JP2014092350A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner that reduces discomfort caused by irregular and intermittent noise generated from a drain pump.SOLUTION: The air conditioner comprises an indoor heat exchanger, an indoor fan, a drain water storage part for storing drain water generated in the indoor heat exchanger, and a drain pump 10 for discharging the drain water stored in the drain water storage part. The air conditioner also includes a generated drain water quantity calculation unit 31 for calculating quantity of generated drain water on the basis of an air conditioning operation state and a drain pump control unit 32 that increases motor rotation speed of the drain pump 10 when the quantity of the generated drain water increases and reduces the motor rotation speed of the drain pump 10 when the quantity of the generated drain water decreases.

Description

  The present invention relates to an air conditioner, and more particularly to an air conditioner equipped with a drain pump for draining drain water.

  Conventionally, some air conditioners, for example, air conditioners installed in high places such as a ceiling-embedded type and a ceiling-suspended type, drain the drain water generated during cooling or dehumidifying operation by using a drain pump. Yes. Moreover, in an air conditioner equipped with such a drain pump, as described in Patent Document 1, the drain pump is generally operated at a constant rotational speed. Also, in such an air conditioner, the drain pump is operated when the water level in the drain water storage section is above a certain level, and the drain pump is stopped when the water level in the drain water storage section is below a certain level. Was. In addition, when the drain pump is operated when the water level in the drain water storage section is below a certain level, the drain pump performs so-called idling operation that bites air, causing the drain pump noise to increase or the drain pump to be damaged. The drain pump was stopped because it occurred.

Japanese Patent Laid-Open No. 05-141686

  By the way, in the conventional method of starting and stopping the drain pump, no noise is generated by the drain pump during the drain pump stop period, but sudden operation noise of the drain pump is generated during the cooling operation or the dehumidifying operation. Or stop. If the operation sound of the drain pump is generated irregularly and intermittently in this way, an irritating noise will be generated in a quiet place such as a library or bedroom even if the operation sound itself is not too loud. Was uncomfortable. Note that the operation sound when the drain pump is continuously operated is generally not so loud, and is not so noticeable as compared with the change sound accompanying the start and stop of the drain pump.

  The present invention has been made to solve such problems, and it is an object of the present invention to provide an air conditioner that reduces the discomfort caused by the occurrence of irregular and intermittent noise in the drain pump. .

  An air conditioner according to a first aspect of the present invention stores an indoor heat exchanger, an indoor fan that blows air to the indoor heat exchanger, and drain water generated in the indoor heat exchanger during air conditioning operation. A drain water storage unit, a drain pump for draining drain water stored in the drain water storage unit, a drain water generation amount calculation unit that calculates a drain water generation amount estimated from an air conditioning operation state, and the drain water A drain pump control unit that controls to increase the motor speed of the drain pump when the generation amount increases and to decrease the motor rotation number of the drain pump when the drain water generation amount decreases. It is characterized by.

  According to such a configuration, the drain pump control unit increases the drain pump rotation speed when the drain water generation amount calculated by the drain water generation amount calculation unit is large, and drains when the drain water generation amount is small. Control to lower the pump speed. Thereby, the water level change in a drain water storage part can be made smaller than before, and a drain pump can be operated continuously for a long period of time. As a result, it is possible to reduce the frequency of stopping the drain pump for preventing the idle operation of biting the air of the drain pump, and it is possible to suppress irregular and intermittent operation sounds of the drain pump.

  According to a second aspect of the present invention, in the air conditioner according to the first aspect, the drain pump control unit variably controls the motor speed of the drain pump steplessly with respect to a change in the calculated value of the drain water generation amount. It is characterized by that.

  According to such a configuration, the drain pump's drain water drainage capacity is finely controlled with respect to the drain water generation amount by variably controlling the motor speed of the drain pump in response to changes in the calculated value of the drain water generation amount. It is possible to follow and variably control, and the water level change in the drain water reservoir can be further reduced. Therefore, the drain pump can be operated continuously for a longer period.

A third aspect of the present invention is the air conditioner according to the first or second aspect, wherein the drain pump motor is a DC motor.
According to such a configuration, the motor speed of the drain pump can be variably controlled steplessly by simple input voltage control or inverter control, and thereby the drain pump speed can be variably controlled steplessly. .

  According to a fourth aspect of the present invention, in the air conditioner according to any one of the first to third aspects, the drain water storage section is provided with a water level sensor that detects an upper limit water level of the drain water, and the drain pump. When the control unit detects that the water level sensor has reached the upper limit water level, the control unit determines that it is abnormal and transmits an air conditioning operation stop command.

  According to such a configuration, in order to stop the operation of the air conditioner when it is detected that the water level of the drain water storage unit has reached the upper limit water level due to an abnormality of the drain pump or the drain water drainage system, Overflow in the drain water storage part can be prevented.

  According to a fifth aspect of the present invention, in the air conditioner according to any one of the first to third aspects, the drain water storage section is provided with a water level sensor that detects a lower limit water level of the drain water, and the drain pump. The control unit controls to stop the operation of the drain pump when the water level sensor detects a water level lower than a lower limit water level.

  According to such a configuration, it is possible to prevent the drain pump from being idle. In the case of the present invention, since the drain pump rotation speed is variably controlled according to the amount of drain water generated as described above, the frequency of starting and stopping the drain pump is lower than that of the conventional one.

  According to the present invention, since the drain water generation amount is predicted and the drain pump rotation speed is increased or decreased, the drain pump start / stop frequency can be reduced and the operation can be stably performed. As a result, it is possible to prevent idling of the drain pump and reduce noise accompanying the start / stop of the drain pump.

1 is a schematic configuration diagram of a ceiling-embedded air conditioner according to an embodiment of the present invention. It is a schematic diagram of the drain water storage part in the air conditioner. It is a functional block diagram regarding control of the drain pump in the air conditioner. It is an air line figure for demonstrating the calculation method of the drain water generation amount in the air conditioner. It is a related figure of the drain water generation amount and drain pump rotation speed in the same drain pump control. It is a control flowchart of the drain pump in the air conditioner.

Hereinafter, an air conditioner according to an embodiment will be described with reference to the drawings.
This air conditioner is one of high-installation type air conditioners, and is a ceiling-embedded indoor unit in a separate air conditioner. As shown in FIG. 1, the indoor unit includes a main body 1 that houses various devices therein, and a decorative panel 2 that is disposed at a lower portion of the main body 1. The main body 1 is attached to the upper ceiling of the ceiling member 3 of the air conditioning room. The decorative panel 2 is fitted into the opening 3a of the ceiling material 3 and is attached in close contact with the air conditioning room side of the ceiling. A suction port 2a for sucking air in the air-conditioning room is formed in the central portion of the decorative panel 2, and a blower port 2b for blowing out the cooled or dehumidified air is formed on the four peripheral sides surrounding the suction port 2a. ing.

  In the main body 1, an indoor fan 4 that sucks air in the air-conditioned room into the main body 1 through an inlet 2 a provided in the center of the decorative panel 2 and blows it out in the outer peripheral direction, and surrounds the outer periphery of the indoor fan 4. The arranged indoor heat exchanger 5 is accommodated. The indoor fan 4 is configured to be used by switching between strong and weak according to the user's preference. A drain pan 6 that receives dripping of drain water generated in the indoor heat exchanger 5 during the air conditioning operation for cooling or dehumidification is disposed below the indoor heat exchanger 5. In the present specification, the term “air-conditioning operation” means an operation in which cooling or dehumidifying operation is performed.

  A drain water storage part 7 for storing drain water is formed in a part of the drain pan 6, and a drain pump 10 for draining the drain water is attached to the drain water storage part 7. In addition, in FIG. 1, although the indoor side heat exchanger 5 is described in right and left, these are connected integrally when seeing planarly. In addition, the drain pan 6 also appears to be separated into left and right in FIG. 1, but these are integrally connected in plan view.

  The drain pump 10 is a motor-driven (electric motor-driven) centrifugal pump, and as schematically shown in FIG. 2, a main body housing 12 that houses the rotating blades 11 and a DC motor that drives the rotating blades 11. 13, a suction port 14 formed in the lower portion of the main body housing 12, and a discharge port 15 that discharges the drained water. The drain pump 10 having such a configuration sucks drain water from the suction port 14 by centrifugal force generated by rotating the rotary blade 11 and discharges the drain water from the discharge port 15. A drain pipe 16 led out of the apparatus is connected to the discharge port 15 of the drain pump 10. The drain pipe 16 is started up and disposed in order to suppress the backflow of drain water from the drain pipe 16 when the drain pump 10 is stopped.

  As shown in FIG. 2, a water level sensor 20 is installed in the drain water storage unit 7. The water level sensor 20 includes a float 21 that rises or falls according to a change in the water level of the drain water, and a support cylinder 22 that supports the float 21. The water level sensor 20 includes a low level switch 23 that operates at the lower limit water level L of the drain water storage unit 7 and a high level switch 24 that operates at the upper limit water level H of the drain water storage unit 7.

  The low level switch 23 of the water level sensor 20 is for preventing the water level of the drain water storage unit 7 from lowering and the drain pump 10 biting in air, and the water level of the drain water storage unit 7 is the lower limit water level L. When it becomes above, the drain pump 10 is operated, and when it becomes less than the lower limit water level L, the drain pump 10 is stopped. The high level switch 24 of the water level sensor 20 prevents the drain water from overflowing from the drain water storage section 7 when an abnormality occurs in the drain water drainage due to abnormal operation of the drain pump 10 or clogging of the drain pipe 16. When the water level of the drain water storage part 7 reaches the upper limit water level H, this is detected as an abnormal state. When the high level switch 24 of the water level sensor 20 is activated, the operation of the air conditioner is stopped.

Next, a control system for such a drain pump 10 will be described with reference to FIGS.
First, the configuration of the control system of the drain pump 10 will be described with reference to FIG. The control system of the drain pump 10 controls the drain pump rotation speed Rp by the drain pump 10, the water level sensor 20, the drain water generation amount calculation unit 31 that calculates the generation amount of drain water, and the calculated drain water generation amount. It comprises a drain pump control unit 32 and the like.

The drain water generation amount calculation unit 31 includes a CPU (Central Processing Unit), a RAM (Random Access Memory) used for primary storage, a non-volatile memory such as a mask ROM (Read Only Memory) and a flash memory. The nonvolatile memory stores basic data necessary for drain water calculation and a processing program necessary for the calculation. As basic data, for example, the performance characteristics of the air conditioner indicating the refrigeration capacity S (KJ / h) when the evaporation temperature, the condensation temperature, the compressor rotation speed Rc, and the indoor fan rotation speed Rf are variables, the indoor fan The air volume characteristic of the indoor fan 4 indicating the air volume V ((m ³ / h) of the indoor fan 4 when the rotation speed Rf is a variable is included.Further, as basic data, the bypass factor BF of the indoor heat exchanger 5 and Also included are necessary basic data related to the contact factor CF, wet air diagram, etc. Further, the drain water generation amount calculation unit 31 includes sensor information detected by a sensor provided for air conditioning operation, and a compressor. The operation information obtained from operation control devices such as a control unit, indoor fan control unit, and expansion valve control unit is applied to a processing program to calculate the amount of drain water generated.

  As the sensor, as shown in FIG. 3, it is considered to use only those installed for normal cooling operation and dehumidifying operation, and an indoor air temperature sensor 33, an indoor heat exchanger temperature sensor are used. 34, an outdoor air temperature sensor 35, and an outdoor heat exchanger temperature sensor 36 are provided. Moreover, as shown in FIG. 3, indoor fan rotation speed Rf (rpm), compressor rotation speed Rc (rpm), indoor side heat exchanger outlet refrigerant set superheat degree Tec (° C.), outdoor heat exchanger outlet refrigerant The set supercooling degree Tcc (° C.) is transmitted to the drain water generation amount calculation unit 31 from the operation control device that controls the compressor, the electric expansion valve, the indoor fan 4, and the like. These are operation state values for grasping the operation state necessary for drain water calculation.

The drain water generation amount W (kg / h) is basically calculated by the following equation. In the following description, symbols indicating state values on the air diagram are described in the air diagram of FIG.
W = G (Xa−Xb) (Formula 1)
G = Q / Va (Formula 2)
Where, G: air circulation rate (kg / h), Q: air volume of indoor fan 4 (m ³ / h), Va: specific volume of inlet air of indoor heat exchanger 5 (m ³ / kg), Xa The absolute humidity (kg / kg) of the inlet air of the indoor heat exchanger 5, Xb: the absolute humidity (kg / kg) of the outlet air of the indoor heat exchanger 5.

Therefore, the air circulation amount G is calculated by the above equation 2 by reading the air volume Q of the indoor fan 4 from the data of the indoor fan rotation speed Rf and the air volume characteristics of the indoor fan 4.
By the way, the wet bulb temperature (° C.) of the inlet air of the indoor heat exchanger 5 and the dry bulb temperature (° C.) and wet bulb temperature (° C.) of the outlet air of the indoor heat exchanger 5 are not measured. Therefore, the state point A of the inlet air of the indoor heat exchanger 5 and the state point B of the outlet air of the indoor heat exchanger 5 cannot be determined, and the absolute humidity Xa of the inlet air of the indoor heat exchanger 5 is determined. In addition, the absolute humidity Xb of the outlet air from the indoor heat exchanger 5 cannot be obtained directly. Therefore, these are obtained as follows.

  First, the state point E is obtained from the indoor side heat exchanger temperature Te (° C.) detected by the indoor side heat exchanger temperature sensor 34. Since the state point E is a state point of saturated air having the same dry bulb temperature as the indoor heat exchanger temperature Te, it can be directly obtained as shown in FIG. Therefore, the enthalpy Ie (KJ / kg) at the state point E can be obtained.

Next, the enthalpy Ia (KJ / kg) of the inlet air of the indoor heat exchanger 5 is obtained in order to obtain the state point A of the inlet air of the indoor heat exchanger 5 by the following formula 3.
Ia = Ie + (Ia−Ib) / CF = Ie + S / G · CF (Formula 3)
In Expression 3, Ib is the enthalpy (KJ / kg) at the state point B of the outlet air of the indoor heat exchanger 5, and S is the refrigeration capacity (KJ / kg) of the air conditioner.

Here, the refrigerating capacity S of the air conditioner is obtained as follows.
The indoor side heat exchanger temperature Te measured by the indoor side heat exchanger temperature sensor 34 is set as the evaporation temperature, and the outdoor side heat exchanger temperature Tc (° C.) measured by the outdoor side heat exchanger temperature sensor 36 is condensed. And Then, the refrigeration capacity S is calculated from the evaporation temperature, the condensation temperature, the compressor rotational speed Rc, and the indoor fan rotational speed Rf with reference to the performance characteristics of the air conditioner.

  Thus, when the enthalpy Ia of the state point A of the inlet air of the indoor heat exchanger 5 can be obtained by the equation 3, the dry bulb temperature Ta (° C. of the state point A of the inlet air of the indoor heat exchanger 5 is obtained. ) Is measured by the indoor air temperature sensor 33, the state point A can be obtained from these numerical values. Further, the absolute humidity Xa of the inlet air of the indoor heat exchanger 5 can be obtained.

Moreover, in order to obtain | require the state point B of the exit air of the indoor side heat exchanger 5 by the following formula 4, the enthalpy Ib of the exit air of the indoor side heat exchanger 5 is obtained.
Ib = Ie + (Ia−Ib) CF / BF = Ie + S · CF / G · BF (Formula 4)
When the enthalpy Ib is obtained from this equation, the state point B can be obtained as follows. That is, the line connecting the state point A of the inlet air of the indoor heat exchanger 5 and the state point E of the saturated air having the same dry bulb temperature as the indoor heat exchanger temperature Te and the enthalpy obtained by the above-described equation 4 The intersection point with the line Ib becomes the state point B of the outlet air of the indoor heat exchanger 5. Therefore, the absolute humidity Xb of the state point B obtained by such a calculation method can be calculated as the absolute humidity of the outlet air of the indoor heat exchanger 5.

  If it carries out as mentioned above, dry-bulb temperature Ta (degreeC) of entrance air, indoor side heat exchanger temperature Te (degreeC), outdoor side heat exchanger temperature Tc (degreeC), compressor rotation speed Rc (rpm), and indoor A table of drain water generation amount W (kg / h) using the fan rotation speed Rf (rpm) as variable information can be created. In the present embodiment, the drain water generation amount calculation unit 31 stores the table calculated in this way, and by receiving the variable information, the drain water generation amount W (kg / h) at that time ) Is calculated.

  Next, the drain pump control unit 32 will be described. The drain pump control unit 32 is composed of one or a plurality of integrated circuits, and includes a nonvolatile memory such as a mask ROM and a flash memory. The nonvolatile memory stores data indicating an appropriate drain pump rotational speed Rp (rpm) with respect to the drain water generation amount W (kg / h) as shown in FIG. Moreover, the drain pump control part 32 is provided with the motor drive circuit of the drain pump 10, and the drain pump rotation speed Rp becomes a relationship shown in FIG. 5 with respect to the calculated value calculated by the drain water generation amount calculation part 31. Thus, the motor of the drain pump 10 is variably controlled.

Next, as an operation of the air conditioner, variable control of the drain pump 10 will be described based on the control flowchart of FIG.
In the air conditioner according to the present embodiment, when an operation switch (not shown) provided in an operation unit (not shown) is turned on and a cooling or dehumidifying air conditioning operation is started, a certain time has elapsed. The operation is started (step S1). In the first operation, a timer is started in order to predict the drain water generation amount W at regular intervals (step S2). Next, it is determined whether the water level in the drain water storage unit 7 is equal to or higher than the lower limit water level L (step S3). Here, when the water level of the drain water storage unit 7 is equal to or higher than the lower limit water level L (in the case of YES in step S3), the drain water generation amount calculation unit 31 reads the variable information in the operation state at that time and generates drain water The amount W is calculated (step S4).

  The sensor information among the read variable information includes the dry bulb temperature of the inlet air of the indoor heat exchanger 5 (that is, the dry bulb temperature of the indoor air) Ta, the indoor heat exchanger temperature (= evaporation temperature) Te, the room The outer heat exchanger temperature (= condensation temperature) Tc. The operation control units such as the indoor fan control unit, the compressor control unit, and the expansion valve control unit together with variable information such as the indoor fan rotation speed Rf and the compressor rotation speed Rc, and the outlet side refrigerant of the indoor heat exchanger 5 And the set supercooling degree Tcc of the refrigerant on the outlet side of the outdoor heat exchanger are transmitted.

  As described above, the drain water generation amount W calculated by the drain water generation amount calculation unit 31 is transmitted to the drain pump control unit 32. The drain pump control unit 32 variably controls the motor of the drain pump 10 so that the drain water generation amount W calculated by the drain water generation amount calculation unit 31 becomes the drain pump rotation speed Rp shown in the graph of FIG. (Step S5).

  In addition, when the water level of the drain water storage part 7 is less than the minimum water level L in step S3 (in the case of NO in step S3), the drain pump 10 is held in an operation stop state to prevent idling (step S9). .

  When the predetermined time has elapsed with the operation switch turned on (YES in step S6) and the timer has finished counting (YES in step S7), the timer is reset (step S8). Return to step S2. If the timer count has not ended in step S7, the process returns to step 6.

  Thus, it returns to step S2 for every fixed time (for example, 2-3 minutes) progress, and it is confirmed whether the water level in the drain water storage part 7 is the minimum water level L (step S3), and drain water generation | occurrence | production. A quantity W is calculated (step S4). Then, the motor of the drain pump 10 is variably controlled so that the drain pump rotational speed Rp corresponding to the drain water generation amount W is reached (step S5).

  If the operation switch is not ON in step S6 (NO in step S6), that is, if the operation of the air conditioner is stopped, the operation of the drain pump 10 is stopped (step S10). The case where the operation switch is not ON in step S6 is, for example, the case where the operation switch is turned off immediately after the start of operation, or the case where the operation is stopped because the air-conditioning operation becomes unnecessary after a certain time has elapsed from the start of operation. It is.

  In addition, when the water level of the drain water storage unit 7 reaches the upper limit water level H during the air-conditioning operation, an abnormality occurs in the drain water piping system or the drain pump 10, and thus overflow in the drain water storage unit 7 is prevented. Therefore, the drain pump control unit 32 transmits an air conditioning operation stop command regardless of the control of the drain pump 10 described above.

Since the air conditioner according to the present embodiment is configured as described above, the following effects can be achieved.
(1) The drain pump control unit 32 increases the drain pump rotational speed Rp when the drain water generation amount W calculated by the drain water generation amount calculation unit 31 is large, and the drain pump when the drain water generation amount W is small. Control is performed so as to reduce the rotational speed Rp. Thereby, the water level change in the drain water storage part 7 becomes smaller than before, and the drain pump 10 can be operated continuously for a long time. As a result, it is possible to reduce the frequency of stopping the drain pump 10 for preventing so-called idling operation that bites the air of the drain pump 10, and to suppress the generation of irregular and intermittent operation sounds of the drain pump 10. it can.

  (2) The drain pump control unit 32 variably controls the drain pump rotational speed Rp steplessly with respect to a change in the calculated value of the drain water generation amount W. For this reason, the drain water drainage capacity of the drain pump 10 can be finely tracked and controlled with respect to the drain water generation amount W, and the water level change in the drain water reservoir 7 can be further reduced. Therefore, the drain pump 10 can be operated continuously for a longer period.

  (3) Since the drain pump 10 is driven by the DC motor 13, the motor speed of the drain pump 10 can be variably controlled steplessly by simple input voltage control or inverter control. Rp can be variably controlled steplessly.

  (4) The drain water storage unit 7 is provided with a water level sensor 20 that detects the upper limit water level H of the drain water. Thereby, when it is detected that the water level of the drain water storage unit 7 has reached the upper limit water level H due to an abnormality in the drain pump 10 or the drain water drainage system, the drain pump control unit 32 determines that this is abnormal and performs air conditioning. Since the operation stop command is transmitted, overflow in the drain water storage unit 7 can be prevented.

  (5) The drain water storage unit 7 is provided with a water level sensor 20 that detects a lower limit water level L of the drain water. Thereby, when the water level sensor 20 detects a water level lower than the lower limit water level, the drain pump control unit 32 performs control so as to stop the operation of the drain pump 10, so that the drain pump 10 can be prevented from idling. .

(Modification)
The air conditioner is not limited to the above-described embodiments, and the following modifications are possible. In this case, the following modified example is not applied only to the target embodiment, and can be implemented in combination with other embodiments or other modified examples as appropriate.

  In the embodiment, in addition to the sensor used for normal air conditioning operation, the wet bulb temperature sensor for the inlet air of the indoor heat exchanger 5, the dry bulb temperature sensor for the outlet air of the indoor heat exchanger 5, and the room A wet bulb temperature sensor for the outlet air of the inner heat exchanger 5 may be provided. By doing so, the absolute humidity Xa of the inlet air and the absolute humidity Xb of the outlet air of the indoor heat exchanger 5 detected by the sensor can be directly obtained from the air diagram. For this reason, the calculated value of the drain water generation amount W becomes more accurate.

  -In the said embodiment, although the depth of the drain water storage part 7 and the drain pan 6 is not made different especially, you may make the drain water storage part 7 deep with respect to the depth of the general part of the drain pan 6. FIG. In this way, since the difference between the lower limit water level L and the upper limit water level H of the drain water storage unit 7 can be increased, the operation period of the drain pump can be further prolonged.

  -Although the air conditioner in the said embodiment has mention | raise | lifted the ceiling embedded type air conditioner as an example, as an air conditioner, it is not specifically limited to this form. What is necessary is just to drain drain water using a drain pump.

  In the above-described embodiment, one water level sensor 20 detects the lower limit water level L and the upper limit water level H of the drain water storage unit 7, but these water levels are individually detected by another water level sensor. It may be.

  In the above embodiment, the air conditioning operation is stopped when the water level sensor 20 detects that the upper limit water level H has been reached, but a notification device that notifies this simultaneously with this operation may be provided. As the notification device, an alarm lamp, an alarm sound generator, or the like can be used.

  In the above embodiment, when the water level sensor 20 detects a water level lower than the lower limit water level L, the operation of the drain pump 10 is stopped or the stopped state is continued. You may provide alerting | reporting apparatuses, such as a display lamp which alert | reports the driving | running state of the pump 10. FIG.

  In the above embodiment, the water level sensor 20 includes the low level switch 23 that operates at the lower limit water level L of the drain water storage unit 7 and the high level switch 24 that operates at the upper limit water level H of the drain water storage unit 7. Only one of these switches may be provided. For example, only the high level switch 24 may be provided.

  H: Upper water level, L: Lower water level, W: Drain water generation amount, Rp ... Drain pump rotation speed, 4 ... Indoor fan, 5 ... Indoor heat exchanger, 7 ... Drain water reservoir, 10 ... Drain pump, 13 ... DC motor, 20 ... water level sensor, 31 ... drain water generation amount calculation unit, 32 ... drain pump control unit.

Claims (5)

An indoor heat exchanger (5),
An indoor fan (4) for blowing air to the indoor heat exchanger (5);
A drain water storage section (7) for storing drain water generated in the indoor heat exchanger (5) during the air conditioning operation;
A drain pump (10) for draining the drain water stored in the drain water storage section (7);
A drain water generation amount calculation unit (31) for calculating a drain water generation amount estimated from the air conditioning operation state;
When the drain water generation amount (W) increases, the motor rotation speed of the drain pump (10) is increased, and when the drain water generation amount (W) decreases, the motor rotation speed of the drain pump (10). And a drain pump control unit (32) for controlling the air conditioner to be low. The air conditioner according to claim 1,
The said drain pump control part (32) variably controls the motor rotation speed of a drain pump (10) continuously with respect to the change of the calculated value of the said drain water generation amount (W). The air conditioner characterized by the above-mentioned. The air conditioner according to claim 1 or 2,
The air conditioner characterized in that the motor of the drain pump (10) is a DC motor (13). In the air conditioner according to any one of claims 1 to 3,
The drain water reservoir (7) is provided with a water level sensor (20) for detecting the upper limit water level (H) of the drain water,
The drain pump control unit (32) determines that the water level sensor (20) has reached the upper limit water level (H) and issues an air conditioning operation stop command based on an abnormality. Harmony machine. In the air conditioner according to any one of claims 1 to 3,
The drain water reservoir (7) is provided with a water level sensor (20) for detecting a lower limit water level (L) of the drain water,
The drain pump control unit (32) controls to stop the operation of the drain pump (10) when the water level sensor (20) detects a water level lower than a lower limit water level (L). Air conditioner to do.