JP3622817B2 - Control method of air conditioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technology for controlling the degree of opening and closing of an expansion valve (electronic expansion valve) constituting a refrigeration cycle of an inverter type air conditioner, and more particularly, when an operation frequency of a compressor is changed, an expansion valve (electronic expansion valve, etc.) The opening / closing degree of the air conditioner is quickly controlled to a predetermined value to ensure the stability of the refrigeration cycle.
[0002]
[Prior art]
As shown in FIG. 5, for example, this type of air conditioner includes a refrigeration cycle including a compressor 1, a four-way valve 2, an indoor heat exchanger 3, an outdoor heat exchanger 4, an expansion valve (electronic expansion valve) 5, and the like. Have.
[0003]
During cooling operation, the refrigerant by switching the four-way valve 2 to the compressor 1 from the indoor heat exchanger 3 according to dashed line arrow in FIG. 5, further compressor 1 outdoor heat exchanger 4, through the electronic expansion valve 5 Indoor While returning to the heat exchanger 3, the rotation of the indoor fan is controlled according to the amount of air set by the remote controller 6, and the cold air exchanged by the indoor heat exchanger 3 is blown into the room, and the difference between the room temperature and the set temperature of the remote controller 6 The compressor 1 is operated at a predetermined operation frequency according to the control to control the room temperature.
[0004]
In the heating operation, the refrigerant is returned from the outdoor heat exchanger 4 to the compressor 1 and from the compressor 1 to the outdoor heat exchanger 4 via the electronic expansion valve 5 (in contrast to the cooling operation) ( The rotation of the indoor fan is controlled according to the set air volume of the remote controller 6 and the warm air exchanged by the indoor heat exchanger 3 is blown into the room, and the difference between the room temperature and the set temperature of the remote control The compressor 1 is operated at a predetermined operation frequency according to the control to control the room temperature.
[0005]
Therefore, as shown in FIG. 6, an indoor unit control unit (microcomputer, driver circuit, etc.) 7 and an outdoor unit control unit (microcomputer, driver circuit, etc.) 8 are provided. Accordingly, the indoor fan is controlled, and a predetermined command (such as an operating frequency according to the difference between the room temperature and the set value) is transmitted to the outdoor unit control unit 8, and the outdoor unit control unit 8 controls the compressor 1 and the like by the command. .
[0006]
By the way, for example, when the operating frequency of the compressor 1 is changed by operating the remote controller 6 or the like, the degree of opening and closing of the electronic expansion valve 5 is controlled to a predetermined value. When the operating frequency is increased, the electronic expansion valve 5 is opened by a predetermined amount (a certain number of pulses), and when the operating frequency is decreased, the electronic expansion valve 5 is opened by a predetermined amount (a certain number of pulses). close up. In this way, by controlling the degree of opening and closing of the electronic expansion valve 5 in a predetermined manner, a refrigeration cycle corresponding to a change in the operating frequency of the compressor 1 is realized, and the indoor environment is quickly brought into a desired state. Yes.
[0007]
In addition, this air conditioner has various protection functions for the purpose of safety and the like. In discharge temperature release control of the protection functions, the discharge temperature of the refrigerant of the compressor 1 constituting the refrigeration cycle is discharged. The temperature is detected by the temperature thermistor 9, and the operation frequency of the compressor 1 is variably controlled according to the detected temperature, or the operation of the compressor 1 is stopped.
[0008]
For example, when the discharge temperature reaches the operating value, the operating frequency of the compressor 1 is lowered by a predetermined value to prevent overheating of the compressor 1, and when the discharge temperature reaches a predetermined value (a value significantly higher than the operating value) The compressor is shut down to ensure safety.
[0009]
[Problems to be solved by the invention]
However, in the control method of the air conditioner, when the operating frequency of the compressor 1 is greatly changed, the electronic expansion valve 5 does not open and close following the rapid change, that is, the opening and closing of the electronic expansion valve 5 is delayed. The refrigeration cycle becomes unstable.
[0010]
As shown in FIG. 7, for example, when the operating frequency of the compressor 1 is changed from the minimum to the maximum by operating the remote controller 6 or the like, it is necessary to open the electronic expansion valve 5 correspondingly. In order to open the valve 5 by a predetermined amount by a predetermined amount, that is, it takes time until the degree of opening and closing of the electronic expansion valve 5 opens to a predetermined value (a value corresponding to a change in the operating frequency).
[0011]
As a result, the temperature on the refrigerant inlet side of the evaporator rapidly decreases while the electronic expansion valve 5 opens by a predetermined amount by a predetermined amount (that is, while the electronic expansion valve 5 is gradually opened), and the discharge of the compressor 1 Since the temperature rises abruptly, various protection operations (for example, discharge temperature release control) may operate, the refrigeration cycle becomes unstable, and it takes time until the refrigeration cycle stabilizes. It will cause deterioration. As shown in FIG. 7, even when the operating frequency of the compressor 1 greatly decreases, the refrigeration cycle becomes unstable as described above, and it takes time to stabilize.
[0012]
The present invention has been made in view of the above problems, and its purpose is to quickly open and close the opening / closing degree of the expansion valve when the operating frequency of the compressor is changed, thereby speeding up the stabilization of the refrigeration cycle. An object of the present invention is to provide a control method for an air conditioner that can be used.
[0013]
[Means for Solving the Problems]
To achieve the above object, the present invention comprises a refrigeration cycle comprising a compressor and an expansion valve, the opening and closing degree of pre Ki膨 expansion valve when changing the operation frequency of the compressor constant amount by stepwise In the control method of the air conditioner to be controlled, the operating frequency range of the compressor is divided into a plurality of zones, and an increase / decrease value to be added to the constant amount according to the number of the zones included in the change range of the operating frequency is In order to control the opening / closing degree of the expansion valve by changing the operation frequency, the increase / decrease value corresponding to the change width of the operation frequency is obtained from the table, and the increase / decrease value is obtained by the expansion table. It is characterized in that it is added to the first fixed amount or the final fixed amount that controls the degree of opening and closing of the valve .
[0014]
In this case, the increase / decrease value is set to a larger value as the number of zones included in the operating frequency change range is larger . Further, the operation when a frequency change is increased to open by a predetermined value the expansion valve accordingly, in the case change of the operating frequency is lowered to close the expansion valve by a predetermined value.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS. In FIG. 1, the same parts as those in FIG. Refer to FIG. 5 for the refrigeration cycle of the air conditioner.
[0016]
According to the air conditioner control method of the present invention, when the opening / closing degree of the expansion valve is controlled to a predetermined value according to the change in the operating frequency of the compressor, the predetermined value according to the change in the operating frequency is set to the opening / closing degree of the expansion valve. if adding the control of the opening and closing degree of the expansion valve is quickly focused on being able to open and close a predetermined value, dividing the range of the operation frequency to several zones, the number of zones contained in the change of the operating frequency range determining a predetermined decrement value depending on, and to a large value to increase or decrease value as the number of the zone is large, when opening and closing the opening and closing degree of the expansion valve by a predetermined value by a predetermined amount, the increase and decrease value, for example the last In consideration of a certain amount, the degree of opening and closing of the expansion valve is controlled to a predetermined value.
[0017]
For this purpose, as shown in FIGS. 1 and 2, the control device to which the control method for an air conditioner of the present invention is applied realizes the above-described functions in addition to the functions of the outdoor unit control unit 8 shown in FIG. An outdoor unit control unit 10 having a table 10a is provided.
[0018]
The table 10a includes, for example, information on the operating frequency range of the compressor 1 divided into a plurality of first to eleventh zones, and the number of zones where the operating frequency change exceeds the first to eleventh zones is less than three. If the number of zones is 3, the number of increase / decrease pulses is 20 pulses, and if the number of zones is 4, the increase / decrease pulse number is 30 pulses. When the number of zones is 5, the number of increase / decrease pulses is 45 pulses, when the number of zones is 6, the number of increase / decrease pulses is 65 pulses, and when the number of zones is 7, the number of increase / decrease pulses is 90 pulses When the number of zones is 8, the number of increase / decrease pulses is 120 pulses, when the number of zones is 9, the number of increase / decrease pulses is 155 pulses, and when the number of zones is 10, the number of increase / decrease pulses is 195 pulses. It stored and determined information to the.
[0019]
For example, as shown in FIG. 2, the operating frequency range is less than 10 Hz in the first zone, 10 Hz or more, less than 20 Hz in the second zone, 20 Hz or more, and less than 30 Hz in the third zone. 30 Hz or more, less than 40 Hz in the fourth zone, 40 Hz or more, less than 50 Hz in the fifth zone, 50 Hz or more, less than 60 Hz in the sixth zone, 60 Hz or more, and less than 70 Hz in the seventh zone. Zone of 70 Hz or more, less than 80 Hz to the eighth zone, 80 Hz or more, less than 90 Hz to the ninth zone, 90 Hz or more, less than 100 Hz to the tenth zone, 100 Hz or more to the eleventh zone I have to.
[0020]
Next, the operation of the control device for an air conditioner having the above-described configuration will be described with reference to the flowchart of FIG. 3 and the time chart of FIG. 4. First, when a driving operation is performed by the remote controller 6, the indoor unit controller 7 Transfers a signal (such as an operating frequency) necessary for the room temperature adjustment to the outdoor unit control unit 10. The outdoor unit control unit 10 drives at least the compressor 1 in a predetermined manner, and operates the refrigeration cycle with the electronic expansion valve 5 as a predetermined opening / closing degree. As in the prior art, the indoor unit control 7 and the outdoor unit control 10 perform other necessary controls (fan rotation control, etc.) to adjust the room temperature.
[0021]
At this time, the outdoor unit control unit 10 executes the routine shown in FIG. 3 together with the start of the compressor 1, and when a predetermined time (for example, 1 minute) has elapsed since the start of the compressor 1 (step ST1), refer to the table 10a. Then, the zone (first to eleventh zones) to which the current operating frequency belongs is selected and stored (step ST2). The predetermined time is a time until the operation frequency of the compressor 1 is stabilized.
[0022]
Subsequently, it is determined whether or not the current operating frequency has changed to another zone (step ST3). For example, if the temperature setting is changed by the operation of the remote controller 6, the operating frequency of the compressor 1 changes, and if the zone to which it belongs changes, the process proceeds to step ST4 to determine whether the operation of the compressor 1 is stopped. To do. If the operating frequency of the compressor 1 does not change to a zone other than the storage zone, for example, if it is a change of about several Hz, it waits until the change in the operating frequency becomes large.
[0023]
For example, operation of the compressor 1 is finished the routine in case a stop, also so that the routine is executed again by the activation of the compressor 1. If the operation of the compressor 1 is not stopped, the process proceeds from step ST4 to ST5, where the current operating frequency is confirmed again and waits until the current operating frequency is stabilized.
[0024]
When the current operating frequency is stabilized, the increase / decrease value is determined according to the change of the operating frequency (change of the zone to which the current operating frequency belongs with respect to the storage zone) according to the contents of the table 10a, and the degree of opening and closing of the electronic expansion valve 5 is predetermined. When the control is performed, the determined increase / decrease value is taken into consideration (step ST6), and the process returns to step ST2 to repeat the above-described processing.
[0025]
Therefore, as shown in FIG. 4, when the operating frequency of the compressor 1 is changed from the minimum to the maximum, that is, when the operating frequency belongs to the tenth zone from the first zone, the electronic expansion valve The opening / closing degree of 5 is opened by a certain amount (the same number of pulses as in the prior art), but it is greatly opened by adding 155 pulses to the last fixed amount.
[0026]
As a specific example, for example, the case of controlling opening and closing degree of the electronic expansion valve 5 (180 pulses) to 400 pulses, according to the conventional example, the opening and closing degree of the electronic expansion valve 5 (180 pulses) Open 10 pulses, this If it is repeated 22 times, a predetermined opening / closing degree (400 pulses) is obtained. However, according to the present invention, in order to add 155 pulses at the end, 10 pulses are repeated 5 times, and the last one is set to 165 pulses. The opening / closing degree of the electronic expansion valve 5 (395 pulses).
[0027]
Thus, the number of times of opening the fixed amount (10 pulses) is extremely small, that is, the opening / closing degree of the electronic expansion valve 5 does not change gradually, and can be quickly set to a predetermined value. Therefore, since a rapid decrease in the temperature on the refrigerant inlet side of the evaporator can be suppressed and a rapid increase in the discharge temperature of the compressor 1 can be suppressed, various protection operations do not operate, and the refrigeration cycle Stabilizes quickly.
[0028]
Further, when the operating frequency of the compressor 1 is lowered, the electronic expansion valve 5 is closed by a predetermined value. However, if the same processing as described above is executed, the electronic expansion valve 5 can be quickly set to the predetermined value, Cycle stabilization is also accelerated.
[0029]
In the above-described embodiment, the degree of opening and closing of the electronic expansion valve 5 is varied by a certain amount and is greatly varied at the end. For example, the degree of opening and closing is largely varied first, and then is varied by a certain amount. You may make it a value.
[0030]
【The invention's effect】
As described above , according to the control method of the air conditioner , the operating frequency range of the compressor is divided into a plurality of zones, and the constant amount is determined according to the number of the zones included in the change range of the operating frequency. In order to control the degree of opening and closing of the expansion valve by changing the operating frequency, obtaining the increase / decrease value corresponding to the change width of the operating frequency from the table, By adding the same increase / decrease value to the first fixed amount or the last fixed amount that controls the opening / closing degree of the expansion valve, the number of times of opening / closing the electronic expansion valve by a fixed amount can be reduced. The degree can be quickly opened and closed by a predetermined value, the refrigeration cycle can be stabilized quickly, and the deterioration of the indoor environment can be suppressed.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of a control device to which an air conditioner control method is applied according to an embodiment of the present invention.
FIG. 2 is a schematic schematic diagram for explaining the operation of the control device shown in FIG. 1;
FIG. 3 is a schematic flowchart for explaining the operation of the control device shown in FIG. 1;
4 is a schematic time chart for explaining the operation of the control device shown in FIG. 1; FIG.
FIG. 5 is a schematic configuration diagram for explaining a refrigeration cycle of an air conditioner.
FIG. 6 is a schematic block diagram for explaining a conventional control device for an air conditioner.
7 is a schematic time chart for explaining the operation of the control device shown in FIG. 6; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor 5 Electronic expansion valve 6 Remote control 7 Indoor unit control part 8, 10 Outdoor unit control part 9 Discharge temperature thermistor 10a Table

Claims (1)

Comprising a refrigeration cycle comprising a compressor and an expansion valve, a control method of an air conditioner to step controlled by a predetermined amount open degree before Ki膨 expansion valve when changing the operation frequency of the compressor,
Dividing the operating frequency range of the compressor into a plurality of zones, and having a table that determines an increase / decrease value to be added to the constant amount according to the number of zones included in the change range of the operating frequency , When controlling the degree of opening / closing of the expansion valve by changing the operating frequency, the increase / decrease value corresponding to the range of change of the operating frequency is obtained from the table, and the same increase / decrease value is the first constant for controlling the degree of opening / closing of the expansion valve. A method for controlling an air conditioner, characterized in that the air conditioner is added to the quantity or the final fixed amount .

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