JP2002089998A - Control method for operation of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the control method for air conditioner capable of realizing comfortable drying operation by securing a sensitive heat capacity upon the drying operation, which is sufficient to a wide range temperature difference between indoor air and outdoor air. SOLUTION: In the air conditioner constituted of an indoor heat exchanger 3, a compressor 1, a four-way valve 2, an outdoor heat exchanger 5 and an expansion valve 4, the indoor heat exchanger 3 comprises a re-heater 6 and a cooler 7 while the opening degree of the expansion valve 4 is controlled by the output of an indoor temperature detecting means 51 for detecting an indoor temperature, a set temperature reading means 52 for reading a set room temperature, an indoor temperature control means 53, detecting a difference between the indoor temperature and the set temperature to output the difference, and a valve opening degree determining means 59 for changing the opening degree of the expansion valve 4 by the output of the indoor temperature control means 53.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for controlling the operation of an air conditioner, and more particularly to a method for controlling an expansion valve during a dry operation.

[0002]

2. Description of the Related Art In recent years, high-performance type air conditioners equipped with a dehumidifying function have been increasingly commercialized as home air-conditioning and heating equipment in order to further enhance the comfort of a living environment. Above all, technological development of an air conditioner with an isothermal dry operation function that can lower only the humidity without lowering the room temperature, which is one element of comfort, has been progressing.

[0003] As means for realizing the isothermal dry operation, for example, Japanese Patent Laid-Open No. Hei 6-137712 is disclosed.
That is, a compressor, a four-way valve, an outdoor heat exchanger, a decompression device, and an indoor heat exchanger constitute a heat pump refrigeration cycle, and the indoor heat exchanger includes a first heat exchanger and a second heat exchanger. And a cycle reheating dry system that communicates via an auxiliary expansion valve.

[0004] As another method, there is a heater reheating dry method in which a heating element such as an electric heater is provided on the leeward side of an indoor heat exchanger. From the viewpoint of comfort and power consumption, the former cycle reheating dry method is mainly used.

However, the cycle reheat dry method is different from the heater reheat dry method in that the first heat exchanger is used as a reheater and the second heat exchanger is used as a cooler during the dry operation. The cooling part of the indoor heat exchanger is smaller than that of the reheating dry method, and the sensible heat capacity is less than that of normal cooling operation. Especially, the temperature difference between the indoor side and the outdoor side (internal / outdoor temperature difference)
When the driving force is large, the intrusion load from the outside increases, which makes comfortable driving in dry driving difficult.

As a countermeasure, means for increasing the fan air volume of the outdoor heat exchanger to lower the condensing temperature of the reheater on the indoor side to increase the sensible heat capacity is known. Below, there is known a means for increasing the throttle amount of the pressure reducing device so as to lower the refrigerant condensation temperature in the first heat exchanger.

[0007]

However, even if the above-mentioned means are adopted, when the outside air temperature is not so high, and the set temperature of the indoor temperature controller is low and the inside / outside air temperature difference is large, When the outside air temperature is high but the set temperature is low and the inside and outside air temperature difference further increases, it is difficult to secure a sufficient sensible heat capacity only by adjusting the outdoor air flow.

If a sufficient sensible heat capacity cannot be ensured during the dry operation, an isothermal dry operation (operation in which the indoor suction temperature and the blow-out temperature of the air conditioner become substantially the same state) cannot be realized. Even if the cool dry operation or the warm dry operation is selected, satisfactory performance cannot be exhibited, and therefore, the comfort of the living environment cannot be obtained.

Further, when the outside air temperature is high, the throttle control of the auxiliary expansion valve is performed depending on the temperature of the outdoor heat exchanger and the temperature of the outlet pipe thereof. However, there was a problem that a comfortable dry operation that secured the vehicle speed could not be obtained.

SUMMARY OF THE INVENTION The present invention is directed to an air conditioner operation control method capable of realizing a comfortable dry operation by securing sufficient sensible heat capacity during a dry operation with respect to a wide range of inside and outside air temperature differences. It is intended to be provided.

[0011]

According to the first aspect of the present invention, there is provided an indoor heat exchanger, an indoor fan, a compressor, a four-way valve,
In an air conditioner including an outdoor heat exchanger, an outdoor fan, and an expansion valve, the indoor heat exchanger includes a first heat exchanger and a second heat exchanger.
And a room temperature detecting means for detecting a room temperature, a means for reading a set temperature of a temperature controller set by a remote controller or the like, and a difference between the room temperature and the set temperature. Indoor temperature control means for detecting and outputting, valve opening degree determining means for changing the valve opening degree of the expansion valve by the output of the indoor temperature control means, and adjusting the valve opening degree of the expansion valve by the output of the valve opening degree determining means It is made.

With this configuration, the valve opening is set smaller as the difference between the room temperature and the set temperature is larger, and control is performed, thereby lowering the condensing temperature of the first heat exchanger (reheater). A large capacity can be secured, and a sufficient dry heat operation can be performed because a sufficient sensible heat capacity can be secured in response to an intrusion load when the inside / outside temperature difference is large.

[0013] The invention according to claim 2 further comprises a pipe temperature detecting means for detecting a pipe temperature of the second heat exchanger functioning as a cooler, and the second heat exchanger during dry operation. A method in which a specified value of a pipe temperature composed of a plurality of specified values for preventing freezing is provided, and the valve opening of an expansion valve is adjusted based on the pipe temperature detected by the pipe temperature detecting means and the specified value of the pipe temperature. It is.

[0014] With this configuration, the evaporator is maximized by detecting the pipe temperature of the second heat exchanger (cooler) and adjusting the opening degree of the expansion valve while performing the freeze protection operation of the cooler. The latent heat capacity and the sensible heat capacity can be both increased, and more comfortable dry operation can be performed.

The invention according to claim 3 further comprises a pipe temperature control threshold value determining means for controlling the opening degree of the expansion valve for each output value of the indoor temperature control means. The opening degree of the expansion valve is adjusted based on the output value (pipe temperature threshold value) of the determining means.

With this configuration, the valve opening of the expansion valve 4 is adjusted while detecting the temperature of the pipe on the cooler side and performing the freezing protection operation of the cooler, so that the difference between the room temperature and the set temperature becomes larger. By controlling the specified value of the pipe temperature to be low, the latent heat capacity and the sensible heat capacity can be increased by making the most of the evaporator, and a more comfortable dry operation can be performed.

Further, the invention according to claim 4 is characterized in that the outdoor fan has a variable air volume and includes means for controlling the outdoor air volume by the output of the indoor temperature control means.

With this configuration, the greater the difference between the outdoor air flow and the indoor temperature and the set temperature, the larger the outdoor air flow is set and controlled, so that the sensible heat capacity can be further expanded and more comfortable. Dry operation becomes possible.

Further, the invention according to claim 5 is characterized in that the indoor fan has a variable air volume and includes means for controlling the indoor air volume by the output of the suction temperature control means.

According to this configuration, the greater the difference between the indoor air flow and the indoor temperature and the set temperature, the larger the indoor air flow is set and controlled, whereby the sensible heat capacity can be further expanded and more comfortable. Dry operation becomes possible.

According to a sixth aspect of the present invention, the compressor has a variable operating frequency and includes means for controlling the operating frequency of the compressor based on the output of the indoor temperature control means.

According to this configuration, the operating frequency of the compressor is set to be smaller as the difference between the indoor temperature and the set temperature is larger, and the compressor is controlled so as to further increase the sensible heat capacity. And more comfortable dry driving becomes possible.

The invention according to claim 7 further comprises an outside air temperature detecting means for detecting and outputting the outside air temperature, and detecting and outputting a difference between the output of the indoor temperature detecting means and the output of the outside air temperature detecting means. The inside and outside air temperature difference detecting means and the output of the inside and outside air temperature difference detecting means adjust the opening degree of the expansion valve.

With this configuration, the expansion valve is adjusted for each difference between the room temperature and the outside air temperature. The larger the difference is, the smaller the valve opening is set and the control is performed. Correspondingly, the expansion and contraction of the sensible heat capacity can be appropriately controlled, and more comfortable dry operation can be performed.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a refrigeration cycle diagram of the air conditioner of the present invention. In FIG. 1, reference numeral 1 denotes a compressor, which sequentially connects a four-way valve 2, an indoor heat exchanger 3, a pulse expansion valve 4, and an outdoor heat exchanger 5 to form a heat pump refrigeration cycle.

The indoor heat exchanger 3 includes a first heat exchanger (reheater) 6, a second heat exchanger (reheater) 7, a solenoid valve 8, and a capillary pressure reducing device 9. The first heat exchanger 6 and the second heat exchanger 7 are communicated via an electromagnetic valve 8,
Further, a capillary pressure reducing device 9 is arranged in parallel with the solenoid valve 8.

An indoor fan 10 that ventilates the indoor heat exchanger 3 and an outdoor fan 11 that ventilates the outdoor heat exchanger 5 are provided.

Reference numeral 12 denotes a control unit which controls the rotational speeds of the indoor fan 10, the outdoor fan 11 and the compressor 1 together with the fan drive control circuits 13 and 14 and the inverter circuit 15, and controls the opening of the expansion valve 4. Is further controlled, an indoor temperature sensor 16 for detecting an indoor temperature, an outside air temperature sensor 17 for detecting an outside air temperature, a cooler pipe temperature sensor 18 for detecting a pipe temperature of the second heat exchanger 7, and an air conditioner. Is connected to a control signal input unit 19 provided with an operation stop unit, a temperature adjustment setting unit for setting an indoor temperature, and the like. The control signal input means may be connected to the main body by a communication line, or may be a wireless type such as a remote controller.

The control unit 12 comprises a microcomputer, its peripheral circuits, and its program software. As shown in FIG.
2. Indoor temperature control means 53, compressor operating frequency control means 54, indoor air flow control means 55, outdoor air flow control means 5
6, piping temperature detecting means 57, piping temperature control threshold value determining means 58, valve opening degree determining means 59, expansion valve driving means 60 and the like.

Next, the air conditioning operation of the air conditioner having the above configuration will be described.

During the cooling operation, the solenoid valve 8 is controlled to the fully open state, and the refrigerant sucked and compressed by the compressor 1 is sent to the outdoor heat exchanger 5 via the four-way valve 2, where it is condensed and liquefied. . The refrigerant that has exited the outdoor heat exchanger 5 is decompressed by the expansion valve 4 and guided to the first heat exchanger 6. The refrigerant flowing out of the first heat exchanger 6 flows into the second heat exchanger 7 through the electromagnetic valve 8 in a fully opened state. In each of the heat exchangers 6 and 7, the refrigerant evaporates and takes out latent heat of evaporation from room air to be vaporized. The refrigerant that has passed through the heat exchangers 6 and 7 is sucked into the compressor 1 again through the four-way valve 2.

During the heating operation, the solenoid valve 8 is controlled to the fully open state, and the refrigerant sucked and compressed by the compressor 1 is sent to the second heat exchanger 7 via the four-way valve 2. The refrigerant flowing out of the second heat exchanger 7 flows into the first heat exchanger 6 through the electromagnetic valve 8 in a fully opened state. Each heat exchanger 6,
At 7, the refrigerant condenses and releases heat of condensation to room air to liquefy. The refrigerant that has passed through the heat exchangers 6 and 7 is depressurized by the expansion valve 4 and guided to the outdoor heat exchanger 5. Here, the refrigerant takes the latent heat of vaporization from the outdoor air and vaporizes, and again the four-way valve 2
Is sucked into the compressor 1.

During the dry operation, the solenoid valve 8 is controlled to a fully closed state, and the refrigerant sucked and compressed by the compressor 1 is sent to the outdoor heat exchanger 5 through the four-way valve 2 and further fully opened. It is led to the first heat exchanger 6 via the expansion valve 4 in the state. The refrigerant is the outdoor heat exchanger 5 and the first heat exchanger (reheater)
The condensed liquid is condensed and liquefied in 6 and, at this time, the first heat exchanger 6 releases the condensed heat to the indoor air. Since the solenoid valve 8 is closed, the liquid refrigerant is decompressed by the capillary decompression device 9 and flows into the second heat exchanger (cooler) 7. The refrigerant evaporates in the second heat exchanger 7 to remove the latent heat of evaporation from the indoor air and vaporize. At this time, the indoor air is dehumidified to lower the indoor humidity. Then, the refrigerant that has exited the second heat exchanger 7 is sucked into the compressor 1 again via the four-way valve 2.

The second heat exchanger 7 functions as a cooler for dehumidifying and cooling the indoor air sucked from the suction port of the air conditioner, and the first heat exchanger 6 functions as a dehumidified and cooled indoor air. To heat the reheater. That is, the air is blown into the room as dry air to perform a dehumidifying action.

When the room air temperature is lower than the set temperature of the remote controller, the warm dry operation is selected. In this warm dry operation, the outdoor fan 11 is operated at an extremely low rotation speed. As a result, the heat radiation of the refrigerant in the outdoor heat exchanger 5 is reduced, the amount of heat applied to the first heat exchanger 6 functioning as a reheater is increased, and the dehumidified and cooled dry air is sufficiently warmed into the room. Be blown out.

When the room air is close to the temperature set by the remote controller, the isothermal dry operation is selected. In this isothermal dry operation, the outdoor fan 11 is operated at an extremely low rotation speed. As a result, the heat radiation of the refrigerant in the outdoor heat exchanger 5 is reduced, and the dry air is heated to the same temperature as the room temperature and blown out into the room.

When the room air temperature is higher than the set temperature of the remote controller, the cool dry operation is selected. In this cool dry operation, the outdoor fan 11 is operated at an extremely low rotation speed. Further, by controlling the degree of opening of the expansion valve 4 to be smaller as the difference between the room temperature and the set temperature of the remote controller is larger, the condensing temperature of the first heat exchanger 6 is reduced to increase the sensible heat capacity. We are trying to secure.

Therefore, according to the present invention, the difference between the room temperature and the set temperature is detected, and the expansion valve 4 is detected for each difference.
The valve opening is adjusted so that the larger the difference is, the smaller the valve opening is set and the control is performed. According to this configuration, by reducing the condensation temperature of the first heat exchanger 6 (reheater) in accordance with the indoor load, a large sensible heat capacity can be secured, and when the temperature difference between the inside and outside is large. A sufficient dry heat operation can be performed because sufficient sensible heat capacity can be secured in response to the intrusion load.

Further, according to the second aspect of the present invention, the valve opening of the expansion valve 4 is controlled while detecting the temperature of the piping of the second heat exchanger 7 (cooler) to perform the freeze protection operation of the cooler. It is to adjust. According to this configuration, the latent heat capacity and the sensible heat capacity can be increased by making the most of the evaporator, and a more comfortable dry operation can be performed.

The third aspect of the present invention is to adjust the valve opening of the expansion valve 4 while detecting the temperature of the pipe on the side of the cooler and performing a freezing protection operation of the cooler, thereby setting the indoor temperature and the room temperature. The control is performed by setting the specified value of the pipe temperature lower as the difference from the temperature is larger. According to this configuration, both the latent heat capacity and the sensible heat capacity can be increased by making the most of the evaporator, and a more comfortable dry operation can be performed.

Further, the invention according to claims 4, 5 and 6 provides:
The outdoor air flow, the indoor air flow, and the operating frequency of the compressor 1 are adjusted for each difference between the indoor temperature and the set temperature. The larger the difference, the larger the outdoor air flow and the indoor air flow are set, and the operating frequency of the compressor 1 is increased. The control is performed with a small setting. According to this configuration, the sensible heat capacity can be further expanded, and a more comfortable dry operation can be performed.

The invention according to claim 7 detects the outside air temperature and adjusts the expansion valve 4 for each difference from the room temperature. The larger the difference is, the smaller the valve opening is set and control is performed. It is something to do. According to this configuration, the expansion and contraction of the sensible heat capacity can be appropriately controlled in accordance with the difference between the inside and outside temperatures, and a more comfortable dry operation can be performed.

Next, the control of the present invention will be described more specifically with reference to the drawings.

(Embodiment 1) The control of Embodiment 1 will be described with reference to FIGS.

2 and 3, the dry operation starts in step s201. Thereafter, the expansion valve 4 is operated with the initial setting pulse (step s202). After a certain period of time, the indoor temperature T1 is sampled by the indoor temperature detecting means 51, and the value and the set temperature Ta of the remote controller are read by the set temperature reading means 52, and the difference ΔT between the indoor temperature T1 (suction temperature) and the set temperature Ta is calculated. Temperature control means 5
3 (steps s203 and s204).

If the difference is larger than the specified value Tb1 of ΔT, the pulse is set to Pua (step s205). If the difference is smaller than Tb1 and larger than the specified value Tb2 of the difference ΔT, the pulse is set to Pub (step s207). (s209), the valve opening degree of the expansion valve 4 is changed by the valve opening degree determining means 59 and driven by the expansion valve driving means 60 (steps s206 and s20).
8, s210).

As a specified value in the memory of the microcomputer in advance,
Since Tb1> Tb2 and the pulse Pua <Pub <Puc are set, when the difference ΔT between the room temperature and the set temperature is large, the valve opening of the expansion valve 4 is narrowed and reduced, so that the condensation temperature of the reheater 6 is reduced. Is reduced to increase the sensible heat capacity, and conversely, when the difference is small, the sensible heat capacity can be reduced, so that the sensible heat capacity suitable for the change in the indoor load can be adjusted.

Note that the specified values Tb1, Tb2,
By providing the control value of Tb3 in more stages, a more comfortable dry operation control effect can be obtained.

(Embodiment 2) The control of Embodiment 2 will be described with reference to FIGS.

Steps s301 to s310 in FIG. 4 correspond to step s201 of the first embodiment.
Since the operation is the same as that of steps S210 to S210, the description is omitted.

In FIG. 2 and FIG.
7, the pipe temperature T2 on the indoor cooler 7 side is detected (step s312). If the pipe temperature T2 is larger than a specified value Th1 of the pipe temperature, the current pulse-α is throttled (step s31).
4) If it is smaller than Th1 and larger than Th2, the current pulse is fixed (step s315), and conversely, Th
If it is smaller than 2, the setting of the valve opening of the expansion valve 4 is changed by the “current pulse + β” and the valve opening determining means 59, and the expansion valve 4 is driven by the expansion valve driving means 60.

Further, the specified value of the pipe temperature is set as Th1> th2 as a specified value in the memory of the microcomputer in advance, and the pipe temperature T2 is sampled for a certain time, for example, every Z minutes (step s311). The valve opening of the expansion valve 4 can be adjusted while protecting the cooler 7 from freezing,
In addition, it is possible to maximize both the latent heat capacity and the sensible heat capacity by maximizing the use of the cooler 7 while preventing the hunting phenomenon of the expansion valve 4 due to sampling.

The specified values of the pipe temperatures Th1, Th2,
By providing more control values of Th3, a more comfortable dry operation control effect can be obtained.

(Third Embodiment) The control of the third embodiment will be described with reference to FIGS.

From the second embodiment, the pipe temperature control threshold value deciding means 58 further sets the specified value T of the difference ΔT.
The pipe temperature threshold values of the pipe temperature specified values Th1 and Th2 are respectively set to Th11, Th21, and Th1 for each of b1 and Tb2.
2, Th22, Th13, and Th23 (steps s419 to s421), and the larger the difference ΔT, the more the specified pipe temperature values Th1, Th2 are Th11, Th21 <T21.
h12, Th22 <Th13, Th23 are set to be low values, and the valve opening of the expansion valve 4 is controlled based on the output value (pipe temperature threshold value) of the pipe temperature control threshold value determination means 58. .

By this control, freezing of the cooler 7 can be prevented to a lower room temperature, so that the cooler 7 can be maximized to increase both the latent heat capacity and the sensible heat capacity.

Steps s401 to s410 and steps s411 to s418 in FIG. 5 operate in the same manner as steps s301 to s318 of the second embodiment, and a description thereof will be omitted.

(Embodiment 4) The control of Embodiment 4 will be described with reference to FIGS.

From the second embodiment, the specified values Tb1 and Tb2 of the difference ΔT are further
The outdoor fan speed Nout is changed every time (step s51).
9 to s521), the larger the difference ΔT, the larger the outdoor fan speed Nout is set and controlled.

With this control, as the difference ΔT increases, the outdoor air flow increases, the condensation temperature of the reheater 6 decreases, the sensible heat capacity can be increased, and more comfortable dry operation can be realized.

Steps s501 to s510 and steps s511 to s518 in FIG. 6 operate in the same manner as steps s301 to s318 of the second embodiment, and a description thereof will be omitted.

(Fifth Embodiment) The control of the fifth embodiment will be described with reference to FIGS.

In the second embodiment, the specified values Tb1 and Tb2 of the difference ΔT are further
The indoor fan speed is changed every time (steps s619 to s6).
21), the larger the difference ΔT is, the larger the indoor fan speed Nin is set and controlled.

According to this control, the larger the difference ΔT, the larger the indoor air volume and the greater the sensible heat capacity, and a more comfortable dry operation can be realized.

Steps s601 to s610 and steps s611 to s618 in FIG. 7 operate in the same manner as steps s301 to s318 of the second embodiment, and a description thereof will be omitted.

(Sixth Embodiment) The control of the sixth embodiment will be described with reference to FIGS.

From the second embodiment, the operating frequency control means 54 further sets the specified values Tb1, Tb2 of the difference ΔT.
The operating frequency of the compressor 1 is changed every time (step s719).
To s721), the larger the difference ΔT, the more the operating frequency F (f
1, f2, f3) are set small and controlled.

With this control, as the difference ΔT is larger, the refrigerant circulation amount is reduced and the condensing temperature of the reheater 6 is reduced, so that the sensible heat capacity can be increased. Conversely, when the difference is small, the sensible heat capacity is reduced. Therefore, more comfortable dry driving can be realized.

Steps s701 to s710 and steps s711 to s718 in FIG. 8 operate in the same manner as steps s301 to s318 of the second embodiment, and a description thereof will be omitted.

(Seventh Embodiment) The control of the seventh embodiment will be described with reference to FIGS.

Further, from the second embodiment, the room temperature T1 and the outside air temperature T3 are read by the room temperature detecting means 51 and the outside air temperature detecting means 61 (steps s819 and s82).
0), the inside / outside temperature difference detecting means 62 detects the inside / outside temperature difference (step 821). If the inside / outside air temperature difference is larger than the specified value Tc of the inside / outside air temperature difference, steps s803 to s810 of the expansion valve control in which the pulse set value is set small are performed. Steps s803a to s810a are performed.

As a predetermined value in the memory of the microcomputer in advance,
Specified value of ΔT Tb1> Tb2 and pulse Pua1 <Pua
2. Since the expansion valve control is performed by setting Pub1 <Pub2 and Puc1 <Puc2, the expansion valve 4 is throttled as a smaller pulse when the inside / outside air temperature difference is large and the intrusion load into the room is large. When the condensing temperature of the heater 6 is reduced and the sensible heat capacity is increased, and when the temperature difference between the inside and outside is large and the load on the room is small, the expansion valve 4 is opened more. And the sensible heat capacity can be reduced, so that more comfortable dry operation is possible.

Note that steps s801 to s818 (including s803a to s810a) in FIG. 10 operate in the same manner as steps s301 to s318 of the second embodiment, and a description thereof will be omitted.

In each of the above embodiments, the capillary pressure reducing device 9 is provided as a pressure reducing device between the reheater 6 and the cooler 7 during the dry operation, but instead of the capillary pressure reducing device 9, The same effect can be obtained by using a constant-pressure expansion valve, an electric expansion valve, or the like.

The same effect can be obtained also by using an electric on-off valve or the like in place of the solenoid valve 8 for the solenoid valve 8.

[0077]

As is clear from the above embodiment, the invention according to claim 1 detects a difference between the room temperature and the set temperature and adjusts the opening degree of the expansion valve for each difference. Yes, the larger the difference is, the smaller the valve opening is set and control is performed.By lowering the condensing temperature of the reheating unit corresponding to the indoor load, it becomes possible to secure a large sensible heat capacity. In addition, since sufficient sensible heat capacity can be ensured in response to the intrusion load when the temperature difference between the inside and outside is large, the comfort of the living environment during dry driving can be improved.

According to the second aspect of the present invention, the evaporator is maximized by adjusting the opening degree of the expansion valve while detecting the temperature of the piping on the cooler side and performing the freeze protection operation. The latent heat capacity and the sensible heat capacity can be made large by making the best use, and the comfort of the living environment during dry driving can be further improved.

According to a third aspect of the present invention, the valve opening of the expansion valve is adjusted while detecting the temperature of the pipe on the side of the cooler and performing the freeze protection operation. By controlling the temperature control value to a small value, the latent heat capacity and the sensible heat capacity can be increased by making the most of the evaporator, making the living environment more comfortable during dry operation. Can be improved.

According to the fourth, fifth and sixth aspects of the present invention, the outdoor air volume, the indoor air volume, and the operating frequency of the compressor are adjusted for each difference between the indoor temperature and the set temperature. Alternatively, the control is performed by setting the indoor air volume large or the operation frequency small, so that the sensible heat capacity can be further expanded, and the comfort of the living environment during dry operation can be further improved. .

The invention according to claim 7 is for detecting the outside air temperature and adjusting the expansion valve for each difference from the room temperature. The larger the difference, the smaller the valve opening of the expansion valve is set and the control is performed. By doing so, it is possible to appropriately control the expansion and contraction of the sensible heat capacity in accordance with the temperature difference between inside and outside, and it is possible to further improve the comfort of the living environment during dry driving.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle of an air conditioner of the present invention.

FIG. 2 is a control block diagram showing an embodiment of the present invention.

FIG. 3 is a control flowchart showing the first embodiment of the present invention.

FIG. 4 is a control flowchart showing a second embodiment of the present invention.

FIG. 5 is a control flowchart showing a third embodiment of the present invention.

FIG. 6 is a control flowchart showing a fourth embodiment of the present invention.

FIG. 7 is a control flowchart showing a fifth embodiment of the present invention.

FIG. 8 is a control flowchart showing a sixth embodiment of the present invention.

FIG. 9 is a control block diagram showing a seventh embodiment of the present invention.

FIG. 10 is a control flowchart showing a seventh embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Expansion valve 5 Outdoor heat exchanger 6 First heat exchanger (reheater) 7 Second heat exchanger (cooler) 8 Solenoid valve 9 Decompression device 10 Indoor Fan 11 Outdoor fan 12 Control unit 13, 14 Drive control circuit 15 Inverter circuit 16 Indoor suction temperature sensor 17 Outdoor suction temperature sensor 18 Cooler piping temperature sensor 51 Indoor temperature detection means 52 Indoor temperature reading means 53 Indoor temperature control means 54 Operating frequency Control means 55 indoor air flow control means 56 outdoor air flow control means 57 pipe temperature detection means 58 pipe temperature control threshold value determination means 59 valve opening degree determination means 60 expansion valve drive means 61 outside air temperature detection means 62 inside and outside air temperature difference detection means T1 indoor Temperature Ta Set temperature ΔT Difference Tb1, Tb2 Specified value of ΔT T2 Pipe temperature Th1, Th2 Specified value of pipe temperature T3 Outside air temperature Tc Inside / outside air temperature difference specified value Th Pipe temperature specified value Pua Setting pulse a Pub Setting pulse b Puc Setting pulse c α Number of subtraction pulses β Number of addition pulses

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Tsutomu Shimizu 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Teruo Fujisha 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference) 3L060 AA05 CC02 CC03 CC04 CC19 DD02 DD08 EE04 EE05 EE06 EE09

Claims (7)

[Claims] 1. A heat pump type air conditioner comprising an indoor heat exchanger, an indoor fan, a compressor, a four-way valve, an outdoor heat exchanger, an outdoor fan, and an expansion valve having a variable opening. The heat exchanger comprises a first heat exchanger and a second heat exchanger, and the first heat exchanger and the second heat exchanger during a dry operation.
The heat exchanger communicates via a decompression device, and further detects an indoor temperature, an indoor temperature detecting means, a set temperature input means for inputting a set value of the indoor temperature, and an indoor temperature detected by the indoor temperature detecting means. An indoor temperature control means for detecting and outputting a difference between a temperature and a set temperature inputted by the set temperature input means, and a valve opening determination for changing a valve opening of the expansion valve based on an output of the indoor temperature control means. Means and an operation control method of the air conditioner, wherein the valve opening of the expansion valve is adjusted by the output of the valve opening determining means. And a pipe temperature detecting means for detecting a pipe temperature of the second heat exchanger functioning as a cooler during a dry operation, and a pipe temperature detected by the pipe temperature detecting means during a dry operation. 2. The operation control method for an air conditioner according to claim 1, wherein the valve opening of the expansion valve is adjusted so as not to fall below a preset value for preventing freezing. 3. A pipe temperature detecting means for detecting a pipe temperature of a second heat exchanger functioning as a cooler during a dry operation, and a pipe temperature threshold value is set in accordance with an output value of the indoor temperature control means. The air according to claim 1 or 2, wherein the valve opening of the expansion valve is controlled by a piping temperature control threshold value determining means, and an output value (piping temperature threshold value) of the piping temperature control threshold value determining means. Harmonic machine operation control method. 4. The operation control method for an air conditioner according to claim 1, wherein the outdoor fan has a variable air flow, and an outdoor fan control means for controlling an outdoor air flow by an output of the indoor temperature control means is provided. 5. The operation control method for an air conditioner according to claim 1, wherein the indoor fan has a variable air flow, and further includes indoor fan control means for controlling the indoor air flow by an output of the suction temperature control means. 6. The operation control of an air conditioner according to claim 1, wherein the compressor has an operation frequency variable, and comprises an operation frequency control means for controlling an operation frequency of the compressor by an output of the indoor temperature control means. Method. 7. An inside / outside air temperature difference detecting means for detecting and outputting a difference between the output of the indoor temperature detecting means and the output of the outside air temperature detecting means. 3. The operation control method for an air conditioner according to claim 1, wherein the degree of opening of the expansion valve is adjusted by an output of the inside / outside temperature difference detecting means.