JP5407342B2 - Air conditioner - Google Patents

Description

  The present invention relates to control of an air conditioner.

In the conventional air conditioner, in order to improve the heating capacity, the motor's rotor magnetic flux is weakened by the magnetic flux generated by the motor coil by shifting the current phase of the motor for driving the compressor in the advance direction. Is increased to increase the heating capacity (see, for example, Patent Document 1).
JP-A-5-272823

  However, in the above conventional configuration, it is necessary to greatly advance the phase of the motor current in order to increase the maximum rotational speed of the compressor. However, if the phase of the motor current is advanced, the torque decreases and the current value increases significantly at high loads. (Stopping when the current value increases significantly to prevent destruction of the drive circuit) or step out. Therefore, it is necessary to set the motor current phase advance angle small in order to step out even at the maximum load or to suppress a significant increase in motor current. As a result, the maximum compressor speed cannot be increased and the maximum heating capacity There was a problem that the increase in the number was reduced.

  The present invention solves the above-described conventional problems, and an object thereof is to prevent step-out and improve the maximum heating capacity.

In order to solve the above-described conventional problems, an air conditioner according to the present invention includes an indoor heat exchanger temperature detection device that detects an indoor heat exchanger temperature of an indoor unit, and a compression that detects the temperature of refrigerant discharged from the compressor. A compressor discharge temperature detection device is provided, and when the difference temperature between the detection temperature of the indoor heat exchanger temperature detection device and the detection temperature of the compressor discharge temperature detection device is small, the compressor maximum rotation speed is set low It is what.

  By determining the wet state (ratio of liquid phase component) on the compressor suction side, the target compressor maximum rotational speed is set low when the amount of wetness (liquid phase) is large and the compressor is loaded. When the amount of wetness decreases (the gas phase component increases) and the compressor load decreases, the target compressor maximum rotation speed can be set high to improve the heating capacity. In addition, the phase advance angle of the motor current is weakened when the compressor suction side is wet, and the phase advance angle is increased when the amount of wetness is reduced and the load is low. It becomes.

  The air conditioner of the present invention supplies an optimal motor current phase and rotation speed to the compressor to prevent step-out, improve the maximum heating capacity, and provide an air conditioner with high comfort and reliability. it can.

A first aspect of the present invention is an air conditioner in which a compressor driven by a motor, an outdoor heat exchanger, an outdoor unit having an outdoor fan, an indoor heat exchanger, and an indoor unit having an indoor fan are connected to the indoor unit. The apparatus further includes an indoor heat exchanger temperature detecting device that detects an indoor heat exchanger temperature, and the outdoor unit is further provided with a compressor discharge temperature detecting device that detects the temperature of refrigerant discharged from the compressor. The wet state of the compressor suction is determined based on the difference between the temperature detected by the heat exchanger temperature detecting device and the temperature detected by the compressor discharge temperature detecting device, and the rotational speed of the compressor motor is controlled from this value. If the temperature difference is small at this time, the suction of the compressor is moist and the compressor load is high, so by setting the maximum compressor speed (target speed) slightly lower, the compressor current will increase significantly. Stopping of equipment due to step-out can be prevented. Also, since the load is small when the differential temperature is large, even if the maximum compressor speed (target speed) is set high, maximum heating is achieved without stopping the equipment due to a significant increase or step-out of the compressor current. Capability can be improved, and an air conditioner with high comfort and reliability can be supplied.

  According to a second aspect of the present invention, in particular, in the air conditioner of the first aspect, the wet state of the compressor suction is determined based on the difference between the temperature detected by the indoor heat exchanger temperature detector and the temperature detected by the compressor discharge temperature detector. The current phase of the compressor motor and the rotation speed of the compressor motor are controlled. As a result, when the temperature difference is small, the compressor suction is moist and the compressor load is high, so the maximum compressor speed (target speed) is set slightly lower and the current phase of the compressor motor is adjusted. Set a little lower, and when the differential temperature increases, by setting the maximum compressor speed (target speed) and the compressor motor current phase high, there is no significant increase in compressor current or equipment shutdown due to step-out. The maximum heating capacity can be improved, and an air conditioner with high comfort and reliability can be supplied.

  According to a third aspect of the present invention, in the air conditioner of the first or second aspect of the invention, an outdoor suction temperature detection device for detecting the outdoor suction temperature is provided, and the detection of the indoor heat exchanger temperature detection device is performed only when the outdoor air temperature is low. The wet state of the compressor suction is determined based on the temperature difference between the temperature and the temperature detected by the compressor discharge temperature detecting device, and the compressor motor is controlled by this. When the temperature difference is small, that is, when the compressor suction is wet and the compressor load is high, the compressor maximum rotation speed (target rotation speed) is set slightly lower, and the current phase of the compressor motor is set. When the temperature difference is increased, the maximum compressor speed (target speed) is set higher and the motor current phase is set higher. This eliminates a significant increase in compressor motor current or equipment outage due to step-out, improves maximum heating capacity, provides a comfortable and reliable air conditioner, and lowers the need for higher heating capacity. By limiting to the outside temperature, it becomes possible to perform control more efficiently.

  According to a fourth aspect of the present invention, in the air conditioner of the first to third aspects of the invention, a compressor discharge pressure detecting device for detecting the pressure of refrigerant discharged from the compressor is provided, and the detected pressure of the compressor discharge pressure detecting device is provided. The wet state of the compressor suction is determined based on the temperature difference between the saturation temperature converted from the above and the detected temperature of the compressor discharge temperature detecting device, and the compressor motor is controlled from this value. As a result, when the compressor suction is wet and the compressor load is high, the maximum compressor speed (target speed) is set slightly lower, and when the differential temperature increases, the maximum compressor speed (target) By setting the number of rotations to be high, there is no significant increase in the compressor current or the stoppage of equipment due to step-out, the maximum heating capacity is improved, and an air conditioner with high comfort and reliability can be supplied.

  According to a fifth aspect of the invention, in particular, in the air conditioning apparatus of the first to third aspects of the invention, a compressor suction pressure detecting device for detecting the pressure of the refrigerant sucked into the compressor and the temperature of the refrigerant sucked into the compressor are detected. Compressor intake temperature detection device is provided, and the wet state of the compressor intake is determined by the difference between the saturation temperature converted from the detected pressure of the compressor intake pressure detection device and the detected temperature of the compressor intake temperature detection temperature device The compressor motor is controlled from this value. As a result, when the compressor suction is wet and the compressor load is high, the maximum compressor speed (target speed) is set slightly lower, and when the differential temperature increases, the maximum compressor speed (target) By setting the rotational speed) high, there is no significant increase in compressor motor current or equipment outage due to step-out, and the maximum heating capacity is improved, and an air conditioner with high comfort and reliability can be supplied.

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

(Embodiment 1)
FIG. 1 is a refrigeration cycle diagram of the air-conditioning apparatus according to the first embodiment of the present invention, FIG. 2 is a control block diagram thereof, and FIG. 3 is a control flowchart of the air-conditioning apparatus.

  In FIG. 1, the outdoor unit 1 is provided with a compressor 2, an outdoor heat exchanger 3, an outdoor blower 4, a four-way valve 5 for switching between heating and cooling, and a throttle device 6. The outdoor unit 1 is provided with an outdoor suction temperature detection device 7 for detecting the outdoor suction temperature, and a compressor discharge temperature detection device 8 for detecting the compressor discharge temperature Td in the pipe discharged from the compressor 2. Yes.

  On the other hand, the indoor unit 9 includes an indoor blower 10, an indoor heat exchanger 11, an indoor heat exchanger temperature detection device 12 that detects the temperature of the indoor heat exchanger 11, and an indoor suction temperature detection device that detects the room temperature of the room. 13 and an operation setting device 14 capable of setting an operation mode (cooling or heating) desired by the resident, room temperature, operation or stop, air volume and direction.

  In the refrigeration cycle having the above-described configuration, during heating operation, the refrigerant discharged from the compressor 2 flows to the indoor heat exchanger 11 through the four-way valve 5 and is driven by the indoor blower 10 in the indoor heat exchanger 11. The refrigerant is condensed and liquefied by heat exchange with the refrigerant, and then reduced in pressure by passing through the expansion device 6 evaporates in the outdoor heat exchanger 3 and then sucked into the compressor 2 again through the four-way valve 5 (cooling). The description of dehumidification is omitted).

  Next, the control flow of the air conditioner in the present embodiment will be described with reference to FIGS.

  As shown in the control block diagram of FIG. 2, the air conditioner according to the present embodiment includes an operation setting device 14 including an operation mode changeover switch 16 (cooling, drying, blowing, or heating) desired by a resident, The apparatus includes a temperature detection device, a control device 20 that takes in signals from these devices and controls operation, and an indoor unit 1 and an outdoor unit 9 that are operated by an output from the control device 20.

  The control device 20 also has an operation mode storage device 21 for storing a signal from the operation setting device 14, an indoor suction temperature detection device 13, an indoor heat exchanger temperature detection device 12, an outdoor suction temperature detection device 7, and a compressor discharge temperature. A determination device 22 that receives the signal of the detection device 8 at every sampling time to determine the operation status, and determines the driving frequency of the compressor 2 and the rotational speed of the blower based on the signal, and the compressor 2, the indoor blower 10, and the outdoor blower The output relay circuit 23 and the like for driving 4 and the like are included.

  Here, when the resident selects heating with the operation mode changeover switch 16 and starts operation, the control device 20 uses the signal of the indoor suction temperature detection device 13 and the difference temperature signal of the indoor temperature setting device 17 to drive the compressor. And the compressor 2 is driven via the output relay circuit 23.

  Further, the drive frequency of the compressor 2 is uniquely determined by the signal of the indoor suction temperature detection device 13, the differential temperature signal of the indoor temperature setting device 17, and the value of the outdoor suction temperature detection device 7, as shown in (Equation 1) below. It comes to be decided.

That is, in the present embodiment (the same applies to other embodiments of the present invention), the compressor drive frequency is
Compressor drive frequency = basic frequency A [Hz] × load coefficient × outside temperature correction coefficient (Formula 1)
It shall be uniquely determined by The outside temperature correction coefficient for each outside temperature is
Table 1) shows. Here, in (Table 1), the outside air temperature is a temperature detected by the outdoor suction temperature detector 7.

  Further, the load coefficient is determined by the temperature difference between the set temperature set by the indoor set temperature setting device 17 and the detected value of the indoor suction temperature detecting device 13 as shown in Table 2 below.

  Next, the control method in this Embodiment is demonstrated based on the flowchart shown in FIG. First, when the air conditioner starts operation, in order to suppress oil discharge of the compressor 2, the compressor drive frequency is set to a certain value (here, for example, 30 Hz) for a certain time (for example, 3 minutes here) after the operation is started. (STEP 2 and 3). Thereafter, the compressor drive frequency of the compressor 2 is increased.

  Further, the compressor discharge temperature detecting device 8 detects the compressor discharge temperature Td, and the indoor heat exchanger temperature detecting device 12 detects the indoor heat exchanger temperature Tc (STEPs 4 and 5), and the difference between these temperatures SH = Td−. Tc is calculated (STEP 6).

At this time, when the temperature difference SH between the compressor discharge temperature Td and the indoor heat exchanger temperature Tc is less than a certain temperature (eg, 10 ° C. here) (YES in STEP 7), the state of the refrigerant sucked by the compressor 2 is wet. It is determined that the state (the liquid phase component is large), and the upper limit of the compressor driving frequency is limited to the value of the frequency setting device a24 (here, the upper limit frequency setting value is 100 Hz, for example) (STEP 8). That is, the maximum rotational speed (target rotational speed) of the compressor is set slightly lower. When the temperature difference SH becomes equal to or higher than the predetermined temperature (here, for example, 10 ° C.) (NO in STEP 7), it is determined that the state of the refrigerant sucked in the compressor 2 has changed to a dry state (there are many gas phase components) The value of the frequency setting device b25 (here, for example, the upper limit frequency setting value 120 Hz) is changed to a slightly higher value (
(STEP 9).

  As described above, the air conditioner according to the present embodiment determines the wet state of the compressor suction based on the difference between the detected temperature of the indoor heat exchanger temperature detecting device 12 and the detected temperature of the compressor discharge temperature detecting device 8. From this value, the rotational speed of the compressor motor is controlled. For example, when the temperature difference is small, it is determined that the suction of the compressor 2 is in a wet state. In this case, since the compressor load is high, the compressor maximum rotation speed (target rotation speed) is set slightly lower, and when the temperature difference increases, the compressor maximum rotation speed (target rotation speed) is set higher.

  And according to this structure, the stop of the apparatus by the remarkable increase in a compressor electric current or a step-out can be lose | eliminated, the maximum heating capability can be improved, and an air conditioning apparatus with high comfort and reliability can be supplied.

(Embodiment 2)
Since the refrigeration cycle diagram of the air conditioner in the present embodiment is the same as that of the first embodiment, the description thereof is omitted. Further, the present embodiment is different from the first embodiment in that a phase angle setting device c and a phase angle setting device d are provided. 4 is a control block diagram according to the present embodiment, FIG. 5 is a diagram showing the relationship between compressor frequency and phase angle setting, and FIG. 6 is a control flowchart. Hereinafter, the same parts as those of the first embodiment will be described using the same reference numerals, and the description of the same points will be omitted.

  As shown in FIG. 4, the control device 20 is provided with a phase angle setting device c26 and a phase angle setting device d27, which sets the phase angle of the compressor motor current and controls the phase of the current. Further, the drive frequency of the compressor 2 is uniquely determined by (Equation 1) as in the first embodiment.

  Further, the phase advance angle β of the compressor motor current is uniquely set by the compressor rotational speed as shown in FIG. That is, until the compressor frequency reaches 45 Hz (point A), the current phase advance angle β is changed as shown in FIG. 6 regardless of the set value by the phase angle setting device. When the compressor frequency exceeds 45 Hz (point A), the current phase advance angle β is increased as the compressor frequency increases. When the compressor frequency is 100 Hz or more, the maximum phase advance angle set by the phase angle setting device. Set to the set value. Therefore, the inclination from the point A changes depending on the set maximum phase advance angle.

  Next, control of the air conditioning apparatus of the present embodiment will be described using the flowchart of FIG.

  When the temperature difference SH between the detection value Td of the compressor discharge temperature detection device 8 and the detection value Tc of the indoor heat exchanger temperature detection device 12 is less than a certain temperature (here, for example, 10 ° C.) (YES in STEP 7), the compressor 2 is determined to be a heavy load (the liquid phase component is large) and the load is large, and the maximum phase angle β is limited to a value of the phase angle setting device c26 (here, for example, β1 = 45 deg) (STEP 11). ). At the same time, the upper limit of the compressor driving frequency is limited to the value of the frequency setting device a24 (here, for example, the compressor frequency max 100 Hz) (STEP 8).

  Further, when the temperature difference SH is equal to or higher than a certain temperature (for example, 10 ° C. here) (NO in STEP 7), it is determined that the state of the refrigerant sucked by the compressor has changed to a dry state (there are many gas phase components). That is, in this case, assuming that the load is small, the maximum phase angle is changed to the value of the phase angle setting device d27 (here, for example, β2 = 55 deg) (STEP 12), and the upper limit of the compressor driving frequency is set to the frequency setting device b25. The value is changed (here, for example, compressor frequency max120 Hz) (STEP 9).

In the above control, β1 <β2, and the upper limit value of the compressor frequency set simultaneously with β1 and β2 is smaller for β1 (100 Hz) than for β2 (120 Hz).

  As described above, the air conditioner according to the present embodiment changes the wet state of the compressor suction by the temperature difference between the detected temperature Tc of the indoor heat exchanger temperature detector 12 and the detected temperature Td of the compressor discharge temperature detector 8. The phase angle and the rotational speed of the compressor motor current are controlled based on this value.

  For example, when the differential temperature SH is small, the suction side of the compressor 2 is moist and the compressor load is large. Therefore, the phase angle β of the compressor motor current and the compressor drive frequency, that is, the maximum compressor speed (target speed) Is set slightly lower, and when the differential temperature SH increases, the phase angle β of the compressor motor current and the maximum compressor speed (target speed) are set high.

  When the compressor suction side is wet, a load is applied to the compressor and torque is required. Therefore, the torque can be increased by setting the maximum phase angle of the compressor motor to be low. Furthermore, when the compressor suction side changes to a dry state, the load on the compressor becomes weaker and the required torque decreases. In this case, by setting the maximum phase angle of the compressor motor current to be high, the number of revolutions is easily increased and the torque is decreased.

  In the present embodiment, by controlling as described above, there is no significant increase in compressor motor current or equipment stoppage due to step-out, so the maximum heating capacity is improved, and air with high comfort and reliability is achieved. A harmony device can be supplied, and the necessary torque can be effectively obtained by further setting the maximum value of the phase angle of the compressor motor current.

(Embodiment 3)
The air conditioner of the present embodiment is provided with an outdoor suction temperature detection device that detects the outdoor suction temperature, and only when the outdoor air temperature is low, the detection temperature of the indoor heat exchanger temperature detection device and the detection of the compressor discharge temperature detection device The wet state of the compressor suction is determined based on the temperature difference from the temperature, and thereby at least one of the rotational speed of the compressor motor and the phase current of the compressor motor is controlled.

  The refrigeration cycle diagram of the air conditioner according to the present embodiment is the same as FIG. 1 of the first embodiment, and the control block diagram is the same as that of FIG. 4 of the second embodiment. FIG. 5 is a diagram showing the relationship between the compressor frequency and the phase angle setting, and FIG. 7 is a control flowchart.

  A control flow of the air conditioner in the present embodiment will be described with reference to a control flowchart of FIG.

  The present embodiment is different from the second embodiment in that a condition based on the outdoor temperature is provided when setting the maximum phase angle and the compressor upper limit frequency.

  That is, when the outdoor air temperature (Tout) detected by the outdoor suction temperature detection device 7 is relatively high (YES in STEP 22) (here, 5 ° C. or more, for example), the heating load is relatively low. Therefore, the maximum phase angle is set to the value of the phase angle setting device c26 (here, for example, β1 = 45 deg) (STEP 23). Further, the upper limit of the compressor driving frequency is set to the value of the frequency setting device a24 (here, the upper limit frequency setting value is 100 Hz, for example) (STEP 24).

However, when the outdoor air temperature becomes low (NO in STEP 22) (here, less than 5 ° C., for example), a high heating capacity is required, the heating load increases, and the compressor rotation speed needs to be increased. Therefore, in such a case, the load weight is further determined by the temperature difference SH between the detection temperature Td detected by the compressor discharge temperature detection device 8 and the detection temperature Tc detected by the indoor heat exchanger temperature detection device 12, and the maximum phase angle β is determined. Set the compressor frequency (maximum compressor speed).

  As described above, in the present embodiment, only when the outdoor air temperature is low, the compressor is determined by the difference between the detected temperature Tc of the indoor heat exchanger temperature detector 12 and the detected temperature Td of the compressor discharge temperature detector 8. The wet state of the suction is predicted, and the current phase angle and the rotational speed of the compressor motor are controlled from this value.

  In other words, when the outdoor air temperature decreases, the heating load increases, and it is necessary to set the compressor frequency high. When the differential temperature is small, the compressor suction is wet and the compressor load is high. Set the motor current phase angle and compressor maximum speed (target speed) slightly lower, and increase the compressor motor current phase angle and compressor maximum speed (target speed) as the differential temperature increases. .

  By controlling with the light load as described above, there is no significant increase in compressor current or equipment outage due to out-of-step, improving the maximum heating capacity and supplying a comfortable and reliable air conditioner . Further, in the present embodiment, by further using the value of the outdoor air temperature Tout as the setting condition of the phase angle of the compressor motor current and the maximum compressor speed, it becomes possible to make a more accurate load determination, and comfort and reliability. Can be improved.

(Embodiment 4)
The air conditioning apparatus of the present embodiment is provided with a compressor discharge pressure detection device that detects the pressure of refrigerant discharged from the compressor, and a saturation temperature and a compressor discharge temperature converted from the detection pressure of the compressor discharge pressure detection device The rotational speed of the compressor motor is controlled by the temperature difference from the detected temperature of the detected temperature device.

  8 is a refrigeration cycle diagram of the air-conditioning apparatus according to Embodiment 4, FIG. 9 is a control block diagram, and FIG. 10 is a control flowchart.

  The same components as those in the above embodiment are denoted by the same reference numerals, and the description of the same portions is omitted.

  As shown in FIG. 8, the air conditioner of the present embodiment includes a compressor discharge pressure detection device 28, detects the pressure (Pd) on the discharge side of the compressor, and discharge temperature ( Td) is detected.

  Moreover, as shown in FIG. 9, the detection signal from the compressor discharge temperature detection apparatus 8, the discharge pressure detection apparatus 28, etc. is determined by the determination apparatus 21 provided in the control apparatus 20 of the air conditioner, and the determination result is as follows. Based on this, the frequency setting and the phase angle are set.

  Next, control of the air conditioner in the present embodiment will be described using the flowchart of FIG.

  When the outdoor air temperature (Tout) in STEP 22 of FIG. 10 is relatively high (in this case, for example, 5 ° C. or higher) (NO in STEP 22), since the heating load is relatively low, the compressor speed can be set low. The maximum phase angle is set to the value of the phase angle setting device c26, for example, β1 = 45 deg (STEP 23), and the upper limit of the compressor driving frequency is set to the value of the frequency setting device a24, for example, the upper limit frequency setting value 100 Hz (STEP 24). ). And if outdoor temperature becomes low (here, for example, less than 5 degreeC) (NO of STEP22), a high heating capability will be needed, heating load will go up, and it will be necessary to raise a compressor rotation speed.

  Therefore, in the present embodiment, the temperature difference SH (Td−Pd) between the saturation temperature (Pd conversion value) calculated from the values of the compressor discharge temperature detection device 8 (Td) and the compressor discharge pressure detection device 28 (Pd). (Converted values) (STEPs 4, 31, 32) are calculated, and the motor current phase and the maximum rotational speed of the compressor 2 are set based on the calculated values. That is, when the temperature difference SH is lower than a certain temperature (here, for example, 10 ° C.) (NO in STEP 7), it is determined that the state of the refrigerant sucked in the compressor 2 is a wet state (a lot of liquid phase components). The phase angle is limited to the value of the phase angle setting device c26 (here, for example, β1 = 45 deg) (STEP 11), and the upper limit of the compressor driving frequency is set to the value of the frequency setting device a24 (here, the upper limit frequency setting value is 100 Hz, for example). (STEP 8). When the temperature difference SH becomes equal to or higher than a certain temperature (here, for example, 10 ° C.) (YES in STEP 7), it is determined that the state of the refrigerant sucked in the compressor 2 has changed to a dry state (there are many gas phase components). The maximum phase angle is changed to the value of the phase angle setting device d27 (here, for example, β2 = 55 deg) (STEP 12), and the upper limit of the compressor driving frequency is changed to the value of the frequency setting device b25 (here, the upper limit frequency setting value is 120 Hz, for example). (STEP 9).

  As described above, the air conditioning apparatus according to the present embodiment is the difference between the saturation temperature (Pd conversion value) converted from the detection pressure of the compressor discharge pressure detection device 28 and the detection temperature Td of the compressor discharge temperature detection device 8. The wet state of the compressor suction is predicted based on the temperature, and the phase angle and the rotational speed of the compressor motor current are controlled from this value.

  According to this configuration, as in the third embodiment, when the compressor suction becomes wet and the compressor is loaded and torque is required, the maximum phase angle of the compressor motor current is reduced. In a situation where the compressor suction changes to a dry state and the compressor load is weakened and the required torque is reduced, the compressor motor current can be set to a higher value by setting the maximum phase angle of the compressor motor higher. The stoppage of equipment due to a significant increase in current and out-of-step can be eliminated, the maximum heating capacity can be improved, and an air conditioner with high comfort and reliability can be supplied. Furthermore, in the present embodiment, the load condition is determined by obtaining the differential temperature SH only when the outdoor air temperature is low, so that more accurate load determination is possible, and comfort and reliability can be improved.

(Embodiment 5)
The air conditioner of the present embodiment includes a compressor suction pressure detection device that detects the pressure of refrigerant sucked into the compressor, and a compressor suction temperature detection device that detects the temperature of refrigerant sucked into the compressor. The current phase angle and the rotational speed of the compressor motor are controlled by the temperature difference between the saturation temperature converted from the detected pressure of the compressor suction pressure detection device and the detected temperature of the compressor suction temperature detection temperature device. is there.

  FIG. 11 is a refrigeration cycle diagram of the air-conditioning apparatus according to Embodiment 5, FIG. 12 is a control block diagram, and FIG. 13 is a control flowchart.

  The same components as those in the above embodiment are denoted by the same reference numerals, and the description of the same portions is omitted.

  As shown in FIG. 11, the air conditioning apparatus of the present embodiment includes a compressor suction temperature detection device 29 and a suction pressure detection device 30, and detects the suction temperature (Ts) and the suction pressure (Ps) of the compressor 2, respectively. To do.

  Further, as shown in FIG. 12, the signals from the compressor suction temperature detection device 29 and the suction pressure detection device 20 are input and determined to a determination device 21 provided in the air conditioner 20, and based on the determination result. The frequency of the compressor 2 and the phase angle of the compressor motor current are set.

Next, control of the air conditioner in the present embodiment will be described with reference to the flowchart of FIG.

  In the control flowchart shown in FIG. 13, in STEP41 to STEP43, the temperature of the saturation temperature (Ps conversion value) calculated from the values of the compressor suction temperature detection device 29 (Ts) and the compressor suction pressure detection device 30 (Ps). The difference SH (Ts-Ps conversion value) is calculated. When the calculated value SH is lower than a certain temperature (here, for example, 10 ° C.) (YES in STEP 7), it is determined that the state of the refrigerant sucked by the compressor 2 is wet (the liquid phase component is large), and the maximum The phase angle is limited to the value of the phase angle setting device c26 (here, for example, β1 = 45 deg) (STEP 11), and the upper limit of the compressor driving frequency is limited to the value of the frequency setting device a24 (here, the upper limit frequency setting value is 100 Hz, for example). (STEP 8). When the temperature difference SH is equal to or higher than a certain temperature (here, for example, 10 ° C.) (STEP 7), it is determined that the state of the refrigerant sucked in the compressor 2 has changed to a dry state (a large amount of gas phase components). The phase angle is changed to the value of the phase angle setting device d27 (here, for example, β2 = 55 deg) (STEP 104), and the upper limit of the compressor driving frequency is changed to the value of the frequency setting device b25 (here, the upper limit frequency setting value is 120 Hz, for example). (STEP 9).

  As described above, in the present embodiment, the wet state of the compressor suction is determined based on the difference between the saturation temperature converted from the detected pressure of the compressor suction pressure detecting device and the detected temperature of the compressor suction temperature detecting device, The magnitude of the required torque is judged, and the phase angle of the compressor motor current and the compressor rotational speed are controlled.

  As a result, the apparatus can be prevented from being stopped due to a significant increase in current or out of step, the maximum heating capacity can be improved, and an air conditioner with high comfort and reliability can be supplied.

  The air conditioner of the present invention can control the current phase and rotation speed of the compressor motor by the load and improve the maximum heating capacity, so that it can be applied not only to room air conditioners but also to various refrigeration cycle devices such as large air conditioners. Applicable.

Refrigeration cycle diagram of the air-conditioning apparatus according to Embodiment 1 of the present invention Control block diagram of the air conditioner Control flow chart of the air conditioner Control block diagram of air-conditioning apparatus according to Embodiment 2 of the present invention Diagram showing the relationship between compressor frequency and compressor motor current phase angle setting Control flowchart of the air-conditioning apparatus according to Embodiment 2 of the present invention. Control flowchart of the air-conditioning apparatus according to Embodiment 3 of the present invention. Refrigeration cycle diagram of the air-conditioning apparatus according to Embodiment 4 of the present invention Control block diagram of the air conditioner Flow chart of the air conditioner Refrigeration cycle diagram of the air-conditioning apparatus according to Embodiment 5 of the present invention Control block diagram of the air conditioner Flow chart of the air conditioner

DESCRIPTION OF SYMBOLS 1 Outdoor unit 2 Compressor 3 Outdoor heat exchanger 4 Outdoor fan 5 Four-way valve 6 Throttle device 7 Outdoor suction temperature detection device 8 Compressor discharge temperature detection device 9 Indoor unit 10 Indoor blower 11 Indoor unit heat exchanger 12 Indoor heat exchanger Temperature detection device 13 Indoor suction temperature detection device 14 Operation setting device 20 Control device 28 Compressor discharge pressure detection device 29 Compressor suction temperature detection device 30 Compressor suction pressure detection device

Claims (5)

A compressor driven by a motor, an outdoor heat exchanger, an outdoor unit having an outdoor fan, an indoor heat exchanger, and an air conditioner connected to the indoor unit having an indoor fan, the indoor unit having an indoor heat exchange An indoor heat exchanger temperature detecting device for detecting the temperature of the compressor, and the outdoor unit further comprising a compressor discharge temperature detecting device for detecting the temperature of the refrigerant discharged from the compressor, and the indoor heat exchanger temperature detecting device When the difference temperature between the detected temperature of the compressor and the detected temperature of the compressor discharge temperature detecting device is small, the compressor maximum rotational speed is set low . If the difference between the detected temperature of the indoor heat exchanger temperature detector and the detected temperature of the compressor discharge temperature detector is small, set the maximum compressor speed lower and lower the current phase of the compressor motor. air conditioner according to claim 1, characterized in that the set. The air conditioner according to claim 1 or 2, wherein the compressor motor is controlled by a detected temperature of the outdoor suction temperature detecting device. A compressor discharge pressure detection device that detects the pressure of the refrigerant discharged from the compressor is provided, and a difference between a saturation temperature converted from a detection pressure of the compressor discharge pressure detection device and a detection temperature of the compressor discharge temperature detection device The air conditioner according to any one of claims 1 to 3, wherein the compressor motor is controlled by temperature. A compressor suction pressure detection device for detecting the pressure of the refrigerant sucked into the compressor and a compressor suction temperature detection device for detecting the temperature of the refrigerant sucked into the compressor are provided, and the detection of the compressor suction pressure detection device is provided. according to any one of claims 1 to 3, wherein the controller controls the compressor motor by the temperature difference between the detection temperature of the compressor suction temperature detection TomoSo location and the saturation temperature converted from the pressure Air conditioner.