maximum value can be corrected to a value that allows for changes due to internal disturbances. Similarly, even when the internal disturbance disappears, the initial maximum value can be corrected to a value that allows for a change due to the cancellation of the internal disturbance,
Even when the internal disturbance has disappeared, erroneous detection of frost formation can be prevented.

Therefore, according to the present invention, even when disturbances due to external factors or internal factors occur in the air conditioner, frost formation on the outdoor heat exchanger can be accurately detected.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an air conditioner according to one embodiment of the present invention.

FIG. 2 is a schematic block diagram showing a control device for detecting and removing frost from the above.

FIG. 3 is a flowchart for explaining a processing procedure by the control device of the above.

FIG. 4 is a diagram illustrating an example of each temperature change of a room temperature and an indoor heat exchanger temperature.

FIG. 5 is a flowchart illustrating a processing procedure for detecting and removing frost formation according to another embodiment of the present invention.

FIG. 6A is a diagram showing an operating state of a blower fan on the indoor side, and FIGS. 6B and 6C are diagrams showing examples of changes in room temperature and indoor heat exchanger temperature.

FIG. 7 is a block diagram illustrating a configuration for detecting and removing frost in a conventional air conditioner.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 indoor unit 2 outdoor unit 4 outdoor heat exchanger 8 refrigerant circulation circuit 14 indoor heat exchanger 21 controller 22 room temperature detector 23 indoor heat exchanger temperature detector 24 microcomputer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadashi Matsubara 32nd Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Pref. 56) References JP-A-58-120035 (JP, A)

Claims (2)

(57) [Claims] 1. A room temperature detecting means for detecting an indoor temperature, an indoor heat exchanger temperature detecting means for detecting an indoor heat exchanger temperature during a heating operation, and a temperature difference between the detected indoor heat exchanger temperature and the indoor temperature. Is provided with frost detection means for detecting frost generated in the outdoor heat exchanger by determining that the frost has decreased by a predetermined value or more from the initial maximum value, and the detected frost is removed by a defrost operation. In the air conditioner, the time change rate of the room temperature detected by the room temperature detecting means is determined.
A disturbance recognition means for determining the occurrence of disturbance by comparing with a constant value, and a temperature difference between an indoor temperature and an indoor heat exchanger temperature immediately before the occurrence of the disturbance and a temperature difference between the indoor temperature and the indoor heat exchanger temperature after the disturbance is stabilized. An operation control device for an air conditioner, comprising: an initial maximum value correcting means for correcting an initial maximum value. 2. A room temperature detecting means for detecting an indoor temperature, an indoor heat exchanger temperature detecting means for detecting an indoor heat exchanger temperature during a heating operation, and a temperature difference between the detected indoor heat exchanger temperature and the indoor temperature. Is provided with frost detection means for detecting frost generated in the outdoor heat exchanger by determining that the frost has decreased by a predetermined value or more from the initial maximum value, and the detected frost is removed by a defrost operation. In the air conditioner, the room temperature is detected based on the time change rate of the room temperature detected by the room temperature detecting means.
And disturbance recognition means for determining the occurrence of a disturbance Zui, disturbance recognition
Independently of the means, the indoor heat exchanger temperature detecting means
A civil recognition means for determining the occurrence of inner turbulence based on the time rate of change of the detected indoor heat exchanger temperature, the temperature difference between the indoor temperature and the indoor heat exchanger temperature in immediately before the occurrence of civil if disturbance also verses and disturbances and civil An operation control device for an air conditioner, comprising: an initial maximum value correction unit that corrects the initial maximum value based on a temperature difference between the indoor temperature and the indoor heat exchanger temperature after stabilization.