JP3371935B2 - Control method of air conditioner - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner, and more particularly, to an air conditioner for removing frost adhering to an outdoor heat exchanger by a defrosting operation. The present invention relates to a method of controlling a machine. 2. Description of the Related Art A split-type air conditioner generally has a structure shown in FIG. 3, and is controlled by an outdoor unit controller (microcomputer) in accordance with a command from an indoor unit controller (microcomputer) 1. 2) drives the four-way valve 3, the compressor 4 and the outdoor fan 5, and the compressor (compressor)
The refrigerant obtained in 4 is circulated to the heat exchanger of the indoor unit. [0003] The outdoor unit includes a heat exchange temperature detecting section 6 for detecting an outdoor heat exchange temperature and an outdoor temperature detecting section 7 for detecting an outdoor air temperature. Although not shown, the indoor unit includes a room temperature detecting unit that detects an indoor temperature (room temperature). At this time, the indoor unit control device 1 controls the indoor fan 8 to a predetermined number of revolutions in accordance with the setting of the remote controller (setting of strong wind or weak wind), the difference between the indoor temperature and the set temperature, and the heat of the indoor unit. Blows cold or hot air that has been heat-exchanged in the exchanger into the room,
Maintain a comfortable indoor environment. Further, the heat exchange temperature is detected by a heat exchange temperature detector (temperature sensor) 6 arranged at the outlet pipe of the outdoor heat exchanger (condenser), and the outdoor unit controller 2 detects the detected outdoor heat exchange. The frost formation state of the outdoor heat exchanger is determined based on the temperature. For example, during the heating operation, the operating time of the compressor 4 is integrated, and the outdoor heat exchange temperature is detected every time the integrated time reaches a predetermined value (for example, 40 minutes). If the outdoor heat exchange temperature has reached the defrosting operation value (for example, -6 ° C.), it is determined that frost has formed on the outdoor heat exchanger or the possibility of frost formation is high. By this judgment, defrosting operation,
That is, the heating operation is temporarily stopped, and when the outdoor heat exchange temperature reaches the defrost release value, it is determined that the outdoor heat exchanger has no frost, and the defrost operation is terminated. In the above defrosting operation, since the capacity is significantly reduced by stopping the heating operation, it is preferable to end the operation in as short a time as possible. Therefore, the defrost release value of the defrost operation is set as low as possible. However, if the defrost release value is set too low, when the outside air temperature is extremely low, the base drain port freezes (freezes) and blocks,
In addition, frost may remain in the outdoor heat exchanger. [0008] As shown in FIG.
Is provided in order to discharge the frost attached to the outdoor unit heat exchanger that has turned into water to the outside of the outdoor unit. Therefore, if the base drain port 9 freezes and becomes clogged, water may accumulate inside the outdoor unit and cause a failure or the like. Conversely, when the defrosting release value is set to a high value in consideration of the defrosting operation under the condition where the outside air temperature is extremely low, the defrosting time becomes longer as described above, and the time for giving the user uncomfortable feeling. Becomes longer. Therefore, the outside air temperature is detected by the outside air temperature detecting section 7, and the defrosting release value is switched between when the detected temperature is extremely low and when it is not so low. That is,
When the outside air temperature is extremely low, the defrost release value is set low,
When the outside air temperature is not so low, the defrost release value is increased. [0011] Thus, when the outside air temperature is not so low, the defrosting operation can be shortened, and the frost of the outdoor heat exchanger can be removed without giving the user any discomfort. When the outside air temperature is extremely low, the defrosting operation is prolonged, but there is no icing or clogging of the base drain port, and no frost remains in the outdoor heat exchanger. [0012] However, in the control method of the air conditioner, the defrosting time is lengthened or shortened in accordance with the outside air temperature. This may cause malfunctions (freezing at the base drain, leaving frost on the outdoor heat exchanger). For example, if the outside air temperature is not so low, but the humidity is high, the amount of frost in the outdoor heat exchanger is large and the speed of frost formation is high, so that the outdoor heat exchanger is blocked.
The temperature of the heat exchanger itself becomes extremely low, creating a situation similar to the case where the outside air temperature is extremely low. That is, FIG.
As shown in (2), the outdoor heat exchange temperature (the outlet temperature of the condenser) becomes extremely lower than usual. As described above, when the temperature inside the outdoor unit becomes extremely low, the base is abnormally cooled, so that the base discharge port 9 is frozen and clogged, and the amount of frost on the outdoor heat exchanger is large. There is a great risk that frost will remain. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to prevent clogging of a base drain port due to icing in a defrosting operation and eliminate frost remaining in an outdoor heat exchanger. An object of the present invention is to provide a control method of an air conditioner which can be performed. [0016] To achieve the above object, the present invention provides an outdoor heat exchange temperature detecting means for detecting an outdoor heat exchange temperature in a heat exchanger of an outdoor unit; An outdoor air temperature detecting means for detecting an outdoor air temperature at the installation location, wherein the outdoor heat exchange temperature is monitored each time the cumulative operation time of the compressor reaches a predetermined value, and the outdoor heat exchange temperature is a defrost of a defrost operation. In the control method of the air conditioner, which starts the defrosting operation when the operation value is reached, and thereafter returns to the original operation when the outdoor heat exchange temperature reaches the defrost release value, the defrosting operation value Also has a first reference temperature value set to a lower temperature and a second reference temperature value with respect to the detected outside air temperature detected by the outside air temperature detection means, and the outdoor heat exchange temperature is a defrosting operation of a defrosting operation. Reach the value of the defrost In starting the rotation, the outdoor heat exchange temperature is compared with the first reference temperature value, and the detected outside air temperature is compared with the second reference temperature value, and the outdoor heat exchange temperature is lower than the first reference temperature value. When the outdoor heat exchange temperature is higher than the first reference temperature value, but the detected outside air temperature is lower than the second reference temperature value, or in any of the above, the defrost release is performed. A positive correction temperature is added to the value to extend the time of the defrosting operation. The operation will be described. During the heating operation of the air conditioner, the accumulated driving time of the compressor is a predetermined value (for example, 40 minutes).
When the outdoor heat exchange temperature becomes equal to or lower than a predetermined value (for example, −6 ° C.), the defrosting operation is started by the control unit of the outdoor unit. When the start of the defrosting operation is determined, the outdoor heat exchange temperature and the outside air temperature are detected. When the detected outdoor heat exchange temperature is, for example, -10 ° C. or less, the base outlet freezes during the defrosting operation. The defrosting release value is determined to be higher by, for example, + 10 ° C. because the defrosting operation is likely to cause clogging, and the defrosting operation easily causes the frost to remain in the outdoor heat exchanger. Further, the heat exchange temperature outside the detection chamber is -10 ° C.
If the detected outside air temperature is not more than -3 ° C., for example, the base outlet is also liable to be clogged and clogged in the same manner, and the defrosting operation easily causes the frost to remain in the outdoor heat exchanger. Defrost release value is also, for example, +10
° C is determined higher. On the other hand, when the heat exchange temperature outside the detection chamber is -10 ° C.
If the detected outside air temperature is not lower than −3 ° C., the base outlet is frozen more than the above case,
Since the possibility of clogging is low and the possibility of remaining frost in the outdoor heat exchanger due to the defrosting operation is low, the defrost release temperature is determined to be higher by, for example, + 5 ° C. As described above, the time for the defrosting operation is changed by changing the defrosting release value. Therefore, the lower the outdoor heat exchange temperature, or the lower the outdoor heat exchange temperature, the lower the outdoor air temperature, the longer the defrosting operation time is set to be longer than the normal defrosting operation time by the control unit of the outdoor unit. You. Therefore, the base outlet is not frozen and clogged during the defrosting operation, and no frost remains in the outdoor heat exchanger due to the defrosting operation. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention focuses on the fact that the frost condition of an outdoor heat exchanger can be determined based on the outside air temperature and the outdoor heat exchange temperature, and the outdoor heat exchange temperature at the start of a defrosting operation. The defrosting release value is determined based on the temperature and the outside air temperature, and the time of the defrosting operation is changed (advanced or delayed) according to the frost formation state of the outdoor heat exchanger to perform the optimal defrosting operation. Therefore, as shown in FIG. 1, the outdoor unit control device (microcomputer) 10 of the heat pump type air conditioner has a function of the compressor 4 in addition to the function of the outdoor unit control device 2 shown in FIG. The drive integration time is a predetermined value (for example, 40
Min) and the outdoor heat exchange temperature is equal to or lower than the defrosting operation value (for example, −6 ° C.), the defrosting operation is started. The frost release value is determined by the defrost release value determination unit 10a. Next, the control method of the air conditioner having the above configuration will be described in detail with reference to the flowchart of FIG.
First, it is assumed that the air conditioner is operated for heating by operating a remote controller, for example. In this case, the indoor unit control device 1 sends a heating operation command (a signal including an operation frequency) to the outdoor unit control device 10, and the outdoor unit control device 10 drives the compressor 4 and the outdoor fan 5 according to the command. At the same time, the integration timer for integrating the driving time of the compressor 4 is reset and started (step ST1). Subsequently, it is determined whether or not the time measured by the integration timer has reached a predetermined value (40 minutes) (step ST2). When the accumulated time has not reached 40 minutes, the above-described heating operation is continued. When the accumulated time has reached 40 minutes, the process proceeds from step ST2 to ST3, and it is determined whether or not the outdoor heat exchange temperature is −6 ° C. or less. to decide. In addition,
The outdoor heat exchange temperature is detected by the heat exchange temperature detector 6. When the outdoor heat exchange temperature is lower than -6 ° C., it is determined that the defrosting operation needs to be performed. This is because, as described in the conventional example, when the accumulated driving time of the compressor 4 has passed for 40 minutes or more and the outdoor heat exchange temperature has become −6 ° C. or less, the possibility that frost is formed on the outdoor heat exchanger is extremely high. Because it is expensive. Subsequently, since the outdoor heat exchange temperature may be lower, it is determined whether or not the outdoor heat exchange temperature is -10 ° C or lower (step ST4). When the outdoor heat exchange temperature is lower than −10 ° C. or lower, the defrost release value determination unit 10a of the outdoor unit controller 10 determines the defrost release value of the defrost operation to be higher than a predetermined value (for example, + 10 ° C.). Then, a long defrosting operation is performed (step ST5). The outdoor heat exchange temperature is extremely low,
This is because in the same defrosting operation as in the related art, an increase in the outdoor heat exchange temperature cannot be expected, and as a result, there is a very high possibility that the frost of the outdoor heat exchanger remains and the base drain port 9 shown in FIG. If the outdoor heat exchange temperature is not higher than -6.degree. C. but not lower than -10.degree.
Proceeding to 6, it is determined whether or not the outside air temperature is equal to or lower than a predetermined value (for example, −3 ° C.). When the outside air temperature is equal to or lower than −3 ° C., the process proceeds to step ST5 and performs the above-described processing. That is, the defrost release value determination unit 10a sets the defrost release value of the defrost operation to a value higher than a predetermined value (for example, + 10 ° C.). Decide and perform defrosting operation. For example, when the outside air temperature is low, it is not possible to expect an increase in the outdoor heat exchange temperature in the same defrosting operation as in the prior art. As a result, there is a possibility that the frost remains in the outdoor heat exchanger and the base drain port 9 is frozen and clogged. Because it is expensive. If the outside air temperature is not lower than -3.degree. C., the process proceeds from step ST6 to step ST7, where the defrost release value determining section 10a sets the defrost release value of the defrost operation to a value higher by + 5.degree. Determined to be no higher than the defrost release value, and perform a slightly longer defrost operation. For example, even when the outside air temperature is not so low, in the same defrosting operation as in the related art, an increase in the outdoor heat exchange temperature cannot be expected, and as a result, frost remains in the outdoor heat exchanger, and the base drain port 9 is frozen and clogged. Because the possibility is not so high. As described above, when performing the defrosting operation, the defrosting release value is determined according to the outdoor heat exchange temperature and the outside air temperature, and the time of the defrosting operation is varied. For example, as the outdoor heat exchange temperature is extremely low, or the outdoor heat exchange temperature is low and the outdoor temperature is low, the defrost release value is set higher than usual, and the time of the defrost operation is set longer than usual. When the outdoor heat exchange temperature is low and the outside air temperature is not so low, the defrost release value is not made much higher than usual, and the defrosting operation time is made slightly longer than usual. Therefore, during the defrosting operation, the base discharge port is not frozen and clogged, and the frost of the outdoor heat exchanger due to the defrosting operation is not left. For example, the outdoor air temperature is as high as 0 ° C. or higher to some extent, and even if the defrosting operation is not lengthened (the frost release value is not increased), there is no frost removal in the outdoor heat exchanger, and the base discharge port 9 is In the case where there is no icing and the possibility of clogging is low, a conventional length of defrosting operation may be performed with the same defrosting release value as before. As described above, according to the present invention,
In the heat pump type air conditioner, when performing the defrosting operation, since the defrost release value is determined based on the outdoor heat exchange temperature and the outside air temperature, for example, the lower the outdoor heat exchange temperature, or the outdoor The lower the heat exchange temperature and the lower the outside air temperature, the longer the time for the defrosting operation can be. As a result, it is possible to prevent the base drain port from being clogged due to icing during the defrosting operation and, consequently, the malfunction of the outdoor unit. Is prevented, and there is an effect that frost remaining in the outdoor heat exchanger can be eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic block diagram of a control device according to an embodiment of the present invention, to which a control method of an air conditioner is applied. FIG. 2 is a schematic flowchart illustrating the air conditioner shown in FIG. FIG. 3 is a schematic block diagram of a conventional control device for an air conditioner. FIG. 4 is a schematic side sectional view of an outdoor unit of the air conditioner. FIG. 5 is a schematic graph illustrating the operation of the air conditioner shown in FIG. 3; [Description of Signs] 1 Indoor unit control device 2, 10 Outdoor unit control device 4 Compressor 6 Heat exchange temperature detection unit (outdoor heat exchange temperature sensor) 7 Outside air temperature detection unit 9 Base outlet 10a Defrost release value determination unit

Claims (1)

(57) [Claims] (1)Outdoor heat exchange temperature in outdoor unit heat exchanger
Outdoor heat exchange temperature detecting means for detecting the temperature of the outdoor unit,
Outside air temperature detection means for detecting the outside air temperature at the installation location
Each time the accumulated drive time of the compressor reaches a predetermined value.
Monitoring the outdoor heat exchange temperature,Outdoor heat exchange temperature
When the defrost operation value of the defrost operation is reachedRemoveStart frost operation
AndAfter thatThe outdoor heat exchange temperature is set to the defrost release value.
Return to the original operation when the air conditioner is reached.
AndThe first set at a temperature lower than the defrost operation value
Detected by the reference temperature value and the outside air temperature detecting means.
A second reference temperature value for the detected outside air temperature; Before the outdoor heat exchange temperature reaches the defrost operation value of the defrost operation
When starting the defrosting operation, the outdoor heat exchange temperature
And the first reference temperature value, the detected outside air temperature and the second
Compare the quasi-temperature values, The outdoor heat exchange temperature is lower than the first reference temperature value
If The outdoor heat exchange temperature is higher than the first reference temperature value
However, the detected outside air temperature is lower than the second reference temperature value.
If If any of the above,
Add the positive correction temperature to the divided value, The time of the defrosting operation is
Control of air conditioner characterized by lengthening
Method.