JPH0239134Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is intended for ceiling-mounted air conditioners that are used by being embedded in the ceiling or suspended from the ceiling, and particularly for indoor heat exchangers. This invention relates to a control system for a drain pump for discharging drain water generated in a drain pump.

(Prior Art) In this type of ceiling-mounted air conditioner, drain water is discharged through a drain channel provided in the ceiling. Therefore, for example, as disclosed in Japanese Utility Model Application Publication No. 51-72954, there is a system in which drain water is pumped up to a predetermined height in order to obtain an appropriate drain gradient in the ceiling. Conventionally, in these air conditioners, in order to prevent drain water from overflowing from the drain pan due to a malfunction of the drain pump, the water level of the drain water in the drain pan is detected, and the water level is detected slightly before overflow. When an abnormal water level is reached, a water level switch detects this and forcibly stops the operation of the air conditioner thereafter. Note that the drain pump is constantly driven when the air conditioner is operating, regardless of the drain water level.

(Problem that the invention aims to solve) By the way, when the air conditioner is stopped during cooling operation or dehumidification operation, the drain water that had been adhering to the heat exchanger until then gradually drips into the drain pan. The water may accumulate in the drain pan until it reaches an abnormal water level. In that case, the conventional system described above has a problem in that the water level switch is activated and the cooling operation of the air conditioner cannot be resumed.

To deal with this, the water level switch is activated after the air conditioner stops operating, and only the drain pump is driven when an abnormal water level is detected, which solves the above problem. However, in this case,
It is necessary to take new measures to control the operation of only the drain pump separately from the operation control of the air conditioner, and there is a problem that activating only the drain pump after the operation has stopped becomes a source of noise, for example late at night. arise.

(Purpose of the invention) In view of the above points, the present invention has been developed to remove heat from the heat exchanger after stopping the cooling or dehumidifying operation of the air conditioner, without adding new means or causing problems such as noise sources as described above. The purpose is to enable cooling or dehumidification operation to be resumed even if the water level switch detects an abnormal water level due to dripping drain water, unless there is a malfunction in the drain pump, etc. do.

(Means for solving the problem) Therefore, in the present invention, when restarting the air conditioner, the drain pump is unconditionally operated for a predetermined period of time regardless of the operating state of the water level switch. Based on the subsequent change in the state of the water level switch, it is determined whether normal operation can be resumed. In other words, the operation of the water level switch at the time of startup is masked, so that it is possible to accurately distinguish between a true abnormal state and a pseudo state that the water level switch was originally intended to detect.

Specifically, as shown in FIG. 1, a drain pan 8 is installed below the heat exchanger 3 that exchanges heat between refrigerant and air.
In an air conditioner in which drain water stored in the drain pan 8 is pushed up to a predetermined height position and discharged by a drain pump 10 driven by a motor 9, an abnormality in the drain water in the drain pan 8 is detected. A water level switch 20 for detecting the water level E is provided. Furthermore, a drain pump control means 21 that controls the motor 9 to operate the drain pump 10 for a predetermined time when the air conditioner is restarted after the operation is stopped, and A switch determining means 22 that determines the operating state of the water level switch 20, and a signal that prohibits restarting the air conditioner when the water level switch 20 outputs an abnormal water level signal based on the output of the switch determining means 22. An operation control means 23 is provided for outputting.

Here, when starting the air conditioner, drain pump 1
As long as there is no failure in the drain pump 10 and the drain pipe system, the time period for operating the drain pump 0 may be at least as long as the drain water level can be lowered from the abnormal water level E to a lower level.

(Function) When the drain water level reaches the abnormal water level E due to drainage generated after the cooling or dehumidifying operation is stopped, the water level switch 20 outputs an abnormal water level signal. However, in the present invention, the drain pump control means 21 functions when the air conditioner is started, the motor 9 is started regardless of the output of the abnormal water level signal from the water level switch 20, and the drain pump 10 is activated for a predetermined period of time. Operate. After a predetermined period of time has elapsed, the operating state of the water level switch 20 is determined by a switch determining means 22, and if the water level switch 20 is in a normal state, that is, if the drain water level is in the normal range, restart of operation is allowed. In addition, if the water level switch 20 is still outputting the abnormal water level signal, it is assumed that the drain pump 10 is malfunctioning or the drain pipe system is abnormal, and the operation control means 23 outputs a restart prohibition signal and prohibits operation. shall be taken as a thing. Thereby, it is possible to eliminate pseudo-failures of the air conditioner caused by the generation of drain after the operation is stopped.

(Example) Hereinafter, an example in which the present invention is applied to a ceiling-embedded air conditioner will be described.

In FIG. 2, the air conditioner consists of an outdoor unit (not shown) and an indoor unit 1, and the outdoor unit is equipped with a compressor, an outdoor heat exchanger, an expansion valve, an outdoor fan, and the like. On the other hand, indoor unit 1
In the case 2 fitted into the opening in the ceiling C, an indoor heat exchanger 3 having a U-shaped cross section for exchanging heat between the refrigerant supplied from the compressor and indoor air, and a fan 4 for ventilation are installed. The case 2 has an inlet 5 and an outlet 6 opened toward the indoor side. Therefore, while the indoor air sucked by the fan 4 passes through the heat exchanger 3, heat is removed by the heat exchanger 3, and the air is discharged from the outlet 6. Note that 7 is a chamber for effectively flowing the air sent out from the fan 4 to the heat exchanger 3.

A drain pan 8 is disposed below the heat exchanger 3 to receive water droplets condensed on the heat exchanger 3 during cooling or dehumidifying operation. A motor 9 is fixed to a fixed wall inside the case 2 facing the drain pan 8, and rotates a drain pump 10 installed in the drain pan 8 with this motor 9. As shown in FIG. 1, this drain pump 10 consists of a pump casing 13 having a suction port 11 at the center of its lower surface and a discharge port 12 at its outer periphery, and an impeller 14 housed in the pump casing 13. In order to obtain an appropriate drain pan slope in the ceiling C, a discharge passage 15 connected to the discharge port 12 is raised to a predetermined height position and exposed to the outside of the case 2, and a connecting device is connected to the discharge passage 15. Drain hose 17 through 16
is connected to the drain pump 10, which sucks the drain water in the drain pan 8 in a state mixed with air, and pushes it up to a predetermined height position through the discharge port 12 that opens laterally through the discharge passage 15, and discharges it. is configured to do so.

As shown in FIG. 1, the operation of the motor 9 that drives the drain pump 10 is controlled by a control device 18 together with operating equipment A such as a compressor in an air conditioner. The control device 18 receives an operation command signal output from a remote controller 19, an output signal from a water level switch 20 for detecting an abnormal water level E of drain water in the drain pan 8, and the like. Note that 19a is a warning lamp in case of drain water abnormality.

Here, the control procedure performed in the control device 18 will be explained with reference to FIG. 3. step
In step _S1 , when a cooling operation command signal is input by turning on the cooling operation switch provided on the remote controller 19, the motor 9 is started and the drain pump 10 is operated in step _S2 .
At this time, the alarm lamp 19a is designed not to blink for one minute from the input of the cooling operation command signal even if an abnormal water level signal from the water level switch 20 is received. Next, in step _S3 , it is determined whether the water level switch 20 is in an operating state, that is, whether the drain water in the drain pan 8 is at an abnormal water level E. When this judgment is NO, that is, when the drain water level is below the abnormal water level E and the water level switch 20 is in the inactive state, the step immediately starts.
Proceed to S ₄ and enter normal operation.

On the other hand, when the water level switch 20 is in the operating state in step _S3 , after one minute has elapsed in step _S5 , the alarm lamp 19a is blinked in step _S6 .

If the water level switch 20 remains in operation even though the predetermined time has elapsed, the process proceeds to step _S7 and enters the abnormality processing mode.
In other words, in the abnormality processing mode, step _S1
After operating the drain pump 10 for a predetermined time (5 minutes), restarting the drain pump 10 after a predetermined stop time (5 seconds), and maintaining the operating state for a further predetermined time (5 minutes). .

In this abnormality processing mode, in parallel with the operation of the drain pump 10, the operating state of the water level switch 20 is repeatedly determined in step _S8 , and when the water level switch 20 returns to the non-operating state, the water level switch 20 is reset to a state where normal operation is possible. Then, turn on the cooling operation switch again to return to normal operation. The roller has an abnormally large amount of drain water, and steps S ₂ to S ₆
This is based on the assumption that the drain water level cannot return to below the abnormal water level E with only the operating time required to shift to the abnormal water level. Further, while the abnormality processing mode continues, the abnormal state is displayed by blinking the lamp.

If the water level switch 20 remains in operation even after the abnormality processing mode has ended, it is determined that there is a malfunction such as a malfunction in the drain pump 10 or a blockage in the drain pipe system, and in step S9 the water level switch ₂₀ is turned off. Then, each unit in the room is stopped and the lamp mentioned above is displayed blinking.

Therefore, in the above control procedure, steps S ₁ and S ₂ constitute the drain pump control means 21 that controls the motor 9 to operate the drain pump 10 for a predetermined period of time when the operation is restarted after the operation is stopped. . Further, step _S3 constitutes a switch determining means 22 which determines the operating state of the water level switch 20 after the drain pump 10 is operated by the drain pump control means 21. Furthermore, in steps S ₄ to _{S 9} , based on the output of the switch determining means 22, when the water level switch 20 is outputting an abnormal water level signal, a signal for prohibiting restart of the air conditioner is output. , an operation control means 23 is configured to stop the operation of the operating device A and cause the lamp to flicker.

Therefore, in the above embodiment, when starting the cooling operation, the drain pump 10 operates regardless of the operating state of the water level switch 20, and then the operating state of the water level switch 20 is determined by the switch determining means 2.
If the drain water level is within the normal range as determined in step 2, normal operation can proceed as is.
As a result, as long as there is no failure of the drain pump 10, even if the drain water level reaches the abnormal water level E at the time of startup, it will not be treated as abnormal, and cooling or dehumidification operation can be started immediately.

In addition, in the abnormality processing mode, if there is simply too much drain water, it is possible to return to normal operation, so it is possible to accurately distinguish between the above-mentioned condensation failure, excessive drain water abnormality, and true drain abnormality. This allows for easy failure diagnosis.

Although the above embodiment shows the control mode during cooling operation, it is sufficient to operate an air heater (not shown) during dehumidification operation. It is of course possible to do so.

In addition, in the above embodiment, it was assumed that normal operation could be restored in the case of an abnormality of excessive drain water.
Depending on the capacity of the drain pan 8 or the set level of the abnormal water level E, it may be assumed that the drain is abnormal and all indoor and outdoor units are stopped.

(Effects of the invention) As described above, according to the invention, the drain water that drips from the heat exchanger and accumulates in the drain pan is discharged by the drain pump, and the water level switch 20 that detects the drain water level prevents the failure of the drain pump 10, etc. In an air conditioner that can be monitored, when restarting the system after it has been stopped, the drain pump 10 is first activated to discharge drain water regardless of the state of the water level switch 20, so that cooling or Even if the drain water reaches the abnormal water level E due to the drain water dripping into the drain pan 8 after the dehumidification operation has stopped, normal operation should be resumed immediately unless there is an abnormality in the drain pump 10 or the drain pipe system. Can be done. Thereby, it is possible to eliminate condensation failures caused by the generation of condensate after the operation is stopped, and to prevent unnecessary abnormal shutdowns during cooling or dehumidifying operation.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a diagram showing the overall configuration of an air conditioner, Fig. 2 is a vertical front view of the indoor unit, and Fig. 3 is an explanatory diagram showing the control procedure by the control device. It is. 3... Heat exchanger, 8... Drain pan, 9... Motor, 10... Drain pump, 18... Control device, 20... Water level switch, 21... Drain pump control means, 22... Switch determination means, 23...
...Operation control means, E...Abnormal water level.

Claims (1)

[Scope of utility model registration request] Drain pan 8 disposed below the heat exchanger 3
and a drain pump 1 that pushes up the drain water stored in the drain pan 8 to a predetermined height and discharges it.
In an air harmonist with a motor 9 that drives the drain pump 10, a water level that detects the abnormal water level of drain water in drain bread 8, and the re -operation after the air conditioner is stopped. Drain pump control means 2 for controlling the motor 9 to operate the drain pump 10 for a predetermined period of time
1, and the water level switch 2 after the drain pump 10 is operated by the drain pump control means 21.
Switch determination means 22 for determining the operating state of 0
and an operation control means 23 for outputting a signal for prohibiting restart of the air conditioner when the water level switch 20 is outputting an abnormal water level signal based on the output of the switch determination means 22. Characteristic air conditioner.