JP6188631B2 - Air conditioner and control method thereof - Google Patents

Description

  The present invention relates to an air conditioner and a control method thereof.

  Conventionally, in an air conditioner having a refrigeration cycle in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are sequentially connected, an auxiliary heater is built in the indoor unit for heating assistance, or outside the indoor unit. Some have an auxiliary heater that can be controlled.

  This heater plays a role of making up for the lack of heating capacity by only the air conditioner by operating or stopping based on the difference between the set temperature and the room temperature during heating operation.

  In such heater control, since the capacity of the compressor is generally not taken into consideration, the heating capacity of the air conditioner can be increased although the capacity of the compressor can be increased to increase the heating capacity of the air conditioner. There is a problem that the heater may continue to operate without increasing the value.

  Therefore, when the capacity of the compressor is low, the operation of the heater is prevented, so that the capacity of the compressor increases corresponding to the required heating capacity and the number of start / stop times of the compressor can be reduced. A possible technique is disclosed (for example, see Patent Document 1).

  Moreover, when the outside air temperature is high and the indoor air conditioning load is small, a technique is disclosed in which the use of the heater is stopped even if the heater operation is requested from the indoor side due to a decrease in room temperature or the like (for example, Patent Document 2). reference).

JP-A-5-256696 Japanese Patent Laid-Open No. 62-162840

  However, in the control method of Patent Document 1, since there are portions where the operating conditions of the air conditioner and the heater are not linked, there is a risk that the variation in the room temperature may increase depending on the interrelationship of the operating conditions.

  In Patent Document 1, the temperature condition for operating or stopping the heater is defined by the difference between the set temperature and room temperature and the capacity of the compressor. Here, the temperature adjustment of the air conditioner, that is, the temperature condition for operating or stopping the compressor is also defined by the difference between the set temperature and the room temperature, similar to the heater, and the compressor starts operation. Assume that the temperature is intermediate between the temperature at which the heater starts and stops.

  At this time, since the temperature at which the heater starts to operate is close to the temperature at which the compressor starts to operate, the room temperature fluctuates in the downward direction immediately after the operation of the compressor starts, and thus reaches the temperature at which the heater starts to operate. The room temperature may rise rapidly.

  Here, in the case of an air conditioning load that can be adjusted only with an air conditioner, in addition to the temperature increase due to the air conditioner, the temperature increase due to the heater is added, so that the room temperature increases immediately after the heater stops. Due to the large swing, the compressor may reach a temperature at which it stops, and the room temperature may drop rapidly. As a result, there is a risk that the room temperature will greatly hunting.

  In addition, there is a possibility that the current heater may be replaced with a heater having a different specification from the current one due to a specification change. In particular, when an external heater is used, detailed parameters of the heater cannot be specified unless the specification is specified. For example, there is a possibility of selecting from a small capacity that can be used as auxiliary heating to a large capacity that can be used as a backup of the capacity equivalent to that of an air conditioner.

  Normally, when the heater is operated and the room temperature rises, the rotation speed of the compressor is reduced as compared with that before the heater is operated. If the heater stops in this state, the room temperature does not drop for a while after the stop depending on the heater specifications, while the reduced rotational speed does not increase easily for the compressor. For this reason, particularly in a cold district where the air conditioning load is large, the room temperature greatly drops before the compressor speed increases or the heater is activated again.

  On the other hand, when the capacity is a small heater, the heater does not operate sufficiently when the temperature range that must be dependent on the heater or the indoor air conditioning load is large, and the heating capacity is insufficient. Problems arise.

  In addition, if a heater with a capacity larger than that assumed in the design stage is selected, the heater may be activated even when the indoor air conditioning load is small and the temperature can be adjusted only with the air conditioner. . As a result, although the air conditioner has a heating capability, the heater continues to operate, resulting in non-energy saving.

  The present invention has been made in view of the above, and suppresses unnecessary operation of the heater, sufficiently exhibits the heating capacity of the air conditioner, suppresses hunting at room temperature, and saves energy and comfort. An object is to provide an excellent air conditioner and a control method thereof.

In order to solve the above-described problems and achieve the object, an air conditioner according to the present invention is configured by sequentially connecting a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger. an air conditioner having a refrigerant circuit, the compressor speed control unit for controlling the rotational speed of the compressor, and a heater provided outside of the built-in or the indoor unit to the indoor unit for the heating aid A heater control unit that controls the heater; and a room temperature detection unit that is provided in the indoor unit and detects a room temperature as an air temperature in an air-conditioning region, and the compressor rotation speed control unit is When the differential temperature obtained by subtracting the room temperature detected by the room temperature detector from the set temperature is equal to or higher than the first differential temperature, the compressor is started to operate, and the differential temperature obtained by subtracting the room temperature from the set temperature is A second smaller than the first differential temperature When the temperature is equal to or lower than the temperature, control is performed to stop the compressor, and the heater control unit, during the heating operation, when the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or higher than a third temperature difference, When the differential temperature obtained by starting the operation of the heater and subtracting the room temperature from the set temperature is smaller than the third differential temperature and not higher than the fourth differential temperature not lower than the first differential temperature, The heater control unit controls the heater so that the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or less than a fifth temperature difference until a predetermined time elapses after the heater is stopped. The heater is controlled, and when the temperature difference obtained by subtracting the room temperature from the set temperature is not equal to or lower than the fifth temperature difference, the heater control is stopped .

  ADVANTAGE OF THE INVENTION According to this invention, while suppressing the unnecessary driving | operation of a heater, while fully exhibiting the heating capability of an air conditioner, the air conditioner excellent in energy saving and comfort by suppressing hunting at room temperature, and its control method Can be provided.

1 is a refrigerant circuit diagram illustrating a refrigeration cycle of an air conditioner according to Embodiment 1. FIG. FIG. 2 is a diagram showing hysteresis in the state of the compressor and the heater. FIG. 3 is a state transition diagram of the compressor and the heater. FIG. 4 is a flowchart for explaining the control method for the air conditioner according to the first embodiment. FIG. 5 is a flowchart in which specific numerical values are applied to the flowchart of FIG. FIG. 6 is a graph showing a specific example of a compressor and heater control method. FIG. 7 is a flowchart for explaining the control method for the air conditioner according to the second embodiment. FIG. 8 is a flowchart for explaining the control method for the air conditioner according to the third embodiment. FIG. 9 is a flowchart for explaining a control method of the air conditioner according to the fourth embodiment. FIG. 10 is a flowchart for explaining a control method of the air conditioner according to the fifth embodiment. FIG. 11 is a refrigerant circuit diagram illustrating a refrigeration cycle of an air conditioner according to Embodiment 6. FIG. 12 is a flowchart for illustrating the control method for the air conditioner according to the sixth embodiment.

  Hereinafter, embodiments of an air conditioner and a control method thereof according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a refrigerant circuit diagram showing a refrigeration cycle of the air conditioner according to the present embodiment. The air conditioner 10 includes an indoor unit 11 and an outdoor unit 12, the indoor unit 11 includes an indoor heat exchanger 4, a room temperature thermistor 6, and a heater control unit 21, and the outdoor unit 12 includes the compressor 1 and an outdoor heat exchanger. 2, an expansion valve 3, an outside temperature thermistor 7, a four-way valve 8, and a compressor rotation speed control unit 22 (compressor control unit). The air conditioner 10 is configured by sequentially connecting a compressor 1, a four-way valve 8, an outdoor heat exchanger 2, an expansion valve 3, and an indoor heat exchanger 4 through a refrigerant pipe 9. The indoor unit 11 and the outdoor unit 12 are also connected to each other by a communication line (not shown).

  A heater 5 is connected to the indoor unit 11 for heating assistance of the air conditioner 10. Here, the heater 5 is a heater 5 a built in the indoor unit 11 or a heater 5 b provided outside the indoor unit 11. That is, the indoor unit 11 has a built-in heater 5a, or a configuration that can connect an external heater 5b. In FIG. 1, both the heaters 5a and 5b are shown at the same time, but either one is actually provided.

  The heater control unit 21 controls the operation and stop of the heater 5. The heater 5 can be controlled by the heater control unit 21.

  A room temperature thermistor 6 is attached to the indoor unit 11 as a room temperature detector. The room temperature thermistor 6 detects the room temperature as the air temperature in the air-conditioned area. The room temperature detected by the room temperature thermistor 6 is input to the heater control unit 21 and the compressor rotation speed control unit 22.

  An outdoor temperature thermistor 7 is attached to the outdoor unit 12 as an outside air temperature detector. The outside air temperature detected by the outside air temperature thermistor 7 is input to the heater controller 21 and the compressor rotation speed controller 22.

  The compressor rotation speed control unit 22 controls the operation and stop of the compressor 1. Furthermore, the compressor rotation speed control unit 22 can control the rotation speed (capacity) when the compressor 1 is operating. That is, the compressor rotation speed control unit 22 can control the rotation speed including operation and stop of the compressor 1. The compressor 1 can change the rotation speed (capacity).

  The four-way valve 8 is a valve for switching the direction of the refrigerant flow. The four-way valve 8 sets the refrigerant flow path so as to connect the discharge side of the compressor 1 and the indoor heat exchanger 4 and also connect the suction side of the compressor 1 and the outdoor heat exchanger 2 during heating operation. To do. The indoor heat exchanger 4 functions as a refrigerant condenser during heating operation, and heats indoor air.

  In the refrigerant circuit configured as described above, the refrigerant circulates along a path indicated by a solid arrow during heating operation.

  During the heating operation, the high-temperature and high-pressure refrigerant discharged from the compressor 1 flows into the indoor heat exchanger 4 mounted on the indoor unit 11 via the four-way valve 8. Here, the refrigerant condenses by exchanging heat with the air taken in by the indoor unit 11. The refrigerant exiting the indoor heat exchanger 4 is expanded by the expansion valve 3 and flows into the outdoor heat exchanger 2 in a low temperature and low pressure state. Here, the refrigerant evaporates by exchanging heat with the air sucked by the outdoor unit 12, and is sucked into the compressor 1 again via the four-way valve 8.

  Next, the operation during the heating operation of the present embodiment will be described. Hereinafter, the set temperature of the indoor unit 11 is Tset, and the room temperature detected by the room temperature thermistor 6 is Ta. The set temperature Tset and the room temperature Ta are given to the heater control unit 21 and the compressor rotation speed control unit 22 as operation information.

  When the temperature difference obtained by subtracting the room temperature Ta from the set temperature Tset is equal to or higher than a preset temperature difference α (first temperature difference), that is, Ta ≦ Tset−α. Then, the operation of the compressor 1 is started. α is generally a positive value.

  On the other hand, when the temperature difference obtained by subtracting the room temperature Ta from the set temperature Tset is equal to or lower than the preset temperature difference β (second temperature difference), that is, Ta ≧ Tset−β. Sometimes, the compressor 1 is stopped. Here, α> β.

  For example, when Tset = 24 ° C., α = + 0.5 ° C., and β = −0.5 ° C., the compressor 1 starts operation when Ta ≦ 23.5 ° C., and Ta ≧ 24.5 Stop operation when at ℃.

  Further, the heater control unit 21 determines that the temperature difference obtained by subtracting the room temperature Ta from the set temperature Tset is equal to or higher than a preset temperature difference γ (third temperature difference), that is, Ta ≦ Tset−γ. Then, the operation of the heater 5 is started.

  On the other hand, when the temperature difference obtained by subtracting the room temperature Ta from the set temperature Tset is equal to or lower than the temperature difference δ (fourth temperature difference) set in advance, that is, when Ta ≧ Tset−δ. Then, the heater 5 is stopped. Here, γ> δ.

  In this embodiment, α ≦ δ. That is, the upper limit (Tset−α) of the room temperature Ta at which the compressor rotation speed control unit 22 starts the operation of the compressor 1 with respect to the set temperature Tset is the lower limit of the room temperature Ta at which the heater control unit 21 stops the heater 5. It is (Tset−δ) or more.

  For example, when Tset = 24 ° C., γ = + 1.5 ° C., and δ = + 0.5 ° C., the heater 5 starts operating when Ta ≦ 22.5 ° C., and Ta ≧ 23.5 ° C. Stop at some point.

  FIG. 2 is a diagram illustrating the hysteresis of the state of the compressor 1 and the heater 5. In FIG. 2, the right side of the position indicating Tset represents the high temperature side, and the left side represents the low temperature side. P indicates a region where the compressor 1 can be operated. That is, when the room temperature Ta is equal to or lower than (Tset−α) and the compressor 1 starts operation, the compression is performed until the room temperature Ta reaches the temperature indicated by the arrow indicated by P (Ta = Tset−β). The machine 1 continues to operate. Moreover, Q has shown the area | region which the compressor 1 can stop. That is, when the room temperature Ta reaches (Tset-β) or more and the compressor 1 is stopped, the compressor 1 is kept until the room temperature Ta reaches the temperature indicated by the tip of the arrow indicated by Q (Ta = Tset-α). Continues to stop.

  Further, in FIG. 2, R indicates a region where the heater 5 can be operated. That is, when the heater 5 starts operating when the room temperature Ta is equal to or lower than (Tset−γ), the heater 5 is heated until the room temperature Ta reaches the temperature indicated by the arrow indicated by R (Ta = Tset−δ). Will continue to operate. Moreover, S has shown the area | region which the heater 5 can stop. That is, when the heater 5 stops when the room temperature Ta becomes (Tset−δ) or more, the heater 5 stops until the room temperature Ta reaches the temperature indicated by the tip of the arrow indicated by S (Ta = Tset−γ). Continue state.

  FIG. 3 is a state transition diagram of the compressor 1 and the heater 5. In FIG. 3, the time change of room temperature, the time change of the rotation speed of the compressor 1, and the time change of the state of the heater 5 are compared and shown. The rotation speed of the compressor 1 is shown in two states, ON (on) or OFF (off). Here, when the compressor 1 is on, the compressor 1 is in an operating state, and when the compressor 1 is off, the compressor 1 is in a stopped state. Similarly, the state of the heater 5 is shown in two states, ON (on) or OFF (off). Here, when the heater 5 is on, the heater 5 is in an operating state, and when the heater 5 is off, the heater 5 is in a stopped state.

  Next, with reference to FIG. 4, the control method of the air conditioner which concerns on this Embodiment is demonstrated. FIG. 4 is a flowchart for explaining the control method for the air conditioner according to the present embodiment.

  As shown in FIG. 4, first, it is assumed that the compressor 1 is in an on state (operating state) and the heater 5 is in an off state (stopped state) (S1).

  Next, the heater control unit 21 determines whether or not the temperature difference obtained by subtracting the room temperature Ta from the set temperature Tset is equal to or higher than the temperature difference γ, that is, Ta ≦ Tset−γ (S2).

  If the result of determination in S2 is Ta ≦ Tset−γ (S2, Yes), the heater control unit 21 turns on the heater 5 (S3).

  Subsequently, the heater control unit 21 determines whether or not the temperature difference obtained by subtracting the room temperature Ta from the set temperature Tset is equal to or lower than the temperature difference δ, that is, Ta ≧ Tset−δ (S4).

  As a result of the determination in S4, if Ta ≧ Tset−δ is not satisfied (S4, No), the process of S4 is performed again. As a result of the determination in S4, if Ta ≧ Tset−δ (S4, Yes), the heater control unit 21 turns off the heater 5 (S5).

  On the other hand, if Ta ≦ Tset−γ is not satisfied as a result of the determination in S <b> 2 (S <b> 2, No), the heater 5 continues to be turned off, and thus the process proceeds to S <b> 6.

  Next, the compressor rotation speed control unit 22 determines whether or not the temperature difference obtained by subtracting the room temperature Ta from the set temperature Tset is equal to or lower than the temperature difference β, that is, Ta ≧ Tset−β ( S6).

  As a result of the determination in S6, if Ta ≧ Tset−β is not satisfied (S6, No), the process of S2 is performed again. As a result of the determination in S6, if Ta ≧ Tset−β (S6, Yes), the compressor rotation speed control unit 22 turns off the compressor 1 (S7).

  Subsequently, the compressor rotation speed control unit 22 determines whether or not the temperature difference obtained by subtracting the room temperature Ta from the set temperature Tset is equal to or higher than the temperature difference α, that is, Ta ≦ Tset−α ( S8).

  As a result of the determination in S8, if Ta ≦ Tset−α is not satisfied (S8, No), the process of S8 is performed again. If the result of determination in S8 is Ta ≦ Tset−α (S8, Yes), the compressor rotation speed control unit 22 turns on the compressor 1 (S9). In this state, since the compressor 1 is on and the heater 5 is off, the process returns to S2 and the same process is repeated.

  5 is a specific numerical value (Tset = 24 ° C., α = + 0.5 ° C., β = −0.5 ° C., γ = + 1.5 ° C., δ = + 0.5 ° C.) in the flowchart of FIG. Is applied.

  According to the present embodiment, the range between the operation start temperature and the stop temperature of the compressor 1 and the range between the operation start temperature and the stop temperature of the heater 5 do not interfere (overlap). When the temperature can be adjusted only by the machine 10, the heater 5 is activated when the operation of the air conditioner 10 is started, and even when the heater 5 is stopped due to an increase in the room temperature, the temperature difference for the heater 5 to operate again is reached. By sufficiently increasing the number of revolutions of the compressor 1 and raising the room temperature before, the heating capacity of the air conditioner 10 is sufficiently exerted, and hunting at room temperature is suppressed and unnecessary operation of the heater 5 is suppressed. be able to.

  On the other hand, when the air conditioner 10 alone has insufficient heating capacity, the air conditioner 10 and the heater 5 operate simultaneously. At this time, even when the heater 5 is stopped due to a significant increase in the room temperature, it is possible to prevent the compressor 1 from stopping by ensuring the likelihood until the room temperature reaches the temperature difference at which the compressor 1 stops. It is possible to suppress a rapid drop in room temperature. Thereby, the heating capability of the air conditioner 10 can be fully exhibited.

  FIG. 6 is a graph showing a specific example of a method for controlling the compressor 1 and the heater 5. In FIG. 6, the time change of the room temperature is shown in the upper stage, the time change of the rotational speed of the compressor 1 is shown in the middle stage, and the on / off state of the heater 5 is shown in the lower stage. Regarding the rotational speed of the compressor 1, Hi represents the largest rotational speed, and Med. Represents the number of rotations having a magnitude following Hi, and Lo represents the number of rotations 0, that is, the heater stopped state. A solid line indicates a time change when the air conditioner control method of the present embodiment is applied, and a broken line indicates a time change when the conventional air conditioner control method is applied. Here, in the conventional control method, the temperature at which the operation of the compressor is started is located between the temperature at which the operation of the heater is started and the temperature at which the heater is stopped. As shown in FIG. 6, according to the control method for the air conditioner of the present embodiment, unnecessary operation of the heater 5 is suppressed and the compressor 1 is rotated as compared with the conventional control method for the air conditioner. It can be seen that by increasing the number, the heating capacity of the air conditioner 10 can be sufficiently exerted, and hunting at room temperature can be suppressed. Thereby, it becomes possible to provide the air conditioner 10 excellent in energy saving and comfort.

Embodiment 2. FIG.
FIG. 7 is a flowchart for explaining the control method for the air conditioner according to the present embodiment. FIG. 7 is a flowchart in which specific numerical values (Tset = 24 ° C., α = + 0.5 ° C., β = −0.5 ° C., γ = + 1.5 ° C., δ = + 0.5 ° C.) are applied. Show. The configuration of the present embodiment is the same as the configuration of the first embodiment shown in FIG.

  First, it is assumed that the compressor 1 is in an on state (operating state) and the heater 5 is in an off state (stopped state) (S1).

Next, the heater control unit 21 determines whether or not an elapsed time T _interval after the heater 5 has stopped has passed a predetermined time (for example, 3 minutes) (S2). Here, the heater control unit 21 has a function of measuring an elapsed time after the heater 5 is stopped, for example, by counting clock signals.

As a result of the determination in S2, if T _interval ≧ 3 minutes (S2, Yes), the heater control unit 21 determines whether or not room temperature ≦ 22.5 ° C. (S3).

  If the result of determination in S3 is that room temperature ≦ 22.5 ° C. (S3, Yes), the heater controller 21 turns on the heater 5 (S4).

Subsequently, the heater control unit 21 determines whether or not room temperature ≧ 23.5 ° C. (S5). If the room temperature ≧ 23.5 ° C. (S5, Yes), the heater 5 is turned off. T _interval is reset and the count is started (S6), and the process proceeds to S7. That is, the heater control unit 21 starts measuring the elapsed time after the heater 5 is turned off. If the result of the determination in S5 is not room temperature ≧ 23.5 ° C. (S5, No), the process of S5 is performed again.

If T _interval ≧ 3 minutes is not the result of the determination in S2 (S2, No), or if the determination in S3 is not room temperature ≦ 22.5 ° C. (S3, No), the process proceeds to S7. .

  The processes in S7 to S10 are the same as the processes in S6 to S9 in FIG.

  As described above, in the present embodiment, the operation of the heater 5 is prohibited until a certain time elapses after the heater 5 is stopped. That is, the heater control unit 21 stops the control of the heater 5 until a certain time (for example, 3 minutes) elapses after the heater 5 is stopped, and the room temperature ≦ 22.5 ° C. (Ta ≦ Tset−γ) is established. Even in this case, the heater 5 is not restarted.

  Thereby, when the air conditioning load on the indoor side, which can be air-conditioned only by the air conditioner 10, is small, the time for increasing the number of rotations of the compressor 1 to a value necessary for normal operation is ensured. The heating capability originally provided in the machine 10 can be sufficiently exhibited.

  Other configurations, operations, and effects of the present embodiment are the same as those of the first embodiment.

Embodiment 3 FIG.
FIG. 8 is a flowchart for explaining the control method for the air conditioner according to the present embodiment. FIG. 8 is a flowchart in which specific numerical values (Tset = 24 ° C., α = + 0.5 ° C., β = −0.5 ° C., γ = + 1.5 ° C., δ = + 0.5 ° C.) are applied. Show. The configuration of the present embodiment is the same as the configuration of the first embodiment shown in FIG.

  First, it is assumed that the compressor 1 is in an on state (operating state) and the heater 5 is in an off state (stopped state) (S1).

Next, similarly to the case of FIG. 7, the heater control unit 21 determines whether or not an elapsed time T _interval after the heater 5 has stopped has passed a predetermined time (for example, 3 minutes). (S2).

As a result of the determination in S2, if T _interval ≧ 3 minutes (S2, Yes), the heater control unit 21 determines whether or not room temperature ≦ 22.5 ° C. (S4).

On the other hand, if T _interval ≧ 3 minutes is not satisfied as a result of the determination in S2 (S2, No), the heater control unit 21 determines that the temperature difference obtained by subtracting the room temperature Ta from the set temperature Tset is a preset temperature difference ε (first temperature). 5) or more, that is, whether Ta ≦ Tset−ε. Here, for example, when ε = + 2.0 ° C., the heater control unit 21 determines whether or not room temperature ≦ 22 ° C. (S3). If the result of determination in S3 is that room temperature ≦ 22 ° C. (S3, Yes), the process proceeds to S4. If the result of determination in S3 is not room temperature ≦ 22 ° C. (S3, No), the process proceeds to S8.

  The processing of S4 to S11 is the same as the processing of S3 to S10 in FIG. Since ε = + 2.0 ° C.> γ = + 1.5 ° C., in this case, the room temperature ≦ 22.5 ° C. is established in S4.

  As described above, in the present embodiment, when Ta ≦ Tset−ε (room temperature ≦ 22 ° C.) is satisfied while the reactivation of the heater 5 is prohibited as in S2 of FIG. Enables operation. That is, the heater control unit 21 controls the heater 5 until Ta ≦ Tset−ε (room temperature ≦ 22 ° C.) until 3 minutes elapse after the heater 5 stops, and Ta ≦ Tset. When it is not −ε (room temperature ≦ 22 ° C.), the control of the heater 5 is stopped.

  As a result, when the indoor air conditioning load that must depend on the heater 5 is large, the heater 5 is operated to make up for the heating capacity that is insufficient with the air conditioner 10 alone.

  Other configurations, operations, and effects of the present embodiment are the same as those of the second embodiment.

Embodiment 4 FIG.
FIG. 9 is a flowchart for explaining the control method for the air conditioner according to the present embodiment. FIG. 9 is a flowchart in which specific numerical values (Tset = 24 ° C., α = + 0.5 ° C., β = −0.5 ° C., γ = + 1.5 ° C., δ = + 0.5 ° C.) are applied. Show. The configuration of the present embodiment is the same as the configuration of the first embodiment shown in FIG.

  First, it is assumed that the compressor 1 is in an on state (operating state) and the heater 5 is in an off state (stopped state) (S1).

Next, similarly to FIG. 7, the heater control unit 21 determines whether or not an elapsed time T _interval after the heater 5 stops has passed a predetermined time (for example, 3 minutes) (S2). ).

As a result of the determination in S2, when T _interval ≧ 3 minutes (S2, Yes), the heater control unit 21 sets the compressor rotation speed control unit 22 so that the rotation speed f of the compressor 1 becomes f _initial. The rotation speed of the compressor 1 is controlled (S3). Here, f _initial is the number of rotations of the compressor 1 set after a lapse of a certain time after the heater 5 is stopped, and is the number of rotations set according to the temperature difference between the room temperature Ta and the set temperature Tset. .

  Next, the heater control unit 21 determines whether or not room temperature ≦ 22.5 ° C. (S4). If the result of determination in S4 is that room temperature ≦ 22.5 ° C. (S4, Yes), the heater control unit 21 turns on the heater 5 (S5).

Subsequently, the heater control unit 21 determines whether or not the room temperature ≧ 23.5 ° C. (S6). If the room temperature ≧ 23.5 ° C. (S6, Yes), the heater 5 is turned off, and T _{The interval} is reset and starts counting, and the compressor speed controller 22 controls the speed of the compressor 1 so that the speed f of the compressor 1 becomes f _initial × c (c> 1). (S7). For example, c is 1.1. That is, the rotation speed of the compressor 1 is increased within a certain time after the heater 5 is stopped than when the heater 5 is operated. If the result of determination in S6 is not room temperature ≧ 23.5 ° C. (S6, No), the process of S6 is performed again.

If T _interval ≧ 3 minutes is not the result of the determination in S2 (S2, No), or if the determination in S4 is not room temperature ≦ 22.5 ° C. (S4, No), the process proceeds to S8. .

  The processes of S8 to S11 are the same as the processes of S7 to S10 in FIG.

  Thus, in the present embodiment, while the re-operation of the heater 5 is prohibited (S2, No), the rotation speed of the compressor 1 is increased as compared with the time of operation of the heater 5.

  Thereby, by increasing the rotation speed of the compressor 1, which has been reduced by the operation of the heater 5, the temperature drop immediately after the heater 5 is stopped can be suppressed, and the rapid drop in room temperature can be suppressed.

  Other configurations, operations, and effects of the present embodiment are the same as those of the second embodiment.

Embodiment 5. FIG.
FIG. 10 is a flowchart for explaining the control method for the air conditioner according to the present embodiment. FIG. 10 is a flowchart in which specific numerical values (Tset = 24 ° C., α = + 0.5 ° C., β = −0.5 ° C., γ = + 1.5 ° C., δ = + 0.5 ° C.) are applied. Show. The configuration of the present embodiment is the same as the configuration of the first embodiment shown in FIG.

  First, it is assumed that the compressor 1 is in an on state (operating state) and the heater 5 is in an off state (stopped state) (S1).

Next, the heater control unit 21 determines whether or not room temperature ≦ 22.5 ° C. (S2). As a result of the determination in S2, if the room temperature ≦ 22.5 ° C. (S2, Yes), the heater control unit 21 indicates that the rotation speed f of the compressor 1 is 90% or more of the maximum rotation speed f _max of the compressor 1. It is determined whether or not (S3).

As a result of the determination in S3, if f ≧ f _max × 0.9 (S3, Yes), the heater control unit 21 turns on the heater 5 (S4).

  Subsequently, the heater control unit 21 determines whether or not room temperature ≧ 23.5 ° C. (S5). If the room temperature ≧ 23.5 ° C. (S5, Yes), the heater 5 is turned off (S6). ), The process proceeds to S7.

If the result of determination in S2 is not room temperature ≦ 22.5 ° C. (S2, No), or if the result of determination in S3 is not f ≧ f _max × 0.9 (S3, No), S7 Proceed to processing.

  The processes in S7 to S10 are the same as the processes in S6 to S9 in FIG.

  Thus, in the present embodiment, the reactivation of the heater 5 is prohibited until the rotation speed of the compressor 1 reaches 90% of the maximum rotation speed after the heater 5 is stopped. More generally, S3 can be replaced with a determination as to whether or not the rotation speed f of the compressor 1 is equal to or greater than a predetermined value. Here, this fixed value can be set to a value larger than the rotational speed of the compressor 1 when the heater 5 is operated, for example.

  Thereby, even when the air conditioning load on the indoor side that can be air-conditioned only by the air conditioner 10 is small, the air conditioner 10 is originally provided by increasing the number of rotations of the compressor 1 to a value necessary for normal operation. The heating capacity can be ensured.

  Other configurations, operations, and effects of the present embodiment are the same as those of the second embodiment.

Embodiment 6 FIG.
FIG. 11 is a refrigerant circuit diagram illustrating a refrigeration cycle of the air conditioner according to the present embodiment. As shown in FIG. 11, the indoor unit 11 is provided with an outside air temperature threshold value changing unit 23 connected to the heater control unit 21.

  In the present embodiment, the heater control unit 21 stops the control of the heater 5 when the outside air temperature is equal to or higher than a preset threshold, and operates the heater 5 even when Ta ≦ Tset−γ is satisfied. Do not start. The outside air temperature detected by the outside air temperature thermistor 7 is input to the heater control unit 21. Information relating to the threshold value is given to the heater control unit 21 in advance. The outside air temperature threshold value changing unit 23 enables the threshold value given to the heater control unit 21 to be changed.

  The outside air temperature threshold value changing unit 23 can be realized by a circuit using a jumper wire on the substrate of the indoor unit 11 on which the heater control unit 21 is mounted, for example. That is, if a different threshold value is assigned depending on whether or not a detour route by a jumper line is taken, the threshold value can be changed by selecting the route. Further, the threshold value may be changed by a remote controller for air conditioning operation. In this case, the outside air temperature threshold value changing unit 23 has a function of giving a threshold value set via the remote controller to the heater control unit 21.

  FIG. 12 is a flowchart for explaining the control method for the air conditioner according to the present embodiment. FIG. 12 is a flowchart in which specific numerical values (Tset = 24 ° C., α = + 0.5 ° C., β = −0.5 ° C., γ = + 1.5 ° C., δ = + 0.5 ° C.) are applied. Show.

  First, it is assumed that the compressor 1 is in an on state (operating state) and the heater 5 is in an off state (stopped state) (S1).

The heater control unit 21 determines whether or not the outside air temperature _Tout is 10 ° C. or higher (S2). As a result of the determination in S2, if T _out ≧ 10 ° C. is not satisfied (S2, No), the processing of S3 to S6 is performed. In addition, the process of S3-S6 is the same as the process of S2-S5 of FIG. Further, the processes of S7 to S10 are the same as the processes of S6 to S9 in FIG.

As a result of the determination in S2, if T _out ≧ 10 ° C. (S2, Yes), the heater control unit 21 does not restart the heater 5 even when the room temperature ≦ 22.5 ° C. is satisfied, that is, Control of the heater 5 is stopped and the process proceeds to S7.

  As a result, regardless of the specifications of the external heater 5b selected by the installer, the heater 5b can be used effectively by adjusting the operating range according to the specifications.

  Other configurations, operations, and effects of the present embodiment are the same as those of the second embodiment.

  The present invention is useful as an air conditioner and a control method thereof.

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Outdoor heat exchanger, 3 Expansion valve, 4 Indoor heat exchanger, 5, 5a, 5b Heater, 6 Room temperature thermistor, 7 Outside temperature thermistor, 8 Four way valve, 9 Refrigerant piping, 10 Air conditioner, 11 Indoor unit, 12 outdoor unit, 21 heater control unit, 22 compressor rotation speed control unit, 23 outdoor temperature threshold value changing unit.

Claims (8)

Compressor, four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger to a sequentially connected to an air conditioner having a refrigerant circuit which is configured,
A compressor speed controller for controlling the speed of the compressor;
A heater built in the indoor unit or provided outside the indoor unit for heating assistance,
A heater control unit for controlling the heater;
A room temperature detector that is provided in the indoor unit and detects a room temperature as an air temperature in an air-conditioning area;
With
The compressor rotation speed control unit starts the operation of the compressor when the temperature difference obtained by subtracting the room temperature detected by the room temperature detection unit from the set temperature during the heating operation is equal to or higher than the first temperature difference. When the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or less than a second temperature difference smaller than the first temperature difference, the compressor is controlled to stop,
The heater control unit starts the heater operation and subtracts the room temperature from the set temperature when the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or higher than a third temperature difference during the heating operation. When the differential temperature is lower than the third differential temperature and not higher than the fourth differential temperature not lower than the first differential temperature, the heater is controlled to stop .
The heater control unit controls the heater when a temperature difference obtained by subtracting the room temperature from the set temperature is equal to or lower than a fifth temperature difference until a predetermined time has elapsed since the heater stopped. When the temperature difference obtained by subtracting the room temperature from the set temperature is not less than or equal to the fifth temperature difference, the control of the heater is stopped . An air conditioner including a refrigerant circuit configured by sequentially connecting a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger,
A compressor speed controller for controlling the speed of the compressor;
A heater built in the indoor unit or provided outside the indoor unit for heating assistance,
A heater control unit for controlling the heater;
A room temperature detector that is provided in the indoor unit and detects a room temperature as an air temperature in an air-conditioning area;
With
The compressor rotation speed control unit starts the operation of the compressor when the temperature difference obtained by subtracting the room temperature detected by the room temperature detection unit from the set temperature during the heating operation is equal to or higher than the first temperature difference. When the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or less than a second temperature difference smaller than the first temperature difference, the compressor is controlled to stop,
The heater control unit starts the heater operation and subtracts the room temperature from the set temperature when the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or higher than a third temperature difference during the heating operation. When the differential temperature is lower than the third differential temperature and not higher than the fourth differential temperature not lower than the first differential temperature, the heater is controlled to stop.
The heater control unit stops the control of the heater until a certain time elapses after the heater stops,
The heater control unit sends the rotation speed to the compressor rotation speed control section so that the rotation speed of the compressor is larger than that at the time of operation of the heater until a certain time elapses after the heater stops. air conditioner you, characterized in that to control the. An air conditioner including a refrigerant circuit configured by sequentially connecting a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger,
A compressor speed controller for controlling the speed of the compressor;
A heater built in the indoor unit or provided outside the indoor unit for heating assistance,
A heater control unit for controlling the heater;
A room temperature detector that is provided in the indoor unit and detects a room temperature as an air temperature in an air-conditioning area;
With
The compressor rotation speed control unit starts the operation of the compressor when the temperature difference obtained by subtracting the room temperature detected by the room temperature detection unit from the set temperature during the heating operation is equal to or higher than the first temperature difference. When the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or less than a second temperature difference smaller than the first temperature difference, the compressor is controlled to stop,
The heater control unit starts the heater operation and subtracts the room temperature from the set temperature when the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or higher than a third temperature difference during the heating operation. When the differential temperature is lower than the third differential temperature and not higher than the fourth differential temperature not lower than the first differential temperature, the heater is controlled to stop.
In the case where the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or higher than the third temperature difference, the heater control unit is configured such that when the rotational speed of the compressor is equal to or higher than a predetermined value, to start of operation, the when the rotational speed of the compressor is not the predetermined value or more, the air conditioner you characterized in that does not operate the heater. It has an outside air temperature detector that detects the outside air temperature,
2. The air conditioner according to claim 1, wherein the heater control unit stops the control of the heater when the outside air temperature detected by the outside air temperature detecting unit is equal to or higher than a preset threshold value. Machine. The air conditioner according to claim 4 , further comprising an outside air temperature threshold changing unit capable of changing the threshold. Compressor, four-way valve, an indoor heat exchanger, an expansion valve, and a refrigerant circuit configured the outdoor heat exchanger are sequentially connected, the compressor rotational speed control unit for controlling the rotational speed of the compressor, heating A heater built in the indoor unit or provided outside the indoor unit as an auxiliary unit, a heater control unit that controls the heater, and a room temperature detection that is provided in the indoor unit and detects the room temperature as the air temperature in the air-conditioned area A control method at the time of heating operation of the air conditioner provided with a section,
When the temperature difference obtained by subtracting the room temperature detected by the room temperature detection unit from the set temperature is equal to or higher than the first temperature difference, the compressor rotation speed control unit starts the operation of the compressor, and starts from the set temperature. When the differential temperature obtained by subtracting the room temperature is equal to or lower than the second differential temperature that is smaller than the first differential temperature, the compressor is controlled to stop,
When the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or higher than a third temperature difference, the heater control unit starts the operation of the heater, and the temperature difference obtained by subtracting the room temperature from the set temperature is When the temperature difference is smaller than the third temperature difference and not more than the fourth temperature difference not less than the first temperature difference, the heater is controlled to stop ,
The heater control unit controls the heater when a temperature difference obtained by subtracting the room temperature from the set temperature is equal to or lower than a fifth temperature difference until a predetermined time has elapsed since the heater stopped. Then, when the temperature difference obtained by subtracting the room temperature from the set temperature is not equal to or less than the fifth temperature difference, the control of the heater is stopped . A refrigerant circuit configured by sequentially connecting a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger, a compressor rotation speed control unit that controls the rotation speed of the compressor, and heating assistance A heater built in the indoor unit or provided outside the indoor unit, a heater control unit that controls the heater, and a room temperature detection unit that is provided in the indoor unit and detects the room temperature as the air temperature in the air-conditioning region A control method during heating operation of an air conditioner comprising:
  The compressor rotation speed control unit starts the operation of the compressor when the temperature difference obtained by subtracting the room temperature detected by the room temperature detection unit from the set temperature during the heating operation is equal to or higher than the first temperature difference. When the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or less than a second temperature difference smaller than the first temperature difference, the compressor is controlled to stop,
  The heater control unit starts the heater operation and subtracts the room temperature from the set temperature when the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or higher than a third temperature difference during the heating operation. When the differential temperature is lower than the third differential temperature and not higher than the fourth differential temperature not lower than the first differential temperature, the heater is controlled to stop.
  The heater control unit stops the control of the heater until a certain time elapses after the heater stops,
  The heater control unit sends the rotation speed to the compressor rotation speed control section so that the rotation speed of the compressor is larger than that at the time of operation of the heater until a certain time elapses after the heater stops. A control method for an air conditioner characterized by controlling the air conditioner. A refrigerant circuit configured by sequentially connecting a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger, a compressor rotation speed control unit that controls the rotation speed of the compressor, and heating assistance A heater built in the indoor unit or provided outside the indoor unit, a heater control unit that controls the heater, and a room temperature detection unit that is provided in the indoor unit and detects the room temperature as the air temperature in the air-conditioning region A control method during heating operation of an air conditioner comprising:
The compressor rotation speed control unit starts the operation of the compressor when the temperature difference obtained by subtracting the room temperature detected by the room temperature detection unit from the set temperature during the heating operation is equal to or higher than the first temperature difference. When the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or less than a second temperature difference smaller than the first temperature difference, the compressor is controlled to stop,
The heater control unit starts the heater operation and subtracts the room temperature from the set temperature when the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or higher than a third temperature difference during the heating operation. When the differential temperature is lower than the third differential temperature and not higher than the fourth differential temperature not lower than the first differential temperature, the heater is controlled to stop.
In the case where the temperature difference obtained by subtracting the room temperature from the set temperature is equal to or higher than the third temperature difference, the heater control unit is configured such that when the rotational speed of the compressor is equal to or higher than a predetermined value, The air conditioner control method is characterized in that the operation of the air conditioner is started and the heater is not operated when the rotation speed of the compressor is not equal to or greater than the predetermined value .

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