JP3495858B2 - Air conditioner - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an alternative refrigerant that replaces HCFC (hydrochlorofluorocarbon) 22 (hereinafter referred to as R22) and has a higher saturation pressure at the same temperature than R22, in other words, an alternative refrigerant that operates at a higher pressure. The present invention relates to an air conditioner using a refrigerant.

[0002]

2. Description of the Related Art An air conditioner such as a room air conditioner circulates a refrigerant in a refrigerating cycle to cool or (and) heat the indoor air by the condensation and evaporation of the refrigerant. It is one of the necessities in buildings.

As the refrigerant used in the above-mentioned air conditioner, R22 which is non-toxic and non-flammable and which is stable both thermally and chemically is currently used.

By the way, in the conventional air conditioner using R22 as a refrigerant, as shown in the heating operation flowchart of FIG. 15, when the air conditioner is operated to start heating, the indoor blower louver is normally heated. The compressor is ON-driven in a state in which the setting is controlled to a position (the position where the blown wind is directed toward the floor in the room (downward)) to which the compressor is directed. At this time, the temperature T of the indoor heat exchanger rises and the temperature T
Until the temperature exceeds the heat exchange (condensable) temperature T0 (T ≧ T0) (NO as a result of the determination in step S2), the operation of the indoor fan is stopped and controlled so as not to send the cool air to the indoor space (step S1). ).

When the temperature T of the indoor heat exchanger rises and the temperature T exceeds the heat exchangeable temperature T0 and hot air is blown out after a while (T ≧ T)
0; YES as a result of the determination in step S2), the indoor fan was started to be controlled to perform normal operation (step S3).

On the other hand, in an air conditioner, frost in the outside air may adhere (frost) to the outer surface of the outdoor heat exchanger, which is an evaporator, during heating. It was one of the factors that hindered the evaporation effect of. Therefore, in the air conditioner, a so-called defrosting operation, which is an operation for temporarily removing frost on the outdoor heat exchanger during heating, is performed.

In the defrosting operation of the air conditioner, for example, the four-way valve that is ON during the heating operation is reversed to OFF, and the circulation direction of the refrigerant is reversed from that during heating. The opening of the expansion valve, which is a flow rate adjusting valve (electronic control valve, PMV), is controlled to be kept constant at a predetermined opening, and the operation of the indoor / outdoor fan is stopped.

That is, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor is introduced into the outdoor heat exchanger,
The heat is radiated and liquefied in the outdoor heat exchanger. At this time, the frost attached to the outer surface of the outdoor heat exchanger is heated and removed by the heat radiation of the refrigerant. Further, the liquid refrigerant condensed and liquefied in the outdoor heat exchanger flows into the indoor heat exchanger through the expansion valve and is evaporated and vaporized in the indoor heat exchanger. The vaporized refrigerant (gaseous refrigerant) is returned to the compressor again, and the operation cycle described above is repeated thereafter.

Here, the discharge pressure when the defrosting operation is performed in the air conditioner using R22 as the refrigerant (pressure from the compressor to the expansion valve via the indoor heat exchanger (condenser)) The difference between Pd and the suction pressure (pressure from the expansion valve to the suction through the outdoor heat exchanger (evaporator) to the compressor) Ps was about 20 kg / cm ² as shown in FIG. 16. Therefore, even if a sudden pressure change occurs at the time of reversing the four-way valve, the noise and vibration generated in the piping of the four-way valve based on the pressure change hardly affect the surroundings.

[0010]

R22, which has been used as a refrigerant in an air conditioner in the past, may destroy the ozone layer, so it has been officially decided to discontinue its use in the future. Research and development of air conditioners using alternative refrigerants are underway.

As an alternative refrigerant to R22,
An alternative refrigerant having a higher saturation pressure (condensation pressure) at the same temperature as R22 (for example, a saturation pressure at 50 ° C. is 250).
An air conditioner using 0 kPa or more) is considered.

However, in the conventional air conditioner, when an alternative refrigerant having the same temperature and a higher saturation pressure than R22 is used, the high pressure side (from the compressor to the expansion valve via the condenser (the indoor heat exchanger during heating)) is used. The system leading to the above; since the system leading from the expansion valve to the compressor via the evaporator (the outdoor heat exchanger during heating) is called the low pressure side, the pressure rises (in other words, the discharge pressure rises) rapidly. When the heating operation is started, the pressure on the high-pressure side abnormally rises when the operation is stopped until the above-described indoor fan starts operating.

As a result, the reliability of the compressor is adversely affected and there is a risk of damaging each heat exchanger, piping and the like. When ester oil or other highly compatible oil having a high relative dielectric constant is used as the lubricating oil (refrigerating machine oil) of the compressor, the refrigerant in the lubricating oil in the compressor is changed due to the rapid increase in the pressure on the high pressure side. Melted, the oil level of the lubricating oil rose. And due to this rise in oil level,
Even the motor winding part in the compressor was immersed in the lubricating oil, and the leakage current increased.

For example, in FIG. 17, after the heating operation is started (when the indoor fan operation is stopped) in the air conditioner using the alternative refrigerant having the higher saturated pressure at the same temperature as that of the conventional R22, the horizontal axis indicates 6 is a graph showing an example of changes in the high-pressure side pressure P, the oil level height H, and the leakage current I when the elapsed time t from the start of the heating operation is set. This FIG.
According to this, it is understood that the high-pressure side pressure P rises rapidly and abnormally immediately after the start of the heating operation, and the height H of the oil surface and the amount of the leakage current I increase in accordance with the rise.

On the other hand, the above-mentioned abnormal pressure rise on the high pressure side causes a problem even during the defrosting operation. That is, as an alternative refrigerant having a higher saturation pressure at the same temperature than R22, for example, the saturation pressure at 50 ° C. is 2500 kP.
FIG. 18 shows the relationship between the discharge pressure Pd ′ and the suction pressure Ps ′ corresponding to the above-mentioned FIG. 16 when the refrigerant of a or more is used. According to FIG. 18, the difference between the Pd ′ and Ps ′ is about 30 kg due to the abnormal increase in the discharge pressure Pd ′ during the defrosting operation.
/ Cm ² has been reached. Therefore, there is a possibility that noise and vibration generated from the piping of the four-way valve and the like increase due to a sudden pressure change at the time of reversing the four-way valve and adversely affect the surroundings.

The present invention has been made in view of the above circumstances, and an object thereof is to rapidly and abnormally increase the pressure on the high pressure side in an air conditioner using an alternative refrigerant having a saturation pressure higher than that of R22 at the same temperature. By suppressing the above, it is to maintain the performance and reliability of the compressor at a high level, prevent damage to the heat exchanger and the like, and provide a comfortable heating space.

Another object of the present invention is to provide an abnormal increase in discharge pressure in an air conditioner using an alternative refrigerant having a saturation pressure higher than that of R22 at the same temperature, for example, a saturation pressure at 50 ° C. of 2500 kPa or more. Is suppressed to reduce the difference between the discharge pressure and the suction pressure, thereby reducing noise and vibration generated from the pipe and the like when the four-way valve is reversed in the defrosting operation.

[0018]

[Means for Solving the Problems] The saturated pressure is higher than that of R22 at the same temperature, for example, the saturated pressure at 50 ° C. is 25.
When an alternative refrigerant of 00 kPa or more is used, one of the reasons why the pressure on the high pressure side sharply increases from the start of heating operation is that the operation of the indoor fan is stopped and the heat exchange action of the indoor heat exchanger is performed. Sometimes it is not. However, since the cold blow-off air that has undergone heat exchange in the indoor heat exchanger that has not reached the state where heat can be exchanged by operating the indoor fan normally flows into the room, in the first invention,
The blowing angle to the ceiling side above and the floor side below in the indoor space is set to a position where the blowing air is directed upward toward the ceiling side at the start of the heating operation, and for example, the temperature of the indoor side heat exchanger rises and heat exchange is possible. When the state is reached, the blowing angle is set to a position where the blowing air is directed downward toward the floor. With this setting, the heating operation can be started without impairing the comfort of the room while avoiding a rapid pressure increase on the high pressure side.

On the other hand, in the second invention, means for reducing the difference between the discharge pressure and the suction pressure at the time of reversing the four-way valve at the start of the defrosting operation (for example, turning off the operation of the compressor for a predetermined time before reversing the four-way valve). And means for increasing or decreasing the opening of the expansion mechanism from the predetermined time of reversing the four-way valve for a predetermined time)
Since the above is provided, it is possible to suppress a sudden pressure change when the four-way valve is reversed. Therefore, it is possible to reduce noise and vibration generated from the piping of the four-way valve when the defrosting operation is started.

That is, in order to achieve the above object, the claims
The invention according to 1 has a compressor, a four-way valve, and an indoor fan.
Room with indoor heat exchanger, expansion mechanism, and outdoor fan
Refrigerant circulation cycle is constructed by sequentially connecting outer heat exchangers
However, the indoor fan and the indoor heat exchanger are installed on the indoor side.
This indoor unit is installed in the placed indoor unit.
Is the indoor heat exchanger that sucks indoor air into the front side.
Front panel with a suction grill and the front
Temperature control by the indoor heat exchanger located below the panel
Blows the generated air into the indoor space through the indoor fan.
Equipped with a blow-out grill, at the same temperature as the refrigerant
With an alternative refrigerant whose saturation pressure is higher than that of HCFC22
In the air conditioner, it is installed indoors near the outlet grill.
Above the ceiling side in the indoor space where the wind blows from the fan
Direction adjusting hand to adjust the direction of the blowout angle toward the bottom and the floor side
And the temperature of the indoor heat exchanger and the indoor heat exchange
Temperature detection to detect at least one of the blowout temperature of the vessel
Means and the temperature of the room provided near the indoor heat exchanger.
Room temperature sensor to detect the temperature
The blowout angle is set at a position where the blowout air is directed upward toward the ceiling.
After that, the blowing angle is set to the lower side of the floor.
The outlet angle adjusting means is controlled so that it is set to the facing position.
Controlling the blowout angle and setting at the start of heating
The position of the outlet angle is
The blown outflow is short-circuited to the suction grill.
Set to the vertical position, and the blowout air is directed upwards toward the ceiling.
When the outlet angle is set to the
And a room temperature compensation means for correcting the detected temperature of the capacitor.

According to a second aspect of the present invention, the indoor heat exchange is performed.
A room temperature sensor that is installed near the chamber and detects the temperature inside the room
And has the blowing air at a position where the blowing air is directed upward toward the ceiling.
The temperature detected by the room temperature sensor when the angle is set
I am trying to disable it .

The invention according to claim 3 is a compressor, a four-way valve,
Indoor heat exchanger having indoor fan, expansion mechanism, and room
Refrigerant circulation by sequentially connecting outdoor heat exchangers with external fans
A ring cycle is formed, and the indoor fan and the indoor heat exchange
The exchange is installed in the indoor unit installed on the indoor side,
This indoor unit draws indoor air on the front side
The front panel on which the suction grill to be sent to the indoor heat exchanger is placed
And the indoor heat located below the front panel.
Air conditioned by the exchanger is passed through the indoor fan.
And a blowing grill for blowing into the indoor space, wherein the refrigerant
The saturation pressure at the same temperature is higher than that of HCFC22.
In an air conditioner using a replacement refrigerant, the four-way valve
The discharge side of the compressor is connected to the indoor heat exchanger,
The heating operation with the suction side of the machine connected to the outdoor heat exchanger.
At the start of defrosting operation during rotation, the four-way valve is controlled to reverse
The discharge side of the compressor to the outdoor heat exchanger,
Inverting the suction side of the compressor to each of the indoor heat exchangers
The reversing control means that continues, and the reversing control of the four-way valve
Set the compressor operating frequency to the specified defrosting operating frequency
Along with the reversing control of the four-way valve,
And the rotation of the outdoor fan are stopped, and the expansion mechanism
Defrosting operation control means for setting the opening degree to a predetermined defrosting opening degree,
Stop the operation of the compressor for a predetermined time before starting the reversal control.
Stop Discharge side pressure and suction side in the refrigerant circulation cycle
Pressure difference adjusting means for reducing the difference with the pressure.
It

The invention according to claim 4 is a compressor, a four-way valve,
Indoor heat exchanger having indoor fan, expansion mechanism, and room
Refrigerant circulation by sequentially connecting outdoor heat exchangers with external fans
A ring cycle is formed, and the indoor fan and the indoor heat exchange
The exchange is installed in the indoor unit installed on the indoor side,
The indoor unit before inhale indoor air on the front side
The front panel on which the suction grill to be sent to the indoor heat exchanger is placed
And the indoor heat located below the front panel.
Air conditioned by the exchanger is passed through the indoor fan.
And a blowing grill for blowing into the indoor space, wherein the refrigerant
The saturation pressure at the same temperature is higher than that of HCFC22.
In an air conditioner using a replacement refrigerant, the four-way valve
The discharge side of the compressor is connected to the indoor heat exchanger,
The heating operation with the suction side of the machine connected to the outdoor heat exchanger.
At the start of defrosting operation during rotation, the four-way valve is controlled to reverse
The discharge side of the compressor to the outdoor heat exchanger,
Inverting the suction side of the compressor to each of the indoor heat exchangers
The reversing control means that continues, and the reversing control of the four-way valve
Set the compressor operating frequency to the specified defrosting operating frequency
Along with the reversing control of the four-way valve,
And the rotation of the outdoor fan are stopped, and the expansion mechanism
Defrosting operation control means for setting the opening degree to a predetermined defrosting opening degree,
The operating frequency of the compressor during the reversal control is
Refrigerant circulation cycle set lower than the defrosting operation frequency
Pressure that reduces the difference between the discharge side pressure and the suction side pressure at
And a force difference adjusting means.

The invention according to claim 5 is a compressor, a four-way valve,
Indoor heat exchanger having indoor fan, expansion mechanism, and room
Refrigerant circulation by sequentially connecting outdoor heat exchangers with external fans
A ring cycle is formed, and the indoor fan and the indoor heat exchange
The exchange is installed in the indoor unit installed on the indoor side,
This indoor unit draws indoor air on the front side
The front panel on which the suction grill to be sent to the indoor heat exchanger is placed
And the indoor heat located below the front panel.
Air conditioned by the exchanger is passed through the indoor fan.
And a blowing grill for blowing into the indoor space, wherein the refrigerant
The saturation pressure at the same temperature is higher than that of HCFC22.
In an air conditioner using a replacement refrigerant, the four-way valve
The discharge side of the compressor is connected to the indoor heat exchanger,
The heating operation with the suction side of the machine connected to the outdoor heat exchanger.
At the start of defrosting operation during rotation, the four-way valve is controlled to reverse
The discharge side of the compressor to the outdoor heat exchanger,
Inverting the suction side of the compressor to each of the indoor heat exchangers
The reversing control means that continues, and the reversing control of the four-way valve
Set the compressor operating frequency to the specified defrosting operating frequency
Along with the reversing control of the four-way valve,
And the rotation of the outdoor fan are stopped, and the expansion mechanism
Defrosting operation control means for setting the opening degree to a predetermined defrosting opening degree,
The operation of the compressor is performed a predetermined time before the start of the reversal control.
Set the rotation frequency to the defrosting operation frequency and perform the reversal control.
The pressure difference that maintains the defrosting operation frequency until the start
Equipped with adjustment means .

The invention according to claim 6 is the pressure difference adjusting hand.
The stage is configured such that the expansion mechanism is operated for a predetermined time before the start of the inversion control.
Increase the opening by a specified amount compared to the opening during the heating operation
Equipped with opening control means for temporarily lowering the discharge pressure
ing.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 is a diagram showing a configuration of a refrigeration cycle of an air conditioner in the present embodiment. Then, in the refrigeration cycle of the air conditioner of this configuration, the saturation pressure is higher than that of R22 at the same temperature, for example, the saturation pressure at 50 ° C. is 250.
An alternative refrigerant of 0 kPa or more is used. In addition, as such an alternative refrigerant, a refrigerant that does not particularly destroy the ozone layer is R
The composition of 32 (CH ₂ F ₂ ) and R125 (CHF ₂ CF ₃ ) is 80% or more, and the composition of R143a (CH ₃ CF ₃ ) and R125 (CHF ₂ CF ₃ ) is 80% or more. There are refrigerants and refrigerants having a composition of R32 (CH ₂ F ₂ ) of 45% or more.

As shown in FIG. 1, an air conditioner 1 includes a compressor (compressor) 2, a four-way valve 3 having a refrigerant flow path switching function, and an indoor heat exchanger 4 having an indoor fan 4a.
An electronically controlled valve (PMV) 5 as an expansion valve and an outdoor heat exchanger 6 having an outdoor fan 6a are sequentially and annularly connected via a pipe 7 to form a refrigeration cycle for reversibly circulating a refrigerant. There is.

As can be seen from this refrigeration cycle, in the air conditioner 1, the refrigerant is controlled by the switching control of the four-way valve 3 (four-way valve 3 → OFF) during operation of the indoor fan 4a and the outdoor fan 6a, in the direction of the solid line arrow in the figure. Circulate to (compressor 2
→ Four-way valve 3 → Outdoor heat exchanger (condensing action) 6 → PMV5
→ The indoor heat exchanger (evaporative cooling function) 4 → The four-way valve 3 → The compressor 2 → ...
By switching control of the four-way valve 3 (four-way valve 3 → ON), the refrigerant is circulated in the direction of the broken line in the figure (compressor 2 → four-way valve 3 → indoor heat exchanger (condensing heating function) 4 → expansion valve 5 → outdoor heat Exchanger (evaporation function) 6-> four-way valve 3-> compressor 2->)
By doing so, the heating operation is performed.
Further, during the heating operation, the indoor fan 4a and the outdoor fan 6a are stopped and the four-way valve 3 is switched and controlled so that the refrigerant is circulated in the direction opposite to the circulation direction during heating (the solid line direction in the figure) to perform the defrosting operation. Is executable.

Then, the compressor 2, the four-way valve 3, the PM
The V5, the outdoor heat exchanger 6, and the outdoor fan 6a are provided in an outdoor unit installed outdoors. The outdoor unit is installed in the outdoor heat exchanger 6, and an evaporation temperature sensor 9 for detecting the refrigerant evaporation temperature of the outdoor heat exchanger 6 is installed.
And an outdoor air temperature sensor 10 provided on the outdoor heat exchanger 6 itself or in the vicinity of the outdoor heat exchanger 6 to detect the outdoor air temperature. The evaporation temperature sensor 9 and the outdoor air temperature sensor 10 detect the temperature. It has a function of controlling the entire outdoor side including the compressor 2 and the like based on the generated signal and the like.

Further, the indoor heat exchanger 4 and the indoor fan 4a
And are provided in an indoor unit installed indoors.
The indoor unit includes an indoor temperature sensor 11 that detects an indoor temperature, and a heat exchanger temperature sensor 12 that is installed in the indoor heat exchanger 4 and that detects a refrigerant condensation temperature of the indoor heat exchanger 4.
And has a function of controlling the entire indoor side including the indoor heat exchanger 4 and the indoor fan 4a based on signals detected by the indoor temperature sensor 11 and the heat exchanger temperature sensor 12, respectively. There is. The indoor temperature sensor 1
1 is installed near the indoor heat exchanger 4 in the indoor unit (for example, on the windward side).

Here, FIG. 2 shows a schematic configuration of the indoor unit in FIG. According to FIG. 2, the indoor unit 15 including the indoor heat exchanger 4 and the indoor fan 4a is formed in a substantially rectangular parallelepiped shape as a whole, and the longitudinal direction corresponding to the rotation axis direction of the indoor fan 4a is the horizontal direction in the room. For example, it is installed on an indoor wall or the like so as to follow.

The indoor unit 15 has a main body casing 16, and a front panel 17 is mounted on the front surface side of the main body casing 16 facing the indoor wall installation side. The suction grill 18 is provided on the front side of the front panel 17.
An outlet grill 19 as an outlet is provided below the front floor side (lower side in the figure) of the front panel 17. Then, in the fan casing 20 of the main body casing 16, the suction grill 18 and the blowout grill 1 are provided.
An air passage 21 is formed to communicate with 9.

The ventilation passage 21 is provided with, for example, an indoor side heat exchanger 4 which is bent in an inverted V shape, and an indoor fan 4a, which is, for example, a cross-flow fan, downstream of the indoor heat exchanger 4 for sucking air. The indoor air sucked from the grill 18 into the main casing 16 is heat-exchanged by the indoor heat exchanger 4, and cool air or temperature-controlled air for heating is blown again from the grill 19 to the room by the indoor fan 4a to cool or heat the room. It is supposed to do.

The indoor fan 4a is constructed as a blower together with the fan casing 20 and the nose 25, and the nose 25 is fixed to the rear side wall of the drain pan 26 which receives the drain from the indoor heat exchanger 4.

Inside the blowing grille 19, blown air (blowing wind) w blown outward from the blowing grille 19 is blown upward above the ceiling and below the floor in the indoor space (hereinafter referred to as vertical direction). Up and down wind direction adjustment louver 2 to adjust the angle
7 and a left-right airflow direction adjusting louver 28 that adjusts the blowing angle in the horizontal direction (left-right direction) along the fan rotation axis.

The vertical airflow direction adjusting louver 27 has, for example, a pair of upper and lower horizontal louvers 27a and 27b which are strip-shaped thin plates. The horizontal louvers 27a and 27b extend along the longitudinal direction of the blowout grill 19 substantially parallel to the fan rotation axis. Are arranged parallel to each other over substantially the entire length thereof and are arranged in parallel in the vertical direction at a required interval. Each of the horizontal louvers 27a and 27b is configured to swing vertically by a swing mechanism (not shown) about an axis (swing axis) along the longitudinal direction.
By appropriately adjusting the vertical swing angle of 7a and 27b by a louver motor of the swing mechanism, which will be described later, the blowing air w
It is designed to control the blowing angle in the vertical direction.

Here, FIG. 3 shows a control system of the entire air conditioner 1 including the indoor unit 15 and the outdoor unit 30.

As shown in FIG. 3, the indoor unit 15 is provided with an indoor control unit 31 for controlling the entire indoor unit 15, for example, a microcomputer mounted therein, and the indoor control unit 31 has an AC for power supply. A power source S and a remote control R for remote operation control are connected to each other.

The indoor unit 15 can control the indoor temperature sensor 11 and the heat exchanger temperature sensor 12, the fan motor (FM) 32 for rotating the indoor fan 4a, and the rotational speed of the FM 32 at a variable speed. The speed control circuit 33 and the vertical louver 27 (lateral louvers 27a, 2)
7b) is provided with a louver motor (RM) 34 for rotating the oscillating shaft about the oscillating shaft, and a louver drive circuit 35 for driving the RM 34 while controlling its rotation angle. The indoor temperature sensor 11, the heat exchanger temperature sensor 12, the speed control circuit 34, and the louver drive circuit 35 are connected to the indoor control unit 31, respectively.

The indoor control section 31 controls the temperature T0 at which heat can be exchanged (condensed) in the indoor heat exchanger 4 during heating, the high-pressure side pressure P0 corresponding to the heat-exchangeable temperature T0, and the indoor side from the start of heating operation. At least one of the time t0 until the heat exchanger 4 is ready for heat exchange (condensation) is stored in advance in the internal memory, and the detection signals from the indoor temperature sensor 11 and the heat exchanger temperature sensor 12 are detected. And the outdoor unit 30
It is configured to control the speed control circuit 33 and the louver drive circuit 34 in accordance with the outdoor information signal or the like sent from (the outdoor control unit).

On the other hand, the outdoor unit 30 is connected to the outdoor control unit 40, which controls the entire outdoor unit 30, for example, an outdoor control unit 40, and information necessary for controlling the outdoor control unit 40. A memory (EEPROM) 41 capable of storing data and the like is provided, and an AC power supply line L is connected to the outdoor control section 40 via an indoor control section 31.

Further, the outdoor unit 30 includes a compressor motor (CM) 42 for driving the compressor 2 to rotate.
And an inverter circuit 43 for converting the AC power supplied from the AC power supply S via the AC power supply line L into DC once, smoothing it, and then converting the AC power again to drive the CM 42 in rotation. This inverter circuit 43
By controlling the rotation frequency of the CM 42 according to the control signal from the outdoor control unit 40, the cooling and heating capacity can be adjusted in a wide range.

Further, the outdoor unit 30 includes a fan motor (FM) 44 for rotating the outdoor fan 6a and an FM4.
4, a fan drive circuit 45 for controlling the rotational speed of the motor 4 while controlling the rotational speed of the motor 4, and the above-described four-way valve (4V) 3, PMV 5,
And an outdoor air temperature sensor 10, and the outdoor control unit 4
0 is a fan drive circuit 45 according to the detection signals from the evaporation temperature sensor 9 and the outside air temperature sensor 10 and the indoor information signal sent from (the indoor control section 31 of) the indoor unit 15.
Drive control, ON / OFF switching control of the four-way valve 3, and P
The opening degree of the MV5 is controlled.

Next, the overall operation of this embodiment, particularly the operation of the indoor unit at the start of the heating operation, will be described.

When the air conditioner 1 is operated and heating is started, the indoor control unit 31 controls the rotation of the RM 34 via the louver drive circuit 35 and the lateral louvers 27a, 27a.
The angular position of b is a position where the blowing air w is directed in the ceiling direction (upward direction) of the indoor space (for example, a horizontal position substantially parallel to the ceiling surface or the floor surface (or a horizontal position that is directed upward to the ceiling side from this horizontal position). ), Or a position where the blowout air w is sucked into the suction grill 18 in a short-circuited manner (a short circuit position facing upward from the horizontal position to the ceiling side) (FIG. 2).
The positions of the horizontal louvers 27a 'and 27b' shown by the broken lines and the blowing air w1 (louver horizontal position) and the blowing air w2 (louver short circuit position) shown by the broken line arrows). In this state, the outdoor control unit 40 turns on the four-way valve 3.
To the CM4 via the inverter circuit 43.
2 is rotationally driven to activate the compressor 2, and the FM 32 is rotationally driven via the fan drive circuit 45 to drive the outdoor fan 44.

On the other hand, the indoor control section 31 is connected to the outdoor control section 40.
In response to the compressor 2 start-up information sent from, the FM 44 is rotationally driven via the fan drive circuit 45 at substantially the same time as the compressor 2 start-up to start the operation of the indoor fan 4a (indoor fan ON). As a result, the indoor heat exchange is performed via the indoor heat exchanger 4 by the operation of the indoor fan 4a from the start of the heating operation. (See FIG. 4, step S10).

At this time, the indoor controller 31 constantly refers to the detection signal detected by the heat exchanger temperature sensor 12, and the temperature T of the indoor heat exchanger 4 based on the detection signal.
Rises and the T exceeds the heat exchangeable temperature T0 (T
It is determined whether ≧ T0) (step S11).

That is, when the temperature T of the indoor heat exchanger 4 detected by the heat exchanger temperature sensor 12 does not exceed the heat exchangable temperature T0 (T <T0).
After that, the determination in step S11 is NO, and the determination process in step S11 is repeated. At this time, since T <T0, the blowing air blown from the blowing grille 19 under the operation of the indoor fan 4a is cold air. However, this cold blowing air is such that the angular position of the horizontal louvers 27a and 27b is at the horizontal position or Since it is set to the short circuit position, it is blown out above the ceiling side of the indoor space as shown as blowout air w1 and blowout air w2, or is blown so as to be short-circuited by the suction grille 18. The temperature of the indoor space is kept small without cooling the entire indoor space.

When the temperature T of the indoor heat exchanger 4 exceeds the heat exchangable temperature T0 (T ≧ T0), the result of the determination in step S11 is YES, and the indoor control unit 31 drives the louver. The RM 34 is rotationally controlled via the circuit 35 to set the angular position of the lateral louvers 27a, 27b to a position where the blown air, which is a position to be directed during normal heating, is directed toward the floor (downward) in the room (in FIG. 2). (See the positions of the horizontal louvers 27a and 27b indicated by the solid line). Then, the normal heating operation is performed. That is, the indoor fan 4a
The blowing air blown from the blowing grille 19 under the operation of T is T ≧ T0, and therefore is warm air, and this warm blowing air is directed toward the floor (downward) in the room as indicated by the solid arrow w. Since it is blown out, the indoor space is heated (step S12).

In the above heating operation starting operation, an example of changes in the high pressure side pressure PA, the oil level height HA, and the leakage current IA when the horizontal axis represents the elapsed time t from the heating operation start time is shown in FIG. Shown in.

That is, in this configuration, even in the air conditioner using the alternative refrigerant having the same saturated temperature and higher saturation pressure than R22, the indoor fan 4a is operated immediately after the heating operation is started, and the heating operation is started. Immediately after the indoor heat exchanger 4
Since the heat exchange is carried out at, the high pressure side pressure PA gradually rises as shown in FIG. As a result, the maximum pressure (peak) of the high-pressure side pressure PA is lower than that of the conventional one, and the rapid rise and high peak of the high-pressure side pressure PA may affect the reliability and life of the compressor 2, the indoor heat exchanger 4, etc. It can be avoided.

Further, as shown in FIG. 5, the high pressure side pressure PA
However, the melting of the refrigerant into the lubricating oil does not occur excessively, and the oil level rise is very small compared to the conventional case (see oil level height HA). Therefore, the peak of the leakage current IA caused by the rise of the oil level can be made much lower than in the conventional case.

In this configuration, the horizontal louver 27a ',
If the position of 27b 'is set to the short circuit position, the suction temperature of the indoor heat exchanger 4 rises, so the time until the normal heating operation (louver downward operation) is started is shortened.

Further, in this configuration, the horizontal louvers 27a, 27
Although the angular position of b is controlled by the temperature T of the indoor heat exchanger 4 detected by the heat exchanger temperature sensor 12, the present invention is not limited to this, and the temperature T of the indoor heat exchanger 4 is controlled. May exceed the heat exchangeable temperature T0 based on the change in the room temperature detected by the indoor temperature sensor 11 in response to the temperature change, and the angular position control of the lateral louvers 27a and 27b may be performed. . In addition, the horizontal louver 27
The angular position control of a and 27b is performed based on the time t0 from the start of the heating operation until the indoor heat exchanger 4 becomes in a state where heat exchange (condensation) is possible, based on the elapsed time from the start of the heating operation. Good. Furthermore, the horizontal louvers 27a, 27
The angular position control of b is performed based on the high pressure side pressure value obtained by the temperature T of the indoor heat exchanger 4 with reference to the high pressure side pressure P0 in the heat exchange (condensation) state of the indoor heat exchanger 4. You may go.

While the horizontal louvers 27a and 27b are directed to the horizontal position or the short circuit position, the blowing air is blown upward toward the ceiling and sucked into the suction grill 18, so that the room temperature detected by the indoor temperature sensor 11 is detected. May be perceived as exceeding the actual room temperature. Therefore, while the horizontal louvers 27a and 27b are facing the horizontal position or the short circuit position, the room temperature detected by the indoor temperature sensor 11 is added to the temperature rise amount due to the amount of blown air blown upward toward the ceiling. And the room control unit 31 based on the corrected room temperature.
The operation of the horizontal louvers 27a, 27b.
It may be configured to invalidate the room temperature detected by the indoor temperature sensor 11 and control the operation of the indoor control unit 31 while the is directed to the horizontal position or the short circuit position. According to this structure, it is possible to avoid the malfunction caused by the operation control of the indoor control unit 31 based on the detected value of the indoor temperature sensor 11 different from the actual room temperature, and further improve the reliability. it can.

Second Embodiment The configuration of the air conditioner in this embodiment is substantially the same as the configuration shown in FIGS. 1 to 3, and the description thereof will be omitted. That is, since the air conditioner 1 of the present embodiment is characterized by the control operation when performing the defrost control, the overall operation based on the defrost control will be described in detail below with reference to FIG. 6, and other operations will be described. The description is omitted. As in the first embodiment, the refrigerant used is not R22, but an alternative refrigerant having a higher saturation pressure at the same temperature than R22, for example, a saturation pressure at 50 ° C. of 2500 kPa or more.

Now, assuming that the air conditioner 1 is performing heating operation, the compressor 2 is driven at a predetermined constant operating frequency (rotation speed), and the four-way valve 3 is switched on and controlled. . The operating frequency (rotational speed) is hereinafter referred to as the heating operating frequency.

The indoor fan 4a is operated (ON) at a predetermined constant number of revolutions, and the outdoor fan 6a is operated.
Also is operated (ON) at a predetermined constant number of revolutions. Further, the PMV 5 is controlled to a constant opening based on the control (superheat (SH) control) based on the heating operation.

That is, during the heating operation, the high-temperature high-pressure refrigerant (alternative refrigerant) compressed by the compressor 2 is guided to the indoor heat exchanger 4 via the four-way valve 3 as shown by the solid line, and the indoor fan 4a is cooled. The room is heated by radiating heat according to the rotation. The refrigerant condensed by heating the room,
The PMV 5 receives the expansion action to reduce the pressure and is guided to the outdoor heat exchanger 6. With this outdoor heat exchanger 6, the outdoor fan 6
The refrigerant that has absorbed heat from the outside air and evaporated according to the rotation speed of a is
It is again sent to the compressor 2 via the four-way valve 3 and compressed, and is again guided to the indoor heat exchanger 4 via the four-way valve 3 as a high-temperature high-pressure refrigerant. Heating operation is performed by repeating such a heating cycle (FIG. 6;
See step S20).

During the heating operation described above, the evaporation temperature Te of the refrigerant evaporated in the outdoor heat exchanger 6 detected by the evaporation temperature sensor 9 is lower than the predetermined temperature Ts (eg, -2 ° C.) (Te <Ts). The outdoor control unit 40 always determines whether or not the state is continued for a predetermined time (for example, 30 minutes) (step S21), and if not continued (step S21).
As a result of the determination in No. 21, it is determined that it is not necessary to perform the defrosting operation, and the operation of step S20, that is, the heating operation is repeated.

On the other hand, as a result of the judgment in step S21, YE
When S, that is, "Te <Ts" is continued for a predetermined time or more, the indoor control unit 31 and the outdoor control unit 40 execute the defrosting operation control.

At this time, the outdoor control section 40 first controls the driving of the CM 42 via the inverter circuit 43 to stop the rotation operation of the compressor 2 (compressor 2 OFF; step S22). And compressor 2
After a lapse of a predetermined time after the stop, the outdoor control unit 40 reverses the ON four-way valve 3 to OFF to reverse the circulation direction of the refrigerant to that during heating, and at the same time, opens the PMV 5 at a constant opening (defrost opening). Control to hold. Further, at the same time when the four-way valve 3 is reversed, the FM 44 is controlled via the fan drive circuit 45 to stop the operation of the outdoor fan 6a. The indoor control unit 31 also controls the FM 32 via the speed control circuit 33 at the same time when the four-way valve 3 is reversed (at the same time as the operation of the outdoor fan 6a is stopped).
Is controlled to stop the operation of the indoor fan 4a (step S23).

As a result, the defrosting operation is started. That is, the high-temperature high-pressure gaseous refrigerant discharged from the compressor 2 is guided into the outdoor heat exchanger 6 via the four-way valve 3 in the OFF state, and radiates heat in the outdoor heat exchanger 6 to be liquefied. . At this time, the frost adhered to the outer surface of the outdoor heat exchanger 6 is heated and removed by the heat radiation of the refrigerant. The liquid refrigerant condensed and liquefied in the outdoor heat exchanger 6 is sent to the indoor heat exchanger 4 via the PMV 5, and the indoor heat exchanger 4
Inside, the heat is absorbed by natural convection to evaporate and vaporize. The vaporized refrigerant (gaseous refrigerant) is returned to the compressor 2 again, and the above operation cycle is repeated thereafter (step S24).

On the other hand, on the basis of the evaporation temperature Te value of the refrigerant evaporated in the outdoor heat exchanger 6 detected by the evaporation temperature sensor 9, the outdoor controller 40 sets the evaporation temperature Te to a predetermined temperature Tu (for example, 5 ° C.). ) Is exceeded (Te> Tu) (step S25), and the result of this determination is NO.
If (Te ≦ Tu), the defrosting operation in step S24 is repeated. On the other hand, if the result of the determination in step S25 is YES, that is, if “Te> Tu”, the outdoor control unit 31 determines that defrosting has been completed, returns to the process of step S20, and repeats the heating operation described above. .

FIG. 7 shows a sequence diagram of the air conditioner 1 (the compressor 2, the four-way valve 3, the indoor fan 4a, the outdoor fan 6a, and the PMV 5) in the heating operation and the defrosting operation shown in the flowchart of FIG. 6 above. As shown in FIG. 7, in this configuration, the compressor 2 is turned off before the defrosting is started.
Since the four-way valve 3 is reversed and the defrosting operation is started in a state where the discharge pressure and the suction pressure in the compressor 2 are zero, the difference between the overall discharge pressure and the suction pressure becomes small, and the four-way valve The pressure change at the time of 3 inversion also occurs gently.
Therefore, it is possible to reduce the noise and vibration generated in the piping of the four-way valve 3 when the four-way valve 3 is reversed so that the surroundings are hardly affected.

When it is determined that the defrosting has been completed and the process returns to step S20 and the heating operation is repeated, the outdoor control section 40 causes the inverter circuit 43 and C
The operating frequency of the compressor 2 may be increased from the defrosting frequency to the heating operating frequency while controlling M42 to continue the operation of the compressor 2. Further, the outdoor control unit 40 may control the inverter circuit 43 and the CM 42 to temporarily stop the operation of the compressor 2 and raise the operating frequency of the compressor 2 to the heating operating frequency after a predetermined time has elapsed (see FIG. 7). (Refer to the sequence of compressor operating frequencies indicated by the dashed line).

Further, in this configuration, the compressor 2 is turned off before the start of the defrosting operation to reduce the difference between the entire discharge pressure and suction pressure, but the present invention is not limited to this, and various A modified example of is conceivable.

As a first modification, for example, as shown in the sequence diagram of FIG. 8, the outdoor control unit 40 gradually lowers the operating frequency of the compressor 2 in the process of step S22 of FIG. When the frequency becomes lower than the defrosting frequency (the operating frequency Hmin at this time), the four-way valve 3 is reversed and the defrosting operation is started. Even with this configuration, as in the case where the compressor 2 is turned off as described above, the operating frequency of the compressor 2 is sufficiently lower than the heating operating frequency and the defrosting operating frequency at the start of defrosting, so the discharge pressure is reduced. Is sufficiently reduced, and the difference between the discharge pressure and the suction pressure is small. Therefore,
Noise and vibration generated in the piping of the four-way valve 3 at the time of reversing the four-way valve 3 can be reduced to such an extent that it hardly affects the surroundings. Further, in the configuration of the present modification, the operating frequency of the compressor 2 is controlled to be gradually decreased and is not turned off. Therefore, the discharge pressure and the suction pressure at the start of defrosting (when the four-way valve 3 is reversed) are Although the degree of the difference is smaller than that in the case of “compressor 2 → OFF control”, on the other hand, since the compressor 2 is always driven before the defrosting operation is started, the heating operation during that time is continuously performed. Therefore, there is an advantage that the comfort by heating before defrosting operation start is not impaired. In addition,
It goes without saying that the operating frequency Hmin may be set to "0 Hz".

A second modification is shown in FIG. 9 as a sequence diagram. According to FIG. 9, the outdoor control unit 40 gradually reduces the operating frequency of the compressor 2 in the process of step S22 of FIG. 6 and sets the operating frequency in a state where the operating frequency is substantially matched with the defrosting frequency. Hold for a certain time,
The defrosting operation may be started by reversing the four-way valve 3 in this held state. In the case of such a configuration, at the start of defrosting, the operating frequency of the compressor 2 is maintained at a constant defrosting frequency without change while being sufficiently lower than the heating operating frequency. The discharge pressure can be reduced, and the difference between the discharge pressure and the suction pressure can be reduced. Therefore, the four-way valve 3
It is possible to reduce the noise and vibration generated in the piping of the four-way valve 3 at the time of reversal to such an extent that it hardly affects the surroundings.

In this modified example, as in the first modified example, since the compressor 2 is always driven before the defrosting operation is started, the heating operation can be continuously performed during the defrosting operation. It has the advantage of not compromising the comfort of heating before the start.

Furthermore, a third modification is shown in FIG. 10 as a sequence diagram. According to FIG. 10, the outdoor control unit 40 starts gradually lowering the operating frequency of the compressor 2 in the process of step S22 of FIG. 6 and sets the opening degree of the PMV 5 to a predetermined opening degree from the opening degree based on the SH control. Control to open only (opening "up"). Then, when the operating frequency reaches the defrosting frequency, the outdoor control unit 40 reverses the four-way valve 3 to OFF to reverse the circulation direction of the refrigerant to that during heating, and further opens the opening degree of the PMV 5 to defrost. Control to maintain the opening. Further, at the same time when the four-way valve 3 is reversed, the operation of the outdoor fan 6a is turned off, and the operation of the indoor fan 4a is turned off under the control of the indoor control unit 31 to start the defrosting operation.

According to the configuration of this modification, the P
Since the opening degree of the MV5 is further opened from the opening degree based on the SH control by a predetermined opening degree, the time from opening the PMV5 to the start of defrosting is via the PMV5 and the outdoor heat exchanger 6 (evaporator). The liquefied refrigerant is contained in the refrigerant gas sent to the compressor 2 (liquid back state). The liquefied refrigerant is removed from the refrigerant gas containing the liquefied refrigerant via an accumulator (not shown), and only the refrigerant gas is sucked into the compressor 2.

That is, according to the configuration of this modification, by opening the opening of the PMV 5 by a predetermined opening before the defrosting operation to perform the heating operation to create the liquid back state, and separating the liquefied component via the accumulator. Since the amount of the refrigerant gas that circulates in the heating cycle is reduced, the discharge pressure can be temporarily reduced (until the start of the defrosting operation). Therefore, similarly to the above-described embodiment and each modification, the difference between the discharge pressure and the suction pressure becomes small, and the pressure change at the time of reversing the four-way valve 3 also occurs gently. As a result, it is possible to reduce the noise and vibration generated in the piping of the four-way valve 3 when the four-way valve 3 is reversed, to the extent that the noise and vibration hardly affect the surroundings.

The fourth modification is shown in FIG. 11 as a sequence diagram. According to FIG. 11, the outdoor control unit 40 is
In the process of step S22 of FIG. 6, the compressor 2
The operation frequency is gradually reduced, and the opening degree of the PMV 5 is controlled to be further closed from the opening degree based on the SH control by a predetermined opening degree (opening degree “down”). And
When the operating frequency reaches the defrosting frequency, the outdoor control unit 4
At 0, the four-way valve 3 is turned off to reverse the circulation direction of the refrigerant to that during heating, and the opening of the PMV 5 is controlled to be wide open to maintain the defrost opening. Further, at the same time as reversing the four-way valve 3, the operation of the outdoor fan 6a is turned off, and the operation of the indoor fan 4a is controlled under the control of the indoor control unit 31 → O.
FF is started and defrosting operation is started.

According to the configuration of this modification, P
Since the opening degree of the MV5 is closed from the opening degree based on the SH control by a certain opening degree, the amount of the refrigerant gas circulating in the heating cycle is reduced from the closing of the PMV5 to the start of defrosting. Therefore, the discharge pressure can be reduced until the defrosting operation starts. As a result, similarly to the above-described second embodiment and each modification, the difference between the discharge pressure and the suction pressure becomes small, and the pressure change at the time of reversing the four-way valve 3 also occurs gently, and the second embodiment and each modification. Noise and vibration suppression effects similar to are obtained.

Next, FIG. 12 shows a fifth modification as a sequence diagram. According to FIG. 12, the outdoor control unit 40 is
In the process of step S22 of FIG. 6, the compressor 2
Gradually reduce the operating frequency of. This outdoor control unit 40
The indoor control unit 31
Causes the rotational speed of the indoor fan 4a to be increased by a predetermined number ("up") via the speed control circuit 33 and the FM 32. Then, when the operating frequency reaches the defrosting frequency, the outdoor control unit 40 reverses the four-way valve 3 to OFF to reverse the circulation direction of the refrigerant to that during heating, and also opens the PMV 5 to open the defrosting opening. Control to hold every time. Furthermore, four-way valve 3
The outdoor fan 6a is turned off at the same time as the reversing.
Then, the indoor control unit 31 simultaneously with the reversal of the four-way valve 3 (at the same time as the operation of the outdoor fan 6a is turned off), the speed control circuit 33.
Also, the operation (rotation) of the indoor fan 4a is turned off via the FM 32 to start the defrosting operation.

According to the configuration of this modification, the rotation speed of the indoor fan 4a is increased by a predetermined number before the start of defrosting.
During the period from the rotation speed of the indoor fan 4a up to the start of defrosting, the condensation amount (heat radiation amount) of the indoor heat exchanger 4 (condenser) increases. Therefore, the discharge pressure can be reduced until the defrosting operation starts. As a result, similarly to the above-described second embodiment and each modification, the difference between the discharge pressure and the suction pressure becomes small, and the pressure change at the time of reversing the four-way valve 3 also occurs gently, and the second embodiment and each modification. Noise and vibration suppression effects similar to are obtained.

A sixth modification is shown in FIG. 13 as a sequence diagram. According to FIG. 13, in the process of step S22 of FIG. 6, the outdoor control unit 40 gradually starts to decrease the operating frequency of the compressor 2 and sets the rotation speed of the outdoor fan 6a to a predetermined value via the fan drive circuit 45 and FM44. A few down (“down”). Then, when the operating frequency reaches the defrosting frequency, the outdoor control unit 40 reverses the four-way valve 3 to OFF to reverse the circulation direction of the refrigerant to that during heating, and also opens the PMV 5 to open the defrosting opening. Control to hold every time. Furthermore, the outdoor control unit 40
At the same time as reversing the four-way valve 3, the fan drive circuit 45 and FM4
The operation (rotation) of the outdoor fan 6 a is turned off via the indoor fan 4 and the indoor fan 4 a is controlled by the indoor controller 31.
The operation of a is turned off and the defrosting operation is started.

According to the configuration of this modification, the rotation speed of the outdoor fan 6a is reduced by a predetermined number before the start of defrosting.
The evaporation amount (heat absorption amount) of the outdoor heat exchanger 6 (evaporator) decreases during the period from when the rotation speed of the outdoor fan 6a decreases to when defrosting starts. Therefore, although the suction pressure decreases until the defrosting operation starts, the refrigerant circulation amount in the heating cycle can be reduced. The discharge pressure decreases due to the reduction of the refrigerant circulation amount, and since the decrease amount is larger than the decrease amount of the suction pressure, the difference between the discharge pressure and the suction pressure is small as in the second embodiment and each modification described above. Become. Therefore, the pressure change at the time of reversing the four-way valve 3 also occurs gently, and the same noise / vibration suppressing effect as that of the second embodiment and each modification can be obtained.

By the way, in the present embodiment, various controls for reducing the difference between the discharge pressure and the suction pressure are shown in the flowchart of FIG. 6 and the sequence diagrams of FIGS. 7 to 13, but are shown in FIGS. It is also possible to combine and execute the respective controls. That is, one of the frequency controls of the compressor 2 shown in FIGS.
One of the PMV5 opening controls shown in FIG.
The rotational speed control of the indoor fan 4a shown in 2 and the rotational speed control of the outdoor fan 6a shown in FIG. 13 can be combined and executed. For example, in FIG. 14, compressor 2 OFF control (FIG. 7), PMV5 opening increase control (FIG. 10), indoor fan 4a rotation speed increase (FIG. 12),
And shows a sequence diagram executed outdoor fan 6a rpm down (FIG. 13) in combination, respectively.

By executing the respective operation controls in combination as described above, a synergistic effect is produced and a larger noise
A vibration suppressing effect can be obtained.

In this embodiment, as the alternative refrigerant,
A refrigerant having a saturation pressure of 2500 kPa or more at 50 ° C. was used, but the present invention is not limited to this, and R
Any refrigerant may be used as long as it is a refrigerant having a higher saturated pressure at the same temperature than 22 and does not destroy the ozone layer.

[0084]

As described above, according to the air conditioner of the first aspect, the blowing angle to the ceiling side upper side and the floor side lower side in the indoor space is set so that the blowing air is upward to the ceiling side at the start of the heating operation. Set to a position to face (a position to be directed during cooling, or a position above which air blown from the blowout grill is short-circuited to the suction grill, etc.), for example, the temperature of the indoor heat exchanger rises and heat is exchanged. When it reaches a possible state, the blowing angle is set to a position where the blowing wind is directed downward toward the floor. With this setting, the heating operation can be started without impairing the comfort of the room while avoiding a rapid pressure increase on the high pressure side. That is, since the pressure on the high pressure side gradually rises, it is possible to maintain the performance and reliability of the compressor at a high level and prevent damage to the heat exchanger and the like.

Further, according to the air conditioner of the third aspect, since the difference between the discharge pressure and the suction pressure at the time of reversing the four-way valve at the start of the defrosting operation is made small, the rapid pressure change at the time of reversing the four-way valve is suppressed. can do. Therefore, it is possible to reduce noise and vibration generated from the piping and the like when the four-way valve is reversed in the defrosting operation, and it is possible to provide an air conditioner that is easy to use.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a refrigeration cycle of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a schematic configuration of an indoor unit in FIG.

FIG. 3 is a control system diagram of the entire air conditioner including an indoor unit and an outdoor unit.

FIG. 4 is a schematic flowchart showing an example of an operation from a heating operation start to a normal heating operation in the first embodiment.

FIG. 5 is a high-side pressure PA when the horizontal axis represents an elapsed time t from the start of the heating operation in an air conditioner using an alternative refrigerant having a higher saturated pressure at the same temperature than R22 of the present embodiment, The graph which shows an example of the change of oil surface height HA and leakage current IA.

FIG. 6 is a schematic flowchart showing an example of an operation in a defrosting operation during a heating operation in the second embodiment.

FIG. 7 is a sequence diagram of a compressor, a four-way valve, an indoor fan, an outdoor fan, and a PMV in the heating operation and the defrosting operation when the horizontal axis is the time axis.

FIG. 8 is a sequence diagram of a compressor, a four-way valve, an indoor fan, an outdoor fan, and a PMV in the heating operation and the defrosting operation when the horizontal axis is the time axis in the first modified example.

FIG. 9: Compressor, four-way valve in heating operation and defrosting operation when the horizontal axis is the time axis in the second modification
The sequence diagram of an indoor fan, an outdoor fan, and PMV.

FIG. 10 is a sequence diagram of a compressor, a four-way valve, an indoor fan, an outdoor fan, and a PMV in the heating operation and the defrosting operation when the horizontal axis is the time axis in the third modified example.

FIG. 11 is a sequence diagram of a compressor, a four-way valve, an indoor fan, an outdoor fan, and a PMV in the heating operation and the defrosting operation when the horizontal axis is the time axis in the fourth modified example.

FIG. 12 is a sequence diagram of a compressor, a four-way valve, an indoor fan, an outdoor fan, and a PMV in the heating operation and the defrosting operation when the horizontal axis is the time axis in the fifth modified example.

FIG. 13 is a sequence diagram of a compressor, a four-way valve, an indoor fan, an outdoor fan, and a PMV in the heating operation and the defrosting operation when the horizontal axis is the time axis in the sixth modified example.

FIG. 14 is a sequence diagram of a compressor, a four-way valve, an indoor fan, an outdoor fan, and a PMV in the heating operation and the defrosting operation when the horizontal axis is the time axis in another example.

FIG. 15 is a schematic flow chart showing an example of an operation from a heating operation start to a normal heating operation in the related art.

FIG. 16 shows the discharge pressure Pd and the suction pressure P when the defrosting operation is performed in an air conditioner using R22 as a refrigerant and the horizontal axis represents the elapsed time t from the start of the defrosting operation.
The graph which shows the difference with s.

FIG. 17 is a high-side pressure P and an oil level when the horizontal axis represents an elapsed time t from the start of the heating operation in an air conditioner using an alternative refrigerant having a higher saturation pressure at the same temperature than that of the conventional R22. 3 is a graph showing an example of changes in height H and leakage current I.

FIG. 18: Discharge when the defrosting operation is performed in an air conditioner using an alternative refrigerant having a saturation pressure of 2500 kPa or more at 50 ° C., when the horizontal axis indicates the elapsed time t from the start of the defrosting operation The graph which shows the difference of pressure Pd 'and suction pressure Ps'.

[Explanation of symbols]

1 air conditioner 2 compressor 3 four-way valve 4 Indoor heat exchanger 4a indoor fan 5 PMV 6 Outdoor heat exchanger 6a outdoor fan 9 Evaporation temperature sensor 10 Outside air temperature sensor 11 Indoor temperature sensor 12 Heat exchanger temperature sensor 15 Indoor unit 18 Suction grill 19 blowout grill 27 Vertical louver 27a, 27b Horizontal louver 30 outdoor units 31 Indoor control unit 32 FM (fan motor) 33 Speed control circuit 34 RM (louver motor) 35 Louver drive circuit 40 Outdoor control unit 41 EEPROM 42 CM (compressor motor) 43 Inverter circuit 44 FM (fan motor) 45 Fan drive circuit

Continuation of front page (51) Int.Cl. ⁷ identification code FI F25B 47/02 570 F25B 47/02 570F 570M (56) References JP-A-63-143446 (JP, A) JP-A-8-233386 (JP) , A) JP-A-5-50038 (JP, A) JP-A-5-288386 (JP, A) JP-A-8-210711 (JP, A) JP-A-8-327193 (JP, A) JP-A 60-243436 (JP, A) JP-A-56-49834 (JP, A) JP-A-4-24454 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F24F 11/02 102

Claims (6)

(57) [Claims] 1. Room with compressor, four-way valve, indoor fan
Outdoor with an internal heat exchanger, expansion mechanism, and outdoor fan
A side-by-side heat exchanger is sequentially connected to form a refrigerant circulation cycle,
The indoor fan and the indoor heat exchanger are installed indoors.
The indoor unit is located inside the
The indoor air is sucked into the front side and sent to the indoor heat exchanger.
Front panel with a suction grill and the front panel
Temperature is controlled by the indoor heat exchanger located below
Blows out the air into the indoor space through the indoor fan
It is equipped with a blow-out grill and is used as the refrigerant at the same temperature.
Air conditioning using an alternative refrigerant whose sum pressure is higher than HCFC22
In Japanese machines, It is installed near the outlet grill and blows out from the indoor fan.
Of the wind blown to the ceiling side above and floor side below in the indoor space
The blowout angle adjusting means for adjusting the blowout angle, and the indoor heat
Of the temperature of the heat exchanger and the blowing temperature of the indoor heat exchanger.
Temperature detecting means for detecting at least one of the above, and the indoor side
A room temperature sensor installed near the heat exchanger that detects the temperature inside the room.
And the blowing angle at the start of heating operation.
Set the position where the wind blows upward to the ceiling side, then
Set the blowout angle to the position where the blowout air goes downward on the floor side.
Angle control for controlling the outlet angle adjusting means so that
Means and the position of the outlet angle set at the start of heating.
The air blown from the blowout grill is short-circuited.
And set the position to be sucked into the suction grill.
At the position where the blown wind is directed upward toward the ceiling,
Temperature detected by the room temperature sensor when the temperature is set.
A room temperature correcting means for correcting the temperature
Japanese machine. 2. A chamber disposed near the indoor heat exchanger
There is a room temperature sensor that detects the temperature inside the
The blowout angle is set at a position that goes upward on the well side.
At that time, the temperature detected by the room temperature sensor was invalidated.
The air conditioner according to claim 1. 3. Room with compressor, four-way valve, indoor fan
Outdoor with an internal heat exchanger, expansion mechanism, and outdoor fan
Refrigerant circulation cycle by sequentially connecting side heat exchangers Configure
The indoor fan and the indoor heat exchanger are installed indoors.
The indoor unit is located inside the
The indoor air is sucked into the front side and sent to the indoor heat exchanger.
Front panel with a suction grill and the front panel
Temperature is controlled by the indoor heat exchanger located below
Blows out the air into the indoor space through the indoor fan
It is equipped with a blow-out grill and is used as the refrigerant at the same temperature.
Air conditioning using an alternative refrigerant whose sum pressure is higher than HCFC22
In Japanese machines, The four-way valve allows the discharge side of the compressor to be in heat exchange with the indoor side.
Connect the suction side of the compressor to the outdoor heat exchanger.
At the start of the defrosting operation during the heating operation that continued,
The discharge side of the compressor is controlled to the outside by controlling the four-way valve to reverse.
In the heat exchanger, the suction side of the compressor is connected to the indoor heat exchanger.
And a reversing control means for reversing connection with the four-way valve
Predetermined defrosting operation of the compressor operating frequency during reverse control
The frequency is set, and the reversing control of the four-way valve is performed.
The rotation of the indoor fan and the outdoor fan is stopped, and
Defrosting that sets the opening of the expansion mechanism to a predetermined defrosting opening
The operation control means, and a predetermined time before starting the reversal control
The operation of the compressor is stopped and the discharge in the refrigerant circulation cycle is performed.
Pressure difference adjuster that reduces the difference between the outlet pressure and the suction pressure
An air conditioner characterized by having steps. 4. Room with compressor, four-way valve, indoor fan
Outdoor with an internal heat exchanger, expansion mechanism, and outdoor fan
A side-by-side heat exchanger is sequentially connected to form a refrigerant circulation cycle,
The indoor fan and the indoor heat exchanger are installed indoors.
The indoor unit is located inside the
The indoor air is sucked into the front side and sent to the indoor heat exchanger.
Front panel with a suction grill and the front panel
Temperature is controlled by the indoor heat exchanger located below
Blows out the air into the indoor space through the indoor fan
It is equipped with a blow-out grill and is used as the refrigerant at the same temperature.
Air conditioning using an alternative refrigerant whose sum pressure is higher than HCFC22
In Japanese machines, The four-way valve allows the discharge side of the compressor to be in heat exchange with the indoor side.
Connect the suction side of the compressor to the outdoor heat exchanger.
At the start of the defrosting operation during the heating operation that continued,
The discharge side of the compressor is controlled to the outside by controlling the four-way valve to reverse.
In the heat exchanger, the suction side of the compressor is connected to the indoor heat exchanger.
And a reversing control means for reversing connection with the four-way valve
Predetermined defrosting operation of the compressor operating frequency during reverse control
To frequency In addition to setting, when reversing the four-way valve
The rotation of the indoor fan and the outdoor fan is stopped, and
Defrosting that sets the opening of the expansion mechanism to a predetermined defrosting opening
The operation control means and the compressor during the reversal control
Set the operating frequency lower than the defrosting operating frequency
Between the discharge side pressure and the suction side pressure in the refrigerant circulation cycle
And a pressure difference adjusting means for reducing the difference.
And an air conditioner. 5. Room with compressor, four-way valve, indoor fan
Outdoor with an internal heat exchanger, expansion mechanism, and outdoor fan
A side-by-side heat exchanger is sequentially connected to form a refrigerant circulation cycle,
The indoor fan and the indoor heat exchanger are installed indoors.
The indoor unit is located inside the
The indoor air is sucked into the front side and sent to the indoor heat exchanger.
Front panel with a suction grill and the front panel
Temperature is controlled by the indoor heat exchanger located below
Blows out the air into the indoor space through the indoor fan
It is equipped with a blow-out grill and is used as the refrigerant at the same temperature.
Air conditioning using an alternative refrigerant whose sum pressure is higher than HCFC22
In Japanese machines, The four-way valve allows the discharge side of the compressor to be in heat exchange with the indoor side.
Connect the suction side of the compressor to the outdoor heat exchanger.
At the start of the defrosting operation during the heating operation that continued,
The discharge side of the compressor is controlled to the outside by controlling the four-way valve to reverse.
In the heat exchanger, the suction side of the compressor is connected to the indoor heat exchanger.
And a reversing control means for reversing connection with the four-way valve
Predetermined defrosting operation of the compressor operating frequency during reverse control
The frequency is set, and the reversing control of the four-way valve is performed.
The rotation of the indoor fan and the outdoor fan is stopped, and
Defrosting that sets the opening of the expansion mechanism to a predetermined defrosting opening
Operation control means and a predetermined time before the start of the reversal control
Set the operating frequency of the compressor to the defrosting operating frequency
The defrosting operation frequency is maintained until the start of the reversal control.
An empty space provided with the pressure difference adjusting means for
Air conditioner. 6. The pressure difference adjusting means is provided for the inversion control.
During the heating operation, the opening degree of the expansion mechanism is set for a predetermined time before starting.
The discharge pressure is temporarily increased by increasing the opening amount by a specified amount.
6. An opening control means for reducing the pressure to a low level is provided.
Air conditioner on board.