WO2002004874A1

WO2002004874A1 - Air conditioning system

Info

Publication number: WO2002004874A1
Application number: PCT/JP2001/006065
Authority: WO
Inventors: Norihiro Takenaka
Original assignee: Daikin Industries, Ltd.
Priority date: 2000-07-12
Filing date: 2001-07-12
Publication date: 2002-01-17
Also published as: JP2002022243A; JP4650649B2; AU2001269514A1

Abstract

Headwind (R) is detected based on the deviation between the detected rotation speeds of motors (11, 12) for driving blowers (7, 8) and a target rotation speed. At a strong headwind, an operation is shifted to a headwind mode to stop the driving of the blowers (7, 8) and allow them to be naturally rotated by headwind (R). Air streams (R1) by the headwind (R) flow through a duct (3) to ensure an air volume passing through a heat exchanger (6) and radiation fins (9).

Description

Specification

Air Conditioner Technical Field

The present invention relates to an air conditioner that sends air to a heat exchanger by a blower. Background art

For example, an air conditioner installed outdoors has a blower that rotates in a certain direction to send air to an air passage including a heat exchanger. As this type of blower, there is an air-conditioner type that controls a target rotation speed in accordance with the temperature of outside air.

By the way, air conditioners are sometimes installed on the rooftop of buildings or in places where strong winds tend to blow. In this case, the blower may be exposed to headwind. In the case of a weak headwind, it is possible to maintain the motor speed at the target speed simply by slightly increasing the load of the motor speed, which is sufficient.

However, it is difficult to maintain the target speed during strong headwinds. For this reason, the volume of air passing through the heat exchanger decreases, and the heat exchange capacity decreases.

In addition, usually, radiation fins for cooling the components of the control circuit are arranged in the air path of the air conditioner. In the case of strong headwind, the airflow to the radiating fins is reduced, so the protection circuit may be activated and the compressor may stop.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an air conditioner capable of suppressing a decrease in heat exchange capacity at the time of a headwind and improving reliability. is there. Disclosure of the invention

Means taken by the present invention to achieve the above object are as follows.

The first invention includes a blower for sending wind to an air passage including a heat exchanger, a backwind detection unit, and a blower control unit having a backwind mode for controlling the blower according to a signal from the backwind detection unit. I have. Here, the backward wind is the wind flowing in the direction opposite to the normal blow direction (forward direction) of the blower. In the present invention, by stopping or rotating the blower in the reverse wind mode, it is possible to use the reverse wind to flow air in the direction opposite to the normal flow to the heat exchanger. As a result, the heat exchange capacity of the heat exchanger can be maintained even in the case of a headwind, and it is possible to prevent the occurrence of a situation in which the compressor stops operating.

A second invention is based on the first invention, and further comprises a rotation speed detecting means for detecting a rotation speed of a motor driving the blower. Then, the blower control means has a normal mode for bringing the mode closer to the target rotation speed. The headwind detecting means includes a means for detecting a headwind based on a deviation between the detected rotation speed and the target rotation speed.

According to the present invention, a headwind can be detected using a sensor originally provided to control the rotation speed of the motor. As a result, there is no need to newly provide a headwind detecting means, and the structure can be simplified.

In a third aspect based on the first aspect, the backwind detection means includes a means for detecting a backwind with a current value of a motor that drives the blower. During strong headwinds, the motor load increases to maintain the motor speed at the target speed, and the current flowing through the motor increases. Therefore, the strong wind is detected by focusing on this current value. Since the motor current is originally used for motor control, headwind can be easily detected without complicating the structure.

In a fourth aspect based on the first, second or third aspect, the blower control means is configured to stop the blower in a reverse wind mode.

In the present invention, by stopping the blower, the headwind passes through the heat exchanger while rotating the blower in the reverse direction. Therefore, the heat exchange capacity of the heat exchanger can be maintained without applying unnecessary load to the blower.

In a fifth aspect based on the fourth aspect, the blower control means restarts the motor based on the reverse rotation speed of the blower detected during the backward wind mode and returns to the normal mode.

In the present invention, when the headwind stops during the blowing mode, the mode is returned to the normal mode. As a result, the headwind mode does not continue until unnecessary.

According to a sixth aspect, in any one of the first to fifth aspects, a plurality of blowers are provided in parallel. At the same time, a motor, rotation speed detecting means and blower control means are provided for each blower.

According to the present invention, even when a plurality of blowers are provided in parallel, the same operation and effect as any of the first to fifth inventions can be obtained.

A seventh invention is configured such that, in accordance with the sixth invention, when any of the blower control means shifts to the reverse wind mode, the remaining blower control means also shifts to the reverse wind mode.

It is assumed that one of the blowers is rotated in the reverse wind mode by a reverse wind or the like, and the remaining blowers are rotating forward. In this case, an air current drifts due to the short circuit between the blowers rotating in opposite directions. As a result, there is a possibility that the amount of ventilation to the heat exchanger will be insufficient. On the other hand, in the present invention, since all the blower control means shift to the reverse wind mode, the short circuit does not cause the shortage of the ventilation volume.

In an eighth aspect based on the sixth aspect, when a state in which any of the blower control means shifts to the reverse wind mode continues for a predetermined time, the remaining blower control means also shifts to the reverse wind mode.

Originally, the wind direction and wind speed of the wind blowing outdoors tend to fluctuate. Therefore, in the present invention, all blowers are stopped or the like after checking the state of the headwind for a predetermined time, so that thorough care is taken. 9 The ninth invention is directed to the sixth invention in which a backwind detecting means is provided for each blower in accordance with the sixth invention.- Depending on the situation of surrounding obstacles, etc., a considerable amount of headwind is received by each blower. According to the present invention, even if any blower receives a strong headwind, this can be detected.

In a tenth aspect based on the ninth aspect, each of the blower control means shifts to the reverse wind mode independently of each other according to a signal from the corresponding reverse wind detection means.

In the present invention, the blower that has received a strong headwind is controlled in the headwind mode independently of the other blowers. According to a eleventh aspect of the present invention, in the tenth aspect, each blower control means shifts to the reverse wind mode in a state where another blower control means is stopped in the normal mode or the reverse wind mode. .

Even in the normal mode, the operation of some blowers may be stopped to save energy. According to the present invention, even in such a case, the operating blower can shift to the backward wind mode. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic cross-sectional view showing an internal configuration of an air conditioner according to an embodiment of the present invention, in which a blower blows forward air into a housing.

FIG. 2 is a block diagram showing an electric configuration of the blower control.

FIG. 3 is a flowchart showing the flow of the blower control.

FIG. 4 is a schematic cross-sectional view of the air conditioner showing a state in which the operation of each blower is stopped during a strong headwind.

FIG. 5 is a schematic cross-sectional view of an air conditioner in the case where the drive of only some of the blowers is stopped during a strong headwind. BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an air conditioner according to an embodiment of the present invention, which is arranged outdoors. The air conditioner 1 includes a housing 2 as a main body. An air passage 3 is defined in the housing 2. The air passage 3 is opened to the outside by providing an inlet 4 and an outlet 5 on the opposing first surface 3a and second surface 3b of the housing 2, respectively. For example, a fin coil type heat exchanger 6 is disposed in the suction port 4 of the first surface 3a. In the air path 3, a plurality of blowers 6 and 7 are vertically arranged in parallel.

'' The blowers 6 and 7 normally generate a forward airflow F1 so that the outdoor air is sucked into the housing 2 through the heat exchanger 6 and the suction port 4 and discharged from the outlet 5. Is set to As outdoor air passes through heat exchanger 6, heat The exchanger 6 exchanges heat between the refrigerant flowing inside and the outdoor air. Further, in the air passage 3 in the housing 2, a radiation fin 9 is arranged. The radiating fins 9 are for cooling a circuit for controlling inversion (corresponding to the blower control units 14 and 15 described later). An outside air temperature sensor 10 is arranged at a predetermined portion of the housing 2.

The blowers 6 and 7 are driven by motors 11 and 12 composed of DC motors and motors. The rotation speed of each motor 11 and 12 is detected by the speed sensor 13. The speed sensor 13 constitutes a rotation speed detecting means, and constitutes a part of a headwind detecting means. As the speed sensor 13, for example, a DC tacho generator, a pulse generator, a low speed encoder, or the like is used.

Next, the electrical configuration of the blower control will be described with reference to the block diagram of FIG.

In the blower control according to the present embodiment, a method will be described in which a voltage converted to direct current is subjected to pulse width modulation (PWM) to control the voltage to each of the motors 11 and 12 composed of a DC mode. However, the present invention is not limited to this, and may control the AC mode by pulse width control or vector control.

The outside air temperature sensor 10, the speed sensor 13, and the current sensor 16 are connected to the blower control units 14, 15 corresponding to the motors 11, 12, respectively. The blower control units 14, 15 constitute a part of the blower control means, and receive signals from the sensors 10, 13, 16 respectively.

In addition, each of the blower control units 14 and 15 is connected to a modulation unit 18 including, for example, a transistor via a dryino 17. The current value of the electric power supplied to the motors 11 and 12 under the voltage control is detected by the current sensors 16. The detected current values of the current sensors 16 are fed back to the blower control units 14 and 15 corresponding to the motors 11 and 12, respectively.

Each of the blower control units 14 and 15 controls the modulation unit 18 by receiving signals from the outside air temperature sensor 10, the speed sensor 13 and the current sensor 16, respectively. The voltage converted to DC by the rectifier 19 is pulse width modulated by the modulator 18, the applied voltages of the motors 11 and 12 are controlled, and the speeds of the motors 11 and 12 are controlled. Further, each of the blower control units 14 and 15 is provided with a transmission / reception unit 20 for mutually transmitting and receiving a switching signal to a backwind mode described later. An operation signal of the protection circuit is input to each transmitting / receiving unit 20.

Each of the blower controllers 14 and 15 has a normal mode in which the corresponding motors 11 and 12 approach the target rotation speed. The target rotation speed is set based on the outside air temperature detected by the outside air temperature sensor 10. Each of the blower controllers 14 and 15 controls the voltage applied to each of the motors 11 and 12 according to the deviation between the rotation speed detected by the corresponding speed sensor 13 and the target rotation speed. The normal mode includes a case where only some of the fans 7 and 8 are driven and the remaining fans 7 and 8 are stopped to save energy.

Each of the blower control units 14, 15 constitutes a part of the backwind detecting means, and detects the strength of the backwind based on a deviation between the rotation speed detected by the corresponding speed sensor 13 and the target rotation speed. I do. Then, for example, each of the blower controllers 14 and 15 shifts to a headwind mode in which the blowers 7 and 8 are stopped in response to detection of a strong headwind. However, in the reverse wind mode, each of the blowers 7, 8 may be driven in the reverse rotation direction.

It is to be noted that the value of the current flowing through each motor 11 and 12 may be used to detect the headwind without using the above-described deviation of the rotation speed. In other words, during strong headwinds, the loads on motors 11 and 12 increase to maintain motors 11 and 12 at the target speed. Therefore, the value of the current flowing through motors 11 and 12 increases, and this current value is detected to detect a headwind. Since the current values of the motors 11 and 12 are originally used for the control of 11 and 12, the headwind can be easily detected without complicating the structure. Next, the flow of the blower control will be described with reference to the flowchart of FIG.

During the normal mode in which each of the blowers 7, 8 is operating, the strength of the headwind received by each of the blowers 7, 8 is monitored individually (step S1). If a headwind exceeding the specified intensity is detected, the mode is switched to the headwind mode, provided that the protection circuit is activated (step S2). After the cessation of all blowers 7, 8 to confirm whether it is set (step S ^3), it stops the driving of all of the blower 7, 8 (step S4).

As a result, as shown in Fig. 4, the normal flow to heat exchanger 6 is The airflow R1 can flow in the direction opposite to the direction of the airflow. As a result, it is possible to maintain the heat exchange capacity of the heat exchanger 6 by securing the air flow to the heat exchanger 6 even in the case of a strong head wind. As a result, a situation in which the compressor is stopped can be avoided.

During the headwind mode, the strength of the headwind is monitored by the blowers 7, 8 based on the rotation speed in the reverse direction (step S5). When the headwind falls below the predetermined strength, the mode shifts to the normal mode and all the blowers 7, 8 are restarted (step S6).

On the other hand, if it is determined in step S3 that the stop of only some of the blowers 7 (or 8) is set, the drive of only some of the blowers 7 (or 8) is stopped (step S7). A predetermined time (for example, T seconds) elapses based on the number of reverse winds received by the blower 7 (or 8) that has stopped driving, based on the number of rotations of the blower 7 (or 8) in the reverse direction. Monitoring (Steps S8, S9). If the strong headwind stops during monitoring, the mode switches to the normal mode, restarts the blower 7 (or 8) whose driving has been stopped, and returns to the last sword (steps S8, S10, S1). ).

If the strong wind does not stop during the monitoring in steps S8 and S9 and the above-mentioned predetermined time has elapsed, the blower 8 (or 7) operating in the normal mode is also shifted to the backwind mode, and all the blowers are operated. Stop 7, 8 (Steps S8, S9, S4). This embodiment has the following advantages.

Even in the case of a strong head wind, the amount of air flow to the heat exchanger 6 can be secured, and the heat exchange capacity of the heat exchanger 6 can be maintained. As a result, the situation of stopping the compressor can be avoided.

Since the backwind can be detected using the speed sensor 13 originally provided for controlling the rotation speed of the motors 11 and 12, the structure can be simplified without the necessity of providing a new backwind detecting means. The same applies to the case where a method of detecting headwinds using the current values of motors 11 and 12 is adopted.

Since the blowers 7 and 8 are stopped in the reverse wind mode and entrained by the backward wind, the heat exchange capacity of the heat exchanger 6 can be maintained without applying unnecessary load to the blowers 7 and 8.

If the strong wind stops during the ventilation mode, the mode returns to the normal mode, and the headwind mode does not continue until it is unnecessary. Further, when one of the blowers 7 or 8 stops in the reverse wind mode, the remaining blowers 8 also stop, so that the short circuit does not cause a shortage of air flow.

That is, as shown in FIG. 5, it is assumed that one of the blowers 7 is rotated in the reverse wind mode by the reverse wind R, and the remaining blowers 8 are driven to rotate forward. In this case, a short circuit 21 causes a drift between the airflows R1 and F1 of the blowers 7 and 8 rotating in opposite directions. As a result, there may be a shortage of air flow to the heat exchanger 6. On the other hand, in the present embodiment, shortage of air flow due to the short circuit can be prevented.

The wind direction and wind speed of the wind blowing outdoors are variable. In the present embodiment, as shown in Steps S8 and S9, all the blowers 7, 8 are stopped for a predetermined time after observing the headwind, so that the blowers are not inadvertently stopped. I have to.

Depending on the surrounding obstacles, there is a considerable difference in the headwind received by each blower 7,8. In the present embodiment, since the back wind detecting means is provided for each of the blowers 7, 8, even if any of the blowers 7, 8 receives a strong back wind, this can be detected. Further, the blower 7 (or 8) that has received a strong headwind can shift in the headwind mode independently of the other blowers 8 (or 7).

In addition, since a decrease in the air volume to the radiation fins 9 can be suppressed, the operation of the protection circuit can be prevented, and the stop of the compressor can be prevented.

In addition, since a predetermined amount of air flows through the motors 11 and 12, the motors 11 and 12 can be reliably cooled.

The present invention is not limited to the above embodiment. For example, in a normal mode, some blowers may be stopped for energy saving. Even in such a case, it is possible to allow the operating blower to shift to the reverse wind mode. In addition, various changes can be made within the scope of the present invention. Industrial applicability

As described above, the air conditioner according to the present invention is useful when placed outdoors, and is particularly suitable when the blower is exposed to strong headwinds.

Claims

The scope of the claims

1. A blower (7, 8) for sending air to an air passage (3) including a heat exchanger (6);

Headwind detection means (13, 16);

A blower control means (14, 15) having a backwind mode for controlling the blower (7, 8) according to a signal from the backwind detection means (13, 16)

An air conditioner characterized by the above-mentioned.

2. In Claim 1,

A rotation speed detecting means (13) for detecting the rotation speed of the motor (11, 12) for driving the blower (7, 8);

The blower control means (14, 15) has a normal mode in which the motor (11, 12) approaches the target rotation speed,

The headwind detection means (13, 16) includes a means for detecting headwind based on the deviation between the detected rotation speed and the target rotation speed.

An air conditioner characterized by the above-mentioned.

3. In claim 1,

The backwind detecting means (13, 16) includes means for detecting a backwind (R) based on a current value of a motor (11, 12) for driving the blower (7, 8).

An air conditioner characterized by the above-mentioned.

4. In Claim 1, 2 or 3,

The blower control means (14, 15) stops the blower (7, 8) in the reverse wind mode

An air conditioner characterized by the above-mentioned.

5. In Claim 4,

The blower control means (14, 15) detects the blower (7, 8) detected during the reverse wind mode. An air conditioner characterized by restarting the motor (11, 12) based on the reverse rotation speed of the motor and returning to the normal mode.

6. In Claim 2,

With multiple blowers (7, 8) installed in parallel,

Motors (11, 12), rotation speed detection means (13), and blower control means (14, 15) are provided for each of the blowers (7, 8).

An air conditioner characterized by the above-mentioned.

7. In Claim 6,

When one of the blower control means (14, 15) shifts to the reverse wind mode, the other blower control means (, 14) also shifts to the reverse wind mode.

An air conditioner characterized by the above-mentioned.

8. In Claim 6,

An air conditioner characterized in that, when a state in which one of the blower control means (14, 15) shifts to the reverse wind mode continues for a predetermined time, the remaining blower control means (15, 14) also shifts to the reverse wind mode.

9. In Claim 6,

Backflow detection means (13, 16) are provided for each blower (7, 8).

An air conditioner characterized by the above-mentioned.

10. In claim 9,

Each of the blower control means (14, 15) shifts to the reverse wind mode independently of each other according to the signal from the corresponding reverse wind detection means (13, 16).

An air conditioner characterized by the above-mentioned.

1 1. In claim 10,

Each of the blower control means (14, 15) is characterized in that, in a state where the other blower control means (15, 14) is stopped in the normal mode or the reverse wind mode, there is a case where the mode shifts to the reverse wind mode. Air conditioner.