JPH04203830A - Air conditioner - Google Patents

Abstract

PURPOSE:To provide an air conditioner capable of reducing the deterioration of cooling capability accompanied by surrounding air temperature rise and capable of increasing a cooling operation capability without shortening the life of some electrical parts by a method wherein when a surrounding air temperature during a cooling operation exceeds a predetermined value, an air volume of an out door blower is increased and at the same time an upper limit value of an electrical current control zone is set higher by a predetermined value. CONSTITUTION:A surrounding air temperature detected by a surrounding air temperature sensing means 6 exceeds a predetermined reference value, 30 deg.C, for example, at the time of (t1), a micro-computer 12b at an outdoor control part 12 increases the number of rotation of an outdoor blower 5, increase an air volume and control an upper limit value in an electrical current control zone of a compressor 3 by a predetermined value. Such a control is carried out, resulting in that even if the surrounding air temperature is high, a cooling effect of the outdoor heat exchanger or electrical parts in the outdoor control device or the like can be increased and the upper limit value in the electrical current control zone is increased up to enable an operating capability of the compressor 3 to be increased and also a cooling capability can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an air conditioner, and more particularly to the operation control of a compressor and an outdoor blower during cooling operation.

[Prior Art] Electric power is supplied to a compressor that constitutes a refrigeration cycle of an air conditioner via a frequency converter that is connected to a commercial power source.

This frequency converter includes a converter section that converts a commercial power supply voltage into a DC voltage doubler, an inverter section that converts the DC voltage doubler from this converter section into three-phase AC power and supplies it to the compressor, and this inverter section. This outdoor control section receives operation command information from the indoor unit and information from the outside air temperature detection means, operating current detection means, etc. provided in the outdoor unit. , the inverter section is controlled by an operating frequency determined based on this information.

By the way, since the operating current of the compressor increases as the load increases and may exceed the rated current, an upper limit value of the operating current is set in advance, and the current value detected by the operating current detection means is set in advance. When the current reaches this preset upper limit, current release control is performed to reduce the operating frequency of the compressor to suppress the increase in operating current.

In addition, the electric components that make up the frequency converter must be carefully monitored for usage conditions, and the lifespan of capacitors in particular is affected by the operating temperature and the magnitude of the current value. When the heat exchanger is air-cooled, it is simultaneously air-cooled, and the upper limit of the compressor operating current is set lower during cooling operation when the outside air temperature is high than that during heating operation when the outside air temperature is low (for example, 18.5 during heating operation). The current release control described above is performed by setting the amperage to 16.0 amperes during cooling operation.

[Problems to be Solved by the Invention] However, as mentioned above, if the upper limit of operating current (current release control value) of the compressor during cooling operation is set lower than during heating operation, the life of electrical components can certainly be extended. However, there is a problem in that sufficient cooling capacity cannot be obtained because the capacity of the compressor cannot be fully utilized.

Therefore, an object of the present invention is to provide an air conditioner that can solve these problems and further improve the cooling operation ability without shortening the life of electrical components.

[Means to solve the problem]

The present invention has been made in order to solve the above-mentioned problems, and it converts commercial power into a frequency converter based on operation command information from the indoor unit and information from outside temperature detection means installed in the outdoor unit. In an air conditioner that converts the frequency and supplies it to a compressor, and controls the input current flowing to the compressor within a preset current control zone, the outside air temperature detecting means controls the input current flowing to the compressor within a preset current control zone during cooling operation. When the detected outside air temperature exceeds a preset value, the air volume of the outdoor blower is increased and the upper limit value of the current control zone is increased by a predetermined value.

[Effect]

With the above configuration, when the outside air temperature exceeds a preset value during cooling operation, the air volume of the outdoor fan is increased and the upper limit of the current control zone used to control the input current of the compressor. Since the value is set higher by a predetermined value, it is possible to further reduce a decrease in cooling capacity due to a rise in outside air temperature, and by increasing the air volume, electrical components can be air-cooled more strongly.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 to 4.

Figure 1 shows the schematic configuration of an outdoor unit of an air conditioner, where 1 is a heath, 2 is a partition plate, 3 is a compressor attached to one side of the heath 1, and 4 is partitioned by a partition plate 2. 5 is an outdoor heat exchanger placed on the other side of 1;
6 is an outdoor air temperature detection sensor, 7 is an outdoor blower that cools
is a frequency conversion device attached to the partition plate 2.

Although not shown, the partition plate 2 to which the frequency converter 7 is attached has a shape that allows ventilation, and the outdoor blower 5
During operation, not only the outdoor heat exchanger 4 but also the compression 41
! 3 and the frequency converter 7 are also air-cooled.

FIG. 2 is a block diagram showing the control system of the outdoor unit. Detection means 9 are provided.

The frequency converter 7 includes a converter unit 10 that converts AC power supplied from a commercial power source 8 into a DC voltage doubler, and converts the DC voltage doubler from the converter unit 10 into three-phase AC power, which is supplied to the compressor 3. The outdoor control section 12 converts analog signals outputted from the outdoor temperature detection means 6 and the operating current detection means 9 into digital signals. The converting A/D converter 12a generates a PWM (pulse width modulation) waveform signal based on A/D converted information on outside air temperature and operating current, operation command information from an indoor unit (not shown), etc. A microcomputer 12b that controls the number of rotations of the outdoor blower 5, and a PWM from this microcomputer 12b.
It is composed of a drive circuit 12c that converts a waveform signal into an inverter drive signal, and the like.

Next, operation control during cooling operation will be explained.

FIG. 3 is a time chart showing an example of the operation control of the present invention, in which the outside air temperature detected by the outside air temperature detection means 6 exceeds a preset reference value, for example, 30°C at the time tl. Then, the microcomputer 12b of the outdoor control unit 12 sends the outdoor signal 1! Ll! 50 rotation speed is increased to increase the air volume, and the upper limit value of the current control zone of the compressor 3 is controlled to be increased by a predetermined value.

FIG. 4 is a flowchart showing the state of this control. When the cooling operation is started in step STI, the process proceeds to step ST2, where the outside air temperature To detected by the outside air temperature detection means 6 and the preset reference value Tc are shown. If the outside air temperature To is equal to or lower than the reference value Tc, the process proceeds to step ST3, and the cooling operation is performed under preset normal operating conditions, but if the outside air temperature To compared in step ST2 is If it exceeds the reference value Tc, the process proceeds to step ST4.

Then, in step ST4, the rotation speed of the outdoor blower 5 is changed to increase the air volume, and the process proceeds to the next step ST5.

In step ST5, the upper limit value of the operating current of the compressor 3, that is, the upper limit value of the current control zone, is increased by a predetermined value to increase the operating capacity of the compressor 3.

In step ST6, the operation is continued under the conditions provisionally set in steps ST4 and ST5 until a predetermined period of time, for example, 30 minutes has elapsed, and when the time is amplified, the process proceeds to step ST7.

In step ST7, the upper limit value of the higher current control zone temporarily set in step ST5 is reset, and then the process proceeds to step ST8, where the air volume of the blower 5, which was temporarily set higher in step ST4, is reset to the normal air volume. , control is made to return to step ST2.

This kind of control can improve the cooling effect of electrical components such as the outdoor heat exchanger and outdoor control section even when the outside air temperature is particularly high, and by raising the upper limit of the current control zone, the compressor operation can be improved. You can improve your abilities.

Note that step ST6 in the flowchart (FIG. 4) described above is not limited to control based on time, and may be determined based on outside temperature, for example, as in step ST2.

[Effects of the Invention] As described above, if the air conditioner is as described above, when the outside air temperature exceeds a predetermined value, the air volume of the outdoor blower is increased and electric components such as the outdoor heat exchanger and the outdoor control unit are activated. In addition to increasing the cooling effect of the compressor, the upper limit of the operating current of the compressor is also controlled to increase, so the operating capacity of the compressor is increased without shortening the life of electrical components, and the cooling capacity is also increased.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an outdoor unit showing an embodiment of the present invention;
Fig. 2 is a block diagram showing the control system of the same embodiment, Fig. 3 is a time chart showing an example of operation control of the same embodiment, and Fig. 4 is a block diagram showing the control system of the same embodiment.
The figure is a control flowchart of the same embodiment. In the figure, 1-base, 2-partition plate, 3-compression edge 4-outdoor heat exchanger, 5-outdoor blower, 6-outside air temperature detection means,
7-frequency converter, 8-commercial power supply, 9-operating current detection means, 10-converter section, 11-inverter section, 1
2-Outdoor control section. Patent applicant Fujitsu General Ltd. Figure 1 Figure 2 Figure 3 tl Time t

Claims (1)

[Claims] Based on the operation command information from the indoor unit and the information from the outside air temperature detection means installed in the outdoor unit, commercial power is frequency-converted by a frequency converter and supplied to the compressor, and at that time, the commercial power is supplied to the compressor. In an air conditioner configured to control input current within a preset current control zone, if the outside air temperature detected by the outside air temperature detection means exceeds a preset value during cooling operation,
An air conditioner characterized in that the air volume of an outdoor blower is increased and the upper limit value of the current control zone is increased by a predetermined value.