JPH11294871A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve insufficient heating capacity for suppressing and stabilizing hunting of a cycle temperature and indoor air delivery volume by setting the initial travel of an electronic expansion valve to a predetermined travel of a long piping or a reverse head which is greater than the initial travel in the case of the long piping or the reverse head. SOLUTION: Whether or not hunting exists in the speed of rotation is judged (S4), in the case of Yes, it is judged as a long piping or a reverse head (S5), and 100 pulses are added to the initial travel (100 pulses) of an electronic expansion valve to increase a travel (S6). On the other hand, in the case S4 is No, whether a degree of superheat is greater than a target degree of superheat is judged (S9), in the case of No, the travel of the electronic expansion valve is opened by 2 pulses (S10), in the case of Yes, the travel of the electronic expansion valve is closed by 2 pulses to control the travel of the electronic expansion valve so as to cause the degree of superheat to agreed with the target super heat degree (S11). As a result, hunting of the degree of superheat is solved at an early stage, causing the degree of superheat to agree with the target superheat degree for stabilization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner.
m) The control of the opening degree of the electronic expansion valve and the control of the number of rotations of the indoor fan in the so-called reverse head mode in which the long pipe or longer or the outdoor heat exchanger is installed at a position higher than the indoor heat exchanger. The present invention relates to an air conditioner having an improved method.

[0002]

2. Description of the Related Art Generally, a heat pump type air conditioner of this type includes a compressor, a four-way valve, an indoor heat exchanger having an indoor fan, a decompressor such as a capillary tube or an electronic expansion valve, and an outdoor fan having an outdoor fan. Heat exchangers and the like are sequentially connected and communicated by refrigerant pipes to constitute a closed refrigeration cycle for circulating the refrigerant. Further, by controlling the circulation direction of the refrigerant by the switching operation of the four-way valve, it is possible to appropriately switch between the cooling operation and the heating operation, and the opening degree of the electronic expansion valve and the unit time of the compressor per unit time according to the load. Control means for controlling the rotation speed of the indoor fan and reducing the rotation speed of the indoor fan per unit time when the temperature of the indoor heat exchanger is equal to or lower than a predetermined value.

Conventionally, this type of air conditioner is often installed in a two-story house or the like, and a refrigerant pipe is, for example, about 10 m or less, and is installed at a position lower than an indoor heat exchanger. The height difference from the outdoor heat exchanger, that is, the head is 6
m or less.

[0004]

In recent years, however, the number of three-storey buildings has been increasing in the case of new construction, especially for improving the housing environment in urban areas. For this reason, the refrigerant pipe of the air conditioner installed in the three-story building is often a long pipe of 10 m or more and the head of the indoor / outdoor heat exchanger is 6 m or more. In addition, an outdoor unit incorporating an outdoor heat exchanger is installed on a rooftop or the like, and is often installed at a higher position than an indoor unit incorporating an indoor heat exchanger.

[0005] However, even in the case of such a long pipe or a head, the air conditioning control does not correspond to the long pipe or the head and is the same as the conventional control (normal control). There is a problem that such inconveniences occur remarkably during the heating operation.

That is, during the heating operation, the high-temperature and high-pressure gas refrigerant from the compressor radiates heat in the indoor heat exchanger, and the warm air exchanged with the outside air is blown into the room by the blower of the indoor fan to heat the room. The refrigerant that has been condensed and liquefied while radiating heat in the indoor heat exchanger is pumped into the outdoor heat exchanger through the liquid pipe of the refrigerant pipe. It has a large resistance and is subject to a throttle action. Moreover,
In the case of a head drop, the liquid refrigerant must rise against the gravity from the lower indoor heat exchanger to the upper outdoor heat exchanger, further increasing the flow path resistance and increasing the throttling effect. I do.

[0007] Therefore, when the restriction of the liquid refrigerant is excessive, the flow of the liquid refrigerant in the liquid pipe is deteriorated, causing an increase in pressure, an increase in the degree of superheat, and a decrease in the flow rate of the refrigerant.

For this reason, the temperature of the indoor heat exchanger may drop to, for example, about 15 ° C. In such a case, the conventional normal control reduces the air flow of the indoor fan to a minimum by the cool air prevention control. Here, the cool air prevention control means that when the temperature of the indoor heat exchanger falls below a predetermined value (for example, 30 ° C.), the amount of air blown by the indoor fan is reduced to a minimum, and cool air is blown into the room during the heating operation. This is a control to reduce the feeling of cold wind by reducing the amount of heat generated.

When the amount of air blown by the indoor fan becomes extremely small, the amount of air blown becomes too narrow, and the pressure in the indoor heat exchanger rises at a stretch, resulting in a high temperature (for example, about 50 ° C. or more). Then, in order to prevent the danger caused by such high temperature and high pressure, the control means lowers the compressor operating frequency while canceling the cold air prevention control, and slowly increases the blown amount which was the minimum of the indoor fan. .

[0010] However, while the compressor operating frequency is reduced rapidly to prevent danger, the indoor air flow is increased slowly so as to make the user unaware to improve pleasure.

For this reason, the operating frequency of the compressor is lowered to a place where the heating capacity is hardly obtained due to the excessive throttling of the liquid refrigerant, and the amount of air blown by the indoor fan increases a little later. The heat exchanger temperature drops.

[0012] Since such changes of the indoor heat exchanger temperature, the amount of air blown by the indoor fan, and the air temperature occur repeatedly, the user feels discomfort due to the hunting of the indoor air flow amount and the temperature in addition to the insufficient heating capacity. This will lead to an erroneous determination of a failure.

When the expansion valve is an electronic expansion valve whose opening can be controlled, the opening is controlled so that excessive throttling is eliminated. Generally, the temperature is determined based on the superheat degree, which is the difference between the outdoor heat exchange temperature and the compressor refrigerant suction temperature, and the cycle temperature, such as the deviation of the target superheat degree. Therefore, as shown in FIG. Due to the hunting of the cycle temperature (e.g., the temperature of the exchanger), the electronic expansion valve is controlled to open to α when the degree of superheat is lower than the target degree of superheat. For this reason, it takes a long time until the hunting between the cycle temperature and the indoor air flow rate is eliminated and stabilized, and it takes about 30 minutes, for example, from the start of the compressor to the stabilization of the cycle temperature.

The hunting phenomenon between the cycle temperature and the indoor air flow rate is based on the assumption that the indoor air flow rate, the operating frequency of the compressor, and the control constants of the electronic expansion valve are based on a long pipe or a reverse drop for a three-story building. Although it is possible to solve the problem by changing the constant to the above value, a new problem arises in that the operation at the time of a short pipe for a two-story building and a head drop is not optimal.

Further, when the indoor heat exchanger side ambient temperature is relatively low (for example, about 18 ° C. or less) and the outdoor heat exchanger side atmospheric temperature is high (for example, about 18 ° C. or more), the high pressure side of the refrigeration cycle Since the pressure difference between the electronic expansion valve and the low-pressure side is small, it is appropriate even if the opening of the electronic expansion valve is considerably widened.

The present invention has been made in consideration of the above circumstances, and has as its object to improve the heating capacity shortage by changing the control method of the air-conditioning operation suitable for the condition at the time of a long pipe or a head drop. An object of the present invention is to provide an air conditioner capable of suppressing and stabilizing hunting of a temperature and an indoor air flow rate.

[0017]

According to the first aspect of the present invention, there is provided an indoor heat exchanger having a compressor, a four-way valve, an indoor fan whose rotation speed can be controlled, an electronic expansion valve, and an outdoor heat exchanger having an outdoor fan. A refrigeration cycle communicating with a refrigerant pipe, the opening degree of the electronic expansion valve and the number of revolutions of the compressor per unit time are controlled according to the load, and the temperature of the indoor heat exchanger is equal to or less than a predetermined value. Control means for reducing the number of revolutions per unit time of the indoor fan at the time of the operation, the initial opening of the electronic expansion valve at the start of operation, the length of the refrigerant pipe is more than a predetermined value When the long pipe, or the outdoor heat exchanger is a reverse head installed at a position higher than the indoor heat exchanger, when the long pipe or the reverse heat head is not the reverse opening, the initial opening degree set by the control means To a large opening The long piping / reverse drop mode control means for, an air conditioner which is characterized in that it comprises.

Here, the long pipe means a pipe having a total length of, for example, 10 m or more.

According to the present invention, in the case of a long pipe or a reverse head, the initial opening of the electronic expansion valve is larger than the initial opening in the case of no long pipe or the reverse head by the long pipe / reverse head mode control means. The opening is controlled to a predetermined degree.

For this reason, in the heating operation, the flow path resistance when the liquid refrigerant from the indoor heat exchanger flows into the outdoor heat exchanger through the electronic expansion valve increases due to a long pipe or a reverse drop,
Since the initial opening of the electronic expansion valve is large even if the liquid refrigerant is close to the limit, the inflow of the liquid refrigerant flowing into the outdoor heat exchanger through the electronic expansion valve can be increased.

Therefore, the flow rate of the refrigerant circulating in the refrigeration cycle during the heating operation can be increased, so that the heating capacity in a long pipe or a head drop can be improved.

The invention according to claim 2 is characterized in that it comprises a manual operation means for manually inputting to the long pipe / reverse head mode control means that the pipe is a long pipe or a reverse head. It is an air conditioner.

According to the present invention, the control of the air-conditioning operation is performed by inputting the long piping or the reverse head mode by the remote controller for remotely controlling the air-conditioning operation or the manual operation means provided in the indoor or outdoor unit. Can be easily, quickly and reliably switched from the conventional control to the long pipe or the long pipe / reverse head mode control means adapted to the reverse head mode.

According to a third aspect of the present invention, it is determined whether or not there is a long pipe or a head drop based on hunting of the number of revolutions of the indoor fan per unit time or hunting of the refrigeration cycle temperature, and the result of the determination is made. The air conditioner according to claim 1 or 2, further comprising: a long pipe / reverse head determining means input to the pipe / reverse head mode control means.

According to the present invention, the long pipe / reverse head determination means automatically determines whether or not the pipe is a long pipe or a reverse head, and inputs the determination result to the long pipe / reverse head mode control means. Therefore, even if there is no manual operation means of claim 2 or if the manual operation means forgets to input a long pipe or a reverse head, the mode is automatically switched to the long pipe / reverse head mode control means. be able to.

According to a fourth aspect of the present invention, the long pipe / reverse head mode control means includes an indoor fan rotation speed control means for setting a predetermined upper limit to the number of rotations of the indoor fan at the time of long pipe or reverse head. 4. The method according to claim 1, wherein
The air conditioner according to any one of the above.

According to the present invention, at the time of a long pipe or a head drop, the rotation speed of the indoor fan is set to the predetermined upper limit value by the long pipe / reverse head mode control means, thereby reducing the hunting width of the indoor air flow. As well as suppressing a decrease in the indoor blast (blowing) temperature,
User discomfort can be reduced.

Also, since the hunting width of the indoor air flow rate is reduced, the hunting width of the cycle temperature is also reduced, and the opening degree is smoothly opened by controlling the opening degree of the electronic expansion valve. Hunting of the cycle temperature can be quickly eliminated and stabilized.

According to a fifth aspect of the present invention, the long pipe / reverse head mode control means includes an indoor fan rotation number control means for fixing the number of rotations of the indoor fan to a predetermined value at the time of long pipe or reverse head. The air conditioner according to any one of claims 1 to 3, wherein

According to the present invention, the rotation speed of the indoor fan is fixed to a predetermined value at the time of a long pipe or a head drop, so that hunting of the amount of air blown into the room and the temperature of the blown air can be prevented or reduced.

As a result, the hunting of the cycle temperature can be prevented or reduced, and the opening of the electronic expansion valve also opens smoothly, thereby suppressing the shortage of the heating capacity due to the excessive restriction of the liquid refrigerant. be able to.

According to a sixth aspect of the present invention, the long pipe / reverse head mode control means sets the upper limit value of the number of revolutions of the indoor fan within a predetermined time from the start of the air conditioning operation or the start of the compressor at the time of the long pipe or the reverse head. The air conditioner according to any one of claims 1 to 5, further comprising means for setting a fixed value.

According to the present invention, the fluctuation of the cycle temperature such as the temperature of the indoor heat exchanger is large within a predetermined time (for example, 15 minutes) from the start of the air-conditioning operation or the start of the compressor. Initially, the cycle temperature can be stabilized by setting an upper limit value for the rotation speed of the indoor fan or fixing the rotation speed to a predetermined rotation speed.

According to a seventh aspect of the present invention, the long pipe / reverse head mode control means sets the change speed for changing the indoor fan speed at the time of the long pipe or the reverse head to the indoor fan speed change rate set by the control means. 7. A means for setting a predetermined value later than the predetermined value.
The air conditioner according to any one of the above.

According to the present invention, the change speed at which the indoor fan rotation speed is changed at the time of a long pipe or a head drop is made slower than the change speed by the conventional control means so that the change of the indoor air flow rate is made transparent to the user. Therefore, it is possible to reduce the discomfort caused by the user being aware of the change in the indoor air flow rate.

According to an eighth aspect of the present invention, in the long pipe / reverse head mode control means, when the long pipe or the reverse head is used, the indoor heat exchanger side ambient temperature and the outdoor heat exchanger side ambient temperature are within a predetermined range. 5. The apparatus according to claim 4, further comprising: means for fixing the number of revolutions of the indoor fan to a predetermined value.
The air conditioner according to any one of claims 1 to 7.

According to the present invention, when the number of rotations of the indoor fan is fixed and the indoor air flow rate is fixed, the indoor air flow rate should be as small as possible, considering the feeling of cool air generated by blowing cool air during the heating operation. desirable. Therefore, when the indoor and outdoor atmosphere temperatures are within a predetermined range and the temperature difference between the two is small at the time of a long pipe or a head drop, it is possible to control the amount of air blown by the indoor fan to a necessary minimum. Pleasure can be minimized.

[0038]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
A description will be given based on FIG. In these figures, the same or corresponding parts are denoted by the same reference characters.

FIG. 1 is a refrigeration cycle diagram of the air conditioner 1 according to the first embodiment of the present invention, and FIG. 2 is a block diagram of a control system of the air conditioner 1. This air conditioner 1 is shown in FIG.
, A compressor 2 whose rotation speed is controlled by an inverter 22, a four-way valve 3, an indoor heat exchanger 5 having an indoor fan 4 whose rotation speed can be controlled, an electronic expansion valve 6 whose opening can be controlled, and an outdoor fan (not shown) The outdoor refrigeration cycle is provided by sequentially connecting and connecting the outdoor heat exchangers 7 with the refrigerant pipes 8 to circulate the refrigerant.

In this refrigeration cycle, when the refrigerant is circulated in the direction of the solid line arrow by switching operation of the four-way valve 3, heating operation is performed, and when the refrigerant is circulated in the direction of the broken line arrow in the diagram, cooling operation is performed.

The indoor heat exchanger 5 is provided with an indoor heat exchange temperature sensor 9 for detecting its temperature.
Is provided with an outdoor heat exchange temperature sensor 10 for detecting the temperature thereof, and a compressor refrigerant suction temperature sensor 11 is provided on the suction side of the compressor 2.

The indoor heat exchanger 5 and the indoor fan 4 are built in the indoor unit 12, and the compressor 2, the four-way valve 3, the electronic expansion valve 6, and the outdoor heat exchanger 7 are built in the outdoor unit 13. I have.

As shown in FIG. 2, the control system of the air conditioner 1 is constituted by an indoor controller 14 comprising a microprocessor and the like built in the indoor unit 12 and a microprocessor and the like built in the outdoor unit 13. And an outdoor controller 15.

The indoor controller 14 detects the number of rotations of the fan motor 4a of the indoor fan 4 per unit time, and controls the number of rotations per unit time as appropriate. In addition, during the heating operation, when the temperature of the indoor heat exchanger 5 is low, for example, 30 ° C. or lower, the cool air that reduces the number of rotations of the indoor fan 4 in order to prevent a feeling of cool air blown (blowed) into the room. Prevention control is performed.

The indoor controller 14 sets the room temperature detected by the indoor atmosphere temperature sensor 16, the detected temperature detected by the indoor heat exchange temperature sensor 9, the remote controller 17 shown in FIG. Via the indoor communication unit 19 and the outdoor communication unit 20 to provide the outdoor controller 15 with an operation command frequency signal required for setting the room temperature to the set temperature. It has become.

On the other hand, the outdoor controller 15 is connected to an outdoor atmosphere temperature sensor 21 for detecting the outside air temperature, and detects the outside air temperature via the outside air temperature sensor 21. Also, the outdoor controller 15 is
Is supplied to the inverter 22 to control the number of revolutions of the compressor 2 per unit time, and to control the compression capacity according to the load. That is, the rotation speed of the compressor 2 is controlled according to the air conditioning load.

The outdoor controller 15 reads the detected temperature detected by the outdoor heat exchange temperature sensor 10 and the detected temperature detected by the comp refrigerant suction temperature sensor 11, respectively, and determines the difference between the two. Is controlled to match the target degree of superheat. Since the target degree of superheat varies according to the air conditioning load, the opening degree of the electronic expansion valve 6 is ultimately controlled according to the air conditioning load. The degree of opening of the electronic expansion valve 6 is increased stepwise in accordance with an increase in the number of drive pulses input thereto.

The control of the opening degree of the electronic expansion valve 6 and the control of the rotational speed of the indoor fan 4 are performed in the air conditioner 1 for a two-story house, for example, when the total length of the refrigerant pipe 8 is less than 10 m.
This is executed when the outdoor heat exchanger 7 is installed at a position lower than the indoor heat exchanger 5 and the head is less than 6 m.

However, since the air conditioner 1 is installed in, for example, a three-story house, the total length of the refrigerant pipe 8 is, for example, 10 m or more, or the outdoor heat exchanger 7 is installed on the roof. And the like, and the head may be installed at a position higher than the indoor heat exchanger 5, so that the outdoor controller 15 controls both the short piping / forward head and the long piping / reverse head. It can be done as appropriate.

FIG. 3 is a flowchart of a control program for the outdoor controller 15 during the heating operation.
22 shows each step of the flowchart.

First, when the outdoor controller 15 starts the control program, in S1, the long pipe / reverse head switch 2
It is determined whether or not there is an input of the long pipe or the reverse head mode by the ON manual operation of 3. This long pipe or reverse head mode switch 23 is, for example, as shown in FIG.
7 or as shown in FIG.
3 may be provided on the outer surface or both. Here, the long pipe refers to a case where the total length of the refrigerant pipe 8 is 10 m or more, and the reverse head refers to a case where the installation height of the outdoor heat exchanger 7 is higher than the installation height of the indoor heat exchanger 5.

In S1, if the long pipe / reverse head switch 23 is not operated (No), that is,
If it is not a long pipe or a reverse head, the initial opening of the electronic expansion valve 6 at the start of operation is set to, for example, 100 pulses in S2.

However, if the long pipe / reverse head switch 23 is input at S1 (Yes), then at S3 the initial opening of the electronic expansion valve 6 is set to the opening when it is not a long pipe or a reverse head (for example, It is installed at an opening degree (e.g., 200 pulses) larger than 100 pulses), and starts from the limit. For this reason, it is possible to alleviate the above-described various adverse effects caused by the electronic expansion valve 6 being excessively throttled during the heating operation. That is, the flow resistance of the liquid refrigerant flowing from the indoor heat exchanger 5 to the outdoor heat exchanger 7 is reduced to increase the inflow flow rate, thereby preventing a decrease in the heating capacity.

Next, at S4, the temperature of the indoor heat exchanger 5 detected by the indoor heat exchange temperature sensor 9 or the temperature of the outdoor heat exchanger 7 detected by the outdoor heat exchange temperature sensor 10 and the comp refrigerant suction temperature sensor It is determined whether there is hunting in the degree of superheat, which is the difference from the temperature of the refrigerant sucked into the suction side of the compressor 2 detected by 11 or the amount of air blown by the indoor fan 4, that is, whether there is hunting in the rotational speed. In this case, it is determined that the pipe is a long pipe or a head drop.

In other words, even if the long pipe / reverse head switch 23 is not turned on due to the negligence of the installer or the like in S1, the long pipe or In the case of a head drop, the temperature of the indoor heat exchanger 5, the degree of superheat, or the amount of air blown into the room hunts. By detecting the hunting, it is possible to automatically determine that the pipe is a long pipe or a head drop. . Moreover, if it is determined in S5 that the pipe is a long pipe or a head drop, 100 pulses are added to the initial opening (100 pulses) of the electronic expansion valve 6 in S6 to increase the opening in S6. However, the adjustment of the initial opening is performed only once after the compressor 2 is started.

On the other hand, if No in S4, it is determined in S7 that the pipe is not a long pipe or a head drop, and the flow advances to S8. In S8,
The superheat degree is compared with the target superheat degree, and it is determined whether or not the superheat degree is larger than the target superheat degree in S9. If No, the opening degree of the electronic expansion valve 6 is opened by two pulses in S10, and if Yes, S1
In step 1, the opening degree of the electronic expansion valve 6 is closed by two pulses, and the opening degree of the electronic expansion valve 6 is controlled so that the degree of superheat matches the target degree of superheat. As a result, as shown in FIG. 6, the degree of superheat is larger than the target degree of superheat, so that the opening of the electronic expansion valve 6 can be smoothly closed. For this reason, hunting of the degree of superheat can be eliminated at an early stage, and can be made consistent with the target degree of superheat and stabilized.

In the next S12, the temperature of the indoor heat exchanger 5 becomes 5
It is determined whether the temperature is higher than 0 ° C. That is, if the opening degree of the electronic expansion valve 6 is too narrow, the indoor heat exchanger 5 is rapidly increased in pressure and becomes high temperature (50 ° C. or higher). However, in the case of No in S12, the operating frequency (Hz) of the compressor 2 is not restricted or changed in S13, but in the case of Yes, it is determined that overheating is performed in S14 and the operating frequency (Hz) of the compressor 2 is determined. ) Is reduced by a predetermined value to prevent danger due to overheating of the compressor 2.

Thereafter, in S15, it is determined whether or not the temperature of the indoor heat exchanger 5 is a low temperature of 30 ° C. or less. In the case of Yes, the cool air is blown into the room in S16 to give a feeling of cool air to the user. In order to prevent or reduce the airflow, the number of rotations of the indoor fan 6 is reduced by a predetermined value to reduce the amount of air blown (blown) into the room.

However, in the case of No in S15, that is, when the temperature of the indoor heat exchanger 5 is higher than 30 ° C., it is confirmed again in S17 whether or not it is a long pipe or a head drop. In the case of No, in S18 The process proceeds to S20 without restricting (changing) the air flow rate of the indoor fan 4, but in the case of Yes, an upper limit is set for the air flow rate of the indoor fan 4 in S19.

For this reason, the hunting width of the temperature of the indoor heat exchanger 5 can be reduced as shown in FIG. 6, so that the hunting of the indoor heat exchanger 5 can be eliminated early (for example, about 15 minutes). The conventional example shown in FIG.
While it takes about 0 minutes, the temperature of the indoor heat exchanger 5 can be quickly stabilized in about half the time.

Next, in S20, it is again confirmed whether or not the pipe is a long pipe or a head drop. If the result is No, the flow rate of the indoor fan 4, that is, the rotation speed is gradually changed in S21, and the result is Yes.
In the case of (2), the change of the air blowing amount of the indoor fan 4, that is, the rotation speed is further slowed down in S22.

[0062] For this reason, the change in the amount of air blown into the room can be performed without the user being conscious of the change, so that the comfort can be improved.

After S21 and S22, the process returns to S4 and repeats the following steps.

FIG. 7 is a flowchart of a control program according to the second embodiment of the present invention. In FIG. 7, steps from the start to S44, which is the fourteenth step, are the same as those in the flowchart shown in FIG. The description that has been given is omitted, and the steps following S15, which is the fifteenth step, will be described.

That is, in S45, it is confirmed again whether or not it is a long pipe / reverse head. In the case of No, it is further determined in S46 whether or not the temperature of the indoor heat exchanger 5 is 30 ° C. or less. In the case of Yes, the number of rotations of the indoor fan 4 is reduced in S47 to reduce or prevent the feeling of cool air by reducing the amount of indoor air blown, and then the process returns to S34 again to repeat the following steps. Alternatively, in the case of No in S46, that is, when the temperature of the indoor heat exchanger 5 is higher than 30 ° C., there is almost no possibility of generating a feeling of cool air.
Then, the process returns to S34, and the subsequent steps are repeated.

On the other hand, if it is confirmed in S45 that the pipe is a long pipe or a head drop, it is determined in S49 whether the indoor and outdoor atmosphere temperatures are within a predetermined temperature range (zone). That is, it is further determined whether or not the indoor temperature read from the indoor atmosphere temperature sensor 16 is low (for example, about 18 ° C. or less) and the outdoor temperature read from the outdoor atmosphere temperature 21 is high (for example, about 18 ° C. or more). In the case of (5), it is further determined whether or not the temperature range is within a predetermined time (for example, about 15 minutes) from the start of the compressor 2, and here (S5)
In the case of Yes in 0), the number of rotations of the indoor fan 4 is fixed to a predetermined value, and the amount of indoor air blown is fixed to a predetermined amount.

Since the indoor air flow rate is fixed, even when the initial cycle temperature of the compressor 2 is unstable and fluctuates greatly, hunting between the indoor air flow rate and the blow-out temperature can be reduced or prevented. , Hunting of the cycle temperature can be reduced or prevented.
Is smoothly opened by the control. In addition, since the indoor air flow rate is fixed, the indoor and outdoor atmosphere temperatures are within a predetermined temperature range (zone) and within a predetermined time from the start of the compressor 2, so that the indoor air flow rate is reduced to a necessary minimum. be able to. For this reason, the feeling of cool air can be further reduced.

If it is determined in step S49 that the indoor / outdoor ambient temperature is not within the predetermined temperature range (No), the process proceeds to step S50
If not within 15 minutes from the start of the compressor 2 (No)
Proceeds to S46 and repeats the following steps.

[0069]

As described above, according to the present invention, in the case of a long pipe or a reverse head, the initial opening of the electronic expansion valve is not long pipe or the reverse head by the long pipe / reverse head mode control means. The opening is controlled to a predetermined opening larger than the opening.

For this reason, in the heating operation, the flow path resistance when the liquid refrigerant from the indoor heat exchanger flows into the outdoor heat exchanger through the electronic expansion valve increases due to the long piping or the head drop,
Since the initial opening of the electronic expansion valve is large even if the liquid refrigerant is close to the limit, the inflow of the liquid refrigerant flowing into the outdoor heat exchanger through the electronic expansion valve can be increased.

Therefore, the flow rate of the refrigerant circulating in the refrigeration cycle during the heating operation can be increased, so that the heating capacity in a long pipe or a head drop can be improved.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a configuration of a control system of the air conditioner according to the first embodiment of the present invention.

FIG. 3 is a flowchart of a control program for the air conditioner according to the first embodiment of the present invention.

FIG. 4 is a front view of a remote controller of the air conditioner according to the first embodiment of the present invention.

FIG. 5 is an external perspective view of the outdoor unit of the air conditioner according to the first embodiment of the present invention.

FIG. 6 is a graph showing changes in the indoor heat exchange temperature and the degree of superheat of the air conditioner according to the first embodiment of the present invention.

FIG. 7 is a flowchart of a control program for an air conditioner according to a second embodiment of the present invention.

FIG. 8 is a graph showing changes in indoor heat exchange temperature and superheat of a conventional air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Compressor 3 Four-way valve 4 Indoor fan 5 Outdoor fan 6 Electronic expansion valve 7 Outdoor heat exchanger 8 Refrigerant piping 9 Indoor heat exchange temperature sensor 10 Outdoor heat exchange temperature sensor 11 Comp refrigerant suction temperature sensor 12 Indoor unit 13 Outdoor unit 23 Long piping / Reverse head switch

Claims (8)

[Claims] 1. A refrigeration cycle comprising a refrigerant pipe connected to an indoor heat exchanger having a compressor, a four-way valve, an indoor fan capable of controlling the number of revolutions, an electronic expansion valve, and an outdoor heat exchanger having an outdoor fan. Controlling the degree of opening of the electronic expansion valve and the number of revolutions per unit time of the compressor according to the load, and rotating the indoor fan per unit time when the temperature of the indoor heat exchanger is equal to or lower than a predetermined value. Control means for reducing the number of refrigerant pipes, the initial opening of the electronic expansion valve at the start of operation, the length of the refrigerant pipe is longer than a predetermined value, or the outdoor heat exchanger is installed indoors. When the head is installed at a position higher than the heat exchanger, the head is set to a predetermined opening larger than the initial opening set by the control means when the head is not the head. Reverse head mode control hand The air conditioner characterized in that it comprises. 2. The air conditioner according to claim 1, further comprising manual operation means for manually inputting the long pipe or the reverse head to the long pipe / reverse head mode control means. 3. A long pipe / reverse drop mode is determined based on hunting of the number of revolutions of the indoor fan per unit time or refrigeration cycle temperature based on hunting. 3. The air conditioner according to claim 1, further comprising: a long pipe / reverse head determining means input to the control means. 4. The long pipe / reverse head mode control means includes an indoor fan rotation speed control means for setting a predetermined upper limit value for the number of rotations of the indoor fan at the time of long pipe or reverse head. The air conditioner according to any one of claims 1 to 3, wherein: 5. The long pipe / reverse head mode control means includes an indoor fan speed control means for fixing the number of revolutions of the indoor fan to a predetermined value at the time of long pipe or reverse head. The air conditioner according to any one of claims 1 to 3. 6. The long pipe / reverse head mode control means sets an upper limit value of the number of rotations of the indoor fan within a predetermined time from the start of the air conditioning operation or the start of the compressor when the long pipe or the reverse head is used, or sets a fixed value. The air conditioner according to any one of claims 1 to 5, further comprising a setting unit. 7. The long pipe / reverse head mode control means, when the long pipe or the reverse head, changes the indoor fan rotation speed to a predetermined value lower than the indoor fan rotation speed change speed set by the control means. The air conditioner according to any one of claims 4 to 6, further comprising means for setting the air conditioner. 8. The long pipe / reverse head mode control means, when the long pipe or the reverse head is in use, and the indoor heat exchanger side ambient temperature and the outdoor heat exchanger side ambient temperature are within a predetermined range. 8. A device according to claim 4, further comprising means for fixing the number of revolutions of the indoor fan to a predetermined value.
An air conditioner according to the item.