JP6418147B2 - air conditioner - Google Patents

Description

  The present invention relates to an air conditioner. More specifically, the present invention relates to an air conditioner that controls the rotational speed of a motor such as an indoor fan based on a temperature difference between a suction temperature and a target temperature.

  2. Description of the Related Art Conventionally, there is an air conditioner that performs automatic air volume control that lowers the number of rotations of a motor that drives an indoor fan as the value of a suction temperature sensor approaches a set temperature or a target temperature (hereinafter represented by “target temperature”).

  According to the air conditioner that performs such air volume automatic control, the air volume supplied to the room can be adjusted according to the air conditioning load in the room, so that energy consumption can be suppressed and the room temperature can be adjusted efficiently.

  However, when an indoor unit of an air conditioner is disposed in a space where warm air tends to accumulate, the following problems may occur during heating operation.

  In other words, if the indoor unit is installed in a space near the ceiling where warm air tends to accumulate, even if the temperature of the surrounding room where the user lives is not warm, the warm air is accumulated in the vicinity of the indoor unit. Is determined to have approached the target temperature, and the rotational speed of the motor of the indoor fan is set to be low. As a result, the amount of air blown by the indoor fan becomes insufficient, the heating capacity is insufficient, the room temperature does not readily warm, and the user's comfort may be impaired.

  This invention is made | formed in view of such a situation, and it aims at providing the air conditioner which can prevent that a heating capability runs short and can improve a user's comfort.

The air conditioner according to the first aspect of the present invention is:
(1) An air conditioner including a suction temperature sensor, a sensor for detecting a room temperature, and a control unit for controlling operation of the motor,
The said control part calculates | requires the temperature difference of the suction temperature when it becomes thermo-on after the air-conditioner driving | operation start, and room temperature, and changes the minimum tap which is the minimum rotation speed of the said motor based on the calculated | required temperature difference.

  In the air conditioner according to the first aspect of the present invention, the control unit changes the lower limit tap that is the minimum rotation speed of the motor based on the temperature difference between the suction temperature of the indoor unit of the air conditioner and the room temperature. Therefore, when warm air accumulates near the ceiling and the temperature difference between the suction temperature of the indoor unit installed near the ceiling and the temperature of the area where the user lives (room temperature) is large, the lower limit tap of the motor When the automatic control is performed based on the temperature difference between the suction temperature and the target temperature, for example, if the motor is a motor that drives an indoor fan, a certain amount of airflow can be maintained. it can. In other words, since the number of rotations of the motor of the indoor fan does not decrease below the set lower limit tap, it is possible to prevent the heating capacity from being insufficient and improve user comfort.

(2) In the air conditioner of (1), the control unit may increase the lower limit tap as the temperature difference increases. In this case, when the automatic control is performed based on the temperature difference between the suction temperature and the target temperature, the motor speed is prevented from being lowered more than necessary, and for example, the motor is a motor that drives an indoor fan. A certain amount of airflow can be maintained. Thereby, it is possible to prevent the heating capacity from being insufficient and improve the comfort of the user.

(3) In the air conditioner of (1) or (2), the control unit may lower the lower limit tap as time elapses after the motor is started. In this case, it is considered that the room temperature gradually increases and approaches the target temperature as time elapses after the motor is started. Can be adjusted.

( 4 ) In the air conditioners of (1) to ( 3 ), the motor can be a motor that drives an indoor fan. In this case, when warm air accumulates near the ceiling and the temperature difference between the suction temperature of the indoor unit arranged near the ceiling and the temperature of the area where the user lives (indoor temperature) is large, Even if the suction temperature of an indoor unit installed near the ceiling approaches the target temperature earlier than the actual indoor temperature, the lower limit tap of the motor that drives the indoor fan is changed to be higher. Thus, a certain amount of airflow can be maintained when performing the airflow automatic control based on the temperature difference between the suction temperature and the target temperature. In other words, since the number of rotations of the motor of the indoor fan does not decrease below the set lower limit tap, it is possible to prevent the heating capacity from being insufficient and improve user comfort.

( 5 ) In the air conditioners of (1) to ( 3 ), the motor can be a motor that drives a compressor. In this case, when warm air accumulates near the ceiling and the temperature difference between the suction temperature of the indoor unit arranged near the ceiling and the temperature of the area where the user lives (indoor temperature) is large, Even when the suction temperature of an indoor unit installed near the ceiling approaches the target temperature earlier than the actual indoor temperature, the lower limit tap of the motor that drives the compressor is changed to be higher. Thus, it is possible to maintain a certain amount of refrigerant supply when performing operation control of the compressor based on the temperature difference between the suction temperature and the target temperature. In other words, since the refrigerant supply amount does not decrease below the set lower limit tap, it is possible to prevent the heating capacity from being insufficient and improve the user comfort.

  According to the indoor unit of the present invention, it is possible to provide an air conditioner that can prevent a heating capability from being insufficient and maintain user comfort.

It is explanatory drawing of one Embodiment of the air conditioner of this invention. It is sectional explanatory drawing of the indoor unit of the air conditioner shown by FIG. It is a figure which shows an example of the temperature change at the time of the heating operation of an air conditioner.

Hereinafter, embodiments of an air conditioner of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to the claim are included.
FIG. 1 is an explanatory view of an air conditioner A according to an embodiment of the present invention, and FIG. 2 is a cross-sectional explanatory view of the indoor unit 1 of the air conditioner A shown in FIG.

The air conditioner A includes an indoor unit 1, a driving operation unit 2, and an outdoor unit 3. The indoor unit 1 in the present embodiment is a ceiling-embedded indoor unit, and the operation operation unit 2 is a type of operation operation unit installed on the wall of an air conditioning room or a room where the indoor unit 1 is disposed. . In addition, as a driving operation part, it can also be set as the remote control type driving operation part which can be detachably attached to a wall, and it shall be a general remote control type driving operation part which is not assumed to be attached to a wall etc. You can also. The outdoor unit 3 is provided with a compressor 5 including a motor 4.
The operation unit 2 in this embodiment includes a button 2a for switching the operation mode (cooling, heating and dehumidification) of the air conditioner A, a button 2b for adjusting the air volume of the indoor fan 12, a button 2c for setting a target temperature, and an air conditioner A. A display screen 2d for displaying the set operating state is provided. The driving operation unit 2, the control unit P of the indoor unit 1 described later, and the control unit (not shown) of the outdoor unit 3 are connected to be communicable.

  The indoor unit 1 includes a casing 6 that houses various elements such as an indoor fan and a heat exchanger, which will be described later, and a decorative panel 7. The casing 6 is formed of a box-like body having an open lower end surface, and is disposed in an opening formed in the ceiling C as shown in FIG. The decorative panel 7 is made of a rectangular plate, and a suction port 8 for sucking air in the air-conditioned room is formed at the center. In addition, an elongated rectangular air outlet 9 that blows conditioned air into the air-conditioned room is formed around the inlet 8 along each side of the decorative panel 7.

  Each air outlet 9 is provided with a flap 9a that adjusts the direction of the conditioned air blown from the air outlet 9 into the air-conditioned room. The flap 9a is rotatable around an axis along the longitudinal direction of the air outlet 9. The flap 9a can be rotated by a motor (not shown).

  A suction grill 10 and a filter 11 for removing dust in the indoor air sucked from the suction port 8 are arranged in this order from the indoor side to the suction port 8 of the decorative panel 7.

  Inside the casing 6, the air in the air-conditioned room is sucked from the air inlet 8 of the decorative panel 7, and after heat exchange is performed on the air, the indoor fan 12 that blows conditioned air from the air outlet 9 of the decorative panel 7 into the air-conditioned room. And the heat exchanger 13 arrange | positioned so that the said indoor fan 12 may be enclosed. The indoor fan 12 has a motor 14 and an impeller 15. Further, a control unit P that controls the operation of the motor 14 of the indoor fan 12 and the motor 4 of the compressor 5 is disposed in the casing 6.

  The heat exchanger 13 is a cross fin tube type heat exchanger formed by being bent so as to surround the indoor fan 12. Below the heat exchanger 13, air is exchanged by the heat exchanger 13. A drain pan 16 is provided for receiving drainage generated by the condensation of water.

  In the drain pan 16, a suction hole 17 corresponding to the suction port 8 of the decorative panel 7 and a blowout hole 18 corresponding to the blowout port 9 of the decorative panel 7 are formed. A bell mouth 19 for guiding air sucked from the suction port 8 of the decorative panel 7 to the impeller 115 of the indoor fan 12 is attached to the inner edge of the suction hole 17.

  In the present embodiment, a suction temperature sensor 20 that detects the temperature of the air sucked from the suction port 8 of the decorative panel 7 (the temperature of the air near the indoor unit and before heat exchange) is adjacent to the control unit P. Is provided. Further, a floor temperature sensor 21 for detecting the temperature of the floor surface of the air conditioning room is provided on the lower surface (surface on the air conditioning room side) 7a of the decorative panel 7. The “floor temperature” detected by the floor temperature sensor 21 is slightly different from the so-called “room temperature”, which is the temperature of the area where the user lives, as shown in FIG. In the specification, the floor temperature sensor 21 is also included in the “sensor for detecting the room temperature”. As a sensor for detecting the room temperature, in addition to the floor temperature sensor 21, for example, a temperature sensor (not shown) built in the operation unit 2, or a wireless temperature portable to a desired place in the air-conditioning room A sensor or the like can be used. Data on the temperature detected by the wireless temperature sensor is transmitted to the control unit P of the indoor unit 1.

  In the present embodiment, during the heating operation, the air volume automatic operation is performed in which the rotational speed of the motor 14 of the indoor fan 12 is changed based on the temperature difference between the target temperature and the suction temperature. Thereby, since the air volume supplied indoors can be adjusted according to indoor air-conditioning load, indoor temperature can be adjusted efficiently. The rotation speed of the motor 14 of the indoor fan 12 in the automatic air volume operation is selected based on, for example, an automatic air volume control fan table shown in Table 1 below. The rotation speed of the motor 14 is selected according to ΔT, which is the difference between the corrected target temperature and the suction temperature. The “target temperature after correction” is a target temperature corrected for the influence of heat in the electrical component box and other heat generating components.

  In the example shown in Table 1, the temperature of the intermediate portion of the heat exchanger 13 is added as a parameter for selecting the rotation speed of the motor 14 of the indoor fan 12 in order to reduce user discomfort due to cold air. . In the present embodiment, the rotation speed is selected from the three rotation speeds of “H (High)”, “M (Medium)”, and “L (Low)”. The rotation speed of the motor 14 can be updated every predetermined time, for example, every 90 seconds. In Table 1, for example, when the indoor heat exchanger intermediate temperature Hth3 is 40 ° C. or higher and lower than 50 ° C., if the difference ΔT between the corrected target temperature and the suction temperature is 8 ° C., the rotational speed of the motor 14 is the uppermost stage. When “H” is selected and the difference ΔT reaches 3 ° C. after a predetermined time has elapsed, “M” in the third stage from the top is selected as the rotational speed of the motor 14. In the example shown in Table 1, the number of rotations of the motor is selected from the number of rotations in three stages, but the number of rotations can be selected from a plurality of other stages such as five stages.

  When the indoor unit 1 of the air conditioner A is arranged in a space near the ceiling where warm air is likely to accumulate, the indoor unit 1 can be operated even if the temperature of the surrounding room where the user lives is not warmed by performing the automatic air volume operation described above. Since warm air is accumulated in the vicinity of 1, it is determined that the suction temperature has approached the target temperature, and the rotational speed of the motor 14 of the indoor fan 12 is set to be low. As a result, the amount of air blown by the indoor fan 12 becomes insufficient, the heating capacity is insufficient, the temperature of the room does not warm easily, and the user's comfort may be impaired.

  FIG. 3 is a diagram illustrating an example of a temperature change during the heating operation of the air conditioner. This example shows a temperature change when the indoor unit is arranged in an environment where warm air tends to accumulate. When the suction temperature reaches the target temperature after the start of operation, the thermostat is turned off (thermo-OFF) and the compressor is stopped. However, since it is necessary for the indoor fan 12 to keep air flowing in the vicinity of the suction temperature sensor 20 in order to make the suction temperature sensor 20 function, the indoor fan 12 does not completely stop but sucks in a small amount of air. It is operated at a rotational speed of about. At this time, the user hardly feels the wind.

  When a predetermined time elapses after the thermo-off and the suction temperature is lowered by a predetermined temperature from the target temperature, the thermo-ON (thermo ON) is set and the compressor resumes operation. At this time, in a situation where warm air tends to accumulate near the ceiling where the indoor unit 1 is disposed, the temperature difference (target temperature-suction temperature) indicated by the symbol a in FIG. Despite the inadequate heating, the motor speed of the indoor fan selected according to Table 1 is reduced, the heating capacity is insufficient, and the room temperature does not warm up easily. Damaged.

  Therefore, in this embodiment, when performing the air volume automatic operation, the control unit P changes the lower limit tap that is the minimum rotation speed of the motor 14 based on the temperature difference between the suction temperature and the floor temperature as the room temperature. Yes.

  Table 2 shows an example of a table for determining the lower limit tap. In this example, the lower limit tap is determined using the difference ΔTmura between the suction temperature and the bed temperature and the elapsed time Tthermon from the thermo-on as parameters. Specifically, the lower limit of the motor 14 of the indoor fan 12 based on the difference between the suction temperature and the floor temperature (temperature difference indicated by symbol b in FIG. 3) when the thermostat is turned on after the start of operation of the air conditioner (operation ON). The tap is decided. For example, if the temperature difference indicated by symbol b in FIG. 3 is 11 ° C., Tthermon is “0” at this time, so that “H” in the leftmost column and the top row in Table 2 is “H”. It is determined as the lower limit tap. Therefore, if the temperature difference indicated by symbol a in FIG. 3 is 3 ° C., “M” is selected as the rotation speed of the motor 14 in the automatic air volume operation according to Table 1, but it is determined according to Table 2. Since the lower limit tap is “H”, the rotational speed of the motor 14 of the indoor fan 12 does not decrease below “H” in this embodiment. Therefore, it is possible to prevent the heating capacity from being insufficient and maintain user comfort. In the automatic air volume operation, the rotation speed of the motor 14 is periodically selected according to Table 1. If this selected rotation speed is lower than the lower limit tap determined in Table 2, it is selected even if it is selected. The motor 14 is operated with a lower limit tap. That is, the lower limit tap determined in Table 2 is adopted in preference to the rotation speed selected in Table 1.

  As can be seen from Table 2, in this embodiment, the larger the ΔTmura, the higher the lower limit tap. Thereby, when performing automatic control based on the temperature difference between the suction temperature and the target temperature, it is possible to prevent the motor 14 from rotating more than necessary and maintain a certain amount of airflow. As a result, it is possible to prevent the heating capacity from being insufficient and improve the comfort of the user.

  In the present embodiment, the lower limit tap can be lowered as time elapses after the motor 14 is started. For example, when ΔTmura is 8 ° C. or higher, the lower limit tap is lowered from “H” to “M” with time. In this case, as the time elapses after the start of the motor 14, it is considered that the room temperature gradually increases and approaches the target temperature, so by lowering the lower limit tap with the elapse of time after the start of the motor 14, The room temperature can be adjusted efficiently while suppressing energy consumption.

[Other Embodiments]
In the embodiment described above, the lower limit tap of the motor 14 of the indoor fan 12 is changed based on the temperature difference between the suction temperature when the thermostat is turned on after the start of the operation of the air conditioner A and the floor temperature as the indoor temperature. The lower limit tap of the motor 14 can be changed based on the temperature difference between the suction temperature at the start of operation of the air conditioner A and the indoor target temperature. Also in this case, the control unit P changes the lower limit tap of the motor 14.

  In the present embodiment, when the indoor unit 1 of the air conditioner A is disposed near the ceiling where warm air tends to accumulate, the warm air accumulates near the ceiling, and the suction temperature of the indoor unit 1 disposed near the ceiling is Even when the target temperature is approached sooner than the actual room temperature, the air flow is automatically controlled based on the temperature difference between the suction temperature and the target temperature by changing the lower limit tap of the motor 14 to be higher. The air volume can be maintained. In other words, since the rotation speed of the motor 14 of the indoor fan 12 does not become lower than the set lower limit tap, it is possible to prevent the heating capacity from being insufficient and improve the user comfort.

[Other variations]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.
For example, in the above-described embodiment, the ceiling unit is exemplified as the indoor unit. However, as long as the indoor unit is installed in an environment in which warm air easily accumulates, for example, a ceiling-suspended indoor unit or a wall hanging unit The present invention can also be applied to an air conditioner including a type of indoor unit.

  Moreover, in embodiment mentioned above, although the motor 14 of the indoor fan 12 of the indoor unit 1 is employ | adopted as a motor which determines a minimum tap, this invention is not limited to this, The heating of the air conditioner A It is also possible to change the lower limit tap of the motor 4 of the compressor 5 involved in the capacity. That is, when the operation control of the compressor 5 is performed based on the temperature difference between the suction temperature and the target temperature, a certain amount of refrigerant supply can be maintained by changing the lower limit tap of the motor 4 of the compressor 5. Specifically, when warm air accumulates near the ceiling, and the temperature difference between the suction temperature of the indoor unit 1 disposed near the ceiling and the temperature of the area where the user lives (indoor temperature), and Even when warm air accumulates in the vicinity of the ceiling and the suction temperature of the indoor unit 1 disposed near the ceiling approaches the target temperature earlier than the actual indoor temperature, the control unit P causes the motor 4 to drive the compressor 5. By changing the lower limit tap to be higher, a certain amount of refrigerant supply can be maintained. In other words, since the refrigerant supply amount does not decrease below the set lower limit tap, it is possible to prevent the heating capacity from being insufficient and improve the user comfort.

In the above-described embodiment, the lower limit tap is determined from three types “H” to “L”. However, the present invention is not limited to this, and the type of the lower limit tap is appropriately selected. Can be selected.
In the above-described embodiment, the lower limit tap is determined when the thermostat is first turned on after the operation of the air conditioner A is started. The lower limit tap is determined for the second time after the operation of the air conditioner A is disclosed. This can also be done when the thermo is on.

Further, in the above-described embodiment, when the lower limit tap is lowered with the lapse of time after the thermo-on, the lower limit tap value is lowered with 10 minutes or 20 minutes as a break, but this “10 minutes” or “ The division of “20 minutes” can be changed as appropriate. Similarly, in Table 2, the lower limit tap is determined by dividing the value of ΔTmura into four cases (i) to (iv). However, the lower limit tap may be divided into three cases, and in the case of five or more cases. The lower limit tap can also be determined separately.
In the above-described embodiment, the air conditioner during the heating operation is described as an object. However, the present invention is not limited to the heating operation but can be applied during the cooling operation. For example, in the case of a floor-mounted indoor unit provided with a suction port near the bottom surface, cold air can easily collect downward, so that the same thing can occur as the warm air accumulates upward, but the present invention also applies to this case. In this way, user comfort can be maintained.

DESCRIPTION OF SYMBOLS 1: Indoor unit 2: Operation operation part 3: Outdoor unit 4: Motor 5: Compressor 6: Casing 7: Cosmetic panel 7a: Lower surface 8: Suction port 9: Air outlet 9a: Flap 10: Suction grill 11: Filter 12: Indoor fan 13: Heat exchanger 14: Motor 15: Impeller 16: Drain pan 17: Suction hole 18: Blow hole 19: Bell mouth 20: Suction temperature sensor 21: Floor temperature sensor A: Air conditioner C; Ceiling P: Control unit

Claims (5)

An air conditioner (A) comprising a suction temperature sensor (20), a sensor (21) for detecting the room temperature, and a control unit (P) for controlling the operation of the motors (4, 14),
The control unit (P) obtains a temperature difference between the suction temperature and the room temperature when the thermo-on is started after the operation of the air conditioner (A) is started, and based on the obtained temperature difference, the minimum of the motor (4, 14). An air conditioner (A) that changes a lower limit tap that is the number of revolutions.   The air conditioner (A) according to claim 1, wherein the control unit (P) increases the lower limit tap as the temperature difference increases. The said control part (P) is an air conditioner (A) of Claim 1 or Claim 2 which makes the said lower limit tap low with progress of the time after a motor (4, 14) starting. The air conditioner (A) according to any one of claims 1 to 3 , wherein the motor is a motor (14) that drives an indoor fan (12). The air conditioner (A) according to any one of claims 1 to 3 , wherein the motor is a motor (4) that drives a compressor (5).

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