JPS62242752A - Operation control unit of air conditioner - Google Patents

Abstract

PURPOSE:To greatly reduce the frosting of an indoor heat exchanger and to increase the range of temperatures during a space cooling operation of the air conditioner by making variable the maximum operational frequency of a compressor during a space cooling operation in the case of a thermostat set temperature being low and both indoor and outdoor temperatures being also low. CONSTITUTION:Firstly, a set value is read in and set, and then an indoor temperature is read in, and the read-in value is compared with the set temperature value to judge whether the former value is larger or smaller than the latter value. When the indoor temperature value is higher than the set temperature value, a first output mode setting the maximum operational frequency of a normal space cooling operation is selected. When the indoor temperature is lower than the temperature set value, a second output mode setting the maximum operational frequency of a value which is smaller than the maximum frequency of the first output mode is selected. A power transistor device 12 produces a three-phase waveform by means of an unequal-width pulse outputted from a microcomputer (LSI) 11, and a compressor 18 is driven at a designated frequency. Further, the frequency-voltage characteristic of the compressor 18 is set depending upon the width and period of the pulse outputted from the LSI 11, and the compressor is operated. Thus, the frosting of the indoor heat exchanger can be greatly reduced, and the using temperature range in the space cooling operation can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an operation control device for an air conditioner equipped with a frequency converter.

Conventional technology In recent years, air conditioners equipped with a frequency converter set the operating frequency according to the thermoset temperature and the indoor temperature detected within the indoor unit during cooling operation, in order to improve efficiency and power saving. There is. In addition, during cooling operation when the thermoset temperature is low and both indoor and outdoor temperatures are low, piping temperature,
There is a function to stop the compressor when the blowout temperature is below zero degrees.

Hereinafter, an example of the above-mentioned conventional air conditioner equipped with a frequency converter will be described with reference to the drawings.

FIGS. 4 and 5 show conventional electrical circuit diagrams and flowcharts.

In Fig. 4, 101 is a temperature detection thermistor provided in the indoor unit body, 102 is a temperature detection circuit, 103 is a resistance circuit for setting zero temperature, 104 is a ratio 11/93, 105 is a microcomputer, and 106 is for a compressor. This is a V-circuit.

The operation of the air conditioner equipped with a frequency converter configured as above will be described below.

First, the temperature detection thermistor 1101 senses the pipe temperature of the indoor heat exchanger, and the temperature detection circuit 102 outputs an electric signal t1 corresponding to the temperature, which is then outputted to the electric signal T1 of the zero temperature setting resistance circuit 103 and the comparator 104 compares and determines the magnitude, and when the electric signal t1 is lower than the electric signal T1 (the pipe temperature is below zero), the microcomputer 105 receives the L output signal from the comparator 104, and the compressor relay circuit 106 The transistor is turned off and the compressor is stopped.

The flowchart shown in FIG. 5 shows the flow described above.

Problems to be Solved by the Invention However, in the conventional configuration, when the thermoset temperature is low and the indoor and outdoor temperatures are low, the suction pressure of the compressor is low due to the high operating frequency during cooling operation and during stable operation. Because it is not possible to improve the phenomenon of frost formation on the indoor heat exchanger,
There was a problem in that the operating temperature range for cooling operation was reduced.

The present invention solves the above-mentioned problems by widening the operating temperature range during cooling operation and significantly improving the temperature M1 of the indoor heat exchanger.

Means for Solving the Problems In order to solve the above problems, the frequency conversion device of the present invention includes a control device for varying the rotational speed of a compressor, a drive means for varying the operating frequency of the compressor, and a cooling device for varying the operating frequency of the compressor. During operation, an indoor temperature detection means detects the indoor temperature or the piping temperature at of the indoor heat exchanger, a variable value storage means stores a variable value temperature, and the temperature detected by the indoor temperature detection means is stored in the variable value storage means. a comparison means that compares and determines the variable temperature values obtained and outputs an output signal of H-L; a plurality of frequency value storage means that stores the maximum value of the operating frequency of the compressor as different values; and an output signal of the comparison means. a calculation means for determining the maximum frequency value of the compressor operating frequency; and a selection output means for determining the frequency value of one of the frequency value storage means as the maximum frequency value of the compressor operation frequency based on the determination result of the calculation means. It is composed of

Effect of the Invention The present invention has the configuration described in the following, so that the maximum operating frequency can be varied during cooling operation when the thermoset temperature is low and both the indoor and outdoor temperatures are low. This can be improved and the operating temperature range of cooling operation can be expanded.

Embodiment Hereinafter, an embodiment of the operation control device for an air conditioner equipped with a frequency converter according to the present invention will be described with reference to the drawings.

FIG. 1 shows a circuit diagram of an operation control device for an air conditioner equipped with a frequency converter according to an embodiment of the present invention.

In Figure 1, 11 is a microcomputer (hereinafter referred to as L).
12 is a power transistor device, 13 is a resistance circuit for temperature setting value, 14 is a thermistor for detecting indoor temperature, 15 is a circuit for detecting indoor temperature, 16 is a comparator, 17 is a power supply, a fuse, a noise filter, A power supply device includes a diode bridge, etc., and 18 is a compressor.

The operation of the operation control device for an air conditioner equipped with a frequency converter configured as described above will be described below with reference to FIGS. 1 to 3.

First, FIG. 2 is a block diagram expressing the control device as a function realizing means, in which the temperature setting resistor circuit 13 shown in FIG.
The indoor temperature detection circuit 16 corresponds to the indoor temperature detection means in FIG. 2, and the comparator 16 shown in FIG. 1 corresponds to the comparison means in FIG. 2. LS shown in Figure 1
A memory circuit built into the comparator 16 that stores the first and second output modes in which different values of the maximum operating frequency are set corresponds to the memory means in FIG. The arithmetic circuit that selects the first and second output modes of the memory circuit corresponds to the arithmetic means in FIG. The power supply device 17 shown in FIG. 1 corresponds to the output means shown in FIG.

Figure 3 is a flowchart showing the operation flow of the operation control device.First, the temperature set value T is read and set, then the indoor temperature tf is read and compared with the set temperature value T, and the indoor temperature If t is higher than the temperature set value T, the first output mode t, which sets the maximum operating frequency for normal cooling operation, is selected; if the indoor temperature t is lower than the temperature set value T, the first output mode t is selected. Select the second output mode in which the maximum operating frequency is set to a value smaller than the maximum frequency of the output mode of 18 at the specified frequency. Also, LSI
Depending on the pulse width and period output from II, the compressor 18
The frequency-voltage characteristics are set and the system is operated.

As described above, according to this embodiment, in an air conditioner equipped with a frequency converter, when the indoor temperature t is lower than the temperature set value T, by varying the maximum operating frequency, the indoor heat exchanger It is possible to significantly improve frost formation and expand the operating temperature range of cooling operation.

Note that a plurality of temperature setting values may be provided and the maximum frequency may be varied accordingly.

Further, similar effects can be obtained even if the functions shown in the conventional example are added to the above embodiment.

Furthermore, in the embodiment described above, control was performed based on the indoor temperature, but the pipe temperature (refrigerant inlet side heating box) of the indoor heat exchanger that constitutes the refrigeration cycle/L' is detected and similarly controlled. You can do it like this.

Effects of the Invention As described above, the present invention provides an air-electric conditioner equipped with a frequency converter by varying the maximum operating frequency according to the indoor temperature or the pipe temperature of the indoor heat exchanger during cooling operation. It has the effect of significantly improving frost formation on the indoor heat exchanger at low temperatures, expanding the operating temperature range of cooling operation, and dramatically improving the feeling during operation.

[Brief explanation of drawings]

Fig. 1 is an electrical circuit diagram of an operation control device for an air conditioner equipped with a frequency converter according to an embodiment of the present invention, Fig. 2 is a block diagram expressing the operation control device as a function realizing means, and Fig. 3 is The flowchart of the operation control device, Figure 4 is an electric circuit diagram of a conventional air conditioner equipped with a frequency converter, and Figure 5 is a flowchart of the operation control device.
The figure is a conventional flowchart. 11...Microcomputer, 12...
... Power transistor device, 13... Resistance circuit for temperature setting value, 14... Thermistor for indoor temperature detection, 16... Circuit for indoor temperature detection, 16.
... Comparator, 17 ... Power supply device, 18.
...Compressor. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 r-co No. 5511

Claims (1)

[Claims] A refrigeration cycle is constructed by connecting a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger in a ring, and the temperature of the compressor is adjusted depending on the indoor temperature or the piping temperature of the indoor heat exchanger. A control device that varies the rotational speed is provided, and this control device is combined with a drive device that varies the operating frequency of the compressor, and an indoor temperature detection device that detects the indoor temperature or the piping temperature of the indoor heat exchanger during cooling operation. means, a variable value storage means for storing a variable value temperature, and a comparison means for comparing and determining the temperature detected by the indoor temperature detecting means and the variable value temperature stored in the variable value storage means and outputting an H/L output signal. , a plurality of frequency value storage means storing the maximum value of the operating frequency of the compressor as different values, a calculating means for determining the maximum frequency value of the compressor operating frequency based on the output signal of the comparing means, and this calculating means. An air conditioner operation control device comprising a selection output means for setting the frequency value of one of the frequency value storage means as the maximum frequency value of the compressor operating frequency according to the determination result of the means.