JP3092532B2 - 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 air conditioner having a function of detecting an outside air temperature by a temperature sensor during operation or during operation stop.

[0002]

2. Description of the Related Art Conventionally, the outside air temperature is detected by a temperature sensor comprising a thermistor attached to a suction portion of an outdoor unit. Judgment of defrost and frequency control of a compressor in an inverter unit are performed based on the detected outside air temperature. It is carried out. Some products display the outside air temperature as the outdoor temperature in the room. In addition,
A conventional example in which the outside air temperature is detected by a temperature sensor and control is simply performed using the detected output is disclosed in, for example, JP-A-6-159736.

[0003]

The temperature sensor for detecting the outside air temperature is often mounted on an outdoor heat exchanger using a holder on the suction side of the outdoor unit. However, at this mounting position, when solar radiation is received during operation stoppage, the ambient temperature of the temperature sensor rises, so that a temperature higher than the actual outside air temperature is detected.
Therefore, even when the operation is stopped, when the outside air temperature is displayed on the indoor side, there is a problem that an erroneous outdoor temperature is displayed and the use comfort is reduced. In addition, during the heating operation, a temperature lower than the actual outside air temperature is detected due to frost on the outdoor heat exchanger, and if the frequency control of the compressor or the defrost judgment is directly performed based on these detected temperatures, the air conditioner However, there is a problem that the device operates abnormally.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and has an object to solve the problem, for example, when the temperature sensor receives insolation while the operation is stopped, or when an outdoor heat exchanger is used. It is an object of the present invention to provide an air conditioner that can always accurately grasp the outside air temperature even when frost is formed on the air conditioner.

[0005]

Accordingly, the air conditioner of the present invention includes a temperature sensor 5 disposed on the outdoor heat exchanger 3 side. In an air conditioner which detects temperature at predetermined time intervals and grasps the outside air temperature based on the detected temperature,
If the difference between the previously detected outside air temperature and the current temperature detected by the temperature sensor 5 is greater than or equal to a predetermined temperature while the operation is stopped, the control unit holds the immediately detected outside air temperature as the current outside air temperature. 10 is provided.

In the air conditioner of the first aspect, when the operation of the air conditioner is stopped, heat is accumulated around the temperature sensor 5 due to, for example, solar radiation, and the temperature is higher than the predetermined outside air temperature by a predetermined temperature or more. Is detected by the temperature sensor 5, the outside air temperature can be maintained without being updated.

An air conditioner according to a second aspect of the present invention includes an outdoor fan 4 for generating an air flow in a range including the temperature sensor 5, and the control means 10 controls the outside air temperature detected immediately before, the current detected temperature, If the difference is more than the predetermined temperature,
The outdoor fan 4 is operated for a predetermined time.

In the air conditioner according to the second aspect, when the current detected temperature is abnormally higher than the immediately detected outside air temperature, the outdoor fan 4 is turned on for a predetermined time to cause an air flow near the temperature sensor 5. Can be created.

The air conditioner according to a third aspect of the present invention further includes a temperature sensor 5 disposed on the side of the outdoor heat exchanger 3, and the temperature sensor 5 detects a temperature at predetermined time intervals, and adjusts the detected temperature. If the current temperature detected by the temperature sensor 5 is lower than the immediately detected outside air temperature and is 0 ° C. or less in the air conditioner configured to determine the outside air temperature based on the Is maintained as a current outside air temperature.

In the air conditioner according to the third aspect, even when the outdoor heat exchanger 3 is temporarily frosted during a heating operation and the temperature detected by the temperature sensor 5 is lower than the actual outside air temperature, The grasped outside air temperature can be maintained.

According to a fourth aspect of the present invention, when the temperature detected by the temperature sensor 5 is continuously lower than the outside air temperature detected immediately before for a predetermined plurality of times and is 0 ° C. or less, the control is performed. The means 10 is characterized in that the outside air temperature is grasped based on the current temperature detected by the temperature sensor 5.

In the air conditioner according to the fourth aspect, even when the temperature detected by the temperature sensor 5 is 0 ° C. or less and lower than the outside air temperature detected immediately before, if the temperature is continuously determined a plurality of times, The outside air temperature is being updated. Therefore, when the outside air itself is low, this can be accurately grasped.

In the air conditioner of the present invention, an outdoor heat exchange temperature sensor 6 is provided, and the outdoor heat exchange temperature detected by the outdoor heat exchange temperature sensor 6 causes the outdoor heat exchanger 3 to enter a defrosting operation. When the temperature is equal to or lower than the temperature, the control means 10 is characterized in that the outside air temperature grasped immediately before the temperature is held as the current outside air temperature.

In the air conditioner according to the fifth aspect, when frost is formed on the outdoor heat exchanger 3 and defrosting operation is started, it is possible to maintain the outside air temperature immediately before. Become.

[0015]

Next, specific embodiments of the air conditioner of the present invention will be described in detail with reference to the drawings. FIG. 7 is a schematic configuration diagram of the outdoor unit 1 of the air conditioner. An outdoor heat exchanger 3 and an outdoor fan 4 are provided inside a main body case 2. By the operation of the outdoor fan 4, air flows as shown by the arrow in the figure, and the right side in the figure is the suction side, and the left side is the discharge side. On the suction side of the outdoor heat exchanger 3, a temperature sensor 5 composed of a thermistor for detecting the ambient temperature is provided. The outdoor heat exchanger 3 is provided with an outdoor heat exchange temperature sensor 6 called a heat exchange thermometer.

In the above-mentioned air conditioner, the temperature of the temperature sensor 5 is used to display the outside air temperature inside the room even during operation or stoppage of the operation, and based on the outside air temperature, frequency control of the compressor and defrosting are performed. Control is performed. FIG. 9 is a block diagram for displaying the outside air temperature or the like based on the output from the temperature sensor 5. In FIG. 1, reference numeral 10 denotes a control unit (control means) including a microcomputer. The control unit 10 stores a temperature data from the temperature sensor 5 and a memory 12 storing a control program. It is composed of a CPU 11 and the like for controlling the entire system. The control unit 10 grasps the outside air temperature based on the temperature detected by the temperature sensor 5 as described later, and displays the outside air temperature on the display unit 9 and the refrigerant circuit 8.
, Frequency control and defrost control of the compressor.

According to the present invention, the temperature is detected by the temperature sensor 5 at predetermined time intervals, for example, every one minute, in order to reduce the temperature deviation at the time of solar radiation or frost (frost formation). By observing the temperature difference from the grasped outside air temperature (hereinafter referred to as “obtained outside air temperature”), by maintaining or updating this grasped outside air temperature, it is possible to grasp the more accurate outside air temperature. It was made. This will be specifically described below.

First, the display control of the outside air temperature while the operation is stopped will be described with reference to FIGS. The display control of the outside air temperature is performed by the control unit 10 shown in FIG.
In FIG. 2, the mark x represents the actual outside air temperature, and the mark ● represents the detected temperature detected by the temperature sensor 5. A small black circle on the lower side indicates a detection timing at which the temperature sensor 5 samples the ambient temperature, and a circle indicates that the grasped outside air temperature is updated and the outside air temperature is newly grasped again.
As described above, this air conditioner displays the outside air temperature on the display unit 9 on the indoor side even during operation or even when operation is stopped.

Until time t ₁ , the air conditioner is operating. During the operation, the outdoor fan 4 is driven to rotate, the air flows from the suction side to the discharge side, and the air flows near the temperature sensor 5. No accumulation. The ambient temperature is detected by the temperature sensor 5 every minute, for example, and the detected temperature is directly grasped and displayed on the display unit 9 as the outside air temperature. Time t
_{When the} operation is stopped in step ₁ , the outdoor fan 4 also stops.
The ambient temperature is detected by the temperature sensor 5 every minute. FIG.
And displays the grasped outside air temperature in step S1 shown in, the display temperature until the next At time t ₂ it is determined whether detection timing in step S2 and waits in the intact,
(If the time t ₂₎ a long if detection timing for detecting the ambient temperature at a temperature sensor 5 proceeds to step S3. In step S4, the detected temperature at this time (time t ₂ ) is compared with the outside air temperature grasped immediately before (time t ₁ ). In this case, the difference between both temperatures, as shown in FIG. 2 is smaller, and updates the temperature detected grasping the outside air temperature at time t ₂ in step S5, the updated figure outside air temperature on the display unit 9 of the indoor side indicate.

[0020] At time t ₄ the temperature sensor 5 then detects the ambient temperature, when compared ambient temperature and after grasping it at time t ₃ (step S4), and the difference is large.
For example, if the grasped outside air temperature is 25 ° C and the current detected temperature is 2
When the temperature is set to 9 ° C., the detected temperature is unnaturally high at 4 ° C. or more. This is because the outdoor fan 4 stops and the temperature sensor 5
This is probably due to the effects of solar radiation, which became significant due to the accumulation of surrounding air. Therefore, for example, when the detected temperature is higher than the grasped outside air temperature by 3 ° C. or more, the grasped outside air temperature is not updated and displayed with the detected temperature, but the outside air temperature grasped at time t ₃ is held and the temperature is held. It is displayed (step S1). At the same time, as shown in step S6, the outdoor fan 4 is operated at a low speed to generate an airflow, and the air near the temperature sensor 5 is replaced to reduce the influence of the accumulation of air. The operation time of the outdoor fan 4 is, for example, about 1 to 2 minutes. After the lapse of 1 to 2 minutes, the outdoor fan 4 is stopped (step S7). On the other hand, the smaller the difference in time t ₅ and temperature detected by the temperature sensor 5 and grasping the outside air temperature, that is, if both the temperature difference is less than 3 ° C. (Step S
4), and updated in temperature detected grasping the outside air temperature at time t ₅ (step S5), and displays the temperature (step S
1). Further, as shown in FIG. 2, the outside air temperature and the difference grasped detected temperature at time t ₆ at time t ₇ is large, display holds the outside air temperature after grasping immediately before repeating the control described above (step S4 , Step S6). Although the above update timing is set to every minute, the present invention is not limited to this, and an arbitrary interval can be set.

As described above, even if the temperature sensor 5 detects a temperature higher than the actual outside temperature due to the influence of solar radiation or the like while the operation is stopped, in such a case, the immediately preceding outside air temperature is retained. By displaying, the outside air temperature can be accurately displayed without performing abnormal temperature display.
In addition, the temperature difference when the temperature is not updated is set to 3 ° C. or more in the above description, but the temperature difference is not limited to this, and can be appropriately selected according to the expected use condition of the air conditioner. Further, in the above description, the outdoor fan 4 is operated under the same condition as that of maintaining the grasped outside air temperature.
For example, the outdoor fan 4 may be operated when the detected temperature is higher by 2 ° C. than the grasped outside air temperature.

Next, the case of reducing the temperature deviation at the time of frost during operation will be described with reference to FIGS. In this case, when the detected temperature of the temperature sensor 5 is lower than the grasped outside air temperature and is 0 ° C. or less, the grasped outside air temperature is held, and the control and display of the compressor are performed at the held temperature. It is. However, if a temperature that satisfies the same condition is detected N times (four times in this embodiment) continuously at the detection timing, the outside air temperature is updated based on the Nth detected temperature, and is displayed based on the updated temperature. And control. In step S11, the grasped outside air temperature is displayed or the compressor is controlled based on the temperature, and then, in step S12, it is determined whether or not the detection timing is reached. When detecting the temperature at a temperature sensor 5 at time t ₂ shown in FIG. 4 (step S13), and since it is lower than the outside air temperature grasped at time t ₁ a or 0 ° C. (step S14), and
Update grasped outside air temperature to the temperature detected at the time t ₂ (step S16). Next, when the temperature is detected at time t ₃ , the temperature is lower than the outside air temperature grasped at time t ₂ and equal to or lower than 0 ° C., so that the process proceeds from step S 14 to step S 15, and it is determined whether or not this condition has continued four times. At time t ₃ , this condition is the first time, so the process proceeds to step S 11 and time t 3
_The outside air temperature grasped in step ₂ is held, and based on this, a temperature display or the like is performed. At time t ₄ , the temperature is lower than the outside air temperature grasped at the previous time t ₂ and is 0 ° C. or less, so that step S 1
Proceeds from 4 to step S15, but the temperature display and the like based on this holding the outside air temperature after grasping at time t ₂ since yet a second time. Then, when detecting the temperature at time t _5, higher than the outside air temperature was grasped at time t _2, the addition since 0 ℃ above, to update the grasped outside air temperature at temperature detected at time t ₅ (step S16), and Display and the like are performed based on the updated grasped outside air temperature (step S11).

Since the detected temperature at the time t ₇ is lower than the grasped outside air temperature at the time t ₆ and is 0 ° C. or less, the time t ₆
The outside air temperature grasped in (1) is held (step S14, step S15). Lower than the outside air temperature also recognizes at time t ₆ in update timing at the time t ₇ ~ time t _9, and it is 0 ℃ or less, and since the as yet less than 4 times satisfy this condition (step S14, step S15) , to hold the outside air temperature was grasped at the time t _6. On the other hand, the time t _{1 0}
Detected temperature lower than the outside air temperature grasped at time t ₆ similar, although and is 0 ℃ or less, because this condition occurs four consecutive times at step S15, the grasping ambient temperature the time t _{1 0} for Update with the detected temperature (step S16). Also, it is not updated during defrost,
This will be described later. Hereinafter, the above control operation is repeated. In the above description, the condition for updating the grasped outside air temperature is four times, but the condition may be two or three times, or five or more times.

As described above, when the frost temporarily adheres to the outdoor heat exchanger ₃ at time t ₃ and time t ₄ and becomes unnaturally lower than 0 ° C., the temperature detected by the temperature sensor 5 Is not held as it is as the outside air temperature, but the held outside air temperature is maintained. Therefore, it is possible to eliminate the influence of temporary frost (frost formation), display an accurate outside air temperature, and perform frequency control of the compressor based on the accurate outside air temperature. If the detected temperature is lower than the grasped outside air temperature and 0 ° C. or less continuously for N times, it is determined that the actual outside air temperature is also the temperature, and the grasped outside air temperature is set to N.
Since the detected temperature is updated to the second detected temperature, it is possible to more accurately grasp the outside air temperature.

Next, the control in the case where the temperature of the outdoor heat exchanger 3 becomes lower than a certain value during the operation and the defrost operation is performed will be described with reference to FIGS. The temperature of the outdoor heat exchanger 3 is detected by an outdoor heat exchange temperature sensor 6 shown in FIG.
As shown in FIG. 8, there is a correlation between the operating frequency and the outside air temperature in the determination temperature when the defrost operation is performed. In general, when the operation frequency is high and the outside air temperature is low, the determination temperature T ₁ when the defrost operation is started. Will be lower. For example, when the operating frequency of the air conditioner is 90 Hz and the outside air temperature is 0 ° C., the state in which the temperature detected by the outdoor heat exchange temperature sensor 6 is about −6 ° C. or less continues for a predetermined time (eg, 1 minute), and defrosting is performed. Rush into driving. That is, the determination temperature T ₁ of entering the defrosting operation has been made to vary depending on the operation frequency and ambient temperature rather than what is constant, so therefore to grasp the accurate outside air temperature in this case is needed is there.

[0026] In FIGS. 5 and 6, for detecting the temperature of the outdoor heat exchanger 3 by the outdoor heat exchanger temperature sensor 6 with at time t ₁ of the same detection timing and the detection timing shown in FIG. 3 (step S21) (step S22 ). The mark “△” indicates the time of detection by the outdoor heat exchange temperature sensor 6. The detected temperature is shifted to step S24 is higher than the determination temperature T ₁ of a defrost operation start temperature, as shown in step S23, the process proceeds to the routine shown in FIG. On the other hand, when the detected temperature of the outdoor heat exchanger temperature sensor 6 at time t ₂ is less than the determination temperature T _1, the process proceeds from step S23 to step S25, it does not update the grasping outside air temperature, outside air temperature grasped at time t ₁ Hold. In this case, time t
_The defrost operation is started in ₂ and the defrost operation of the outdoor heat exchanger 3 is started. Since even the detected temperature is lower than the determination temperature T ₁ of the detection timing of time t ₃ ~ time t _5, not updated grasping the outside air temperature. Since the temperature detected by the At time t ₆ the outdoor heat exchanger temperature sensor 6 is higher than the determination temperature T _1,
The process shifts from step S23 to step S24, and shifts to a normal routine of updating and maintaining the grasped outside air temperature as shown in FIG.

In a state where the defrost operation for removing the frost adhering to the outdoor heat exchanger 3 is performed, the temperature sensor 5 cannot accurately detect the outside air temperature. However, since when the detected temperature of the outdoor heat exchange temperature sensor 6 is greater than the judgment temperature T ₁ of which enters the defrost operation retains the grasping ambient temperature, to grasp the correct outside air temperature, the normal defrost operation control and accurate It is possible to display an appropriate outside air temperature.

Although the specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be implemented with various modifications within the scope of the present invention. For example, in the above description, the grasped outside air temperature is updated based on the detected temperature of the temperature sensor 5, but this may be performed by performing a predetermined correction on the detected temperature and updating the detected temperature.

[0029]

According to the air conditioner of the first aspect of the present invention, when the operation of the air conditioner is stopped, heat is trapped around the temperature sensor due to, for example, solar radiation, and the temperature is lower than the outside temperature detected immediately before. When the temperature sensor detects a temperature higher than the temperature, the outside air temperature is maintained without being updated. Therefore, it is possible to display an accurate outside air temperature without grasping an abnormal temperature due to the influence of solar radiation or the like.

According to the air conditioner of the second aspect, when the temperature detected by the temperature sensor is abnormally high, the outdoor fan is turned on for a predetermined time to generate an air flow near the temperature sensor. . Therefore, the surroundings of the temperature sensor can be made closer to the actual outside air temperature, and the accurate outside air temperature can be grasped.

Further, according to the air conditioner of the third aspect, even when the outdoor heat exchanger is temporarily frosted during a heating operation and the temperature detected by the temperature sensor is lower than the actual outside air temperature, By maintaining the grasped outside air temperature, accurate outside air temperature can be grasped.

According to the air conditioner of the fourth aspect, even when the temperature detected by the temperature sensor is 0 ° C. or lower and lower than the outside air temperature detected immediately before, if this is repeated a plurality of times, the outside air temperature is reduced. It is updated without holding. Therefore, when the outside air itself is low, this can be accurately grasped.

According to the air conditioner of the fifth aspect, when the outdoor heat exchanger is frosted and the defrost operation is started, the outside air temperature immediately before grasped is maintained. Therefore, the accurate outside air temperature can be grasped even during the defrost operation in which the accurate outside air temperature cannot be detected by the temperature sensor.

[Brief description of the drawings]

FIG. 1 is a control flow chart during an operation stop according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of the embodiment of the present invention during operation stop.

FIG. 3 is a control flow chart during operation of the embodiment of the present invention.

FIG. 4 is an explanatory diagram during operation of the embodiment of the present invention.

FIG. 5 is a control flow chart during operation of the embodiment of the present invention.

FIG. 6 is an explanatory diagram during operation of the embodiment of the present invention.

FIG. 7 is a schematic sectional view of the outdoor heat exchanger according to the embodiment of the present invention.

FIG. 8 is an explanatory diagram when a defrost operation is entered according to the embodiment of the present invention.

FIG. 9 is a control block diagram according to the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 3 outdoor heat exchanger 4 outdoor fan 5 temperature sensor 6 outdoor heat exchange temperature sensor 10 control unit (control means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F24F 11/02 103 F24F 11/02 102 F24F 11/02

Claims (5)

(57) [Claims] 1. A temperature sensor (5) arranged on the side of an outdoor heat exchanger (3), and the temperature sensor (5) detects temperature at predetermined time intervals during operation or during stoppage. In the air conditioner which grasps the outside air temperature based on the detected temperature, the difference between the outside air temperature immediately before grasped and the current temperature detected by the temperature sensor (5) during the operation stop is a predetermined temperature. If it is larger than the above, the control means (1) for holding the outside air temperature detected immediately before as the current outside air temperature
0) An air conditioner comprising: 2. An outdoor fan (4) for generating an air flow in a range including the temperature sensor (5), wherein the control means (10) determines a difference between an outside air temperature detected immediately before and a current detected temperature. 2. The air conditioner according to claim 1, wherein when the temperature is equal to or higher than a predetermined temperature, the outdoor fan (4) is operated for a predetermined time. 3. A temperature sensor (5) disposed on the side of the outdoor heat exchanger (3), the temperature sensor (5) detects a temperature at predetermined time intervals, and based on the detected temperature. In the air conditioner which grasps the outside air temperature, when the current detection temperature by the temperature sensor (5) is lower than the outside air temperature immediately before grasped and is 0 ° C or less, the outside air temperature immediately before grasped. An air conditioner comprising a control means (10) for maintaining the current temperature as the current outside air temperature. 4. When the temperature detected by the temperature sensor (5) is continuously lower than the outside air temperature detected immediately before by a predetermined plurality of times and is 0 ° C. or less, the control means (10) The air conditioner according to claim 3, wherein the outside air temperature is grasped based on the current detection temperature by the temperature sensor (5). 5. An outdoor heat exchange temperature sensor (6) is provided, and the outdoor heat exchange temperature detected by the outdoor heat exchange temperature sensor (6) is a predetermined temperature at which the outdoor heat exchanger (3) enters into a defrosting operation. The air conditioner according to claim 3 or 4, wherein in the following cases, the control means (10) holds the outside air temperature detected immediately before as the current outside air temperature.