JP2006336888A - Control method of indoor machine unit, control method of air conditioner, indoor machine unit and air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control method of an indoor machine unit, a control method of an air conditioner, the indoor machine unit and the air conditioner, capable of surely preventing dew condensation on a ventilating duct mounted under the roof, with respect to the ceiling embedded indoor machine. <P>SOLUTION: In this control method of the indoor machine unit 5A having a housing mounted under the roof, an indoor heat exchanger 19A mounted in the housing for exchanging the heat between a refrigerant and indoor air, the ventilation duct for guiding the heat exchanged-indoor air into a room, dew condensation information detecting portions 41A, 43A mounted outside of the housing for detecting the humidity of air under the roof, and a blow out air temperature control portion 137A for controlling a temperature of the air flowing in the ventilation duct, the supply air temperature control portion 137A increases the temperature of the air flowing in the ventilation duct by a prescribed temperature when the humidity detected by the dew condensation information detecting portions 41A, 43A is higher than a prescribed humidity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an indoor unit control method, an air conditioner control method, an indoor unit, and an air conditioner.

Conventionally, indoor air is sucked into an indoor unit placed behind the ceiling, cooled by exchanging heat in the internal indoor heat exchanger, and then blown away from the indoor unit through a ventilation duct placed behind the ceiling. 2. Description of the Related Art An air conditioner that supplies a room through a mouth is known.
In the air conditioner described above, when the environment behind the ceiling is in a hot and humid state, dew may adhere to the surface of the ventilation duct through which the cooled air passes. This dew drops from the ventilation duct and wets the ceiling, creating stains on the ceiling and even leaking into the room.

Therefore, in the above-described air conditioner, various techniques for preventing dew are proposed in order to prevent dew on the ventilation duct (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 10-103743

In the above-mentioned patent document 1, a temperature sensor and a humidity sensor for detecting the humidity of air behind the ceiling are provided in the indoor unit, and an air conditioner technology for controlling the performance of the compressor based on the output of these sensors is disclosed. Has been.
According to this technique, the temperature of the indoor air cooled by the indoor heat exchanger can be controlled by controlling the capacity of the compressor. Therefore, the temperature of the air flowing through the ventilation duct can be controlled, and dew condensation on the outer surface of the ventilation duct in the atmosphere behind the ceiling can be prevented.

  However, in the technique described in Patent Document 1 described above, since the temperature sensor and the humidity sensor are mounted in the indoor unit, there is a possibility that the temperature and humidity of the air behind the ceiling cannot be accurately detected. For this reason, the capacity of the compressor cannot be appropriately controlled, and there is a possibility that dew may occur on the outer surface of the ventilation duct.

  The present invention has been made to solve the above-described problems, and is an indoor unit that can reliably prevent dew condensation on a ventilation duct disposed on the back of a ceiling in a ceiling-embedded indoor unit. An object is to provide a control method, a control method for an air conditioner, an indoor unit, and an air conditioner.

In order to achieve the above object, the present invention provides the following means.
The control method for an indoor unit of the present invention includes a housing disposed behind the ceiling, an indoor heat exchanger disposed in the housing, for exchanging heat between the refrigerant supplied from the outside and room air, and the housing. An indoor fan that is disposed in the body and sucks indoor air and conducts to the indoor heat exchanger; a ventilation duct that is disposed behind the ceiling and that conducts heat exchanged into the room; and A control method for an indoor unit comprising: a dew information detection unit that detects at least air humidity in the back of the ceiling; and a blown air temperature adjustment unit that adjusts the temperature of air flowing through the ventilation duct. When the humidity detected by the dew information detection unit is higher than a predetermined humidity, the blown air temperature adjustment unit increases the temperature of the air flowing through the ventilation duct by a predetermined temperature. And wherein the Rukoto.

According to the present invention, when the humidity detected by the dew information detection unit is higher than the predetermined humidity, the blown air temperature adjustment unit increases the temperature of the air flowing through the ventilation duct by a predetermined temperature. Dew can be prevented.
Since the dew information detection unit is disposed outside the casing, it is in direct contact with the air in the back of the ceiling and can detect the accurate humidity of the air. Therefore, when it is necessary to increase the temperature of the air flowing through the ventilation duct, that is, when the outer surface of the ventilation duct is likely to be dewed, the air temperature can be reliably increased by a predetermined temperature.

  In the above invention, the dew information detection unit includes a relative humidity detection unit that detects a relative humidity of air in the back of the ceiling, and an air temperature detection unit that detects a temperature of air in the back of the ceiling, When the relative humidity detected by the relative humidity detection unit is higher than a predetermined relative humidity with respect to the air temperature detected by the air temperature detection unit, the blowing air temperature adjustment unit increases the temperature of the air flowing through the ventilation duct by a predetermined temperature. It is desirable to do.

  According to the present invention, only when the relative humidity detected by the relative humidity detection unit is higher than the predetermined relative humidity with respect to the air temperature detected by the air temperature detection unit, the temperature of the air flowing in the ventilation duct is increased by the predetermined temperature. For this reason, it is possible to more reliably prevent dew on the ventilation duct. In other words, since the predetermined relative humidity is selected based on the air temperature detected by the air temperature detection unit, a lower predetermined relative humidity is selected under the condition where dew condensation on the ventilation duct is likely to occur. Dew can be prevented more reliably.

  In addition, by setting the predetermined relative humidity low, the temperature of the air flowing in the ventilation duct can be adjusted more quickly. Therefore, a sudden change in the air temperature can be prevented, and the discomfort felt by the user can be reduced.

In the above invention, the dew information detecting unit has a dew point detecting unit that detects whether or not an air temperature in the ceiling is equal to or lower than a dew point temperature, and the dew point temperature detecting unit detects the air in the ceiling. When it is detected that the temperature is equal to or lower than the dew point temperature, it is desirable that the blown air temperature adjustment unit raises the temperature of the air flowing through the ventilation duct by a predetermined temperature.
According to the present invention, when the dew point detection unit detects that the air temperature in the back of the ceiling is equal to or lower than the dew point temperature, the temperature of the air flowing in the ventilation duct is increased, so that dew condensation on the ventilation duct is more reliably performed. Can be prevented.

In the above invention, it is desirable that the blown air temperature adjustment unit is an indoor fan control unit that controls a rotation speed of the indoor fan.
According to the present invention, since the blown air temperature adjustment unit is the indoor fan control unit, the rotational speed of the indoor fan can be controlled, and the flow rate of the indoor air guided to the indoor heat exchanger can be controlled. By increasing the indoor air flow rate that passes through the indoor heat exchanger, the amount of heat exchange per unit volume of the passing indoor air can be reduced, and the temperature of the air flowing through the ventilation duct can be increased by a predetermined temperature. .

  An air conditioner control method according to the present invention includes a housing disposed behind a ceiling, an indoor heat exchanger disposed within the housing, for exchanging heat between the refrigerant and room air, and the ceiling. An indoor unit having a ventilation duct that guides indoor air heat-exchanged into the room, a dew information detection unit that is provided outside the housing and detects at least the humidity of the air in the ceiling, and A compressor that compresses the refrigerant and supplies the refrigerant to an outdoor heat exchanger; an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; and a throttle that depressurizes the high-pressure refrigerant supplied from the outdoor heat exchanger An air conditioner control method comprising: an outdoor unit unit having a unit; and a compressor control unit that adjusts the rotational speed of the compressor, wherein the humidity detected by the dew information detecting unit is If it is higher than the specified humidity, Serial compressor control unit, characterized in that lowering the rotational speed of the compressor by a predetermined rotational speed.

  According to the present invention, when the humidity detected by the dew information detection unit is higher than the predetermined humidity, the compressor control unit lowers the rotational speed of the compressor by the predetermined rotational speed. Can be reduced and the refrigeration capacity can be lowered. When the refrigeration capacity is reduced, the amount of heat exchange with the indoor air in the indoor heat exchanger is reduced, and the temperature of the indoor air, that is, the air flowing through the ventilation duct can be increased by a predetermined temperature.

  An air conditioner control method according to the present invention includes a housing disposed behind a ceiling, an indoor heat exchanger disposed within the housing, for exchanging heat between the refrigerant and room air, and the ceiling. An indoor unit having a ventilation duct that guides indoor air heat-exchanged into the room, a dew information detection unit that is provided outside the housing and detects at least the humidity of the air in the ceiling, and A compressor that compresses the refrigerant and supplies the refrigerant to an outdoor heat exchanger; an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; and a throttle that depressurizes the high-pressure refrigerant supplied from the outdoor heat exchanger An air conditioner control method comprising: an outdoor unit unit having an opening unit; and an opening degree control unit that controls the opening degree of the throttle unit, wherein the humidity detected by the dew information detection unit is If higher than the predetermined humidity, Degree control section, and controlling the opening degree of the throttle portion.

  According to the present invention, for example, when the humidity detected by the dew information detection unit is higher than a predetermined humidity, the opening degree control unit controls the opening degree of the throttle unit to increase, thereby passing the throttle unit. It is possible to control the degree of decompression of the refrigerant during the operation. Since the degree of pressure reduction in the throttle unit can be controlled, the refrigerant pressure and the refrigerant temperature in the indoor heat exchanger can be controlled. That is, by controlling the opening of the throttle unit, the temperature of the air flowing in the ventilation duct can be increased by a predetermined temperature by increasing the refrigerant temperature in the indoor heat exchanger.

  In the above invention, the dew information detection unit includes a relative humidity detection unit that detects a relative humidity of air in the back of the ceiling, and an air temperature detection unit that detects a temperature of air in the back of the ceiling, When the relative humidity detected by the relative humidity detection unit is higher than a predetermined relative humidity with respect to the air temperature detected by the air temperature detection unit, the compressor control unit decreases the rotation speed of the compressor by a predetermined rotation speed. Is desirable.

  According to the present invention, since the rotational speed of the compressor is reduced only when the relative humidity detected by the relative humidity detection unit is higher than the predetermined relative humidity with respect to the air temperature detected by the air temperature detection unit, the ventilation is more reliably performed. It is possible to prevent dew on the duct. In other words, since the predetermined relative humidity is selected based on the air temperature detected by the air temperature detection unit, a lower predetermined relative humidity is selected under the condition where dew condensation on the ventilation duct is likely to occur. Dew can be prevented more reliably.

  In the above invention, the dew information detection unit includes a relative humidity detection unit that detects a relative humidity of air in the back of the ceiling, and an air temperature detection unit that detects a temperature of air in the back of the ceiling, When the relative humidity detected by the relative humidity detection unit is higher than a predetermined relative humidity with respect to the air temperature detected by the air temperature detection unit, it is desirable that the opening degree control unit controls the opening degree of the throttle unit.

  According to the present invention, for example, only when the relative humidity detected by the relative humidity detection unit is higher than the predetermined relative humidity with respect to the air temperature detected by the air temperature detection unit, the opening degree of the throttle unit is controlled to be increased. For this reason, it is possible to more reliably prevent dew on the ventilation duct. In other words, since the predetermined relative humidity is selected based on the air temperature detected by the air temperature detection unit, a lower predetermined relative humidity is selected under the condition where dew condensation on the ventilation duct is likely to occur. Dew can be prevented more reliably.

In the above invention, the dew information detecting unit has a dew point detecting unit that detects whether or not an air temperature in the ceiling is equal to or lower than a dew point temperature, and the dew point temperature detecting unit detects the air in the ceiling. When it is detected that the temperature is equal to or lower than the dew point temperature, it is preferable that the compressor control unit lowers the rotational speed of the compressor by a predetermined rotational speed.
According to the present invention, when the air temperature in the back of the ceiling is detected by the dew point detection unit to be equal to or lower than the dew point temperature, the rotation speed of the compressor is reduced, so that dew condensation on the ventilation duct is more reliably prevented. be able to.

In the above invention, the dew information detecting unit has a dew point detecting unit that detects whether or not an air temperature in the ceiling is equal to or lower than a dew point temperature, and the dew point temperature detecting unit detects the air in the ceiling. When it is detected that the temperature is equal to or lower than the dew point temperature, it is desirable that the opening control unit controls the opening of the throttle unit.
According to the present invention, for example, when the dew point detection unit detects that the air temperature in the back of the ceiling is equal to or lower than the dew point temperature, the opening degree control unit controls the opening degree of the throttle unit to be increased. It is possible to more reliably prevent dew on the ventilation duct.

An air conditioner control method of the present invention includes an indoor unit in which the above-described indoor unit control method of the present invention is performed, a compressor that compresses the refrigerant and supplies the refrigerant to the indoor heat exchanger, and the refrigerant. And an outdoor unit having an outdoor heat exchanger for exchanging heat with outdoor air.
According to the present invention, when the humidity detected by the dew information detection unit is higher than the predetermined humidity, the blown air temperature adjustment unit increases the temperature of the air flowing through the ventilation duct by a predetermined temperature. It is possible to prevent the occurrence of dew.
Since the dew information detection unit is located outside the housing, it can detect the exact humidity of the air and reliably increase the air temperature by a predetermined temperature when dew is likely to occur on the outer surface of the ventilation duct. can do.

  The indoor unit of the present invention includes a housing disposed behind the ceiling, an indoor heat exchanger disposed in the housing, for exchanging heat between the refrigerant supplied from the outside and room air, and disposed in the housing. An indoor fan that sucks indoor air and conducts it to the indoor heat exchanger, a ventilation duct that is arranged behind the ceiling and guides indoor air that has been heat-exchanged, and is provided outside the housing. A dew information detecting unit that detects at least the humidity of air in the back of the ceiling, and when the humidity detected by the dew information detecting unit is higher than a predetermined humidity, the ventilation duct A blown air temperature adjustment unit is provided to increase the temperature of the air flowing through the inside by a predetermined temperature.

  According to the present invention, since the dew information detection unit is disposed outside the housing, it is in direct contact with the air in the back of the ceiling and can detect the accurate humidity of the air. Therefore, when it is necessary to increase the temperature of the air flowing through the ventilation duct, that is, when the outer surface of the ventilation duct is likely to be dewed, the air temperature can be reliably increased by a predetermined temperature.

  An air conditioner according to the present invention includes a housing disposed on the back of the ceiling, an indoor heat exchanger disposed in the housing for exchanging heat between the refrigerant and room air, and disposed on the back of the ceiling and performing heat exchange. An indoor unit having a ventilation duct that guides indoor air to the room, a dew information detector that is provided outside the casing and detects at least the humidity of air in the back of the ceiling, and the refrigerant A compressor for compressing and supplying to the outdoor heat exchanger; an outdoor heat exchanger for exchanging heat between the refrigerant and outdoor air; and a throttle unit for reducing the pressure of the high-pressure refrigerant supplied from the outdoor heat exchanger; And an outdoor unit having an air conditioner, wherein when the humidity detected by the dew information detector is higher than a predetermined humidity, the compressor control reduces the rotational speed of the compressor by a predetermined rotational speed. Having a department And it features.

  According to the present invention, when the humidity detected by the dew information detection unit is higher than the predetermined humidity, the compressor control unit lowers the rotational speed of the compressor by the predetermined rotational speed. Can be reduced and the refrigeration capacity can be lowered. When the refrigeration capacity is reduced, the amount of heat exchange with the indoor air in the indoor heat exchanger is reduced, and the temperature of the indoor air, that is, the air flowing through the ventilation duct can be increased by a predetermined temperature.

  An air conditioner according to the present invention includes a housing disposed on the back of the ceiling, an indoor heat exchanger disposed in the housing for exchanging heat between the refrigerant and room air, and disposed on the back of the ceiling and performing heat exchange. An indoor unit having a ventilation duct that guides indoor air to the room, a dew information detector that is provided outside the casing and detects at least the humidity of air in the back of the ceiling, and the refrigerant A compressor for compressing and supplying to the outdoor heat exchanger; an outdoor heat exchanger for exchanging heat between the refrigerant and outdoor air; and a throttle unit for reducing the pressure of the high-pressure refrigerant supplied from the outdoor heat exchanger; An outdoor unit having an air conditioner, wherein when the humidity detected by the dew information detection unit is higher than a predetermined humidity, the opening control unit controls the opening of the throttle unit It is characterized by doing.

  According to the present invention, for example, when the humidity detected by the dew information detection unit is higher than a predetermined humidity, the opening degree control unit controls the opening degree of the throttle unit to be increased by a predetermined opening degree, By raising the refrigerant temperature in the indoor heat exchanger, the temperature of the indoor air, that is, the air flowing in the ventilation duct can be increased by a predetermined temperature.

The air conditioner of the present invention includes the indoor unit of the present invention, a compressor that compresses the refrigerant and supplies the refrigerant to the indoor heat exchanger, and outdoor heat that performs heat exchange between the refrigerant and outdoor air. It has an outdoor unit which has an exchanger and a throttle part which depressurizes high-pressure refrigerant supplied from an outdoor heat exchanger.
According to the present invention, since the dew information detecting unit is arranged outside the housing, it is possible to detect the accurate humidity of the air, and the air reliably when the dew is likely to occur on the outer surface of the ventilation duct. The temperature can be increased by a predetermined temperature.

According to the indoor unit control method, the air conditioner control method, the indoor unit and the air conditioner of the present invention, when the humidity detected by the dew information detector is higher than a predetermined humidity, the blown air temperature adjustment Since the temperature of the air flowing through the ventilation duct is increased by a predetermined temperature, it is possible to prevent the outer surface of the ventilation duct from being dewed.
The dew information detection unit is in direct contact with the air behind the ceiling and can detect the accurate humidity of the air. Therefore, when the dew is likely to be attached to the outer surface of the ventilation duct, the air temperature can be surely increased by a predetermined temperature, and the dew condensation on the ventilation duct can be reliably prevented.

[First Embodiment]
A multi-type air conditioner according to a first embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is a diagram illustrating a circuit configuration of a multi-type air conditioner according to the present embodiment. FIG. 2 is a schematic diagram illustrating the arrangement of the multi-type air conditioner of FIG.
As shown in FIGS. 1 and 2, the multi-type air conditioner (air conditioner) 1 includes an outdoor unit 3 and a plurality of indoor unit units 5 (in the illustrated example, connected to the outdoor unit 3). And two indoor unit units 5A and 5B). Between the indoor unit 5 and the outdoor unit 3, a refrigerant pipe 7 for flowing a refrigerant, an electric wiring 9, and the like are arranged.
In addition, A and B attached to each code | symbol in a figure shall be used only when distinguishing and explaining two indoor unit units.

  As shown in FIG. 2, the outdoor unit 3 is disposed outside a house or the like, and the indoor unit 5 is disposed inside the house and on the ceiling of the room, that is, behind the ceiling. In the present embodiment, description will be made by applying to an embodiment in which the indoor unit 5 is lowered and disposed inside the ceiling.

  The outdoor unit 3 includes a compressor 11 that compresses and sends out the refrigerant, a four-way valve 13 that switches the refrigerant circulation direction, an outdoor heat exchanger 15 that exchanges heat between the refrigerant and the outside air, and an electronic expansion valve. (Diaphragm | squeeze part) 21 and are comprised roughly. The compressor 11 is inverter-controlled and can change its rotational speed. The outdoor unit 3 is provided with other devices such as an outdoor fan, a receiver, a service valve, and a strainer, which are not shown, and sensors such as a temperature sensor.

FIG. 3 is a cross-sectional view illustrating the configuration of the indoor unit 5 in FIG.
As shown in FIGS. 1 to 3, the indoor unit 5 includes an indoor heat exchanger 19 and an indoor fan 23 arranged in a casing (housing) 17, and a control box 25 arranged outside the casing 17. An air duct 27 through which air blown out from the casing 17 circulates is schematically configured.

As shown in FIGS. 2 and 3, a suction port 29 for sucking indoor air is formed on the lower surface of the casing 17, and a blower outlet 31 for blowing out the air heat-exchanged by the indoor heat exchanger 19 is formed on the side surface. Has been. The ventilation duct 27 is arranged at a position facing the air outlet 31, and is configured such that air that has flowed out of the air outlet 31 flows into the air duct 27.
Inside the casing 17, an indoor fan 23 is disposed adjacent to the suction port 29, and an indoor heat exchanger 19 is disposed adjacent to the air outlet 31.

  As shown in FIG. 1, the indoor heat exchanger 19 is provided with an inflow refrigerant temperature sensor 33 that measures the inflow refrigerant temperature and an outflow refrigerant temperature sensor 35 that measures the outflow refrigerant temperature.

FIG. 4 is a partial perspective view for explaining the arrangement position of the control unit in the indoor unit of FIG.
As shown in FIGS. 1 and 4, the control unit (compressor control unit, throttle unit opening control unit, blown air temperature adjustment unit) 37 is a side surface of the casing 17 and is disposed outside the control box 25. Is housed inside. The control box 25 includes a box formed of sheet metal or the like and a leg member 39 formed in a substantially L shape. The control box 25 is fixed to the casing 17 via the leg member 39 and is arranged away from the casing 17.
On the side surface of the control box 25, an air temperature sensor (air temperature detection unit, dew information detection unit) 41 for detecting the temperature of air in the back of the ceiling, and an air humidity sensor (relative to the air in the ceiling) are detected. A sensor box 45 that houses therein a humidity detection unit and a dew information detection unit 43 is disposed. A slit 47 is formed in the sensor box 45 so that the air behind the ceiling and the air temperature sensor 41 and the air humidity sensor 43 are in direct contact with each other.

  As shown in FIG. 1, the control unit 37 is electrically connected to an air temperature sensor 41 and an air humidity sensor 43, and the outputs of the sensors 41 and 43 are input to the control unit 37. On the other hand, the control unit 37 is also electrically connected to the compressor 11 of the outdoor unit 3 and outputs a rotation speed control signal to the compressor 11.

  As shown in FIG. 2, the ventilation duct 27 is arranged behind the ceiling, and is configured to guide the air blown from the indoor unit 5 to a position away from the indoor unit 5 and blow it into the room.

  As shown in FIG. 1, the two indoor unit units 5A and 5B are connected to refrigerant pipes 7A and 7B branched by a pipe connector 49 and a header 51 in the outdoor unit 3, respectively. In addition, each refrigerant pipe 7A, 7B in the outdoor unit 3 has electronic expansion valves 21A, 21B that operate independently between the outdoor heat exchanger 15 and the indoor unit 5A, 5B. Arranged in the outdoor unit 3.

Next, the operation of the multi-type air conditioner 1 having the above configuration will be described.
First, the effect | action at the time of the heating operation in the multi type air conditioner 1 is demonstrated.
The refrigerant is made high temperature and high pressure in the compressor 11, passes through the four-way valve 13, and is guided to the header 51. This refrigerant is guided from the header 51 to the indoor heat exchanger 19 of the indoor unit 5 and radiates heat to the indoor air. The radiated refrigerant is reduced in pressure when passing through the electronic expansion valve 21 to become a low-temperature and low-pressure refrigerant and flows into the outdoor heat exchanger 15.
The refrigerant flowing into the outdoor heat exchanger 15 absorbs heat from the outdoor air when passing through the heat exchanger. The refrigerant that has absorbed heat passes through the four-way valve 13 and is sucked into the compressor 11. Thereafter, the same process as described above is repeated.

Next, the operation at the time of cooling operation and dry operation in the multi-type air conditioner 1 will be described.
The cooling operation and the dry operation are performed by operating the four-way valve 13 and switching the refrigerant circulation direction from the above-described heating operation.
In the cooling operation and the dry operation, the refrigerant flow from the compressor 11 to the four-way valve 13 is the same as in the heating operation. The compressed refrigerant is guided from the four-way valve 13 to the outdoor heat exchanger 15, and in the outdoor heat exchanger 15, the refrigerant dissipates the heat to the outdoor air. The radiated refrigerant is depressurized by passing through the electronic expansion valve 21, passes through the refrigerant pipe 7 again, and is sent to the indoor heat exchanger 19 of the indoor unit 5.

The refrigerant flowing into the indoor heat exchanger 19 absorbs heat from the indoor air in the indoor heat exchanger 19 and cools the indoor air.
The refrigerant flowing out from the indoor heat exchanger 19 passes through the header 51 and the four-way valve 13 and is sucked into the compressor 11 again.

Next, dew prevention control for the ventilation duct 27, which is a feature of the present embodiment, will be described.
FIG. 5 is a flowchart illustrating dew prevention control according to the present embodiment.
First, the control unit 37 determines whether the air conditioner 1 is performing a cooling operation or a dry operation (step 1). When the air conditioner 1 is performing the cooling operation or the dry operation, the process proceeds to the next control step, and when performing the other operation, that is, the heating operation, there is a possibility that the ventilation duct 27 may be dewed. Therefore, the dew prevention control is terminated.
When the air conditioner 1 is performing a cooling operation or a dry operation, the control unit 37 detects the air in the ceiling from the air temperature sensor 41 and the air humidity sensor 43 after a predetermined time (for example, 30 minutes) has elapsed since the start of the operation. The temperature and humidity are acquired (step 2).

FIG. 6 is a map used to determine the start and end of dew prevention control.
Then, the control unit 37 determines whether to start or end the dew prevention control based on the acquired ceiling air temperature and ceiling air humidity (step 3). This determination is made based on the acquired air temperature and air humidity and the map shown in FIG. That is, when the point determined by the air temperature and the air humidity is included in the ON region A in FIG. 6, dew prevention control is started (step 4), and is included in the OFF region B in FIG. The dew prevention control is terminated.
Note that the ON region A is included on the broken line L that is the boundary between the ON region A and the OFF region B.

In the map shown in FIG. 6, the horizontal axis represents the air temperature TO (° C.) in the ceiling, and the vertical axis represents the air humidity HS (%) in the ceiling. The air temperature TO and the air humidity HS correspond to the air temperature and the air humidity detected by the air temperature sensor 41 and the air humidity sensor 43, respectively.
The broken line L is a straight line that rises to the right when the air temperature TO is in the range of 5 ° C. to 50 ° C., and the air humidity HS is substantially constant at 95% when the air temperature TO is higher than 50 ° C. It extends in the horizontal direction. Further, when the air temperature TO is 5 ° C., the air humidity HS extends substantially vertically upward from the point where the air humidity HS is 58%. The above-mentioned ON area A is the upper area (high humidity area) of the broken line L, and the OFF area B is the lower area (low humidity area).

Here, the air in the back of the ceiling is generally affected by indoor air and also by outdoor air. That is, when the air temperature TO is low, it is estimated that the temperature of the outdoor air is low, and when the air temperature TO is high, it is estimated that the temperature of the outdoor air is high.
When the temperature of the outdoor air is low, the pressure in the refrigerant circuit is the high pressure side pressure from the discharge side of the compressor 11 to the electronic expansion valve 21 and the low pressure side pressure from the electronic expansion valve 21 to the suction side of the compressor 11. It is low. Since this state is a state in which the air conditioner 1 is likely to have the cooling capacity, the ventilation duct 27 is likely to be exposed. Therefore, dew prevention control is started from a region where the air humidity HS is relatively low.
On the other hand, when the temperature of the outdoor air is high, the pressure in the refrigerant circuit is high for both the high-pressure side pressure and the low-pressure side pressure. This state is a state in which the cooling capacity of the air conditioner 1 is difficult to be obtained, so that the ventilation duct 27 is not easily exposed to dew. Therefore, it is not necessary to perform dew control to a region where the air humidity HS is relatively high.

  When the dew prevention control is started, the control unit 37 outputs a command to the compressor 11 to reduce the operation rotational speed by a predetermined rotational speed (for example, 20 revolutions per minute (rpm)). The rotation speed of the compressor 11 is controlled so as not to be less than the minimum rotation speed corresponding to the rotation speed of the indoor fan 23.

After the start of the dew prevention control, the control unit 37 acquires the temperature and humidity of the ceiling air from the air temperature sensor 41 and the air humidity sensor 43 again (step 2). And the control part 37 determines whether dew prevention control is continued or complete | finished based on the air temperature and air humidity which were reacquired (step 3).
In step 3, as long as the control unit 37 determines to continue the dew prevention control, the dew prevention control is continued.

  However, when the operation mode of the air conditioner 1 is an operation mode other than the cooling operation or the dry operation such as the heating operation, the dew prevention control is ended regardless of the above-described determination condition.

In addition, when anti-frost control and refrigeration cycle system protection control are performed, priority is given to these controls, and the above-described dew prevention control is not performed.
Here, the anti-frost control refers to control for preventing the indoor heat exchanger 19 and the like from freezing. The refrigeration cycle system protection control refers to a case where the temperature difference between the heat exchanger temperature and the intake air temperature in the indoor heat exchanger 19 is small and the compressor 11 is operated at a high speed (for example, the refrigerant amount is insufficient). In this case, the control is to reduce the operating rotational speed of the compressor 11 for a predetermined time.

  According to the above configuration, when the air temperature and the air humidity in the ceiling air detected by the air temperature sensor 41 and the air humidity sensor 43 are higher than the predetermined temperature and the predetermined humidity, the control unit 37 controls the compressor 11. By controlling, the temperature of the air flowing through the ventilation duct 27 can be increased by a predetermined temperature. Therefore, the outer surface temperature of the ventilation duct 27 can be raised, and dew can be prevented from being attached to the ventilation duct 27.

  Since the air temperature sensor 41 and the air humidity sensor 43 are disposed outside the casing 17, the air temperature sensor 41 and the air humidity sensor 43 are in direct contact with the air behind the ceiling and can detect the accurate temperature and relative humidity of the air. Therefore, when it is necessary to increase the temperature of the air flowing through the ventilation duct 27, that is, when dew is likely to be attached to the outer surface of the ventilation duct 27, the air temperature can be reliably increased by a predetermined temperature.

Only when the relative humidity detected by the air humidity sensor 43 is higher than the predetermined relative humidity with respect to the air temperature detected by the air temperature sensor 41, the temperature of the air flowing in the ventilation duct 27 is increased by the predetermined temperature, so that it is more reliable. It is possible to prevent dew on the ventilation duct 27. That is, the dew prevention control is performed only when the point determined by the air temperature detected by the air temperature sensor 41 and the relative humidity detected by the air humidity sensor 43 on the map shown in FIG. In this way, it is possible to more reliably prevent dew on the ventilation duct 27.
More specifically, in the area where the air temperature of the multi-type air conditioner 1 is likely to be high and the air temperature is relatively low, dew prevention control is performed from a low relative humidity state, thereby preventing dew condensation on the ventilation duct 27 reliably. it can. On the other hand, dew prevention control is performed in a high relative humidity state in a relatively high air temperature region where the cooling capability of the multi-type air conditioner 1 is difficult to achieve.

  In addition, by performing dew prevention control from a relative humidity lower than the relative humidity at which dew generation occurs in the ventilation duct 27, the temperature of the air flowing in the ventilation duct 27 can be adjusted more quickly. Therefore, a sudden change in the temperature of the air flowing into the room from the ventilation duct 27 can be prevented, and the discomfort felt by the user can be reduced.

As in the above-described embodiment, the start and end of dew prevention control are determined based on the temperature and humidity detected by the air temperature sensor 41 and the air humidity sensor 43 arranged on the side surface of the control box 25. Alternatively, instead of the air temperature sensor 41 and the air humidity sensor 43, a dew point sensor (dew point detection unit) is arranged on the side surface of the control box 25, and the start and end of dew prevention control are determined based on the output of the dew point sensor. May be. Here, the dew point sensor is a sensor that outputs a predetermined signal when the air to be measured reaches the dew point.
With this configuration, the number of sensors used can be reduced.

As described above, a compressor that is inverter-controlled and has a variable rotation speed may be used as the compressor 11, or a compressor that operates only at a fixed rotation speed may be used.
When using a compressor having a constant rotational speed, the control unit 37 can perform dew prevention control (step 4 in FIG. 5) by outputting an operation stop signal to the compressor.

[Modification of First Embodiment]
Next, a modification of the first embodiment of the present invention will be described with reference to FIG.
The basic configuration of the multi-type air conditioner of the present embodiment is the same as that of the first embodiment, but differs from the first embodiment in the dew prevention control termination method. Therefore, in this embodiment, only the method for ending the dew prevention control will be described with reference to FIG. 7, and description of other components will be omitted.
FIG. 7 is a flowchart for explaining another example of dew control in the present embodiment.
In addition, about the component etc. which are the same as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

In the present modification, the process up to the start of the dew prevention control (from step 1 to step 4) is the same as that in the first embodiment, and a description thereof will be omitted.
When the dew prevention control is started in step 4, the control unit 37 determines whether or not a certain time (for example, about 1 hour) has passed (step 15).
When the predetermined time has elapsed, the process returns to step 2, and the control unit 37 acquires again the temperature and humidity of the air in the back of the ceiling (step 2), and determines whether to continue or end the dew prevention control (step 3). . When the dew prevention control is continued, the above steps 2 to 15 are repeated.
When such control is performed, the dew prevention control is terminated even if the air temperature and the air humidity are included in the OFF region B in FIG. This is the time after the determination in step 15.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The basic configuration of the multi-type air conditioner of the present embodiment is the same as that of the first embodiment, but the dew prevention control is different from that of the first embodiment. Therefore, in the present embodiment, only the dew prevention control will be described with reference to FIG. 8, and description of other components and the like will be omitted.
FIG. 8 is a diagram illustrating a circuit configuration of the multi-type air conditioner according to the present embodiment.
In addition, about the component etc. which are the same as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 8, the multi-type air conditioner (air conditioner) 101 includes an outdoor unit 3 and a plurality of indoor unit units 5 (in the illustrated example, an indoor unit unit) connected to the outdoor unit 3. 5A and 5B).
The indoor unit 5 includes an indoor heat exchanger 19, a control unit (opening control unit, blown air temperature adjustment unit) 137 disposed outside, an air temperature sensor 41 that detects the temperature of the air behind the ceiling, An air humidity sensor 43 that detects the relative humidity of air in the back of the ceiling is schematically configured. The electronic expansion valve (throttle part) 121 is disposed in the outdoor unit 3.

  The control unit 137 is electrically connected to the electronic expansion valve 121 disposed in the outdoor unit 3 and outputs an opening degree control signal to the electronic expansion valve 121. On the other hand, the control unit 137 is also electrically connected to the air temperature sensor 41 and the air humidity sensor 43, and the outputs of the sensors 41 and 43 are input to the control unit 137.

Next, dew prevention control for the ventilation duct 27, which is a feature of the multi-type air conditioner 101 having the above-described configuration, will be described.
Since the flow of dew prevention control in this embodiment is the same as that in the first embodiment, description thereof is omitted.

  When the dew prevention control is started, the control unit 137 outputs an opening degree control signal for increasing the opening degree to the electronic expansion valve 121. The electronic expansion valve 121 increases the opening according to the opening control signal, and reduces the pressure reduction of the refrigerant passing through the electronic expansion valve 121.

According to said structure, since the control part 137 can make the pressure reduction degree of the refrigerant | coolant which passes the electronic expansion valve 137 small, it can make the refrigerant | coolant in the indoor heat exchanger 19 high pressure, and can make refrigerant | coolant temperature high.
That is, by controlling the opening degree of the electronic expansion valve 137, the refrigeration capacity of the multi-type air conditioner 101 can be suppressed, and the temperature of the air flowing through the ventilation duct 27 can be increased by a predetermined temperature. As a result, it is possible to prevent dew on the outer surface of the ventilation duct 27.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
The basic configuration of the multi-type air conditioner of the present embodiment is the same as that of the first embodiment, but the dew prevention control is different from that of the first embodiment. Therefore, in the present embodiment, only the dew prevention control will be described with reference to FIG. 9, and description of other components and the like will be omitted.
FIG. 9 is a diagram illustrating a circuit configuration of the multi-type air conditioner according to the present embodiment.
In addition, about the component etc. which are the same as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 9, the multi-type air conditioner (air conditioner) 201 includes an outdoor unit 3 and a plurality of indoor unit units 5 (in the illustrated example, an indoor unit unit) connected to the outdoor unit 3. 5A and 5B).
The indoor unit 5 includes an indoor heat exchanger 19, an indoor fan 223, a control unit (indoor fan control unit, blown air temperature adjustment unit) 237 disposed outside, and air that detects the temperature of air in the ceiling. The temperature sensor 41 and an air humidity sensor 43 that detects the relative humidity of the air behind the ceiling are schematically configured.

  The control unit 237 is electrically connected to the indoor fans 223 disposed in each indoor unit 5 and outputs a rotation speed control signal to the indoor fans 223. On the other hand, the control unit 237 is also electrically connected to the air temperature sensor 41 and the air humidity sensor 43, and the outputs of the sensors 41 and 43 are input to the control unit 237.

Next, dew prevention control for the ventilation duct 27, which is a feature of the multi-type air conditioner 201 having the above-described configuration, will be described.
Since the flow of dew prevention control in this embodiment is the same as that in the first embodiment, description thereof is omitted.

  When the dew prevention control is started, the control unit 237 outputs a control signal for increasing the rotation speed to the indoor fan 223. The indoor fan 223 increases the rotational speed in accordance with the control signal and increases the flow rate of air passing through the indoor heat exchanger 19.

  According to said structure, the control part 237 can control the rotational speed of the indoor fan 223, and can control the flow volume of the indoor air guide | induced to the indoor heat exchanger 19. FIG. By increasing the flow rate of the indoor air passing through the indoor heat exchanger 19, the amount of heat exchange per unit volume of the passing indoor air can be reduced, and the temperature of the air flowing through the ventilation duct 27 is increased by a predetermined temperature. Can do. As a result, it is possible to prevent dew on the outer surface of the ventilation duct 27.

  In addition, in the outdoor unit 3, when the outdoor air temperature sensor which detects the temperature of the outdoor air suck | inhaled in order to exchange heat with the outdoor heat exchanger 15 is provided, it is based on the output of an outdoor air temperature sensor. It is also possible to determine the start and stop of the dew prevention control. In such a case, since there is a predetermined temperature difference between the temperature of the outdoor air and the temperature of the air behind the ceiling, it is preferable to determine whether to start or stop the dew prevention control by correcting the outdoor air temperature. Furthermore, since the temperature difference described above varies depending on the season, it is preferable to use a correction coefficient that takes into account the season.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the description has been made by applying the present invention to a configuration that controls only one of the compressor, the electronic expansion valve, and the indoor fan. Further, the present invention can be applied to various other configurations such as a configuration in which any two of indoor fans are controlled simultaneously, a configuration in which all of the compressor, the electronic expansion valve, and the indoor fan are controlled simultaneously.

It is a figure explaining the circuit structure of the multi type air conditioner concerning a 1st embodiment in the present invention. It is the schematic explaining arrangement | positioning of the multi-type air conditioner of FIG. It is sectional drawing explaining the structure of the indoor unit of FIG. It is a fragmentary perspective view explaining the arrangement position of the control part in the indoor unit of FIG. It is a flowchart explaining the dew prevention control in the multi type air conditioner of FIG. It is a map used for determination of the start and completion | finish of dew prevention control in the multi type air conditioner of FIG. It is a flowchart explaining the dew prevention control of the multi type air conditioner which concerns on the modification of 1st Embodiment in this invention. It is a figure explaining the circuit structure of the multi type air conditioner which concerns on 2nd Embodiment in this invention. It is a figure explaining the circuit structure of the multi type air conditioner which concerns on 3rd Embodiment in this invention.

Explanation of symbols

1,101,201 Multi-type air conditioner (air conditioner)
3 Outdoor unit 5 Indoor unit 15 Outdoor heat exchanger 17 Casing (housing)
19, 19A, 19B Indoor heat exchanger 21, 21A, 21B, 121, 121A, 121B Electronic expansion valve (throttle part)
23, 23A, 23B, 223, 223A, 223B Indoor fan 27 Ventilation duct 37, 37A, 37B Control unit (compressor control unit, blown air temperature adjustment unit)
41, 41A, 41B Air temperature sensor (air temperature detector, dew information detector)
43, 43A, 43B Air humidity sensor (relative humidity detector, dew information detector)
137, 137A, 137B control unit (opening control unit)
237, 237A, 237B control unit (indoor fan control unit, blown air temperature adjustment unit)

Claims (15)

A housing arranged behind the ceiling;
An indoor heat exchanger that is arranged in the housing and exchanges heat between the refrigerant supplied from the outside and room air;
An indoor fan that is disposed within the housing and sucks indoor air and conducts to the indoor heat exchanger;
A ventilation duct that is arranged behind the ceiling and guides indoor air that has undergone heat exchange;
A dew information detection unit that is provided outside the housing and detects at least air humidity in the ceiling,
A blowing air temperature adjusting unit for adjusting the temperature of the air flowing in the ventilation duct;
A control method for an indoor unit having
When the humidity detected by the dew information detection unit is higher than a predetermined humidity,
The blowout air temperature adjustment unit increases the temperature of air flowing through the ventilation duct by a predetermined temperature, and controls the indoor unit. The dew information detection unit includes a relative humidity detection unit that detects a relative humidity of air in the ceiling, and an air temperature detection unit that detects the temperature of air in the ceiling,
When the relative humidity detected by the relative humidity detector is higher than a predetermined relative humidity with respect to the air temperature detected by the air temperature detector,
The method of controlling an indoor unit according to claim 1, wherein the blown air temperature adjustment unit increases the temperature of air flowing through the ventilation duct by a predetermined temperature. The dew information detecting unit has a dew point detecting unit for detecting whether or not an air temperature in the ceiling is equal to or lower than a dew point temperature;
When the dew point temperature detection unit detects that the air temperature in the ceiling is below the dew point temperature,
The method of controlling an indoor unit according to claim 1, wherein the blown air temperature adjustment unit increases the temperature of air flowing through the ventilation duct by a predetermined temperature.   The method for controlling an indoor unit according to any one of claims 1 to 3, wherein the blown air temperature adjustment unit is an indoor fan control unit that controls a rotation speed of the indoor fan. A housing disposed behind the ceiling, an indoor heat exchanger disposed within the housing and exchanging heat between the refrigerant and room air, and the indoor air disposed behind the ceiling and subjected to heat exchange are led into the room. An indoor unit having a ventilation duct and a dew information detecting unit that is provided outside the casing and detects at least the humidity of air in the ceiling.
A compressor that compresses the refrigerant and supplies the refrigerant to an outdoor heat exchanger; an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; and a throttle that depressurizes the high-pressure refrigerant supplied from the outdoor heat exchanger An outdoor unit having a unit,
A compressor controller for adjusting the rotational speed of the compressor;
A control method for an air conditioner having
When the humidity detected by the dew information detection unit is higher than a predetermined humidity,
The method of controlling an air conditioner, wherein the compressor control unit lowers the rotational speed of the compressor by a predetermined rotational speed. A housing disposed behind the ceiling, an indoor heat exchanger disposed within the housing and exchanging heat between the refrigerant and room air, and the indoor air disposed behind the ceiling and subjected to heat exchange are led into the room. An indoor unit having a ventilation duct and a dew information detecting unit that is provided outside the casing and detects at least the humidity of air in the ceiling.
A compressor that compresses the refrigerant and supplies the refrigerant to an outdoor heat exchanger; an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; and a throttle that depressurizes the high-pressure refrigerant supplied from the outdoor heat exchanger An outdoor unit having a unit,
An opening control unit for controlling the opening of the throttle unit;
A control method for an air conditioner having
When the humidity detected by the dew information detection unit is higher than a predetermined humidity,
The air conditioner control method, wherein the opening control unit controls the opening of the throttle unit. The dew information detection unit includes a relative humidity detection unit that detects a relative humidity of air in the ceiling, and an air temperature detection unit that detects the temperature of air in the ceiling,
When the relative humidity detected by the relative humidity detector is higher than a predetermined relative humidity with respect to the air temperature detected by the air temperature detector,
6. The method of controlling an air conditioner according to claim 5, wherein the compressor control unit lowers the rotational speed of the compressor by a predetermined rotational speed. The dew information detection unit includes a relative humidity detection unit that detects a relative humidity of air in the ceiling, and an air temperature detection unit that detects the temperature of air in the ceiling,
When the relative humidity detected by the relative humidity detector is higher than a predetermined relative humidity with respect to the air temperature detected by the air temperature detector,
The method of controlling an air conditioner according to claim 6, wherein the opening control unit controls the opening of the throttle unit. The dew information detecting unit has a dew point detecting unit for detecting whether or not an air temperature in the ceiling is equal to or lower than a dew point temperature;
When the dew point temperature detection unit detects that the air temperature in the ceiling is below the dew point temperature,
6. The method of controlling an air conditioner according to claim 5, wherein the compressor control unit lowers the rotational speed of the compressor by a predetermined rotational speed. The dew information detecting unit has a dew point detecting unit for detecting whether or not an air temperature in the ceiling is equal to or lower than a dew point temperature;
When the dew point temperature detection unit detects that the air temperature in the ceiling is below the dew point temperature,
The method of controlling an air conditioner according to claim 6, wherein the opening control unit controls the opening of the throttle unit. An indoor unit in which the method for controlling an indoor unit according to any one of claims 1 to 4 is performed;
A compressor that compresses the refrigerant and supplies the refrigerant to an outdoor heat exchanger; an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; and a throttle that depressurizes the high-pressure refrigerant supplied from the outdoor heat exchanger An outdoor unit having a unit,
A method for controlling an air conditioner, comprising: A housing arranged behind the ceiling;
An indoor heat exchanger that is arranged in the housing and exchanges heat between the refrigerant supplied from the outside and room air;
An indoor fan that is disposed within the housing and sucks indoor air and conducts to the indoor heat exchanger;
A ventilation duct that is arranged behind the ceiling and guides indoor air that has undergone heat exchange;
A dew information detection unit that is provided outside the housing and detects at least air humidity in the ceiling,
An indoor unit having
When the humidity detected by the dew information detection unit is higher than a predetermined humidity,
An indoor unit unit comprising a blown air temperature adjusting unit that increases a temperature of air flowing through the ventilation duct by a predetermined temperature. A housing disposed behind the ceiling, an indoor heat exchanger disposed within the housing and exchanging heat between the refrigerant and room air, and the indoor air disposed behind the ceiling and subjected to heat exchange are led into the room. An indoor unit having a ventilation duct and a dew information detecting unit that is provided outside the casing and detects at least the humidity of air in the ceiling.
A compressor that compresses the refrigerant and supplies the refrigerant to an outdoor heat exchanger; an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; and a throttle that depressurizes the high-pressure refrigerant supplied from the outdoor heat exchanger An outdoor unit having a unit,
An air conditioner having
When the humidity detected by the dew information detection unit is higher than a predetermined humidity,
An air conditioner comprising a compressor control unit that lowers the rotational speed of the compressor by a predetermined rotational speed. A housing disposed behind the ceiling, an indoor heat exchanger disposed within the housing and exchanging heat between the refrigerant and room air, and the indoor air disposed behind the ceiling and subjected to heat exchange are led into the room. An indoor unit having a ventilation duct and a dew information detecting unit that is provided outside the casing and detects at least the humidity of air in the ceiling.
A compressor that compresses the refrigerant and supplies the refrigerant to an outdoor heat exchanger; an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; and a throttle that depressurizes the high-pressure refrigerant supplied from the outdoor heat exchanger An outdoor unit having a unit,
An air conditioner having
When the humidity detected by the dew information detection unit is higher than a predetermined humidity,
The air conditioner, wherein the opening control unit controls an opening of the throttle unit. The indoor unit according to claim 12,
A compressor that compresses the refrigerant and supplies the refrigerant to an outdoor heat exchanger; an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; and a throttle that depressurizes the high-pressure refrigerant supplied from the outdoor heat exchanger And an outdoor unit having an air conditioner.

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