JP2008175490A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner, controlling dehumidification in cooling operation. <P>SOLUTION: This air conditioner includes: an outdoor unit; an interior unit; and a control part for controlling various operations of the indoor unit and the outdoor unit, wherein the air conditioner is provided with a humidity detecting means for detecting the relative humidity in an air conditioning object space and inputting the same to the control part and a temperature detecting means for detecting the air temperature in the air conditioning object space and inputting the same to the control part. The control part is provided with an operation mode select control process of deciding selection and execution for a dehumidifying operation mode for performing dehumidification in the state of holding down the cooling capability based on a predetermined condition of a dew-point temperature calculated from the detection values of the humidity detecting means and the temperature detecting means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat pump type air conditioner that performs cooling / dehumidifying operation and heating operation in a room, for example.

2. Description of the Related Art Conventionally, a heat pump type air conditioner (hereinafter referred to as “air conditioner”) that provides a comfortable environment by air-conditioning a space to be air-conditioned such as a room is widely known. This air conditioner includes an outdoor unit having a compressor, an outdoor heat exchanger, etc., an indoor unit having an indoor heat exchanger, an indoor fan, etc., and a control for performing various controls of the outdoor unit and the indoor unit. And is configured.
During the cooling operation of the air conditioner described above, if the temperature difference ΔT (ΔT = Ti−Ts) between the set temperature Ts instructed to the air conditioner and the intake air temperature Ti becomes equal to or less than a predetermined value ts (ΔT ≦ ts), the cooling is performed. A thermo-off that does not require driving is established. Here, the set temperature Ts is an air conditioning target air temperature set by the user of the air conditioner to a desired value via a remote controller or the like, and the intake air temperature Ti is a suction installed near the inlet of the indoor unit. This is the air temperature detected by the air temperature sensor.

The establishment of the thermo-off means that the intake air temperature Ti, which substantially matches the air temperature (room temperature) in the air-conditioning target space, has dropped to the air temperature of the air-conditioning target. It is determined that the above cooling operation is unnecessary, and the operation of the compressor or the like is stopped. The cooling operation stopped in this way is resumed by the establishment of a thermo-on in which the intake air temperature Ti continuously detected by the intake air temperature sensor rises and the temperature difference ΔT becomes larger than the predetermined value ts.
In order to prevent frequent switching between the thermo-on state and the thermo-off state, in other words, in order to prevent frequent on / off of the compressor, an appropriate hysteresis is usually provided in the temperature difference ΔT.

Air that reduces the amount of condensed water remaining on the fins of the heat exchanger during cooling operation, reduces re-evaporation into the room, shortens the time to dry, and suppresses the return of moisture to the room A harmony device has been proposed. This air conditioner uses the indoor temperature or humidity and the rotational speed of the compressor controlled according to the indoor set temperature or humidity when stopping the operation using the indoor heat exchanger as a cooler or shifting to another operation. Stop or perform other operations after a water-reducing operation for reducing the compressor speed for a predetermined time. When the operation mode is set to the dehumidification mode, at the start of operation, if the room temperature is higher than the room set temperature, the cooling operation is performed, the room temperature is lower than the room set temperature, and the room humidity is higher than the room set humidity. If so, dehumidify. When the room temperature is lower than the indoor set temperature and the indoor humidity is lower than the indoor set humidity, the compressor and the blower are stopped and the room temperature and humidity are monitored. (For example, see Patent Document 1)
JP 2006-170503 A

  By the way, the conventional air conditioner detects the indoor air temperature sucked into the indoor unit by a suction air temperature sensor installed near the suction port, and the detected temperature of the suction air temperature sensor establishes the thermo-off control. The cooling operation is stopped when the temperature value (ΔT reaches a predetermined value Ts or less). For this reason, although the humidity in the room changes in accordance with the on / off of the cooling operation, no substantial control is performed, and therefore, it is left to the expected humidity to be dehumidified with the cooling operation. Is the actual situation.

Thus, since the conventional air conditioning apparatus is not subjected to dehumidification control during the cooling operation, even if the temperature in the air-conditioning target space decreases to a desired value, there may be cases where the humidity does not become comfortable. For this reason, in order to provide a more comfortable space by air-conditioning the air-conditioning target space, it is desired to develop an air conditioner that enables dehumidification control during cooling operation.
The present invention has been made in view of the above circumstances, and an object thereof is to provide an air conditioner that enables dehumidification control during cooling operation.

In order to solve the above problems, the present invention employs the following means.
An air conditioner according to the present invention performs various operation controls of an outdoor unit, an indoor unit installed with a suction port and a blowout outlet facing the air-conditioning target space, and the indoor unit and the outdoor unit. And an air conditioner comprising a control unit,
Humidity detection means for detecting relative humidity in the air-conditioning target space and inputting it to the control unit; and temperature detection means for detecting air temperature in the air-conditioning target space and inputting it to the control unit; Operation mode selection control for determining whether to perform dehumidification operation mode for dehumidification with reduced cooling capacity based on a predetermined condition of dew point temperature calculated from detection values of the humidity detection means and the temperature detection means A process is provided.

  According to such an air conditioner, humidity detection means for detecting the relative humidity in the air-conditioning target space and inputting it to the control unit, and temperature detection means for detecting the air temperature in the air-conditioning target space and inputting it to the control unit In addition, the control unit performs selection of a dehumidifying operation mode for dehumidifying with a reduced cooling capacity based on a predetermined condition of the dew point temperature calculated from the detected values of the humidity detecting means and the temperature detecting means. Since the operation mode selection control process to be determined is provided, the operation mode selection control process selects and executes the dehumidification operation mode depending on whether or not the dew point temperature in the air-conditioning target space is in a predetermined condition. In this dehumidifying operation mode, the dehumidifying operation is performed in a state in which the cooling capacity is suppressed until the dew point temperature reaches a predetermined condition. Therefore, dehumidification can be performed even if the air temperature in the air-conditioned space decreases.

  In the present invention, in the dehumidifying operation mode, at least one of the predetermined conditions of the dew point temperature or the relative humidity detected by the relative humidity detecting means is satisfied in the operation mode selection control process. In this case, it is preferable to select and execute the dehumidifying operation mode more accurately.

  In the above invention, the dehumidifying operation mode is set such that the compressor rotational speed and the indoor blowing air volume are set to minimum values, and then the temperature of the indoor heat exchanger installed in the indoor unit is higher than the dew point temperature. It is preferable to gradually increase only the rotational speed of the compressor until it enters an operating region where the temperature is low, and this makes it possible to perform an operation of dehumidification while suppressing the cooling capacity.

  In the above invention, after the dehumidifying operation mode is set to a minimum value at which the indoor blown air volume can be set, an operating region in which the temperature of the indoor heat exchanger installed in the indoor unit is lower than the dew point temperature. In order to maintain the inside, it is preferable to gradually decrease only the rotational speed of the compressor, and this makes it possible to perform dehumidification while suppressing the cooling capacity.

  According to the above-described present invention, in the operation mode selection control process, the dehumidifying operation mode is selected according to whether or not the dew point temperature in the air conditioned space is a predetermined condition. Even when the temperature is lowered, dehumidification can be performed by operating in a dehumidifying operation mode in which dehumidification is performed with the cooling capacity suppressed until the dew point temperature reaches a predetermined condition. As a result, an air conditioner that can perform dehumidification control that controls the humidity together with the air temperature in the air-conditioning target space during the cooling operation is provided, and a remarkable effect of providing a more comfortable space by air-conditioning the air-conditioning target space is obtained. It is done.

Hereinafter, an embodiment of an air conditioner according to the present invention (hereinafter referred to as “air conditioner”) will be described with reference to the drawings.
The air conditioner 1 shown in FIG. 5 includes an indoor unit 10, an outdoor unit 20, and a control device 30 serving as a control unit. The air conditioner 1 also includes a remote controller (hereinafter referred to as “remote controller”) 40 that performs remote operations such as operation on / off operation and temperature setting. In addition, the air conditioner 1 described below has a configuration in which one indoor unit 10 and one outdoor unit 20 are provided.

The indoor unit 10 is installed with a suction port and a blowout port (not shown) directed toward the room serving as the air-conditioning target space. Inside the casing of the indoor unit 10, an indoor heat exchanger 11 that receives refrigerant supplied from an outdoor unit 20, which will be described later, and air is introduced from the room, and the air passes through the indoor heat exchanger 11. The indoor fan 12 which blows off the air-conditioning air heat-exchanged with the refrigerant | coolant is provided.
The indoor unit 10 includes an indoor air temperature sensor 13 that detects the air temperature of the indoor air introduced from the room, an indoor heat exchanger temperature sensor 14 that detects the temperature of the indoor heat exchanger 11, and a room introduced from the room. And a relative humidity sensor 15 for detecting the relative humidity of the atmosphere.

The indoor air temperature sensor 13 is a temperature detection means installed in the vicinity of the suction port of the indoor unit 10, and the detected value is input to the control device 30 as the suction air temperature Ti.
The indoor heat exchange temperature sensor 14 is installed in close contact with an appropriate place of the indoor heat exchanger 11, and the detected value is input to the control device 30 as the indoor heat exchange temperature Te.
The relative humidity sensor 15 is humidity detection means installed near the suction port of the indoor unit 10, and the detected value is input to the control device 30 as room air relative humidity Hi.
The installation positions of the indoor air temperature sensor 13 and the relative humidity sensor 15 described above are not limited to the vicinity of the suction port of the indoor unit 10, and are installed in the remote controller 40 and transmitted to the control device 30, for example. For example, it is only necessary to detect the air temperature and the relative humidity of the room air that indicates the current state of the room that is the air-conditioning target space.

Inside the casing of the outdoor unit 20, as main components, a compressor 21 that compresses gas refrigerant and sends it to the refrigeration cycle, and a four-way valve 22 that switches the flow direction of the gas refrigerant sent from the compressor 21. And an outdoor heat exchanger 23 that exchanges heat between the refrigerant and the outdoor air (outdoor air), an expansion valve 24 that functions as a refrigerant throttling mechanism, and the outdoor air that has passed through the outdoor heat exchanger 23 An outdoor air fan 25 is provided.
As a result, the compressor 21, the four-way valve 22, the outdoor heat exchanger 23, and the expansion valve 24 in the outdoor unit 20 are connected to the indoor heat exchanger 11 in the indoor unit 10 by the refrigerant pipe 2, It forms the refrigeration cycle of heat pump air conditioners.

  The above-described operation control of the air conditioner 1 is performed by the control device 30 whose main part is installed in the indoor unit 10. That is, the control device 30 determines whether the compressor 21 is turned on / off, the rotational speed, the flow path switching of the four-way valve 22, the indoor fan 12 and the outdoor fan 25 is turned on / off, the rotational speed, and the like. In response to detection values input from various sensors including the heat exchanger temperature sensor 14 and the relative humidity sensor 15 and transmission input from the remote controller 40, a control signal based on a predetermined program is output. In addition, the code | symbol 3 in a figure is the wiring which connects between the control apparatus 30, and the indoor unit 10 and the outdoor unit 20. FIG.

In the air conditioner 1 configured as described above, the refrigerant circulation directions during the cooling operation and the heating operation are as follows.
During the cooling operation, the refrigerant circulates in the direction indicated by the solid line arrow in the figure. As a result, the outdoor heat exchanger 23 functions as a radiator (evaporator) and the indoor heat exchanger 11 functions as a heat absorber (condenser), so that the indoor air passing through the indoor heat exchanger 11 is converted into a refrigerant. Air-conditioned air that has absorbed heat and has a reduced temperature is blown out into the room.
During the heating operation, the refrigerant circulates in the direction indicated by the dashed arrow in the figure. As a result, since the indoor heat exchanger 11 functions as a radiator (evaporator) and the outdoor heat exchanger 23 functions as a heat absorber (condenser), the indoor air passing through the indoor heat exchanger 11 Air-conditioned air that has risen in temperature due to heat dissipation is blown out into the room.

The air conditioner 1 having the above-described configuration includes an operation mode selection control process (hereinafter referred to as “mode selection control”) in which the control device 30 determines selection of the dehumidifying operation mode. Below, the detail regarding this mode selection control is demonstrated based on the flowchart of FIG.1 and FIG.2.
Here, the dehumidifying operation mode means an operation of dehumidifying in a state where the cooling capacity is suppressed, preferably in a state where the cooling capacity is minimized. The mode selection control of the present invention is based on a predetermined condition of the dew point temperature Td calculated from the intake air temperature Ti detected by the indoor air temperature sensor 13 and the relative humidity sensor 15 and the indoor air relative humidity Hi. Is determined to be selected. That is, when the dew point temperature Td calculated based on the air diagram is equal to or higher than the predetermined value td (Td ≧ td), it is determined that the humidity control by the operation in the dehumidifying operation mode is necessary.

  Further, the above-described mode selection control is selected and executed when at least one of the predetermined conditions of the dew point temperature Td or the predetermined condition of the relative humidity Hi is satisfied in order to more accurately determine the selection. It is preferable. That is, at least one of the predetermined condition that the dew point temperature Td is higher than the predetermined value td (Td ≧ td) or the predetermined condition that the relative humidity Hi is higher than the predetermined value hi (Hi> hi) is satisfied. If it is, the humidity control by the operation in the dehumidifying operation mode is selected and executed. Below, the flowchart which employ | adopted this mode selection control is illustrated and demonstrated.

In the flowchart of the mode selection process shown in FIG. 1, an operation start command for the air conditioner 1 is issued in step S1, and the operation of the air conditioner 1 is started when the thermo-ON is established in step S2. At this time, when the operation of the air conditioner 1 is the cooling operation, the dehumidifying operation mode is selected and executed through the following mode selection process.
First, in step S3, “dehumidification operation transition determination # 1” is performed. In this step, the temperature difference ΔT (ΔT = Ti−Ts) between the intake air temperature Ti detected by the indoor air temperature sensor 13 and the set temperature Ts set by the user using the remote controller 40 and instructed to the air conditioner 1. Is determined to be equal to or less than a predetermined value ts (ΔT ≦ ts), and it is determined whether or not the same thermo-off as in the prior art is established. Note that the temperature difference ΔT in this case is a small value, for example, about 1 ° C. Therefore, it is determined whether or not the temperature drop in the room due to the cooling operation has reached the desired set temperature Ts or in the vicinity thereof.

If the temperature difference ΔT is NO greater than the predetermined value ts as determined in step S3, the intake air temperature Ti, which means the room temperature, is higher than the set temperature Ts, so the thermo-off is not established. The cooling operation is continued in order to lower the temperature.
However, if the temperature difference ΔT is determined to be YES in step 3 based on the determination in step 3, the intake air temperature Ti, which means the room temperature, substantially matches the set temperature Ts. It is considered unnecessary to continue. Accordingly, by proceeding to the next step S4, “dehumidification operation transition determination # 2” is performed.

In step S4, it is determined for each of two predetermined conditions whether the dew point temperature Td is equal to or higher than the predetermined value td (Td ≧ td) and whether the relative humidity Hi is higher than the predetermined value hi (Hi> hi).
As a result, if it is determined that at least one of the predetermined conditions of the dew point temperature Td or the relative humidity Hi is satisfied, the process proceeds to the next step S5 and the dehumidifying operation mode is selected and executed. . In this dehumidifying operation mode, the operating speed of the compressor 21 is reduced to a settable minimum value, and the operating speed of the indoor fan 12 is reduced to a settable minimum value, whereby the indoor air volume can also be set. Change to a value.

When the dehumidifying operation mode is selected and executed in this way, end control of the dehumidifying operation mode shown in the flowchart of FIG. 2 is performed.
However, in addition to the predetermined condition that the dew point temperature Td is equal to or higher than the predetermined value td (Td ≧ td), it is determined that the predetermined condition that the relative humidity Hi is higher than the predetermined value hi (Hi> hi) is not satisfied. In this case, that is, when the dew point temperature Td is smaller than the predetermined value td (Td <td) and the relative humidity Hi is smaller than the predetermined value hi (Hi ≦ hi), the cooling operation is continued.

By the way, from the viewpoint of comfort, the dew point temperature Td affects the sweating from the body because it affects the vapor pressure of the air, and therefore the dew point temperature Td has a more immediate effect than the relative humidity Hi. It becomes. That is, when the dew point temperature Td is low, the body can quickly and easily release heat by sweating, whereas when the dew point temperature Td is high, sweating becomes slow and difficult.
In general, the dew point temperature Td is high in summer and the release of heat due to perspiration is inhibited. Conversely, in the winter, the dew point temperature Td is low, and drying and heat of evaporation are considerably faster than in a comfortable state. Therefore, human comfort is best when the dew point temperature Td is moderate, and the uncertainty of the comfort range is higher than the room temperature, but people with little movement feel comfortable throughout the year. This is when the dew point temperature Td is approximately between -1 ° C and 13.9 ° C. Therefore, for example, a temperature of 13.9 ° C. may be set as the predetermined value td of the above dew point temperature Td.

As for the relative humidity Hi, clothes absorb and release moisture in proportion to the relative humidity on the surface, and as a result, affect human comfort. For this relative humidity Hi, for example, a relative humidity of 60% may be set to a predetermined value hi.
Here, the reason why the relative humidity is added to the control will be described with reference to FIG. FIG. 4 is a schematic diagram of an air diagram, and if control is performed only with the air temperature (dry bulb temperature), for example, a hatched area W1 in the figure causes a control inconvenience such as a relative humidity exceeding 100%. There are rare cases. Therefore, for example, by setting the conditions such that the relative humidity is 60% or less, control within the hatched area W2 in the figure is possible, so that the above-described inconvenience can be solved and control in accordance with the actual situation is possible. become.

Next, the termination control of the above-described dehumidifying operation mode will be described based on the flowchart shown in FIG.
In this control, first, the process proceeds to step S11, and the compressor rotational speed control determination is performed. That is, it is determined whether or not the current operation rotational speed is appropriate, and is substantially a determination as to whether or not the indoor heat exchanger 11 is in a state capable of dehumidifying operation. Here, by comparing the dew point temperature Td and the indoor heat exchange temperature Te described above, when the dew point temperature Td is equal to or higher than the indoor heat exchange temperature Te (Td ≧ Te), it can be determined that the dehumidifying state is present. Therefore, it progresses to the following step S12 and the completion | finish determination of a dehumidification operation is implemented.

  However, if NO is determined that the dew point temperature Td is lower than the indoor heat exchange temperature Te (Td <Te), the moisture in the air is not condensed in the heat exchanger and is not dehumidified. Proceeding to S16, a compressor rotation speed increase command is issued, the rotation speed of the compressor 21 is increased by a predetermined number, and the indoor heat exchanger temperature Te of the indoor heat exchanger 11 is controlled to be equal to or lower than the dew point temperature of the indoor air. Such a compressor rotation speed increase command is continued until YES is determined in step S11 described above, and control for increasing the rotation speed of the compressor 21 in a stepwise manner is performed.

In the determination of completion of the dehumidifying operation in step S12, substantially the same determination as the dehumidifying operation transition determination # 2 in step S4 (see FIG. 1) described above is repeated. That is, it is determined for each of two predetermined conditions: whether the dew point temperature Td is equal to or higher than the predetermined value td (Td ≧ td), and whether the relative humidity Hi is higher than the predetermined value hi (Hi> hi).
As a result, in the case of YES where it is determined that at least one of the predetermined conditions of the dew point temperature Td or the relative humidity Hi is satisfied, the process proceeds to the next step S13 and the cooling operation return determination is performed.

  However, in addition to the predetermined condition that the dew point temperature Td is equal to or higher than the predetermined value td (Td ≧ td), it is determined that the predetermined condition that the relative humidity Hi is higher than the predetermined value hi (Hi> hi) is not satisfied. In other words, that is, when the dew point temperature Td is smaller than the predetermined value td (Td <td) and the relative humidity Hi is smaller than the predetermined value hi (Hi ≦ hi), the process proceeds to step S17. In step S17, after the operating speed of the indoor fan 12 changed in step S5 is returned to the initial set value (the set air volume of the indoor air volume), the process proceeds to establishment of the thermo-on in step S2 and returns to the cooling operation.

  In the cooling operation return determination of step S13, substantially the same determination as the dehumidifying operation transition determination # 1 of step S3 (see FIG. 1) described above is repeated by changing the set value ts of the temperature difference ΔT to ts ′. That is, it is determined whether or not the temperature difference ΔT (ΔT = Ti−Ts) between the intake air temperature Ti and the set temperature Ts is equal to or less than a predetermined value ts ′ (ΔT ≦ ts ′), and the cooling operation is resumed. Determine whether or not. In this case, the set value ts ′ of the temperature difference ΔT is set to a small value of about 3 ° C., for example, slightly larger than the set value ts of 1 ° C. Therefore, the room temperature rises during the dehumidifying operation and the cooling capacity is restored. A determination is made whether it is necessary to return to driving.

If the temperature difference ΔT is NO greater than the predetermined value ts ′ according to the determination in step S13, the thermo-off is not established because the intake air temperature Ti meaning the room temperature is higher than the set temperature Ts. The cooling operation is continued to lower the temperature. That is, the process proceeds to step S17, the operating speed of the indoor fan 12 changed in step S5 is returned to the initial set value (the set air volume of the indoor air volume), and further, the thermo-ON is established in step S2 to return to the cooling operation. To do.
However, if the difference in temperature ΔT is determined to be YES or less according to the determination in step 13, the intake air temperature Ti, which means the room temperature, substantially matches the set temperature Ts. It is considered unnecessary to continue driving. Accordingly, by proceeding to the next step S14, a thermo-off determination is performed to determine whether or not the thermo-off is established.

  If YES in step S14, the process proceeds to the next step S15 and the next operation mode determination is performed. This next operation mode determination is substantially the same as the determination of the dehumidifying operation end in step S12, whether the dew point temperature Td is equal to or higher than a predetermined value td (Td ≧ td), and the relative humidity Hi is Judgment is made for each of two predetermined conditions of whether the value is larger than the predetermined value hi (Hi> hi).

As a result, if it is determined that at least one of the predetermined conditions of the dew point temperature Td or the relative humidity Hi is satisfied, the process proceeds to step S5 in FIG. 1 to select the dehumidifying operation mode. Selected.
However, if the dew point temperature Td is smaller than the predetermined value td (Td <td) and the relative humidity Hi is smaller than the predetermined value hi (Hi ≦ hi), the process proceeds to step S17 and the indoor fan changed in step S5. After the operation rotational speed of 12 is returned to the initial set value (the set air volume of the indoor air volume), the return of the cooling operation to proceed to establishment of the thermo-on in step S2 is selected.

  By such operation control, the indoor temperature and humidity environment can be controlled simultaneously. In such control, temperature control based on the dew point temperature Td and an increase in the amount of dehumidification due to continuous operation with reduced cooling capacity are important points. That is, the cooling operation is performed until the room temperature Te is lowered to the set temperature Ts, and thereafter, the dehumidifying operation is performed with the cooling capacity suppressed to perform dehumidification. In this dehumidifying operation, in order to suppress the cooling capacity, the air volume of the indoor fan 12 and the operating rotational speed of the compressor 21 are set to minimum values, and the indoor heat exchange temperature Te is compressed to a dehumidifying state where the dew point temperature Td or less. The operating speed of the machine 21 is increased. Such dehumidifying operation is continued until the dew point temperature Td of the thermo-off or the intake air reaches a predetermined value td.

  As described above, in the operation mode selection control process, the dehumidifying operation mode is selected according to whether or not the dew point temperature Td in the air-conditioning target space is the predetermined value td, so that the intake air temperature ( Even if the air temperature (Ti) decreases, dehumidification can be performed by operating in a dehumidifying operation mode in which dehumidification is performed while the cooling capacity is suppressed until the dew point temperature Td reaches a predetermined value td. As a result, the air conditioning apparatus capable of dehumidification control that controls humidity together with the air temperature in the air-conditioning target space during cooling operation can provide a more comfortable space by air-conditioning the air-conditioning target space.

Subsequently, the end control of the dehumidifying operation mode described above will be described based on the flowchart shown in FIG. The same control steps as those in FIG. 2 described above are denoted by the same reference numerals, and detailed description thereof is omitted.
In this modified example, the operation control of the compressor 21 in selecting and executing the dehumidifying operation mode (see step S5 ′) is different. Specifically, the operating speed of the compressor 21 is left as it is, and the operating speed of the indoor fan 12 is changed. That is, the operating rotational speed of the indoor fan 12 is reduced to a settable minimum value, and only the indoor air volume is changed to a settable minimum value.

Then, as a result of proceeding to step S11 ′ and determining the compressor speed control, the temperature difference ΔT ′ (ΔT ′ = Td−Te) between the dew point temperature Td and the indoor heat exchange temperature Te is smaller than the predetermined value te (ΔT). In the case of NO determined as'> te), it can be determined that the dehumidifying operation in which the cooling capacity is further suppressed can be performed. For this reason, the process proceeds to step S16 ′ and a compressor rotation speed down command is issued. In this case, the predetermined value te is a small temperature of about 1 ° C., for example.
By receiving a command to reduce the compressor speed, the operating speed of the compressor 21 is reduced by a predetermined number. Therefore, each time the operating speed is reduced, the routine proceeds to step S11 'and the same compressor speed control judgment is made. repeat. As a result, the operating rotational speed of the compressor 21 can be reduced to a settable minimum value, and the dehumidification amount can be increased by continuous operation with reduced cooling capacity. In step S11 ′, if the temperature difference ΔT ′ between the dew point temperature Td and the indoor heat exchange temperature Te is equal to or greater than te (ΔT ′ ≦ te), it can be determined that the dehumidifying situation is present. Proceeding to next step S12, the dehumidifying operation end determination is performed.

  Even in this case, the indoor temperature and humidity environment can be controlled simultaneously. That is, the cooling operation is performed until the room temperature Te is lowered to the set temperature Ts, and thereafter, the dehumidifying operation is performed with the cooling capacity suppressed to perform dehumidification. In this dehumidifying operation, in order to suppress the cooling capacity, the air volume of the indoor fan 12 is set to the minimum value, and the dehumidification is performed with the minimum ability so that the temperature difference ΔT ′ between the indoor heat exchange temperature Te and the dew point temperature Td is not more than a predetermined value te. The operating rotational speed of the compressor 21 is reduced to a possible state. Such dehumidifying operation is continued until the dew point temperature Td of the thermo-off or the intake air reaches a predetermined value td.

Even in the operation mode selection control process of such a modification, the dehumidification operation mode is selected and executed depending on whether or not the dew point temperature Td in the air-conditioning target space is the predetermined value td. Even when the temperature (air temperature) Ti decreases, dehumidification can be performed by operating in the dehumidifying operation mode in which dehumidification is performed with the cooling capacity suppressed until the dew point temperature Td reaches a predetermined value td. As a result, the air conditioning apparatus capable of dehumidification control that controls humidity together with the air temperature in the air-conditioning target space during cooling operation can provide a more comfortable space by air-conditioning the air-conditioning target space.
The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the scope of the present invention.

It is a flowchart which shows the operation mode selection control process of a control apparatus as one Embodiment of the air conditioning apparatus which concerns on this invention. It is a flowchart which shows completion | finish control of the dehumidification operation mode following the operation mode selection control process of FIG. It is a flowchart which shows the modification which concerns on completion | finish control of the dehumidification operation mode shown in FIG. 1 is a schematic diagram of an air diagram. It is a figure which shows the structural example of an air conditioning apparatus.

Explanation of symbols

1 Air conditioner (air conditioner)
2 Refrigerant piping 10 Indoor unit 11 Indoor heat exchanger 12 Indoor fan 13 Indoor air temperature sensor 14 Indoor heat exchange temperature sensor 15 Relative humidity sensor 20 Outdoor unit 21 Compressor 22 Four-way valve 23 Outdoor heat exchanger 24 Expansion valve 25 Outdoor Machine fan 30 Control device (control unit)
40 Remote controller (remote control)
Ti Intake air temperature Te Indoor heat exchange temperature Hi Indoor air relative humidity Td Dew point temperature ΔT, ΔT 'Temperature difference ts, td, hi, te, ts' Predetermined value

Claims (4)

An outdoor unit, an indoor unit that is installed with the suction port and the air outlet facing the air-conditioning target space, and a control unit that controls various operations of the indoor unit and the outdoor unit. In the air conditioner,
Humidity detection means that detects relative humidity in the air-conditioning target space and inputs it to the control unit; and temperature detection means that detects air temperature in the air-conditioning target space and inputs it to the control unit,
An operation mode in which the control unit determines whether to perform dehumidification operation mode for dehumidification in a state where the cooling capacity is suppressed based on a predetermined condition of dew point temperature calculated from detection values of the humidity detection unit and the temperature detection unit. An air conditioner characterized in that a selection control process is provided.   The dehumidifying operation mode is selected when at least one of a predetermined condition of the dew point temperature or a predetermined condition of the relative humidity detected by the relative humidity detecting means is satisfied in the operation mode selection control process. The air conditioning apparatus according to claim 1, wherein   The dehumidifying operation mode is an operation region in which the temperature of the indoor heat exchanger installed in the indoor unit is lower than the dew point temperature after setting the compressor rotation speed and the indoor blowing air volume to the minimum values that can be set. 3. The air conditioner according to claim 1, wherein only the compressor rotational speed is gradually increased until entering.   The dehumidifying operation mode is set so that the temperature of the indoor heat exchanger installed in the indoor unit is lower than the dew point temperature after the indoor blowing air volume is set to a minimum value that can be set. 3. The air conditioner according to claim 1, wherein only the compressor rotational speed is gradually lowered.

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