JP5171759B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner, and more particularly to wind direction control that can suppress the occurrence of condensation around a blowout port.

  A conventional air conditioner calculates the load of the air conditioner from the difference between the room temperature and the set temperature in order to suppress the occurrence of condensation, and changes the position of the wind direction control blade when a predetermined condition is satisfied. Is prevented (for example, see Patent Document 1).

Japanese Patent Laying-Open No. 2005-257192 (first page, FIG. 2)

In a conventional air conditioner, the load of the air conditioner is calculated from the difference between the room temperature and the set temperature, and condensation is prevented by changing the angle of the wind direction control blade when a predetermined condition is satisfied. In this case, the time until the control is divided, it is a normal wind direction angle for a long time at a low temperature, and the humidity is not observed at a low temperature and high humidity, so it cannot be handled.
Condensation occurs when the air condition around the outlet is below the dew point, but if there is no means to detect the surrounding humidity condition, it is better to think that it can occur when the outlet temperature is low. In order to prevent the occurrence of dew condensation, it is necessary to consider the conditions such as low temperature and high humidity.

In addition, although the control conditions for preventing the occurrence of condensation are divided into high load, medium load, and low load, these conditions cannot be detected at the same time, so for example, low load conditions and medium loads There is a problem that if the condition is changed at an interval that does not satisfy the predetermined time, the control for preventing the occurrence of condensation does not work and there is a possibility that the condensation may occur.
The present invention has been made to solve such a problem, and the wind direction control blade can be changed to a dew condensation prevention position under conditions where the occurrence of dew condensation is predicted, thereby preventing the occurrence of dew condensation around the outlet. The purpose is to obtain an air conditioner that can provide a comfortable space for the user.

  The air conditioner according to the present invention includes a condenser, an evaporator, a refrigeration cycle having a compressor that compresses the refrigerant flowing through the condenser and the evaporator, and heat exchange between the air sucked from the suction port by the evaporator. A blower that blows air to the air outlet, and a wind direction control blade that is rotatably provided to the air outlet and that blows air in a direction different from the direction of air blown from the air outlet by the air blower, and the air direction control blade An air conditioner including a wind direction control blade actuator for rotating the air outlet, a blown air temperature detecting means for detecting a temperature of air blown from the blowout port, and a blown air temperature detected by the blown air temperature detecting means; Comparing a plurality of preset air temperature thresholds when no condensation occurs around the air outlet, the air temperature detected by the air temperature detecting means is Among the plurality of blown air temperature thresholds, the wind direction control blade actuator is set when an integrated time less than or equal to at least one blown air temperature threshold reaches an upper limit time set to generate dew condensation. And a wind direction plate control device configured to change the wind direction control blade to a predetermined position capable of preventing the occurrence of condensation by driving control.

  The air conditioner of the present invention compares the blown air temperature detected by the blown air temperature detection means by the wind direction plate control device with a plurality of blown air temperature threshold values of the blown air temperature when no condensation occurs around the blower outlet. The blown air temperature detected by the blown air temperature detecting means is set to be at least one of the plurality of blown air temperature thresholds or less, and an accumulated time that is less than or equal to the blown air temperature threshold is set to generate condensation. The wind direction control vane actuator is driven and controlled when the upper limit time is reached, and the wind direction control vane is changed to a predetermined position where condensation can be prevented. There is an effect that the control blade can be changed to a predetermined position where condensation can be prevented to prevent condensation around the air outlet, and a comfortable space can be provided to the user.

The schematic diagram which shows the refrigerant circuit of the air conditioner which concerns on Embodiment 1 of this invention. The block diagram which shows the indoor unit of the air conditioner. The block diagram which shows the blower outlet periphery of the indoor unit of the air conditioner. The transition flowchart of the piping temperature in the indoor unit of the air conditioner. The control flowchart of the dew condensation prevention in the indoor unit of the air conditioner.

Embodiment 1 FIG.
1 is a schematic diagram illustrating a refrigerant circuit of an air conditioner according to Embodiment 1 of the present invention, FIG. 2 is a configuration diagram illustrating an indoor unit of the air conditioner, and FIG. 3 is a blower of the indoor unit of the air conditioner. FIG. 4 is a flow chart showing a transition of piping temperature in the indoor unit of the air conditioner, and FIG. 5 is a control flowchart for preventing condensation in the indoor unit of the air conditioner.
In FIG. 1, the refrigerant circuit of the air conditioner according to Embodiment 1 of the present invention includes two heat exchangers 30a and 30b, a compressor 50 that compresses refrigerant flowing in the heat exchangers 30a and 30b, and air Refrigeration cycle having a four-way valve 51 for switching to a refrigerant circuit for cooling and heating and an electronic expansion valve (hereinafter referred to as LEV) 52, which are connected by a refrigerant pipe as shown in the figure to circulate the refrigerant Configure. The entire refrigerant circuit is separated and stored in an indoor unit 100a and an outdoor unit 100b of the air conditioner.

In the cooling operation of the air conditioner, refrigerant piping is connected in the four-way valve 51 as shown by a solid line, and the heat exchanger 30a is operated as an evaporator and the heat exchanger 30b is operated as a condenser. At this time, the low-temperature and low-pressure gas refrigerant flowing inside the refrigerant circuit is compressed by the compressor 50 to become a high-temperature and high-pressure gas refrigerant.
The high-temperature and high-pressure gas refrigerant exchanges heat with outdoor air in the heat exchanger 30b, and the refrigerant itself condenses into a high-pressure and low-temperature liquid refrigerant, and adiabatic expansion in the LEV 52 becomes a low-pressure and low-temperature two-phase refrigerant. . The heat exchanger 30 a exchanges heat with room air to evaporate and returns to the compressor 50.
The heat exchanger 30a functions as an evaporator to evaporate the refrigerant, so that the indoor air is cooled and the room is cooled.

In addition, refrigerant piping is connected within the four-way valve 51 as indicated by a dotted line, and the refrigerant is condensed by causing the heat exchanger 30a on the indoor unit 100a side to function as a condenser, so that the indoor air is heated and the room is heated. Is done. Although not shown in FIG. 1, each of the indoor unit 100 a and the outdoor unit 100 b of the air conditioner includes one or a common control device, and the number of rotations of the compressor 50 and the four-way valve 51 The connection, the opening degree of the LEV 52, the rotational speed of the blower 3 arranged in the vicinity of the heat exchangers 30a and 30b, and the like are controlled. Here, the compressor 50 has at least two stages of compressor operating rotational speeds by the control device.
Although the four-way valve 51 is shown to be capable of switching between cooling operation and heating operation, the present invention is not limited to this, and at least a cooling operation in which cool air having a low temperature with respect to the sucked air is blown into the room or It is also applicable to air conditioners that perform dehumidifying operation.

  In FIG. 2, the indoor unit 100a of the air conditioner includes an evaporator 30a, a suction port 1, a suction temperature sensor 2 that detects the temperature of air sucked from the suction port 1, and a blower disposed inside the indoor unit. 3, a pipe temperature sensor 4 that detects the pipe temperature of the evaporator 30 a, a wind direction control blade 5 that changes the direction of the air blown from the outlet 7, a wind direction control blade actuator 6 that rotates the wind direction control blade 5, The direction of the airflow which flows through the inside unit 100a of the air conditioner is shown by a white arrow.

Air blown from the suction port 1 is blown by the blower 3 through the evaporator 30a, and cool air is blown out from the air outlet 7 during cooling and warm air is blown out during heating. Meanwhile, the temperature of the piping of the evaporator 30 a is detected by the piping temperature sensor 4, and the temperature of the air sucked from the suction port 1 is detected by the suction temperature sensor 2.
Further, since the air outlet 7 is provided with the air direction control blade 5 and the air direction control blade actuator 6 that can control the air direction control blade 5 to be rotatable, the angle of the air blown out from the air outlet 7 can be changed. Here, the position of the wind direction control blade 5 by the user is set to the normal blowing position P1 shown in FIG. The normal blowing position P1 of the wind direction control blade 5 is defined as an angle of air inclined at an angle of 20 degrees to 30 degrees outward with reference to the angle parallel to the flow of air blown out from the blowout port 7 as 0 degrees. It is a position that blocks the flow.

Next, the relationship between the piping temperature threshold and the integration time will be described with reference to FIG.
Before that, the relationship between the blowing temperature of the air blown out from the blower outlet 7 and dew condensation, and the relationship between the blowing temperature and the piping temperature will be described.
Condensation occurs at the air outlet 7 when cold air flows through the air outlet 7, the air outlet 7 reaches a dew point below the ambient air, and the ambient air flows through the air outlet 7. The temperature drop around the outlet 7 is dependent on the temperature of the outlet 7 and its time.
When the time is counted, the temperature of the air outlet 7 changes and may be higher than the temperature that causes condensation. Therefore, instead of counting the continuous time, only the temperature that causes condensation is accumulated. It is to be counted.
Moreover, since the blowing temperature of the air of the blower outlet 7 depends on the piping temperature of the evaporator 30a, and the piping temperature is several times lower than the temperature of the air of the blowing outlet 7, if the piping temperature is known, The temperature can also be estimated.
And although the piping temperature sensor 4 is usually provided, since the blowing temperature sensor which detects the temperature of the air blown out from the blower outlet 7 is not provided in the blower outlet 7, the relationship between piping temperature and time is shown. This will be described based on the graph of FIG.

In FIG. 4, time is plotted on the horizontal axis, pipe temperature is plotted on the vertical axis, and sections t1, t2, and t3 are shown in time series order.
The pipe temperature thresholds are Ta and Tb (Ta ≧ Tb). The pipe temperature threshold value does not cause condensation, but condensation occurs after a predetermined time at a temperature equal to or lower than the pipe temperature threshold value. Therefore, the predetermined temperature is used as the pipe temperature threshold value.
In the air conditioner indoor unit 100a, a timer TM1 that counts an accumulated time H1 that is less than or equal to the pipe temperature threshold Ta, a timer TM2 that counts an accumulated time H2 that is less than or equal to the pipe temperature threshold Tb, a wind direction control blade actuator 6, A wind direction plate control device (not shown) for controlling the wind direction control blade actuator 6 is provided.
Further, the upper limit time of the integrated time H1 that is less than or equal to the pipe temperature threshold Ta counted by the timer TM1 is H1max, and the upper limit time of the accumulated time H2 that is less than or equal to the pipe temperature threshold Tb counted by the timer TM2 is H2max.
The upper limit time H1max is longer than the upper limit time H2max because the pipe temperature threshold Ta is higher than the pipe temperature threshold Tb.
When the upper limit time H1max or the upper limit time H2max reaches that time, dew condensation starts to occur at the air outlet 7, and the upper limit time H1max or the upper limit time H2max is obtained by experiments in relation to the piping temperature.

As described above, the upper limit time H1max and the upper limit time H2max are set in the timers TM1 and TM2 provided in the wind direction plate control device, respectively.
First, in the period t1, since the pipe temperature detected by the pipe temperature sensor 4 is equal to or less than the pipe temperature threshold Ta, the timer TM1 counts the accumulated time H1, and since it is not less than the pipe temperature threshold Tb, the timer TM2 does not count. .
In the next period t2, since the pipe temperature detected by the pipe temperature sensor 4 is equal to or lower than the pipe temperature threshold Ta and equal to or lower than the pipe temperature threshold Tb, the timer TM1 and the timer TM2 simultaneously calculate the accumulated times H1 and H2. Counting.
Furthermore, in the period t3, the pipe temperature detected by the pipe temperature sensor 4 is not lower than the pipe temperature threshold Ta and not lower than the pipe temperature threshold Tb, so the timer TM1 and the timer TM2 do not count.
From the period t1 to the period t3, the counting continues until the accumulated time counted by the timer TM1 reaches the upper limit time H1max, and the timer TM2 also continues counting until the upper limit time H2max is reached.

Then, for example, when the accumulated time H1 counted by the timer TM1 reaches the upper limit time H1max in the period t1, the wind direction plate control device operates the wind direction control blade actuator 6 to move the wind direction control blade 5 from the normal blowing position P1. Change to the dew condensation prevention position P2.
In this dew condensation prevention position P2, when the angle parallel to the air flow blown out from the blowout port 7 is 0 degree, the most dew condensation occurs so that the blown air flow smoothly flows at an angle close to 0 degree. This is a difficult position and is obtained in advance by experiments.
Further, the wind direction control device also controls the wind direction control blade when the accumulated time H1 counted by the timer TM1 reaches the upper limit time H1max or the accumulated time H2 counted by the timer TM2 reaches the upper limit time H2max in the period t2. The actuator 6 is operated to change the wind direction control blade 5 to the dew condensation prevention position P2.

Next, control for preventing the occurrence of condensation in the indoor unit of the air conditioner according to Embodiment 1 of the present invention will be described based on the flowchart of FIG.
First, in step ST1, the control for preventing the occurrence of condensation by the wind direction plate control device starts from the start of the cooling operation.
Next, in step ST2, the pipe temperature sensor 4 detects the pipe temperature. This detection continues to be detected even if it proceeds to the next step.
Next, when the pipe temperature is equal to or lower than the pipe temperature threshold Ta in step ST3a, the timer TM1 starts counting in step ST4a. At the same time, if the pipe temperature is equal to or lower than the pipe temperature threshold value Tb in step ST3b, the timer TM2 starts counting in step ST4b.
Next, in step ST5a, when the accumulated time H1 counted by the timer TM1 has reached the upper limit time H1max, or when the accumulated time H2 counted by the timer TM2 has reached the upper limit time H2max, in step ST6, the wind direction plate The control device operates the wind direction control blade actuator 6 to change the wind direction control blade 5 to the dew condensation prevention position P2.
Finally, in step ST7, the counts of the timer TM1 and the timer TM2 are cleared.

  In this way, condensation is likely to occur by separately counting the accumulated times H1 and H2 that reach the upper limit time H1max and the upper limit time H2max when the pipe temperature detected by the pipe temperature sensor 4 is below the pipe temperature thresholds Ta and Tb, respectively. When the blowing temperature is low, the wind direction control blade 5 can be changed to the dew condensation prevention position P2 in a short time. When the blowing temperature at which condensation is difficult to occur is high, the wind direction control blade 5 is changed to the dew condensation prevention position P2 in a long time. Therefore, it is possible to prevent the occurrence of condensation according to the conditions, and to maintain the position of the wind direction control blade set by the user as much as possible according to the operating conditions. The problem of giving a sense of discomfort is eliminated.

  3 and 4, the pipe temperature thresholds Ta and Tb and the upper limit times for these pipe temperature thresholds Ta and Tb are set to two, H1max and H2max, but the number of pipe temperature thresholds is further increased to cope with detailed operating conditions. It is also possible to do.

  Moreover, although the blowing temperature detected by the blowing temperature detecting means in the first embodiment is calculated and used by the calculating means of the wind direction plate controller from the pipe temperature detected by the pipe temperature sensor 4, An air temperature sensor is provided to directly detect the blowout temperature, or the blowout temperature is calculated by the calculation means of the wind direction plate controller from the rotation speed of the compressor detected by the rotation speed detection means for detecting the rotation speed of the compressor. May be used.

    DESCRIPTION OF SYMBOLS 1 Suction port, 2 Suction temperature sensor, 3 Blower, 4 Piping temperature sensor, 5 Air direction control blade, 6 Air direction control blade actuator, 7 Air outlet, 8 Normal position, 9 Condensation prevention position, 30a Evaporator, 30b Condenser, 50 Compressor, 51 Four-way valve, 52 Electronic expansion valve (LEV), 100a Air conditioner indoor unit, 100b Air conditioner outdoor unit.

Claims (5)

A condenser, an evaporator, and a refrigeration cycle having a compressor that compresses the refrigerant flowing in the condenser and the evaporator; and a blower that blows air sucked from the suction port to the outlet after heat exchange with the evaporator A wind direction control blade that is rotatably provided at the air outlet and that blows air in a direction different from the direction of air blown from the air outlet by the blower, and a wind direction control blade actuator that rotates the air direction control blade. In an air conditioner equipped with
Blown air temperature detection means for detecting the temperature of the air blown from the blowout port;
The blown air detected by the blown air temperature detecting means is compared with the blown air temperature detected by the blown air temperature detecting means and a plurality of preset blown air temperature threshold values when no condensation occurs around the blower outlet. The wind direction control when the temperature is equal to or lower than at least one of the plurality of blown air temperature thresholds and an accumulated time equal to or less than the blown air temperature threshold has reached an upper limit time set to cause condensation. A wind direction plate control device that drives and controls a blade actuator to change the wind direction control blade to a predetermined position that can prevent the occurrence of condensation; and
An air conditioner characterized by comprising:   The relationship between the plurality of blown air temperature thresholds and the upper limit time corresponding to each blown air temperature threshold is such that when each of the blown air temperature thresholds is large or small, the higher the blown air temperature threshold is, the higher the upper limit time is. 2. The air conditioner according to claim 1, wherein the upper limit time is set shorter as the air temperature threshold value is longer and lower.   The air conditioner according to claim 1 or 2, wherein the blown air temperature detecting means is a blown air temperature sensor that is provided at the blower outlet and detects an air temperature passing through the blower outlet.   The blown air temperature detection means is provided in the evaporator and calculates a pipe temperature sensor for detecting a pipe temperature of the evaporator and a temperature of the air passing through the outlet from the pipe temperature detected by the pipe temperature sensor. The air conditioner according to claim 1, further comprising a calculation unit.   The blown air temperature detection means includes a rotation speed detection means for detecting the rotation speed of the compressor, and a calculation means for calculating an air temperature passing through the outlet from the rotation speed of the compressor detected by the rotation speed detection means. The air conditioner according to claim 1 or 2, further comprising:

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