JP2007255884A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of reducing power loss in an inverter 13, and of enhancing efficiency. <P>SOLUTION: This air conditioner is structured such that the number of revolutions of a compressor driving motor 14 is variably controlled by PAM (Pulse Amplitude Modulation) control; an indoor auxiliary heat exchanger 126 is arranged on the downstream side of an indoor heat exchanger 101 of a cooling medium passage in a heating operation to lower condensation pressure; the motor 14 is driven at an output voltage obtained by chopper-controlling a current in an on-period of a second switch element when the number of revolutions of the motor 14 is below a predetermined value; and, when the number of revolutions of the motor 14 exceeds the predetermined value, the output voltage is set at a value in response to the number of revolutions by controlling on/off power distribution of a first switch element 6, and the motor is driven at an output voltage obtained by setting the power distribution rate in the on-period of the second switch element to 100%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an air conditioner using a compressor that is driven by an inverter so that the number of revolutions can be varied. In particular, it reduces the time required to reach a set temperature after the start of heating operation, or is comfortable in a cold region. TECHNICAL FIELD The present invention relates to an electric motor driving device and an air conditioner combined with a refrigeration cycle that enable simple heating, and an electric motor driving device used for the air conditioner.

  Conventional air conditioners have been designed to improve performance in a low range of compressor speeds that do not require relatively large capacity in order to reduce annual power consumption. As a recent technique for improving the performance, there is a technique of variably controlling the rotation speed of the motor for driving the compressor by a PWM (Palse Width Modulation) control inverter. The rotational speed control in the PWM control is intended to increase the efficiency without increasing the driving torque so much.

  Further, there is an air conditioner that uses a compressor having a large refrigerant compression capacity corresponding to the operating load and that corresponds to a case where the outside air temperature is relatively low or a heating operation load is large.

  When the outdoor air temperature is low or the required heating capacity is large, the refrigerant discharge pressure of the compressor becomes high and the condensation pressure of the indoor heat exchanger also becomes high. In order to reduce the condensation pressure, the heat transfer area of the indoor heat exchanger is increased to facilitate the condensation of the refrigerant gas, thereby reducing the condensation pressure and reducing the driving torque of the electric motor to improve efficiency. It is possible to raise.

  As a conventional technique for controlling the rotation speed of an electric motor so as to increase the efficiency, for example, an electric motor driving device using a high power factor power converter that suppresses harmonics of an input current as a power source is disclosed in Japanese Patent Publication No. 7-89743. It is shown in the publication. FIG. 10 is a block diagram showing such a conventional motor drive device, in which 1 is an AC power source, 2 is a rectifier, 2a, 2b, 2c and 2d are diodes, 3 is a reactor, 4 is a diode, 5 is a capacitor, and 6 is Switch element, 7 is a voltage comparator, 8 is a multiplier, 9 is a load current detector, 10 is a current comparator, 11 is an oscillator, 12 is a drive circuit, 13 is an inverter, 14 is an electric motor, 15 is a microcomputer, and 16 is An inverter drive circuit 17 is a modulator.

  In the figure, a rectifier 2, a reactor 3, a diode 4, a capacitor 5, a switching element 6, a voltage comparator 7, a multiplier 8, a load current detector 9, a current comparator 10, an oscillator 11, a drive circuit 12, and a modulator 17 are shown. The part which comprises comprises a power converter, and the inverter 13 uses this power converter as a power supply.

  First, this power converter will be described.

  The AC power supply voltage from the AC power supply 1 is full-wave rectified by the rectifier 2 including the diodes 2a to 2d and converted into the rectified voltage Es. This rectified voltage Es is applied to the capacitor 5 via the reactor 3 and the diode 4 to obtain a smoothed DC voltage Ed. A switch element 6 is provided in parallel with the diode 4 and the capacitor 5.

  The DC voltage Ed smoothed by the capacitor 5 is divided by resistors R3 and R4 to form a DC voltage Ed ′. A deviation value between the DC voltage Ed ′ and the reference voltage Eo is obtained by the voltage comparator 7, and the voltage control signal Ve is obtained. Created.

  The rectified voltage Es obtained by full-wave rectifying the sinusoidal AC power supply voltage by the rectifier 2 is also divided by the resistors R1 and R2 to obtain a sine wave synchronization signal Es ′, and this sine wave synchronization signal Es ′. And the voltage control signal Ve from the voltage comparator 7 are calculated by a multiplier 8 to form a current reference signal Vi ′. This current reference signal Vi 'is compared with the current signal Vi obtained by the load current detector 9 by the current comparator 10 to obtain a modulation signal Vk. This modulation signal Vk is supplied to the modulator 17 to modulate the sawtooth wave or triangular wave carrier wave Vk ′ from the oscillator 11, and a switching drive signal Vg of PWM wave whose duty ratio changes according to this modulation signal Vk is created. Is done. With this switching drive signal Vg, the drive circuit 12 drives the switching element 6 on and off.

  As described above, in this conventional example, the switching element 6 is turned on / off while following the waveform of the sine wave-shaped rectified voltage Es, whereby the input AC current i is generated at a high power factor with high harmonics. A small sinusoidal current can be obtained, and the flow ratio of the switching element 6 is changed in accordance with the deviation value between the reference voltage Eo and the DC voltage Ed. A stable DC voltage Ed can be obtained. Therefore, it is described that the DC voltage Ed can be set to a desired voltage value by appropriately setting the reference voltage Eo and the resistance values of the resistors R3 and R4, and the input AC power can be converted into a DC output. Yes.

  Next, the motor drive circuit in FIG. 10 will be described.

  The DC power created by the power converter is converted back to AC power by the inverter 13 and supplied to the motor 14 to drive it. Also, a PWM signal calculated and output from the microcomputer 15 based on the speed command is supplied to the inverter 13 via the inverter drive circuit 16, whereby the inverter 13 is driven and its switching element (not shown) is driven. Turns on and off at a predetermined duty ratio.

  Next, a conventional air conditioner in which the heat transfer area of the indoor heat exchanger is increased has been proposed (see, for example, Non-Patent Document 1).

As described in Non-Patent Document 1, recently, an indoor heat exchanger is provided from the front side to the back side of the indoor unit, or as a subcooler on the downstream side of the indoor heat exchanger during heating operation. An air conditioner having an indoor auxiliary heat exchanger to be used has been developed.
"Energy-saving air conditioner GD series using a new dehumidification method": Toshiba Review, Vol.51, No.2, 1996, pages 67 to 70

  Each of the above prior arts has the following problems.

  1) When the above operation load is large, especially when the outdoor temperature is extremely low such as -10 ° C, -15 ° C, etc., such as in a cold region, and the room temperature is extremely low at the start of operation. When walls and furniture are cold, the rotational torque control that increases the efficiency without increasing the driving torque by the PWM control mentioned above, the driving torque is insufficient and the required high rotational speed is reached. It could not be rotated and could not reach the set room temperature or took a long time.

  2) When a compressor having a large refrigerant compression capacity corresponding to the operation load is used, the compressor is intermittently connected due to excessive operation capacity when the outside air temperature is relatively high and the heating operation load becomes small. When this intermittent operation is performed, the power consumption increases, and the room temperature rises and falls and the comfort is impaired.

  3) The home air conditioner is designed with an upper limit on the input current of the air conditioner in consideration of the average breaker capacity. For this reason, the driving torque cannot be increased too much.

  4) When the outdoor air temperature is low, the required heating capacity is large, so that the refrigerant discharge pressure of the compressor is high and the condensation pressure of the indoor heat exchanger is also high. If this condensing pressure is high, the amount of compression work of the compressor increases, leading to an increase in power consumption.

  5) In order to reduce the power consumption, it is necessary to reduce the condensation pressure. For this purpose, it is conceivable to increase the heat transfer area of the indoor heat exchanger so that the refrigerant gas is easily condensed. However, since air conditioners have established standard indoor unit dimensions that take into account installation characteristics and room size, the heat transfer area of the indoor heat exchanger that is directly related to the dimensions of the indoor unit. It was difficult to enlarge.

  As described above, in the case of an air conditioner having an indoor unit with a sufficiently large indoor heat exchanger or an indoor auxiliary heat exchanger, the piping configuration of the indoor heat exchanger and the air flow It is necessary to improve the heat transfer performance in the indoor heat exchanger as much as possible and keep the performance of the refrigeration cycle sufficiently high in each operation of cooling and heating by devising the relationship.

More specifically, in the above-described conventional motor driving apparatus, the DC voltage Ed can be obtained stably even if the input AC power supply voltage changes. However, the DC voltage Ed depends on the voltage value of the input AC power supply voltage. When it is desired to change the voltage Ed, it is necessary to correct the circuit constant. In particular, in the above conventional example, since it is a boosting type power converter, in order to perform stable control, the following formula: DC voltage Ed ≧ AC power supply voltage × 1.41 + 10 [V]
Thus, when the input AC power supply voltage is 100V, the DC voltage Ed is set to 150V or higher, and when the input AC power supply voltage is 200V, the DC voltage Ed is set to 300V or higher.

  Therefore, when the AC power supply 1 is a power converter that can be used at either 100 V or 200 V, the set value of the DC voltage Ed needs to be 300 V or more.

  For example, in the case of an input AC power supply voltage of 100 V, the DC voltage Ed is set to a constant voltage of about 300 V, and the arbitrary speed of 150 V or more is controlled rather than the inverter 13 being chopper-driven at an arbitrary power supply rate. Although it is conceivable that the loss is reduced when the voltage Ed is controlled without a chopper having a 100% conduction rate, the above-mentioned conventional example does not take that point into consideration, and thus there is a problem that the loss becomes larger than necessary. Arise.

  In the above conventional example, the sinusoidal rectified voltage Es obtained by full-wave rectifying the AC power supply voltage from the AC power supply 1 is divided by resistors R1 and R2 to form a sine wave synchronization signal Es ′. The voltage control signal Ve is calculated by the multiplier 8 to create a current reference signal Vi ′, and the input AC current is controlled in a sine wave shape with reference to the current reference signal Vi ′. In the case of 100V and 200V, since the rectified voltage Es is different, the shape and value of the sine wave are significantly different between the two. For this reason, when the AC power supply voltage is shared by 100 V and 200 V, the power converter has a low power factor and a high harmonic content.

  Moreover, in the electric motor drive device and air conditioner using the above power converter, when using 100V and 200V for an alternating current power supply voltage, it is necessary to make it the power converter of the specification corresponding to each. Therefore, the number of models increases, and problems such as a decrease in production efficiency occur.

  Further, when the input AC current is small and it is not necessary to perform the above-described control, on the contrary, it is not considered to eliminate the unstable operation, loss, noise, etc. of the control when the input current is low.

  For example, when a resistor is used as the load current detector 9 and the current signal Vi is obtained by the voltage generated at both ends, it is necessary to generate a sufficient voltage for control even for a minute current. Specifically, it is necessary to set a large resistance value for this resistor. In this case, when the load current increases, the power consumed by this resistor increases, leading to an increase in loss.

  Furthermore, in the inverter 13, the DC power supply voltage Ed is made constant, and the DC power supply voltage Ed is chopped at a current rate according to the duty ratio of the PWM signal from the microcomputer 15, so that a predetermined value corresponding to the duty ratio is obtained. The electric motor 14 rotates at the number of rotations. By changing this duty ratio, the rotational speed of the electric motor 14 changes, but in such a conventional electric motor driving device, the inverter 13 is always chopper-driven in this way, so that the power loss (chopper) due to this is reduced. Loss) and the efficiency was inevitably lowered.

  An object of the present invention is to provide an air conditioner that can reduce the power loss in the inverter and reduce the condensation pressure in the indoor heat exchanger and increase the efficiency among such problems, And it is providing the air conditioner provided with the electric motor drive device which reduces the power loss in an inverter.

  In order to achieve the above object, the compressor drive motor is variably controlled by PAM (Palse Amplitude Modulation) control, and indoor auxiliary heat exchange is performed downstream of the indoor heat exchanger in the refrigerant flow path during heating operation. It is conceivable to lower the condensation pressure by arranging a vessel.

  That is, the object is to compress a refrigerant, an indoor heat exchanger into which refrigerant from the compressor flows, and an indoor room disposed downstream of the indoor heat exchanger in the refrigerant flow path during heating operation. An auxiliary heat exchanger, an electric motor for driving the compressor, and an electric motor driving device that drives the electric motor by supplying an AC voltage, the electric motor driving device rectifying the input AC voltage; A power converter having a first switch element for controlling voltage by turning on and off the rectified output of the rectifier, and using the output voltage controlled as an input voltage. An inverter having a second switch element to be converted and driving the electric motor with this AC voltage; ON / OFF current control of the first switch element; ON / OFF control and ON period of the second switch element Current And a control means for controlling the chopper, which drives the motor with an output voltage obtained by chopper-controlling the current during the ON period of the second switch element when the rotation speed of the motor is less than a predetermined rotation speed. When the rotational speed of the motor exceeds a predetermined rotational speed, the on / off energization rate of the first switch element is controlled to obtain an output voltage corresponding to the rotational speed, and the on-period of the second switch element This is achieved by using an air conditioner that drives an electric motor with an output voltage with an energization rate of 100%.

  Another object of the present invention is to provide a power converter having a rectifier that rectifies an input AC voltage, a first switch element that controls voltage by turning on and off the rectified output of the rectifier, and the voltage-controlled output voltage. The inverter includes a second switch element that converts the input voltage into an alternating current by turning the input voltage on and off, and an inverter that drives the motor for driving the compressor with the alternating voltage, and the on-state of the first switch element. , And an air conditioner comprising control means for controlling off-energization rate and on-off control of the second switch element and control means for chopper-controlling the current during the on-period. If the rotation speed is less than the predetermined rotation speed, the motor is driven with an output voltage obtained by chopper-controlling the current during the ON period of the second switch element. An air conditioner that drives the motor with an output voltage that controls the ON / OFF energization rate of the switch element to obtain an output voltage corresponding to the number of rotations, and that the energization rate during the ON period of the second switch element is 100%. This is achieved.

  According to the air conditioner of the present invention, the condensing pressure is reduced by adopting a cycle configuration in which an indoor auxiliary heat exchanger is provided downstream of the heater during heating operation, and the chopper operation is performed at a predetermined low power supply voltage of the inverter. Thus, the rotation speed control of the motor is performed, and when the energization rate in the chopper operation in the inverter becomes 100%, the rotation speed of the motor is controlled by controlling the power supply voltage of the inverter. In cooling and heating operations, the heat transfer area can be made sufficiently large.In particular, in heating operations, the indoor auxiliary heat exchanger can be used effectively as a subcooler. Electricity can be planned.

  In addition, according to the present invention, for example, a 100% conduction rate with an arbitrary DC voltage of 150 V or more is achieved rather than performing chopper operation of the inverter with an arbitrary conduction rate with a constant DC voltage of about 300 V and controlling the rotational speed. Control without the chopper can reduce the loss, and is effective in increasing the efficiency.

  Furthermore, according to the present invention, the motor speed is controlled by the chopper operation at a predetermined low power supply voltage of the inverter, and when the energization rate in the chopper operation at the inverter becomes 100%, the power supply voltage of the inverter is reduced. Since the rotation speed of the electric motor is controlled by the control, the chopper loss of the inverter and the loss in the electric motor can be greatly reduced, and the efficiency can be greatly increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a first embodiment of an air conditioner according to the present invention, wherein 18 is a DC voltage changeover switch, 19 is a trigger element, 20 is a synchronization signal changeover switch, 21 is a voltage command changeover switch, 22 Is a drive signal changeover switch, 23 is an input current detector, 24 is an active converter block, and 25 is an LPF (low-pass filter). The parts corresponding to those in FIG.

In FIG. 1, a DC voltage Ed obtained by smoothing with a capacitor 5 is divided by a voltage dividing circuit including resistors R4, R5, and R6 to form DC voltages Ed1 and Ed2. here,
Ed1 = Ed × (R5 + R6) / (R4 + R5 + R6)
Ed2 = Ed × R6 / (R4 + R5 + R6)
And Ed1> Ed2.

  The DC voltage Ed1 is supplied to the contact B of the DC voltage changeover switch 18, and the DC voltage Ed2 is supplied to the contact A of the changeover switch. The DC voltage changeover switch 18 is controlled by the microcomputer 15 in accordance with the divided voltage Ed1 of the DC voltage Ed. From the DC voltage changeover switch 18, the DC voltage Ed1, Ed2 that is selected is the DC voltage. It is output as Ed1 ′.

  The output DC voltage Ed1 'of the DC voltage changeover switch 18 is supplied to the contact B of the voltage command changeover switch 21. Further, the contact A of the voltage command changeover switch 21 is supplied with a DC voltage Ed2 'formed by smoothing the PWM signal output from the microcomputer 15 for speed control of the motor 14 by the LPF 25. The voltage command changeover switch 21 is also controlled by the microcomputer 15 so that the contact B side is applied when the energization rate is less than 100%, and the contact A side is set when the motor load is large and the energization rate is 100%. Selected.

  One of the DC voltages Ed1 ′ and Ed2 ′ selected by the voltage command changeover switch 21 is supplied to the voltage comparator 7 as the DC voltage Ed ′, a deviation value from the reference voltage Eo is obtained, and the voltage control signal Ve is obtained. It is formed.

  In the conventional example shown in FIG. 10, the voltage control signal Ve is obtained by comparing one type of DC voltage Ed ′ obtained by dividing the DC voltage Ed smoothed by the capacitor 5 with the reference voltage Eo. However, in the first embodiment, one of the two types of DC voltages Ed1, Ed2 obtained by dividing the DC voltage Ed and the DC voltage Ed2 ′ obtained from the LPF 25 is set as the DC voltage Ed ′. It is obtained by comparing this with the reference voltage Eo.

On the other hand, the rectified voltage Es having a sine wave full-wave rectified waveform output from the rectifier 2 is divided by a voltage dividing circuit including resistors R1, R2, and R3 to form voltages Es1 and Es2. here,
Es1 = Es × (R2 + R3) / (R1 + R2 + R3)
Es2 = Ed × R3 / (R1 + R2 + R3)
And Es1> Es2.

  The voltage Es1 is supplied to the contact B of the synchronization signal changeover switch 20, and the voltage Es2 is supplied to the contact A of the synchronization signal changeover switch 20, respectively. The synchronization signal changeover switch 20 is also controlled by the microcomputer 15 in accordance with the divided voltage Ed1 of the DC voltage Ed smoothed by the capacitor 5 in the same manner as the DC voltage changeover switch 18, and is output from the synchronization signal changeover switch 20. The voltage Es1 or Es2 is supplied to the multiplier 8 as a sine wave synchronization signal Es ′.

  From the multiplier 8, a current reference signal Vi 'is obtained, and on / off control of the switch element 6 is performed in the same manner as in the conventional example shown in FIG.

  As described above, also in the first embodiment, the switch element 6 is turned on / off while following the waveform of the rectified voltage Es of the sine wave full-wave rectified waveform. Therefore, a sinusoidal input AC current with less harmonics can be obtained, and the duty ratio of the switch element 6 is changed according to the deviation value between the reference voltage Eo and the DC voltage Ed ′. Regardless of the fluctuation, a stable DC voltage Ed can be obtained. Therefore, the DC voltage Ed can be set to a desired voltage value by appropriately setting the reference voltage Eo and the resistance values of the resistors R4, R5, and R6.

  Here, the microcomputer 15 also detects the input alternating current Is by the input current detector 23, and the period “L” (low level) until the current value of the input alternating current Is exceeds a predetermined value. The trigger signal VT is supplied to the trigger element 19. The trigger element 19 controls the drive circuit 12 during the “L” period of the trigger signal VT to turn off the switch element 6. When the trigger signal VT changes from “L” to “H” (high level), the trigger element 19 brings the switch element 6 into an operating state at this time.

  The PWM signal output from the microcomputer 15 is supplied to the inverter drive circuit 16 via the drive signal switching switch 22 that is normally closed to the setting A side. The inverter drive circuit 16 sets the duty ratio of the PWM signal. A switching element (not shown) of the inverter 13 is turned on / off at a corresponding energization rate. As a result, in the inverter 13, the DC power of the DC voltage Ed supplied from the capacitor 5 is chopped at this energization rate and converted into AC power, which is supplied to the motor 14 at a rotation speed corresponding to the duty ratio of the PWM signal. Rotate.

  Next, the control operation method of the first embodiment will be described with reference to FIG. In the case of domestic use, there are two types of AC power supply voltage, 100V and 200V.

First, when the power is turned on (step 100), the microcomputer 15 is set to an initial state, whereby the microcomputer 15 brings the DC voltage switch 18, the synchronization signal switch 20 and the voltage command switch 21 to the contact B side. The drive signal selector switch 22 is closed to the contact A side. As a result, the DC voltage changeover switch 18 selects the DC voltage Ed1, and the voltage comparator 7 has the following DC voltage Ed ′,
Ed ′ = Ed × (R5 + R6) / (R4 + R5 + R6)
Is supplied. In addition, the synchronization signal changeover switch 20 selects the sine wave synchronization signal Es1.

In this state, the charging operation is started with the capacitor 5, and the microcomputer 15 detects the divided voltage Ed1 of the DC voltage Ed of the capacitor 5 (step 101). From the voltage value of the detected DC voltage Ed1,
Ed = Ed1 × (R4 + R5 + R6) / (R5 + R6)
Thus, if the DC voltage Ed is higher than 160V, for example (step 102), it is determined that the input AC power supply voltage is 200V, and the DC voltage changeover switch 18 is switched to the contact A (step 103). As a result, the DC voltage Ed ′ becomes the DC voltage Ed2, and the DC voltage Ed obtained at the capacitor 5 is
Ed = Ed2 × {1+ (R5 + R4) / R6}
It becomes.

Further, the synchronization signal changeover switch 20 is switched to the contact A (step 104). Therefore, the sinusoidal synchronization signal Es ′ at this time is
Es ′ = Es × R3 / (R1 + R2 + R3)
It becomes.

On the other hand, if the DC voltage Ed is lower than 120V, for example (step 102), it is determined that the input AC power supply voltage is 100V, and the DC voltage changeover switch 18 is kept closed on the contact B side (step 110). ). Therefore, the DC voltage Ed of the capacitor 5 is
Ed = Ed1 × {1 + R4 / (R5 + R6)}
It becomes.

Further, the synchronization signal changeover switch 20 is kept closed at the contact B (step 111). Therefore, the sinusoidal synchronization signal Es ′ at this time is
Es ′ = Es × (R2 + R3) / (R1 + R2 + R3)
It becomes.

  In this way, when the input AC power supply voltage is 200 V, the DC voltage changeover switch 18 and the synchronization signal changeover switch 20 are controlled to switch according to the magnitude of the input AC power supply voltage. Es ′ is set to the lower DC voltages Ed2 and Es2, respectively, and when the input AC power supply voltage is 100V, the DC voltage Ed ′ and the sine wave synchronization signal Es ′ are set to the higher DC voltages Ed1 and Es1, respectively.

  As a result, the difference in the DC voltage Ed ′ between when the input AC power supply voltage is 100V and when it is 200V can be suppressed, and the control error due to the amplitude of the voltage control signal Ve becoming too large and being saturated. It is possible to prevent problems such as stability, the current reference signal Vi ′ calculated from the sine wave synchronization signal Es ′ and the voltage control signal Ve being disturbed, and the current waveform not being a sine wave.

  In this embodiment, there are two types of input AC power supply voltages of 100 V and 200 V, but in general, there are n types of input AC power supply voltages of V1, V2,..., Vn, and DC voltages Ed ′, Es. ′ Is also determined as n types, and it is determined whether the input AC power supply voltage is V1, V2,..., Vn, and the DC voltage Ed ′, corresponding to this input AC power supply voltage is determined according to the determination result. By setting Es ′, a similar effect can be obtained.

If it is determined in step 102 that the input AC power supply voltage is 200 V, the voltage command changeover switch 21 is kept closed on the contact B side (step 105). At this time, approximately E0 = Ed ′, and therefore the DC voltage Ed is
Ed = E0 × {1+ (R5 + R4) / R6}
It becomes. In this case, for example, Ed = 300V.

  At this time, the drive signal switching switch 22 is kept closed on the contact A side (step 105), and the PWM signal output from the microcomputer 15 is sent to the inverter drive circuit 16 via the drive signal switching switch 22. Supplied.

  With the above operation, the DC power Ed created by the power converter is reversely converted to AC by the inverter 13, thereby driving the motor 14 (step 106). Similarly to the conventional example shown in FIG. 10, the microcomputer 15 generates and outputs the PWM signal by calculation based on the speed command, whereby the inverter 13 is driven via the inverter drive circuit 16, and this inverter The number of switch elements 13 is turned on and off at a predetermined conduction rate corresponding to the duty ratio of the PWM signal to control the rotational speed of the motor 14.

  Generally, when the AC power supply voltage is Vj (j = 1, 2,..., Vn) of V1, V2,..., Vn, the DC voltage Ed corresponding to this input AC power supply voltage Vj. Is compared with a constant reference voltage Eo, the DC voltage Ed obtained by rectifying and smoothing the input AC power supply voltage Vj is set to an arbitrary constant value (for example, 300 V), and the switch element of the inverter 13 is arbitrarily set Turn on and off at a current rate of.

  In the booster circuit, when the DC voltage Ed is lowered below the full-wave rectified voltage Es of the input AC power supply voltage, the power factor is reduced and the input current waveform is disturbed. In order to avoid this problem, when it is determined that the voltage is 200V, the control is performed with Ed = 300V constant. Of course, the condition is that Ed = 300V and the motor 14 can obtain a desired rotational speed sufficiently, and even if the voltage is increased to 300V or higher, the gist of the present invention is not impaired.

  The microcomputer 15 detects the input alternating current Is with the input current detector 23 (step 107), outputs a trigger signal VT during the period “H” during which the input alternating current Is is large to the trigger element 19, and this period switch element 6 Is turned on and off (step 108), and the operation is continued (step 109).

Even when it is determined in step 102 that the input AC power supply voltage is 100 V, the voltage command changeover switch 21 remains closed on the contact B side (step 112). Therefore, in the same manner as described above, E0 = Ed ′, and the DC voltage Ed is
Ed = E0 × {1 + R4 / (R5 + R6)}
In this case, for example, Ed = 150V. Thus, the DC voltage Ed at the capacitor 5 can be set to a voltage value different from that when the input AC power supply voltage is 200 V while sharing the reference voltage E0.

  At this time, if the energization rate of the inverter 13 is less than 100% (step 116), the motor 14 is driven (steps 112 and 113) in the same manner as steps 105 and 106, and steps 107 and 108 are also performed. In the same manner as described above, the switch element 6 is turned on and off (steps 114 and 115), and the operation is continued as it is (step 118).

  However, when the input AC power supply voltage is operating at 100 V, for example, when the motor load increases and the energization rate of the switch element in the inverter 13 becomes 100% (step 116), the voltage command changeover switch 21 is connected to the contact A. Further, the drive signal switching switch 22 is switched to the contact B side (step 117).

  As a result, the DC voltage Ed2 ′ obtained by smoothing the switch element drive signal (PWM signal) from the microcomputer 15 calculated based on the speed command by the LPF 25 is output from the voltage command changeover switch 21 as the DC voltage Ed ′. A voltage control signal Ve formed from the DC voltage Ed ′ is supplied to the voltage comparator 7. In response to this, on / off control of the switch element 6 is performed so that the DC voltage Ed at the capacitor 5 becomes, for example, an arbitrary voltage of 150 V or more. At the same time, the drive signal switching switch 22 is switched to the contact B side, so that the voltage Ei for driving the inverter 13 at an energization rate of 100% is supplied to the inverter drive circuit 16 via the drive signal switching switch 22. Supplied.

  Here, the above-described operation of this embodiment in the case where the input AC power supply voltage is 100 V will be described in more detail with reference to FIG. 3, taking the case of the heating operation of the air conditioner as an example. 3 is the same as FIG. 1 except that a room temperature sensor 29 is additionally shown.

  In the figure, the air conditioner is provided with a room temperature sensor 29, and the microcomputer 15 detects the indoor temperature by the room temperature sensor 29 (this detected temperature is hereinafter referred to as measured room temperature). Is compared with the desired room temperature (set room temperature) set by the user, and when the measured room temperature is low and does not reach the set room temperature, the duty ratio of the PWM signal is increased according to these differences, and the switching element in the inverter 13 To increase the rotation speed of the electric motor 14.

  At this time, the DC voltage Ed of the capacitor 5, that is, the DC power supply voltage of the inverter 13 is fixed to 150 V, and the switching element of the inverter 13 is operating as a chopper, but the duty ratio of the PWM signal is 100%. However, if the measured room temperature does not reach the set room temperature, the microcomputer 15 switches the drive signal changeover switch 22 to the contact B side and supplies the constant voltage Ei to the inverter drive circuit 16 as described in step 117 above. By doing so, the current ratio of the switch element of the inverter 13 is maintained at 100%, and at the same time, the voltage Ed2 obtained by smoothing the PWM signal with the LPF 25 by switching the voltage command changeover switch 21 to the contact A side. 'Is supplied to the voltage comparator 7 as the voltage Ed'. Then, the duty ratio of the PWM signal is made smaller than 100% so that the voltage Ed ′ is successively smaller than the reference voltage Eo.

  As a result, the energization rate of the switch element 6 becomes larger than the energization rate when the DC voltage Ed of the capacitor 5 is 150V, and as a result, the DC voltage Ed of the capacitor 5 increases sequentially from 150V. The rotation speed of the electric motor 14 increases. Along with this, the room temperature further increases, and the measured room temperature reaches the set room temperature.

  As described above, when the input AC power supply voltage is 100 V, the drive control signals for the switch element 6 and the inverter 13 can be output from the microcomputer 15 through a single port by switching each switch. When the energization rate of the switch element 13 is 100%, a command voltage Ed2 ′ (PWM signal) for changing the DC voltage Ed as the power supply voltage of the inverter 13 is output. A control voltage (PWM signal) for driving 13 is output. In each of these cases, the signal input to the drive circuit 16 of the inverter 13 is either a predetermined constant voltage for driving the switch element of the inverter 13 at an energization rate of 100% or an inverter from a single port of the microcomputer 15. By providing means (drive signal changeover switch 22) for switching and outputting a drive signal (PWM signal), the above control can be performed even if a relatively low-function and inexpensive microcomputer is used as the microcomputer 15. Inexpensive products can be supplied.

  When the energization rate reaches 100%, the rotational speed of the motor 14 is controlled by controlling the DC voltage Ed obtained by the capacitor 5.

  Therefore, when the ON / OFF energization ratio of the switching element of the inverter 13 is less than 100%, the DC voltage Ed1 ′ is set to a relatively low arbitrary constant value of about 150 V while comparing with the constant reference voltage Eo. Above, the switching element of the inverter 13 is turned on and off at an arbitrary energization rate to control the rotational speed of the motor 14, so that the loss in the inverter 13 or the motor 14 is reduced and its efficiency is improved. Can do.

  Further, when the energization rate of the switching element of the inverter 13 is 100%, an arbitrary command voltage Ed2 ′ is switched to be supplied to the voltage comparator 7 instead of the DC voltage Ed1 ′ and compared with the reference voltage Eo. The command voltage Ed2 ′ is changed in accordance with the desired rotational speed of 14, and thus the chopper is not performed by the inverter 13, and the DC voltage value Ed is controlled in magnitude, thereby controlling the rotational speed of the motor 14 to be high or low. Thus, the chopper loss in the inverter 13 can be reduced.

  With such rotation control, switching loss can be reduced in the inverter 13 and efficiency can be improved by driving the inverter of the motor 14 at a low DC voltage, and high efficiency can be achieved.

  FIG. 4 is a diagram comparing the relationship between the motor speed and efficiency of this embodiment and a conventional air conditioner at a certain motor load, and A is when the input AC power supply voltage is 100V. The characteristic of this embodiment which performs the above-mentioned operation is shown, and B is a conventional air conditioner in which the DC power supply voltage of the inverter is kept constant, or B of this embodiment which performs the above operation when the input AC voltage is 200V Each characteristic is shown.

  In the figure, in an air conditioner (hereinafter referred to as a known air conditioner) in which the DC power supply voltage of the inverter is kept constant, for example, 300 V, and the number of revolutions of the motor is controlled by controlling the conduction rate of the chopper of the inverter. The efficiency changes as shown in the characteristic B with respect to the rotation speed n (rpm) of the electric motor. The increase in efficiency with the increase in the number of revolutions n is due to the increase in the power supply rate of the inverter chopper.

  On the other hand, if the input AC power supply voltage is 100 V and the current ratio of the chopper of the inverter is less than 100% as described above, the DC power supply voltage of the inverter is kept constant at 150 V, and the control of the current ratio of the chopper is controlled by the inverter. When the rotational speed control of the motor is performed and this energization rate reaches 100%, an embodiment for controlling the rotational speed of the motor by controlling the DC power supply voltage of the inverter (hereinafter referred to as an embodiment of the input 100V) With respect to the rotation speed n, the efficiency changes as shown by the characteristic A, which is considerably higher than the efficiency B of the conventional air conditioner.

Here, the region N ₁ is an inverter in the embodiment with an input of 100 V and the current ratio of the chopper is less than 100%, and the region N ₂ is an inverter in the embodiment of the input with 100 V and the current ratio of the chopper is 100%. The maximum number of rotations that the motor can take is 4000 at the boundary between the regions N ₁ and N ₂ , that is, when the inverter is chopper-driven when the DC power supply voltage is 150 V. (Rpm). In any case, when the DC power supply voltage of the inverter is 300 V and the energization of the switch element of the inverter is 100%, the rotation speed of the motor is 9000 (rpm).

In a known air conditioner, the DC power supply voltage of the inverter is set to 300 V in the entire region including the regions N ₁ and N _2, and the rotational speed of the motor is controlled by controlling the energization rate of the switching elements of the inverter. On the other hand, in the embodiment of the input 100 V, in the region N ₁ , the DC power supply voltage of the inverter is set to 150 V, which is half of 300 V, and the rotation speed control of the motor is performed by controlling the energization rate of the switch elements of the inverter. Therefore, the efficiency of the input 100V embodiment is increased by the lower DC power supply voltage of the inverter.

In the region N ₂ , in the embodiment of the input 100 V, the energization rate of the switching element of the inverter is set to 100%, and the chopper is not performed by the inverter. By controlling the DC power supply voltage of the inverter, the rotational speed control of the motor is performed. Is done. For this reason, although the efficiency is substantially constant, as shown as the characteristic A, the efficiency is higher than that of the known air conditioner because the chopper is not performed by the inverter.

  When the rotational speed of the electric motor is approximately 9000 (rpm), in the embodiment of the input 100V, the current supply rate of the inverter becomes 100% and the DC power supply voltage becomes 300V, and the current supply rate of the inverter in a known air conditioner Therefore, the characteristics A and B coincide with each other.

  In the first embodiment shown in FIG. 1, the power converter is controlled according to the above procedure. For the sine wave synchronization signal Es ′, the resistance values of the resistors R1, R2, and R3 are set to the DC voltage Ed ′. With respect to, by appropriately setting the resistance values of the resistors R4, R5, and R6, an arbitrary DC voltage Ed can be obtained regardless of whether the input AC power supply voltage is 100V or 200V, respectively. It becomes a high power factor power converter with few harmonics.

  At this time, the detected output voltage of the input current detector 23 is supplied to the microcomputer 15, and when this exceeds a predetermined value, the drive trigger signal VT of the switch element 6 (first switch element) is output from the microcomputer 15. Output and start the switching operation. Therefore, when the supply current is large, a stable high power factor can be obtained.

  For example, when a resistor is used as the load current detector 9 and the current signal Vi is obtained by the voltage generated at both ends, it is necessary to generate a sufficient voltage for control even for a minute current. Specifically, it is necessary to set a large resistance value. In this case, when the load current increases, the power consumed by the load current detector 9 composed of this resistor increases, leading to an increase in loss. Therefore, in order to reduce this loss, the resistance value of the input current detector 23 is reduced in order to make the resistance value as small as possible and prevent an unstable operation with respect to a minute detection voltage at a low load current. When the detected output value is smaller than the predetermined value, the driving of the switch element 6 is prohibited. In this way, unstable operation at low input current is avoided, and loss at high input is reduced. In addition, since the chopper operation of the switch element 6 is not performed at the time of a low input current, it is possible to reduce the loss and reduce the noise.

  In FIG. 1, the active converter block 24 is formed by blocking an active converter drive unit, a circuit switching unit using 100 V / 200 V, a switching unit between an inverter drive signal and a DC voltage command signal, and the like on a single substrate. is there.

  By making this active converter block 24 a substrate configuration independent of other circuits, as shown in FIG. 5, the power factor correction circuit Q composed entirely of passive elements such as a capacitor 26, a reactor 27, a diode 28, etc. The peripheral circuit board including the microcomputer 15 can be shared.

  FIG. 6 shows an air conditioner using a circuit composed of passive elements as shown in FIG. 5 and an active element, and controls the rotational speed of the motor in accordance with the DC power supply voltage of the inverter. FIG. 2 is a diagram showing a comparison of the output range of the motor with the first embodiment shown in FIG. 2, wherein the horizontal axis represents the motor rotation speed N and the vertical axis represents the load torque T, respectively. W is represented by N × T.

  In the figure, the input current is limited by the capacity of the home breaker (for example, 20 A), and the air conditioner using the circuit shown in FIG. 5 has a power factor of about 90%, so it is lower than the Y line. The input restriction range (that is, the range that can be taken by the output of the electric motor) is restricted to this area. On the other hand, in the first embodiment, as described above, since the power factor is improved to almost 100%, the area below the X-ray is the input restriction range, which is shown in FIG. Compared to an air conditioner that uses a circuit, the effective power applied to the motor is increased by approximately 10%. And especially when the load torque of an electric motor is large, it is restrict | limited by this input restriction | limiting range.

  Further, when the rotation speed of the motor increases, the maximum output range of the motor is limited by the DC power supply voltage Ed of the inverter. In the air conditioner using the circuit shown in FIG. 5, the DC power supply voltage Ed is, for example, approximately 230 V to approximately 280 V at the maximum, and the limit range when Ed = 230 V is indicated by the Y ′ line. Only the range on the left side of the Y 'line can take the output of the motor. On the other hand, in the first embodiment, the DC power supply voltage Ed is 300 V in the above example and is variable from 150 V to 300 V, and the limit range at the maximum 300 V is the X ′ line. Is shown. From this, the output range of the electric motor is expanded.

  FIG. 7 is a block diagram showing a second embodiment of an air conditioner according to the present invention, in which 30 is an AC power supply voltage detector, and parts corresponding to those in FIG. Omitted.

  In the figure, the difference from the first embodiment shown in FIG. 1 is that an AC power supply voltage detector 30 is provided. The AC power supply voltage detector 30 receives the input AC power supply voltage from the AC power supply 1. The microcomputer 15 determines the input AC power supply voltage based on the detected output signal Vs ′. Then, according to the determination result, the DC voltage changeover switch 18 and the synchronization signal changeover switch 20 are controlled to be switched as in the first embodiment.

  In the first and second embodiments, the determination of the input AC power supply voltage and the output of the control signal are performed by the software of the microcomputer 15, but a hardware circuit may be used to obtain the same effect. It is clear that

  FIG. 8 is a block diagram showing a third embodiment of an air conditioner according to the present invention, in which 31 is an AC / DC changeover switch, 32 is a DC power supply, and parts corresponding to those in FIG. A duplicate description is omitted.

  In this figure, in the third embodiment, instead of the rectifier 2, a DC power supply 32 (for example, about 150 V) such as a solar power supply is also provided, and a DC power supply voltage EA from now on and a rectified voltage Es from the rectifier 2 are provided. Any one of them can be selected by the AC / DC switching switch 31, and can function as a DC voltage booster circuit.

  When the DC power supply 32 is selected, the same operation as that performed when the microcomputer 15 determines that the DC voltage of the capacitor 5 is 160 V or less in FIG. 2 (step 102) is performed. Therefore, in the third embodiment, the electric motor 14 can be driven by the low-voltage DC power supply 32.

  When a DC power source such as a solar cell is connected to the power source side of the reactor 3, even if there is a fluctuation in the DC power source voltage, it can be stabilized to a desired DC voltage Ed. Thereby, it becomes possible to connect regardless of power supply voltage fluctuations of a solar battery or the like and the type of DC power supply (solar battery, storage battery, fuel cell, etc.). The same effect can be obtained even when a DC power source such as a solar cell is connected between the collector and emitter of the switch element 6 via a diode and a reactor.

  When the output DC voltage EA of the DC power supply 32 is higher than the DC voltage Ed obtained by full-wave rectification of the input AC power supply voltage from the AC power supply 1, the AC / DC changeover switch 31 is switched and the motor is driven by the DC power supply 32. The control may be performed, or the circuit may be switched in advance by a manual operation.

  When a DC power source such as a solar cell is connected to the smoothing capacitor 5 via a diode (not shown), when the output voltage of the DC power source reaches the desired DC voltage, the DC power source When electric power is supplied and the desired DC voltage is not reached, the electric power is supplied from the AC power source to boost the voltage to the desired DC voltage, thereby turning on and off the switching element of the inverter 13 to turn the electric motor 14 By controlling the number of rotations, it is possible to use a commercial AC power source and the DC power source in combination, thereby saving power.

  FIG. 9 is a block diagram showing a fourth embodiment of an air conditioner according to the present invention, in which parts corresponding to those in FIG.

  In this figure, the microcomputer 15 also has functions of a DC voltage changeover switch 18, a voltage command changeover switch 21 and a drive signal changeover switch 22, and is different from the first embodiment shown in FIG. The output port to the circuit 16 and the output port to the voltage comparator 7 are provided independently.

  Similarly to the first embodiment, the microcomputer 15 outputs a signal for switching the synchronization signal changeover switch 20 in accordance with the input power supply voltage, and also converts the divided DC voltage Ed1 of the DC voltage Ed within the microcomputer 15 to A / D. Convert and read. Then, a DC voltage Ed ′ corresponding to the input AC power supply voltage of 100 V or the input AC power supply voltage of 200 V is obtained according to the value of the divided DC voltage Ed1, and the DC voltage obtained by integration is the DC voltage Ed. A PWM signal having a duty ratio such that becomes' is formed and output. This PWM signal is smoothed by the low-pass filter 25 to become a DC voltage Ed ′, which is supplied to the voltage comparator 7.

  The operation by such software switches and controls the DC voltage changeover switch 18, the voltage command changeover switch 21, and the drive signal changeover switch 22 according to the DC voltage Ed in the smoothing capacitor 5 in the first embodiment. This corresponds to an operation by hardware in which one of the divided voltages Ed1 and Ed2 is selected. Compared to the operation by hardware, the configuration is simplified and the same control operation can be performed. .

  The signal supplied from the microcomputer 15 to the inverter drive unit 16 is a constant voltage Ei of a predetermined value when the energization rate of the switch element (second switch element) of the inverter 13 is 100%. Is less than 100%, a control voltage (PWM signal) for driving the inverter 13 is used.

  The DC voltage Ed 'supplied to the voltage comparator 7 is also the command voltage Ed2' (PWM signal) for changing the DC voltage Ed when the above-described energization rate is 100%. The PWM signal is smoothed by the low-pass filter 25 to obtain a DC voltage Ed ′, which is supplied to the voltage comparator 7.

  On the other hand, when the above-described energization rate is less than 100%, the microcomputer 15 obtains a predetermined low DC voltage Ed ′ from the divided DC voltage Ed2 (or DC voltage Ed), integrates the low DC voltage Ed ′. A PWM signal with a duty ratio of This PWM signal is smoothed by the low-pass filter 25 to become a DC voltage Ed ′, which is supplied to the voltage comparator 7.

  Therefore, peripheral circuits such as switches for voltage switching can have the same function in the microcomputer 15, so that the number of parts can be greatly reduced, especially when multi-stage switching is required. In addition, since the wiring to each switch is reduced, the reliability is improved and the noise resistance is improved.

  7 to 9, the operation described with reference to FIGS. 2 and 3 is performed similarly to the embodiment illustrated in FIG. 1, and the effects described with reference to FIGS. 4 and 6 can be obtained. Needless to say.

  As described above, when the motor load is large, for example, under conditions where the outdoor temperature is low such as −10 ° C. and −15 ° C., the compressor drive is performed by the above-described PAM control in order to increase the heating capacity. The electric motor was variably controlled and continuously operated at a necessary high rotational speed (9000 rpm, the maximum rotational speed set in the example). With the PAM control described above, the variable speed control of the compressor driving motor can be controlled in accordance with the change in the heating load as shown in FIG.

  On the other hand, as shown in FIG. 11, the heating capacity of various compressors is sufficiently driven to the required number of revolutions when the motor is driven by PWM control because the driving torque is insufficient when the outdoor temperature is low. I can't. In addition, when a large capacity compressor is used, it can be rotated to the required number of rotations even when the outdoor air temperature is low, but in the case of a low load condition such as when the outdoor air temperature is high, the heating capacity However, the intermittent operation is frequently repeated, and the vertical fluctuation of the room temperature frequently occurs, thereby deteriorating the comfort and increasing the power consumption. Although the above was demonstrated with heating, the same tendency is shown, although there is a difference in the degree even during cooling.

  Further, by adopting a circuit configuration in which both PWM control and PAM control can be used in combination with the inverter, power-saving operation at low load and high-capacity operation at high load can be performed. In other words, when the outdoor temperature is high and the load is low, the compressor driving motor can be operated with a low driving voltage and low rotation speed under PWM control and high motor efficiency, and operation with low power consumption can be performed. When the outdoor air temperature is low, switching to PAM control is performed to increase the driving voltage, and the compressor driving motor can be operated at a high rotational speed, so that it can be operated with the required heating capacity.

  FIG. 12 shows AC power supply input waveforms before and after operation as an active converter. Compared with the operation before (a), the waveform after the operation (b) follows the sine wave of the input voltage and shapes the current waveform. Therefore, the power factor is approximately 100%, and before the operation, it is 70% or less. is there. (C) is a power factor improvement of an analog system, which is about 90% power factor.

  FIG. 13 shows reactor 3 current and inverter current (capacitor 5 → inverter 13 flow) before and after PWM / PAM switching. (A) is a case of a relatively low rotational speed and a low load, and is a reactor current before switching. ON indicates the ON time of the switch element, and the chopper period is the active converter chopper period.

  (B) is the inverter current before switching, the chopper period is the chopper of the inverter, and r is the ripple of the chopper component. (C) is a case of a relatively high rotation speed and a high load, and is a waveform of the reactor current after switching. It is the same waveform as (a). (D) is the inverter current, which is the inverter current after switching, and has a smooth curved waveform.

  FIG. 14 shows the waveform of the reactor current when the voltage is controlled to be constant at 150 V by PWM control with respect to load fluctuation. (A) has shown in the case of a light load, The enlarged view is shown to the time axis of the b part of this (a) in (b). (C) shows a case of high load, and an enlarged view of the time axis of the d part of (c) is shown in (d). As can be seen from FIG. 14, when the DC voltage is the same (150 V), the duty of the switch element of the converter is the same, and the waveform height of the current varies depending on the size of the load.

  FIG. 15 shows a waveform of the reactor current with respect to the DC voltage, and (a) shows a PWM region of a constant voltage (150 V) at a relatively low rotational speed. An enlarged view of the time axis of part b of (a) is shown in (b). (C) shows a PAM control region in which the voltage is variable (150 to 300 V) at a relatively high rotation speed with a high load. An enlarged view of the time axis of the d part of (c) is shown in (d). (C) Comparing the waveforms of (d), the ON duty increases in the PAM control region. Even if there is no load in the PAM control region, the ON duty is increased to increase the DC voltage.

  Combining with the embodiment of the air conditioner provided with the electric motor drive device of the present invention, realizing a comfortable heating operation with low power consumption and refrigerant in a cold region (including a case where the heating load is large at the start of operation other than the cold region) and refrigerant The refrigeration cycle is provided for the purpose of preventing the increase in the work of compression when the refrigerant discharge pressure of the compressor becomes high and reducing the power consumption by keeping the condensing pressure of the compressor low. One embodiment of the air conditioner is shown in FIGS. 16, 17, and 18. FIG. FIG. 16 is a diagram showing a side cross section of the indoor unit according to the present embodiment. In FIG. 16, reference numeral 101 denotes an indoor heat exchanger having a multi-stage (three-stage) bending structure incorporated in the indoor unit. The thermal cutting line 124 causes the rear surface from the lower front portion 102 and the front-side upper portion 103 in the indoor unit. It is configured to be thermally separated from the portion over the portion 104. Reference numeral 126 denotes a refrigerant flow path, which is provided at a position on the upstream side of the indoor heat exchanger 101 during the dehumidifying operation or the cooling operation and on the downstream side of the indoor heat exchanger 101 during the heating operation. It is. In these heat exchangers, 120 indicated by a circle is a heat transfer tube provided so as to pass through the plurality of heat dissipating fins 123, and 121 and a broken line 122 are connection tubes between the heat transfer tubes 120. Further, reference numeral 105 denotes a dehumidifying squeezing device that performs a squeezing action during the dehumidifying operation. The front upper stage portion 103 and the rear surface portion 104 of the indoor heat exchanger 101 are thermally integrated together, and the dehumidifying squeezing device 105 is connected by a connecting pipe 106. Connected to one connection port, the other connection port of the dehumidifying expansion device 105 is connected to the front lower portion 102 of the indoor heat exchanger 101 that is thermally separated through the connection pipe 107.

  Further, 109 is a cross-flow fan type indoor fan, 110 is a front suction grille, 111 is a full upper suction grille, 112 is an upper back suction grille, 113 is a filter, 114 is a rear casing, 115 is an outlet, and 116 is an outlet. The indoor air is sucked through the filter 113 from the front suction grill 110, the entire upper suction grill 111, and the upper rear suction grill 1112 by the indoor fan 9, as indicated by arrows 191, 192, and 193. After the heat exchange with the refrigerant in the multistage bending indoor heat exchanger 101, the indoor fan 109 passes through the indoor fan 109 and is blown into the room from the outlet 115.

  117 is a dew tray for the front side portions 102 and 103 of the multi-stage bending indoor heat exchanger 101, 118 is a dew tray for the rear portion 104 of the multi-stage bending indoor heat exchanger 101, and dehumidifying water generated during cooling operation and dehumidifying operation is obtained. Work to receive.

  FIG. 17 is a view showing an embodiment of the dehumidifying squeezing device 105 in FIG. 16, in which FIG. 17 (a) is a diagram showing an operating state of the dehumidifying squeezing device 105 during the dehumidifying operation, and FIG. b) is a diagram showing the operating state of the dehumidifying expansion device 105 during cooling and heating operations. In these drawings, 130 is a valve body, 131 is a valve seat, 132 is a valve body, 133 is a valve portion of the valve body 132, 134 and 135 are connection pipes, 136 is an electromagnetic motor that moves the valve body 132, Larger arrows 138 and 139 indicate the refrigerant flow direction (pipe direction), and an arrow 140 indicates the refrigerant flow direction during the dehumidifying operation.

  During the dehumidifying operation, the valve element 132 is closed by the electromagnetic motor 136 as shown in FIG. At this time, the high-pressure condensate refrigerant that has passed through the indoor auxiliary heat exchanger 126 serving as a condenser and the portions 103 and 104 from the upper front to the rear of the indoor heat exchanger 101 flows in from the connection pipe 134, and the valve portion 133. After flowing through a narrow passage 137 formed by a gap between the valve seat 131 and the valve seat 131 as indicated by an arrow 140, the refrigerant becomes a low-pressure and low-temperature refrigerant by being squeezed here, and then passes through the connection pipe 135 to generate the indoor heat that becomes an evaporator. It flows into the lower front portion 102 of the exchanger 101.

  As a result, the indoor auxiliary heat exchanger 126 and the indoor heat exchanger 101 have portions 103 and 104 from the upper front to the rear to be heaters (reheaters), and the lower front portion 102 is a cooler to heat indoor air. At the same time, the dehumidifying operation for cooling and dehumidifying becomes possible.

  In the cooling and heating operation, as shown in FIG. 17B, the dehumidifying throttle device 105 is fully opened with the valve element 132 pulled up by the electromagnetic motor 136. As a result, the connecting pipes 134 and 135 communicate with each other with almost no flow resistance, and the refrigerant flows with almost no resistance.

  FIG. 18 is a diagram showing the overall cycle configuration of the present embodiment, in which 150 is a compressor for refrigerant compression whose capacity is variable by controlling the rotational speed, 151 is a four-way valve for switching the operating state, and 152 is outdoor heat. The exchanger 153 is an electric expansion valve that can be fully opened without a throttling action. Further, the indoor auxiliary heat exchanger 126, the multi-stage bending indoor heat exchanger 101, and the dehumidifying throttle device 105 are added and connected. The refrigeration cycle is configured by being annularly connected by piping. FIG. 18 schematically shows an embodiment of the flow path state of the heat transfer tubes of the indoor auxiliary heat exchanger 126 and the multistage bending indoor heat exchanger 101. In the indoor auxiliary heat exchanger 126, the heat transfer tube is configured by a single refrigerant flow path 159, and is connected to the indoor heat exchanger 101 by a connection tube 129.

  The indoor heat exchanger 101 is configured such that the front upper stage portion 103 and the rear portion 104 are integrally connected, and the heat transfer tubes become two refrigerant flow paths 154 and 155, and are further thermally separated by the cutting line 124. The lower heat exchanger portion 102 is composed of two refrigerant channels 156 and 157. Further, these heat transfer pipe refrigerant flow paths 154, 155 and 156, 157 are connected by connecting pipes 106 and 107 via a dehumidifying throttle device 105. Reference numeral 158 denotes an outdoor fan.

  In the indoor unit structure and the refrigeration cycle configuration described above, at the time of dehumidifying operation, the four-way valve 102 is switched in the same manner as at the time of cooling operation, and the dehumidifying throttle device 105 is appropriately throttled to fully open the electric expansion valve 153, so that the refrigerant As indicated by the chain line, the compressor 150, the four-way valve 151, the outdoor heat exchanger 152, the electric expansion valve 153, the indoor auxiliary heat exchanger 126, the front upper stage portion 103 and the rear surface portion 104 of the indoor heat exchanger 101, and the dehumidifying throttle device 105, the front lower portion 102 of the indoor heat exchanger 101, the four-way valve 151, and the compressor 150 are circulated in this order, and the outdoor heat exchanger 152 is connected to the upstream condenser, the indoor auxiliary heat exchanger 126, and the indoor heat exchanger 101. The operation is performed so that the front upper stage portion 103 and the rear surface portion 104 serve as a downstream condenser, and the front lower stage portion 102 of the indoor heat exchanger 101 serves as an evaporator.

  When the indoor air is passed through the indoor fan 109 as indicated by arrows 191, 192, 193, the indoor air is cooled and dehumidified by the lower front heat exchanger portion 102 acting as an evaporator, and at the same time, a downstream condenser That is, it is heated by the indoor auxiliary heat exchanger 126 serving as a heater and the front upper stage portion 103 and the back surface portion 104 of the indoor heat exchanger, and these air are further mixed and blown into the room.

  In this case, the capacities of the cooler 102 and the heaters 126, 103, and 104 can be adjusted by controlling the rotation speed to control the capacity of the compressor 150 and the air blowing capacity of the indoor fan 19 and the outdoor fan 158. The amount of dehumidification and the temperature of the blown air can be changed over a wide range.

  As described above, when there is no indoor auxiliary heat exchanger 126 during the dehumidifying operation, the room temperature is set to room temperature despite the presence of the upper front portion 103 and the rear portion 104 of the indoor heat exchanger 101 acting as a reheater. The reason for the decrease will be explained. Referring to FIG. 16, in such a fan structure, 70% of the intake air of arrows 191, 192 and 193 is air from arrow 191 from the front of the panel, and the remaining 30% is from arrows 1192 and 193. If the heat exchanger that is air and acts as a cooler is placed in the upper stage and the reheater is placed in the lower stage, the dehumidified water is evaporated again by the reheater and is not dehumidified. As shown in FIG. 16, it is necessary to arrange a reheater and a cooler, and the apparatus flows through the front upper part 103 and the back part 104 that act as the reheater. The air is less than the air flowing through the lower front portion 102 acting as a cooler, and there is a problem that the room temperature is lowered when the outside air temperature is low.

  In this embodiment, since the indoor auxiliary heat exchanger 126 that acts as a reheater during the dehumidifying operation is provided in the ventilation path, a decrease in temperature during the dehumidifying operation can be suppressed. In addition, since this indoor auxiliary heat exchanger is provided on the reheat side, the heat exchange amount of the reheater increases, the amount of refrigerant condensed increases, the overall cycle performance improves, and the dehumidifying expansion device 105 The gas phase of the gas-liquid two-phase flow that causes the refrigerant flow noise is reduced, and the refrigerant flow noise during the operation of the dehumidifying expansion device 105 (during the dehumidifying operation) can be reduced.

  As described above, according to the present embodiment, during the dehumidifying operation, the upstream side of the dehumidifying expansion device in the indoor auxiliary heat exchanger and the thermally divided indoor heat exchanger are the heater 101 and the heater, respectively. 102, the downstream side of the dehumidifying throttling device is a cooler, and the air sucked into the indoor unit is heated by the heater 101 and the heater 102 and simultaneously cooled by the cooler to remove moisture, and then mixed and blown out. Comfortable dehumidifying operation without excessive cooling can be performed. In particular, since there are two heaters and the heat transfer area of the heater is sufficiently larger than the heat transfer area of the cooler and the heating capacity is increased, a comfortable dehumidifying operation without excessive cooling is possible.

  Furthermore, the heater (the indoor auxiliary heat exchanger 26 and the portions 103 and 104 from the upper front to the rear of the indoor heat exchanger) are not disposed below the cooler (the front lower portion 102 of the indoor heat exchanger). The dehumidified water generated in the oven does not re-evaporate on the heater.

  Next, at the time of cooling operation, the dehumidifying expansion device 105 is opened, the electric expansion valve 153 is appropriately throttled, and the refrigerant is circulated as indicated by the solid line arrow, whereby the outdoor heat exchanger 152 is a condenser, the indoor auxiliary heat exchanger. 126 and the multistage bending indoor heat exchanger 101 are used as an evaporator to cool the room.

  During the heating operation, the four-way valve 151 is switched, the dehumidifying throttle device 105 is opened, the electric expansion valve 153 is appropriately throttled, and the refrigerant is circulated as indicated by the dashed arrow, thereby allowing the multi-stage bending indoor heat exchanger 101 to be a condenser, The indoor auxiliary heat exchanger 126 is used as a supercooler and the outdoor heat exchanger 152 is used as an evaporator to heat the room.

  And it is necessary to ensure efficient cycle operation and heat exchange performance in the multistage bending indoor heat exchanger 101 and the indoor auxiliary heat exchanger 126 for each operation of cooling and heating.

  This method will be described below.

  First, in FIG. 18, in the cooling operation, the refrigerant flows from the indoor auxiliary heat exchanger 126 to the multistage bending indoor heat exchanger 101, and both of these heat exchangers are low pressures, the specific volume of the gas refrigerant is large, and the volumetric flow rate is increased. Therefore, if the flow path area is small, the pressure loss here increases and the cycle performance deteriorates. Accordingly, in FIG. 18, the refrigerant flow paths 154, 155, 156, and 157 of the parts 103 and 104 and the front lower part 102 from the upper front stage to the rear face of the multi-stage bending indoor heat exchanger 101 that is the main heat exchanger are shown. There are two systems. As a result, the pressure loss in the refrigerant flow path becomes sufficiently small, and the performance degradation due to this can be sufficiently reduced. Furthermore, the indoor auxiliary heat exchanger 126 is provided, or the indoor heat exchanger 1 is provided from the front side to the back side so that the heat transfer area as the evaporator can be sufficiently increased, so that the performance can be improved, and the overall performance can be improved. Is possible.

  Moreover, in order to improve the performance in heating operation, it is necessary to take sufficient supercooling at the outlet of the heat exchanger on the indoor side serving as a condenser. In this supercooling region, the refrigerant temperature is gradually lowered from the condensing temperature at the same time as the refrigerant is in the liquid state. Therefore, the liquid refrigerant flow speed is increased to increase the heat transfer coefficient in the heat transfer tube, and the heat transfer tube. Must be on the windward side to exchange heat with a relatively cool air stream before heat exchange. Furthermore, since the temperature of the high-temperature gas refrigerant decreases to the condensing temperature at the inlet portion during heating operation in the lower front portion 102 of the indoor heat exchanger 101, the refrigerant flow and the air flow are also opposed to each other in this portion. Good.

  The indoor auxiliary heat exchanger 126 may be arranged with a gap of 1 mm to 5 mm between the indoor heat exchanger 101. By providing a gap in this way, it is possible to prevent dew condensation between the indoor heat exchanger 101 and the indoor heat exchanger 101 from being bridged between the two heat exchangers, and to prevent an increase in the ventilation resistance of the heat exchanger. It is possible to prevent a decrease in capacity and an increase in blowing sound.

  In addition, if the position to be placed is superimposed on the heat exchanger on the back side of the top surface in the airflow direction, the wind speed of the airflow will slow down and it will be difficult for dew to fall toward the fan, so the inclination angle of the heat exchanger on the back side To increase the vertical dimension of the heat exchanger. Thereby, the height dimension of the indoor unit can be reduced, or the size of the sentence heat exchanger can be increased. Furthermore, if the position to be placed is superimposed on the heat exchanger on the back side of the upper surface in the airflow direction, the air velocity distribution is made uniform when an air purifying filter or deodorizing filter is placed on the front side of the heat exchanger on the upper front side. It is possible to suppress the deterioration of the heat exchange performance.

  In FIG. 18, the outlet side of the condenser is an indoor auxiliary heat exchanger 126, and this part has a single refrigerant flow path and can sufficiently reduce the flow area, so that the heat flow rate is increased and the heat transfer coefficient is sufficiently high. Further, it is arranged on the windward side of the indoor heat exchanger 101. Therefore, the indoor auxiliary heat exchanger 101 can exhibit sufficient performance as a supercooler. Further, in the lower stage portion 102 of the front surface of the indoor heat exchanger having two refrigerant passages 156 and 157, a piping configuration is provided in which the inlet side of the high-temperature gas refrigerant flow at the time of heating operation is provided on the leeward side of the air flow. In the vessel portion 2, the refrigerant flow and the air flow are opposed to each other, and the heat exchange performance can be improved.

  Here, when the indoor unit size cannot be sufficiently large, the indoor auxiliary heat exchanger 126 may not be sufficiently large as a supercooler in heating operation. An embodiment capable of solving this problem is shown in FIG.

  In FIG. 19, the parts 103 and 104 from the upper front to the rear of the multi-stage bending indoor heat exchanger 101 are separated from one system of refrigerant flow path parts 160 provided on the windward side and two systems of refrigerant flow path parts 161 and 162. Constitute. Further, the refrigerant flow path of the lower front portion 102 of the indoor heat exchanger 101 is made into two systems 156 and 157, and at the same time, the refrigerant inlet portion in the heating operation in the lower front portion 102 is provided on the leeward side of the air flow. It is. Moreover, what attached the same number as FIG. 18 shows the same part.

  With this cycle configuration, in the heating operation, the high-temperature and high-pressure gas refrigerant after leaving the compressor 150 and passing through the four-way valve 151 enters the indoor heat exchanger 1, and the refrigerant flow path in the front lower stage portion 102 has two systems. After passing through the heat transfer tubes 156 and 157, the dehumidifying expansion device 105 is fully opened, and enters the portions 103 and 104 from the upper front to the rear of the indoor heat exchanger 101, and the refrigerant flow path is The two heat transfer tubes 161 and 162 flow in a divided manner, and then merge, and the refrigerant flow passes through one heat transfer tube 160, and the refrigerant flow passes through one indoor auxiliary heat exchanger 126.

  In this case, in the lower front portion 102 of the indoor heat exchanger 101, the inlet side through which the high-temperature gas refrigerant flows is the leeward side of the air flow, and the outlet side through which the two-phase refrigerant flows is the leeward side of the low-temperature air flow. In the portion 102, the refrigerant flow and the air flow are in a counterflow state with excellent heat exchange performance. In addition, the heat transfer pipe 160 on the refrigerant outlet side of the portions 103 and 104 from the upper front to the back of the multistage bending indoor heat exchanger 101 and the heat transfer pipe 159 of the indoor auxiliary heat exchanger 126 form a single-system refrigerant flow path. Furthermore, since these heat transfer tubes 160 and 159, which are in the subcool region where the temperature gradually decreases from the saturation temperature, exchange heat with the upstream air flow having a low temperature, a sufficient subcool can be taken, and the refrigerant temperature from the indoor unit toward the outdoor unit Since the temperature is approximately room temperature, the heating performance can be improved.

  Further, in the cooling operation, the two-phase refrigerant that has been throttled by the electric expansion valve 153 and has become low pressure / low temperature first enters the indoor auxiliary heat exchanger 126, and the refrigerant flow path passes through one heat transfer tube 159, and then the indoor After entering the heat exchanger 101, the heat exchanger parts 103 and 104 from the front upper stage to the rear face are separated after passing through one heat transfer pipe 160 and then into two heat transfer pipes 161 and 162, and further a dehumidifying throttle device 105 passes through the front lower stage portion 102 and flows into two heat transfer tubes 156 and 157. In this case, in the heat transfer tubes 159 and 160, since the dryness of the refrigerant is relatively small, the pressure loss is relatively small even in a single refrigerant flow path. In addition, the heat loss tubes 161, 162 and 156, 157, which have a relatively high degree of dryness, have two refrigerant flow paths, so that the pressure loss is sufficiently small. As a result, a decrease in cooling performance due to pressure loss can be prevented. Furthermore, by providing the indoor auxiliary heat exchanger 126, the heat transfer area as an evaporator increases and the cooling performance is improved.

  Here, in the embodiment shown in FIGS. 18 and 19, the case where the heat transfer tubes of the indoor heat exchanger 101 are divided into two systems and the case where one system and two systems are combined are shown, but the present invention is not limited to these. It is also possible to divide the refrigerant flow path into more systems, and in this case as well, the refrigerant flow pressure loss in the indoor heat exchanger 101 can be reduced, and in particular, the cooling performance can be prevented from being lowered. However, if there are too many refrigerant flow paths, the pressure loss of the refrigerant flow will decrease, but the heat transfer rate will decrease significantly, and the overall performance of the air conditioner, such as the capacity and operating coefficient in cooling and heating operations, will decrease. Therefore, it is necessary to set the optimum number of refrigerant flow paths, and this number is mainly determined according to the inner diameter of the refrigerant pipe. Further, in the indoor heat exchanger 101, the same effect can be obtained by using a multi-system refrigerant flow path as a heat transfer pipe having a large pipe diameter and a single-system refrigerant flow path (not shown). In other words, by increasing the pipe diameter, the flow rate of the refrigerant flow is slowed down, and it is possible to prevent deterioration in performance particularly in the cooling operation.

  Furthermore, since the indoor auxiliary heat exchanger 126 in FIGS. 16, 18 and 19 is provided on the windward side of the indoor heat exchanger 101 with respect to the air flow, the indoor auxiliary heat exchanger 126 and the indoor heat exchanger 101 overlap each other. In the portion, the air flow is reduced due to the increase of the ventilation resistance, and the heat transfer performance is deteriorated. Therefore, the indoor auxiliary heat exchanger 126 needs to have a small ventilation resistance with respect to the indoor heat exchanger 101. For this purpose, the indoor auxiliary heat exchanger 126 has a larger fin pitch, a smaller depth dimension (dimension in the direction of the wind flow), or an indoor heat exchanger than the indoor heat exchanger 101. In order to improve heat transfer performance, 101 has a structure in which slits are not provided in the fins (not shown).

  Next, in the indoor unit structure of FIG. 16, the wind speed distribution of the intake air indicated by arrows 191, 192, and 193 in the multistage bending indoor heat exchanger 101 has a relatively fast 191 corresponding to the front lower stage portion 102. Further, from the viewpoint of design, as shown in FIG. 19, there is a case in which the upper portion 180 is closed at the front of the indoor unit so that it does not serve as an air suction port, and only the lower portion has a suction grille 181. , 191, 192, 193, the wind speed distribution of the suction air flow is the fastest in the arrow 191 corresponding to the front lower suction grille 181. In FIG. 20, the same reference numerals as those in FIG. 16 denote the same parts.

  In such a case, as shown in a representative example in FIG. 20, by providing the auxiliary heat exchanger 126 on the windward side of the lower front stage portion 102 of the multistage bending indoor heat exchanger 101, the cooling and heating performance can be further improved. it can. That is, in the cooling and heating operation, the air volume corresponding to the arrow 191 is relatively large. Therefore, the heat exchanger portion including the indoor auxiliary heat exchanger 126 and the lower front portion 102 of the indoor heat exchanger corresponding to this air volume Even if it becomes thicker in the flowing depth direction, the temperature efficiency of this heat exchanger portion is kept relatively high. Furthermore, since the auxiliary heat exchanger 126 that provides (somewhat) ventilation resistance is provided at a place where the wind speed distribution in the indoor heat exchanger 101 is fast, the suction air speed distribution on the front surface of the entire indoor heat exchanger 101 becomes more uniform. As a result, the indoor unit structure of FIG. 20 can improve the cooling and heating performance compared to the indoor unit structure of FIG.

  Further, the performance of the dehumidifying operation in the structure of FIG. 20 is not much different from the indoor unit structure of FIG. 16 according to actual measurements (the dehumidifying amount tends to decrease slightly, but the blown air temperature tends to increase). It is possible to perform a comfortable dehumidifying operation while suppressing overcooling.

  Still further, due to structural limitations of the indoor unit, if the indoor auxiliary heat exchanger 126 cannot be placed on the windward side of the rear part 104 or the front lower part 102 of the indoor heat exchanger, Even on the windward side of the upper front stage portion 103 of the exchanger, although the performance may be somewhat deteriorated, the effect of the auxiliary heat exchanger in the dehumidifying, cooling and heating operations described so far can be obtained.

  18 and 19, the indoor unit structure shown in FIG. 20 or the indoor unit structure in which the indoor auxiliary heat exchanger 126 is provided on the windward side of the front upper stage portion 103 of the indoor heat exchanger can be applied. An effect can be obtained (not shown).

  In the embodiment of FIGS. 16, 18, 19, and 20, the indoor heat exchanger 101 is bent into three stages, that is, the front lower part 102, the front upper part 103, and the rear part 104. However, the present invention is not limited to this, and each part may be configured in multiple stages as necessary. FIG. 21 shows a case where the front lower portion 102 ′ of the indoor heat exchanger 101, which is the lower portion of the thermal cutting line 163, has three stages 164, 165, and 166. Thereby, a heat transfer area can be made larger than FIG. Furthermore, as shown in FIG. 22, the front lower stage, the front upper stage, and the back are integrated into a continuous curve instead of a broken line, and further, a part from the front upper stage to the rear that becomes a heater during dehumidification operation and a cooler. The front lower portion may be structured to be thermally separated into two parts 168 and 169 by a cutting line 167, and the heat transfer area can be similarly increased. In particular, room air conditioners, which are small air conditioners, often do not have enough space to store the indoor heat exchanger. In this case, the indoor heat exchanger can be bent more times or curved. Thus, an indoor heat exchanger having a sufficient heat transfer area in a narrow space can be accommodated. In the case of these indoor heat exchangers, the same effect can be obtained by providing an indoor auxiliary heat exchanger on the windward side of the indoor heat exchanger as shown in FIG. 16 or FIG.

  Further, the dehumidifying throttling device 105 and the electric expansion valve 153 in FIGS. 16, 18, 19, and 20 may have a configuration in which a capillary tube or a normal expansion valve and a two-way valve are provided in parallel (illustrated). (Omitted), the opening and closing of the two-way valve can realize the same operation as in the previous embodiments.

  Heretofore, the indoor heat exchanger has been considered to have a structure provided from the front to the back of the indoor unit. However, the present invention is not limited to this, and the indoor heat exchanger is provided only on the front of the indoor unit and provided on the back. Even in the case of an indoor unit structure in which an auxiliary heat exchanger is provided on the windward side (not shown; for example, equivalent to the case where the back surface portion 104 of the indoor heat exchanger 101 is not provided in FIG. 16 or 20). The effect of the indoor auxiliary heat exchanger 126 similar to that described so far can be obtained.

  Also, the refrigerant flow paths of the front and back portions of the indoor heat exchanger are each made up of two or more lines, or the refrigerant flow paths of the indoor auxiliary heat exchanger 126 are made one line and at the same time arranged on the windward side of the indoor heat exchanger. Thus, the pressure loss can be reduced in the cooling operation and the heating operation, and the refrigerant flow and the air flow can be made to counter flow, and further, the indoor auxiliary heat exchanger 126 acts as a subcooler during the heating operation. Supercooling can be taken. Therefore, in the cooling operation and the heating operation, a sufficiently efficient operation can be performed as in the embodiment described with reference to FIGS.

  By the way, in embodiment described above, it has demonstrated about the case where single refrigerant | coolants, such as HCFC22 (abbreviation of hydrochlorofluorocarbon 22) often used with an air conditioner, are used. Recently, however, research on alternative refrigerants to replace HCFC 22 has been active from the viewpoint of ozone layer destruction and global warming, and the use of mixed refrigerants as well as single refrigerants has been studied as alternative refrigerants. On the other hand, it is clear that the indoor unit structure, cycle configuration, and operation control method described in the embodiments shown in FIGS. 16 to 20 can be applied, and similar effects can be obtained.

  According to an experiment with an air conditioner equipped with the indoor auxiliary heat exchanger 126, at −10 ° C. and −15 ° C., −10 ° C. has a lower refrigerant gas suction density and a smaller compression work. As a result, the compressor drive motor could be operated at a high rotational speed for a long time. This is because the amount of refrigerant condensed by the indoor auxiliary heat exchanger 126 increases, and the pressure of the refrigerant gas sucked into the compressor suppresses or decreases, thereby reducing the amount of work of the compressor. The limit current value is not reached even if the operation at the set maximum rotational speed (9000 rpm) is performed for a long time.

  As a result, in an experiment in the case of only PAM control, when the outdoor air temperature is −10 ° C. and −15 ° C., the condensation pressure increases before the indoor temperature reaches the set temperature 23 ° C., reaches the limit current, and rotates. The number was controlled to be between 5000 and 7000 rpm, and it took a very long time to reach the set temperature, but this could be eliminated. This has the same heating capacity as that of an oil fan heater even when the outdoor temperature is −15 ° C., and the electric charge can be equal to the oil cost of the oil fan heater.

It is a block diagram which shows 1st Embodiment of the air conditioner by this invention. It is a flowchart figure which shows the control method of 1st Embodiment shown in FIG. FIG. 3 is a diagram for explaining the control method shown in FIG. 2 when the input AC power supply voltage of the first embodiment shown in FIG. 1 is 100V. It is a figure which shows the effect by the control method demonstrated in FIG. 3 compared with a prior art example. It is a block diagram which shows the modification of 1st Embodiment shown in FIG. It is a figure which compares and shows the effect of 1st Embodiment shown in FIG. 1, and the air conditioner using the circuit shown in FIG. It is a block diagram which shows 2nd Embodiment of the air conditioner by this invention. It is a block diagram which shows 3rd Embodiment of the air conditioner by this invention. It is a block diagram which shows 4th Embodiment of the air conditioner by this invention. It is a circuit block diagram of the electric motor drive device in the conventional air conditioner. It is a figure which shows the heating characteristic with respect to external temperature. It is a figure which shows the alternating current power supply input waveform immediately after operation | movement as an active converter in one embodiment of this invention. It is a figure which shows the reactor 3 electric current and inverter current before and behind PWM / PAM switching. It is a figure which shows the waveform of the profit 3 electric current with respect to load operation | movement. It is a figure which shows the waveform of the reactor current with respect to DC voltage. It is a figure which shows the indoor unit structure of the air conditioner which is one embodiment of this invention. It is a figure which shows the structure and operation | movement state of an example of the dehumidification diaphragm | throttle device in FIG. It is a figure which shows the cycle structure of the air conditioner which is one embodiment of this invention. It is a figure which shows the piping structure of the indoor heat exchanger which is other embodiment of this invention. It is a figure which shows the indoor unit structure of the air conditioner which is other embodiment of this invention. It is a figure which shows the shape of the indoor heat exchanger which is other embodiment of this invention. It is a figure which shows the shape of the indoor heat exchanger which is further another embodiment of this invention.

Explanation of symbols

2 Rectifier 3 Reactor 4 Diode 5 Capacitor 6 Switch element 7 Voltage comparator 8 Multiplier 9 Load current detector 10 Current comparator 11 Oscillator 12 Drive circuit 13 Inverter 14 Electric motor 15 Microcomputer 16 Inverter drive circuit 18 DC voltage signal switch 19 Trigger Element 20 Synchronous signal selector switch 21 Voltage command selector switch 22 Drive signal selector switch 23 Supply current detector 24 Active converter block 25 Low-pass filter 26 Power supply capacitor 27 Reactor 28 Diode 29 Room temperature sensor 30 AC power source voltage detector 31 AC / DC selector switch 32 DC power source Q Power factor correction circuit 101 Indoor heat exchanger 102, 102 'Lower front portion of indoor heat exchanger 103 Upper front portion of indoor heat exchanger 104 Back of indoor heat exchanger Surface portion 105 Dehumidifying throttle device 106, 107, 127, 128, 129 Connection pipe 109 Indoor fan 110 Front suction grill 111 Upper suction grill 112 Rear suction grill 113 Filter 114 Rear casing 115 Outlet 116 Outlet wind direction plate 117 Front dew plate 118 Back Dew Pan 120 Heat Transfer Tube 121, 122 Connection Pipe for Heat Transfer Tube 123 Radiation Fin 124, 163, 167 Thermal Cutting Line 126 Indoor Auxiliary Heat Exchanger 130 Valve Body 131 Valve Seat 132 Valve Body 133 Valve Portion 134, 135 Connection Tube 136 Electromagnetic motor 137 Refrigerant flow path during dehumidification operation 150 Compressor 151 Four-way valve 152 Outdoor heat exchanger 153 Electric expansion valve 154, 155, 156, 157, 159, 160, 161, 162 Refrigerant flow path 158 Outdoor fans 164, 165 166 , 168, 169 Heat exchanger portion 180 Front upper panel 181 Front lower suction grill 191, 192, 193 Indoor unit intake air flow.

Claims (10)

Compressor for driving compressor compressor, compressor for refrigerant compression, refrigeration cycle in which four-way valve for switching air-conditioning operation state, outdoor heat exchanger, expansion valve, and indoor heat exchanger are connected in a ring by connecting pipes A motor drive device for a machine,
The electric motor driving device for the compressor is
A power converter that rectifies and smoothes the input AC voltage to generate an output DC voltage;
In an air conditioner having an output DC voltage of the power converter as a power supply voltage and an inverter that variably drives the rotation speed of the compressor motor,
It has a function of varying the output DC voltage of the power converter, and by increasing the output DC voltage of the power converter, the rotational speed of the compressor motor when changing the conduction rate of the inverter Rotate the compressor motor at a high speed,
The indoor heat exchanger has an operating current lower than the limiting current even when the compressor motor is operated at a high rotational speed by increasing the output DC voltage of the power converter during heating operation with a low outdoor temperature. An air conditioner characterized by having a refrigerant condensing amount for maintaining the temperature. Compressor for driving compressor compressor, compressor for refrigerant compression, refrigeration cycle in which four-way valve for switching air-conditioning operation state, outdoor heat exchanger, expansion valve, and indoor heat exchanger are connected in a ring by connecting pipes A motor drive device for a machine,
The electric motor driving device for the compressor is
A power converter that rectifies and smoothes the input AC voltage to generate an output DC voltage;
In an air conditioner having an output DC voltage of the power converter as a power supply voltage and an inverter that variably drives the rotation speed of the compressor motor,
It has a function of varying the output DC voltage of the power converter, and by increasing the output DC voltage of the power converter, the rotational speed of the compressor motor when changing the conduction rate of the inverter Rotate the compressor motor at a high speed,
The indoor-side heat exchanger has a maximum output DC voltage of the power converter during the heating operation at an outdoor temperature of −10 ° C., and even if the compressor motor is operated at the maximum rotational speed, An air conditioner characterized by having a refrigerant condensing amount that maintains a low operating current. Compressor for driving compressor compressor, compressor for refrigerant compression, refrigeration cycle in which four-way valve for switching air-conditioning operation state, outdoor heat exchanger, expansion valve, and indoor heat exchanger are connected in a ring by connecting pipes A motor drive device for a machine,
The electric motor driving device for the compressor is
A power converter that rectifies and smoothes the input AC voltage to generate an output DC voltage;
In an air conditioner having an output DC voltage of the power converter as a power supply voltage and an inverter that variably drives the rotation speed of the compressor motor,
It has a function of varying the output DC voltage of the power converter, and by increasing the output DC voltage of the power converter, the rotational speed of the compressor motor when changing the conduction rate of the inverter Rotate the compressor motor at a high speed,
The indoor-side heat exchanger has a maximum current DC voltage of the power converter during the heating operation at an outdoor temperature of −15 ° C. or less, and the compressor motor operates at the maximum rotational speed. An air conditioner characterized by having a refrigerant condensing amount that maintains a low operating current. Compressor for driving compressor compressor, compressor for refrigerant compression, refrigeration cycle in which four-way valve for switching air-conditioning operation state, outdoor heat exchanger, expansion valve, and indoor heat exchanger are connected in a ring by connecting pipes A motor drive device for a machine,
The electric motor driving device for the compressor is
A power converter that rectifies and smoothes the input AC voltage to generate an output DC voltage;
In an air conditioner having an output DC voltage of the power converter as a power supply voltage and an inverter that variably drives the rotation speed of the compressor motor,
It has a function of varying the output DC voltage of the power converter, and by increasing the output DC voltage of the power converter, the rotational speed of the compressor motor when changing the conduction rate of the inverter Rotate the compressor motor at a high speed,
The indoor heat exchanger reduces the flow passage area on the outlet side of the refrigerant flow channel during heating operation, and increases the output DC voltage of the power converter during heating operation when the outdoor temperature is low. An air conditioner characterized by having a refrigerant condensing amount that maintains an operating current lower than the limit current even when the motor is operated at a high rotational speed. Compressor for driving compressor compressor, compressor for refrigerant compression, refrigeration cycle in which four-way valve for switching air-conditioning operation state, outdoor heat exchanger, expansion valve, and indoor heat exchanger are connected in a ring by connecting pipes A motor drive device for a machine,
The electric motor driving device for the compressor is
A power converter that rectifies and smoothes the input AC voltage to generate an output DC voltage;
In an air conditioner having an output DC voltage of the power converter as a power supply voltage and an inverter that variably drives the rotation speed of the compressor motor,
It has a function of varying the output DC voltage of the power converter, and by increasing the output DC voltage of the power converter, the rotational speed of the compressor motor when changing the conduction rate of the inverter Rotate the compressor motor at a high speed,
The indoor-side heat exchanger has an outlet-side refrigerant flow path during heating operation and two or more inlet-side refrigerant flow paths, and the output DC voltage of the power converter during heating operation with a low outdoor temperature. The air conditioner is characterized in that it has a refrigerant condensing amount that maintains an operating current lower than the limit current even when the compressor motor is operated at a high rotational speed by increasing the pressure. Compressor for driving compressor compressor, compressor for refrigerant compression, refrigeration cycle in which four-way valve for switching air-conditioning operation state, outdoor heat exchanger, expansion valve, and indoor heat exchanger are connected in a ring by connecting pipes A motor drive device for a machine,
The electric motor driving device for the compressor is
A power converter that rectifies and smoothes an input AC voltage to generate an output DC voltage, and variably controls the output DC voltage;
An output DC voltage of the power converter as a power supply voltage, and an inverter that variably drives the rotation speed of the compressor motor,
The power converter has a variable output DC voltage,
The indoor heat exchanger includes an indoor heat exchanger and an auxiliary heat exchanger that is disposed on the air inlet side of the indoor air that is on the windward side of the indoor heat exchanger and that is used for supercooling during heating operation. The refrigerant condensing amount that maintains the operating current lower than the limit current even when the compressor motor is operated at a high rotational speed by increasing the output DC voltage of the power converter during the heating operation at a low outdoor temperature. An air conditioner characterized by having a size. Compressor for driving compressor compressor, compressor for refrigerant compression, refrigeration cycle in which four-way valve for switching air-conditioning operation state, outdoor heat exchanger, expansion valve, and indoor heat exchanger are connected in a ring by connecting pipes A motor drive device for a machine,
The electric motor driving device for the compressor is
A power converter that rectifies and smoothes an input AC voltage to generate an output DC voltage, and variably controls the output DC voltage;
An output DC voltage of the power converter as a power supply voltage, and an inverter that variably drives the rotation speed of the compressor motor,
The indoor heat exchanger includes an indoor heat exchanger and the power converter, the output DC voltage of which is variable,
The indoor heat exchanger includes an indoor heat exchanger and an auxiliary heat exchanger that is disposed on the air inlet side of the indoor air that is on the windward side of the indoor heat exchanger and that is used for supercooling during heating operation. A refrigerant that maintains an operating current lower than the limit current even when the compressor motor is operated at the maximum rotation speed by maximizing the output DC voltage of the power converter during heating operation at an outdoor temperature of −10 ° C. An air conditioner characterized by having a size with a condensed amount. Compressor for driving compressor compressor, compressor for refrigerant compression, refrigeration cycle in which four-way valve for switching air-conditioning operation state, outdoor heat exchanger, expansion valve, and indoor heat exchanger are connected in a ring by connecting pipes A motor drive device for a machine,
The electric motor driving device for the compressor is
A power converter that rectifies and smoothes an input AC voltage to generate an output DC voltage, and variably controls the output DC voltage;
An output DC voltage of the power converter as a power supply voltage, and an inverter that variably drives the rotation speed of the compressor motor,
The indoor heat exchanger includes an indoor heat exchanger and an auxiliary heat exchanger that is disposed on the air inlet side of the indoor air that is on the windward side of the indoor heat exchanger and that is used for supercooling during heating operation. A refrigerant that maintains an operating current lower than the limit current even when the compressor motor is operated at the maximum rotation speed by maximizing the output DC voltage of the power converter during heating operation at an outdoor temperature of −15 ° C. An air conditioner characterized by having a size with a condensed amount. Compressor for driving compressor compressor, compressor for refrigerant compression, refrigeration cycle in which four-way valve for switching air-conditioning operation state, outdoor heat exchanger, expansion valve, and indoor heat exchanger are connected in a ring by connecting pipes A motor drive device for a machine,
The electric motor driving device for the compressor is
A power converter that rectifies and smoothes an input AC voltage to generate an output DC voltage, and variably controls the output DC voltage;
An output DC voltage of the power converter as a power supply voltage, and an inverter that variably drives the rotation speed of the compressor motor,
The indoor heat exchanger includes an indoor heat exchanger and an auxiliary heat exchanger that is disposed on the air inlet side of the indoor air that is on the windward side of the indoor heat exchanger and that is used for supercooling during heating operation. The refrigerant condensing amount that maintains the operating current lower than the limit current even when the compressor motor is operated at a high rotational speed by increasing the output DC voltage of the power converter during the heating operation at a low outdoor temperature. An air conditioner characterized by having a size. Compressor for driving compressor motor, compressor for refrigerant compression, refrigeration cycle in which four-way valve for switching between cooling and heating operation state, outdoor heat exchanger, expansion valve and indoor heat exchanger are connected in a ring by connecting pipe A motor drive device for a machine,
The electric motor driving device for the compressor is
A power converter that rectifies and smoothes an input AC voltage to generate an output DC voltage, and variably controls the output DC voltage;
An output DC voltage of the power converter as a power supply voltage, and an inverter that variably drives the rotation speed of the compressor motor,
The indoor heat exchanger is disposed on the indoor heat exchanger and on the inlet side of indoor air, which is on the windward side of the indoor heat exchanger, and on the refrigerant passage, on the downstream side of the indoor heat exchanger. And a subcooling auxiliary heat exchanger for supercooling during heating operation with a small channel area, and for the compressor by increasing the output DC voltage of the power converter during heating operation with a low outdoor temperature. An air conditioner characterized by having a refrigerant condensing amount that maintains an operating current lower than a limit current even when the electric motor is operated at a high rotational speed.

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