JPS6354547A - Air conditioner - Google Patents

Abstract

PURPOSE:To allow a steady operation if the fan speed is changed by a room fan speed selecting switch by changing the operation frequency of a compressor. CONSTITUTION:When the room fan speed is switched by the operation of a room fan speed selecting switch 100, a controller determines a change of frequency. The frequency signal is inputted to a frequency converter 300, where the frequency is changed to change the speed of a compressor 400. That is, if the fan speed has been dropped, the operation frequency is changed in accordance with the fan speed change, and, if the fan speed change is large, a reduction of the operation frequency becomes larger according to the fan speed change step because if the fan speed change is larger, the increase of load of the compressor 400 becomes also larger. Because of this, a sudden change of load of the compressor 400 due to the fan speed change can be controlled, allowing a steady operation in which there is no torque deficiency of the compressor 400.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air conditioner that changes the rotational speed of a compressor based on an air conditioning load.

[Conventional technology]

Conventional air conditioners that change the rotation speed of the compressor based on the air conditioning load change the rotation speed of the compressor depending on the difference between the room temperature and the set temperature, as shown in Japanese Patent Laid-Open No. 60-101440, for example. There is.

FIG. 5 is an example of control of a conventional air conditioner. The difference between the room temperature and the set temperature is divided into a plurality of zones 2) to Z7, and the operating frequency of the compressor is made to correspond to each zone Z1 to Z7 as shown in Table 1 below. As described above, in the past, the operating frequency was determined only by the difference between the room temperature and the set temperature.

[Table 1] [Problems to be solved by the invention] As described above, conventional air conditioners change the operating frequency only depending on the difference between the room temperature and the set temperature. If the speed is changed, especially when the fan speed is reduced during heating, the frequency will not change even if the load on the refrigeration cycle suddenly increases.

If the operating frequency is kept constant during such a sudden load change, there is a problem that the compressor torque cannot keep up with the increase in load and the compressor stops due to insufficient torque.

This invention was made to solve this problem, and provides an air conditioner that can operate stably without causing a compressor torque shortage even if the user suddenly changes the indoor fan speed. The purpose is to

[Means for solving problems]

The air conditioner according to the present invention is provided with a frequency conversion device that changes the frequency when an indoor fan speed changeover switch is switched, and a control device that provides a frequency signal to the frequency conversion device.

[Operation] In this invention, when the indoor fan speed is changed by operating the indoor fan speed changeover switch, the control device determines frequency variation, gives a frequency signal to the frequency conversion device, and causes the frequency conversion device to change the frequency. Change the rotation speed of the compressor.

〔Example〕

Embodiments of the air conditioner of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the basic configuration of one embodiment. In FIG. 1, when the user operates the indoor fan speed changeover switch 100, the frequency determination means 200 receives input from the indoor fan speed changeover switch 100, and determines the operating frequency of the pressure m machine 400. Output the determined operating frequency to the frequency converter 300,
The frequency converter 300 controls the operating frequency of the compressor 400, that is, the rotation speed.

FIG. 2 shows a refrigeration cycle and a control circuit showing the configuration of a specific embodiment of the present invention based on the block diagram of FIG. 1.

In FIG. 2, the same parts as in FIG. 1 will be described with the same reference numerals. In this FIG. 2, a compressor 400, a four-way valve 2, an indoor heat exchanger 3. Throttle device 4, outdoor heat exchanger 5
are connected to form a refrigeration cycle.

An indoor fan 6 is provided adjacent to the indoor heat exchanger 3, and this indoor fan 6 is driven by an indoor fan moke 8. B's indoor fan motor 8
is adapted to be driven and controlled by a control device 14.

The control device 14 includes an indoor fan speed selector switch 100.
is connected. This control device] 4 guides the signal from the indoor fan speed selector switch 100 as an input to a microcomputer, and corresponds to the frequency determining means 200 in FIG. It operates the indoor fan motor 8 and outputs a frequency determination signal to the frequency conversion device 300.

A DC voltage obtained by rectifying the voltage of the AC TI source 10 by a rectifier circuit 11 is applied to the frequency converter 300.
The frequency conversion device 300 continuously varies the output frequency and applies it to the compressor motor 13, thereby changing the rotation speed of the compressor motor 13.

Further, an outdoor fan 7 is disposed adjacent to the outdoor heat exchanger 15, and this outdoor fan 7 is connected to an outdoor fan motor 9.
It is designed to be driven by

Next, the operation of the air conditioner of the present invention having the above configuration will be explained.

Since this invention has a great effect during heating, the operation during cooling operation will be omitted and only the heating operation will be explained.

In FIG. 2, during heating operation, the refrigerant discharged from the compressor 400 passes through the four-way valve 2, is condensed in the indoor heat exchanger 3, and radiates heat toward the indoor side. Thereafter, the pressure is reduced by the throttle device 4, evaporated by the outdoor heat exchanger 5, and then passed through the four-way valve 2 again and sucked into the compressor 400, forming a cycle.

In this case, if the indoor fan 6 operates at a constant speed and a constant air volume, the refrigeration cycle system will be stable, but if the user operates the indoor fan speed changeover switch 100, the indoor heat exchange amount will suddenly change. As a result, the stability of the cycle is disrupted.

When the speed of the indoor fan 6 is rapidly decreased, the amount of air passing through the indoor heat exchanger 3 decreases, and the amount of heat exchange decreases, so that the condensing pressure increases and the compressor load rapidly increases.

When the compressor load increases rapidly, the compressor torque may become insufficient depending on the load conditions, and the compressor 4. There may be cases where OO stalls and stops.

In order to respond to this, it may not be enough to detect a sudden increase in load and reduce the load in time. We must try to reduce the load.

This invention aims to reduce the load when the fan speed changes by lowering the frequency, and the microcomputer program of the control device 14 is provided with a frequency determining means 200 that varies the frequency when the indoor fan speed changes.

The operation flowchart 1 of this program is shown in FIG. In this Figure 3, the fan speed setting value of the indoor fan speed changeover switch 100 is inputted in step 20, and compared with the previous fan speed, and if the fan speed has not decreased in step 2), the operating frequency is changed. I won't let you.

If the fan speed has decreased in step 2), the operating frequency is changed in steps 22 to 26 in accordance with the change in fan speed. If the fan speed change is large, the compressor load increase will also be large, so the reduction in operating frequency is also increased in accordance with the fan speed change step.

That is, in step 22, the instruction to change the indoor fan speed changeover switch "00" by one step is issued.
Step 3 lowers the operating frequency to GHz.

Further, in step 22, if the indoor fan speed selector switch 100 has not changed by one step, step 22
4, if the indoor fan speed changeover switch 100 changes, the operating frequency is lowered to "j2 Hz" in step 25.

Furthermore, if there is no change in the step of the indoor fan speed changeover switch 100 in step 24, step 2
6, the operating frequency is reduced to Xa Hz.

In the case of this flowchart 1, the operating frequency x1~)J is set as l"t<, c<b. The component force for changing the operating frequency.

M, Th is the compressor 40 for each fan speed step change.
An appropriate value is set so that the zero load is reduced and the compressor 400 does not stall.

In the above embodiment, the frequency determining means determines the frequency change according to the fan speed change, but if there is no problem with the compressor other than a significant decrease in fan speed, the flowchart in FIG. The same effect can be obtained by performing the following actions.

That is, when the fan speed decreases, the operating frequency is decreased in step 28 only when the change in fan speed is equal to or greater than a certain value in step 27.

〔Effect of the invention〕

As explained above, this invention changes the operating frequency of the compressor when the fan speed changes using the indoor fan speed selector switch, thereby suppressing sudden changes in the load on the compressor due to changes in fan speed. This has the effect of providing stable operation without causing a compressor torque shortage.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of the air conditioner of the invention of B, and FIG. 2 is a block diagram showing the specific configuration of an embodiment of the air conditioner of this invention based on the block diagram of FIG. 1. 3 is a flowchart 1 showing the flow of operation of the air conditioner mentioned above, FIG. 4 is a flowchart showing the flow of operation of another embodiment of the air conditioner of the present invention, and FIG. It is a figure showing an example of control of an air conditioner. 2 Four-way valve, 3 Indoor heat exchanger, 5 Outdoor heat exchanger, 6
Indoor fan, 7 Outdoor fan, 8 Indoor fan motor, 9 Outdoor fan motor, 13 Compressor motor, 1
4 Control device, 100 Indoor fan speed changeover switch, 200 Frequency determining means, 300 Frequency conversion device, 400 Compressor Note that the same reference numerals in the drawings indicate the same or corresponding parts. Agent Masuo Otou (2 others) Figure 1 Figure 3 Figure 4 Sister - Vagina ”51

Claims (3)

[Claims] (1) An indoor fan speed selection switch and a frequency conversion device that changes the rotation speed of the compressor by changing the frequency;
a frequency determining means for determining the operating frequency of the compressor when the indoor fan speed is changed by the indoor fan speed changeover switch, and outputs a signal corresponding to the determined operating frequency to the frequency converter to compress the compressor. An air conditioner characterized by comprising: a control device that controls the number of rotations of the air conditioner. (2) The air conditioner according to claim 1, wherein the frequency determining means determines the frequency change according to the difference in fan speed before and after the fan speed is changed. (3) The air conditioner according to claim 1, wherein the frequency determining means varies the frequency when the difference in fan speed before and after the fan speed is changed exceeds a certain value.