JPH0721348B2 - Dehumidifying operation controller for air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a dehumidifying operation control device for controlling the dehumidifying operation of an air conditioner, and in particular, a temperature sensor that detects a suction air temperature is used for indoor heat exchange. Regarding the improvement of what is installed in the vessel.

(Prior Art) Conventionally, as a dehumidification operation control device for an air conditioner, an indoor fan of a variable air volume type has been proposed, as proposed in, for example, Japanese Patent Application No. 61-216233 (Japanese Patent Application Laid-Open No. 63-73044). In the air conditioner provided with the intake air temperature detecting means, when the dehumidifying operation command is issued during the cooling operation of the air conditioner, the dehumidifying operation is performed by reducing the air volume of the indoor fan, and the intake air temperature and the set temperature are set. When the deviation of reaches a certain value or less, the indoor fan is forcibly stopped, and when the deviation between the intake air temperature and the set temperature recovers above a predetermined value,
It is known that the indoor fan is operated again at a low air volume to perform the dehumidifying operation.

(Problems to be Solved by the Invention) By using the above conventional one, the indoor fan is forcibly stopped when the deviation between the intake air temperature and the set temperature is less than a certain value during the dehumidifying operation of the air conditioner. By letting
It is possible to prevent re-evaporation of drain water in the air heat exchanger.

By the way, in some air conditioners, for example, a ceiling-embedded air conditioner, a thermistor for detecting the intake air temperature is installed below the air heat exchanger inside the indoor unit. . In this type, the air cooled by the indoor heat exchanger flows down to the thermistor while the indoor fan is stopped, and the apparent intake air temperature is detected to be low.
As a result, the deviation between the intake air temperature and the set temperature is delayed in recovery to a predetermined value or more, and it takes a considerable time to return to the dehumidifying operation in which the indoor fan is operated at a low air flow rate. Therefore, when the above conventional dehumidification operation control device is applied to the air conditioner having such a structure, the dehumidification performance may not be sufficiently exhibited.

The present invention has been made in view of such a point, and an object thereof is after the indoor fan is stopped when the deviation between the intake air temperature and the set temperature becomes a certain value or less during the dehumidifying operation of the air conditioner. , The thermistor is an air conditioner of the type that is affected by the cold air from the indoor heat exchanger by providing a means for returning to an appropriate dehumidifying operation without controlling the indoor fan by the signal from the intake air temperature detecting means. However, the delay of the return to the dehumidifying operation due to the erroneous detection of the intake air temperature detecting means is prevented, and the dehumidifying operation performance is sufficiently exhibited.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention is, as shown in FIG. 1, a compressor (1), an outdoor heat exchanger (3),
It is premised on an air conditioner including a refrigerant circulation circuit (7) in which a pressure reducing mechanism (4) and an indoor heat exchanger (5) having a variable air volume indoor fan (5a) are sequentially connected.

Then, a suction air temperature detecting means (TH1) arranged below the indoor heat exchanger (5) for detecting the suction air temperature.
When the dehumidifying operation command is issued during the cooling operation, the temperature difference (Ta-Ts) between the intake air temperature (Ta) detected by the intake air temperature detecting means (TH1) and the set temperature (Ts) is greater than the reference value. When the difference is large, the dehumidification operation is performed by controlling the air volume of the indoor fan (5a) to be small while operating the compressor (1), while when the temperature difference (Ta-Ts) is less than or equal to the reference value, the compressor is (1) and a control means (8a) for controlling to perform a thermo-stop operation for stopping the operation of the indoor fan (5a),
After a lapse of a predetermined time from the start of the thermo-stop operation by the control means (8a), the indoor fan (5a) is forcibly forced until the temperature difference (Ta-Ts) becomes equal to or higher than a return value larger than the reference value. A forced fan operation means (20) for controlling to operate by reducing the air volume is provided.

(Operation) With the above configuration, in the present invention, when the dehumidifying operation command is issued during the cooling operation of the air conditioner, the intake air temperature detected by the intake air temperature detecting means (TH1) by the control means (8a). (Ta) and room temperature setting (Ts)
s), when the temperature difference is larger than the reference value, the dehumidifying operation is performed to control the air volume of the indoor fan (5a) to a small value.
When the temperature difference (Ta-Ts) falls below the standard value, the compressor (1)
And the thermo-stop operation is performed to stop the indoor fan (5a). By this thermo-stop operation, the indoor fan (5
Since a) is stopped, the re-evaporation of drain water is prevented.
At that time, in the intake air temperature detecting means (TH1) arranged below the indoor heat exchanger (5), while the indoor fan (5a) is stopped, the cold air accumulated below the indoor heat exchanger (5) Due to the influence, the detected value is apparently lower than the actual intake air temperature, so that the temperature difference (Ta-Ts) may be below the reference value although it is originally above the reference value.

Here, in the present invention, when a predetermined time elapses after the indoor fan (5a) has stopped, the indoor fan (5a) is operated by the forced fan operation means (10) with a small air volume as in the dehumidifying operation. Therefore, the cool air that accumulates below the indoor heat exchanger (5) is blown out into the room. As a result, the value detected by the intake air temperature detection means (TH1) reflects the actual room temperature, so the temperature difference (Ta-Ts) quickly recovers above the reference value and returns to dehumidification operation. . Therefore, the return to the dehumidification operation is delayed due to an erroneous detection that the intake air temperature detection unit (TH1) detects the intake air temperature (Ta) lower than the indoor air temperature due to the influence of the cool air in the indoor heat exchanger (5). Will be prevented as much as possible.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings starting from FIG.

FIG. 2 shows an embodiment in which the present invention is applied to a ceiling-embedded air conditioner. In FIG. 2, (A) is an outdoor unit,
(B) is an indoor unit, and the outdoor unit (A) includes a compressor (1) and a four-way switching valve that switches as shown by the solid line in the drawing during cooling operation and as shown by the broken line in the drawing during heating operation. (2) and an outdoor heat exchanger (3), which serves as a condenser during cooling operation and an evaporator during heating operation, are built-in.
On the other hand, in the indoor unit (B), an electric expansion valve (4) serving as an expansion mechanism for expanding the refrigerant, an indoor heat exchanger (5) serving as an evaporator during cooling operation and a condenser during heating operation. , An indoor fan (5a) that variably adjusts the number of revolutions to change the air volume is built in as a main device, and the main devices (1) to (5) enable refrigerant to flow through a refrigerant pipe (6). The refrigerant circulation circuit (7) is formed by being connected in order.

The indoor unit (B) is provided in a ceiling-embedded structure as shown in FIG. That is, the indoor unit (B) has a casing (10) embedded in the ceiling.
Inside the room, the indoor heat exchanger (5) and a sirocco type indoor fan (5) in which a blower opening faces the indoor heat exchanger (5)
a) and the indoor fan (5a) sucks indoor air sucked from the air suction port (11a) provided near the center of the casing (10) through the suction air passageway (11). After exchanging heat with the heat exchanger (5), it blows out into the room from the air outlet (12) provided on the lower left side of the casing (10), and also opens downstream of the indoor heat exchanger (5) to divide the flow. The conditioned air is blown into the room from the air outlet (12) on the lower right side of the casing (10) via a duct (not shown). Further, in the suction air passageway (11), a thermistor (TH1) as a suction air temperature detecting means for detecting the suction air temperature is attached below the indoor heat exchanger (5).

FIG. 3 shows the internal circuit configuration of the indoor control unit (8) that controls the operation of the indoor unit (B) and the main wiring of each device connected to the unit (B).
(MF) is a fan motor for an indoor fan (5a), which receives a single-phase AC power source and switches the air volume between three levels, strong wind, weak wind, and light wind, by each relay terminal (RY ₁ ) to (RY ₃ ). It is done like this. A pulse motor (EV) for adjusting the opening of the electric expansion valve (4) is connected to the terminal CN of the printed circuit board of the outdoor control unit (8), and the thermistor (TH1) and remote control switch (R) are connected.
CS) is connected so that signals can be input, and the indoor control unit (8) has an indoor control as a control means for performing a dehumidifying operation and a thermo-stop operation at the time of a dehumidifying operation command, as indicated by a broken line in the figure. The device (8a) is built in.

Then, in FIG. 2, during the cooling operation of the air conditioner,
The gas refrigerant compressed by the compressor (1) is condensed and liquefied by the outdoor heat exchanger (3) (condenser), and then subjected to expansion action by the electric expansion valve (4) to be indoor heat exchanger (5). It vaporizes in the (evaporator) and returns to the compressor (1) in a gas state. At that time, in the indoor unit (B), the temperature difference (Ta−Ta) between the intake air temperature Ta detected by the thermistor (TH1) and the set temperature Ts is controlled by the indoor control device (8a) of the indoor control unit (8). The opening of the electric expansion valve (4) is controlled according to the indoor load represented by (Ts), while the air volume of the indoor fan (5a) is set by the user by the control switch (RCS), and indoor heat exchange is performed. It is arranged such that the capacity of the vessel (5) is adjusted.

The opening control of the electric expansion valve (4) and the air volume control of the indoor fan (5a) performed by the indoor control device (8a) will be described with reference to the flowchart of FIG. 5. In step S ₁ , the thermistor (TH1) is used. determine whether a predetermined sampling time of the suction air temperature Ta and the set temperature Ts has elapsed is detected, at the elapsed YES, in accordance with the intake air temperature Ta in step S _2, the allowable range that do not wet operation The maximum allowable opening Amax of the electric expansion valve (4), which is the maximum value of, is calculated as a function of the intake air temperature Ta, and at the same time, at the lower limit of the allowable range so as to have a constant ratio to the maximum allowable opening Amax. Calculate a certain minimum allowable opening Amin.

Next, in step S ₃ , the remote control switch (RC
It is determined whether or not the dehumidifying operation command signal from S) is input, and if NO is not input, the normal control operation is performed in step S ₄ . That is, the air volume of the indoor fan (5a) is set as set, and the opening A of the electric expansion valve (4) is shown by the temperature difference between the intake air temperature Ta and the set temperature Ts (Ta-
Based on the relationship between Ts) and the opening A, control is performed so that the equation A = Amin + (Amax-Amin) x (Ta-Ts) / 4 (however, when A≥Amax, A = Amax
And A = Amin when A ≦ Amin).

On the other hand, if being made dehumidifying operation command from the remote control switch (RCS) is the discrimination at the step S ₃ becomes to YES, the differential temperature in step S ₅ (Ta-Ts) a first reference value (4 ° C.)
And the second reference value (0 ° C), the difference in temperature (Ta-T
It is determined whether s) is in a region of 4 ° C. or higher, a region of 0 ° C. to 4 ° C., or a region of 0 ° C. or lower. Then, if the determination is (Ta-Ts) ≧ 4 a ° C., to do dehumidifying operation determines that the room air temperature is too high, the setpoint exactly the indoor fan (5a) proceeds to step S _6, the opening degree a of the electric expansion valve (4) achieving rapid drop in the indoor air temperature by performing the same normal thermo operation and the normal control operation for controlling the above calculated value, at step S ₇ (Ta-Ts) ≦ After carrying out normal thermo-operation until the temperature reaches 2 ° C, return to step S ₁ .

Then, the determination in step S ₅ is 0 ° C. ≦ (Ta−Ts) ≦
4 at ℃, it is determined that there is a suitable temperature range for dehumidifying operation, the indoor fan (5a) to the breeze "LL" side in Step S _8, so that the opening degree A of the electric expansion valve (4) to Amax Control the dehumidification operation.

On the other hand, Step S ₅ drops indoor air temperature during the dehumidifying operation
When determination is (Ta-Ts) ≦ 0 ℃ in, it is determined that it is necessary to prevent re-evaporation of the drain of the indoor heat exchanger (5), the process proceeds to the following thermo shutdown step S _9. First, in step ₉ , the indoor fan (5a) is forcibly stopped and the opening A of the electric expansion valve (4) is set to "0". Then, in step S ₁₀ , the control in step S ₈ is repeated for 3 minutes, and 3
After a lapse of minutes, proceed to step S ₁₁ and move to the indoor fan (5a).
Is switched to the breeze “LL” side again, the opening A is controlled as “0”, and in step ₁₂ , the thermo stop control is performed until (Ta−Ts) ≧ 2 ° C. (reset value), Ta−Ts) ≧ 2 ℃
When YES, the operation returns to the above dehumidification operation.

Therefore, in the above flow, the control of step S ₁₀ to S _12, referred to in the invention of claim 1 fan forced operation means (2
0) is configured.

Therefore, in the above embodiment, when the dehumidifying operation command is issued from the remote control switch (RCS) during the cooling operation of the air conditioner, the dehumidifying operation is performed by the control means (8a) in response to the signal from the thermistor (TH1). Done. That is, the temperature difference between the intake air temperature Ta and the set temperature Ts (Ta-Ts)
Based on the change of the value of 0, as shown in FIG.
Within the range of Ts <4 ° C, the air volume of the indoor fan (5a) is changed to
"L" side, and controlling the opening A of the electric expansion valve (4) to the maximum allowable opening Amax to perform dehumidification operation with high dehumidification efficiency with low power consumption, and Ta-Ts ≥ 4 ° C, Since the indoor fan (5a) is set as it is, and the normal thermo control for controlling the opening A of the electric expansion valve (4) to a calculated value is performed,
The indoor air temperature quickly converges to the set value Ts to maintain a good feeling of air conditioning. Then, the normal thermo control is performed, and T-
When Ts ≦ 2 ° C., the dehumidification operation is resumed, so the dehumidification efficiency does not decrease. Further, when Ta−Ts ≦ 0 ° C., the indoor fan (5a) is forcibly stopped by shifting to the thermo-stop operation, so that re-evaporation of drain water accumulated in the drain during the cooling operation is prevented. Further, when the intake air temperature Ta rises due to the thermo-stop operation and Ta−Ts ≧ 2 ° C., the drain water is almost discharged and the dehumidification operation is resumed to dehumidify the indoor air.

At that time, in the case where the thermistor (TH1) is installed in the lower part of the indoor heat exchanger (5), such as a ceiling-embedded air conditioner, the indoor fan (5a) stops and the indoor heat exchange is stopped. The cooled air around the device (5) naturally flows down to the air suction passage (11) side, and the thermistor (TH
In 1), the value of the intake air temperature Ta is detected to be lower than the indoor air temperature, which may cause a state in which the return from the thermo-stop operation to the dehumidification operation is delayed, but in the above embodiment, the indoor fan (5a) is stopped. Then, when the predetermined time (3 minutes) has passed,
As shown in FIG. 7, the fan forced operation means (20) controls the indoor fan (5a) to the breeze “LL” side to operate, so that the cold air of the indoor heat exchanger (5) is circulated in the room. The suction air temperature Ta detected by the thermistor (TH1) quickly returns to the state in which the indoor air temperature is accurately displayed. Therefore, the temperature difference (Ta-Ts) quickly recovers above the reference value,
The dehumidifying operation can be performed again, and the delay in returning to the dehumidifying operation can be prevented as much as possible. In addition, step
Since the drain of the indoor heat exchanger (5) would be substantially discharged during the indoor fan (5a) is 3 minutes suspended in S _9, S _10, never re-evaporation of the drain is caused.

The present invention is not limited to the above-embedded ceiling air conditioner, but includes a ceiling suspended air conditioner or a temperature sensor such as a thermistor (TH1) disposed below the indoor unit (B). The present invention can be applied to other air conditioners having.

Further, the above-described embodiment is an example in which the present invention is applied to an air conditioner in which one indoor unit (B) is arranged with respect to one outdoor unit (A), but one outdoor unit ( It goes without saying that the present invention can also be applied to a multi-type air conditioner in which a large number of indoor units are arranged for A).

(Effects of the Invention) As described above, according to the present invention, in the air conditioner having the intake air temperature detecting means, the indoor fan is forcibly stopped only for a predetermined time to discharge drain water during the dehumidifying operation. After the lapse of a predetermined time, the indoor fan is operated in the same way as during dehumidifying operation, so the intake air temperature detection means erroneously detects the intake air temperature due to the flow of cold air from the indoor heat exchanger, and the dehumidifying operation is started. It is possible to prevent the recovery from being delayed as much as possible, and thus it is possible to sufficiently exhibit the dehumidification performance.

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of the present invention. 2 and the following show an embodiment of the present invention, FIG. 2 is a refrigerant system diagram thereof, and FIG. 3 is a longitudinal sectional view showing a schematic configuration of a ceiling-embedded indoor unit.
FIG. 4 is an electric circuit diagram of the indoor control unit, FIG. 5 is a flow chart showing control of the indoor control device, FIG. 6 is a switching characteristic diagram of normal thermostat operation, dehumidifying operation and thermostat stop operation, and FIG. 7 is thermostat stop. It is an operation mode figure of an indoor fan at the time of operation. (1) ... Compressor, (3) ... Indoor heat exchanger, (4) ...
… Electric expansion valve (expansion mechanism), (5) …… Indoor heat exchanger,
(5a) …… Indoor fan, (7) …… Refrigerant circulation circuit, (8
a) …… Indoor control device (control means), (TH1) …… Thermistor (suction air temperature detection means), (20) …… Fan forced operation means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akio Higuchi 1304 Kanaoka-machi, Sakai City, Osaka Prefecture Daikin Industry Co., Ltd., Kanaoka Plant, Sakai Manufacturing Co., Ltd. (56) Reference JP 58-153032 (JP, A) 55-59239 (JP, U)

Claims (1)

[Claims] 1. A compressor (1), an outdoor heat exchanger (3),
An air conditioner comprising a refrigerant circulation circuit (7) in which a pressure reducing mechanism (4) and an indoor heat exchanger (5) having a variable air volume type indoor fan (5a) are sequentially connected to each other. (5) Suction air temperature detection means (TH1) arranged below the suction air temperature and the suction air temperature detection means (TH1) for dehumidifying operation command during cooling operation. When the temperature difference (Ta-Ts) between the intake air temperature (Ta) and the set temperature (Ts) is larger than the reference value, the indoor fan (5a) while operating the compressor (1).
The dehumidifying operation is performed by controlling the air flow rate of the air to a small value, and when the temperature difference (Ta-Ts) is less than or equal to the reference value, the thermo-stop operation is performed to stop the operation of the compressor (1) and the indoor fan (5a). When a predetermined time elapses after the control means (8a) for controlling so as to perform the thermo-stop operation by the control means (8a), the temperature difference (Ta-Ts) becomes equal to or higher than the return value larger than the reference value. Until then, a dehumidifying operation control device for an air conditioner, comprising: a forced fan operation means (20) for forcibly reducing the air volume of the indoor fan (5a) to operate.