JP2875576B2 - Air conditioner - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a duct type air conditioner that controls room temperature by controlling the air flow to each room to be air-conditioned.

2. Description of the Related Art A conventional example will be described below with reference to the drawings.

FIG. 4 is a schematic diagram showing an example of a conventional air conditioner. Reference numeral 1 denotes an indoor unit main body, an indoor side blower 2 therein, and a blower controller for controlling an operation frequency of the indoor side blower 2.
2a, an indoor heat exchanger 3, and an indoor expansion valve 4 for expanding the refrigerant. 5 is an outdoor unit main body and has a compressor 6 inside.
Outdoor heat exchanger 7, outdoor blower 8, outdoor expansion valve 9,
Frost detector 1 for detecting the amount of frost on the outdoor heat exchanger 7
0, a defrost controller 11 for controlling start and end of the defrost operation is provided.

A duct 12 is provided from the indoor-side blower 2 to the room to be air-conditioned 13. In the middle of duct 12, variable air volume unit 14
Is installed. The variable air volume unit 14, a damper 14a inside, a motor 14b for driving the damper 14a
And an air volume controller 14c for controlling the motor 14b. In the air-conditioned room 13, a temperature controller 15 having an indoor temperature setter 15a and an indoor temperature detector 15b is provided.
Is arranged.

A pressure detector 16 for detecting the external static pressure is provided in the duct 12.
And a pressure setting device 16a for setting the external static pressure to be constant.

 Next, the operation will be described.

The hot or cold air blown out from the indoor unit main body 1 passes through the duct 12 and is guided to the room to be air-conditioned 13. The variable air volume unit 14 provided in the middle of the duct 12 is
A known control circuit is configured, and a difference between the temperature set by the room temperature setter 15a in the temperature controller 15 and the temperature detected by the room temperature detector 15b is used to control the air flow controller 1
The motor 14b is driven via 4c to change the opening of the damper 14a to change the passing air flow.

 This will be described below with reference to FIG.

When the air volume changes in the variable air volume unit 14, the external static pressure inside the duct 12 changes, and in step 21, the change is detected by the pressure detector 16 and the blower controller 2a
Thus, the operating frequency of the indoor blower 2 is controlled so that the external static pressure is set to the value set by the pressure setting device 16a.

During the heating operation, it is necessary to perform a defrosting operation in accordance with the frosting of the outdoor heat exchanger 7, and the change in the amount of frosting is detected by the frosting detector 10. In step 22, the frost detector
When the blower controller 2a receives an instruction to start defrosting from the defrost controller 11 according to the detected amount of 10, the operation frequency A of the indoor side blower 2 is read in step 23, and the defrosting is performed in step 24. The frequency of the indoor blower A is maintained and kept constant. Thereafter, when a signal indicating the end of defrost is received from the defrost controller 11 in step 25, the process returns to step 21 again, and the normal static pressure control operation is performed.

Problems to be Solved by the Invention However, in the above configuration, during the defrosting operation, the amount of air blown to the room to be air-conditioned is almost the same as before defrosting, but the temperature of air blown to the room to be air-conditioned at the time of defrost drops sharply. Therefore, when the amount of air blows is large, there is a problem that a sense of cool air is given to the human body in the room to be air-conditioned, and comfort is greatly impaired.

The present invention has been made in view of the above problems, and provides an air conditioner having a function of setting an operating frequency of an indoor-side blower at the time of defrost to a predetermined frequency or less in a variable air volume type air conditioner.

Means for Solving the Problems Therefore, in the air conditioner of the present invention, in addition to the conventional, when receiving a defrost start signal from the defrost controller, when the operating frequency of the indoor blower is equal to or higher than a predetermined frequency, When the operating frequency of the indoor blower during defrosting is changed to a predetermined frequency and kept constant, while the frequency at the start of defrosting is equal to or lower than a predetermined frequency, the frequency is maintained and kept constant during defrosting. It is equipped with a controller for a blower with a cool air prevention function.

Operation The present invention suppresses the amount of air blown to the air-conditioned room to a predetermined amount or less during the defrosting operation in which the temperature of the air blown out to the air-conditioned room is reduced by the above-described configuration, and eliminates the feeling of cool air to the human body in the air-conditioned room. By doing so, comfortable air conditioning is realized.

Embodiment FIG. 1 is a schematic diagram showing an embodiment of the present invention.
This will be described below with reference to the drawings. Components having the same configuration as the conventional example are denoted by the same reference numerals, and detailed description is omitted.

In one embodiment of the present invention, a pressure detector
When the rotation frequency of the indoor blower 2 is controlled by the pressure difference between the pressure controller 16 and the pressure setter 16a to vary the air volume, and the defrost start signal is received from the defrost controller 11, the operating frequency of the indoor blower is reduced. If the frequency is equal to or higher than the predetermined frequency, the indoor blower 2 is being defrosted.
Change the operating frequency to a predetermined frequency and keep it constant during defrosting,
When the frequency at the start of defrosting is equal to or lower than a predetermined frequency, a controller 17 for a blower with a function to prevent cold air at the time of defrosting, which keeps the defrosting intact and keeps it constant, is provided.

Next, the operation will be described with reference to the block diagram of FIG. 18 is a CPU (not shown) for controlling the air conditioner,
The set pressure X internally set by the pressure setter 16a
And a pressure comparator 19 that compares the pressure Y detected by the pressure detector 16 with the pressure Y detected by the pressure detector 16 and a defrosting operation that controls the start and end of the defrosting operation based on the detected amount detected by the frost detection detector 10. Controller
11 built-in. The CPU 18 varies the operating frequency of the indoor blower 2 based on the comparison result of the pressure comparator 19, and changes the operating frequency of the indoor blower 2 according to an instruction from the defrost controller 11.

Next, a specific example of this operation is shown in the flowchart of FIG. Except for the control during the defrosting operation during the heating, the control and the basic operation during the normal operation are the same as those in the conventional example, and thus the description thereof is omitted.

Normally, when the air volume changes with the variable air volume unit 14, the external static pressure inside the duct 12 changes, and in step 31, the change is captured by the pressure detector 16 and the controller 17 The operation frequency of the indoor blower 2 is controlled so that the external static pressure is set to the value set by the pressure setting device 16a. However, in step 32, the defrosting start signal is sent from the defrosting controller 11 to the controller 17
Is received, the operation frequency A of the indoor blower 2 is read in step 33, and whether or not A ≧ B is compared with a predetermined frequency B in step 34;
At 35, the frequency A of the indoor-side blower 2 is changed to B, and is maintained during defrosting to be constant. If A <B, in step 36, the frequency A of the indoor-side blower is maintained as it is during defrosting to be constant. Then, in step 37, the defrost controller
Upon receiving a signal indicating the completion of defrosting from step 11, the process returns to step 31 again to perform a normal static pressure control operation.

As described above, according to the present embodiment, during defrosting, the operating frequency of the indoor-side blower is set to a predetermined value or less, so that the amount of air blown to the room to be air-conditioned is suppressed to a predetermined amount or less, and the blowing air at the time of defrosting It is possible to solve the problem of giving a cool air feeling to a human body in a room to be air-conditioned due to a decrease in temperature, thereby improving comfort.

Effect of the Invention As described above, the rotational speed of the indoor-side blower is controlled by the pressure difference between the pressure detector that detects the pressure in the duct and the pressure setter to vary the amount of air blow, and the defrost controller starts defrosting. When the signal is received, when the operating frequency of the indoor blower is equal to or higher than a predetermined frequency, the operating frequency of the indoor blower during defrosting is changed to a predetermined frequency and is constant during defrosting, and the frequency at the start of defrosting is changed. When the frequency is equal to or lower than a predetermined frequency, by providing a controller for a blower with a cool air prevention function to maintain and maintain a constant level during defrosting, during the defrosting, the amount of air blown to the room to be air-conditioned is set to a predetermined amount or less. The object of the present invention is to achieve a comfortable air conditioning by suppressing the problem of giving a feeling of cool air to the human body in the room to be air conditioned due to a decrease in the temperature of the blown air during the defrosting.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of the configuration of an air conditioner according to one embodiment of the present invention, FIG. 2 is a block diagram showing the operation of the present invention, FIG. 3 is a flowchart showing the operation of a specific example of the present invention, FIG. FIG. 1 is a conceptual diagram of the configuration of a conventional air conditioner (same as FIG. 1), and FIG. 5 is a flowchart showing a conventional operation. DESCRIPTION OF SYMBOLS 1 ... indoor unit main body, 2 ... indoor side blower, 3 ... indoor side heat exchanger, 5 ... outdoor unit main body, 6 ... compressor, 7 ... outdoor heat exchanger, 8 ... outdoor Blower, 10 frost detector, 11 defrost controller, 12 duct, 13 conditioned room, 14 variable air flow unit, 16 pressure detector, 16a
… Pressure setting device, 17… Controller for a blower with a function to prevent cold air during defrosting.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-256160 (JP, A) JP-A-63-129238 (JP, A) JP-A-61-89436 (JP, A) 29741 (JP, U) Japanese Utility Model Showa 56-45737 (JP, U) Japanese Utility Model Showa 56-166416 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24F 11/02

Claims (1)

(57) [Claims] 1. An indoor heat exchanger, a duct-connected indoor unit body having an operation frequency-controlled indoor blower, a compressor, an outdoor heat exchanger, an outdoor blower, and the outdoor heat exchanger A frost detector that detects frost formation on the exchanger, and a defrost controller that controls the start and end of the defrost operation from the amount detected by the frost detector, and a cool air or A duct that sends warm air to the room to be conditioned, a variable air volume unit that varies the air volume in the duct according to the room temperature of the room to be conditioned, and a pressure detector that detects the pressure in the duct; The operating frequency of the indoor blower is controlled by controlling the operating frequency of the indoor blower according to the pressure difference between the air blower and the pressure setter, and varying the amount of air blown, and when a defrost start signal is received from the defrost controller. If the frequency is higher than the specified frequency, Change the rotation frequency to a predetermined frequency, keep it constant during defrosting, and if the frequency at the start of defrosting is less than or equal to the predetermined frequency, keep it constant during defrosting and keep it constant. An air conditioner characterized by comprising a vessel.