JPH10141744A - Control of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable lessening the hunting of S-H quantity in an air conditioner so that its operation can be stabilized and degeneration in comfortableness is suppressed. SOLUTION: In an outdoor apparatus control part 11 the initial opening (pulse number) of the expansion valve part 15 and one-time pulse variation are preliminarily decided in accordance with the operation frequency of the compressor 1 and stored. From the indoor heat-exchanger temperature detected by an indoor heat-exchanger sensor 12 or the outdoor heatexchanger temperature detected by an outdoor heat-exchanger sensor 14 and from the suction temperature by a succession 13 an expansion valve drive control circuit 11c calculates the S-H quantity and controls the motor of the expansion valve part 15 in such a manner as to have the S-H quantity in agreement with the target value. When the operation frequency changes at this time, an operation frequency-judgment part 11b judges the new operation frequency and an expansion valve drive control circuit 11c sets the expansion valve at a preliminarily decided initial opening, and when the operation frequency does not change, this condition is maintained for a prescribed length of time and, after that, every time a prescribed time elapses before change of the operation frequency the degree of the opening of the expansion valve is adjusted by a preliminarily decided pulse number within one-time variation in such a manner as to have the S H quantity in agreement with the target value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an expansion valve (electronic expansion valve) constituting a refrigeration cycle of an inverter type air conditioner.
More specifically, the present invention relates to a control method of an air conditioner that reduces hunting of the SH amount by switching the operating frequency of a compressor, enables stable operation, and further suppresses deterioration of comfort. Things.

[0002]

2. Description of the Related Art As shown in FIG. 4, for example, this type of air conditioner has a refrigeration cycle comprising a compressor 1, a four-way valve 2, an indoor heat exchanger 3, an outdoor heat exchanger 4, an electronic expansion valve 5, and the like. Having.

During the heating operation, the four-way valve 2 is switched to circulate the refrigerant according to the solid arrow in FIG.
The rotation of the indoor fan is controlled in accordance with the set air volume of the remote controller and the like, and the warm air exchanged by the indoor heat exchanger 3 is blown out into the room, while at a predetermined operation frequency corresponding to the difference between the indoor temperature and the set temperature of the remote controller. The compressor 1 is operated to control the room temperature. During the cooling operation, the four-way valve 2 is switched to circulate the refrigerant according to the dashed arrow in FIG. 4, and the rotation of the indoor fan is controlled in accordance with the set air volume and the like of the remote controller. While blowing into the room,
The compressor 1 is operated at a predetermined operating frequency according to the difference between the room temperature and the set temperature of the remote controller to control the room temperature.

In controlling the degree of opening and closing of the electronic expansion valve 5, the suction temperature of the compressor 1 (the temperature of the refrigerant input port) and the evaporator (the indoor heat exchanger 3 during the cooling operation, and the outdoor heat exchange during the heating operation). The difference (S-H amount) from the temperature of the unit 4) is adjusted to the target value. For example, the SH amount is detected every minute, and the electronic expansion valve 5 is detected in accordance with the difference between the SH amount and the target value.
To control the motor. That is, it is necessary to suppress a rapid change in the refrigeration cycle, that is, to suppress a rapid change in the room temperature and keep the room temperature at the set temperature. Note that the target value is determined by the set temperature of the remote controller, the room temperature, and the like.

[0005]

In the control of the degree of opening and closing of the electronic expansion valve 5, when the operating frequency of the compressor 1 is switched, the above-mentioned SH amount greatly changes. The electronic expansion valve 5 is widely opened or closed. That is, it is necessary to quickly adjust the SH amount to the target value.

However, when the electronic expansion valve 5 is greatly opened,
Alternatively, when the valve is closed greatly, the SH amount also changes greatly, that is, the SH amount changes abruptly and deviates from the target value. It will close or open widely. As a result, the SH amount deviates in the opposite direction from the target value, that is, hunting is repeated and the hunting is large. This causes a problem that the driving becomes unstable and the indoor environment is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object thereof is to suppress the hunting of the SH amount to be small, thereby enabling stable driving and suppressing deterioration of comfort. An object of the present invention is to provide an air conditioner as described above.

[0008]

In order to achieve the above-mentioned object, the present invention is to adjust a difference (SH amount) between a suction temperature of a compressor constituting a refrigeration cycle and a temperature of an evaporator to a target value. In the control method of an air conditioner for adjusting an opening / closing degree of an expansion valve constituting the refrigeration cycle, an initial opening degree of the expansion valve and a single adjustment amount are previously determined according to an operation frequency of the compressor. When the operating frequency of the compressor is switched, the expansion valve is set to the predetermined initial opening while the operating frequency is set to a predetermined time (T1) from the setting of the initial opening. When the switching is not performed, the degree of opening and closing of the expansion valve is adjusted within the predetermined one-time adjustment amount range every predetermined time (T2) after the lapse of the predetermined time (T1) until the operation frequency is switched. Specially It is set to.

According to the present invention, the degree of opening and closing of the expansion valve constituting the refrigeration cycle is adjusted so that the difference (SH amount) between the suction temperature of the compressor constituting the refrigeration cycle and the temperature of the evaporator matches the target value. In the control method of an air conditioner in which the number of pulses of a motor of the expansion valve is adjusted, an initial opening degree (number of pulses) of the expansion valve and an amount of one pulse change are determined in advance according to an operation frequency of the compressor. When the operating frequency of the compressor is switched, the expansion valve is set to the predetermined initial opening while the operating frequency is set to a predetermined time (T1) from the setting of the initial opening. When the switching is not performed, the opening / closing degree of the expansion valve is determined in advance so that the SH amount matches the target value every predetermined time (T2) after the lapse of the predetermined time (T1) until the operating frequency is switched. One change It is characterized in that so as to adjust a pulse number of the inner.

In this case, it is preferable that the larger the amount of change in the operating frequency of the compressor, the longer the time (predetermined time (T2)) for maintaining the expansion valve at the initial opening degree. Further, the initial opening degree of the expansion valve and the value of the single adjustment amount range, or the initial opening degree (number of pulses) of the expansion valve and the value of the single pulse change amount may be stored as a table.
Further, the table may be different between the air conditioner during the cooling operation and the heating operation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Note that FIG. 4 was referred to for the configuration of the refrigeration cycle. Also, in FIG. 1, the same parts and corresponding parts as those in FIG. 4 are denoted by the same reference numerals, and redundant description will be omitted.

According to the air conditioner of the present invention, when the operating frequency of the compressor is switched, the electronic expansion valve is set to a predetermined initial opening, and if the initial opening is maintained for a predetermined time, the suction temperature of the compressor is maintained. And the temperature of the evaporator (the amount of SH) settles near the target value.

For this purpose, as shown in FIGS. 1 to 3, the control device for an air conditioner according to the present invention includes an indoor unit control unit (including a microcomputer and the like) 10 and an outdoor unit control unit (including a microcomputer and the like). The indoor unit control unit 10 includes an indoor heat exchange temperature transfer unit 10a that detects the temperature of the indoor heat exchanger based on a detection signal from the indoor heat exchange thermistor 12 and transfers the temperature to the outdoor unit control unit 11. ing.

The outdoor unit control section 11 includes a compressor drive circuit 11a for driving the compressor 1, an operation frequency determination section 11b for determining an operation frequency based on a drive signal of the compressor 1, a suction thermistor 13, and an outdoor heat exchanger. While detecting the refrigerant suction temperature and the temperature of the indoor heat exchanger based on the detection signal from the thermistor 14, at least the difference (SH amount) between the suction temperature and the temperature of the evaporator (indoor heat exchange temperature or outdoor heat exchange temperature) is detected. )
The motor of the expansion valve section 15 is driven to adjust the opening degree of the electronic expansion valve 5 according to the operating frequency in accordance with the following table 1 in order to adjust the opening frequency to the target value. And an expansion valve drive control circuit 11a for maintaining and controlling the initial opening of the electronic expansion valve 5 for the same predetermined time when there is no switching. The expansion valve drive control circuit 11a stores Table 1 below in an internal memory. The expansion valve section 15 includes the electronic expansion valve 5 and a motor (such as a stepping motor).

[0015]

[Table 1]

According to Table 1, for example, when the operating frequency of the compressor 1 is switched from 70 Hz to 40 Hz, the initial opening of the electronic expansion valve 5 is set to 200 pulses. In this case, the motor is rotated reversely by 300-200 = 100 pulses, and the electronic expansion valve 5 is slightly closed.

After holding the state of the initial opening degree of the electronic expansion valve 5 for a predetermined time (for example, 3 minutes), S- is performed every predetermined time (for example, 1 minute) until the operating frequency is switched.
The value (-6 pulses or +6 pulses) of the amount of change (adjustment amount) for one time is determined according to the amount of H. That is, when the SH amount deviates significantly from the target value, the value of the maximum pulse (6) is determined Then, the motor is rotated based on the determined number of pulses, and the opening / closing degree of the electronic expansion valve 5 is finely adjusted. When the operating frequency of the compressor 1 is switched between the predetermined time (3 minutes) and the predetermined time (1 minute), the initial opening of the electronic expansion valve 5 must be reset according to the switched operating frequency. become.

Further, the air conditioner has an indoor unit control unit 12 and an outdoor unit control unit 13 of the control means, and the indoor unit control unit 11 and the outdoor unit control unit 12 provide signals necessary for the operation (for example, a remote control). Of the compressor 1 according to the temperature difference between the set temperature and the room temperature, etc., the operation stop, the refrigerant discharge temperature, etc.). Perform room temperature control (room temperature control).

Next, the operation of the control device for an air conditioner having the above configuration will be described with reference to the flowchart of FIG. 2 and the time chart of FIG. The unit 10 transmits a signal (operation frequency or the like) necessary for the room temperature adjustment to the outdoor unit control unit 11. The outdoor unit control unit 11 drives at least the compressor 1 to a predetermined degree, sets the electronic expansion valve 5 to a predetermined opening / closing degree, and operates a refrigeration cycle. The indoor unit control unit 10
The outdoor unit control unit 11 performs other necessary control (such as rotation control of a fan) to adjust the room temperature.

Here, the outdoor unit controller 11 detects the operating frequency of the compressor 1 (step ST1), and controls the degree of opening and closing of the electronic expansion valve 5 according to the operating frequency based on Table 1 above. (Step ST2). For example, as shown in FIG. 3, when the operating frequency is 70 Hz, the pulse is set to 300 pulses corresponding to the initial opening of the electronic expansion valve 5. Thereby, as described above, the motor can be driven based on the pulse setting, and the electronic expansion valve 5 can be set to the predetermined opening / closing degree.

Subsequently, it is determined whether or not the operating frequency of the compressor 1 has been switched (step ST3). If the operating frequency has not been switched, the process proceeds to step ST4.
It is determined whether a predetermined time T1 (for example, three minutes) has elapsed. If the operating frequency has not been switched during the predetermined time T1, the initial opening of the electronic expansion valve 5 is maintained. If the operating frequency has been switched during the predetermined time T1, step ST.
1, the operating frequency switched as described above is detected, and the electronic expansion valve 5 is operated in accordance with the detected operating frequency.
(Step ST)
2).

Subsequently, when the initial opening degree of the electronic expansion valve 5 is maintained at the predetermined time T1, steps ST4 to ST4 are performed.
In step 5, the degree of opening and closing of the electronic expansion valve 5 is finely adjusted according to Table 1. For example, if the current operating frequency is 70 Hz,
The pulse value is determined and set in the range of -9 to +9 according to the difference between the current SH amount and the target value. Thus, as described above, the motor can be driven according to the determined pulse value, and the degree of opening and closing of the electronic expansion valve 5 can be finely adjusted.

Subsequently, it is determined whether or not the operating frequency of the compressor 1 has been switched (step ST6). If the operating frequency has not been switched, it is determined whether or not a predetermined time T2 (for example, one minute) has elapsed. (Step ST
7). If the operating frequency is not switched during the predetermined time T2, the process returns from step ST7 to ST5, and the SH amount is controlled based on the pulse change amount shown in Table 1 above. In step ST5, since the current operating frequency is 70 Hz as described above, the pulse value is determined and set in the range of -9 to +9 according to the difference between the current SH amount and the target value. Thus, as described above, the motor can be driven according to the determined pulse value, and the degree of opening and closing of the electronic expansion valve 5 can be finely adjusted.

In this way, until the operating frequency of the compressor 1 is switched, the step ST5 is executed at every predetermined time T2, that is, the SH amount is detected at every predetermined time T2, and the SH amount is set at the target. The pulse value is determined in the range of -9 to +9 to match the value, and the motor is driven according to the determined pulse value.

When the operating frequency of the compressor 1 is switched while the opening / closing degree of the electronic expansion valve 5 is finely adjusted, the process returns from step ST6 to step ST1 to detect the operating frequency of the compressor 1, and Electronic expansion valve 5 according to operating frequency
Is set (step ST2). For example, as shown in FIG. 3, when the operating frequency is switched from 70 Hz to 40 Hz, the current operating frequency of 40 Hz is detected, and based on Table 1 above, the initial opening of the electronic expansion valve 5 according to the operating frequency of 40 Hz. Set 200 pulses corresponding to the degree. In this case, as described above, the motor is reversely rotated by 100 pulses and the electronic expansion valve 5 is slightly closed. When the opening degree of the electronic expansion valve 5 is finely adjusted in step ST6, the motor is rotated reversely in consideration of the number of pulses of the fine adjustment.

Subsequently, as described above, when the initial opening state of the electronic expansion valve 5 is maintained for a predetermined time T1, the process proceeds from step ST4 to ST5, and the opening / closing degree of the electronic expansion valve 5 is determined according to Table 1. Fine tune. In this case, since the current operation frequency is 40 Hz, the pulse value is determined and set in the range of -6 to +6 according to the difference between the current SH amount and the target value. Thus, as described above, the motor can be driven according to the determined pulse value, and the degree of opening and closing of the electronic expansion valve 5 can be finely adjusted.

Step ST5 is executed at predetermined time intervals T2 until the operating frequency of the compressor 1 is switched. That is, the SH amount is detected every predetermined time T2, and -6 to + is set so that the SH amount becomes the target value.
The pulse value is determined and set in the range of 6, and the motor is driven according to the determined pulse value.

As described above, the routine shown in FIG. 3 is repeated, and when the operating frequency of the compressor 1 is switched, the electronic expansion valve 5 is set to the predetermined initial opening, and if the operating frequency is not switched thereafter, the initial opening is set. The state is maintained for a predetermined time, and after this predetermined time elapses, the opening / closing degree of the electronic expansion valve 5 is finely adjusted every predetermined time until the operating frequency is switched.

Therefore, as shown in FIG. 3, for example, when the operating frequency of the compressor 1 is switched and the degree of opening and closing of the electronic expansion valve 5 is changed, the SH amount greatly changes. When the degree is maintained for the predetermined time T1 (3 minutes), the SH amount calms down, so that the opening / closing degree of the electronic expansion valve 5 can be finely adjusted after this point.
That is, when adjusting the opening / closing degree of the electronic expansion valve 5 so as to reduce the difference between the current SH amount and the target value, the electronic expansion valve 5
May be small, that is, the hunting of the SH amount can be suppressed small, and as a result, the deterioration of the indoor environment is suppressed.

The predetermined time T1 may be made longer as the change in the operating frequency of the compressor 1 becomes larger. That is, as the opening / closing degree of the electronic expansion valve 5 increases, S
This is because the change in the -H amount is large and it takes time for the S-H amount to settle. Although one table 1 is used in the embodiment of the present invention, for example, the values may be slightly different between the cooling operation and the heating operation, that is, two types of tables may be provided. A plurality of tables may be provided in consideration of the type of the harmony device and various conditions of the use environment.

[0031]

As described above, according to the first aspect of the air conditioner control method, the degree of opening and closing of the expansion valve is changed according to the operating frequency of the compressor. Since the SH amount settles, the opening / closing degree of the expansion valve can be finely adjusted after a predetermined time according to the SH amount, and as a result, the hunting of the SH amount can be reduced (the refrigeration cycle can be reduced). Abrupt fluctuations can be suppressed), and stable operation can be performed, and the deterioration of the indoor environment can be suppressed.

According to the second aspect of the present invention, the motor is driven based on the number of pulses determined in advance according to the operating frequency of the compressor to change the opening / closing degree of the expansion valve. After elapse, the amount of S-H calms down,
After a predetermined time, the motor is driven according to the SH amount with a small number of pulses, and the degree of opening and closing of the expansion valve can be finely adjusted.
As a result, hunting of the SH amount can be reduced (abrupt fluctuation of the refrigeration cycle can be suppressed), stable operation can be performed, and deterioration of the indoor environment can be suppressed.

According to the third aspect of the present invention, the larger the amount of change in the operating frequency of the compressor in the first or second aspect, the more
Since the time (predetermined time) for maintaining the expansion valve at the initial opening degree is lengthened, switching of the operating frequency causes S
-Even if the change in H amount becomes large, S
Since the -H amount is settled, the same effect as that of the first or second aspect is obtained.

According to the fourth aspect of the invention, the values of the initial opening degree and one adjustment amount range (or pulse change amount) of the expansion valve according to the first or third aspect are stored as a table. In addition to the effects of item 1 or 3, it is only necessary to store the table in the control means of the air conditioner. Also, if a table suitable for various conditions is provided and switched as necessary, the expansion valve can be controlled more appropriately. can do.

According to the fifth aspect of the present invention, the initial opening degree (number of pulses) and the value of one pulse change of the expansion valve according to the second or third aspect are stored as a table. In addition to the effect of 3, the table only needs to be stored in the control means of the air conditioner, and the table can be rewritten into a table that meets various conditions, etc., and thus there is an effect that the usability is good.

According to the sixth aspect of the invention, the table according to the fourth or fifth aspect is different between the cooling operation and the heating operation of the air conditioner. The degree of opening and closing of the electronic expansion valve can be optimally controlled during cooling and heating, and when matching the SH amount to the target value, hunting of the SH amount can be appropriately reduced.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a control device to which an air conditioner control method according to an embodiment of the present invention is applied.

FIG. 2 is a schematic flowchart illustrating the operation of the control device shown in FIG.

FIG. 3 is a schematic time chart illustrating the operation of the control device shown in FIG. 1;

FIG. 4 is a schematic configuration diagram illustrating a refrigeration cycle of the air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 5 Electronic expansion valve 10 Indoor unit control part 10a Indoor heat exchange temperature transfer part 11 Outdoor unit control part 11a Compressor drive circuit 11b Operating frequency determination part 11c Expansion valve drive control circuit 12 Indoor heat exchange thermistor 13 Suction thermistor 14 Outdoor Heat exchange thermistor 15 Expansion valve (Electronic expansion valve 5 and motor)

Claims (6)

[Claims] An opening degree of an expansion valve constituting the refrigeration cycle is adjusted so that a difference (SH amount) between a suction temperature of a compressor constituting the refrigeration cycle and a temperature of the evaporator is adjusted to a target value. In the method for controlling an air conditioner, an initial opening degree and a single adjustment amount of the expansion valve are previously determined according to an operation frequency of the compressor, and the expansion is performed when the operation frequency of the compressor is switched. While the valve is set to the predetermined initial opening, if the operating frequency is not switched for a predetermined time (T1) from the setting of the initial opening, the operating frequency is not changed after the lapse of the predetermined time (T1). Controlling the degree of opening and closing of the expansion valve within the once-determined adjustment amount range at predetermined time intervals (T2) until the control is switched. 2. The degree of opening and closing of expansion valves constituting the refrigeration cycle is adjusted so that the difference (SH amount) between the suction temperature of the compressor constituting the refrigeration cycle and the temperature of the evaporator matches the target value. In a control method of an air conditioner that adjusts by a pulse number of a motor of an expansion valve, an initial opening degree (number of pulses) and a pulse change amount of one time of the expansion valve are determined in advance according to an operation frequency of the compressor. When the operating frequency of the compressor is switched, the expansion valve is set to the predetermined initial opening, and the operating frequency is not switched during a predetermined time (T1) from the setting of the initial opening. At one time, the opening / closing degree of the expansion valve is determined in advance so that the SH amount matches the target value every predetermined time (T2) after the lapse of the predetermined time (T1) until the operating frequency is switched. Number of pulses within the variation of Control method of an air conditioner which is characterized in that so as to adjust. 3. The air according to claim 1, wherein the longer the change amount of the operating frequency of the compressor is, the longer the predetermined time (T1) for maintaining the expansion valve at the initial opening degree. Harmonizer control method. 4. The control method for an air conditioner according to claim 1, wherein the initial opening degree of the expansion valve and the value of a single adjustment amount range (or pulse change amount) are stored as a table. 5. The control method for an air conditioner according to claim 2, wherein the initial opening degree (number of pulses) of the expansion valve and the value of one pulse change amount are stored as a table. 6. The control method for an air conditioner according to claim 4, wherein the table is different between a cooling operation and a heating operation of the air conditioner.