JP2016099022A - Air conditioner indoor unit - Google Patents

Abstract

An air conditioner that not only suppresses wasteful power consumption but also prevents chattering noise of a float by preventing an empty operation of a drain pump without newly adding a lower limit water level detection means. Provide a drainage device for indoor units. An indoor unit of an air conditioner having a drain water drainage device including a drain pump for draining drain generated in a cooling operation by a heat exchanger in a housing, wherein the drain is discharged during the cooling operation of the indoor unit. The pump is operated at a low speed that is lower than the rated operation to detect the presence or absence of idle operation, and when there is an idle operation, the drain pump is not shifted to the rated operation, and when there is no idle operation, the drain pump is rated. Transition to driving. [Selection] Figure 3

Description

  The present invention relates to an indoor unit of an air conditioner, and more particularly to an indoor unit of an air conditioner that is excellent in preventing noise generation and energy saving in a drainage device provided in the indoor unit.

  In recent years, the quietness and energy saving of air conditioners have become an important selling point of products, and they are sharpening the competition. Under such circumstances, the air blowing performance has been improved so as not to be comparable to that of a long time ago, greatly contributing to the reduction in noise and power consumption.

  Along with this, noise and power consumption of a drainage device that drains drain water, which has had a small influence ratio as a whole, can no longer be ignored. From such a background, a DC low-voltage power drain pump with low vibration and low current consumption is recently used from the AC power drain pump that has been used so far.

  On the other hand, many indoor units are equipped with a water level detection device for preventing overflow in case of a situation in which drainage cannot be normally performed for some reason, such as a failure of a drain pump or a poor construction of an indoor unit. In the unlikely event that the allowable upper limit water level is reached, the air conditioning operation itself is stopped to prevent overflow.

  However, in many products, an inexpensive float switch or the like is used for water level detection. In this case, only whether or not the allowable upper limit water level is reached is detected. Even with such a configuration, it is possible to prevent overflow, but the amount of drain water cannot be detected. Therefore, it is necessary to continuously operate the drain pump during the cooling operation regardless of the presence or absence of the drain water. In particular, the idling operation not only consumes unnecessary power, but also causes problems such as pump failure and chatter noise between the float / float shafts due to pump vibration.

  With respect to these background arts, in the technique shown in Patent Document 1, not only the upper limit water level but also the lower limit water level can be detected by using a plurality of floats, so that the drain pump can be prevented from running idly.

  In the technique shown in Patent Document 2, the drain pump is operated after a predetermined time delay from the start of the cooling operation. As a result, the water level is sufficiently raised and the pump is operated to prevent idling. By estimating the delay time in this case from the indoor temperature, humidity, heat exchanger temperature, etc., it is possible to prevent idling without using a lower limit water level detection means such as a float switch.

JP-A-8-121807 JP 2009-204257 A

  However, in the technique shown in Patent Document 1, it is necessary to add a float switch, which causes an increase in cost.

  Moreover, in the technique shown in Patent Document 2, there are many cases where the target indoor unit does not include a humidity sensor, and there is a limit in accurately estimating the amount of drain water generated from other operating information, air conditions, and the like. . Moreover, if there is less drain water than expected, it will run idle, and if there is too much, there is a risk of overflow. Moreover, since the residual drain water before the start of operation is unknown, an error occurs in the estimated water level.

  Further, in Patent Document 2, the residual drain water is kept constant by delaying the drain pump for a predetermined time after the air-conditioning operation. However, the appropriate time varies depending on the construction state of the drain hose (raised, etc.). If the operation time is short, the drain water will remain, and if the delay operation time is set long with a margin, it will eventually result in idling and an abnormal noise will be generated. Furthermore, because the specifications of the indoor unit, such as the heat exchanger area and the air volume, are slightly different for each capacity, it is necessary to consider an appropriate predetermined time for each specification, which increases the design and development man-hours.

  An object of the present invention is to not only reduce wasteful power consumption but also prevent float chatter noise by preventing idle operation of the drain pump without newly adding a lower limit water level detection means. An object of the present invention is to provide a drainage device for an indoor unit of an air conditioner.

  In order to solve the above problems, the present invention is an indoor unit of an air conditioner including a drain water drainage device including a drain pump for draining drain generated in a cooling operation by a heat exchanger in a housing, During cooling operation of the indoor unit, the drain pump is operated at a low speed that is lower than the rated operation to detect the presence or absence of idle operation, and when there is idle operation, the drain pump is not shifted to rated operation and there is no idle operation In this case, the drain pump is shifted to rated operation.

  According to one aspect of the present invention, it is possible not only to reduce wasteful power consumption but also prevent float chatter noise by preventing the drain pump from being idled without newly adding a lower limit water level detection means. can do.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view which shows the structure in the indoor unit housing of the air conditioner which concerns on Example 1 of this invention. The figure which shows the structure of the drainage device of the air conditioner of Example 1 of this invention. The flowchart which showed the driving | running mode after the air_conditionaing | cooling operation start. The figure which shows the example which paid its attention to the load current of the drain pump drive motor as a concrete implementation means of an idle driving | running detection part. The figure which shows the example which paid its attention to the increase / decrease command of the rotation speed which an indoor unit control part gives as a concrete implementation means of an idle driving | running | working detection part.

  Hereinafter, an embodiment of a drainage device for an air conditioner according to the present invention will be described with reference to the drawings. In addition, the part which attached | subjected the same code | symbol in each figure has shown the part which is the same or corresponds.

  An embodiment of the present invention will be described with reference to an example applied to a ceiling-embedded indoor unit. FIG. 1 is a longitudinal cross-sectional view illustrating a configuration of a housing of an air conditioner according to Embodiment 1 of the present invention.

  According to FIG. 1, the indoor unit 100 is installed facing the ceiling surface (not shown) by the suspension rod 26 from the ceiling. The indoor air 90 is sucked into the housing from the suction port 25 by the turbo fan 24 that is disposed in the approximate center of the housing 21 of the indoor unit 100 and is driven to rotate by the fan motor 23, and is heat-exchanged by the heat exchanger 20. After that, the air is blown into the room from the air outlet 28 of the housing. During the cooling operation, when the indoor air 90 is cooled by the heat exchanger 20, drain water 91 is generated and accumulated in the drain pan 11 disposed at the lower end of the heat exchanger 20. Reference numeral 22 denotes an electrical component box that stores electrical components such as the indoor unit control unit 53 and the motor control unit 52 described in FIG.

  A drainage device 50 for draining the drain water 91 accumulated in the drain pan 11 will be described with reference to FIG. The drainage device 50 includes a drain pump 10, a drainage hose 15, a water level detection means 51, and a motor control unit 52. The drain water 91 in the drain pan 11 is pumped up by the drain pump 10 and drained through the drain hose 15.

  On the other hand, if the drainage does not function well for some reason, such as a failure of the drain pump 10 or the drainage hose 15 being clogged or inclined, if the cooling operation is continued as it is, the drain water 91 will eventually overflow from the drain pan 11. End up. Therefore, a water level detection means 51 for preventing overflow is provided. For the water level detection means 51, a relatively inexpensive magnet type float switch 12 is often used. The float switch 12 is in an energized state below the permissible water level, but when the float becomes above the permissible water level, the energization is released, and this is detected, and the indoor unit control unit 53 stops the cooling operation.

  In the case of such a configuration of the water level detection means 51, since only the allowable upper limit water level is detected, conventionally, the drain pump 10 is operated with the start of the cooling operation regardless of the presence or absence of the drain water 91. As a result, wasteful power is consumed, and the operation sound of the drain pump 10 is unnecessarily generated. In particular, when there is almost no drain water 91, the float 12 is only on the stopper 14 at the lower end of the float shaft 13, and therefore the float 12, the float shaft 13, and the stopper are driven by the vibration of the drain pump 10. Chatter noise is likely to be generated on the contact surface with 14. Therefore, in the first embodiment of the present invention, the idling operation detecting unit 54 for preventing the idling operation of the drain pump 10 is provided.

  In Embodiment 1 of the present invention, the operation after the start of the cooling operation is performed as follows by the idle operation detection unit 54, the motor control unit 52, and the indoor unit control unit 53. FIG. 3 is a flowchart showing an operation mode after the start of the cooling operation.

  In the first processing step S100 in this flow, the indoor unit control unit 53 receives the cooling operation start command and starts the cooling operation. In the next processing step S101, the indoor unit control unit 53 instructs the motor control unit 52 of the drain pump 10 to operate the drain pump 10 at a low speed. The low speed operation is an operation that is operated at a lower rotational speed than the rated operation, and is set at, for example, 10 to 30% of the rated rotational speed, and instructs to perform an operation at about 20% in the following embodiments. Shall.

  Further, the indoor unit control unit 53 determines whether or not the drain pump 10 is idling using the detection signal of the idling operation detection unit 54 in processing step S102. If the idling operation is present, the indoor unit control unit 53 proceeds to the processing of processing step S103. If there is no operation, the process proceeds to processing step S104.

  When there is no idle operation, the drain water 91 is considered to be at a sufficient level or more, and therefore the indoor unit control unit 53 stops the low speed operation so far and shifts to the rated operation in the processing step S104. In process step S105, the rated operation is continued thereafter.

  In the case of idling, the drain water 91 is considered to be below a sufficient level. There are several processes in process step S103 as processes in this case. One of them is to continue the low speed operation of the drain pump 10 as shown in the processing step S103A. In this case, since the indoor unit continues the cooling operation, the drain water 91 when the indoor air 90 is cooled by the heat exchanger 20 is accumulated in the drain pan 11 as time passes. This is a process in which the drain pump 10 is expected to return to the rated operation in the determination of the processing step S102 of the flow 3. During the low-speed operation period of the drain pump 10, the chatter noise of the float can be prevented because of the low-speed operation.

  The other processing when the idle operation is present and the drain water 91 is below a sufficient level is to stop the low speed operation of the drain pump 10 and restart the low speed operation after a predetermined time as shown in the processing step S103B. The processing in this case also expects the accumulation of drain water 91 due to the continuous cooling operation of the indoor unit, and the drain pump 10 is stopped for a period until a certain time has elapsed. In this case, since the drain pump 10 is stopped, the chatter noise of the float does not occur.

  Some methods of processing step S103 are shifted to the rated operation after waiting for the accumulation of drain water 91 due to the continuous execution of the cooling operation of the indoor unit.

  According to the first embodiment of the present invention, it is possible not only to reduce wasteful power consumption but also to generate float chatter noise by preventing idle operation of the drain pump without newly adding a lower limit water level detection means. Can be prevented.

  In the case of the present invention, the number of revolutions for detecting the idle operation is the minimum necessary for detecting the idle operation, which is effective in preventing chatter noise and reducing power consumption, but consumes a little electric power. Yes. On the other hand, although it depends on the amount of water retained in the drain pan 11 and the amount of generated drain water, it usually takes 10 minutes or more for the idling state, that is, for the drain water 91 to become full from a very small amount.

  About this point, when employ | adopting the system of process step S103B, the driving | running | working for the idle driving | running | working detection in the drainage apparatus 50 will be performed intermittently. In the case where the idling operation is continuously detected, it is possible to further suppress the power consumption necessary for detecting the idling operation by performing the sensing operation intermittently. Even with such a configuration, a drainage device capable of preventing idling can be provided.

  Also, in this example, the presence or absence of idling is detected during low-speed operation, but the operation shifts to rated operation to detect the presence or absence of idling, and if there is idling, return to low-speed operation (or stop) When there is no idle operation, the rated operation may be continued as it is.

  In the second embodiment, an example of specific means for realizing the idle driving detection unit 54 in FIG. 2 will be described. In Example 2 shown in FIG. 4, attention is paid to the current flowing through the load of the drive motor of the drain pump 10.

  In order to drive the drain pump 10, a DC low voltage motor 15 is used in order to reduce power consumption. The DC motor 15 is driven by a motor control unit 52 that has received a voltage (or current) command from the indoor unit control unit 53, and the motor control unit 52 detects a current flowing through the load of the DC motor, Information from the rotational speed detecting means 56 for detecting the rotational speed of the DC motor is used as a feedback signal, and the DC motor is controlled to have a predetermined rotational speed by an adjustment calculation based on a difference signal from the target setting signal. .

  For example, in the state of the drain pump low-speed operation after starting the cooling operation, the voltage (or current) command from the indoor unit control unit 53 is, for example, about 20% during the rated operation, and as a result, the current flowing to the load of the DC motor Also, the feedback signal such as the rotational speed of the DC motor should also hold a value of about 20% of its rated value.

  At this time, when idling, i.e., driving with no load, the current value detected by the current detecting means 55 is extremely small as compared with the load state. Normally, a value of about 20% corresponding to low-speed operation should be maintained, but an extremely small value is detected compared to this value. In the second embodiment, the idling operation is determined when the measured current I is smaller than the current IL during the low speed operation.

  Therefore, using the current value detected by the current detection means 55, the idle operation itself can be easily detected. However, in order to detect it, it is necessary to drive the motor regardless of the presence or absence of the drain water 91. is there.

  Therefore, in the second embodiment of the present invention, the low speed operation for detecting the idling operation is performed before the actual drainage operation, and the normal operation, that is, the drainage operation is performed only when the current value is equal to or higher than a predetermined current value. It is characterized by that. In the flow of the example of FIG. 3, the low speed operation is instructed to the motor control unit immediately after startup, and the current detected by the current detection means 55 is monitored for a certain period of time immediately after startup in the processing of the processing step S102. When the idle operation is detected (below the predetermined current value IL), the stop of the drainage operation is instructed (processing step S103: stop of the drain pump 10), and when the idle operation is not detected (the predetermined current value IL or more), the drainage is performed. A full-scale start of operation (processing step S104: stop of low-speed operation of drain pump 10 and rated operation) is instructed. By setting it as such a structure, the drainage device which can prevent idle driving | running can be provided.

  In the third embodiment, an example of specific means for realizing the idle driving detection unit 54 in FIG. 2 will be described. In Example 3 shown in FIG. 5, attention is paid to the rotation speed increase / decrease command given by the indoor unit control unit 53.

  In FIG. 5, the indoor unit control unit 53 receives the rotational speed information 57a obtained by the rotational speed detection means 56, collates a predetermined rotational speed 57c set in advance with the actual rotational speed 57a, and determines the rotational speed information. The increase / decrease command 57b is fed back to the motor control unit 52 so as to be controlled to a predetermined rotational speed.

  In the processing of the indoor unit control unit 53, the rotation speed information 57a uses a pulse wave, and the rotation speed increase / decrease command 57b uses a voltage value (referred to herein as a speed command voltage). In such a configuration, the speed command voltage increases as the load increases at the same rotation speed. For example, in the state of the drain pump low-speed operation after starting the cooling operation, the predetermined rotational speed 57c in the indoor unit control unit 53 is, for example, about 20% during the rated operation.

  On the other hand, in the idling operation, that is, the operation with no load, the rotation speed is about 20%, but the speed command voltage fed back to the motor control unit 52 is small because the load is small. That is, the idling operation can be detected using the rotation speed increase / decrease command information 57b.

  According to the third embodiment of FIG. 5, it is also easy to provide the idling operation detection unit 54 outside the drainage device 50, that is, on the indoor unit control unit 53 side. In many cases, since the drainage device 50 is an outsourced product, it may be difficult to change the design after the specification of the motor control unit 52 is determined. In this regard, since the indoor unit control unit 53 is normally a product designed in-house, there is an advantage that it is possible to easily change the rotation speed for detecting the idling operation and the threshold value for judging the idling operation. Even with such a configuration, a drainage device capable of preventing idling can be provided.

  In the fourth embodiment, an example of specific means for realizing the idle driving detection unit 54 in FIG. 2 will be described. In Example 2 shown in FIG. 6, attention is paid to the current waveform of the current flowing through the load of the drive motor of the drain pump 10.

  In the fourth embodiment of the present invention, a pulsation current calculation unit that calculates current disturbance (pulsation value) from the current waveform obtained by the current detection means 55 is provided, and the idling operation is determined from the calculated pulsation amount. The pulsation component included in the current waveform is characterized by the fact that the pulsation of the current is very small compared to when there is a load because the air is only stirred in the idle operation, that is, in the no-load state. This method is particularly suitable when the difference due to the presence / absence of the load is larger than the determination based on the simple average current magnitude (Example 2 in FIG. 4).

  Furthermore, if the presence / absence of a load is determined by combining two variables of the current magnitude (average value) and the pulsation amount, the determination can be made with higher accuracy. For example, as a discrimination method combining two variables, an RT method using Mahalanobis distance is well known.

  The pulsation amount can be calculated by simply calculating from the difference between the maximum and minimum values in a predetermined time, or using a bandpass filter for the rotational frequency component determined from the number of rotations of the pump or the number of rotations × the number of blades. The method of extracting is mentioned. Even with such a configuration, a drainage device capable of preventing idling can be provided.

10: Drain pump 11: Drain pan 12: Float switch 13: Float shaft 14: Stopper 15: Drain hose 16: Mounting plate 20: Heat exchanger 21: Housing 22: Electrical box 23: Fan motor 24: Turbo fan 25: Suction port 26: suspension rod 28: outlet 50: drainage device 51: water level detection means 52: motor control unit 53: indoor unit control unit 54: idle operation detection unit 55: current detection means 56: rotation speed detection means 57a: rotation Number information 57b: Rotational speed command voltage 91: Drain water 27: Panel

Claims (6)

An indoor unit of an air conditioner including a drain water drainage device including a drain pump for draining drain generated by cooling operation by a heat exchanger in a housing,
During the cooling operation of the indoor unit, the drain pump is operated at a low speed that is lower than the rated operation to detect whether or not the drain pump is idling, and when there is idling, the drain pump is set to a rated operation. An indoor unit of an air conditioner, wherein the drain pump is shifted to a rated operation when no idle operation is performed and no transition is made. An indoor unit for an air conditioner according to claim 1,
An indoor unit of an air conditioner, wherein the low-speed operation of the drain pump is continuously executed when the drain pump is idling. An indoor unit for an air conditioner according to claim 1,
When the drain pump is idle, stop the drain pump, re-execute the low-speed operation of the drain pump after a predetermined time, and detect whether the drain pump is idle during the low-speed operation again An air conditioner indoor unit. The indoor unit for an air conditioner according to any one of claims 1 to 3,
An indoor unit of an air conditioner that detects whether or not the drain pump is idling during low-speed operation from the magnitude of a load current of a drive motor for the drain pump. The indoor unit for an air conditioner according to any one of claims 1 to 3,
For the drain pump drive motor, the rotational speed is determined by a rotational speed increase / decrease command determined by comparing a predetermined rotational speed with an actual rotational speed, and the magnitude of the rotational speed increase / decrease command Thus, the indoor unit of an air conditioner that detects whether or not the drain pump is idling during low-speed operation. The indoor unit for an air conditioner according to any one of claims 1 to 3,
An indoor unit of an air conditioner that detects whether or not the drain pump is idling during low-speed operation from the magnitude of a pulsating current included in a load current of a motor for driving the drain pump.

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