JPH06337150A - Method for controlling air-conditioning device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a control method of an air conditioner capable of performing dehumidification while maintaining a blowout temperature while maintaining a predetermined amount of air passing through an evaporator without reducing it. [Structure] The controller controls the damper according to the required dehumidification amount, reduces the amount of air passing through the evaporator, and lowers the dew point temperature of this air to accelerate the dehumidification effect and perform dehumidification. When is no longer necessary, close the damper and perform normal operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an air conditioner that performs a cooling operation, and in particular, it dehumidifies while maintaining a blown air amount of an evaporator without lowering the blown air amount. The present invention relates to a control method of an air conditioner suitable for the above.

[0002]

2. Description of the Related Art The prior art is disclosed in JP-A-63-73044.
As described in the publication, the dehumidifying operation is performed by reducing the air blowing amount of the air conditioner.

[0003]

In an air conditioner or the like for cooling a computer, when a computer to be cooled is cooled by air of low humidity, it is damaged by static electricity. It is also desirable not to dehumidify, so increase the air volume passing through the evaporator,
Dehumidification is prevented by keeping the evaporation temperature and pressure in the refrigeration cycle high and making the surface temperature of the heat exchange fins and pipes of the evaporator higher than the dew point temperature of the air sucked in the air conditioner.

However, due to the inflow of high-humidity air into the computer room and the increase in latent heat load by humans,
Humidity in the room becomes too high for people to feel uncomfortable, dehumidification is required in some cases, and dehumidification performance may be required for an air conditioner that responds to the dehumidification. However, in the above cases, if the conventional method is adopted, it is possible to perform the dehumidifying operation, but in that case, it is said that the airflow cannot be sufficiently obtained, for example, the blowing temperature is lowered due to the airflow reduction of the blower fan. I had a problem.

The present invention has been made in order to solve the above problems, and by controlling the amount of air passing through an evaporator, the amount of air blown out is maintained at a predetermined amount without being lowered, and dehumidification is performed while maintaining the temperature of air blown out. It is an object of the present invention to provide a method for controlling an air conditioner that can perform the above.

[0006]

In order to achieve the above object, the present invention provides a cooling and refrigeration cycle by connecting a compressor, a condenser, a pressure reducing device, an evaporator and an accumulator in this order with a refrigerant pipe, In a method for controlling an air conditioner in which cool air cooled by a blower is blown by a blower, a damper is provided at a position where a portion of suction air cooled by the evaporator is bypassed without passing through the evaporator, and a cooling operation is performed. When the humidity of the intake air into the evaporator is higher than the value previously set in the controller of the air conditioner,
The controller opens the damper to allow a part of the intake air to pass through the damper opening to reduce the amount of air passing through the evaporator, and to bring the temperature of the intake air below the dew point temperature to cause dew condensation on the inside surface of the evaporator. When the dehumidification promoting operation is performed and, on the contrary, when it is lower than the set value, the damper is closed, and the entire amount of intake air is passed through the evaporator to stop the dehumidification promoting operation.

Further, in the control method of the air conditioner,
A damper is provided at a position where the outside air can be directly introduced into the blower chamber, and the humidity of the intake air to the evaporator during the cooling operation is higher than the value set in advance in the controller of the air conditioner. The controller opens the damper, and the outside air is directly introduced into the blower chamber through the damper opening to reduce the amount of air passing through the evaporator, and the temperature of the intake air to the evaporator is set to be equal to or lower than the dew point temperature of the inside of the evaporator. A dehumidification promoting operation for causing dew condensation on the surface may be performed, and conversely, when the value falls below the set value, the damper may be closed to shut off the outside air to stop the dehumidification promoting operation.

It is preferable that the opening of the damper can be changed to an arbitrary opening, and the amount of air passing through the opening of the damper can be controlled according to the required dehumidification amount. Further, it is preferable that the compressor is configured to be capable of increasing and decreasing the refrigerant circulation capacity via a controller, and to increase the refrigerant circulation capacity when the cooling capacity is lowered by the dehumidification promoting operation. The cool air cooled through the humidifier is humidified when it is lower than the lower limit value of the humidity of the air blown from the evaporator set in the controller of the air conditioner in advance, and on the contrary, the humidity of the air blown from the evaporator is humidified. It is desirable that the humidification be stopped when the temperature rises above a predetermined value.

[0009]

The high-temperature and high-pressure gas refrigerant discharged from the compressor of the air conditioner is condensed in the condenser to become the high-temperature and high-pressure liquid refrigerant, which is decompressed in the decompression device and evaporated in the evaporator to be a low-temperature and low-pressure gas refrigerant. It becomes a refrigerant, forms an air-conditioning refrigeration cycle that returns to the compressor via the accumulator. When the refrigerant evaporates, the evaporator exchanges heat with the refrigerant and a predetermined flow rate of air is taken in, and the cooled air is blown out into the room for cooling.

In the present invention, by opening the damper, a part of the intake air passes through the damper opening, and the amount of air passing through the evaporator is reduced, so that the heat exchange capacity of the evaporator is lowered, Since the evaporation temperature of the refrigerant in the evaporator is lowered, the temperature of the heat exchange fins of the evaporator or the surface of the pipe is below the dew point temperature of the intake air, and dew condensation occurs on the surface. Further, since the amount of air passing through the evaporator is reduced and the passage speed of air is reduced, the bypass factor is reduced and the operation of the refrigeration cycle in which the dehumidification from the intake air is promoted can be performed.

Further, in another method for controlling an air conditioner of the present invention, by opening the damper, the outside air is directly introduced into the blower chamber through the damper opening, and the amount of air passing through the evaporator is reduced accordingly. Therefore, the heat exchange capacity of the evaporator is lowered, and the refrigerant evaporation temperature in the evaporator is lowered.
The heat exchange fins of the evaporator and the surface of the pipe become below the dew point temperature of the suction air, and dew condensation occurs on the surface. Also, since the amount of air passing through the evaporator is reduced and the air passage speed is reduced,
The bypass factor can be reduced and the refrigeration cycle can be operated with accelerated dehumidification from the intake air.

During the operation of the refrigeration cycle in which dehumidification is promoted, the opening of the damper can be changed to change the amount of air passing through the evaporator, so that the required amount of dehumidification can be achieved.

Further, during the operation of the refrigeration cycle in which dehumidification is promoted, the capacity of the compressor is increased and the refrigerant circulation amount in the refrigeration cycle is increased to prevent the rise of the outlet temperature due to the insufficient cooling capacity. You can

Furthermore, while the refrigeration cycle operation in which dehumidification is promoted is performed, a decrease in cooling capacity can be compensated to ensure the cooling capacity as a whole, and frost formation on the evaporator can be prevented.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First to seventh embodiments of the present invention will be described below with reference to FIGS.

First Embodiment FIG. 1 is a structural diagram of an indoor unit of an air conditioner of a first embodiment of the present invention, FIG. 2 is a refrigeration cycle system diagram, FIG. 3 is a humidity condition diagram of intake air, and FIG. 4 is this case. 3 is a control flowchart of FIG.

As shown in FIG. 2, the air conditioner in this embodiment is composed of main parts of a compressor 5, a condenser 6, an expansion valve 7, an evaporator 2 and an accumulator 8, which are connected by refrigerant pipes. ing. Further, a sensor 9 for detecting the temperature and humidity of the intake air of the air conditioner and a sensor 10 for detecting the temperature and humidity of the blown air are provided, and as shown in FIG. 1, a motor is provided between the evaporator 2 and the back cover. A damper 4 for driving is provided, and the sensors 9, 10 and the damper 4 are connected to a controller 11 equipped with a microcomputer. 1 is an evaporator 2, a damper 4 and a blower 3
It is an indoor air conditioner that stores.

During the cooling operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 5 is sent to the condenser 6 and condensed to become the high-temperature and high-pressure liquid refrigerant, which is decompressed by the expansion valve 7 and then transferred to the evaporator 2. A refrigeration cycle that enters and evaporates to become a low-temperature low-pressure gas refrigerant, and returns to the compressor 5 via the accumulator 8 constitutes a refrigeration cycle. When the refrigerant evaporates, a predetermined flow rate of air that is cooled by exchanging heat with the refrigerant is sucked into the evaporator 2, and the cooled air is blown into the room through the blower 3 for cooling.

The above cooling operation is controlled according to the flow chart shown in FIG. That is, when the intake air humidity detected by the sensor 9 becomes a value higher than the upper limit value a set in the controller 11 and shown in FIG. 3, the control is performed in order to reduce the humidity of the intake air. The device 11 sends a signal to the damper driving motor to open the damper 4, and a part of sucked air is passed through the opening of the damper 4 to bypass the evaporator 2 to start the dehumidification promotion operation. When the amount of air passing through the evaporator 2 is reduced by the above operation, the heat exchange capacity of the evaporator 2 is lowered and the refrigerant evaporation temperature of the evaporator 2 is lowered, so that the heat exchange fins and pipes of the evaporator 2 are reduced. The surface temperature of the air drops to below the dew point temperature of the intake air, and condensation occurs on the surface. Further, since the amount of air passing through the evaporator 2 is reduced and the passage speed of the air is reduced, the bypass factor is reduced, the dehumidification from the intake air is promoted, and the humidity is reduced. The dehumidification promoting operation is performed within the range of the upper limit value a and the lower limit value b shown in FIG.

When the humidity of the intake air detected by the controller 11 becomes lower than the lower limit value b set in the controller 11 shown in FIG. 3, the controller 11 sends a signal to the damper driving motor. Then, the damper 4 is closed, the dehumidification promotion operation is released, the heat exchange capacity of the evaporator 2 is increased, and the normal cooling operation is restored.

Second Embodiment FIG. 5 is a structural diagram of an indoor unit of an air conditioner according to a second embodiment of the present invention. The present embodiment is an example in which the damper 4 used in the first embodiment is provided at a position where air can be introduced from the outside of the indoor air conditioner 1. That is, instead of the method in which the suction air in the first embodiment bypasses the evaporator 2 by the damper 4, as shown in FIG. 5, the front cover on the outlet side of the evaporator 2 is driven by a motor. The damper 4 is provided.

In the normal cooling operation state, when the humidity of the intake air becomes higher than the upper limit value a shown in FIG. 3 set in the controller 11 in advance, the humidity of the intake air is lowered. Then, the controller 11 sends a signal to the damper driving motor to open the damper 4 and introduce air from the outside of the indoor air conditioner 1. Therefore, the amount of air passing through the evaporator 2 is reduced by the amount introduced from the outside, and dehumidification is promoted by the same action as in the first embodiment to lower the humidity. Then, when the humidity of the intake air detected by the controller 11 becomes lower than the lower limit value b set in the controller 11 shown in FIG. 3, the controller 11 sends a signal to the damper driving motor, 4 is closed to cancel the dehumidification promotion operation and return to the normal cooling operation.

Third Embodiment FIG. 6 is an explanatory view of a third embodiment of the present invention, in which the damper 3
It is a figure which shows the structure which can adjust an opening degree in steps. In this embodiment, as shown in FIG. 6, the damper 4 in the first and second embodiments is fully closed by a signal sent from the controller 11 according to the set value of the intake air humidity shown in FIG. ,
The configuration is such that the opening can be adjusted in three stages of half-opening and full-opening.

FIG. 7 shows a control flow chart in the case of this embodiment. The humidity of the suction air detected by the sensor 9 shown in FIG. 2 is set in the controller 11 in advance as shown in FIG.
When the value is higher than the upper limit value a shown in, the damper 4 is opened via the controller 11 from the fully closed state to the half opened state. In this state, when the intake air humidity falls below the lower limit value b shown in FIG. 3, the damper 4 is immediately returned to the fully closed p state to cancel the dehumidification promotion operation, but in the half open q state for a predetermined time (for example, After the lapse of 1 minute), when the humidity of the intake air remains higher than the upper limit value a, the state of half open q is changed to the state of full open r. Here, when the humidity of the intake air is between the upper limit value a and the lower limit value b, half open q
Is maintained.

With the above operation, it becomes possible to prevent the dehumidification from the intake air more than necessary amount and to carry out the operation of suppressing the decrease of the cooling capacity generated by promoting the dehumidification.

Fourth Embodiment FIG. 8 is a refrigeration cycle system diagram of an air conditioner of a fourth embodiment of the present invention. The refrigeration cycle system of this embodiment is a controller 11 in the refrigeration cycle system configuration shown in FIG.
Is changed to a controller 16 equipped with an inverter circuit, and the compressor 5 is changed to a compressor 15 whose capacity can be changed by changing the frequency.

A control flow chart in the case of this embodiment is shown in FIG. When the blown air temperature detected by the temperature / humidity sensor 10 is higher or lower than the target blown air temperature set in the controller 16 in advance, the blown air temperature is preset by the program installed in the controller 16. The rotation frequency of the motor of the compressor 15 is calculated so that the temperature becomes a target temperature, and the rotation speed of the motor of the compressor 15 is controlled by the frequency. When the blown air temperature is a predetermined temperature, the frequency is not changed.

Similar to the first embodiment, when the intake air humidity exceeds the upper limit value a shown in FIG. 3 and the damper is opened to perform the dehumidification promoting operation, the refrigerant circulation pressure is decreased due to the decrease of the refrigerant evaporation pressure. However, as a result, the cooling capacity may decrease and the temperature of the blown air may increase and become higher than the target temperature.
In such a case, the controller 16 controls the rotation frequency of the motor of the compressor 15 to increase the rotation speed of the motor so that the blown air temperature drops to the target temperature. As a result, the refrigerant circulation amount in the cycle increases, the refrigerant pressure in the evaporator 2 decreases, and the operation that promotes dehumidification becomes possible, and at the same time, the cooling capacity decreases due to the evaporation pressure decrease, and the refrigerant circulation amount increases. By this, it is possible to carry out a part of the supplementary operation.

Fifth Embodiment FIG. 10 is a control flowchart of the air conditioner of the fifth embodiment of the present invention. The present embodiment is another example of a case in which the operation of compensating for the decrease in the cooling capacity at the time of performing the dehumidification promoting operation as in the fourth embodiment by the rotation speed control of the compressor 15 is performed. Has reached the upper limit of the operating range, and the operation to compensate for the decrease in the cooling capacity cannot be performed any more, as shown in the flowchart in FIG. 10, a predetermined time (for example, 60 minutes) during which the dehumidification promotion operation can be continuously performed. The controller 16 sends a signal to the damper driving motor when the predetermined time is exceeded, and the damper 4 is closed to perform normal cooling operation. Further, a predetermined time (for example, 30 minutes) until the cycle state stabilizes after the control switching is set in the controller 16, and when the predetermined time is exceeded, the controller 16 detects the humidity of the intake air from the temperature / humidity sensor 9. When the detected humidity is higher than the upper limit value a, the controller 16 again sends a signal to the damper driving motor to open the damper 4 and perform the operation for promoting dehumidification. As described above, it is possible to minimize the decrease in the cooling capacity due to the operation that promotes dehumidification, and to secure the cooling capacity as a whole.

Sixth Embodiment FIG. 11 is a control flowchart of the air conditioner of the sixth embodiment of the present invention. The present embodiment is another example of the case where the operation for compensating for the decrease in the cooling capacity at the time of performing the dehumidification acceleration operation by the rotation speed control of the compressor 15 is performed as in the fifth embodiment. Has reached the upper limit of the operating range, and when it is no longer possible to perform the operation of compensating for the decrease in the cooling capacity, the allowable upper limit value c of the blown air temperature is set in advance in the controller 16 as shown in FIG. As shown in the flowchart in FIG. 11, when the blown air temperature exceeds the upper limit value c, the controller 16 sends a signal to the damper driving motor to close the damper 4 and perform normal cooling operation. Then, when the temperature of the blown air drops to a predetermined value d set in advance by the controller 16, the controller 16 detects the humidity of the intake air from the temperature / humidity sensor 9 and again when the humidity is higher than the upper limit value a. The controller 16 sends a signal to the damper driving motor to open the damper 4 and perform the dehumidification promotion operation. As described above, it is possible to minimize the decrease in the cooling capacity due to the operation that promotes dehumidification, and to secure the cooling capacity as a whole.

Seventh Embodiment FIG. 13 is a structural view of an indoor unit of an air conditioner according to a seventh embodiment of the present invention, which is an example of a structure in which a humidifier 17 is provided in the indoor air conditioner 1. As shown in FIG. 14, the controller 11 or 16 sets the allowable range of the humidity of the blown air in the range from the lower limit value e to the predetermined value f, and when the humidity of the blown air is lower than the lower limit value e, Humidifier 17 to increase the humidity of the air
On the other hand, when the humidity of the blown air becomes higher than a preset predetermined value f, the operation of the humidifier 17 is stopped via the controller 11 or 16. Further, as in the first to sixth embodiments, when the humidity of the intake air exceeds the preset upper limit value a shown in FIG. 3, the damper 4 is opened to perform the dehumidification promotion operation, When the humidity falls below the preset lower limit value b, the damper 4 is closed and the dehumidification promotion operation is stopped. As described above, it is possible to perform the operation of keeping the humidity of the blown air within the predetermined range regardless of the humidity of the intake air.

[0032]

As described above, according to the present invention, a damper is provided in the air conditioner and the amount of air passing through the evaporator is controlled so that the amount of air blown out is maintained at a predetermined amount without lowering the amount of air blown out. There is an effect that dehumidification can be performed while maintaining the above.

[Brief description of drawings]

FIG. 1 is a structural diagram of an indoor unit of an air conditioner of a first embodiment of the present invention.

FIG. 2 is a refrigeration cycle system diagram in FIG.

FIG. 3 is a humidity state diagram of the intake air in FIG.

FIG. 4 is a control flowchart of the air conditioner of the first embodiment.

FIG. 5 is a structural diagram of an indoor unit of an air conditioner of a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of the third embodiment of the present invention, and is a diagram showing a configuration in which the opening degree of the damper can be adjusted in three stages.

FIG. 7 is a control flowchart of a third embodiment.

FIG. 8 is a refrigeration cycle system diagram of an air conditioner of a fourth embodiment of the present invention.

FIG. 9 is a control flowchart of the air conditioner of the fourth embodiment.

FIG. 10 is a control flowchart of the air conditioner of the fifth embodiment of the present invention.

FIG. 11 is a control flowchart of the air conditioner of the sixth embodiment of the present invention.

FIG. 12 is a blowout temperature state diagram of the sixth embodiment.

FIG. 13 is a structural diagram of an indoor unit of an air conditioner of a seventh embodiment of the present invention.

FIG. 14 is a blown-air state diagram of the seventh embodiment.

[Explanation of symbols]

1 ... Indoor air conditioner, 2 ... Evaporator, 3 ... Blower, 4 ... Damper, 5,15 ... Compressor, 6 ... Condenser, 7 ... Expansion valve, 8 ...
Accumulator, 9, 10 ... Temperature and humidity sensor, 11, 16
… Controller, 17… Humidifier.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akiyoshi Taga 390 Muramatsu, Shimizu City, Shizuoka Prefecture Hitachi Ltd. Shimizu Plant

Claims (5)

[Claims] 1. An air conditioner in which a compressor, a condenser, a decompression device, an evaporator and an accumulator are sequentially connected by a refrigerant pipe to form a cooling and refrigeration cycle, and cold air cooled through the evaporator is blown by a blower. In the control method of the device, a damper is provided at a position where a part of the suction air cooled by the evaporator is bypassed without passing through the evaporator, and the humidity of the suction air to the evaporator during air-cooling operation is preliminarily air. If it becomes higher than the value set in the controller of the harmony device,
The controller opens the damper to allow a part of the intake air to pass through the damper opening to reduce the amount of air passing through the evaporator, and to bring the temperature of the intake air below the dew point temperature to cause dew condensation on the inside surface of the evaporator. When the dehumidification acceleration operation is performed and, on the contrary, when it is lower than the set value, the damper is closed, and the dehumidification acceleration operation is stopped by allowing the entire amount of intake air to pass through the evaporator. Device control method. 2. An air conditioner in which a compressor, a condenser, a decompression device, an evaporator and an accumulator are sequentially connected by a refrigerant pipe to form a cooling and refrigeration cycle, and cool air cooled through the evaporator is blown by a blower. In the control method of the device, a damper is provided at a position where the outside air can be directly introduced into the blower chamber, and the humidity of the intake air to the evaporator during the cooling operation is more than the value preset in the controller of the air conditioner. When it gets higher, the controller opens the damper,
External air is introduced directly into the blower chamber from the damper opening to reduce the amount of air passing through the evaporator, and the dehumidification acceleration operation is performed to bring the temperature of intake air into the evaporator below its dew point temperature to cause dew condensation on the inner surface of the evaporator. On the contrary, when it is lower than the set value, the damper is closed, the outside air is shut off, and the dehumidification accelerating operation is stopped. 3. The damper according to claim 1, wherein the damper is configured so that its opening can be changed to an arbitrary opening, and the amount of air passing through the damper opening can be controlled according to the required dehumidification amount. Air conditioner control method. 4. The compressor is configured such that the refrigerant circulation capacity can be increased or decreased via a controller, and the refrigerant circulation capacity is increased when the cooling capacity is lowered by the dehumidification promotion operation. A method for controlling the air conditioner described. 5. The cold air cooled through the evaporator,
Humidified when it is lower than the lower limit of the humidity of air blown from the evaporator set in advance in the controller of the air conditioner,
On the contrary, the method for controlling the air conditioner according to claim 1 or 2, wherein the humidification is stopped when the humidity of the air blown from the evaporator rises above a predetermined value.