JP2006170558A - Air conditioner - Google Patents

Abstract

[PROBLEMS] When the outdoor temperature is extremely high, such as in a subtropical region, even if the refrigerant flows normally, sufficient condensing capacity cannot be obtained, and the difference between the low-temperature indoor temperature and the indoor heat exchanger temperature is small. As a result, there has been a problem that the compressor is stopped due to erroneous detection of blockage of the refrigeration cycle.
The indoor / outdoor temperature is increased by changing the judgment time for judging whether or not the refrigeration cycle is blocked between when the indoor suction temperature or the compressor discharge temperature is lower than a predetermined temperature and when it is higher than the predetermined temperature. Even in the case of using the special control for the subtropical region by the field setting mode, it is possible to determine the blockage of the refrigeration cycle, and to stop and protect the compressor.
[Selection] Figure 5

Description

  The present invention relates to an air conditioner in which at least one indoor unit is connected to one outdoor unit. More specifically, the present invention is mounted on the air conditioner and is based on the difference between the temperature of the indoor heat exchanger and the indoor suction temperature. The present invention relates to control for protecting a compressor by detecting blockage of a refrigeration cycle.

  Conventionally, in order to protect the compressor by assuming that the refrigerant does not flow due to some trouble in the air conditioner, the compressor discharge temperature is detected, and when the discharge temperature rises, the compressor is stopped. Is controlling.

  Moreover, in order to shorten the judgment time until the compressor is stopped, a method is employed in which the compressor is stopped by control based on a change in the indoor heat exchanger temperature and a fluctuation range between the indoor heat exchanger temperature and the indoor suction temperature ( For example, see Patent Document 1).

  FIG. 6 is a flowchart showing the blockage abnormality detection control of the refrigeration cycle of the conventional air conditioner described in Patent Document 1.

  As shown in FIG. 6, it is determined whether or not the operation of the compressor has passed for 30 minutes or more (step 101), and if it has passed, it is determined whether or not the discharge temperature of the compressor is 115 ° C. or higher ( Step 102) If 115 ° C. or higher, it is determined that the refrigerant is insufficient due to outgassing from the refrigeration cycle, and the compressor is stopped (Step 104).

  A timer is set when the engine is stopped (step 105). In step 106, it is determined whether or not 3 minutes have elapsed after the compressor is stopped. If it has elapsed, the operation of the compressor is restarted in step 107, and at the same time, step 108 is performed. In step 109, it is determined whether the compressor operation and stop processing has been repeated three times in succession. If it has been repeated three times, the operation is stopped in step 110 so as not to restart the operation. Yes.

  If the discharge temperature is 115 ° C. or lower in step 102, it is determined in step 103 whether the temperature difference between the indoor suction temperature and the indoor heat exchange temperature is within 2 ° C. In step 104, the compressor is stopped, and thereafter, the operation from step 105 to step 110 is performed as described above.

If the temperature difference between the indoor suction temperature and the indoor heat exchange temperature is 2 ° C. or more in step 103, it is determined in step 111 whether the temperature difference between the outside air temperature and the outdoor heat exchange temperature is within 2 ° C. If it is 2 degrees C or less, it will be judged that the refrigerant | coolant is not flowing in the refrigerating cycle, the compressor will be stopped in step 104, and the operation | movement from step 105 to step 110 is performed after that similarly to the above.
JP 2003-090582 A

  However, in the above-described conventional configuration, when the outdoor temperature is extremely high, even if the refrigerant normally flows with the electronic expansion valve opened to the upper limit, sufficient condensing capacity cannot be obtained, and the outside on the high pressure side is not obtained. There is a possibility that the difference between the temperature and the outdoor heat exchanger temperature and the difference between the indoor temperature and the indoor heat exchanger temperature on the low pressure side become small, and the blockage of the refrigeration cycle is erroneously detected.

In addition, in air conditioners for subtropical areas, special control can be set locally so that the air conditioner can be quickly cooled at startup. In this case as well, control by the difference between the indoor heat exchanger temperature and the indoor suction temperature is not possible. There was a possibility of false detection.

  The present invention solves such a conventional problem, and immediately detects the vacuum operation of the compressor when the refrigeration cycle is blocked to protect the compressor, and is highly versatile and reliable. It aims at providing a high air conditioner.

  In order to solve the above-mentioned conventional problems, the air conditioner of the present invention has an indoor heat exchanger temperature sensor, an indoor suction temperature sensor, an initial indoor heat exchanger temperature storage means, a temperature difference, as shown in the control block diagram of FIG. Consists of a detection means, a determination device, and an alarm device. During cooling operation, if the indoor intake air temperature is less than a predetermined temperature, the fluctuation range of the indoor heat exchanger temperature is equal to or less than the first predetermined value or the indoor intake air If the difference between the air temperature and the indoor heat exchanger temperature is equal to or less than the second predetermined value, the refrigeration cycle is determined to be blocked when the compressor has been started for the first predetermined time, and the indoor intake air When the temperature is equal to or higher than a predetermined temperature, the fluctuation range of the indoor heat exchanger temperature is equal to or less than the first predetermined value, or the difference between the indoor intake air temperature and the indoor heat exchanger temperature is a second predetermined value. After starting the compressor, make sure that If continued for a predetermined time, the refrigeration cycle is determined to closed, the compressor is stopped, it is capable of protecting.

  Further, as shown in the control block diagram of FIG. 4, the air conditioner of the present invention has an indoor heat exchanger temperature sensor, indoor suction temperature means, initial indoor heat exchanger temperature storage means, temperature difference detection means, outdoor compressor discharge temperature. Consists of a sensor, an electronic expansion valve, a determination device, and an alarm device.When the compressor discharge temperature is lower than a predetermined temperature during cooling operation, the fluctuation range of the indoor heat exchanger temperature is equal to or less than the first predetermined value, or If the difference between the indoor intake air temperature and the indoor heat exchanger temperature is equal to or less than a second predetermined value, after starting the compressor, if the first predetermined time is continued, the refrigeration cycle is determined to be blocked, When the compressor discharge temperature is equal to or higher than the predetermined temperature, the fluctuation range of the indoor heat exchanger temperature is equal to or less than the first predetermined value, or the difference between the indoor intake air temperature and the indoor heat exchanger temperature is the second After starting up the compressor, If you continue the second predetermined time, the refrigeration cycle is determined to closed, the compressor is stopped, it is capable of protecting.

  According to the method for controlling an air conditioner according to the present invention, the blockage of the refrigeration cycle can be determined and the compressor is stopped even when the indoor / outdoor temperature is high or when special control based on the field setting mode is used. Can be protected.

  1st invention provides an indoor unit with an indoor side heat exchanger, the indoor side heat exchanger temperature sensor which detects the temperature of the said indoor side heat exchanger, and an indoor side intake air temperature sensor, a compressor and the said room | chamber In an air conditioner having a refrigeration cycle connected to an inner heat exchanger, when the indoor suction temperature is below a predetermined temperature and above the predetermined temperature by an indoor suction temperature sensor that detects the indoor suction temperature. Thus, the determination time for determining whether or not the refrigeration cycle is blocked is made different.

  The second aspect of the invention is the control method of the first aspect of the invention, in particular, in the cooling operation, when the indoor suction temperature is less than a predetermined temperature, the fluctuation range of the indoor heat exchanger temperature is equal to or less than the first predetermined value or If the difference between the indoor intake air temperature and the indoor heat exchanger temperature is equal to or less than a second predetermined value after the compressor is started for a first predetermined time, the refrigeration cycle is determined to be blocked. When the compressor suction temperature is equal to or higher than the predetermined temperature, the fluctuation range of the indoor heat exchanger temperature is equal to or less than the first predetermined value, or the difference between the indoor intake air temperature and the indoor heat exchanger temperature is the second If the compressor is started for a second predetermined time after the compressor is started, the refrigeration cycle is determined to be blocked.

  According to a third aspect of the present invention, an indoor unit is provided with an indoor heat exchanger, an indoor heat exchanger temperature sensor for detecting the temperature of the indoor heat exchanger, and an indoor intake air temperature sensor. In an air conditioner having a refrigeration cycle connected to an inner heat exchanger, when a predetermined control set in a special environment such as a subtropical region is used, the discharge temperature of the compressor is detected. By the discharge temperature sensor, the determination time for determining whether or not the refrigeration cycle is blocked differs between when the compressor discharge temperature is lower than the predetermined temperature and when the compressor discharge temperature is higher than the predetermined temperature.

  The fourth aspect of the invention is the control method of the third aspect of the invention, in particular, in the cooling operation, when the compressor discharge temperature is lower than a predetermined temperature, the fluctuation range of the indoor heat exchanger temperature is equal to or less than the first predetermined value or If the difference between the indoor intake air temperature and the indoor heat exchanger temperature is equal to or less than a second predetermined value after the compressor is started for a first predetermined time, the refrigeration cycle is determined to be blocked. When the compressor discharge temperature is equal to or higher than the predetermined temperature, the fluctuation range of the indoor heat exchanger temperature is equal to or less than the first predetermined value, or the difference between the indoor intake air temperature and the indoor heat exchanger temperature is the second If the compressor is started for a second predetermined time after the compressor is started, the refrigeration cycle is determined to be blocked.

  According to the fifth aspect of the invention, it is determined by the control method of the second or fourth aspect of the invention that either one or both of the refrigerant inlet / outlet is closed.

  In the sixth aspect of the present invention, the user is notified of the blockage of the refrigeration cycle by an alarm device such as a lamp or a buzzer after the entire stop.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the implementation of the present invention.

(Embodiment 1)
FIG. 1 is a refrigeration cycle diagram showing an air conditioner according to an embodiment of the present invention.

  In the figure, 101 is a compressor, 102 is a four-way valve, 103 is an outdoor heat exchanger, 104 is an indoor heat exchanger, and 105 is an electronic expansion valve. A refrigeration cycle is formed, and cooling is performed by switching the four-way valve 2. Operation or heating operation is possible.

  106 is an indoor suction temperature sensor that detects the indoor temperature, 107 is an indoor heat exchanger temperature sensor that detects the temperature of the intermediate portion of the indoor heat exchanger 104, and 108 is a discharge that detects the discharge temperature of the discharge port of the compressor 101. A temperature sensor 109 is an intake temperature sensor that detects the intake temperature of the intake port of the compressor 1.

  FIG. 2 is a block diagram of the air conditioner in the first and second embodiments.

  The determination device 201 detects the indoor heat exchanger temperature by the indoor heat exchanger temperature sensor 202 at the time of starting the compressor, stores this in the initial indoor suction temperature storage device 203, and then detects the current detected by the indoor heat exchanger temperature sensor 202. The temperature difference between the detected temperature and the current suction temperature detected by the indoor suction temperature sensor 204 is detected, and the temperature difference between these detected temperatures and a predetermined temperature difference set in advance are compared and determined by the temperature difference detection device 205. A predetermined command is sent to the compressor drive device 206 in accordance with the temperature difference to control the operation / stop of the compressor 207.

  The compressor driving device 206 measures the time from the stop of the compressor 207 to the next restart by the time measuring device 208, while counting the number of repetitions of the operation and stop processing of the compressor 207. When the number of times reaches three, the determination device 201 issues an instruction to stop the operation, and the warning device 209 warns the user.

(Embodiment 2)
FIG. 3 is a flowchart of the air conditioner in the first and second embodiments.

  First, the air conditioner is started in cooling, the initial indoor heat exchanger temperature at the start of operation is detected (step 1), and it is determined whether the compressor is operating within 10 minutes (step 2). If it is within minutes, the indoor heat exchanger temperature and the indoor intake air temperature at that time are detected (step 3), and it is determined whether the intake temperature is 30 ° C. or higher (step 4). It is determined whether the fluctuation range of the indoor heat exchanger temperature is 3 ° C. or less (step 5) or the difference between the indoor intake air temperature and the indoor heat exchanger temperature is 3 ° C. or less (step 6) with a time of minutes, If either condition is satisfied, it is determined that the refrigeration cycle is blocked, and the compressor is stopped (step 9).

  If the intake temperature is 30 ° C. or less in the step 4, the fluctuation range of the indoor heat exchanger temperature is 3 ° C. or less in 5 minutes (step 7), or the difference between the indoor intake air temperature and the indoor heat exchanger temperature is 3 It is determined that the temperature is below 0 ° C. (step 8). If either condition is satisfied, it is determined that the refrigeration cycle is blocked. In step 9, the compressor is stopped.

  In step 10, it is determined whether or not the stop process has been repeated three times. If the stop process has been repeated three times, a warning device such as lighting of a lamp or a buzzer is used in step 11 to notify the user of an abnormal refrigerant cycle blockage.

(Embodiment 3)
FIG. 4 is a block diagram of the air conditioner according to the third and fourth embodiments.

  After receiving the special control command in the field setting mode from the remote controller 310, the determination device 201 detects the indoor heat exchanger temperature by the indoor heat exchanger temperature sensor 202 at the time of starting the compressor, and this is detected as the initial indoor suction temperature storage device 203. , The compressor discharge temperature is detected by the compressor discharge temperature sensor 311, and it is determined by the determination device 201 whether the temperature is equal to or higher than the predetermined temperature. If the temperature is higher than the predetermined temperature, the electronic expansion valve 312 is opened. The temperature is opened up to the upper limit value, and the current temperature detected by the indoor heat exchanger temperature sensor 202 and the current suction temperature detected by the indoor suction temperature sensor 204 are detected, and a temperature difference between these detected temperatures is set in advance. The predetermined temperature difference is compared and judged by the temperature difference detecting device 205, and a predetermined command is sent to the compressor driving device 206 in accordance with the temperature difference to control the operation / stop of the compressor 207. It is configured to perform.

  The compressor driving device 206 measures the time from the stop of the compressor 207 to the next restart by the time measuring device 208, and counts the number of repetitions of the operation and stop processing of the compressor 207. Yes.

  When the operation of the compressor and the stop process are repeated three times in succession, the determination device 301 issues a complete stop instruction and the warning device 209 warns the user.

(Embodiment 4)
FIG. 5 is a flowchart of the air conditioner according to the third and fourth embodiments.

  First, a predetermined local setting control command is recognized by the determination device (step 21).

Thereafter, the air conditioner is started to operate in cooling, the initial indoor heat exchanger temperature at the start of operation is detected (step 1), and it is determined whether the operation of the compressor is within 10 minutes (step 2). If within minutes, the current indoor heat exchanger temperature, indoor intake air temperature and compressor discharge temperature are detected (step 22), and it is determined whether the compressor discharge temperature is 50 ° C. or higher (step 23). If it is 50 ° C. or more, the expansion valve opening is set to the upper limit value (step 24), and the fluctuation range of the indoor heat exchanger temperature is 3 ° C. or less (step 5) over the time of 8 minutes, or the indoor intake air temperature It is determined whether the difference in indoor heat exchanger temperature is 3 ° C. or less (step 6). If either condition is satisfied, it is determined that the refrigeration cycle is blocked, and the compressor is stopped (step 9).

  If the compressor discharge temperature is 50 ° C. or less in step 23, the fluctuation range of the indoor heat exchanger temperature is 3 ° C. or less (step 7) in 5 minutes, or the difference between the indoor intake air temperature and the indoor heat exchanger temperature Is determined to be 3 ° C. or less (step 8), and if either condition is satisfied, it is determined that the refrigeration cycle is blocked, and the compressor is stopped in step 9.

  In step 10, it is determined whether or not the stop process has been repeated three times. If the stop process has been repeated three times, a warning device such as lighting of a lamp or a buzzer is used in step 11 to notify the user of an abnormal refrigerant cycle blockage.

(Embodiment 5)
As explained above, the fluctuation range of the indoor heat exchanger temperature is 3 ° C. with a judgment time of 8 minutes when the indoor intake air temperature is 30 ° C. or more and 5 minutes when the indoor intake air temperature is 30 ° C. or less. If the difference between the indoor intake air temperature and the indoor heat exchanger temperature is 3 ° C or less, it can be determined that the refrigerant is not flowing in the refrigeration cycle. When the compressor discharge temperature is 50 ° C. or higher, it takes 8 minutes, and when the compressor discharge temperature is 50 ° C. or less, the determination time is 5 minutes, and the fluctuation range of the indoor heat exchanger temperature is 3 ° C. or less, or When the difference in the heat exchanger temperature is 3 ° C. or less, it can be determined that the refrigerant is not flowing through the refrigeration cycle.

  The blockage of the refrigeration cycle can be detected by the control method according to the present invention as long as it is blocked at any one point in the refrigerant circuit. The machine can be stopped and protected.

  As is clear from the above, it is possible to make a highly accurate judgment by varying the judgment time of the refrigeration cycle blockage using the temperature detecting means, and to immediately detect abnormal operation of the compressor and protect the compressor. it can.

  In addition, when the protection means is operated a predetermined number of times during a predetermined time, the compressor is not restarted, so that the compressor is not repeatedly operated and stopped due to forgetting to open the closing valve. , You can reliably protect the compressor.

  Furthermore, since the erroneous detection when the outdoor temperature is very high can be prevented, the air conditioner according to the present invention can be applied to an air conditioner directed to a high temperature area.

Refrigeration cycle configuration diagram of the air conditioner of the present invention Control block diagram of the air conditioner in Embodiment 1 of the present invention The flowchart of the control method of the air conditioner in Embodiment 2 of this invention Control block diagram of air conditioner in Embodiment 3 of the present invention The flowchart of the control method of the air conditioner in Embodiment 4 of this invention Flowchart of conventional air conditioner control method

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Compressor 102 Four-way valve 103 Outdoor heat exchanger 104 Indoor heat exchanger 105 Electronic expansion valve 106 Room temperature suction temperature sensor 107 Indoor heat exchanger temperature sensor 108 Compressor discharge temperature sensor 201 Judgment device 202 Indoor heat exchanger temperature sensor 203 Initial indoor suction Temperature storage device 204 Indoor suction temperature sensor 205 Temperature difference detection device 206 Timing device 207 Compressor 208 Timing device 209 Alarm device 310 Remote control 311 Compressor discharge temperature sensor 312 Electronic expansion valve

Claims (6)

The indoor unit is provided with an indoor heat exchanger, an indoor heat exchanger detecting means for detecting the temperature of the indoor heat exchanger, and an indoor intake air temperature detecting means, and a compressor and the indoor heat exchanger are provided. In an air conditioner having a connected refrigeration cycle, the indoor intake air temperature detecting means for detecting the indoor intake air temperature is used when the indoor intake air temperature is less than a predetermined temperature and when it is equal to or higher than the predetermined temperature. An air conditioner characterized in that the determination time for determining whether the refrigeration cycle is blocked is different. When the indoor intake air temperature is less than the predetermined temperature, the fluctuation range of the indoor heat exchanger temperature is equal to or less than the first predetermined value, or the difference between the indoor intake air temperature and the indoor heat exchanger temperature is the second If the refrigeration cycle is determined to be blocked when the compressor is started for the first predetermined time after the compressor is started, and if the indoor intake air temperature is equal to or higher than the predetermined temperature, the indoor heat exchanger temperature is The fluctuation range is equal to or less than the first predetermined value, or the difference between the indoor intake air temperature and the indoor heat exchanger temperature is equal to or less than the second predetermined value. The air conditioner according to claim 1, wherein if it continues, the refrigeration cycle is determined to be blocked. The indoor unit is provided with an indoor heat exchanger, an indoor heat exchanger detecting means for detecting the temperature of the indoor heat exchanger, and an indoor intake air temperature detecting means, and a compressor and the indoor heat exchanger are provided. In an air conditioner having a connected refrigeration cycle, by a discharge temperature detection means for detecting the discharge temperature of the compressor, when the compressor discharge temperature is lower than a predetermined temperature, and when it is equal to or higher than the predetermined temperature, An air conditioner characterized in that the determination time for determining whether the refrigeration cycle is blocked is different. When the compressor discharge temperature is lower than the predetermined temperature, the fluctuation range of the indoor heat exchanger temperature is equal to or less than the first predetermined value, or the difference between the indoor intake air temperature and the indoor heat exchanger temperature is the second If the compressor is started for the first predetermined time after starting the compressor, it is determined that the refrigeration cycle is blocked, and if the compressor discharge temperature is equal to or higher than the predetermined temperature, the indoor heat exchanger temperature is The fluctuation range is equal to or less than the first predetermined value, or the difference between the indoor intake air temperature and the indoor heat exchanger temperature is equal to or less than the second predetermined value. The air conditioner according to claim 3, wherein if it continues, the refrigeration cycle is determined to be blocked. The air conditioner according to any one of claims 1 to 4, wherein blockage of the refrigeration cycle determines that both refrigerant inlets and outlets of the outdoor unit of the air conditioner are blocked. The air conditioner according to claim 6, wherein after the stoppage, the user is notified of the blockage of the refrigeration cycle by a lamp or a buzzer.

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